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10,828,731 | ACCEPTED | Door system for transit vehicle utilizing compression lock arrangement | A locking arrangement for a door system of a transit vehicle includes a combination of a lock mechanism and an electromagnetic brake. The lock mechanism enables positive locking of at least one door but does not require substantial contact between moving and stationary lock elements. The lock mechanism is connected with the manual release means for door opening during an emergency. The electromagnetic brake maintains door seal compression in the closed and locked condition which improves sealing capabilities and provides for reliable lock mechanism operation. Such combination provides locking redundancy and meets various requirements regarding annunciation and manual release operation. | 1. A compression locking arrangement for a door system disposed within a door portal aperture of a vehicle, said door system including at least one door having a sealing means and a door drive means having a prime mover with an output shaft connected to a drive spindle with a coupling means, said door drive means further having at least one door hanger attached to said at least one door, said at least one door hanger connected to a drive nut coupled to said drive spindle, said compression locking arrangement comprising a brake attached to one of said output shaft of said prime mover and said drive spindle for maintaining said at least one door in a first locked position, said brake maintaining a compression of said sealing means, said compression produced by said door drive means, said brake adapted for receiving at least one brake signal for an application and a release thereof. 2. A compression locking arrangement according to claim 1 wherein said compression locking arrangement further includes a first locking member adapted for attachment to one of said door drive means and said at least one door and a stationary lock mechanism disposed within said vehicle, said lock mechanism having a second locking member for engagement with said first locking member, said lock mechanism further having an unlocking means for disengaging said second locking member from said first locking member to enable movement of said at least one door in an opening direction, said second locking member is fitted with a second locked position. 3. A compression locking arrangement according to claim 2 wherein said lock mechanism is adapted for locking said at least one door in said second locked position and in a third locked position, said second locked position is at a second predetermined distance from said third locked position, said at least one door is adapted for manual movement between said second and said third locked positions to enable a passenger to withdraw one of a garment, body part and an object. 4. A compression locking arrangement according to claim 1 wherein said compression locking arrangement further includes a manual release disposed within said vehicle, said manual release enabling release of said brake and disengagement of said second locking member from said first locking member. 5. A door system in a transit vehicle for at least partially covering and uncovering a door portal aperture of said transit vehicle, said door portal aperture having a first sealing means attached to at least one edge thereof, said door system comprising: (a) at least one door having a second sealing means disposed at a leading edge thereof; (b) a door drive means disposed within said transit vehicle for moving said at least one door in an opening and a closing direction, said door drive means including: (i) a rotatable drive spindle; (ii) a prime mover connected to one end of said drive spindle with a coupling means, said prime mover enabling rotation of said drive spindle, said prime mover is adapted for receiving a prime signal, said prime mover enabling compression of said first sealing means with said second sealing means to establish a first locked position which is a substantially closed and locked position; (iii) a drive nut engaging said drive spindle; (iv) a drive guide member disposed substantially parallel to said drive spindle; and (v) at least one hanger bracket coupled to said drive guide means and to said at least one door, said at least one hanger bracket adapted for linear movement about said drive guide means; said at least one hanger bracket having a connection with said drive nut, said at least one hanger bracket enabling substantially linear movement of said drive nut upon rotation of said drive spindle in said closing and said opening directions, said at least one hanger bracket further enabling movement of said at least one door in said closing and said opening directions to at least partially cover and uncover said door portal aperture; and (c) a brake attached to one of an output shaft of said prime mover and said drive spindle for preventing rotation of said drive spindle, said brake maintaining said at least one door in said first locked position, said brake further maintaining said compression of said first and second sealing means, said brake adapted for receiving at least one brake signal for an application and a release thereof. 6. A door system for a transit vehicle according to claim 5 wherein said door system further includes a door control unit disposed within said transit vehicle for providing said prime signal to said prime mover and said at least one brake signal to said brake, said door control unit further providing an unlock signal; said door control unit is adapted for receiving a door open signal and a door close signal and at least one position feedback signal and at least one annunciation signal. 7. A door system for a transit vehicle according to claim 5 wherein said brake includes: (a) a stationary magnet; (b) an armature axially disposed at a predetermined air gap X from said stationary magnet, said armature is attracted by a force of the magnetic field over said predetermined air gap X to said magnet resulting in a frictionally engaged connection; (c) a hub attached to said armature, said hub coupled to one of said prime mover shaft and said drive spindle to be rotated upon rotation thereof; (d) at least one spring disposed between said armature and said hub; and (e) a wiring connection for receiving said at least one brake signal. 8. A door system for a transit vehicle according to claim 5 wherein said door system further includes a redundant locking arrangement having: (a) a first locking member engageable with one of said at least one hanger bracket and said at least one door; (b) a stationary lock mechanism disposed within said transit vehicle, said stationary lock mechanism having a second locking member for engagement with said first locking member and an unlocking means for disengaging said second locking member from said first locking member to enable movement of said at least one door in said opening direction, said second locking member fitted with a second locked position. 9. A door system for a transit vehicle according to claim 8, wherein said stationary lock mechanism provides a first annunciation signal to said door control unit indicating an engagement of said first locking member with said second locking member, said stationary lock mechanism is adapted to directly receive at least one zero speed signal indicating a predetermined speed of said transit vehicle. 10. A door system for a transit vehicle according to claim 8, wherein said a stationary lock mechanism having a pushback means including said second locking member fitted with a third locked position enabling said at least one door to be manually and partially moved in said opening direction between said second locked position and said third locked position and further enabling a passenger to withdraw one of a garment, body part and an object captured by said first and said second sealing means. 11. A door system for a transit vehicle according to claim 5 wherein said door system further includes a manual release disposed within said transit vehicle for enabling manual unlocking of said at least one door by deenergizing said brake. 12. A door system for a transit vehicle according to claim 11 wherein said manual release is connected to said stationary locking mechanism with one of a cable and a lever, said manual release for disengaging said second locking member from said first locking member to enable movement of said at least one door in said opening direction. 13. A door system for a transit vehicle according to claim 6 wherein said door system further includes at least one first switch of a predetermined type disposed therein for one of providing a second annunciation signal to said door control unit indicating engagement with said at least one hanger bracket and indicating engagement of said first locking member with said second locking member, said second annunciation signal redundant to said first annunciation signal provided by said lock mechanism. 14. A door system for a transit vehicle according to claim 6 wherein said door system further includes a second switch of a predetermined type disposed within said transit vehicle for providing a second brake signal to deenergize said brake for enabling movement of said at least one door in said opening direction. 15. A door system for a transit vehicle according to claim 14, wherein said second switch is disposed within said lock mechanism. 16. A door system for a transit vehicle, said door system comprising: (a) a first door having a first sealing means; (b) a second door having a second sealing means arranged complimentary to said first sealing means; (c) a drive means connected to said first and said second door for moving said first and said second door for covering and uncovering a door portal aperture; and (d) a brake attached to said drive means for locking said first and said second door in a first locked position, said brake maintaining compression of said first sealing means with said second sealing means. 17. A door system for a transit vehicle according to claim 16 wherein said door system is selected form the group consisting of a sliding, pocket sliding, swing, and swing/sliding combination types. 18. A door system for a transit vehicle according to claim 5 wherein said prime mover is selected from the group consisting of electric mover, pneumatic mover, and hydraulic mover. 20. A method for determining failure of a brake in a transit vehicle door system by a door control unit, said method comprising the steps of: (a) at a beginning of movement of at least one door in an opening direction maintaining a first brake signal to energize said brake and providing a prime signal to energize a prime mover; (b) monitoring at least one door position by receiving at least one position feedback signal from an encoder disposed within said door drive means; and (c) thereafter annunciating said failure of said brake upon detecting an at least one door position change indicating movement of said at least one door in an opening direction. | FIELD OF THE INVENTION The present invention relates, in general, to a door system for transit vehicles and, more particularly, the instant invention relates to transit vehicle door systems employing locking arrangements for locking one or two doors in either a pushback or non-pushback mode. BACKGROUND OF THE INVENTION The following background information is provided to assist the reader to understand the environment in which the invention will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless specifically stated otherwise in this document. Powered door systems have been extensively utilized in various vehicle applications. Specifically, it is well known in the transit vehicle art to employ a door system having a powered door drive means and a lock mechanism for locking at least one door connected to such powered door drive means and driven thereby to at least partially cover and uncover a door portal aperture in the transit vehicle. Door systems, generally used, are of a sliding, pocket sliding, swing, or swing/sliding combination type. Lock mechanisms employed are generally either of a powered type, employing a solenoid or a cylinder as a lock/unlock mover, or of an over center type depending on the specific requirements. During locking movement, a first locking member mounted on the door or on its carrying member engages a second locking member stationaryly disposed within such lock mechanism, to be restrained from movement while the door is in the substantially closed and locked position and, more importantly, prevent such door from movement in the opening direction. Such lock mechanisms are taught, for example, in U.S. Pat. No. 6,139,073; U.S. Pat. No. 5,927,015; and U.S. Pat. No. 5,280,754; all owned by the assignee of the present invention. The teachings of U.S. Pat. No. 6,139,073; U.S. Pat. No. 5,927,015; and U.S. Pat. No. 5,280,754 are incorporated herein by reference thereto. An alternative configuration of the lock mechanism allows the door to be closed and locked in, what is well known, a pushback mode. In the pushback mode, a second locking member disposed within the lock mechanism is adapted with a second locked position and a third locked position. The second and third locked positions are spaced apart by a predetermined distance. The door is considered at least partially closed, in terms that it cannot be manually opened to its full open position, when the first locking member passes such third locked position. However, the door is enabled to be manually moved in the opening direction between the second and third locked position to enable the riding patron to withdraw an object or a garment trapped between mating door edges. This manual movement does not require an action by a drive element disposed within powered door drive means and generally does not provide a signal to the control system of the transit vehicle. After a predetermined time interval the door is commanded to substantially close and lock, at which point the first locking member passes the second locked position preventing any substantial door movement. Such lock mechanisms are taught in U.S. Pat. No. 6,282,970 and U.S. Pat. No. 6,032,416 owned by the assignee of the present invention. The teachings of U.S. Pat. No. 6,282,970 and U.S. Pat. No. 6,032,416 are incorporated herein by reference thereto. Alternatively, the lock mechanism design may allow the door to be continually in the pushback mode during the transit vehicle movement in which case, the door is allowed to be manually moved in the opening direction until the first locking member reaches the third locked position. A well-known means of achieving continuous pushback is to incorporate a mechanical spring disposed either within the lock mechanism or between the drive nut and the door. However, the significant disadvantage of the spring pushback is unrestricted and undesirable incremental longitudinal movement of the door during transit vehicle motion, particularly, as the spring fatigues over time. This undesirable movement compromises the sealing capabilities of the door system. It is of utmost importance to maintain sufficient sealing engagement between adjacent doors disposed within door portal opening or between a single door and the mating edge member of the door portal opening. It is well known that rubber elements, otherwise known as sealing means, which are attached to the mating leading edges of each door, or a door and door portal edge provide the best sealing protection from outside environmental factors, such as moisture, noise and dust, penetrating the interior of the moving transit vehicle. Generally, surfaces of such mating rubber edge elements are in close proximity to each other to minimize the gap between rubber edge elements and, on many installations, such surfaces are in substantial contact with each other. Additional compression of the rubber edge elements is employed to maintain such contact and further to prevent vibration of the door system due to component and assembly tolerances and mechanical wear as the door system ages. The difficulties of such an arrangement lie in that the lock mechanism must overcome additional frictional forces during locking and unlocking sequences. Tolerances of the rubber edge elements, general door system tolerances and environmental factors affect the engagement between such rubber edge elements resulting in either a frequent need for lock mechanism adjustments and fine tuning, decreased sealing capabilities, or decreased reliability of the lock mechanism operation. As it can be seen from the above discussion, there is a need to enable sufficient sealing capabilities of the mating rubber edge elements while at least one door is in the closed and locked position without compromising the operation of the lock mechanism. For passenger safety reasons, some Transit Authorities mandate that during transit vehicle motion the door cannot be manually opened upon actuation of the interior emergency release until the transit vehicle reaches a predetermined speed, typically under 3 miles per hour, generally referred to as zero speed. The resulting zero speed signal which is produced by a speed sensor within the propulsion system of such transit vehicle is transmitted to the door system via the specially designated trainlines of such transit vehicles. Such mandate is best met with the lock mechanisms of the powered type due to presence of the powered unlock mover and its interface with such trainlines of the transit vehicle enabling positive locking of the first locking member. Yet, the door must be opened regardless of the speed if the exterior emergency release is actuated so that emergency personnel can ingress the vehicle from outside in case of emergency. Further, as a general requirement related to passenger safety, the door system of the transit vehicle must contain redundancy within the locking arrangement so as to prevent unintentional door opening due to a single point failure within such locking arrangement. Furthermore, it is preferred, that such single point failure must be detectable by the control system of the transit vehicle. Therefore, there is a need to provide a locking arrangement that meets operational safety requirements and enables sufficient sealing capabilities of the door system. The U.S. Pat. No. 6,189,285, One- Or Two-Leaf Sliding Door, Swinging Door or Pocket Door, discloses a door system wherein the locking of the door is achieved without the use of the over center or solenoid type lock mechanisms. As illustrated in FIG. 5, the locking arrangement consists of a complex clutch (24-28) or brake in combination with a freewheel (23) which is mounted on the spindle (12) disposed within a powered door drive. The freewheel (23) is disposed at the first end of the spindle (12) and connected to a clutch or a brake via a receptacle (22). The freewheel, essentially, enables rotation of the spindle (12) in the closing direction without disengagement with the clutch (24-28). The clutch (24-28) controls rotation of the spindle (12) in the opening direction. A drive element (10) enabling spindle (12) rotation and, more importantly enabling door (1, 2) movement, is disposed at the distal end of the spindle (12). The special arrangement of the freewheel (23) and brake results in a final closing position region in which the door (1, 2) is secured against unwanted opening instead of the fixed final closing position determined by the over center or solenoid type lock mechanisms. This results in a substantial simplification in assembly because, for example, there is no longer any need to allow for rubber seals of varying width to achieve required sealing against environmental factors. The receptacle (22), when held in a stationary condition with respect to spindle (12) rotation, enables rotation of the spindle (12) in the closing direction. In order to open the doors (1, 2), the receptacle (22) must be released and enabled to rotate with the spindle (12). This is achieved by electrical release of the clutch (24-28) enabling the release of the disk (25) from engagement with counter disks (27, 28) which are disposed within the clutch and further enabling rotation of the shaft (24) and the receptacle (22) which is integral with shaft (24) with respect to the rotation of the spindle (12) in the opening direction. In the emergency condition, manual opening of the door (1, 2) is enabled via a Bowden cable (15) attached to the rod (14) at one end and attached to the manual release handle at the distal end. Actuation of the cable (15) displaces rod (14) enabling release of the clutch (24-28) via a swiveling cam (not shown) so that disk (25) connected to shaft (24) is likewise released. There are several disadvantages to the prior art design disclosed in U.S. Pat. No. 6,189,285. In the first aspect, the prior art design requires the use of the freewheel (23) and receptacle (22), in addition to clutch (24-28) and brake, as essential elements, to achieve locking and unlocking of the door (1, 2). Such components increase the complexity and cost of the door system and reduce its reliability. In a second aspect, failure of the clutch mechanism, or failure of the freewheel (23), or failure of the receptacle (22), which are all single point failures, may create a hazardous condition wherein the spindle (12) unintentionally rotates in the opening direction and, more importantly, the door (1, 2) opens unintentionally during transit vehicle movement due to normal vibration, vehicle deceleration and acceleration or the patron leaning against the door (1, 2) thus enabling its movement in the opening direction. The disclosure does not teach means for detecting and annunciating such failures. Additionally, the adaptation of the roller (18) and a stop surface (17) provides locking redundancy only in the case of a swinging or swinging/sliding combination door type and not in the case of the sliding type, particularly, of the pocket configuration, as those skilled in the art will appreciate that such roller (18) will be disposed within the path of the sliding door (1, 2), thereby preventing its full movement. Adaptation of the prior art design to enable roller (18) to disengage from the door (1, 2) prior to opening movement will result in a presence of the mechanical lock mechanism (or a dead-center mechanism) that the prior art claims to have eliminated. Therefore, the prior art design does not provide locking redundancy in preventing unintentional opening of the door (1, 2) of the sliding or sliding pocket type. In a third aspect, the described locking arrangement does not provide for combination of locking the door (1, 2) in the pushback mode and enabling claimed sealing advantages due to presence of the freewheel (23) and receptacle (22). A spring loaded link arrangement may be fitted between the drive nut (21) and the door (1, 2) enabling pushback thereof. However, as was aforementioned, such spring loaded link arrangement will negate the adaptation of the clutch (24-28), or brake, to achieve desirable sealing by enabling incremental longitudinal movement of the door (1, 2) which is independent from the action of the clutch (24-28). As it can be seen from the above discussion, there is a further need to enable sufficient sealing capabilities while at least one door is in the closed and locked position without compromising the safety of the door system operation and providing for a pushback operation. SUMMARY OF THE INVENTION The present invention teaches a door system, particularly for a transit vehicle, having at least one door with a sealing means disposed at leading edge thereof. A door drive means is disposed within the transit vehicle for moving the door in an opening and a closing direction. A brake is attached to either an output shaft of the prime mover or the drive spindle for preventing rotation of the drive spindle, thus maintaining the door in a substantially closed and locked position and for maintaining a compression of the sealing means. The door drive means includes a drive spindle, a prime mover having an output shaft attached to one end of the drive spindle with a coupling means, a drive nut collared around the drive spindle, a drive guide member disposed substantially parallel to the drive spindle and at least one hanger bracket attached to the door and connected to the drive nut for enabling its substantially linear movement upon rotation of such drive spindle in the closing and the opening direction, and further enabling movement of the door. A door control unit provides various signals to the prime mover and brake and receives various status and position annunciation signals as well as door open and door close commands. A mechanical lock is provided to positively lock the door thus providing redundancy of a locking operation. The utilization of the brake enables avoiding a preload of the movable locking member against the stationary locking member thus improving reliability of the lock mechanism operation. A manual release is provided to enable manual opening of the door in an emergency condition or for maintenance purposes. Compression of the sealing means maintains superior protection against environmental factors such as moisture, noise and dust as well as prevent component vibration due to tolerance and wear. Various annunciation means are incorporated to provide position and status feedback to the door control unit. Combination of the brake and lock mechanism eliminates any possibility for unintentional door opening due to a single component failure. OBJECTS OF THE INVENTION It is, therefore, one of the primary objects of the present invention to provide a lock arrangement for a door system of a transit vehicle which enables door seal compression. Another object of the present invention is to provide a lock arrangement for a door system of a transit vehicle which enables door locking in a pushback and non-pushback condition. Yet another object of the present invention is to provide a lock arrangement for a door system of a transit vehicle which enables door seal compression without affecting the reliability of the lock arrangement operation. Another object of the present invention is to provide a lock arrangement for a door system of a transit vehicle which enables redundancy of maintaining the door in a closed and locked position. Still another object of the present invention is to provide a lock arrangement for a door system of a transit vehicle which eliminates the vibration of the door system due to tolerances and component wear. It is an additional object of the present invention to provide a lock arrangement for a door system of a transit vehicle which maintains the door in the closed position after the activation of the interior emergency release until the transit vehicle reaches a predetermined speed. In addition to the various objects and advantages of the present invention which have been generally described above, there will be various other objects and advantages of the invention that will become more readily apparent to those persons who are skilled in the relevant art from the following more detailed description of the invention, particularly, when the detailed description is taken in conjunction with the attached drawing figures and with the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial perspective view of a typical transit vehicle door system. FIG. 2 is a partial perspective view of the door system, particularly showing a powered door drive means and door. FIG. 3 is a partial cross-sectional plan view of the electromagnetic brake. FIG. 4 is a schematic illustration which shows an embodiment of the invention connected to the door system control unit. FIG. 5 is a partial cross-sectional elevation view of the prior art design. DESCRIPTION OF THE PRESENTLY PREFERRED AND VARIOUS ALTERNATIVE EMBODIMENTS OF THE INVENTION Before describing the invention in detail, the reader is advised that, for the sake of clarity and understanding, identical components having identical functions have been marked where possible with the same reference numerals in each of the Figures provided in this document. The following description will be concerned with a door system for a transit vehicle since those skilled in the art will appreciate its features and adaptations to other vehicle types. In reference to FIG. 1, there is shown a first transit vehicle door system, generally designated 20, for at least partially covering and uncovering a door portal aperture 12 for ingress and egress of passengers in a wall 14 of a transit vehicle 10. The first door system 20 may be selected from a group of a sliding, pocket sliding, swing, or swing/sliding combination types. The first door system 20 has a first door 30 mounted for movement in a first door closing direction 32 to a first door closed position at least partially covering the door portal aperture 12 and for movement in a first door opening direction 31 to a first door open position at least partially uncovering the door portal aperture 12. The first door opening direction 31 being opposite to the first door closing direction 32. Such first door system 20 further has a door drive means, generally indicated 40, connected to the first door 30 for moving the first door 30 to a first door closed position and for moving the first door 30 to a first door open position. A second door system, generally designated 80, is disposed adjacent the first door system 20 in the portal opening 12. The second door system 80 has a second door 90 for longitudinal movement opposite to the first door 30, the second door 90 moving in a second door closing direction 92 to a second door closed position at least partially covering aperture 12 when first door 30 moves in the first door closing direction 32, and second door 90 moving in a second door opening direction 91 to a second door open position at least partially uncovering aperture 12 when first door 30 moves in the first door opening direction 31. The second door closing direction 92 is generally opposite to the first door closing direction 32 and the second door opening direction 91 is generally opposite to the first door opening direction 31. Hence, the first door 30 and the second door 90 cooperate to cover and uncover the aperture 12. Such second door system 80 further has a door drive, generally indicated 100, connected to second door 90 for moving the second door 90 to a second door closed position and for moving the second door 90 to a second door open position. The first door system 20 and the second door system 80 are essentially mirror images of each other. Therefore, only the first door system 20 is described hereinafter. Furthermore, the description will be provided for a sliding or pocket sliding door system type as adaptations for a swing and swing/sliding combination door type will be obvious to those skilled in the relevant art form. As illustrated in FIGS. 2 and 4, the first door drive means 40 includes a prime mover 42 rotatably connected to a drive spindle 44 with a coupling means 46 at one end of first door drive means 40. The prime mover 42 may be of a pneumatic or hydraulic type, but preferably is an electric motor. An encoder 45 is connected to the prime mover 42 and provides at least one output position feedback signal 234 to a door control unit 200. A drive nut 48 engages such drive spindle 44 to be substantially linearly driven thereby upon rotation of such drive spindle 44 enabled by prime mover 40. Additionally, drive nut 48 engages a first door hanger bracket 50 coupled with a drive guide member 52 and substantially connected to the first door 30, for carrying such first door 30 in the door portal aperture 12. The drive guide member 50 is disposed substantially parallel to the drive spindle 44. The first door hanger bracket 50 provides rotational constraint in order to prevent drive nut 48 from rotating about an axis of drive spindle 42. First door hanger bracket 50 further provides linear constraint of such drive nut 48 along the longitudinal axis of drive spindle 42 so that rotation of drive spindle 42 causes motion of drive nut 48 parallel to the longitudinal axis of drive spindle 42 and further causes the movement of the first door 30 in the directions 32 and 31 to at least partially cover and uncover the door portal opening 12. The first door drive means 40 further includes a second door hanger bracket 54 coupled to the drive guide member 52 and connected to the first door 30. Second door hanger bracket 54 may be fitted with a first locking member 56 adapted for engagement with a second locking member 182 disposed within lock mechanism 180 which is stationaryly mounted within such first door system 20. Alternatively, first locking member 56 may be attached directly to first door 30. It will be understood that second door hanger bracket 54 may be integral with such first door hanger bracket 50 to form a single door hanger bracket for carrying the first door 30. Lock mechanism 180 may be adapted to provide a first annunciation signal 228 to the door control unit 200 indicating the engagement of such first locking member 56 with the second locking member 182. The lock mechanism 180 may be further adapted to directly receive at least one zero speed signal 240 originated within the propulsion system (not shown) of the transit vehicle 10. At least one first switch 58 of a predetermined type provides a second annunciation signal 242 to the door control unit 200 of the first door system 20 indicating engagement with either first or second hanger brackets 50 and 54 respectively or directly with the first door 30. Additionally, the at least one first switch 58 may indicate engagement of the first locking member 56 with the second locking member 182 in applications using such lock mechanism 180 and such first locking member 56. A typical electromagnetic brake, generally designated 60, is illustrated in FIG. 3. The electromagnetic brake 60 is provided for locking the first door 30 and further for maintaining required sealing engagement and compression between the first door 30 and the second door 90. Preferably it is integral to the electric motor 42 and is stationaryly coupled to the motor shaft 43. Alternatively the electromagnetic brake 60 may be attached directly to the drive spindle 44 intermediate coupling means 46 and the drive spindle 44 end which is adjacent coupling means 46, particularly in applications utilizing a pneumatic or hydraulic prime mover 42. The electromagnetic brake 60 contains an armature 62, a brake magnet 64 which is stationaryly disposed at a predetermined gap X from the armature 62, a hub 66 stationaryly coupled to the motor shaft 43 and further coupled to the armature 62, and at least one spring 68 which is attached to both armature 62 and hub 66. A wiring connection 70 receives a first brake signal 234 from the door control unit 200 and receives a second brake signal 232 from the second switch 210 disposed within the first door system 20. As further illustrated in FIG. 2, the first door 30 includes a first sealing means 34 which is attached by any well known means to a leading edge of the first door 30. Such first sealing means 34 engages a second sealing means 94 which is attached to the second door 90 to substantially seal the door portal aperture 12 at a vertical center plane thereof. Those skilled in the art will readily understand that such second sealing means 94 may be attached directly to the edge of the door portal opening 12 where only the first door 30 is disposed therein. To close and lock the first door 30, the door control unit 200 receives a door close signal 220 from the transit vehicle control system (not shown) and provides a prime signal 222 which energizes electric motor 42 thus enabling rotation of the drive spindle 44 and subsequent longitudinal motion of the first door 30 in the first closing direction 32. In applications where only the electromagnetic brake 60 is used for locking purposes, such first door 30 is generally driven to its first locked position wherein the first sealing means 34 and the second sealing means 94 are compressed by the force from the electric motor 42. Such first locked position is generally known as substantially closed and locked position. At this point, the door control unit 200 provides a brake signal 224 to energize the electromagnetic brake 60 and then discontinues the prime signal 222 to deenergize the electric motor 42. The least one first switch 58 is activated providing a second annunciation signal 242 to the door control unit 200, indicating that such first door 30 is closed and locked. In the non-pushback mode, when the first locking member 56 engages the second locking member 182 of the lock mechanism 180 and is restrained thereby from moving back toward the opening direction 31, the first door 30 is in a second locked position, which is maintained at a first predetermined distance, which is typically about 5 mm from the first locking position being a substantially closed and locked position. Once the transit vehicle 10 is ready to depart from the station, the first door 30 is further driven to its first locked position wherein the first sealing means 34 and the second sealing means 94 are compressed by force from the electric motor 42. However, the first locked member 56 is maintained at such first predetermined distance from substantial contact with the second locking member 182. At this point, the door control unit 200 provides a brake signal 224 to energize the electromagnetic brake 60 and then discontinues the prime signal 222 to deenergize electric motor 42. The lock mechanism 180 provides a first annunciation signal to the control unit 200 and the at least one first switch 58 is activated providing a second annunciation signal 242 to the door control unit 200. Lock mechanism 180 and the at least one first switch 58 thus independently indicate that such first door 30 is closed and locked. In the pushback mode, the second locking member 182 is further fitted with the third locked position, which is at a second predetermined distance, typically of about 60 mm, from such first locked position. At his point the first door 30 cannot be reopened because of positive engagement of the first locking member 56 with the second locking member 182. However, the first door 30 is enabled for manual movement toward the opening direction 31 between such second and such third locked positions so that a riding patron can withdraw an object, a body part or a garment captured between the first sealing means 34 and the second sealing means 94. As further related to the pushback mode, once the transit vehicle 10 is ready to depart from the station, the first door 30 is powered for additional movement to the first locked position, which is a substantially closed and locked position, wherein the first sealing means 34 and the second sealing means 94 are compressed by the force from the electric motor 42. At this point, the door control unit 200 provides a brake signal 224 to energize the electromagnetic brake 60 and then discontinues the prime signal 222 to deenergize the electric motor 42. The lock mechanism 180 provides a first annunciation signal to the control unit 200 and the at least one first switch 58 is activated providing a second annunciation signal 242 to the door control unit 200. Such lock mechanism 180 and the at least one first switch 58 thus independently indicate that such first door 30 is closed and locked. Internal to the electromagnetic brake 60, the armature 62 is attracted by the force of the magnetic field over the predetermined air gap X to the brake magnet 64 resulting in a frictionally engaged connection. This frictionally engaged connection prevents rotation of the hub 66 which is stationaryly coupled to the motor shaft 43 and further coupled to armature 62 and, more particularly, prevents rotation of the motor shaft 43. The first door 30 thus remains tightly sealed against either the second door 90 or the edge of the door portal aperture 12. To open the first door 30 in normal operation, door control unit 200 receives a door open signal 221 from the transit vehicle control system (not shown) and provides an unlock signal 226 which energizes the unlock mover 184 (not shown) disposed within the lock mechanism 180 thus enabling disengagement of the second locking member 182 from the first locking member 56. Additionally the lock mechanism 180 may receive the at least one zero speed signal 240 indicating that the transit vehicle 10 is at a predetermined speed. Next, the door control unit 200 discontinues the output brake signal 224 to the electromagnetic brake 60. Internal to the electromagnetic brake 60, the magnetic field over the gap X is removed causing frictional disengagement between the armature 62 with the brake magnet 64 thus enabling rotation of the hub 66 and, more particularly, enabling rotation of the motor shaft 43. Finally, the door control unit 200 reactivates the prime signal 222 to the electric motor 42 enabling it to move the first door 30 toward the opening direction 31. To manually open the first door 30 in an emergency condition or for maintenance purposes, a manual release mechanism 190 is generally provided within the transit vehicle 10. When the first door system 20 employs only the electromagnetic brake 60 for locking purposes, the manual release mechanism 190 may simply provide an electrical signal 237 to the door control unit 200 or an electrical signal 236 to the at least one second switch 210 thus discontinuing the first brake signal 224 or providing a second brake signal 236 respectively to deenergize the electromagnetic brake 60. When first door system 20 further employs lock mechanism 180, the manual release 190 is generally connected thereof via a cable or a lever 192 to disengage the second locking member 182 from the first locking member 56 and generally remove the first annunciation signal 228 to the door control unit 200 causing it to discontinue the first brake signal 224 and deenergize electromagnetic brake 60. With first locking member 56 disengaged and electromagnetic brake 60 deenergized, the door 30 is enabled to be manually moved toward the opening direction 31. Alternatively, deenergization of the electromagnetic brake 60 may be achieved via the at least one second switch 210 and various signals 230, 232, 236, and 238, as best illustrated in FIG. 4. Such at least one second switch 210 may also be disposed within the lock mechanism 180. Those skilled in the art would appreciate that desired pneumatic or hydraulic signals may be provided through the use of well-known electro/pneumatic or electro/hydraulic components where the prime mover 42 is of a respective type. The at least one first switch 58 and the at least one second switch 210 may be of a proximity sensor type but are preferably of a solid state type having contacts of a predetermined current rating. It can be easily seen that the electrical motor 42 applies a predetermined compression force onto the first sealing means 34 against the adjacent sealing means 94 and that the electromagnetic brake 60 maintains such predetermined compression force enabling substantial reduction of the exterior noise, moisture and dust from penetrating the interior of the transit vehicle 10. The application of the permanent force further overcomes mechanical tolerances and slack of the first door system 20 and, more importantly, it enables a substantially reduction in vibration and rattling of such first door system 20 during motion of such transit vehicle 10. It is understood that such predetermined compression force will be varied depending on specific requirements and design of the first sealing means 34 and the second sealing means 94 by varying the torque output of the electrical motor 42 prior to the electromagnetic brake 60 application. Ability of the present invention to achieve and maintain compression of the adjacent sealing means without direct contact between the first locking member 56 and the locking member 182 substantially eliminates the need for frequent adjustments and fine tuning of the lock mechanism 180 during the life of the first door system 20. Such compression ability further enables compensation for assembly and component tolerances, deflection of the transit vehicle 10 structure, mechanical wear of the first door system 20, and flexibility of the first and second sealing means 34 and 94 respectively due to temperature and moisture fluctuations. Additionally, such predetermined compression force enables simplification of the sealing means design and interface between adjacent sealing means and, more importantly, enables standardization of such sealing means. And finally, absence of external frictional forces acting on the first locking member 56 while the first door 30 is in the closed and locked position substantially reduces the force required to manually unlock such first door 30 in the emergency conditions. The combination of the electromagnetic brake 60 and lock mechanism 180 enables redundancy of maintaining the first door 30 in the closed and locked position. As such, a failure of one of these components will not result in unintentional movement of the first door 30 in the opening direction 31. As best illustrated in FIGS. 2 and 4, the first annunciation signal 228 generated by the lock mechanism 180 and a second annunciation signal from the first switch 58 provide distinct annunciations of the first door 30 in the closed and locked conditions respectively. Failure of any of such first and second annunciation signals to be received by the door control unit 200 at a predetermined time will annunciate an unsafe condition of the first door 30 to the control system (not shown) of the transit vehicle 10. In addition, electromagnetic brake 60 and electric motor 42 may be energized simultaneously at the beginning of the opening movement of the first door 30 to test for electromagnetic brake 60 operation. A failed electromagnetic brake 60 will enable the opening movement of first door 30 with encoder 45 providing at least one position feedback signal 234 to door control unit 200. In applications where the lock mechanism 180 of the over center type is provided and the first door 30 can not be manually opened after actuation of the emergency release 190 unless the transit vehicle 10 reaches the predetermined speed, typically under about 3 miles per hour, such combination of the electromagnetic brake 60 and the lock mechanism 180 enables to maintain such first door 30 in the closed position after disengagement of the first locking member 56 from the lock mechanism 180. While the presently preferred embodiment of the instant invention has been described in detail above in accordance with the patent statutes, it should be recognized that various other modifications and adaptations of the invention may be made by those persons who are skilled in the relevant art without departing from either the spirit of the invention or the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The following background information is provided to assist the reader to understand the environment in which the invention will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless specifically stated otherwise in this document. Powered door systems have been extensively utilized in various vehicle applications. Specifically, it is well known in the transit vehicle art to employ a door system having a powered door drive means and a lock mechanism for locking at least one door connected to such powered door drive means and driven thereby to at least partially cover and uncover a door portal aperture in the transit vehicle. Door systems, generally used, are of a sliding, pocket sliding, swing, or swing/sliding combination type. Lock mechanisms employed are generally either of a powered type, employing a solenoid or a cylinder as a lock/unlock mover, or of an over center type depending on the specific requirements. During locking movement, a first locking member mounted on the door or on its carrying member engages a second locking member stationaryly disposed within such lock mechanism, to be restrained from movement while the door is in the substantially closed and locked position and, more importantly, prevent such door from movement in the opening direction. Such lock mechanisms are taught, for example, in U.S. Pat. No. 6,139,073; U.S. Pat. No. 5,927,015; and U.S. Pat. No. 5,280,754; all owned by the assignee of the present invention. The teachings of U.S. Pat. No. 6,139,073; U.S. Pat. No. 5,927,015; and U.S. Pat. No. 5,280,754 are incorporated herein by reference thereto. An alternative configuration of the lock mechanism allows the door to be closed and locked in, what is well known, a pushback mode. In the pushback mode, a second locking member disposed within the lock mechanism is adapted with a second locked position and a third locked position. The second and third locked positions are spaced apart by a predetermined distance. The door is considered at least partially closed, in terms that it cannot be manually opened to its full open position, when the first locking member passes such third locked position. However, the door is enabled to be manually moved in the opening direction between the second and third locked position to enable the riding patron to withdraw an object or a garment trapped between mating door edges. This manual movement does not require an action by a drive element disposed within powered door drive means and generally does not provide a signal to the control system of the transit vehicle. After a predetermined time interval the door is commanded to substantially close and lock, at which point the first locking member passes the second locked position preventing any substantial door movement. Such lock mechanisms are taught in U.S. Pat. No. 6,282,970 and U.S. Pat. No. 6,032,416 owned by the assignee of the present invention. The teachings of U.S. Pat. No. 6,282,970 and U.S. Pat. No. 6,032,416 are incorporated herein by reference thereto. Alternatively, the lock mechanism design may allow the door to be continually in the pushback mode during the transit vehicle movement in which case, the door is allowed to be manually moved in the opening direction until the first locking member reaches the third locked position. A well-known means of achieving continuous pushback is to incorporate a mechanical spring disposed either within the lock mechanism or between the drive nut and the door. However, the significant disadvantage of the spring pushback is unrestricted and undesirable incremental longitudinal movement of the door during transit vehicle motion, particularly, as the spring fatigues over time. This undesirable movement compromises the sealing capabilities of the door system. It is of utmost importance to maintain sufficient sealing engagement between adjacent doors disposed within door portal opening or between a single door and the mating edge member of the door portal opening. It is well known that rubber elements, otherwise known as sealing means, which are attached to the mating leading edges of each door, or a door and door portal edge provide the best sealing protection from outside environmental factors, such as moisture, noise and dust, penetrating the interior of the moving transit vehicle. Generally, surfaces of such mating rubber edge elements are in close proximity to each other to minimize the gap between rubber edge elements and, on many installations, such surfaces are in substantial contact with each other. Additional compression of the rubber edge elements is employed to maintain such contact and further to prevent vibration of the door system due to component and assembly tolerances and mechanical wear as the door system ages. The difficulties of such an arrangement lie in that the lock mechanism must overcome additional frictional forces during locking and unlocking sequences. Tolerances of the rubber edge elements, general door system tolerances and environmental factors affect the engagement between such rubber edge elements resulting in either a frequent need for lock mechanism adjustments and fine tuning, decreased sealing capabilities, or decreased reliability of the lock mechanism operation. As it can be seen from the above discussion, there is a need to enable sufficient sealing capabilities of the mating rubber edge elements while at least one door is in the closed and locked position without compromising the operation of the lock mechanism. For passenger safety reasons, some Transit Authorities mandate that during transit vehicle motion the door cannot be manually opened upon actuation of the interior emergency release until the transit vehicle reaches a predetermined speed, typically under 3 miles per hour, generally referred to as zero speed. The resulting zero speed signal which is produced by a speed sensor within the propulsion system of such transit vehicle is transmitted to the door system via the specially designated trainlines of such transit vehicles. Such mandate is best met with the lock mechanisms of the powered type due to presence of the powered unlock mover and its interface with such trainlines of the transit vehicle enabling positive locking of the first locking member. Yet, the door must be opened regardless of the speed if the exterior emergency release is actuated so that emergency personnel can ingress the vehicle from outside in case of emergency. Further, as a general requirement related to passenger safety, the door system of the transit vehicle must contain redundancy within the locking arrangement so as to prevent unintentional door opening due to a single point failure within such locking arrangement. Furthermore, it is preferred, that such single point failure must be detectable by the control system of the transit vehicle. Therefore, there is a need to provide a locking arrangement that meets operational safety requirements and enables sufficient sealing capabilities of the door system. The U.S. Pat. No. 6,189,285, One- Or Two-Leaf Sliding Door, Swinging Door or Pocket Door, discloses a door system wherein the locking of the door is achieved without the use of the over center or solenoid type lock mechanisms. As illustrated in FIG. 5 , the locking arrangement consists of a complex clutch ( 24 - 28 ) or brake in combination with a freewheel ( 23 ) which is mounted on the spindle ( 12 ) disposed within a powered door drive. The freewheel ( 23 ) is disposed at the first end of the spindle ( 12 ) and connected to a clutch or a brake via a receptacle ( 22 ). The freewheel, essentially, enables rotation of the spindle ( 12 ) in the closing direction without disengagement with the clutch ( 24 - 28 ). The clutch ( 24 - 28 ) controls rotation of the spindle ( 12 ) in the opening direction. A drive element ( 10 ) enabling spindle ( 12 ) rotation and, more importantly enabling door ( 1 , 2 ) movement, is disposed at the distal end of the spindle ( 12 ). The special arrangement of the freewheel ( 23 ) and brake results in a final closing position region in which the door ( 1 , 2 ) is secured against unwanted opening instead of the fixed final closing position determined by the over center or solenoid type lock mechanisms. This results in a substantial simplification in assembly because, for example, there is no longer any need to allow for rubber seals of varying width to achieve required sealing against environmental factors. The receptacle ( 22 ), when held in a stationary condition with respect to spindle ( 12 ) rotation, enables rotation of the spindle ( 12 ) in the closing direction. In order to open the doors ( 1 , 2 ), the receptacle ( 22 ) must be released and enabled to rotate with the spindle ( 12 ). This is achieved by electrical release of the clutch ( 24 - 28 ) enabling the release of the disk ( 25 ) from engagement with counter disks ( 27 , 28 ) which are disposed within the clutch and further enabling rotation of the shaft ( 24 ) and the receptacle ( 22 ) which is integral with shaft ( 24 ) with respect to the rotation of the spindle ( 12 ) in the opening direction. In the emergency condition, manual opening of the door ( 1 , 2 ) is enabled via a Bowden cable ( 15 ) attached to the rod ( 14 ) at one end and attached to the manual release handle at the distal end. Actuation of the cable ( 15 ) displaces rod ( 14 ) enabling release of the clutch ( 24 - 28 ) via a swiveling cam (not shown) so that disk ( 25 ) connected to shaft ( 24 ) is likewise released. There are several disadvantages to the prior art design disclosed in U.S. Pat. No. 6,189,285. In the first aspect, the prior art design requires the use of the freewheel ( 23 ) and receptacle ( 22 ), in addition to clutch ( 24 - 28 ) and brake, as essential elements, to achieve locking and unlocking of the door ( 1 , 2 ). Such components increase the complexity and cost of the door system and reduce its reliability. In a second aspect, failure of the clutch mechanism, or failure of the freewheel ( 23 ), or failure of the receptacle ( 22 ), which are all single point failures, may create a hazardous condition wherein the spindle ( 12 ) unintentionally rotates in the opening direction and, more importantly, the door ( 1 , 2 ) opens unintentionally during transit vehicle movement due to normal vibration, vehicle deceleration and acceleration or the patron leaning against the door ( 1 , 2 ) thus enabling its movement in the opening direction. The disclosure does not teach means for detecting and annunciating such failures. Additionally, the adaptation of the roller ( 18 ) and a stop surface ( 17 ) provides locking redundancy only in the case of a swinging or swinging/sliding combination door type and not in the case of the sliding type, particularly, of the pocket configuration, as those skilled in the art will appreciate that such roller ( 18 ) will be disposed within the path of the sliding door ( 1 , 2 ), thereby preventing its full movement. Adaptation of the prior art design to enable roller ( 18 ) to disengage from the door ( 1 , 2 ) prior to opening movement will result in a presence of the mechanical lock mechanism (or a dead-center mechanism) that the prior art claims to have eliminated. Therefore, the prior art design does not provide locking redundancy in preventing unintentional opening of the door ( 1 , 2 ) of the sliding or sliding pocket type. In a third aspect, the described locking arrangement does not provide for combination of locking the door ( 1 , 2 ) in the pushback mode and enabling claimed sealing advantages due to presence of the freewheel ( 23 ) and receptacle ( 22 ). A spring loaded link arrangement may be fitted between the drive nut ( 21 ) and the door ( 1 , 2 ) enabling pushback thereof. However, as was aforementioned, such spring loaded link arrangement will negate the adaptation of the clutch ( 24 - 28 ), or brake, to achieve desirable sealing by enabling incremental longitudinal movement of the door ( 1 , 2 ) which is independent from the action of the clutch ( 24 - 28 ). As it can be seen from the above discussion, there is a further need to enable sufficient sealing capabilities while at least one door is in the closed and locked position without compromising the safety of the door system operation and providing for a pushback operation. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention teaches a door system, particularly for a transit vehicle, having at least one door with a sealing means disposed at leading edge thereof. A door drive means is disposed within the transit vehicle for moving the door in an opening and a closing direction. A brake is attached to either an output shaft of the prime mover or the drive spindle for preventing rotation of the drive spindle, thus maintaining the door in a substantially closed and locked position and for maintaining a compression of the sealing means. The door drive means includes a drive spindle, a prime mover having an output shaft attached to one end of the drive spindle with a coupling means, a drive nut collared around the drive spindle, a drive guide member disposed substantially parallel to the drive spindle and at least one hanger bracket attached to the door and connected to the drive nut for enabling its substantially linear movement upon rotation of such drive spindle in the closing and the opening direction, and further enabling movement of the door. A door control unit provides various signals to the prime mover and brake and receives various status and position annunciation signals as well as door open and door close commands. A mechanical lock is provided to positively lock the door thus providing redundancy of a locking operation. The utilization of the brake enables avoiding a preload of the movable locking member against the stationary locking member thus improving reliability of the lock mechanism operation. A manual release is provided to enable manual opening of the door in an emergency condition or for maintenance purposes. Compression of the sealing means maintains superior protection against environmental factors such as moisture, noise and dust as well as prevent component vibration due to tolerance and wear. Various annunciation means are incorporated to provide position and status feedback to the door control unit. Combination of the brake and lock mechanism eliminates any possibility for unintentional door opening due to a single component failure. | 20040421 | 20070612 | 20051027 | 78065.0 | 0 | MCCARRY JR, ROBERT J | DOOR SYSTEM FOR TRANSIT VEHICLE UTILIZING COMPRESSION LOCK ARRANGEMENT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,828,827 | ACCEPTED | Hypoallergenic metal amino acid chelates and metal amino acid chelate-containing compositions | Hypoallergenic metal amino acid chelate compositions, hypoallergenic formulations containing hypoallergenic metal amino acid chelates, methods of preparing hypoallergenic metal amino acid chelate, and methods of administering hypoallergenic metal amino acid chelates are provided. Specifically, the present invention provides metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates to a subject in an effective amount to cause a medicinal or nutritional result does not produce a discernable adverse allergic reaction. The metal amino acid chelates can include chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1. | 1. A hypoallergenic metal amino acid chelate composition, comprising metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates in an effective amount to cause a medicinal, cosmetic, or nutritional result in a subject does not produce a discernable adverse allergic reaction, said metal amino acid chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1. 2. A composition as in claim 1, wherein the naturally occurring amino acid is selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamine, glutamic acid, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and combinations thereof. 3. A composition as in claim 1, wherein the metal is selected from the group consisting of iron, zinc, copper, manganese, calcium, chromium, vanadium, selenium, silicon, molybdenum, tin, nickel, boron, cobalt, gold, silver, and combinations thereof. 4. A composition as in claim 1, wherein the metal is a polyvalent metal, and the naturally occurring amino acid to metal molar ratio is from about 1:1 to 3:1. 5. A composition as in claim 1, wherein the metal is ferrous iron and the naturally occurring amino acid is glycine, and wherein the iron to glycine molar ratio is about 2:1. 6. A composition as in claim 1, wherein the metal is copper and the naturally occurring amino acid is glycine, and wherein the copper to glycine molar ratio is about 2:1. 7. A composition as in claim 1, wherein the metal is zinc and the naturally occurring amino acid is glycine, and wherein the zinc to glycine molar ratio is about 2:1. 8. A composition as in claim 1, wherein the metal is manganese and the naturally occurring amino acid is glycine, and wherein the manganese to glycine molar ratio is about 2:1. 9. A composition as in claim 1, wherein the metal is ferric iron and the naturally occurring amino acid is glycine, and wherein the ferric iron to glycine molar ratio is about 3:1. 10. A composition as in claim 1, wherein the metal is chromium and the naturally occurring amino acid is glycine, and wherein the chromium to glycine molar ratio is about 3:1. 11. A composition as in claim 1, wherein the metal is magnesium and the naturally occurring amino acid is glycine, and wherein the magnesium to glycine molar ratio is about 1:1. 12. A composition as in claim 1, wherein the metal is calcium and the naturally occurring amino acid is glycine, and wherein the calcium to glycine molar ratio is about 1:1. 13. A composition as in claim 1, wherein the naturally occurring amino acid used to prepare the metal amino acid chelates is prepared by a method other than protein hydrolysis. 14. A composition as in claim 1, wherein the naturally occurring amino acid used to prepare the metal amino acid chelates is prepared by protein hydrolysis, and wherein the protein used in the hydrolysis is hypoallergenic. 15. A composition as in claim 1, wherein the allergens are removed from the naturally occurring amino acid after formation, but before chelation with the metal. 16. A composition as in claim 1, wherein specific allergens are identified with respect to the subject, and the subject is susceptible to an allergic reaction upon exposure to the allergens. 17. A composition as in claim 1, wherein the subject is an animal. 18. A composition as in claim 1, wherein the subject is human. 19. A hypoallergenic metal amino acid chelate-containing composition, a) hypoallergenic metal amino acid chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1, said metal amino acid chelates being blended with, b) a hypoallergenic formulation additive, wherein the metal amino acid chelates and the formulation additive are substantially free of allergens such that administration of the composition to a subject in an effective amount to cause a medicinal or nutritional result does not produce a discernable adverse allergic reaction. 20. A composition as in claim 19, wherein the formulation additive is a hypoallergenic organic acid. 21. A composition as in claim 20, wherein the hypoallergenic organic acid is selected from the group consisting of citric acid, fumaric acid, succinic acid, tartaric acid, malic acid, lactic acid, gluconic acid, ascorbic acid, pantothenic acid, folic acid, lipoic acid, oxalic acid, maleic acid, formic acid, acetic acid, pyruvic acid, adipic acid, alpha-ketoglutaric acid, and mixtures thereof. 22. A composition as in claim 19, wherein the formulation additive is a hypoallergenic filler. 23. A composition as in claim 19, wherein the hypoallergenic filler is selected from the group consisting of grain flours, maltodextrins, vegetable flours or powders, inulin, and combinations thereof. 24. A composition as in claim 19, wherein the formulation additive is a hypoallergenic flow control agent. 25. A composition as in claim 24, wherein the hypoallergenic flow control agent is selected from the group consisting of fumed silica, stearic acid, talc, and combinations thereof. 26. A composition as in claim 19, wherein the formulation additive is selected from the group consisting of free amino acids, amino acid salts, and combinations thereof. 27. A composition as in claim 19, wherein the formulation additive is selected from the group consisting of vitamins, coenzymes, cofactors, herbs, herbal extracts, protein powders, and combinations thereof. 28. A composition as in claim 19, wherein the formulation additive is selected from the group consisting of mineral oils, binders, flavoring or taste-free additives, and combinations thereof. 29. A composition as in claim 19, wherein the naturally occurring amino acid is selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamine, glutamic acid, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and combinations thereof. 30. A composition as in claim 19, wherein the metal is selected from the group consisting of iron, zinc, copper, manganese, calcium, chromium, vanadium, selenium, silicon, molybdenum, tin, nickel, boron, cobalt, gold, silver, and combinations thereof. 31. A composition as in claim 19, wherein the metal is a polyvalent metal, and the naturally occurring amino acid to metal molar ratio is from about 2:1 to 3:1. 32. A composition as in claim 19, wherein the naturally occurring amino acid used to make the metal amino acid chelates is not prepared by protein hydrolysis. 33. A composition as in claim 19, wherein the naturally occurring amino acid used to make the metal amino acid chelates is prepared by protein hydrolysis, and wherein the protein used in the hydrolysis is hypoallergenic. 34. A composition as in claim 19, wherein the allergens are removed from the metal amino acid chelate after formation, but before chelation with the metal. 35. A composition as in claim 19, wherein the subject is an animal. 36. A composition as in claim 19, wherein the subject is a human. 37. A composition as in claim 19, wherein the subject is predisposed to an allergic reaction when exposed to metal amino acid chelates and formulation additives that are non-hypoallergenic. 38. A method of preparing hypoallergenic metal amino acid chelates, comprising: a) selecting an amino acid source determined to be hypoallergenic; b) selecting a metal source determined to be hypoallergenic; and c) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. 39. A method as in claim 38, wherein during the step of selecting the amino acid source, if a first amino acid source is not hypoallergenic, additional amino acid sources are evaluated until a hypoallergenic amino acid source is ascertained. 40. A method as in claim 38, wherein during the step of selecting the metal source, if a first metal source is not hypoallergenic, additional metal sources are evaluated until a hypoallergenic metal source is ascertained. 41. A method as in claim 38, wherein the amino acid source is not prepared by protein hydrolysis. 42. A method as in claim 38, wherein the amino acid source is prepared by protein hydrolysis, and wherein the protein used in the hydrolysis is hypoallergenic. 43. A method as in claim 38, wherein the amino acid source is rendered hypoallergenic after formation, but before chelation with the metal. 44. A method as in claim 38, further comprising selecting an additive determined to be hypoallergenic, and including the additive as a mixture with the hypoallergenic metal amino acid chelate. 45. A method as in claim 44, wherein the additive is selected from the group consisting of hypoallergenic organic acids, hypoallergenic free amino acids, hypoallergenic amino acid salts, hypoallergenic fillers, hypoallergenic flow control agents, hypoallergenic lubricants, hypoallergenic flow agents, hypoallergenic hydroscopicity reducing agents, hypoallergenic pH control agents, hypoallergenic catalysts, hypoallergenic vitamins, hypoallergenic dust control agents, hypoallergenic binders, hypoallergenic disintegrating agents, hypoallergenic flavoring agents, hypoallergenic flavoring agents, hypoallergenic taste-reducing agents, hypoallergenic capsule shells, hypoallergenic shellacs, hypoallergenic waxes, hypoallergenic gelatin sources, hypoallergenic emulsifiers, hypoallergenic oils, and combinations thereof. 46. A method of administering metal amino acid chelates, comprising: a) identifying a subject susceptible to a type of allergic reaction; b) formulating a metal amino acid chelate by: i) selecting an amino acid source determined to be hypoallergenic with respect to the type of allergic reaction; ii) selecting a metal source determined to be hypoallergenic with respect to the type of allergic reaction, and iii) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate; and c) administering the hypoallergenic amino acid to the subject. 47. A method as in claim 46, wherein the subject is allergic to at least one of soy, peanuts, tree nuts, crustaceans, finfish, dairy, wheat, eggs, corn, gelatin, whey, chocolate, and strawberries. 48. A method as in claim 46, wherein during the step of selecting the amino acid source, if a first amino acid source is not hypoallergenic, additional amino acid sources are evaluated until a hypoallergenic amino acid source is ascertained. 49. A method as in claim 48, wherein during the step of selecting the metal source, if a first metal source is not hypoallergenic, additional metal sources are evaluated until a hypoallergenic metal source is ascertained. 50. A method as in claim 46, wherein the amino acid source is prepared by a method other than protein hydrolysis. 51. A method as in claim 46, wherein the amino acid source is prepared by protein hydrolysis, and wherein the protein used in the hydrolysis is hypoallergenic. 52. A method as in claim 46, wherein the amino acid source is rendered hypoallergenic after formation, but before chelation with the metal. 53. A method as in claim 46, further comprising steps of selecting an additive determined to be hypoallergenic, and including the additive as a mixture with the hypoallergenic metal amino acid chelate. 54. A method as in claim 52, wherein the additive is selected from the group consisting of hypoallergenic organic acids, hypoallergenic free amino acids, hypoallergenic amino acid salts, hypoallergenic fillers, hypoallergenic flow control agents, hypoallergenic lubricants, hypoallergenic flow agents, hypoallergenic hydroscopicity reducing agents, hypoallergenic pH control agents, hypoallergenic catalysts, hypoallergenic vitamins, hypoallergenic dust control agents, hypoallergenic binders, hypoallergenic disintegrating agents, hypoallergenic flavoring agents, hypoallergenic flavoring agents, hypoallergenic taste-reducing agents, hypoallergenic capsule shells, hypoallergenic shellacs, hypoallergenic waxes, hypoallergenic gelatin sources, hypoallergenic emulsifiers, hypoallergenic oils, and combinations thereof. | FIELD OF THE INVENTION The present invention is drawn to hypoallergenic metal amino acid chelates and hypoallergenic formulations containing hypoallergenic metal amino acid chelates. BACKGROUND OF THE INVENTION Amino acid chelates are generally produced by the reaction between α-amino acids and metal ions having a valence of two or more to form a ring structure. In such a reaction, the positive electrical charge of the metal ion can be neutralized by the electrons available through the carboxylate or free amino groups of the α-amino acid. Traditionally, the term “chelate” has been loosely defined as a combination of a polyvalent metallic ion bonded to one or more ligands to form a heterocyclic ring structure. Under this definition, chelate formation through neutralization of the positive charge(s) of the metal ion may be through the formation of ionic, covalent, or coordinate covalent bonding. An alternative and more modern definition of the term “chelate” requires that the polyvalent metal ion be bonded to the ligand solely by coordinate covalent bonds forming a heterocyclic ring. In either case, both are definitions that describe a metal ion and a ligand forming a heterocyclic ring. Chelation can be confirmed and differentiated from mixtures of components by infrared spectra through comparison of the stretching of bonds or shifting of absorption caused by bond formation. As applied in the field of mineral nutrition, there are certain “chelated” products that are commercially utilized. One product is referred to as an “amino acid chelate.” When properly formed, an amino acid chelate is a stable product having one or more five-membered rings formed by a reaction between the amino acid and the metal. The American Association of Feed Control Officials (AAFCO) has also issued a definition for amino acid chelates. It is officially defined as the product resulting from the reaction of a metal ion from a soluble metal salt with amino acids having a mole ratio of one mole of metal to one to three (preferably two) moles of amino acids to form coordinate covalent bonds. The products are identified by the specific metal forming the chelate, e.g., iron amino acid chelate, copper amino acid chelate, etc. In further detail with respect to amino acid chelates, the carboxyloxygen and the α-amino group of the amino acid each bond with the metal ion. Such a five-membered ring is defined by the metal atom, the carboxyloxygen, the carbonyl carbon, the α-carbon, and the α-amino nitrogen. The actual structure will depend upon the ligand to metal mole ratio and whether the carboxyloxygen forms a coordinate covalent bond or a more ionic bond with the metal ion. Generally, the amino acid to metal molar ratio is at least 1:1 and is preferably 2:1 or 3:1. However, in certain instances, the ratio can be 4:1. Most typically, an amino acid chelate with a divalent metal can be represented at a ligand to metal molar ratio of 2:1 according to Formula 1 as follows: In the above formula, the dashed lines represent coordinate covalent bonds, covalent bonds, or ionic bonds. Further, when R is H, the amino acid is glycine, which is the simplest of the α-amino acids. However, R could be representative of any other side chain that, when taken in combination with the rest of the amino acid structure(s), results in any of the other twenty or so naturally occurring amino acids that are typically derived from proteins. All of the amino acids have the same configuration for the positioning of the carboxyloxygen and the α-amino nitrogen with respect to the metal ion. In other words, the chelate ring is defined by the same atoms in each instance, even though the R side chain group may vary. The reason a metal atom can accept bonds over and above the oxidation state of the metal is due to the nature of chelation. For example, at the α-amino group of an amino acid, the nitrogen contributes to both of the electrons used in the bonding. These electrons fill available spaces in the d-orbitals forming a coordinate covalent bond. Thus, a metal ion with a normal valency of +2 can be bonded by four bonds when fully chelated. In this state, the chelate is completely satisfied by the bonding electrons and the charge on the metal atom (as well as on the overall molecule) can be zero. As stated previously, it is possible that the metal ion can be bonded to the carboxyloxygen by either coordinate covalent bonds or more ionic bonds. The structure, chemistry, bioavailability, and various applications of amino acid chelates are well documented in the literature, e.g. Ashmead et al., Chelated Mineral Nutrition, (1982), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Intestinal Absorption of Metal Ions, (1985), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Foliar Feeding of Plants with Amino Acid Chelates, (1986), Noyes Publications, Park Ridge, N.J.; U.S. Pat. Nos. 4,020,158; 4,167,564; 4,216,143; 4,216,144; 4,599,152; 4,725,427; 4,774,089; 4,830,716; 4,863,898; 5,292,538; 5,292,729; 5,516,925; 5,596,016; 5,882,685; 6,159,530; 6,166,071; 6,207,204; 6,294,207; 6,458,981, 6,518,240, 6,614,553; each of which is incorporated herein by reference. One advantage of amino acid chelates in the field of mineral nutrition is attributed to the fact that these chelates are readily absorbed from the gut and into mucosal cells by means of active transport. In other words, the minerals can be absorbed along with the amino acids as a single unit utilizing the amino acids as carrier molecules. Therefore, the problems associated with the competition of ions for intestinal absorption sites and the suppression of specific nutritive mineral elements by others can be avoided. Many persons suffer from various allergies, which can be caused by ingesting food, liquids, or supplements containing allergens. Although the biochemistry of allergic reactions is not precisely understood, it is believed that the allergens cause, upon ingestion or other contact with the body, a specific reagin to be formed in the bloodstream. A response to an allergen by some is thought to be an inherited characteristic. In a person that is allergic to a specific allergen, the allergen, which is often a protein, can be regarded as a key which fits the corresponding structural shape of the reagin molecule. Allergic reactions can result in symptoms ranging from very mild to very severe, some of which can cause death. For example, symptoms, both mild and severe, include skin rashes (allergic eczema and urticaria), dermal symptoms, respiratory symptoms (including allergic rhinitis and bronchial asthma), gastrointestinal symptoms, and migraine headaches. Violent illnesses have been known to include shock-like reactions, vascular collapse, and allergic anaphylaxis. As amino acids used to prepare amino acid chelates are typically derived from protein hydrolysis, such amino acids can cause allergic reactions in a small percentage of the population. As a result, it would be an advancement in the art to provide hypoallergenic amino acid chelates and hypoallergenic formulations that contain amino acid chelates in order to avoid undesired allergic reactions. SUMMARY OF THE INVENTION It has been recognized that the preparation and/or administration of hypoallergenic chelates and formulations containing such chelates would be beneficial. In accordance with this recognition, a hypoallergenic metal amino acid chelate composition can comprise metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates in an effective amount to cause a medicinal or nutritional result in a subject does not produce a discernable adverse allergic reaction. The metal amino acid chelate composition can include chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1. In another embodiment, a hypoallergenic metal amino acid chelate-containing composition can comprise hypoallergenic metal amino acid chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1, wherein the metal amino acid chelates are blended with one or more hypoallergenic formulation additive(s). The metal amino acid chelates and the formulation additive can be substantially free of allergens such that administration of the composition in an effective amount to cause a medicinal or nutritional result in a subject does not produce a discernable adverse allergic reaction. In another embodiment, a method of preparing hypoallergenic metal amino acid chelates can comprise steps of a) selecting an amino acid source determined to be hypoallergenic; b) selecting a metal source determined to be hypoallergenic; and c) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. Optionally, hypoallergenic additives, including reagents for promoting the chelation process, can be added to the hypoallergenic metal amino acid chelates for formulation or finished product properties. A method of administering metal amino acid chelates is also disclosed, and can comprise steps of a) identifying a subject susceptible to a type of allergic reaction; b) formulating a metal amino acid chelate; and c) administering the hypoallergenic amino acid to the subject. The formulating step can be carried out by i) selecting an amino acid source determined to be hypoallergenic with respect to the type of allergic reaction; ii) selecting a metal source determined to be hypoallergenic with respect to the type of allergic reaction, and iii) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. Optionally, hypoallergenic additives, including reagents for promoting the chelation process, can be added to the hypoallergenic metal amino acid chelates for formulation or finished product properties prior to or in conjunction with the administering step. Additional features and advantages of the invention will be apparent from the following detailed description which illustrates, by way of example, features of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) Before the present invention is disclosed and described, it is to be understood that this invention is not limited to the particular process steps and materials disclosed herein because such process steps and materials may vary somewhat. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only. The terms are not intended to be limiting because the scope of the present invention is intended to be limited only by the appended claims and equivalents thereof. It is to be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. The term “substantially” is a term of magnitude. For example, when stating that a composition is “substantially free of allergens,” what is meant is that allergens are not present to an extent that causes an allergic reaction in susceptible subjects. The term “naturally occurring amino acid” or “traditional amino acid” shall mean amino acids that are known to be used for forming the basic constituents of proteins, including alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamine, glutamic acid, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and combinations thereof. The term “naturally occurring” does not mean that the amino acid used in accordance with embodiments of the present invention is necessarily derived naturally, but that it can occur naturally, e.g., essential and non-essential amino acids. The term “amino acid chelate(s)” or “metal amino acid chelate(s)” is intended to cover both the traditional definitions and the more modern definition of chelate as cited previously. Specifically, with respect to chelates that utilize traditional amino acid ligands, i.e. those used in forming proteins, chelate is meant to include metal ions bonded to amino acid ligands forming heterocyclic rings. Between the carboxyloxygen and the metal, the bond can be covalent or more ionic, but is preferably coordinate covalent. Additionally, at the α-amino group, the bond is typically a covalent or coordinate covalent bond. When referring to “metal amino acid chelates” in the plural form, this phraseology does not necessarily infer that two distinct metal amino acid chelates are present. For example, a particulate batch of a single species of a metal amino acid chelate can be referred to as “metal amino acid chelates.” Alternatively, the term “metal amino acid chelates” can also include multiple types of metal amino acid chelates in a batch, depending on the context. The term “nutritionally relevant metal” is meant to include any polyvalent, e.g., divalent or trivalent, metal that can be used as part of a nutritional supplement, drug therapy, food fortificant, topical cosmetic, etc., that is known to be beneficial to animals including humans, and in some instances, plants. Nutritionally relevant metals are also known to be substantially non-toxic when administered in traditional amounts, as is known in the art. Examples of such metals include iron, zinc, copper, manganese, calcium, magnesium, chromium, vanadium, selenium, silicon, molybdenum, tin, nickel, boron, cobalt, gold, silver, and combinations thereof. The term “hypoallergenic” refers to compositions where care has been taken in formulation and/or production to ensure minimal instance of allergic reactions in a target subject or class of subjects. Hypoallergenic can also refer to a composition that when contacted, e.g., topical, or ingested, e.g., food fortification or nutritional supplement, at customary levels to provide a nutritional, cosmetic, or medicinal effect, the contact or ingestion does not produce an adverse discernable allergic reaction to a target subject or class of subjects. “Allergy” refers to an acquired and abnormal immune response to a substance or moiety of a substance (allergen) that produces an altered bodily reaction. Sensitization, or initial exposure to the allergen, precedes the allergic response, and subsequent contact with the allergen results in the altered bodily reactivity or response. An allergy can be an inherited or acquired trait. The term “allergen” refers to a substance that causes manifestations of allergy, such as a protein or antigen. The FDA lists eight major allergen sources in the FDA Compliance Policy Guide, CPG 555.250, which includes: soy, peanuts, tree nuts (almonds, walnuts, etc.), crustaceans, fin fish, dairy, wheat, and eggs. Other known allergens that affect a relatively large percentage of the population may include corn, from which maltodextrin is derived, gelatin, whey, chocolate, strawberries, etc. The term “subject” refers to a target warm-blooded animal to which hypoallergenic metal amino acid chelates or hypoallergenic metal amino acid chelate-containing compositions can be administered. In one embodiment, the subject or class of subjects can be human. “Protein hypersensitivity” is a form of an allergy wherein an immune-mediated adverse reaction to the ingestion or contact with a protein or amino acid derived from that protein can occur. Amino acids prepared by “synthetic” methods include chemical preparations that do not involve protein hydrolysis. Amino acids prepared by “fermentation” methods typically include a bioprocess wherein an engineered or unengineered cell or organism produces the amino acids, usually on a relatively large scale. With these definitions in mind, a hypoallergenic metal amino acid chelate composition can comprise metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates in an effective amount to cause a medicinal, cosmetic, or nutritional result in a subject does not produce a discernable adverse allergic reaction. The metal amino acid chelate composition can include chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1. In another embodiment, a hypoallergenic metal amino acid chelate-containing composition can comprise hypoallergenic metal amino acid chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1, wherein the metal amino acid chelates are blended with a hypoallergenic formulation additive, including hypoallergenic reagents. The metal amino acid chelates and the formulation additive can be substantially free of allergens such that administration of the composition in an effective amount to cause a medicinal, cosmetic, or nutritional result in a subject does not produce a discernable adverse allergic reaction. In another embodiment, a method of preparing hypoallergenic metal amino acid chelates can comprise selecting an amino acid source determined to be hypoallergenic; selecting a metal source determined to be hypoallergenic; and chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. In one embodiment, during the step of selecting the amino acid source, if the amino acid source is not hypoallergenic, alternative amino acid sources can be evaluated until a hypoallergenic amino acid source is ascertained. In another embodiment, during the step of selecting the metal source, if the metal source is not hypoallergenic, alternative metal sources can be evaluated until a hypoallergenic metal source is ascertained. In another embodiment, a method of administering metal amino acid chelates is disclosed, and can comprise steps of identifying a subject susceptible to a type of allergic reaction, formulating a metal amino acid chelate, and administering the hypoallergenic amino acid to the subject. The formulating step can be carried out i) selecting an amino acid source determined to be hypoallergenic with respect to the type of allergic reaction; ii) selecting a metal source determined to be hypoallergenic with respect to the type of allergic reaction, and iii) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. Determining whether a composition or its source is hypoallergenic indicates that some type of evaluative step be performed. For example, in determining whether an amino acid, including its source, as well as a metal source is hypoallergenic, an evaluation step can include steps such as reviewing literature or interviewing manufacturers associated with a product obtained from a third party, preparing the compositions or sources oneself to ensure that all components are hypoallergenic, and/or conducting an assay to verify that a composition is truly hypoallergenic. Hypoallergenic Metal Amino Acid Chelates In accordance with embodiments of the present invention, metal amino acid chelates that are hypoallergenic can be prepared by reacting hypoallergenic amino acids with hypoallergenic metal sources. As such, steps of preparing or selecting hypoallergenic amino acids as well as preparing or selecting hypoallergenic metal sources can be carried out to achieve this result. Exemplary metals that can be used include iron, zinc, copper, calcium, magnesium, and/or manganese, which are common nutritional minerals used when supplementing the mineral balance of subjects, including humans. Further, trace metals, such as chromium, vanadium, selenium, silicon, molybdenum, tin, nickel, boron, cobalt, gold, and/or silver, or the like, can also be used. Regarding the metals that can be prepared or selected for use, metal sources that may include allergens can be avoided. For example, biological sources of metal may more likely include allergens that certain target subjects may be allergic to. Heme iron from hemoglobin, magnesium from chlorophyll, calcium from lactose, magnesium from magnesium stearate each exemplify metal sources that may be undesireable for use in certain circumstances. However, if such metal sources are processed such that allergens present are reduced to a level that is acceptable, or the use of the metal source would not be problematic with respect to a target subject class, then these metal sources may be acceptable for use. In other words, on a case by case basis, a metal source can be selected for use to meet the goals of the hypoallergenic composition to be formed. Examples of metal sources that typically do not include allergens include metal sulfates, metal carbonates, metal oxides, metal hydroxides, elemental metals, and the like. Examples of amino acid sources that can be hypoallergenic include those not prepared by protein hydrolysis, those wherein the amino acid source is prepared by protein hydrolysis using a hypoallergenic protein, and amino acids that have been purified of allergens, such as by chromatography or bind-release separation technologies. The naturally occurring amino acids that can be used include alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamine, glutamic acid, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and combinations thereof. Specific examples of preferred metal amino acid chelates that can be used include embodiments wherein the amino acid to metal molar ratio is about 2:1, and wherein the metal is ferrous iron and the naturally occurring amino acid is glycine, the metal is copper and the naturally occurring amino acid is glycine, the metal is zinc and the naturally occurring amino acid is glycine, or the metal is manganese and the naturally occurring amino acid is glycine. Alternatively, the amino acid to metal molar ratio can be about 3:1, the metal can be ferric iron or chromium, and the naturally occurring amino acid can be glycine. In yet another embodiment, the amino acid to metal molar ratio can be about 1:1, the metal can be magnesium or calcium, and the naturally occurring amino acid can be glycine. In each of the compositions and methods, the naturally occurring amino acid used to make the metal amino acid chelates may be provided by a production method other than protein hydrolysis, e.g., synthetic preparation or fermentation. Alternatively, if protein hydrolysis is used to provide the amino acid, then care can be taken to select or render the proteins hypoallergenic. For example, proteins derived from soy, peanuts, tree nuts, crustaceans, finfish, dairy, wheat, eggs, corn, gelatin, whey, chocolate, strawberries, etc., may be desirable to avoid, depending on the target subject class. Conversely, certain proteins derived from mammals, such as bovine or porcine protein, may be more generally acceptable for use across the spectrum of target subject classes. In still another embodiment, if the allergens are present due to residual proteins or peptides that may be present with the amino acid, then the allergens can be removed from the composition after formation of the metal amino acid chelates, such as by multiple washing steps, or by chromatography or non-chromatography bind-release separation methods. There are many methods that can be used to ensure that a resulting metal amino acid chelate composition is hypoallergenic. For example, synthetic synthesis of amino acids can be used to provide hypoallergenic amino acids. In one embodiment, the synthesis of α-amino acids can be carried out by reaction of aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. Amino acids prepared by this method are available from Dow Chemical and Chattem Chemicals, Inc., among others. Alternatively, amino acids can be prepared by the formation of azlactones by intramolecular condensation of acylglycines in the presence of acetic anhydride. The reaction of azlactones with carbonyl compounds followed by hydrolysis to the unsaturated α-acylamino acid and by reduction yields the amino acid. These synthetic methods of preparation are exemplary only, and are not intended to be limiting. Fermentation can also be used to prepare amino acids that may be hypoallergenic. Amino acid fermentation is a method for producing amino acids using microorganisms to convert nutrients to amino acids. Specifically, raw materials, such as broths or syrups, can be added to microorganism culture media, and the microorganisms are allowed to produce the amino acids. For example, L-amino acids can be accumulated in a fermentation broth, from which they are subsequently isolated and purified. A common amino acid producer includes mutants of coryneform bacteria represented by the genera Corynebacterium and Brevibacterium. In addition to mutants of various types, obtained by mutation and selection (auxotrophic mutants, regulatory mutants, auxotrophic-regulatory mutants), the amino acid producers can be obtained by the methods of gene manipulation. The producers are able to synthesize amino acids from such carbon sources as sugar, ethanol, or methanol under optimal conditions of aeration. These conditions can be very different for the individual amino acids. Amino acids overproduction is influenced by the mechanisms of metabolic regulations (on the level of both activity and expression) and amino acid secretion (as diffusion and carrier-mediated membrane transport). Other amino acid preparative process are described in part or in whole the following articles: Determination of Amino Acids in Cell Cultures and Fermentation Broths, Dionex Application Note 150, pp 1-15; Production of Amino Acids by Analog-Resistant Mutants of Cyanobacterium Spirulina platenis, Riccardi, G. et al., Journal of Bacteriology, pp. 102-107 (September 1981); Cattle Nutrition—Mycotoxins and Intoxications, various authors, Abstracts—XXII World Buiatrics Congress 2002, Hannover, Germany (Aug. 18-23, 2002—Abstract Nos. 1-364, 2-689, 3-229, 4-788, 5-755, 6-157, 7-825, 7-757, 9-226, 10-393, 11-645, 12-904, 13-802); Lysine and other amino acids for feed: production and contribution to protein utilization in animal feeding, Toride, Y. et al.; and Acid-neutralizing activity during amino acid fermentation by Porphyromonas gingivalis, Prevotell intermedia and Fusobacterium nucleatum, Takahashi, N. et al., Oral Microbiology Immunology, vol. 18, no. 2, 109-113(5) (April 2003), each of which are incorporated herein by reference in their entireties. In addition to synthetic and fermentation preparation methods, as well as certain proteolytic methods, there are other methods that can be used to render amino acids hypoallergenic. For example, U.S. Pat. No. 5,039,032, which is incorporated herein by reference, describes a method of preparing hypoallergenic protein from whey. Whey is typically recognized as a composition that many humans who are lactose intolerant are susceptible. In that patent, the protein is first hydrolyzed with a proteolytic enzyme and then the enzymatic hydrolyzate is subjected to a heat treatment to denature allergen-containing proteins which remain intact after the first hydrolysis. Then, the heated hydrolyzate is cooled, followed by further proteolytic enzyme hydrolysis to provide a hydrolyzate substantially free of allergens of protean origin. This hypoallergenic protein can then be hydrolyzed to form hypoallergenic amino acids to be used to form the hypoallergenic metal amino acid chelates in accordance with embodiments of the present invention. Other methods used to denature protein to render it hypoallergenic include ultrafiltration to remove undesirable proteins or other materials. For example, U.S. Pat. No. 4,293,571, which is incorporated herein by reference, discloses a process for the purification of purified protein hydrolysate. In this process, an aqueous solution of protein is subjected to hydrolysis, and then is heat treated to denature the protein. The heat-treated material can then be ultrafiltered to eliminate protein. Hypoallergenic Additives Depending on the amount of a specific mineral to be administered in a metal amino acid chelate (or combination of minerals to be administered), hypoallergenic additives are typically formulated within a common composition with the metal amino acid chelates to provide desired properties that may not be inherently present in the metal amino acid chelate itself. As one embodiment of the present invention is drawn hypoallergenic metal amino acid chelate-containing compositions, care should be taken in selecting additives to administer with the metal amino acid chelates such that the composition, as a whole, is hypoallergenic. Examples of formulation additives that can be admixed or co-administered with the metal amino acid chelates of the present invention include hypoallergenic organic acids, hypoallergenic free amino acids, hypoallergenic amino acid salts, hypoallergenic fillers, hypoallergenic flow control agents, hypoallergenic lubricants, hypoallergenic flow agents, hypoallergenic hydroscopicity minimizing agents, hypoallergenic pH control agents, hypoallergenic catalysts, hypoallergenic vitamins, hypoallergenic dust control agents, hypoallergenic binders, hypoallergenic disintegrating agents, hypoallergenic flavoring agents, hypoallergenic taste-reducing agents, hypoallergenic capsule shells, hypoallergenic shellacs, hypoallergenic waxes, hypoallergenic emulsifiers, hypoallergenic oils, combinations thereof, and other known additives that can be prepared to be hypoallergenic. There are certain additives that can be formulated to be hypoallergenic, which can be included in amino-acid chelate-containing compositions that provide desired properties to the composition during formulation or to the finished composition. For example, maltodextrin can be added as a filler and a flow agent. Additionally, maltodextrin can help to reduce the hydroscopicity of the composition as a whole. Grain flours, such as rice flour or wheat flour, can also be added as a filler, as well as vegetable flours or powders, such as soy flour. In another embodiment, a filler that can be added is inulin, such as hypoallergenic low fiber inulin derived from chicary. Fumed silica, stearic acids, and/or talc can also be added as a flow controlling agents. When including a flow control agent or filler, as described above, care should be taken to select or prepare the additive such that it meets target subject allergic criteria, e.g., will not illicit an allergic reaction. For example, if a class of subjects is believed to be allergic to corn (maize), then corn-derived maltodextrin may be undesirable for use. In addition to the flow agents and fillers, other compositions that can be added include organic acids. Citric acid, fumaric acid, succinic acid, tartaric acid, malic acid, lactic acid, gluconic acid, ascorbic acid, pantothenic acid, folic acid, lipoic acid, oxalic acid, maleic acid, formic acid, acetic acid, pyruvic acid, adipic acid, and alpha-ketoglutaric acid are each exemplary of such organic acids, though others can also be used. Free amino acids or amino acid salts can also be present in the composition. Additionally, mineral oils for dust control, binders for tableting (carboxymethyl cellulose, ethyl cellulose, glycerol, etc.), flavoring agents or taste-free additives for organoleptic properties, or the like can also be included. Other classes of formulation additives that can be included with the hypoallergenic metal amino acid chelates are vitamins, coenzymes, cofactors, herbs or herbal extracts, protein powders, or the like. Hypoallergenic vitamins that can be used include Vitamin A, the Vitamin B group of vitamins, e.g., folic acid, Vitamin B1, Vitamin B2, Vitamin B3, Vitamin B5, Vitamin B6, or Vitamin B12, Vitamin C, Vitamin D, Vitamin E, and the like. Coenzymes can also be used, which are organic compounds that combine with apoenzymes to form active enzymes. Cofactors that can be present include coenzymes and metals that are required for an enzyme to be active, some of which can be provided by the metal amino acid chelate itself. In each of the embodiments described herein, the compositions can be in the form of tablets, capsules, powders, crystals, granules, liquids, or the like. Shellacs or waxes can be used as tablet coatings, provided they are hypoallergenic to the class of subjects being targeted. Likewise, if using capsules to deliver a composition in accordance with embodiments of the present invention, the encapsulating material should also be hypoallergenic. For example, the encapsulating material can be of vegetable sterols or gelatin, for example, provided the encapsulating material is hypoallergenic to the class of subjects that the composition is to be delivered, e.g., bovine or porcine gelatin can often be desirable for use. Regarding liquids, compositions can also be included in liquid formulations that act to main the solubility of the metal amino acid chelate and/or other additives that may be present. For example, U.S. Pat. No. 6,716,814, which is incorporated herein by reference in its entirety, describes a method enhancing the solubility of iron amino acid chelates and iron proteinates. Such methods and solubility enhancing compositions can be used, provided the compositions used are hypoallergenic. EXAMPLES The following examples are illustrative of a present hypoallergenic metal amino acid chelates and metal amino acid chelate-containing formulations. As such, the following examples should not be considered as limitations of the present invention, but merely demonstrate the effectiveness of the methods and compositions described herein. Example 1 To about 700 ml of deionized water containing 50 g citric acid is added 225 g of a synthetically produced glycine to form a clear solution. The synthetic production method for preparing the glycine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. To this solution, 55.8 g of elemental iron substantially free of allergens is slowly added. The solution is heated at about 50° C. for 48 hours, or until all the iron is observed to go into solution. The product is cooled, filtered, and spray dried yielding an iron triglycine amino acid chelate. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 2 A solution is prepared including 10.1 parts by weight of fermentation-produced glycine dissolved in 82.2 parts by weight water. To this solution is added 4.4 parts by weight zinc oxide. The molar ratio of glycine to zinc is 2:1. The reaction mixture is allowed to stand for about 14 hours and turned an opalescent color. After standing, the mixture is heated to about 70° C. and spray dried to obtain a zinc bisglycinate amino acid chelate powder having a melting point of about 209° C. which turned red upon melting. The zinc content of the chelate is about 20 wt %. The dried product has a moisture content of about 7 wt %, and when reconstituted in water, has a pH of about 8.0. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 3 A copper carbonate solution is prepared by adding 6.1 parts by weight of hypoallergenic cupric carbonate to 80.9 parts by weight water. This solution is allowed to stand without agitation for about two hours. To this solution is added 8.2 parts by weight of a synthetically prepared glycine, and the mixture is slowly stirred for about two more hours. A hazy blue solution is observed. The synthetic production method for preparing the glycine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. To the hazy blue solution is added 65 parts by weight of a 15 wt % citric acid solution and the mixture is stirred until a clear blue solution is observed. This solution is spray dried resulting in a copper bisglycinate powder having a copper content of about 14 wt % and which melts at about 194° C. Upon being reconstituted in water, the pH of the resulting solution is about 7.5. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 4 A mixture of 42.93 grams of zinc sulfate, 12 grams of methionine, and 30 grams of glycine are reacted in an aqueous environment for 60 minutes at a temperature of about 65 to 70° C. The glycine and methionine are prepared using synthetic processes. Specifically, the synthetic production method for preparing the glycine and methionine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. The reaction of the zinc sulfate, methionine, and glycine produces a zinc amino acid chelate having a ligand component to metal molar ratio of about 2:1, a theoretical average zinc content of about 26.8% by weight, and a glycine to methionine molar ratio of about 5:2. Due to the presence of the sulfate anion, the actual average zinc weight percentage is about 18.2%. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 5 Into about 1300 grams of water is dissolved 210.72 grams of a synthetic glycine and 79.86 grams of calcium oxide. The synthetic production method for preparing the glycine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. The solution of calcium oxide and glycine is stirred until all of the calcium oxide appeared to be fully dissolved, i.e. about 15 minutes. The resulting reaction forms a calcium bisglycinate chelate or complex solution. Next, to the calcium bisglycinate chelate or complex solution is added 381.55 grams of ferrous sulfate hydrate containing 20% ferrous iron by weight. Again, the solution is constantly stirred while the ferrous sulfate dissolves and a white precipitate of calcium sulfate forms. About 287 grams of a ferrous glycine chelate is formed having a ligand to metal molar ratio of about 2:1. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 6 About 2252 grams of water is used to dissolve 450.42 grams of fermentation-produced glycine and 168.24 grams of calcium oxide into solution. The resulting reaction formed a calcium trisglycinate chelate or complex solution. Next, 500.18 grams of chromic sulfate hydrate containing 19 wt % chromium is added to the calcium chelate solution. The solution is stirred while the copper sulfate is dissolved and as a white precipitate of calcium sulfate formed. Upon completion of the reaction, about 545 grams of a chromic trisglycinate chelate having a ligand to metal molar ratio of about 3:1 is formed. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 7 Into about 923 grams of water is dissolved 150.14 grams of synthetic glycine. The synthetic production method for preparing the glycine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. Next, 57.25 grams of calcium oxide, which is about 70 wt % calcium, is added. The solution is continually stirred until all of the calcium oxide is dissolved. This takes about 15 minutes. No heat is applied for this particular reaction. The resulting reaction forms a calcium bisglycinate chelate or complex and water. Next, 254.18 grams of copper sulfate hydrate containing 25% copper by weight is added to the calcium chelate solution. Again, the solution is constantly stirred while the copper sulfate is dissolved. As the copper sulfate goes into solution, a white precipitate of calcium sulfate is formed. Upon completion of the reaction, about 214 grams of a copper glycine chelate having a ligand to metal molar ratio of 2:1 is formed. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 8 About 250 grams of fermentation-produced glycine is dissolved into 937.8 grams of water. Once the glycine is significantly dissolved, about 95 grams of calcium oxide is added. The solution is continually stirred for about 15 minutes until all of the calcium is dissolved. The resulting reaction forms a calcium bisglycinate chelate or complex and water. Next, 299.97 grams of zinc sulfate hydrate containing 35% zinc by weight is added to the calcium chelate solution. Upon constant stirring, the zinc sulfate goes into solution and a white precipitate of calcium sulfate is formed. About 355 grams of a zinc glycine chelate having a ligand to metal molar ratio of about 2:1 is also formed. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use should affect the hypoallergenic nature of the chelates. Example 9 An open electrolytic cell is constructed consisting of an anode compartment and a cathode compartment divided by a cation permselective membrane. The anode is pure copper metal, providing the metal to form the chelate at the appropriate time. The volume of the anode compartment is approximately 400 cc and the volume of the cathode compartment is about 650 cc. A transformer and rectifier system is utilized to apply a direct current voltage across the cell. The anolyte solution includes a synthetically produced aqueous glycine having a glycine concentration of about 20%, which is circulated continuously throughout the cell compartment and past the anode. The synthetic production method for preparing the glycine is by reacting aldehydes with ammonia and hydrogen cyanide, followed by hydrolysis of the resulting α-aminonitriles. The catholyte solution is a 1 wt % citric acid solution. The initial temperature of the analyte and catholyte solutions is about 40° C. The applied voltage to the transformer is 75 V A.C. The initial voltage across the cell is 5 V D.C. at an amperage of 27 amps. The temperature within each compartment rises quite rapidly and levels off at about 90° C. in the anode compartment and 94° C. in the cathode compartment. The amperage slowly increases to about 34 amps and then remains constant and the voltage across the cell decreases slowly during the entire hour of operation from 5 V D.C. to 2.2 V D.C. Upon cooling to room temperature, a blue precipitate is formed and separates from the anolyte solution. Upon assay, the blue precipitate is shown to be a copper glycine chelate containing 6% copper and having a ligand to copper ration of 2:1. The resulting chelate precipitate is free of any anions. The current flow between the anode and cathode compartments is made possible by the migration of hydrogen ions through the cation permselective membrane. Also, upon cooling it is found that certain of the copper ions had also migrated through the membrane and are loosely plated on the cathode. All of the compositional components used in the preparation are hypoallergenic, and none of the equipment selected for use affected the hypoallergenic nature of the prepared chelates. Example 10 The metal amino acid chelate prepared in accordance with Example 1 is spray dried and blended with hypoallergenic fumed silica (about 0.1 wt % to 5 wt % of composition) and hypoallergenic maltodextrin (about 0.1 wt % to 85 wt % of composition). A free flowing powder having acceptable hydroscopicity is formed. While the invention has been described with reference to certain preferred embodiments, those skilled in the art will appreciate that various modifications, changes, omissions, and substitutions can be made without departing from the spirit of the invention. It is therefore intended that the invention be limited only by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Amino acid chelates are generally produced by the reaction between α-amino acids and metal ions having a valence of two or more to form a ring structure. In such a reaction, the positive electrical charge of the metal ion can be neutralized by the electrons available through the carboxylate or free amino groups of the α-amino acid. Traditionally, the term “chelate” has been loosely defined as a combination of a polyvalent metallic ion bonded to one or more ligands to form a heterocyclic ring structure. Under this definition, chelate formation through neutralization of the positive charge(s) of the metal ion may be through the formation of ionic, covalent, or coordinate covalent bonding. An alternative and more modern definition of the term “chelate” requires that the polyvalent metal ion be bonded to the ligand solely by coordinate covalent bonds forming a heterocyclic ring. In either case, both are definitions that describe a metal ion and a ligand forming a heterocyclic ring. Chelation can be confirmed and differentiated from mixtures of components by infrared spectra through comparison of the stretching of bonds or shifting of absorption caused by bond formation. As applied in the field of mineral nutrition, there are certain “chelated” products that are commercially utilized. One product is referred to as an “amino acid chelate.” When properly formed, an amino acid chelate is a stable product having one or more five-membered rings formed by a reaction between the amino acid and the metal. The American Association of Feed Control Officials (AAFCO) has also issued a definition for amino acid chelates. It is officially defined as the product resulting from the reaction of a metal ion from a soluble metal salt with amino acids having a mole ratio of one mole of metal to one to three (preferably two) moles of amino acids to form coordinate covalent bonds. The products are identified by the specific metal forming the chelate, e.g., iron amino acid chelate, copper amino acid chelate, etc. In further detail with respect to amino acid chelates, the carboxyloxygen and the α-amino group of the amino acid each bond with the metal ion. Such a five-membered ring is defined by the metal atom, the carboxyloxygen, the carbonyl carbon, the α-carbon, and the α-amino nitrogen. The actual structure will depend upon the ligand to metal mole ratio and whether the carboxyloxygen forms a coordinate covalent bond or a more ionic bond with the metal ion. Generally, the amino acid to metal molar ratio is at least 1:1 and is preferably 2:1 or 3:1. However, in certain instances, the ratio can be 4:1. Most typically, an amino acid chelate with a divalent metal can be represented at a ligand to metal molar ratio of 2:1 according to Formula 1 as follows: In the above formula, the dashed lines represent coordinate covalent bonds, covalent bonds, or ionic bonds. Further, when R is H, the amino acid is glycine, which is the simplest of the α-amino acids. However, R could be representative of any other side chain that, when taken in combination with the rest of the amino acid structure(s), results in any of the other twenty or so naturally occurring amino acids that are typically derived from proteins. All of the amino acids have the same configuration for the positioning of the carboxyloxygen and the α-amino nitrogen with respect to the metal ion. In other words, the chelate ring is defined by the same atoms in each instance, even though the R side chain group may vary. The reason a metal atom can accept bonds over and above the oxidation state of the metal is due to the nature of chelation. For example, at the α-amino group of an amino acid, the nitrogen contributes to both of the electrons used in the bonding. These electrons fill available spaces in the d-orbitals forming a coordinate covalent bond. Thus, a metal ion with a normal valency of +2 can be bonded by four bonds when fully chelated. In this state, the chelate is completely satisfied by the bonding electrons and the charge on the metal atom (as well as on the overall molecule) can be zero. As stated previously, it is possible that the metal ion can be bonded to the carboxyloxygen by either coordinate covalent bonds or more ionic bonds. The structure, chemistry, bioavailability, and various applications of amino acid chelates are well documented in the literature, e.g. Ashmead et al., Chelated Mineral Nutrition, (1982), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Intestinal Absorption of Metal Ions, (1985), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Foliar Feeding of Plants with Amino Acid Chelates, (1986), Noyes Publications, Park Ridge, N.J.; U.S. Pat. Nos. 4,020,158; 4,167,564; 4,216,143; 4,216,144; 4,599,152; 4,725,427; 4,774,089; 4,830,716; 4,863,898; 5,292,538; 5,292,729; 5,516,925; 5,596,016; 5,882,685; 6,159,530; 6,166,071; 6,207,204; 6,294,207; 6,458,981, 6,518,240, 6,614,553; each of which is incorporated herein by reference. One advantage of amino acid chelates in the field of mineral nutrition is attributed to the fact that these chelates are readily absorbed from the gut and into mucosal cells by means of active transport. In other words, the minerals can be absorbed along with the amino acids as a single unit utilizing the amino acids as carrier molecules. Therefore, the problems associated with the competition of ions for intestinal absorption sites and the suppression of specific nutritive mineral elements by others can be avoided. Many persons suffer from various allergies, which can be caused by ingesting food, liquids, or supplements containing allergens. Although the biochemistry of allergic reactions is not precisely understood, it is believed that the allergens cause, upon ingestion or other contact with the body, a specific reagin to be formed in the bloodstream. A response to an allergen by some is thought to be an inherited characteristic. In a person that is allergic to a specific allergen, the allergen, which is often a protein, can be regarded as a key which fits the corresponding structural shape of the reagin molecule. Allergic reactions can result in symptoms ranging from very mild to very severe, some of which can cause death. For example, symptoms, both mild and severe, include skin rashes (allergic eczema and urticaria), dermal symptoms, respiratory symptoms (including allergic rhinitis and bronchial asthma), gastrointestinal symptoms, and migraine headaches. Violent illnesses have been known to include shock-like reactions, vascular collapse, and allergic anaphylaxis. As amino acids used to prepare amino acid chelates are typically derived from protein hydrolysis, such amino acids can cause allergic reactions in a small percentage of the population. As a result, it would be an advancement in the art to provide hypoallergenic amino acid chelates and hypoallergenic formulations that contain amino acid chelates in order to avoid undesired allergic reactions. | <SOH> SUMMARY OF THE INVENTION <EOH>It has been recognized that the preparation and/or administration of hypoallergenic chelates and formulations containing such chelates would be beneficial. In accordance with this recognition, a hypoallergenic metal amino acid chelate composition can comprise metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates in an effective amount to cause a medicinal or nutritional result in a subject does not produce a discernable adverse allergic reaction. The metal amino acid chelate composition can include chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1. In another embodiment, a hypoallergenic metal amino acid chelate-containing composition can comprise hypoallergenic metal amino acid chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1, wherein the metal amino acid chelates are blended with one or more hypoallergenic formulation additive(s). The metal amino acid chelates and the formulation additive can be substantially free of allergens such that administration of the composition in an effective amount to cause a medicinal or nutritional result in a subject does not produce a discernable adverse allergic reaction. In another embodiment, a method of preparing hypoallergenic metal amino acid chelates can comprise steps of a) selecting an amino acid source determined to be hypoallergenic; b) selecting a metal source determined to be hypoallergenic; and c) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. Optionally, hypoallergenic additives, including reagents for promoting the chelation process, can be added to the hypoallergenic metal amino acid chelates for formulation or finished product properties. A method of administering metal amino acid chelates is also disclosed, and can comprise steps of a) identifying a subject susceptible to a type of allergic reaction; b) formulating a metal amino acid chelate; and c) administering the hypoallergenic amino acid to the subject. The formulating step can be carried out by i) selecting an amino acid source determined to be hypoallergenic with respect to the type of allergic reaction; ii) selecting a metal source determined to be hypoallergenic with respect to the type of allergic reaction, and iii) chelating an amino acid of the amino acid source to a metal of the metal source to form a hypoallergenic metal amino acid chelate. Optionally, hypoallergenic additives, including reagents for promoting the chelation process, can be added to the hypoallergenic metal amino acid chelates for formulation or finished product properties prior to or in conjunction with the administering step. Additional features and advantages of the invention will be apparent from the following detailed description which illustrates, by way of example, features of the invention. detailed-description description="Detailed Description" end="lead"? | 20040421 | 20101123 | 20051027 | 57686.0 | 1 | ARNOLD, ERNST V | HYPOALLERGENIC METAL AMINO ACID CHELATES AND METAL AMINO ACID CHELATE-CONTAINING COMPOSITIONS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,828,884 | ACCEPTED | Compensated linearity voltage-control-capacitor device by standard CMOS process | Apparatus and method of providing a CMOS varactor device having improved linearity. At least two differential varactor elements are connected in parallel. Each of the differential elements includes first, second and third doped regions in a well. A first gate controls the first and second regions and a second gate controls the second and third regions. A resistor is formed such that power applied to the bulk region of the two differential elements will differ by the voltage drop across the resistor. | 1. A method of forming a semiconductor varactor device having improved linearity comprising the steps of: providing a semiconductor substrate; forming at least a first and a second differential varactor element on said semiconductor substrate, the forming of each of said differential varactor elements comprising the steps of forming first, second and third N+ doped regions in an N well, forming a first gate for controlling said first and second N+ doped regions and forming a second gate for controlling said second and third N+ doped regions; connecting said first, second and third N+ doped regions of said first differential varactor element to receive power having a first voltage; and connecting said first, second and third N+ doped regions of said second differential varactor element to receive power having a second voltage different than said first voltage. 2. The method of claim 1 further comprising forming a first resistor in said semiconductor varactor device connected to receive power from a voltage source, and wherein said step of connecting said first, second and third N+ doped regions of said first differential varactor comprises connecting to said voltage source, and wherein said step of connecting said first, second and third N+ doped regions of said second differential varactor comprises connecting to said voltage source through said first resistor. 3. The method of claim 1 wherein said step of forming said first and second gates comprises the step of forming a first N-type gate and forming a second N-type gate. 4. The method of claim 2 wherein said step of forming a first resistor comprises the step of forming another resistor and said first resistor and wherein said another resistor is connected in series and between said voltage source and said first resistor, wherein said step of connecting said first, second and third N+ doped regions of said first differential varactor element to receive power from said voltage source comprises the step of connecting said regions to said voltage source through said another resistor, and such that said second differential varactor elements receive power from said voltage source through both of said another and said first resistors. 5. The method of claim 2 wherein said step of forming at least a first and a second differential varactor element comprises the step of forming at least a first, a second and a third differential varactor element, wherein said step of forming a first resistor comprises the step of forming first and second resistors connected in series and further comprising the step of connecting said first, second and third N+ doped regions of said third differential varactor element to receive power from said voltage source through both of said first and second resistors. 6. The method of claim 5 wherein said step of forming first and second resistors comprises the step of forming another resistor and said first and second resistors and wherein said another resistor is connected in series between said voltage source and said first and second resistors and wherein said step of connecting said first, second and third N+ doped regions of said first differential varactor element to receive power from said voltage source comprises the step of connecting said voltage source to said regions only through said another resistor. 7. The method of claim 2 wherein said step of forming first and second differential varactor elements comprises the step of forming a plurality of differential varactor elements, wherein said step of forming a first resistor comprises the step of forming a plurality of resistors connected in series such that nodes are defined between adjacent ones of said serially connected plurality of resistors and further comprising the step of connecting said first, second and third N+ doped regions of one each of said plurality of differential varactor elements to one each of said nodes such that said first, second and third N+ doped regions of different ones of said plurality of differential varactor elements are electrically separated by one of said plurality of resistors. 8. The method of claim 7 wherein said step of forming a plurality of resistors further comprises the step of forming said plurality of resistors and another resistor and connecting said another resistor in series between said voltage source and said serially connected plurality of resistors and wherein said step of connecting said first differential varactor element to receive power from said voltage source comprises the step of connecting said voltage source to said varactor element through said another resistor. 9. The method of claim 1 further comprising the steps of connecting said first gate of said first and second differential varactor elements together at a first terminal and connecting said second gate of said first and second differential varactor elements together at a second terminal. 10. The method of claim 5 further comprising the steps of connecting said first gate of said first, second and third differential varactor elements together at a first terminal and connecting said second gate of said first, second and third differential varactor element together at a second terminal. 11. The method of claim 7 further comprising the steps of connecting said first gate of said plurality of differential varactor elements together at a first terminal and connecting said second gate of said plurality of differential varactor elements together at a second terminal. 12. The method of claim 9 further comprising connecting said first and second terminals to an oscillator circuit as a voltage controlled capacitor. 13. The method of claim 11 further comprising connecting said first and second terminals to an oscillator circuit as a voltage controlled capacitor. 14. The method of claim 1 wherein said forming steps are according to a CMOS process. 15. The method of claim 9 wherein said first and second gates are N-type gates. 16. The method of claim 10 wherein said first and second gates are N-type gates. 17. The method of claim 11 wherein said first and second gates are N-type gates. 18. The method of claim 1 further comprising the steps of forming another differential varactor element on said semiconductor, said another differential varactor element comprising first, second and third P+ doped regions in a P well, a first gate for controlling said first and second P+ doped regions and a second gate for controlling said second and third P+ doped regions, and connecting said first, second and third P+ doped regions to receive power from said voltage source. 19. The method of claim 2 wherein said step of forming a first resistor comprises the step of forming said first resistor from a polysilicon material. 20. A semiconductor varactor device having improved linearity and suitable for being manufactured by a standard CMOS process comprising: a semiconductor substrate; at least two N wells formed in said semiconductor substrate; first, second and third N+ doped regions formed in each of said at least two N wells; a first gate connected to a first junction and formed between said first and second N+ doped regions of a first one of said at least two N wells, and a first gate connected to said first junction and formed between said first and second N+ doped regions of the other one of said at least two N wells; a second gate connected to a second junction and formed between said second and third N+ doped regions of said first one of said at least two N wells and a second gate connected to said second junction and formed between said second and third N+ doped regions of said other one of said at least two N wells; and a power source for providing a first voltage level and a second voltage level, said power source connecting said first resistor and said first, second and third N+ doped regions formed in said first one of said at least two N wells to receive power having said first voltage level and connecting said first, second and third N+ doped regions formed in said second one of said at least two N wells to receive power having said second voltage level. 21. The semiconductor varactor of claim 20 wherein said first voltage level is the output of said power source, and further comprising a first resistor formed on said semiconductor substrate and having a first end and a second end, said first end connected to the output of said power source and said second end connected to said first, second and third N+ doped regions formed in said second of said at least two N wells to provide said second voltage level. 22. The semiconductor varactor of claim 20 wherein said first and second gates are N-type gates. 23. The semiconductor varactor of claim 21 further comprising another resistor connected in series with said first resistor, said another resistor further connected between said voltage source and said first resistor such that said first, second and third N+ doped regions formed in said first one of said at least two N wells receives power from said voltage source through said another resistor. 24. The semiconductor varactor of claim 21 wherein said at least two N wells comprise at least three N wells and further comprising another first gate connected to said first junction and formed between said first and second N+ doped regions of the third one of said at least three N wells, another second gate connected to said second junction and formed between said second and third N+ doped regions of the third one of said at least three N wells, a second resistor connected in series with said first resistor and said first, second and third N+ doped regions of the third one of said at least three N wells connected to receive power from said voltage source through said first and second resistors. 25. The semiconductor varactor of claim 24 further comprising another resistor connected in series with said first and second resistor, said another resistor further connected between said voltage source and said first resistor such that said first, second and third N+ doped regions formed in said first one of said at least three N wells receives power from said voltage source through said another resistor. 26. The semiconductor varactor of claim 21 wherein said at least two N wells comprise a plurality of N wells, and further comprising a plurality of first gates connected to said first junction and formed between said first and second N+ doped regions of said plurality of N wells, a plurality of second gates connected to said second junction and formed between said second and third N+ doped region of said plurality of N wells, a plurality of resistors connected in series such that nodes are defined between two adjacent ones of said plurality of resistors, and wherein said first, second and third N+ doped regions of each one of said plurality of N wells are connected to one each of said nodes such that said first, second and third N+ doped regions of each one of said plurality are electrically separated by one of said plurality of resistors. 27. The semiconductor varactor of claim 26 further comprising another resistor connected in series with said plurality of resistors, said another resistor further connected between said voltage source and said plurality of resistors such that said first, second and third N+ doped regions formed in said first one of said plurality of N wells receive power from said voltage source through said another resistor. 28. The semiconductor varactor of claim 21 further comprising circuitry for forming an oscillator circuit when connected with said semiconductor varactor, said first and second junctions of said varactor device connected such that said semiconductor varactor operates as a voltage controlled capacitor of said oscillator circuit. 29. The semiconductor varactor of claim 20 wherein said first resistor is made of a polysilicon material. 30. The semiconductor varactor of claim 20 further comprising a P well formed in said semiconductor substrate and first, second and third P+ doped regions formed in said P well, a first gate for controlling said first and second P+ doped regions and a second gate for controlling said second and third P+ doped regions, said first, second and third P+ doped regions connected to receive power from said voltage source. | TECHNICAL FIELD The present invention relates to varactor (or voltage controlled capacitors) devices and more specifically to a varactor using a multiplicity of parallel back-to-back CMOS devices to provide a large capacitance range over a large and substantially linear voltage range. BACKGROUND The capacitance and/or frequency of a varactor or Variable Voltage Capacitor varies directly as the applied voltage varies, and consequently finds significant application with oscillator circuits such as used in communication devices. As an example, an oscillator circuit that is controlled by a varactor offers high-speed operation, low noise and low power consumption. The operating frequency of such an oscillator can be controlled or tuned by varying the voltage across the terminals of the varactor and, therefore, ideally the varactor will have a high maximum to minimum capacitance ratio. This is because the difference between the maximum and minimum capacitance over the full range of the controlled voltage will be proportional to the tuning range of the oscillator. Thus, a large capacitance range results in a large tuning range of the oscillator. The ideal variable voltage capacitor will also operate substantially linearly over a large voltage range such that the oscillator changes its operating frequency smoothly over a large voltage range. FIG. 1A illustrates the circuit schematic of an ideal LC oscillator (inductive capacitance) voltage controlled variable circuit or varactor, and FIG. 1B illustrates a linear relationship between the applied voltage Vc (on the horizontal axis 10) and the operating frequency Hz of the oscillator (on the vertical axis 12). Unfortunately, as will be appreciated by those skilled in the art, semiconductor varactors or Variable Voltage Capacitors, simply do not demonstrate such a linear relationship. Prior art semiconductor varactors are primarily of two types: a PN-junction varactor and a MOS varactor. The PN-junction varactor has the advantage that it can be implemented in a standard CMOS semiconductor process. Unfortunately, the PN-junction has a low maximum to minimum capacitance ratio, which, of course, as discussed above limits the operating frequency range of an oscillator using such a PN-junction varactor. On the other hand, a MOS varactor, such as shown in the semiconductor structure diagram of FIG. 2A and the electrical schematic of the back-to-back pair of varactors shown in FIG. 2B has an acceptable capacitance ratio, but the transition from the minimum C1 to the maximum C2 as shown in the graph of FIG. 2C from maximum to minimum or minimum to maximum, and as will be discussed later, is very abrupt over a small gate voltage (Vg) range V1, V2 such that the device is very non-linear. One attempt to achieve the goal is described in U.S. Pat. No. 6,407,412 entitled “MOS Varactor Structure with Engineered Voltage Control Range” and issued to Krzysztof Iniewski, et al. on Jun. 18, 2002. However, the device requires a somewhat complicated process flow to provide the necessary P+ and N+ parallel-connected regions. Therefore, it would be advantageous to provide a semiconductor varactor having a large capacitance ratio, which varies linearly over a large input voltage and can be manufactured by using standard CMOS processing. SUMMARY OF THE INVENTION These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by embodiments of the present invention, which describes a method of forming a semiconductor varactor device having improved linearity. The method comprises the following steps. The device is formed on a semiconductor substrate and includes forming at least first and second differential varactor elements. Each of the differential varactor elements formed on the semiconductor substrate comprises forming first, second and third N+ doped regions in an N well and forming a first gate for controlling the first and second N+ doped regions and forming a second gate for controlling the second and third N+ doped regions. In addition, a first resistor is also formed on the semiconductor substrate to be connected to and receive power from a selected voltage source. The first resistor is formed so that after the first, second and third N+ doped regions of the first differential varactor elements receive power from the voltage source, the first, second and third N+ doped regions of the second differential varactor elements are connected to the other end of the first resistor such that there is a voltage drop across the first resistor before the power reaches the second differential varactor elements. According to one embodiment, the first and second gates are formed as N-type gates. Although the forming of first and second (or two) differential varactor elements connected in parallel may be used to manufacture an improved oscillator according to this invention, it should be appreciated that even better linearity over a wider range of voltages may be achieved by using three or more differential varactor elements connected in parallel. That is, as many differential varactor elements as necessary may be connected in parallel according to the present invention so long as a series of resistors are also formed to control the bulk voltage of the regions of the differential varactor elements by connecting the resistors to provide a series of different voltage drops. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: FIG. 1A illustrates the circuit schematic of an LC oscillator with ideal voltage controlled capacitor or varactor; FIG. 1B illustrates the linear relationship between the applied voltage Vc on the horizontal axis and the operating frequency Hz of the varactor on the vertical axis; FIG. 2A is a prior art semiconductor structure portion of a single stage varactor; FIG. 2B is an electrical schematic of an oscillator with a pair of back-to-back varactors having the prior art structure of FIG. 2A; FIG. 2C is a graph illustrating the steep rise in capacitance with respect to voltage changes of the varactor of FIGS. 2A and 2B; FIG. 3A illustrates electrical schematics of three varactors of the prior art semiconductor structure of FIG. 2A having three different bulk bias voltages applied to the structure; FIG. 3B shows the three steep capacitance vs. voltage curves of the circuits of FIG. 3A as solid line graphs; FIG. 3C is an electrical schematic of the three circuits of FIG. 3A connected in parallel; FIG. 4A is a cross-sectional view of a semiconductor structure of back-to-back varactors according to the present invention and having a capacitance voltage output similar to that shown in FIG. 4D; FIG. 4B is a top view of the semiconductor structure of FIG. 4A; FIG. 4C is an electrical schematic illustrating the semiconductor structure of FIGS. 4A and 4B of a plurality of back-to-back varactors according to the present invention; and FIG. 4D is a graph illustrating the idealized resulting capacitance to voltage curve achieved by the present invention when a plurality of different optimized voltages are applied to the bulk region of the electrical schematic of FIG. 4A. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. Referring again to FIG. 2A, there is shown a semiconductor variable capacitance circuit that may be used in an oscillator circuit. As shown, a standard CMOS process is used except that an N well 14 is formed in the semiconductor 16 rather than the typical P well. This may be achieved by simply changing the P well implant mask to an N well implant mask. N well 14 includes a couple of N+ regions 18a and 18b that are connected together to a voltage or bulk voltage source 20. A gate member 22 is formed between the N+ regions 18a and 18b such that a voltage can be applied to the gate 22 to control the operation of the circuit. Referring to FIG. 2B, there is shown an LC oscillator circuit, which includes two of the circuits shown in FIG. 2A and identified in the circuit of FIG. 2B as circuits 24a and 24b. As shown, these circuits are connected as back-to-back differential varactor circuits with the bulk voltage Vc being applied to terminal 26. Therefore, as will be appreciated by those skilled in the art, when the back-to-back varactor elements are connected in parallel to an inductive element, such as inductive elements 28a and 28b, an LC circuit having a linear portion is provided. The variable capacitance of the circuit of the device shown in FIG. 2B is illustrated in FIG. 2C. As can be seen, a graph of the capacitance vs. voltage of such a circuit has a linear area 30 of capacitance change between a small voltage change 40 between voltages V1 and V2. At each side of the linear change 30, however, there is very little change in the capacitance with increase in voltage as seen in areas 41 a and 41 b. As was discussed before, it is desirable for an oscillator used in communications to have a variable capacitor that varies substantially linear over a wide range of voltages. Such a linear change over a wide voltage range allows for easy tuning of a communication circuit. Therefore, although the graph indicates a linear area 30 in FIG. 2C, the change in capacitance occurs over the very small voltage range (between V1 and V2), which makes it difficult to provide discrete changes in the capacitance. Various attempts have been made to solve this problem. For example, referring to FIG. 3A there is shown three circuits of the type discussed above with respect to FIG. 2A and FIG. 2B except that the bulk voltage V of each of the three circuits is different as indicated at V1, V2 and V3. The solid line curves 42a, 42b and 42c of FIG. 3B illustrate how the voltages for the three circuits of FIG. 3A are optimally selected. Referring to FIG. 3C, there is illustrated an electrical schematic of three circuits 43A, 43B and 43C similar to those of FIG. 3A connected in parallel according to the present invention. As discussed above, the solid line graphs of FIG. 3B illustrate the different outputs of the three circuits 43a, 43b and 43c of FIG. 3C when the voltages V1, V2 and V3 are optimally selected. The dashed line curve 44 of FIG. 3B illustrates the combined outputs of the three circuits when the voltages V1, V2 and V3 are optimally selected and the circuits are connected in parallel. Referring now to FIGS. 4A and 4B, there are shown a cross-sectional view and a top view of a semiconductor structure incorporating the teachings of the present invention. As shown, the structure is built upon a P-type substrate 50, which, according to the present embodiment, includes four N well areas 52a, 52b, 52c and 52d. Each of the N wells includes a first region 54, a second region 56 and a third region 58 all of which are N+ regions within the N wells 52a-52d. Silicon oxide areas 60 are shown separating each of the N wells 52a-52d. A first gate 62 above each of the N wells will control the electron flow between the first and second N+ regions 54 and 56 whereas a second gate 64 will control electron flow between the second and third regions 56 and 58. All of the first gates 62 are connected in parallel and have a common output terminal 66. Likewise, each of the second gates 64 is also connected in parallel and have a common output terminal 68. Further, although the above discussions, as well as the following discussions are with respect to N well varactors, it is also possible to include a PMOS-like varactor by forming P+ doped regions in a P well with first and second gate members. There is also included a group of resistors 70a, 70b, 70c, 70d and 70e, connected in series as is better shown in FIG. 4B. These serially connected resistors, as will be discussed hereinafter, provide a series of voltage drops so that each of the N wells 52a-52d has a different bulk voltage. This can be seen better in FIG. 4B wherein a voltage terminal 72 receives voltage from a voltage source, not shown, and this voltage is provided to the bulk region of N well 52a as shown by the connections 74a more clearly seen in FIG. 4B. The resistor 70a is also connected to the voltage source 72 and, in turn, it creates a voltage drop such that a second and lower voltage is provided to the N well 52b as indicated by electrical connections 74b. A second resistor 70b provides a second voltage drop to the N well 52c by the connections 74c. In a similar manner, resistors 70c, 70d and 70e provide additional voltage drops to the N well 52d and any other N wells. Resistors 70d and 70e illustrate that other additional N wells may be included in the circuitry. It is also possible of course, that another resistor be included between the voltage source 72 and the first bulk region 52a, such as resistor 76 shown in dashed lines in FIG. 4B to drop the voltage from that received from source 72 before it is applied to the first N well 52a. Therefore, referring now to FIG. 4C, there is shown an electrical schematic of a plurality of back-to-back varactors of the type shown in FIGS. 4A and 4B and similar to that of FIG. 3C, except that there is included the resistors 70a, 70b, 70c, 70N and 76 for providing voltage drops such that each of the back-to-back differential varactors is operating at a different bulk voltage. Consequently, if these resistors are optimally selected to provide specific voltage drops, the plurality of back-to-back vectors connected in parallel will generate a capacitance to voltage output similar to curve 44 shown in FIG. 4D. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | <SOH> BACKGROUND <EOH>The capacitance and/or frequency of a varactor or Variable Voltage Capacitor varies directly as the applied voltage varies, and consequently finds significant application with oscillator circuits such as used in communication devices. As an example, an oscillator circuit that is controlled by a varactor offers high-speed operation, low noise and low power consumption. The operating frequency of such an oscillator can be controlled or tuned by varying the voltage across the terminals of the varactor and, therefore, ideally the varactor will have a high maximum to minimum capacitance ratio. This is because the difference between the maximum and minimum capacitance over the full range of the controlled voltage will be proportional to the tuning range of the oscillator. Thus, a large capacitance range results in a large tuning range of the oscillator. The ideal variable voltage capacitor will also operate substantially linearly over a large voltage range such that the oscillator changes its operating frequency smoothly over a large voltage range. FIG. 1A illustrates the circuit schematic of an ideal LC oscillator (inductive capacitance) voltage controlled variable circuit or varactor, and FIG. 1B illustrates a linear relationship between the applied voltage Vc (on the horizontal axis 10 ) and the operating frequency Hz of the oscillator (on the vertical axis 12 ). Unfortunately, as will be appreciated by those skilled in the art, semiconductor varactors or Variable Voltage Capacitors, simply do not demonstrate such a linear relationship. Prior art semiconductor varactors are primarily of two types: a PN-junction varactor and a MOS varactor. The PN-junction varactor has the advantage that it can be implemented in a standard CMOS semiconductor process. Unfortunately, the PN-junction has a low maximum to minimum capacitance ratio, which, of course, as discussed above limits the operating frequency range of an oscillator using such a PN-junction varactor. On the other hand, a MOS varactor, such as shown in the semiconductor structure diagram of FIG. 2A and the electrical schematic of the back-to-back pair of varactors shown in FIG. 2B has an acceptable capacitance ratio, but the transition from the minimum C 1 to the maximum C 2 as shown in the graph of FIG. 2C from maximum to minimum or minimum to maximum, and as will be discussed later, is very abrupt over a small gate voltage (Vg) range V 1 , V 2 such that the device is very non-linear. One attempt to achieve the goal is described in U.S. Pat. No. 6,407,412 entitled “MOS Varactor Structure with Engineered Voltage Control Range” and issued to Krzysztof Iniewski, et al. on Jun. 18, 2002. However, the device requires a somewhat complicated process flow to provide the necessary P+ and N+ parallel-connected regions. Therefore, it would be advantageous to provide a semiconductor varactor having a large capacitance ratio, which varies linearly over a large input voltage and can be manufactured by using standard CMOS processing. | <SOH> SUMMARY OF THE INVENTION <EOH>These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by embodiments of the present invention, which describes a method of forming a semiconductor varactor device having improved linearity. The method comprises the following steps. The device is formed on a semiconductor substrate and includes forming at least first and second differential varactor elements. Each of the differential varactor elements formed on the semiconductor substrate comprises forming first, second and third N+ doped regions in an N well and forming a first gate for controlling the first and second N+ doped regions and forming a second gate for controlling the second and third N+ doped regions. In addition, a first resistor is also formed on the semiconductor substrate to be connected to and receive power from a selected voltage source. The first resistor is formed so that after the first, second and third N+ doped regions of the first differential varactor elements receive power from the voltage source, the first, second and third N+ doped regions of the second differential varactor elements are connected to the other end of the first resistor such that there is a voltage drop across the first resistor before the power reaches the second differential varactor elements. According to one embodiment, the first and second gates are formed as N-type gates. Although the forming of first and second (or two) differential varactor elements connected in parallel may be used to manufacture an improved oscillator according to this invention, it should be appreciated that even better linearity over a wider range of voltages may be achieved by using three or more differential varactor elements connected in parallel. That is, as many differential varactor elements as necessary may be connected in parallel according to the present invention so long as a series of resistors are also formed to control the bulk voltage of the regions of the differential varactor elements by connecting the resistors to provide a series of different voltage drops. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. | 20040421 | 20070529 | 20051027 | 68486.0 | 0 | NGUYEN, KHIEM D | COMPENSATED LINEARITY VOLTAGE-CONTROL-CAPACITOR DEVICE BY STANDARD CMOS PROCESS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,828,933 | ACCEPTED | Tile lighting methods and systems | A tile lighting system is provided in which an interior space of a tile is lit by LEDs, such as in a grid or edge-lit formation, and a light diffusing panel is disposed over the interior space. The tile lighting system can be combined with others to tile any surface, such as a floor, ceiling, wall, or building exterior. Lighting control signals can be supplied to generate a wide range of effects on the tile lighting units, including effects coordinated among different tile lighting units. Two- and three-dimensional embodiments are contemplated. | 1. A tile lighting system, comprising: a plurality of addressable lighting units disposed in a grid; a controller for controlling the illumination from the addressable lighting units; and a light diffusing cover for covering the grid. 2. A system of claim 1, wherein the light diffusing cover includes a phosphorescent material. 3. A system of claim 1, wherein the light diffusing cover is substantially translucent. 4. A system of claim 1, wherein the light diffusing cover is provided with a geometric shape. 5. A system of claim 1, wherein the light diffusing cover is provided with an irregular pattern. 6. A system of claim 1, wherein the lighting system is configured to be disposed in proximity to similar lighting systems in a tile arrangement. 7. A lighting system of claim 1, wherein the lighting units are controlled using a string light protocol. 8. A system of claim 1, further comprising an authoring system for authoring effects on the tile lighting system. 9. A system of claim 1 wherein the lighting system is capable of coordinating effects with another similar lighting system. 10. A system of claim 1, wherein the system is disposed in an architectural environment. 11. A system of claim 1, wherein the system is disposed on a building exterior. 12. A tile light, comprising: a plurality of LED lighting units disposed on a circuit board in an array, wherein the LED lighting units respond to control signals to produce mixed light of varying colors; and a diffuser for receiving light from the lighting units. 13. A tile light of claim 12, wherein the diffuser includes a phosphorescent material. 14. A tile light of claim 12, wherein the diffuser is substantially translucent. 15. A tile light of claim 12, wherein the diffuser is provided with a geometric shape. 16. A tile light of claim 12, wherein the diffuser is provided with an irregular pattern. 17. A tile light of claim 12, further comprising an authoring facility for authoring effects for the lighting system. 18. A tile light of claim 17, wherein the authoring facility is an object-oriented authoring facility. 19. A tile light of claim 17, wherein an effect displayed on the tile light corresponds to a graphical representation of the authoring facility. 20. A tile light of claim 17, wherein an effect displayed on the tile light corresponds to an incoming video signal. 21. A tile light of claim 12, wherein the tile light is disposed in an architectural environment. 22. A tile light of claim 12, wherein the tile light is disposed on a building exterior. 23. A tile light, comprising a plurality of linear LED lighting units disposed about the perimeter of a substantially rectangular housing; and a diffuser for diffusing light from the lighting units. 24. A tile light of claim 23, wherein the diffuser includes a phosphorescent material. 25. A tile light of claim 23, wherein the diffuser is substantially translucent. 26. A tile light of claim 23, wherein the diffuser is provided with a geometric shape. 27. A tile light of claim 23, wherein the diffuser is provided with an irregular pattern. 28. A tile light of claim 23, further comprising a reflector interior to the housing for providing a consistent level of light output to different portions of the diffuser. 29. A tile light of claim 23, wherein the housing is divided into a plurality of cells. 30. A tile light of claim 23, wherein the cells are rectangular. 31. A tile light of claim 23, wherein the cells are triangular. 32. A tile light of claim 23, further comprising an authoring system for authoring effects for the lighting system. 33. A tile light of claim 32, wherein the authoring system is an object-oriented authoring facility. 34. A tile light of claim 32, wherein an effect displayed on the tile light corresponds to a graphical representation of the authoring facility. 35. A tile light of claim 23, wherein the tile light is disposed in an architectural environment. 36. A tile light of claim 23, wherein the tile light is disposed on a building exterior. 37. A lighting system, comprising: a series of LED-based lighting units, wherein each lighting unit is configured to respond to data addressed to it in a serial addressing protocol, wherein the series of lighting units is configured in a flexible string; and a fastening facility for holding the flexible string in a predetermined configuration. 38. A lighting system of claim 37, wherein the fastening facility is a substantially linear channel for holding the flexible string. 39. A lighting system of claim 37, wherein the fastening facility holds the flexible string in an array. 40. A lighting system of claim 37, further comprising an authoring system for authoring effects for the lighting system. 41. A lighting system of claim 40, wherein the authoring system is an object-oriented authoring facility. 42. A lighting system of claim 41, wherein an effect displayed on the array corresponds to a graphical representation of the authoring facility. 43. A lighting system of claim 39, wherein an effect displayed on the array corresponds to an incoming video signal. 44. A lighting system of claim 39, wherein the array is disposed in an architectural environment. 45. A lighting system of claim 39, wherein the array is disposed on a building exterior. 47. A modular component for a lighting system, comprising: a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured to respond to data addressed to it in a serial addressing protocol. 48. A component of claim 47, further comprising an authoring system for authoring effects for the lighting system. 49. A component of claim 48, wherein the authoring system is an object-oriented authoring facility. 50. A component of claim 48, wherein an effect displayed on the component corresponds to a graphical representation of the authoring facility. 51. A component of claim 48, wherein an effect displayed on the component corresponds to an incoming video signal. 52. A component of claim 47, wherein the circuit board is a flexible circuit board. 53. A component of claim 47, wherein the circuit board is a printed circuit board. 54. A component of claim 47, wherein the component is disposed in an architectural environment. 55. A component of claim 47, wherein the array is disposed on a building exterior. 56. A lighting system, comprising: a plurality of modular components, wherein each modular component includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured to respond to data addressed to it in a serial addressing protocol. 57. A system of claim 56, wherein the modular components are disposed adjacent to each other to form a large array of modular components. 58. A system of claim 56, further comprising an authoring system for authoring effects for the lighting system. 59. A system of claim 58, wherein the authoring system is an object-oriented authoring facility. 60. A system of claim 58, wherein an effect displayed on the large array corresponds to a graphical representation of the authoring facility. 61. A system of claim 58, wherein an effect displayed on the array corresponds to an incoming video signal. 62. A system of claim 58, wherein the array is disposed in an architectural environment. 63. A system of claim 58, wherein the array is disposed on a building exterior. 64. A method of providing a tile lighting system, comprising: providing a plurality of addressable lighting units disposed in a grid; providing a controller for controlling the illumination from the addressable lighting units; and covering the grid with a light diffusing cover. 65. A method of claim 64, wherein the light diffusing cover includes a phosphorescent material. 66. A method of claim 64, wherein the light diffusing cover is substantially translucent. 67. A method of claim 64, wherein the light diffusing cover is provided with a geometric shape. 68. A method of claim 64, wherein the light diffusing cover is provided with an irregular pattern. 69. A method of claim 64, wherein the lighting system is configured to be disposed in proximity to similar lighting systems in a tile arrangement. 70. A method of claim 64, wherein the lighting units are controlled using a string light protocol. 71. A method of claim 64, further comprising providing an authoring system for authoring effects on the tile lighting system. 72. A method of claim 64 wherein the lighting system is capable of coordinating effects with another similar lighting system. 73. A method of claim 64, wherein the system is disposed in an architectural environment. 74. A method of claim 64, wherein the system is disposed on a building exterior. 75. A method of providing a tile light, comprising: providing a plurality of LED lighting units disposed on a circuit board in an array, wherein the LED lighting units respond to control signals to produce mixed light of varying colors; and providing a diffuser for receiving light from the lighting units. 76. A method of claim 75, wherein the diff-user includes a phosphorescent material. 77. A method of claim 75, wherein the diffuser is substantially translucent. 78. A method of claim 75, wherein the diffuser is provided with a geometric shape. 79. A method of claim 75, wherein the diffuser is provided with an irregular pattern. 80. A method of claim 75, further comprising an authoring facility for authoring effects for the lighting system. 81. A method of claim 80, wherein the authoring facility is an object-oriented authoring facility. 82. A method of claim 80, wherein an effect displayed on the tile light corresponds to a graphical representation of the authoring facility. 83. A method of claim 80, wherein an effect displayed on the tile light corresponds to an incoming video signal. 84. A method of claim 75, wherein the tile light is disposed in an architectural environment. 85. A method of claim 75, wherein the tile light is disposed on a building exterior. 86. A method of providing a tile light, comprising providing a plurality of linear LED lighting units disposed about the perimeter of a substantially rectangular housing; and providing a diffuser for diffusing light from the lighting units. 87. A method of claim 86, wherein the diffuser includes a phosphorescent material. 88. A method of claim 86, wherein the diffuser is substantially translucent. 89. A method of claim 86, wherein the diffuser is provided with a geometric shape. 90. A method of claim 86, wherein the diffuser is provided with an irregular pattern. 91. A method of claim 86, further comprising a reflector interior to the housing for providing a consistent level of light output to different portions of the diffuser. 92. A method of claim 86, wherein the housing is divided into a plurality of cells. 93. A method of claim 86, wherein the cells are rectangular. 94. A method of claim 86, wherein the cells are triangular. 95. A method of claim 86, further comprising an authoring system for authoring effects for the lighting system. 96. A method of claim 95, wherein the authoring system is an object-oriented authoring facility. 97. A method of claim 95, wherein an effect displayed on the tile light corresponds to a graphical representation of the authoring facility. 98. A method of claim 86, wherein the tile light is disposed in an architectural environment. 99. A method of claim 86, wherein the tile light is disposed on a building exterior. 100. A method of providing lighting, comprising: providing a series of LED-based lighting units, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol, wherein the series of lighting units is configured in a flexible string; and providing a fastening facility for holding the flexible string in a predetermined configuration. 101. A lighting method of claim 100, wherein the fastening facility is a substantially linear channel for holding the flexible string. 102. A lighting method of claim 100, wherein the fastening facility holds the flexible string in an array. 103. A lighting method of claim 100, further comprising an authoring system for authoring effects for the lighting system. 104. A lighting method of claim 103, wherein the authoring system is an object-oriented authoring facility. 105. A lighting method of claim 104, wherein an effect displayed on the array corresponds to a graphical representation of the authoring facility. 106. A lighting method of claim 103, wherein an effect displayed on the array corresponds to an incoming video signal. 107. A lighting method of claim 103, wherein the array is disposed in an architectural environment. 108. A lighting method of claim 103, wherein the array is disposed on a building exterior. 109. A method of providing a modular component for a lighting system, comprising: providing a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. 110. A method of claim 109, further comprising an authoring system for authoring effects for the lighting system. 111. A method of claim 110, wherein the authoring system is an object-oriented authoring facility. 112. A method of claim 110, wherein an effect displayed on the component corresponds to a graphical representation of the authoring facility. 113. A method of claim 110, wherein an effect displayed on the component corresponds to an incoming video signal. 114. A method of claim 109, wherein the circuit board is a flexible circuit board. 115. A method of claim 109, wherein the circuit board is a printed circuit board. 116. A method of claim 109, wherein the component is disposed in an architectural environment. 117. A method of claim 109, wherein the array is disposed on a building exterior. 118. A method of providing a lighting system, comprising: providing a plurality of modular components, wherein each modular component includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. 119. A method of claim 118, wherein the modular components are disposed adjacent to each other to form a large array of modular components. 120. A method of claim 118, further comprising an authoring system for authoring effects for the lighting system. 121. A method of claim 120, wherein the authoring system is an object-oriented authoring facility. 122. A method of claim 120, wherein an effect displayed on the large array corresponds to a graphical representation of the authoring facility. 123. A method of claim 120, wherein an effect displayed on the array corresponds to an incoming video signal. 124. A method of claim 120, wherein the array is disposed in an architectural environment. 125. A method of claim 118, wherein the array is disposed on a building exterior. | CROSS-REFERENCES TO RELATED APPLICATIONS This application claims the benefit, under 35 U.S.C. §119(e), of the following U.S. Provisional Applications: Ser. No. 60/464,185, filed Apr. 21, 2003, entitled “Tile Lighting Methods and Systems; Ser. No. 60/467,913, filed May 5, 2003, entitled “Tile Lighting Methods and Systems; Ser. No. 60/500,754, filed Sep. 5, 2003, entitled “Tile Lighting Methods and Systems; Ser. No. 60/523,903, filed Nov. 20, 2003, entitled “Light System Manager;” and Ser. No. 60/558,400, filed Mar. 31, 2004, entitled “Methods and Systems for Providing Lighting Components.” This application also claims the benefit, under 35 U.S.C. §120, as a continuation-in-part (CIP) of U.S. Non-provisional application Ser. No. 10/803,540, filed Mar. 18, 2004, entitled “Geometric Panel Lighting Apparatus and Methods,” which in turn is a continuation of Ser. No. 09/213,540, filed Dec. 17, 1998, entitled “Data Delivery Track,” now U.S. Pat. No. 6,720,745, issued Apr. 13, 2004. Each of the aforementioned applications is incorporated herein by reference. BACKGROUND LED-based lighting methods and systems are known, including those developed and marketed by Color Kinetics Incorporated and those disclosed in the patents, patent applications and other documents incorporated by reference herein. A need exists for improved lighting fixtures that take full advantage of the inventive aspects of LED-based illumination methods and systems, including lighting fixtures with particular forms, including lighting fixtures that take the form of tiles. SUMMARY The methods and systems disclosed herein include those for providing a tile lighting system that may comprise a lighting system configured in a two-dimensional shape, such as a square, rectangle, circle, polygon, or other shape. Methods and systems are disclosed herein for controlling light output from such a tile light, for mechanically constructing a tile light to provide optimal light output, for connecting tile lights to each other to facilitate addressing and controlling such tile lights, for authoring effects to be presented with such a tile light, for supplying power and data to such a tile light, and other aspects. Methods and systems disclosed herein also encompass three-dimensional lights that comprise combinations of flat circuit boards of simple geometries. For example, a substantially spherical lighting unit can be formed from circuit boards of simple polygons, such as triangles, hexagons or pentagons. Similarly, a pyramidal lighting unit can be formed of triangular lighting units. Such three-dimensional lighting units can be addressed, powered, and controlled in the manner described for other lighting units herein, and effects for such lighting units can be authored using methods and systems described herein. The methods and systems disclosed herein may further comprise control protocols, which may include disposing a plurality of lighting units in a serial configuration and controlling all of them by a stream of data to respective ASICs (Application Specific Integrated Circuits) of each of them, wherein each lighting system responds to the first unmodified bit of data in the stream, modifies that bit of data, and transmits the stream to the next ASIC. This protocol is described herein in some cases as a “string light” protocol or as a Chromasic protocol, such as that offered by Color Kinetics Incorporated and described in the patent applications incorporated herein by reference. The methods and systems may further include providing a communication facility of the lighting system, wherein the lighting system responds to data from a source exterior to the lighting system. The data may come from a signal source exterior to the lighting system. The signal source may be a wireless signal source. In embodiments the signal source includes a sensor for sensing an environmental condition, and the control of the lighting system is in response to the environmental condition. In embodiments the signal source generates a signal based on a scripted lighting program for the lighting system. In embodiments the control of the lighting system is based on assignment of lighting system units as objects in an object-oriented computer program. In embodiments the computer program is an authoring system. In embodiments the authoring system relates attributes in a virtual system to real world attributes of lighting systems. In embodiments the real world attributes include positions of lighting units of the lighting system. In embodiments the computer program is a computer game. In other embodiments the computer program is a music program. In embodiments of the methods and systems provided herein, the lighting system includes a power supply. In embodiments the power supply is a power-factor-controlled power supply. In embodiments the power supply is a two-stage power supply. In embodiments the power factor correction includes an energy storage capacitor and a DC-DC converter. In embodiments the PFC and energy storage capacitor are separated from the DC-DC converter by a bus. In embodiments of the methods and systems provided herein, the lighting systems further include disposing at least one such lighting unit in or on a building. In embodiments the lighting units are disposed in an array on a building. In embodiments the array is configured to facilitate displaying at least one of a number, a word, a letter, a logo, a brand, and a symbol. In embodiments the array is configured to display a light show with time-based effects. Methods and systems disclosed herein include methods and systems for providing a tile lighting system. The tile lighting system may include a plurality of addressable lighting units disposed in a grid, a controller for controlling the illumination from the addressable lighting units and a light diffusing cover for covering the grid. In embodiments the light diffusing cover may include a phosphorescent material. In embodiments the light diffusing cover is substantially translucent. In embodiments the light diffusing cover is provided with a geometric shape. In embodiments the light diffusing cover is provided with an irregular pattern. In embodiments the lighting system is configured to be disposed in proximity to similar lighting systems in a tile arrangement. In embodiments the lighting units are controlled using a string light protocol. In embodiments the light system may further include an authoring system for authoring effects on the tile lighting system. In embodiments lighting system is capable of coordinating effects with another similar lighting system. In embodiments the lighting system is disposed in an architectural environment. In embodiments the lighting system is disposed on a building exterior. Methods and systems described herein include providing a tile light that includes a plurality of LED lighting units disposed on a circuit board in an array, wherein the LED lighting units respond to control signals to produce mixed light of varying colors and a diffuser for receiving light from the lighting units. In embodiments the light diffusing cover may include a phosphorescent material. In embodiments the light diffusing cover is substantially translucent. In embodiments the light diffusing cover is provided with a geometric shape. In embodiments the light diffusing cover is provided with an irregular pattern. In embodiments the methods and systems may include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems described herein include providing a tile light that includes a plurality of linear LED lighting units disposed about the perimeter of a substantially rectangular housing and a diffuser for diffusing light from the lighting units. In embodiments the diffuser may include a phosphorescent material, may be substantially translucent, may be provided with a geometric shape or may be provided with an irregular pattern. In embodiments the methods and systems include a reflector in the housing for providing a consistent level of light output to different portions of the diffuser. In embodiments to divided into a plurality of cells. In embodiments the cells are rectangular. In embodiments the cells are triangular. In embodiments the methods and systems include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems described herein include lighting systems that include a series of LED-based lighting units, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol, wherein the series of lighting units is configured in a flexible string and a fastening facility for holding the flexible string in a predetermined configuration. In embodiments the fastening facility is a substantially linear channel for holding the flexible string. In embodiments the fastening facility holds the flexible string in an array. In embodiments the methods and systems include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems disclosed herein include a modular component for a lighting system that includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. The methods and systems may further include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the circuit board is a flexible circuit board. In embodiments the circuit board is a printed circuit board. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems disclosed herein include methods and systems for providing a lighting system that includes a plurality of modular components, wherein each modular component includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. In embodiments the modular components are disposed adjacent to each other to form a large array of modular components. The methods and systems may further include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the large array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Method and systems disclosed herein include controlled, networked or non-networked illumination devices. The fundamental building blocks include semiconductor-based illumination devices such as light-emitting diodes (LEDs) that are used to illuminate surfaces. Included are system and methods for creating surfaces that can provide patterns of color and color changing capability at a variety of scales. The devices, in many embodiments, can be incorporated into any 2D or 3D surface. In embodiments, the illuminated surfaces include geometries to maximize light output, homogenize and diffuse light output, and to shape light output. The viewed surfaces incorporate textures and 2D or 3D forms to guide and direct light towards the viewer. A variety of fastening methods are also described to mount and connect devices onto or into surfaces. As used herein for purposes of the present disclosure, the term “LED” should be understood to include any light emitting diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, light-emitting strips, electro-luminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured to generate radiation having various bandwidths for a given spectrum (e.g., narrow bandwidth, broad bandwidth). It should be noted that LED(S) in systems according to the present invention might be any color including white, ultraviolet, infrared or other colors within the electromagnetic spectrum. As used herein, the term “LED” should be further understood to include, without limitation, light emitting diodes of all types, light emitting polymers, semiconductor dies that produce light in response to current, organic LEDs, electro-luminescent strips, and other such systems. In an embodiment, an “LED” may refer to a single light emitting diode having multiple semiconductor dies that are individually controlled. It should also be understood that the term “LED” does not restrict the package type of the LED. The term “LED” includes packaged LEDs, non-packaged LEDs, surface mount LEDs, chip on board LEDs and LEDs of all other configurations. The term “LED” also includes LEDs packaged or associated with material (e.g. a phosphor) wherein the material may convert energy from the LED to a different wavelength. For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectrums of luminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts luminescence having a first spectrum to a different second spectrum. In one example of this implementation, luminescence having a relatively short wavelength and narrow bandwidth spectrum “pumps” the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum. It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectrums of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc. The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources as defined above, incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of luminescent sources, electro-lumiscent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers. A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms “light” and “radiation” are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication and/or illumination. An “illumination source” is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. An LED system is one type of illumination source. As used herein “illumination source” should be understood to include all illumination sources, including LED systems, as well as incandescent sources, including filament lamps, pyro-luminescent sources, such as flames, candle-luminescent sources, such as gas mantles and carbon arch radiation sources, as well as photo-luminescent sources, including gaseous discharges, fluorescent sources, phosphorescence sources, lasers, electro-luminescent sources, such as electro-luminescent lamps, light emitting diodes, and cathode luminescent sources using electronic satiation, as well as miscellaneous luminescent sources including galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, and radioluminescent sources. Illumination sources may also include luminescent polymers capable of producing primary colors. The term “illuminate” should be understood to refer to the production of a frequency of radiation by an illumination source. The term “color” should be understood to refer to any frequency of radiation within a spectrum; that is, a “color,” as used herein, should be understood to encompass frequencies not only of the visible spectrum, but also frequencies in the infrared and ultraviolet areas of the spectrum, and in other areas of the electromagnetic spectrum. The term “spectrum” should be understood to refer to any one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term “spectrum” refers to frequencies (or wavelengths) not only in the visible range, but also frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Also, a given spectrum may have a relatively narrow bandwidth (essentially few frequency or wavelength components) or a relatively wide bandwidth (several frequency or wavelength components having various relative strengths). It should also be appreciated that a given spectrum may be the result of a mixing of two or more other spectrums (e.g., mixing radiation respectively emitted from multiple light sources). For purposes of this disclosure, the term “color” is used interchangeably with the term “spectrum.” However, the term “color” generally is used to refer primarily to a property of radiation that is perceivable by an observer (although this usage is not intended to limit the scope of this term). Accordingly, the terms “different colors” implicitly refer to different spectrums having different wavelength components and/or bandwidths. It also should be appreciated that the term “color” may be used in connection with both white and non-white light. The term “color temperature” generally is used herein in connection with white light, although this usage is not intended to limit the scope of this term. Color temperature essentially refers to a particular color content or shade (e.g., reddish, bluish) of white light. The color temperature of a given radiation sample conventionally is characterized according to the temperature in degrees Kelvin (K) of a black body radiator that radiates essentially the same spectrum as the radiation sample in question. The color temperature of white light generally falls within a range of from approximately 700 degrees K (generally considered the first visible to the human eye) to over 10,000 degrees K. Lower color temperatures generally indicate white light having a more significant red component or a “warmer feel,” while higher color temperatures generally indicate white light having a more significant blue component or a “cooler feel.” By way of example, a wood burning fire has a color temperature of approximately 1,800 degrees K, a conventional incandescent bulb has a color temperature of approximately 2848 degrees K, early morning daylight has a color temperature of approximately 3,000 degrees K, and overcast midday skies have a color temperature of approximately 10,000 degrees K. A color image viewed under white light having a color temperature of approximately 3,000 degree K has a relatively reddish tone, whereas the same color image viewed under white light having a color temperature of approximately 10,000 degrees K has a relatively bluish tone. The terms “lighting unit” and “lighting fixture” are used interchangeably herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An “LED-based lighting unit” refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. The terms “processor” or “controller” are used herein interchangeably to describe various apparatus relating to the operation of one or more light sources. A processor or controller can be implemented in numerous ways, such as with dedicated hardware, using one or more microprocessors that are programmed using software (e.g., microcode or firmware) to perform the various functions discussed herein, or as a combination of dedicated hardware to perform some functions and programmed microprocessors and associated circuitry to perform other functions. Among other things, processor can include an integrated circuit, such as an application specific integrated circuit. In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present invention discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers, including by retrieval of stored sequences of instructions. The term “addressable” is used herein to refer to a device (e.g., a light source in general, a lighting unit or fixture, a controller or processor associated with one or more light sources or lighting units, other non-lighting related devices, etc.) that is configured to receive information (e.g., data) intended for multiple devices, including itself, and to selectively respond to particular information intended for it. The term “addressable” often is used in connection with a networked environment (or a “network,” discussed further below), in which multiple devices are coupled together via some communications medium or media. In one implementation, one or more devices coupled to a network may serve as a controller for one or more other devices coupled to the network (e.g., in a master/slave relationship). In another implementation, a networked environment may include one or more dedicated controllers that are configured to control one or more of the devices coupled to the network. Generally, multiple devices coupled to the network each may have access to data that is present on the communications medium or media; however, a given device may be “addressable” in that it is configured to selectively exchange data with (i.e., receive data from and/or transmit data to) the network, based, for example, on one or more particular identifiers (e.g., “addresses”) assigned to it. In another implementation, devices may be configured to receive data in a certain order or along a certain path, such as by being placed along a line or string. In such an implementation, data may be addressed to a particular lighting unit according to its ordinal position in the string. Thus, the first unit responds to the first packet of data, the second unit responds to the second packet of data, and so on. This may be accomplished, for example, by having each lighting unit modify the packet of data that is addressed to it (such as by placing a “1” in the first position of a byte of data) and by having each lighting unit respond to the first unmodified packet of data. This and other implementations that rely on the ordinal position of the lighting units along a string of lighting units are referred to herein as “string light” protocols. The term “network” as used herein refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transport of information (e.g. for device control, data storage, data exchange, etc.) between any two or more devices and/or among multiple devices coupled to the network. As should be readily appreciated, various implementations of networks suitable for interconnecting multiple devices may include any of a variety of network topologies and employ any of a variety of communication protocols. Additionally, in various networks according to the present invention, any one connection between two devices may represent a dedicated connection between the two systems, or alternatively a non-dedicated connection. In addition to carrying information intended for the two devices, such a non-dedicated connection may carry information not necessarily intended for either of the two devices (e.g., an open network connection). Furthermore, it should be readily appreciated that various networks of devices as discussed herein may employ one or more wireless, wire/cable, and/or fiber optic links to facilitate information transport throughout the network. The lighting systems described herein may also include a user interface used to change and or select the lighting effects displayed by the lighting system. The communication between the user interface and the processor may be accomplished through wired or wireless transmission. The term “user interface” as used herein refers to an interface between a human user or operator and one or more devices that enables communication between the user and the device(s). Examples of user interfaces that may be employed in various implementations of the present invention include, but are not limited to, switches, human-machine interfaces, operator interfaces, potentiometers, buttons, dials, sliders, a mouse, keyboard, keypad, various types of game controllers (e.g., joysticks), track balls, display screens, various types of graphical user interfaces (GUIs), touch screens, microphones and other types of sensors that may receive some form of human-generated stimulus and generate a signal in response thereto. The following patents and patent applications are hereby incorporated herein by reference: U.S. Pat. No. 6,016,038, issued Jan. 18, 2000, entitled “Multicolored LED Lighting Method and Apparatus;” U.S. Pat. No. 6,608,453, issued Aug. 19, 2003, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” U.S. Pat. No. 6,548,967, issued Apr. 15, 2003, entitled “Universal Lighting Network Methods and Systems;” U.S. patent application Ser. No. 09/886,958, filed Jun. 21, 2001, entitled Method and Apparatus for Controlling a Lighting System in Response to an Audio Input;” U.S. patent application Ser. No. 10/078,221, filed Feb. 19, 2002, entitled “Systems and Methods for Programming Illumination Devices;” U.S. patent application Ser. No. 09/344,699, filed Jun. 25, 1999, entitled “Method for Software Driven Generation of Multiple Simultaneous High Speed Pulse Width Modulated Signals;” U.S. patent application Ser. No. 09/805,368, filed Mar. 13, 2001, entitled “Light-Emitting Diode Based Products;” U.S. patent application Ser. No. 09/716,819, filed Nov. 20, 2000, entitled “Systems and Methods for Generating and Modulating Illumination Conditions;” U.S. patent application Ser. No. 09/675,419, filed Sep. 29, 2000, entitled “Systems and Methods for Calibrating Light Output by Light-Emitting Diodes;” U.S. patent application Ser. No. 09/870,418, filed May 30, 2001, entitled “A Method and Apparatus for Authoring and Playing Back Lighting Sequences;” U.S. patent application Ser. No. 09/923,223, filed Aug. 8, 2001, entitled “Ultraviolet Light Emitting Diode Systems and Methods”; U.S. patent application Ser. No. 10/045,604, filed Oct. 23, 2001, entitled “Systems and Methods for Digital Entertainment;” U.S. patent application Ser. No. 09/989,677, filed Nov. 20, 2001, entitled “Information Systems; U.S. patent application Ser. No. 10/045,629, filed Oct. 25, 2001, entitled “Methods and Apparatus for Controlling Illumination;” U.S. patent application Ser. No. 10/158,579, filed May 30, 2002, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” U.S. patent application Ser. No. 10/163,085, filed Jun. 5, 2002, entitled “Systems and Methods for Controlling Programmable Lighting Systems;” U.S. patent application Ser. No. 10/325,635, filed Dec. 19, 2002, entitled “Controlled Lighting Methods and Apparatus;” and U.S. patent application Ser. No. 10/360,594, filed Feb. 6, 2003, entitled “Controlled Lighting Methods and Apparatus.” It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates one example of a lighting unit that may serve as a device in a lighting environment according to one embodiment of the present invention. FIG. 2 depicts a lighting system with a plurality of lighting units and a central controller. FIG. 3 is a schematic diagram for a programming device for programming a lighting unit in accordance with the principles of the invention. FIG. 4 depicts various configurations of lighting units in accordance with the invention. FIG. 5 depicts a tile lighting fixture in accordance with the invention. FIG. 6 depicts wall mounting methods and systems for a tile light embodiment of the invention. FIG. 7 depicts a wall mounting rail system for a tile lighting system. FIG. 8 is a schematic diagram of an electrical and mechanical connection between units of a tile lighting system. FIG. 9 illustrates a magnetic connection among two tile light units. FIG. 10 illustrates a bracket system for connecting tile lighting units. FIG. 11 illustrates a portion of a lighting unit controller including a power-sensing module according to one embodiment of the present invention. FIG. 12 shows an example of a circuit implementation of a lighting unit controller including a power-sensing module according to one embodiment of the invention. FIG. 13 illustrates a bracket system for connecting tile lighting units and for attaching the tile lighting units to a wall or other surface. FIG. 14 illustrates a system for creating a halo effect about a tile lighting unit. FIG. 15 illustrates an edge-lit embodiment of the interior of a tile light as well as the lit exterior cover of the tile light. FIG. 16 illustrates embodiments of a diffusing panel exterior for a tile lighting unit. FIG. 17 illustrates additional embodiments of a diffusing panel exterior of a tile lighting unit. FIG. 18 illustrates a tile lighting unit designed to be placed flush to a flat surface. FIG. 19 illustrates additional form factors for a tile lighting unit that is designed to be placed flush on a flat surface. FIG. 20 depicts an array or grid of addressable lighting units that can form the interior of a tile lighting unit. FIG. 21 depicts another embodiment of an array or grid of addressable lighting units for the interior of a tile lighting units. FIG. 22 depicts an embodiment of a diffusing element disposed proximally to an LED lighting unit for diffusing light in a tile lighting unit. FIG. 23 depicts a Penrose tile configuration for a lighting unit. FIG. 24 is a schematic diagram showing elements for authoring a lighting control signal. FIG. 25 is a schematic diagram showing elements for generating a lighting control signal from an animation facility and light management facility. FIG. 26 illustrates a configuration file for data relating to light systems in an environment. FIG. 27 illustrates a virtual representation of an environment using a computer screen. FIG. 28 is a representation of an environment with light systems that project light onto portions of the environment. FIG. 29 is a schematic diagram showing the propagation of an effect through a light system. FIG. 30 is a flow diagram showing steps for using an image capture device to determine the positions of a plurality of light systems in an environment. FIG. 31 is a flow diagram showing steps for interacting with a graphical user interface to generate a lighting effect in an environment. FIG. 32 is a schematic diagram depicting light systems that transmit data that is generated by a network transmitter. FIG. 33 is a flow diagram showing steps for generating a control signal for a light system using an object-oriented programming technique. FIG. 34 shows a configuration of multiple tile lighting units in a self-configuring network. FIG. 35 shows a substantially spherical lighting unit formed of a plurality of flat circuit board lighting units. FIG. 36 shows a close view of elements of the embodiment of FIG. 35. FIG. 37 shows a substantially triangular circuit board element designed to interlock with other circuit board elements to form the substantially spherical lighting unit of FIG. 35. FIG. 38 shows platonic solids that can be formed from polygons and that can comprise lighting unit configurations according to the principles of the invention. FIG. 39 shows a network configuration for a plurality of lighting units. FIG. 40 shows a plurality of tile lights connected by a very high speed serial bus. FIG. 41 shows a set of LEDs placed in varying proximity to a diffuser. FIG. 42 shows a direct view of an LED board with a plurality of lighting elements disposed on it. FIG. 43 shows an LED board with a diffuser disposed in proximity to it at an angle relative to the surface of the board. FIG. 44 shows embodiments of different shapes and types of materials that can be used as diffusers. FIG. 45 shows examples of fastening facilities for light nodes of the methods and systems described herein. FIG. 46 shows a push-through fastening mechanism for a light node. FIG. 47 shows a three-dimensional, complex surface of a diffuser. FIG. 48 shows a hemispherical diffuser with a graphical element included on it. FIG. 49 shows the superposition of materials on top of an array of light nodes, including transparent and translucent materials. FIG. 50 shows superposition of a logo or other graphical element on an array of light nodes. FIG. 51 shows a regular, planar array of LEDs on a board. FIG. 52 shows an irregular pattern of LEDs in an array. FIG. 53 shows a three-dimensional, Mobius strip configuration of an array of LEDs. FIG. 54 shows a grid for holding light nodes. FIG. 55 shows an embodiment of a grid holding light nodes configured to represent a picture. FIG. 56 shows a string light node with a short lens cap. FIG. 57 shows a string light node with an elongated lens cap. FIG. 58 shows a string light node with no lens cap. FIG. 59 shows a CAD drawing of a string light node. FIG. 60 shows a CAD drawing of a string light node in a no-lens embodiment. FIG. 61 shows a tile light with a sensing user interface. FIG. 62 shows surfaces on which a tile lighting unit may be disposed or in which it may be integrated. FIG. 63 shows an embodiment of a tile light for lighting a water environment. FIG. 64 shows a circuit board with an array of light sources. FIG. 65 shows another embodiment of a circuit board with an array of light sources. FIG. 66 shows a back view of the printed circuit board of FIGS. 64 and 65. FIG. 67 shows additional configurations for lighting units. FIG. 68 shows an array created from a plurality of nodes. FIG. 69 shows a light system manager facility. FIG. 70 shows an embodiment of a networked light system manager facility. FIG. 71 shows an embodiment of a light system manager where control instructions are relayed as XML scripts. DETAILED DESCRIPTION The description below pertains to several illustrative embodiments of the invention. Although many variations of the invention may be envisioned by one skilled in the art, such variations and improvements are intended to fall within the compass of this disclosure. Thus, the scope of the invention is not to be limited in any way by the disclosure below. Various embodiments of the present invention are described below, including certain embodiments relating particularly to LED-based light sources. It should be appreciated, however, that the present invention is not limited to any particular manner of implementation, and that the various embodiments discussed explicitly herein are primarily for purposes of illustration. For example, the various concepts discussed herein may be suitably implemented in a variety of environments involving LED-based light sources, other types of light sources not including LEDs, environments that involve both LEDs and other types of light sources in combination, and environments that involve non-lighting-related devices alone or in combination with various types of light sources. FIG. 1 illustrates one example of a lighting unit 100 that may serve as a device in a lighting environment according to one embodiment of the present invention. Some examples of LED-based lighting units similar to those that are described below in connection with FIG. 1 may be found, for example, in U.S. Pat. No. 6,016,038, issued Jan. 18, 2000 to Mueller et al., entitled “Multicolored LED Lighting Method and Apparatus,” and U.S. Pat. No. 6,211,626, issued Apr. 3, 2001 to Lys et al, entitled “Illumination Components,” which patents are both hereby incorporated herein by reference. In various embodiments of the present invention, the lighting unit 100 shown in FIG. 1 may be used alone or together with other similar lighting units in a system of lighting units (e.g., as discussed further below in connection with FIG. 2). Used alone or in combination with other lighting units, the lighting unit 100 may be employed in a variety of applications including, but not limited to, interior or exterior space illumination in general, direct or indirect illumination of objects or spaces, theatrical or other entertainment-based/special effects illumination, decorative illumination, safety-oriented illumination, vehicular illumination, illumination of displays and/or merchandise (e.g. for advertising and/or in retail/consumer environments), combined illumination and communication systems, etc., as well as for various indication and informational purposes. Additionally, one or more lighting units similar to that described in connection with FIG. 1 may be implemented in a variety of products including, but not limited to, various forms of lighting fixtures, various forms of light modules or bulbs having various shapes and electrical/mechanical coupling arrangements (including replacement or “retrofit” modules or bulbs adapted for use in conventional sockets or fixtures), as well as a variety of consumer and/or household products (e.g., night lights, toys, games or game components, entertainment components or systems, utensils, appliances, kitchen aids, cleaning products, etc.). In one embodiment, the lighting unit 100 shown in FIG. 1 may include one or more light sources 104, such as the light sources 104A, 104B, 104C, and 104D of FIG. 1, wherein one or more of the light sources may be an LED-based light source that includes one or more light emitting diodes (LEDs). In one aspect of this embodiment, any two or more of the light sources 104A, 104B, 104C and 104D may be adapted to generate radiation of different colors (e.g. red, green, and blue, respectively). Although FIG. 1 shows four light sources 104A, 104B, 104C, and 104D, it should be appreciated that the lighting unit is not limited in this respect, as different numbers and various types of light sources (all LED-based light sources, LED-based and non-LED-based light sources in combination, etc.) adapted to generate radiation of a variety of different colors, including essentially white light, may be employed in the lighting unit 100, as discussed further below. As shown in FIG. 1, the lighting unit 100 also may include a processor 102 that is configured to output one or more control signals to drive the light sources 104A, 104B, 104C and 104D so as to generate various intensities of light from the light sources. For example, in one implementation, the processor 102 may be configured to output at least one control signal for each light source so as to independently control the intensity of light generated by each light source. Some examples of control signals that may be generated by the processor to control the light sources include, but are not limited to, pulse modulated signals, pulse width modulated signals (PWM), pulse amplitude modulated signals (PAM), pulse displacement modulated signals, analog control signals (e.g., current control signals, voltage control signals), combinations and/or modulations of the foregoing signals, or other control signals. In one aspect, the processor 102 may control other dedicated circuitry (not shown in FIG. 1), which in turn controls the light sources so as to vary their respective intensities. Lighting systems in accordance with this specification can operate LEDs in an efficient manner. Typical LED performance characteristics depend on the amount of current drawn by the LED. The optimal efficacy may be obtained at a lower current than the level where maximum brightness occurs. LEDs are typically driven well above their most efficient operating current to increase the brightness delivered by the LED while maintaining a reasonable life expectancy. As a result, increased efficacy can be provided when the maximum current value of the PWM signal may be variable. For example, if the desired light output is less than the maximum required output the current maximum and/or the PWM signal width may be reduced. This may result in pulse amplitude modulation (PAM), for example; however, the width and amplitude of the current used to drive the LED may be varied to optimize the LED performance. In an embodiment, a lighting system may also be adapted to provide only amplitude control of the current through the LED. While many of the embodiments provided herein describe the use of PWM and PAM to drive the LEDs, one skilled in the art would appreciate that there are many techniques to accomplish the LED control described herein and, as such, the scope of the present invention is not limited by any one control technique. In embodiments, it is possible to use other techniques, such as pulse frequency modulation (PFM), or pulse displacement modulation (PDM), such as in combination with either or both of PWM and PAM. Pulse width modulation (PWM) involves supplying a substantially constant current to the LEDs for particular periods of time. The shorter the time, or pulse-width, the less brightness an observer will observe in the resulting light. The human eye integrates the light it receives over a period of time and, even though the current through the LED may generate the same light level regardless of pulse duration, the eye will perceive short pulses as “dimmer” than longer pulses. The PWM technique is considered on of the preferred techniques for driving LEDs, although the present invention is not limited to such control techniques. When two or more colored LEDs are provided in a lighting system, the colors may be mixed and many variations of colors can be generated by changing the intensity, or perceived intensity, of the LEDs. In an embodiment, three colors of LEDs are presented (e.g., red, green and blue) and each of the colors is driven with PWM to vary its apparent intensity. This system allows for the generation of millions of colors (e.g., 16.7 million colors when 8-bit control is used on each of the PWM channels). In an embodiment the LEDs are modulated with PWM as well as modulating the amplitude of the current driving the LEDs (Pulse Amplitude Modulation, or PAM). LED efficiency increases to a maximum followed by decreasing efficiency as a function of current. Typically, LEDs are driven at a current level beyond its maximum efficiency to attain greater brightness while maintaining acceptable life expectancy. The objective is typically to maximize the light output from the LED while maintaining an acceptable lifetime. In an embodiment, the LEDs may be driven with a lower current maximum when lower intensities are desired. PWM may still be used, but the maximum current intensity may also be varied depending on the desired light output. For example, to decrease the intensity of the light output from a maximum operational point, the amplitude of the current may be decreased until the maximum efficiency is achieved. If further reductions in the LED brightness are desired the PWM activation may be reduced to reduce the apparent brightness. In one embodiment of the lighting unit 100, one or more of the light sources 104A, 104B, 104C and 104D shown in FIG. 1 may include a group of multiple LEDs or other types of light sources (e.g., various parallel and/or serial connections of LEDs or other types of light sources) that are controlled together by the processor 102. Additionally, it should be appreciated that one or more of the light sources 104A, 104B, 104C and 104D may include one or more LEDs that are adapted to generate radiation having any of a variety of spectra (i.e., wavelengths or wavelength bands), including, but not limited to, various visible colors (including essentially white light), various color temperatures of white light, ultraviolet, or infrared. In another aspect of the lighting unit 100 shown in FIG. 1, the lighting unit 100 may be constructed and arranged to produce a wide range of variable color radiation. For example, the lighting unit 100 may be particularly arranged such that the processor-controlled variable intensity light generated by two or more of the light sources combines to produce a mixed colored light (including essentially white light having a variety of color temperatures). In particular, the color (or color temperature) of the mixed colored light may be varied by varying one or more of the respective intensities of the light sources (e.g., in response to one or more control signals output by the processor 102). Furthermore, the processor 102 may be particularly configured (e.g., programmed) to provide control signals to one or more of the light sources so as to generate a variety of static or time-varying (dynamic) multi-color (or multi-color temperature) lighting effects. As shown in FIG. 1, the lighting unit 100 also may include a memory 114 to store various information. For example, the memory 114 may be employed to store one or more lighting programs for execution by the processor 102 (e.g., to generate one or more control signals for the light sources), as well as various types of data useful for generating variable color radiation (e.g., calibration information, discussed further below). The memory 114 also may store one or more particular identifiers (e.g., a serial number, an address, etc.) that may be used either locally or on a system level to identify the lighting unit 100. In various embodiments, such identifiers may be pre-programmed by a manufacturer, for example, and may be either alterable or non-alterable thereafter (e.g., via some type of user interface located on the lighting unit, via one or more data or control signals received by the lighting unit, etc.). Alternatively, such identifiers may be determined at the time of initial use of the lighting unit in the field, and again may be alterable or non-alterable thereafter. One issue that may arise in connection with controlling multiple light sources in the lighting unit 100 of FIG. 1, and controlling multiple lighting unit 100 in a lighting system (e.g., as discussed below in connection with FIG. 2), relates to potentially perceptible differences in light output between substantially similar light sources. For example, given two virtually identical light sources being driven by respective identical control signals, the actual intensity of light output by each light source may be perceptibly different. Such a difference in light output may be attributed to various factors including, for example, slight manufacturing differences between the light sources, normal wear and tear over time of the light sources that may differently alter the respective spectrums of the generated radiation, etc. For purposes of the present discussion, light sources for which a particular relationship between a control signal and resulting intensity are not known are referred to as “uncalibrated” light sources. The use of one or more uncalibrated light sources in the lighting unit 100 shown in FIG. 1 may result in generation of light having an unpredictable, or “uncalibrated,” color or color temperature. For example, consider a first lighting unit including a first uncalibrated red light source and a first uncalibrated blue light source, each controlled by a corresponding control signal having an adjustable parameter in a range of from zero to 255 (0-255). For purposes of this example, if the red control signal is set to zero, blue light is generated, whereas if the blue control signal is set to zero, red light is generated. However, if both control signals are varied from non-zero values, a variety of perceptibly different colors may be produced (e.g., in this example, at very least, many different shades of purple are possible). In particular, perhaps a particular desired color (e.g., lavender) is given by a red control signal having a value of 125 and a blue control signal having a value of 200. Now consider a second lighting unit including a second uncalibrated red light source substantially similar to the first uncalibrated red light source of the first lighting unit, and a second uncalibrated blue light source substantially similar to the first uncalibrated blue light source of the first lighting unit. As discussed above, even if both of the uncalibrated red light sources are driven by respective identical control signals, the actual intensity of light output by each red light source may be perceptibly different. Similarly, even if both of the uncalibrated blue light sources are driven by respective identical control signals, the actual intensity of light output by each blue light source may be perceptibly different. With the foregoing in mind, it should be appreciated that if multiple uncalibrated light sources are used in combination in lighting units to produce a mixed colored light as discussed above, the observed color (or color temperature) of light produced by different lighting units under identical control conditions may be perceivably different. Specifically, consider again the “lavender” example above; the “first lavender” produced by the first lighting unit with a red control signal of 125 and a blue control signal of 200 indeed may be perceptibly different than a “second lavender” produced by the second lighting unit with a red control signal of 125 and a blue control signal of 200. More generally, the first and second lighting units generate uncalibrated colors by virtue of their uncalibrated light sources. In view of the foregoing, in one embodiment of the present invention, the lighting unit 100 includes calibration means to facilitate the generation of light having a calibrated (e.g., predictable, reproducible) color at any given time. In one aspect, the calibration means is configured to adjust the light output of at least some light sources of the lighting unit so as to compensate for perceptible differences between similar light sources used in different lighting units. For example, in one embodiment, the processor 102 of the lighting unit 100 is configured to control one or more of the light sources 104A, 104B, 104C and 104D so as to output radiation at a calibrated intensity that substantially corresponds in a predetermined manner to a control signal for the light source(s). As a result of mixing radiation having different spectra and respective calibrated intensities, a calibrated color is produced. In one aspect of this embodiment, at least one calibration value for each light source is stored in the memory 114, and the processor is programmed to apply the respective calibration values to the control signals for the corresponding light sources so as to generate the calibrated intensities. In one aspect of this embodiment, one or more calibration values may be determined once (e.g., during a lighting unit manufacturing/testing phase) and stored in the memory 114 for use by the processor 102. In another aspect, the processor 102 may be configured to derive one or more calibration values dynamically (e.g. from time to time) with the aid of one or more photosensors, for example. In various embodiments, the photosensor(s) may be one or more external components coupled to the lighting unit, or alternatively may be integrated as part of the lighting unit itself. A photosensor is one example of a signal source that may be integrated or otherwise associated with the lighting unit 100, and monitored by the processor 102 in connection with the operation of the lighting unit. Other examples of such signal sources are discussed further below, in connection with the signal source 124 shown in FIG. 1. One exemplary method that may be implemented by the processor 102 to derive one or more calibration values includes applying a reference control signal to a light source, and measuring (e.g., via one or more photosensors) an intensity of radiation thus generated by the light source. The processor may be programmed to then make a comparison of the measured intensity and at least one reference value (e.g., representing an intensity that nominally would be expected in response to the reference control signal). Based on such a comparison, the processor may determine one or more calibration values for the light source. In particular, the processor may derive a calibration value such that, when applied to the reference control signal, the light source outputs radiation having an intensity that corresponds to the reference value (i.e., the “expected” intensity). In various aspects, one calibration value may be derived for an entire range of control signal/output intensities for a given light source. Alternatively, multiple calibration values may be derived for a given light source (i.e., a number of calibration value “samples” may be obtained) that are respectively applied over different control signal/output intensity ranges, to approximate a nonlinear calibration function in a piecewise linear manner. In another aspect, as also shown in FIG. 1, the lighting unit 100 optionally may include one or more user interfaces 118 that are provided to facilitate any of a number of user-selectable settings or functions (e.g., generally controlling the light output of the lighting unit 100, changing and/or selecting various pre-programmed lighting effects to be generated by the lighting unit, changing and/or selecting various parameters of selected lighting effects, setting particular identifiers such as addresses or serial numbers for the lighting unit, etc.). In various embodiments, the communication between the user interface 118 and the lighting unit may be accomplished through wire or cable, or wireless transmission. In one implementation, the processor 102 of the lighting unit monitors the user interface 118 and controls one or more of the light sources 104A, 104B, 104C and 104D based at least in part on a user's operation of the interface. For example, the processor 102 may be configured to respond to operation of the user interface by originating one or more control signals for controlling one or more of the light sources. Alternatively, the processor 102 may be configured to respond by selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources. In particular, in one implementation, the user interface 118 may constitute one or more switches (e.g., a standard wall switch) that interrupt power to the processor 102. In one aspect of this implementation, the processor 102 is configured to monitor the power as controlled by the user interface, and in turn control one or more of the light sources 104A, 104B, 104C and 104D based at least in part on a duration of a power interruption caused by operation of the user interface. As discussed above, the processor may be particularly configured to respond to a predetermined duration of a power interruption by, for example, selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources. LED based lighting systems may be preprogrammed with several lighting routines, such as for use in a non-networked mode or to executed stored programs when triggered by a signal in a networked mode. For example, the switches on the lighting device may be set such that the lighting device produces a solid color, a program that slowly changes the color of the illumination throughout the visible spectrum over a few minutes, or a program designed to change the illumination characteristics quickly or even strobe the light. Generally, the switches used to set the address of the lighting system may also be used to set the system into a preprogrammed non-networked lighting control mode. Each lighting control programs may also have adjustable parameters that are adjusted by switch settings. All of these functions can also be set using a programming device according to the principles of the invention. For example, a user interface may be provided in the programming device to allow the selection of a program in the lighting system, adjust a parameter of a program in the lighting system, set a new program in the lighting system, or make another setting in the lighting system. By communicating to the lighting system through a programming device according to the principles of the invention, a program could be selected and an adjustable parameter could be set. The lighting device can then execute the program without the need of setting switches. Another problem with setting switches for such a program selection is that the switches do not provide an intuitive user interface. The user may have to look to a table in a manual to find the particular switch setting for a particular program, whereas a programming device according to the principles of the invention may contain a user interface screen. The user interface may display information relating to a program, a program parameter or other information relating to the illumination device. The programmer may read information from the illumination apparatus and provide this information of the user interface screen. In embodiments, a non-networked device may detect a signal, such as a sync signal, or the presence of power “on” in a circuit, to initiate playing of an effect. Thus, multiple lighting units that are not formally networked can be synchronized by synchronizing lighting program initiation to such external factors. FIG. 1 also illustrates that the lighting unit 100 may be configured to receive one or more signals 122 from one or more other signal sources 124. In one implementation, the processor 102 of the lighting unit may use the signal(s) 122, either alone or in combination with other control signals (e.g., signals generated by executing a lighting program, one or more outputs from a user interface, etc.), so as to control one or more of the light sources 104A, 104B, 104C and 104D in a manner similar to that discussed above in connection with the user interface. By way of example, a lighting unit 100 may also include sensors and or transducers and or other signal generators (collectively referred to hereinafter as sensors) that serve as signal sources 124. The sensors may be associated with the processor 102 through wired or wireless transmission systems. Much like the user interface and network control systems, the sensor(s) may provide signals to the processor and the processor may respond by selecting new LED control signals from memory 114, modifying LED control signals, generating control signals, or otherwise change the output of the LED(s). Examples of the signal(s) 122 that may be received and processed by the processor 102 include, but are not limited to, one or more audio signals, video signals, power signals, various types of data signals, signals from a hand-held remote control, signals representing information obtained from a network (e.g., the Internet), signals representing some detectable/sensed condition, signals from lighting units, signals consisting of modulated light, etc. In various implementations, the signal source(s) 124 may be located remotely from the lighting unit 100, or included as a component of the lighting unit. For example, in one embodiment, a signal from one lighting unit 100 could be sent over a network to another lighting unit 100. Some examples of a signal source 124 that may be employed in, or used in connection with, the lighting unit 100 of FIG. 1 include any of a variety of sensors or transducers that generate one or more signals 122 in response to some stimulus. Examples of such sensors include, but are not limited to, various types of environmental condition sensors, such as thermally sensitive (e.g., temperature, infrared) sensors, humidity sensors, motion sensors, photosensors/light sensors (e.g., sensors that are sensitive to one or more particular spectra of electromagnetic radiation), sound or vibration sensors or other pressure/force transducers (e.g., microphones, piezoelectric devices), and the like. Additional examples of a signal source 124 include various metering/detection devices that monitor electrical signals or characteristics (e.g., voltage, current, power, resistance, capacitance, inductance, etc.) or chemical/biological characteristics (e.g., acidity, a presence of one or more particular chemical or biological agents, bacteria, etc.) and provide one or more signals 122 based on measured values of the signals or characteristics. Yet other examples of a signal source 124 include various types of scanners, image recognition systems, voice or other sound recognition systems, artificial intelligence and robotics systems, and the like. A signal source 124 could also be a lighting unit 100, a processor 102, or any one of many available signal generating devices, such as media players, MP3 players, computers, DVD players, CD players, television signal sources, camera signal sources, microphones, speakers, telephones, cellular phones, instant messenger devices, SMS devices, wireless devices, personal organizer devices, and many others. In one embodiment, the lighting unit 100 shown in FIG. 1 also may include one or more optical facilities 130 to optically process the radiation generated by the light sources 104A, 104B, 104C and 104D. For example, one or more optical facilities may be configured so as to change one or both of a spatial distribution and a propagation direction of the generated radiation. In particular, one or more optical facilities may be configured to change a diffusion angle of the generated radiation. In one aspect of this embodiment, one or more optical facilities 130 may be particularly configured to variably change one or both of a spatial distribution and a propagation direction of the generated radiation (e.g., in response to some electrical and/or mechanical stimulus). Examples of optical facilities that may be included in the lighting unit 100 include, but are not limited to, reflective materials, refractive materials, translucent materials, filters, lenses, mirrors, and fiber optics. The optical facility 130 also may include a phosphorescent material, luminescent material, or other material capable of responding to or interacting with the generated radiation. As also shown in FIG. 1, the lighting unit 100 may include one or more communication ports 120 to facilitate coupling of the lighting unit 100 to any of a variety of other devices. For example, one or more communication ports 120 may facilitate coupling multiple lighting units together as a networked lighting system, in which at least some of the lighting units are addressable (e.g., have particular identifiers or addresses) and are responsive to particular data transported across the network. The lighting unit 100 may also include a communication port 120 adapted to communicate with a programming device. The communication port may be adapted to receive data through wired or wireless transmission. In an embodiment of the invention, information received through the communication port 120 may relate to address information and the lighting unit 100 may be adapted to receive and then store the address information in the memory 114. The lighting system 100 may be adapted to use the stored address as its address for use when receiving data from network data. For example, the lighting unit 100 may be connected to a network where network data is communicated. The lighting unit 100 may monitor the data communicated on the network and respond to data it ‘hears’ that correspond to the address stored in the lighting systems 100 memory 114. The memory 114 may be any type of memory including, but not limited to, non-volatile memory. A person skilled in the art would appreciate that there are many systems and methods for communicating to addressable lighting fixtures through networks (e.g. U.S. Pat. No. 6,016,038) and the present invention is not limited to a particular system or method. In an embodiment, the lighting system 100 may be adapted to select a given lighting program, modify a parameter of a lighting program, or otherwise make a selection or modification or generate certain lighting control signals based on the data received from a programming device. In particular, in a networked lighting system environment, as discussed in greater detail further below (e.g., in connection with FIG. 2), as data is communicated via the network, the processor 102 of each lighting unit coupled to the network may be configured to be responsive to particular data (e.g., lighting control commands) that pertain to it (e.g., in some cases, as dictated by the respective identifiers of the networked lighting units). Once a given processor identifies particular data intended for it, it may read the data and, for example, change the lighting conditions produced by its light sources according to the received data (e.g., by generating appropriate control signals to the light sources). In one aspect, the memory 114 of each lighting unit coupled to the network may be loaded, for example, with a table of lighting control signals that correspond with data the processor 102 receives. Once the processor 102 receives data from the network, the processor may consult the table to select the control signals that correspond to the received data, and control the light sources of the lighting unit accordingly. In one aspect of this embodiment, the processor 102 of a given lighting unit, whether or not coupled to a network, may be configured to interpret lighting instructions/data that are received in a DMX protocol (as discussed, for example, in U.S. Pat. Nos. 6,016,038 and 6,211,626), which is a lighting command protocol conventionally employed in the lighting industry for some programmable lighting applications. However, it should be appreciated that lighting units suitable for purposes of the present invention are not limited in this respect, as lighting units according to various embodiments may be configured to be responsive to other types of communication protocols so as to control their respective light sources. In one embodiment, the lighting unit 100 of FIG. 1 may include and/or be coupled to one or more power sources 108. In various aspects, examples of power source(s) 108 include, but are not limited to, AC power sources, DC power sources, batteries, solar-based power sources, thermoelectric or mechanical-based power sources and the like. Additionally, in one aspect, the power source(s) 108 may include or be associated with one or more power conversion devices that convert power received by an external power source to a form suitable for operation of the lighting unit 100. While not shown explicitly in FIG. 1, the lighting unit 100 may be implemented in any one of several different structural configurations according to various embodiments of the present invention. For example, a given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes to partially or fully enclose the light sources, and/or electrical and mechanical connection configurations. In particular, a lighting unit may be configured as a replacement or “retrofit” to engage electrically and mechanically in a conventional socket or fixture arrangement (e.g., an Edison-type screw socket, a halogen fixture arrangement, a fluorescent fixture arrangement, etc.). Additionally, one or more optical elements as discussed above may be partially or fully integrated with an enclosure/housing arrangement for the lighting unit. Furthermore, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry such as the processor and/or memory, one or more sensors/transducers/signal sources, user interfaces, displays, power sources, power conversion devices, etc.) relating to the operation of the light source(s). FIG. 2 illustrates an example of a networked lighting system 200 according to one embodiment of the present invention. In the embodiment of FIG. 2, a number of lighting units 100, similar to those discussed above in connection with FIG. 1, are coupled together to form the networked lighting system. It should be appreciated, however, that the particular configuration and arrangement of lighting units shown in FIG. 2 is for purposes of illustration only, and that the invention is not limited to the particular system topology shown in FIG. 2. Thus, lighting units 100 may be associated with a network such that the lighting unit 100 responds to network data. For example, the processor 102 may be an addressable processor that is associated with a network. Network data may be communicated through a wired or wireless network and the addressable processor may be ‘listening’ to the data stream for commands that pertain to it. Once the processor ‘hears’ data addressed to it, it may read the data and change the lighting conditions according to the received data. For example, the memory 114 in the lighting unit 100 may be loaded with a table of lighting control signals that correspond with data the processor 102 receives. Once the processor 102 receives data from a network, user interface, or other source, the processor may select the control signals that correspond to the data and control the LED(s) accordingly. The received data may also initiate a lighting program to be executed by the processor 102 or modify a lighting program or control data or otherwise control the light output of the lighting unit 100. Additionally, while not shown explicitly in FIG. 2, it should be appreciated that the networked lighting system 200 may be configured flexibly to include one or more user interfaces, as well as one or more signal sources such as sensors/transducers. For example, one or more user interfaces and/or one or more signal sources such as sensors/transducers (as discussed above in connection with FIG. 1) may be associated with any one or more of the lighting units of the networked lighting system 200. Alternatively (or in addition to the foregoing), one or more user interfaces and/or one or more signal sources may be implemented as “stand alone” components in the networked lighting system 200. Whether stand alone components or particularly associated with one or more lighting unit 100, these devices may be “shared” by the lighting units of the networked lighting system. Stated differently, one or more user interfaces and/or one or more signal sources such as sensors/transducers may constitute “shared resources” in the networked lighting system that may be used in connection with controlling any one or more of the lighting units of the system. As shown in the embodiment of FIG. 2, the lighting system 200 may include one or more lighting unit controllers 208 (hereinafter “LUCs”), such as LUCs 208A, 208B, 208C and 208D, wherein each LUC is responsible for communicating with and generally controlling one or more lighting units 100 coupled to it. Although FIG. 2 illustrates three lighting units 100 coupled in a serial fashion to a given LUC, it should be appreciated that the invention is not limited in this respect, as different numbers of lighting units 100 may be coupled to a given LUC in a variety of different configurations using a variety of different communication media and protocols. In the system of FIG. 2, each LUC in turn may be coupled to a central controller 202 that is configured to communicate with one or more LUCs. Although FIG. 2 shows three LUCs coupled to the central controller 202 via a switching or coupling device 204, it should be appreciated that according to various embodiments, different numbers of LUCs may be coupled to the central controller 202. Additionally, according to various embodiments of the present invention, the LUCs and the central controller may be coupled together in a variety of configurations using a variety of different communication media and protocols to form the networked lighting system 200. Moreover, it should be appreciated that the interconnection of LUCs and the central controller, and the interconnection of lighting units to respective LUCs, may be accomplished in different manners (e.g., using different configurations, communication media, and protocols). For example, according to one embodiment of the present invention, the central controller 202 shown in FIG. 2 may by configured to implement Ethernet-based communications with the LUCs, and in turn the LUCs may be configured to implement DMX-based communications with the lighting unit 100. In particular, in one aspect of this embodiment, each LUC may be configured as an addressable Ethernet-based controller and accordingly may be identifiable to the central controller 202 via a particular unique address (or a unique group of addresses) using an Ethernet-based protocol. In this manner, the central controller 202 may be configured to support Ethernet communications throughout the network of coupled LUCs, and each LUC may respond to those communications intended for it. In turn, each LUC may communicate lighting control information to one or more lighting units coupled to it, for example, via a DMX protocol, based on the Ethernet communications with the central controller 202. More specifically, according to one embodiment, the LUCs 208A, 208B, 208C and 208D shown in FIG. 2 may be configured to be “intelligent” in that the central controller 202 may be configured to communicate higher level commands to the LUCs that need to be interpreted by the LUCs before lighting control information can be forwarded to the lighting unit 100. For example, a lighting system operator may want to generate a color changing effect that varies colors from lighting unit to lighting unit in such a way as to generate the appearance of a propagating rainbow of colors (“rainbow chase”), given a particular placement of lighting units with respect to one another. In this example, the operator may provide a simple instruction to the central controller 202 to accomplish this, and in turn the central controller may communicate to one or more LUCs using an Ethernet-based protocol high-level command to generate a “rainbow chase.” The command may contain timing, intensity, hue, saturation or other relevant information, for example. When a given LUC receives such a command, it may then interpret the command so as to generate the appropriate lighting control signals which it then communicates using a DMX protocol via any of a variety of signaling techniques (e.g., PWM) to one or more lighting units that it controls. It should again be appreciated that the foregoing example of using multiple different communication implementations (e.g., Ethernet/DMX) in a lighting system according to one embodiment of the present invention is for purposes of illustration only, and that the invention is not limited to this particular example. One aspect of the methods and systems described herein is how the colored LEDs (such as red, green, blue LEDs, or in the case of white light products, the different color temperatures of white or amber LEDs) are turned on and off to achieve color changing or color-temperature-changing effects. The balance of this section discusses controlling the red, green and blue LEDs, but the same approach is used to control different LEDs, such as white and amber LEDs, white light embodiments. In embodiments a processor 102 may have, for example, three output pins, such as one for a red LED, one for a green LED and one for a blue LED (of course other numbers of output pins and other types of LEDs are encompassed herein). In embodiments multiple LEDs of the same color are connected to an output channel, so that the output channel or pin controls a group of, for example, red, green or blue LEDs at the same time. In embodiments, an interrupt service routine (ISR) can run on the processor 102 at a specific frequency. The ISR can convert a set of desired intensity values for each LED channel into a stream of digital “on” and “off” pulses on each channel's corresponding output pin. In embodiments the ISR processes the output channels sequentially. That is, the ISR can be implemented as a software or firmware routine running on a processor 102 that updates the “on” or “off” state of each output pin. In embodiments the first color is updated first, and the routine continues through to the point where the second color is updated. The routine progresses through the third color and begins again to update the first color, and so on. In embodiments the interrupt service routine converts a desired set of LED intensity values into a stream of on and off commands for each LED channel. In embodiments networked lighting units 100 systems receive control instructions through the DMX protocol, a protocol widely used for many years in theatrical lighting systems. Lighting control signals in the DMX protocol format can be sent from a central controller over a network to individual lighting units 100, each of which has a processor 102 that controls groups of red, green and blue LEDs. In some cases an intermediate power/data supply (PDS) converts instructions that are initially sent in another protocol, such as Ethernet, into the DMX protocol format for delivery to individual lightings units 100. The DMX protocol instructions include a channel for red, a channel for blue and a channel for green. In embodiments each channel value has 8-bit resolution, producing 256 possible values for each channel. For networked lighting units 100, a DMX collection routine runs on the processor of the individual lighting unit. The collection routine cycles through incoming DMX-protocol instructions until it receives an instruction for red, an instruction for blue and an instruction for green. Next, the collection routine converts each 8-bit DMX channel value into a higher-resolution 14- (or 16-) bit desired intensity value by looking up the 8-bit DMX channel value in an internally stored table of 14-bit intensity values. The 14- (or 16-) bit intensity values allow these networked lighting units 100 to have 64 (or 128) times the dynamic resolution of 8-bit products, allowing for much finer-grained control over the generated color values. For non-networked lighting units 100, pre-programmed instructions for lighting shows can be stored in memory of the individual lighting unit 100. A user interface, such as a button or power-interrupt device, allows the user to select among different shows or software/firmware programs that generate data to be used by an ISR similar to that described above. Values for the individual channels of red, green and blue for each pre-programmed show are stored in the table for access by the interrupt service routine. In certain other embodiments that use a serial data protocol, control instructions for lighting units 100 are placed in a data stream that consists of a series of bytes, with each byte representing a control instruction for a channel of LEDs. In embodiments, the incoming stream of data for the first unmodified byte (as described further below) is clocked into three different 12-bit shift registers, one for the red channel, one for the green channel and one for the blue channel. In embodiments an oscillator clocks out the first shift register, then the second shift register, then the third shift register and delivers the signal 120 degrees out-of-phase to each of three transistor drivers that drive the red, green and blue LEDs respectively. Optionally driving the LEDs out of phase evens out the load on the system. For networked products that use a serial addressing protocol, control instructions are sent in a series of bytes to a series of individual lighting units, each of which can be equipped with a custom application specific integrated circuit (ASIC) 3600 that is programmed to respond to the incoming stream of instructions. The stream of control data from the central controller includes control instructions for individual lighting units 100 in a series, where positions of the control instructions in the series correspond to positions of individual lighting units along a string of such lighting units. Each individual lighting unit 100 receives the stream of data and responds to the byte of data that is intended for it, as follows. Each lighting unit 100 receives the entire stream of bytes of data in order and begins to check bytes of data for a bit that indicates whether the byte has been modified, such as by determining whether a “1” is present in a predetermined position of that byte of data. If the byte of data has been modified, then the ASIC 3600 proceeds to check the next byte, and so on, until an unmodified byte is found. The lighting unit 100 then stores values corresponding to the control instructions indicated by that unmodified byte of data in the table that holds the input values for the interrupt service routine. Once the lighting unit 100 has found and used the first three unmodified bytes of data in the data stream, the lighting unit 100 modifies those bytes, such as by changing a zero in the predetermined position to a “1” or vice versa, or by stripping the byte of data from the stream entirely. The entire modified data stream is then sent to the next lighting unit 100 in the string, which will as a result respond to the next byte of data in the stream, which is now the first unmodified byte. The result is that the string of lighting units 100 responds to control instructions in series according to the order of the series of bytes in the data stream. FIG. 3 illustrates a programming device 300 in communicative association with a lighting system 100. The programming device 300 may include a processor 302, a user interface 304 associated with the processor 302, a communication port 306 in association with the processor 302, and memory 308 associated with the processor 302. The communication port 306 may be arranged to communicate a data signal to the lighting system 100 and the lighting system 100 may be adapted to receive the data signal. For example, the communication port 306 may be arranged to communicate data via wired transmission and the communication port 120 of the lighting system 100 may be arranged to receive the wired transmission. Likewise, the communication ports may be arranged to communicate through wireless transmission. The programming device processor 302 may be associated with a user interface 304 such that the user interface 304 can be used to generate an address in the processor 302. The user interface 304 may be used to communicate a signal to the processor and the processor may, in turn, generate an address and or select an address from the memory 308. In an embodiment, the user interface may be used to generate or select a starting address and the programming device may then be arranged to automatically generate the next address. For example, a user may select a new address by making a selection on the user interface and then the address may be communicated to a lighting system 100. Following the transmission of the address a new address may be selected or generated so that it is transmitted to the next lighting system 100. Of course the actual timing of the selection and or generation of the new address is not critical and may actually be generated prior to the transmission of the previous address or at any other appropriate time. This method of generating addresses may be useful in situations where the user wants to address more than one lighting systems 100. For example, the user may have a row of one hundred lighting systems 100 and may desire the first such lighting system include the address number one thousand. The user may select the address one thousand on the programming device and cause the programming device to communicate the address to the lighting system. Then the programming device may automatically generate the next address in the desired progression (e.g. one thousand one). This newly generated address (e.g. one thousand one) may then be communicated to the next lighting system in the row. This eliminates the repeated selection of the new addresses and automates one more step for the user. The addresses may be selected/generated in any desired pattern (e.g. incrementing by two, three, etc.). The programming device may be arranged to store a selected/generated address in its memory to be recalled later for transmission to a lighting system. For example, a user may have a number of lighting systems to program and he may want to preprogram the memory of the programming device with a set of addresses because he knows in advance the lighting systems he is going to program. He may have a layout planned and it may be desirable to select an address, store it in memory, and then select a new address to be place in memory. This system of selecting and storing addresses could place a long string of addresses in memory. Then he could begin to transmit the address information to the lighting systems in the order in which he loaded the addresses. The programming device 300 may include a user interface 304 and the user interface may be associated with the processor 302. The user interface 304 may be an interface, button, switch, dial, slider, encoder, analog-to-digital converter, digital to analog converter, digital signal generator, or other user interface. The user interface 304 may be capable of accepting address information, program information, lighting show information, or other information or signals used to control an illumination device. The device may communicate with a lighting device upon receipt of user interface information. The user interface information may also be stored in memory and be communicated from the memory to an illumination device. The user interface 304 may also contain a screen for the displaying of information. The screen may be a screen, LCD, plasma screen, backlit display, edge-lit display, monochrome screen, color screen, screen, or any other type of display. Many of the embodiments illustrated herein involve setting an address in a lighting system 100. However, a method or system according to the principles of the present invention may involve selecting a mode, setting, program or other setting in the lighting system 100. An embodiment may also involve the modification of a mode, setting, program or other setting in the lighting system 100. In an embodiment, a programming device may be used to select a preprogrammed mode in the lighting system 100. For example, a user may select a mode using a programming device and then communicate the selection to the lighting system 100 wherein the lighting system 100 would then select the corresponding mode. The programming device 300 may be preset with modes corresponding to the modes in the lighting system 100. For example, the lighting system 100 may have four preprogrammed modes: color wash, static red, static green, static blue, and random color generation. The programming device 300 may have the same four mode selections available such that the user can make the selection on the programming device 300 and then communicate the selection to the lighting system 100. Upon receipt of the selection, the lighting system 100 may select the corresponding mode from memory for execution by the processor 102. In an embodiment, the programming device may have a mode indicator stored in its memory such that the mode indicator indicates a particular mode or lighting program or the like. For example, the programming device may have a mode indicator stored in memory indicating the selection and communication of such a mode indicator would initiate or set a mode in the lighting system corresponding to the indicator. An embodiment of the present invention may involve using the programming device 300 to read the available selections from the lighting systems memory 114 and then present the available selections to the user. The user can then select the desired mode and communicate the selection back to the lighting system 100. In an embodiment, the lighting system may receive the selection and initiate execution of the corresponding mode. In an embodiment, the programming device 300 may be used to download a lighting mode, program, setting or the like to a lighting system 100. The lighting system 100 may store the lighting mode in its memory 114. The lighting system 100 may be arranged to execute the mode upon download and or the mode may be available for selection at a later time. For example, the programming device 300 may have one or more lighting programs stored in its memory 308. A user may select one or more of the lighting programs on the programming device 300 and then cause the programming device 300 to download the selected program(s) to a lighting system 100. The lighting system 100 may then store the lighting program(s) in its memory 114. The lighting system 100 and or downloaded program(s) may be arranged such that the lighting system's processor 102 executes one of the downloaded programs automatically. As used herein, the terms “wired” transmission and or communication should be understood to encompass wire, cable, optical, or any other type of communication where the devices are physically connected. As used herein, the terms “wireless” transmission and or communication should be understood to encompass acoustical, RF, microwave, IR, and all other communication and or transmission systems were the devices are not physically connected. Having identified a variety of geometric configurations for a lighting unit 100 and certain optional methods for identifying lighting units 100, it can be recognized that providing illumination control signals to the configurations requires the operators to be able to relate the appropriate control signal to the appropriate lighting unit 100. A configuration of networked lighting unit 100 might be arranged arbitrarily, requiring the operator to develop a table or similar facility that relates a particular light to a particular geometric location in an environment. For large installations requiring many lighting unit 100, the requirement of identifying and keeping track of the relationship between a lighting unit's physical location and its network address can be quite challenging, particularly given that the lighting installer may not be the same operator who will use and maintain the lighting system over time. Accordingly, in some situations it may be advantageous to provide addressing schemes that enable easier relation between the physical location of a lighting unit 100 and its virtual location for purposes of providing it a control signal. Thus, one embodiment of the invention is directed to a method of providing address information to a lighting unit 100. The method includes acts of A) transmitting data to an independently addressable controller coupled to at least one LED lighting unit 100 and at least one other controllable device, the data including at least one of first control information for a first control signal output by the controller to the at least one LED lighting unit 100 and second control information for a second control signal output by the controller to the at least one other controllable device, and B) controlling at least one of the at least one LED light source and the at least one other controllable device based on the data. Another embodiment of the invention is directed to a method, comprising acts of: A) receiving data for a plurality of independently addressable controllers, at least one independently addressable controller of the plurality of independently addressable controllers coupled to at least one LED light source and at least one other controllable device, B) selecting at least a portion of the data corresponding to at least one of first control information for a first control signal output by the at least one independently addressable controller to the at least one LED light source and second control information for a second control signal output by the at least one independently addressable controller to the at least one other controllable device, and C) controlling at least one of the at least one LED light source and the at least one other controllable device based on the selected portion of the data. Another embodiment of the invention is directed to a lighting system, comprising a plurality of independently addressable controllers coupled together to form a network, at least one independently addressable controller of the plurality of independently addressable controllers coupled to at least one LED light source and at least one other controllable device, and at least one processor coupled to the network and programmed to transmit data to the plurality of independently addressable controllers, the data corresponding to at least one of first control information for a first control signal output by the at least one independently addressable controller to the at least one LED light source and second control information for a second control signal output by the at least one independently addressable controller to the at least one other controllable device. Another embodiment of the invention is directed to an apparatus for use in a lighting system including a plurality of independently addressable controllers coupled together to form a network, at least one independently addressable controller of the plurality of independently addressable controllers coupled to at least one LED light source and at least one other controllable device. The apparatus comprises at least one processor having an output to couple the at least one processor to the network, the at least one processor programmed to transmit data to the plurality of independently addressable controllers, the data corresponding to at least one of first control information for a first control signal output by the at least one independently addressable controller to the at least one LED light source and second control information for a second control signal output by the at least one independently addressable controller to the at least one other controllable device. Another embodiment of the invention is directed to an apparatus for use in a lighting system including at least one LED light source and at least one other controllable device. The apparatus comprises at least one controller having at least first and second output ports to couple the at least one controller to at least the at least one LED light source and the at least one other controllable device, respectively, the at least one controller also having at least one data port to receive data including at least one of first control information for a first control signal output by the first output port to the at least one LED light source and second control information for a second control signal output by the second output port to the at least one other controllable device, the at least one controller constructed to control at least one of the at least one LED light source and the at least one other controllable device based on the data. Another embodiment of the invention is directed to a method in a lighting system including at least first and second independently addressable devices coupled to form a series connection, at least one device of the independently addressable devices including at least one light source. The method comprises an act of: A) transmitting data to at least the first and second independently addressable devices, the data including control information for at least one of the first and second independently addressable devices, the data being arranged based on a relative position in the series connection of at least the first and second independently addressable devices. Another embodiment of the invention is directed to a method in a lighting system including at least first and second independently addressable devices, at least one device of the independently addressable devices including at least one light source. The method comprises acts of: A) receiving at the first independently addressable device first data for at least the first and second independently addressable devices, B) removing at least a first data portion from the first data to form second data, the first data portion corresponding to first control information for the first independently addressable device. and C) transmitting from the first independently addressable device the second data. Another embodiment of the invention is directed to a lighting system, comprising at least first and second independently addressable devices coupled to form a series connection, at least one device of the independently addressable devices including at least one light source, and at least one processor coupled to the first and second independently addressable devices, the at least one processor programmed to transmit data to at least the first and second independently addressable devices, the data including control information for at least one of the first and second independently addressable devices, the data arranged based on a relative position in the series connection of at least the first and second independently addressable devices. Another embodiment of the invention is directed to an apparatus for use in a lighting system including at least first and second independently addressable devices coupled to form a series connection, at least one device of the independently addressable devices including at least one light source. The apparatus comprises at least one processor having an output to couple the at least one processor to the first and second independently addressable devices, the at least one processor programmed to transmit data to at least the first and second independently addressable devices, the data including control information for at least one of the first and second independently addressable devices, the data arranged based on a relative position in the series connection of at least the first and second independently addressable devices. Another embodiment of the invention is directed to an apparatus for use in a lighting system including at least first and second independently controllable devices, at least one device of the independently controllable devices including at least one light source. The apparatus comprises at least one controller having at least one output port to couple the at least one controller to at least the first independently controllable device and at least one data port to receive first data for at least the first and second independently controllable devices, the at least one controller constructed to remove at least a first data portion from the first data to form second data and to transmit the second data via the at least one data port, the first data portion corresponding to first control information for at least the first independently controllable device. Another embodiment of the present invention is directed to lighting system. The lighting system comprises an LED lighting system adapted to receive a data stream through a first data port, generate an illumination condition based on a first portion of the data stream and communicate at least a second portion of the data stream through a second data port; a housing wherein the housing is adapted to retain the LED lighting system and adapted to electrically associate the first and second data ports with a data connection; wherein the data connection comprises an electrical conductor with at least one discontinuous section; wherein the first data port is associated with the data connection on a first side of the discontinuous section and the second data port is associated with a second side of the discontinuous section wherein the first and second sides are electrically isolated. Another embodiment of the present invention is directed at an integrated circuit. The integrated circuit comprises a data recognition circuit wherein the data recognition circuit is adapted to read at least a first portion of a data stream received through a first data port; an illumination control circuit adapted to generate at least one illumination control signal in response to the first portion of data; and an output circuit adapted to transmit at least a second portion of the data stream through a second data port. Another embodiment of the present invention is directed at a method for controlling lighting systems. The method comprises the steps of providing a plurality of lighting systems; communicating a data stream to a first lighting system of the plurality of lighting systems; causing the first lighting system to receive the data stream and to read a first portion of the data stream; causing the first lighting system to generate a lighting effect in response to the first portion of the data stream; and causing the first lighting system to communicate at least a second portion of the data stream to second lighting system of the plurality of lighting systems. Referring to FIG. 4, various configurations can be provided for lighting units 100, in each case with an optional communications facility 120. Configurations include a linear configuration 404 (which may be curvilinear in embodiments), a circular configuration 402, an oval configuration 414, a three-dimensional configuration 418, such as a pyramid, or a collection of various configurations 402, 404, etc. Lighting unit 100 can also include a wide variety of colors of LED, in various mixtures, including red, green, and blue LEDs to produce a color mix, as well as one or more other LEDs to create varying colors and color temperatures of white light. For example, red, green and blue can be mixed with amber, white, UV, orange, IR or other colors of LED. Amber and white LEDs can be mixed to offer varying colors and color temperatures of white. Any combination of LED colors can produce a gamut of colors, whether the LEDs are red, green, blue, amber, white, orange, UV, or other colors. The various embodiments described throughout this specification encompass all possible combinations of LEDs in lighting unit 100, so that light of varying color, intensity, saturation and color temperature can be produced on demand under control of a processor 102. Combinations of LEDs with other mechanisms, such as phosphors, are also encompassed herein. Although mixtures of red, green and blue have been proposed for light due to their ability to create a wide gamut of additively mixed colors, the general color quality or color rendering capability of such systems are not ideal for all applications. This is primarily due to the narrow bandwidth of current red, green and blue emitters. However, wider band sources do make possible good color rendering, as measured, for example, by the standard CRI index. In some cases this may require LED spectral outputs that are not currently available. However, it is known that wider-band sources of light will become available, and such wider-band sources are encompassed as sources for lighting unit 100 described herein. Additionally, the addition of white LEDs (typically produced through a blue or UV LED plus a phosphor mechanism) does give a ‘better’ white it is still limiting in the color temperature that is controllable or selectable from such sources. The addition of white to a red, green and blue mixture may not increase the gamut of available colors, but it can add a broader-band source to the mixture. The addition of an amber source to this mixture can improve the color still further by ‘filling in’ the gamut as well. This combinations of light sources as lighting unit 100 can help fill in the visible spectrum to faithfully reproduce desirable spectrums of lights. These include broad daylight equivalents or more discrete waveforms corresponding to other light sources or desirable light properties. Desirable properties include the ability to remove pieces of the spectrum for reasons that may include environments where certain wavelengths are absorbed or attenuated. Water, for example tends to absorb and attenuate most non-blue and non-green colors of light, so underwater applications may benefit from lights that combine blue and green sources for lighting unit 100. Amber and white light sources can offer a color temperature selectable white source, wherein the color temperature of generated light can be selected along the black body curve by a line joining the chromaticity coordinates of the two sources. The color temperature selection is useful for specifying particular color temperature values for the lighting source. Orange is another color whose spectral properties in combination with a white LED-based light source can be used to provide a controllable color temperature light from a lighting unit 100. The combination of white light with light of other colors as light sources for lighting unit 100 can offer multi-purpose lights for many commercial and home applications, such as in pools, spas, automobiles, building interiors (commercial and residential), indirect lighting applications, such as alcove lighting, commercial point of purchase lighting, merchandising, toys, beauty, signage, aviation, marine, medical, submarine, space, military, consumer, under cabinet lighting, office furniture, landscape, residential including kitchen, home theater, bathroom, faucets, dining rooms, decks, garage, home office, household products, family rooms, tomb lighting, museums, photography, art applications, and many others. Referring still to FIG. 4, lighting units 100 can be arranged in many different forms. Thus, one or more light sources 104A-104D can be disposed with a processor 102 in a housing. The housing can take various shapes, such as one that resembles a point source 402, such as a circle or oval. Such a point source 402 can be located in a conventional lighting fixture, such as lamp or a cylindrical fixture. Lighting units 100 can be configured in substantially linear arrangements, either by positioning point sources 402 in a line, or by disposing light sources 104A-104D substantially in a line on a board located in a substantially linear housing, such as a cylindrical housing. A linear lighting unit 404 can be placed end-to-end with other linear elements 404 or elements of other shapes to produce longer linear lighting systems comprised of multiple lighting units 100 in various shapes. A housing can be curved to form a curvilinear lighting unit. Similarly, junctions can be created with branches, “Ts,” or “Ys” to created a branched lighting unit 410. A bent lighting unit can include one or more “V” elements. Combinations of various configurations of point source 402, linear 404, curvilinear, branched 410 and bent lighting units 100 can be used to create any shape of lighting system, such as one shaped to resemble a letter, number, symbol, logo, object, structure, or the like. An embodiment of a lighting unit 100 suitable for being joined to other lighting units 100 in different configurations is disclosed below. In one embodiment, the present invention relates to controlled, networked or non-networked, lighting units 100 configured into panels or tiles. A lighting unit 100 with one or more LEDs can be mounted or embedded into such a lighting unit 100 to provide patterns of color and color changing capability at a variety of scales. Such lighting units, 100, in one embodiment, can be mounted or integrated into walls, ceilings, doors, windows or floors. Referring to FIG. 5, a lighting unit 100 is disposed in a tile 500 that includes a plurality of triangular regions 502, each of whose color can be selected and controlled for a wide variety of pleasing effects. Light and color patterns can be created and manipulated, faded and moved. The tiles 500 can be networked for coordinated effects or run in stand-alone modes. In various embodiments, the particulars of the illuminated surfaces include geometries to maximize light output, homogenize and diffuse light output, and to shape light output. The viewed surfaces incorporate textures and 2D or 3D forms to guide and direct light towards the viewer. The embodiment of FIG. 5 is a tile 500 that is designed for a panel wall installation comprising a 12-element panel with four controllable areas per element 504. This is just one of many combinations of tiles 500 that are possible. Tiles 500 of all shapes can be combined to cover any surface, just as conventional floor, wall or ceiling tiles or other construction materials are fitted together to cover structures or parts of structures. Tiles 500 can be fitted together to form furniture and fixtures as well, in each case with the lighting system capabilities described throughout this disclosure and in the patent and patent applications incorporated herein by reference. Referring to FIG. 6, there are a variety of mounting provisions for mounting of the tiles 500 or panels to surfaces or for interconnecting elements. In one embodiment, wall mounting 602 is used. Wall mounting uses mounting clips 604 to provide desired spacing, to secure units to the wall, and to provide spacing from the wall. Attachment to a wall can be through a bracket or two-piece cleats such as Z-clips or French-cleats. Tiles 500 can also be hung like a picture from a hook by a wire across the back. These cleat designs also can incorporate features such as channels or recessed surfaces to allow the running of wires for communication of data and positioning of power supplies between adjacent units or to better route such cabling for the purposes of termination and passage through wall cavities and junction boxes. FIG. 6 and the subsequent figures show more details on how the tiles 500 can be used and mounted. FIG. 6 also shows ceiling mounting 608. While the devices can be secured to a ceiling via brackets and other attachments as described in the wall mounting embodiment, ceilings are often covered with a suspended grid infrastructure that allows for a variety of ceiling tiles as well as lights and HVAC-related elements. Ceiling tile elements 610 can be sized to fit into standard suspended ceiling grids. For example a 2-foot by 2-foot element 610 could fit directly into a standard ceiling grid 612. Additional wiring options for ceiling mounting can include jumper cables from unit to unit to give flexibility in installation. In other embodiments, the tiles 500 can be incorporated as flooring elements. The housing design can be of sufficient structural strength to form a flooring element much like that of raised flooring used in computer centers or even structural tiles used as a direct application flooring material. Alternatively, the tiles 500 can be mounted beneath transparent or translucent flooring elements to provide illumination through such elements. For example, the combination of many of these panel elements can then be used as dance floors or for studios and stage sets for a variety of dramatic and pleasing effects. For ceiling mounted embodiments all materials and construction are preferably plenum rated, since air spaces above suspended ceilings are typically used for air handling as well. Selected materials including panels and wiring insulation should meet all required fire ratings and should not emit volatile gases. Additionally, for high power LED devices or where large concentrations of LEDs are used, heat dissipation facilities can be directly incorporated into the panel structure. There are many embodiments of heat dissipation facilities. These can take the form of traditional cast or extruded metal heat sinks, as well as fans and appropriate venting and air flow channels. Other facilities include liquid-cooled systems that allow for convection currents to transfer heat and provide a flow of heat away from the source. Additional means for thermal dissipation include thermoelectric cooling devices, such as those using the Peltier-effect, which uses electricity to create a cold side and dissipate heat to a ‘hot’ side. FIG. 7 shows a rail mounting facility 700 for a tile 500. This embodiment is a mounting system that includes rails to connect a larger number of the tiles 500 or panel elements together. The same rails 700 can be used as a hanging or mounting system as shown in FIG. 7. Referring to FIG. 8, another aspect of this invention is that wiring of the devices can be done through a direct connector 802 between tiles 500 similar in principle to building blocks. That is, the modular tiles 500 or panel elements can be directly connected to each other with both mechanical and electrical attachments 802. Referring to FIG. 9, the tiles 500 can be equipped with a magnetic facility 900, so that the tiles 500 are held together by the attraction of magnets 900. The panels can be light enough and incorporate either ferrous materials or magnets whose fields are properly aligned so as to allow coupling between adjacent elements. Referring to FIG. 10, a facility for connecting and attaching tiles 500 or panels with dual-purpose connections is disclosed. In FIG. 10, the diamond and triangular-shaped elements 1002 are brackets to interconnect the tiles 500. The zoom-in feature shows the electrical and data connections between the tiles 500. FIG. 11 shows a block diagram of a portion of a generic LUC 208 that includes a LUC processor 1102 and a power-sensing module 1114. As indicated in FIG. 11, the power sensing module 1114 may be coupled to a power supply input connection 1112 and may in turn provide power to one or more lighting units coupled to the LUC via a power output connection 1110. The power-sensing module 1114 also may provide one or more output signals 1116 to the processor 1102, and the processor in turn may communicate to the central controller 202 information relating to power sensing, via the connection 1108. In one aspect of the LUC shown in FIG. 11, the power sensing module 1114, together with the processor 1102, may be adapted to determine merely when any power is being consumed by any of the lighting units coupled to the LUC, without necessarily determining the actual power being drawn or the actual number of units drawing power. Such a “binary” determination of power either being consumed or not consumed by the collection of lighting units coupled to the LUC facilitates an identifier determination/learning algorithm (e.g., that may be performed by the LUC processor 1102 or the central controller 202) according to one embodiment of the invention. In other aspects, the power sensing module 1114 and the processor 1102 may be adapted to determine, at least approximately, and actual power drawn by the lighting units at any given time. If the average power consumed by a single lighting unit is known a priori, the number of units consuming power at any given time can then be derived from such an actual power measurement. Such a determination is useful in other embodiments of the invention, as discussed further below. FIG. 12 shows an example of a portion of a circuit implementation of a LUC including a power-sensing module 1114 according to one embodiment of the invention. In FIG. 12, the power supply input connection is shown as a positive terminal 1112A and a ground terminal 1112B. Similarly, the power output connection to the lighting units is shown as a positive terminal 1110A and a ground terminal 1110B. In FIG. 12, the power sensing module 1114 is implemented essentially as a current sensor interposed between the ground terminal 1112B of the power supply input connection and the ground terminal 1110B of the power output connection. The current sensor includes a sampling resistor R3 to develop a sampled voltage based on power drawn from the power output connection. The sampled voltage is then amplified by operational amplifier U6 to provide an output signal 1116 to the processor 1102 indicating that power is being drawn. In one aspect of the embodiment shown in FIG. 12, the power input supply Is connection 1112A and 1112B may provide a supply voltage of approximately 20 volts, and the power sensing module 314 may be designed to generate an output signal 316 of approximately 2 volts per amp of load current (i.e., a gain of 2 V/A) drawn by the group of lighting units coupled to the LUC. In other aspects, the processor 1102 may include an A/D converter having a detection resolution on the order of approximately 0.02 volts, and the lighting units may be designed such that each lighting unit may draw approximately 0.1 amps of current when energized, resulting in a minimum of approximately a 0.2 volt output signal 1116 (based on the 2 V/A gain discussed above) when any unit of the group is energized (i.e., easily resolved by the processor's A/D converter). In another aspect, the minimum quiescent current (off-state current, no light sources energized) drawn by the group of lighting units may be measured from time to time, and an appropriate threshold may be set for the power sensing module 1114, so that the output signal 1116 accurately reflects when power is being drawn by the group of lighting units due to actually energizing one or more light sources. As discussed above, according to one embodiment of the invention, the LUC processor 1102 may monitor the output signal 1116 from the power sensing module 1114 to determine if any power is being drawn by the group of lighting units, and use this indication in an identifier determination/learning algorithm to determine the collection of identifiers of the group of lighting units coupled to the LUC. Referring to FIG. 13, tiles 500 can be joined on the back by bracket elements 1302 that fit into a recessed area 1304 to join and interconnect tiles 500. The recessed areas 1304 can serve as a channel to facilitate wiring or cabling of a lighting system with lighting units 100. The zoomed-in area shows an embodiment of bracket elements 1302. The brackets also form an element that provides spacing, wall hanging and connection between adjacent tiles 500. Brackets 1302 provide spacing, attachment and hanging capability as well as an integral wire channel. A bracket 1302 can use one or more of these features. In the case of spacing of a tile 500 from a wall, floor, ceiling or other surface, optical elements can provide a path for light on the backside edge of the tile to frame the lighting panels and to give a “halo effect” to the tiles 500. This halo light can also be provided with separate light emitting elements to provide separate control of both forward and backside lightings. The halo effect can also use a shadow mask or shaped silhouettes to give different lighting shapes such as crenellated, wavy, lines, diffusing materials with varying fade over the surface or even a simple sharp edge frame. The halo or frame effect can also be instantiated through distinct and separately controlled lighting units 100. The lines or adjoining surfaces can be strips of light that are incorporated as accent pieces within a grid or pattern of tiles or panels. FIG. 14 shows square tiles 500 separated by separately controlled rectangular lighting elements 1404. The lighting elements 1404 are modular and can be made in any shape so that any pattern or sets of patterns can be created. In various embodiments, each tile 500 can be partitioned into a variety of individual shapes. With the underlying grid of controllable nodes, there would be sufficient illumination to light each node down to the resolution of the grid itself. Arbitrary shapes including polygons, circles and any other set of interlocking patterns can be isolated and individually controlled within a tile 500. To reduce the number of light emitting elements required for a tile 500, boards with LEDs can be mounted as a lighting unit 100 or light source 1502 on the edges facing in towards the center of the shape as shown in the right hand side of FIG. 15. Light radiating away from the light source 1502 will fade in intensity as a function of distance away from the light source 1502. In order to provide more uniform illumination, the shape of the interior of the tile 500 can be configured in such a way as to capture and reflect the illumination to provide a more uniformly illuminated surface for a cover 1512 that is placed over the region in which the light sources 1502 are placed. In FIG. 15, a pyramid 1510 is shown in relief, coming towards the viewer and providing an increase in light towards the viewer. The faces of the pyramid 1504 near the base of the pyramid 1510 are brighter than the flat area 1508 that is nearer to the light source 1502, because the angle of incidence of light from the light source 1502 is such that more light is reflected upward (toward the eye of a viewer who is looking on the tile 500 from a direction substantially toward the top of the pyramid 1508) from the angled faces 1504 than from the flat areas 1508. With the diffusing cover 1512, this effect provides nearly uniform intensity of illumination from the whole tile 500, as shown in the left hand side of FIG. 15. Thus, FIG. 15 shows a tile 500 with an edge lit interior, both with, and without, the diffusing cover 1512. Note the use of the pyramidal element 1508 to guide, diffuse and homogenize light output. Diagonals provide separation between adjacent areas and can be provided at a variety of heights to eliminate or allow overlap of colors from adjacent sections. While the pyramid 1508 is a simple shape to implement a favorable light effect, other shapes may be provided and may be more effective over different differences and different configurations of tiles 500. Curved shapes, specifically those tailored to the mathematical model of light distribution, can provide even better uniformity over the distance. A shape described by a 2nd order equation, such as a parabola, may be better suited to giving the correct properties of uniformity of reflected light toward the eye of a viewer of the tile 500. In embodiments, the surface material for the interior of the tile 500 may be a matte white surface, namely, a Lambertian surface. A Lambertian surface is a surface of perfectly matte properties and thus adheres to Lambert's cosine law which states that the reflected light in any direction from a perfectly diffusing surface varies as the cosine of the angle between that direction and the perpendicular to the surface. The result is that the luminance of that surface is the same regardless of the viewing angle. This in combination with the shape as described above gives a pleasing uniform lit surface with little perceptible variation. Of course, in embodiments, it may be desired to use a variety of shapes and materials to give an effect other than uniform illumination. Various shapes may provide variance, shadows and textures to give sculptural effects from the light. For example, a symbol, letter, number, logo, character, picture or other element can be formed by designing the interior configuration of the tile 500, the reflective nature of the interior, or the light-transmitting capacity of the cover 1512, to vary light intensity in particular regions of the tile 500. Note that the use of a surface in the interior of the tile 500, such as the pyramid 1508, can create a void beneath which space can be used to hide power supplies and controllers, connectors and other related pieces of the system of tiles 500. While the embodiment of FIG. 15 shows an edge-lit system, other configurations of lighting units 100 can be used to light the interior of the tile 500. These include regular or irregular grids, columnar arrays, circles, or other shapes of lighting units 100 serving as light emitting elements. These elements can also provide fixed color or have independently controlled nodes within the interior of the tile 500. In embodiments, a circuit board can use a white solder mask to maximize reflectance and light output from the tile 500. The cover 1512 of FIG. 15 is an example of a diffusing panel for a tile 500. Such diffusing panels can be shaped and sculpted into a variety of pleasing forms for aesthetic and decorative purposes. These can be modular units that can be substituted for one another to change the overall appearance or to represent different themes. In combinations of colors and shapes, each installation can be unique. The use of colorful translucent or opaque coverings such as silk-screens can provide still more effects. This can be used for advertising or information purposes, the front of dispensing or vending machines, signs, accessible services, such as phones or kiosks, and any other application where artwork, signs or displays are used. With translucent colors a flare effect can be made using changing colors behind colored graphics. Using modular diffusing panels then allows a larger variety of color changing effects based on the colors of the materials. FIGS. 16 and 17 show a variety of textures and shapes that can be used to diffuse and diffract light among the wide variety that are encompassed by this disclosure. The covers 1600 can incorporate graphics and other elements such as characters and artwork. Tessellations can be provided in Escher-like or Penrose-type patterns that are either periodic or aperiodic. The tiles 500 in these many textures and shapes can be disposed in many environments, such as to cover parts of building interiors and exteriors, including walls, doors, windows, ceilings, floors, furniture, tables, shelves, and other surfaces. FIGS. 18 and 19 show diffuse surfaces that form the panels that are designed to be easily formed and molded with conventional manufacturing techniques. Here the tile 500 can be designed to fit flush with a surface 1802, so that it requires no framing on the outside of a multiple unit configuration by going all the way back to the wall with no gaps, exposing wiring and other mechanical aspects of the tile. FIG. 19 shows several embodiments of such tiles 500, with different designs for the diffusing panels. FIG. 20 shows a configuration 2000 with regular grids of color changing elements 2002, each using an LED package that incorporates a red, a green and a blue LED. Of course other LED colors can be used. The light emitting elements are coupled with an integrated control, power and communications chip or ASIC on the back of the board, which makes the development of arbitrarily shaped configurations a very straightforward process. FIGS. 20 and 21 show two different printed circuit boards 2000, 2100, with different spacing between the lighting elements 2002, 2102. Configuration 2000 is a 6 by 6 array, or 36 units per square foot. Configuration 2100 is an 8 by 8 array, or 64 elements 2102 per square foot. This number can be varying in accordance with particular applications, and there are no limits until the entire space is completely filled with light-emitting elements 2002, 2102. These controlled light boards can be made in any shape. Each node can be made individually controllable, whether by an addressing scheme such as DMX, or more preferably in some embodiments, a string light protocol described elsewhere herein, in which each node receives data in a series and responds to the first unmodified data element in the stream. In this particular embodiment, and RGB cluster is co-located in a single package. When the lighting elements are placed in such a grid configuration, a diffusing panel can be placed directly over the elements, and any shape, symbol, character or the like can be created by authoring signals to each grid element, varying the intensity and color of the grid element. One embodiment is a plurality of boards 204 arranged in a square pattern and covered by a diffuser to form a tile light 500. In embodiments, the control can be object-oriented control, such as in conjunction with a software authoring system as described elsewhere herein. In embodiments the authoring can be a geometric authoring method, such as described elsewhere herein. Thus, effects authored in software, such as Flash animations, can be replicated in the configurations 2000, 2100, then diffused in a diffusing panel, resulting in very pleasing effects, such as explosions of color, chasing rainbows, tie-dye-like effects, and the like. Effects can include scrolling text, graphics, animations, and the like. In embodiments effects can be authored to respond to an input signal 124, such as an incoming video signal, where the individual lighting units 100 that form a grid or array respond to elements of the video signal, such as to represent pixels, or portions of pixels, of the incoming video signal. Another method of providing a tile 500 uses edge lighting, with one embodiment using a reflective underside or extruded reflector shape. Referring to FIG. 22, another embodiment 2200 uses different physical layers for an effect. The method uses integral LED nodes 2204 with diffusers 2202. Using polygonal PCBs with white solder mask; each node 2202 sits under a bump on the diffuser material 2204. The effect is a number of separately addressable controllable nodes floating in a uniform color field. Light emitting nodes 2204, shown as small circles, emit light upwards into the diffusers 2202, which can have a variety of shapes and textures. This can be in addition to edge lighting units whose light is shown by the horizontal arrows in FIG. 22. Referring to FIG. 23, Penrose tiles are a set of tiles that form no regular pattern no matter how many are used. The patterns are termed aperiodic. The simplest set of two tiles that have this property are the two rhomboids shown in FIG. 23, with all edges of unit length. Tiled surfaces produced with these shapes will, through color control, have some very interesting patterns. These are arrangements of tiles that fill the plane in such a way that there are no regularly recurring patterns. The same-looking cluster of tiles can recur infinitely often, but not evenly spaced apart. Such shapes are discussed in U.S. Pat. No. 4,133,152, which is incorporated by reference, entitled Set of Tiles for Covering a Surface. Other tiles can include versatile tiles that can form both periodic and aperiodic tilings of the plane. These effects can be geometry-based and coupled to other systems such as media (music, video, video and computer games, movies etc). Having developed a variety of embodiments for relating a lighting unit 100 that has a physical location to an address for the lighting unit 100, whether it be a network address, a unique identifier, or a position within a series or string of lighting unit 100 that pass control signals along to each other, as well as a variety of configurations for lighting units 100, including arrangements of tiles in various geometries, it is further desirable to have facilities for authoring control signals for the lighting units. An example of such an authoring system is a software-based authoring system, such as COLORPLAY™ offered by Color Kinetics Incorporated of Boston, Mass. An embodiment of this invention relates to systems and methods for generating control signals. While the control signals are disclosed herein in connection with authoring lighting shows and displays for lighting unit 100 in various configurations, it should be understood that the control signals may be used to control any system that is capable of responding to a control signal, whether it be a lighting system, lighting network, light, LED, LED lighting system, audio system, surround sound system, fog machine, rain machine, electromechanical system or other systems. Lighting systems like those described in U.S. Pat. Nos. 6,016,038, 6,150,774, and 6,166,496 illustrate some different types of lighting systems where control signals may be used. In certain computer applications, there is typically a display screen (which could be a personal computer screen, television screen, laptop screen, handheld, gameboy screen, computer monitor, flat screen display, LCD display, PDA screen, or other display) that represents a virtual environment of some type. There is also typically a user in a real world environment that surrounds the display screen. The present invention relates, among other things, to using a computer application in a virtual environment to generate control signals for systems, such as lighting systems, that are located in real world environments, such as lighting unit 100 positioned in various configurations described above, including linear configurations, arrays, curvilinear configurations, 3D configurations, and other configurations, and in particular including configurations that can be formed by arranging tiles 500 in various two- and three-dimensional configurations. An embodiment of the present invention describes a method for generating control signals as illustrated in the block diagram in FIG. 24. The method may involve providing or generating an image or representation of an image, i.e., a graphical representation 2402. The graphical representation may be a static image such as a drawing, photograph, generated image, or image that is or appears to be static. The static image may include images displayed on a computer screen or other screen even though the image is continually being refreshed on the screen. The static image may also be a hard copy of an image. Providing a graphical representation 2402 may also involve generating an image or representation of an image. For example, a processor may be used to execute software to generate the graphical representation 2402. Again, the image that is generated may be or appear to be static or the image may be dynamic. An example of software used to generate a dynamic image is Flash 5 computer software offered by Macromedia, Incorporated. Flash 5 is a widely used computer program to generate graphics, images and animations. Other useful products used to generate images include, for example, Adobe Illustrator, Adobe Photoshop, and Adobe LiveMotion. There are many other programs that can be used to generate both static and dynamic images. For example, Microsoft Corporation makes a computer program Paint. This software is used to generate images on a screen in a bit map format. Other software programs may be used to generate images in bitmaps, vector coordinates, or other techniques. There are also many programs that render graphics in three dimensions or more. Direct X libraries, from Microsoft Corporation, for example generate images in three-dimensional space. The output of any of the foregoing software programs or similar programs can serve as the graphical representation 2402. In embodiments the graphical representation may correspond to an incoming video signal, where individual video frames are represented as graphical representations. In embodiments the graphical representation 2402 may be generated using software executed on a processor, but the graphical representation 2402 may never be displayed on a screen. In an embodiment, an algorithm may generate an image or representation thereof, such as an explosion in a space for example. The explosion function may generate an image and this image may be used to generate control signals as described herein with or without actually displaying the image on a screen. The image may be displayed through a lighting network for example without ever being displayed on a screen. In an embodiment, generating or representing an image may be accomplished through a program that is executed on a processor. In an embodiment, the purpose of generating the image or representation of the image may be to provide information defined in a space. For example, the generation of an image may define how a lighting effect travels through a space. The lighting effect may represent an explosion, for example. The representation may initiate bright white light in the corner of a grid of tiles 500 and the light may travel away from this corner a velocity (with speed and direction) and the color of the light may change as the propagation of the effect continues. In an embodiment, an image generator may generate a function or algorithm. The function or algorithm may represent an event such as an explosion, lighting strike, headlights, train passing through a space or grid, bullet shot through a space or grid, light moving through a space or grid, sunrise across a space or grid, spinning pinwheel moving around a space or grid, color-chasing rainbow, or other event. The function or algorithm may represent an image such as lights swirling in a space or grid, balls of light bouncing in a space or grid, sounds bouncing in a space, or other images. The function or algorithm may also represent randomly generated effects or other effects. The term “grid” is intended to encompass any two-dimensional arrangement, such as a grid, array, lattice, or similar surface, including such an arrangement that is bent or curved, such as a wall going around a corner. The term “space” is intended to encompass any three-dimensional arrangement. Referring again to FIG. 24, a light system configuration facility 2404 may accomplish further steps for the methods and systems described herein. The light system configuration facility may generate a system configuration file, configuration data or other configuration information for a lighting system, such as the one depicted in connection with FIG. 1. The light system configuration facility can represent or correlate a system, such as a lighting unit 100, sound system or other system as described herein with a position or positions in an environment 100. For example, an LED lighting unit 100 may be correlated with a position within a space. In an embodiment, the location of a lighted surface may also be determined for inclusion into the configuration file. The position of the lighted surface may also be associated with a lighting unit 100. In embodiments, the lighted surface 107 may be the desired parameter while the lighting unit 100 that generates the light to illuminate the surface is also important. Lighting control signals may be communicated to a lighting unit 100 when a surface is scheduled to be lit by the lighting unit 100. For example, control signals may be communicated to a lighting system when a generated image calls for a particular section of a space to change in hue, saturation or brightness. In this situation, the control signals may be used to control the lighting system such that the lighted surface 107 is illuminated at the proper time. The lighted surface 107 may be located on a wall but the lighting unit 100 designed to project light onto the surface 107 may be located on the ceiling. The configuration information could be arranged to initiate the lighting unit 100 to activate or change when the surface 107 is to be lit. Referring still to FIG. 24, the graphical representation 2402 and the configuration information from the light system configuration facility 2404 can be delivered to a conversion module 2408, which associates position information from the configuration facility with information from the graphical representation and converts the information into a control signal, such as a control signal for a lighting unit 100. Then the conversion module can communicate the control signal, such as to the lighting unit 100. In embodiments the conversion module maps positions in the graphical representation to positions of lighting units 100 in the environment, as stored in a configuration file for the environment (as described below). The mapping might be a one-to-one mapping of pixels or groups of pixels in the graphical representation to lighting units 100 or groups of lighting units 100 in the environment 100. It could be a mapping of pixels in the graphical representation to surfaces 107, polygons, or objects in the environment that are lit by lighting units 100. A mapping relation could also map vector coordinate information, a wave function, or an algorithm to positions of lighting units 100. Many different mapping relations can be envisioned and are encompassed herein. Referring to FIG. 25, another embodiment of a block diagram for a method and system for generating a control signal is depicted. A light management facility 2502 is used to generate a map file 2504 that maps lighting units 100 to positions in an environment, to surfaces that are lit by the light systems, and the like. An animation facility 2508 generates a sequence of graphics files for an animation effect. A conversion module 2512 relates the information in the map file 2504 for the lighting units 100 to the graphical information in the graphics files. For example, color information in the graphics file may be used to convert to a color control signal for a lighting unit 100 to generate a similar color. Pixel information for the graphics file may be converted to address information for lighting units 100, which will correspond to the pixels in question. In embodiments, the conversion module 2512 includes a lookup table for converting particular graphics file information into particular lighting control signals, based on the content of a configuration file for the lighting system and conversion algorithms appropriate for the animation facility in question. The converted information can be sent to a playback tool 2514, which may in turn play the animation and deliver control signals 2518 to lighting units 100 in an environment. Referring to FIG. 26, an embodiment of a configuration file 2600 is depicted, showing certain elements of configuration information that can be stored for a lighting unit 100 or other system. Thus, the configuration file 2600 can store an identifier 2602 for each lighting unit 100, as well as the position 2608 of that light system in a desired coordinate or mapping system for the environment 100 (which may be (x,y,z) coordinates, polar coordinates, (x,y) coordinates, or the like). The position 508 and other information may be time-dependent, so the configuration file 2600 can include an element of time 2604. The configuration file 2600 can also store information about the position 2610 that is lit by the lighting unit 100. That information can consist of a set of coordinates, or it may be an identified surface, polygon, object, or other item in the environment. The configuration file 2600 can also store information about the available degrees of freedom for use of the lighting unit 100, such as available colors in a color range 2612, available intensities in an intensity range 2614, or the like. The configuration file 2600 can also include information about other systems in the environment that are controlled by the control systems disclosed herein, information about the characteristics of surfaces 107 in the environment, and the like. Thus, the configuration file 2600 can map a set of lighting units 100 to the conditions that they are capable of generating in an environment 100. In an embodiment, configuration information such as the configuration file 2600 may be generated using a program executed on a processor. Referring to FIG. 27, the program may run on a computer 2700 with a graphical user interface 2712 where a representation of an environment 2702 can be displayed, showing lighting units 100, lit surfaces 107 or other elements in a graphical format. The interface may include a representation 2702 of a space for example. Representations of lights, lighted surfaces or other systems may then be presented in the interface 2712 and locations can be assigned to the system. In an embodiment, position coordinates or a position map may represent a system, such as a light system. A position map may also be generated for the representation of a lighted surface for example. FIG. 27 illustrates a space with lighting units 100. In other embodiments, the lighting units 100 could be positioned on the exterior of a building, in windows of a building, or the like. The representation 2702 can also be used to simplify generation of effects. For example, a set of stored effects can be represented by icons 2710 on the screen 2712. An explosion icon can be selected with a cursor or mouse, which may prompt the user to click on a starting and ending point for the explosion in the coordinate system. By locating a vector in the representation, the user can cause an explosion to be initiated in the upper corner of the space 2702 and a wave of light and or sound may propagate through the environment. With all of the lighting units 100 in predetermined positions, as identified in the configuration file 2600, the representation of the explosion can be played in the space by the light system and or another system such as a sound system. In use, a control system such as used herein can be used to provide information to a user or programmer from the lighting units 100 in response to or in coordination with the information being provided to the user of the computer 2700. One example of how this can be provided is in conjunction with the user generating a computer animation on the computer 2700. The lighting unit 100 may be used to create one or more light effects in response to displays 2712 on the computer 2700. The lighting effects, or illumination effects, can produce a vast variety of effects including color-changing effects; stroboscopic effects; flashing effects; coordinated lighting effects; lighting effects coordinated with other media such as video or audio; color wash where the color changes in hue, saturation or intensity over a period of time; creating an ambient color; color fading; effects that simulate movement such as a color chasing rainbow, a flare streaking across a space, a sun rising, a plume from an explosion, other moving effects; and many other effects. The effects that can be generated are nearly limitless. Light and color continually surround the user, and controlling or changing the illumination or color in a space can change emotions, create atmosphere, provide enhancement of a material or object, or create other pleasing and or useful effects. The user of the computer 2700 can observe the effects while modifying them on the display 2712, thus enabling a feedback loop that allows the user to conveniently modify effects. In an embodiment, the information generated to form the image or representation may be communicated to a lighting unit 100 or plurality of lighting units 100. The information may be sent to lighting systems as generated in a configuration file. For example, the image may represent an explosion that begins in the upper right hand corner of a space and the explosion may propagate through the space. As the image propagates through its calculated space, control signals can be communicated to lighting systems in the corresponding space. The communication signal may cause the lighting system to generate light of a given hue, saturation and intensity when the image is passing through the lighted space the lighting systems projects onto. An embodiment of the invention projects the image through a lighting system. The image may also be projected through a computer screen or other screen or projection device. In an embodiment, a screen may be used to visualize the image prior or during the playback of the image on a lighting system. In an embodiment, sound or other effects may be correlated with the lighting effects. For example, the peak intensity of a light wave propagating through a space may be just ahead of a sound wave. As a result, the light wave may pass through a space followed by a sound wave. The light wave may be played back on a lighting system and the sound wave may be played back on a sound system. This coordination can create effects that appear to be passing through a space or they can create various other effects. Referring to FIG. 27, an effect can propagate through a virtual environment that is represented in 3D on the display screen 2712 of the computer 2700. In embodiments, the effect can be modeled as a vector or plane moving through space over time. Thus, all lighting units 100 that are located on the plane of the effect in the real world environment can be controlled to generate a certain type of illumination when the effect plane propagates through the light system plane. This can be modeled in the virtual environment of the display screen, so that a developer can drag a plane through a series of positions that vary over time. For example, an effect plane 2718 can move with the vector 2708 through the virtual environment. When the effect plan 2718 reaches a polygon 2714, the polygon can be highlighted in a color selected from the color palette 2704. A lighting unit 100 positioned on a real world object that corresponds to the polygon can then illuminate in the same color in the real world environment. Of course, the polygon could be any configuration of light systems on any object, plane, surface, wall, or the like, so the range of 3D effects that can be created is unlimited. In an embodiment, the image information may be communicated from a central controller. The information may be altered before a lighting system responds to the information. For example, the image information may be directed to a position within a position map. All of the information directed at a position map may be collected prior to sending the information to a lighting system. This may be accomplished every time the image is refreshed or every time this section of the image is refreshed or at other times. In an embodiment, an algorithm may be performed on information that is collected. The algorithm may average the information, calculate and select the maximum information, calculate and select the minimum information, calculate and select the first quartile of the information, calculate and select the third quartile of the information, calculate and select the most used information calculate and select the integral of the information or perform another calculation on the information. This step may be completed to level the effect of the lighting system in response to information received. For example, the information in one refresh cycle may change the information in the map several times and the effect may be viewed best when the projected light takes on one value in a given refresh cycle. In an embodiment, the information communicated to a lighting system may be altered before a lighting system responds to the information. The information format may change prior to the communication for example. The information may be communicated from a computer through a USB port or other communication port and the format of the information may be changed to a lighting protocol such as DMX when the information is communicated to the lighting system. In an embodiment, the information or control signals may be communicated to a lighting system or other system through a communications port of a computer, portable computer, notebook computer, personal digital assistant or other system. The information or control signals may also be stored in memory, electronic or otherwise, to be retrieved at a later time. Systems such the iPlayer and SmartJack systems manufactured and sold by Color Kinetics Incorporated can be used to communicate and or store lighting control signals. In an embodiment, several systems may be associated with position maps and the several systems may a share position map or the systems may reside in independent position areas. For example, the position of a lighted surface from a first lighting system may intersect with a lighted surface from a second lighting system. The two systems may still respond to information communicated to the either of the lighting systems. In an embodiment, the interaction of two lighting systems may also be controlled. An algorithm, function or other technique may be used to change the lighting effects of one or more of the lighting systems in a interactive space. For example, if the interactive space is greater than half of the non-interactive space from a lighting system, the lighting system's hue, saturation or brightness may be modified to compensate the interactive area. This may be used to adjust the overall appearance of the interactive area or an adjacent area for example. In an embodiment, the lighting effects could also be coupled to sound that will add to and reinforce the lighting effects. An example is a ‘red alert’ sequence where a ‘whoop whoop’ siren-like effect is coupled with the lighting unit 100 pulsing red in concert with the sound. One stimulus reinforces the other. Sounds and movement of an earthquake using low frequency sound and flickering lights is another example of coordinating these effects. Movement of light and sound can be used to indicate direction. In an embodiment the lights are represented in a two-dimensional or plan view. This allows representation of the lights in a plane where the lights can be associated with various pixels. Standard computer graphics techniques can then be used for effects. Animation tweening and even standard tools may be used to create lighting effects. Macromedia Flash works with relatively low-resolution graphics for creating animations on the web. Flash uses simple vector graphics to easily create animations. The vector representation is efficient for streaming applications such as on the World Wide Web for sending animations over the net. The same technology can be used to create animations that can be used to derive lighting commands by mapping the pixel information or vector information to vectors or pixels that correspond to positions of lighting units 100 within a coordinate system for an environment 100. For example, an animation window of a computer 2700 can represent a space or other environment of the lights. Pixels in that window can correspond to lights within the space or a low-resolution averaged image can be created from the higher resolution image. In this way lights in the space can be activated when a corresponding pixel or neighborhood of pixels turn on. Because LED-based lighting technology can create any color on demand using digital control information, see U.S. Pat. Nos. 6,016,038, 6,150,774, and 6,166,496, the lights can faithfully recreate the colors in the original image. Some examples of effects that could be generated using systems and methods according to the principles of the invention include, but are not limited to, explosions, colors, underwater effects, turbulence, color variation, fire, missiles, chases, rotation of a space, shape motion, Tinkerbell-like shapes, lights moving in a space, and many others. Any of the effects can be specified with parameters, such as frequencies, wavelengths, wave widths, peak-to-peak measurements, velocities, inertia, friction, speed, width, spin, vectors, and the like. Any of these can be coupled with other effects, such as sound. In computer graphics, anti-aliasing is a technique for removing staircase effects in imagery where edges are drawn and resolution is limited. This effect can be seen on television when a narrow striped pattern is shown. The edges appear to crawl like ants as the lines approach the horizontal. In a similar fashion, the lighting can be controlled in such a way as to provide a smoother transition during effect motion. The effect parameters such as wave width, amplitude, phase or frequency can be modified to provide better effects. For example, referring to FIG. 29, a schematic diagram 2900 has circles that represent a single light 2904 over time. For an effect to ‘traverse’ this light, it might simply have a step function that causes the light to pulse as the wave passes through the light. However, without the notion of width, the effect might be indiscernible. The effect preferably has width. If however, the effect on the light was simply a step function that turned on for a period of time, then might appear to be a harsh transition, which may be desirable in some cases but for effects that move over time (i.e. have some velocity associated with them) then this would not normally be the case. The wave 2902 shown in FIG. 29 has a shape that corresponds to the change. In essence it is a visual convolution of the wave 2902 as it propagates through a space. So as a wave, such as from an explosion, moves past points in space, those points rise in intensity from zero, and can even have associated changes in hue or saturation, which gives a much more realistic effect of the motion of the effect. At some point, as the number and density of lights increases, the space then becomes an extension of the screen and provides large sparse pixels. Even with a relatively small number of lighting units 100 the effect eventually can serve as a display similar to a large screen display. Effects can have associated motion and direction, i.e. a velocity. Even other physical parameters can be described to give physical parameters such as friction, inertia, and momentum. Even more than that, the effect can have a specific trajectory. In an embodiment, each light may have a representation that gives attributes of the light. This can take the form of 2D position, for example. A lighting unit 100 can have all various degrees of freedom assigned (e.g., xyz-rpy), or any combination. The techniques listed here are not limited to lighting. Control signals can be propogated through other devices based on their positions, such as special effects devices such as pyrotechnics, smell-generating devices, fog machines, bubble machines, moving mechanisms, acoustic devices, acoustic effects that move in space, or other systems. Another embodiment of the invention is depicted in FIG. 30, which contains a flow diagram 3000 with steps for generating a control signal. First, at a step 3002 a user can access a graphical user interface, such as the display 2712 depicted in FIG. 27. Next, at a step 3003, the user can generate an image on the display, such as using a graphics program or similar facility. The image can be a representation of an environment, such as a room, space, wall, building, surface, object, or the like, in which lighting units 100 are disposed. It is assumed in connection with FIG. 30 that the configuration of the lighting units 100 in the environment is known and stored, such as in a table or configuration file 2600. Of course similar information could be stored simply by knowing the ordinal position of a lighting unit 100, such as its position along a string of lights in a string light protocol (which in turn could be used to form a grid by stringing the grid in a particular order). Next, at a step 3004, a user can select an effect, such as from a menu of effects. In an embodiment, the effect may be a color selected from a color palette. The color might be a color temperature of white. The effect might be another effect, such as described herein. In an embodiment, generating the image 3003 may be accomplished through a program executed on a processor. The image may then be displayed on a computer screen. Once a color is selected from the palette at the step 3004, a user may select a portion of the image at a step 3008. This may be accomplished by using a cursor on the screen in a graphical user interface where the cursor is positioned over the desired portion of the image and then the portion is selected with a mouse. Following the selection of a portion of the image, the information from that portion can be converted to lighting control signals at a step 3010. This may involve changing the format of the bit stream or converting the information into other information. The information that made the image may be segmented into several colors such as red, green, and blue. The information may also be communicated to a lighting system in, for example, segmented red, green, and blue signals. The signal may also be communicated to the lighting system as a composite signal at a step 3012. This technique can be useful for changing the color of a lighting system. For example, a color palette may be presented in a graphical user interface and the palette may represent millions of different colors. A user may want to change the lighting in a space or other area to a deep blue. To accomplish her task, the user can select the color from the screen using a mouse and the lighting in the space changes to match the color of the portion of the screen she selected. Generally, the information on a computer screen is presented in small pixels of red, green and blue. LED systems, such as those found in U.S. Pat. Nos. 6,016,038, 6,150,774 and 6,166,496, may include red, green and blue lighting elements as well. The conversion process from the information on the screen to control signals may be a format change such that the lighting system understands the commands. However, in an embodiment, the information or the level of the separate lighting elements may be the same as the information used to generate the pixel information. This provides for an accurate duplication of the pixel information in the lighting system. Using the techniques described herein, including techniques for determining positions of light systems in environments, techniques for modeling effects in environments (including time- and geometry-based effects), and techniques for mapping light system environments to virtual environments, it is possible to model an unlimited range of effects in an unlimited range of environments. Effects need not be limited to those that can be created on a square or rectangular display, such as the tile 500. Instead, light systems can be disposed in a wide range of lines, strings, curves, polygons, cones, cylinders, cubes, spheres, hemispheres, non-linear configurations, clouds, and arbitrary shapes and configurations, then modeled in a virtual environment that captures their positions in selected coordinate dimensions. Thus, light systems can be disposed in or on the interior or exterior of any environment, such as a room, space, building, home, wall, object, product, retail store, vehicle, ship, airplane, pool, spa, hospital, operating space, or other location. In embodiments, the light system may be associated with code for the computer application, so that the computer application code is modified or created to control the light system. For example, object-oriented programming techniques can be used to attach attributes to objects in the computer code, and the attributes can be used to govern behavior of the light system. Object oriented techniques are known in the field, and can be found in texts such as “Introduction to Object-Oriented Programming” by Timothy Budd, the entire disclosure of which is herein incorporated by reference. It should be understood that other programming techniques may also be used to direct lighting systems to illuminate in coordination with computer applications, object oriented programming being one of a variety of programming techniques that would be understood by one of ordinary skill in the art to facilitate the methods and systems described herein. In an embodiment, a developer can attach the light system inputs to objects in the computer application. For example, the developer may have an abstraction of a lighting unit 100 that is added to the code construction, or object, of an application object. An object may consist of various attributes, such as position, velocity, color, intensity, or other values. A developer can add light as an instance in the object in the code of a computer application. For example, the object could be vector in an object-oriented computer animation program or solid modeling program, with attributes, such as direction and velocity. A lighting unit 100 can be added as an instance of the object of the computer application, and the light system can have attributes, such as intensity, color, and various effects. Thus, when events occur in the computer application that call on the object of the vector, a thread running through the program can draw code to serve as an input to the processor of the light system. The light can accurately represent geometry, placement, spatial location, represent a value of the attribute or trait, or provide indication of other elements or objects. Referring to FIG. 31, in one embodiment of a networked lighting system according to the principles of the invention, a network transmitter 3102 communicates network information to the lighting units 100. In such an embodiment, the lighting units 100 can include an input port 3104 and an export port 3108. The network information may be communicated to the first lighting unit 100 and the first lighting unit 100 may read the information that is addressed to it and pass the remaining portion of the information on to the next lighting unit 100. A person with ordinary skill in the art would appreciate that there are other network topologies that are encompassed by a system according to the principles of the present invention. Referring to FIG. 32, a flow chart 3200 provides steps for a method of providing for coordinated illumination. At the step 3202, the programmer codes an object for a computer application, using, for example, object-oriented programming techniques. At a step 3204, the programming creates instances for each of the objects in the application. At a step 3208, the programmer adds light as an instance to one or more objects of the application. At a step 3210, the programmer provides for a thread, running through the application code. At a step 3212, the programmer provides for the thread to draw lighting system input code from the objects that have light as an instance. At a step 3214, the input signal drawn from the thread at the step 3212 is provided to the light system, so that the lighting system responds to code drawn from the computer application. Using such object-oriented light input to the lighting unit 100 from code for a computer application, various lighting effects can be associated in the real world environment with the virtual world objects of a computer application. For example, in animation of an effect such as explosion of a polygon, a light effect can be attached with the explosion of the polygon, such as sound, flashing, motion, vibration and other temporal effects. Further, the lighting unit 100 could include other effects devices including sound producing devices, motion producing devices, fog machines, rain machines or other devices which could also produce indications related to that object. Referring to FIG. 33, a flow diagram 3300 depicts steps for coordinated illumination between a representation on virtual environment of a computer screen and a lighting unit 100 or set of lighting units 100 in a real environment. In embodiments, program code for control of the lighting unit 100 has a separate thread running on the machine that provides its control signals. At a step 3302 the program initiates the thread. At a step 3304 the thread as often as possible runs through a list of virtual lights, namely, objects in the program code that represent lights in the virtual environment. At a step 3308 the thread does three-dimensional math to determine which real-world lighting units 100 in the environment are in proximity to a reference point in the real world (e.g., is a selected surface 107) that is projected as the reference point of the coordinate system of objects in the virtual environment of the computer representation. Thus, the (0,0,0) position can be a location in a real environment and a point on the screen in the display of the computer application (for instance the center of the display. At a step 3310, the code maps the virtual environment to the real world environment, including the lighting units 100, so that events happening outside the computer screen are similar in relation to the reference point as are virtual objects and events to a reference point on the computer screen. In embodiments the virtual world is two-dimensional, so that a two-dimensional real world grid, such as formed of tiles 500, is represented by two-dimensional object in the virtual environment. In other cases the virtual world represents three-dimensional objects, such as spaces or polygons, in the real world. Such three-dimensional objects include those formed of two-dimensional objects, such as tiles 500. At a step 3312, the host of the method may provide an interface for mapping. The mapping function may be done with a function, e.g., “project-all-lights,” as described in the Directlight API described herein below, that maps real world lights using a simple user interface, such as drag and drop interface. In some embodiments, the placement of the lights may not be as important as the surface the lights are directed towards. It may be this surface that reflects the illumination or lights back to the environment and as a result it may be this surface that is the most important for the mapping program. The mapping program may map these surfaces rather than the light system locations or it may also map both the locations of the light systems and the light on the surface. A system for providing the code for coordinated illumination may be any suitable computer capable of allowing programming, including a processor, an operating system, and memory, such as a database, for storing files for execution. Each real lighting unit 100 may have attributes that are stored in a configuration file. An example of a structure for a configuration file is depicted in FIG. 26. In embodiments, the configuration file may include various data, such as a light number, a position of each light, the position or direction of light output, the gamma (brightness) of the light, an indicator number for one or more attributes, and various other attributes. By changing the coordinates in the configuration file, the real world lights can be mapped to the virtual world represented on the screen in a way that allows them to reflect what is happening in the virtual environment. The developer can thus create time-based effects, such as an explosion. There can then be a library of effects in the code that can be attached to various application attributes. Examples include explosions, rainbows, color chases, fades in and out, etc. The developer attaches the effects to virtual objects in the application. For example, when an explosion is done, the light goes off in the display, reflecting the destruction of the object that is associated with the light in the configuration file. To simplify the configuration file, various techniques can be used. In embodiments, hemispherical cameras, sequenced in turn, can be used as a baseline with scaling factors to triangulate the lights and automatically generate a configuration file without ever having to measure where the lights are. In embodiments, the configuration file can be typed in, or can be put into a graphical user interface that can be used to drag and drop light sources onto a representation of an environment. The developer can create a configuration file that matches the fixtures with true placement in a real environment. For example, once the lighting elements are dragged and dropped in the environment, the program can associate the virtual lights in the program with the real lights in the environment. An example of a light authoring program to aid in the configuration of lighting is included in U.S. patent application Ser. No. 09/616,214 “Systems and Methods for Authoring Lighting Sequences.” Color Kinetics Inc. also offers a suitable authoring and configuration program called “ColorPlay.” Further details as to one implementation of authoring code can be found in the Directlight API described below. Directlight API is an example of a programmer's interface that allows a programmer to incorporate lighting effects into a program. Object oriented programming is just one example of a programming technique used to incorporate lighting effects. Lighting effects could be incorporated into any programming language or method of programming. In object oriented programming, the programmer is often simulating a 2D or 3D space. In the above examples, lights were used to indicate the position of objects which produce the expected light or have light attached to them. There are many other ways in which light can be used. The lights in the light system can be used for a variety of purposes, such as to indicate events in a computer application (such as a game), or to indicate levels or attributes of objects. Having appreciated that a computer screen or similar facility can be used to represent a configuration of lighting units 100 in an environment, and having appreciated that the representation of the lighting units 100 can be linked to objects in an objected-oriented program that generates control signals for the lighting units 100 that correspond to events and attributes of the representation in the virtual world, one can understand that the control signals for lighting units 100 can be linked not only to a graphical representation for purposes of authoring lighting shows, but to graphical representations that are created for other purposes, such as entertainment purposes, as well as to other signals and data sources that can be represented graphically, and thus in turn represented by lighting units 100 in an environment. For example, music can be represented graphically, such as by a graphic equalizer that appears on a display, such as a consumer electronics display or a computer display screen. The graphical representation of the music can in turn be converted into an authoring signal for lighting units 100, in the same way that a scripted show can be authored in a software authoring tool. Thus, any kind of signal or information that can be presented graphically can be translated into a representation on a lighting unit 100, using signal generating facilities similar to those described above, coupled with addressing and configuration facilities described above that translate real world locations of lighting units 100 into coordinates in a virtual environment. For example, anything that can be sensed by a signal source 124 can be represented graphically as data, and in turn represented in color, such as on an array of tiles 500 in a room. For example, tiles 500 can glow red if the outside temperature is warm, blue if the stock market is up, or the like. One example of a representation that can be translated to a control signal for a lighting unit 100 is a computer game representation. In computer games, there is typically a display screen (which could be a personal computer screen, television screen, laptop screen, handheld, gameboy screen, computer monitor, flat screen display, LCD display, PDA screen, or other display) that represents a virtual world of some type. The display screen may contain a graphical representation, which typically embodies objects, events and attributes coded into the program code for the game. The code for the game can attach a lighting control signal for a lighting unit 100, so that events in the game are represented graphically on the screen, and in turn the graphics on the screen are translated into corresponding lighting control signals, such as signals that represent events or attributes of the game in the real world, such as flashing lights for an explosion. In some games the objects in the game can be represented directly on an array of lights, such as an array of tiles 500; for example, the game “pong” could be played on a wall or the side of a building, with tiles 500 representing game elements, such as paddles and the “ball.” For configurations whereby electrical connections are facilitated between adjacent units, as described in connection with FIG. 8, these connections can be used to establish proximity and geometry. This can be used, in turn, to generate a general map of the system, which can then be used to author effects across a number of tiles 500. Referring to FIG. 34, if Tile A is linked or connected to Tile B, and Tile B, in turn, is connected to Tile C, then we now have three tiles whose general topology or relationship to each other is established. This can be done automatically through a system that identifies specific tiles either by type or by unit. This information can be stored or represented through memory elements, or electrical jumpers or resistors that represent an identifier. Thus, each tile 500 or panel element knowing who its neighbor is and knowing what tiles 500 are in the network of light emitting elements and knowing exactly what is in each tile, allows the system to know where each and every controllable light-emitting element is located. This, in turn allows effects or imagery to treat the whole system as one integral unit. In such an implementation, each tile 500 can either have a unique ID or an ID that represents the type of tile 500. It might be one of several varieties. When adjacent tiles are connected edge-to-edge electrically through edge connections, there can be a handshaking routine to communicate between those tiles and provide information to each other. This is very similar to the protocol followed when devices are connected to a computer network. To determine the overall topology then requires a sequence of communications from one tile or panel to the next to a central controller. There are two types of tiles 500 depicted in FIG. 34, a triangle and square. The adjacent tiles 500 have an electrical connection that allows the transmission of information from one unit to the next using serial protocols and low overhead communication. The connections between tiles allow a path of communication to determine the configuration of the complete installation. Knowledge of neighbors and tile types gives an unambiguous layout in this two-neighbor configuration. It is also possible to have more than two neighbors as long as the connecting geometry is known. Self-configuration of networks for the purpose of creating physical pixels is described, for example, in the works of Kelly Heaton of Massachusetts Institute of Technology, such as “Physical Pixels” submitted to the program in Media Arts and Sciences, School of Architecture and Planning, in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences at the Massachusetts Institute of Technology, June 2000. Another application of the use of tiles 500 is the use of these devices, as described above, under the ice at a skating rink or other ice-centric venue including ice sculptures. The tiles can be laid under the ice. To protect the tiles an encapsulant or transparent protective coating is used to prevent water damage and damage from the weight of people or vehicles to the units. As the layers of water are added to the rink and built-up atop the units, the ice will diffuse the light from the tiles 500. Once the ice is ready, additional sensing devices on skaters and props on the ice can be tied to position systems to determine absolute position of skaters or other artifacts on the ice, such as pucks and then track that position over time with light. A skater can thus trace out shapes as they skate and particular effects such as persistence of the light or color change and shift can be emplaced to give a ‘tail’ to movement. For Ice Capades and the like, the light can be used as a display for a wide variety of themes including patriotic or related to characters in the ice event—i.e. Cinderella, Winnie-the-Pooh and more. Additional sensing can be used to detect the presence of a person or a person hand or arm or instrument and respond to ‘unveil’ an image by sensing the proximity of said arm or instrument. For example, as an arm moves across a surface, the lighting pattern is revealed as though you simply wiped away a surface covering. No touching is required, although it would be possible to have that as well as the use of a pad or pad that would move across. For example, a squeegee-like instrument whose presence and proximity would be detected and turn on lighting elements in close proximity. The movement and velocity of the motion could be detected to adjust the timing of the ‘unveiling’ of the light pattern beneath. This could be used for movement tracking and indication during dancing, movement, etc. The surface could be treated as a canvas and color could be selected by other actuation or signaling means. Persistance effects could also be added so the movement has a ‘tail’ to it. In general, any of the display modes described for the tiles 500 can be coupled to sensing means (electromagnetic, IR, wireless, capacitive, visible light, hall effect, acoustic and more) to trigger effects or to tie an effect to the amplitude or position of a sensed signal. A person moving by a wall, floor or ceiling can trigger effects. Proximity detectors operating on many principles can be used to couple sensed information to lighting. Music can provide and couple to lighting effects based on frequency and amplitude of a musical signal (a responsive system) or a pre-scripted effect can be triggered that is then synchronized to music. Acoustic effects are typically done through a microphone coupled directly to control and changing an illumination pattern or sequence as a function of amplitude. More sophisticated effects are possible based on temporal and spatial effects that propagate effects or have a show sequence coordinated with the music or audio. Additional sensing can adjust the light output as a function of ambient light by coupling a light sensors such as the TAOS sensor or even simpler photoelectric sensors that provide a measure of ambient light. This information is then used by the controller to dim the overall light accordingly or change the color or color temperature. Even the passage of time or the image of the sky can be used and the panels can be used to match that color. A virtual skylight can be created even on floor and in spaces where the ceiling is not the roof. The tile lights lend themselves well to the concept of a Virtual Skylight™ or a Virtual Window™ where you can have a very inexpensive camera pointing outside of a building (even a cheap webcam will suffice) and use that imagery in slow-time or real-time to give a virtual window that doesn't necessarily give a high resolution window but gives a sense of what it is doing outside—even the passage of a cloud or the shadow of something moving by. The VS or VW could also be a non-sensing based system with a simple dimmer-style interface, or an interface like that of the ColorDial from Color Kinetics Incorporated of Boston, Mass. Other control related aspects to the invention include the incorporation of scaling factors for dimming and calibration which can be set and programmed at the factory into controller memory or set by the user via dip-switches or PC-interface or other similar means into the tile light. Tiles 500 can take any shapes, including arbitrary shapes, polygons, squares, rectangles, triangles, circles, ovals, rhombuses, pentagons, hexagons, septagons, octagons, nonagons, decagons and any other shape. While much of the above discussion has surrounded the concept of two-dimensional shapes for the panels or tiles 500, these elements can be in 3D as well and form any three-dimensional shape. Many polygonal solids including pyramids, tetrahedrons, dodecahedronss, parallelpipeds and the like can be formed, as well as arbitrary three-dimensional shapes. The present invention encompasses the combination of the physical shape of a luminaire and the ability to individually address and control sections of that luminaire, to achieve specific illumination effects throughout a room or space. It also relates to a way of construction for a luminaire or display that utilizes interlocking, substantially similar, repeated subassemblies whose interlocking mechanism can provide both mechanical strength and electrical connectivity. It also relates to the exploitation of the geometry of interlocking repeated subassemblies for the purpose of enabling accurate and precise positioning of light sources. It further relates to the combination of the physical shape of a display and the ability to individually address and control sections of that display, to achieve a general illumination effect. As shown in FIGS. 35, 36 and 37, for a particular and representative shape, a sphere 3500, an interlocking design in the form of a 2D triangle was created that, when connected and interlocked with other boards of the same design can form a sphere 3500. Although not a platonic solid (see below) the principle can be used to create scaled forms and many shapes based on interlocking elements. While mechanical connections using rigid supports and fasteners can be used to hold the shaped board elements together, the electrical connection can also be used or soldering of the adjacent boards can provide sufficient connections for many smaller shapes as well. Each board in this case, is an individually controllable and networked lighting element. This can be accomplished through individual controllers on each board, which can use off-the-shelf microprocessors or an integrated control chip such as the Chromasic chip using a string light protocol by Color Kinetics. Other shapes include, a cube, an octahedron, a rhombic dodecahedron, the pyritohedron, the deltoidal dodecahedron, the tetartoid, the tetrahedron, the diploid, the gyroid, the tetartoid, the trapezohedron, the hexoctahedron, the tetrahexahedron, the tristetrahedron, the trisoctahedron and the hextetrahedron. Each of these shapes has the advantage of being formed of simple geometric elements that can be designed as circuit board elements for lighting control and illumination. Also disclosed are the platonic solids, which are those polyhedra whose faces are all regular polygons, which means they have congruent legs and angles. There are only five such polyhedra, shown in FIG. 38. In various embodiments, interconnection and modularity can be further improved through the use of inductive elements that co-align through proximity to one another. Inductive coupling uses an AC signal, akin to a transforner, which can be used to provide power, for example 12 VAC, from one element to another. Simultaneously, data can be superimposed upon the power signal to create a multiplexed data and power connection. The multiplexing can also happen through a direct electrical connection and using a multiplexed data and DC power between elements. This concept is similar to the Color Kinetics iColor MR product, but in a very different physical form factor, a tile 500, rather than a lamp. Even simpler, communication between elements can occur through optical (such as visible or IR) means whereby adjacent panels are aligned and optical coupling elements allows data to stream from one element to the next. In this way a wide variety of coordinated and synchronized patterns can occur across a variety of panels. Another way is the use of RF techniques to allow many panels to interconnect without wires and the like. This disclosure includes many ways information can be transferred between modules. The underlying architecture is also relevant. In FIG. 39, each of the numbered blocks (1,2, . . . N) represents a tile 500 with a plurality of controllable nodes (e.g. RGB or RGBW and control chip). A network, for example Ethernet, can be used to connect a series of hubs or routers each of which is, in turn, connected to many tiles 500. In this way a hierarchy of elements from the processor, computer or controller provides a control data stream to the hubs that, in turn, take their information and distribute it to the lighting units 100 and the nodes within the tiles 500. This is in contrast, for example, to video screens that listen to an entire video signal and pick off a particular section of that signal to display. Referring to FIG. 40, an additional invention uses a conceptually simpler but higher speed approach using a very high-speed serial bus 4002. The bus 4002 could be a higher speed version of FireWire. The interconnection between tiles 500 could be wireless, such as Bluetooth or any other known wireless connection protocol. Referring to FIG. 41, in embodiments of the invention various mounting configurations can be used. In the embodiment of FIG. 41, the distance L 4108 of the light sources 4102 to a surface 4104 can be chosen to minimize overlap between light from the light sources 4102 and to maximize coverage. As seen in FIG. 41, the distance is a function of the beam angle of the LEDs 4102. It is desirable to choose a distance 4108 that, within a practical percentage, is chosen to eliminate much overlap or to provide frames or boxes between adjacent light elements. As can be seen in FIG. 41, the function relating beam angle and distance is a trigonometric value. If the half-angle spread is alpha and the distance between adjacent LEDs is L then the distance at which the beams from adjacent LEDs meet is L/(2 tan (alpha)). This is the desired distance. However, due to absorption, reflectance and other optical characteristics it may prove desirable to adjust this distance slightly to one side of the other of this distance to obtain the most pleasing effect. Referring still to FIG. 41, the proximity of the LEDs to the surface defines the resulting pattern. FIG. 41 shows a line of light emitting diodes 4102 and the effect of distance of a diffusing surface 4104. If the LEDs 4102 are too close to the surface then, depending of diffusive qualities of the surface 4104, a series of points will result. If too far, then overlap causes mixing of adjacent light sources. Finally in the rightmost figure is shown a diffuser position corresponding to the point at which the beams from adjacent light sources meet. In typical embodiments the light sources 4102 do not have a perfect beam, such as with full light at one angle and then none at the next increment. However, a rapid fall-off of light is typical, and beam patterns and angles are often defined by the angle at which the light falls to one-half of center intensity. Another mechanical means to prevent overlap and potentially increase light output is for each light source 4102 to be mechanically isolated from its neighbors such as that used in egg-crate lighting diffusers. Thin materials can be used and a small offset distance to prevent lines of the mechanical piece from showing through the diffuser. Referring to FIG. 42, the light sources 4102 are now viewed directly, without intervening diff-using materials. FIG. 42 is a direct view image of the LEDs 4102 mounted in a regular array on a board 4202. No diffuser is used. As can be seen in this image, the light sources 4202 appear as bright points of light. Each can be individually controlled or they can be synchronized to do the same thing over time. On top of FIG. 42 are shown a row of LEDs that are facing outwards; no materials interrupt the light path to the view. In the bottom image, the boards show four 1′ square boards each within 8×8 (64) grid of RGB LED light sources. Referring to FIG. 43, in embodiments the diffusing surface 4104 can be slanted with respect to the light sources 4102. In FIG. 43, a diffusing surface is illustrated in the front of the 4104 LEDs 4102 between the light sources and the viewer. The diffusing surface is at an angle with respect to the LEDs. As can be seen from FIG. 43, as the distance is varied the points of light are visible and merge together with adjacent points of light. If merged too closely, then the colors from adjacent light sources overlap and it becomes difficult to differentiate sources and color mixing occurs. In the case of differing colors then, there is a resultant loss of resolution—similar to an out of focus images where blur occurs. This example can be used in applications where a transition is desired between distinct points of light and blurred areas where resolution is reduced for effect. Referring to FIG. 44, a variety of configurations and surfaces can be used with light sources 4102. In FIG. 44, LED elements 4102 are shown, from left to right, in contact with a surface 4104. Embedded features within the diffusing material form a mating shape to the LED. This is true whether the LED is in a standard 5 mm (T 1¾) package, SMT, or other power package. This tight coupling reduces reflection losses and optical gel materials can be used in conjunction to minimize or eliminate optical losses. In embodiments of FIG. 44, a material is used to form a shape that has general optical properties for shaping the output from a series of individual light sources 4102. In the embodiment 4408, the material is shaped as a flat surface. In the embodiment 4410, the material 4104 is an optical lens. In the embodiment 4412, an undulating surface forms a variety of patterns and shapes resulting from the light interaction with the changing distance. In the embodiment 4414, such a shape or any other, can be adjusted in distance from the LED sources. This adjustment can be one of many mechanical means for adjusting or setting the distance. A simple screw 4418 is shown, such that when the screw 4418 is turned, the material moves further away or closer to the LED board. Such adjustments could also be latches and serrated patterns that catch a mechanical pawl or indent mechanism or any other mechanism for adjusting distance and height. Referring to FIG. 45, there are many embodiments of fastening and mounting facilities for light sources of the present invention to hold LED modules to a surface. The embodiments of FIG. 45 are meant to be illustrative of general fastening facilities, and not limiting. This example set in no way limits the means by which one material or surface may be attached to another. IN the embodiment 4502, small features on the side lock into a circular hole in a panel as it pressed into the hole from the top of the panel. The cable connecting the modules is shown in cross-section and passes from one module to the next in a continuous fashion and is tied into the module via insulation displacement means (IDC-style). The module 4505 has a small flat tab 4506 to the side that is integral to the package and is used as a hold down area via a screw, nail, staple or other fastener. In the embodiment 4508, a small separate flat piece with a mating feature is fastened to a surface and the module is snapped atop the separate piece. In the embodiment 4510, the embodiment is similar to the embodiment 4504, but the area of the tab is either circular or extends through the bottom of the module. In the embodiment 4512, a smaller hole is created in the panel and the screw feature shown in 4516 can be threaded or used with a self-tapping screw from the other side of the mounting surface. In the embodiment 4524, a panel fastener 4526 is attached or integrated into the module design and is pushed through an appropriately sized hole and thus held directly in place. In the embodiment 4518, a two piece arrangement is provided in which the first bottom piece 4528 is attached to a mounting surface via one of many possible means including but not limited to screws, nails, adhesives etc. The second piece 4530 with the cabling preattached, is snapped into the bottom piece via mating features that provide a locking action when the module is pressed in from above. Additional features, not shown, fore and aft prevent the unit from sliding or moving in the bottom mounting piece 4528. In the embodiment 4514, a tab extending from the bottom piece 4528 can then be attached to the surface. The module attaches to the bottom piece 4528 in a similar manner as described in connection with the embodiment 4518. In the embodiment 4520, the module pokes through from the bottom of the panel. Similar features provide a snap-in capability and the cabling remains on the bottom of the panel. In the embodiment 4522, adhesive, in the form of a double-sided piece, can be attached to the bottom of the module and to the module itself. For installation, protective material is peeled away from the adhesive revealing the sticky surface and then pressed onto the mounting surface. In the event of direct or other materials, the adhesive can be scraped or removed and a new piece of DST applied. Referring to FIG. 46, details are provided for a push-through assembly mechanism. In FIG. 46, the light node 4602 is pressed through a hole 4604 in the Is mounting surface 4608 from the bottom. A rim 4610 on the bottom of the light node 4602 that is larger than the diameter of the hole 4604 prevents the light node 4602 from pushing all the way through. The cable 4612 joining a plurality of light nodes 4602 is thus protected from engagement on the shearing edge of the mounting hole 4604. From the other side, a retaining ring 4614 is pressed onto the outside of the light node 4602 and internal teeth 4618 or other similar features engage the light node 4602 and prevent it from backing into the hole 4604. Once engaged and pressed flush with the mounting surface 4608 this positive engagement holds the unit securely in place. By prying up the retaining ring 4614 with a suitably thin edged tool, it is also possible to remove the retaining ring 4614. Referring to FIG. 47, a surface lit by a light node 4102 as described herein need not be a two-dimensional surface. For example, it can be a complex topology, such as the surface 4700 of FIG. 47. In this example, a heavily sculptured or textured 3D surface can also be used in conjunction with an array of light elements or light nodes 4102. Various pleasing effects due to the varying distances to the surface can be achieved with such a surface 4700. The 3D surface 4700 can be of any suitably translucent or transparent material. Varying depths and thicknesses may actually become opaque, providing a rich set of variation in color and translucency. The surface itself may be colorless or have intrinsic color and depth of color. Referring to FIG. 48, it is also possible to have three dimensional illuminated shapes 4800 that have features and color that are augmented and enhanced by the set of controllable light nodes 4102 behind the shapes. For example, a hemispherical shape 4800 can include a map of part of the globe on it, and the light nodes 4102 can be lit to enhance the colors, such as by shining blue light to enhance the oceans, or yellow light to enhance yellow surface features. Referring to FIG. 49 and FIG. 50, it is also possible to establish arrays of lighting elements with superimposed graphical elements, such as translucent graphics and materials. For example, an array 4900 of lighting elements can be covered with superimposed translucent elements 4902 or a transparent element 4904 to enhance the effects of lighting from the array 4900. Referring to FIG. 50, the superimposed element might be a logo 5002, or similar element of a brand, trademark, trade name, business name, personal name, or the like. The superimposed element might also be a graphic 5004, such as a graphic designed to produce a changing, or “flair” effect when lighting elements illuminate the graphic 5004 with different colors of light. As shown in the above figures, these lighting arrays 4900 can be used to emphasize and delineate graphical elements for use in display or advertising applications as well as novel elements in consumer products and more. Graphics, printed on a variety of materials with varying light transmission qualities, can be overlaid onto the arrays to provide flexible and controllable backlit illumination for said graphical materials. These graphics can be any printed materials. Referring to FIG. 51, arrays 4900 can be provided with various spacing. In one embodiment, an array 4900 is a regularly spaced, linear, planar array 5100. In other embodiments, the arrays can be spaced irregularly. FIG. 52 depicts an irregularly spaced, planar array 5200 of lighting elements 4102. FIGS. 51 and 52 illustrate variations in spacing of the lighting elements. The spacing can be regular or freeform. The spacing can vary linearly or non-linearly across the units and even in three dimensions, such as with the substantially spherical embodiment described above. FIG. 53 depicts a three dimensional loop 5300 in the form of a Mobius strip. As shown in FIG. 53, a mesh of lighting elements 4102 can be created at varying densities and spacing as well as an infinite variety of overall shapes in 3D. The Mobius strip is a topological surface with only one edge and one side. The lighting elements can be easily incorporated into these types of complex surfaces (toruses, klein bottles, hypercube representations in 3-space, etc.). Methods and systems described herein also include use of thermoset materials as the grid or mounting surface material to which light nodes are mounted. A thermoset plastic can be shaped under heat in a mold or even by hand and then cooled to assume the desired shape. In this way a custom surface can be molded, twisted or otherwise formed into the desired shape under heat or pressure and be made to maintain that form. Some examples of thermoset materials include ABS, Acrylics, Fluoropolymers, Nylons, Polyarylates, Polyesters, Polyphenylene Sulfide, Polystyrenes, Acetals, Acrylonitrile, Methacrylates, Phthalates, Polybutylenes, Polyethers, Polyphenylenes, Polysulfones, Styrenes, Acrylates, Cellulosics, Molding Resins, Polyamides, Polycarbonates, Polyethylenes, Polypropylenes, Polytethylene Terephthalate, and Vinyls & Polyvinyls. This list is not meant to be limiting in any way of the types and varieties of thermoset materials. Another method of shape creation is the use of bendable and formable materials such as metals, which, in one form of wire grids, can be twisted and shaped into many forms. Wire mesh, screen and cloth can be made from metal, coated metals (like Gumby® figures) or even plastic materials and then pushed and pulled into a wide variety of shapes. As shown below in FIG. 54, a grid arrangements of such materials provide for wide flexibility in the placement of said modules. Referring to FIG. 54, light nodes 4102 can be arranged in the spacing within a wire grid 5402 with complete flexibility in the mounting subject only to the constraints of the grid 5402 itself. In this disclosure, the mounting surfaces themselves can also be shaped and 3-dimensional. There are no limitations on the shape of the mounting surface so long as provision is made for the mounting or attachment of the lighting elements. Referring to FIG. 55, complex arrangements of light nodes 4102 disposed in grids. 5402 can themselves form graphical elements, icons, and other representations of subject matter or artistic freedom, such as in the display 5502. As shown in FIG. 55, the location of the light nodes can form specific patterns and shapes that conform to a particular design. Although a dense array of such modules can be used to form any colored pattern, it may prove to be more economical to use specific patterns if the application only requires a subset of the dense array. This may be more economical and practical for many installations. Again, the grid 5402 shown in the figure is meant only to be illustrative of the potential for mounting and routing of light nodes 4102. Methods and systems described herein also provide for various cap and lens options for light nodes or elements described herein. FIG. 56 depicts a light node 5602 with a snap module 5604 with a short lens option 5608. The design of FIG. 56 is one of many module designs. In this illustration the unit incorporates a hemispherical lens 5608. Such a lens 5608 is designed with a particular mating format to engage the base module 5604 and, as a result, the lens 5608 is modular and can take on many shapes depending on desired function such as optical characteristics or purely form-based based aesthetic appearance or application usage. Such lens designs may be in for form of licensed characters or jewel shaped or icons or corporate logos or any one of many custom shapes. FIG. 57 shows a long lens 5702 wherein the exterior appearance may be a uniform light color along the entire lens assembly. FIG. 58 shows a light node 5802 without a lens. A module with no lens can accept a variety of lens configurations or no lens at all. In FIG. 58, the well 5804 surrounding the lighting emitter and electronics can be adapted to via a variety of cap or lens modules. The term ‘lens’ is not intended to be limiting in any way. The material and form of the ‘lens’ design can be optical facility to refract, reflect and diffuse the light but may be transparent, opaque in areas or translucent. It can be of any shape, part of which can conform to the module design. There is also no limitation on the scale of the unit—dimensions are meant to be illustrative of a particular design but the unit can be scaled up or down in size to provide functionality for many applications. FIG. 59 shows a computer aided design (CAD) drawing 5900 of a single node holder embodiment of a light node. FIG. 60 shows a CAD drawing 6000 of a no-lens embodiment of a light node. The modules showed in FIGS. 59 and 60 are representative modules with dimensions on the order of 10 mm or so. A light node can be easily scaled to much smaller sizes (1 mm scales for example) or even much larger sizes (100 or 1000 mm), wherein the modules are comprised of a plurality of light emitting elements within the module. FIG. 59 also shows a track mounting system 5902 for lighting elements or modules. In FIG. 59 the modules are shown being snapped or attached to a track shape providing for linear forms of module arrangement for many applications. A complete lighting unit can be provided for a variety of applications. In addition a bendable radius can be provided that gives, literally, flexibility in the lateral direction as well as the vertical direction for mounting to other surfaces. Referring to FIG. 61, other embodiments of the invention may include embodiments that take advantage of various signal sources 124, such as sensors, as a basis for authoring a control signal for the tile 500. For example, a proximity sensor 6102 could be placed on or near a tile 500, in communication with the control system for the tile 500, so that when a user 6104 is in proximity to the tile 500, the tile changes color in a predetermined way. Thus, the proximity sensor 6102 serves as a user interface for the tile 500. An array of such tiles 500 with sensors 6102 can then be disposed, for example on a wall, so that the user 6104 can author various effects, such as by waving near various tiles in various sequences. For example, swiping a hand across the tiles 500 could produce a color-chasing rainbow or similar effect on the array of tiles 500. Tiles 500 could be of any size, ranging from very small tiles on the order of the size of a group of LEDs to very large tiles. Referring to FIG. 62, tiles 500 are sized to cover an entire ceiling, floor, or wall, such as for a room or elevator. Thus, for example, a metal board could be made the size of a wall panel, with LEDs disposed on it and controlled, for example, with a string light or serial protocol as described above. The metal board could be shaped into any shape to fit a space, such as a rectangle, circle, regular polygon, or irregular shape. In embodiments, the metal board with LEDs could then be covered with a diffusing material, such as a translucent, elastic plastic or polymer that could be stretched over the board for installation as a unit. Such a unit could serve as a wall, a door, a ceiling, a floor, an elevator wall, or other construction units. In embodiments, the tiles 500 may be made water resistant for outdoor use or waterproof for underwater use. Thus, the tiles 500 can be covered with waterproof polymers, rubber, plastic, or other waterproof materials, and constructed with watertight construction, such as sealed connections for power and control cables. Such embodiments may include materials for thermally conducting heat away from the LEDs to increase the length of their use, such as metal or other conductive materials, which may be in thermal connection to water or other materials outside the tile 500. Water proof underwater tiles 500 can be used to illuminate the bottom or sides of an in ground or above ground swimming pool, a portable or in ground spa, the bottom or sides of a fountain, a pond or water display, a garden water display, an aquarium, or any other underwater environment. Thus, referring to FIG. 63, a tile 500 may be displayed, for example, in the bottom of a swimming pool 6300, spa, fountain, pond or aquarium, to provide digitally controlled illumination shows of various colors or color temperatures in the pool 6300. In embodiments, the light sources 104 may be disposed on a support structure, such as a board 204. The board 204 may be a circuit board or similar facility suitable for holding light sources 104 as well as electrical components, such as components used in the electrical facility 202. Referring to FIG. 64, in embodiments the board 204 may consist of a rectangular board 204, with an array or grid 2208 of light sources 104. In the embodiment depicted in FIG. 64, the array is a six-by-six array on a square board 204 with six-inch sides. The array 2208 can have any number of light sources 104 and take on any other dimensions. The light sources may consist of miniature groups of LEDs, such as red, green, blue, white or other colors of LEDs. In embodiments each light source 104 is comprised of a triad of red, green and blue surface mount LEDs. The square array makes it very convenient for the array 2208 to be placed side by side with other boards 204 containing similar arrays 2208, so that effects can be generated across multiple arrays 2208, such as an extended system covering a wall or the outside of a building. That is, the arrays 2208 can serve as modular components of larger lighting systems. To facilitate rapid installation, the board 204 may have a plurality of pre-fabricated screw holes 2210 that make it very convenient to attach the board 204 to a wall or other mounting area. In embodiments the board 204 is provided with a protective cover 2212, such as a plastic cover to protect the board from damage and to prevent a user from touching electrical connections on the board 204. The cover 2212 may include spaces 2214, so that a viewer can see the light sources 104 directly without having light diffused through the cover 2212. In other embodiments the cover 2212 may be a light transmitting cover or a light diffusing cover. Referring to FIG. 65, in another embodiment the array 2208 of light sources 104 may be a three-by-three array, less dense than the six-by-six array of FIG. 65, but including similar elements, such as the board 204 (again a six-inch by six-inch board 204), the cover 2212, the screw holes 2210 and the spaces 2214 through which the viewer can directly see the light sources 104. Again the light sources 104 may consist of various colors of LED, such as a trio of red, green and blue surface mount LEDs. FIG. 66 shows the back of a board 204 such as the rectangular array 2208 boards 204 described in connection with FIGS. 64 and 65. The board 204 includes a jack 2218 for taking in power and data from a source and a jack 2220 for sending power and data out. In embodiments the jacks 2218, 2220 allow the board 204 to be aligned in series with other boards 204, where data from a central controller is passed from board-to-board by the jacks 2218, 2220. In embodiments each group of light sources 104 in the array 2208 may be provided with a processor, such as an ASIC 3600, for handling lighting control signals for the light sources 104. In embodiments the ASICs 3600 are disposed in series and are controlled by a serial control facility such as described herein, where each ASIC takes a data stream, responds to the first unmodified byte, modifies the byte to which it responds, and sends the modified data stream to the next ASIC. The ASICs 3600 on the back of the board 204 may be strung in an array, such as the six-by-six array 2208 or the three-by-three array 2208. In embodiments each of the ASICs 3600 is disposed along with a resistor and a capacitor on the back of the board 204. The board 204 may also contain an additional ASIC 2230, such as to allow a central controller to identify the particular type of board 204 on which the ASICs are disposed, such as to identify the board 204 as a six-by-six or three-by-three array. The board 204 may also include extrusions 2228 from the screw holes 2210 of the board. The extrusions 2228 guide the screws that attached the board 204 to a surface, and they also provide an offset between the back of the board 204 and the surface, so that the ASICs 3600 or other components are not crushed when the board 204 is attached to the surface. Corner extrusions 2224 provide an offset at the corners of the board 204 as well. In embodiments the cover 2212 may be fitted with lenses, diffusers or other optical facilities 400 that shape the light coming from the light sources 104 that make up the arrays 2208, such as to increase the viewing angle of light sources 104. In embodiments the lighting units 100 may include a dipline style mounting panel that allows units to be placed anywhere on a surface. The boards 204 may include integrated hash marks for aligning units 100 during installation. In embodiments boards 204 may have an integrated laser level to facilitate accurate installation. In this embodiment a layered surface of conductors such as Dipline-style (Dipline is a trademarked layered conductive mounting material) surface material is used to allow units to be placed anywhere on surface by inserting of modular attached pin connectors to be pushed through the surface of the materials to make contact with selected conductive layers within the surface. Referring to FIG. 67, housings may also take the form of a flexible band 6750, tape or ribbon to allow the user to conform the housing to particular shapes or cavities. Thus, the various embodiments of tiles 500 described herein can be flexible tiles. Similarly, housings can take the form of a flexible string 6754. Such a band 6750 or string 6754 can be made in various lengths, widths and thicknesses to suit specific demands of applications that benefit from flexible housings, such as for shaping to fit body parts or cavities for surgical lighting applications, shaping to fit objects, shaping to fit unusual spaces, or the like. In flexible embodiments it may be advantageous to use thin-form batteries, such as polymer or “paper” batteries for small bands 6750 or strings 6754. Referring to FIG. 68, an array 6800 can be formed from a flexible string 6754, such as a string of string light nodes as described in connection with FIGS. 56 through 59 and in documents incorporated herein by reference. While such an array 6800 can be flexible, once positioned, the array can be used to display similar effects to a rigid grid, such as one disposed on a circuit board as described in connection with FIGS. 64 through 66. For example, an array 6800 can be strung on the outside of the building, such as by clipping flexible strings of nodes in rows and/or columns, or by stringing nodes in channels to create a linear arrangement. Such an array can be used, for example, to display effects that are designed to run on large arrays, including color-changing shows, graphical effects, animation effects, video-type effects, scrolling text effects, and others. Referring to FIG. 69a, it is desirable to provide a light system manager 5000 to manage control of a plurality of lighting units 100 or light systems. Referring to FIG. 69b, the light system manager 5000 is provided, which may consist of a combination of hardware and software components. Included is a mapping facility 5002 for mapping the locations of a plurality of light systems. The mapping facility may use various techniques for discovering and mapping the locations of lights, such as described herein or as known to those of skill in the art. Locations may be physical locations in the world or may be relative locations, such as the relative position of a lighting unit 100 in a string or array of lighting units 100. Also provided is a light system composer 5004 for composing one or more lighting shows that can be displayed on a light system. The authoring of the shows may be based on geometry and an object-oriented programming approach, such as the geometry of the light systems that are discovered and mapped using the mapping facility, according to various methods and systems disclosed herein and in the documents incorporated herein by reference or known in the art. Also provided is a light system engine, for playing lighting shows by executing code for lighting shows and delivering lighting control signals, such as to one or more lighting systems, or to related systems, such as power/data systems, that govern lighting systems. Further details of the light system manager 5000, mapping facility 5002, light system composer 5004 and light system engine 5008 are provided herein. The light system manager 5000, mapping facility 5002, light system composer 5004 and light system engine 5008 may be provided through a combination of computer hardware, telecommunications hardware and computer software components. The different components may be provided on a single computer system or distributed among separate computer systems. Referring to FIG. 70, in an embodiment, the mapping facility 5002 and the light system composer 5004 are provided on an authoring computer 5010. The authoring computer 5010 may be a conventional computer, such as a personal computer. In embodiments the authoring computer 5010 includes conventional personal computer components, such as a graphical user interface, keyboard, operating system, memory, and communications capability. In embodiments the authoring computer 5010 operates with a development environment with a graphical user interface, such as a Windows environment. The authoring computer 5010 may be connected to a network, such as by any conventional communications connection, such as a wire, data connection, wireless connection, network card, bus, Ethernet connection, Firewire, 802.11 facility, Bluetooth, or other connection. In embodiments, such as in FIG. 70, the authoring computer 5010 is provided with an Ethernet connection, such as via an Ethernet switch 5102, so that it can communicate with other Ethernet-based devices, optionally including the light system engine 5008, a light system itself (enabled for receiving instructions from the authoring computer 5010), or a power/data supply (PDS) 1758 that supplies power and/or data to a light system comprised of one or more lighting units 100. For example the light system might be a tile light 500 or board 204 with an array 2208, with a plurality of lighting units 100 arranged in a grid pattern. The mapping facility 5002 and the light system composer 5004 may comprise software applications running on the authoring computer 5010. Referring still to FIG. 70, in an architecture for delivering control systems for complex shows to one or more light systems, shows that are composed using the authoring computer 5010 are delivered via an Ethernet connection through one or more Ethernet switches to the light system engine 5008. The light system engine 5008 downloads the shows composed by the light system composer 5004 and plays them, generating lighting control signals for light systems. In embodiments, the lighting control signals are relayed by an Ethernet switch to one or more power/data supplies and are in turn relayed to light systems that are equipped to execute the instructions, such as by turning LEDs on or off, controlling their color or color temperature, changing their hue, intensity, or saturation, or the like. In embodiments the power/data supply may be programmed to receive lighting shows directly from the light system composer 5004. In embodiments a bridge may be programmed to convert signals from the format of the light system engine 5008 to a conventional format, such as DMX or DALI signals used for entertainment lighting. The light system composer 5004 can employ the graphical representation and object-oriented authoring techniques described in connection with FIGS. 24 through 33 above. Thus, graphical representations, including those that represent video signals, can thus be converted to control instructions, where the lighting control signals map locations of lighting units 100 to corresponding locations in the graphical representation. In the case of a graphical representation of an incoming video signal, the row/column format of a conventional video signal can be mapped to the format of a group of lighting units 100, such as units disposed in a tile light 500 or array 2208 on a board 204. Thus, a tile light 500 or array 2208 can be used to display video effects in various resolutions, as well as other animated effects, graphics, scrolling text effects, and a wide variety of color-changing effects. Referring to FIG. 71, in embodiments the lighting shows composed using the light system composer 5004 are compiled into simple scripts that are embodied as XML documents. The XML documents can be transmitted rapidly over Ethernet connections. In embodiments, the XML documents are read by an XML parser of the light system engine 5008. Using XML documents to transmit lighting shows allows the combination of lighting shows with other types of programming instructions. For example, an XML document type definition may include not only XML instructions for a lighting show to be executed through the light system engine 5008, but also XML with instructions for another computer system, such as a sound system, and entertainment system, a multimedia system, a video system, an audio system, a sound-effect system, a smoke effect system, a vapor effect system, a dry-ice effect system, another lighting system, a security system, an information system, a sensor-feedback system, a sensor system, a browser, a network, a server, a wireless computer system, a building information technology system, or a communication system. Thus, methods and systems provided herein include providing a light system engine for relaying control signals to a plurality of light systems, wherein the light system engine plays back shows. The light system engine 5008 may include a processor, a data facility, an operating system and a communication facility. The light system engine 5008 may be configured to communicate with a DALI or DMX lighting control facility. In embodiments, the light system engine communicates with a lighting control facility that operates with a serial communication protocol. In embodiments the lighting control facility is a power/data supply for a lighting unit 102. In embodiments, the light system engine 5008 executes lighting shows downloaded from the light system composer 5004. In embodiments the shows are delivered as XML files from the light system composer 5004 to the light system engine 5008. In embodiment the shows are delivered to the light system engine over a network. In embodiments the shows are delivered over an Ethernet facility. In embodiments the shows are delivered over a wireless facility. In embodiments the shows are delivered over a Firewire facility. In embodiments shows are delivered over the Internet. In embodiments lighting shows composed by the light system composer 5004 can be combined with other files from another computer system, such as one that includes an XML parser that parses an XML document output by the light system composer 5004 along with XML elements relevant to the other computer. In embodiments lighting shows are combined by adding additional elements to an XML file that contains a lighting show. In embodiments the other computer system comprises a browser and the user of the browser can edit the XML file using the browser to edit the lighting show generated by the lighting show composer. In embodiments the light system engine 5008 includes a server, wherein the server is capable of receiving data over the Internet. In embodiments the light system engine 5008 is capable of handling multiple zones of light systems, wherein each zone of light systems has a distinct mapping. In embodiments the multiple zones are synchronized using the internal clock of the light system engine 5008. The methods and systems included herein include methods and systems for providing a mapping facility 5002 of the light system manager 5000 for mapping locations of a plurality of light systems. In embodiments, the mapping system discovers lighting systems in an environment, using techniques described above. In embodiments, the mapping facility then maps light systems in a two-dimensional space, such as using a graphical user interface. In embodiments of the invention, the light system engine 5008 comprises a personal computer with a Linux operating system. In embodiments the light system engine is associated with a bridge to a DMX or DALI system. An embodiment of the DirectLight API described above follows on the subsequent pages. ps A Programming Interface for Controlling Lighting Important Items You Should Read First. 1) The sample program and Real Light Setup won't run until you register the DirectLight.dll COM object with Windows on your computer. Two small programs cleverly named “Register DirectLight.exe” and “Unregister DirectLight.exe” have been included with this install. 2) DirectLight assumes that you have a SmartJack hooked up to COM1. You can change this assumption by editing the DMX_INTERFACE_NUM value in the file “my_lights.h.” About DirectLight Organization An application (for example, a 3D rendered game) can create virtual lights within its 3D world. DirectLight can map these lights onto real-world digital lights with color and brightness settings corresponding to the location and color of the virtual lights within the game. In DirectLights three general types of virtual lights exist: Dynamic light. The most common form of virtual light has a position and a color value. This light can be moved and it's color changed as often as necessary. Dynamic lights could represent glowing space nebulae, rocket flares, a yellow spotlight flying past a corporate logo, or the bright red eyes of a ravenous mutant ice-weasel. Ambient light is stationary and has only color value. The sun, an overhead room light, or a general color wash are examples of ambient. Although you can have as many dynamic and indicator lights as you want, you can only have one ambient light source (which amounts to an ambient color value). Indicator lights can only be assigned to specific real-world lights. While dynamic lights can change position and henceforth will affect different real-world lights, and ambient lights are a constant color which can effect any or all real-world lights, indicator lights will always only effect a single real-world light. Indicators are intended to give feedback to the user separate from lighting, e.g. shield status, threat location, etc. All these lights allow their color to be changed as often as necessary. In general, the user will set up the real-world lights. The “my_lights.h” configuration file is created in, and can be edited by, the “DirectLight GUI Setup” program. The API loads the settings from the “my_lights.h” file, which contains all information on where the real-world lights are, what type they are, and which sort of virtual lights (dynamic, ambient, indicator, or some combination) are going to affect them. Virtual lights can be created and static, or created at run time dynamically. DirectLights runs in it's own thread; constantly poking new values into the lights to make sure they don't fall asleep. After updating your virtual lights you send them to the real-world lights with a single function call. DirectLights handles all the mapping from virtual world to real world. If your application already uses 3D light sources, implementing DirectLight can be very easy, as your light sources can be mapped 1:1 onto the Virtual_Light class. A typical setup for action games has one overhead light set to primarily ambient, lights to the back, side and around the monitor set primarily to dynamic, and perhaps some small lights near the screen set to indicators. The ambient light creates a mood and atmosphere. The dynamic lights around the player give feedback on things happening around him: weapons, environment objects, explosions, etc. The indicator lights give instant feedback on game parameters: shield level, danger, detection, etc. Effects (LightingFX) can be attached to lights which override or enhance the dynamic lighting. In Star Trek: Armada, for example, hitting Red Alert causes every light in the space to pulse red, replacing temporarily any other color information the lights have. Other effects can augment. Explosion effects, for example, can be attached to a single virtual light and will play out over time, so rather than have to continuously tweak values to make the fireball fade, virtual lights can be created, an effect attached and started, and the light can be left alone until the effect is done. Real lights have a coordinate system based on the space they are installed in. Using a person sitting at a computer monitor as a reference, their head should be considered the origin. X increases to their right. Y increases towards the ceiling. Z increases towards the monitor. Virtual lights are free to use any coordinate system at all. There are several different modes to map virtual lights onto real lights. Having the virtual light coordinate system axis-aligned with the real light coordinate system can make your life much easier. Light positions can take on any real values. The DirectLight GUI setup program restricts the lights to within 1 meter of the center of the space, but you can change the values by hand to your heart's content if you like. Read about the Projection Types first, though. Some modes require that the real world and virtual world coordinate systems have the same scale. Getting Started Installing DirectLight SDK Running the Setup.exe file will install: In /Windows/System/ three dll files, one for DirectLight, two for low-level communications with the real-world lights via DMX. DirectLight.dll DMXIO.dll DLPORTIO.dll In the folder you installed DirectLight in: Visual C++ project files, source code and header files: DirectLight.dsp DirectLight.dsw etc. DirectLight.h DirectLight.cpp Real_Light.h Real_Light.cpp Virtual_Light.h Virtual_Light.cpp etc. compile time libraries: FX_Library.lib DirectLight.lib DMXIO.lib and configuration files: my_lights.h light_definitions.h GUI_config_file.h Dynamic_Localized_Strings.h The “my_lights.h” file is referenced both by DirectLight and DirectLight GUI Setup.exe. “my_lights.h” in turn references “light_definitions.h” The other files are referenced only by DirectLight GUI Setup. Both the DLL and the Setup program use a registry entry to find these files: HKEY_LOCAL_MACHINE\Software\ColorKinetics\DirectLight\1.00.000\location Also included in this directory is this documentation, and subfolders: FX_Libraries contain lighting effects which can be accessed by DirectLights. Real Light Setup contains a graphical editor for changing info about the real lights. Sample Program contains a copiously commented program demonstrating how to use DirectLight. DirectLight COM The DirectLight DLL implements a COM object which encapsulates the DirectLight functionality. The DirectLight object possesses the DirectLight interface, which is used by the client program. In order to use the DirectLight COM object, the machine on which you will use the object must have the DirectLight COM server registered (see above: Important Stuff You Should Read First). If you have not done this, the Microsoft COM runtime library will not know where to find your COM server (essentially, it needs the path of DirectLight.dll). To access the DirectLight COM object from a program (we'll call it a client), you must first include “directlight.h” , which contains the definition of the DirectLight COM interface (among other things) and “direct light_i.c”, which contains the definitions of the various UIDs of the objects and interfaces (more on this later). Before you can use any COM services, you must first initialize the COM runtime. To do this, call the CoInitialize function with a NULL parameter: CoInitialize(NULL); For our purposes, you don't need to concern yourself with the return value. Next, you must instantiate a DirectLight object. To do this, you need to call the CoCreateInstance function. This will create an instance of a DirectLight object, and will provide a pointer to the DirectLight interface: HRESULT hCOMError = CoCreateInstance( CLSID_CDirectLight, NULL, CLSCTX_ALL , IID_IDirectLight, (void **)&pDirectLight); CLSID_CDirectLight is the identifier (declared in directlight_i.c) of the DirectLight object, IID_IDirectLight is the identifier of the DirectLight interface, and pDirectLight is a pointer to the implementation of the DirectLight interface on the object we just instantiated. The pDirectLight pointer will be used by the rest of the client to access the DirectLights functionality. Any error returned by CoCreateInstance will most likely be REGDB_E_CLASSNOTREG, which indicates that the class isn't registered on your machine. If that's the case, ensure that you ran the Register DirectLight program, and try again. When you're cleaning up your app, you should include the following three lines: // kill the COM object pDirectLight->Release( ); // We ask COM to unload any unused COM Servers. CoFreeUnusedLibraries( ); // We're exiting this app so shut down the COM Library. CoUninitialize( ); You should release the COM interface when you are done using it. Failure to do so will result in the object remaining in memory after the termination of your application. CoFreeUnusedLibraries( ) will ask COM to remove our DirectLight factory (a server that created the COM object when we called CoCreateInstance( )) from memory, and CoUninitialize( ) will shut down the COM library. DirectLight Class The DirectLight class contains the core functionality of the API. It contains functionality for setting ambient light values, global brightness of all the lights (gamma), and adding and removing virtual lights. Types: enum Projection_Type{ SCALE_BY_VIRTUAL_DISTANCE_TO— CAMERA_ONLY = 0, SCALE_BY_DISTANCE_AND_ANGLE = 1, SCALE_BY_DISTANCE_VIRTUAL_TO_REAL = 2 }; For an explanation of these values, see “Projection Types” in Direct Light Class enum Light_Type{ C_75 = 0, COVE_6 = 1 }; For an explanation of these values, see “Light Types” in Direct Light Class, or look at the online help for “DirectLight GUI Setup.” enum Curve_Type{ DIRECTLIGHT_LINEAR = 0, DIRECTLIGHT_EXPONENTIAL = 1, DIRECTLIGHT_LOGARITHMIC = 2 }; These values represent different curves for lighting effects when fading from one color to another. Public Member Functions: void Set_Ambient_Light( int R, int G, int B ); The Set_Ambient_Light function sets the red, green and blue values of the ambient light to the values passed into the function. These values are in the range 0-MAX_LIGHT_BRIGHTNESS. The Ambient light is designed to represent constant or “Room Lights” in the application. Ambient Light can be sent to any or all real of the real-world lights. Each real world light can include any percentage of the ambient light. void Stir_Lights( void *user_data ); Stir_Lights sends light information to the real world lights based on the light buffer created within DirectLights. The DirectLight DLL handles stirring the lights for you. This function is normally not called by the application Virtual_Light * Submit_Virtual_Light( float xpos, float ypos, float zpos, int red, int green, int blue ); Submit_Virtual_Light creates a Virtual_Light instance. Its virtual position is specified by the first three values passed in, it's color by the second three. The position should use application space coordinates. The values for the color are in the range 0-MAX_LIGHT_BRIGHTNESS. This function returns a pointer to the light created. void Remove_Virtual_Light( Virtual_Light * bad_light ); Given a pointer to a Virtual_Light instance, Remove_Virtual_Light will delete the virtual light. void Set_Gamma( float gamma ); The Set_Gamma function sets the gamma value of the Direct Light data structure. This value can be used to control the overall value of all the lights, as every virtual light is multiplied by the gamma value before it is projected onto the real lights. void Set_Cutoff_Range( float cutoff_range ); Set_Cutoff_Range sets the cutoff distance from the camera. Beyond this distance virtual lights will have no effect on real-world lights. Set the value high to allow virtual lights to affect real world lights from a long way away. If the value is small virtual lights must be close to the camera to have any effect. The value should be in application space coordinates. void Clear_All_Real_Lights( void ); Clear_All_Lights destroys all real lights. void Project_All_Lights( void ); Project_All_Lights calculates the effect of every virtual on every real-world light, taking into account gamma, ambient and dynamic contributions, position and projection mode, cutoff angle and cutoff range, and sends the values to every real-world light. void Set Indicator Color( int which indicator, int red, int green, int blue ); Indicators can be assigned to any of the real world lights via the configuration file(my_lights.h). Each indicator must have a unique non-negative integer ID. Set_Indicator_Color changes the color of the indicator designated by which_indicator to the red, green, and blue values specified. If Set_Indicator_Color is called with an indicator id which does not exist, nothing will happen. The user specifies which lights should be indicators, but note that lights that are indicators can still be effected by the ambient and dynamic lights. Indicator Get Indicator( int which indicator ); Returns a pointer to the indicator with the specified value. int Get_Real_Light_Count( void ); Returns the number of real lights. void Get_My_Lights_Location( char buffer[MAX_PATH] ); Looks in the directory and finds the path to the “my_lights.h” file. void Load_Real_Light_Configuration( char * fullpath = NULL ); Loads the “my_lights.h” file from the default location determined by the registry. DirectLight will create a list of real lights based on the information in the file. void Submit_Real_Light( char * indentifier, int DMX_port, Projection_Type projection_type, int indicator_number, float add_ambient, float add_dynamic, float gamma, float cutoff_angle, float x, float y, float z ); Creates a new real light in the real world. Typically DirectLight will load the real light information from the “my_lights.h” file at startup. void Remove_Real_Light( Real_Light * dead_light ); Safely deletes an instance of a real light. Light GetAmbientLight ( void ); Returns a pointer to the ambient light. bool RealLightListEmpty ( void ); Returns true if the list of real lights is empty, false otherwise. Light Class Ambient lights are defined as lights. Light class is the parent class for Virtual Lights and Real Lights. Member variables: static const int MAX_LIGHT_BRIGHTNESS. Defined as 255 LightingFX_List*m FX_currently_attached. A list of the effects currently attached to this light. ColorRGB m_color. Every light must have a color! ColorRGB is defined in ColorRGB.h void Attach_FX( LightingFX * new_FX ) Attach a new lighting effect to this virtual light. void Detach_FX( LightingFX * old_FX ) Detach an old lighting effect from this virtual light. Real Lights Real Light inherits from the Light class. Real lights represent lights in the real world. Member variables: static const int NOT_AN_INDICATOR_LIGHT defined as −1. char m_identifier[100] is the name of the light (like “overhead” or “covelight1”). Unused by DirectLight except as a debugging tool. int DMX_port is a unique non-negative integer representing the channel the given light will receive information on. DMX information is sent out in a buffer with 3 bytes (red, green and blue ) for each light. (DMX_port*3) is actually the index of the red value for the specified light. DirectLight DMX buffers are 512 bytes, so DirectLight can support approximately 170 lights. Large buffers can cause performance problems, so if possible avoid using large DMX_port numbers. Light_Type m_type describes the different models of Color Kinetics lights. Currently unused except by DirectLight GUI Setup to display icons. float m_add_ambient the amount of ambient light contribution to this lights color. Range 0-1 float m_add_dynamic the amount of dynamic light contribution to this lights color. Range 0-1 float m_gamma is the overall brightness of this light. Range 0-1. float m_cutoff_angle determines how sensitive the light is to the contribtions of the virtual lights around it. Large values cause it to receive information from most vitual lights. Smaller values cause it to receive contributions only from virtual lights in the same arc as the real light. Projection_Type m_projection_type defines how the virtual lights map onto the real lights. SCALE_BY_VIRTUAL_DISTANCE_TO_CAMERA_ONLY this real light will receive contributions from virtual lights based soley on the distance from the origin of the virtual coordinate system to the position of the virtual light. The virtual light contribution fades linearly as the distance from the origin approaches the cutoff range. SCALE_BY_DISTANCE_AND_ANGLE this real light will receive contributions from virtual lights based on the distance as computed above AND the difference in angle between the real light and the virtual light. The virtual light contribution fades linearly as the distance from the origin approaches the cutoff range and the angle approaches the cutoff angle. SCALE_BY_DISTANCE_VIRTUAL_TO_REAL this real light will receive contributions from virtual lights based on the distance in 3-space from real light to virtual light. This mode assumes that the real and virtual coordinate systems are identical. The virtual light contribution fades linearly as the distance from real to virtual approaches the cutoff range. float m_xpos x,y,z position in virtual space. float m_ypos float m_zpos int m_indicator_number. if indicator is negative the light is not an indicator. If it is non-negative it will only receive colors sent to that indicator number. Virtual Lights Virtual Lights represent light sources within a game or other real time application that are mapped onto real-world Color Kinetics lights. Virtual Lights may be created, moved, destroyed, and have their color changed as often as is feasible within the application. static const int MAX_LIGHT_BRIGHTNESS; MAX_LIGHT_BRIGHTNESS is a constant representing the largest value a light can have. In the case of most Color Kinetics lights this value is 255. Lights are assumed to have a range that starts at 0 void Set_Color( int R, int G, int B ); The Set_Color function sets the red, green and blue color values of the virtual light to the values passed into the function. void Set_Position( float x_pos, float y_pos, float z_pos ); The Set_Position function sets the position values of the virtual light to the values passed into the function. The position should use application space coordinates. void Get_Position( float *x_pos, float *y_pos, float *z_pos ); Gets the position of the light. Lighting FX Lighting FX are time-based effects which can be attached to real or virtual lights, or indicators, or even the ambient light. Lighting effects can have other effects as children, in which case the children are played sequentially. static const int FX_OFF; Defined as −1. static const int START_TIME; Times to start and stop the effect. This is a virtual value. The static const int STOP_TIME; individual effects will scale their time of play based on the total. void Set_Real_Time( bool Real_Time ); If TRUE is passed in, this effect will use real world time and update itself as often as Stir _Lights is called. If FALSE is passed in the effect will use application time, and update every time Apply-FX is called. void Set_Time_Extrapolation ( bool extrapolate ); If TRUE is passed in, this effect will extrapolate it's value when Stir_Lights is called. void Attach_FX_To_Light ( Light * the_light ); Attach this effect to the light passed in. void Detach_FX_From_Light (Light * the_light, bool remove_FX_from_light = true ); Remove this effect's contribution to the light. If remove_FX_from_light is true, the effect is also detached from the light. The above functions also exist as versions to effect Virtual lights, Indicator lights (referenced either by a pointer to the indicator or it's number), Ambient light, and all Real Lights. void Start ( float FX_play_time, bool looping = false ); Start the effect. If looping is true the effect will start again after it ends. void Stop ( void ); Stop the effect without destroying it. void Time_Is_Up ( void ); Either loop or stop playing the effect, since time it up for it. void Update_Time ( float time_passed ); Change how much game time has gone by for this effect. void Update_Real_Time ( void ); Find out how much real time has passed for this effect. void Update_Extrapolated_Time ( void ); Change the FX time based on extrapolating how much application time per real time we have had so far. virtual void Apply_FX ( ColorRGB &base_color ); This is the principle lighting function. When Lighting_FX is inherited, this function does all the important work of actually changing the light's color values over time. Note that you can choose to add your value to the existing light value, replace the existing value with your value, or any combination of the two. This way Lighting effects can override the existing lights or simply supplant them. static void Update_All_FX_Time ( float time_passed ); Update the time of all the effects. void Apply_FX_To_All_Virtual_Lights ( void ); Apply this effect to all virtual, ambient and indicator lights that are appropriate. void Apply_All_FX_To_All_Virtual_Lights ( void ); Apply each effect to all virtual, ambient and indicator lights that are appropriate. void Apply_All_FX_To _Real_Light ( Real_Light * the_real_light ); Apply this effect to a single real light. void Start_Next_ChildFX ( void ); If this effect has child effect, start the next one. void Add_ChildFX ( LightingFX * the_child, float timeshare ); Add a new child effect onto the end of the list of child effects that this effect has. Timeshare is this child's share of the total time the effect will play. The timeshares don't have to add up to one, as the total shares are scaled to match the total real play time of the effect void Become_Child_Of ( Lighting_FX * the_parent ); Become a parent of the specified effect. void Inherit_Light_List ( Affected_Lights * our_lights ); Have this effect and all it's children inherit the list of lights to affect. Configuration File The file “my_lights.h” contains information about real-world lights, and is loaded into the DirectLight system at startup. The files “my_lights.h” and “light_definitions.h” must be included in the same directory as the application using DirectLights. “my_lights.h” is created and edited by the DirectLight GUI Setup program. For more information on how to use the program check the online help within the program. Here is an example of a “my_lights.h” file: //////////////////////////////////////////////////////////// // // my_lights.h // // Configuration file for Color Kinetics lights // used by DirectLights // // This file created with DirectLights GUI Setup v1.0 // //////////////////////////////////////////////////////////// // Load up the basic structures #include “Light_Definitions.h” // overall gamma float OVERALL_GAMMA = 1.0; // which DMX interface do we use? int DMX_INTERFACE_NUM = 0; //////////////////////////////////////////////////////////// // // This is a list of all the real lights in the world // Real_Light my_lights[MAX_LIGHTS] = { //NAME PORT TYPE PRJ IND AMB DYN GAMMA CUTOFF X Y Z “Overhead”, 0, 1, 0, −1, 1.000, 0.400, 1.000, 3.142, 0.000, −1.000, 0.000, “Left”, 1, 0, 1, −1, 0.000, 1.000, 1.000, 1.680, −1.000, 0.000, 0.000, “Right”, 2, 0, 1, −1, 0.000, 1.000, 0.800, 1.680, 1.000, 0.000, 0.000, “Back”, 3, 0, 1, −1, 0.000, 1.000, 1.000, 1.680, 0.000, 0.000, −1.000, “LeftCove0”, 4, 0, 1, 0, 0.000, 0.000, 1.000, 0.840, −0.500, −0.300, 0.500, “LeftCove1”, 5, 0, 1, 1, 0.000, 0.000, 1.000, 0.840, −0.500, 0.100, 0.500, “LeftCove2”, 6, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, −0.500, 0.500, 0.500, “CenterCove0”, 7, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, −0.400, 0.700, 0.500, “CenterCove1”, 8, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, −0.200, 0.700, 0.500, “CenterCove2”, 9, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, 0.200, 0.700, 0.500, “CenterCove3”, 10, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, 0.400, 0.700, 0.500, “RightCove0”, 11, 0, 1, 2, 0.000, 0.000, 1.000, 0.840, 0.500, 0.500, 0.500, “RightCove1”, 12, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, 0.500, 0.100, 0.500, “RightCove2”, 13, 0, 1, −1, 0.000, 0.000, 1.000, 0.840, 0.500, −0.300, 0.500, }; This example file is taken from our offices, where we had lights setup around a computer, with the following lights (referenced from someone sitting at the monitor): One overhead (mostly ambient); one on each side of our head (Left and Right); one behind our head; Three each along the top, left and right side of the monitor in front of us. Each line in the “my_lights” file represents one Real_Light. Each Real_Light instance represents, surprise surprise, one real-world light. The lower lights on the left and right side of the monitor are indicators 0 and 2, the middle light on the left side of the monitor is indicator 1. The positional values are in meters. Z is into/out of the plane of the monitor. X is vertical in the plane of the monitor, Y is horizontal in the plane of the monitor. MAX_LIGHTS can be as high as 170 for each DMX universe. Each DMX universe is usually a single physical connection to the computer (COM1, for example). The larger MAX_LIGHTS is, the slower the lights will respond, as MAX_LIGHTS determines the size of the buffer sent to DMX (MAX_LIGHTS*3) Obviously, larger buffers will take longer to send. OVERALL_GAMMA can have a value of 0-1. This value is read into DirectLights and can be changed during run-time. This represents the end of the DirectLight API. While the invention has been disclosed in connection with the embodiments shown and described above, various equivalents, modifications and improvements will be apparent to one of ordinary skill in the art and are encompassed herein. | <SOH> BACKGROUND <EOH>LED-based lighting methods and systems are known, including those developed and marketed by Color Kinetics Incorporated and those disclosed in the patents, patent applications and other documents incorporated by reference herein. A need exists for improved lighting fixtures that take full advantage of the inventive aspects of LED-based illumination methods and systems, including lighting fixtures with particular forms, including lighting fixtures that take the form of tiles. | <SOH> SUMMARY <EOH>The methods and systems disclosed herein include those for providing a tile lighting system that may comprise a lighting system configured in a two-dimensional shape, such as a square, rectangle, circle, polygon, or other shape. Methods and systems are disclosed herein for controlling light output from such a tile light, for mechanically constructing a tile light to provide optimal light output, for connecting tile lights to each other to facilitate addressing and controlling such tile lights, for authoring effects to be presented with such a tile light, for supplying power and data to such a tile light, and other aspects. Methods and systems disclosed herein also encompass three-dimensional lights that comprise combinations of flat circuit boards of simple geometries. For example, a substantially spherical lighting unit can be formed from circuit boards of simple polygons, such as triangles, hexagons or pentagons. Similarly, a pyramidal lighting unit can be formed of triangular lighting units. Such three-dimensional lighting units can be addressed, powered, and controlled in the manner described for other lighting units herein, and effects for such lighting units can be authored using methods and systems described herein. The methods and systems disclosed herein may further comprise control protocols, which may include disposing a plurality of lighting units in a serial configuration and controlling all of them by a stream of data to respective ASICs (Application Specific Integrated Circuits) of each of them, wherein each lighting system responds to the first unmodified bit of data in the stream, modifies that bit of data, and transmits the stream to the next ASIC. This protocol is described herein in some cases as a “string light” protocol or as a Chromasic protocol, such as that offered by Color Kinetics Incorporated and described in the patent applications incorporated herein by reference. The methods and systems may further include providing a communication facility of the lighting system, wherein the lighting system responds to data from a source exterior to the lighting system. The data may come from a signal source exterior to the lighting system. The signal source may be a wireless signal source. In embodiments the signal source includes a sensor for sensing an environmental condition, and the control of the lighting system is in response to the environmental condition. In embodiments the signal source generates a signal based on a scripted lighting program for the lighting system. In embodiments the control of the lighting system is based on assignment of lighting system units as objects in an object-oriented computer program. In embodiments the computer program is an authoring system. In embodiments the authoring system relates attributes in a virtual system to real world attributes of lighting systems. In embodiments the real world attributes include positions of lighting units of the lighting system. In embodiments the computer program is a computer game. In other embodiments the computer program is a music program. In embodiments of the methods and systems provided herein, the lighting system includes a power supply. In embodiments the power supply is a power-factor-controlled power supply. In embodiments the power supply is a two-stage power supply. In embodiments the power factor correction includes an energy storage capacitor and a DC-DC converter. In embodiments the PFC and energy storage capacitor are separated from the DC-DC converter by a bus. In embodiments of the methods and systems provided herein, the lighting systems further include disposing at least one such lighting unit in or on a building. In embodiments the lighting units are disposed in an array on a building. In embodiments the array is configured to facilitate displaying at least one of a number, a word, a letter, a logo, a brand, and a symbol. In embodiments the array is configured to display a light show with time-based effects. Methods and systems disclosed herein include methods and systems for providing a tile lighting system. The tile lighting system may include a plurality of addressable lighting units disposed in a grid, a controller for controlling the illumination from the addressable lighting units and a light diffusing cover for covering the grid. In embodiments the light diffusing cover may include a phosphorescent material. In embodiments the light diffusing cover is substantially translucent. In embodiments the light diffusing cover is provided with a geometric shape. In embodiments the light diffusing cover is provided with an irregular pattern. In embodiments the lighting system is configured to be disposed in proximity to similar lighting systems in a tile arrangement. In embodiments the lighting units are controlled using a string light protocol. In embodiments the light system may further include an authoring system for authoring effects on the tile lighting system. In embodiments lighting system is capable of coordinating effects with another similar lighting system. In embodiments the lighting system is disposed in an architectural environment. In embodiments the lighting system is disposed on a building exterior. Methods and systems described herein include providing a tile light that includes a plurality of LED lighting units disposed on a circuit board in an array, wherein the LED lighting units respond to control signals to produce mixed light of varying colors and a diffuser for receiving light from the lighting units. In embodiments the light diffusing cover may include a phosphorescent material. In embodiments the light diffusing cover is substantially translucent. In embodiments the light diffusing cover is provided with a geometric shape. In embodiments the light diffusing cover is provided with an irregular pattern. In embodiments the methods and systems may include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems described herein include providing a tile light that includes a plurality of linear LED lighting units disposed about the perimeter of a substantially rectangular housing and a diffuser for diffusing light from the lighting units. In embodiments the diffuser may include a phosphorescent material, may be substantially translucent, may be provided with a geometric shape or may be provided with an irregular pattern. In embodiments the methods and systems include a reflector in the housing for providing a consistent level of light output to different portions of the diffuser. In embodiments to divided into a plurality of cells. In embodiments the cells are rectangular. In embodiments the cells are triangular. In embodiments the methods and systems include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems described herein include lighting systems that include a series of LED-based lighting units, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol, wherein the series of lighting units is configured in a flexible string and a fastening facility for holding the flexible string in a predetermined configuration. In embodiments the fastening facility is a substantially linear channel for holding the flexible string. In embodiments the fastening facility holds the flexible string in an array. In embodiments the methods and systems include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems disclosed herein include a modular component for a lighting system that includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. The methods and systems may further include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the circuit board is a flexible circuit board. In embodiments the circuit board is a printed circuit board. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Methods and systems disclosed herein include methods and systems for providing a lighting system that includes a plurality of modular components, wherein each modular component includes a series of LED-based lighting units disposed in an array on a circuit board, wherein each lighting unit is configured respond to data addressed to it in a serial addressing protocol. In embodiments the modular components are disposed adjacent to each other to form a large array of modular components. The methods and systems may further include an authoring system for authoring effects for the lighting system. In embodiments the authoring system is an object-oriented authoring facility. In embodiments an effect displayed on the large array corresponds to a graphical representation of the authoring facility. In embodiments an effect displayed on the array corresponds to an incoming video signal. In embodiments the array is disposed in an architectural environment. In embodiments the array is disposed on a building exterior. Method and systems disclosed herein include controlled, networked or non-networked illumination devices. The fundamental building blocks include semiconductor-based illumination devices such as light-emitting diodes (LEDs) that are used to illuminate surfaces. Included are system and methods for creating surfaces that can provide patterns of color and color changing capability at a variety of scales. The devices, in many embodiments, can be incorporated into any 2D or 3D surface. In embodiments, the illuminated surfaces include geometries to maximize light output, homogenize and diffuse light output, and to shape light output. The viewed surfaces incorporate textures and 2D or 3D forms to guide and direct light towards the viewer. A variety of fastening methods are also described to mount and connect devices onto or into surfaces. As used herein for purposes of the present disclosure, the term “LED” should be understood to include any light emitting diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, light-emitting strips, electro-luminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured to generate radiation having various bandwidths for a given spectrum (e.g., narrow bandwidth, broad bandwidth). It should be noted that LED(S) in systems according to the present invention might be any color including white, ultraviolet, infrared or other colors within the electromagnetic spectrum. As used herein, the term “LED” should be further understood to include, without limitation, light emitting diodes of all types, light emitting polymers, semiconductor dies that produce light in response to current, organic LEDs, electro-luminescent strips, and other such systems. In an embodiment, an “LED” may refer to a single light emitting diode having multiple semiconductor dies that are individually controlled. It should also be understood that the term “LED” does not restrict the package type of the LED. The term “LED” includes packaged LEDs, non-packaged LEDs, surface mount LEDs, chip on board LEDs and LEDs of all other configurations. The term “LED” also includes LEDs packaged or associated with material (e.g. a phosphor) wherein the material may convert energy from the LED to a different wavelength. For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectrums of luminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts luminescence having a first spectrum to a different second spectrum. In one example of this implementation, luminescence having a relatively short wavelength and narrow bandwidth spectrum “pumps” the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum. It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectrums of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc. The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources as defined above, incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of luminescent sources, electro-lumiscent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers. A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms “light” and “radiation” are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication and/or illumination. An “illumination source” is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. An LED system is one type of illumination source. As used herein “illumination source” should be understood to include all illumination sources, including LED systems, as well as incandescent sources, including filament lamps, pyro-luminescent sources, such as flames, candle-luminescent sources, such as gas mantles and carbon arch radiation sources, as well as photo-luminescent sources, including gaseous discharges, fluorescent sources, phosphorescence sources, lasers, electro-luminescent sources, such as electro-luminescent lamps, light emitting diodes, and cathode luminescent sources using electronic satiation, as well as miscellaneous luminescent sources including galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, and radioluminescent sources. Illumination sources may also include luminescent polymers capable of producing primary colors. The term “illuminate” should be understood to refer to the production of a frequency of radiation by an illumination source. The term “color” should be understood to refer to any frequency of radiation within a spectrum; that is, a “color,” as used herein, should be understood to encompass frequencies not only of the visible spectrum, but also frequencies in the infrared and ultraviolet areas of the spectrum, and in other areas of the electromagnetic spectrum. The term “spectrum” should be understood to refer to any one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term “spectrum” refers to frequencies (or wavelengths) not only in the visible range, but also frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Also, a given spectrum may have a relatively narrow bandwidth (essentially few frequency or wavelength components) or a relatively wide bandwidth (several frequency or wavelength components having various relative strengths). It should also be appreciated that a given spectrum may be the result of a mixing of two or more other spectrums (e.g., mixing radiation respectively emitted from multiple light sources). For purposes of this disclosure, the term “color” is used interchangeably with the term “spectrum.” However, the term “color” generally is used to refer primarily to a property of radiation that is perceivable by an observer (although this usage is not intended to limit the scope of this term). Accordingly, the terms “different colors” implicitly refer to different spectrums having different wavelength components and/or bandwidths. It also should be appreciated that the term “color” may be used in connection with both white and non-white light. The term “color temperature” generally is used herein in connection with white light, although this usage is not intended to limit the scope of this term. Color temperature essentially refers to a particular color content or shade (e.g., reddish, bluish) of white light. The color temperature of a given radiation sample conventionally is characterized according to the temperature in degrees Kelvin (K) of a black body radiator that radiates essentially the same spectrum as the radiation sample in question. The color temperature of white light generally falls within a range of from approximately 700 degrees K (generally considered the first visible to the human eye) to over 10,000 degrees K. Lower color temperatures generally indicate white light having a more significant red component or a “warmer feel,” while higher color temperatures generally indicate white light having a more significant blue component or a “cooler feel.” By way of example, a wood burning fire has a color temperature of approximately 1,800 degrees K, a conventional incandescent bulb has a color temperature of approximately 2848 degrees K, early morning daylight has a color temperature of approximately 3,000 degrees K, and overcast midday skies have a color temperature of approximately 10,000 degrees K. A color image viewed under white light having a color temperature of approximately 3,000 degree K has a relatively reddish tone, whereas the same color image viewed under white light having a color temperature of approximately 10,000 degrees K has a relatively bluish tone. The terms “lighting unit” and “lighting fixture” are used interchangeably herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An “LED-based lighting unit” refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. The terms “processor” or “controller” are used herein interchangeably to describe various apparatus relating to the operation of one or more light sources. A processor or controller can be implemented in numerous ways, such as with dedicated hardware, using one or more microprocessors that are programmed using software (e.g., microcode or firmware) to perform the various functions discussed herein, or as a combination of dedicated hardware to perform some functions and programmed microprocessors and associated circuitry to perform other functions. Among other things, processor can include an integrated circuit, such as an application specific integrated circuit. In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present invention discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers, including by retrieval of stored sequences of instructions. The term “addressable” is used herein to refer to a device (e.g., a light source in general, a lighting unit or fixture, a controller or processor associated with one or more light sources or lighting units, other non-lighting related devices, etc.) that is configured to receive information (e.g., data) intended for multiple devices, including itself, and to selectively respond to particular information intended for it. The term “addressable” often is used in connection with a networked environment (or a “network,” discussed further below), in which multiple devices are coupled together via some communications medium or media. In one implementation, one or more devices coupled to a network may serve as a controller for one or more other devices coupled to the network (e.g., in a master/slave relationship). In another implementation, a networked environment may include one or more dedicated controllers that are configured to control one or more of the devices coupled to the network. Generally, multiple devices coupled to the network each may have access to data that is present on the communications medium or media; however, a given device may be “addressable” in that it is configured to selectively exchange data with (i.e., receive data from and/or transmit data to) the network, based, for example, on one or more particular identifiers (e.g., “addresses”) assigned to it. In another implementation, devices may be configured to receive data in a certain order or along a certain path, such as by being placed along a line or string. In such an implementation, data may be addressed to a particular lighting unit according to its ordinal position in the string. Thus, the first unit responds to the first packet of data, the second unit responds to the second packet of data, and so on. This may be accomplished, for example, by having each lighting unit modify the packet of data that is addressed to it (such as by placing a “1” in the first position of a byte of data) and by having each lighting unit respond to the first unmodified packet of data. This and other implementations that rely on the ordinal position of the lighting units along a string of lighting units are referred to herein as “string light” protocols. The term “network” as used herein refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transport of information (e.g. for device control, data storage, data exchange, etc.) between any two or more devices and/or among multiple devices coupled to the network. As should be readily appreciated, various implementations of networks suitable for interconnecting multiple devices may include any of a variety of network topologies and employ any of a variety of communication protocols. Additionally, in various networks according to the present invention, any one connection between two devices may represent a dedicated connection between the two systems, or alternatively a non-dedicated connection. In addition to carrying information intended for the two devices, such a non-dedicated connection may carry information not necessarily intended for either of the two devices (e.g., an open network connection). Furthermore, it should be readily appreciated that various networks of devices as discussed herein may employ one or more wireless, wire/cable, and/or fiber optic links to facilitate information transport throughout the network. The lighting systems described herein may also include a user interface used to change and or select the lighting effects displayed by the lighting system. The communication between the user interface and the processor may be accomplished through wired or wireless transmission. The term “user interface” as used herein refers to an interface between a human user or operator and one or more devices that enables communication between the user and the device(s). Examples of user interfaces that may be employed in various implementations of the present invention include, but are not limited to, switches, human-machine interfaces, operator interfaces, potentiometers, buttons, dials, sliders, a mouse, keyboard, keypad, various types of game controllers (e.g., joysticks), track balls, display screens, various types of graphical user interfaces (GUIs), touch screens, microphones and other types of sensors that may receive some form of human-generated stimulus and generate a signal in response thereto. The following patents and patent applications are hereby incorporated herein by reference: U.S. Pat. No. 6,016,038, issued Jan. 18, 2000, entitled “Multicolored LED Lighting Method and Apparatus;” U.S. Pat. No. 6,608,453, issued Aug. 19, 2003, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” U.S. Pat. No. 6,548,967, issued Apr. 15, 2003, entitled “Universal Lighting Network Methods and Systems;” U.S. patent application Ser. No. 09/886,958, filed Jun. 21, 2001, entitled Method and Apparatus for Controlling a Lighting System in Response to an Audio Input;” U.S. patent application Ser. No. 10/078,221, filed Feb. 19, 2002, entitled “Systems and Methods for Programming Illumination Devices;” U.S. patent application Ser. No. 09/344,699, filed Jun. 25, 1999, entitled “Method for Software Driven Generation of Multiple Simultaneous High Speed Pulse Width Modulated Signals;” U.S. patent application Ser. No. 09/805,368, filed Mar. 13, 2001, entitled “Light-Emitting Diode Based Products;” U.S. patent application Ser. No. 09/716,819, filed Nov. 20, 2000, entitled “Systems and Methods for Generating and Modulating Illumination Conditions;” U.S. patent application Ser. No. 09/675,419, filed Sep. 29, 2000, entitled “Systems and Methods for Calibrating Light Output by Light-Emitting Diodes;” U.S. patent application Ser. No. 09/870,418, filed May 30, 2001, entitled “A Method and Apparatus for Authoring and Playing Back Lighting Sequences;” U.S. patent application Ser. No. 09/923,223, filed Aug. 8, 2001, entitled “Ultraviolet Light Emitting Diode Systems and Methods”; U.S. patent application Ser. No. 10/045,604, filed Oct. 23, 2001, entitled “Systems and Methods for Digital Entertainment;” U.S. patent application Ser. No. 09/989,677, filed Nov. 20, 2001, entitled “Information Systems; U.S. patent application Ser. No. 10/045,629, filed Oct. 25, 2001, entitled “Methods and Apparatus for Controlling Illumination;” U.S. patent application Ser. No. 10/158,579, filed May 30, 2002, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” U.S. patent application Ser. No. 10/163,085, filed Jun. 5, 2002, entitled “Systems and Methods for Controlling Programmable Lighting Systems;” U.S. patent application Ser. No. 10/325,635, filed Dec. 19, 2002, entitled “Controlled Lighting Methods and Apparatus;” and U.S. patent application Ser. No. 10/360,594, filed Feb. 6, 2003, entitled “Controlled Lighting Methods and Apparatus.” It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. | 20040421 | 20080415 | 20050602 | 63595.0 | 2 | SHAPIRO, LEONID | TILE LIGHTING METHODS AND SYSTEMS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,829,106 | ACCEPTED | Benzamide 2-hydroxy-3-diaminoalkanes | The present invention relates to compounds of formula (I): useful in treating Alzheimer's disease and other similar diseases. These compounds include inhibitors of the beta-secretase enzyme that are useful in the treatment of Alzheimer's disease and other diseases characterized by deposition of A beta peptide in a mammal. The compounds of the invention are also useful in pharmaceutical compositions and methods of treatment to reduce A beta peptide formation. | 1. A compound of formula (I): or a pharmaceutically acceptable salt or ester thereof, wherein Z is aryl, heteroaryl or heterocyclyl, wherein said groups are optionally substituted with 1 or 2 RB groups, wherein, where RB at each occurrence is independently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, (CH2)0-3(C3-C7 cycloalkyl), aryl, heteroaryl, or heterocyclyl wherein, the alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, heteroaryl, orheterocyclyl groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101; where R100 and R101 are at each occurrence are independently H, C1-C6 alkyl, or phenyl; X is —(C═O)— or —(SO2)—; wherein R1 is C1-C10 alkyl optionally substituted with 1, 2, or 3 groups independently selected from halogen, —OH, ═O, —SH, —CN, —CF3, —OCF3, —C3-7 cycloalkyl, —C1-C4 alkoxy, amino, mono-dialkylamino, aryl, heteroaryl, heterocycloalkyl, wherein each aryl group is optionally substituted with 1, 2 or 3 R50 groups; wherein R50 is selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy and C3-C8 cycloalkyl; wherein the alkyl, alkenyl, alkynyl, alkoxy and cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of C1-C4 alkyl, halogen, OH, —NR5R6, CN, C1-C4 haloalkoxy, NR7R8, and C1-C4 alkoxy; wherein R5 and R6 are independently H or C1-C6 alkyl; or wherein R5 and R6 and the nitrogen to which they are attached form a 5 or 6 membered heterocycloalkyl ring; and wherein R7 and R8 are independently selected from the group consisting of H; —C1-C4 alkyl optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —OH, —NH2, and halogen; —C3-C6 cycloalkyl; —(C1-C4 alkyl)-O—(C1-C4 alkyl); —C2-C4 alkenyl; and —C2-C4 alkynyl; wherein each heteroaryl is optionally substituted with 1 or 2 R50 groups; wherein each heterocycloalkyl group is optionally substituted with 1 or 2 groups that are independently R50 or ═O; R2 and R3 are independently selected from —H; —F; —C1-C6 alkyl optionally substituted with a substituent selected from the group consisting of —F, —OH, —C≡N, —CF3, C1-C3 alkoxy, and —NR5R6; —(CH2)0-2—R17; —(CH2)0-2—R18; —C2-C6 alkenyl or C2-C6 alkynyl, wherein each is optionally substituted with an indepdent substituent selected from the group consisting of —F, —OH, —C≡N, —CF3 and C1-C3 alkoxy; —(CH2)0-2—C3-C7 cycloalkyl, optionally substituted an independent substituent selected from the group consisting of —F, —OH, —C≡N, —CF3, C1-C3 alkoxy and —NR5R6; or R2, R3 and the carbon to which they are attached form a carbocycle of three thru seven carbon atoms, wherein one carbon atom is optionally replaced by a group selected from —O—, —S—, —SO2—, or —NR7—; where R17 at each occurrence is an aryl group selected from phenyl, 1-naphthyl, 2-naphthyl, indanyl, indenyl, dihydronaphthyl and tetralinyl, wherein said aryl groups are optionally substituted with one or two groups that are independently —C1-C3 alkyl; —C1-C4 alkoxy; CF3; or —C2-C6 alkenyl or —C2-C6 alkynyl each of which is optionally substituted with one substituent selected from the group consisting of F, OH, C1-C3 alkoxy; or -halogen; —OH; —C≡N; —C3-C7 cycloalkyl; —CO—(C1-C4 alkyl); —SO2—(Cl-C4 alkyl); where R18 is a heteroaryl group selected from pyridinyl, pyrimidinyl, quinolinyl, indolyl, pryidazinyl, pyrazinyl, isoquinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, imidazolyl, isoxazolyl, oxazolyl, thiazolyl, furanyl, thienyl, pyrrolyl, oxadiazolyl or thiadiazolyl, wherein each of said heteroaryl groups is optionally substituted with one or two groups that are independently —C1-C6 alkyl optionally substituted with one substituent selected from the group consisting of OH, C≡N, CF3, C1-C3 alkoxy, and —NR5R6; R15 is selected from the group consisting of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkoxy C1-C6 alkyl, hydroxy C1-C6 alkyl, halo C1-C6 alkyl, each of which is unsubstituted or substituted with 1, 2, 3, or 4 groups independently selected from halogen, C1-C6 alkyl, hydroxy, C1-C6 alkoxy, NH2, and —R26—R27; wherein R26 is selected from the group consisting of a bond, —C(O)—, —SO2—, —CO2—, —C(O)NR5—, and —NR5C(O)—, wherein R27 is selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, aryl C1-C6 alkyl, heterocycloalkyl, and heteroaryl, wherein each of the above is unsubstituted or substituted with 1, 2, 3, 4, or 5 groups that are independently C1-C4 alkyl, C1-C4 alkoxy, halogen, haloalkyl, hydroxyalkyl, —NR5R6, —C(O)NR5R6; Rc is selected from the group consisting of —(CH2)0-3—(C3-C8) cycloalkyl wherein the cycloalkyl is optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —R205, —CO2—(C1-C4 alkyl), and aryl, wherein aryl is optionally substituted with 1 or 2 independently selected R200 groups; —(CR245R250)0-4-aryl; —(CR245R250)0-4-heteroaryl; —(CR245R250)0-4-heterocycloalkyl; —(CR245R250)0-4-aryl-heteroaryl; —(CR245R250)0-4-aryl-heterocycloalkyl; —(CR245R250)0-4-aryl-aryl; —(CR245R250)0-4-heteroaryl-aryl; —(CR245R250)0-4-heteroaryl-heterocycloalkyl; —(CR245R250)0-4-heteroaryl-heteroaryl; —(CR245R250)0-4-heterocycloalkyl-heteroaryl; —(CR245R250)0-4-heterocycloalkyl-heterocycloalkyl; —(CR245R250)0-4-heterocycloalkyl-aryl; a monocyclic or bicyclic ring of 5, 6, 7 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N(CO)0-1R215, —N(CO)0-1R220, —O, or —S(═O)0-2, and wherein the monocyclic or bicyclic ring is optionally substituted with 1, 2 or 3 groups that are independently —R205, —R245, —R250 or ═O; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; wherein each aryl group attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3 or 4 R200 groups; wherein each heteroaryl group attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3, or 4 R200; wherein each heterocycloalkyl attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3, or 4 R210; wherein R200 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —OH; —NO2; -halogen; —C≡N; —(CH2)0-4—CO—NR220R225; —(CH2)0-4—CO—(C1-C8 alkyl); —(CH2)0-4—CO—(C2-C8 alkenyl); —(CH2)0-4—CO—(C2-C8 alkynyl); —(CH2)0-4—CO—(C3-C7 cycloalkyl); —(CH2)0-4—CO—(CO)0-1-aryl; —(CH2)0-4—CO—(CO)0-1-heteroaryl; —(CH2)0-4—CO—(CO)0-1-heterocycloalkyl; —(CH2)0-4—CO2R215; —(CH2)0-4—SO2—NR220R225; —(CH2)0-4—S(O)0-2—(C1-C8 alkyl); —(CH2)0-4—S(O)0-2—(C3-C7 cycloalkyl); —(CH2)0-4—N(H or R215)—CO2R215; —(CH2)0-4—N(H or R215)—SO2—R220; —(CH2)0-4—N(H or R215)—CO—N(R215)2; —(CH2)0-4—N(—H or R215)—CO—R220; —(CH2)0-4—NR220R225; —(CH2)0-4—O—CO—(C1-C6 alkyl); —(CH2)0-4—O—(R215); —(CH2)0-4—S—(R215); —(CH2)0-4—O—(C1-C6 alkyl optionally substituted with 1, 2, 3, or 5-F) —C2-C6 alkenyl optionally substituted with 1 or 2 R205 groups; —C2-C6 alkynyl optionally substituted with 1 or 2 R205 groups; and —(CH2)0-4—C3-C7 cycloalkyl; wherein each aryl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210 or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently R205 or R210; wherein each heterocycloalkyl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently R210; wherein each heteroaryl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210, or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently —R205 or —R210; wherein R205 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C1-C6 haloalkoxy —(CH2)0-3(C3-C7 cycloalkyl) -halogen, —(CH2)0-6—OH, —O-phenyl, —SH, —(CH2)0-6—C≡N, —(CH2)0-6—C(═O)NR235R240 —CF3, —C1-C6 alkoxy, and —NR235R240, wherein R210 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; -halogen; —C1-C6 alkoxy; —C1-C6 haloalkoxy; —NR220R225; —OH; —C≡N; —C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —CO—(C1-C4 alkyl); —SO2—NR235R240; —CO—NR235R240; —SO2—(C1-C4 alkyl); and ═O; wherein wherein R215 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl, —(CH2)0-2-(aryl), —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, —(CH2)0-2-(heteroaryl), and —(CH2)0-2-(heterocycloalkyl); wherein the aryl group included within R215 is optionally substituted with 1, 2, or 3 groups that are independently —R205 or —R210; wherein the heterocycloalkyl group included within R215 is optionally substituted with 1, 2, or 3 R210; wherein each heteroaryl group included within R215 is optionally substituted with 1, 2, or 3 R210; wherein R220 and R225 at each occurrence are independently selected from the group consisting of —H, —C1-C6 alkyl, -hydroxy C1-C6 alkyl, -amino C1-C6 alkyl, -halo C1-C6 alkyl, —(CH2)0-2—(C3-C7 cycloalkyl), —(C1-C6 alkyl)—O—(C1-C3 alkyl), —C2-C6 alkenyl, —C2-C6 alkynyl, -aryl, -heteroaryl, and -heterocycloalkyl; wherein the aryl, heteroaryl or heterocycloalkyl group included within R220 and R225 is optionally substituted with 1, 2, or 3 R270 groups, wherein R270 at each occurrence is independently —R205, —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; -halogen; —C1-C6 alkoxy; —C1-C6 haloalkoxy; —NR235R240; —OH; —C≡N; —C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —CO—(C1-C4 alkyl); —SO2—NR235R240; —CO—NR235R240; —SO2—(C1-C4 alkyl); and ═O; wherein R235 and R240 at each occurrence are independently —H, or —C1-C6 alkyl; -phenyl wherein R245 and R250 at each occurrence are independently selected from the group consisting of —H, —(CH2)0-4CO2C1-C4 alkyl —(CH2)0-4C(═O)C1-C4 alkyl —C1-C4 alkyl, —C1-C4 hydroxyalkyl, —C1-C4 alkoxy, —C1-C4 haloalkoxy, —(CH2)0-4—C3-C7 cycloalkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —(CH2)0-4 aryl, —(CH2)0-4 heteroaryl, and —(CH2)0-4 heterocycloalkyl, or wherein R245 and R250 are taken together with the carbon to which they are attached to form a monocycle or bicycle of 3, 4, 5, 6, 7 or 8 carbon atoms, optionally where 1 or 2 carbon atoms is replaced by a heteroatom selected from the group consisting of —O—, —S—, —SO2—, and —NR220—; wherein the aryl, heteroaryl or heterocycloalkyl group included within R245 and R250 is optionally substituted with 1, 2, or 3 groups that are independenly halogen, C1-6 alkyl, CN or OH; wherein R255 and R260 at each occurrence are independently selected from the group consisting of —H; —Cl-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —(CH2)1-2—S(O)0-2—(C1-C6 alkyl); —(CH2)0-4—C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —(CH2)0-4-aryl; —(CH2)0-4-heteroaryl; —(CH2)0-4-heterocycloalkyl; wherein each aryl group included within R255 and R260 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210, or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently —R205 or —R210; where each heteroaryl group included within R255 and R260 is optionally substituted with 1, 2, 3, or 4 R200 groups, and where each heterocycloalkyl group included within R255 and R260 is optionally substituted with 1, 2, 3, or 4 R210 groups. 2. A compound according to claim 1, wherein: Z is aryl or heteroaryl, wherein each ring is independently optionally substituted with 1 or 2 groups independendently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, (CH2)0-3 (C3-C7 cycloalkyl), aryl, heteroaryl, or heterocyclyl wherein, the alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, heteroaryl, orheterocyclyl groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101. 3. A compound according to claim 1, wherein X is —(C═O)—. 4. A compound according to claim 1, wherein: R1 is —C1-C6 alkyl-aryl, —C1-C6 alkyl-heteroaryl, or —C1-C6 alkyl-heterocyclyl, wherein each aryl group at each occurrence is optionally substituted with 1, 2 or 3 R50 groups; wherein R50 is independently selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, or C3-C8 cycloalkyl; wherein the alkyl, alkenyl, alkynyl, alkoxy, or cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of C1-C4 alkyl, halogen, OH, —NR5R6, CN, C1-C4 haloalkoxy, NR7R8, and C1-C4 alkoxy; wherein R5 and R6 at each occurrence are independently H or C1-C6 alkyl; or wherein R5 and R6 and the nitrogen to which they are attached, at each occurrence form a 5 or 6 membered heterocycloalkyl ring; and wherein R7 and R8 are independently selected from the group consisting of H; —C1-C4 alkyl optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —OH, —NH2, and halogen; —C3-C6 cycloalkyl; —(C1-C4 alkyl)—O—(C1-C4 alkyl); —C2-C4 alkenyl; and —C2-C4 alkynyl; wherein each heteroaryl at each occurrence is optionally substituted with 1 or 2 R50 groups; wherein each heterocycloalkyl group at each occurrence is optionally substituted with 1 or 2 groups that are independently R50 or ═O. 5. A compound according to claim 1, wherein R2 and R3 are hydrogen. 6. A compound according to claim 1, wherein R15 is hydrogen. 7. A compound according to claim 1, wherein: Rc is selected from the group consisting of: —(CH2)0-3—(C3-C8) cycloalkyl wherein the cycloalkyl is optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —R205, and —CO2—(C1-C4 alkyl); and a monocyclic or bicyclic ring of 5, 6, 7 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N(CO)0-1R215, —N(CO)0-1R220, —O, or —S(═O)0-2, and wherein the monocyclic or bicyclic ring can be optionally substituted with 1, 2 or 3 groups that are independently —R205 —R245, R250 or ═O. 8. A compound according to claim 1 wherein Rc is wherein x1, x2, and X3 are independently —CHR245, SO2, or NH, and wherein the phenyl ring is optionally substituted with 1 or 2 —R245 groups. 9. A compound according to claim 8 wherein one of x1, x2, or x3 is SO2. 10. A compound according to claim 8 wherein one of x1, x2, or x3 is NH. 11. A compound according to claim 8 wherein x1, x2, and x3 are each CH2. 12. A compound according to claim 1 selected from the group consisting of: N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)pyridine-2-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)pyrazine-2-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-1-ethyl-3-methyl-1H-pyrazole-5-carboxamide; 3-amino-N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-1H-1,2,4-triazole-5-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-5-methylisoxazole-3-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-6-hydroxypyridine-2-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-1H-imidazole-4-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)nicotinamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)-1H-pyrazole-4-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)isonicotinamide; 5-chloro-N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2-hydroxypropyl)thiophene-2-carboxamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4S)-6-neopentyl-3,4-dihydro-2H-chromen-4-yl]amino}propyl)benzamide; N-[(1S,2R)-3-{[(4S)-6-tert-butoxy-3,4-dihydro-2H-chromen-4-yl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4S)-6-neopentyl-1,2,3,4-tetrahydroquinolin-4-yl]amino}propyl)benzamide; N-[(1S,2R)-3-{[(4S)-6-tert-butoxy-1,2,3,4-tetrahydroquinolin-4-yl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(1S)-7-neopentyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}propyl)benzamide; N-[(1S,2R)-3-{[(1S)-7-tert-butoxy-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4R)-6-neopentyl-2,2-dioxido-3,4-dihydro-1H-isothiochromen-4-yl]amino}propyl)benzamide; N-[(1S,2R)-3-{[(4R)-6-tert-butoxy-2,2-dioxido-3,4-dihydro-1H-isothiochromen-4-yl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[1-(3-neopentylphenyl)cyclohexyl]amino}propyl)benzamide; N-[(1S,2R)-3-{[1-(3-tert-butoxyphenyl)cyclohexyl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[1-(3-neopentylphenyl)cyclopropyl]amino}propyl)benzamide; N-[(1S,2R)-3-{[1-(3-tert-butoxyphenyl)cyclopropyl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4-neopentyl-1,1′-biphenyl-2-yl)methyl]amino}propyl)benzamide; N-[(1S,2R)-3-{[(4-tert-butoxy-1,1′-biphenyl-2-yl)methyl]amino}-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-{(1S,2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-[(2-neopentyl-9H-fluoren-9-yl)amino]propyl}benzamide; N-[(1S,2R)-3-[(2-tert-butoxy-9H-fluoren-9-yl)amino]-1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide; N-((1S,2R)-1-(3,5-difluorobenzyl)-3-{[(4R)-6-ethyl-2,2-dioxido-3,4-dihydro-1H-isothiochromen-4-yl]amino}-2-hydroxypropyl)-3,5-dimethylbenzamide; and N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(4R)-6-ethyl-2,2-dioxido-3,4-dihydro-1H-isothiochromen-4-yl]amino}-2-hydroxypropyl)-4-(2-methoxyethyl)benzamide. 13. A method for making a compound of formula (I) or a pharmaceutically acceptable salt or ester thereof, wherein Z, X, R1, R2, R3, R15 and Rc are as defined in claim 1. 14. A method for the treatment or prevention of Alzheimer's disease, mild cognitive impairment Down's syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, cerebral amyloid angiopathy, other degenerative dementias, dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, diffuse Lewy body type of Alzheimer's disease comprising administration of a therapeutically effective amount of a compound or salt according to claim 1, to a patient in need thereof. 15. A method of treatment as in claim 14, wherein the patient is a human. 16. A method of treatment according to claim 14, wherein the disease is dementia. 17. A pharmaceutical composition comprising a compound according to claim 1 in combination with a physiologically acceptable carrier or excipient. | CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. provisional application Ser. No. 60/464,687, filed Apr. 21, 2003, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to benzamide 2-hydroxy-3-diaminoalkanes and to such compounds that are useful in the treatment of Alzheimer's disease and related diseases. More specifically, it relates to such compounds that are capable of inhibiting beta-secretase, an enzyme that cleaves amyloid precursor protein to produce amyloid beta peptide (A beta), a major component of the amyloid plaques found in the brains of Alzheimer's sufferers. 2. Background of the Invention Alzheimer's disease (AD) is a progressive degenerative disease of the brain primarily associated with aging. Clinical presentation of AD is characterized by loss of memory, cognition, reasoning, judgment, and orientation. As the disease progresses, motor, sensory, and linguistic abilities are also affected until there is global impairment of multiple cognitive functions. These cognitive losses occur gradually, but typically lead to severe impairment and eventual death in the range of four to twelve years. Alzheimer's disease is characterized by two major pathologic observations in the brain: neurofibrillary tangles and beta amyloid (or neuritic) plaques, comprised predominantly of an aggregate of a peptide fragment know as A beta. Individuals with AD exhibit characteristic beta-amyloid deposits in the brain (beta amyloid plaques) and in cerebral blood vessels (beta amyloid angiopathy) as well as neurofibrillary tangles. Neurofibrillary tangles occur not only in Alzheimer's disease but also in other dementia-inducing disorders. On autopsy, large numbers of these lesions are generally found in areas of the human brain important for memory and cognition. Smaller numbers of these lesions in a more restricted anatomical distribution are found in the brains of most aged humans who do not have clinical AD. Amyloidogenic plaques and vascular amyloid angiopathy also characterize the brains of individuals with Trisomy 21 (Down's Syndrome), Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type (HCHWA-D), and other neurodegenerative disorders. Beta-amyloid is a defining feature of AD, now believed to be a causative precursor or factor in the development of disease. Deposition of A beta in areas of the brain responsible for cognitive activities is a major factor in the development of AD. Beta-amyloid plaques are predominantly composed of amyloid beta peptide (A beta, also sometimes designated betaA4). A beta peptide is derived by proteolysis of the amyloid precursor protein (APP) and is comprised of 39-42 amino acids. Several proteases called secretases are involved in the processing of APP. Cleavage of APP at the N-terminus of the A beta peptide by beta-secretase and at the C-terminus by one or more gamma-secretases constitutes the beta-amyloidogenic pathway, i.e. the pathway by which A beta is formed. Cleavage of APP by alpha-secretase produces alpha-sAPP, a secreted form of APP that does not result in beta-amyloid plaque formation. This alternate pathway precludes the formation of A beta peptide. A description of the proteolytic processing fragments of APP is found, for example, in U.S. Pat. Nos. 5,441,870; 5,721,130; and 5,942,400. An aspartyl protease has been identified as the enzyme responsible for processing of APP at the beta-secretase cleavage site. The beta-secretase enzyme has been disclosed using varied nomenclature, including BACE, Asp, and Memapsin. See, for example, Sinha et al., 1999, Nature 402:537-554 (p501) and published PCT application WO00/17369. Several lines of evidence indicate that progressive cerebral deposition of beta-amyloid peptide (A beta) plays a seminal role in the pathogenesis of AD and can precede cognitive symptoms by years or decades. See, for example, Selkoe, 1991, Neuron 6:487. Release of A beta from neuronal cells grown in culture and the presence of A beta in cerebrospinal fluid (CSF) of both normal individuals and AD patients has been demonstrated. See, for example, Seubert et al., 1992, Nature 359:325-327. It has been proposed that A beta peptide accumulates as a result of APP processing by beta-secretase, thus inhibition of this enzyme's activity is desirable for the treatment of AD. In vivo processing of APP at the beta-secretase cleavage site is thought to be a rate-limiting step in A beta production, and is thus a therapeutic target for the treatment of AD. See for example, Sabbagh, M., et al., 1997, Alz. Dis. Rev. 3, 1-19. BACE1 knockout mice fail to produce A beta, and present a normal phenotype. When crossed with transgenic mice that over express APP, the progeny show reduced amounts of A beta in brain extracts as compared with control animals (Luo et al., 2001 Nature Neuroscience 4:231-232). This evidence further supports the proposal that inhibition of beta-secretase activity and reduction of A beta in the brain provides a therapeutic method for the treatment of AD and other beta amyloid disorders. At present there are no effective treatments for halting, preventing, or reversing the progression of Alzheimer's disease. Therefore, there is an urgent need for pharmaceutical agents capable of slowing the progression of Alzheimer's disease and/or preventing it in the first place. Compounds that are effective inhibitors of beta-secretase, that inhibit beta-secretase-mediated cleavage of APP, that are effective inhibitors of A beta production, and/or are effective to reduce amyloid beta deposits or plaques, are needed for the treatment and prevention of disease characterized by amyloid beta deposits or plaques, such as AD. SUMMARY OF THE INVENTION The invention encompasses the compounds of formula (I) shown below, pharmaceutical compositions containing the compounds and methods employing such compounds or compositions in the treatment of Alzheimer's disease and more specifically compounds that are capable of inhibiting beta-secretase, an enzyme that cleaves amyloid precursor protein to produce A-beta peptide, a major component of the amyloid plaques found in the brains of Alzheimer's sufferers. In a broad aspect, the invention provides compounds of formula I and pharmaceutically acceptable salts or esters thereof, wherein Z is aryl, heteroaryl or heterocyclyl, wherein said groups are optionally substituted with 1 or 2 RB groups, wherein, where RB at each occurrence is independently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, (CH2)0-3(C3-C7 cycloalkyl), aryl, heteroaryl, or heterocyclyl wherein, the alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, heteroaryl, orheterocyclyl groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101; where R100 and R101 are at each occurrence are independently H, C1-C6 alkyl, or phenyl; X is —(C═O)— or —(SO2)— R1 is C1-C10 alkyl optionally substituted with 1, 2, or 3 groups independently selected from halogen, —OH, ═O, —SH, —CN, —CF3, —OCF3, —C3-7 cycloalkyl, —C1-C4 alkoxy, amino, mono-dialkylamino, aryl, heteroaryl, heterocycloalkyl, wherein each aryl group is optionally substituted with 1, 2 or 3 R50 groups; wherein R50 is selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy and C3-C8 cycloalkyl; wherein the alkyl, alkenyl, alkynyl, alkoxy and cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of C1-C4 alkyl, halogen, OH, —NR5R6, CN, C1-C4 haloalkoxy, NR7R8, and C1-C4 alkoxy; wherein R5 and R6 are independently H or C1-C6 alkyl; or wherein R5 and R6 and the nitrogen to which they are attached form a 5 or 6 membered heterocycloalkyl ring; and wherein R7 and R8 are independently selected from the group consisting of H; —C1-C4 alkyl optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —OH, —NH2, and halogen; —C3-C6 cycloalkyl; —(C1-C4 alkyl)-O—(C1-C4 alkyl); —C2-C4 alkenyl; and —C2-C4 alkynyl; wherein each heteroaryl is optionally substituted with 1 or 2 R50 groups; wherein each heterocycloalkyl group is optionally substituted with 1 or 2 groups that are independently R50 or ═O; R2 and R3 are independently selected from —H; —F; —C1-C6 alkyl optionally substituted with a substituent selected from the group consisting of —F, —OH, —C≡N, —CF3, C1-C3 alkoxy, and —NR5R6; —(CH2)0-2—R17; —(CH2)0-2—R18; —C2-C6 alkenyl or C2-C6 alkynyl, wherein each is optionally substituted with an indepdent substituent selected from the group consisting of —F, —OH, —C≡N, —CF3 and C1-C3 alkoxy; —(CH2)0-2—C3-C7 cycloalkyl, optionally substituted an independent substituent selected from the group consisting of —F, —OH, —C≡N, —CF3, C1-C3 alkoxy and —NR5R6; or R2, R3 and the carbon to which they are attached form a carbocycle of three thru seven carbon atoms, wherein one carbon atom is optionally replaced by a group selected from —O—, —S—, —SO2—, or —NR7—; where R17 at each occurrence is an aryl group selected from phenyl, 1-naphthyl, 2-naphthyl, indanyl, indenyl, dihydronaphthyl and tetralinyl, wherein said aryl groups are optionally substituted with one or two groups that are independently —C1-C3 alkyl; —C1-C4 alkoxy; CF3; or —C2-C6 alkenyl or —C2-C6 alkynyl each of which is optionally substituted with one substituent selected from the group consisting of F, OH, C1-C3 alkoxy; or -halogen; —OH; —C≡N; —C3-C7 cycloalkyl; —CO—(C1-C4 alkyl); —SO2—(C1-C4 alkyl); where R18 is a heteroaryl group selected from pyridinyl, pyrimidinyl, quinolinyl, indolyl, pryidazinyl, pyrazinyl, isoquinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, imidazolyl, isoxazolyl, oxazolyl, thiazolyl, furanyl, thienyl, pyrrolyl, oxadiazolyl or thiadiazolyl, wherein each of said heteroaryl groups is optionally substituted with one or two groups that are independently —C1-C6 alkyl optionally substituted with one substituent selected from the group consisting of OH, C—N, CF3, C1-C3 alkoxy, and —NR5R6; R15 is selected from the group consisting of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkoxy C1-C6 alkyl, hydroxy C1-C6 alkyl, halo C1-C6 alkyl, each of which is unsubstituted or substituted with 1, 2, 3, or 4 groups independently selected from halogen, C1-C6 alkyl, hydroxy, C1-C6 alkoxy, NH2, and —R26—R27; wherein R26 is selected from the group consisting of a bond, —C(O)—, —SO2—, —CO2—, —C(O)NR5—, and —NR5C(O)—, wherein R27 is selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, aryl C1-C6 alkyl, heterocycloalkyl, and heteroaryl, wherein each of the above is unsubstituted or substituted with 1, 2, 3, 4, or 5 groups that are independently C1-C4 alkyl, C1-C4 alkoxy, halogen, haloalkyl, hydroxyalkyl, —NR5R6, —C(O)NR5R6; Rc is selected from the group consisting of —(CH2)0-3—(C3-C8) cycloalkyl wherein the cycloalkyl is optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —R205, —CO2—(C1-C4 alkyl), and aryl, wherein aryl is optionally substituted with 1 or 2 independently selected R200 groups; —(CR245R250)0-4-aryl; —(CR245R250)0-4-heteroaryl; —(CR245R250)0-4-heterocycloalkyl; —(CR245R250)0-4-aryl-heteroaryl; —(CR245R250)0-4-aryl-heterocycloalkyl; —(CR245R250)0-4-aryl-aryl; —(CR245R250)0-4-heteroaryl-aryl; —(CR245R250)0-4-heteroaryl-heterocycloalkyl; —(CR245R250)0-4-heteroaryl-heteroaryl; —(CR245R250)0-4-heterocycloalkyl-heteroaryl; —(CR245R250)0-4-heterocycloalkyl-heterocycloalkyl; —(CR245R250)0-4-heterocycloalkyl-aryl; a monocyclic or bicyclic ring of 5, 6, 7 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N (CO)0-1R215, —N (CO)0-1R220, —O, or —S(═O)0-2, and wherein the monocyclic or bicyclic ring is optionally substituted with 1, 2 or 3 groups that are independently —R205, —R245, —R250 or ═O; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; wherein each aryl group attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3 or 4 R200 groups; wherein each heteroaryl group attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3, or 4 R200; wherein each heterocycloalkyl attached directly or indirectly to the —(CR245R250)0-4 group is optionally substituted with 1, 2, 3, or 4 R210; wherein R200 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —OH; —NO2; -halogen; —C≡N; —(CH2)0-4—CO—NR220R225; —(CH2)0-4—CO—(C1-C8 alkyl); —(CH2)0-4—CO—(C2-C8 alkenyl); —(CH2)0-4—CO—(C2-C8 alkynyl); —(CH2)0-4—CO—(C3-C7 cycloalkyl); —(CH2)0-4—(CO)0-1-aryl; —(CH2)0-4—(CO)0-1-heteroaryl; —(CH2)0-4—(CO)0-1-heterocycloalkyl; —(CH2)0-4—CO2R215; —(CH2)0-4—SO2—NR220R225; —(CH2)0-4—S(O)0-2—(C1-C8 alkyl); —(CH2)0-4—S(O)0-2—(C3-C7 cycloalkyl); —(CH2)0-4—N(H or R215)—CO2R215; —(CH2)0-4—N(H or R215)—SO2—R220; —(CH2)0-4—N(H or R215)—CO—N(R215)2; —(CH2)0-4—N(—H or R215)—CO—R220; —(CH2)0-4—NR22OR225; —(CH2)0-4—O—CO—(C1-C6 alkyl); —(CH2)0-4—O—(R215); —(CH2)0-4—S—(R215); —(CH2)0-4—O—(C1-C6 alkyl optionally substituted with 1, 2, 3, or 5-F); —C2-C6 alkenyl optionally substituted with 1 or 2 R205 groups; —C2-C6 alkynyl optionally substituted with 1 or 2 R205 groups; and —(CH2)0-4—C3-C7 cycloalkyl; wherein each aryl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210 or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently R205 or R210; wherein each heterocycloalkyl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently R210; wherein each heteroaryl group included within R200 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210, or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently —R205 or —R210; wherein R205 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —C1-C6 haloalkoxy —(CH2)0-3(C3-C7 cycloalkyl) -halogen, —(CH2)0-6—OH, —O-phenyl, —SH, —(CH2)0-6—C≡N, —(CH2)0-6—C(═O) NR235R240 —CF3, —C1-C6 alkoxy, and —NR235R240, wherein R210 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; -halogen; —C1-C6 alkoxy; —C1-C6 haloalkoxy; —NR220R225; —OH; —C≡N; —C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —CO—(C1-C4 alkyl); SO2—NR235R240; —CO—NR235R240; —SO2—(C1-C4 alkyl); and ═O; wherein wherein R215 at each occurrence is independently selected from the group consisting of —C1-C6 alkyl, —(CH2)0-2-(aryl), —C2-C6 alkenyl, —C2-C6 alkynyl, —C3-C7 cycloalkyl, —(CH2)0-2-(heteroaryl), and —(CH2)0-2-(heterocycloalkyl); wherein the aryl group included within R215 is optionally substituted with 1, 2, or 3 groups that are independently —R205 or —R210; wherein the heterocycloalkyl group included within R215 is optionally substituted with 1, 2, or 3 R210; wherein each heteroaryl group included within R215 is optionally substituted with 1, 2, or 3 R210; wherein R220 and R225 at each occurrence are independently selected from the group consisting of —H, —C1-C6 alkyl, -hydroxy C1-C6 alkyl, -amino C1-C6 alkyl, -halo C1-C6 alkyl, —(CH2)0-2—(C3-C7 cycloalkyl), —(C1-C6 alkyl)—O—(C1-C3 alkyl), —C2-C6 alkenyl, —C2-C6 alkynyl, -aryl, -heteroaryl, and -heterocycloalkyl; wherein the aryl, heteroaryl or heterocycloalkyl group included within R220 and R225 is optionally substituted with 1, 2, or 3 R270 groups, wherein R270 at each occurrence is independently —R205, —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkenyl optionally substituted with 1, 2, or 3 R205 groups; —C2-C6 alkynyl optionally substituted with 1, 2, or 3 R205 groups; -halogen; —C1-C6 alkoxy; —C1-C6 haloalkoxy; —NR235R240; —OH; —C≡N; —C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —CO—(C1-C4 alkyl); —SO2—NR235R240; —CO—NR235R240; —SO2—(C1-C4 alkyl); and ═O; wherein R235 and R240 at each occurrence are independently —H, or —C1-C6 alkyl; -phenyl wherein R245 and R250 at each occurrence are independently selected from the group consisting of —H, —(CH2)0-4CO2C1-C4 alkyl —(CH2)0-4C(O)C1-C4 alkyl —C1-C4 alkyl, —C1-C4 hydroxyalkyl, —C1-C4 alkoxy, —C1-C4 haloalkoxy, —(CH2)0-4—C3-C7 cycloalkyl, —C2-C6 alkenyl, —C2-C6 alkynyl, —(CH2)0-4 aryl, —(CH2)0-4 heteroaryl, and —(CH2)0-4 heterocycloalkyl, or wherein R245 and R250 are taken together with the carbon to which they are attached to form a monocycle or bicycle of 3, 4, 5, 6, 7 or 8 carbon atoms, optionally where 1 or 2 carbon atoms is replaced by a heteroatom selected from the group consisting of —O—, —S—, —SO2—, and —NR220—; wherein the aryl, heteroaryl or heterocycloalkyl group included within R245 and R250 is optionally substituted with 1, 2, or 3 groups that are independenly halogen, C1-6 alkyl, CN or OH; wherein R255 and R260 at each occurrence are independently selected from the group consisting of —H; —C1-C6 alkyl optionally substituted with 1, 2, or 3 R205 groups; —(CH2)1-2—S(O)0-2—(C1-C6 alkyl); —(CH2)0-4—C3-C7 cycloalkyl optionally substituted with 1, 2, or 3 R205 groups; —(CH2)0-4-aryl; —(CH2)0-4-heteroaryl; —(CH2)0-4-heterocycloalkyl; wherein each aryl group included within R255 and R260 is optionally substituted with 1, 2, or 3 groups that are independently —R205, —R210, or —C1-C6 alkyl substituted with 1, 2, or 3 groups that are independently —R205 or —R210; where each heteroaryl group included within R255 and R260 is optionally substituted with 1, 2, 3, or 4 R200 groups, and where each heterocycloalkyl group included within R255 and R260 is optionally substituted with 1, 2, 3, or 4 R210 groups. The invention also provides methods for the treatment or prevention of Alzheimer's disease, mild cognitive impairment Down's syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, cerebral amyloid angiopathy, other degenerative dementias, dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, diffuse Lewy body type of Alzheimer's disease comprising administration of a therapeutically effective amount of a compound or salt of formula I, to a patient in need thereof. Preferably, the patient is a human. More preferably, the disease is Alzheimer's disease. More preferably, the disease is dementia. The invention also provides pharmaceutical compositions comprising a compound or salt of formula I and at least one pharmaceutically acceptable carrier, solvent, adjuvant or diluent. The invention also provides the use of a compound or salt according to formula I for the manufacture of a medicament. The invention also provides the use of a compound or salt of formula I for the treatment or prevention of Alzheimer's disease, mild cognitive impairment Down's syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, cerebral amyloid angiopathy, other degenerative dementias, dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, or diffuse Lewy body type of Alzheimer's disease. The invention also provides compounds, pharmaceutical compositions, kits, and methods for inhibiting beta-secretase-mediated cleavage of amyloid precursor protein (APP). More particularly, the compounds, compositions, and methods of the invention are effective to inhibit the production of A-beta peptide and to treat or prevent any human or veterinary disease or condition associated with a pathological form of A-beta peptide. The compounds, compositions, and methods of the invention are useful for treating humans who have Alzheimer's Disease (AD), for helping prevent or delay the onset of AD, for treating patients with mild cognitive impairment (MCI), and preventing or delaying the onset of AD in those patients who would otherwise be expected to progress from MCI to AD, for treating Down's syndrome, for treating Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch Type, for treating cerebral beta-amyloid angiopathy and preventing its potential consequences such as single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, for treating dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, and diffuse Lewy body type AD, and for treating frontotemporal dementias with parkinsonism (FTDP). The compounds of the invention possess beta-secretase inhibitory activity. The inhibitory activities of the compounds of the invention is readily demonstrated, for example, using one or more of the assays described herein or known in the art. Unless the substituents for a particular formula are expressly defined for that formula, they are understood to carry the definitions set forth in connection with the preceding formula to which the particular formula makes reference. The invention also provides methods of preparing the compounds of the invention and the intermediates used in those methods. DETAILED DESCRIPTION OF THE INVENTION As noted above, the invention provides compounds of formula I. Preferred compounds of formula I include those of formula I-1, i.e., compounds of formula I wherein X is —(C═O)—. Preferred compounds of the formula I and formula I-1 include compounds of the formula I-2, i.e., compounds of the formula I or formula I-1 wherein: Z is aryl or heteroaryl, wherein each ring is independently optionally substituted with 1 or 2 groups independendently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, (CH2)0-3(C3-C7 cycloalkyl), aryl, heteroaryl, or heterocyclyl wherein, the alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, heteroaryl, orheterocyclyl groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101; where R100 and R101 at each occurrence are independently H, C1-C6 alkyl, or phenyl. Preferred compounds of the formula I-2 also include those wherein: Z is aryl or heteroaryl, wherein each ring is independently optionally substituted with 1 or 2 groups independendently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, wherein the alkyl, alkenyl, alkynyl, or alkoxy groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101; where R100 and R101 at each occurrence are independently H, C1-C6 alkyl, or phenyl. Preferred compounds of the formula I-2 also include those wherein: Z is phenyl, pyridinyl, pyrazinyl, pyrazolyl, triazolyl, isoxazolyl, imidazolyl, or thiophenyl, wherein each ring is independently optionally substituted with 1 or 2 groups independendently selected from halogen, —OH, —OCF3, —O-phenyl, —CN, —NR100R101, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, wherein the alkyl, alkenyl, alkynyl, or alkoxy groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, halogen, —OH, —CN, or —NR100R101; where R100 and R101 at each occurrence are independently H, C1-C6 alkyl, or phenyl. Preferred compounds of the formula I, formula I-1, and formula I-2 include compounds of the formula I-3, i.e., compounds of the formula I, formula I-1, or formula I-2 wherein: R1 is —C1-C6 alkyl-aryl, —C1-C6 alkyl-heteroaryl, or —C1-C6 alkyl-heterocyclyl, wherein each aryl group at each occurrence is optionally substituted with 1, 2 or 3 R50 groups; wherein R50 is independently selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, or C3-C8 cycloalkyl; wherein the alkyl, alkenyl, alkynyl, alkoxy, or cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of C1-C4 alkyl, halogen, OH, —NR5R6, CN, C1-C4 haloalkoxy, NR7R8, and C1-C4 alkoxy; wherein R5 and R6 at each occurrence are independently H or C1-C6 alkyl; or wherein R5 and R6 and the nitrogen to which they are attached, at each occurrence form a 5 or 6 membered heterocycloalkyl ring; and wherein R7 and R8 are independently selected from the group consisting of H; —C1-C4 alkyl optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —OH, —NH2, and halogen; —C3-C6 cycloalkyl; —(C1-C4 alkyl)-O—(C1-C4 alkyl); —C2-C4 alkenyl; and —C2-C4 alkynyl; wherein each heteroaryl at each occurrence is optionally substituted with 1 or 2 R50 groups; wherein each heterocycloalkyl group at each occurrence is optionally substituted with 1 or 2 groups that are independently R50 or ═O. Preferred compounds of formula I-3 also include those wherein R1 is —(CH2)-aryl, where the aryl is optionally substituted with 1, 2 or 3 R50 groups; wherein R50 is independently selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, and C3-C8 cycloalkyl. Preferred compounds of formula I-3 also include those wherein R1 is —CH2-phenyl where the phenyl ring is optionally substituted with 1, 2, or 3 groups independently selected from halogen, OH, SH, CN, —CO—(C1-C4 alkyl), —NR7R8, —S(O)0-2—(C1-C4 alkyl), C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkoxy, and C3-C8 cycloalkyl. Preferred compounds of formula I-3 also include those wherein R1 is —CH2-phenyl where the phenyl ring is optionally substituted with 1 or 2 groups independently selected from halogen, C1-C2 alkyl, C1-C2 alkoxy, hydroxy. Preferred compounds of formula I-3 also include those wherein R1 is benzyl or 3,5-difluorobenzyl. Preferred compounds of the formula I, formula I-1, formula I-2 and formula I-3 include compounds of the formula I-4, i.e., compounds of the formula I, formula I-1, formula I-2, or formula I-3 wherein: R2 and R3 are both hydrogen. Preferred compounds of the formula I, formula I-1, formula I-2 formula I-3 and formula I-4 include compounds of the formula I-5, i.e., compounds of the formula I, formula I-1, formula I-2, formula I-3, or formula I-4 wherein R15 is hydrogen. Preferred compounds of the formula I, formula I-1, formula I-2 formula I-3 formula I-4 and formula I-5 include compounds of the formula I-6, i.e., compounds of the formula I, formula I-1, formula I-2, formula I-3, formula I-4 or formula I-5 wherein: wherein Rc is selected from the group consisting of: —(CH2)0-3—(C3-C8) cycloalkyl wherein cycloalkyl is optionally substituted with 1, 2, or 3 groups independently selected from —R205, —CO2—(C1-C4 alkyl) and aryl; —(CH2)0-3-aryl; —(CH2)0-3-heteroaryl; —(CH2)0-3-heterocycloalkyl; -aryl-aryl; and a monocyclic or bicyclic ring of 5, 6, 7, 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups, wherein each aryl, heteroaryl and heterocycloalkyl group is optionally independently substituted with 1, 2, or 3 R200 groups and wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N(CO)0-1R215, —N(CO)0-1R220, —O—, or —S(═O)0-2, and wherein the monocyclic or bicyclic ring can be optionally substituted with 1, 2 or 3 groups that are independently —R205 —R245, R250 or ═O; wherein each aryl is optionally substituted with 1, 2, or 3 independently selected R200 groups; each heteroaryl is optionally substituted with 1, 2, or 3 independently selected R200 groups; and each heterocycloalkyl is optionally substituted with 1, 2, or 3 independently selected R200 groups. Preferred compounds of the formula I-6 include those wherein: Rc is a monocyclic or bicyclic ring of 5, 6, 7 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N(CO)0-1R215, —N(CO)0-1R220, —O, or —S(═O)0-2, and wherein the monocyclic or bicyclic ring can be optionally substituted with 1, 2 or 3 groups that are independently —R205 —R245, R250 or ═O. Preferred compounds of the formula I-6 include those wherein: Rc is a cyclohexyl ring fused to 1 aryl, heteroaryl, or heterocycloalkyl group wherein 1 carbon of the cyclohexyl ring is optionally replaced with —SO2, or —NH— and wherein the bicyclic ring can be optionally substituted with 1, 2 or 3 groups that are independently —R205, —R245, R250 or ═O. Preferred compounds of the formula I-6 also include those wherein: Rc is wherein x1, x2, and x3 are independently —CHR245, SO2, or NH, and wherein the phenyl ring is optionally substituted with 1 or 2 —R245 groups. More preferred compounds of the formula I-6 also include those wherein one of x1, x2, or X3 is SO2. More preferred compounds of the formula I-6 also include those wherein one of x1, x2, or x3 is NH. More preferred compounds of the formula I-6 also include those wherein x1, x2, and x3 are each CH2. In another aspect, the invention provides the intermediates that are useful in the preparation of the compounds of interest. The invention also provides methods for treating a patient who has, or in preventing a patient from getting, a disease or condition selected from the group consisting of Alzheimer's disease, for helping prevent or delay the onset of Alzheimer's disease, for treating patients with mild cognitive impairment (MCI) and preventing or delaying the onset of Alzheimer's disease in those who would progress from MCI to AD, for treating Down's syndrome, for treating humans who have Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, for treating cerebral amyloid angiopathy and preventing its potential consequences, i.e. single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, or diffuse Lewy body type of Alzheimer's disease and who is in need of such treatment which includes administration of a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salts thereof. In an embodiment, this method of treatment can be used where the disease is Alzheimer's disease. In an embodiment, this method of treatment can help prevent or delay the onset of Alzheimer's disease. In an embodiment, this method of treatment can be used where the disease is mild cognitive impairment. In an embodiment, this method of treatment can be used where the disease is Down's syndrome. In an embodiment, this method of treatment can be used where the disease is Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type. In an embodiment, this method of treatment can be used where the disease is cerebral amyloid angiopathy. In an embodiment, this method of treatment can be used where the disease is degenerative dementias. In an embodiment, this method of treatment can be used where the disease is diffuse Lewy body type of Alzheimer's disease. In an embodiment, this method of treatment can treat an existing disease. In an embodiment, this method of treatment can prevent a disease from developing. In an embodiment, this method of treatment can employ therapeutically effective amounts: for oral administration from about 0.1 mg/day to about 1,000 mg/day; for parenteral, sublingual, intranasal, intrathecal administration from about 0.5 to about 100 mg/day; for depo administration and implants from about 0.5 mg/day to about 50 mg/day; for topical administration from about 0.5 mg/day to about 200 mg/day; for rectal administration from about 0.5 mg to about 500 mg. In an embodiment, this method of treatment can employ therapeutically effective amounts: for oral administration from about 1 mg/day to about 100 mg/day; and for parenteral administration from about 5 to about 50 mg daily. In an embodiment, this method of treatment can employ therapeutically effective amounts for oral administration from about 5 mg/day to about 50 mg/day. The invention also includes pharmaceutical compositions which include a compound of formula (I) or a pharmaceutically acceptable salts thereof. The invention also includes the use of a compound of formula (I) or pharmaceutically acceptable salts thereof for the manufacture of a medicament for use in treating a patient who has, or in preventing a patient from getting, a disease or condition selected from the group consisting of Alzheimer's disease, for helping prevent or delay the onset of Alzheimer's disease, for treating patients with mild cognitive impairment (MCI) and preventing or delaying the onset of Alzheimer's disease in those who would progress from MCI to AD, for treating Down's syndrome, for treating humans who have Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, for treating cerebral amyloid angiopathy and preventing its potential consequences, i.e. single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, diffuse Lewy body type of Alzheimer's disease and who is in need of such treatment. In an embodiment, this use of a compound of formula (I) can be employed where the disease is Alzheimer's disease. In an embodiment, this use of a compound of formula (I) can help prevent or delay the onset of Alzheimer's disease. In an embodiment, this use of a compound of formula (I) can be employed where the disease is mild cognitive impairment. In an embodiment, this use of a compound of formula (I) can be employed where the disease is Down's syndrome. In an embodiment, this use of a compound of formula (I) can be employed where the disease is Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type. In an embodiment, this use of a compound of formula (I) can be employed where the disease is cerebral amyloid angiopathy. In an embodiment, this use of a compound of formula (I) can be employed where the disease is degenerative dementias. In an embodiment, this use of a compound of formula (I) can be employed where the disease is diffuse Lewy body type of Alzheimer's disease. In an embodiment, this use of a compound employs a pharmaceutically acceptable salt selected from the group consisting of salts of the following acids hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, phosphoric, citric, methanesulfonic, CH3—(CH2)n—COOH where n is 0 thru 4, HOOC—(CH2)n—COOH where n is as defined above, HOOC—CH═CH—COOH, and phenyl-COOH. The invention also includes methods for inhibiting beta-secretase activity, for inhibiting cleavage of amyloid precursor protein (APP), in a reaction mixture, at a site between Met596 and Asp597, numbered for the APP-695 amino acid isotype, or at a corresponding site of an isotype or mutant thereof; for inhibiting production of amyloid beta peptide (A beta) in a cell; for inhibiting the production of beta-amyloid plaque in an animal; and for treating or preventing a disease characterized by beta-amyloid deposits in the brain. These methods each include administration of a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salts thereof. The invention also includes a method for inhibiting beta-secretase activity, including exposing said beta-secretase to an effective inhibitory amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of less than 50 micromolar. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 10 micromolar or less. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 1 micromolar or less. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 10 nanomolar or less. In an embodiment, this method includes exposing said beta-secretase to said compound in vitro. In an embodiment, this method includes exposing said beta-secretase to said compound in a cell. In an embodiment, this method includes exposing said beta-secretase to said compound in a cell in an animal. In an embodiment, this method includes exposing said beta-secretase to said compound in a human. The invention also includes a method for inhibiting cleavage of amyloid precursor protein (APP), in a reaction mixture, at a site between Met596 and Asp597, numbered for the APP-695 amino acid isotype; or at a corresponding site of an isotype or mutant thereof, including exposing said reaction mixture to an effective inhibitory amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof. In an embodiment, this method employs a cleavage site: between Met652 and Asp653, numbered for the APP-751 isotype; between Met 671 and Asp 672, numbered for the APP-770 isotype; between Leu596 and Asp597 of the APP-695 Swedish Mutation; between Leu652 and Asp653 of the APP-751 Swedish Mutation; or between Leu671 and Asp672 of the APP-770 Swedish Mutation. In an embodiment, this method exposes said reaction mixture in vitro. In an embodiment, this method exposes said reaction mixture in a cell. In an embodiment, this method exposes said reaction mixture in an animal cell. In an embodiment, this method exposes said reaction mixture in a human cell. The invention also includes a method for inhibiting production of amyloid beta peptide (A beta) in a cell, including administering to said cell an effective inhibitory amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof. In an embodiment, this method includes administering to an animal. In an embodiment, this method includes administering to a human. The invention also includes a method for inhibiting the production of beta-amyloid plaque in an animal, including administering to said animal an effective inhibitory amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof. In an embodiment, this method includes administering to a human. The invention also includes a method for treating or preventing a disease characterized by beta-amyloid deposits in the brain including administering to a patient an effective therapeutic amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of less than 50 micromolar. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 10 micromolar or less. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 1 micromolar or less. In an embodiment, this method employs a compound that inhibits 50% of the enzyme's activity at a concentration of 10 nanomolar or less. In an embodiment, this method employs a compound at a therapeutic amount in the range of from about 0.1 to about 1000 mg/day. In an embodiment, this method employs a compound at a therapeutic amount in the range of from about 15 to about 1500 mg/day. In an embodiment, this method employs a compound at a therapeutic amount in the range of from about 1 to about 100 mg/day. In an embodiment, this method employs a compound at a therapeutic amount in the range of from about 5 to about 50 mg/day. In an embodiment, this method can be used where said disease is Alzheimer's disease. In an embodiment, this method can be used where said disease is Mild Cognitive Impairment, Down's Syndrome, or Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch Type. The invention also includes a composition including beta-secretase complexed with a compound of formula (I), or a pharmaceutically acceptable salt thereof. The invention also includes a method for producing a beta-secretase complex including exposing beta-secretase to a compound of formula (I), or a pharmaceutically acceptable salt thereof, in a reaction mixture under conditions suitable for the production of said complex. In an embodiment, this method employs exposing in vitro. In an embodiment, this method employs a reaction mixture that is a cell. The invention also includes a component kit including component parts capable of being assembled, in which at least one component part includes a compound of formula I enclosed in a container. In an embodiment, this component kit includes lyophilized compound, and at least one further component part includes a diluent. The invention also includes a container kit including a plurality of containers, each container including one or more unit dose of a compound of formula (I):, or a pharmaceutically acceptable salt thereof. In an embodiment, this container kit includes each container adapted for oral delivery and includes a tablet, gel, or capsule. In an embodiment, this container kit includes each container adapted for parenteral delivery and includes a depot product, syringe, ampoule, or vial. In an embodiment, this container kit includes each container adapted for topical delivery and includes a patch, medipad, ointment, or cream. The invention also includes an agent kit including a compound of formula (I), or a pharmaceutically acceptable salt thereof; and one or more therapeutic agent selected from the group consisting of an antioxidant, an anti-inflammatory, a gamma secretase inhibitor, a neurotrophic agent, an acetyl cholinesterase inhibitor, a statin, an A beta peptide, and an anti-A beta antibody. The invention also includes a composition including a compound of formula (I), or a pharmaceutically acceptable salt thereof; and an inert diluent or edible carrier. In an embodiment, this composition includes a carrier that is an oil. The invention also includes a composition including: a compound of formula (I), or a pharmaceutically acceptable salt thereof; and a binder, excipient, disintegrating agent, lubricant, or gildant. The invention also includes a composition including a compound of formula (I), or a pharmaceutically acceptable salt thereof; disposed in a cream, ointment, or patch. The invention provides compounds of formula (I) that are useful in treating and preventing Alzheimer's disease. The compounds of the invention can be prepared by one skilled in the art based only on knowledge of the compound's chemical structure. The chemistry for the preparation of the compounds of this invention is known to those skilled in the art. In fact, there is more than one process to prepare the compounds of the invention. Specific examples of methods of preparation can be found in the art. An example of one of many various processes that can be used to prepare the compounds of the invention is set forth in Scheme I. The epoxide opening in the first step in Scheme I is carried out with a 1:1 to 1:5 ratio of the erythro epoxide and C-terminal R—NH2 piece. 1-6 Equivalents of a tertiary amine base (such as diisopropylethylamine or triethylamine) are then added, followed by 10 mL/mmol alcoholic solvent, such as methanol or isopropanol. This reaction is run at room temperature to 110° C. for a time until reaction is deemed complete, between 0.5-16 hr. Upon completion, the reaction mixture is concentrated under reduced pressure, or by overflow of inert gas. The BOC-group deprotection in the second step is accomplished by using 3-5 equivalents of acid, such as hydrogen chloride or trifluoroacetic acid in appropriate solvent, such as dioxane, diethyl ether, or methylene chloride, with respect to the amount of starting material. This reaction is run at room temperature to 100° C. for 0.5-16 hr, until reaction is deemed complete. The solvent is then removed under reduced pressure, or by overflow of inert gas. The starting amine in the final step is placed with 2-4 equiv tertiary amine base, such as triethylamine or diisopropylethylamine. Then, 1.1 equiv of the R′—COOH carboxylic acid is added. The starting reagents are then dissolved in 2 ml/mmol of appropriate polar aprotic solvent, such as THF or DMF. Finally, 1.1 equiv of coupling reagent, such as HBTU, dissolved in an appropriate amount of solvent, is added. Each reaction is run for 0.5-16 hr at anywhere between room temperature and 100° C., until LC/MS analysis indicates reaction is complete. Final purification is achieved using preparative HPLC. Scheme II illustrates the preparation of compounds using the readily obtainable 6-iodo-chroman-4ol (1) as a starting material (see Synthesis, 1997, 23-25). One skilled in the art will recognize that there are several methods for the conversion of the alcohol functionality to the desired amino compounds of formula (2). In Scheme II the alcohol (1) is first activated with methane sulfonyl chloride and the resulting mesylate displaced with sodium azide NaN3. Alternative methods for the conversion of an alcohol to an azide are well known to one skilled in the art. The resulting azide is subsequently reduced using trimethylphosphine in a mixture of THF and water. One skilled in the art will recognize that there are several methods for the reduction of an azide to the corresponding amine. For examples, see Larock, R. C. in Comprehensive Organic Transformations, Wiley-VCH Publishers, 1999. This reduction of the azide produces a mixture of enantiomers of the amine (2). This enantiomeric mixture can be separated by means known to those skilled in the art such as low temperature recrystallization of a chiral salt or by chiral preparative HPLC, most preferably by HPLC, employing commercially available chiral columns. The resulting amine (2) is used to open the epoxide (3) to afford the protected (6-iodo-3,4-dihydro-2H-chromen-4-yl)amino propyl carbamate (4). Suitable reaction conditions for opening the epoxide (3) include running the reaction in a wide range of common and inert solvents. C1-C6 alcohol solvents are preferred and isopropyl alcohol most preferred. The reactions can be run at temperatures ranging from 20-25° C. up to the reflux temperature of the alcohol employed. The preferred temperature range for conducting the reaction is between 50° C. and the refluxing temperature of the alcohol employed. The protected iodo-chromen (4) is deprotected to the corresponding amine by means known to those skilled in the art for removal of amine protecting groups. Suitable means for removal of the amine protecting group depend on the nature of the protecting group. Those skilled in the art, knowing the nature of a specific protecting group, know which reagent is preferable for its removal. For example, it is preferred to remove the preferred protecting group, BOC, by dissolving the protected iodo-chroman in a trifluoroacetic acid/dichloromethane (1/1) mixture. When complete the solvents are removed under reduced pressure to give the corresponding amine (as the corresponding salt, i.e. trifluoroacetic acid salt) which is used without further purification. However, if desired, the amine can be purified further by means well known to those skilled in the art, such as for example recrystallization. Further, if the non-salt form is desired that also can be obtained by means known to those skilled in the art, such as for example, preparing the free base amine via treatment of the salt with mild basic conditions. Additional BOC deprotection conditions and deprtotection conditions for other protecting groups can be found in T. W. Green and P. G. M. Wuts in Protecting Groups in Organic Chemistry, John Wiley and Sons, 1999. The amine is then reacted with an appropriately substituted amide forming agent Z-(CO)—Y to produce coupled amides (5) by nitrogen acylation means known to those skilled in the art. Nitrogen acylation conditions for the reaction of amine with an amide forming agent Z-(CO)—Y are known to those skilled in the art and can be found in R. C. Larock in Comprehensive Organic Transformations, VCH Publishers, 1989, p. 981, 979, and 972. Y comprises —OH (carboxylic acid) or halide (acyl halide), preferably chlorine, imidazole (acyl imidazole), or a suitable group to produce a mixed anhydride. The acylated iodo-chromen (5) is coupled with an appropriately functionalzed organometallic R200M to afford compounds of formula (6) using conditions known to those skilled in the art. One skilled in the art will recognize that there are several methods for coupling various alkyl and aryl groups to an aromatic iodide. For examples, see L. S. Hegedus Transition Metals in the Synthesis of Complex Organic Molecules, University Science, 1999. Amines of formula (8) can be prepared by coupling the appropriately functionalized organometallic to 6-iodo-chroman-4-ol (1) or to the appropriately protected iodo-amino chroman of the formula (7), as shown in Scheme III. The chemistry from this point forward follows the generalizations described for Scheme II. The protection of amines is conducted, where appropriate, by methods known to those skilled in the art. Amino protecting groups are known to those skilled in the art. See for example, “Protecting Groups in Organic Synthesis”, John Wiley and sons, New York, N.Y., 1981, Chapter 7; “Protecting Groups in Organic Chemistry”, Plenum Press, New York, N.Y., 1973, Chapter 2. When the amino protecting group is no longer needed, it is removed by methods known to those skilled in the art. By definition the amino protecting group must be readily removable. A variety of suitable methodologies are known to those skilled in the art; see also T. W. Green and P. G. M. Wuts in “Protective Groups in Organic Chemistry, John Wiley and Sons, 1991. Suitable amino protecting groups include t-butoxycarbonyl, benzyl-oxycarbonyl, formyl, trityl, phthalimido, trichloro-acetyl, chloroacetyl, bromoacetyl, iodoacetyl, 4-phenylbenzyloxycarbonyl, 2-methylbenzyloxycarbonyl, 4-ethoxybenzyloxycarbonyl, 4-fluorobenzyloxycarbonyl, 4-chlorobenzyloxycarbonyl, 3-chlorobenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, 2,4-dichlorobenzyloxycarbonyl, 4-bromobenzyloxycarbonyl, 3-bromobenzyloxycarbonyl, 4-Nitrobenzyloxycarbonyl, 4-cyanobenzyloxycarbonyl, 2-(4-xenyl)isopropoxycarbonyl, 1,1-diphenyleth-1-yloxycarbonyl, 1,1-diphenylprop-1-yloxycarbonyl, 2-phenylprop-2-yloxycarbonyl, 2-(p-toluyl)prop-2-yloxycarbonyl, cyclopentanyloxycarbonyl, 1-methylcyclopentanyloxycarbonyl, cyclohexanyloxycarbonyl, 1-methylcyclohexanyloxycabonyl, 2-methylcyclohexanyloxycarbonyl, 2-(4-toluylsulfonyl)ethoxycarbonyl, 2-(methylsulfonyl)ethoxycarbonyl, 2-(triphenylphosphino)ethoxycarbonyl, fluorenylmethoxycarbonyl, 2-(trimethylsilyl)ethoxy-carbonyl, allyloxycarbonyl, 1-(trimethylsilylmethyl)prop-1-enyloxycarbonyl, 5-benzisoxalylmethoxycarbonyl, 4-acetoxybenzyloxycarbonyl, 2,2,2-trichloroethoxycarbonyl, 2-ethynyl-2-propoxycarbonyl, cyclopropylmethoxycarbonyl, 4-(decyloxyl)benzyloxycarbonyl, isobornyloxycarbonyl, 1-piperidyloxycarbonyl, 9-fluoroenylmethyl carbonate, —CH—CH═CH2 and phenyl-C(═N—)—H. It is preferred that the protecting group be t-butoxycarbonyl (BOC) and/or benzyloxycarbonyl (CBZ), it is more preferred that the protecting group be t-butoxycarbonyl. One skilled in the art will recognize suitable methods of introducing a t-butoxycarbonyl or benzyloxycarbonyl protecting group and may additionally consult T. W. Green and P. G. M. Wuts in “Protective Groups in Organic Chemistry, John Wiley and Sons, 1991 for guidance. The compounds of the invention may contain geometric or optical isomers as tautomers. Thus, the invention includes all tautomers and pure geometric isomers, such as the E and Z geometric isomers, as mixtures thereof. Further, the invention includes pure enantiomers and diastereomers as mixtures thereof, including racemic mixtures. The individual geometric isomers, enantiomers or diastereomers may be prepared or isolated by methods known to those skilled in the art, including but not limited to chiral chromatography; preparing diastereomers, separating the diastereomers and then converting the diastereomers into enantiomers through methods well known in the art. Compounds of the invention with designated stereochemistry can be included in mixtures, including racemic mixtures, with other enantiomers, diastereomers, geometric isomers or tautomers. In a preferred aspect, compounds of the invention are typically present in these mixtures in diastereomeric and/or enantiomeric excess of at least 50 percent. Preferably, compounds of the invention are present in these mixtures in diastereomeric and/or enantiomeric excess of at least 80 percent. More preferably, compounds of the invention with the desired stereochemistry are present in diastereomeric and/or enantiomeric excess of at least 90 percent. Even more preferably, compounds of the invention with the desired stereochemistry are present in diastereomeric and/or enantiomeric excess of at least 99 percent. Several of the compounds of formula (I) are amines, and as such form salts when reacted with acids. Pharmaceutically acceptable salts are preferred over the corresponding amines of formula (I) since they produce compounds which are more water soluble, stable and/or more crystalline. Pharmaceutically acceptable salts are any salt which retains the activity of the parent compound and does not impart any deleterious or undesirable effect on the subject to whom it is administered and in the context in which it is administered. Pharmaceutically acceptable salts include salts of both inorganic and organic acids. The preferred pharmaceutically acceptable salts include salts of the following acids acetic, aspartic, benzenesulfonic, benzoic, bicarbonic, bisulfuric, bitartaric, butyric, calcium edetate, camsylic, carbonic, chlorobenzoic, citric, edetic, edisylic, estolic, esyl, esylic, formic, fumaric, gluceptic, gluconic, glutamic, glycollylarsanilic, hexamic, hexylresorcinoic, hydrabamic, hydrobromic, hydrochloric, hydroiodic, hydroxynaphthoic, isethionic, lactic, lactobionic, maleic, malic, malonic, mandelic, methanesulfonic, methylnitric, methylsulfuric, mucic, muconic, napsylic, nitric, oxalic, p-nitromethanesulfonic, pamoic, pantothenic, phosphoric, monohydrogen phosphoric, dihydrogen phosphoric, phthalic, polygalactouronic, propionic, salicylic, stearic, succinic, sulfamic, sulfanilic, sulfonic, sulfuric, tannic, tartaric, teoclic and toluenesulfonic. For other acceptable salts, see Int. J. Pharm., 33, 201-217 (1986) and J. Pharm. Sci., 66(1), 1, (1977). The invention provides compounds, compositions, kits, and methods for inhibiting beta-secretase enzyme activity and A beta peptide production. Inhibition of beta-secretase enzyme activity halts or reduces the production of A beta from APP and reduces or eliminates the formation of beta-amyloid deposits in the brain. Methods of the Invention The compounds of the invention, and pharmaceutically acceptable salts thereof, are useful for treating humans or animals suffering from a condition characterized by a pathological form of beta-amyloid peptide, such as beta-amyloid plaques, and for helping to prevent or delay the onset of such a condition. For example, the compounds are useful for treating Alzheimer's disease, for helping prevent or delay the onset of Alzheimer's disease, for treating patients with MCI (mild cognitive impairment) and preventing or delaying the onset of Alzheimer's disease in those who would progress from MCI to AD, for treating Down's syndrome, for treating humans who have Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, for treating cerebral amyloid angiopathy and preventing its potential consequences, i.e. single and recurrent lobal hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, and diffuse Lewy body type Alzheimer's disease. The compounds and compositions of the invention are particularly useful for treating or preventing Alzheimer's disease. When treating or preventing these diseases, the compounds of the invention can either be used individually or in combination, as is best for the patient. As used herein, the term “treating” means that the compounds of the invention can be used in humans with at least a tentative diagnosis of disease. The compounds of the invention will delay or slow the progression of the disease thereby giving the individual a more useful life span. The term “preventing” means that the compounds of the invention are useful when administered to a patient who has not been diagnosed as possibly having the disease at the time of administration, but who would normally be expected to develop the disease or be at increased risk for the disease. The compounds of the invention will slow the development of disease symptoms, delay the onset of the disease, or prevent the individual from developing the disease at all. Preventing also includes administration of the compounds of the invention to those individuals thought to be predisposed to the disease due to age, familial history, genetic or chromosomal abnormalities, and/or due to the presence of one or more biological markers for the disease, such as a known genetic mutation of APP or APP cleavage products in brain tissues or fluids. In treating or preventing the above diseases, the compounds of the invention are administered in a therapeutically effective amount. The therapeutically effective amount will vary depending on the particular compound used and the route of administration, as is known to those skilled in the art. In treating a patient displaying any of the diagnosed above conditions a physician may administer a compound of the invention immediately and continue administration indefinitely, as needed. In treating patients who are not diagnosed as having Alzheimer's disease, but who are believed to be at substantial risk for Alzheimer's disease, the physician should preferably start treatment when the patient first experiences early pre-Alzheimer's symptoms such as, memory or cognitive problems associated with aging. In addition, there are some patients who may be determined to be at risk for developing Alzheimer's through the detection of a genetic marker such as APOE4 or other biological indicators that are predictive for Alzheimer's disease. In these situations, even though the patient does not have symptoms of the disease, administration of the compounds of the invention may be started before symptoms appear, and treatment may be continued indefinitely to prevent or delay the onset of the disease. Dosage Forms and Amounts The compounds of the invention can be administered orally, parenterally, (IV, IM, depo-IM, SQ, and depo SQ), sublingually, intranasally (inhalation), intrathecally, topically, or rectally. Dosage forms known to those of skill in the art are suitable for delivery of the compounds of the invention. Compositions are provided that contain therapeutically effective amounts of the compounds of the invention. The compounds are preferably formulated into suitable pharmaceutical preparations such as tablets, capsules, or elixirs for oral administration or in sterile solutions or suspensions for parenteral administration. Typically the compounds described above are formulated into pharmaceutical compositions using techniques and procedures well known in the art. About 1 to 500 mg of a compound or mixture of compounds of the invention or a physiologically acceptable salt or ester is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in those compositions or preparations is such that a suitable dosage in the range indicated is obtained. The compositions are preferably formulated in a unit dosage form, each dosage containing from about 2 to about 100 mg, more preferably about 10 to about 30 mg of the active ingredient. The term “unit dosage from” refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient. To prepare compositions, one or more compounds of the invention are mixed with a suitable pharmaceutically acceptable carrier. Upon mixing or addition of the compound(s), the resulting mixture may be a solution, suspension, emulsion, or the like. Liposomal suspensions may also be suitable as pharmaceutically acceptable carriers. These may be prepared according to methods known to those skilled in the art. The form of the resulting mixture depends upon a number of factors, including the intended mode of administration and the solubility of the compound in the selected carrier or vehicle. The effective concentration is sufficient for lessening or ameliorating at least one symptom of the disease, disorder, or condition treated and may be empirically determined. Pharmaceutical carriers or vehicles suitable for administration of the compounds provided herein include any such carriers known to those skilled in the art to be suitable for the particular mode of administration. In addition, the active materials can also be mixed with other active materials that do not impair the desired action, or with materials that supplement the desired action, or have another action. The compounds may be formulated as the sole pharmaceutically active ingredient in the composition or may be combined with other active ingredients. Where the compounds exhibit insufficient solubility, methods for solubilizing may be used. Such methods are known and include, but are not limited to, using cosolvents such as dimethylsulfoxide (DMSO), using surfactants such as Tween®, and dissolution in aqueous sodium bicarbonate. Derivatives of the compounds, such as salts or prodrugs may also be used in formulating effective pharmaceutical compositions. The concentration of the compound is effective for delivery of an amount upon administration that lessens or ameliorates at least one symptom of the disorder for which the compound is administered. Typically, the compositions are formulated for single dosage administration. The compounds of the invention may be prepared with carriers that protect them against rapid elimination from the body, such as time-release formulations or coatings. Such carriers include controlled release formulations, such as, but not limited to, microencapsulated delivery systems. The active compound is included in the pharmaceutically acceptable carrier in an amount sufficient to exert a therapeutically useful effect in the absence of undesirable side effects on the patient treated. The therapeutically effective concentration may be determined empirically by testing the compounds in known in vitro and in vivo model systems for the treated disorder. The compounds and compositions of the invention can be enclosed in multiple or single dose containers. The enclosed compounds and compositions can be provided in kits, for example, including component parts that can be assembled for use. For example, a compound inhibitor in lyophilized form and a suitable diluent may be provided as separated components for combination prior to use. A kit may include a compound inhibitor and a second therapeutic agent for co-administration. The inhibitor and second therapeutic agent may be provided as separate component parts. A kit may include a plurality of containers, each container holding one or more unit dose of the compound of the invention. The containers are preferably adapted for the desired mode of administration, including, but not limited to tablets, gel capsules, sustained-release capsules, and the like for oral administration; depot products, pre-filled syringes, ampoules, vials, and the like for parenteral administration; and patches, medipads, creams, and the like for topical administration. The concentration of active compound in the drug composition will depend on absorption, inactivation, and excretion rates of the active compound, the dosage schedule, and amount administered as well as other factors known to those of skill in the art. The active ingredient may be administered at once, or may be divided into a number of smaller doses to be administered at intervals of time. It is understood that the precise dosage and duration of treatment is a function of the disease being treated and may be determined empirically using known testing protocols or by extrapolation from in vivo or in vitro test data. It is to be noted that concentrations and dosage values may also vary with the severity of the condition to be alleviated. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that the concentration ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed compositions. If oral administration is desired, the compound should be provided in a composition that protects it from the acidic environment of the stomach. For example, the composition can be formulated in an enteric coating that maintains its integrity in the stomach and releases the active compound in the intestine. The composition may also be formulated in combination with an antacid or other such ingredient. Oral compositions will generally include an inert diluent or an edible carrier and may be compressed into tablets or enclosed in gelatin capsules. For the purpose of oral therapeutic administration, the active compound or compounds can be incorporated with excipients and used in the form of tablets, capsules, or troches. Pharmaceutically compatible binding agents and adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches, and the like can contain any of the following ingredients or compounds of a similar nature: a binder such as, but not limited to, gum tragacanth, acacia, corn starch, or gelatin; an excipient such as microcrystalline cellulose, starch, or lactose; a disintegrating agent such as, but not limited to, alginic acid and corn starch; a lubricant such as, but not limited to, magnesium stearate; a gildant, such as, but not limited to, colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; and a flavoring agent such as peppermint, methyl salicylate, or fruit flavoring. When the dosage unit form is a capsule, it can contain, in addition to material of the above type, a liquid carrier such as a fatty oil. In addition, dosage unit forms can contain various other materials, which modify the physical form of the dosage unit, for example, coatings of sugar and other enteric agents. The compounds can also be administered as a component of an elixir, suspension, syrup, wafer, chewing gum or the like. A syrup may contain, in addition to the active compounds, sucrose as a sweetening agent and certain preservatives, dyes and colorings, and flavors. The active materials can also be mixed with other active materials that do not impair the desired action, or with materials that supplement the desired action. Solutions or suspensions used for parenteral, intradermal, subcutaneous, or topical application can include any of the following components: a sterile diluent such as water for injection, saline solution, fixed oil, a naturally occurring vegetable oil such as sesame oil, coconut oil, peanut oil, cottonseed oil, and the like, or a synthetic fatty vehicle such as ethyl oleate, and the like, polyethylene glycol, glycerine, propylene glycol, or other synthetic solvent; antimicrobial agents such as benzyl alcohol and methyl parabens; antioxidants such as ascorbic acid and sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid (EDTA); buffers such as acetates, citrates, and phosphates; and agents for the adjustment of tonicity such as sodium chloride and dextrose. Parenteral preparations can be enclosed in ampoules, disposable syringes, or multiple dose vials made of glass, plastic, or other suitable material. Buffers, preservatives, antioxidants, and the like can be incorporated as required. Where administered intravenously, suitable carriers include physiological saline, phosphate buffered saline (PBS), and solutions containing thickening and solubilizing agents such as glucose, polyethylene glycol, polypropyleneglycol, and mixtures thereof. Liposomal suspensions including tissue-targeted liposomes may also be suitable as pharmaceutically acceptable carriers. These may be prepared according to methods known for example, as described in U.S. Pat. No. 4,522,811. The active compounds may be prepared with carriers that protect the compound against rapid elimination from the body, such as time-release formulations or coatings. Such carriers include controlled release formulations, such as, but not limited to, implants and microencapsulated delivery systems, and biodegradable, biocompatible polymers such as collagen, ethylene vinyl acetate, polyanhydrides, polyglycolic acid, polyorthoesters, polylactic acid, and the like. Methods for preparation of such formulations are known to those skilled in the art. The compounds of the invention can be administered orally, parenterally (IV, IM, depo-IM, SQ, and depo-SQ), sublingually, intranasally (inhalation), intrathecally, topically, or rectally. Dosage forms known to those skilled in the art are suitable for delivery of the compounds of the invention. Compounds of the invention may be administered enterally or parenterally. When administered orally, compounds of the invention can be administered in usual dosage forms for oral administration as is well known to those skilled in the art. These dosage forms include the usual solid unit dosage forms of tablets and capsules as well as liquid dosage forms such as solutions, suspensions, and elixirs. When the solid dosage forms are used, it is preferred that they be of the sustained release type so that the compounds of the invention need to be administered only once or twice daily. The oral dosage forms are administered to the patient 1, 2, 3, or 4 times daily. It is preferred that the compounds of the invention be administered either three or fewer times, more preferably once or twice daily. Hence, it is preferred that the compounds of the invention be administered in oral dosage form. It is preferred that whatever oral dosage form is used, that it be designed so as to protect the compounds of the invention from the acidic environment of the stomach. Enteric coated tablets are well known to those skilled in the art. In addition, capsules filled with small spheres each coated to protect from the acidic stomach, are also well known to those skilled in the art. When administered orally, an administered amount therapeutically effective to inhibit beta-secretase activity, to inhibit A beta production, to inhibit A beta deposition, or to treat or prevent AD is from about 0.1 mg/day to about 1,000 mg/day. It is preferred that the oral dosage is from about 1 mg/day to about 100 mg/day. It is more preferred that the oral dosage is from about 5 mg/day to about 50 mg/day. It is understood that while a patient may be started at one dose, that dose may be varied over time as the patient's condition changes. Compounds of the invention may also be advantageously delivered in a nano crystal dispersion formulation. Preparation of such formulations is described, for example, in U.S. Pat. No. 5,145,684. Nano crystalline dispersions of HIV protease inhibitors and their method of use are described in U.S. Pat. No. 6,045,829. The nano crystalline formulations typically afford greater bioavailability of drug compounds. The compounds of the invention can be administered parenterally, for example, by IV, IM, depo-IM, SC, or depo-SC. When administered parenterally, a therapeutically effective amount of about 0.5 to about 100 mg/day, preferably from about 5 to about 50 mg daily should be delivered. When a depot formulation is used for injection once a month or once every two weeks, the dose should be about 0.5 mg/day to about 50 mg/day, or a monthly dose of from about 15 mg to about 1,500 mg. In part because of the forgetfulness of the patients with Alzheimer's disease, it is preferred that the parenteral dosage form be a depo formulation. The compounds of the invention can be administered sublingually. When given sublingually, the compounds of the invention should be given one to four times daily in the amounts described above for IM administration. The compounds of the invention can be administered intranasally. When given by this route, the appropriate dosage forms are a nasal spray or dry powder, as is known to those skilled in the art. The dosage of the compounds of the invention for intranasal administration is the amount described above for IM administration. The compounds of the invention can be administered intrathecally. When given by this route the appropriate dosage form can be a parenteral dosage form as is known to those skilled in the art. The dosage of the compounds of the invention for intrathecal administration is the amount described above for IM administration. The compounds of the invention can be administered topically. When given by this route, the appropriate dosage form is a cream, ointment, or patch. Because of the amount of the compounds of the invention to be administered, the patch is preferred. When administered topically, the dosage is from about 0.5 mg/day to about 200 mg/day. Because the amount that can be delivered by a patch is limited, two or more patches may be used. The number and size of the patch is not important, what is important is that a therapeutically effective amount of the compounds of the invention be delivered as is known to those skilled in the art. The compounds of the invention can be administered rectally by suppository as is known to those skilled in the art. When administered by suppository, the therapeutically effective amount is from about 0.5 mg to about 500 mg. The compounds of the invention can be administered by implants as is known to those skilled in the art. When administering a compound of the invention by implant, the therapeutically effective amount is the amount described above for depot administration. Given a particular compound of the invention and a desired dosage form, one skilled in the art would know how to prepare and administer the appropriate dosage form. The compounds of the invention are used in the same manner, by the same routes of administration, using the same pharmaceutical dosage forms, and at the same dosing schedule as described above, for preventing disease or treating patients with MCI (mild cognitive impairment) and preventing or delaying the onset of Alzheimer's disease in those who would progress from MCI to AD, for treating or preventing Down's syndrome, for treating humans who have Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, for treating cerebral amyloid angiopathy and preventing its potential consequences, i.e. single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, and diffuse Lewy body type of Alzheimer's disease. The compounds of the invention can be used in combination, with each other or with other therapeutic agents or approaches used to treat or prevent the conditions listed above. Such agents or approaches include: acetylcholine esterase inhibitors such as tacrine (tetrahydroaminoacridine, marketed as COGNEX®), donepezil hydrochloride, (marketed as Aricept® and rivastigmine (marketed as Exelon®); gamma-secretase inhibitors; anti-inflammatory agents such as cyclooxygenase II inhibitors; anti-oxidants such as Vitamin E and ginkolides; immunological approaches, such as, for example, immunization with A beta peptide or administration of anti-A beta peptide antibodies; statins; and direct or indirect neurotropic agents such as Cerebrolysin®, AIT-082 (Emilieu, 2000, Arch. Neurol. 57:454), and other neurotropic agents of the future. In addition, the compounds of formula (I) can also be used with inhibitors of P-glycoprotein (P-gp). P-gp inhibitors and the use of such compounds are known to those skilled in the art. See for example, Cancer Research, 53, 4595-4602 (1993), Clin. Cancer Res., 2, 7-12 (1996), Cancer Research, 56, 4171-4179 (1996), International Publications WO99/64001 and WO01/10387. The important thing is that the blood level of the P-gp inhibitor be such that it exerts its effect in inhibiting P-gp from decreasing brain blood levels of the compounds of formula (A). To that end the P-gp inhibitor and the compounds of formula (A) can be administered at the same time, by the same or different route of administration, or at different times. The important thing is not the time of administration but having an effective blood level of the P-gp inhibitor. Suitable P-gp inhibitors include cyclosporin A, verapamil, tamoxifen, quinidine, Vitamin E-TGPS, ritonavir, megestrol acetate, progesterone, rapamycin, 10,11-methanodibenzosuberane, phenothiazines, acridine derivatives such as GF120918, FK506, VX-710, LY335979, PSC-833, GF-102,918 and other steroids. It is to be understood that additional agents will be found that have the same function and therefore achieve the same outcome; such compounds are also considered to be useful. The P-gp inhibitors can be administered orally, parenterally, (IV, IM, IM-depo, SQ, SQ-depo), topically, sublingually, rectally, intranasally, intrathecally and by implant. The therapeutically effective amount of the P-gp inhibitors is from about 0.1 to about 300 mg/kg/day, preferably about 0.1 to about 150 mg/kg daily. It is understood that while a patient may be started on one dose, that dose may have to be varied over time as the patient's condition changes. When administered orally, the P-gp inhibitors can be administered in usual dosage forms for oral administration as is known to those skilled in the art. These dosage forms include the usual solid unit dosage forms of tablets and capsules as well as liquid dosage forms such as solutions, suspensions and elixirs. When the solid dosage forms are used, it is preferred that they be of the sustained release type so that the P-gp inhibitors need to be administered only once or twice daily. The oral dosage forms are administered to the patient one thru four times daily. It is preferred that the P-gp inhibitors be administered either three or fewer times a day, more preferably once or twice daily. Hence, it is preferred that the P-gp inhibitors be administered in solid dosage form and further it is preferred that the solid dosage form be a sustained release form which permits once or twice daily dosing. It is preferred that what ever dosage form is used, that it be designed so as to protect the P-gp inhibitors from the acidic environment of the stomach. Enteric coated tablets are well known to those skilled in the art. In addition, capsules filled with small spheres each coated to protect from the acidic stomach, are also well known to those skilled in the art. In addition, the P-gp inhibitors can be administered parenterally. When administered parenterally they can be administered IV, IM, depo-IM, SQ or depo-SQ. The P-gp inhibitors can be given sublingually. When given sublingually, the P-gp inhibitors should be given one thru four times daily in the same amount as for IM administration. The P-gp inhibitors can be given intranasally. When given by this route of administration, the appropriate dosage forms are a nasal spray or dry powder as is known to those skilled in the art. The dosage of the P-gp inhibitors for intranasal administration is the same as for IM administration. The P-gp inhibitors can be given intrathecally. When given by this route of administration the appropriate dosage form can be a parenteral dosage form as is known to those skilled in the art. The P-gp inhibitors can be given topically. When given by this route of administration, the appropriate dosage form is a cream, ointment or patch. Because of the amount of the P-gp inhibitors needed to be administered the patch is preferred. However, the amount that can be delivered by a patch is limited. Therefore, two or more patches may be required. The number and size of the patch is not important, what is important is that a therapeutically effective amount of the P-gp inhibitors be delivered as is known to those skilled in the art. The P-gp inhibitors can be administered rectally by suppository as is known to those skilled in the art. The P-gp inhibitors can be administered by implants as is known to those skilled in the art. There is nothing novel about the route of administration nor the dosage forms for administering the P-gp inhibitors. Given a particular P-gp inhibitor, and a desired dosage form, one skilled in the art would know how to prepare the appropriate dosage form for the P-gp inhibitor. It should be apparent to one skilled in the art that the exact dosage and frequency of administration will depend on the particular compounds of the invention administered, the particular condition being treated, the severity of the condition being treated, the age, weight, general physical condition of the particular patient, and other medication the individual may be taking as is well known to administering physicians who are skilled in this art. Inhibition of APP Cleavage The compounds of the invention inhibit cleavage of APP between Met595 and Asp596 numbered for the APP695 isoform, or a mutant thereof, or at a corresponding site of a different isoform, such as APP751 or APP770, or a mutant thereof (sometimes referred to as the “beta secretase site”). While not wishing to be bound by a particular theory, inhibition of beta-secretase activity is thought to inhibit production of beta amyloid peptide (A beta). Inhibitory activity is demonstrated in one of a variety of inhibition assays, whereby cleavage of an APP substrate in the presence of a beta-secretase enzyme is analyzed in the presence of the inhibitory compound, under conditions normally sufficient to result in cleavage at the beta-secretase cleavage site. Reduction of APP cleavage at the beta-secretase cleavage site compared with an untreated or inactive control is correlated with inhibitory activity. Assay systems that can be used to demonstrate efficacy of the compound inhibitors of the invention are known. Representative assay systems are described, for example, in U.S. Pat. Nos. 5,942,400, 5,744,346, as well as in the Examples below. The enzymatic activity of beta-secretase and the production of A beta can be analyzed in vitro or in vivo, using natural, mutated, and/or synthetic APP substrates, natural, mutated, and/or synthetic enzyme, and the test compound. The analysis may involve primary or secondary cells expressing native, mutant, and/or synthetic APP and enzyme, animal models expressing native APP and enzyme, or may utilize transgenic animal models expressing the substrate and enzyme. Detection of enzymatic activity can be by analysis of one or more of the cleavage products, for example, by immunoassay, fluorometric or chromogenic assay, HPLC, or other means of detection. Inhibitory compounds are determined as those having the ability to decrease the amount of beta-secretase cleavage product produced in comparison to a control, where beta-secretase mediated cleavage in the reaction system is observed and measured in the absence of inhibitory compounds. Beta-Secretase Various forms of beta-secretase enzyme are known, and are available and useful for assay of enzyme activity and inhibition of enzyme activity. These include native, recombinant, and synthetic forms of the enzyme. Human beta-secretase is known as Beta Site APP Cleaving Enzyme (BACE), Asp2, and memapsin 2, and has been characterized, for example, in U.S. Pat. No. 5,744,346 and published PCT patent applications WO98/22597, WO00/03819, WO01/23533, and WO00/17369, as well as in literature publications (Hussain et al., 1999, Mol. Cell. Neurosci. 14:419-427; Vassar et al., 1999, Science 286:735-741; Yan et al., 1999, Nature 402:533-537; Sinha et al., 1999, Nature 40:537-540; and Lin et al., 2000, PNAS USA 97:1456-1460). Synthetic forms of the enzyme have also been described (WO98/22597 and WO00/17369). Beta-secretase can be extracted and purified from human brain tissue and can be produced in cells, for example mammalian cells expressing recombinant enzyme. Preferred compounds are effective to inhibit 50% of beta-secretase enzymatic activity at a concentration of less than 50 micromolar, preferably at a concentration of 10 micromolar or less, more preferably 1 micromolar or less, and most preferably 10 nanomolar or less. APP Substrate Assays that demonstrate inhibition of beta-secretase-mediated cleavage of APP can utilize any of the known forms of APP, including the 695 amino acid “normal” isotype described by Kang et al., 1987, Nature 325:733-6, the 770 amino acid isotype described by Kitaguchi et. al., 1981, Nature 331:530-532, and variants such as the Swedish Mutation (KM670-1NL) (APP-SW), the London Mutation (V7176F), and others. See, for example, U.S. Pat. No. 5,766,846 and also Hardy, 1992, Nature Genet. 1:233-234, for a review of known variant mutations. Additional useful substrates include the dibasic amino acid modification, APP-KK disclosed, for example, in WO 00/17369, fragments of APP, and synthetic peptides containing the beta-secretase cleavage site, wild type (WT) or mutated form, e.g., SW, as described, for example, in U.S. Pat. No 5,942,400 and WO00/03819. The APP substrate contains the beta-secretase cleavage site of APP (KM-DA or NL-DA) for example, a complete APP peptide or variant, an APP fragment, a recombinant or synthetic APP, or a fusion peptide. Preferably, the fusion peptide includes the beta-secretase cleavage site fused to a peptide having a moiety useful for enzymatic assay, for example, having isolation and/or detection properties. A useful moiety may be an antigenic epitope for antibody binding, a label or other detection moiety, a binding substrate, and the like. Antibodies Products characteristic of APP cleavage can be measured by immunoassay using various antibodies, as described, for example, in Pirttila et al., 1999, Neuro. Lett. 249:21-4, and in U.S. Pat. No. 5,612,486. Useful antibodies to detect A beta include, for example, the monoclonal antibody 6E10 (Senetek, St. Louis, Mo.) that specifically recognizes an epitope on amino acids 1-16 of the A beta peptide; antibodies 162 and 164 (New York State Institute for Basic Research, Staten Island, N.Y.) that are specific for human A beta 1-40 and 1-42, respectively; and antibodies that recognize the junction region of beta-amyloid peptide, the site between residues 16 and 17, as described in U.S. Pat. No. 5,593,846. Antibodies raised against a synthetic peptide of residues 591 to 596 of APP and SW192 antibody raised against 590-596 of the Swedish mutation are also useful in immunoassay of APP and its cleavage products, as described in U.S. Pat. Nos. 5,604,102 and 5,721,130. Assay Systems Assays for determining APP cleavage at the beta-secretase cleavage site are well known in the art. Exemplary assays, are described, for example, in U.S. Pat. Nos. 5,744,346 and 5,942,400, and described in the Examples below. Cell Free Assays Exemplary assays that can be used to demonstrate the inhibitory activity of the compounds of the invention are described, for example, in WO00/17369, WO 00/03819, and U.S. Pat. Nos. 5,942,400 and 5,744,346. Such assays can be performed in cell-free incubations or in cellular incubations using cells expressing a beta-secretase and an APP substrate having a beta-secretase cleavage site. An APP substrate containing the beta-secretase cleavage site of APP, for example, a complete APP or variant, an APP fragment, or a recombinant or synthetic APP substrate containing the amino acid sequence: KM-DA or NL-DA, is incubated in the presence of beta-secretase enzyme, a fragment thereof, or a synthetic or recombinant polypeptide variant having beta-secretase activity and effective to cleave the beta-secretase cleavage site of APP, under incubation conditions suitable for the cleavage activity of the enzyme. Suitable substrates optionally include derivatives that may be fusion proteins or peptides that contain the substrate peptide and a modification useful to facilitate the purification or detection of the peptide or its beta-secretase cleavage products. Useful modifications include the insertion of a known antigenic epitope for antibody binding; the linking of a label or detectable moiety, the linking of a binding substrate, and the like. Suitable incubation conditions for a cell-free in vitro assay include, for example: approximately 200 nanomolar to 10 micromolar substrate, approximately 10 to 200 picomolar enzyme, and approximately 0.1 nanomolar to 10 micromolar inhibitor compound, in aqueous solution, at an approximate pH of 4-7, at approximately 37 degrees C., for a time period of approximately 10 minutes to 3 hours. These incubation conditions are exemplary only, and can be varied as required for the particular assay components and/or desired measurement system. Optimization of the incubation conditions for the particular assay components should account for the specific beta-secretase enzyme used and its pH optimum, any additional enzymes and/or markers that might be used in the assay, and the like. Such optimization is routine and will not require undue experimentation. One useful assay utilizes a fusion peptide having maltose binding protein (MBP) fused to the C-terminal 125 amino acids of APP-SW. The MBP portion is captured on an assay substrate by anti-MBP capture antibody. Incubation of the captured fusion protein in the presence of beta-secretase results in cleavage of the substrate at the beta-secretase cleavage site. Analysis of the cleavage activity can be, for example, by immunoassay of cleavage products. One such immunoassay detects a unique epitope exposed at the carboxy terminus of the cleaved fusion protein, for example, using the antibody SW192. This assay is described, for example, in U.S. Pat. No 5,942,400. Cellular Assay Numerous cell-based assays can be used to analyze beta-secretase activity and/or processing of APP to release A beta. Contact of an APP substrate with a beta-secretase enzyme within the cell and in the presence or absence of a compound inhibitor of the invention can be used to demonstrate beta-secretase inhibitory activity of the compound. Preferably, assay in the presence of a useful inhibitory compound provides at least about 30%, most preferably at least about 50% inhibition of the enzymatic activity, as compared with a non-inhibited control. In one embodiment, cells that naturally express beta-secretase are used. Alternatively, cells are modified to express a recombinant beta-secretase or synthetic variant enzyme as discussed above. The APP substrate may be added to the culture medium and is preferably expressed in the cells. Cells that naturally express APP, variant or mutant forms of APP, or cells transformed to express an isoform of APP, mutant or variant APP, recombinant or synthetic APP, APP fragment, or synthetic APP peptide or fusion protein containing the beta-secretase APP cleavage site can be used, provided that the expressed APP is permitted to contact the enzyme and enzymatic cleavage activity can be analyzed. Human cell lines that normally process A beta from APP provide a useful means to assay inhibitory activities of the compounds of the invention. Production and release of A beta and/or other cleavage products into the culture medium can be measured, for example by immunoassay, such as Western blot or enzyme-linked immunoassay (EIA) such as by ELISA. Cells expressing an APP substrate and an active beta-secretase can be incubated in the presence of a compound inhibitor to demonstrate inhibition of enzymatic activity as compared with a control. Activity of beta-secretase can be measured by analysis of one or more cleavage products of the APP substrate. For example, inhibition of beta-secretase activity against the substrate APP would be expected to decrease release of specific beta-secretase induced APP cleavage products such as A beta. Although both neural and non-Neural cells process and release A beta, levels of endogenous beta-secretase activity are low and often difficult to detect by EIA. The use of cell types known to have enhanced beta-secretase activity, enhanced processing of APP to A beta, and/or enhanced production of A beta are therefore preferred. For example, transfection of cells with the Swedish Mutant form of APP (APP-SW); with APP-KK; or with APP-SW-KK provides cells having enhanced beta-secretase activity and producing amounts of A beta that can be readily measured. In such assays, for example, the cells expressing APP and beta-secretase are incubated in a culture medium under conditions suitable for beta-secretase enzymatic activity at its cleavage site on the APP substrate. On exposure of the cells to the compound inhibitor, the amount of A beta released into the medium and/or the amount of CTF99 fragments of APP in the cell lysates is reduced as compared with the control. The cleavage products of APP can be analyzed, for example, by immune reactions with specific antibodies, as discussed above. Preferred cells for analysis of beta-secretase activity include primary human neuronal cells, primary transgenic animal neuronal cells where the transgene is APP, and other cells such as those of a stable 293 cell line expressing APP, for example, APP-SW. In vivo Assays: Animal Models Various animal models can be used to analyze beta-secretase activity and/or processing of APP to release A beta, as described above. For example, transgenic animals expressing APP substrate and beta-secretase enzyme can be used to demonstrate inhibitory activity of the compounds of the invention. Certain transgenic animal models have been described, for example, in U.S. Pat. Nos. 5,877,399; 5,612,486; 5,387,742; 5,720,936; 5,850,003; 5,877,015, and 5,811,633, and in Ganes et al., 1995, Nature 373:523. Preferred are animals that exhibit characteristics associated with the pathophysiology of AD. Administration of the compound inhibitors of the invention to the transgenic mice described herein provides an alternative method for demonstrating the inhibitory activity of the compounds. Administration of the compounds in a pharmaceutically effective carrier and via an administrative route that reaches the target tissue in an appropriate therapeutic amount is also preferred. Inhibition of beta-secretase mediated cleavage of APP at the beta-secretase cleavage site and of A beta release can be analyzed in these animals by measure of cleavage fragments in the animal's body fluids such as cerebral fluid or tissues. Analysis of brain tissues for A beta deposits or plaques is preferred. On contacting an APP substrate with a beta-secretase enzyme in the presence of an inhibitory compound of the invention and under conditions sufficient to permit enzymatic mediated cleavage of APP and/or release of A beta from the substrate, the compounds of the invention are effective to reduce beta-secretase-mediated cleavage of APP at the beta-secretase cleavage site and/or effective to reduce released amounts of A beta. Where such contacting is the administration of the inhibitory compounds of the invention to an animal model, for example, as described above, the compounds are effective to reduce A beta deposition in brain tissues of the animal, and to reduce the number and/or size of beta amyloid plaques. Where such administration is to a human subject, the compounds are effective to inhibit or slow the progression of disease characterized by enhanced amounts of A beta, to slow the progression of AD in the, and/or to prevent onset or development of AD in a patient at risk for the disease. Unless defined otherwise, all scientific and technical terms used herein have the same meaning as commonly understood by one of skill in the art to which this invention belongs. All patents and publications referred to herein are hereby incorporated by reference for all purposes. Definitions The definitions and explanations below are for the terms as used throughout this entire document including both the specification and the claims. It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. Where multiple substituents are indicated as being attached to a structure, it is to be understood that the substituents can be the same or different. Thus for example “Rm optionally substituted with 1, 2 or 3 Rq groups” indicates that Rm is substituted with 1, 2, or 3 Rq groups where the Rq groups can be the same or different. APP, amyloid precursor protein, is defined as any APP polypeptide, including APP variants, mutations, and isoforms, for example, as disclosed in U.S. Pat. No. 5,766,846. A beta, amyloid beta peptide, is defined as any peptide resulting from beta-secretase mediated cleavage of APP, including peptides of 39, 40, 41, 42, and 43 amino acids, and extending from the beta-secretase cleavage site to amino acids 39, 40, 41, 42, or 43. Beta-secretase (BACE1, Asp2, Memapsin 2) is an aspartyl protease that mediates cleavage of APP at the amino-terminal edge of A beta. Human beta-secretase is described, for example, in WO00/17369. Pharmaceutically acceptable refers to those properties and/or substances that are acceptable to the patient from a pharmacological/toxicological point of view and to the manufacturing pharmaceutical chemist from a physical/chemical point of view regarding composition, formulation, stability, patient acceptance and bioavailability. A therapeutically effective amount is defined as an amount effective to reduce or lessen at least one symptom of the disease being treated or to reduce or delay onset of one or more clinical markers or symptoms of the disease. By “alkyl” and “C1-C6 alkyl” in the present invention is meant straight or branched chain alkyl groups having 1-6 carbon atoms, such as, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl, and 3-methylpentyl. It is understood that in cases where an alkyl chain of a substituent (e.g. of an alkyl, alkoxy or alkenyl group) is shorter or longer than 6 carbons, it will be so indicated in the second “C” as, for example, “C1-C10” indicates a maximum of 10 carbons. By “alkoxy” and “C1-C6 alkoxy” in the present invention is meant straight or branched chain alkyl groups having 1-6 carbon atoms, attached through at least one divalent oxygen atom, such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy, neopentoxy, hexoxy, and 3-methylpentoxy. By the term “halogen” in the present invention is meant fluorine, bromine, chlorine, and iodine. “Alkenyl” and “C2-C6 alkenyl” means straight and branched hydrocarbon radicals having from 2 to 6 carbon atoms and from one to three double bonds and includes, for example, ethenyl, propenyl, 1-but-3-enyl, 1-pent-3-enyl, 1-hex-5-enyl and the like. “Alkynyl” and “C2-C6 alkynyl” means straight and branched hydrocarbon radicals having from 2 to 6 carbon atoms and one or two triple bonds and includes ethynyl, propynyl, butynyl, pentyn-2-yl and the like. As used herein, the term “cycloalkyl” refers to saturated carbocyclic radicals having three to twelve carbon atoms. The cycloalkyl can be monocyclic, or a polycyclic fused system. Examples of such radicals include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. Preferred cycloalkyl groups are cyclopentyl, cyclohexyl, and cycloheptyl. The cycloalkyl groups herein are unsubstituted or, as specified, substituted in one or more substitutable positions with various groups. For example, such cycloalkyl groups may be optionally substituted with, for example, C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxy, cyano, nitro, amino, mono(C1-C6)alkylamino, di(C1-C6)alkylamino, C2-C6alkenyl, C2-C6alkynyl, C1-C6 haloalkyl, C1-C6 haloalkoxy, amino(C1-C6)alkyl, mono(C1-C6)alkylamino(C1-C6)alkyl or di(C1-C6)alkylamino(C1-C6)alkyl. By “aryl” is meant an aromatic carbocyclic group having a single ring (e.g., phenyl) or multiple condensed rings in which at least one is aromatic, (e.g., 1,2,3,4-tetrahydronaphthyl, naphthyl), which is optionally mono-, di-, or trisubstituted. Preferred aryl groups of the present invention are phenyl, 1—Naphthyl, 2-naphthyl, indanyl, indenyl, dihydronaphthyl, fluorenyl, tetralinyl or 6,7,8,9-tetrahydro-5H-benzo[a]cycloheptenyl. The aryl groups herein are unsubstituted or, as specified, substituted in one or more substitutable positions with various groups. For example, such aryl groups may be optionally substituted with, for example, C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxy, cyano, nitro, amino, mono(C1-C6)alkylamino, di(C1-C6)alkylamino, C2-C6alkenyl, C2-C6alkynyl, C1-C6 haloalkyl, C1-C6 haloalkoxy, amino(C1-C6)alkyl, mono(C1-C6)alkylamino (C1-C6)alkyl or di (C1-C6)alkylamino (C1-C6)alkyl. By “heteroaryl” is meant one or more aromatic ring systems of 5-, 6-, or 7-membered rings which includes fused ring systems of 9-11 atoms containing at least one and up to four heteroatoms selected from nitrogen, oxygen, or sulfur. Preferred heteroaryl groups of the present invention include pyridinyl, pyrimidinyl, quinolinyl, benzothienyl, indolyl, indolinyl, pryidazinyl, pyrazinyl, isoindolyl, isoquinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, imidazolyl, isoxazolyl, pyrazolyl, oxazolyl, thiazolyl, indolizinyl, indazolyl, benzothiazolyl, benzimidazolyl, benzofuranyl, furanyl, thienyl, pyrrolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, oxazolopyridinyl, imidazopyridinyl, isothiazolyl, naphthyridinyl, cinnolinyl, carbazolyl, beta-carbolinyl, isochromanyl, chromanyl, tetrahydroisoquinolinyl, isoindolinyl, isobenzotetrahydrofuranyl, isobenzotetrahydrothienyl, isobenzothienyl, benzoxazolyl, pyridopyridinyl, benzotetrahydrofuranyl, benzotetrahydrothienyl, purinyl, benzodioxolyl, triazinyl, phenoxazinyl, phenothiazinyl, pteridinyl, benzothiazolyl, imidazopyridinyl, imidazothiazolyl, dihydrobenzisoxazinyl, benzisoxazinyl, benzoxazinyl, dihydrobenzisothiazinyl, benzopyranyl, benzothiopyranyl, coumarinyl, isocoumarinyl, chromonyl, chromanonyl, pyridinyl-N-oxide, tetrahydroquinolinyl, dihydroquinolinyl, dihydroquinolinonyl, dihydroisoquinolinonyl, dihydrocoumarinyl, dihydroisocoumarinyl, isoindolinonyl, benzodioxanyl, benzoxazolinonyl, pyrrolyl N-oxide, pyrimidinyl N-oxide, pyridazinyl N-oxide, pyrazinyl N-oxide, quinolinyl N-oxide, indolyl N-oxide, indolinyl N-oxide, isoquinolyl N-oxide, quinazolinyl N-oxide, quinoxalinyl N-oxide, phthalazinyl N-oxide, imidazolyl N-oxide, isoxazolyl N-oxide, oxazolyl N-oxide, thiazolyl N-oxide, indolizinyl N-oxide, indazolyl N-oxide, benzothiazolyl N-oxide, benzimidazolyl N-oxide, pyrrolyl N-oxide, oxadiazolyl N-oxide, thiadiazolyl N-oxide, triazolyl N-oxide, tetrazolyl N-oxide, benzothiopyranyl S-oxide, benzothiopyranyl S,S-dioxide, tetrahydrocarbazole, tetrahydrobetacarboline. The heteroaryl groups herein are unsubstituted or, as specified, substituted in one or more substitutable positions with various groups. For example, such heteroaryl groups may be optionally substituted with, for example, C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxy, cyano, nitro, amino, mono(C1-C6)alkylamino, di(C1-C6)alkylamino, C2-C6alkenyl, C2-C6alkynyl, C1-C6 haloalkyl, C1-C6 haloalkoxy, amino (C1-C6)alkyl, mono(C1-C6)alkylamino(C1-C6)alkyl or di(C1-C6)alkylamino(C1-C6)alkyl. By “heterocycle”, “heterocycloalkyl” or “heterocyclyl” is meant one or more carbocyclic ring systems of 4-, 5-, 6-, or 7-membered rings which includes fused ring systems of 9-11 atoms containing at least one and up to four heteroatoms selected from nitrogen, oxygen, or sulfur. Preferred heterocycles of the present invention include morpholinyl, thiomorpholinyl, thiomorpholinyl S-oxide, thiomorpholinyl S,S-dioxide, piperazinyl, homopiperazinyl, pyrrolidinyl, pyrrolinyl, tetrahydropyranyl, piperidinyl, tetrahydrofuranyl, tetrahydrothienyl, homopiperidinyl, homomorpholinyl, homothiomorpholinyl, homothiomorpholinyl S,S-dioxide, oxazolidinonyl, dihydropyrazolyl, dihydropyrrolyl, dihydropyrazinyl, dihydropyridinyl, dihydropyrimidinyl, dihydrofuryl, dihydropyranyl, tetrahydrothienyl S-oxide, tetrahydrothienyl S,S-dioxide and homothiomorpholinyl S-oxide. The heterocycle groups herein are unsubstituted or, as specified, substituted in one or more substitutable positions with various groups. For example, such heterocycle groups may be optionally substituted with, for example, C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxy, cyano, nitro, amino, mono(C1-C6)alkylamino, di(C1-C6)alkylamino, C2-C6alkenyl, C2-C6alkynyl, C1-C6 haloalkyl, C1-C6 haloalkoxy, amino(C1-C6)alkyl, mono(C1-C6)alkylamino (C1-C6)alkyl, di(C1-C6)alkylamino(C1-C6)alkyl or ═O. All patents and publications referred to herein are hereby incorporated by reference for all purposes. Structures were named using Name Pro IUPAC Naming Software, version 5.09, available from Advanced Chemical Development, Inc., 90 Adelaide Street West, Toronto, Ontario, M5H 3V9, Canada, or with Chemdraw Ultra, version 8.0.3, available from Cambridgesoft Corporation, Cambridge, Mass. 02140, USA. The present invention may be better understood with reference to the following examples. These examples are intended to be representative of specific embodiments of the invention, and are not intended as limiting the scope of the invention. CHEMISTRY EXAMPLES The following abbreviations may be used in the Examples: EDC stands for 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide or the hydrochloride salt; DIEA stands for diisopropylethylamine; PyBOP stands for benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate; HATU stands for O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; THF stands for tetrahydrofuran; EtBz stands for ethylbenzene; DCM stands for dichloromethane. Example 1 1-(3-Ethyl-phenyl)-cyclohexanol from 1-bromo-3-ethylbenzene Magnesium turnings (1.35 g, 55.53 mmol) were activated via vigorous stirring overnight under N2 (g) inlet. A few crystals of iodine were added to the flask, which was then flamed-dried under vacuum. Anhydrous THF (3 mL) was added to the reaction flask followed by 1-bromo-3-ethylbenzene (Avocado, 2.0 mL, 14.59 mmol). The reaction was initiated after briefly heating with a heat gun. To this was added the remainder of 1-bromo-3-ethylbenzene (1.7 mL, 12.43 mmol) in a THF solution (15 mL). The reaction mixture was refluxed for 2 h. A cyclohexanone (2.2 mL, 21.22 mmol) in THF (8 mL) solution was added once the flask was cooled to 0° C. After 3.5 h the reaction mixture was quenched with H2O over an ice bath and partitioned between Et2O and H2O. The organic layer was removed and acidified with 1N HCl. The organic layer was separated, dried (Na2SO4), and concentrated under reduced pressure. The residue was purified by flash chromatography (100% CHCl3) to give the desired alcohol (4.152 g, 96%): mass spec (CI) 187.1 (M-16). Example 2 1-(1-Azido-cyclohexyl)-3-ethyl-benzene from 1-(3-Ethyl-phenyl)-cyclohexanol 1-(3-Ethyl-phenyl)-cyclohexanol (4.02 g, 19.68 mmol) in anhydrous chloroform (45 mL) was cooled to 0° C. under N2 (g) inlet. Sodium azide (3.97 g, 61.07 mmol) was added followed by dropwise addition of trifluoroacetic acid (7.8 mL, 101.25 mmol). The reaction mixture was refluxed for 2 h and allowed to stir at rt o/n. This was then partitioned between H2O and Et2O. The aqueous layer was removed and the mixture was washed with H2O followed by 1.0N NH4OH. The organic layer was separated, dried (Na2SO4), and concentrated under reduced pressure. The crude product was used without further purification (3.30 g, 73%): mass spec (CI) 187.1 (M-42). Example 3 1-(3-Ethyl-phenyl)-cyclohexylamine from 1-(1-azido-cyclohexyl)-3-ethyl-benzene A solution of 1-(1-azido-cyclohexyl)-3-ethyl-benzene (1.94 g, 8.39 mmol) in Et2O (8 mL) was added dropwise to a suspension of lithium aluminum hydride (0.31 g, 8.17 mmol) in THF (30 mL). This was stirred at rt under N2 (g) inlet for 3 h, whereupon the reaction was quenched with 1.0N NaOH. The reaction mixture was then partitioned between EtO2 and 1N HCl. The aqueous layer was collected and basified with 2N NH4OH and extracted with CHCl3. The organic layer was separated, dried (Na2SO4), and concentrated under reduced pressure. The crude product was used without further purification: mass spec (CI) 187.1 (M-16). Example 4 Preparation of 7-Bromo-1-tetralone (note 1) A 500 mL three-necked flask fitted with an addition funnel, reflux condenser and thermometer was charged with aluminum chloride (33.34 g, 250 mmol) and heated to 75-80° C. 1-Tetralone (14.6 g, 13.3 mL, 100 mmol) was added dropwise over 10 min. The resulting brown slurry was stirred for 3 min before dropwise addition of bromine (19.21 g, 6.15 ml, 120 mmol) over 15 min. The mixture was stirred for 5 min and then poured into a mixture of ice (300 g) and 12N HCl (40 mL). The mixture was stirred until the aluminum chloride was dissolved and then diluted with water (200 mL). The mixture was extracted with diethyl ether (3×300 mL) and the combined organics were washed with water (2×300 mL), dried (sodium sulfate), filtered and evaporated in vacuo to give a dark brown mixture of 5- and 7-bromo-1-tetralone. The isomers were separated using silica gel flash chromatography (Biotage Flash 75, elution solvent 20/1 hexanes:MTBE) to yield 5-bromo-1-tetralone (11.59 g, 51%) and 7-bromo-1-tetralone (9.45 g, 42%). [Note 1. Procedure: Cornelius, L. A. M.; Combs, D. W. Synthetic Communications 1994, 24, 2777-2788]. Example 5 (R)-7-Ethyltetralin-1-ol (see note 2) 7-Ethyl-1-tetralone (2.29 g, 13.1 mmol) was placed in a 100 mL round bottomed flask and dissolved in anhydrous THF (40 mL). Activated 4A molecular sieves were added and the mixture was aged for 2 h before transferring via cannula to a 250 ml three-necked round bottom flask fitted with a dropping funnel, thermometer, and a nitrogen inlet. The solution was cooled to −25° C. and 1M (S)-tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrollo[1,2-c][1,3,2]oxazaborole in toluene (1.3 mL, 1.3 mmol, notes 3 and 4) was added. The dropping funnel was charged with a solution of borane-methylsulfide (0.70 g, 0.87 mL, 9.3 mmol) in anhydrous THF (15 mL, dried over 4A sieves). The borane solution was added dropwise over 20 min keeping the reaction temperature less than −20° C. The mixture was stirred for 1 h at −15 to −20° C. whereupon TLC analysis indicated consumption of the ketone. The reaction was quenched by careful addition of methanol (15 mL) at −20° C. and allowed to warm to ambient temperature and stir for 16 h. The volatiles were removed in vacuo and the residue was purified by silica gel chromatography (Biotage Flash 65, elution solvent 6/1 hexanes:ethyl acetate) to yield (R)-7-ethyltetralin-1-ol (1.82 g, 79%, note 5). [Note 2. Procedure adapted from: Jones, T. K.; Mohan, J. J.; Xavier, L. C.; Blacklock, T. J.; Mathre, D. J.; Sohar, P.; Turner-Jones, E. T.; Reamer, R. A.; Roberts, F. E.; Grabowski, E. J. J. J. Org. Chem. 1991, 56, 763-769. Note 3. Source: Aldrich cat. # 45,770-1, “(S)-2-methyl-CBS-oxazaborolidine”. Use of the S-auxilliary produces R-alcohols. Note 4. The reference in note 1 indicates that use of 5 mol % oxazaborolidine catalyst gives comparable results. Note 5. Analytical chiral HPLC indicated a 96.6/3.4 mixture of enantiomers (Chirocel OD-H column, isocratic elution 2:98 IPA/hexane, 0.9 mL/min, RT 15.2 min (minor enantiomer), 17.5 min (major enantiomer)]. Example 6 (S)-7-Ethyl-1,2,3,4-tetrahydro-1-napthylamine hydrochloride (see note 6) A solution of (R)-7-ethyltetralin-1-ol (1.77 g, 10.1 mmol) in toluene (25 mL) was cooled in an ice bath and treated with diphenylphosphorylazide (DPPA, 3.3 g, 2.7 mL, 12 mmol). A solution of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 1.8 g, 1.8 mL, 12 mmol) in toluene (8 mL) was added over 20 min and the mixture was allowed to stir at 0° C. for 2 h and ambient temp for 16 h. The mixture was filtered through a pad of silica gel (eluted 6:1 hexanes/ethyl acetate) to remove precipitates and the volatiles were removed in vacuo to give an oily residue of the crude S-azide. This material was used directly in the next step without further characterization. The azide was dissolved in dry THF (20 mL) and added dropwise at RT to a slurry of lithium aluminum hydride (0.459 g, 12 mmol) in dry THF (20 mL). The mixture was stirred at RT for 1 h and then heated to reflux for 1 h. The reaction was cooled to RT and quenched by successive addition of water (0.45 mL), 15% aq NaOH (0.45 mL) and water (1.4 mL). The resulting mixture was stirred for 1 h and then filtered through a pad of Celite (eluted diethyl ether). The volatiles were removed in vacuo and the residue taken up into ethyl acetate (40 mL) and treated with 4N HCl in dioxane (3 mL). The resulting precipitate was filtered (wash ethyl acetate), collected and vacuum dried to give (S)-7-ethyl-1,2,3,4-tetrahydro-1-napthylamine hydrochloride as a white solid (1.09 g, 51%, note 7). [Note 6. Procedure adapted from: Rover, S.; Adam, G.; Cesura, A. M.; Galley, G.; Jenck, F.; Monsma Jr., F. J.; Wichmann, J.; Dautzenberg, F. M. J. Med. Chem. 2000, 43, 1329-1338. Authors report a somewhat diminished yield due to partial formation of a dihydronapthalene via elimination of the hydroxyl moiety]. [Note 7. Analytical chiral HPLC indicated a 96:4 mixture of enantiomers (Daicel Crownpak (−) column, isocratic elution 10% methanol in water (0.1% TFA), 0.8 mL/min, RT 56.2 min (minor enantiomer), 78.2 min (major enantiomer)]. Example 7 (R)-7-Bromotetralin-1-ol (see note 8) 7-Bromo-1-tetralone (8.28 g, 36.8 mmol) was placed in a 250 mL round bottomed flask and dissolved in anhydrous THF (100 mL). Activated 4A molecular sieves were added and the mixture was aged for 5 h before transferring via cannula to a 500 ml three-necked round bottom flask fitted with a dropping funnel, thermometer, and a nitrogen inlet. The solution was cooled to −25° C. and 1M (S)-tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrollo[1,2-c][1,3,2]oxazaborole in toluene (3.7 mL, 3.7 mmol, notes 9 and 10) was added. The dropping funnel was charged with a solution of borane-methylsulfide (1.96 g, 2.44 mL, 25.8 mmol) in anhydrous THF (45 mL, dried over 4A sieves). The borane solution was added dropwise over 20 min keeping the reaction temperature less than −20° C. The mixture was stirred for 1 h at −15 to −20° C. whereupon TLC analysis indicated consumption of the ketone. The reaction was quenched by careful addition of methanol (50 mL) at −20° C. and allowed to warm to ambient temperature and stir for 16 h. The volatiles were removed in vacuo and the residue was purified by silica gel chromatography (Biotage Flash 65, elution solvent 6/1 hexanes:ethyl acetate) to yield (R)-7-bromotetralin-1-ol (8.18 g, 98%, notes 11 and 12). [Note 8. Procedure adapted from: Jones, T. K.; Mohan, J. J.; Xavier, L. C.; Blacklock, T. J.; Mathre, D. J.; Sohar, P.; Turner-Jones, E. T.; Reamer, R. A.; Roberts, F. E.; Grabowski, E. J. J. J. Org. Chem. 1991, 56, 763-769. Note 9. Source: Aldrich cat. # 45,770-1, “(S)-2-methyl-CBS-oxazaborolidine”. Use of the S-auxilliary produces R-alcohols. Note 10. The reference in note 1 indicates that use of 5 mol % oxazaborolidine catalyst gives comparable results. Note 11. Analytical chiral HPLC indicated a 98:2 mixture of enantiomers (Chirocel OD-H column, isocratic elution 2:98 IPA/hexane, 0.9 mL/min, RT 18.4 min (minor enantiomer), 19.5 min (major enantiomer). Note 12. Proton NMR was consistent with that previously reported for the racemate: Saito, M.; Kayama, Y.; Watanabe, T.; Fukushima, H.; Hara, T. J. Med. Chem. 1980, 23, 1364-1372]. Example 8 (S)-7-Bromo-1,2,3,4-tetrahydro-1-naphylamine hydrochloride, (see note 13). A solution of (R)-7-bromotetralin-1-ol (8.13 g, 35.8 mmol) in toluene (75 mL) was cooled in an ice bath and treated with diphenylphosphorylazide (DPPA, 11.8 g, 9.6 mL, 43 mmol). A solution of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 6.5 g, 6.4 mL, 43 mmol) in toluene (20 mL) was added over 35 min and the mixture was allowed to stir at 0° C. for 2 h and ambient temp for 16 h. The mixture was filtered through a pad of silica gel (eluted 6:1 hexanes/ethyl acetate) to remove precipitates and the volatiles were removed in vacuo to give an oily residue of the crude S-azide. This material was used directly in the next step without further characterization. The azide was dissolved in dry THF (60 mL) and added dropwise at RT to a slurry of lithium aluminum hydride (1.63 g, 43 mmol) in dry THF (50 mL). The mixture was stirred at RT for 1 h and then heated to reflux for 1 h. The reaction was cooled to RT and quenched by successive addition of water (1.63 mL), 15% aq NaOH (1.63 mL) and water (4.9 mL). The resulting mixture was stirred for 1 h and then filtered through a pad of Celite (eluted diethyl ether). The volatiles were removed in vacuo and the residue taken up into ethyl acetate (120 mL) and treated with 4N HCl in dioxane (10 mL). The resulting precipitate was filtered (wash ethyl acetate), collected and vacuum dried to give (S)-7-bromo-1,2,3,4-tetrahydro-1-naphylamine hydrochloride as a white solid (6.23 g, 66.3%, note 14). [Note 13. Procedure adapted from: Rover, S.; Adam, G.; Cesura, A. M.; Galley, G.; Jenck, F.; Monsma Jr., F. J.; Wichmann, J.; Dautzenberg, F. M. J. Med. Chem. 2000, 43, 1329-1338. Authors report a somewhat diminished yield due to partial formation of a dihydronapthalene via elimination of the hydroxyl moiety Note 14. Analytical chiral HPLC indicated a 96:4 mixture of enantiomers (Daicel Crownpak (−) column, isocratic elution 10% methanol in water (0.1% TFA), 0.8 mL/min, RT 39.4 min (minor enantiomer), 57.6 min (major enantiomer)]. The following compounds are prepared essentially according to the procedures described in the schemes, charts, examples and preparations set forth herein. Ex. No. Compound 9 mass spec: 480.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)pyridine-2-carboxamide, 10 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)pyrazine-2-carboxamide (mass spec: 481.2), 11 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)-1-ethyl-3-methyl-1H-pyrazole-5- carboxamide (mass spec: 511.2), 12 mass spec: 485.2 3-amino-N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7- ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)-1H-1,2,4-triazole-5-carboxamide, 13 mass spec: 484.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)-5-methylisoxazole-3-carboxamide, 14 mass spec: 496.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)-6-hydroxypyridine-2-carboxamide, 15 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)-1H-imidazole-4-carboxamide (mass spec: 469.2), 16 mass spec: 480.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)nicotinamide, 17 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2 hydroxypropyl)-1H-pyrazole-4-carboxamide (mass spec: 469.2), 18 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)-7-ethyl- 1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)isonicotinamide (mass spec: 480.2), 19 mass spec: 520.1 5-chloro-N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(1S)- 7-ethyl-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-2- hydroxypropyl)thiophene-2-carboxamide. 20 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4S)- 6-neopentyl-3,4-dihydro-2H-chromen-4- yl]amino}propyl)benzamide, 21 N-[(1S, 2R)-3-{[(4S)-6-tert-butoxy-3,4-dihydro-2H- chromen-4-yl]amino}-1-(3,5-difluorobenzyl)-2- hydroxypropyl]benzamide, 22 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4S)- 6-neopentyl-1,2,3,4-tetrahydroquinolin-4- yl]amino}propyl)benzamide, 23 N-[(1S, 2R)-3-{[(4S)-6-tert-butoxy-1,2,3,4- tetrahydroquinolin-4-yl]amino}-1-(3,5- difluorobenzyl)-2-hydroxypropyl]benzamide, 24 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(1S)- 7-neopentyl-1,2,3,4-tetrahydronaphthalen-1- yl]amino}propyl)benzamide, 25 N-[(1S, 2R)-3-{[(1S)-7-tert-butoxy-1,2,3,4- tetrahydronaphthalen-1-yl]amino}-1-(3,5- difluorobenzyl)-2-hydroxypropyl]benzamide, 26 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4R)- 6-neopentyl-2,2-dioxido-3,4-dihydro-1H- isothiochromen-4-yl]amino}propyl)benzamide, 27 N-[(1S, 2R)-3-{[(4R)-6-tert-butoxy-2,2-dioxido-3,4- dihydro-1H-isothiochromen-4-yl]amino}-1-(3,5- difluorobenzyl)-2-hydroxypropyl]benzamide, 28 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[1-(3- neopentylphenyl)cyclohexyl]amino}propyl)benzamide, 29 N-[(1S, 2R)-3-{[1-(3-tert- butoxyphenyl)cyclohexyl]amino}-1-(3,5- difluorobenzyl)-2-hydroxypropyl]benzamide, 30 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[1-(3- neopentylphenyl)cyclopropyl]amino}propyl)benzamide, 31 N-[(1S, 2R)-3-{[1-(3-tert- butoxyphenyl)cyclopropyl]amino}-1-(3,5- difluorobenzyl)-2-hydroxypropyl]benzamide, 32 N-((1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-{[(4- neopentyl-1,1′-biphenyl-2- yl)methyl]amino}propyl)benzamide, 33 N-[(1S, 2R)-3-{[(4-tert-butoxy-1,1′-biphenyl-2- yl)methyl]amino}-1-(3,5-difluorobenzyl)-2- hydroxypropyl]benzamide, 34 N-{(1S, 2R)-1-(3,5-difluorobenzyl)-2-hydroxy-3-[(2- neopentyl-9H-fluoren-9-yl)amino]propyl}benzamide, 35 N-[(1S, 2R)-3-[(2-tert-butoxy-9H-fluoren-9-yl)amino]- 1-(3,5-difluorobenzyl)-2-hydroxypropyl]benzamide. 36 mass spec 557.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(4R)- 6-ethyl-2,2-dioxido-3,4-dihydro-1H- isothiochromen-4-yl]amino}-2-hydroxypropyl)- 3,5-dimethylbenzamide 37 587.2 N-((1S, 2R)-1-(3,5-difluorobenzyl)-3-{[(4R)- 6-ethyl-2,2-dioxido-3,4-dihydro-1H- isothiochromen-4-yl]amino}-2-hydroxypropyl)- 4-(2-methoxyethyl)benzamide BIOLOGY EXAMPLES Example A Enzyme Inhibition Assay The compounds of the invention are analyzed for inhibitory activity by use of the MBP-C125 assay. This assay determines the relative inhibition of beta-secretase cleavage of a model APP substrate, MBP-C125SW, by the compounds assayed as compared with an untreated control. A detailed description of the assay parameters can be found, for example, in U.S. Pat. No. 5,942,400. Briefly, the substrate is a fusion peptide formed of maltose binding protein (MBP) and the carboxy terminal 125 amino acids of APP-SW, the Swedish mutation. The beta-secretase enzyme is derived from human brain tissue as described in Sinha et al, 1999, Nature 40:537-540) or recombinantly produced as the full-length enzyme (amino acids 1-501), and can be prepared, for example, from 293 cells expressing the recombinant cDNA, as described in WO00/47618. Inhibition of the enzyme is analyzed, for example, by immunoassay of the enzyme's cleavage products. One exemplary ELISA uses an anti-MBP capture antibody that is deposited on precoated and blocked 96-well high binding plates, followed by incubation with diluted enzyme reaction supernatant, incubation with a specific reporter antibody, for example, biotinylated anti-SW192 reporter antibody, and further incubation with streptavidin/alkaline phosphatase. In the assay, cleavage of the intact MBP-C125SW fusion protein results in the generation of a truncated amino-terminal fragment, exposing a new SW-192 antibody-positive epitope at the carboxy terminus. Detection is effected by a fluorescent substrate signal on cleavage by the phosphatase. ELISA only detects cleavage following Leu 596 at the substrate's APP-SW 751 mutation site. Specific Assay Procedure: Compounds are diluted in a 1:1 dilution series to a six-point concentration curve (two wells per concentration) in one 96-plate row per compound tested. Each of the test compounds is prepared in DMSO to make up a 10 millimolar stock solution. The stock solution is serially diluted in DMSO to obtain a final compound concentration of 200 micromolar at the high point of a 6-point dilution curve. Ten (10) microliters of each dilution is added to each of two wells on row C of a corresponding V-bottom plate to which 190 microliters of 52 millimolar NaOAc, 7.9% DMSO, pH 4.5 are pre-added. The NaOAc diluted compound plate is spun down to pellet precipitant and 20 microliters/well is transferred to a corresponding flat-bottom plate to which 30 microliters of ice-cold enzyme-substrate mixture (2.5 microliters MBP-C125SW substrate, 0.03 microliters enzyme and 24.5 microliters ice cold 0.09% TX100 per 30 microliters) is added. The final reaction mixture of 200 micromolar compound at the highest curve point is in 5% DMSO, 20 millimolar NaOAc, 0.06% TX100, at pH 4.5. Warming the plates to 37 degrees C starts the enzyme reaction. After 90 minutes at 37 degrees C., 200 microliters/well cold specimen diluent is added to stop the reaction and 20 microliters/well was transferred to a corresponding anti-MBP antibody coated ELISA plate for capture, containing 80 microliters/well specimen diluent. This reaction is incubated overnight at 4 degrees C. and the ELISA is developed the next day after a 2 hour incubation with anti-192SW antibody, followed by Streptavidin-AP conjugate and fluorescent substrate. The signal is read on a fluorescent plate reader. Relative compound inhibition potency is determined by calculating the concentration of compound that showed a fifty percent reduction in detected signal (IC50) compared to the enzyme reaction signal in the control wells with no added compound. In this assay, preferred compounds of the invention exhibit an IC50 of less than 50 micromolar. Example B Cell Free Inhibition Assay Utilizing a Synthetic APP Substrate A synthetic APP substrate that can be cleaved by beta-secretase and having N-terminal biotin and made fluorescent by the covalent attachment of Oregon green at the Cys residue is used to assay beta-secretase activity in the presence or absence of the inhibitory compounds of the invention. Useful substrates include the following: [SEQ ID NO: 1] Biotin-SEVNL-DAEFRC [oregon green] KK [SEQ ID NO: 2] Biotin-SEVKM-DAEFRC [oregon green] KK [SEQ ID NO: 3] Biotin-GLNIKTEEISEISY-EVEFRC [oregon green] KK [SEQ ID NO: 4] Biotin-ADRGLTTRPGSGLTNIKTEEISEVNL-DAEFRC [oregongreen] KK [SEQ ID NO: 5] Biotin-FVNQHLCoxGSHLVEALY-LVCoxGERGFFYTPKAC [oregon green] KK The enzyme (0.1 nanomolar) and test compounds (0.001-100 micromolar) are incubated in pre-blocked, low affinity, black plates (384 well) at 37 degrees for 30 minutes. The reaction is initiated by addition of 150 millimolar substrate to a final volume of 30 microliter per well. The final assay conditions are: 0.001-100 micromolar compound inhibitor; 0.1 molar sodium acetate (pH 4.5); 150 nanomolar substrate; 0.1 nanomolar soluble beta-secretase; 0.001% Tween 20, and 2% DMSO. The assay mixture is incubated for 3 hours at 37 degrees C., and the reaction is terminated by the addition of a saturating concentration of immunopure streptavidin. After incubation with streptavidin at room temperature for 15 minutes, fluorescence polarization is measured, for example, using a LJL Acqurest (Ex485 nm/Em530 nm). The activity of the beta-secretase enzyme is detected by changes in the fluorescence polarization that occur when the substrate is cleaved by the enzyme. Incubation in the presence or absence of compound inhibitor demonstrates specific inhibition of beta-secretase enzymatic cleavage of its synthetic APP substrate. In this assay, preferred compounds of the invention exhibit an IC50 of less than 50 micromolar. More preferred compounds of the invention exhibit an IC50 of less than 10 micromolar. Even more preferred compounds of the invention exhibit an IC50 of less than 5 micromolar. Example C Beta-Secretase Inhibition: P26-P4′SW Assay Synthetic substrates containing the beta-secretase cleavage site of APP are used to assay beta-secretase activity, using the methods described, for example, in published PCT application WO00/47618. The P26-P4′SW substrate is a peptide of the sequence: (biotin)CGGADRGLTTRPGSGLTNIKTEEISEVNLDAEF [SEQ ID NO: 6] The P26-P1 standard has the sequence: (biotin)CGGADRGLTTRPGSGLTNIKTEEISEVNL [SEQ ID NO: 7]. Briefly, the biotin-coupled synthetic substrates are incubated at a concentration of from about 0 to about 200 micromolar in this assay. When testing inhibitory compounds, a substrate concentration of about 1.0 micromolar is preferred. Test compounds diluted in DMSO are added to the reaction mixture, with a final DMSO concentration of 5%. Controls also contain a final DMSO concentration of 5%. The concentration of beta secretase enzyme in the reaction is varied, to give product concentrations with the linear range of the ELISA assay, about 125 to 2000 picomolar, after dilution. The reaction mixture also includes 20 millimolar sodium acetate, pH 4.5, 0.06% Triton X100, and is incubated at 37 degrees C. for about 1 to 3 hours. Samples are then diluted in assay buffer (for example, 145.4 nanomolar sodium chloride, 9.51 millimolar sodium phosphate, 7.7 millimolar sodium azide, 0.05% Triton X405, 6 g/liter bovine serum albumin, pH 7.4) to quench the reaction, then diluted further for immunoassay of the cleavage products. Cleavage products can be assayed by ELISA. Diluted samples and standards are incubated in assay plates coated with capture antibody, for example, SW192, for about 24 hours at 4 degrees C. After washing in TTBS buffer (150 millimolar sodium chloride, 25 millimolar Tris, 0.05% Tween 20, pH 7.5), the samples are incubated with streptavidin-AP according to the manufacturer's instructions. After a one hour incubation at room temperature, the samples are washed in TTBS and incubated with fluorescent substrate solution A (31.2 g/liter 2-amino-2-methyl-1-propanol, 30 mg/liter, pH 9.5). Reaction with streptavidin-alkaline phosphate permits detection by fluorescence. Compounds that are effective inhibitors of beta-secretase activity demonstrate reduced cleavage of the substrate as compared to a control. Example D Assays Using Synthetic Oligopeptide-Substrates Synthetic oligopeptides are prepared that incorporate the known cleavage site of beta-secretase, and optionally detectable tags, such as fluorescent or chromogenic moieties. Examples of such peptides, as well as their production and detection methods are described in U.S. Pat. No: 5,942,400, herein incorporated by reference. Cleavage products can be detected using high performance liquid chromatography, or fluorescent or chromogenic detection methods appropriate to the peptide to be detected, according to methods well known in the art. By way of example, one such peptide has the sequence SEVNL-DAEF [SEQ ID NO: 8], and the cleavage site is between residues 5 and 6. Another preferred substrate has the sequence ADRGLTTRPGSGLTNIKTEEISEVNL-DAEF [SEQ ID NO: 9], and the cleavage site is between residues 26 and 27. These synthetic APP substrates are incubated in the presence of beta-secretase under conditions sufficient to result in beta-secretase mediated cleavage of the substrate. Comparison of the cleavage results in the presence of the compound inhibitor to control results provides a measure of the compound's inhibitory activity. Example E Inhibition of Beta-Secretase Activity—Cellular Assay An exemplary assay for the analysis of inhibition of beta-secretase activity utilizes the human embryonic kidney cell line HEKp293 (ATCC Accession No. CRL-1573) transfected with APP751 containing the naturally occurring double mutation Lys651Met52 to Asn651Leu652 (numbered for APP751), commonly called the Swedish mutation and shown to overproduce A beta (Citron et al., 1992, Nature 360:672-674), as described in U.S. Pat. No. 5,604,102. The cells are incubated in the presence/absence of the inhibitory compound (diluted in DMSO) at the desired concentration, generally up to 10 micrograms/ml. At the end of the treatment period, conditioned media is analyzed for beta-secretase activity, for example, by analysis of cleavage fragments. A beta can be analyzed by immunoassay, using specific detection antibodies. The enzymatic activity is measured in the presence and absence of the compound inhibitors to demonstrate specific inhibition of beta-secretase mediated cleavage of APP substrate. Example F Inhibition of Beta-Secretase in Animal Models of AD Various animal models can be used to screen for inhibition of beta-secretase activity. Examples of animal models useful in the invention include, but are not limited to, mouse, guinea pig, dog, and the like. The animals used can be wild type, transgenic, or knockout models. In addition, mammalian models can express mutations in APP, such as APP695-SW and the like described herein. Examples of transgenic non-human mammalian models are described in U.S. Pat. Nos. 5,604,102, 5,912,410 and 5,811,633. PDAPP mice, prepared as described in Games et al., 1995, Nature 373:523-527 are useful to analyze in vivo suppression of A beta release in the presence of putative inhibitory compounds. As described in U.S. Pat. No. 6,191,166, 4 month old PDAPP mice are administered compound formulated in vehicle, such as corn oil. The mice are dosed with compound (1-30 mg/ml; preferably 1-10 mg/ml). After time, e.g., 3-10 hours, the animals are sacrificed, and brains removed for analysis. Transgenic animals are administered an amount of the compound inhibitor formulated in a carrier suitable for the chosen mode of administration. Control animals are untreated, treated with vehicle, or treated with an inactive compound. Administration can be acute, i.e., single dose or multiple doses in one day, or can be chronic, i.e., dosing is repeated daily for a period of days. Beginning at time 0, brain tissue or cerebral fluid is obtained from selected animals and analyzed for the presence of APP cleavage peptides, including A beta, for example, by immunoassay using specific antibodies for A beta detection. At the end of the test period, animals are sacrificed and brain tissue or cerebral fluid is analyzed for the presence of A beta and/or beta-amyloid plaques. The tissue is also analyzed for necrosis. Animals administered the compound inhibitors of the invention are expected to demonstrate reduced A beta in brain tissues or cerebral fluids and reduced beta amyloid plaques in brain tissue, as compared with non-treated controls. Example G Inhibition of A Beta Production in Human Patients Patients suffering from Alzheimer's Disease (AD) demonstrate an increased amount of A beta in the brain. AD patients are administered an amount of the compound inhibitor formulated in a carrier suitable for the chosen mode of administration. Administration is repeated daily for the duration of the test period. Beginning on day 0, cognitive and memory tests are performed, for example, once per month. Patients administered the compound inhibitors are expected to demonstrate slowing or stabilization of disease progression as analyzed by changes in one or more of the following disease parameters: A beta present in CSF or plasma; brain or hippocampal volume; A beta deposits in the brain; amyloid plaque in the brain; and scores for cognitive and memory function, as compared with control, non-treated patients. Example H Prevention of A Beta Production in Patients at Risk for AD Patients predisposed or at risk for developing AD are identified either by recognition of a familial inheritance pattern, for example, presence of the Swedish Mutation, and/or by monitoring diagnostic parameters. Patients identified as predisposed or at risk for developing AD are administered an amount of the compound inhibitor formulated in a carrier suitable for the chosen mode of administration. Administration is repeated daily for the duration of the test period. Beginning on day 0, cognitive and memory tests are performed, for example, once per month. Patients administered the compound inhibitors are expected to demonstrate slowing or stabilization of disease progression as analyzed by changes in one or more of the following disease parameters: A beta present in CSF or plasma; brain or hippocampal volume; amyloid plaque in the brain; and scores for cognitive and memory function, as compared with control, non-treated patients. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to benzamide 2-hydroxy-3-diaminoalkanes and to such compounds that are useful in the treatment of Alzheimer's disease and related diseases. More specifically, it relates to such compounds that are capable of inhibiting beta-secretase, an enzyme that cleaves amyloid precursor protein to produce amyloid beta peptide (A beta), a major component of the amyloid plaques found in the brains of Alzheimer's sufferers. 2. Background of the Invention Alzheimer's disease (AD) is a progressive degenerative disease of the brain primarily associated with aging. Clinical presentation of AD is characterized by loss of memory, cognition, reasoning, judgment, and orientation. As the disease progresses, motor, sensory, and linguistic abilities are also affected until there is global impairment of multiple cognitive functions. These cognitive losses occur gradually, but typically lead to severe impairment and eventual death in the range of four to twelve years. Alzheimer's disease is characterized by two major pathologic observations in the brain: neurofibrillary tangles and beta amyloid (or neuritic) plaques, comprised predominantly of an aggregate of a peptide fragment know as A beta. Individuals with AD exhibit characteristic beta-amyloid deposits in the brain (beta amyloid plaques) and in cerebral blood vessels (beta amyloid angiopathy) as well as neurofibrillary tangles. Neurofibrillary tangles occur not only in Alzheimer's disease but also in other dementia-inducing disorders. On autopsy, large numbers of these lesions are generally found in areas of the human brain important for memory and cognition. Smaller numbers of these lesions in a more restricted anatomical distribution are found in the brains of most aged humans who do not have clinical AD. Amyloidogenic plaques and vascular amyloid angiopathy also characterize the brains of individuals with Trisomy 21 (Down's Syndrome), Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type (HCHWA-D), and other neurodegenerative disorders. Beta-amyloid is a defining feature of AD, now believed to be a causative precursor or factor in the development of disease. Deposition of A beta in areas of the brain responsible for cognitive activities is a major factor in the development of AD. Beta-amyloid plaques are predominantly composed of amyloid beta peptide (A beta, also sometimes designated betaA4). A beta peptide is derived by proteolysis of the amyloid precursor protein (APP) and is comprised of 39-42 amino acids. Several proteases called secretases are involved in the processing of APP. Cleavage of APP at the N-terminus of the A beta peptide by beta-secretase and at the C-terminus by one or more gamma-secretases constitutes the beta-amyloidogenic pathway, i.e. the pathway by which A beta is formed. Cleavage of APP by alpha-secretase produces alpha-sAPP, a secreted form of APP that does not result in beta-amyloid plaque formation. This alternate pathway precludes the formation of A beta peptide. A description of the proteolytic processing fragments of APP is found, for example, in U.S. Pat. Nos. 5,441,870; 5,721,130; and 5,942,400. An aspartyl protease has been identified as the enzyme responsible for processing of APP at the beta-secretase cleavage site. The beta-secretase enzyme has been disclosed using varied nomenclature, including BACE, Asp, and Memapsin. See, for example, Sinha et al., 1999, Nature 402:537-554 (p501) and published PCT application WO00/17369. Several lines of evidence indicate that progressive cerebral deposition of beta-amyloid peptide (A beta) plays a seminal role in the pathogenesis of AD and can precede cognitive symptoms by years or decades. See, for example, Selkoe, 1991, Neuron 6:487. Release of A beta from neuronal cells grown in culture and the presence of A beta in cerebrospinal fluid (CSF) of both normal individuals and AD patients has been demonstrated. See, for example, Seubert et al., 1992, Nature 359:325-327. It has been proposed that A beta peptide accumulates as a result of APP processing by beta-secretase, thus inhibition of this enzyme's activity is desirable for the treatment of AD. In vivo processing of APP at the beta-secretase cleavage site is thought to be a rate-limiting step in A beta production, and is thus a therapeutic target for the treatment of AD. See for example, Sabbagh, M., et al., 1997, Alz. Dis. Rev. 3, 1-19. BACE1 knockout mice fail to produce A beta, and present a normal phenotype. When crossed with transgenic mice that over express APP, the progeny show reduced amounts of A beta in brain extracts as compared with control animals (Luo et al., 2001 Nature Neuroscience 4:231-232). This evidence further supports the proposal that inhibition of beta-secretase activity and reduction of A beta in the brain provides a therapeutic method for the treatment of AD and other beta amyloid disorders. At present there are no effective treatments for halting, preventing, or reversing the progression of Alzheimer's disease. Therefore, there is an urgent need for pharmaceutical agents capable of slowing the progression of Alzheimer's disease and/or preventing it in the first place. Compounds that are effective inhibitors of beta-secretase, that inhibit beta-secretase-mediated cleavage of APP, that are effective inhibitors of A beta production, and/or are effective to reduce amyloid beta deposits or plaques, are needed for the treatment and prevention of disease characterized by amyloid beta deposits or plaques, such as AD. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention encompasses the compounds of formula (I) shown below, pharmaceutical compositions containing the compounds and methods employing such compounds or compositions in the treatment of Alzheimer's disease and more specifically compounds that are capable of inhibiting beta-secretase, an enzyme that cleaves amyloid precursor protein to produce A-beta peptide, a major component of the amyloid plaques found in the brains of Alzheimer's sufferers. In a broad aspect, the invention provides compounds of formula I and pharmaceutically acceptable salts or esters thereof, wherein Z is aryl, heteroaryl or heterocyclyl, wherein said groups are optionally substituted with 1 or 2 R B groups, wherein, where R B at each occurrence is independently selected from halogen, —OH, —OCF 3 , —O-phenyl, —CN, —NR 100 R 101 , C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, (CH 2 ) 0-3 (C 3 -C 7 cycloalkyl), aryl, heteroaryl, or heterocyclyl wherein, the alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, heteroaryl, orheterocyclyl groups are optionally substituted with 1 or 2 substitutents independently selected from the groupconsisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, halogen, —OH, —CN, or —NR 100 R 101 ; where R 100 and R 101 are at each occurrence are independently H, C 1 -C 6 alkyl, or phenyl; X is —(C═O)— or —(SO 2 )— R 1 is C 1 -C 10 alkyl optionally substituted with 1, 2, or 3 groups independently selected from halogen, —OH, ═O, —SH, —CN, —CF 3 , —OCF 3 , —C 3-7 cycloalkyl, —C 1 -C 4 alkoxy, amino, mono-dialkylamino, aryl, heteroaryl, heterocycloalkyl, wherein each aryl group is optionally substituted with 1, 2 or 3 R 50 groups; wherein R 50 is selected from halogen, OH, SH, CN, —CO—(C 1 -C 4 alkyl), —NR 7 R 8 , —S(O) 0-2 —(C 1 -C 4 alkyl), C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy and C 3 -C 8 cycloalkyl; wherein the alkyl, alkenyl, alkynyl, alkoxy and cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of C 1 -C 4 alkyl, halogen, OH, —NR 5 R 6 , CN, C 1 -C 4 haloalkoxy, NR 7 R 8 , and C 1 -C 4 alkoxy; wherein R 5 and R 6 are independently H or C 1 -C 6 alkyl; or wherein R 5 and R 6 and the nitrogen to which they are attached form a 5 or 6 membered heterocycloalkyl ring; and wherein R 7 and R 8 are independently selected from the group consisting of H; —C 1 -C 4 alkyl optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —OH, —NH 2 , and halogen; —C 3 -C 6 cycloalkyl; —(C 1 -C 4 alkyl)-O—(C 1 -C 4 alkyl); —C 2 -C 4 alkenyl; and —C 2 -C 4 alkynyl; wherein each heteroaryl is optionally substituted with 1 or 2 R 50 groups; wherein each heterocycloalkyl group is optionally substituted with 1 or 2 groups that are independently R 50 or ═O; R 2 and R 3 are independently selected from —H; —F; —C 1 -C 6 alkyl optionally substituted with a substituent selected from the group consisting of —F, —OH, —C≡N, —CF 3 , C 1 -C 3 alkoxy, and —NR 5 R 6 ; —(CH 2 ) 0-2 —R 17 ; —(CH 2 ) 0-2 —R 18 ; —C 2 -C 6 alkenyl or C 2 -C 6 alkynyl, wherein each is optionally substituted with an indepdent substituent selected from the group consisting of —F, —OH, —C≡N, —CF 3 and C 1 -C 3 alkoxy; —(CH 2 ) 0-2 —C 3 -C 7 cycloalkyl, optionally substituted an independent substituent selected from the group consisting of —F, —OH, —C≡N, —CF 3 , C 1 -C 3 alkoxy and —NR 5 R 6 ; or R 2 , R 3 and the carbon to which they are attached form a carbocycle of three thru seven carbon atoms, wherein one carbon atom is optionally replaced by a group selected from —O—, —S—, —SO 2 —, or —NR 7 —; where R 17 at each occurrence is an aryl group selected from phenyl, 1-naphthyl, 2-naphthyl, indanyl, indenyl, dihydronaphthyl and tetralinyl, wherein said aryl groups are optionally substituted with one or two groups that are independently —C 1 -C 3 alkyl; —C 1 -C 4 alkoxy; CF 3 ; or —C 2 -C 6 alkenyl or —C 2 -C 6 alkynyl each of which is optionally substituted with one substituent selected from the group consisting of F, OH, C 1 -C 3 alkoxy; or -halogen; —OH; —C≡N; —C 3 -C 7 cycloalkyl; —CO—(C 1 -C 4 alkyl); —SO 2 —(C 1 -C 4 alkyl); where R 18 is a heteroaryl group selected from pyridinyl, pyrimidinyl, quinolinyl, indolyl, pryidazinyl, pyrazinyl, isoquinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, imidazolyl, isoxazolyl, oxazolyl, thiazolyl, furanyl, thienyl, pyrrolyl, oxadiazolyl or thiadiazolyl, wherein each of said heteroaryl groups is optionally substituted with one or two groups that are independently —C 1 -C 6 alkyl optionally substituted with one substituent selected from the group consisting of OH, C—N, CF 3 , C 1 -C 3 alkoxy, and —NR 5 R 6 ; R 15 is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 alkoxy C 1 -C 6 alkyl, hydroxy C 1 -C 6 alkyl, halo C 1 -C 6 alkyl, each of which is unsubstituted or substituted with 1, 2, 3, or 4 groups independently selected from halogen, C 1 -C 6 alkyl, hydroxy, C 1 -C 6 alkoxy, NH 2 , and —R 26 —R 27 ; wherein R 26 is selected from the group consisting of a bond, —C(O)—, —SO 2 —, —CO 2 —, —C(O)NR 5 —, and —NR 5 C(O)—, wherein R 27 is selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, aryl C 1 -C 6 alkyl, heterocycloalkyl, and heteroaryl, wherein each of the above is unsubstituted or substituted with 1, 2, 3, 4, or 5 groups that are independently C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halogen, haloalkyl, hydroxyalkyl, —NR 5 R 6 , —C(O)NR 5 R 6 ; R c is selected from the group consisting of —(CH 2 ) 0-3 —(C 3 -C 8 ) cycloalkyl wherein the cycloalkyl is optionally substituted with 1, 2, or 3 groups independently selected from the group consisting of —R 205 , —CO 2 —(C 1 -C 4 alkyl), and aryl, wherein aryl is optionally substituted with 1 or 2 independently selected R 200 groups; —(CR 245 R 250 ) 0-4 -aryl; —(CR 245 R 250 ) 0-4 -heteroaryl; —(CR 245 R 250 ) 0-4 -heterocycloalkyl; —(CR 245 R 250 ) 0-4 -aryl-heteroaryl; —(CR 245 R 250 ) 0-4 -aryl-heterocycloalkyl; —(CR 245 R 250 ) 0-4 -aryl-aryl; —(CR 245 R 250 ) 0-4 -heteroaryl-aryl; —(CR 245 R 250 ) 0-4 -heteroaryl-heterocycloalkyl; —(CR 245 R 250 ) 0-4 -heteroaryl-heteroaryl; —(CR 245 R 250 ) 0-4 -heterocycloalkyl-heteroaryl; —(CR 245 R 250 ) 0-4 -heterocycloalkyl-heterocycloalkyl; —(CR 245 R 250 ) 0-4 -heterocycloalkyl-aryl; a monocyclic or bicyclic ring of 5, 6, 7 8, 9, or 10 carbons fused to 1 or 2 aryl, heteroaryl, or heterocycloalkyl groups wherein 1, 2 or 3 carbons of the monocyclic or bicyclic ring is optionally replaced with —NH, —N (CO) 0-1 R 215 , —N (CO) 0-1 R 220 , —O, or —S(═O) 0-2 , and wherein the monocyclic or bicyclic ring is optionally substituted with 1, 2 or 3 groups that are independently —R 205 , —R 245 , —R 250 or ═O; —C 2 -C 6 alkenyl optionally substituted with 1, 2, or 3 R 205 groups; —C 2 -C 6 alkynyl optionally substituted with 1, 2, or 3 R 205 groups; wherein each aryl group attached directly or indirectly to the —(CR 245 R 250 ) 0-4 group is optionally substituted with 1, 2, 3 or 4 R 200 groups; wherein each heteroaryl group attached directly or indirectly to the —(CR 245 R 250 ) 0-4 group is optionally substituted with 1, 2, 3, or 4 R 200 ; wherein each heterocycloalkyl attached directly or indirectly to the —(CR 245 R 250 ) 0-4 group is optionally substituted with 1, 2, 3, or 4 R 210 ; wherein R 200 at each occurrence is independently selected from the group consisting of —C 1 -C 6 alkyl optionally substituted with 1, 2, or 3 R 205 groups; —OH; —NO 2 ; -halogen; —C≡N; —(CH 2 ) 0-4 —CO—NR 220 R 225 ; —(CH 2 ) 0-4 —CO—(C 1 -C 8 alkyl); —(CH 2 ) 0-4 —CO—(C 2 -C 8 alkenyl); —(CH 2 ) 0-4 —CO—(C 2 -C 8 alkynyl); —(CH 2 ) 0-4 —CO—(C 3 -C 7 cycloalkyl); —(CH 2 ) 0-4 —(CO) 0-1 -aryl; —(CH 2 ) 0-4 —(CO) 0-1 -heteroaryl; —(CH 2 ) 0-4 —(CO) 0-1 -heterocycloalkyl; —(CH 2 ) 0-4 —CO 2 R 215 ; —(CH 2 ) 0-4 —SO 2 —NR 220 R 225 ; —(CH 2 ) 0-4 —S(O) 0-2 —(C 1 -C 8 alkyl); —(CH 2 ) 0-4 —S(O) 0-2 —(C 3 -C 7 cycloalkyl); —(CH 2 ) 0-4 —N(H or R 215 )—CO 2 R 215 ; —(CH 2 ) 0-4 —N(H or R 215 )—SO 2 —R 220 ; —(CH 2 ) 0-4 —N(H or R 215 )—CO—N(R 215 ) 2 ; —(CH 2 ) 0-4 —N(—H or R 215 )—CO—R 220 ; —(CH 2 ) 0-4 —NR 22 OR 225 ; —(CH 2 ) 0-4 —O—CO—(C 1 -C 6 alkyl); —(CH 2 ) 0-4 —O—(R 215 ); —(CH 2 ) 0-4 —S—(R 215 ); —(CH 2 ) 0-4 —O—(C 1 -C 6 alkyl optionally substituted with 1, 2, 3, or 5-F); —C 2 -C 6 alkenyl optionally substituted with 1 or 2 R 205 groups; —C 2 -C 6 alkynyl optionally substituted with 1 or 2 R 205 groups; and —(CH 2 ) 0-4 —C 3 -C 7 cycloalkyl; wherein each aryl group included within R 200 is optionally substituted with 1, 2, or 3 groups that are independently —R 205 , —R 210 or —C 1 -C 6 alkyl substituted with 1, 2, or 3 groups that are independently R 205 or R 210 ; wherein each heterocycloalkyl group included within R 200 is optionally substituted with 1, 2, or 3 groups that are independently R 210 ; wherein each heteroaryl group included within R 200 is optionally substituted with 1, 2, or 3 groups that are independently —R 205 , —R 210 , or —C 1 -C 6 alkyl substituted with 1, 2, or 3 groups that are independently —R 205 or —R 210 ; wherein R 205 at each occurrence is independently selected from the group consisting of —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 1 -C 6 haloalkoxy —(CH 2 ) 0-3 (C 3 -C 7 cycloalkyl) -halogen, —(CH 2 ) 0-6 —OH, —O-phenyl, —SH, —(CH 2 ) 0-6 —C≡N, —(CH 2 ) 0-6 —C(═O) NR 235 R 240 —CF 3 , —C 1 -C 6 alkoxy, and —NR 235 R 240 , wherein R 210 at each occurrence is independently selected from the group consisting of —C 1 -C 6 alkyl optionally substituted with 1, 2, or 3 R 205 groups; —C 2 -C 6 alkenyl optionally substituted with 1, 2, or 3 R 205 groups; —C 2 -C 6 alkynyl optionally substituted with 1, 2, or 3 R 205 groups; -halogen; —C 1 -C 6 alkoxy; —C 1 -C 6 haloalkoxy; —NR 220 R 225 ; —OH; —C≡N; —C 3 -C 7 cycloalkyl optionally substituted with 1, 2, or 3 R 205 groups; —CO—(C 1 -C 4 alkyl); SO 2 —NR 235 R 240 ; —CO—NR 235 R 240 ; —SO 2 —(C 1 -C 4 alkyl); and ═O; wherein wherein R 215 at each occurrence is independently selected from the group consisting of —C 1 -C 6 alkyl, —(CH 2 ) 0-2 -(aryl), —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, —(CH 2 ) 0-2 -(heteroaryl), and —(CH 2 ) 0-2 -(heterocycloalkyl); wherein the aryl group included within R 215 is optionally substituted with 1, 2, or 3 groups that are independently —R 205 or —R 210 ; wherein the heterocycloalkyl group included within R 215 is optionally substituted with 1, 2, or 3 R 210 ; wherein each heteroaryl group included within R 215 is optionally substituted with 1, 2, or 3 R 210 ; wherein R 220 and R 225 at each occurrence are independently selected from the group consisting of —H, —C 1 -C 6 alkyl, -hydroxy C 1 -C 6 alkyl, -amino C 1 -C 6 alkyl, -halo C 1 -C 6 alkyl, —(CH 2 ) 0-2 —(C 3 -C 7 cycloalkyl), —(C 1 -C 6 alkyl)—O—(C 1 -C 3 alkyl), —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, -aryl, -heteroaryl, and -heterocycloalkyl; wherein the aryl, heteroaryl or heterocycloalkyl group included within R 220 and R 225 is optionally substituted with 1, 2, or 3 R 270 groups, wherein R 270 at each occurrence is independently —R 205 , —C 1 -C 6 alkyl optionally substituted with 1, 2, or 3 R 205 groups; —C 2 -C 6 alkenyl optionally substituted with 1, 2, or 3 R 205 groups; —C 2 -C 6 alkynyl optionally substituted with 1, 2, or 3 R 205 groups; -halogen; —C 1 -C 6 alkoxy; —C 1 -C 6 haloalkoxy; —NR 235 R 240 ; —OH; —C≡N; —C 3 -C 7 cycloalkyl optionally substituted with 1, 2, or 3 R 205 groups; —CO—(C 1 -C 4 alkyl); —SO 2 —NR 235 R 240 ; —CO—NR 235 R 240 ; —SO 2 —(C 1 -C 4 alkyl); and ═O; wherein R 235 and R 240 at each occurrence are independently —H, or —C 1 -C 6 alkyl; -phenyl wherein R 245 and R 250 at each occurrence are independently selected from the group consisting of —H, —(CH 2 ) 0-4 CO 2 C 1 -C 4 alkyl —(CH 2 ) 0-4 C(O)C 1 -C 4 alkyl —C 1 -C 4 alkyl, —C 1 -C 4 hydroxyalkyl, —C 1 -C 4 alkoxy, —C 1 -C 4 haloalkoxy, —(CH 2 ) 0-4 —C 3 -C 7 cycloalkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —(CH 2 ) 0-4 aryl, —(CH 2 ) 0-4 heteroaryl, and —(CH 2 ) 0-4 heterocycloalkyl, or wherein R 245 and R 250 are taken together with the carbon to which they are attached to form a monocycle or bicycle of 3, 4, 5, 6, 7 or 8 carbon atoms, optionally where 1 or 2 carbon atoms is replaced by a heteroatom selected from the group consisting of —O—, —S—, —SO 2 —, and —NR 220 —; wherein the aryl, heteroaryl or heterocycloalkyl group included within R 245 and R 250 is optionally substituted with 1, 2, or 3 groups that are independenly halogen, C 1-6 alkyl, CN or OH; wherein R 255 and R 260 at each occurrence are independently selected from the group consisting of —H; —C 1 -C 6 alkyl optionally substituted with 1, 2, or 3 R 205 groups; —(CH 2 ) 1-2 —S(O) 0-2 —(C 1 -C 6 alkyl); —(CH 2 ) 0-4 —C 3 -C 7 cycloalkyl optionally substituted with 1, 2, or 3 R 205 groups; —(CH 2 ) 0-4 -aryl; —(CH 2 ) 0-4 -heteroaryl; —(CH 2 ) 0-4 -heterocycloalkyl; wherein each aryl group included within R 255 and R 260 is optionally substituted with 1, 2, or 3 groups that are independently —R 205 , —R 210 , or —C 1 -C 6 alkyl substituted with 1, 2, or 3 groups that are independently —R 205 or —R 210 ; where each heteroaryl group included within R 255 and R 260 is optionally substituted with 1, 2, 3, or 4 R 200 groups, and where each heterocycloalkyl group included within R 255 and R 260 is optionally substituted with 1, 2, 3, or 4 R 210 groups. The invention also provides methods for the treatment or prevention of Alzheimer's disease, mild cognitive impairment Down's syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, cerebral amyloid angiopathy, other degenerative dementias, dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, diffuse Lewy body type of Alzheimer's disease comprising administration of a therapeutically effective amount of a compound or salt of formula I, to a patient in need thereof. Preferably, the patient is a human. More preferably, the disease is Alzheimer's disease. More preferably, the disease is dementia. The invention also provides pharmaceutical compositions comprising a compound or salt of formula I and at least one pharmaceutically acceptable carrier, solvent, adjuvant or diluent. The invention also provides the use of a compound or salt according to formula I for the manufacture of a medicament. The invention also provides the use of a compound or salt of formula I for the treatment or prevention of Alzheimer's disease, mild cognitive impairment Down's syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, cerebral amyloid angiopathy, other degenerative dementias, dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, or diffuse Lewy body type of Alzheimer's disease. The invention also provides compounds, pharmaceutical compositions, kits, and methods for inhibiting beta-secretase-mediated cleavage of amyloid precursor protein (APP). More particularly, the compounds, compositions, and methods of the invention are effective to inhibit the production of A-beta peptide and to treat or prevent any human or veterinary disease or condition associated with a pathological form of A-beta peptide. The compounds, compositions, and methods of the invention are useful for treating humans who have Alzheimer's Disease (AD), for helping prevent or delay the onset of AD, for treating patients with mild cognitive impairment (MCI), and preventing or delaying the onset of AD in those patients who would otherwise be expected to progress from MCI to AD, for treating Down's syndrome, for treating Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch Type, for treating cerebral beta-amyloid angiopathy and preventing its potential consequences such as single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, for treating dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, and diffuse Lewy body type AD, and for treating frontotemporal dementias with parkinsonism (FTDP). The compounds of the invention possess beta-secretase inhibitory activity. The inhibitory activities of the compounds of the invention is readily demonstrated, for example, using one or more of the assays described herein or known in the art. Unless the substituents for a particular formula are expressly defined for that formula, they are understood to carry the definitions set forth in connection with the preceding formula to which the particular formula makes reference. The invention also provides methods of preparing the compounds of the invention and the intermediates used in those methods. detailed-description description="Detailed Description" end="lead"? | 20040421 | 20070529 | 20050210 | 71496.0 | 0 | DENTZ, BERNARD I | BENZAMIDE 2-HYDROXY-3-DIAMINOALKANES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,829,156 | ACCEPTED | Ink jet printer | An ink jet printer having: an ink heating device for heating an ink whose viscosity decreases as temperature increases; a printing head for jetting an ink heated by the heating device onto a recording medium; a carrying device for carrying the recording medium while supporting the recording medium to face a nozzle-plate of the printing head; and a cooling device for cooling the recording medium in an upstream side with respect to a position where an ink placed on the recording medium is cured, in a carrying direction of the recording medium by the carrying device. | 1. An ink jet printer comprising: an ink heating device for heating an ink whose viscosity decreases as temperature increases; a printing head for jetting an ink heated by the heating device onto a recording medium; a carrying device for carrying the recording medium while supporting the recording medium to face a nozzle-plate of the printing head; and a cooling device for cooling the recording medium in an upstream side with respect to a position where an ink placed on the recording medium is cured, in a carrying direction of the recording medium by the carrying device. 2. The printer of claim 1, wherein the cooling device and the ink heating device are connected to be capable of conducting heat, and the ink heating device heats an ink by utilizing a heat radiation which is generated from the cooling device by cooling the recording medium. 3. The printer of claim 2, wherein the cooling device and the ink heating device are connected by a heat pipe. 4. The printer of claim 1, wherein the cooling device comprises a peltier device. 5. The printer of claim 1, wherein the cooling device comprises a frigistor device. 6. The printer of claim 1, further comprising a cap member to cover the nozzle-plate at a time of maintenance of the printing head, the cap member being separated from the nozzle-plate at a time of image recording, wherein the cooling device cools the recording medium between the cap member and the printing head at a time of image recording, and is removed from a position where the recording medium is cooled at a time of maintenance. 7. The printer of claim 6, wherein a rotary shaft is provided at one end side or the other end side of the cooling device so as to be spaced from the nozzle-plate of the printing head, the rotary shaft extending along a direction perpendicular to the carrying direction, and the cooling device is removed from the position where the recording medium is cooled by rotating the cooling device about 90 degrees around the rotary shaft as a center. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer and particularly, to an ink jet printer in which an ink is jetted after being heated. 2. Description of the Related Art Recently, an ink jet printer has been widely used because images can be easily formed at a low cost in comparison to a method such as a gravure printing method or a flexographic method which needs a plate. In the field of performing image recording on goods or packing material for goods by using the ink jet printer, material with no ink absorptivity such as resin or metal is generally used for goods or packing for goods. There is known a ink jet printer of photo curable type in which a recording medium made from material with no ink absorptivity and photo curable ink are used, and for example, the ink jetted onto the recording medium is irradiated with light such as ultraviolet rays to cure and fix the ink thereon (for example, refer to JP-2002-283545A). JP-2002-283545A discloses an example of an ink jet printer in which photo curable ink is used. Specifically, a recording apparatus in JP-2002-283545A is provided with a rotatable and transparent dram shaped intermediate transfer body and a printing head facing the outer periphery of the intermediate transfer body. In a recording operation, ink is jetted from the printing head onto the outer periphery of the intermediate transfer body and the ink placed on the intermediate transfer body is irradiated with light from outside of the intermediate transfer body, and thereafter, the ink irradiated with light is transferred onto the recording medium while rotating the intermediate transfer body. Such a recording method is successful in preventing deterioration of image quality such as beading or bleeding as well as transferring the ink with optimum viscosity onto the recording medium by adjusting the viscosity of the ink placed on the intermediate transfer body. Generally, photo curable ink has high viscosity in a normal room temperature (around 18 to 28° C.), therefore having a difficulty in stably jetting the ink. For stably jetting the ink, ink viscosity is preferably 3 to 20 mPas, so that an ink jet printer has been developed in which photo curable ink is heated to 40 to 80° C. to have low ink viscosity of 3 to 20 mPas before being jetted. However, when the photo curable ink with decreased viscosity is jetted from the printing head, the ink spreads until being irradiated with light after placed on the recording medium, thereby causing images to blur. SUMMARY OF THE INVENTION An object of the present invention is to suppress spread of ink placed on a recording medium by increasing ink viscosity of ink placed on the recording medium to achieve high image quality. In accordance with a first aspect of the present invention, the ink jet printer comprises: an ink heating device for heating an ink whose viscosity decreases as temperature increases; a printing head for jetting an ink heated by the heating device onto a recording medium; a carrying device for carrying the recording medium while supporting the recording medium to face a nozzle-plate of the printing head; and a cooling device for cooling the recording medium in an upstream side with respect to a position where an ink placed on the recording medium is cured, in a carrying direction of the recording medium by the carrying device. Accordingly, since the recording medium is cooled in the upstream side with respect to a position where the ink placed on the recording medium is cured, in the carrying direction, the ink can be cooled before the ink placed on the recording medium is cured. Thus, ink viscosity placed on the recording medium can be increased, thereby preventing the ink spread. This results in obtaining high image quality. Preferably, in the printer of the first aspect of the present invention, the cooling device and the ink heating device are connected to be capable of conducting heat, and the ink heating device heats an ink by utilizing a heat radiation which is generated from the cooling device by cooling the recording medium. Accordingly, since the ink heating device heats the ink by utilizing heat radiation generated from the cooling device by cooling the recording medium, heat can be effectively used. Preferably, in the printer of the first aspect of the present invention, the cooling device and the ink heating device are connected by a heat pipe. Accordingly, since the cooling device and the ink heating device are connected by the heat pipe, heat exchange is effectively performed. Preferably, in the printer of the first aspect of the present invention, the cooling device comprises a peltier device. Accordingly, since the cooling device comprises a peltier device, the recording medium can be cooled by utilizing peltier effect by the peltier device. Moreover, combination of a peltier device and a heatlane plate enables the recording medium to be cooled uniformly. Preferably, in the printer of the first aspect of the present invention, the cooling device comprises a frigistor device. Preferably, in the printer of the first aspect of the present invention, the printer further comprises a cap member to cover the nozzle-plate at a time of maintenance of the printing head, the cap member being separated from the nozzle-plate at a time of image recording, wherein the cooling device cools the recording medium between the cap member and the printing head at a time of image recording, and is removed from a position where the recording medium is cooled at a time of maintenance. Accordingly, since the cooling device is removed from a position where the recording medium is cooled at a time of maintenance, the cap member is not obstructed by the cooling device from covering the nozzle-plate of the printing head, enabling to smoothly perform the maintenance. Preferably, in the printer of the first aspect of the present invention, a rotary shaft is provided at one end side or the other end side of the cooling device so as to be spaced from the nozzle-plate of the printing head, the rotary shaft extending along a direction perpendicular to the carrying direction, and the cooling device is removed from the position where the recording medium is cooled by rotating the cooling device about 90 degrees around the rotary shaft as a center. Accordingly, since the cooling device is removed from the position where the recording medium is cooled by rotating the cooling device about 90 degrees around the rotary shaft as a center, the cooling device is adapted to be removed with a simple structure, and moreover, space-saving can be realized. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, and wherein; FIG. 1 is a schematic view of an ink jet printer of the embodiment when performing image recording; FIG. 2 is a schematic view of the ink jet printer of FIG. 1 on stand-by; FIG. 3 is a sectional view showing the ink jet printer of FIG. 1 taken along the line A-A; FIG. 4 is a sectional view showing the ink jet printer of FIG. 2 taken along the line B-B; FIG. 5A is a schematic view of a peltier device provide on the ink jet printer of FIG. 1; FIG. 5B is a schematic view of a frigistor device provide on the ink jet printer of FIG. 1; and FIG. 6 is a block diagram showing a main control device of the ink jet printer of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the preferred embodiments of the present invention will be described in detail by reference to FIGS. 1 to 6. Incidentally, the description in this column does not limit the technical scope of claims and the meaning of terminologies. Moreover, the affirmative descriptions in the following embodiments of the present invention indicate the best mode, and thus the descriptions do not limit the meaning of terminologies and the technical scope of the present invention. FIGS. 1 and 2 show one embodiment of an ink jet printer of the present invention, FIG. 3 is a sectional view taken along the line A-A in FIG. 1, and FIG. 4 is a sectional view taken along the line B-B in FIG. 2. As shown in FIGS. 1 and 2, an ink jet printer 1 comprises a paper storage tray 3 for storing a plurality of stacked recording media 2 at a lower portion inside of the ink jet printer 1. A paper feed device 31 is provided at an upper side of one end portion of the storage tray 3 to feed the recording medium 2 to be recorded from the storage tray 3 one by one. The recording medium 2 to be applied includes various types of papers such as a plain paper, a recycled paper and a gloss paper, and a cut sheet shaped recording medium made from a material such as various types of textiles, non-woven fabrics, resin or the like. A carrying device 4 is provided at an upper portion of the storage tray 3 for carrying the recording medium 2. The carrying device 4 comprises an annular carrying belt 41 for carrying the recording medium 2 in a horizontal direction while supporting it in a flat shape, and the annular carrying belt 41 is rotatably stretched by a plurality of stretching rollers 42. Also, the carrying device 4 comprises a rotatable press roller 43 for pressing the recording medium 2 onto the carrying belt 41 to carry it in a flat shape at a position where the carrying belt 41 and the recording medium 2 starts to contact with each other. The ink jet printer 1 is provided with a discharge tray 5 on a side portion thereof for discharging the recording medium 2 on which an image was recorded. Further, the ink jet printer 1 is provided with a carrying path 6 inside thereof. After the recording medium 2 fed from the storage tray 3 was carried along the periphery of the carrying belt 41, the recording medium 2 is guided from the carrying belt 41 to the discharge tray 5 by the carrying path 6. There are provided a plurality pair of carrying rollers 61, 61 . . . at predetermined positions of the carrying path 6 for carrying the recording medium 2 in a carrying direction X. A plurality of printing heads 7 are provided adjacent to the upper portion of the carrying belt 41 for jetting each color of inks of black (Bk), cyan (C), magenta (M) and yellow (Y) in this order along the carrying direction X onto the recording medium 2. Each printing head 7 is disposed all along the width of the carrying belt 41. A number of nozzles (not shown) are arranged in a nozzle-plate 71 (refer to FIG. 3) of each printing head 7 for jetting ink toward the recording medium 2, and the carrying belt 41 and the printing heads 7 are arranged such that the periphery of the carrying belt 41 faces the nozzle-plates 71. Thereby, the recording medium 2 supported by the carrying belt 41 is adapted to face the nozzle-plates 71 of the printing heads 7. There are provided ink tanks 8 for storing each color of inks and a pipe 81 for connecting the ink tanks 8 and the printing heads 7 at backside of the carrying belt 41 (right side in FIG. 1), thereby supplying ink from the ink tanks 8 to each printing head 7 through the pipe 81. The ink used in the embodiment is the type of ink which is cured by irradiation with light, specially, ultraviolet curable ink which is cured by irradiation with ultraviolet rays. The ultraviolet curable ink is classified into radical polymerizable ink having radical polymerizable compound and cationic polymerizable ink having cationic polymerizable compound, both of which are adaptable as the ink to be used in the embodiment. Hybrid ink in which the radical polymerizable ink and the cationic polymerizable ink are combined may also be applied. Since photo curable ink represented by the above described ultraviolet curable ink has a property that viscosity decreases as temperature increases, the temperature of the ink is needed to be increased at least in the nozzles of the printing heads 7 so as to obtain viscosity necessary for stably jetting ink. Therefore, as shown in FIG. 3, an ink heating device 9 is provided on the outer surface of each printing head 7 for heating the ink in the nozzles. The ink heating device 9 is provided with a heating heatlane plate 91 along the whole width of the printing head 7 near the nozzle-plate 71 in contact relation with the printing head 7, so that the ink inside the nozzles can be heated. The heating heatlane plate 91 is connected to a peltier device 92 as a heat source through a heat pipe 93. There is provided a temperature sensor 94 (refer to FIG. 6) on the heating heatlane plate 91 for detecting temperature of the heating heatlane plate 91. In the embodiment, the example is described where the ink heating device 9 is provided outside of the printing head 7, however, the ink heating device may be provided at any position as long as viscosity of the ink reached into the nozzles decreases enough to stably jet the ink from the printing head 7. For example, the ink heating device 9 may be provided inside of the printing head 7, at a pipe route of the ink and the pipe 81, or the ink tank 8, thereby enabling to obtain the effect to decrease ink viscosity. There are a plurality of light irradiation devices 10 for curing surface of ink jetted onto the recording medium 2 from each printing head 7 by irradiating the ink with light having a predetermined wave length, each of which is provided corresponding to each printing head 7, that is, on the downstream side of each printing head 7 in the carrying direction X near the upper portion of the carrying belt 41. A light source used for the light irradiation device 10 is not particularly limited, however, for example a light emitting diode (LED) array in which LEDs for emitting ultraviolet rays are arranged along the whole width of the carrying belt 41 is preferably used. A plurality of cooling devices 11 for cooling the recording medium 2 on the carrying belt 41 are provided under the printing heads 7 to face the nozzle-plates 71 through the carrying belt 41, each of which corresponds to one of the printing head 7. The cooling device 11 is provided with a flat shaped facing plate 111 facing the recording medium 2 through the carrying belt 41 as shown in FIG. 3. A cooling heatlane plate 112 is laminated on almost all the back surface of the facing plate 111. The above described peltier device 92 is provided at one end portion of the cooling heatlane plate 112 such that the peltier device 92 contacts with the cooling heatlane plate 112 on the upper surface thereof. The cooling operation would cause dew condensation depending upon the environment where the apparatus is mounted and used. Therefore, a cleaning member to clean droplets due to dew condensation may be provided on a cooling surface which the recording medium 2 contacts. The cleaning member is indispensable in a case that the recording medium 2 has high water absorptivity. Description will be made of the peltier device 92 referring to FIG. 5A. FIG. 5A is a side view showing a schematic configuration of the peltier device 92. As shown in FIG. 5A, a plurality of p-type semiconductors (P-Type Bi2Te3) 921 and n-type semiconductors (N-Type Bi2Te3) 922 as thermoelectric elements are alternately arranged in the peltier device 92. In the p-type and n-type semiconductors 921, 922, one ends of adjacent semiconductors 921, 922 are connected by, for example, a connecting metal piece 923 consisting of copper electrodes. The connecting metal pieces 923 at upper and lower sides are coated with ceramic plates 924, 925, respectively, and a power source 926 is connected to the connecting metal pieces 923 positioned at both ends at lower side. When direct current is supplied by the power source 926, the ceramic plate 924 at upper side absorbs heat and the ceramic plate 925 at lower side radiates the absorbed heat. There is known a frigistor device as an improved product of the peltier device. FIG. 5B is a side view showing a schematic configuration of a frigistor device. As shown in FIG. 5B, a plurality of the p-type semiconductors (P-Type Bi2Te3) 921 and the n-type semiconductors (N-Type Bi2Te3) 922 as thermoelectric elements are alternately arranged in the frigistor device 95. These p-type and n-type semiconductors 921, 922 are fixed by a plastic called separator 951, and one ends of adjacent semiconductors 921, 922 are connected by, for example, the connecting metal piece 923 consisting of copper electrodes. The connecting metal pieces 923 at upper and lower sides are coated with insulating materials 952, 953, respectively, and the power source 926 is connected to the connecting metal pieces 923 positioned at both ends at lower side. When direct current is supplied by the power source 926, the insulating material 952 at upper side absorbs heat and the insulating material 953 at lower side radiates the absorbed heat. Unlike the peltier device 92 which is fixed by a hard ceramic plates 924, 925, the frigistor device 95 is fixed by a plastic called separator 951, so that the frigistor device 95 can be fixed even in the case that a fixing member of the cooling device 11 has a slightly curved surface, and is less likely to be damaged. Further, the peltier device 92 life is decreased due to ON/OFF control (quick cooling), however, the frigistor device 95 is capable of performing quick cooling by ON/OFF control and its life is less decreased due to quick cooling. In view of shortening warm-up time of the apparatus, use of the frigistor device 95 which is an improved product of the peltier device 92 is more effective. That is, in the cooling device 11 in the embodiment, since the cooling heatlane plate 112 contacts with the ceramic plate for heat absorption 924, the whole surface of the cooling heatlane plate 112 is adapted to be cooled. The cooling control of the cooling device 11 is determined depending upon the size of the peltier device 92 or the frigistor device 95, current or voltage, so that variable current is applied in the case that voltage is specified, and variable voltage is applied in the case that current is specified, thereby enabling to control the cooling temperature. Since the heat pipe 93 contacts with the ceramic plate for heat radiation 925, the heat radiated from the ceramic plate 925 is conducted to the heating heatlane plate 91 through the heat pipe 93. There is disposed a rotary shaft (not shown) at one end side of the front side of the cooling device 11 under the printing head 7 to be spaced from the nozzle-plate 71, the rotary shaft extending along the direction perpendicular to the carrying direction X. The rotary shaft and the cooling device 11 are connected. The cooling device 11 is adapted to rotate about 90 degrees downward around the rotary shaft as a center with the rotation of the rotary shaft to make the facing plate 111 be in the vertical state from the horizontal state (refer to FIGS. 2 and 4). The horizontal state of the facing plate 111 is referred to as a cooling state, and the vertical state of the facing plate 111 is referred to as a removed state. In the embodiment, the example is described where the rotary shaft is disposed at one end side of the front side of the cooling device 11, however, the rotary shaft may be disposed at the other end side of the back side. A plurality of cap members 12 to perform maintenance to the printing heads 7 are liftably provided under the cooling devices 11 so as to correspond to the printing heads 7, respectively. As shown in FIG. 2, when the cap members 12 are moved upward to contact with the nozzle-plates 71 of the printing heads 7, the nozzle-plates 71 and the nozzles are covered with the cap members 12, thereby enabling to keep a moist condition thereof. A suction pump 122 (refer to FIG. 6) is connected to each cap member 12 through a waste ink pipe 121 shown in FIG. 4. When the suction pumps 122 are activated in a state that the nozzle-plates 71 and the nozzles are covered by the cap members 12, the ink adhered to the nozzle-plates 71 or inside the nozzles can be suctioned. The operations to maintain normal operation by keeping the printing heads 7 in a moist condition and suctioning and removing ink are referred to as maintenance. The cap members 12 move downward as the ink jet printer 1 starts image recording to be separated from the nozzle-plates 71. In the cooling state, each cooling device 11 is positioned between the cap member 12 and the printing head 7 to obstruct the moving up operation of the cap members 12. Thus, when the cap members 12 move upward, the cooling devices 11 become in the removed state. That is, the cooling devices 11 are removed from the route of the cap members 12. The carrying belt 41 is interposed between the cap members 12 and the printing heads 7, so that the carrying belt 41 may obstruct the cap members 12 to cover the nozzle-plates 71 of the printing heads 7. In order to prevent this, for example, the carrying belt 41 may be removed from the position just below the printing heads 7 at the time of the maintenance, or the carrying belt 41 may have openings or clearances to be capable of inserting the cap members 12. The ink jet printer 1 is provided with a control device 15 for controlling each drive section as shown in FIG. 6. An input section 16 to which instructions for image recording are input, a drive source for carrying 44 as a drive source for the carrying device 4, a light source 101 of the light irradiation device 10, a rotary shaft drive source 20 as a drive source for the rotary shaft, a drive source for capping 123 as a drive source for the cap members 12, the printing heads 7, the storing section 17, a peltier device 92, and a temperature sensor 94 are electrically connected to the control section 15. Moreover, each drive section of the ink jet printer 1 is also connected to the control device 15. The control device 15 controls each section according to the control programs or control data written in the storing section 17. Operations of the embodiment will be explained. As shown in FIGS. 2 and 4, when the ink jet printer 1 is on stand-by, the cooling device 11 is in the removed state, and each cap member 12 contacts the nozzle-plate 71 of each printing head 7. After the image recording start instruction is input to the input section 16, the control device 15 controls the drive source for capping 123 so as to make the cap members 12 be separated from the nozzle-plates 71 of the printing heads 7. Thereafter, the control device 15 controls the rotary shaft drive source 20 to make the cooling devices 11 be in the cooling state. Thereby, the ink jet printer 1 becomes in a state capable of performing image recording as shown in FIG. 1. The control device 15 controls the peltier device 92 based on the detected result of the temperature sensor 94 so as to make the cooling devices 11 and the ink heating device 9 actuate, enabling the cooling devices 11 to cool the recording medium 2 and the ink heating device 9 to heat ink in the nozzles. Since viscosity necessary for stably jetting ink from the printing heads 7 is 3 to 20 mPas, the control device 15 controls the peltier device 92 to decrease viscosity of the ink to 3 to 20 mPas. For reducing the spread of the ink placed on the recording medium 2, it is desired to cool the ink with temperature difference of 10° C. or more with respect to the temperature of the ink jetted. Thus, it is preferable to control the peltier device 92 such that the temperature of the recording medium 2 before the ink placed thereon is at least 20° C. or more lower than the temperature of the ink jetted. Since the carrying belt 41 is interposed between the recording material 2 and the cooling devices 11 at the time of image recording, the control device 15 is needed to control the peltier device 92 in view of heat conductivity, thickness or the like of the carrying belt 41. When the detected result of the temperature sensor 94 is 80° C. or more, it is difficult to stably jet ink because ink viscosity is too decreased, therefore, the temperature of the printing heads 7 needs to be controlled. For example, the temperature of the printing heads 7 can be controlled as follows. The heating heatlane plate 91 capable of contacting with or being apart from the printing head 7 may be applied. In this case, when the detected result of the temperature sensor 94 becomes 80° C. or more, the printing head 7 is separated from the heating heatlane plate 91, thereby insulting heat conduction to the printing head 7. Also, a cooling fan for the heating heatlane plate 91 may be provided. In this case, when the detected result of the temperature sensor 94 becomes 80° C. or more, the cooling fan is operated for cooling. Therefore, the temperature of each printing head 7 can be controlled. When the ink in the nozzles is heated to obtain the temperature for stably jetting the ink, the control device 15 activates the paper feed device 31 to feed the uppermost recording medium 2 stored in the storing tray 3, and then rotates the carrying roller 61 to carry the recording medium 2 fed. When the recording medium 2 reaches to the pressure roller 43, the control device 15 activates the pressure roller 43 to press the recording medium 2 to the periphery of the carrying belt 41 from the edge thereof. When the recording medium 2 is carried to the position where the printing heads 7 are mounted with the rotation of the carrying belt 41, the recording medium 2 is cooled by the cooling effect by the cooling device 11. The control device 15 controls the printing heads 7 to jet ink to the recording medium 2. The ink placed on the recording medium 2 was cooled to have high viscosity, so that the ink is unlikely to spread. Hereupon, the ink placed on the recording medium 2 is irradiated with light emitted from the light irradiation device 10 to be cured. After an image is formed on the recording medium 2, when the recording medium 2 is carried and the edge thereof is separated from the carrying belt 41, the recording medium 2 is carried to the carrying roller 61 to be discharged to outside from the discharge tray 5. After the completion of the image recording, the control device 15 controls the rotary shaft drive source 20 to make the cooling device be in the removed condition, and then, controls the drive source for capping 123 so as to make the capping members 12 be contact with the nozzle-plates 71 of the printing heads 7. As described above, according to the ink jet printer 1 in this embodiment, the recording medium 2 is cooled by the cooling device 11 at the position which is in the upstream side with respect to the position where the ink placed on the recording medium 2 is cured in the carrying direction X, so that the ink placed on the recording medium 2 can be cooled before being cured. Thus, ink viscosity placed on the recording medium 2 can be increased, thereby preventing the ink spread. This results in obtaining high image quality. The cooling device 11 is connected to the ink heating device 9, capable of conducting heat through the heat pipe 93 bilaterally. Thus, the ink heating device 9 utilizes heat radiation which is caused when the cooling device 11 cools the recording medium 2 for heating ink, thereby heat can be utilized effectively. The cooling device 11 rotates about 90 degrees around the rotary shaft as a center to be removed from the position where the recording medium 2 is cooled, so that the cooling device 11 can be removed with a simple structure, and moreover, space-saving can be realized. It is to be understood that the present invention is not limited to the embodiment and appropriate changes may be made. For example, the example was explained in the case that photo curable ink represented by ultraviolet curable ink is used as the ink whose ink viscosity decreases as the temperature increases, however, the ink is not limited thereto as long as ink viscosity decreases as the temperature increases, and for example, water-based ink or oil-based ink other than the ink in the embodiment may also be used. In this embodiment, the configuration is such that the temperature sensor 94 detects the temperature of the heating heatlane plate 911 to indirectly detect the temperature of the ink, however, it may be a configuration wherein, for example, a temperature sensor is disposed in a nozzle to directly detect the temperature of the ink. Further in this embodiment, the example is explained in the case that the cooling devices 11 are disposed at positions to face the nozzle-plates 71 of the printing heads 7, respectively, however, they may be disposed at any position as long as each cooling device 11 is positioned on the upstream side with respect to a position where the ink placed on the recording medium 2 is cured in the carrying direction X. For example, in this embodiment, since the ink is cured by the irradiation with light from the light irradiation device 10, it is preferable that the cooling device 10 is disposed on the upstream side with respect to a position to face the light irradiation device 10. The entire disclosure of Japanese Patent Application No. Tokugan 2003-295263 which was filed on Aug. 19, 2003, including specification, claims, drawings and summary are incorporated herein by reference in its entirety. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an ink jet printer and particularly, to an ink jet printer in which an ink is jetted after being heated. 2. Description of the Related Art Recently, an ink jet printer has been widely used because images can be easily formed at a low cost in comparison to a method such as a gravure printing method or a flexographic method which needs a plate. In the field of performing image recording on goods or packing material for goods by using the ink jet printer, material with no ink absorptivity such as resin or metal is generally used for goods or packing for goods. There is known a ink jet printer of photo curable type in which a recording medium made from material with no ink absorptivity and photo curable ink are used, and for example, the ink jetted onto the recording medium is irradiated with light such as ultraviolet rays to cure and fix the ink thereon (for example, refer to JP-2002-283545A). JP-2002-283545A discloses an example of an ink jet printer in which photo curable ink is used. Specifically, a recording apparatus in JP-2002-283545A is provided with a rotatable and transparent dram shaped intermediate transfer body and a printing head facing the outer periphery of the intermediate transfer body. In a recording operation, ink is jetted from the printing head onto the outer periphery of the intermediate transfer body and the ink placed on the intermediate transfer body is irradiated with light from outside of the intermediate transfer body, and thereafter, the ink irradiated with light is transferred onto the recording medium while rotating the intermediate transfer body. Such a recording method is successful in preventing deterioration of image quality such as beading or bleeding as well as transferring the ink with optimum viscosity onto the recording medium by adjusting the viscosity of the ink placed on the intermediate transfer body. Generally, photo curable ink has high viscosity in a normal room temperature (around 18 to 28° C.), therefore having a difficulty in stably jetting the ink. For stably jetting the ink, ink viscosity is preferably 3 to 20 mPas, so that an ink jet printer has been developed in which photo curable ink is heated to 40 to 80° C. to have low ink viscosity of 3 to 20 mPas before being jetted. However, when the photo curable ink with decreased viscosity is jetted from the printing head, the ink spreads until being irradiated with light after placed on the recording medium, thereby causing images to blur. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is to suppress spread of ink placed on a recording medium by increasing ink viscosity of ink placed on the recording medium to achieve high image quality. In accordance with a first aspect of the present invention, the ink jet printer comprises: an ink heating device for heating an ink whose viscosity decreases as temperature increases; a printing head for jetting an ink heated by the heating device onto a recording medium; a carrying device for carrying the recording medium while supporting the recording medium to face a nozzle-plate of the printing head; and a cooling device for cooling the recording medium in an upstream side with respect to a position where an ink placed on the recording medium is cured, in a carrying direction of the recording medium by the carrying device. Accordingly, since the recording medium is cooled in the upstream side with respect to a position where the ink placed on the recording medium is cured, in the carrying direction, the ink can be cooled before the ink placed on the recording medium is cured. Thus, ink viscosity placed on the recording medium can be increased, thereby preventing the ink spread. This results in obtaining high image quality. Preferably, in the printer of the first aspect of the present invention, the cooling device and the ink heating device are connected to be capable of conducting heat, and the ink heating device heats an ink by utilizing a heat radiation which is generated from the cooling device by cooling the recording medium. Accordingly, since the ink heating device heats the ink by utilizing heat radiation generated from the cooling device by cooling the recording medium, heat can be effectively used. Preferably, in the printer of the first aspect of the present invention, the cooling device and the ink heating device are connected by a heat pipe. Accordingly, since the cooling device and the ink heating device are connected by the heat pipe, heat exchange is effectively performed. Preferably, in the printer of the first aspect of the present invention, the cooling device comprises a peltier device. Accordingly, since the cooling device comprises a peltier device, the recording medium can be cooled by utilizing peltier effect by the peltier device. Moreover, combination of a peltier device and a heatlane plate enables the recording medium to be cooled uniformly. Preferably, in the printer of the first aspect of the present invention, the cooling device comprises a frigistor device. Preferably, in the printer of the first aspect of the present invention, the printer further comprises a cap member to cover the nozzle-plate at a time of maintenance of the printing head, the cap member being separated from the nozzle-plate at a time of image recording, wherein the cooling device cools the recording medium between the cap member and the printing head at a time of image recording, and is removed from a position where the recording medium is cooled at a time of maintenance. Accordingly, since the cooling device is removed from a position where the recording medium is cooled at a time of maintenance, the cap member is not obstructed by the cooling device from covering the nozzle-plate of the printing head, enabling to smoothly perform the maintenance. Preferably, in the printer of the first aspect of the present invention, a rotary shaft is provided at one end side or the other end side of the cooling device so as to be spaced from the nozzle-plate of the printing head, the rotary shaft extending along a direction perpendicular to the carrying direction, and the cooling device is removed from the position where the recording medium is cooled by rotating the cooling device about 90 degrees around the rotary shaft as a center. Accordingly, since the cooling device is removed from the position where the recording medium is cooled by rotating the cooling device about 90 degrees around the rotary shaft as a center, the cooling device is adapted to be removed with a simple structure, and moreover, space-saving can be realized. | 20040422 | 20061114 | 20050224 | 93540.0 | 0 | TRAN, LY T | INK JET PRINTER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,829,339 | ACCEPTED | Overheated steam oven | An overheated steam oven including a cabinet to define a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity. The overheated steam generator includes a steam generating vessel of which an outlet is connected to and communicates with the cooking cavity, with a predetermined amount of water contained in the steam generating vessel. A first heater is installed in the steam generating vessel to be immersed in the water contained in the steam generating vessel so as to generate steam, and a second heater is mounted to an upper portion in the steam generating vessel so as to overheat the steam generated by the first heater. | 1. An overheated steam oven, having a cabinet to define a cooking cavity therein and an overheated steam generator to supply overheated steam into the cooking cavity, comprising: a steam generating vessel having a predetermined amount of water contained therein; an outlet, connected to the steam generating vessel, to communicate with the cooking cavity; and first and second heaters to produce steam from the water contained in the steam generating vessel, and to overheat the produced steam wherein the steam generating vessel comprises: an inner vessel part to contain the first and the second heaters; and an outer vessel part to surround an outer surface of the inner vessel part. 2. The overheated steam oven according to claim 1, wherein the steam generating vessel provides insulation. 3. The overheated steam oven according to claim 2, wherein a vacuum is maintained between the inner vessel part and the outer vessel part. 4. The overheated steam oven according to claim 3, further comprising a shielding material between the inner vessel part and the outer vessel part to intercept radiant heat. 5. The overheated steam oven according to claim 1, wherein the first heater is installed in the steam generating vessel to be immersed in the water contained in the steam generating vessel, and the second heater is mounted to the upper portion of the steam generating vessel to overheat the steam generated by the first heater, and the first heater and the second heater each has a spiral shape. 6. The overheated steam oven according to claim 1, wherein the first heater and the second heater are supported by a lower plate which closes a lower end of the steam generating vessel. 7. The overheated steam oven according to claim 1, further comprising a feed pipe and a drain pipe respectively coupled to the steam generating vessel, to feed and drain water into and from the steam generating vessel. 8. The overheated steam oven according to claim 1, further comprising a water level sensor installed in the steam generating vessel, to monitor a level of the water contained in the steam generating vessel. 9. The overheated steam oven according to claim 1, further comprising a steam inlet part provided on the rear wall of the cooling cavity, wherein the steam generating vessel comprises a bent part, which is formed by bending an upper end of the steam generating vessel toward a rear wall of the cooking cavity, the bent part being connected at a front end thereof to the steam inlet port. 10. The overheated steam oven according to claim 1, further comprising an exhaust path, provided at an upper portion in the cooking cavity, to discharge the steam from the cooking cavity to an outside of the cooking cavity. 11. The overheated steam oven according to claim 1, further comprising each of walls of the cooking cavity comprising a multi-layered panel that comprises a plurality of sheets spaced apart from each other to insulate the cooking cavity. 12. An overheated steam oven, including a cabinet to define a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity, the overheated steam generator comprising: a steam generating vessel having upper and lower ends, through which an outlet communicates with the cooking cavity, and containing a predetermined amount of water therein; a first heater installed under the lower end of the steam generating vessel to boil the water contained in the steam generating vessel, thus generating steam; and a second heater mounted to the upper portion in the steam generating vessel, to overheat steam generated by the first heater wherein the steam generating vessel comprises: an inner vessel part to contain the first and the second heaters; and an outer vessel part to surround an outer surface of the inner vessel part. 13. The overheated steam oven according to claim 12, wherein the steam generating vessel provides insulation. 14. The overheated steam oven according to claim 13, wherein a vacuum is maintained between the inner vessel part and the outer vessel part. 15. The overheated steam oven according to claim 14, further comprising a shielding material between the inner vessel part and the outer vessel part to intercept radiant heat. 16. The overheated steam oven according to claim 12, wherein the first heater is supported by a lower plate which closes the lower end of the steam generating vessel, and the second heater, in the upper portion of the steam generating vessel, has a spiral shape and is supported at a terminal thereof by the lower plate. 17. The overheated steam oven according to claim 12, further comprising a feed pipe and a drain pipe respectively coupled to the steam generating vessel to feed and drain water into and from the steam generating vessel. 18. The overheated steam oven according to claim 12, further comprising a water level sensor installed in the steam generating vessel to monitor a level of the water contained in the steam generating vessel. 19. The overheated steam oven according to claim 12, further comprising a steam inlet part provided on the rear wall of the cooling cavity, wherein the steam generating vessel comprises a bent part, which is formed by bending an upper end of the steam generating vessel toward a rear wall of the cooking cavity, the bent part being connected at a front end thereof to the steam inlet port. 20. The overheated steam oven according to claim 12, further comprising an exhaust path, provided at an upper portion in the cooking cavity, to discharge the steam from the cooking cavity to an outside of the cooking cavity. 21. The overheated steam oven according to claim 12, wherein each of walls of the cooking cavity comprises a multi-layered panel that comprises a plurality of sheets spaced apart from each other to insulate the cooking cavity. 22. An overheated steam oven, having a cabinet to define a cooking cavity therein and an overheated steam generator to supply overheated steam into the cooking cavity, comprising: a steam generating vessel including an inner vessel part and an outer vessel part to surround an outer surface of the inner vessel part, the steam generating vessel having a lower end and an upper portion and containing a predetermined amount of water therein; an outlet, connected to the steam generating vessel, to communicate with the cooking cavity; and first and second heaters, contained within the inner vessel part, to produce steam from the water contained in the steam generating vessel, and to overheat the produced steam, respectively, wherein the production of steam from the water takes place under the lower end of the steam generating vessel, and the overheating of the produced steam takes place in the upper portion of the steam generating vessel. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Korean Patent Application No. 2003-63009, filed Sep. 9, 2003 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates, in general, to overheated steam ovens and, more particularly, to an overheated steam oven which is designed for home use by simplifying a construction and reducing a size of the overheated steam oven. 2. Description of the Related Art Generally, to cook foods, the foods may be roasted by heat, such as in a gas oven, the foods may be steamed by vapor, such as in a steaming vessel, or the foods may be boiled with water, such as in a cooking vessel. Also, there are methods to cook foods using microwaves, far infrared rays, and overheated steam, etc. Cooking while using gas ovens may, relatively evenly, heat foods in the gas oven, but it is problematic in that a taste of the foods reduces due to oxidation of the foods which results from contact with oxygen in air. Cooking using vapor needs plenty of water, and the foods may be insipid because some water is absorbed into the foods during cooking. Cooking using the cooking vessels have a problem in that the foods may be burnt by overly heating a part of the foods. For cooking using microwaves or far infrared rays, the foods must be rotated due to fixed radiating directions of the microwaves or the far infrared rays, and controlling the temperature of the food is difficult. Further, the foods may easily dry during cooking. To summarize, to appropriately cook foods, cooking apparatuses must evenly heat the foods at suitable temperatures, however, using the above-mentioned conventional cooking methods, it is difficult to satisfy cooking conditions. Cooking using overheated steam is a method in that overheated steam is discharged into a cooking cavity. Since cooking using overheated steam evenly heats foods, the foods may not be partially burnt, and a cooking temperature is easily controlled by controlling a volume of the discharged overheated steam. Also, since oxidation of foods does not occur, cooking using the overheated steam has an advantage in that cooked foods have a better taste. However, conventional cooking apparatuses using the overheated steam include a cooking cavity to contain foods therein, a steam boiler to generate the overheated steam, a water tank to supply water into the steam boiler, and a plurality of steam pipes to discharge the overheated steam generated by the steam boiler into the cooking cavity. Hence, cooking apparatuses are complex and costly. Accordingly, the conventional cooking apparatuses using overheated steam are both difficult to use at home and in a wide open establishment, as in a large restaurant for business. Also, in the conventional overheated steam cooking apparatuses, the overheated steam generated by the steam boiler is discharged into the cooking cavity through the steam pipes, resulting in increased heat loss. SUMMARY OF THE INVENTION Accordingly, it is an aspect of the present invention to provide an overheated steam oven which is designed for home use by simplifying a construction and reducing a size of the overheated steam oven. It is another aspect of the present invention to provide an overheated steam oven which minimizes energy loss by effectively reducing heat loss due to an insulating construction thereof. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. The above and/or other aspects are achieved by providing an overheated steam oven, having a cabinet with a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity. The overheated steam generator includes a steam generating vessel, of which an outlet is connected to and communicates with the cooking cavity, with a predetermined amount of water contained in the steam generating vessel, a first heater which is installed in the steam generating vessel to be immersed in the water contained in the steam generating vessel to generate steam, and a second heater mounted to an upper portion in the steam generating vessel to overheat the steam generated by the first heater. The steam generating vessel may be an insulating vessel. The steam generating vessel may include an inner vessel part which contains the first heater and the second heater therein, and an outer vessel part which surrounds an outer surface of the inner vessel part while being spaced apart from the outer surface of the inner vessel part, with a space between the inner vessel part and the outer vessel part being maintained in a vacuum state. A shielding material may fill the space between the inner vessel part and the outer vessel part to intercept radiant heat. The first heater and the second heater each may have a spiral shape. The first heater and the second heater may be supported by a lower plate which closes a lower end of the steam generating vessel. A feed pipe and a drain pipe may be respectively coupled to the steam generating vessel to feed and drain water into and from the steam generating vessel. A water level sensor may be installed in the steam generating vessel to monitor a level of the water contained in the steam generating vessel. The steam generating vessel may include a bent part which is formed by bending an upper end of the steam generating vessel toward a rear wall of the cooking cavity, the bent part being connected at a front end thereof to a steam inlet port provided on the rear wall of the cooking cavity. An exhaust path may be provided at an upper portion in the cooking cavity to discharge the steam from the cooking cavity to an outside of the cooking cavity. Each of the walls of the cooking cavity may include a multi-layered panel that includes a plurality of sheets spaced apart from each other to insulate the cooking cavity. The above and/or other aspects are achieved by providing an overheated steam oven, having a cabinet to define a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity. The overheated steam generator includes a steam generating vessel of which an outlet communicates with the cooking cavity, and containing a predetermined amount of water therein, a first heater installed under a lower end of the steam generating vessel to boil the water contained in the steam generating vessel, thus generating steam, and a second heater mounted to an upper portion in the steam generating vessel to overheat steam generated by the first heater. BRIEF DESCRIPTION OF THE DRAWINGS These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which: FIG. 1 is a perspective view of an overheated steam oven, according to a first embodiment of the present invention; FIG. 2 is a sectional view illustrating an internal construction of the overheated steam oven of FIG. 1; FIG. 3 is an exploded perspective view illustrating a construction of an overheated steam generator of the overheated steam oven of FIG. 2; FIG. 4 is a sectional view illustrating the construction of the overheated steam generator of the overheated steam oven of FIG. 2; and FIG. 5 is a sectional view illustrating a construction of an overheated steam generator of an overheated steam oven, according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. As shown in FIGS. 1 and 2, an overheated steam oven according to the first embodiment of the present invention includes a cabinet 10 to define a cooking cavity 11 therein, and an overheated steam generator 20 which is mounted to a rear wall in the cabinet 10 to supply overheated steam into the cooking cavity 11. The cabinet 10 includes an outer casing 12, and an inner casing 13 which is installed in the outer casing 12 to be spaced apart from the outer casing 12, thus defining the cooking cavity 11 therein. The cooking cavity 11 is open at a front thereof so as to place and remove foods into and from the cooking cavity 11. Also, the inner casing 13 includes a first casing 13a and a second casing 13b which are spaced apart from each other so as to insulate the cooking cavity 11 from an outside of the cooking cavity 11. That is, each of walls of the cooking cavity 11 includes a multi-layered panel that has a plurality of sheets spaced apart from each other. A door 14, which is opened downward and closed upward, is attached to the open front of the cabinet 10 so as to allow a user to open and close the cooking cavity 11. A control unit 15, which includes a display 15a to display an operational state of the overheated steam oven thereon, various kinds of control buttons 15b, and control switches 15c, are provided at a portion of the cabinet 10 above the door 14. Upper and lower racks 16 are provided at upper and lower portions in the cooking cavity 11 to respectively support foods. Each of the upper and lower racks 16 is removably installed in the cooking cavity 11 to slide in a drawer-type movement along guide rails 17 which are oppositely formed on inner surfaces of both side walls of the inner casing 13. As shown in FIGS. 2 and 3, the overheated steam generator 20, which is provided on the rear wall of the cooking cavity 11, includes a steam generating vessel 21 of which an outlet is connected to a steam inlet port 18 provided on the rear wall of the cooking cavity 11, with a predetermined amount of water contained in the steam generating vessel 21. The overheated steam generator further includes a first heater 22 which is mounted to a lower portion in the steam generating vessel 21, and a second heater 23 which is mounted to an upper portion in the steam generating vessel 21. As shown in FIGS. 3 and 4, the steam generating vessel 21 is a vacuum insulating vessel so that a space therein is insulated from an outside thereof, thus minimizing heat loss. The steam generating vessel 21 includes an inner vessel part 21a, and an outer vessel part 21b which surrounds an outer surface of the inner vessel part 21a while being spaced apart from the outer surface of the inner vessel part 21a. A shielding material 21c fills a space between the inner vessel part 21a and the outer vessel part 21b to intercept radiant heat. The space between the inner vessel part 21a and the outer vessel part 21b is sealed in a vacuum state, once the vacuum state is induced. The steam generating vessel 21 further includes a bent part 21d which is formed by bending an upper end of the steam generating vessel 21 toward the rear wall of the cooking cavity 11. A front end of the bent part 21d, which is the outlet of the steam generating vessel 21, is connected to the steam inlet port 18 provided on the rear wall of the cooking cavity 11. At this time, an upper flange 24, which is provided around the outlet of the steam generating vessel 21, is mounted to a predetermined portion of the inner casing 13 around the steam inlet port 18 by a plurality of locking members 25, with a first packing 26 interposed between the upper flange 24 and the inner casing 13 to prevent the leakage of steam. A cover 19, on which a plurality of steam discharging holes are formed, is mounted to an inner surface of the rear wall of the cooking cavity 11 to allow the overheated steam generated by the overheated steam generator 20 to pass into the cooking cavity 11. A lower flange 27 is provided at a lower end of the steam generating vessel 21. A lower plate 28, which closes an opening of the lower end of the steam generating vessel 21, is mounted to the lower flange 27 by a plurality of locking members 29. At this time, a second packing 30 is interposed between the lower plate 28 and the lower flange 27 to prevent the leakage of water from the steam generating vessel 21. The first heater 22, which is mounted to the lower portion in the steam generating vessel 21, and the second heater 23, which is mounted to the upper portion in the steam generating vessel 21, each has a spiral shape to maximize a heat transferring surface area. First and second terminals 22a and 23a, which are respectively provided at the first and second heaters 22 and 23, are extended downward, and are supported by the lower plate 28. Accordingly, the first and second heaters 22 and 23 are supported on the lower plate 28. Also, third and fourth packings 31a and 31b are respectively interposed between the first and second terminals 22a and 23a of the first and second heaters 22 and 23 and the lower plate 28 to prevent the leakage of water from the steam generating vessel 21. When the predetermined amount of water is fed into the steam generating vessel 21, the first heater 22, which is provided at the lower portion of the steam generating vessel 21, is immersed in the water contained in the steam generating vessel 21, and the second heater 23, which is provided at the upper portion of the steam generating vessel 21, is placed above the water, which is contained in the steam generating vessel 21 and reaches a maximum water level. Due to the above-mentioned construction, the overheated steam is generated by allowing the second heater 23 to further heat the steam generated by an operation of the first heater 22 while the steam rises toward the outlet of the steam generating vessel 21. Also, a feed pipe 32, to feed water into the steam generating vessel 21, a drain pipe 33, to drain the water from the steam generating vessel 21, and a water level sensor 34, to monitor a level of the water contained in the steam generating vessel 21, are respectively mounted to the lower plate 28 of the steam generating vessel 21. A fifth packing 31d is provided between the feed pipe 32 and the lower plate 28 to prevent the leakage of water from the steam generating vessel 21. A sixth packing 31c is provided between the water level sensor 34 and the lower plate 28 to prevent the leakage of water from the steam generating vessel 21. At this time, the feed pipe 32 is connected to an external water source (not shown). The water level of the water contained in the steam generating vessel 21 is maintained by controlling the amount of the water supplied from the water source (not shown) in response to a monitoring operation of the water level sensor 34. Also, a control valve (not shown) is provided on the drain pipe 33 to drain the residual water from the steam generating vessel 21 after a cooking operation. As shown in FIG. 2, the overheated steam oven of the present invention further includes an exhaust duct 40 at an upper portion in the cooking cavity 11 to discharge the overheated steam from the cooking cavity 11 to an outside of the cooking cavity 11. The operation of the overheated steam oven of the present invention will be described hereinbelow. First, foods are placed on the upper and lower racks 16 of the cooking cavity 11. After, the overheated steam oven is operated and the water is fed into the steam generating vessel 21 through the feed pipe 32 of the overheated steam generator 20. At this time, the water level in the steam generating vessel 21 is controlled in response to the monitoring operation of the water level sensor 34. After a predetermined amount of water is fed into the steam generating vessel 21, the water contained in the steam generating vessel 21 is heated by the first heater 22 to generate steam. The steam is then generated by boiling the water contained in the lower portion of the steam generating vessel 21 by using the first heater 22 which is immersed in the water. Overheated steam is generated by further heating the steam using the second heater 23 while the steam rises in the steam generating vessel 21. The overheated steam is supplied into the cooking cavity 11 through the outlet of the steam generating vessel 21. The foods in the cooking cavity 11 are cooked by the heat of the overheated steam. After cooking is finished, the overheated steam is discharged to the outside of the cooking cavity 11 through the exhaust duct 40 provided at the upper portion of the cooking cavity 11. In the above-mentioned operation, since the steam generating vessel 21 has an insulating construction and the outlet of the steam generating vessel 21 is mounted to the rear wall of the cooking cavity 11, the overheated steam oven of the present invention generates overheated steam while minimizing heat loss. In addition, since the overheated steam oven of the present invention rapidly supplies overheated steam into the cooking cavity 11, the energy loss is further minimized. Also, since the first heater 22, which has a spiral shape, is immersed in the water contained in the steam generating vessel 21, the overheated steam oven of the present invention may rapidly boil the water in the steam generating vessel 21. Also, since the second heater 23, which has a spiral shape, further heats the steam, the overheated steam oven of the present invention generates the overheated steam within a short period of time while reducing energy requirements. FIG. 5 is a sectional view showing a construction of an overheated steam generator 20 of an overheated steam oven, according to a second embodiment of the present invention. As shown in FIG. 5, a first heater 36 to generate steam in an overheated steam vessel 21 is installed under a lower end of the steam generating vessel 21. In the second embodiment of the present invention, the first heater 36 is embedded in a heat transfer unit 37 which is made of a metal. The heat transfer unit 37 having the first heater 36 is mounted to a lower surface of a lower plate 28 of the steam generating vessel 21. In the construction of the overheated steam oven as described above, since the first heater 36 heats the lower plate 28, the water contained in the steam generating vessel 21 is heated, hence, the steam is generated in the steam generating vessel 21. The general construction of the overheated steam oven according to the second embodiment expect for the above-mentioned structure remains the same as the first embodiment, and further explanation is thus not deemed necessary. As is apparent from the above description, in an overheated steam oven of the present invention, since an overheated steam generator is mounted on a rear wall of a cooking cavity and the construction of the overheated steam generator is simple in comparison with steam boilers of conventional overheated steam cooking apparatuses etc., the present invention may be simply manufactured at a reduced cost. In addition, the overheated steam oven of the present invention may be used at home due to the simplified construction and the reduced size of the overheated steam oven. Also, since a steam generating vessel of the overheated steam generator has an insulating construction, the overheated steam oven of the present invention generates overheated steam while minimizing heat loss. Since an outlet of the steam generating vessel is directly connected to the rear wall of the cooking cavity, the overheated steam oven of the present invention rapidly supplies the overheated steam into the cooking cavity. Also, since each of walls of the cooking cavity includes a multi-layered panel that has a plurality of sheets spaced apart from each other, the overheated steam oven of the present invention further minimizes heat loss. Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates, in general, to overheated steam ovens and, more particularly, to an overheated steam oven which is designed for home use by simplifying a construction and reducing a size of the overheated steam oven. 2. Description of the Related Art Generally, to cook foods, the foods may be roasted by heat, such as in a gas oven, the foods may be steamed by vapor, such as in a steaming vessel, or the foods may be boiled with water, such as in a cooking vessel. Also, there are methods to cook foods using microwaves, far infrared rays, and overheated steam, etc. Cooking while using gas ovens may, relatively evenly, heat foods in the gas oven, but it is problematic in that a taste of the foods reduces due to oxidation of the foods which results from contact with oxygen in air. Cooking using vapor needs plenty of water, and the foods may be insipid because some water is absorbed into the foods during cooking. Cooking using the cooking vessels have a problem in that the foods may be burnt by overly heating a part of the foods. For cooking using microwaves or far infrared rays, the foods must be rotated due to fixed radiating directions of the microwaves or the far infrared rays, and controlling the temperature of the food is difficult. Further, the foods may easily dry during cooking. To summarize, to appropriately cook foods, cooking apparatuses must evenly heat the foods at suitable temperatures, however, using the above-mentioned conventional cooking methods, it is difficult to satisfy cooking conditions. Cooking using overheated steam is a method in that overheated steam is discharged into a cooking cavity. Since cooking using overheated steam evenly heats foods, the foods may not be partially burnt, and a cooking temperature is easily controlled by controlling a volume of the discharged overheated steam. Also, since oxidation of foods does not occur, cooking using the overheated steam has an advantage in that cooked foods have a better taste. However, conventional cooking apparatuses using the overheated steam include a cooking cavity to contain foods therein, a steam boiler to generate the overheated steam, a water tank to supply water into the steam boiler, and a plurality of steam pipes to discharge the overheated steam generated by the steam boiler into the cooking cavity. Hence, cooking apparatuses are complex and costly. Accordingly, the conventional cooking apparatuses using overheated steam are both difficult to use at home and in a wide open establishment, as in a large restaurant for business. Also, in the conventional overheated steam cooking apparatuses, the overheated steam generated by the steam boiler is discharged into the cooking cavity through the steam pipes, resulting in increased heat loss. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an aspect of the present invention to provide an overheated steam oven which is designed for home use by simplifying a construction and reducing a size of the overheated steam oven. It is another aspect of the present invention to provide an overheated steam oven which minimizes energy loss by effectively reducing heat loss due to an insulating construction thereof. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. The above and/or other aspects are achieved by providing an overheated steam oven, having a cabinet with a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity. The overheated steam generator includes a steam generating vessel, of which an outlet is connected to and communicates with the cooking cavity, with a predetermined amount of water contained in the steam generating vessel, a first heater which is installed in the steam generating vessel to be immersed in the water contained in the steam generating vessel to generate steam, and a second heater mounted to an upper portion in the steam generating vessel to overheat the steam generated by the first heater. The steam generating vessel may be an insulating vessel. The steam generating vessel may include an inner vessel part which contains the first heater and the second heater therein, and an outer vessel part which surrounds an outer surface of the inner vessel part while being spaced apart from the outer surface of the inner vessel part, with a space between the inner vessel part and the outer vessel part being maintained in a vacuum state. A shielding material may fill the space between the inner vessel part and the outer vessel part to intercept radiant heat. The first heater and the second heater each may have a spiral shape. The first heater and the second heater may be supported by a lower plate which closes a lower end of the steam generating vessel. A feed pipe and a drain pipe may be respectively coupled to the steam generating vessel to feed and drain water into and from the steam generating vessel. A water level sensor may be installed in the steam generating vessel to monitor a level of the water contained in the steam generating vessel. The steam generating vessel may include a bent part which is formed by bending an upper end of the steam generating vessel toward a rear wall of the cooking cavity, the bent part being connected at a front end thereof to a steam inlet port provided on the rear wall of the cooking cavity. An exhaust path may be provided at an upper portion in the cooking cavity to discharge the steam from the cooking cavity to an outside of the cooking cavity. Each of the walls of the cooking cavity may include a multi-layered panel that includes a plurality of sheets spaced apart from each other to insulate the cooking cavity. The above and/or other aspects are achieved by providing an overheated steam oven, having a cabinet to define a cooking cavity therein, and an overheated steam generator to supply overheated steam into the cooking cavity. The overheated steam generator includes a steam generating vessel of which an outlet communicates with the cooking cavity, and containing a predetermined amount of water therein, a first heater installed under a lower end of the steam generating vessel to boil the water contained in the steam generating vessel, thus generating steam, and a second heater mounted to an upper portion in the steam generating vessel to overheat steam generated by the first heater. | 20040422 | 20050628 | 20050310 | 93328.0 | 0 | FUQUA, SHAWNTINA T | OVERHEATED STEAM OVEN | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,829,485 | ACCEPTED | Mixed-gas insufflation system | A mixed-gas insufflation system for mixing insufflation gases includes a gas supply providing at least two sources of insufflation gas and a mixer system. The mixer system includes a chamber having at least two inlets and at least one outlet. The at least two inlets of the chamber are in fluid communication with the gas supply. The mixer system mixes the at least two sources of insufflation gas. | 1. A mixed-gas insufflation system for mixing insulation gases, comprising: a gas supply providing at least two sources of insulation gas; and a mixer system including a chamber having at least two inlets and at least one outlet, wherein the at least two inlets of the chamber are in fluid communication with the gas supply, the mixer system for mixing the at least two sources of insulation gas. 2. The mixed-gas insulation system of claim 1 wherein the mixer system further comprises a tubing system corresponding to each source of insulation gas, the tubing system having a first end attached to the source of insufflation gas and a second end attached with an inlet of the at least two inlets of the chamber. 3. The mixed-gas insulation system of claim 2, further comprising activation means for selecting an insufflation gas to enter the corresponding tubing system. 4. The mixed-gas insulation system of claim 2, wherein the tubing system further comprises a flow valve to allow the flow of insufflation gas and a metering valve to control the flow of insufflation gas. 5. The mixed-gas insulation system of claim 1, wherein the chamber further comprises at least one baffle. 6. The mixed-gas insufflation system of claim 5, wherein the chamber further comprises four baffles. 7. The mixed-gas insufflation system of claim 1, wherein the chamber further comprises a plate having a plurality of holes. 8. The mixed-gas insufflation system of claims 1, 5, 6 or 7, wherein the mixing chamber further comprises a fan. 9. The mixed-gas insufflation system of claim 1, wherein the at least two sources of insufflation gas are different from each other. 10. The mixed-gas insufflation system of claim 1, wherein the at least two sources of insufflation gas include oxygen. 11. The mixed-gas insufflation system of claim 1, wherein the mixer system further comprises a sensor for identifying the presence of the insufflating gas associated with the corresponding tubing system. 12. The mixed-gas insufflation system of claim 11, wherein the sensor further comprises a resistor block that senses the assigned ohmic value assigned to the insufflating gas. 13. The mixed-gas insufflation system of claim 11, wherein the sensor further comprises a gas analyzer. 14. The mixed-gas insufflation system of claim 1, wherein the mixer system further comprises at least one dual-capacity tube having an inlet for attachment to at least one outlet of an insufflator; 15. The mixed-gas insufflation system of claim 1, further comprising a multi-output insulator having: at least two inputs; at least two delivery paths attached to the at least two inputs for allowing the flow of insufflation gases from at least two pressurized sources attached to the at least two delivery paths; a central processing unit for monitoring and controlling the flow of insufflation gas passing through the at least two delivery paths; at least two output lines attached to the at least two delivery paths; and wherein the mixer system is located internal to the multi-output insufflator and along the at least two delivery paths for mixing the insufflation gas. 16. The mixed-gas insufflation system of claims 1 or 15 further comprising a multi-lumen catheter having at least one inlet attached with the at least one output of the chamber and at least one inlet for attachment with a source of liquid. 17. The mixed-gas insufflation system of claims 1 or 15 further comprising a humidification system having at least one inlet attached with the at least one output of the mixing chamber. 18. The mixed-gas insulation system of claim 1, wherein the chamber further comprises at least one output in fluid communication with a connector for insertion into a surgical site and a catheter having at least one lumen and an outlet for insertion into the surgical site. 19. An insufflator comprising: at least two inputs, each for supplying a source of insufflating gas; a mixing chamber in fluid communication with the at least two inputs; the mixing chamber having at least one output; at least one delivery path attached to the at least one output of the mixing chamber; a central processing unit electrically connected with the at least one delivery path for monitoring and controlling the flow of insulation gas passing through the at least one delivery path; at least one output line attached to the at least one delivery path; and wherein the at least one delivery path and the at least one output line allows for the continuous supply of mixed insufflation gas to a surgical site during a laparoscopic procedure. 20. The insufflator of claim 19 further comprising a multi-output insulator having at least two delivery paths and at least two output lines each attached to a delivery path, and a mixing chamber having at least two outputs. 21. The insufflator of claim 20 further comprising at least one dual-capacity tube attached to the at least two output lines; and wherein the at least two delivery paths and the at least one dual-capacity tube allow for the continuous supply of insulation gases. 22. The insufflator of claim 19 further comprising a multi-lumen catheter having at least one inlet attached with the at least one output of the mixing chamber and at least one inlet for attachment with a source of liquid. 23. The insulator of claim 19 further comprising a humidification system having at least one inlet attached with the at least one output of the mixing chamber. 24. A mixed-gas insufflation system for mixing insufflation gases, comprising: a gas supply providing at least two sources of insulation gas; and mixing means in fluid communication with the gas supply, the mixing means for mixing the at least two sources of insulation gas. 25. The mixed-gas insufflation of claim 24 further comprising an insulator having at least one input, wherein the mixing means are attached with the at least one input. 26. The mixed-gas insufflation of claim 24, wherein the mixing means further comprise sensing means to identify the presence of each of the at least two sources of insufflation gas. 27. The mixed-gas insulation system of claim 24, further comprising a multi-output insufflator having: at least two inputs; at least two delivery paths attached to the at least two inputs for allowing the flow of insulation gases from at least two pressurized sources attached to the at least two delivery paths; a central processing unit for monitoring and controlling the flow of insulation gas passing through the at least two delivery paths; at least two output lines attached to the at least two delivery paths; and wherein the mixing means are located internal to the multi-output insulator and along the at least two delivery paths. 28. The mixed-gas insufflation system of claim 24 further comprising a multi-lumen catheter having at least one inlet attached with the at least one output of the mixing means and at least one inlet for attachment with a source of liquid. 29. The mixed-gas insulation system 24 further comprising a humidification system having at least one inlet attached with the at least one output of the mixing means. 30. A method for mixing at least two insulation gases comprising: providing at least two sources of pressurized insulation gases, wherein at least two of the insufflation gases are different from each other; delivering insulation gas from each source into a tubing system; controlling the flow and pressure of each insulation gas within the tubing system; delivering in parallel each insulation gas into a mixing chamber; mixing the at least two insufflation gases within the mixing chamber; and expelling the mixed insulation gas from the mixing chamber through at least one outlet. 31. The method of claim 30 wherein expelling the mixed insulation gas from the mixing chamber further comprises delivering the mixed insulation gas through at least one delivery path in an insulator. 32. The method of claim 30 wherein expelling the mixed insulation gas from the mixing chamber further comprises supplying the insulation gas to at least one inlet of a catheter. 33. The method of claim 32 further comprising: supplying a liquid medicine to at least one inlet of the catheter; aerosolizing with the medicine with the insulation gas; and delivering the aerosolized medicine to a surgical site. 34. The method of claim 30, wherein controlling the flow and pressure of each insulation gas within the tubing system further comprises: delivering each insufflation gas to at least two inlets of an insufflator; and delivering each insufflation gas through at least two delivery paths, wherein each delivery path is in fluid communication with an inlet. 35. The method of claim 30, wherein mixing the at least two insulation gases within the mixing chamber further comprises: creating turbulence within the mixing chamber by passing the at least two insufflation gases around at least one baffle. 36. The method of claim 30, wherein mixing the at least two insufflation gases within the mixing chamber further comprises: creating turbulence within the mixing chamber by passing the at least two insulation gases through and around a plate with holes. 37. The method of claims 30, 35 or 36, wherein mixing the at least two insufflation gases within the mixing chamber further comprises: creating turbulence within the mixing chamber by passing the at least two insufflation gases through a fan. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/465,081, filed Apr. 23, 2003. FIELD OF THE INVENTION The present invention relates to the field of surgical instruments, and in particular, relates to the technology and instrumentation used to achieve pneumoperitoneum during laparoscopy and laparoscopic surgery. BACKGROUND Surgeons have used laparoscopic surgery to perform a variety of procedures. By manipulating laparoscopes and video telescopes, surgeons gain a visualization of the abdominal cavity while minimizing tissue and muscle injury that normally accompanies conventional invasive procedures. Compared to conventional surgery, laparoscopy reduces patient trauma, decreases patient recovery time, and yields significant cost savings by reducing post-operative care. The proper hardware and instrumentation are essential to the performance of laparoscopic procedures. To create a sufficient area for the introduction of a laparoscope and other instruments, the abdominal wall is first raised from the organs enclosed in the abdominal cavity. Separation is conventionally attained by pressurizing the abdominal cavity with an insufflation gas. Typically one insufflation gas, such as carbon dioxide, nitric oxide, nitrous oxide, helium or argon, is used. The presence of artificial gas in the peritoneal cavity to achieve exposure of the cavity during laparoscopy is referred to as pneumoperitoneum. Studies have shown that different gasses have differing effects on post-surgical healing, pain, and tumor formation. For example, a problem that may occur when using one of the above-named gases to create pneumoperitoneum is hypoxia. Hypoxia is a condition that occurs in the tissues due to a lack of oxygen and may lead to the growth of tumor sites around the surgical area, post-operative adhesions, and cellular decay. If however, oxygen is used to create pneumoperitoneum, there may be problems with embolisms occurring due to air bubbles forming at the surgical site. Moreover, oxygen is a substance that that supports combustion and should be used in lower levels to avoid a flammable environment and yet be used in a large enough quantity to avoid hypoxia. Normally, the use of two or more insufflation gases will optimize the post-surgical healing process. One approach to achieve this benefit is to use two insufflators so that two insufflation gases, one perhaps being oxygen, may be used. It may, however, be cumbersome to have two insufflators located at the surgical area. Moreover, this method is expensive. Accordingly, it is desirable to have a device that overcomes the disadvantages and limitations described above. SUMMARY In order to address the need for an improved apparatus to provide a mixed composition of insufflation gases, a novel mixed-gas insufflation system is described below. The mixed-gas insufflation system includes a gas supply providing at least two sources of insufflation gas and a mixer system. The mixer system includes a chamber having at least two inlets and at least one outlet. The at least two inlets of the chamber are in fluid communication with the gas supply. The mixer system mixes the at least two sources of insufflation gas. Another aspect of the invention includes an insufflator having at least two inputs, each for supplying a source of insufflating gas. A mixing chamber is in fluid communication with the at least two inputs and has at least one output. At least one delivery path is attached to the at least one output of the mixing chamber. A central processing unit is electrically connected with the at least one delivery path monitors and controls the flow of insufflation gas passing through the at least one delivery path. At least one output line is attached to the at least one delivery path. The at least one delivery path and the at least one output line allows for the continuous supply of mixed insufflation gas to a surgical site during a laparoscopic procedure. An additional aspect of the invention includes a mixed-gas insufflation system for mixing insufflation gases. A gas supply provides at least two sources of insulation gas and mixing means are in fluid communication with the gas supply. The mixing means mix the at least two sources of insufflation gas. Another aspect of the invention encompasses a method for mixing at least two insulation gases. The method includes providing at least two sources of pressurized insufflation gases and delivering gas from each source into a tubing system. The flow and pressure of each insufflation gas are controlled within the tubing system. Each insufflation gas is delivered in parallel from the tubing system into a mixing chamber. The at least two sources of insulation gas are mixed within the mixing chamber and expelled from the mixing chamber through at least one outlet. For purposes of simplicity and convenience, the mixer system will be described with respect to the insufflation of a peritoneal cavity. One skilled in the art, however, will readily understand that the use of the mixer system is not limited to the insufflation of the peritoneal cavity. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a diagram of a first embodiment of a mixer system; FIG. 2 is a view of a display associated with the mixer of FIG. 1; FIG. 3 is a diagram of the mixing chamber supplying insulation gas to an insufflator; FIG. 4 is a diagram of a second embodiment of a mixing chamber incorporated into a multi-output insufflator; FIG. 5 is a view of an insufflator and dual-capacity tube; FIG. 6 is a side view of a mixing chamber having baffles; FIG. 7 is a plan view of a mixing chamber having a plate with a plurality of holes; FIG. 8 is a side view of a mixing chamber having a fan; FIG. 9 is a view of a mixer system utilizing a catheter with the catheter in cutaway view; FIG. 10 is a view of a mixer system utilizing a multi-lumen catheter with the catheter in cutaway view; FIG. 11 is a plan view of the outlet of a multi-lumen catheter; and FIG. 12 is a view of a mixer system utilizing a humidification system. DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS Disclosed below are various embodiments of a mixing area for providing a mixed insufflation gas during laparoscopic surgery. The mixing area includes at least two inlets for the delivery of insufflation gases for mixing and a chamber for mixing the gases. As will be described in detail below, the mixing area may be embodied in a mixer system 2 external to an insufflator or within the insufflator. In addition, and as will also be detailed below, the insufflation gases may be mixed external to the insufflator after passing through the insufflator. Referring to FIGS. 1 and 2, an embodiment of a mixer system 2 for use with an insufflator 12 to provide a mixed insufflation gas during laparoscopic surgery is shown. The mixer system 2 includes a mixing chamber 4, at least two tubing systems 6, and a gas supply 8. As will be discussed further below, the insufflation gas flows via at least one external output line from the insufflator 12 to laparoscopic equipment 260 that is inserted into a peritoneal cavity. The gas supply 8 provides various insufflation gases for mixing in the mixing chamber 4. The gas supply 8 may be several separate sources 9, or bottles, that each act as a source of an insulation gas. Alternatively, the gas supply may be a central supply that houses the various insufflation gases. A variety of insulation gases may be used. However, so that the tissue affected during a laparoscopic procedure may be oxygenated, which is desirable in order to promote the health and ultimate healing of the tissue, one of the gases preferably is oxygen, although oxygen is not required. In one embodiment utilizing oxygen, oxygen preferably should make up no more than approximately five percent of any gaseous mixture. In other embodiments oxygen may be present in amounts anywhere from approximately five percent through 100 percent of any gaseous mixture, with, of course, the appropriate controls being in place. The amount of oxygen may be varied so long as it is below an amount that supports combustion. Other gases may include, but are not limited to, carbon-dioxide, argon, helium, nitric oxide and nitrous oxide, as well as other inert gases known to be compatible for laparoscopic surgery by those in the art. The tubing system 6 provides for the fluid communication of insufflating gas, which exits on an outlet 18 on the gas supply 8 and proceeds to the mixing chamber 4. There is one outlet for each source 9, and there is a tubing system 6 associated with each insulating gas. In one embodiment, the tubing system 6 includes a tube 19, a transducer 20, a pressure regulator 22, a flow valve 24, and a sensor 26. The tube 19 provides for the travel of the insulating gas from the gas supply 8 to the mixing chamber 4. The tube, 19 is a disposable polyvinyl chloride tube, although in other embodiments any suitable materials may be used. For example, in alternate embodiments, the tubing may be made of a silicone material that is reusable, stainless steel, copper, chrome-plated brass or a high-pressure nylon. A connector 21 on a first end 23 of the tube 19 connects the tubing system to the gas supply 8. Any suitable connector 21 may be used, but the connector 21 should be of a type so the flow capacity of insufflation gas from the gas supply 8 is not restricted. Examples of connectors include, but are not limited to, barb, spring-loaded, or quick-disconnect connectors. The transducer 20 reads an input pressure of the insufflating gas as it enters the tubing system 6 from the gas supply 8 to determine if a sufficient supply of insulating gas exists. Whether a supply of insufflating gas is sufficient will depend on surgical requirements and any regulations that are in place. A typical input pressure, however, is generally in the range of 2,000-3,000 pounds per square inch for separate sources such as bottles and approximately 60-100 pounds per square inch for sources supplied via a central supply. If there is an insufficient supply of insulating gas, the mixing system will be shut down via a CPU 23 associated with the mixer system 2. Further detail about the CPU 23 is provided below. An example of a suitable pressure transducer is a transducer available from ASHCROFT in Stratford, Conn. Note that a pressure switch, rather than a transducer, may be used in alternate embodiments. The pressure switch may be a standard go/no-go switch. When the switch fails to detect a required, predetermined input pressure, the switch will not allow insulation gas to pass to the tubing system 6. The pressure regulator 22 reduces the input pressure of the insulating gas so that it is suitable for use with the insufflator. Suitable pressures generally are dictated by surgical requirements and any regulations. Generally, however, a suitable pressure for an insulation gas for use with an insufflator is approximately 60 pounds per square inch. An example of a suitable pressure regulator is supplied by NORGEN in St Littleton, Colo. and is rated at approximately 3,000 PSI. The flow valve 24 is a normally closed valve that opens when the insufflating gas associated with the corresponding tubing system (and flow valve) is desired for use during laparoscopic surgery. An example of a suitable flow valve is provided by Pneutronics in Hollis, N.H. Preferably, the valve is of a type and size so that it has a rating, or meters out gas at a rate of, approximately 10 pounds per square inch, which assumes a flow rate of approximately 20 liters per minute. In other embodiments, valves having a different rating may be used, depending on the flow rate of the gas. The flow valve 24 is electronically connected with the CPU 23 associated with the mixer system 2. The CPU 23 is a standard, commercially-available CPU and examples include Northgate's Model 63-13901-2 available from Northgate Technologies, Inc. in Elgin Ill. and CPU Model IND-386S available from Indocomp Systems in Metamora, Mo. When the CPU identifies the presence of an insufflating gas associated with a flow valve 24, it will cause that flow valve 24 to open so that the insufflating gas may enter the mixing chamber 4. The sensor 26 identifies the presence of the insufflating gas that is associated with the tubing system 6. In other words, the sensor prevents the wrong gas from being connected to a tubing system; i.e., the sensor prevents the situation where a tubing system presumed to be connected to a source of argon gas, for example, is actually connected to a source of carbon-dioxide. If the wrong gas is indeed connected to a tubing system, the CPU will shut down the system. Optionally, there also may be an alarm to indicate that the wrong gas has been connected to a tubing system. As shown in FIG. 1, the sensor may be located along the tube 19. In other embodiments, the sensor 26 may be located within the insulator 12. In one embodiment, the sensor 26 is a 100 ohm resistor block that identifies the insulating gas based on an ohmic value pre-assigned to the insufflating gas. The sensor 26 is electrically connected with the CPU 23. When an insulating gas is desired, electronics associated with the CPU 23 will identify the presence of the insufflating gas by reading the sensor 26 associated with a particular tubing system 6. As noted above, the CPU 23 will then open the flow valve 24 so that the insufflating gas may flow to the mixing chamber 4. In alternate embodiments, the sensor may sense voltage or the current drop of the insufflation gas associated with the sensor. In an additional alternate embodiment, sensing may be accomplished mechanically through methods such as mechanical indexing. For example, the threads of each of the connectors 21 may be different from each other so that a connector may only be attached to one gas supply. Moreover, in yet other embodiments, the sensor may be a gas analyzer. The gas analyzer is used to identify the type of gas associated with a tubing system 6 or may be used to identify the types of gases present within a mixture, as well as the amount of each gas that is present as compared to the whole. For example, if a gaseous mixture of one-third oxygen and two-thirds carbon dioxide is present, the gas analyzer can detect both the gases present and the amounts, one-third oxygen and two-thirds carbon dioxide, that are present. An example of a suitable gas analyzer is the Model 224A Quadralyzer Gas Analyzer made by Raytech Instruments, Inc. in North Vancouver, Canada. A gas analyzer may be present on each tubing system, in which instance the gas analyzer will be used to detect the type of gas associated with a particular tubing system. Alternatively, the gas analyzer may be located near the output of the mixing chamber 4, in which instance it may be used, as described above, to both detect the types of gases present and to detect the ration of each gas present. Optionally, and as shown in FIG. 1, a metering valve 28 may be incorporated into the tubing system 6 for redundancy. The metering valve 28 controls the flow of insulation gas into the mixing chamber 4. The metering valve is electrically connected to the CPU 23. The CPU 23, knowing the molecular weight of a particular insulation gas, may open or close the metering valve 28 so that the amount of flow, and hence the volume, of insulation gas passing through the metering valve is controlled. Thus, the metering valve 28 ensures that the desired volume of gas passes from the tubing system 6 into the mixing chamber 4. A filter 36 normally is located in each tube 19 of each tubing system 6 to provide a particulate barrier. In one embodiment, the filter 36 is a glass-fiber hydrophobic filter that provides a particulate barrier of approximately 25 microns and operates at a ninety-nine percent rate of efficiency. In other embodiments any number of commonly used filters, with different filtering capabilities, may also be used. The mixing chamber 4 is a standard manifold, such as a hollow tube, cavity, or chamber. Although a hollow tube able to hold three liters of gas is preferred, the mixing chamber 4 may have any size or shape. The mixing chamber 4 may be made from any materials suitable for use with the particular insulation gases that are to be used. Examples include, but are not limited to, stainless steel, plastics, chrome-plated brass or high-pressure nylon. A purpose of the mixing chamber is to provide an area for the gases dispensed from the gas supply to form a homogenous mix. Because gases each have different properties, with some gases being heavier than others, it may be desirable to incorporate components into the mixing chamber in order to further assist with the mixing of the various insulation gases. In one embodiment, as shown in FIG. 6, at least one baffle 402 may be incorporated into the mixing chamber 404. The baffle acts as an obstruction within the chamber, created within the path of the gases as they flow through the chamber. The baffle creates turbulence as the gases flow (depicted by arrows labeled as 406) to further facilitate the mixing of the gases. As noted, there may be at least one baffle, with four baffles being preferable. In other embodiments, a different number of baffles may be used, depending on the gases used and the size of the mixing chamber. The baffles may be of any shape and made of any material compatible with the material of the mixing chamber, including, but not limited to, plastics, various metals, and composite materials. In an alternate embodiment, as shown in FIG. 7, the mixing of the gases may be facilitated through the use of a plate 402 being incorporated into the mixing chamber 404. The plate 402 includes a series of holes 406, allowing the gases passing through the chamber 404 to both pass through the holes 406 and to be repelled at the parts of the plate not having a hole 406. This motion causes turbulence to be created when the gas hits an area of the plate 402 not having a hole 406, thus further facilitating the mixing of the gases. The mixture of gases may then pass through the output of the chamber. Referring to FIG. 8, an additional embodiment to further facilitate the mixing of gases with the chamber may include a fan 602 located within the chamber 604. Turbulence is created as the gas passes through the fan, with the turbulent gas depicted by arrows labeled as 606. Any suitable fan 602 may be used that can fit within the chamber. The circulation capacity of a suitable fan will depend on the size of the chamber and the amount of turbulence that is desired. An example of a suitable fan is Orion fan model no. OA825AP-11-1WB, distributed by Main Electronic Supplies Ltd. of Vancouver, B.C. Canada. Moreover, the fan may be incorporated into embodiments that include components such as the baffle or the plate described above. Although the mixing chamber may receive only one insufflating gas, preferably the mixing chamber will receive at least two insufflating gases for mixing. As will be further detailed below, the gases enter the mixing chamber 4 via the tubing system 6 at a preset pressure. The gases are then “mixed” as a result of expanding within the confines of the mixing chamber 4. The mixed insufflation gas then exits the mixing chamber 4 through at least one outlet 30. The insufflation gas then flows through tubing 32 attached to the outlet 30 to the insufflator 12. The tubing is a disposable polyvinyl chloride, although in other embodiments any suitable materials may be used. For example, in alternate embodiments, the tubing may be made of a silicone material that is reusable, stainless steel, copper, chrome-plated brass or a high-pressure nylon. When a particular insulation gas is desired, standard toggle switches 35 (FIG. 2) may be used to select the desired insulation gas and thus allow gas to flow from the gas supply 8 to the tubing system 6. In alternate embodiments, by way of example, activation may also be accomplished through a remote activation device or by manually connecting the source supply to the tubing system. FIG. 2 is an example of a display 34 associated with the mixer system 2. Indication on the display 34 may be provided via any standard method such as, by way of example, the use of LEDs (not shown). The display may show the types of insulation gases available (at 40) and the source pressure 42 of each gas. An active status indicator 44 may also be displayed to indicate which insulation gases are in use during a laparoscopic procedure. The selection of a desired insulation gas may be accomplished via methods such as those described above. The display 34 may also indicate the actual volume (at 46) of each gas that is entering the mixing chamber 4. The percent composition of the mixed insulation gas may also be displayed. The actual percent composition 48 as well as the preset percent composition 50 may both be displayed so that any fluctuation may be indicated. In the example shown in FIG. 2, the mixed insufflation gas has been preset to be composed of 66% of a first insufflation gas and 34% of a second insulation gas. The actual composition, however, is 68.2% of the first gas and 31.8% of the second gas. As noted above, the percentage of insulation gas in a mixture is controlled by the metering valve 28 and CPU 23. Moreover, the percentage of insulation gas may either be preset or can be varied as required via inputs to the CPU 23. Referring to FIGS. 1 and 3, and as noted above, upon being mixed in the mixing chamber 4, the mixed insulation gas exits the mixing chamber 4 via at least one output 30 on the mixing chamber 4. The tube 32 connects the mixing chamber 4 to the insufflator 12. Connectors 56 on first and second ends 58, 60 of the tube 32 connect the tube 32 to the mixing chamber 4 and the insufflator 12, respectively. The insufflator 12 is a standard insufflator, such as the OMNIFLATOR Model 6620 available from Northgate Technologies, Inc. in Elgin, Ill. The insufflator receives the mixed insufflation gas via the tube 32 connecting the insufflator 12 to the mixing chamber 4. The mixed insufflation gas is reduced in pressure by the insufflator to approximately 45 through 55 millimeters of mercury (also know as a “push” pressure), although the pressure may be changed depending on the insufflator in use and any regulations that may be in force. The mixed insufflation gas is delivered via a delivery assembly 60 to at least one output line 62 and passes from the insufflator 12 to at least one tube 64 connected to a port 65 associated with the output line 62. The delivery assembly 60 is mainly comprised of electronics and pneumatics which, as noted above, are standard to the insufflator 12. A trocar connector 86 such as a Leur connector is attached to the tube 64. Laparoscopic equipment (not shown) for insertion into a peritoneal cavity may then be attached to the trocar connector. Note that in an alternate embodiment, instead of utilizing a separate mixer system, the insufflation gases may be mixed within a chamber in the insufflator 12. The components are similar to those described in associated with the mixing system 2, except that they are located within, rather than separately from, the insufflator. Examples of a suitable insufflator include the OMNIFLATOR Model 6620 described above or the 7600 series model insufflator, also known as a multi-output insufflator, which is described below, also available from Northgate Technologies, Inc. In yet an alternate embodiment, the insufflation gases may be mixed external to the insufflator after passing through the insufflator. An example of such a suitable insufflator is the 7600 series model insufflator, also known as a multi-output insufflator, also available from Northgate Technologies, Inc. This type of insufflator is also embodied in U.S. Pat. No. 6,299,592, issued Oct. 9, 2001, and is herein incorporated by reference in its entirety. A schematic diagram of the multi-output insulator 100 is shown in FIG. 4. At least two gas sources 102 are connected to inputs 104 on the insulator 100. The sources are connected to the insufflator 100 via tubing 106 and connectors such as those described above. Upon entry into the insufflator 100, each insufflation gas enters a delivery path 110. Although there may be more than two delivery paths 110, for simplicity an insufflator having two delivery paths, a primary and a secondary delivery path 111, 113, will now be described. The delivery paths 111, 113 are virtually identical, with differences being noted below. The delivery path 111 includes a supply pressure sensor 112, a regulator 114, a pressure relief valve 116, a filter assembly 118, and a manifold 120. The supply pressure sensor 112, or pressure-measuring transducer, monitors gas supplied by the gas source 102. The pressure-measuring transducer 112 communicates with a controller or microprocessor (CPU) 122 to indicate the amount of gas available for insufflation. The regulator 114 and the pressure relief valve 116 monitor the delivery pressure of the delivery path 110 of insulating gas. Operation of the regulator 114 and pressure relief valve 116 are statically controlled. The pressure regulator 114 is serially connected to the static pressure relief valve 116 and both have operating values that are selected to provide a proper operating pressure for a given laparoscopic procedure, typically about 55 pounds per square inch. The filter assembly 118 provides a particulate barrier down to approximately 20 microns, although in other embodiments a filter with a different rating may be used. As shown, the manifold 120 is attached to the filter assembly 118 by an air tight connection 122. The manifold 120 is comprised of a flow control valve 130, an internal flow sensor 132, primary and secondary internal pressure sensors 134, 136, and a plurality of pressure relief valves 138, 140. The manifold 120 also includes a primary gas output channel 150 that terminates at a primary gas output connector 152. The flow control valve 130 controls the flow of insulation gas from the filter assembly 118 into the manifold 120 in response to the CPU 122. The CPU 122 communicates to the flow control valve 130 in response to measurements sampled from components that include the internal flow sensor 132, the primary and secondary internal pressure sensors 134, 136 and, as will be further detailed below, an internal pressure sensor 175 associated with the secondary delivery path 113. The gas flow rate in the manifold 120 is calculated by the CPU 122 in response to the signal received from the internal flow sensor 132. The internal flow sensor 132 communicates to the CPU 122 the relative flow rate through a primary precision orifice 142 that provides a gas flow path within the manifold 120. The primary and secondary internal pressure sensors, or transducers, 134, 136 sample the internal pressure within the manifold 120. The primary and secondary internal pressure sensors 134, 136 are in communication with the CPU 122. Two pressure-measuring transducers 134, 136 are used in order to provide redundant pressure calculations. The manifold 120 further includes the pressure relief valve 138, which is a digitally responsive primary pressure relief valve that controls the internal pressure of the primary gas output channel 150 by responding to the CPU 122. The CPU 122 communicates to the digitally responsive primary pressure relief valve 138 in response to one of the two pressure-measuring transducers 134, 136. A static pressure relief valve 140 connected to the primary gas output channel 150 provides further redundant pressure control. As noted above, the components that define the secondary delivery path 113 are similar to the components that define the primary delivery path 111, and therefore, only the differences will be described. The secondary delivery path 113 uses a single pressure-measuring transducer 175 located within the manifold 220. Redundant monitoring of the secondary delivery path 113 is achieved by the CPU's 122 pressure comparisons of the pressure measurements sampled from the primary internal pressure sensors 134, 136, as noted above. A flap valve 180 is slidably attached between the secondary gas output channel 182 and the secondary gas output connector 184. When only the primary gas output channel 150 is engaged, the flap valve 180 is closed and blocks the secondary gas output channel 182. The closure of the secondary gas output channel 182 causes a substantial pressure build up in the manifold 220. When the CPU 122 detects a substantial pressure build up in the manifold 220 by sampling the output of the internal pressure sensor 175, the CPU 122 recognizes that the secondary output connector 184 is not engaged. When the secondary output connector 182 is engaged, the flap valve 180 is swung to an open engagement subjecting the manifold 220 to the pressure passed by the flow control valve 130. An external line connector 250 is connected to each gas output connector 152, 184. A first end 252 of an external output line 254 is attached to the external line connector 250. The gas output connectors 152, 184 and the external line connectors 250 are designed to provide an air tight junction between the gas output channels 150, 182 and the external output line 254. The external output line 254 provides for the fluid communication of an insufflating gas between the insulator 100 and laparoscopic equipment 260 that is inserted into a peritoneal cavity 262. A second end 256 of the external output line 254 has a trocar connector 258 such as a Leur connector attached to it so that laparoscopic equipment 260 may be attached to the external output line 254. Once the insulation gases are processed by the insulator 100, so that they exit at an appropriate pressure and rate of flow, they pass through the external output line 254, trocar 258, and laparoscopic equipment 260 and into the peritoneal cavity 262. Because the insufflator has at least two separate delivery paths, and thus at least two separate external output lines, two different gases may be introduced into the peritoneal cavity 262. The mixing of the gases then occurs within the peritoneal cavity 262. Alternatively, the mixing of the gases may be mixed within a mixing chamber whose inlets are attached to the output line 254 of the insulator and whose output line(s) are attached to tubing, a trocar and laparoscopic equipment for insertion into the peritoneal cavity 262. The external output lines 254 should be made from a flexible material, such as, by way of example, disposable polyvinyl chloride tubing. In other embodiments, however, any suitable materials may be used. For example, the external output lines may be made of a silicone material that is reusable. As with the mixer system 2, when a particular insulation gas is desired, toggle switches 264 may be used to select the desired insulation gas. In alternate embodiments, by way of example, activation may also be accomplished through a remote activation device or by manually connecting the source supply to the tubing system. Moreover, as with the mixer system 2, inputs to the CPU 122 may allow the percentage of gas making up a mixture to either be preset or controlled. In an alternate embodiment, and as shown in FIG. 4, a dual-capacity tube 300, rather than separate external output lines, may be used with the insulator 100. An example of such a tube is embodied in provisional patent application 60/421,662, filed, Oct. 28, 2002, and herein incorporated by reference in its entirety. The dual capacity tube 300 has a pair of tubes 302 and a mixing tube 304. The pair of tubes 302 and mixing tube 304 are attached via an adaptor 306, such as a stepped or barbed adaptor. Each of the pair of tubes 302 is attached to an external line connector 350 which, as noted above, is connected to a gas output connector 152, 184 associated with a delivery path 110 of the insulator 100. Thus, because a different insulating gas is passing through each delivery path of the insufflator, a different insufflating gas will enter each of the pair of tubes 302. Upon entering the mixing tube 304, the insulating gases will then be mixed. As with the external output line described above, an end 308 of the mixing tube 304 has a trocar connector 358 such as a Leur connector attached to it so that laparoscopic equipment 360 may be attached for insertion into the peritoneal cavity as described above. To achieve the greatest benefits of a higher flow rate, the inner diameter of the mixing tube 304 should be at least as large as the inner diameter of each of the pair of tubes 302. Moreover, the mixing tube 304 should be sized so that it is compatible with trocar connectors and laparoscopic equipment. The dual-capacity tube 300 should be made from a flexible material, such as disposable polyvinyl chloride tubes, although in other embodiments any suitable materials may be used. For example, the tubing may be made of a silicone material that is reusable. While the above embodiment contemplates the use of one dual-capacity tube, in other embodiments multiple dual-capacity tubes may be used. For example, four delivery paths associated with the insulator may be used, requiring four gas sources and four external output lines. Thus, two dual-capacity tubes may be used to accommodate the four separate outputs of insufflation gas. In an additional embodiment, shown in FIG. 9, a catheter may be incorporated to deliver gas into the peritoneal cavity 262. In one embodiment, a single-lumen catheter 702, known to those skilled in the art, is attached at a proximal end 704 to a supply of an aerosolized gas 706. The aerosolized gas usually will include a medication for the treatment of a disease or condition affecting the area targeted for treatment with the gas. A distal end 708 of the catheter is configured for disposition within the peritoneal cavity 262. A lumen 710 runs between both ends and allows the aerosolized gas to pass from the supply and into the peritoneal cavity 262. Simultaneously, gas that has been mixed within the mixing chamber 712 may also be introduced into the peritoneal cavity 262, with the mixing chamber taking on any of the configurations with respect to the insufflator that are described above. The mixing between the aerosolized gas 706 and the gas from the mixing chamber 712 may then occur within the peritoneal cavity 262. In another embodiment, shown in FIG. 10, a multi-lumen catheter 802 may be used to deliver medication to a patient. An example of such a catheter is embodied in U.S. Pat. No. 5,964,223, issued Oct. 12, 1999, and herein incorporated by reference in its entirety. The multi-lumen catheter 802 includes a plurality of lumens 804. The multi-lumen catheter 802 includes a proximal end 806 having a manifold 808 with at least two inputs 810. At least one of the inputs 812 is attached to a source of liquid medicine (not shown). Such a source is often manifested as a syringe pump. At least one of the other inputs 814 is attached with at least one source of pressurized gas. In this embodiment, the source of gas is the gaseous mixture that has been mixed within the mixing chamber 816, in accordance with the embodiments described above. Each input is attached to a lumen 804 within the catheter. A distal end 818 of the catheter 802, as with the single-lumen catheter, may be inserted into the peritoneal cavity 262. Referring to FIG. 11, the distal end 818 of the catheter includes a plurality of outputs 820, with an output 820 being in fluid communication with each lumen 822. Liquid passing from the source of liquid medicine will pass through the catheter and exit a first output 824. The pressurized gas will pass through the catheter and exit a second orifice 826. As the pressurized gas passes through the second orifice, it will cause the liquid medicine simultaneously passing through the first orifice to be aerosolized. This will cause the medicine to treat the area targeted for treatment in nebulized form. Note that the outputs and lumen may be configured in a plurality of ways in order to further direct the nebulized medicine. For example, FIG. 11 shows the proximal end having the lumen 820 in a coaxial configuration. Alternatively, by way of example, the lumen may be positioned in a side-by-side configuration. As with embodiments utilizing the single-lumen catheter, the mixing chamber taking on any of the configurations with respect to the insufflator that are described above. In another embodiment, shown in FIG. 12, insufflation gas that has been mixed within the mixing chamber may then pass through a humidification system 902 so that humidified gas may enter the peritoneal cavity. An example of a suitable humidification system is embodied in U.S. application Ser. No. 09/896,821, filed Jun. 29, 2001, and herein incorporated by reference in its entirety. The humidification system includes a first end 904 that is attached to tubing 906. The tubing supplies insufflation gas that has been mixed in the mixing chamber 908, with the mixing chamber having any of the configurations with respect to the insufflator as described above. The humidification system includes a heater 910, a core 912 surrounding the heater to provide a water-tight environment for the heater, and a humidification material 914 surrounding the core 912. A second end 916 includes an outlet 918 for humidified gas to pass through. The gas may then be supplied through tubing 919 and into the peritoneal cavity 262. The heater 910 heats moisture that is applied to the humidification material 914. Preferably, the heater has approximately 10 and 50 watts of power, although other wattages may be used depending on the amount of humidity desired. The humidification material 914 surrounds the heater 910 and both absorbs moisture and releases it when exposed to a dry environment. Any suitable material may be used for the humidification material, with examples including nylon and cotton. Examples of manufacturers of humidification material are Pall Medical located in East Hills, N.Y. and Filtrona Richmond Inc. located in Richmond, Va. The moisture applied to the humidification material is applied via a port 920 for the infusion of fluid for the production of moisture. The moisture may contain medications or other additives that will evaporate and be carried along in the humidified gas to the patient. Moisture may include sterile water, medication, and/or a mixture of fluids required for merely humidifying the insulation gas. When insulation gas, which has been mixed in the mixing chamber 908, enters the humidification system 902 and passes over the humidification material 914, moisture that has been absorbed is released into the insulation gas, thus humidifying and warming the gas. The warmed and humidified insulation gas then exits the humidification system through the output 918. The gas may then enter tubing 919 for delivery into the peritoneal cavity 262. With any of the above-described embodiments, the insufflation gases may, during a laparoscopic procedure, be steadily supplied and mixed throughout the procedure. Alternatively, by way of example, one gas may be steadily supplied while another gas is supplied only sporadically as desired. This could be accomplished through the activation methods described above. The advantages associated with the mixer system and its associated embodiments are numerous. Normally, because only one insulation gas can be used during a laparoscopic procedure, an insulation gas lacking oxygen is generally used. The lack of oxygen to the surgical site may cause hypoxia in the affected tissues. Hypoxia is a condition that occurs in the tissues due to a lack of oxygen and may lead to the growth of tumor sites around the surgical area, post-operative adhesions, and cellular decay. If however, oxygen is used to create pneumoperitoneum, there may be problems with embolisms occurring due to air bubbles forming at the surgical site. Moreover, oxygen is a substance that supports combustion and therefore should be used in lower levels to avoid a flammable environment and yet be used in a large enough quantity to avoid hypoxia. The mixer system and its alternate embodiments described above allow more than one insulation gas to be used. A mixture of two or more gases will optimize the post-surgical healing process. Thus, for example, tissues may receive the benefit of an oxygen-rich environment and yet be able to avoid the problems described above that involve the use of high levels of oxygen. Moreover, because the percentages of gas used may be adjusted, if desired, a gas lacking oxygen may first be used during surgery, thus avoiding a flammable environment. Oxygen may then be introduced sporadically as desired to avoid hypoxia and provide affected tissues with oxygen. While the above description constitutes the presently preferred embodiments of the invention, it will be appreciated that the invention is susceptible of modification, variation, and change without departing from the proper scope and fair meaning of the accompanying claims. | <SOH> BACKGROUND <EOH>Surgeons have used laparoscopic surgery to perform a variety of procedures. By manipulating laparoscopes and video telescopes, surgeons gain a visualization of the abdominal cavity while minimizing tissue and muscle injury that normally accompanies conventional invasive procedures. Compared to conventional surgery, laparoscopy reduces patient trauma, decreases patient recovery time, and yields significant cost savings by reducing post-operative care. The proper hardware and instrumentation are essential to the performance of laparoscopic procedures. To create a sufficient area for the introduction of a laparoscope and other instruments, the abdominal wall is first raised from the organs enclosed in the abdominal cavity. Separation is conventionally attained by pressurizing the abdominal cavity with an insufflation gas. Typically one insufflation gas, such as carbon dioxide, nitric oxide, nitrous oxide, helium or argon, is used. The presence of artificial gas in the peritoneal cavity to achieve exposure of the cavity during laparoscopy is referred to as pneumoperitoneum. Studies have shown that different gasses have differing effects on post-surgical healing, pain, and tumor formation. For example, a problem that may occur when using one of the above-named gases to create pneumoperitoneum is hypoxia. Hypoxia is a condition that occurs in the tissues due to a lack of oxygen and may lead to the growth of tumor sites around the surgical area, post-operative adhesions, and cellular decay. If however, oxygen is used to create pneumoperitoneum, there may be problems with embolisms occurring due to air bubbles forming at the surgical site. Moreover, oxygen is a substance that that supports combustion and should be used in lower levels to avoid a flammable environment and yet be used in a large enough quantity to avoid hypoxia. Normally, the use of two or more insufflation gases will optimize the post-surgical healing process. One approach to achieve this benefit is to use two insufflators so that two insufflation gases, one perhaps being oxygen, may be used. It may, however, be cumbersome to have two insufflators located at the surgical area. Moreover, this method is expensive. Accordingly, it is desirable to have a device that overcomes the disadvantages and limitations described above. | <SOH> SUMMARY <EOH>In order to address the need for an improved apparatus to provide a mixed composition of insufflation gases, a novel mixed-gas insufflation system is described below. The mixed-gas insufflation system includes a gas supply providing at least two sources of insufflation gas and a mixer system. The mixer system includes a chamber having at least two inlets and at least one outlet. The at least two inlets of the chamber are in fluid communication with the gas supply. The mixer system mixes the at least two sources of insufflation gas. Another aspect of the invention includes an insufflator having at least two inputs, each for supplying a source of insufflating gas. A mixing chamber is in fluid communication with the at least two inputs and has at least one output. At least one delivery path is attached to the at least one output of the mixing chamber. A central processing unit is electrically connected with the at least one delivery path monitors and controls the flow of insufflation gas passing through the at least one delivery path. At least one output line is attached to the at least one delivery path. The at least one delivery path and the at least one output line allows for the continuous supply of mixed insufflation gas to a surgical site during a laparoscopic procedure. An additional aspect of the invention includes a mixed-gas insufflation system for mixing insufflation gases. A gas supply provides at least two sources of insulation gas and mixing means are in fluid communication with the gas supply. The mixing means mix the at least two sources of insufflation gas. Another aspect of the invention encompasses a method for mixing at least two insulation gases. The method includes providing at least two sources of pressurized insufflation gases and delivering gas from each source into a tubing system. The flow and pressure of each insufflation gas are controlled within the tubing system. Each insufflation gas is delivered in parallel from the tubing system into a mixing chamber. The at least two sources of insulation gas are mixed within the mixing chamber and expelled from the mixing chamber through at least one outlet. For purposes of simplicity and convenience, the mixer system will be described with respect to the insufflation of a peritoneal cavity. One skilled in the art, however, will readily understand that the use of the mixer system is not limited to the insufflation of the peritoneal cavity. | 20040422 | 20100202 | 20050113 | 59775.0 | 0 | MENDEZ, MANUEL A | MIXED-GAS INSUFFLATION SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,829,917 | ACCEPTED | Devices, systems and methods for diagnosing and treating sinusitus and other disorders of the ears, nose and/or throat | Sinusitis, enlarged nasal turbinates, tumors, infections, hearing disorders, allergic conditions, facial fractures and other disorders of the ear, nose and throat are diagnosed and/or treated using minimally invasive approaches and, in many cases, flexible catheters as opposed to instruments having rigid shafts. Various diagnostic procedures and devices are used to perform imaging studies, mucus flow studies, air/gas flow studies, anatomic dimension studies, endoscopic studies and transillumination studies. Access and occluder devices may be used to establish fluid tight seals in the anterior or posterior nasal cavities/nasopharynx and to facilitate insertion of working devices (e.g., scopes, guidewires, catheters, tissue cutting or remodeling devices, electrosurgical devices, energy emitting devices, devices for injecting diagnostic or therapeutic agents, devices for implanting devices such as stents, substance eluting devices, substance delivery implants, etc. | 1. A method for diagnosing and/or treating sinusitis or another disorder affecting the nose, paranasal sinuses or other anatomical structures of the ear, nose or throat, said method comprising the steps of: (A) placing a port device in the nostril or nasal cavity on at least one side of the intranasal septum, said port device comprising a device insertion port and a valve that is operative to allow a working device to be inserted through said device insertion port while preventing blood or other fluid from backflowing out of the device insertion port at least when no working device is inserted therethrough; (B) advancing at least one working device through the port device to a location within the nose, nasopharynx or paranasal sinus; and (C) using the working device to perform a diagnostic or therapeutic procedure 2. A method according to claim 1 wherein the working device is used to perform a procedure selected from the group consisting of: i) delivering an imageable or traceable substance; ii) delivering a therapeutically effective amount of a therapeutic substance; iii) implanting a stent, tissue remodeling device, substance delivery implant or other therapeutic apparatus; iv) cutting, ablating, debulking, cauterizing, heating, lasing, dilating or otherwise modifying tissue; v) grafting or implanting cells or tissue; vi) reducing, setting, screwing, applying adhesive to, affixing, decompressing or otherwise treating a fracture; vii) delivering a gene or gene therapy preparation; viii) cutting, ablating, debulking, cauterizing, heating, lasing, forming an osteotomy in or otherwise modifying bony or cartilaginous tissue within paranasal sinus or elsewhere within the nose; ix) remodeling or changing the shape, size or configuration of a sinus ostium or other anatomical structure that affects drainage from one or more paranasal sinuses; x) removing puss or aberrant matter from the paranasal sinus or elsewhere within the nose; and xi) scraping or otherwise removing cells that line the interior of a paranasal sinus; xii) removing all or a portion of a tumor; xiii) removing a polyp; and xiv) delivering histamine, an allergen or another substance that causes secretion of mucous by tissues within a paranasal sinus to permit assessment of drainage from the sinus. 3. A method according to claim 1 wherein a port device positioned in Step A comprises an anterior nasal occluder and access device that comprises an occluder and a working device insertion port. 4. A method according to claim 3 wherein Step A further comprises deploying the anterior nasal occluder and access device such that its occluder occludes the nostril or nasal cavity on one side of the nasal septum and wherein Step B comprises inserting the working device through the working device insertion opening and advancing the working device to a location within the nose, nasopharynx or paranasal sinus. 5. A method according to claim 4 wherein a first anterior nasal occluder and access device is positioned on one side of the nasal septum and a second anterior nasal occluder and access device is positioned on the other side of the nasal septum. 6. A method according to claim 1 comprising the steps of: providing a posterior occluder device that is configured to occlude the posterior choanae, nasopharynx or pharynx at a location that is posterior to the intranasal septum and superior to the glotis; and positioning the posterior occluder device such that it does occlude the posterior choanae, nasopharynx or pharynx posterior to the intranasal septum and superior to the glottis, thereby deterring fluid from draining into the patient's esophagus or trachea during the performance of the method. 7. A method according to claim 1 comprising the steps of: providing an anterior/posterior nasal occluder and access device that comprises an anterior occluder member, a working device insertion port and a posterior occluder member; and deploying the anterior/posterior nasal occluder and access such that; its anterior occluder occludes a nostril or nasal cavity on one side of the nasal septum and its posterior occluder occludes the posterior choanae, nasopharynx or pharynx posterior to the intranasal septum and superior to the glottis; and wherein Step B comprises: inserting the working device through the working device insertion opening and advancing the working device to a location within the nose, nasopharynx, middle ear or paranasal sinus. 8. A method according to claim 7 further comprising the step of: providing an anterior nasal occluder device; and and positioning the anterior nasal occluder device such that it occludes the other nostril or nasal cavity on the other side of the nasal septum. 9. A method according to claim 7 further comprising the step of: providing an anterior nasal occluder and access device that comprises an occluder member and a working device insertion port; and positioning the anterior nasal occluder and access device such that its occluder occludes the other nostril or nasal cavity on the other side of the nasal septum. 10. A method according to claim 9 further comprising the step of: inserting a working device through the working device insertion port of the on the anterior nasal occluder and access device and advancing that working device to a location within the nose, nasopharynx or paranasal sinus. 11. A method according to claim 7 wherein the anterior/posterior occlusion and access device comprises 1) a tube having an anterior end, a posterior end and at least one lumen; ii) an anterior occluder at a first location on the tube; iii) a posterior occluder at a second location on the tube, said second location being posterior to said first location; iv) a working device insertion opening located anterior to the anterior occluder; and v) a working device exit opening located between the anterior occluder and the posterior occluder and placing said anterior/posterior nasal occlusion and access device such that its anterior occluder occludes the nostril or nasal cavity on one side of the intranasal septum and its posterior occluder occludes the nasopharynx at a location posterior to the intranasal septum and superior to the glottis. 12. A method according to claim 11 wherein Step B comprises inserting a working device through the working device insertion opening and advancing the working device out of the working device exit opening to a location within the nose, nasopharynx or paranasal sinus. 13. A method according to claim 1 further comprising the step of: suctioning fluid from the nose, nasopharynx or paranasal sinus. 14. A method according to claim 11 wherein the anterior/posterior nasal occlusion and access device comprises a suction lumen and a suction opening formed in said tube between the anterior occluder and the posterior occluder and wherein the method further comprises the step of: applying suction to the suction lumen to suction matter through the suction opening and through the suction lumen. 15. A method according to claim 1 wherein Step B comprises: inserting a guide catheter; and, thereafter, inserting another working device through the guide catheter. 16. A method according to claim 1 wherein: Step B comprises advancing a tube through the port device to a location within a paranasal sinus; and Step C comprises delivering a flowable contrast agent into a paranasal sinus through the tube and subsequently imaging the flowable contrast agent to assess the manner in which the flowable contrast agent drains from the paranasal sinus. 17. A method according to claim 16 wherein the flowable contrast agent has a viscosity similar to the viscosity of mucous. 18. A method according to claim 16 wherein the imaging is carried out using an imaging apparatus that is moveable and wherein the imaging apparatus is moved to different positions to different vantage points relative to the patient's anatomy. 19. A method according to any of claim 1 wherein Step B comprises inserting a scope into the nose or paranasal sinus and wherein Step C comprises using the scope to visualize structures within the nose and/or paranasal sinuses. 20. A method according to claim 19 wherein the scope is used to guide, facilitate or verify positioning of another working device. 21. A method according to claim 19 wherein the scope is used to guide, facilitate or verify positioning of a guide catheter and wherein another working apparatus is then advanced through the guide catheter after the guide catheter has been positioned. 22. A method according to claim 1 wherein Step C comprises implanting a stent. 23. A method according to claim 22 wherein the stent is positioned at least partially within the ostium of a paranasal sinus. 24. A method according to claim 22 wherein the stent comprises a substance eluting stent. 25. A method according to claim 24 wherein the substance eluting stent elutes a therapeutically effective amount of at least one substance selected from the group consisting of: an antibiotic; an antifungal; an antiparacytic; an antimicrobial; a steroid; a vasoconstrictor; a leukotriene inhibitor; an IgE inhibitor; an anti-inflammatory; a mast cell stabilizer; an antihistamine; an imunomodulator; a chemotherapeutic agent; an antineoplastic agent; a mucolytic agent; an agent that thins or otherwise changes the viscosity of mucous; a substance that facilitates remodeling of soft tissue and/or bone and/or cartilage. 26. A method according to claim 1 wherein Step C comprises implanting a device that will change the size, shape, configuration or position of soft tissue, bone or cartilage. 27. A method according to claim 26 wherein the implanted device can be adjusted one or more times after implantation and wherein the method further comprises the step of adjusting the implanted device at least one time subsequent to implantation. 28. A method according to claims 1 wherein Step C comprises enlarging or modifying a sinus ostium, nasal meatus, or other passage way within the nose or nasopharynx. 29. A method according to claim 1 wherein Step C comprises introducing a diagnostically or therapeutically effective amount of a diagnostic or therapeutic substance to a location within the nose, nasopharynx or paranasal sinus. 30. A method according to claim 29 wherein the substance is contained in a substance delivery implant and wherein Step C comprises implanting the substance delivery implant at a location within the nose, nasopharynx or paranasal sinus. 31. A method according to claim 29 wherein Step C comprises injecting the substance at a location within the nose, nasopharynx or paranasal sinus. 32. A method according to claim 29 wherein the substance is selected from the group consisting of: an imageable contrast agent; a diagnostic indicator agent; an antibiotic; an antifungal; an antiparacytic; an antimicrobial; a steroid; a vasoconstrictor; a leukotriene inhibitor; an IgE inhibitor; an anti-inflammatory; a mast cell stabilizer; an antihistamine; an imunomodulator; a chemotherapeutic agent; an antineoplastic agent; a mucolytic agent; an agent that thins or otherwise changes the viscosity of mucous; and a substance that facilitates remodeling of soft tissue and/or bone and/or cartilage. 33. An anterior/posterior occlusion and access device for use in the diagnosis and/or treatment of sinusitis or a disorder of the ear, nose or throat, said device comprising: a tube having an anterior end, a posterior end and at least one lumen; an anterior occluder at a first location on the tube; a posterior occluder at a second location on the tube, said second location being posterior to said first location; a working device insertion opening located anterior to the anterior occluder; and a working device exit opening located between the anterior occluder and the posterior occluder; and at least one additional element selected from the group consisting of a) a valve that is operative to allow a working device to be inserted through said device insertion port while preventing blood or other fluid from backflowing out of the device insertion port at least when no working device is inserted therethrough, b) at least one moveable suction port for suctioning blood, fluid or debris from a plurality of locations between the anterior occluder and posterior occluder and/or c) separate infusion and suction lumens such that fluid may be infused into a location between the anterior and posterior occluders at the same time that fluid is being suctioned from a location between the anterior and posterior occluders. said nasal access and occlusion device being deployable such that i) the anterior occluder occludes the nostril or nasal cavity on one side of the intranasal septum ii) the posterior occluder occludes the nasopharynx at a location posterior to the intranasal septum and iii) a working device may be inserted through the working device insertion opening and advanced out of the working device exit opening to a location within the nose, nasopharynx or paranasal sinus. 34. A device according to claim 33 wherein the anterior occluder comprises a balloon. 35. A device according to claim 33 wherein the posterior occluder comprises a balloon. 36. A device according to claim 33 which includes at least first and second working device exit openings such that a working device may be selectively advanced out of either the first or second working device exit opening. 37. A system that comprises a nasal access and occlusion device according to claim 33 in combination with at least one working device selected from the group consisting of: a guidewire; a guide catheter; a guide catheter shaped to advance into the ostium of a paranasal sinus; a balloon catheter, apparatus for delivery of a stent; apparatus for delivery of a substance-eluting stent; implantable apparatus for exerting pressure on bone or soft tissue to cause reshaping of the bone or soft tissue; apparatus for cutting tissue; apparatus for ablating tissue; apparatus for debulking tissue; apparatus for cauterizing tissue; apparatus for dilating a passageway; apparatus for delivering a cryogen; apparatus for delivering a radiographic contrast agent, apparatus for delivering a diagnostic or therapeutic substance; a cannula; an endoscope; a sensor; a light; a diagnostic device; a therapeutic device. 38. A device according to claim 33 further comprising at least one suction port located on the tube between the anterior occluder and the posterior occluder such that fluid or debris may be aspirated though the aspiration port and through a lumen of the tube. 39. A system comprising a device according to claim 33 in combination with an anterior nasal occlusion and access device that is positionable on the other side of the nasal septum, said anterior nasal occlusion and access device comprising: an anterior occluder for occluding the nostril or nasal cavity on one side of the nasal septum; and a working device insertion opening through which a working device may be inserted and advanced past the anterior occluder to a location within the nose, nasopharynx or paranasal sinus. 40. A system according to claim 39 wherein the anterior occluder of the anterior nasal occlusion and access device comprises a balloon. 41. A device according to claim 33 further comprising a valve associated with the working device insertion opening, said valve being configured to prevent backflow out of the working device opening when no working device is inserted through said working device insertion opening. 42. A system according to claim 39 further comprising a valve associated with the working device insertion opening of the anterior nasal occlusion and access device that is positionable on the other side of the nasal septum, said valve being configured to prevent backflow out of the working device opening when no working device is inserted through said working device insertion opening. 43. A nasal access and anterior occlusion device for use in the diagnosis and/or treatment of sinusitis or a disorder of the ear, nose or throat, said device comprising: an anterior occluder for occluding the nostril or nasal cavity on one side of the nasal septum; and a working device insertion port through which a working device may be inserted and advanced past the anterior occluder to a location within the nose, nasopharynx or paranasal sinus; and at least one valve that allows a working device to be inserted through said working device insertion port and prevents blood or other fluid from backflowing out of the working device insertion port, at least when no working device is inserted therethrough. 44. A device according to claim 43 wherein the anterior occluder comprises a balloon. 45. A system that comprises an anterior nasal occlusion and access and access device according to claim 43 in combination with at least one working device selected from the group consisting of: a guidewire; a guide catheter; a guide catheter shaped to advance into the ostium of a paranasal sinus; a balloon catheter, apparatus for delivery of a stent; apparatus for delivery of a substance-eluting stent; implantable apparatus for exerting pressure on bone or soft tissue to cause reshaping of the bone or soft tissue; apparatus for cutting tissue; apparatus for ablating tissue; apparatus for debulking tissue; apparatus for cauterizing tissue; apparatus for dilating a passageway; apparatus for delivering a cryogen; apparatus for delivering a radiographic contrast agent, apparatus for delivering a diagnostic or therapeutic substance; a cannula; an endoscope; a sensor; a light; a diagnostic device; a therapeutic device. 46. A device according to claim 43 further comprising a valve associated with the working device insertion opening, said valve being configured to prevent backflow out of the working device opening when no working device is inserted through said working device insertion opening. 47. A method for diagnosing or locating an obstruction that impedes drainage from a paranasal sinus or for assessing the efficacy of previously rendered treatment intended to improve or modify drainage from a paranasal sinus, said method comprising the steps of: A. introducing a flowable medium into the paranasal sinus; and, B. monitoring the flow or diffusion of the flowable medium from the paranasal sinus. 48. A method according to claim 47 further comprising the step of occluding the nasopharynx posterior to the nasal septum but superior to the glottis so as to deter drainage of the flowable medium into the esophagus or trachea. 49. A method according to claim 47 further comprising the step of occluding the nostril or nasal cavity on at least one side of the intranasal septum to deter drainage of the flowable medium out of the nostril. 50. A method according to claim 47 wherein Step A comprises inserting a catheter into the paranasal sinus and infusing the flowable medium through the catheter and into the paranasal sinus. 51. A method according to claim 47 further comprising the steps of: providing an anterior nasal occlusion and access device that comprises an anterior occluder and a device insertion passageway; positioning the anterior nasal occlusion and access device such that its occluder occludes the nostril or nasal cavity on one side of the intranasal septum; and wherein Step A comprises inserting a catheter through the device insertion passageway, advancing the catheter to or through the ostium of the paranasal sinus and infusing the contrast medium through the catheter and into the paranasal sinus. 52. A method according to claim 51 wherein the anterior nasal occlusion and access device comprises an anterior occluder for occluding the nostril or nasal cavity on one side of the nasal septum and a working device insertion port through which a working device may be inserted and wherein: Step A comprises i) inserting a catheter through the working device insertion port, ii) advancing the catheter to or through the ostium of the paranasal sinus and iii) infusing the contrast medium through the catheter and into the paranasal sinus. 53. A method according to claim 47 further comprising the steps of: providing an anterior/posterior nasal occlusion and access device that comprises an anterior occluder, a posterior occluder and a device insertion passageway; and positioning the anterior/posterior nasal occlusion and access device such that its anterior occluder occludes the nostril or nasal cavity on one side of the intranasal septum and its posterior occluder occludes the nasopharynx posterior to the intranasal septum and superior to the glottis; and wherein Step A comprises advancing a catheter through the device insertion passageway to or through the ostium of the paranasal sinus and infusing the contrast medium through the catheter and into the paranasal sinus. 54. A method according to claim 47 wherein the flowable medium is an imageable contrast medium and wherein Step B of the method comprises imaging the imageable contrast medium. 55. A method according to claim 47 wherein Step B is carried out using a moveable imaging device and comprises obtaining images from a plurality of vantage points. 56. A method according to claim 55 wherein the movable imaging device comprises a radiographic imaging device and a C-arm and wherein Step B comprises moving the C-arm to obtain images from a plurality of vantage points. 57. A method according to claim 47 wherein the flowable medium is a radioactive or radiolabled fluid and wherein Step B of the method comprises tracing the radioactive or radiolabled fluid using a device that detects radioactivity. 58. A method for diagnosing or locating an obstruction that impedes drainage from a paranasal sinus or for assessing the efficacy of previously rendered treatment intended to improve or modify drainage from a paranasal sinus, said method comprising the steps of: (A) introducing into the paranasal sinus a substance that causes tissues lining the paranasal sinus to secrete mucous or other secretions; and, (B) monitoring the flow of the mucous or other secretions from the paranasal sinus. 59. A method according to claim 58 wherein the substance introduced in Step A comprises histamine. 60. A method according to claim 58 wherein the substance introduced in Step A comprises an allergen to which the patient is allergic. 61. A method according to claim 58 wherein the drainage of the mucous or other secretions is assessed visually using an endoscope. 62. A method according to claim 58 wherein Step A further comprises causing a contrast agent to be combined with the mucous or other secretions and wherein the drainage of mucous or other secretions is assessed by imaging the contrast agent. 63. A device for removing polyps or other tissue from the nose, nasopharynx or paranasal sinus, said device comprising: a flexible catheter having a distal end and a lumen; a flexible tube having an open distal end and a lumen extending therethrough, said flexible tube being rotatably disposed within a lumen of the catheter such that the flexible tube may rotate while the catheter does not rotate; a rotating cutter on the distal end of the flexible tube; and an opening formed in the catheter such that matter may be received through the opening and cut by the rotating cutter. 64. A device according to claim 63, further comprising a connector for connecting the lumen of the flexible tube to a source of negative pressure such that matter that is cut by the rotating cutter will be suctioned though the open distal end and through the lumen of the flexible tube. 65. A device according to claim 63 wherein the opening in the catheter is an opening in the distal end of the catheter. 66. A device according to claim 63 wherein the opening in the catheter is a side opening formed in a side of the catheter. 67. A device according to claim 63 wherein there is at least one bearing disposed between the catheter and the flexible tube. 68. A device according to claim 63 further comprising a scope which is useable to view the distal end of the catheter while the device is inserted in the body of a patient. 69. A device according to claim 68 wherein the scope extends through the lumen of the flexible tube. 70. A device according to claim 68 wherein the scope is attached to the exterior of the catheter. 71. A device according to claim 70 wherein the scope is disposed in a lumen on one side of the catheter. 72. A device according to claim 70 further comprising a side lumen on the catheter. 73. A system comprising a device according to claim 72 in combination with a scope positioned in the side lumen. 74. A system comprising a device according to claim 72 in combination with a guidewire positioned in the side lumen. 75. A device according to claim 66 further comprising moveable retractor apparatus that is operative to retract matter that has entered the opening into contact with the rotating cutter. 76. A device according to claim 75 wherein the moveable retractor apparatus comprises an elongate member having a retractor head, said elongate member being advanceable in a distal direction to move the retractor head to a location distal to the side opening and retractable in the proximal direction to move the retractor head in the proximal direction such that the retractor head will propel matter that has entered the opening into contact with the rotating cutter. 77. A device according to claim 66 wherein the catheter has a closed distal tip. 78. A device according to claim 77 further comprising a lumen that extends through the flexible tube and through an opening formed in the distal tip of the catheter. 79. A system comprising a device according to claim 78 in combination with a scope positioned within the lumen that extends through the flexible tube and through an opening formed in the distal tip of the catheter. 80. A system comprising a device according to claim 78 in combination with a guidewire positioned within the lumen that extends through the flexible tube and through an opening formed in the distal tip of the catheter. 81. A method for treating deafness or hearing impairment in a human or veterinary patient having a Eustachian tube, a cochlea, a tympanic cavity and an outer ear, said method comprising the steps of: (A) inserting a flexible catheter through the patient's nose and into the Eustachian tube; (B) providing a cochlear implant system comprising a cochlear electrode array, a transducer and a power source; (C) advancing the cochlear electrode array through the catheter that is inserted in the Eustachian tube and into the cochlea; and (D) communicating the cochlear electrode array to the transducer and power source such that the cochlear implant system delivers sound-associated electrical impulses to the cochlea. 81. A method according to claim 81 wherein Step A comprises using a scope to visualize the Eustachian tube and guiding said catheter into the Eustachian tube. 83. A method according to claim 81 wherein Step C comprises inserting a cochlear guide through the catheter that is positioned in the Eustachian tube and advancing the electrode array over or through the cochlear guide and into the cochlea. 84. A method according to claim 81 wherein Step C comprises advancing the cochlear electrode array through the round window of the cochlea. 85. A method according to claim 81 wherein Step C further comprises penetrating the secondary tympanic membrane. 86. A method according to claim 81 wherein Step C comprises creating a cochleostomy and advancing the cochlear electrode through the cochleostomy. 87. A method according to claim 81 further comprising the step of passing the transducer through the Eustachian tube and implanting the transducer in the tympanic cavity. 88. A method according to claim 87 wherein the method further comprises the step of removing bones from the tympanic cavity prior to implantation of the transducer in the tympanic cavity. 89. A method according to claim 81 further comprising the step of placing the power supply in the outer ear canal. 90. A method according to claim 7 further comprising the step of adjusting the distance between the anterior occluder member and the posterior occluder member. 91. An anterior/posterior occlusion and access device according to claim 33 wherein the distance between the anterior occluder and posterior occluder is adjustable. | FIELD OF THE INVENTION The present invention relates generally to medical devices and methods and more particularly to minimally invasive, catheter based devices, systems and methods for treating sinusitis and other ear, nose & throat disorders. BACKGROUND The human nose is responsible for warming, humidifying and filtering inspired air and for conserving heat and moisture from expired air. The nose is also an important cosmetic feature of the face. The nose is formed mainly of cartilage, bone, mucous membranes and skin. The right and left nostrils lead into right and left nasal cavities on either side of the intranasal septum. The right and left nasal cavities extend back to the soft palate, where they merge to form the posterior choanae. The posterior choanae opens into the nasopharynx. The roof of the nose is formed, in part, by a bone known as the cribriform plate. The cribriform plate contains numerous tiny perforations through which sensory nerve fibers extend to the olfactory bulbs. The sensation of smell occurs when inhaled odors contact a small area of mucosa in the superior region of the nose, stimulating the nerve fibers that lead to the olfactory bulbs. The paranasal sinuses are cavities formed within the bones of the face. The paranasal sinuses include frontal sinuses, ethmoid sinuses, sphenoidal sinuses and maxillary sinuses. The paranasal sinuses are lined with mucous-producing epithelial tissue. Normally, mucous produced by the linings of the paranasal sinuses slowly drains out of each sinus through an opening known as an ostium, and into the nasopharnyx. Disorders that interfere with drainage of mucous (e.g., occlusion of the sinus ostia) can result in a reduced ability of the paranasal sinuses to function normally. This results in mucosal congestion within the paranasal sinuses. Such mucosal congestion of the sinuses can cause damage to the epithelium that lines the sinus with subsequent decreased oxygen tension and microbial growth (e.g., a sinus infection). The nasal turbinates are three (or sometimes four) bony processes that extend inwardly from the lateral walls of the nose and are covered with mucosal tissue. These turbinates serve to increase the interior surface area of the nose and to impart warmth and moisture to air that is inhaled through the nose. The mucosal tissue that covers the turbinates is capable of becoming engorged with blood and swelling or becoming substantially devoid of blood and shrinking, in response to changes in physiologic or environmental conditions. The curved edge of each turbinate defines a passageway known as a meatus. For example, the inferior meatus is a passageway that passes beneath the inferior turbinate. Ducts, known as the nasolacrimal ducts, drain tears from the eyes into the nose through openings located within the inferior meatus. The middle meatus is a passageway that extends inferior to the middle turbinate. The middle meatus contains the semilunar hiatus, with openings or ostia leading into the maxillary, frontal, and anterior ethmoid sinuses. The superior meatus is located between the superior and medial turbinates. Nasal Polyps: Nasal polyps are benign masses that grow from the lining of the nose or paranasal sinuses. Nasal polyps often result from chronic allergic rhinitis or other chronic inflammation of the nasal mucosa. Nasal polyps are also common in children who suffer from cystic fibrosis. In cases where nasal polyps develop to a point where they obstruct normal drainage from the paranasal sinuses, they can cause sinusitis. Sinusitis: The term “sinusitis” refers generally to any inflammation or infection of the paranasal sinuses. Sinusitis can be caused by bacteria, viruses, fungi (molds), allergies or combinations thereof. It has been estimated that chronic sinusitis (e.g., lasting more than 3 months or so) results in 18 million to 22 million physician office visits per year in the United States. Patients who suffer from sinusitis typically experience at least some of the following symptoms: headaches or facial pain nasal congestion or post-nasal drainage difficulty breathing through one or both nostrils bad breath pain in the upper teeth Proposed Mechanism of Sinus Pain & Diagnosis The sinuses consist of a series of cavities connected by passageways, ultimately opening into the nasal cavity. As described previously, these passageways and cavities are formed by bone, but covered in mucosa. If the mucosa of one of these passageways becomes inflamed for any reason, the cavities which drain through that passageway can become blocked. This trapping of mucous can be periodic (resulting in episodes of pain) or chronic. Chronically blocked passageways are targets of infection. Ultimately, it is the dimensions of the bony passageways and thickness of the overlying mucosa and its chronicity that dictate the duration and severity of sinus symptoms. Thus, the primary target for sinus therapy is the passageway, with the primary goal to regain drainage. Often CT will not reveal these dimensional issues, especially when the patient is not currently experiencing severe symptoms. Therefore there exists a need to dynamically evaluate the sinus passageways under normal conditions, in response to challenging stimuli. As suggested herein, if it would be possible to assess sinus disease and its dynamic component, one might better target therapy for sinusitis and possibly be able to treat patients in a more focused and minimally invasive manner. Such focus on the passageway and the use of flexible instrumentation suggests an entirely new approach to sinus intervention: one utilizing flexible catheters and guidance tools, with passageway and cavity modifying devices capable of being delivered with minimal damage to the surrounding tissues. Deviated Septum: The intranasal septum is a cartilaginous anatomical structure that divides one side of the nose from the other. Normally, the septum is relatively straight. A deviated septum is a condition where the cartilage that forms the septum is abnormally curved or bent. A deviated nasal septum may develop as the nose grows or, in some cases, may result from trauma to the nose. A deviated septum can interfere with proper breathing or may obstruct normal drainage of nasal discharge, especially in patient's whose nasal turbinates are swollen or enlarged due to allergy, overuse of decongestant medications, etc. Such interference with drainage of the sinuses can predispose the patient to sinus infections. A deviated nasal septum that interferes with proper function of the nose can be surgically corrected by a procedure known as septoplasty. In a typical septoplasty procedure, an endoscope is inserted into the nose and the surgeon makes an incision inside the nose, lifts up the lining of the septum, and removes and straightens the underlying bone and cartilage that is abnormally deviated. Such surgical septoplasty procedures can effectively straighten a deviated septum but, because the nasal cartilage has some memory, the septum may tend to resume its original deviated shape. Reduction/Removal of Nasal Turbinates Various surgical techniques, including endoscopic surgery, have been used for reduction and/or removal of the inferior turbinate in patient's whose inferior turbinate is chronically enlarged such that it is obstructing normal breathing and/or normal drainage from the paranasal sinuses. Typically, chronic enlargement of the inferior turbinates is the result of allergies or chronic inflammation. Enlargement of the inferior turbinate can be especially problematic in patient's who also suffer from a deviated septum that crowds or impinges upon the soft tissue of the turbinate. Thus, a septoplasty to straighten the deviated septum is sometimes performed concurrently with a reduction of the inferior turbinates. Sinus Tumors Most polyps are benign, but one form of a nasal polyp, known as an inverting papilloma, can develop into a malignancy. Unlike most benign polyps, which typically occur on both sides of the nose, an inverting papilloma is usually found on just one side. Thus, in cases where a unilateral polyp is observed, it is usually biopsied to determine if it is malignant. If an inverting papilloma is detected before it becomes malignant and is removed completely, it will typically not recur. However, using the technology that has heretofore been available, it has sometimes been difficult to determine if the papilloma has been entirely removed unless and until regrowth of the polyp is observed on long term post-surgical follow-up. Various benign sinus tumors have also been known to occur, but are relatively rare. The most common form of malignant sinus tumor is squamous cell carcinoma. Even with surgery and radiation treatment, squamous cell carcinoma of the paranasal sinus is associated with a relatively poor prognosis. Other types of malignant tumors that invade the paranasal sinuses include adenocarcinoma and, more rarely, lymphoma and even more rarely, melanoma. Facial Fractures The most common cause of fractures of the facial bones is auto accidents, but facial fractures are also frequently caused by sports injuries, industrial accidents, falls, assaults and gunshot wounds. Some facial fractures involve bones that are accessible from inside the nasal cavities or paranasal sinuses. Notably, the nose is the most commonly injured facial structure due to its prominent position on the face. Thus, fractures of the nasal bone (with or without resultant deviated septum) are not uncommon. Other facial fractures such as fractures of the orbital floor and/or the ethmoid or frontal sinuses are also accessible from inside the nose or sinuses. A common type of orbital floor fracture is a “blowout” fracture that typically results from blunt trauma to the eye where the force is transmitted downwardly causing the relatively thin bone that forms the floor of the orbit to fracture downwardly. This can cause the periorbital tissues to herniate into the maxillary sinus and sometimes can also create a “trap door” of bone that extends downwardly into the maxillary sinus. Endoscopic Sinus Surgery and Other Current Procedures Functional Endoscopic Sinus Surgery The most common corrective surgery for chronic sinusitis is functional endoscopic sinus surgery (FESS). In FESS, an endoscope is inserted into the nose and, under visualization through the endoscope, the surgeon may remove diseased or hypertrophic tissue or bone and may enlarge the ostia of the sinuses to restore normal drainage of the sinuses. FESS procedures can be effective in the treatment of sinusitis and for the removal of tumors, polyps and other aberrant growths from the nose. Other endoscopic intranasal procedures have been used to remove pituitary tumors, to treat Graves disease (i.e., a complication of hyperthyroidism which results in protrusion of the eyes) and surgical repair of rare conditions wherein cerebrospinal fluid leaks into the nose (i.e., cerebrospinal fluid rhinorrhea). Surgery to reduce the size of the inferior turbinates can be accomplished with endoscopic visualization (with magnification where desired) and is typically performed with the patient under general anesthesia. An incision is typically made in the mucosa that lines the turbinate to expose the underlying bone. Some quantity of the underlying bone may then be removed. If selective removal of some of the mucosa or soft tissue is also desired, such soft tissue can be debulked or removed through by traditional surgical cutting or by the use of other tissue ablation or debulking apparatus such as microdebriders or lasers. Less frequently, chronically enlarged inferior turbinates have been treated by cryotherapy. It is typically desirable to remove only as much tissue as necessary to restore normal breathing and drainage, as removal of too much tissue from the turbinates can impair the ability of the turbinates to perform their physiological functions of warming and humidifying inspired air and conserving warmth and moisture from expired air. Complications associated with inferior turbinate surgery include bleeding, crusting, dryness, and scarring. In some patients, the middle turbinate is enlarged due to the presence of an invading air cell (concha bullosa), or the middle turbinate may be malformed (paradoxically bent). Severe ethmoid sinusitis or nasal polyps can also result in enlargement or malformation of the middle turbinates. Since a substantial amount of drainage from the sinuses passes through the middle meatus (i.e., the passage that runs alongside middle turbinate) any enlargement or malformation of the middle turbinate can contribute to sinus problems and require surgical correction. Thus, in some FESS procedures carried out to treat sinusitis, the middle meatus is cleared (e.g., the polyps or hypertorophic tissue are removed) thereby improving sinus drainage. However, the middle turbinate can include some of the olfactory nerve endings that contribute to the patient's sense of smell. For this reason, any reduction of the middle turbinate is typically performed in a very conservative manner with care being taken to preserve as much tissue as possible. In patients who suffer from concha bullosa, this may involve removing the bone on one side of an invading air sac. In the cases where the middle turbinate is malformed, just the offending portion(s) of the turbinate may be removed. Extended Endoscopic Frontal Sinus Surgery Because of its narrow anatomical configuration, inflammation of the frontal sinuses can be particularly persistent, even after surgery and/or medical therapy has resolved the inflammation in the other paranasal sinuses. In cases of persistent inflammation of the frontal sinuses, a surgery known as a trans-septal frontal sinusotomy, or modified Lothrop procedure, is sometimes performed. In this procedure, the surgeon removes a portion of the nasal septum and the bony partition between the sinuses to form one large common drainage channel for draining the frontal sinuses into the nose. This complicated procedure, as well as some other ear, nose and throat surgical procedures, can carry a risk of penetrating the cranial vault and causing leakage of cerebrospinal fluid (CSF). Also, some sinus surgeries as well as other ear, nose and throat procedures are performed close to the optic nerves, the eyes, and the brain and can cause damage to those structures. To minimize the potential for such untoward complications or damage, image-guided surgery systems have been used to perform some complex head and neck procedures. In image guided surgery, integrated anatomical information is supplied through CT-scan images or other anatomical mapping data taken before the operation. Data from a preoperative CT scan or other anatomical mapping procedure is downloaded into a computer and special sensors known as localizers are attached to the surgical instruments. Thus, using the computer, the surgeon can ascertain, in three dimensions, the precise position of each localizer-equipped surgical instrument at any given point in time. This information, coupled with the visual observations made through the standard endoscope, can help the surgeon to carefully position the surgical instruments to avoid creating CSF leaks and to avoid causing damage to nerves or other critical structures. Shortcomings of FESS Although FESS continues to be the gold standard therapy for severe sinuses, it has several shortfalls. Often patients complain of the post-operative pain and bleeding associated with the procedure, and a significant subset of patients remain symptomatic even after multiple surgeries. Since FESS is considered an option only for the most severe cases (those showing abnormalities under CT scan), a large population of patients exist that can neither tolerate the prescribed medications nor be considered candidates for surgery. Further, because the methodologies to assess sinus disease are primarily static measurements (CT, MRI), patients whose symptoms are episodic are often simply offered drug therapy when in fact underlying mechanical factors may play a significant role. To date, there is no mechanical therapy offered for these patients, and even though they may fail pharmaceutical therapies, no other course of action is indicated. This leaves a large population of patients in need of relief, unwilling or afraid to take steroids, but not sick enough to qualify for surgery. One of the reasons why FESS and sinus surgery is so bloody and painful relates to the fact that straight instrumentation with rigid shafts are used. Due to the fact that the sinuses are so close to the brain and other important structures, physicians have developed techniques using straight tools and image guidance to reduce the likelihood of penetrating into unwanted areas. In an effort to target deep areas of the anatomy, this reliance on straight instrumentation has resulted in the need to resect and remove or otherwise manipulate any anatomical structures that may lie in the path of the instruments, regardless of whether those anatomical structures are part of the pathology. With the advances in catheter based technology and imaging developed for the cardiovascular system, there exists a significant opportunity to reduce the morbidity of sinus interventional through the use of flexible instrumentation and guidance. If flexible tools could be developed such that sinus intervention may be able to be carried out with even less bleeding and post-operative pain, these procedures may be applicable to a larger group of patients. Further, as described here, flexible instrumentation may allow the application of new diagnostic and therapeutic modalities that have never before been possible. Laser or Radiofrequency Turbinate Reduction (Soft Tissue Only) In cases where it is not necessary to revise the bone that underlies the turbinate, the surgeon may elect to perform a laser or radiofrequency procedure designed to create a coagulative lesion in (or on) the turbinate, which in turn causes the soft tissue of the turbinate to shrink. Also, in some cases, a plasma generator wand may be used create high energy plasma adjacent to the turbinate to cause a reduction in the size of the turbinate. One example of a radio frequency procedure that may be used to shrink enlarged inferior turbinates is radiofrequency volumetric tissue reduction (RFVTR) using the Somnoplasty® system (Somnus Medical Technologies, Sunnyvale, Calif.). The Somnoplasty® system includes a radio frequency generator attached to a probe. The probe is inserted through the mucosa into the underlying soft tissue of the turbinate, usually under direct visualization. Radiofrequency energy is then delivered to heat the submucosal tissue around the probe, thereby creating a submucosal coagulative lesion while allowing the mucosa to remain in tact. As the coagulative lesion heals, the submucosal tissue shrinks thereby reducing the overall size of the turbinate. Radiofrequency volumetric tissue reduction (RFVTR) can be performed as an office procedure with local anesthesia. Many of the above-described procedures and techniques may be adaptable to minimaly invasive approaches and/or the use of flexible instrumentation. There exists a need in the art for the development of such minimally invasive procedures and techniques as well as instrumentaion (e.g., flexible instruments or catheters) useable to perform such procedures and techniques. SUMMARY OF THE INVENTION In general, the present invention provides methods, devices and systems for diagnosing and/or treating sinusitis or other conditions of the ear, nose or throat. In accordance with the present invention, there are provided methods wherein one or more flexible catheters or other flexible elongate devices as described herein are inserted in to the nose, nasopharynx, paranasal sinus, middle ear or associated anatomical passageways to perform an interventional or surgical procedure. Examples of procedures that may be performed using these flexible catheters or other flexible elongate devices include but are not limited to: delivering contrast medium; delivering a therapeutically effective amount of a therapeutic substance; implanting a stent, tissue remodeling device, substance delivery implant or other therapeutic apparatus; cutting, ablating, debulking, cauterizing, heating, freezing, lasing, dilating or otherwise modifying tissue such as nasal polyps, abberant or enlarged tissue, abnormal tissue, etc.; grafting or implanting cells or tissue; reducing, setting, screwing, applying adhesive to, affixing, decompressing or otherwise treating a fracture; delivering a gene or gene therapy preparation; cutting, ablating, debulking, cauterizing, heating, freezing, lasing, forming an osteotomy or trephination in or otherwise modifying bony or cartilaginous tissue within paranasal sinus or elsewhere within the nose; remodeling or changing the shape, size or configuration of a sinus ostium or other anatomical structure that affects drainage from one or more paranasal sinuses; removing puss or aberrant matter from the paranasal sinus or elsewhere within the nose; scraping or otherwise removing cells that line the interior of a paranasal sinus; removing all or a portion of a tumor; removing a polyp; delivering histamine, an allergen or another substance that causes secretion of mucous by tissues within a paranasal sinus to permit assessment of drainage from the sinus; implanting a cochlear implant or indwelling hearing aid or amplification device, etc. Further in accordance with the invention, there are provided methods for diagnosing and assessing sinus conditions, including methods for delivering contrast media into cavities, assessing mucosal flow, assessing passageway resistance and cilliary function, exposing certain regions to antigen challenge, etc Still further in accordance with the invention, there are provided novel devices for performing some or all of the procedures described herein. Further aspects, details and embodiments of the present invention will be understood by those of skill in the art upon reading the following detailed description of the invention and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A (Prior Art) is a frontal view of a human head showing the locations of the paranasal sinuses. FIG. 1B (Prior Art) is a side view of a human head showing the locations of the paranasal sinuses. FIG. 2A is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with an anterior/posterior occluder & access device of the present invention inserted therein. FIG. 2B is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses, with an anterior occluder & access device of the present invention inserted therein. FIG. 2C is a cross sectional view through line C-C of FIG. 2A. FIG. 2D is a cross sectional view through line D-D of FIG. 2B. FIG. 2E is a perspective view of a posterior occluder/suction/access device of the present invention that is insertable through the oral cavity. FIG. 2F is a cross-sectional view through Line 2F-2F of FIG. 2E. FIG. 2G is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with an anterior occluder & access device of the present invention inserted in the right nasal cavity and a posterior occluder/suction/access device of FIG. 2E inserted through the oral cavity. FIG. 2H is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses, with an anterior occluder & access device of the present invention inserted in the left nasal cavity and the same posterior occluder/suction/access device that appears in FIG. 2G extending through the oral cavity. FIG. 2I is a perspective view of a posterior occluder/suction device of the present invention that is insertable transnasally. FIG. 2J is a cross-sectional view through Line 2J-2J of FIG. 21. FIG. 2K is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with the posterior occluder/suction device shown in FIG. 21 inserted through the right nasal cavity. FIG. 2L is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses and showing the posterior occluder portion of the device of FIG. 2K residing in and occluding the nasopharynx at a location posterior to the septum and superior to the glottis. FIG. 2M is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with an extended posterior occluder/suction device inserted through the right nasal cavity. FIG. 2N is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses and showing the posterior occluder and distal tubular extension portions of the device of FIG. 2M residing in the nasopharynx posterior to the septum and superior to the glottis. FIG. 2O is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with a posterior occluder/slidable suction device inserted through the right nasal cavity. FIG. 2P is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses and showing the posterior occluder and distal portion of the slidable suction cannula of the device of FIG. 2O residing in the nasopharynx posterior to the septum and superior to the glottis. FIG. 2Q is a partial sectional view of head of a human patient showing the right nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with another posterior occluder/tapered suction device inserted through the right nasal cavity. FIG. 2R is a partial sectional view of head of a human patient showing the left nasal cavity, the left side of the nasopharynx and the associated paranasal sinuses and showing the posterior occluder and distal portion of the tapered suction cannula of the device of FIG. 2Q residing in the nasopharynx posterior to the septum and superior to the glottis. FIG. 3A is a partial perspective view of one embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3B is a partial perspective view of another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3C is a partial perspective view of another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3C′ is a cross sectional view through line 3C′-3C′ of FIG. 3C. FIG. 3D is a partial perspective view of yet another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3E′, 3E″ and 3E′″ are partial perspective views of still another embodiment of an occluder/suction device of the present invention showing various steps in a process by which the occluder/suction device is positioned within an anatomical passageway. FIG. 3F is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIGS. 3F′, 3F″ and 3F′″ show alternative constructions of the distal portion of the suction cannula of the occluder/suction device shown in FIG. 3F. FIG. 3G is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3H is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3I is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3J is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 3K is a partial perspective view of still another embodiment of an occluder/suction device of the present invention positioned within an anatomical passageway. FIGS. 3L′ and 3L″ show partial longitudinal sectional views of another occluder/suction device of the present invention. FIGS. 3M′ and 3M″ show partial perspective views of another occluder/suction device of the present invention positioned within an anatomical passageway. FIG. 4 is a longitudinal sectional view of the oropharynx and anterior neck of a human patient having a nasopharyngeal occluder/endotracheal tube device of the present invention inserted through the right nasal cavity and into the trachea. FIG. 5A is a partial perspective view of a side cutting or ablation device being used in accordance with the present invention. FIG. 5B is a partial perspective view of a device having laterally deployable needles, electrodes or other treatment delivering projections, being used in accordance with the present invention. FIG. 5C is a partial perspective view of a drill (e.g., a tissue drill, bone drill, or trephine device) being used in accordance with the present invention. FIG. 5D is a partial perspective view of a catheter having a laterally deployed needle or tube for delivering a substance or apparatus to a target location and an optional on-board imaging or guidance apparatus, being used in accordance with the present invention. FIG. 5E is a partial perspective view of a balloon catheter being used in accordance with the present invention. FIG. 5F is a partial perspective view of a balloon catheter having blades or electrodes thereon, being used in accordance with the present invention. FIG. 5G′ is a partial perspective view of a balloon catheter having a stent positioned thereon being inserted into an occluded region within the nose, nasopharynx or paranasal sinus in accordance with the present invention. FIG. 5G″ shows the balloon catheter and stent of FIG. 3G′, with the balloon inflated and the stent expanded so as to open or dilate the occluded region within the nose, nasopharynx or paranasal sinus. FIG. 5G′″ shows the balloon catheter and stent of FIG. 3G′ with the stent implanted, the balloon deflated and the catheter being withdrawn and removed. FIG. 5H is a partial perspective view of a tissue shrinking electrode device being used in accordance with the present invention. FIG. 51 is a partial perspective view of a cryogenic or plasma state treatment device being used in accordance with the present invention. FIG. 5J is a partial perspective view of an expandable tissue expanding device positioned within a passageway in the nose, nasopharynx or paranasal sinus in accordance with the present invention. FIG. 5K is a partial sectional view of one embodiment of a forward cutting/suction catheter of the present invention. FIG. 5K′ shows the device of FIG. 5K being used to remove a nasal polyp or other obstructive mass from an anatomical passage within the nose or paranasal sinus. FIG. 5L is a partial sectional view of a forward cutting/suction catheter/endoscope device of the present invention. FIG. 5M is a partial sectional view of a side cutting/suction catheter device of the present invention. FIG. 5N is a partial sectional view of a side cutting/suction catheter device of the present invention having an optional guidewire lumen and optional endoscopic component(s). FIG. 5O is a partial perspective view of the distal end of a guide catheter/endoscope of the present invention. FIG. 5P is a partial perspective view of a balloon catheter/pressure-expandable intranasal stent/endoscope device of the present invention. FIG. 5Q is a partial perspective view of a delivery catheter/self expanding intranasal stent/endoscope device of the present invention. FIG. 5Q′ is a cross-sectional view through line 5Q′-5Q′ of FIG. 5Q. FIG. 5R′ shows an example of an optional modified shape of the balloon and stent of FIG. 5P. FIG. 5R″ shows another example of an optional modified shape of the balloon and stent of FIG. 5P. FIG. 5S is a partial perspective view of a snare catheter of the present invention with optional endoscopic component(s). FIG. 5T is a partial perspective view of a forceps device of the present invention having optional endoscopic component(s). FIG. 5U is a partial perspective view of a system of the present invention comprising a guide catheter, endoscope and guidewire. FIG. 5U′ is a cross-sectional view through line 5T′-5T′ of FIG. 5T. FIG. 5V is a partial perspective view of a microdebrider catheter of the present invention. FIG. 5W is a partial perspective view of a bone remodeling device of the present invention. FIGS. 5W′ and 5W″ show steps in a method for using the bone remodeling device of FIG. 5W. FIGS. 5X′-5X′″″ are partial perspective views of alternative designs for bone remodeling devices of the present invention. FIGS. 5Y-5Y′″″ are perspective views of examples of substance delivering implant devices useable in the present invention. FIG. 6A is a perspective view of one embodiment of a sphenoid sinus guide catheter of the present invention. FIG. 6B is a perspective view of a frontal sinus guide catheter of the present invention. FIG. 6C is a perspective view of one embodiment of a maxillary sinus guide catheter of the present invention. FIG. 6D is a perspective view of one embodiment of an ethmoid sinus guide catheter of the present invention. FIG. 6E is a perspective view of one embodiment of a plugging guide catheter of the present invention useable for temporarily plugging the opening into a nasolacrimal duct or Eustachian tube. FIG. 7A is a sectional view of a paranasal sinus with a catheter introducing an expandable electrode cage into the sinus in accordance with the present invention. FIG. 7B is a sectional view of a paranasal sinus that is filled with a diagnostic or therapeutic substance and wherein a plug tipped catheter is being used to plug the ostium of the sinus to retain the substance within the sinus, in accordance with the present invention. FIG. 7C is a sectional view of a paranasal sinus with a catheter introducing a diagnostic or therapeutic substance into contact with the tissue lining the sinus, in accordance with the present invention. FIG. 7D is a sectional view of a paranasal sinus with a catheter having emitters and/or sensors for 3 dimensional mapping or navigation, in accordance with the present invention. FIG. 7E is a sectional view of a paranasal sinus with a catheter delivering a coil apparatus into the sinus to embolize the sinus and/or to deliver a diagnostic or therapeutic substance into the sinus in accordance with the present invention. FIG. 7F is a sectional view of a paranasal sinus with a guide catheter, guide wire and over-the-wire flexible endoscope inserted into the sinus, in accordance with the present invention. FIG. 7G shows the guide catheter and endoscope of FIG. 5F with a working device (e.g., a biopsy instrument) inserted through a working channel of the endoscope to perform a procedure within the sinus under endoscopic visualization, in accordance with the present invention. FIGS. 8A-8E show steps in a sinus treatment procedure conducted in accordance with the present invention. FIGS. 9A-9C show steps in a cochlear implant procedure conducted in accordance with the present invention. DETAILED DESCRIPTION The following detailed description and the accompanying drawings are intended to describe some, but not necessarily all, examples or embodiments of the invention only and does not limit the scope of the invention in any way. A number of the drawings in this patent application show anatomical structures of the ear, nose and throat. In general, these anatomical structures are labeled with the following reference letters: Nasal Cavity NC Nasopharynx NP Superior Turbinate ST Middle Turbinate MT Inferior Turbinate IT Frontal Sinus FS Ethmoid Sinus ES Sphenoid Sinus SS Sphenoid Sinus Ostium SSO Maxillary Sinus MS The human nose has right and left nostrils or nares which lead into separate right and left nasal cavities. The right and left nasal cavities are separated by the intranasal septum, which is formed substantially of cartilage and bone. Posterior to the intranasal septum, the nasal cavities converge into a single nasopharyngeal cavity. The right and left Eustachian tubes (i.e., auditory tubes) extend from the middle ear on each side of the head to openings located on the lateral aspects of the nasopharynx. The nasopharynx extends inferiorly over the uvula and into the pharynx. As shown in FIGS. 1A and 1B, paranasal sinuses are formed in the facial bones on either side of the face. The paranasal sinuses open, through individual openings or ostia, into the nasal cavities. The paranasal sinuses include frontal sinuses FS, ethmoid sinuses ES, sphenoidal sinuses SS and maxillary sinuses MS. The present invention provides a comprehensive system of devices and associated methods for diagnosing and treating disorders of the ears, nose and throat in a less invasive fashion than current day approaches. Specifically, examples of which are described below, the invention provides devices that wholly or partially effect a fluid-tight seal of the operative field (e.g., the nasopharynx and/or one or more of the sinus cavities or regional ducts). This fluid-tight sealing of the operative field allows the cavities, ducts and passageways to be imaged using fluid/gas based agents in combination with various imaging modalities without the risk of aspiration or uncontrolled leakage of fluid from the operative field. Further, this fluid-tight sealing of the operative field permits the retention and collection of any blood or flushing fluids released during the procedure. Another aspect of the invention is a set of methods and devices useable to assess the static and dynamic nature of the paranasal sinuses and to provide for the guidance of specific therapies to particular sinuses or particular target regions (e.g., stenotic sinus ostia, infected tissues within sinuses, tumors, other target structures). Another aspect of the invention is the use of devices and methods which are designed for minimally invasive entry into the sinus passageways or regional ducts under image and/or endoscopic guidance to provide local therapy such as dilation, ablation, resection, injection, implantation, etc. to the region of concern. These devices and methods may be disposable or temporary in their application, or they may be implantable with on-going functionality (such as implantable drug delivery systems, cochlear implants, etc.). In a number of embodiments, the present invention utilizes flexible catheters and various working devices that are mounted on or delivered through elongate flexible members or catheters, to diagnose and treat a wide range or ear, nose and throat disorders including; nasal polyps, sinusitis, enlarged turbinates, deviated septum, tumors, infections, deformities, etc. The following pages describe a number of specific devices and methods that are useable in accordance with this invention. It is to be understood that any component, element, limitation, attribute or step described in relation to any particular device or method described herebelow, may be incorporated in or used with any other device or method of the present invention unless to do so would render the resultant device or method unusable for its intended purpose. A. Occluders & Access Port Devices Many of the procedures of the present invention require the insertion and positioning of one or more flexible catheters or other flexible elongate working devices (examples of which are shown in FIGS. 5A-5Y′″″ and described herebelow) within the nose, nasopharynx, middle ear or paranasal sinuses. To facilitate the insertion and proper positioning of such catheters and/or other elongate working devices and to prevent undesirable drainage of blood or debris from the operative site, the present invention includes a number of different occluder and/or access port devices, examples of which are shown in FIGS. 2A-2R, that are inserted through the nose and/or oral cavity and function to a) prevent unwanted drainage or escape of fluid (e.g., gas or liquid) and b) facilitate the insertion and positioning of guides and working devices, examples of such working devices being shown in FIGS. 5A-5Y′″″ and 6A-6E. FIGS. 2A-2B show partial sectional views of opposite sides of the head of a human patient having an anterior/posterior occluder & access device 10 inserted through the right nasal cavity and anterior occluder & access device 12 positioned in the anterior region of the left nasal cavity. Specifically, FIG. 2A shows the nasal cavity, the right side of the nasopharynx and the associated paranasal sinuses, with an anterior/posterior occluder & access device 10 of the present invention inserted therein. The anterior/posterior occluder & access device 10 comprises an anterior occluder 14 which occludes the right nasal cavity on the right side of the nasal septum, a posterior occluder 18 that occludes the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis) and a tube 16 that extends between the anterior occluder 14 and posterior occluder 18. Devices for posterior occlusion and anterior occlusion may be used alone or in combination. They may be coaxially deployed or alternatively they may be deployed in a singular fashion, one in each orifice. It should be noted that any combination of these sealing modalities may be employed to achieve one or more of the stated objectives. A cross-section through the tube 16 is shown in FIG. 2C. Other cross-sectional configurations could also be possible, including those that comprise more lumens to permit the passage of multiple devices or fluids (e.g., liquid or gases). In some embodiments, it may be desirable for the device 10 (or any of the other occluder/access devices described herein) to have separate lumens for infusion and aspiration, thereby allowing for concurrent infusion of an irrigation fluid or other fluid and suctioning of the irrigation fluid or other fluid from the operative field. Such continuous turnover of fluid within a sealed operative field may be useful for clearing blood or debris from the operative field to facilitate unobstructed viewing of the anatomical structures using an endoscope or for various other reasons. A port body 28 as attached to the proximal end of the tube 16. A device insertion aperture 30 extends through the port body 28 into working lumen 50 of tube 16. One or more outlet openings 22, 24 are at location(s) in the tube such that a device (e.g., a catheter, fluid injector or other elongate device examples of which are shown in FIGS. 5A-5Y″″ and described herebelow) or fluid(s) may be inserted into the device insertion opening 30, advanced through the working lumen 50 and out of a selected one of the outlet openings 22, 24 to a position within the nose, nasopharynx or paranasal sinus. In the particular embodiment shown in FIG. 2A the anterior and posterior occluders 14, 18 comprise balloons, but various other types of occluders could be used in place of balloons, examples of which are shown in FIGS. 3A-3K and described herebelow. Balloon inflation/deflation lumens 52, 56 extends from proximal Luer connectors 32, 36, through the tube 16 and to the anterior occluder 14 and posterior occluder 18, respectively. Thus, a syringe or other fluid expelling and/or withdrawing device may be connected to connector 32 and used to selectively inflate and/or deflate the anterior occluder 14. Another syringe or other fluid expelling and/or withdrawing device may be connected to connector 36 and used to selectively inflate and/or deflate the posterior occluder 18. As may be appreciated from the showing of FIG. 2B, the posterior occluder (when fully inflated) may be sized and shaped to occlude the entire posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis), thereby preventing blood or other fluid or debris from draining into the patient's pharynx from either the right or left nasal cavity. When fully inflated, the anterior occluder 14 of the device 10 occludes only the right nasal cavity and serves to prevent blood, other fluid or debris from draining around the tube 16 and out of the right nostril during the operative procedure. A one way valve, such as a flapper valve, duckbill valve, hemostatic valve or other one way valve of the type well known in the art of biomedical device design, may be positioned within the port body 28 to permit a catheter or other elongate device (examples of which are shown in FIGS. 5A-5T and described herebelow) to be advanced in the distal direction though insertion port 30, through the port body 28 and through the working lumen 50 but to prevent blood, other fluid or debris from draining through the working lumen 50 out of the device insertion port 30. In this manner, the device 10 forms a substantially fluid tight anterior seal in the anterior aspect of the right nasal cavity and a substantially fluid tight posterior seal in the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). Since a substantially fluid tight seal is formed, one or more valves (not shown) may be provided to relieve positive or negative pressure created between the anterior or posterior occluders 14, 18 as a result of the injection of matter (e.g., contrast medium, irrigation solution, medicament, etc.) into the operative field and/or suctioning or removal of matter (e.g., blood, other fluid or debris) from the operative field. Additionally, a suction lumen 54 may extend from suction Luer connector 34, through suction lumen 54 and to suction openings 26 may be formed in the tube 16. A suction pump may be connected to the suction connector 34 to aspirate blood, other fluid and/or debris out of the right nasal operative region defined between anterior occluder 14 and posterior occluder 18. It should be appreciated that, while the occlusion/access devices shown in the drawings and described herein are designed to isolate a relatively large operative field (e.g., one or both nasal cavities, sinus, nasal cavities-nasopharynx, etc.), once a specific problem has been diagnosed and/or once a specific target region has been identified, the occluders 14, 18 may be repositioned and/or other occluder devices may be inserted to isolate and form a fluid tight seal of just a portion of the original operative field (e.g., just one sinus, one nasal cavity, one Eustachian tube, etc.) thereby allowing the procedure to go forward with only the necessary region(s) of the nose, nasopharynx, paranasal sinuses or other structures sealed off and/or instrumented, to minimize trauma and improve patient comfort. It should be appreciated that in any embodiment of an anterior/posterior occluder & access device, such as the device 10 shown in FIGS. 2A and 2B, the distance between the anterior occluder 14 and posterior occluder 18 may be adjustable so as to accommodate variations in anatomy and/or specific target regions or isolated operative fields of interest. The anterior and posterior occluders 14, 18 may be separate devices where the anterior occluder may slide or pass through one lumen of the posterior occluder, which may contain several lumens (e.g., inflation, working channel, irrigation, etc.), and may or may not be integrated with the posterior occluder. The posterior occluder may also contain several lumens (e.g., inflation, working channel, irrigation, etc.). Additionally, all lumens for both the anterior and posterior occluders may contain valves so as to prevent leakage or flow of gas, fluid, blood, etc. It is to be further appreciated that in embodiments that have anterior and posterior outlet openings 22, 24 (as shown in the example of FIGS. 2A-2B) tools, instrumentation and fluids may be delivered via either of the posterior or anterior access ports 22, 24. In some cases, access via a posterior outlet 24 is desirable to gain a better perspective on the target anatomical lumen or lumen (i.e. openings to the ethmoid cells). As shown in FIGS. 2B and 2D, in some procedures wherein the anterior/posterior occluder & access device 10 is inserted through one nasal cavity, it may be desirable to position a separate anterior occluder & access device 12 within the opposite nasal cavity to prevent drainage of blood, other fluid or debris from the other nostril and to facilitate insertion of catheters or other elongate devices (examples of which are shown in FIGS. 5A-5T and described herebelow) into the left nasal cavity and the paranasal sinuses or other anatomical structures accessible from the other nasal cavity. As shown, in FIG. 2B, the anterior occluder & access device 12 may comprise a tube 41 having an anterior occluder 40 and a port body 42 attached thereto. A device insertion aperture 44 extends through the port body 42 and through a working lumen 58 of tube 41 to an outlet aperture in the distal end of tube 41. A one way valve (such as the valve described hereabove in connection with the anterior/posterior occluder & access device 10) may optionally be provided within port body 42 to prevent draining of blood, other fluid or debris out of insertion aperture 44. In the particular embodiment shown in FIGS. 2B and 2D, the anterior occluder 40 is a balloon, but such occluder 40 may be of various other constructions, examples of which are shown in FIGS. 3A-3M″ and described herebelow. To facilitate inflation and deflation of this balloon type anterior occluder 40, a balloon inflation/deflation lumen 60 extends from Luer connector 48, through tube 41 to the balloon-type anterior occluder 40. A syringe or other fluid expelling and/or withdrawing device may be connected to connector 48 and used to selectively inflate and/or deflate the anterior occluder 40. Optionally, a side tube and Luer connector 46 may be connected to the working lumen 58 of tube 41 to allow blood, other fluid and debris to be suctioned from the left nasal cavity through the working lumen 58 of tube 41. In some embodiments, dedicated suction and/or irrigation lumen(s) with separate suction and/or irrigation ports may be formed in tube 41 in a manner similar to that described hereabove with respect to the anterior/posterior occluder & access device 10. FIGS. 2E-2H show an alternative system for occlusion and access, wherein anterior occluder & access device(s) 12 is/are positioned in one or both nostrils or nasal cavities and an orally insertable posterior occluder device 300 is inserted through the patient's oral cavity and positioned so as to occlude the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). The embodiment of the orally insertable posterior occluder device 300 shown in FIGS. 2E-2G comprises a curved tube 302 having an occluder 304 positioned at or near the distal end thereof. The device 300 is configured such that it may be inserted through the patient's oral cavity to a position where the occluder 304 is located within, and disposed, so as to substantially occlude the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). The posterior occluder 304 may also be positioned next to the Eustachian tube to block the Eustachian tube, thereby preventing fluid from tracking into the Eustachian tube during the procedure (if access to the Eustachian tube or middle ear or inner ear is not desired). Further, it may be necessary to place specific targeted balloons or occluders in ducts or channels which are not intended to be intervened upon (lacrimal ducts, Eustachian tubes, etc.). In such cases, these extra ductal occluders serve to prevent aberrant fluid/gas loss and/or to maintain the integrity of the lumen, while other nearby structures are being modified. In the particular example shown in FIGS. 2E-2G, the occluder 304 comprises a balloon. However, such occluder 304 may be constructed in various alternative ways, examples of which are shown in FIGS. 3A-3K and described herebelow. As may be appreciated from the cross-sectional showing of FIG. 2F, in this example a balloon inflation/deflation lumen 318 may extend from Luer connector 314, through tube 302 to the balloon-type occluder 304. A syringe or other inflation/deflation apparatus may be attached to the Luer connector 314 and used to inflate and deflate the balloon 304. A stopcock or other valve (not shown) may also be provided on balloon inflation tube 318 to maintain inflation of the balloon when desired. In routine use, the occluder 304 is initially deflated and the device 300 is inserted through the oral cavity and advanced to its desired position with the deflated occluder positioned within the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). Thereafter, the occluder 304 may be expanded (e.g., inflated) such that it occludes or blocks the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis), thereby substantially preventing blood, other fluid or debris from draining into the patient's esophagus or trachea during the procedure. In some cases, as shown in FIGS. 2E-2H, the tube 302 may have one or more lumen(s) 310 that extend(s) through the occluder 304 and open(s) through an opening 310 distal to the balloon. Working devices, such as catheters or other elongate devices examples of which are shown in FIGS. 5A-5Y′″″ and described herebelow may be advanced through such a lumen 310 and into the patient's nasopharynx, nasal cavities, paranasal sinuses, middle ears, etc. Alternatively, suction may be applied to such a lumen 310 to suction blood, other fluid or debris from the area superior to the occluder 304. In some cases, the lumen 310 shown may be divided into a working lumen and a suction lumen. The suction lumen may terminate in separate suction port(s) (not shown) at the distal end of the tube and a connector (not shown) at the proximal end, such that suction may be applied through a lumen that is separate from the lumen through which the working device(s) is/are passed. A port body 306 may be positioned on the proximal end of the tube 302. A device insertion port 308 may extend through the port body 306 into a lumen 310 of the tube 302. A one way valve, such as a flapper valve, duckbill valve, hemostatic valve or other one way valve of the type well known in the art of biomedical device design, may be positioned within the port body 306 to permit a catheter or other elongate device to be advanced in the distal direction though insertion port 308, through the port body 306 and through a lumen 310 but to prevent blood, other fluid or debris from draining through the lumen 310 and out of the device insertion port 308. In some cases, the orally insertable posterior occluder device 300 may be used without any anterior occluder device(s) positioned in the nostril(s) or nasal cavity(ies). In other cases, it will be desirable to use this orally insertable posterior occluder device 300 in combination with one or two anterior occluder & access devices 12 as shown in the example of FIGS. 2G and 2H. The use of these devices 300, 12 in combination serves to establish a substantially fluid tight operative field between the posterior occluder 304 and the anterior occluder(s) 40 while allowing various catheters and other operative instruments to be inserted into the operative field through optional access ports 44 and/or 308. FIGS. 2I-2L show a trans-nasally insertable posterior occluder device 301 that does not include any anterior occluder. This device 301 comprises a curved tube 303 having an occluder 305 positioned at or near the distal end of the tube 303. As shown in FIGS. 2K-2L, this device 301 is inserted through either the right or left nasal cavity and advanced to a position where the occluder 305 substantially occludes the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). In the particular example shown, this occluder 305 comprises a balloon. However, such occluder 305 may be constructed in various alternative ways, examples of which are shown in FIGS. 3A-3K and described herebelow. As may be appreciated from the cross-sectional showing of FIG. 2J, in this example a balloon inflation/deflation lumen 317 may extend from Luer connector 311, through tube 303 to the balloon-type occluder 305. A syringe or other inflation/deflation apparatus may be attached to the Luer connector 311 and used to inflate and deflate the balloon-type occluder 305. A stopcock or other valve (not shown) may also be provided on balloon inflation lumen 317 to maintain inflation of the balloon when desired. In routine use, the occluder 305 is initially deflated and the device 301 is inserted through the right or left nasal cavity and advanced to its desired position where the deflated occluder 305 is positioned within the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). Thereafter, the occluder 305 may be expanded (e.g., inflated) such that it occludes or blocks the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis), thereby substantially preventing blood, other fluid or debris from draining into the patient's esophagus or trachea during the procedure. Optionally, distal suction ports 309 and/or proximal suction ports 307 may open into lumen 315 of the tube 303 and such lumen 315 may be attached to a suction connector 313. In this manner, suction may be applied to remove blood, other fluid or debris from the nasopharynx superior to the occluder 305 and/or from the nasal cavity through which the device 3301 is inserted. As may be appreciated from the showings of FIGS. 2K and 2L, in this example, the trans-nasal posterior occluder device 301 is inserted through the right nasal cavity. A working device WD such as a catheter or other elongate operative apparatus (examples of which are shown in FIGS. 5A-5Y′″″ and described herebelow) may be advanced into the right nasal cavity adjacent to the tube 303 or through the left nasal cavity which remains open, as no anterior occlusion is provided by this trans-nasal posterior occluder device 301. This arrangement may be particularly suitable for procedures where the physician desires to directly visualize, through the nostril(s), the anatomical structures within the nose, such as the inferior, middle or superior turbinates IT, MT, ST, as shown in FIGS. 2K-2L. FIGS. 2M-2N show a modified version of the trans-nasal posterior occluder 301a which includes all of the elements described above with respect to the trans-nasal posterior occluder device 301 shown in FIGS. 2I-2L as well as a distal extension 303a of the tube 303 that extends distal to the occluder 305 and an additional proximal connector 319. A separate lumen (not shown) extends from connector 319 through tube 303 and through distal tube extension 303a, which terminates in a distal end opening 321. Suction may thus be applied to connector 319 to suction matter through distal opening 321, through the distal tube extension 303a and through tube 303. This distal tube extension 303a and additional lumen may be optionally added to any other the other posterior occluder devices described herein in cases where doing so would not render the device unsuitable for its intended application. FIGS. 2O-2P show an alternative posterior occluder system 400 that comprises an intranasal catheter 402 that is inserted into a nasal cavity and an occluder catheter 404 that is inserted through the intranasal catheter 402, as shown. A posterior occluder 406 is located at or near the distal end of the occluder catheter 404. In the particular embodiment shown in FIGS. 2O-2P, the occluder 406 is sized and configured to occlude the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). In the particular example shown, this occluder 406 comprises a balloon. However, such occluder 406 may be constructed in various alternative ways, examples of which are shown in FIGS. 3A-3K and described herebelow. In this example a balloon inflation/deflation lumen may extend from Luer connector 408, through occluder catheter 404 and to the balloon-type proximal occluder 406. A syringe or other inflation/deflation apparatus may be attached to the Luer connector 408 and used to inflate and deflate the balloon-type posterior occluder 406. A stopcock or other valve (not shown) may also be provided on the balloon inflation/deflation lumen to maintain inflation of the balloon-type posterior occluder 406, when desired. Optionally, distal tubular extension 412 may extend distally of the posterior occluder 406 and a separate lumen may extend from an optional second connector 410, through distal tubular extension 412 and through an opening 414 such that matter may also be aspirated from the area distal to the posterior occluder 406. A port body 418 is formed on the proximal end of the intranasal tube 402. An insertion port 420 extends through port body 418 into the lumen 422 of the intra nasal tube. A side suction port 416 may also be connected to the lumen 422 of the intranasal tube 402. In routine operation, the intranasal tube 402 is inserted through the nostril into one nasal cavity and advanced to a position where its distal end is within or near the posterior choanae or nasopharynx. With the posterior occluder 406 in a collapsed (e.g., deflated) configuration, the occluder catheter 404 is advanced through the lumen 422 of the intranasal catheter 402 to a position where the posterior occluder is located in the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis). Thereafter, the posterior occluder 406 may be expanded (e.g., inflated) such that it occludes or blocks the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis), thereby substantially preventing blood, other fluid or debris from draining into the patient's esophagus or trachea during the procedure. Thereafter, suction may be applied to suction port 416 to suction blood, other fluid or debris from the area proximal to the posterior occluder 406. During such suctioning, the intranasal tube 402 may be moved back and/or forth as indicated by arrows on FIG. 2O, while the occluder catheter 404 remains stationary. Such ability to move the intranasal catheter 402 during the suctioning process may facilitate complete removal of blood, other fluid and/or debris from the operative field. FIGS. 2Q and 2R show a modified posterior occluder system 430 which includes the same elements and components as the posterior occluder system 400 described above, but wherein the distal end 434 of the intranasal tube 402a is tapered and wherein a plurality of side apertures 432 are formed in the intranasal tube 402a such that blood, other fluid or debris may be aspirated into the lumen 422a of the intranasal tube 402a through such side apertures 432. B. Variations in Occluder Design and Suction Apparatus: Although the above-described examples of occluder/access devices 10, 12, 300, 400 show occluders that are in nature of inflatable balloons, it will be appreciated that these occluders are not limited to balloons and may be of various other designs and types. Further, it is to be understood that various arrangements of access and/or suction tubing/port(s) may be used to facilitate complete removal of blood, fluid or other debris from the areas adjacent to the occluder(s) and/or elsewhere in the operative field or optimal positioning of working devices within the operative field. In fact, certain occluder and/or suction-access tubing/port designs may be more desirable for certain procedures than others depending on a number of factors including the positioning of the patient's head during surgery, whether the patient will be under a general anesthetic, whether an endotracheal tube will be inserted, etc. In some cases, where a posterior occluder is positioned within the posterior choanae, nasopharynx or pharynx posterior to the nasal septum the completeness with which blood, other fluid or debris may be suctioned out of the area adjacent to that posterior occluder may depend on the shape and/or design of the occluder itself as well as the shape and location of the suction lumen(s) and port(s) through which the blood, fluid or debris is to be suctioned. Beyond optimized fluid control, the posterior occluder and/or associated access tubing may also serve as an essential guiding element for devices, and alternative shapes and trajectories may be particularly useful to access specific structures. FIGS. 3A-3K show examples of varied occluder types and variations in the arrangements of suction lumen(s) and port(s) through which the blood, fluid or debris may be suctioned from areas adjacent to the occluder or elsewhere within the operative field. The examples shown in FIGS. 3A and 3K may be incorporated into the occluder & access devices shown in FIGS. 2A-2R, when appropriate. FIG. 3A shows an occluder 446 mounted on a tube 442, wherein a generally “U” shaped curve is formed in the distal end of the tube such that a distal portion of the tube 442 passes beneath the upper surface 449 of the occluder 446 and curves upwardly such that the distal end of the tube 442 terminates in an opening 444 that is flush with the upper surface 449 of occluder 446. In this manner, any fluid that has accumulated adjacent to the upper surface 449 of occluder 446 may be suctioned into opening 444 and through tube 442. In embodiments where the occluder comprises a balloon, a balloon inflation lumen may extend through the tube and open through an opening 447 into the interior of the balloon, to permit inflation/deflation of the balloon. Optionally, a working device 448, such as a flexible catheter or elongate apparatus examples of which are shown in FIGS. 5A-5T and described herebelow, may also be advanced through the suction lumen of tube 442 and out of opening 444 as indicated on FIG. 3A. FIG. 3B shows another alternative wherein an occluder 450 has a depression or well 454 formed in its upper surface. A tube 452 is attached to the occluder by attachment members 456 and the distal end of the tube 452 protrudes into well 454 such that any blood, fluid or debris that collects within the well 454 may be suctioned through the tube 452. In embodiments where the occluder 450 comprises a balloon, the tube 452 may incorporate a balloon inflation/deflation lumen which may extend through an inflation/deflation side tube 458 into the interior of the balloon to facilitate inflation and deflation of the balloon. FIGS. 3C and 3C′ show another alternative wherein an occluder 460 had a depression or well 462 formed in its upper surface and a tube 464 is attached to the occluder 460, as shown. A lumen of the tube 464 is in communication with the area adjacent the floor of the well to facilitate suctioning of blood, fluid or debris that collects within the well. In embodiments where the occluder 460 comprises a balloon, the tube 464 may incorporate a suction lumen 468 and a balloon inflation/deflation lumen 470. A small curved (e.g., generally “U” shaped) suction tube 466 may be connected in a sealed connection to the distal end of suction lumen 468 and the interior of the well 462 such that blood, other fluid or debris may be suctioned from the well 462, through suction tube 466 and through suction lumen 468. FIG. 3D shows a concave occluder 471 that comprises a self expanding concave structure 472 such as a basket formed of a superelastic or resilient mesh material (e.g., nickel titanium alloy wire mesh). The expanding concave structure 472 is covered by a fluid impermeable flexible covering 474 such as a skin formed of flexible polymer (e.g., expanded polytetrafluoroethylene, polyurethane, polyethylene teraphthalate, etc.). When fully expanded the concave occluder 471 occludes the body lumen in which it is positioned (e.g., the nasal cavity, posterior choanae, nasopharynx, pharynx, etc.) and forms a concave well 479. A tube 480 extends into the well 479 of the concave occluder 471 and may be used to suction blood, fluid or debris from the well 479. The occluder 471 may be advanced from and withdrawn into a delivery catheter 478. Struts 472 may connect the concave occluder 471 to a delivery member (not shown) within the delivery catheter 478, such delivery member being advanceable to push the occluder 471 out of the delivery catheter 478 and retractable to withdraw the occluder 471 into the delivery catheter 478. When inside the delivery catheter, the occluder 471 may be in a collapsed configuration but when expelled out of the delivery catheter the occluder will resiliently spring or self-expand to its expanded concave configuration, as shown in FIG. 3D. The suction catheter 480 may advance from and/or retract into the delivery catheter 478 concurrently with, or separately from, the occluder 471. FIGS. 3E′-3E′″ show yet another occluder/suction arrangement wherein the occluder 484 comprises an everting tubular member that is advanceable from a delivery/suction catheter 486. The everting tubular member comprises a frame 488 that is covered with a covering 500. Initially the everting tubular member is in a substantially cylindrical configuration within the lumen of the delivery/suction catheter 486. The frame may be a resilient or superelastic material that is biased to the everted shape shown in FIG. 3E′″. Such frame 488 may be formed of mesh material (e.g., nickel titanium alloy wire mesh). The covering 500 may be formed of flexible polymer (e.g., expanded polytetrafluoroethylene, polyurethane, polyethylene teraphthalate, etc.) In operation, the delivery/suction catheter 486 is advanced to the position where it is desired to place the occluder 484. Then, the everting tube is advanced from the distal end opening of the delivery/suction tube 486, as shown in FIGS. 3E′ and 3E″. As it advances out of the catheter 486, the everting tube member assumes its everted configuration, forming a concave occluder 484 as shown in FIG. 3E′″. The occluder 484, when fully everted, occludes the body lumen in which it is positioned (e.g., the nasal cavity, posterior choanae, nasopharynx, pharynx, etc.) and creates a concave well 504. The delivery/suction catheter 486 may be advanced into the concave well 504 such that any blood, fluid or debris that collects within concave well 504 may be suctioned through suction ports 502 and through the distal end of the delivery/suction catheter 486. FIG. 3F-3F′″ show another embodiment wherein an occluder 510 is positioned on the end of a tube 512. The occluder 510 has an arched upper surface such that a generally “V” shaped annular collection space 518 is created in the region of the coaptation between the occluder 510 and the adjacent wall of the body lumen in which it is positioned (e.g., a nasal cavity, posterior choanae, nasopharynx, pharynx, etc.). A suction tube 516 extends from tube 512 into the annular collection space 518 and blood, other fluid or debris that collects in the annular collection space 518 may be suctioned through suction tube 516 and through a lumen of tube 512, thereby providing for maintenance of a substantially dry environment adjacent to the upper surface of the occluder 510. The occluder 510 may comprise a balloon or any other suitable occlusion member as described herein or known in the art. As shown in FIGS. 3F′-3F′″ the suction tube 516 may comprise a simple tube having an open distal end or, alternatively, the device may incorporate a suction tube 516a that has a plurality of side apertures 520 formed near its distal end and/or a suction tube 516 that has a guard member 522, such as a screen, formed over its suction ports or openings to deter solid matter (e.g., blood clots or other debris) from clogging the suction ports or openings. FIG. 3G shows an occluder 530 attached to a tube 532 that has a curved (e.g., generally “U” shaped) distal end that does not protrude into the interior of the occluder. Suction apertures 536 are formed in the distal portion of the tube 532 to permit blood, fluid or debris that collects adjacent to the upper surface of the occluder 530 to be suctioned through the tube 532. In embodiments where the occluder is a balloon a balloon/inflation lumen may extend through tube 532 and a small balloon inflation tube 538 may extend into the interior of the balloon to permit the balloon to be inflated and deflated. Optionally, in some embodiments, a separate tube 540 may extend through tube 532 and trough occluder 530 to provide access to the area distal to the occluder 530 for purposes of suctioning, introduction of instruments, or other purposes. FIG. 3H shows another embodiment wherein the occluder 546 is connected to a tube or elongate member 550 and a suction tube 548 having an expanded (e.g., trumpet shaped) distal end is useable to suction blood, fluid or debris from the area adjacent to the upper surface of the occluder. As can be seen from FIG. 3H, where the upper surface of the occluder is arched and annular collection space may be created around the perimeter of the occluder 546 where the occluder 546 coapts with the wall of the anatomical structure in which it is positioned (e.g., a nasal cavity, posterior choanae, nasopharynx, pharynx, etc.) and the expanded end 552 of the suction tube 548 may be sized and shaped to receive the arched upper surface of the occluder 546 and to suction any blood, fluid or debris from that annular collection space. In embodiments where the occluder is a balloon a balloon/inflation lumen may extend through tube 548 and a small balloon inflation tube may extend into the interior of the balloon to permit the balloon to be inflated and deflated. Optionally, in some embodiments, a separate tube 550 may extend through tube 548 and through occluder 546 to provide access to the area distal to the occluder 546 for purposes of suctioning, introduction of instruments or fluid injectors, or other purposes. FIG. 3I shows an embodiment wherein the occluder 570 comprises a mass of absorbent material such as a tampon (e.g., cotton, gauze, hydrogel or other material or composite of materials that will absorb fluid and occlude the desired body lumen). In the particular example shown, the occluder is advanced out of an aperture 578 formed in a tube 572 that has a curved (e.g., generally “U” shaped) tip. Suction apertures 576 are formed in the distal portion of the tube 572 to permit blood, fluid or debris that collects adjacent to the upper surface of the occluder 570 to be suctioned through the tube 572. After the procedure is complete or the occlusion is no longer required, the tube 572 and fluid-soaked occluder 570 may be withdrawn from the body without retraction of the occluder 570 into the tube 572. Optionally, a distal end opening 574 may be formed in tube 572 and such distal end opening may be connected to the same lumen as openings 576 or a separate lumen to the optional distal end opening 574 to be used for suctioning, irrigation or introduction of a working device 580 such those shown in FIGS. 5A-5Y′″″ and described herebelow. FIG. 3J shows an occluder embodiment similar to that of the device shown in FIGS. 2O and 2P and described hereabove. In this embodiment, an occluder 600 is attached to a tube or elongate member 604 and a suction tube 602 is movable back and forth over the tube or elongate member 604 to suction blood, fluid or debris from the area adjacent to the upper surface of the occluder 600 or elsewhere in the body lumen in which the occluder 600 is positioned. In embodiments where the occluder 600 is a balloon, a balloon/inflation lumen may extend through tube or elongate member 604 and into the balloon to permit the balloon to be inflated and deflated. Optionally, in some embodiments, a separate tube 606 may extend trough tube or elongate member 604 and through occluder 600 to provide access to the area distal to the occluder 600 for purposes of suctioning, introduction of instruments, or other purposes. FIG. 3K shows an occluder embodiment similar to that incorporated into the device shown in FIGS. 2Q and 2R and described hereabove. In this embodiment, an occluder 610 is attached to a tube or elongate member 614 and a tapered suction tube 612 having one or more suction apertures 616 formed therein is movable back and forth over the tube or elongate member 614 to suction blood, fluid or debris from the area adjacent to the upper surface of the occluder 610 or elsewhere in the body lumen in which the occluder 600 is positioned. Of course, irrigation solution or other fluids may also be delivered through such apertures 616 or through a separate irrigation/infusion lumen that opens through separate irrigation/infusion aperture(s) (not shown). In embodiments where the occluder 610 is a balloon, a balloon/inflation lumen may extend through tube or elongate member 614 and into the balloon to permit the balloon to be inflated and deflated. Optionally, in some embodiments, a separate tube 618 may extend trough tube or elongate member 614 and through occluder 610 to provide access to the area distal to the occluder 610 for purposes of suctioning, introduction of instruments, or other purposes. FIGS. 3L′-3L″ show yet another occluder/tubing device 1000 comprising an outer tube 1002 and an inner tube 1004 disposed coaxially within the outer tube 1002. An outwardly bendable region 1006 is formed in the wall of the outer tube 1002 near its distal end. The distal end of the outer tube 1002 is affixed to the inner tube 1004. A passageway 1010 extends between the outer tube 1002 and inner tube 1004 and openings 1008 are formed in the wall of the outer tube 1002. In routine operation, this device 1000 is initially disposed in the configuration shown in FIG. 3L′ and is inserted into the desired passageway. Thereafter, the inner tube 1004 is pulled in the proximal direction while the outer tube 1002 is held stationary, thereby causing the outwardly bendable region 1006 to protrude outwardly as shown in FIG. 3L″ and resulting in occlusion of the body lumen in which the distal portion of the device 1000 is positioned. Suction may be applied to passageway 1010 to remove blood, fluid or other debris from the area adjacent to the upper surface of 1007 of the outwardly protruding bendable region 1006. In this regard, the openings 1008 may be formed close to and/or even in the upper surface 1007 of the outwardly protruding bendable region 1006. FIGS. 3M′ and 3M″ show another occluder/tubing device 1020 comprising an outer tube 1022 an inner tube 1024. The inner tube 1024 is advanceable out of the distal end of the outer tube 1022 and a distal portion of the inner tube 1024 expands as it emerges from the inner tube, thereby forming an occluder that occludes the body lumen or passageway in which it is positioned, as shown in FIG. 3M″. Blood, other fluid or debris may be suctioned from the area adjacent to the upper surface of the occluder through the open distal end of the outer tube 1022 and/or through optional side apertures 1026. FIG. 4 shows a nasopharyngeal occluder/endotracheal tube device 620 of the present invention inserted through the right nasal cavity and into the trachea. This device 620 comprises a curved tube 622 having a posterior occluder 626 positioned at or near the distal end of the tube 622 and, optionally an anterior occluder (shown in dotted lines on FIG. 4) formed near the proximal end of the tube 622. An endotracheal tube 624 extends through curved tube 622, through the posterior occluder and into the patient's trachea. Optionally, a cuff 628 may be formed on endotracheal tube 624 to provide a second substantially fluid tight seal within the patient's trachea, inferior to the glottis. A hub 630 is formed on the proximal end of tube 622. A ventilator tube 634 extends from the hub and is connected to endotracheal tube 624 and is attachable to a ventilator, anesthesia machine, t-tube, Ambu-bag, etc. In embodiments where the posterior occluder 626 is a balloon, a posterior occluder inflation/deflation connector 632 extends from hub 630 and is connected to an inflation/deflation lumen that extends through tube 622 for inflation/deflation of the posterior occluder 626. A cuff inflation/deflation connector 634 may also extend from hub 630 and through the endotracheal tube 624 for inflation/deflation of the endotracheal tube cuff 628. Optionally, suction and/or device insertion ports may also be formed in hub 630, as described above in connection with other occluder/access devices. In routine operation, this device 620 is inserted to a position where the posterior occluder 626 occludes the posterior choanae, nasopharynx or pharynx posterior to the nasal septum (but typically superior to the glottis) and the endotracheal tube 624 extends into the patient's trachea with the optional cuff positioned in the trachea inferior to the glottis. C. Working Devices for Delivering Substances or for Cutting, Ablating, Remodeling or Expanding Bone or Soft Tissue The present invention provides a variety of apparatus that may be inserted into the nasal cavity, paranasal sinus, nasopharynx or middle ear to perform diagnostic or therapeutic procedures. These devices may be delivered through or incorporated into flexible catheters or flexible rod-like shafts. Such flexible construction allows these devices to be delivered and positioned to perform the desired diagnostic or therapeutic procedures with minimal trauma to other tissues, as can result from the insertion of rigid scopes and rigid instruments in accordance with the methodology of the prior art. It is within the scope of this approach that these devices may be partially flexible or have rigid portions and flexible portions to facilitate their control and guidance to the appropriate region. Further, they may be used in conjunction or combination with other standard rigid apparatus (scopes, etc.) during some part of the procedure, if desired. Also, in some but not necessarily all procedures, these working devices (and/or the catheters used to deliver them) may be inserted through lumens of the occluder & access devices 10, 12, 300, 301, 400, 430, etc. as shown in FIGS. 2A-2R and described above. As stated earlier, it may also be desirable to focus the access and occlusion to an even smaller territory, through stand-alone guide catheters or subselective guide catheters with or without balloons or other occluders. Optionally, any of the working devices anmd guide catheters described herein may be configured to receive or be advanced over a guidewire unless to do so would render the device inoperable for its intended purpose. Some of the specific examples described herein include guidewires, but it is to be appreciated that the use of guidewires and the incorporation of guidewire lumens is not limited to only the specific examples in which guidewires or guidewire lumens are shown. The guidewires used in this invention may be constructed and coated as is common in the art of cardiology. This may include the use of coils, tapered or non-tapered core wires, radiopaque tips and/or entire lengths, shaping ribbons, variations of stiffness, PTFE, silicone, hydrophilic coatings, polymer coatings, etc. For the scope of this inventions, these wires may possess dimensions of length between 5 and 75 cm and outer diameter between 0.005″ and 0.050″. Also, some of the working devices shown in FIGS. 5A-5Y′″″ and described herein incorporate assemblies, components or mechanisms (e.g., rotating cutters, radiofrequency electrodes, electrocautery devics, recepacles for capturing matter, cryosurgical apparatus, balloons, stents, radioactive or substance-eluting coatings, snares, electro-anatomical mapping and guidance, optical fibers, lenses and other endoscope apparatus, seals, hemostatic valves, etc. The designs and constructions of such components and assemblies are will known in the art. Non-limiting examples of some such designs and constructions are set forth in U.S. Pat. No. 5,722,984 (Fischell et al.), U.S. Pat. No. 5,775,327 (Randolph et al.), U.S. Pat. No. 5,685,838 (Peters, et al.), U.S. Pat. No. 6,013,019 (Fischell et al.), U.S. Pat. No. 5,356,418 (Shturman), U.S. Pat. No. 5,634,908 (Loomas), U.S. Pat. No. 5,255,679 (Imran), U.S. Pat. No. 6,048,299 (Hoffman), U.S. Pat. No. 6,585,794 (Wright et al.), U.S. Pat. No. 6,503,185 (Waksman), U.S. Pat. No. 6,669,689 (Lehmann et al.), U.S. Pat. No. 6,638,233 (Corvi et al.), U.S. Pat. No. 5,026,384 (Farr et al.), U.S. Pat. No. 4,669,469 (Gifford et al.), U.S. Pat. No. 6,685,648 (Flaherty et al.), U.S. Pat. No. 5,250,059 (Andreas et al.), U.S. Pat. No. 4,708,834 (Tsuno), U.S. Pat. No. 5,171,233 (Amplatz), U.S. Pat. No. 6,468,297 (Williams et al.) and U.S. Pat. No. 4,748,869 (Wardle). As shown in the examples of FIGS. 5A-5Y′″″ these working devices include guide catheters, substance delivery catheters, scopes, injectors, cutters, bone breaking apparatus, balloons and other dilators, laser/thermal delivery devices, braces, implants, stents, snares, biopsy tools, forceps, etc. FIG. 5A shows a side suction and/or cutting catheter 70 comprising a flexible catheter body 72 having a side opening 74. The catheter 72 is advanced into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. and positioned so that the opening 74 is adjacent to matter (e.g., a polyp, lesion, piece of debris, tissue, blood clot, etc.) that is to be removed. Suction may be applied through a lumen of the catheter 72 to suction the matter through the opening 74 and into the catheter 72. In some cases, a cutter such as a rotating cutter, linear slicer, pincher, laser beam, electrosurgical cutter, etc. may be incorporated into the catheter 72 to assist in severing or ablating tissue or other matter that has been positioned in the side opening 74. This catheter may incorporate a deflectable tip or a curved distal end which may force the opening of the catheter against the tissue of interest. Further, this device 70 may have an optional stabilizing balloon (similar to that shown in FIG. 5M and described herebelow) incorporated on one side of the catheter 72 to press it against the tissue of interest and may also contain one or more on-board imaging modalities such as ultrasound, fiber or digital optics, OCT, RF or electro-magnetic sensors or emitters, etc. FIG. 5B shows an injector catheter 76 that comprises a flexible catheter shaft 78 having one or more injector(s) 80 that are advanceable into tissue or other matter that is located in or on the wall of the body lumen in which the catheter 78 is positioned. The catheter 78 is advanced, with the injector(s) retracted into the catheter body, through a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. and positioned adjacent the area to which a diagnostic or therapeutic substance is to be injected. Thereafter, the injector(s) are advanced into the adjacent tissue or matter and the desired substance is injected. Energy, such as laser, RF, thermal or other energy may be delivered through these injectors 80 or energy emitting implants (such as gamma or beta radioactive seeds) may also be delivered through these injectors 80, either alone or in combination with a fluid carrier or other substance such as a diagnostic or therapeutic substance (as defined herein). It will be noted that this device 76 as well as other working devices and methods of the present invention (including the various implantable devices described herein) are useable to deliver diagnostic or therapeutic substances. The term “diagnostic or therapeutic substance” as used herein is to be broadly construed to include any feasible drugs, prodrugs, proteins, gene therapy preparations, cells, diagnostic agents, contrast or imaging agents, biologicals, etc. For example, in some applications where it is desired to treat or prevent a microbial infection, the substance delivered may comprise pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, antiparacytic, antifungal, etc.). Some nonlimiting examples of antimicrobial agents that may be used in this invention include acyclovir, amantadine, aminoglycosides (e.g., amikacin, gentamicin and tobramycin), amoxicillin, amoxicillin/Clavulanate, amphotericin B, ampicillin, ampicillin/sulbactam, atovaquone, azithromycin, cefazolin, cefepime, cefotaxime, cefotetan, cefpodoxime, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, chloramphenicol, clotrimazole, ciprofloxacin, clarithromycin, clindamycin, dapsone, dicloxacillin, doxycycline, erythromycin, fluconazole, foscarnet, ganciclovir, atifloxacin, imipenem/cilastatin, isoniazid, itraconazole, ketoconazole, metronidazole, nafcillin, nafcillin, nystatin, penicillin, penicillin G, pentamidine, piperacillin/tazobactam, rifampin, quinupristin-dalfopristin, ticarcillin/clavulanate, trimethoprim/sulfamethoxazole, valacyclovir, vancomycin, mafenide, silver sulfadiazine, mupirocin, nystatin, triamcinolone/nystatin, clotrimazole/betamethasone, clotrimazole, ketoconazole, butoconazole, miconazole, tioconazole, detergent-like chemicals that disrupt or disable microbes (e.g., nonoxynol-9, octoxynol-9, benzalkonium chloride, menfegol, and N-docasanol); chemicals that block microbial attachment to target cells and/or inhibits entry of infectious pathogens (e.g., sulphated and sulponated polymers such as PC-515 (carrageenan), Pro-2000, and Dextrin 2 Sulphate); antiretroviral agents (e.g., PMPA gel) that prevent retroviruses from replicating in the cells; genetically engineered or naturally occurring antibodies that combat pathogens such as anti-viral antibodies genetically engineered from plants known as “plantibodies;” agents which change the condition of the tissue to make it hostile to the pathogen (such as substances which alter mucosal pH (e.g., Buffer Gel and Acidform) or non-pathogenic or “friendly” bacteria or other microbes that cause the production of hydrogen peroxide or other substances that kill or inhibit the growth of pathogenic microbes (e.g., lactobacillus). As may be applied to any of the substances listed previously or below, these substances may be combined with any one or more drug-releasing devices or molecular constructs such as polymers, collagen, gels, implantable osmotic pump devices, etc. to permit their release over an extended period of time once deposited. Further, these substances may also be combined with any of the implantable structural devices described below (stents, expanders, etc.) to reduce infection, encrustation, or encapsulation of the implant itself, or to allow the drug to be deposited in the optimal location mucosally, sub-mucosally or into the bone. Examples of implantable substance delivery devices useable in this invention include those shown in FIGS. 5Y′-5Y′″″ and described herebelow. Additionally or alternatively, in some applications where it is desired to treat or prevent inflamation the substances delivered in this invention may include various steroids. For example, corticosteroids that have previously administered by intranasal administration may be used, such as beclomethasone (Vancenase® or Beconase®), flunisolide (Nasalide®), fluticasone (Flonase®), triamcinolone (Nasacort®) and mometasone (Nasonex®). Also, other steroids that may be useable in the present invention include but are not limited to aclometasone, desonide, hydrocortisone, betamethasone, clocortolone, desoximetasone, fluocinolone, flurandrenolide, mometasone, prednicarbate; amcinonide, desoximetasone, diflorasone, fluocinolone, fluocinonide, halcinonide, clobetasol, augmented betamethasone, diflorasone, halobetasol, prednasone, dexamethasone and methylprednisolone, Additionally or alternatively, in some applications, such as those where it is desired to treat or prevent an allergic or immune response, the substances delivered in this invention may include a) various cytokine inhibitors such as humanized anti-cytokine antibodies, anti-cytokine receptor antibodies, recombinant (new cell resulting from genetic recombination) antagonists, or soluble receptors; b) various leucotriene modifiers such as zafirlukast, montelukast and zileuton; c) immunoglobulin E (IgE) inhibitors such as Omalizumab (an anti-IgE monoclonal antibody formerly called rhu Mab-E25) and secretory leukocyte protease inhibitor). Additionally or alternatively, in some applications, such as those where it is desired to shrink mucosal tissue, cause decongestion or effect hemostasis, the substances delivered in this invention may include various vasoconstrictors for decongestant and or hemostatic purposes including but not limited to pseudoephedrine, xylometazoline, oxymetazoline, phenylephrine, epinephrine, etc. Additionally or alternatively, in some applications, such as those where it is desired to facilitate the flow of mucous, the substances delivered in this invention may include various mucolytics or other agents that modify the viscosity or consistency of mucous or mucoid secretions, including but not limited to acetylcysteine (Mucomyst™, Mucosil™) and guaifenesin. Additionally or alternatively, in some applications such as those where it is desired to prevent or deter histamine release, the substances delivered in this invention may include various mast cell stabilizers or drugs which prevent the release of histamine such as cromolyn (e.g., Nasal Chrom®) and nedocromil. Additionally or alternatively, in some applications such as those where it is desired to prevent or inhibit the effect of histamine, the substances delivered in this invention may include various antihistamines such as azelastine (e.g., Astylin®), diphenhydramine, loratidine, etc. Additionally or alternatively, in some embodiments such as those where it is desired to dissolve, degrade, cut, break or remodel bone or cartilage, the substances delivered in this invention may include substances that weaken or modify bone and/or cartilage to facilitate other procedures of this invention wherein bone or cartilage is remodeled, reshaped, broken or removed. One example of such an agent would be a calcium chelator such as EDTA that could be injected or delivered in a substance delivery implant next to a region of bone that is to be remodeled or modified. Another example would be a preparation consisting or or containing bone degrading cells such as osteoclasts. Other examples would include various enzymes of material that may soften or break down components of bone or cartilage such as collagenase (CGN), trypsin, trypsin/EDTA, hyaluronidase, and tosyllysylchloromethane (TLCM). Additionally or alternatively, in some applications, the substances delivered in this invention may include other classes of substances that are used to treat rhinitis, nasal polyps, nasal inflammation, and other disorders of the ear, nose and throat including but not limited to anticolinergic agents that tend to dry up nasal secretions such as ipratropium (Atrovent Nasal®), as well as other agents not listed here. Additionally or alternatively, in some applications such as those where it is desired to draw fluid from polyps or edematous tissue, the substances delivered in this invention may include locally or topically acting diuretics such as furosemide and/or hyperosmolar agents such as sodium chloride gel or other salt preparations that draw water from tissue or substances that directly or indirectly change the osmolar content of the mucous to cause more water to exit the tissue to shrink the polyps directly at their site. Additionally or alternatively, in some applications such as those wherein it is desired to treat a tumor or cancerous lesion, the substances delivered in this invention may include antitumor agents (e.g., cancer chemotherapeutic agents, biological response modifiers, vascularization inhibitors, hormone receptor blockers, cryotherapeutic agents or other agents that destroy or inhibit neoplasia or tumorigenesis) such as; alkylating agents or other agents which directly kill cancer cells by attacking their DNA (e.g., cyclophosphamide, isophosphamide), nitrosoureas or other agents which kill cancer cells by inhibiting changes necessary for cellular DNA repair (e.g., carmustine (BCNU) and lomustine (CCNU)), antimetabolites and other agents that block cancer cell growth by interfering with certain cell functions, usually DNA synthesis (e.g., 6 mercaptopurine and 5-fluorouracil (5FU), antitumor antibiotics and other compounds that act by binding or intercalating DNA and preventing RNA synthesis (e.g., doxorubicin, daunorubicin, epirubicin, idarubicin, mitomycin-C and bleomycin) plant (vinca) alkaloids and other anti-tumor agents derived from plants (e.g., vincristine and vinblastine), steroid hormones, hormone inhibitors, hormone receptor antagonists and other agents which affect the growth of hormone-responsive cancers (e.g., tamoxifen, herceptin, aromatase ingibitors such as aminoglutethamide and formestane, trriazole inhibitors such as letrozole and anastrazole, steroidal inhibitors such as exemestane), antiangiogenic proteins, small molecules, gene therapies and/or other agents that inhibit angiogenesis or vascularization of tumors (e.g., meth-1, meth-2, thalidomide), bevacizumab (Avastin), squalamine, endostatin, angiostatin, Angiozyme, AE-941 (Neovastat), CC-5013 (Revimid), medi-522 (Vitaxin), 2-methoxyestradiol (2ME2, Panzem), carboxyamidotriazole (CAI), combretastatin A4 prodrug (CA4P), SU6668, SU11248, BMS-275291, COL-3, EMD 121974, IMC-1C11, IM862, TNP-470, celecoxib (Celebrex), rofecoxib (Vioxx), interferon alpha, interleukin-12 (IL-12) or any of the compounds identified in Science Vol. 289, Pages 1197-1201 (Aug. 17, 2000) which is expressly incorporated herein by reference, biological response modifiers (e.g., interferon, bacillus calmette-guerin (BCG), monoclonal antibodies, interluken 2, granulocyte colony stimulating factor (GCSF), etc.), PGDF receptor antagonists, herceptin, asparaginase, busulphan, carboplatin, cisplatin, carmustine, cchlorambucil, cytarabine, dacarbazine, etoposide, flucarbazine, flurouracil, gemcitabine, hydroxyurea, ifosphamide, irinotecan, lomustine, melphalan, mercaptopurine, methotrexate, thioguanine, thiotepa, tomudex, topotecan, treosulfan, vinblastine, vincristine, mitoazitrone, oxaliplatin, procarbazine, streptocin, taxol, taxotere, analogs/congeners and derivatives of such compounds as well as other antitumor agents not listed here. Additionally or alternatively, in some applications such as those where it is desired to grow new cells or to modify existing cells, the substances delivered in this invention may include cells (mucosal cells, fibroblasts, stem cells or genetically engineered cells) as well as genes and gene delivery vehicles like plasmids, adenoviral vectors or naked DNA, mRNA, etc. injected with genes that code for anti-inflammatory substances, etc., and, as mentioned above, osteoclasts that modify or soften bone when so desired. Additionally or alternatively to being combined with a device and/or a substance releasing modality, it may be ideal to position the device in a specific location upstream in the mucous flow path (i.e. frontal sinus or ethmoid cells). This could allow the deposition of fewer drug releasing devices, and permit the “bathing” of all the downstream tissues with the desired drug. This utilization of mucous as a carrier for the drug may be ideal, especially since the concentrations for the drug may be highest in regions where the mucous is retained; whereas non-diseased regions with good mucouse flow will be less affected by the drug. This could be particularly useful in chronic sinusitis, or tumors where bringing the concentration of drug higher at those specific sites may have greater therapeutic benefit. In all such cases, local delivery will permit these drugs to have much less systemic impact. Further, it may be ideal to configure the composition of the drug or delivery system such that it maintains a loose affinity to the mucous permitting it to distribute evenly in the flow. Also, in some applications, rather than a drug, a solute such as a salt or other mucous soluble material may be positioned at a location whereby mucous will contact the substance and a quantity of the substance will become dissolved in the mucous thereby changing some property (e.g., pH, osmolarity, etc) of the mucous. In some cases, this technique may be used to render the mucous hyperosmolar so that the flowing mucous will draw water from polyps, edematous mucosal tissue, etc. thereby providing a desiccating therapeutic effect. Additionally or alternatively to substances directed towards local delivery to affect changes within the sinus cavity, the nasal cavities provide unique access to the olfactory system and thus the brain. Any of the devices and methods described herein may also be used to deliver substances to the brain or alter the functioning of the olfactory system. Such examples include, the delivery of energy or the deposition of devices and/or substances and/or substance delivering implant(s) to occlude or alter olfactory perception, to suppress appetite or otherwise treat obesity, epilepsy (e.g., barbiturates such as phenobarbital or mephoobarbital; iminostilbenes such as carbamazepine and oxcarbazepine; succinimides such as ethylsuximide; valproic acid; benzodiazepines such as clonazepam, clorazepate, diazepam and lorazepam, gabapentin, lamotrigine, acetazolamide, felbamate, levetiraceam, tiagabine, topiramate, zonisamide, etc.), personality or mental disorders (e.g., antidepressants, antianxiety agents, antipsychotics, etc.), chronic pain, Parkinson's disease (e.g., dopamine receptor agonists such as bromocriptine, pergolide, ropinitrol and pramipexole; dopamine precursors such as levodopa; COMT inhibitors such as tolcapone and entacapone; selegiline; muscarinic receptor antagonists such as trihexyphenidyl, benztropine and diphenhydramine) and Alzheimer's, Huntington's Disease or other dementias, disorders of cognition or chronic degenerative diseases (e.g. tacrine, donepezil, rivastigmine, galantamine, fluoxetine, carbamazepine, clozapine, clonazepam and proteins or genetic therapies that inhibit the formation of beta-amyloid plaques), etc. FIG. 5C shows a device 82 that comprises a rotating shaft 84 having a drill, auger or burr 86 that is useable to drill, bore, grind or cut through tissue, bone, cartilage or other matter. This device 82 may deployed as shown or, alternatively, the device 82 may be inserted through a small mucosal incision to preserve the overlying mucosal lining while removing or boring into the bone or cartilage below the mucosal lining. FIG. 5D shows a guided injector catheter device 88 for delivering a diagnostic or therapeutic substance as defined above. This device 88 comprises a flexible catheter 90 having an imaging apparatus 96 thereon and an injector 92 that is advanceable from and retractable into the catheter 90. The imaging apparatus 96 is useable to image the target location 94 at which the substance is to be deposited and to enable orientation of the catheter 88 such that, when the injector 92 is advanced from the catheter 88, the injector 92 will travel to the desired target location 94. Examples of such catheter 88 are described in U.S. Pat. No. 6,195,225 (Makower), U.S. Pat. No. 6,544,230 (Flaherty et al.), U.S. Pat. No. 6,375,615 (Flaherty et al.), U.S. Pat. No. 6,302,875 (Makower et al), U.S. Pat. No. 6,190,353 (Makower et al.) and U.S. Pat. No. 6,685,648 (Flaherty et al.), the entireties of which are expressly incorporated herein by reference. FIG. 5E shows a balloon catheter device 98 comprising a flexible catheter 100 having a balloon 102 thereon. The catheter device 98 is advanced, with balloon 102 deflated, into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. and positioned with the deflated balloon 102 situated within an ostium, passageway or adjacent to tissue or matter that is to be dilated, expanded or compressed (e.g., to apply pressure for hemostasis, etc.). Thereafter, the balloon 102 may be inflated to dilate, expand or compress the ostium, passageway, tissue or matter. Thereafter the balloon 102 may be deflated and the device 98 may be removed. This balloon 102 may also be coated, impregnated or otherwise provided with a medicament or substance that will elute from the balloon into the adjacent tissue (e.g., bathing the adjacent tissue with drug or radiating the tissue with thermal or other energy to shrink the tissues in contact with the balloon 102). Alternatively, in some embodiments, the balloon may have a plurality of apertures or openings through which a substance may be delivered, sometimes under pressure, to cause the substance to bathe or diffuse into the tissues adjacent to the balloon. Alternatively, in some embodiments, radioactive seeds, threads, ribbons, gas or liquid, etc. may be advanced into the catheter shaft 100 or balloon 102 or a completely separate catheter body for some period of time to expose the adjacent tissue and to achieve a desired diagnostic or therapeutic effect (e.g. tissue shrinkage, etc.). FIG. 5F shows a balloon/cutter catheter device 104 comprising a flexible catheter 106 having a balloon 108 with one or more cutter blades 110 formed thereon. The device 104 is advanced, with balloon 108 deflated, into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. and positioned with the deflated balloon 108 situated within an ostium, passageway or adjacent to tissue or matter that is to be dilated, expanded or compressed and in which it is desired to make one or more cuts or scores (e.g. to control the fracturing of tissue during expansion and minimize tissue trauma etc.). Thereafter, the balloon 108 may be inflated balloon to dilate, expand or compress the ostium, passageway, tissue or matter and causing the cutter blade(s) 110 to make cut(s) in the adjacent tissue or matter. Thereafter the balloon 108 may be deflated and the device 104 may be removed. The blade may be energized with mono or bi-polar RF energy or simply be thermally heated to part the tissues in a hemostatic fashion, as well as cause contraction of collagen fibers or other connective tissue proteins, remodeling or softening of cartilage, etc. FIGS. 5G′-5G′″ show a device 160 and method for delivery of a pressure expandable stent 166. This device 160 comprises a flexible catheter 162 having a balloon 164 thereon. Initially, as shown in FIG. 5G′, the balloon 164 is deflated and the stent 166 is radially compressed to a collapsed configuration, around the deflated balloon 164. The catheter 162 with the balloon 164 deflated and the collapsed stent 166 mounted thereon is advanced into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. that is to be stented. Thereafter, the balloon 164 is inflated causing the stent 166 to expand to a size that frictionally engages the surrounding tissue so as to hold the stent 166 in place, as shown in FIG. 5G″. In some instances the procedure will be performed for the purpose of enlarging a passageway (e.g., an ostium, meatus, etc.) and the stent 166 will be expanded to a diameter that is sufficiently large to cause the desired enlargement of the passageway and the stent will then perform a scaffolding function, maintaining the passageway in such enlarged condition. After the stent 166 has been fully expanded and implanted, the balloon 164 may be deflated and the catheter 162 removed as shown in FIG. 5G′″. In some applications, the stent may contain a diagnostic or therapeutic substance as defined herein and such substance may elute from the stent 166 into the surrounding tissue to bring about a desired diagnostic or therapeutic effect. In some cases, the stent 166 may be permanently implanted. In other cases the stent 166 may be temporarily implanted. In cases where the stent 166 is temporarily implanted, it may be removed in a second procedure conducted to retrieve the stent 166 or the stent 166 may be made of bioabsorbable or biodegradable material such that it degrades or is absorbed within a desired period of time after implantation. In some cases, such as when the stent is to be placed within the ostium of a paranasal sinus, the stent and/or the balloon may be specifically shaped to facilitate and/or cause the stent 166 to seat in a desired position and to prevent unwanted slippage of the stent 166. For example, the stent 166 and/or balloon 164 may have an annular groove formed about the middle thereof or may be hourglass or venture shaped, to facilitate seating of the stent 166 within an ostium or orifice without longitudinal slippage of the stent 166. In some cases it may be desirable to leave a tether or suture attached to the stent 166 to allow for simple removal of the stent 166 in the physician's office or other suitable location. In some cases the procedure may be intended to actually break bone (e.g., where the stent is intended to dilate or enlarge a sinus ostium). Thus, the balloon 164 may be made of polymeric material including, but not limited to flexible polyvinyl chloride (PVC), polyethylene terephthalate (PET), cross-linked polyethylene, polyester, polyamide, polyolefin, polyurethane and silicone. Various balloon properties (strength, flexibility, thickness, etc.) may be modified by, but not limited to, blending, layering, mixing, co-extruding, irradiating, and other means of engineering balloon material(s). This allows for the use of compliant balloons that can conform to the surrounding structure or non-compliant balloons that can deform or break the surrounding structures (e.g., bone). FIG. 5H shows an electrosurgical device 208 comprising a flexible shaft 210 (e.g., a catheter or solid shaft) having arched strut members 214 attached thereto. Electrodes 216 are located on the strut members 214. In some cases, the strut members may be of fixed configuration and in other cases the strut members 214 may be collapsible and expandable. In operation, the device 208 is advanced into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. Thereafter, current is applied to the electrodes 216 causing tissue adjacent to the struts 214 to be cauterized or heated. The electrodes 216 may be bipolar, monopolar or facilitated by any other suitable form of energy such as a gas or plasma arc. Additionally, sensing elements may also be attached to the catheter and/or strut members to monitor various parameters of the catheter and/or surrounding tissue (e.g., temperature, etc.). In instances where monopolar electrodes are used, a separate antenna electrode (not shown) will be applied to the patient's body in accordance with processes and techniques that are well known in the art. FIG. 5I shows a device 218 that delivers a flow 222 of material (e.g., cryogenic material, diagnostic or therapeutic agent, etc.) or energy (laser light, infrared light, etc.) to the tissues adjacent to the passage or body cavity in which the device 218 is positioned. This device comprises a flexible catheter 220 with an outlet aperture or lens at or near its distal end, through which the flow of material or energy is delivered. This device may be used to cryogenically freeze polyps or other tissues or to deliver laser energy to turbinates or other tissues for the purpose of ablating the tissue or to heat the tissue to a temperature that results in shrinking of the tissue. FIG. 5J shows an implantable pressure exerting device 224 that is implantable within a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. to exert pressure on bone, cartilage, soft tissue, etc. Examples of situations where it is desirable to apply such pressure to an anatomical structure include those wherein it is desired to splint or maintain approximation of a broken bone or those wherein it is desired to cause remodeling or gradual repositioning or reshaping of bone, cartilage, soft tissue or other structures. This implanatble device 224 comprises a pressure exerting member 228 and two or more plate members 226. The device 224 is initially constrained in a collapsed configuration wherein the pressure exerting member 228 is compressed or collapsed and the device 224 is advanced into a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. where it is desired to apply pressure to an anatomical structure. When the device 224 is in the desired position, the pressure exerting member 228 is expanded or elongated to exert outward pressure on the plate members 226 and onto the anatomical structures against which the plate members 226 are positioned. In some embodiments, the pressure exerting member may comprise a spring. In other embodiments, the pressure exerting member may comprise a ratchet, hydraulic cylinder or other mechanical apparatus that may be adjusted to create a desired amount of pressure on the plate members 226. In some applications, the pressure exerting member 228 may be adjustable in situ (i.e., with the device implanted in the body) so as to allow the operator to periodically change the amount of pressure being applied to the anatomical structures of interest (e.g., the operator may change to position of a ratchet or add fluid to a hydraulic cylinder) thereby bringing about gradual remodeling or movement of an anatomical structure in a manner similar to that achieved during dental orthodontia. Thus, this pressure exerting device 224 has broad applicability in a variety of procedures including those intended to enlarge a sinus ostium or to straighten an intranasal septum. FIGS. 5K-5K′ and 5L show a forward rotary cutting catheter device 700 that comprises a flexible outer tube 702 and a flexible inner tube 704 disposed coaxially and rotatably mounted within the outer tube 702. One or more bearings 708 (e.g., a helical bearing or a series of individual cylindrical bearings) may be disposed between the outer tube 702 and inner tube 704, as shown. Alternatively, one or both apposing tube surfaces may be made of, lined with, or be coated by etc. a lubricious material such as silicone or PTFE to facilitate movement. A rotating cutter 706 is positioned on the distal end of the inner tube 704. In operation, as shown in FIG. 5K′, the device 700 is advanced through a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. to a position where the distal end of the device 700 is positioned just behind some obstructive matter, such as a polyp P. The inner tube 704 and its cutter 706 are rotated as the device is advanced into the obstructive matter P and/or suction is applied through the lumen of the inner tube 704 and/or through the lumen of the outer tube 702 to draw the obstructive matter P into contact with the rotating cutter 706. It is to be appreciated that, although this embodiment shows a rotating cutter 706, various other types of cutters such as lasers, radiofrequency cutters and other mechanical cutters, etc. may be used instead. As the obstructive matter P is severed by the rotating cutter 706 the obstructive matter P or pieces thereof may be suctioned through the lumen of the inner tube 704 and/or through the lumen of the outer tube 702. In some applications, as shown in FIG. 5L, a scope or guidewire 710 may extend through the lumen of the inner tube to facilitate advancement and positioning of the device 700 prior to the removal of the obstructive matter P. FIGS. 5M and 5N show a side rotary cutting device 714 comprising a flexible outer tube 718 and a flexible inner tube 722 that is disposed coaxially and rotatably mounted within the outer tube 718. One or more bearings 730 (e.g., a helical bearing or a series of individual cylindrical bearings) may be disposed between the outer tube 718 and inner tube 722, as shown. Alternatively, one or both apposing tube surfaces may be made of, lined with, or be coated by etc. a lubricious material such as silicone or PTFE to facilitate movement. A rotating cutter 724 is positioned on the distal end of the inner tube 722. A side opening 720 is formed in the outer tube 718 and the cutter 724 is positioned proximal to the side opening 720. A pull member 728 extends through the inner tube 722 and is attached to a retractor head 726. In operation, the device 714 is advanced and/or torqued to a position where the side opening 720 is near a polyp, tissue or other obstructive matter to be removed. The inner tube 722 and its cutter 724 are rotated. In some applications, suction may be applied through the inner tube 722 and/or through the lumen of the outer tube 718 to draw the obstructive matter into the side opening 720. The pull member 728 is pulled in the proximal direction, causing the retractor head 726 to retract or pull the obstructive matter into contact with the rotating cutter 724. As the obstructive matter is severed by the rotating cutter, the severed obstructive matter or pieces thereof may be suctioned through the lumen of the inner tube 722 and/or through the lumen of the outer tube 718. The pull member 728 may then be advanced in the distal direction to return the retractor head 726 to its original position as shown in FIGS. 5M and 5N. An optional balloon 719 or other laterally extendable member may be located on the side of the catheter 718 opposite the side opening 720 to push the side opening 720 against a lumen wall or into the direction of a polyp or other tissue to be removed. Alternatively, the catheter may incorporate a deflectable tip or a curved distal end that may force the side opening of the catheter against a lumen wall or into the direction of a polyp or other tissue to be removed. With specific reference to FIG. 5N, there is shown a side rotary cutting device 714a that includes all of the elements of the device 714 shown in FIG. 5M, but includes a side lumen 731. A scope may be permanently positioned within this side lumen 731 or a scope may be temporarily inserted into (or through) the side lumen 731 to enable the operator to view the area near the side opening 720 and to facilitate the advancement and positioning of the device 714A. Also, the side lumen 731 may function as a guidewire lumen to allow the device 714A to be advanced over a guidewire. It is to be understood that any of the devices described within this document may be further modified to include any one of the following devices within its structure: electromagnetic positioning sensor/detector (Biosense/JNJ, Surgical Navigation Technologies/Medtronic, Calypso Medical), RF sensor/transmitter, magnetic direction localizer (Stereotaxis, Inc.), thermal sensor, radiopaque composition, radioactive detection emitter/sensor, ultrasonic scanner/transmitter/receiver, Doppler scanner, electrical stimulator, fiber optic, digital optic, local diagnostic chip containing elements responsive to the presence or absence of certain substances and therefore having the ability to diagnose the presence of fungus, microbes, viruses, blood, abnormal mucous content, cancer cells, drugs of abuse, genetic abnormalities, metabolic bi-products, etc. It is to be further understood that any and all of the devices described in this patent application may incorporate, or may be used in conjunction with, endoscopes. Such endoscopes will typically include light transmitting optical fibers for casting light in the area to be viewed by the scope and image transmitting optical fibers for carrying an image received by the scope to an eyepiece or monitor device located outside the patient's body. In some embodiments a scope, such as a disposable and/or flexible scope, may be affixed to the working device. Examples of such endoscopes that are suitable for incorporation into the working devices of this invention include that described in U.S. Pat. Nos. 4,708,434; 4,919,112; 5,127,393; 5,519,532; 5,171,233, 5,549,542, 6,551,239 and 6,572,538 as well as published U.S. Patent Application No. 2001/0029317A1, the entireties of which are expressly incorporated herein by reference. It is to be further understood that any catheters or elongate flexible devices of this invention may include design elements that impact performance features which include, but are not limited to, durability, flexibility, stiffness, length, profile, lubricity, trackability, steerability, torqueability, deflectability, guidance, and radiopacity. Design elements can include, but are not limited to, use of various polymers and metals, use of varying durometer materials to establish a desired flexibility gradient along the device, blending/mixing/layering/co-extruding etc. various materials, using bearings or lubricious coatings or lubricious materials (e.g., silicone, PTFE, parylene, polyethene, etc.) where two or more surfaces will move relative to each other (e.g., guidewire or instrument lumen, deflecting tendon in lumen, etc.), use of braiding or springs to increase torque control over the device, using materials (e.g. barium, tantalum, etc.) to increase polymer radiopacity, and use of elements to predictably deflect various sections of the catheter (e.g., tension straps or wires, shape memory alloys such as nitinol, etc.). It is to be further understood that any of the catheters, scopes, elongate working devices or other devices disclosed in this patent application may be rendered steerable or volitionally bendable, unless to do so would make such device inoperative for its intended purpose. Steerable catheters and scopes are well known in the art and may utilize mechanical steering assemblies (e.g., pull wires, hinges, etc.) or shape memory materials (e.g., nickel titanium alloys, shape memory polymers, etc.) to induce the device to undergo the desired bending or curvature after it has been inserted into the body. Examples of apparatus and construction that may be used to render these devices steerable or volitionally bendable include but are not limited to those described in U.S. Pat. No. 5,507,725 (Savage et al.), U.S. Pat. No. 5,656,030 (Hunjan et al.), U.S. Pat. No. 6,183,464 (Webster), U.S. Pat. No. 5,251,092 (Qin et al.), U.S. Pat. No. 6,500,130 (Kinsella et al.), U.S. Pat. No. 6,571,131 (Nguyen), U.S. Pat. No. 5,415,633 (Lazarus et al.), U.S. Pat. No. 4,998,916 (Hammerslag et al.), U.S. Pat. No. 4,898,577 (Badger et al.), U.S. Pat. No. 4,815,478 (Buchbinder et al.) and publised U.S. Patent Applications No. 2003/0181827A1 (Hojeibane et al.) and 2003/0130598A1 (Manning et al.), the entirities of which are expressly incorporated herein by reference. FIG. 5O shows a flexible catheter 733 having a working lumen 734 that extends though the catheter 732 and terminates in a distal end opening. Optionally, a second lumen 736 may also extend though the catheter 732 and terminate in a distal end opening, as shown. An endoscope 738 may be permanently positioned within this lumen 736 or such endoscope 738 may be temporarily inserted into (or through) the lumen 736 to enable the operator to view the area distal to the catheter 732. Additionally or alternatively, a side scope or lumen 740 may be located on the catheter 732 and an endoscope may be permanently embodied by or positioned in or temporarily inserted into (or through) such side scope or lumen 740 to enable the operator to view the area distal to the catheter 732 and, in at least some cases, the distal end of the catheter 732 itself. In any devices which incorporate such optional side scope or lumen 740, the side scope or lumen 740 may be of any suitable length and may terminate distally at any suitable location and such side scope or lumen 740 is not limited to the specific positioning and the specific distal end location shown in the drawings. Also, in embodiments that incorporate a side scope or lumen 740 such side lumen may be employed as a guidewire or working lumen to permit the catheter to be advanced over a guidewire or for other working devices to be inserted therethrough. FIG. 5P shows a balloon catheter and pressure expandable stent system 744 which includes all of the elements of the balloon expandable stent system shown in FIGS. 5G′-5G′″ and, in addition, may incorporate an endoscope or side lumen. Specifically, referring to FIG. 5P, there is shown a balloon catheter and pressure expandable stent system 744 that comprises a flexible catheter 746 having a balloon 750 and pressure expandable stent 748 thereon. A side lumen 756 may be located on the catheter 746 and an endoscope may be permanently positioned in or temporarily inserted into (or through) such side lumen 756 to enable the operator to view the balloon 750 and stent 748 and to advance the catheter 749 to its desired position. Also, in embodiments that incorporate a side lumen 756 such side lumen may be employed as a guidewire lumen to permit the catheter 746 to be advanced over a guidewire. Optionally, a lumen may extend through the catheter 746 and through an opening 752 in the distal end of the catheter 749 and a straight, curved, bendable, deflectable or steerable scope and/or stent 754 may be passed through or received in that lumen to facilitate over the wire and/or scope assisted and/or guided and/or manipulated advancement of the catheter 749 to an intended location. In routine use, the balloon 750 is initially deflated and the stent 748 is radially compressed to a collapsed configuration, around the deflated balloon 750. The catheter 746 with the balloon 750 deflated and the collapsed stent 748 mounted thereon is advanced, under endoscopic guidance or over a guidewire, to a position within a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. that is to be stented. Thereafter, the balloon 750 is inflated causing the stent 748 to expand to a size that frictionally engages the surrounding tissue so as to hold the stent 748 in place. In some instances the procedure will be performed for the purpose of enlarging a passageway (e.g., an ostium, meatus, etc.) and the stent 748 will be expanded to a diameter that is sufficiently large to cause the desired enlargement of the passageway and the stent 748 will then perform a scaffolding function, maintaining the passageway in such enlarged condition. After the stent 748 has been fully expanded and implanted, the balloon 750 may be deflated and the catheter 748 removed. In some applications, the stent 748 may contain a diagnostic or therapeutic substance as defined herein and such substance may elute from the stent 748 into the surrounding tissue to bring about a desired diagnostic or therapeutic effect. In some cases, the stent 748 may be permanently implanted. In other cases the stent 748 may be temporarily implanted. In cases where the stent 748 is temporarily implanted, it may be removed in a second procedure conducted to retrieve the stent 748 or the stent 748 may be made of bioabsorbable or biodegradable material such that it degrades or is absorbed within a desired period of time after implantation. As shown in the examples of FIGS. 5R′ and 5R″, in some cases, such as when a stent is to be placed within the ostium of a paranasal sinus, the stent and/or the balloon may be specifically shaped to facilitate and/or cause the stent to seat in a desired position and to prevent unwanted slippage of the stent. For example, FIG. 5R′ shows a device 1040 comprising a catheter 1042 having a balloon 1044 and stent 1046 mounted thereon as described above. However, in this embodiment, the balloon 1044 and stent 1046 are of a configuration where one end of the balloon 1044 and stent 1046 is larger in diameter than the other end. As described above in connection with other embodiments such as those shown in FIGS. 5P and 5Q, a side scope or side lumen 1048 may optionally be formed on the catheter 1042 and/or a scope or guidewire 1050 may optionally be passed through a lumen of the catheter 1042 and out of its distal end. FIG. 5R″ shows another device 1052 comprising a catheter 1054 having a balloon 1056 and stent 1058 mounted thereon as described above. However, in this embodiment, the balloon 1056 and stent 1058 are of a configuration where both ends of the balloon 1056 and stent 1058 are larger in diameter than the middle of the balloon 1056 and stent 1058. As a result, the stent 1058 has an annular groove or indentation formed circumferentially or about the mid-portion thereof or may be hourglass or venture shaped, to facilitate seating of the stent 1058 within an ostium or orifice without longitudinal slippage of the stent 1058. Again, as described above in connection with other embodiments such as those shown in FIGS. 5P and 5Q, a side scope or side lumen 1060 may optionally be formed on the catheter 1052 and/or a scope or guidewire 1062 may optionally be passed through a lumen of the catheter 1054 and out of its distal end. In cases where the procedure is intended to actually break bone (e.g., where the stent 1046, 1058 is intended to dilate or enlarge a sinus ostium) the specially shaped balloon 1044, 1056 may be made of strong polymeric material as described hereabove to enable it to exert bone-breaking pressure on the adjacent or surrounding bone as it is inflated. FIGS. 5Q and 5Q′ show a self expanding stent and delivery system 760 comprising a flexible outer sheath 762, a flexible inner tube 764 and a stent 768. This stent differs from the stent 748 of FIG. 5P only in that it is resilient and self-expanding rather than pressure expandable. The stent 768 is biased to an expanded configuration. Initially, it is compressed to a radially collapsed configuration on the outer surface of the inner tube 764 and the outer sheath 762 is advanced over the stent 768 to constrain the stent 768 in its collapsed configuration, as can be seen in the cross-sectional showing of FIG. 5Q′. A scope and/or guidewire 770 may be inserted through the lumen of the inner tube 764. Additionally or alternatively, a side lumen 772 may be located on the outer sheath 762 and an endoscope may be permanently positioned in or temporarily inserted into (or through) such side lumen 772 to enable the operator to view the distal portion of the system 760 and the area ahead of the distal end of the sheath 762 as the system is advanced. Also, in embodiments that incorporate a side lumen 772 such side lumen 772 may be employed as a guidewire lumen to permit the system 760 to be advanced over a guidewire. In routine operation the system 760, with its sheath 762 in a distally advanced position such that it surrounds and constrains the collapsed stent 768, is advanced, under endoscopic guidance and/or over a guidewire, to a position within a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. that is to be stented. Thereafter, when the stent 768 is positioned at the location to be stented, the sheath 762 is withdrawn, allowing the self-expanding stent 768 to spring or self expand to a radially expanded configuration in which it frictionally engages the surrounding anatomical structure. Thereafter, the remainder of the system 760 is removed, leaving the stent 768 implanted in the body. The stent 768 may perform dilation and scaffolding and/or substance delivery function(s) as described hereabove with respect to the pressure expandable stent 748 of FIG. 5P. FIG. 5S shows a snare apparatus 780 comprising a flexible catheter 782 having a lumen 784 extending therethrough. A snare 786 having a general loop shape is advanceable out of the lumen 784 of the device 780. In some embodiments, the snare 786 may optionally be charged with electrical current or otherwise heated so that it performs a cauterization function as it cuts through tissue. Additionally or alternatively, in some embodiments, the snare 786 may be of variable diameter (e.g., a noose that may be tightened or loosened by the operator). Also, optionally, a scope or side lumen 788 may be located on the catheter 782 and a stationary or moveable endoscope may be permanently embodied in or temporarily inserted into (or through) such side lumen 788 to enable the operator to view the distal portion of the device 780 and the area of the snare 786. Also, in embodiments where the scope or side lumen 780 comprises a side lumen, such side lumen 788 may be employed as a guidewire lumen to permit the device 780 to be advanced over a guidewire. Alternatively, multiple lumens may run through catheter 782 such that they can accommodate a snare, a guidewire and/or an endoscope. In routine operation, the snare 786 is initially retracted within lumen 784 and the device 780 is advanced under endoscopic guidance and/or over a guidewire, to a position within a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. where a polyp or other matter to be snared or cut away is located. The snare 786 is advanced out of lumen 784 and positioned around the polyp or other matter and, thereafter, the snare may be pulled or moved, heated (if equipped for heating) and/or tightened (if equipped for tightening) so as to sever or cut the polyp or other matter. In some cases, the severed polyp or other matter bay be suctioned through the lumen 784. In other cases, a separate catheter or device may be introduced to retrieve the severed polyp or other matter. After completion of the procedure, the snare 786 may be retracted into lumen 784 and the device 780 may be removed. Also, in some embodiments, the snare 786 may be replaced by a basket, bag or other retrieval receptacle that is useable to capture and retrieve tissue or other matter and to withdraw it into the lumen of the catheter 782. FIG. 5T shows a forceps device 790 which comprises a flexible shaft 792 having jaws or forceps 794 thereon. The jaws or forceps 794 may be volitionally opened and closed by the operator. A scope or side lumen 796 may be located on the flexible shaft 792, as shown. In embodiments where the scope or side lumen 792 comprises a scope, such scope may be fixed or moveable and may be used to observe or view the advancement of the device 790 and/or the use of the forceps 794. In embodiments where the scope or side lumen 796 comprises a side lumen, a stationary or moveable endoscope may be permanently embodied in or temporarily inserted into (or through) such side lumen 796 to enable the operator to view the distal portion of the device 790 and the area of the forceps 794. Also, in embodiments where the scope or side lumen 796 comprises a side lumen, such side lumen 796 may be employed as a guidewire lumen to permit the device 790 to be advanced over a guidewire. In routine operation, the device 790 is advanced, either alone or through the lumen of a catheter, and possibly under endoscopic guidance and/or over a guidewire, to a position within a passageway such as a nostril, nasal cavity, meatus, ostium, interior of a sinus, etc. where matter is to be grasped by the forceps. Thereafter, under optional endoscopic guidance and observation, the forceps 794 are used to grasp the intended matter. In some embodiments, a distal portion of the flexible shaft 792 may be bendable or steerable as indicated by doted lines on the example of FIG. 5T. In some embodiments, the jaws of the forceps 794 may be designed to sever and retain a specimen of tissue for biopsy or other tissue sampling applications or the forceps 794 may comprise scissors for cutting tissue, cartilage, bone, etc. Alternatively, a lumen may pass through flexible shaft 792 and exit through or next to the forceps 794 and allow the passage of a guidewire or endoscope through such lumen. FIGS. 5U and 5U′ show a telescoping system 800 comprising a flexible catheter 802, a flexible scope 804 and a guidewire 806. The flexible scope 804 comprises a plurality of light transmitting pathways 808 (e.g., optical fibers) that transmit light in the distal direction from a light source (not shown) and out of the distal end of the scope 804 such that the light is cast onto the object or anatomical structure to be viewed. Also, the scope comprises an image transmitting pathway 810 (e.g., optical fiber and lens) that carries reflected light from distal end of the scope to an eyepiece or monitor on which the image may be viewed. The scope also has a guidewire lumen 805 extending therethrough and opening through its distal end. The scope 804 is advanceable through the flexible catheter 802 and a guidewire 806 that is advanceable through a guidewire lumen 805 of the scope, as shown. In routine operation, the telescoping system 800 may be inserted into the nose and the scope 804 may be utilized to view an anatomical structure, such as the ostium of a paranasal sinus, and facilitate advancement of the guidewire into that anatomical structure. Thereafter, the scope may be advanced over the guidewire and into the anatomical structure (e.g., though the ostium and into the interior of the paranasal sinus). The scope may then be used to examine the anatomical structure (e.g., to view the condition of the mucosa lining the paranasal sinus and to look for signs of infection, tumors, etc.) The catheter 802 may then be advanced over the scope 804 and into the anatomical structure (e.g., the catheter tip may be advanced through the ostium and into the paranasal sinus). Thereafter, the scope 804 may be removed and a diagnostic or therapeutic substance as defined hereabove may be infused through the catheter 802 and/or another working device, including but not limited to the working devices shown in FIGS. 5A-5T and 5V-5Y′″″, may be advanced through the catheter 802 and into the anatomical structure where it is used to perform a diagnostic or therapeutic function. FIG. 5V shows a side port suction/cutting device 820 which comprises a flexible outer tube 822, a flexible inner tube 830 is disposed coaxially and rotatably mounted within the outer tube 822. One or more bearings 834 (e.g., a helical bearing or a series of individual cylindrical bearings) may be disposed between the outer tube 822 and inner tube 830, as shown. Alternatively, one or both apposing tube surfaces may be made of, lined with, or be coated by etc. a lubricious material such as silicone or PTFE to facilitate movement. A rotating cutter 832 is positioned on the distal end of the inner tube 830. A side opening 828 is formed in the outer tube 822 and the cutter 832 is positioned proximal to the side opening 828. Optionally, a tapered atraumatic distal tip 824 may be formed on the distal end of the outer tube 822 and the side opening 828 may be configured to form a ramp or chute through which matter may pass into the area immediately distal to the cutter 832. Also optionally, an opening may be formed in the distal end of the distal tip such that a guidewire or scope 826 may pass through the lumen of the inner tube 830 and out of the opening in the distal tip, as shown. In operation, the device 820 is advanced to a position where the side opening 828 is near a polyp, tissue or other obstructive matter to be removed. The inner tube 830 and cutter 832 are rotated. Suction may be applied through the lumen of the inner tube 830 and/or through the lumen of the outer tube 822 to draw the obstructive matter into the side opening 828 and into contact with the rotating cutter 832. As the obstructive matter is severed by the rotating cutter 832, the severed obstructive matter or pieces thereof may be suctioned through the lumen of the inner tube 830 and/or through the lumen of the outer tube 822. Of course, as in any of the working devices described in this patent application, a scope or side lumen of any size or length, into which a scope may be inserted (not shown in FIG. 5U but shown in various other figures such as FIGS. 50, 5P, 5Q, 5R, 5S and 5T) may be attached to the outer tube 822 at a position which allows a scope to be used to view the side opening 828 and matter entering the side opening 828. Alternatively, the catheter may incorporate a deflectable tip or a curved distal end which may force the side opening of the catheter against a lumen wall or into the direction of a polyp or other tissue to be removed. In some applications of the invention, it may be desirable to break bone, such as the thin bone that forms the periphery of a sinus ostium. FIGS. 5W-5X″″ show devices that may be used to break bones at specific locations. For example, FIGS. 5W-5W″ show a device 840 that comprises a flexible catheter 842 having a rigid cylindrical member 847 located on the distal end thereof. An advanceable and retractable member 846 extends through the catheter 842 and is connected to a distal tip member 844. The distal tip member 844 has a cylindrical proximal end 849 that is sized to be received within the cylindrical member 847. As shown in FIGS. 5W′ and 5W″, in routine operation, the advanceable and retractable member 846 is advanced to separate the distal tip member 844 from the rigid cylindrical member 847. The device 840 is advanced to a position adjacent to a bony structure, such as a structure formed by bone B covered with mucosal tissue M. The device is positioned such that the bony structure is between the cylindrical proximal end 849 of the distal tip member 844 and the cylindrical member 847. The advanceable and retractable member 846 is then retracted, pulling the distal tip member 844 in the proximal direction and capturing the bony structure between the cylindrical proximal end 849 of the distal tip member 844 and the cylindrical member 847, thereby breaking the bone B. The shape or configuration of the distal tip member 844 and/or cylindrical member 847 may be varied depending on the shape and pattern of break desired to be made in the bone B, In this regard, FIGS. 5X-5X″″ show alternative constructions or configurations that may be used to produce different shapes and patterns of bone breaks. FIG. 5X′ shows an assembly 850 comprising a distal tip member 852 that has three (3) projections on its proximal side and a proximal member 854 that has three (3) notches in its distal surface, such notches being configured to receive the three projections of the distal tip member 852 when the distal tip member 852 is retracted. FIG. 5W″ shows an assembly 860 comprising a distal tip member that forms a pincher for breaking bone. FIG. 5X′″ shows an assembly 870 comprising a collapsible distal tip member 872 and a cylindrical proximal member 874. The distal tip member 872 may be initially deployed in a collapsed configuration that allows it to be advanced through an opening such as the ostium of a sinus. Then, it may be expanded to a size that is too large in diameter to pass through that opening, thereby causing it to strike the periphery of the opening as it is retracted in the proximal direction. In this manner, the assembly 5X′″ may be used to break bone B all the way around an ostium or aperture. FIG. 5X″″ shows another assembly 880 comprising a distal tip 882 that has two projections on its proximal side and a proximal member 884 that has one projection on its distal side. The projection on the distal side of the proximal member 884 is received between the projections formed on the proximal side of the distal member 882 when the distal member 882 is retracted in the proximal direction. FIGS. 5Y′-5Y′″″ show various substance delivery implants that may be implanted into the nasal cavities, paranasal sinuses, middle or inner ear, nasopharynx, etc. to deliver a diagnostic or therapeutic substance as defined herein. These devices may be formed of permanent or bio-absorbable material. In many instances, these devices will be formed of a polymer (e.g., Hydron, hydrogel, collagen, etc.) within which the diagnostic or therapeutic substance is contained or a polymer or metal that is coated with or otherwise contains the substance. FIG. 5Y′ shows an implant 1070 that comprises a bead or pellet. FIG. 5Y″ shows an implant 1072 that comprises a wafer. FIG. 5Y′″ shows an implant 1074 that comprises a brad or staple. FIG. 5Y″″ shows an implant 1076 that comprises a screw or helical coil. FIG. 5Y″″ shows an implant 1078 that comprises a strand or coil, another example of which is shown in FIG. 7E and described herebelow. D. Pre-Shaped Guide Catheters FIGS. 6A-6E show various guide catheters that may be used in the methods of the present invention. FIG. 6A shows a sphenoid sinus guide catheter 120 that incorporates three preformed curves 122, 124, 126. The three dimensional shape of the catheter 120 is such that, when advanced through a nasal cavity, the distal end of the catheter 120 will tend to enter the ostium of the sphenoid sinus. FIG. 6B shows a frontal sinus guide catheter 128 that incorporates two preformed curves 130, 133. The shape of the catheter 128 is such that, when advanced through a nasal cavity, the distal end of the catheter 128 will tend to enter the ostium of the frontal sinus. FIG. 6C shows a maxillary sinus guide catheter 136 that incorporates three preformed curves 138, 140, 142. The three dimensional shape of the catheter 136 is such that, when advanced through a nasal cavity, the distal end of the catheter 136 will tend to enter the ostium of the maxillary sinus. FIG. 6D shows an ethmoid sinus guide catheter 144 that incorporates two preformed curves 146, 148. The three dimensional shape of the catheter 144 is such that, when advanced through a nasal cavity, the distal end of the catheter 144 will tend to enter the ostium of the ethmoid sinus. In some of the methods of the invention, it will be desirable to plug the ostium of a sinus or another opening such as the nasolacrimal duct or the nasopharyngeal opening into the Eustachian tube. Thus, any of the above-described guide catheters 120, 128, 136, 144 may be equipped with a plug on its distal tip such that when its distal end enters the sinus ostium it will plug the sinus thereby preventing fluid from exiting the sinus through the ostium. An example of one such procedure is shown in FIG. 7B and described herebelow. FIG. 6E shows a plug guide catheter 149 that is useable for temporarily plugging the opening into a nasolacrimal duct. This plug guide catheter 149 has two preformed curves 150, 152 and a plug 154 at its distal tip. The three dimensional configuration of this catheter 149 is such that, when advanced through a nasal cavity the distal tip plug 154 will tend to enter the opening into the nasolacrimal duct. The plug may consist of, but is not limited to, a semi-rigid plug or a balloon on the end of the catheter. It will be appreciated that a different shaped plug guide catheter (not shown) may be used to plug the Eustachian tube. E. Devices and Methods for Treatment Within Paranasal Sinuses: FIGS. 7A-7G provide examples of devices and methods for performing diagnostic or therapeutic procedures within the paranasal sinuses. In the methods of the prior art, rigid or flexible scopes are sometimes used to visualize the ostia of sinuses but, typically, such scopes have not actually been advanced into the interior of the sinuses. As described hereabove, the present invention does provide devices and methods for placing endoscopes inside the paranasal sinuses and such methods may or may not be used in conjunction with any of the diagnostic or therapeutic devices and methods shown in FIGS. 7A-7G. FIG. 7A shows an electrode network delivery device 168 being used to deliver radiofrequency or electrical current to the lining of the sphenoid sinus SS. This device 168 comprises a flexible catheter 168 that has been inserted through the sphenoidal sinus ostium SSO. An expandable electrode network such as a cage 170 is advanced out of the distal end of the catheter 169. Electrodes 172 are positioned at spaced apart locations on the cage. As the cage 170 expands, it places the electrodes in contact with the lining of the sinus SS. Current is delivered to the electrodes 172 to ablate all mucous producing tissue within the sinus in preparation for the sinus to be functionally isolated or embolized, or to ablate tumors or polyps located within the sinus. FIG. 7B shows a procedure where a flowable substance, such as a diagnostic or therapeutic substance as defined above, is introduced into the sphenoid sinus SS and the ostium SSO has been plugged by a sphenoid sinus plug guide catheter device 174. This device 174 comprises a flexible catheter 176 having the shape shown in FIG. 6A and described above and a plug member 178 at its distal tip. The fluid is maintained in the sphenoid sinus SS until the plug catheter device 174 is removed, allowing the fluid to then drain through the sphenoid sinus ostium SSO. This procedure may be particularly useful when it is desired to fill a sinus with radiographic contrast agent to visualize the entire sinus or to apply a therapeutic agent to the entire lining of the sinus by entirely filling the sinus with the agent and maintaining such fully filled state for a desired period of time to allow the agent to act on the entire lining of the sinus. Imaging materials may be mixed with visous agents so that they simulate mucous or if simple structural imaging is desired it may be preferable to have substances of lower viscosity. It may be also desirable to use imaging agents which bind with the surface of the mucosa to minimize the amount of injected contrast. FIG. 7C shows a balloon catheter device 180 which comprises a flexible catheter 182 having a balloon 184 that is positioned in the sphenoid sinus ostium SSO and inflated to hold the catheter 182 in position while a quantity of a diagnostic or therapeutic substance 186 (as defined above) is introduced into the interior of the sinus SS. This therapeutic substance may be one or more of any of the drug delivery materials and drugs selected from the previous list, or may additionally include a sclerotic agent such as alcohol to uniformly kill all the tissues within the cavity. Other materials such as capasian or other neuro-toxic substances may be considered to eliminate the pain and other sensation within the caity. FIG. 7D shows a sensor equipped catheter device 190 that comprises a flexible catheter 192 having a sensor 194 thereon for 3 dimensional mapping or navigation. This procedure may be used to map the precise configuration of the interior of the sphenoid sinus SS. Examples of the construction and use of such sensor 194 and associated systems/computers are found in U.S. Pat. Nos. 5,647,361; 5,820,568; 5,730,128; 5,722,401; 5,578,007; 5,558,073; 5,465,717; 5,568,809; 5,694,945; 5,713,946; 5,729,129; 5,752,513; 5,833,608; 5,935,061; 5,931,818; 6,171,303; 5,931,818; 5,343,865; 5,425,370; 5,669,388; 6,015,414; 6,148,823 and 6,176,829, the entirities of which are expressly incorporated herein by reference. FIG. 7E shows an implant delivery device 196 which comprises a flexible catheter 198 that is inserted through the sphenoid sinus ostium SSO and into the sphenoid sinus SS and is being used to implant a coil 200 within the sphenoid sinus. Such coil 200 may comprise an elongate fiber or other elongate member that may contain a diagnostic or therapeutic substance as defined herein. This coil 200 may be constructed to embolize the sinus for the purpose of to permanently close off the sinus and to prevent any further mucous production, trapping of secretions or infection and/or to deliver a diagnostic or therapeutic substance to the tissues lining the sinus. For example, a coil for sustained delivery of an antimicrobial agent may be implanted in a sinus to treat an acute or chronic infection of that sinus. In some cases, the coil may be bioabsorbable. FIG. 7F shows an over-the-wire endoscopic system 240 being used to view the interior of the sphenoid sinus SS. A flexible catheter 242 is positioned in or near the sphenoid sinus ostium SSO and a guidewire 248 is advanced through the sphenoid sinus ostium SSO and into the sphenoid sinus SS. An over-the-wire endoscope 246 (such as a 2.2 mm over-the-wire scope available commercially as Model # AF-28C from Olympus America, Melville, N.Y.) is advanced over the guidewire 248 and is used to examine the interior of the sphenoid sinus SS. FIG. 7G shows a biopsy system 250 being used to obtain a biopsy specimen from a lesion L within the sphenoid sinus SS. A flexible catheter 242 is positioned in or near the sphenoid sinus ostium SSO and an endoscope 246 is advanced through the catheter 242 and into the interior of the sinus SS. A biopsy instrument 252 is inserted through a working channel of the endoscope 246 and is used, under endoscopic visualization and guidance, to obtain a specimen of the lesion L. F. General Examples Of Interventions Using the Occluder & Access Devices and/or Working Devices FIGS. 8A-8D show two of many possible examples of methods wherein the occluder & access devices 10, 12 of FIGS. 2A and 2B and/or various working devices such as those shown in FIGS. 5A-5Y“ ” are used to perform diagnostic and/or therapeutic procedures within the nose, nasopharynx or paranasal sinuses. In general, diagnostic interventions in accordance with this invention may include: a) anatomic studies where obstructions, sizes, parameters or abnormalities in anatomy are visualized and/or identified, b) dynamic studies where gas, mucous or fluid is introduced into the nose, sinus, nasal cavity, nasopharynx, Eustachian tube, inner or middle ear, etc and the movement of such materials is monitored to asses drainage or gas flow issues and c) perturbation studies where an agent (e.g., an allergen, irritant, agent that induces mucous production, etc.) is introduced into the nose, sinus, nasal cavity, nasopharynx, Eustachian tube, inner or middle ear, etc., and the patient's response and/or flow of the endogenously produced mucous or other secretions is assessed. Examples of procedures that may be used to perform these types of diagnostic interventions include, but are not limited to, the following: 1. Gaining Access To Sinus: Access to one of more of the paranasal sinuses is gained by advancement of catheter(s) into the sinus or sinuses of interest. A guidewire may be inserted into the sinus first and the catheter may then be advanced over the guidewire and into the sinus. In some cases, a sinus ostium guide catheter of the type shown in FIGS. 6A-6E may be inserted into the ostium of the sinus and a smaller catheter may be advanced through the guide catheter. One or more scopes may be used to visualize the sinus ostium and to guide the guidewire and/or catheter into the sinus ostium. In some cases, a steerable guidewire, catheter and/or scope may be used to gain entry into the sinus. In some cases, occlusion & access device(s) such as those shown in FIGS. 2A-2R, may be inserted and the guidewire(s), catheter(s) and/or scope(s) used to access the sinus may be inserted through a device insertion port on the occluder & access device. 2. Mucous Flow Study: Optionally, after catheter access to the sinus has been gained, an imageable contrast substance or radioactive material such as microbeads or a flowable contrast medium (e.g., an iodinated contrast solution with or without a thickening agent to adjust its viscosity to that of mucous) that may have a consistency similar to that of mucous may be injected into the sinus. An imaging or scanning technique (e.g., X-ray, fluoroscopy, CT scan, ultrasound, MRI, radiation detector, gamma camera, etc.) may then be used to observe the flow of the contrast medium through and out of the sinus. In some cases a fluoroscope with a C-arm may be used in a fashion similar to that used in coronary artery catheterization and angiography procedures to allow the clinician to view the movement of the contrast medium from different vantage points or angles. To facilitate flow of the contrast medium from the sinus, the previously inserted catheter(s) and/or guidewires and/or scope(s) may be backed out of the sinus and ostium or removed completely, to allow normal flow to occur. The patient's head and/or other body parts may be repositioned to observe different postural drainage effects. In this manner, the clinician may specifically locate and identify which anatomical structures are obstructing or interfering with normal mucous flow from the sinus. 3. Air Flow Study: Optionally, after access to the sinus has been gained as described in No. 1 above, an imageable or traceable gas, such as a radiolabled gas, radiopaque gas or a gas with imageable or radioactive microbeads therein, may be injected through a catheter and into the sinus. An imaging device or tracing device (e.g., radiation detector, gamma camera, X-ray, fluoroscopy, CT scan, ultrasound, MRI) may then be used to observe subsequent movement or dissipation of the gas as it passes out of the sinus and/or equilibrates with other sinus cavities. In this manner, the clinician may determine whether normal gas exchange in the sinus is occurring and may locate and identify any anatomical structures or irregularities that are obstructing or interfering with normal gas flow and/or gas exchange. 4. Anatomic Dimension Study: An entire paranasal sinus or other anatomical passageway or structure may be filled with an imageable substance or otherwise measured to determine its actual dimensions and/or configuration. In some such studies, access to a paranasal sinus will be gained as described in No.1 above and the sinus may be filled with an imageable substance (e.g., contrast medium). A suitable imaging technique (e.g., X-ray, fluoroscopy, CT scan, ultrasound, MRI, radiation detector, gamma camera, etc.) may then be used to determine the size and shape of the sinus. Again, in such procedure, a moveable imaging apparatus such as a fluoroscope with a C-arm may be used to view and measure the contrast filled sinus from different vantage points or angles. One example of such a procedure is shown in FIG. 7B and described hereabove. 5. Endoscopic Study: A flexible and/or steerable endoscope, as described above, may be inserted into the nose, sinus, nasal cavity, nasopharynx, Eustachian tube, inner or middle ear, etc and used to visually examine the anatomy and/or to observe a treatment and/or to assess the efficacy or completeness of a previously rendered treatment. In cases where it is desired to view the interior of a paranasal sinus, access to the sinus may be gained as described in No. 1 above and the endoscope may be advanced into the interior of the sinus either directly or over a guidewire. 6. Transillumination Study: A flexible light emitting instrument (e.g., a catheter having a powerful light emitting apparatus at its distal end) may be advanced into the nose, paranasal sinus, nasal cavity, nasopharynx, Eustachian tube, inner or middle ear, etc and used to illuminate anatomical structures. Direct or endoscopic observation may then be made from outside the body and/or from other locations within the nose, sinus, nasal cavity, nasopharynx, Eustachian tube, inner or middle ear, orbit, cranial vault, etc. to observe anatomical structures and/or to detect aberrant openings or leaks through which the light passes. In cases where the light emitter and/or the viewing instrument (e.g., endoscope) is/are positioned within paranasal sinus(es) access to the sinus(es) may be gained as described in No. 1 above and the light emitter and/or viewing instrument may then be advanced into the sinus(es) either directly or over guidewire(s). 7. Other Imaging Studies: Other imaging techniques such as MRI, CT, etc. in combination with any of the modalities set forth in Nos. 1-6 above and modifications may be made to any of those techniques to adjust for sinus anatomy or other pathology. After any or all of the elected diagnostic studies have been completed, one or more working devices, such as the flexible devices described herein and shown in FIGS. 5A-5Y′″″, may be inserted and used to perform therapeutic procedure(s). As shown in the example of FIG. 8A, an anterior/posterior occluder & access device 10 is inserted through the right nasal cavity NC. The device's anterior occluder 14 is positioned to occlude the nostril on the right side while its posterior occluder (not seen in FIGS. 8A-8E) occludes the posterior choanae or nasopharynx. An anterior occluder & access device 12 is inserted into the left nasal cavity and its occluder 40 occludes the left nostril. In this manner, a sealed operative field is established between the posterior occluder positioned in the posterior choanae or nasopharynx and the anterior occluders 14, 40 positioned in the right and left nostrils or anterior nasal cavities. FIGS. 8B-8C show an example of a method for performing a diagnostic and/or therapeutic procedure in the right frontal sinus FS in the patient in whom the occluder & access devices 10, 14 have been inserted. In FIG. 8B, a frontal sinus guide catheter 128 is inserted into the working device insertion port 30 and advanced through tube 16 and out of outlet aperture 22. The guide catheter 128 is then advanced to a position where its distal end is in the right frontal sinus ostium. In FIG. 8C, a working device 202 is inserted through the guide catheter 128 and into the frontal sinus FS. This working device 202 may comprise any of the devices shown in FIGS. 5A-5Y′″″ or 7A-7G. In some procedures, it may be desired to initially introduce a contrast agent into the frontal sinus FS and pull back the guide catheter 128 to allow the contrast agent to drain from the sinus. Imaging of the draining contrast agent may be used to diagnose drainage impairment and to identify the specific anatomical structures that are causing the impairment of drainage. Thereafter, the guide catheter may be reinserted into the frontal sinus ostium and the working device(s) 202 may be used to modify the structures that have been identified and impairments to drainage. Thereafter, the contrast injection and imaging steps may be repeated to assess whether the procedure(s) performed have overcome or corrected the drainage problem that had been initially diagnosed. A suction device 206 is connected by way of suction line 204 to port 36 to suction blood, other fluid or debris from the operative field during the procedure. FIGS. 8D and 8E show an example of a treatment rendered to the left maxillary sinus MS, in the same patient in whom the occluder & access devices 10, 14 have been inserted. In FIG. 8D, a guide catheter 136 is inserted into device insertion aperture 44 and advanced through tube 41 to a position where the distal end of the guide catheter 136 is positioned in the ostium of the maxillary sinus MS. Thereafter, as shown in FIG. 8E, a working device 202 is inserted through the guide catheter 136 and into the maxillary sinus MS. This working device 202 may comprise any of the devices shown in FIGS. 5A-Y′″″ or 7A-7G. In some procedures, it may be desired to initially introduce a contrast agent into the maxillary sinus MS by the same procedure described above in reference to FIGS. 8B and 8C. After all of the desired procedures have been completed, the anterior occluders 14, 40 and posterior occluder (not shown on FIGS. 8A-8E) are collapsed (e.g., deflated) and the occluder & access devices as well as the guide catheters and working devices are removed (except for implants such as stents, embolic coils, substance delivery implants, etc.). G. Cochlear Implant Procedure FIGS. 9A-9C show a procedure for installation of a cochlear implant in accordance with the present invention. In this procedure, the nasopharyngeal opening into the Eustachian tube ET is located and a guidewire is initially advanced into the Eustachian tube ET. A catheter 900 is advanced over the guidewire to a location where the distal end of the catheter 900 is in or near the tympanic cavity TC of the middle ear. Thereafter, if deemed necessary, a forceps device 790 and/or other devices are advanced through the catheter 900 and used to remove the small bones of the sear (i.e., the malleus, incus and stirrup) as shown in FIG. 9A. This optional removal of the bones of the middle ear may be done under endoscopic visualization using an endoscope equipped device such as the endoscope equipped forceps device 790 shown in FIG. 5T and described above. As shown in FIG. 9B, a cochlear guide catheter 904 having a “J” shaped distal tip 905 is advanced through the catheter 900 to a position where the tip 905 of the cochlear guide catheter 904 is directed into or inserted into the cochlea C. In some applications, the cochlear guide catheter 904 may be configured to advance into the round window of the cochlea and through the secondary tympanic membrane that covers the round window. If necessary, a penetrator such as a needle, drill or cutter may be advanced through or formed or positioned on the distal end of the cochlear guide catheter 904 to penetrate through the secondary tympanic membrane. In other applications, the cochlear guide catheter 904 may be positioned adjacent to the cochlea and a cochleostomy device (e.g., a penetrator such as a drill, needle or cutter) may be advanced through or formed or positioned on the distal end of the cochlear guide catheter 904 and used to form a cochleostomy through which the distal end of the guide catheter 904 is advanced into the cochlea C. Thereafter, a cochlear electrode array 906 is advanced through the cochlear guide catheter 904 and into the cochlea, as seen in FIG. 9B. One example of a commercially available cochlear electrode array is the Nucleus 24 Countour device manufactured by Cochlear Corporation. Thereafter, a sound receiving device or transducer 908 is advanced through the catheter 900 and positioned in the tympanic cavity TC. The sound receiving device or transducer 908 may be of any type that is a) sufficiently small to pass through the Eustachian tube ET and into the tympanic cavity TC and b) useable to perform the desired function of converting sound waves to electrical impulses and delivering such electrical impulses to the cochlear electrode array 906. A microphone/power/electronics device 910 may be positioned in the outer ear canal, as shown in FIG. 9C or may be implanted subcutaneously or in any other way that is acceptable. Certain non-limiting examples of devices 906, 908, 910 that may be useable for this procedure are set forth in PCT International Patent Publication No. WO 2004/018980 A2 designating the United States, the entirety of which is expressly incorporated herein by reference. It is to be appreciated that the invention has been described hereabove with reference to certain examples or embodiments of the invention but that various additions, deletions, alterations and modifications may be made to those examples and embodiemnts without departing from the intended spirit and scope of the invention. For example, any element or attribute of one embodiment or example may be incorporated into or used with another embodiment or example, unless to do so would render the embodiment or example unsuitable for its intended use. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims. | <SOH> BACKGROUND <EOH>The human nose is responsible for warming, humidifying and filtering inspired air and for conserving heat and moisture from expired air. The nose is also an important cosmetic feature of the face. The nose is formed mainly of cartilage, bone, mucous membranes and skin. The right and left nostrils lead into right and left nasal cavities on either side of the intranasal septum. The right and left nasal cavities extend back to the soft palate, where they merge to form the posterior choanae. The posterior choanae opens into the nasopharynx. The roof of the nose is formed, in part, by a bone known as the cribriform plate. The cribriform plate contains numerous tiny perforations through which sensory nerve fibers extend to the olfactory bulbs. The sensation of smell occurs when inhaled odors contact a small area of mucosa in the superior region of the nose, stimulating the nerve fibers that lead to the olfactory bulbs. The paranasal sinuses are cavities formed within the bones of the face. The paranasal sinuses include frontal sinuses, ethmoid sinuses, sphenoidal sinuses and maxillary sinuses. The paranasal sinuses are lined with mucous-producing epithelial tissue. Normally, mucous produced by the linings of the paranasal sinuses slowly drains out of each sinus through an opening known as an ostium, and into the nasopharnyx. Disorders that interfere with drainage of mucous (e.g., occlusion of the sinus ostia) can result in a reduced ability of the paranasal sinuses to function normally. This results in mucosal congestion within the paranasal sinuses. Such mucosal congestion of the sinuses can cause damage to the epithelium that lines the sinus with subsequent decreased oxygen tension and microbial growth (e.g., a sinus infection). The nasal turbinates are three (or sometimes four) bony processes that extend inwardly from the lateral walls of the nose and are covered with mucosal tissue. These turbinates serve to increase the interior surface area of the nose and to impart warmth and moisture to air that is inhaled through the nose. The mucosal tissue that covers the turbinates is capable of becoming engorged with blood and swelling or becoming substantially devoid of blood and shrinking, in response to changes in physiologic or environmental conditions. The curved edge of each turbinate defines a passageway known as a meatus. For example, the inferior meatus is a passageway that passes beneath the inferior turbinate. Ducts, known as the nasolacrimal ducts, drain tears from the eyes into the nose through openings located within the inferior meatus. The middle meatus is a passageway that extends inferior to the middle turbinate. The middle meatus contains the semilunar hiatus, with openings or ostia leading into the maxillary, frontal, and anterior ethmoid sinuses. The superior meatus is located between the superior and medial turbinates. Nasal Polyps: Nasal polyps are benign masses that grow from the lining of the nose or paranasal sinuses. Nasal polyps often result from chronic allergic rhinitis or other chronic inflammation of the nasal mucosa. Nasal polyps are also common in children who suffer from cystic fibrosis. In cases where nasal polyps develop to a point where they obstruct normal drainage from the paranasal sinuses, they can cause sinusitis. Sinusitis: The term “sinusitis” refers generally to any inflammation or infection of the paranasal sinuses. Sinusitis can be caused by bacteria, viruses, fungi (molds), allergies or combinations thereof. It has been estimated that chronic sinusitis (e.g., lasting more than 3 months or so) results in 18 million to 22 million physician office visits per year in the United States. Patients who suffer from sinusitis typically experience at least some of the following symptoms: headaches or facial pain nasal congestion or post-nasal drainage difficulty breathing through one or both nostrils bad breath pain in the upper teeth Proposed Mechanism of Sinus Pain & Diagnosis The sinuses consist of a series of cavities connected by passageways, ultimately opening into the nasal cavity. As described previously, these passageways and cavities are formed by bone, but covered in mucosa. If the mucosa of one of these passageways becomes inflamed for any reason, the cavities which drain through that passageway can become blocked. This trapping of mucous can be periodic (resulting in episodes of pain) or chronic. Chronically blocked passageways are targets of infection. Ultimately, it is the dimensions of the bony passageways and thickness of the overlying mucosa and its chronicity that dictate the duration and severity of sinus symptoms. Thus, the primary target for sinus therapy is the passageway, with the primary goal to regain drainage. Often CT will not reveal these dimensional issues, especially when the patient is not currently experiencing severe symptoms. Therefore there exists a need to dynamically evaluate the sinus passageways under normal conditions, in response to challenging stimuli. As suggested herein, if it would be possible to assess sinus disease and its dynamic component, one might better target therapy for sinusitis and possibly be able to treat patients in a more focused and minimally invasive manner. Such focus on the passageway and the use of flexible instrumentation suggests an entirely new approach to sinus intervention: one utilizing flexible catheters and guidance tools, with passageway and cavity modifying devices capable of being delivered with minimal damage to the surrounding tissues. Deviated Septum: The intranasal septum is a cartilaginous anatomical structure that divides one side of the nose from the other. Normally, the septum is relatively straight. A deviated septum is a condition where the cartilage that forms the septum is abnormally curved or bent. A deviated nasal septum may develop as the nose grows or, in some cases, may result from trauma to the nose. A deviated septum can interfere with proper breathing or may obstruct normal drainage of nasal discharge, especially in patient's whose nasal turbinates are swollen or enlarged due to allergy, overuse of decongestant medications, etc. Such interference with drainage of the sinuses can predispose the patient to sinus infections. A deviated nasal septum that interferes with proper function of the nose can be surgically corrected by a procedure known as septoplasty. In a typical septoplasty procedure, an endoscope is inserted into the nose and the surgeon makes an incision inside the nose, lifts up the lining of the septum, and removes and straightens the underlying bone and cartilage that is abnormally deviated. Such surgical septoplasty procedures can effectively straighten a deviated septum but, because the nasal cartilage has some memory, the septum may tend to resume its original deviated shape. Reduction/Removal of Nasal Turbinates Various surgical techniques, including endoscopic surgery, have been used for reduction and/or removal of the inferior turbinate in patient's whose inferior turbinate is chronically enlarged such that it is obstructing normal breathing and/or normal drainage from the paranasal sinuses. Typically, chronic enlargement of the inferior turbinates is the result of allergies or chronic inflammation. Enlargement of the inferior turbinate can be especially problematic in patient's who also suffer from a deviated septum that crowds or impinges upon the soft tissue of the turbinate. Thus, a septoplasty to straighten the deviated septum is sometimes performed concurrently with a reduction of the inferior turbinates. Sinus Tumors Most polyps are benign, but one form of a nasal polyp, known as an inverting papilloma, can develop into a malignancy. Unlike most benign polyps, which typically occur on both sides of the nose, an inverting papilloma is usually found on just one side. Thus, in cases where a unilateral polyp is observed, it is usually biopsied to determine if it is malignant. If an inverting papilloma is detected before it becomes malignant and is removed completely, it will typically not recur. However, using the technology that has heretofore been available, it has sometimes been difficult to determine if the papilloma has been entirely removed unless and until regrowth of the polyp is observed on long term post-surgical follow-up. Various benign sinus tumors have also been known to occur, but are relatively rare. The most common form of malignant sinus tumor is squamous cell carcinoma. Even with surgery and radiation treatment, squamous cell carcinoma of the paranasal sinus is associated with a relatively poor prognosis. Other types of malignant tumors that invade the paranasal sinuses include adenocarcinoma and, more rarely, lymphoma and even more rarely, melanoma. Facial Fractures The most common cause of fractures of the facial bones is auto accidents, but facial fractures are also frequently caused by sports injuries, industrial accidents, falls, assaults and gunshot wounds. Some facial fractures involve bones that are accessible from inside the nasal cavities or paranasal sinuses. Notably, the nose is the most commonly injured facial structure due to its prominent position on the face. Thus, fractures of the nasal bone (with or without resultant deviated septum) are not uncommon. Other facial fractures such as fractures of the orbital floor and/or the ethmoid or frontal sinuses are also accessible from inside the nose or sinuses. A common type of orbital floor fracture is a “blowout” fracture that typically results from blunt trauma to the eye where the force is transmitted downwardly causing the relatively thin bone that forms the floor of the orbit to fracture downwardly. This can cause the periorbital tissues to herniate into the maxillary sinus and sometimes can also create a “trap door” of bone that extends downwardly into the maxillary sinus. Endoscopic Sinus Surgery and Other Current Procedures Functional Endoscopic Sinus Surgery The most common corrective surgery for chronic sinusitis is functional endoscopic sinus surgery (FESS). In FESS, an endoscope is inserted into the nose and, under visualization through the endoscope, the surgeon may remove diseased or hypertrophic tissue or bone and may enlarge the ostia of the sinuses to restore normal drainage of the sinuses. FESS procedures can be effective in the treatment of sinusitis and for the removal of tumors, polyps and other aberrant growths from the nose. Other endoscopic intranasal procedures have been used to remove pituitary tumors, to treat Graves disease (i.e., a complication of hyperthyroidism which results in protrusion of the eyes) and surgical repair of rare conditions wherein cerebrospinal fluid leaks into the nose (i.e., cerebrospinal fluid rhinorrhea). Surgery to reduce the size of the inferior turbinates can be accomplished with endoscopic visualization (with magnification where desired) and is typically performed with the patient under general anesthesia. An incision is typically made in the mucosa that lines the turbinate to expose the underlying bone. Some quantity of the underlying bone may then be removed. If selective removal of some of the mucosa or soft tissue is also desired, such soft tissue can be debulked or removed through by traditional surgical cutting or by the use of other tissue ablation or debulking apparatus such as microdebriders or lasers. Less frequently, chronically enlarged inferior turbinates have been treated by cryotherapy. It is typically desirable to remove only as much tissue as necessary to restore normal breathing and drainage, as removal of too much tissue from the turbinates can impair the ability of the turbinates to perform their physiological functions of warming and humidifying inspired air and conserving warmth and moisture from expired air. Complications associated with inferior turbinate surgery include bleeding, crusting, dryness, and scarring. In some patients, the middle turbinate is enlarged due to the presence of an invading air cell (concha bullosa), or the middle turbinate may be malformed (paradoxically bent). Severe ethmoid sinusitis or nasal polyps can also result in enlargement or malformation of the middle turbinates. Since a substantial amount of drainage from the sinuses passes through the middle meatus (i.e., the passage that runs alongside middle turbinate) any enlargement or malformation of the middle turbinate can contribute to sinus problems and require surgical correction. Thus, in some FESS procedures carried out to treat sinusitis, the middle meatus is cleared (e.g., the polyps or hypertorophic tissue are removed) thereby improving sinus drainage. However, the middle turbinate can include some of the olfactory nerve endings that contribute to the patient's sense of smell. For this reason, any reduction of the middle turbinate is typically performed in a very conservative manner with care being taken to preserve as much tissue as possible. In patients who suffer from concha bullosa, this may involve removing the bone on one side of an invading air sac. In the cases where the middle turbinate is malformed, just the offending portion(s) of the turbinate may be removed. Extended Endoscopic Frontal Sinus Surgery Because of its narrow anatomical configuration, inflammation of the frontal sinuses can be particularly persistent, even after surgery and/or medical therapy has resolved the inflammation in the other paranasal sinuses. In cases of persistent inflammation of the frontal sinuses, a surgery known as a trans-septal frontal sinusotomy, or modified Lothrop procedure, is sometimes performed. In this procedure, the surgeon removes a portion of the nasal septum and the bony partition between the sinuses to form one large common drainage channel for draining the frontal sinuses into the nose. This complicated procedure, as well as some other ear, nose and throat surgical procedures, can carry a risk of penetrating the cranial vault and causing leakage of cerebrospinal fluid (CSF). Also, some sinus surgeries as well as other ear, nose and throat procedures are performed close to the optic nerves, the eyes, and the brain and can cause damage to those structures. To minimize the potential for such untoward complications or damage, image-guided surgery systems have been used to perform some complex head and neck procedures. In image guided surgery, integrated anatomical information is supplied through CT-scan images or other anatomical mapping data taken before the operation. Data from a preoperative CT scan or other anatomical mapping procedure is downloaded into a computer and special sensors known as localizers are attached to the surgical instruments. Thus, using the computer, the surgeon can ascertain, in three dimensions, the precise position of each localizer-equipped surgical instrument at any given point in time. This information, coupled with the visual observations made through the standard endoscope, can help the surgeon to carefully position the surgical instruments to avoid creating CSF leaks and to avoid causing damage to nerves or other critical structures. Shortcomings of FESS Although FESS continues to be the gold standard therapy for severe sinuses, it has several shortfalls. Often patients complain of the post-operative pain and bleeding associated with the procedure, and a significant subset of patients remain symptomatic even after multiple surgeries. Since FESS is considered an option only for the most severe cases (those showing abnormalities under CT scan), a large population of patients exist that can neither tolerate the prescribed medications nor be considered candidates for surgery. Further, because the methodologies to assess sinus disease are primarily static measurements (CT, MRI), patients whose symptoms are episodic are often simply offered drug therapy when in fact underlying mechanical factors may play a significant role. To date, there is no mechanical therapy offered for these patients, and even though they may fail pharmaceutical therapies, no other course of action is indicated. This leaves a large population of patients in need of relief, unwilling or afraid to take steroids, but not sick enough to qualify for surgery. One of the reasons why FESS and sinus surgery is so bloody and painful relates to the fact that straight instrumentation with rigid shafts are used. Due to the fact that the sinuses are so close to the brain and other important structures, physicians have developed techniques using straight tools and image guidance to reduce the likelihood of penetrating into unwanted areas. In an effort to target deep areas of the anatomy, this reliance on straight instrumentation has resulted in the need to resect and remove or otherwise manipulate any anatomical structures that may lie in the path of the instruments, regardless of whether those anatomical structures are part of the pathology. With the advances in catheter based technology and imaging developed for the cardiovascular system, there exists a significant opportunity to reduce the morbidity of sinus interventional through the use of flexible instrumentation and guidance. If flexible tools could be developed such that sinus intervention may be able to be carried out with even less bleeding and post-operative pain, these procedures may be applicable to a larger group of patients. Further, as described here, flexible instrumentation may allow the application of new diagnostic and therapeutic modalities that have never before been possible. Laser or Radiofrequency Turbinate Reduction (Soft Tissue Only) In cases where it is not necessary to revise the bone that underlies the turbinate, the surgeon may elect to perform a laser or radiofrequency procedure designed to create a coagulative lesion in (or on) the turbinate, which in turn causes the soft tissue of the turbinate to shrink. Also, in some cases, a plasma generator wand may be used create high energy plasma adjacent to the turbinate to cause a reduction in the size of the turbinate. One example of a radio frequency procedure that may be used to shrink enlarged inferior turbinates is radiofrequency volumetric tissue reduction (RFVTR) using the Somnoplasty® system (Somnus Medical Technologies, Sunnyvale, Calif.). The Somnoplasty® system includes a radio frequency generator attached to a probe. The probe is inserted through the mucosa into the underlying soft tissue of the turbinate, usually under direct visualization. Radiofrequency energy is then delivered to heat the submucosal tissue around the probe, thereby creating a submucosal coagulative lesion while allowing the mucosa to remain in tact. As the coagulative lesion heals, the submucosal tissue shrinks thereby reducing the overall size of the turbinate. Radiofrequency volumetric tissue reduction (RFVTR) can be performed as an office procedure with local anesthesia. Many of the above-described procedures and techniques may be adaptable to minimaly invasive approaches and/or the use of flexible instrumentation. There exists a need in the art for the development of such minimally invasive procedures and techniques as well as instrumentaion (e.g., flexible instruments or catheters) useable to perform such procedures and techniques. | <SOH> SUMMARY OF THE INVENTION <EOH>In general, the present invention provides methods, devices and systems for diagnosing and/or treating sinusitis or other conditions of the ear, nose or throat. In accordance with the present invention, there are provided methods wherein one or more flexible catheters or other flexible elongate devices as described herein are inserted in to the nose, nasopharynx, paranasal sinus, middle ear or associated anatomical passageways to perform an interventional or surgical procedure. Examples of procedures that may be performed using these flexible catheters or other flexible elongate devices include but are not limited to: delivering contrast medium; delivering a therapeutically effective amount of a therapeutic substance; implanting a stent, tissue remodeling device, substance delivery implant or other therapeutic apparatus; cutting, ablating, debulking, cauterizing, heating, freezing, lasing, dilating or otherwise modifying tissue such as nasal polyps, abberant or enlarged tissue, abnormal tissue, etc.; grafting or implanting cells or tissue; reducing, setting, screwing, applying adhesive to, affixing, decompressing or otherwise treating a fracture; delivering a gene or gene therapy preparation; cutting, ablating, debulking, cauterizing, heating, freezing, lasing, forming an osteotomy or trephination in or otherwise modifying bony or cartilaginous tissue within paranasal sinus or elsewhere within the nose; remodeling or changing the shape, size or configuration of a sinus ostium or other anatomical structure that affects drainage from one or more paranasal sinuses; removing puss or aberrant matter from the paranasal sinus or elsewhere within the nose; scraping or otherwise removing cells that line the interior of a paranasal sinus; removing all or a portion of a tumor; removing a polyp; delivering histamine, an allergen or another substance that causes secretion of mucous by tissues within a paranasal sinus to permit assessment of drainage from the sinus; implanting a cochlear implant or indwelling hearing aid or amplification device, etc. Further in accordance with the invention, there are provided methods for diagnosing and assessing sinus conditions, including methods for delivering contrast media into cavities, assessing mucosal flow, assessing passageway resistance and cilliary function, exposing certain regions to antigen challenge, etc Still further in accordance with the invention, there are provided novel devices for performing some or all of the procedures described herein. Further aspects, details and embodiments of the present invention will be understood by those of skill in the art upon reading the following detailed description of the invention and the accompanying drawings. | 20040421 | 20100202 | 20051027 | 74715.0 | 1 | HALL, DEANNA K | DEVICES, SYSTEMS AND METHODS FOR DIAGNOSING AND TREATING SINUSITUS AND OTHER DISORDERS OF THE EARS, NOSE AND/OR THROAT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,830,144 | ACCEPTED | Tourniquet article | The present invention relates generally to first aid articles and more specifically tourniquets. One embodiment of the claimed subject matter includes a tourniquet article comprising a base, a cap disposed on said base, a strap having one free end and one end attached to said base, a buckle attached to said base, a handle with an aperture to accommodate a portion of said strap, a ring attached to said base positioned adjacent to said base, wherein said tourniquet article is positioned around a limb, wherein said free end of said strap is pulled through both said ring and said handle aperture whereby said article is initially tightened around the limb, wherein said handle is turned until adequate pressure is applied to the limb, and wherein once adequate pressure is applied to the limb, one end of said handle is inserted into said ring to secure the tightened tourniquet in place. Another embodiment includes a safety screw disposed in said buckle, wherein said screw is tightened to prevent said strap from slipping. Another embodiment has a ring that is movable along the base. Another embodiment of the tourniquet article further includes a second ring disposed on said base positioned adjacent to said buckle. | 1. A tourniquet article comprising: a base; a cap disposed on said base; a strap having one free end and one end attached to said base; a buckle attached to said base; a handle with an aperture to accommodate a portion of said strap; a ring attached to said base positioned adjacent to said base; wherein said tourniquet article is positioned around a limb; and wherein said free end of said strap is pulled through both said ring and said handle aperture whereby said article is initially tightened around the limb; and wherein said handle is turned until adequate pressure is applied to the limb; and wherein once adequate pressure is applied to the limb, one end of said handle is inserted into said ring to secure the tightened tourniquet in place. 2. A tourniquet article of claim 1 further comprising a safety screw disposed in said buckle, wherein said screw is tightened to prevent said strap from slipping. 3. A tourniquet article of claim 1 wherein said ring is moveable along said base. 4. A tourniquet article of claim 1 further comprising a second ring disposed on said base positioned adjacent to said buckle. | CROSS-REFERENCES TO OTHER RELATED PATENT APPLICATIONS Not Applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to medical devices used in first aid. More specifically, this invention relates to improvements in tourniquets used for emergency medical use. 2. Description of Related Art Tourniquet cuffs are used primarily to achieve occlusion of arterial bloodflow. A typical tourniquet is a tightly tied band applied around a body part (an arm or a leg) in an attempt to stop severe bleeding or uncontrolled hemorrhage in an emergency situation. Tourniquets frequently found in the prior art consist of tightly tied bands that are applied around a body part such as an arm or a leg to stem the flow of blood. In one example of the application of a tourniquet, a piece of rubber tubing is wrapped around the limb and tied tightly. A stick is wound underneath the tubing and twisted until the tubing is tightened so that the bleeding is stopped. The tubing must not be tightened more than what is required to stop the bleeding. Once an adequate pressure on the limb is achieved, the stick is tied into its position with additional tubing or bandages. Other items that can be used for a tourniquet include a belt, rope, string, wire, twine, and sections of clothing. BRIEF SUMMARY OF THE INVENTION The present invention relates generally to first aid articles and more specifically tourniquets. One embodiment of the claimed subject matter includes a tourniquet article comprising a base, a cap disposed on said base, a strap having one free end and one end attached to said base, a buckle attached to said base, a handle with an aperture to accommodate a portion of said strap, a ring attached to said base positioned adjacent to said base, wherein said tourniquet article is positioned around a limb, wherein said free end of said strap is pulled through both said ring and said handle aperture whereby said article is initially tightened around the limb, wherein said handle is turned until adequate pressure is applied to the limb, and wherein once adequate pressure is applied to the limb, one end of said handle is inserted into said ring to secure the tightened tourniquet in place. Another embodiment includes a safety screw disposed in said buckle, wherein said screw is tightened to prevent said strap from slipping. Another embodiment has a ring that is movable along the base. Another embodiment of the tourniquet article further includes a second ring disposed on said base positioned adjacent to said buckle. Having thus described embodiments of the present invention, it is the principal object of the present invention to provide an improved tourniquet article that can be used on a limb using one hand to place and secure the tourniquet article. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS The above and other objects, advantages and features of the present invention will be more readily apparent from the following description, when read in conjunction with the accompanying drawings wherein: FIG. 1 is a perspective view of an embodiment of the claimed subject matter; FIG. 2 is a diagram illustrating the components of an embodiment of the claimed subject matter. DETAILED DESCRIPTION OF THE INVENTION The present invention makes use of lightweight and rugged materials which allows the article to be carried into the field. This invention also allows the use to apply the tourniquet article with one hand instead of two which can be a crucial lifesaving feature in the battlefield when assistance from a medic is not immediately available and the injured still has some ability to prevent a large loss of blood in his or her body. The tourniquet can also be used in emergency first aid for animals such as horses. Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the views, FIGS. 1 and 2 illustrate an embodiment of the tourniquet article designated generally by the numeral 10. The tourniquet article 10 as shown in FIGS. 1 and 2 comprises an elongated assembly of multiple components. Illustrated in FIG. 1 is a component view of the article 10. Base 12 is made of a 2″×8½″ section of webbing B, a 2″×8 1/2″ section A of looped end Velcro® affixed to the under side of the webbing B, and a 2″×3″ piece of webbing C affixed to the upper side of the webbing B. Webbing B is made of a 16 point heavy weight polypropylene material and webbing C is made of nylon scuba webbing but each can be made of any other suitable material, for example webbing C can be made of a plastic material. Section A can also be made of a non skid or non slip fabric or any other suitable material. The separate sections can be joined or combined by sewing, bonding or by used any suitable means. In the present embodiment, webbing B and section A are sewn together. The looped end of Velcro® Section A is positioned so the bottommost layer of loop is in contact with the limb when the tourniquet article 10 is used. Section A is used in this embodiment to increase friction between the tourniquet article 10 and the limb and to provide padding between webbing B and the tissue of the limb. Section A also helps protect the skin and soft tissue from pinching and bruising that can be associated with the use of the tourniquet article 10. Section A also helps the user in applying tourniquet article 10 by holding the tourniquet in place and allowing the user to apply article 10 with one hand. Webbing C is attached to the upper facing side of webbing B about 2″ in distance from the end of the webbing B base positioned beneath the handle G. Scuba nylon webbing is used for webbing C in the present embodiment to increase the rigidity of the base 12 and to prevent binding or crushing of base 12 when handle G is twisted or turned. In another embodiment, several sections of scuba webbing can also be used together as webbing C instead on one section, and this can further facilitate the needs of rigidity while still being flexible enough for use with a limb in addition to making article 10 easier to store and carry. Velcro® section A, webbing B and webbing C can each be constructed of scuba webbing and additionally, each section of base 12 can be lengthened, shortened, narrowed or widened. Additional padding can also be added to base 12, or individually to section A, webbing B or webbing C. One or more adhesive strips may also be used to bond one or more of these sections of base 12. In this embodiment, cap F is positioned and attached to the top of base 12. Cap F maintains the strap H in proximity to the base 12 and as such maintains strap H in flat orientation in relation to base 12. Cap F is a 2 inch by 2 inch section of nylon scuba webbing sewn on to base 12 along the two edges or outer sides of webbing B. Cap F can also be made of a plastic sleeve, or a combination of plastic and polypropylene webbing which can be used to increase the rigidity of cap F. Cap F can also be bonded or attached in any suitable manner to base 12. Cap F functions helps maintain the form of strap H when strap H is being tightened and it also prevents twisting of the strap H before strap H is tightened around the top of base 12. Cap F accomplishes maintains the form of strap H by working in conjunction with base 12 acting as a rigid sleeve or a sandwich in which strap H must pass through before making contact with the limb. In this embodiment, cap F also provides a point of attachment for the second locking ring without interfering with the function of strap H. Base 12 and cap F can also be made thinner and with lighter weight material so that the tourniquet article is more pliable and less bulky depending on the needs of the user. This reduction of bulk can make it easier in some situations to apply the tourniquet article 10 to a limb, but in all the embodiments, base 12 and cap F maintain a flat surface against the limb to help prevent cuff migration. The tightening system consists of handle G, strap H, and buckle D. Handle G is constructed of ½″ T016 aircraft grade aluminum rods cut to a length of 5.5 inches. Handle G is beveled and notched on the surface area at each end of handle G to facilitate the securing of handle G into the locking rings. Handle G also has a 0.156″×1.219″ aperture positioned in the center of handle G which allows for the passage of strap H. The slot is slightly wider than strap H which allows more leeway in movement of handle G during tightening of tourniquet article 10 as well as making the article easier to fold and compact for storage. Handle G can also be gnarled, notched or beveled on one or more sides to provide a tighter grip to the user for purpose of tightening the tourniquet article 10. Handle G can also be longer or shorter, made of a larger or smaller diameter, or made of another suitable material such as nylon, plastic, or composite. Buckle D is a quick release type buckle which allows the user to quickly release strap H. The quick release buckle used in the present embodiment is a standard one inch buckle tapped to accept a 1/4 inch machine screw. Buckle D can be any other suitable buckle such as a Fastek 1 and ½ inch buckle and it can also be a different size and dimension. The machine screw threads into the top of the buckle and the head rests on the base of the buckle. When engaged, Buckle D prevents accidental loosening of the tourniquet should buckle D be accidentally bumped or moved while the patient is being transported. Further, cap screw B can be used to help prevent movement of the strap H. In this embodiment, optional cap screw B is positioned in the top of cap F so as to allow the user to tighten the screw down the strap H further securing the strap H against unintended loosening. Cap screw E is a ¼″×⅝″ socket head cap screw, but it can be any desired width and length. Strap H is made of 16 point heavy weight polypropylene webbing that is 1 inch in width and 46 inches in length. It can also be made of any suitable size or material. For example, it can range from 1 inch in width to 2 and 1/2 inches in width. It can also be longer or shorter than 46 inches in length, and the material it is made of can be nylon webbing instead of poypropylene. One end of strap H is routed around the quick release buckle and attached to base 12. In the present embodiment, Strap H is sewn to base 12. The free end of Strap H is first routed through ring K and attached to base 12. From the point of attachment to base 12, the free end of Strap H is then routed through the aperture in handle G and sewn back onto itself forming a small loop that holds the handle in position with strap H. This loop is designed to provide enough slack so that twisting handle G does not cause base 12 to bind or twist. Once strap H is positioned to hold handle G, it is routed through the area above base 12 and below cap F so that the other end remains free to use by the user to be placed into the quick release buckle D in order to tighten the tourniquet article 10. Strap H can also be secured directly to base 12 with an allowance for a loop to run through handle G. As shown in FIGS. 1 and 2, rings K and L are used to in the present embodiment to secure strap H to base 12, but only one ring needs to be used. The rings are used to secure strap H in place when tourniquet article 10 is in use. Rings K and L consist of two 1″ actyl tri-rings. The rings can be of any suitable type such as D type or O type rings, they can also be made to swivel, and they can be made of any suitable material such as steel or aluminum. Ring K is secured to base 12 adjacent to the quick release buckle D. Strap H runs from the quick release buckle D to ring K where strap H is sewn to the base 12. Ring K is then positioned on the upper surface of strap H and, using a section of webbing which is placed over ring K and sewn to base 12, ring K is secured to strap H. Ring K is not able to freely move along the length of strap H, but ring K can be folded over to aid in storage. Ring L is positioned on the upper surface of cap F. Ring L is secured to cap F with a 1 inch by 2 inch 16 point polypropylene webbing J with the sides of webbing J sewn to cap F covering the lower portion of ring K. In this fashion, ring L can be moved closer or farther away from handle G so ring L can be positioned to assist locking handle G in place after tension has been applied to tourniquet article 10. In other embodiments, the one or more rings can be positioned on base 12 or cap F and any on of them can be attached directly or any one can have the ability to slide. Tourniquet article 10 is used in this embodiment with two rings which allow article 10 to be adjusted fit different sized and shaped limbs, for example limbs having conical or noncylindrical shapes, and which allow either or both ends of handle G to be inserted into one or both rings K and L to secure the handle G against slippage. In other instances, it may be desired to use more than two rings to allow more binding points at which strap H can be routed through allowing an even tighter fit for most uses. Base 12 can also be widened to give a greater tissue area allowing less pressure to be used to achieve hemostasis. Initially, tourniquet article 10 should be broken in by applying article 10 to a solid object and tightening the handle two to three times to loosed the webbing. This breaking in facilitates later one handed use. Article 10 is stored in a bag or pouch with strap H running through buckle D and safety cap screw E slightly loosened. To deploy tourniquet article 10 in a situation where one limb is disabled, strap H is grasped with the uninjured arm and tourniquet article 10 is slid over the injured extremity. Strap H is pulled as quickly as possible to remove excess slack in strap H and to initially tighten article 10 around the injured limb. Handle G is twisted until the bleeding is controlled and then handle G is latched into one or both rings K and L. It is not necessary to latch both ends of the handle G. The cap screw E located on quick release buckle D is then tightened to help prevent accidental loosening, and further medical treatment is sought. While the present invention has been illustrated and described by means of specific embodiments and alternatives, it is to be understood that numerous changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it should be understood that the invention is not to be limited in any way except in accordance with the appended claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to medical devices used in first aid. More specifically, this invention relates to improvements in tourniquets used for emergency medical use. 2. Description of Related Art Tourniquet cuffs are used primarily to achieve occlusion of arterial bloodflow. A typical tourniquet is a tightly tied band applied around a body part (an arm or a leg) in an attempt to stop severe bleeding or uncontrolled hemorrhage in an emergency situation. Tourniquets frequently found in the prior art consist of tightly tied bands that are applied around a body part such as an arm or a leg to stem the flow of blood. In one example of the application of a tourniquet, a piece of rubber tubing is wrapped around the limb and tied tightly. A stick is wound underneath the tubing and twisted until the tubing is tightened so that the bleeding is stopped. The tubing must not be tightened more than what is required to stop the bleeding. Once an adequate pressure on the limb is achieved, the stick is tied into its position with additional tubing or bandages. Other items that can be used for a tourniquet include a belt, rope, string, wire, twine, and sections of clothing. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention relates generally to first aid articles and more specifically tourniquets. One embodiment of the claimed subject matter includes a tourniquet article comprising a base, a cap disposed on said base, a strap having one free end and one end attached to said base, a buckle attached to said base, a handle with an aperture to accommodate a portion of said strap, a ring attached to said base positioned adjacent to said base, wherein said tourniquet article is positioned around a limb, wherein said free end of said strap is pulled through both said ring and said handle aperture whereby said article is initially tightened around the limb, wherein said handle is turned until adequate pressure is applied to the limb, and wherein once adequate pressure is applied to the limb, one end of said handle is inserted into said ring to secure the tightened tourniquet in place. Another embodiment includes a safety screw disposed in said buckle, wherein said screw is tightened to prevent said strap from slipping. Another embodiment has a ring that is movable along the base. Another embodiment of the tourniquet article further includes a second ring disposed on said base positioned adjacent to said buckle. Having thus described embodiments of the present invention, it is the principal object of the present invention to provide an improved tourniquet article that can be used on a limb using one hand to place and secure the tourniquet article. | 20040421 | 20100817 | 20051027 | 57862.0 | 3 | NGUYEN, VI X | TOURNIQUET ARTICLE | SMALL | 0 | ACCEPTED | 2,004 |
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10,830,160 | ACCEPTED | Compact co-axial rotor system for a rotary wing aircraft and a control system therefor | A dual, counter rotating, coaxial rotor system provides an upper and lower rotor system, with a reduced axial rotor separation distance along a common axis by means of rotor tip position sensing and rotor position controls to avoid tip contact. | 1. A coaxial rotor system comprising: a first rotor system which rotates about an axis; a second rotor system which rotates about said axis, said second rotor system spaced an axial distance from said first rotor system; and a rotor control system which independently controls said first rotor system and said second rotor system to maintain a minimum rotor blade tip separation between a first rotor blade tips of the first rotor system and a second rotor blade tips of the second rotor system. 2. The coaxial rotor system as recited in claim 1, further comprising a rotor blade tip position sensing system in communication with said rotor control system. 3. The coaxial rotor system as recited in claim 2, further comprising a rotor blade mounted member to independently control each rotor blade of each of said first rotor system and said second rotor system in response to said rotor control system and said blade tip position sensing system. 4. The coaxial rotor system as recited in claim 3, wherein said rotor blade mounted member comprises a servo flap. 5. The coaxial rotor system as recited in claim 3, wherein said rotor blade mounted member comprises a tip brake. 6. The coaxial rotor system as recited in claim 2, further comprising a first pitch control assembly which articulates said first rotor system and a second pitch control assembly which articulates said second rotor system, said first pitch control assembly controlled independent of said second pitch control assembly in response to said rotor control system. 7. The coaxial rotor system as recited in claim 1, further comprising a first swash plate which articulates said first rotor system and a second swash plate which articulates said second rotor system, said first swash plate controlled independent of said second swash plate in response to said rotor control system. 8. The coaxial rotor system as recited in claim 1, further comprising a higher harmonic blade control which independently articulates said first rotor system and said second rotor system in response to said rotor control system. 9. The coaxial rotor system as recited in claim 1, wherein each of said first and second rotor systems comprise a multiple of bend-twist coupled rotor blades. 10. The coaxial rotor system as recited in claim 1, further comprising a flight control system in communication with said rotor control system to prohibit entry into a predefined portion of a flight envelope which exceed said minimum rotor tip separation. 11. A method of controlling a coaxial rotor system comprising the steps of: (1) locating a first rotor system and a second rotor system along a common axis, the second rotor system spaced an axial distance from the first rotor system; and (2) independently controlling the first rotor system and the second rotor system to maintain a minimum rotor blade tip separation between a rotor blade tip of the first rotor system and a rotor blade tip of the second rotor system. 12. A method as recited in claim 11, wherein said step (2) further comprising the step of: independently controlling the first rotor system and the second rotor system through one or more rotor blade mounted control surfaces located on each rotor blade of the first rotor system and the second rotor system. 13. A method as recited in claim 12, further comprising the step of: pitching each of a multiple of rotor blades of the first rotor system a multiple of times during each rotation of the first rotor system through a higher harmonic control system; and independently pitching each of a multiple of rotor blades of the second rotor system a multiple of times during each rotation of the second rotor system through the higher harmonic control system. 14. A method as recited in claim 12, further comprising the step of: actuating a tip brake on at least one of a multiple of rotor blades of the first rotor system to maintain the minimum rotor separation between the first rotor system and the second rotor system. 15. A method as recited in claim 11, wherein said step (2) further comprising the step of: independently controlling the first rotor system and the second rotor system through a respective first pitch control assembly and second pitch control assembly located remotely from the first rotor system and the second rotor system. 16. A method as recited in claim 15, further comprising the step of: pitching each of a multiple of rotor blades of the first rotor system a multiple of times during each rotation of the first rotor system through a higher harmonic control system; and independently pitching each of a multiple of rotor blades of the second rotor system a multiple of times during each rotation of the second rotor system through the higher harmonic control system. 17. A method as recited in claim 11, wherein said step (2) further comprising the step of: limiting a flight envelope to maintain the minimum rotor separation. 18. A method as recited in claim 11, wherein said step (2) further comprising the step of: coupling a rotor blade bend-twist relationship on each of a multiple of rotor blades of the first rotor system and the second rotor system to maintain the minimum rotor separation between the first rotor system and the second rotor system. 19. A method as recited in claim 11, wherein said step (2) further comprising the step of: limiting the minimum rotor blade tip separation to approximately 3 percent of a rotor diameter of the first rotor system. 20. A method as recited in claim 11, wherein said step (2) further comprising the step of: spacing the first rotor system and the second rotor system along the common axis an axial distance less than 10 percent of a rotor diameter of the first rotor system and the second rotor system. 21. A method as recited in claim 11, wherein said step (2) further comprising the step of: adjusting the minimum rotor blade tip separation in response to an area of a flight envelope. | BACKGROUND OF THE INVENTION The present invention relates to a coaxial rotor system, and more particularly to a coaxial rotor system with closely spaced articulated rotors. Future military forces require enhanced vertical lift capabilities in a compact package. The CH-53E is currently the world's largest shipboard compatible helicopter. A significant consideration in the design of the CH-53E was shipboard compatibility. The CH-53E effectively defines the maximum aircraft spatial capacity which will fit on the elevators and in the hangar deck of United States Marine Corps Amphibious Assault Ships, more commonly called an LHA or LHD. Emerging payload weight requirements are beyond the growth capabilities of the CH-53E while maintaining current shipboard compatibility requirements. Thus, a conventional helicopter configuration like the CH-53E would be too large to fit in the hangar deck or on the elevator of an LHA or LHD. Conventional coaxial rotor systems are exceeding efficient as lift generating mechanism for a heavy lift VTOL aircraft. There are no power losses to an anti torque device and rotor efficiency is somewhat improved relative to a single rotor due to swirl recovery. The aircraft also has a much lower foot print due to the lack of a tail rotor and supporting boom structure. Disadvantageously, conventional dual counter rotating coaxial rotor systems require a relatively large separation between the rotor systems. This drives the height of a coaxial rotor aircraft to be taller than that of a single rotor aircraft. Typically the rotor or disks of a conventional dual counter rotating coaxial rotor system are axially spaced a distance of approximately 10 percent of the rotor diameter. Such a separation is required to provide adequate space for differential rotor blade flapping and bending to assure clearance therebetween regardless of aircraft maneuver. The blade tip position of a conventional coaxial rotor system is determined by the natural equilibrium of aerodynamic and inertial forces acting on the blade. Since the rotors are counter rotating, many maneuvers cause mirror image, or differential, rotor tilt, which reduces tips separation at some point in the rotation. It has been found from decades of industry experience that a hub separation distance of 10% of rotor diameter is adequate for most transport types of aircraft. Disadvantageously, application of such rotor spacing to a heavy lift VTOL aircraft which are capable of emerging vertical lift requirements result in an aircraft which will likely not meet current shipboard height compatibility restrictions. Accordingly, it is desirable to provide an affordable heavy lift VTOL aircraft with low to moderate risk technologies while being compatible with current shipboard restrictions. SUMMARY OF THE INVENTION The invention described herein utilizes rotor position control through a variety of methods singularly, or in any combination determined to be most advantageous, to reduce the separation between coaxial rotors and hence reduce the overall height of the aircraft such that the aircraft fits within the hangar deck of an amphibious assault ship. The dual, counter rotating, coaxial rotor system according to the present invention provides an upper and lower rotor system which are separated by an axial rotor separation distance of approximately 7.5% or less of the rotor system diameter along a common axis. The 7.5 percent separation distance is a reduction of approximately 25 percent over conventional coaxial rotor systems which are typically separated by at least 10 percent. The rotor system requires a blade tip separation clearance between the rotor flapping ranges to assure that the rotor blade tips will not contact. As found from decades of industry experience with conventional coaxial rotor systems the minimum tip separation clearance in any maneuver is approximately 3 percent of the rotor system diameter or approximately 35 percent of the axial distance between the rotor systems. The present invention determines the relative position of the blades of each rotor system and independently controls each rotor and or blade such that blade flapping and blade elastic bending are significantly reduced, hence enabling reduced rotor separation. BRIEF DESCRIPTION OF THE DRAWINGS The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows: FIG. 1 is a general schematic view of an exemplary coaxial rotary wing aircraft embodiment for use with the present invention; FIG. 2 is a general schematic view of an exemplary coaxial rotary wing aircraft in a shipboard stored position; FIG. 3 is graphical representation of a tip separation between rotor systems of a coaxial rotor system in response to various maneuvers; FIG. 4 is a block diagram of one embodiment of a rotor control system according to the present invention; FIG. 5 is a block diagram of a servo-flap embodiment of a rotor control system according to the present invention; FIG. 6 is a block diagram of the rotor control system of FIG. 4 illustrating differential swash plate movement; FIG. 7 is a block diagram of a swash plateless servo-flap embodiment of a rotor control system according to the present invention; FIG. 8 is a block diagram of a tip brake embodiment of a rotor control system according to the present invention; FIG. 9 is a schematic view of a composite rotor blade embodiment of a blade bending control system according to the present invention; FIG. 10 is a schematic view of a bend-twist response of a composite rotor blade embodiment of FIG. 9; and FIG. 11 is a schematic view of a flight control envelope embodiment of a rotor control system according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically illustrates a rotary-wing aircraft 10 having a dual, counter rotating, coaxial rotor system 12. The aircraft 10 includes an airframe 14 which supports the dual, counter rotating, coaxial rotor system 12 along a common axis A. Although a particular helicopter configuration is illustrated in the disclosed embodiment, other coaxial propulsor systems which require closely spaced rotors or propellers in helicopter, airplane and/or tilt rotor type aircraft will also benefit from the present invention. The rotor system 12 includes an upper rotor system 16 and a lower rotor system 18 which rotate about the common axis A. Each rotor system 16, 18 include a multiple of rotor blades 20 mounted to a rotor hub 22, 24. The rotor systems 16, 18 are separated by an axial rotor separation distance Sa of less than 10 percent of the rotor system diameter D along common axis A. Preferably, the rotor systems 16, 18 are separated by an axial distance of approximately 7.5 percent or less of the rotor system diameter D along common axis A. The 7.5 percent separation distance is a reduction of approximately 25 percent over conventional coaxial rotor systems which are typically separated by at least 10 percent. Such a separation distance Sa provides a coaxial configuration which is relatively compact to fit within a conventional LHA and LHD hanger deck while permitting other storage under the folded rotor blades (FIG. 2). During various maneuvers, the rotor blade tips t of the rotor blades 20 will move through a flapping and bending range (defined schematically by arrows f1, f2 in FIG. 1 and by a maneuver chart in FIG. 3). The rotor systems 16,18 requires a rotor blade tip separation clearance Sc between the flapping range f1, f2 to assure that the rotor blade tips t will not contact. The separation clearance Sc is preferably 3 percent of the rotor system diameter D or approximately 35 percent of the axial distance Sa between the rotor systems 16,18. It should be understood that other clearances will benefit from the present invention; however, the 35 percent separation clearance has proved to be a relatively consistent effective separation value as practiced by numerous coaxial rotor system designs. Referring to FIG. 3, a chart represents rotor tip separation distances in response to various maneuvers. Applicant has determined that a coaxial rotor system with, for example, a 111 foot diameter rotor systems 16, 18 separated by only a 7% hub spacing results in rotor tip separation convergence which may fall below the separation clearance Sc (defined by the dotted line) when utilizing conventional rotor control systems. The rotor control systems cited below according to the present invention permit a 7% hub spacing while maintaining the 35% separation clearance Sc. Referring to FIG. 4, each rotor system 16a, 18a is independently controlled through a separate swashplate assembly 26a, 28a which selectively articulates each rotor system 16a, 18a. Generally, motion of the swash plate assembly 26a, 28a along the rotor axis A will cause the rotor blades 20 of the respective rotor system 16a, 18a to vary pitch collectively and tilting of the swash plate assembly 26a, 28a with respect to the axis A will cause the rotor blades 20 to vary pitch cyclically and tilt the rotor disk. The swash plate assemblies 26a, 28a translate and/or tilt by a separate servo mechanism 30a, 32a which selectively articulates each rotor system 16, 18 independently in both cyclic and collective in response to a rotor control system 34a (illustrated schematically). The rotor control system 34a communicates with a flight control system 36 which receive pilot inputs from controls such as a collective stick, cyclic stick, foot pedals and the like. A sensor suite 38 measures the relative position of the blades 20 on each rotor system 16, 18 such that the control system 34 determines the relative rotor blade 20 separation. The following paragraphs describe the rotor control methods used to minimize rotor flapping and bending and are applicable to blades controlled by the actuation methods listed above. Referring to FIG. 5, a rotor control system 34b includes a servo flap controlled rotor system 12b. The servo flap control system is a proven rotor control system in which a rotor blade position is achieved through a rotor blade mounted member. Each blade of rotor systems 16b, 18b includes a partial radius servo flap 42 of a servo flap system 40 through, for example only, a series of pushrods and bell cranks that run to relatively small swash plates in the aircraft. It should be understood that various actuators and trailing and leading edge slat mounting arrangements will benefit from the present invention. Actuators such as mechanical, electrical, pneumatic, piezoceramic, piezoelectric, hydraulic and the like, both within the blade and external thereto, will also benefit from the present invention. Referring to FIG. 6, a rotor control system 34a independently controls each swash plate assembly 26a, 28a, which selectively controls each rotor system 16a, 18a. That is, the swash plate assembly 26a, 28a are not mechanically linked together and are articulated separately through independent servo mechanisms 30a, 32a which communicates with the rotor control system 34a through a remote communication system such as a fly-by-wire and/or fly-by-light system. The control system 34a determines the relative position of the blades 20 on each rotor system 16a, 18b and independently controls each swash plate assembly 26a, 28a to reduce the differential flapping between the rotor systems 16a, 18a. In other words, if the rotor blade tips of one rotor system 16a are approaching the rotor blade tips of the other rotor system 18a, the swash plates 26a, 26b are moved differentially to perform the same maneuver while increasing separation between the rotor blade tips. For example, in forward flight or cruise the rotor blade tips will tend toward each other on one lateral side of the rotor systems 16a, 18a (FIG. 3). By articulating lateral differential cyclic in which swash plate 26a is moved to a relative positive position from the original position while swash plate 26b is moved to relatively negative position from the original position, the differential swash plate positions are effectively canceled, forward cyclic is unaffected, and the separation between the rotor blade tips is increased (also illustrated by cruise maneuver point in FIG. 3). The control system 34b preferably controls the servo flap system 40 in a higher harmonic control (HHC) methodology. That is, each servo flap 42 on each blade 20 of each rotor system 16b, 18b (FIG. 7) is pitched independently and at a rate greater than once per rotor revolution. This enables blade lift corrections as the blade travels around the azimuth. HIC includes the acquiring sensor data in real time and as a result of this data, each blade is controlled to provide the desired separation clearance Sc through defined algorithms. In addition the separation clearance Sc may be tailored to multiple performance objectives and different modes of operation, e.g. a high performance mode, a low noise mode, etc., and for different flight conditions and/or configurations, e.g., hover, forward flight, air-to-air engagement, etc. Implementation of HHC may additionally or alternatively include active control and/or prescribed motion functions in response to base conditions, e.g., forward flight, hover, etc. Referring to FIG. 8, another rotor control system 34c controls a tip brake 46 on each rotor blade 20c of each rotor system 16c, 18c (only one illustrated). The tip brakes 46 are preferably split flaps, which may be in addition to or integrated with servo flaps 42 (FIG. 7). That is, the servo flaps may be split flaps which also operate as tip brakes. Tip brakes are deployed on one rotor and create an unbalanced torque between the rotors. The unbalanced torque rotates, or yaws, the aircraft fuselage. The advantage of tip brakes is the zero change in blade lift, and hence no flapping response. Each tip brake 46 is operated in response to the control system 34c to reduce the differential flapping between the rotor systems 16c, 18c to maintaining the desired separation clearance Sc (illustrated by pedal yaw turn maneuver point in FIG. 3). Referring to FIG. 9, another rotor control system is structurally integrated within each rotor blade 20d by coupling the bend and twist deflections of the rotor blade through composite design and manufacturing processes generally understood. Referring to FIG. 10, preferably, the rotor blades 20du of the upper rotor system 16c are designed to increase pitch and hence increase blade lift when bending downward toward the lower rotor system 18c while the rotor blades 20dl of the lower rotor system 18c are designed to decrease pitch and hence reduce lift when bending upward toward the upper rotor system 16c. The coupling in bending and twisting forces the blades 20du, 20dl to maintain the desired separation clearance Sc. In other words, the blades 20du, 20dl will flap away from each other in response to a maneuver which causes the blades 20du, 20dl to bend toward each other. Referring to FIG. 11, another rotor control system 34e communicates with the flight control system 36 to selectively restrict portions of the rectangular flight envelope E. That is, certain control inputs, which will result in undesirable maneuvers within the flight envelope E, are prevented from occurring so as to maintain the desired separation clearance Sc. FIG. 11 shows typical flight envelope parameters; load factor (Nz, measured in g's), airspeed (V, measured in kts), and turn rate (measured in deg/sec). In general maneuvers that case excessive blade bending and flapping are located at the extreme corners of the envelope. A fly-by-wire (FBW) system enables advanced control laws where each rotor is controlled independently and will not accept pilot inputs that could place the coaxial rotor system into a flight state that may cause the rotor systems to converge and possibly contact. The resulting allowable flight envelope is shown as the truncated rectangular volume in FIG. 11. Other envelopes including longitudinal and rotational rates and accelerations in each axis can be superimposed to further restrict the aircraft operating envelope to ensure rotor tip clearance Sc. Moreover, FBW and/or HHC application to co-axial rotor systems permit the reduction or elimination of the tail as well as reduce rotor separation. Although the rotor control systems disclosed herein are discussed individually, any rotor control system may be utilized with any other or a multiple of other rotor control systems disclosed herein or otherwise known. It should be understood that one rotor control system may be preferred in one area or maneuver in the flight envelope while another rotor control system may be preferred for another area or maneuver in the flight envelope. Preferably, a combination of rotor control systems are utilized to assure desired separation clearance Sc throughout the entire flight envelope. It should be understood that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting. Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention. The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a coaxial rotor system, and more particularly to a coaxial rotor system with closely spaced articulated rotors. Future military forces require enhanced vertical lift capabilities in a compact package. The CH-53E is currently the world's largest shipboard compatible helicopter. A significant consideration in the design of the CH-53E was shipboard compatibility. The CH-53E effectively defines the maximum aircraft spatial capacity which will fit on the elevators and in the hangar deck of United States Marine Corps Amphibious Assault Ships, more commonly called an LHA or LHD. Emerging payload weight requirements are beyond the growth capabilities of the CH-53E while maintaining current shipboard compatibility requirements. Thus, a conventional helicopter configuration like the CH-53E would be too large to fit in the hangar deck or on the elevator of an LHA or LHD. Conventional coaxial rotor systems are exceeding efficient as lift generating mechanism for a heavy lift VTOL aircraft. There are no power losses to an anti torque device and rotor efficiency is somewhat improved relative to a single rotor due to swirl recovery. The aircraft also has a much lower foot print due to the lack of a tail rotor and supporting boom structure. Disadvantageously, conventional dual counter rotating coaxial rotor systems require a relatively large separation between the rotor systems. This drives the height of a coaxial rotor aircraft to be taller than that of a single rotor aircraft. Typically the rotor or disks of a conventional dual counter rotating coaxial rotor system are axially spaced a distance of approximately 10 percent of the rotor diameter. Such a separation is required to provide adequate space for differential rotor blade flapping and bending to assure clearance therebetween regardless of aircraft maneuver. The blade tip position of a conventional coaxial rotor system is determined by the natural equilibrium of aerodynamic and inertial forces acting on the blade. Since the rotors are counter rotating, many maneuvers cause mirror image, or differential, rotor tilt, which reduces tips separation at some point in the rotation. It has been found from decades of industry experience that a hub separation distance of 10% of rotor diameter is adequate for most transport types of aircraft. Disadvantageously, application of such rotor spacing to a heavy lift VTOL aircraft which are capable of emerging vertical lift requirements result in an aircraft which will likely not meet current shipboard height compatibility restrictions. Accordingly, it is desirable to provide an affordable heavy lift VTOL aircraft with low to moderate risk technologies while being compatible with current shipboard restrictions. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention described herein utilizes rotor position control through a variety of methods singularly, or in any combination determined to be most advantageous, to reduce the separation between coaxial rotors and hence reduce the overall height of the aircraft such that the aircraft fits within the hangar deck of an amphibious assault ship. The dual, counter rotating, coaxial rotor system according to the present invention provides an upper and lower rotor system which are separated by an axial rotor separation distance of approximately 7.5% or less of the rotor system diameter along a common axis. The 7.5 percent separation distance is a reduction of approximately 25 percent over conventional coaxial rotor systems which are typically separated by at least 10 percent. The rotor system requires a blade tip separation clearance between the rotor flapping ranges to assure that the rotor blade tips will not contact. As found from decades of industry experience with conventional coaxial rotor systems the minimum tip separation clearance in any maneuver is approximately 3 percent of the rotor system diameter or approximately 35 percent of the axial distance between the rotor systems. The present invention determines the relative position of the blades of each rotor system and independently controls each rotor and or blade such that blade flapping and blade elastic bending are significantly reduced, hence enabling reduced rotor separation. | 20040421 | 20060801 | 20051027 | 60177.0 | 0 | COLLINS, TIMOTHY D | COMPACT CO-AXIAL ROTOR SYSTEM FOR A ROTARY WING AIRCRAFT AND A CONTROL SYSTEM THEREFOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,830,173 | ACCEPTED | Powder-coated toner particles | A color toner composition for developing latent electrostatic images includes nanopowder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. Preferably, the weight fraction of colorant powder particles is from about 0.3 to about 3 times the product, (ρp/ρr) (d/r) (1+d/r)2, where ρp is the density of the colorant powder particles, ρr the density of the core resin particles, d, the volumetric mean diameter of the colorant powder particles and r the volumetric mean radius of the toner core resin particles. | 1. A color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. 2. The color toner composition according to claim 1, wherein the ratio of the volume average diameter of the core toner particles to the volume average diameter of the colorant powder particles is at least about 10. 3. The color toner composition according to claim 1, wherein the ratio of the volume average diameter of the core toner particles to the volume average diameter of the colorant powder particles is at least about 50. 4. The color toner composition according to claim 1, wherein the ratio of the volume average diameter of the core toner particles to the volume average diameter of the colorant powder particles is at least about 100. 5. The color toner composition according to claim 1, wherein the weight fraction of colorant powder particles is at least about 0.025 based on the combined weight of core toner particles and colorant particles. 6. The color toner composition according to claim 5, wherein the weight fraction of colorant powder particles is at least about 0.05 based on the combined weight of core toner particles and colorant particles. 7. The color toner composition according to claim 1, wherein the weight fraction of colorant powder particles is from about 0.3 to about 3 times the product, (ρp/ρr) (d/r) (1+d/r)2, where ρp is the density of the colorant powder particles, ρr the density of the core resin particles, d, the volumetric mean diameter of the colorant powder particles and r the volumetric mean radius of the toner core resin particles. 8. The toner composition according to claim 1, wherein 80 vol. % of the core toner particles are in the diameter range of about 0.5 to 1.5 times of the volumetric average diameter. 9. The toner composition according to claim 1, wherein the resin core particles further comprise a wax. 10. The toner composition according to claim 9, wherein the resin core comprises a polymer selected from the group consisting of polyester resins and styrenic copolymer resins. 11. The toner composition according to claim 9, wherein the wax is selected from a group consisting of paraffinic wax, ester wax, amide wax, polyethylene wax, polypropylene wax, Canauba wax and bee's wax. 12. The toner composition according to claim 9, wherein the resin core comprises a wax in the amount of from about 0 to about 30 weight percent parts of the toner composition. 13. The toner composition according to claim 1, further comprising a charge control agent selected from a group consisting of negative and positive charge control agents. 14. The toner composition according to claim 1, wherein the colorant powder particles comprise a pigment selected from the group consisting of cyan, magenta, yellow and black pigments. 15. The toner composition according to claim 1, wherein the toner composition further comprises one or more particle flow agents selected from the group consisting of hydrophobic silica, hydrophilic silica, titanium oxide, zinc stearate, magnesium stearate, alumina, calcium titanate, polymethylmethacrylate particles, polyester particles and silicon polymer particles, as an external additive. 16. A particulate toner composition for development of latent electrostatic images comprising: toner particles consisting of a resin core consisting of a resin with the weight average molecular weight in the range of about 5,000 and about 40,000 g/mol and the glass transition temperature in the range of about 40° C. and about 90° C.; a colorant particle in the amount of about 3 to about 30 weight % embedded in the peripheral region of the core to form powder coated toner particles; and, optionally, a protective resin layer overcoated over the powder coated toner particles, wherein a volume average diameter of the toner particles is in the range of 3 and 12 microns with 80 vol. % of the particles in the diameter range of from about 0.5 to 1.5 times that of the volumetric average diameter. 17. A color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, the toner particles having affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, as well as a melt-fused protective polymer operative to secure the powder to the core toner particles, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles, colorant particles and protective resin. 18. A method of producing a toner composition for developing latent electrostatic images comprising: (a) admixing toner core particles having a volume average diameter, Dp, with a powder colorant composition having a volume average particle diameter, dp, the ratio Dp/dp being at least about 5; and (b) dispersing the powder colorant composition over the surfaces of the toner core particles under conditions effective to affix the powder to the surfaces of the core particles such that the core particles have a plurality of discrete toner particles of lesser size affixed to their surfaces. 19. The method according to claim 18, carried out under substantially dry conditions. 20. A method of producing a toner composition for developing latent electrostatic images comprising: (a) admixing toner core particles having a volume average diameter, Dp, with a powder colorant composition having a volume average particle diameter, dp, the ratio Dp/dp being at least about 5, and with a powder resin component having a volume average particle diameter, dp′, the ratio of Dp/dp′ also being at least about 5; (b) dispersing the powder colorant composition and the powder resin component over the surfaces of the toner core particles under conditions effective to affix the powders to the surfaces of the core particles such that the core particles have a plurality of discrete powder particles of resin and colorant of lesser size than the core toner particles affixed to their surfaces; and (c) melting the powder resin component to further secure the powder colorant composition to the resin core particles. | CLAIM FOR PRIORITY This application claims priority based on Korean Application Number: 10-2003-0030477, filed May 14, 2003. FIELD OF THE INVENTION This invention generally relates to color toner compositions and a method of producing toners for developing latent electrostatic images in electrophotography, electrostatic recording and electrostatic printing. More specifically, this invention is directed to a color toner composition for developing latent electrostatic images that includes powder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. The colorant powder is in the nanosize range as described hereinafter. BACKGROUND OF THE INVENTION The formation and development of images on the surface of photoconductive materials by electrostatic means is well known. The basic electrophotographic imaging process as disclosed in U.S. Pat. No. 2,297,691 describes placing a uniform electrostatic charge on a photoconductive insulating layer known as a photoconductor or photoreceptor, exposing the photoreceptor to a light and shadow image to dissipate the charge on the areas of the photoreceptor exposed to the light, and developing the resulting electrostatic latent image by depositing on the image a finely divided electroscopic toner material. The toner will normally be attracted to those areas of the photoreceptor which retain a charge, thereby forming a toner image corresponding to the electrostatic latent image. This developed image may then be transferred to a substrate such as paper. The transferred image subsequently may be permanently affixed to the substrate by heat, pressure, a combination of heat and pressure, or other suitable fixing means such as solvent or over coating treatment. Electrostatic images formed on an electrophotographic photoconductor and an electrostatic recording medium are typically developed by using (i) a mono-component type dry developer consisting of a toner including a coloring agent such as a dye or pigment and a binder resin in which the coloring agent is dispersed, or with addition of a charge controlling agent thereto when necessary, or (ii) a two-component type dry developer including the above-mentioned powder-coated toner and solid carrier particles. Toners and developer compositions including colored particles are well known. In this regard, see U.S. Pat. Nos. 5,352,521; 4,778,742; 5,470,687; 5,500,321; 5,102,761; 4,645,727; 5,437,953; 5,296,325 and 5,200,290, the disclosures of which are hereby incorporated in their entirety by reference. A traditional toner composition typically contains toner particles consisting of a binder resin and colorants, a wax or a polyolefin, a charge control agent, flow agents and other additives. A typical toner formulation typically contains about 90-95 weight percent resin, about 2-10 weight percent colorant, about 0-6 weight percent wax, about 0-3 weight percent charge control agent, about 0.25-1 weight percent flow agent and 0-about 1 weight percent other additives. Widely-used binder's resins are styrene-acrylic copolymers, styrene-butadiene copolymers and polyesters. The colorants usually are selected from cyan dyes or pigments, magenta dyes or pigments, yellow dyes or pigments, and mixtures thereof. In the course of an electrophotographic printing operation, toner particles are subjected to a number of complex steps such as charging, electrostatic transfer, fusing, etc. There is now a realization that toner particles must possess a balance of compositional, geometrical and physical properties to perform well in a modern electrographic printer. Examples of such properties are a small mean particle size, a uniform size distribution, fast and stable electrostatic charging, fast melting, good particle flowing characteristics, controlled presence of internal additives, such as wax and charge control agent. For example, it is difficult to obtain resolutions better than about 600 dots/inch when the average particle size is larger than about 7 μm. For resolutions, in the order of about 1200 dots/inch, particle sizes smaller than 5 μm are typically needed. Conventionally, color toner particles are produced by a mechanical milling process, for example, described in the U.S. Pat. No. 5,102,761. In that process, an acrylate resin is compounded with a pigment, a charge control agent (“CCA”), and occasionally a wax in a melt mixer. The resulting polymer mixture is mechanically crushed and then milled into small particles. Such a conventional toner process typically produces particles with an irregular shape and a broad distribution in particle size. Improvements in the methods of producing small toner particles with a uniform size distribution have been attempted in the past. For example, the aforementioned U.S. Pat. Nos. 5,352,521, 5,470,687 and 5,500,321 disclose toner particles produced by dispersion polymerization. In such a method, monomers (typically styrenic and acrylate monomers) and additives such as pigment, charge control agent and wax are mixed together to form a monomer dispersion. This is then further dispersed into an aqueous or a non-aqueous medium and the monomer is reacted to form toner particles. This method has the advantage over the aforementioned milling methods that spherical toner particles with a small mean diameter can be prepared. However, the polymerization involves a substantial volume contraction and it results in entrapment of the dispersion medium inside the resulting particles. Furthermore, the polymerization is difficult to complete and a substantial portion of the monomers remain in the toner particles. The residual monomers and the entrapped dispersion solvent are difficult to remove from the particles. Further, agents employed, such as dispersion-stabilizing agent and surface active agent, cause the charging characteristics and preservability of the toner particles to deteriorate by remaining on the surface of the toner particles and are difficult to remove. Another so-called chemical method for forming small toner particles is the emulsion aggregation method disclosed in U.S. Pat. Nos. 5,916,735 and 6,268,103. In a typical emulsion aggregation method, emulsion particles of sub-micron size are first formed using an emulsion polymerization process and toner particles are produced by aggregating the emulsion particles and subsequent drying. The method consists of many delicate process steps including the aggregation step and an extensive drying step. Additionally, the above-described chemical methods of manufacturing toner particles are applicable only for resins such as styrenic copolymer resins that are polymerized by an addition reaction. The methods therefore cannot be used for a polyester resin which is polymerized by a condensation reaction. U.S. Pat. No. 6,132,919 discloses a high-resolution toner composition with a core-shell structure, prepared by a suspension polymerization process. In this case, core particles are first prepared by polymerizing a suspension of monomer for core resin containing a colorant and toner particles and toner particles are then prepared by polymerizing shell monomer on the surface of the core particles that are dispersed in a liquid medium. There are several important limitations with such a core-shell toner. First, the core resin is required to have a lower glass transition temperature than that of the shell resin. The amount of colorant that one can incorporate is limited. Lastly, the process is impractically complex. There is continuing interest in developing improved toner composition including particles which have a novel arrangement of the component compounds and enabling methods of producing the toner particles with such a unique structure and properties for high-resolution color electrophotography. SUMMARY OF THE INVENTION There is provided in accordance with the present invention color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. Typically, the ratio of the volume average diameter of the core toner particles to the volume average diameter of the colorant powder particles is at least about 10, preferably at least about 50, and in some cases, at least about 100. The weight fraction of colorant powder particles usually is at least about 0.025 based on the combined weight of core toner particles and colorant particles, preferably the weight fraction of colorant powder particles is at least about 0.05 based on the combined weight of core toner particles and colorant particles. In preferred cases, the weight fraction of colorant powder particles is from about 0.3 to about 3 times the product, (ρp/ρr) (d/r) (1+d/r)2, where ρp is the density of the colorant powder particles, ρr the density of the core resin particles, d, the volumetric mean diameter of the colorant powder particles and r the volumetric mean radius of the toner core resin particles. So also, it is preferred that 80 vol. % of the core toner particles are in the diameter range of about 0.5 to 1.5 times of the volumetric average diameter. The resin core particles may further comprise a wax, and include a polymer selected from the group consisting of polyester resins and styrenic copolymer resins. Typically, if a wax is present, it is selected from a group consisting of paraffinic wax, ester wax, amide wax, polyethylene wax, polypropylene wax, Canauba wax and bee's wax, and the core includes a wax in the amount of from about 0 to about 30 weight percent parts of the toner composition. Optionally included is a charge control agent selected from a group consisting of negative and positive charge control agents. The colorant powder particles typically incude a pigment selected from the group consisting of cyan, magenta, yellow and black pigments, and the toner composition may further include one or more particle flow agents selected from the group consisting of hydrophobic silica, hydrophilic silica, titanium oxide, zinc stearate, magnesium stearate, alumina, calcium titanate, polymethylmethacrylate particles, polyester particles and silicon polymer particles, as an external additive. In one preferred embodiment, there is a particulate toner composition for development of latent electrostatic images comprising: toner particles consisting of a resin core consisting of a resin with the weight average molecular weight in the range of about 5,000 and about 40,000 g/mol and the glass transition temperature in the range of about 40° C. and about 90° C.; a colorant particle in the amount of about 3 to about 30 weight % embedded in the peripheral region of the core to form powder coated toner particles; and, optionally, a protective resin layer overcoated over the powder coated toner particles, wherein a volume average diameter of the toner particles is in the range of 3 and 12 microns with 80 vol. % of the particles in the diameter range of from about 0.5 to 1.5 times that of the volumetric average diameter. In another preferred embodiment, there is provided a color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, the toner particles having affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, as well as a melt-fused protective polymer operative to secure the powder to the core toner particles, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles, colorant particles and protective resin. A method of producing a toner composition of the present invention includes: admixing toner core particles having a volume average diameter, Dp, with a powder colorant composition having a volume average particle diameter, dp, the ratio Dp/dp being at least about 5; and dispersing the powder colorant composition over the surfaces of the toner core particles under conditions effective to affix the powder to the surfaces of the core particles such that the core particles have a plurality of discrete toner particles of lesser size affixed to their surfaces. The method may be carried out under substantially dry conditions. Another method of producing a toner composition of the present invention includes: admixing toner core particles having a volume average diameter, Dp, with a powder colorant composition having a volume average particle diameter, dp, the ratio Dp/dp being at least about 5, and with a powder resin component having a volume average particle diameter, dp′, the ratio of Dp/dp′ also being at least about 5; dispersing the powder colorant composition and the powder resin component over the surfaces of the toner core particles under conditions effective to affix the powders to the surfaces of the core particles such that the core particles have a plurality of discrete powder particles of resin and colorant of lesser size than the core toner particles affixed to their surfaces; and melting the powder resin component to further secure the powder colorant composition to the resin core particles. Further details will become apparent from the appended Figures and Examples. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic illustrating powder-coated toner particles including a meltable resin core and affixed colorant particles on the meltable resin core; FIG. 2 is a schematic illustrating powder-coated toner particles including a meltable resin core and affixed colorant particles on the meltable resin core with an overcoating of protective polymer resin; FIG. 3 is a scanning electron micrograph of meltable resin core particles in the absence of adhering colorant particles; and FIG. 4 is a scanning electron micrograph of a toner composition that includes meltable resin core particles and colorant particles affixed in the peripheral region of the meltable resin core particles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a particulate toner composition includes powder-coated toner particles 10 with meltable resin core 20 and colorant particles 30 on the peripheral region of the meltable resin core. The peripheral region of the powder-coated toner particles 10 may optionally include a charge control agent, and a wax. The powder-coated toner particles may have an outermost protective layer including a protective resin with the glass transition temperature greater than 55° C. and optionally of a charge control agent. The powder-coated toner particles 10 have a volume average diameter in the range of about 3 to about 12 μm, as well as a narrow diameter distribution of 80 vol. % of the particles having the particle diameter in the range of from about 0.5 to about 1.5 times that of the volumetric average diameter. The meltable resin core of the present invention includes a toner resin selected from a group consisting of polyester and styrenic copolymer resins. The resin is typically an amorphous resin with the glass transition temperature in the range of from about 40° C. to about 90° C. and having a weight average molecular weight in the range of from about 5000 g/mol to about 40,000 g/mol. Furthermore, the meltable resin core may encapsulate a wax in the interior section in the amount of from about 0 to about 30 wt. %. Many different types of waxes may be encapsulated in the meltable resin core particles of the present invention. Examples of a suitable wax are ester waxes, Canauba waxes, paraffin waxes, polyethylene waxes, polypropylene waxes and bee's wax. Among these, the ester waxes and the paraffin waxes are preferred. The meltable resin core 20 may be in any shape. Resin particles of the volumetric mean diameter (D) in the range of about 3 to about 12 μm are used to be the meltable resin core of this invention. Further, the resin particles with a narrow diameter distribution are preferred in this invention. More specifically, the particles with 80 vol. % in the size range of from about 0.5D to about 1.5D are preferred. One of a number of methods of producing resin particles may be used to prepare the meltable resin core 20 of this invention. It may be the aforementioned mechanical milling method. However, for meltable resin core particles of small volumetric mean diameter and a narrow diameter distribution, one of the methods selected from a group of suspension polymerization methods, emulsion polymerization methods, non-aqueous dispersion polymerization methods, emulsion aggregation methods and chemical milling methods is preferred. In the powder-coated toner particles of this invention, colorant particles 30 are affixed in the periphery of the meltable resin cores 20. The affixed structure is typically formed by first forming a layer of colorant particles on the meltable resin core surface utilizing attractive electrostatic interaction between the colorant particles and the meltable resin core and subsequently affixing the colorant particles on the meltable resin core surface by subjecting the structure to a temperature higher than the glass transition temperature of the resin. The amount of affixed colorant may constitute from about 3 to about 30 wt. % of the toner composition. The size of the colorant particles in relation to the size of meltable resin core must be carefully selected as the relative ratio determines the amount colorant one can coat on the meltable resin core surface. The maximum amount of colorant particles (W) that may be attached on the meltable resin core surface as a single particle layer is approximated by a relationship of the formula, W˜3(ρp/ρr) (d/r) (1+d/r)2 where ρp is the density of the colorant particle, ρr the density of the resin, d the volumetric mean diameter of the colorant particles and r the volumetric mean radius of the meltable resin core. This relation assumes that the colorant particles tend to coat the meltable resin core as a monolayer. If the diameter ratio between the meltable resin core and the colorant particles, for example, is about 50, W is in the order of about 0.1. Or, one can achieve 20 wt. % colorant loading with the diameter ratio of about 20. However, it is desirable to have the colorant size substantially smaller than that of the meltable resin core to ensure that the resin particles are coated with the colorant particles rather than the other way around. For the purpose of this invention, the diameter ratio is smaller than 1/5 and, preferably, smaller than 1/10. When the meltable resin core particles and pigment particles are admixed, surprisingly, the dissimilar particles develop opposite electrical charges and consequently attract to each other. Because the meltable resin core particles tend to be much larger than the pigment particles, the latter usually deposit themselves on the surface of meltable resin core particles. The operation can be carried out in a typical dry particle mixer, for example, a Henschel mixer. Without being bound to any theory, colorant particles can be affixed to periphery of the meltable resin core by interactions, for example, ionic, covalent, hydrophobic, hydrophilic, electrostatic, Van der Waals, or strong or weak physiochemical association. The colorants may include commonly known pigments. The pigments are typically selected from cyan pigments, yellow pigments, magenta pigments and black pigments. Illustrative black pigments may include carbon black, aniline black, non-magnetic ferrite and magnetite. Illustrative cyan pigments may include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye chelate compounds. Particularly preferred cyan pigments may include C. I. Pigment Blue 1, 7, 151, 152, 153, 154, 60, 62, and 66. Illustrative magenta pigments may include condensation azo-compounds, diketopyropyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye chelate compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds and perylene compounds. Particularly preferred magenta pigments may include C. I. Pigment Red 2, 3, 5, 6, 7, 23, 482, 483, 484, 811, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254. Illustrative yellow pigments may include condensation azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Particularly preferred yellow pigments may include C. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168 and 180. The colorants are selected by taking into account hue, chroma, brightness, weatherability, and transparency properties. The colorants may be used alone, in the form of a mixture, or in the state of a solid solution. Further, the colorant particles may be coated with a polymer film to facilitate adhesion of the colorant particles to the meltable resin core particles. Various known positive or negative charge controlling additives (CCA) can be incorporated in the toner compositions of the present invention, preferably in an amount of about 0.1 to about 15, more preferably from about 0.5 to about 5 wt. %. Charge control agent may be incorporated in the interior of the meltable resin core, or be affixed in the periphery of the meltable resin core along with the colorant particles, or added as external additive to the powder-coated toner particles. Examples of charge control agent may include quaternary ammonium compounds for example, alkyl pyridinium halides, alkyl pyridinium compounds, reference U.S. Pat. No. 4,298,672; organic sulfate and sulfonate compositions, U.S. Pat. No. 4,338,390; bisulfonates; ammonium sulfates (DDAES); distearyl dimethyl ammonium bisulfate (DDAMS), reference U.S. Pat. No. 5,114,821; cetyl pyridinium tetrafluoroborates; distearyl dimethyl ammonium methyl sulfate, aluminum salts, such as BONTRON E84™ or E88™ (Oriental Chemicals); quaternary ammonium nitrobenzene sulfonates; mixtures of charge enhancing additives, such as DDAMS and DDAES; other known charge additives; and the like, the disclosures of which are incorporated by reference herein in their entirety. Moreover, effective known internal and external additives may be selected for the toners of the present invention. Referring to FIG. 2, the outermost layer of the powder-coated toner particles of this invention may include an overcoating protective resin layer 40. The resin employed for the protective layer may be selected from a group consisting of polyester and styrenic copolymer resins. The protective resin layer 40 is typically an amorphous resin with a glass transition temperature in the range of from about 40° C. to about 150° C. having a weight average molecular weight in the range of from about 5000 g/mol to about 40,000 g/mol. The resin may be the same resin comprising the meltable resin core. The amount of resin used for the protective layer is in the range of from about 0 to about 50, preferably from about 5 to about 25 wt. %. A conventional coating method for powder may be used to deposit the protective layer. The toner particles may be blended with a suitable flowability improvement agent. They generally help to enhance the flowability of the particles during their use as color toner. Suitable flow agents are materials, for example, finely-divided particles of hydrophobic silica, titanium oxide, zinc stearate, magnesium stearate and the like which may be applied by processes such as, for example, dry mixing, solvent mixing and the like. In a typical process, a hydrophobic fumed silica (previously treated with a surface activating reagent such as, for example, hexamethyldisilazane and available under the trade name Cab-O-Sil® T-530 from Cabot Corporation, Tuscola, Ill.) is mixed with the charge control agent-coated particles and blended well in a tumble mixer for about 10-60 minutes to obtain flow agent-coated toner particles. It is preferred that the amount of flowability agents in the toner is in the range of from about 0.01 and about 10 parts per hundred relative to the finished toner weight. In the present invention, it is preferable to produce small powder-coated toner particles which have a volume average particle diameter (D) in the range from about 3 to about 12 μm. The terms “volume average particle diameter” is defined in, for example, Powder Technology Handbook, 2nd edition, by K. Gotoh et al, Marcell Dekker Publications (1997), pages 3-13. More specifically, it is preferable to produce powder-coated toner particles which include particles with a particle diameter distribution in the range of 0.5 times to 1.5 times the volume average diameter in an amount of 80 wt. % or more of the entire weight of the particles. The powder-coated toner particles with such a narrow particle diameter distribution provide powder-coated toner particles which have uniform quantity of electric charge in each powder-coated toner particle, and can provide high-quality copy images with a subsequent ease of charge control in a development unit In the present invention, the particle diameter distribution is measured by a commercially available Coulter LS Particle Size Analyzer (Coulter Electronics Co., Ltd., St. Petersburg, Fla.). The toner of the present invention can be formulated into a developer composition by mixing with carrier particles. Illustrative examples of carriers that can be selected for mixing with the toner compositions include those carriers that are capable of triboelectrically obtaining a charge of opposite polarity to that of the powder-coated toner particles. Accordingly, in embodiments, the carrier particles may be selected so as to be of an opposite polarity, for example, negative or positive polarity to depending on the polarity that of the powder-coated toner particles, which in turn may be positively or negatively charged. For example, positively charged powder-coated toner particles will adhere to and surround negatively charged carrier particles. Illustrative examples of carriers may include granular zircon, granular silicon, glass, steel, iron, nickel ferrites, such as copper zinc ferrites, copper manganese ferrites, and strontium hexaferrites, silicon dioxide, and the like. In embodiments, mixtures of coatings, such as KYNAR® and PMMA as illustrated in U.S. Pat. Nos. 4,937,166 and 4,935,326, mixtures of three polymers, mixtures of four polymers, polymer mixture pairs wherein each pair contains a conductive carrier coating and an insulating earner coating, can be selected. The carrier coating can be selected in various effective amounts, such as, for example, from about 0.1 to about 10 weight percent. Another embodiment of the present invention provides a method for producing a particulate toner composition for development of latent electrostatic images comprising powder-coated toner particles including a meltable resin core and colorants affixed in the peripheral region of the meltable resin core and optionally a protective resin layer coated over the core resin surface and further have the volume average diameter in the range of from about 3 to about 12 μm with 80 vol. % of the particles in the diameter range of from about 0.5 and about 1.5 times that of the volumetric average diameter. The method comprises charging a meltable dry meltable resin core comprising a resin with a glass transition temperature in the range of from about 40° C. to about 90° C. and colorant particles into a dry particle mixer; affixing colorant particles on the surface of the meltable resin core to form powder coated resin particles in the dry mixer; and optionally, fusing a protective resin as an overcoating on the powder coated resin particles. The disclosed method of producing toner affords a number of important technical and commercial advantages. It enables production of toners with a small mean diameter and a narrow diameter distribution while containing a high level of colorant loading. For a high-resolution toner with a small particle diameter in the order of 3-12 microns, it is imperative to have a high colorant loading to realize the high-resolution image with a sufficiently high optical density. The method, comprising a dry blending method that utilizes a surprising finding of attractive triboelectric charging behavior of dissimilar particles, is simple and reproducible, thereby offering a significant economical advantage over existing methods of toner production. Desirable characteristics of the meltable resin core particles were described earlier. Most importantly, the mean particle diameter and diameter distribution need to be carefully regulated as the mean diameter and diameter distribution of the toner particles are primarily determined by the properties of meltable resin core particles. The average diameter of toner particles needs to be smaller as the image resolution of a laser printer increases. However, even with the small size toners, the high image resolution also requires the file height of toner layer on paper to be small. This then necessitates a high colorant loading in the small size toner. Typically, 600 dpi toner particles contain a colorant in the amount about 5-8 wt. % with the particle mean diameter in the order of 8 μm. However, to achieve 2400 dpi resolution, it is expected that the toner particles diameter needs to be from about 3 about 4 μm and the colorant loading in the order of from about 15-20 wt. %. Accomplishing this with a conventional melt blending creates several significant difficulties. First, dispersing such a large amount of colorant in a resin requires a long and extensive mixing operation, which is expensive and often results in degradation of the resin. The particle formation process also becomes difficult to control as the dispersed colorant particles act as physical crosslinks. In contrast, the process of this invention allows incorporation of a large amount of colorant particles onto toner particles in a reproducible manner. Deposition of resin microparticles with the protective resin layer is also carried out in the dry particle mixer using triboelectric charging between dissimilar particles. The protective layer protects the colorant particles from being detached off the meltable resin core particle surface while being intermixed with carrier particles. For a similar reasoning to the above paragraph, the resin microparticles can include a mean diameter of ⅕ of the meltable resin core diameter and, preferably, {fraction (1/10)} of the meltable resin core diameter. The amount of resin microparticles used was in the range of from about 0 to about 50 wt. % of the meltable resin core. Electrostatic attractive force and van der Waals interaction between the meltable resin core particles, the colorant particles and the resin microparticles maintain the overall particle structure in a mild agitating condition. However, toner particles in a printer are subjected to considerable shearing stress. In a two-component development system, the toner particles are admixed with carrier particles and the developer composition is vigorously stirred to generate triboelectric charge on the toner particles. Alternatively, in a single-component development system, the toner particles are sheared against a charging roller or charging bar. It therefore is required to build a strong adhesion between the toner particles so that the vigorous shearing does not remove the colorant particles or the resin microparticles from the surface of the toner particles. This is typically achieved by subjecting the toner particles at a temperature higher than the glass transition temperature for an extended period while taking care not to have agglomeration of the toner particles. In practice, the resin particles coated with colorant particles and resin microparticles are dispersed in a bath containing an aliphatic hydrocarbon liquid medium, the temperature of the content is raised to about 100° C. and the particles are maintained with a mild agitation for about 30 minutes. Subsequently, the toner particles are cooled and the toner particles are separated by filtration and washed. The features of the present invention are further illustrated by the following examples, which are given for illustration of the invention and are not intended to be limiting thereof. EXAMPLE 1 White Meltable Resin Core Particles with 7 μm Average Diameter 200 g of ethyl acetate (Ethyl Acetate, Samchun Fine Chemicals, Pyungtaik, Korea) was introduced into a 1-l beaker and its temperature was raised to 70° C. Then, 100 g of a polyester resin (Toner Polyester Resin No. 2, DPI Solutions, Daejeon, Korea) which had the weight average molecular weight of 14,000 g/mol and the glass transition temperature of 62° C. and 20 g of an ester wax (Ester Wax G-32, Henckel Corporation, Dusseldorf, Germany) with the melting temperature of 55° C. were dissolved in the solvent by maintaining the content under agitation for about 1 hour. Separately, in a 1-liter glass reactor equipped with a reflux condenser, 5 g of poly-(vinyl alcohol) (Polinol P-24, Dongyang Jechul Chemical, Seoul, Korea) was dissolved in 350 g of distilled water maintained at 70° C. by stirring the content for 2 hours at the agitator speed or 200 rpm. Once the solution became clear, the agitator speed was raised to 350 rpm and the resin-wax solution above was introduced and maintained at the stirring condition for 1 hour. Then, refluxing of ethyl acetate back into the reactor was stopped by turning off the cooling water to the condenser and the reactor temperature is raised to 75° C. to evaporate ethyl acetate off the reactor. After removing 60 g of ethyl acetate off the reactor, the refluxing was resumed, 2.5 g of sodium dodecyl sulfate (Junsei Chemical, Tokyo, Japan) is added into the reactor and the content is stirred for 10 minutes. Then the condenser cooling water is turned off completely and the reactant temperature is raised gradually to 95° C. so that ethyl acetate evaporated off the reactor completely and a dispersion of resin-wax particles in water remained. The dispersion was cooled down to ambient temperature (24° C.) and filtered to obtain crude resin particles. The crude resin particles were re-dispersed in water and re-filtered. This step was repeated five times. The particles were dried at 30° C. in a convection oven for 48 hours. Approximately 105 g of white resin-wax particles were obtained. Referring to FIG. 3, scanning electron microscopy examination showed that the white particles so prepared were spherical in shape with the wax component encapsulated in the interior of particles. They had a volume average mean diameter of 7 μm and the 80% span of 0.6. The wax content of the white particle composition was about 18 wt. % when determined using a differential scanning calorimetry method. EXAMPLE 2 A Yellow Toner Composition with Colorant-Coating 10 g of the white particles of Example 1 and 0.5 g of a yellow pigment (Bayplast Yellow 5GN 01, Bayer AG, Liverkusen, Germany) were charged into a laboratory particle mixer (MT-2000, Magic Touch Corporation, Taegu, Korea). Examination of the colorant particles with a scanning electron microscope showed the particle size to be in the region of about 30 nm and about 100 nm. The content was stirred at the agitator speed of 15,000 rpm for 5 minutes and the colorant particles coated the surface of resin particle. Then, 0.3 g of a charge control agent (Copy-Charge N4P, Clariant Frankfurt, Germany) was added into the mixer and the content was agitated for 2.5 minutes. Lastly 0.1 g of a particulate silica composition (Aerosil R805, Degussa-Huls, Frankfurt, Germany) was added as a particle flow agent in the mixer and the content was agitated for additional 2.5 minutes to obtain approximately 8 g of finished single component toner composition. Referring to FIG. 4, scanning electron microscopy of the particles confirmed that the colorant particles and the charge control agent particles are securely adhered to the meltable resin core surface. Electrostatic charging properties of the yellow toner composition were determined by a blow-off method using a Faraday cage (Vertex Charge Analyzer, Vertex Image Products, Yukon, Pa.). The charge of toner after 1 minute mixing with Type-22 carrier was −27 μC/g. Fusing property of the toner was determined using a custom-designed heated roll-type fusing tester. A small amount of toner was spread on a sheet of paper and was passed through a pair of heated roller at a linear speed of about 720 cm/min. When the roller temperature was below 140° C., cold offset phenomena was observed and, above 220° C., hot offset was observed, resulting in a very large fusing latitude of 80° C. for the toner composition. Further, the toner sample was introduced into a cartridge of HP-4500 printer and patterns were printed. Line acuity and solid patches with a uniform optical intensity 1.17 of were observed after printing 5,000 pages. EXAMPLE 3 A Magenta Toner Composition A magenta toner composition was prepared by following the procedure of Example 2 with the exception that 0.5 g of the yellow colorant was replaced by 0.5 g of a magenta pigment (Quindo Magenta RV-6832, Bayer AG, Liverkusen, Germany) with the mean particle diameter (D50) less than 50 nm. The magenta toner exhibited triboelectric charge of −8 μC/g after 1 minute blending with Type 22 carrier particles. The fusing latitude was 40° C. from 160° C. to 200° C. EXAMPLE 4 A Cyan Toner Composition with a Protective Resin Layer 10 g of the white particles of Example 1 and 0.5 g of a cyan pigment (Hostaperm Blue BG, Clariant, Frankfurt, Germany) with D50 less than 50 nm were charged into a laboratory particle mixer (MT-2000, Magic Touch Corporation, Taegu, Korea). The content was stirred at the agitator speed of 15000 rpm for 5 minutes so that the colorant particles were deposited on the resin particle surface. Additionally, 2 g of microparticles of a protective resin, polyester toner resin (DPI Solutions, Daejeon, Korea) was charged and mixed for 2.5 minutes. Particle diameter of the polyester microparticles was determined using a laser scattering method. D50 was 0.47 μm and the 80% span 0.3. The dry blended particle mixture was introduced into a beaker containing 20 g of Isopar-L and a dispersion was formed. The temperature was raised to 90° C. and the content was maintained under agitation for 10 minutes so that the meltable resin core, the pigment and the resin microparticles fused together. Subsequently, toner particles were separated from the medium and washed with n-hexane three times. Then, 0.3 g of a charge control agent (Copy-Charge N4P, Clariant Frankfurt, Germany) was blended with 10 g of the dried toner particles in a mixer 2.5 minutes. Lastly 0.1 g of a particulate silica composition (Aerosil R805, Degussa-Huls, Frankfurt, Germany) was added as a particle flow agent in the mixer and the content was agitated for additional 2.5 minutes to obtain approximately 11 g of finished single component toner composition. Scanning electron microscopic examination showed that a contiguous protective layer was formed on the surface of meltable resin core, as shown schematically in FIG. 2. The blue toner exhibited triboelectric charge of −8 μC/g after 1 minute blending with Type 22 carrier particles. The fusing latitude was 40° C. from 160° C. to 200° C. EXAMPLE 5 A Black Toner Composition with a Protective Resin Layer A black toner composition was prepared by following the procedure of Example 4 with the exception that 0.5 g of the cyan pigment was replaced by 0.5 g of carbon black pigment (Spezialschwarz 4, Frankfurt, Germany) with the particle diameter in the range of about 30 nm to about 100 nm according to scanning electron microscopy. The magenta toner exhibited triboelectric charge of −5 μC/g after 1 minute blending with Type 22 carrier particles. The fusing latitude was 40° C. from 160° C. to 200° C. EXAMPLE 6 A Magnetic Black Toner Composition with a Protective Resin Layer A magnetic black toner composition (MICR) was prepared by following the procedure of Example 4 with the exception that 0.5 g of the cyan pigment was replaced by 1.0 g of a magnetite pigment (Treated magnetite MBDS-5, Rockwood Pigment NA, St. Louis, US) with D50 less than 50 nm. The magenta toner exhibited triboelectric charge of −12 μC/g after 1 minute blending with Type 22 carrier particles. The fusing latitude was 70° C. from 150° C. to 220° C. EXAMPLE 7 A Yellow Toner Composition with a High Optical Density Value A yellow toner composition with a high optical density value was prepared by following the procedure of Example 2 with the exception that 0.5 g of the yellow pigment was replaced by 1.0 g of the same yellow pigment. The yellow toner exhibited the fusing latitude was 50° C. from 180° C. to 230° C. The toner sample was introduced into a cartridge of HP-4500 printer and patterns were printed. Line acuity and solid patches with a uniform optical intensity 1.65 after printing 5,000 pages comparison to the optical density of 1.15 for the toner composition of Example 2. EXAMPLE 8 A Yellow Toner Composition with a High Optical Density Value A yellow toner composition with a high optical density value was prepared by following the procedure of Example 2 with the exception that 0.5 g of the yellow pigment was replaced by 2.0 g of the same yellow pigment. The yellow toner exhibited the fusing latitude was 50° C. from 180° C. to 230° C. The toner sample was introduced into a cartridge of HP-4500 printer and patterns were printed. Line acuity and solid patches with a uniform optical intensity 2.28 after printing 5,000 pages comparison to the optical density of 1.15 for the toner composition of Example 2. EXAMPLE 9 A Yellow Toner with Internal Charge Control Agent Approximately 105 g of white core resin containing a charge control agent were prepared by following the same procedure as in Example 1 with the exception that 0.3 g of Copy-Charge N4P was added to the polymer-wax solution in acetate solution. 10 g of the white particles of Example 1 and 0.5 g of a yellow pigment (Bayplast Yellow 5GN 01, Bayer AG, Liverkusen, Germany) were charged into a laboratory particle mixer (MT-2000, Magic Touch Corporation, Taegu, Korea). The content was stirred at the agitator speed of 15,000 rpm for 5 minutes and the colorant particles coated the surface of resin particle. Then the agitation speed was lowered to about 200 rpm while the mixture was heated to 70° C. and maintained at the temperature for about 20 minutes. Subsequently the content was slowly cooled down to ambient temperature. Lastly 0.1 g of a particulate silica composition (Aerosil R805, Degussa-Huls, Frankfurt, Germany) was added as a particle flow agent in the mixer and the content was agitated for additional 2.5 minutes to obtain approximately 8 g of finished single component toner composition. The charge of toner after I minute mixing with Type-22 carrier was −20 μC/g. Fusing properties of the toner was determined at a linear speed of about 720 cm/min. The cold offset temperature was 140° C. and the hot offset temperature 220° C., resulting in a large fusing latitude of 70° C. for the toner composition. Further, printing test of the toner sample using a HP-4500 printer gave good line acuity and solid patches with a uniform optical intensity 1.16 after 5,000 pages of printing. EXAMPLE 10 A Yellow Toner Composition with a Small Particle Diameter and High Optical Density 200 g of ethyl acetate was introduced into a 1-l beaker and its temperature was raised to 70° C. Then, 100 g of a DPI polyester resin and 20 g of an ester wax (Ester Wax G-32, Henckel Corporation, Dusseldorf, Germany) with the melting temperature of 55° C. were dissolved in the solvent by maintaining the content under agitation for about 1 hour. Separately, in a 1 liter glass reactor equipped with a reflux condenser, 4.8 g of poly-(vinyl alcohol) (Dongyang Jechul Chemical, Seoul, Korea) was dissolved in 350 g of distilled water maintained at 70° C. by stirring the content for 2 hours at the agitator speed or 200 rpm. Once the solution became clear, the agitator speed was raised to 350 rpm and the resin-wax solution above was introduced and maintained at the stirring condition for 1 hour. Then, refluxing of ethyl acetate back into the reactor was stopped by turning off the cooling water to the condenser and the reactor temperature is raised to 75° C. to evaporate ethyl acetate off the reactor. After removing 80 g of ethyl acetate off the reactor, the refluxing was resumed, 2.3 g of sodium dodecyl sulfate (Junsei Chemical, Tokyo, Japan) is added into the reactor and the content is stirred for 10 minutes. Then the condenser cooling water is turned off completely and the reactant temperature is raised gradually to 95° C. so that ethyl acetate evaporated off the reactor completely and a dispersion of resin-wax particles in water resin particles. The dispersion was cooled down to ambient temperature and filtered to obtain crude resin particles. The crude resin particles were re-dispersed in water and re-filtered. This step was repeated five times. The particles were dried at 30° C. in a convection oven for 48 hours. Approximately 105 g of white resin-wax particles were obtained, which were spherical in shape with the wax component encapsulated in the interior of particles. They had a volume average mean diameter of 5 μm and the 80% span of 0.6. The wax content of the white particle composition was about 18 wt. %. The white particles, 10 g and 2.0 g of a yellow pigment (Bayplast Yellow 5GN 01, Bayer AG, Liverkusen, Germany) were charged into a laboratory particle mixer (MT-2000, Magic Touch Corporation, Taegu, Korea). The contents were stirred at the agitator speed of 15,000 rpm for 5 minutes and the colorant particles coated the surface of resin particle. Then, 0.3 g of a charge control agent (Copy-Charge N4P, Clariant Frankfurt, Germany) was added into the mixer and the content was agitated for 2.5 minutes. Lastly, 0.1 g of a particulate silica composition (Aerosil R805, Degussa-Huls, Frankfurt, Germany) was added as a particle flow agent in the mixer and the content was agitated for additional 2.5 minutes to obtain approximately 8 g of finished single component toner composition. The charge of toner after I minute mixing with Type-22 carrier was −10 μC/g. Fusing properties of the toner was determined at a linear speed of about 720 cm/min. The cold offset temperature was 160° C. and the hot offset temperature 200° C., resulting in a fusing latitude of 40° C. for the toner composition. Further, printing test of the toner sample using a HP-4500 printer gave good line acuity and solid patches with a uniform optical intensity 2.4 after 5,000 pages of printing. The results demonstrate that the toner preparation method of the present invention can produce toner particles with a small average particle diameter and an exceptionally high optical density. While the invention has been illustrated and described in connection with numerous embodiments, modification to such embodiments within the spirit and scope of the present invention will be readily apparent to those of skill in the art. The invention is defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The formation and development of images on the surface of photoconductive materials by electrostatic means is well known. The basic electrophotographic imaging process as disclosed in U.S. Pat. No. 2,297,691 describes placing a uniform electrostatic charge on a photoconductive insulating layer known as a photoconductor or photoreceptor, exposing the photoreceptor to a light and shadow image to dissipate the charge on the areas of the photoreceptor exposed to the light, and developing the resulting electrostatic latent image by depositing on the image a finely divided electroscopic toner material. The toner will normally be attracted to those areas of the photoreceptor which retain a charge, thereby forming a toner image corresponding to the electrostatic latent image. This developed image may then be transferred to a substrate such as paper. The transferred image subsequently may be permanently affixed to the substrate by heat, pressure, a combination of heat and pressure, or other suitable fixing means such as solvent or over coating treatment. Electrostatic images formed on an electrophotographic photoconductor and an electrostatic recording medium are typically developed by using (i) a mono-component type dry developer consisting of a toner including a coloring agent such as a dye or pigment and a binder resin in which the coloring agent is dispersed, or with addition of a charge controlling agent thereto when necessary, or (ii) a two-component type dry developer including the above-mentioned powder-coated toner and solid carrier particles. Toners and developer compositions including colored particles are well known. In this regard, see U.S. Pat. Nos. 5,352,521; 4,778,742; 5,470,687; 5,500,321; 5,102,761; 4,645,727; 5,437,953; 5,296,325 and 5,200,290, the disclosures of which are hereby incorporated in their entirety by reference. A traditional toner composition typically contains toner particles consisting of a binder resin and colorants, a wax or a polyolefin, a charge control agent, flow agents and other additives. A typical toner formulation typically contains about 90-95 weight percent resin, about 2-10 weight percent colorant, about 0-6 weight percent wax, about 0-3 weight percent charge control agent, about 0.25-1 weight percent flow agent and 0-about 1 weight percent other additives. Widely-used binder's resins are styrene-acrylic copolymers, styrene-butadiene copolymers and polyesters. The colorants usually are selected from cyan dyes or pigments, magenta dyes or pigments, yellow dyes or pigments, and mixtures thereof. In the course of an electrophotographic printing operation, toner particles are subjected to a number of complex steps such as charging, electrostatic transfer, fusing, etc. There is now a realization that toner particles must possess a balance of compositional, geometrical and physical properties to perform well in a modern electrographic printer. Examples of such properties are a small mean particle size, a uniform size distribution, fast and stable electrostatic charging, fast melting, good particle flowing characteristics, controlled presence of internal additives, such as wax and charge control agent. For example, it is difficult to obtain resolutions better than about 600 dots/inch when the average particle size is larger than about 7 μm. For resolutions, in the order of about 1200 dots/inch, particle sizes smaller than 5 μm are typically needed. Conventionally, color toner particles are produced by a mechanical milling process, for example, described in the U.S. Pat. No. 5,102,761. In that process, an acrylate resin is compounded with a pigment, a charge control agent (“CCA”), and occasionally a wax in a melt mixer. The resulting polymer mixture is mechanically crushed and then milled into small particles. Such a conventional toner process typically produces particles with an irregular shape and a broad distribution in particle size. Improvements in the methods of producing small toner particles with a uniform size distribution have been attempted in the past. For example, the aforementioned U.S. Pat. Nos. 5,352,521, 5,470,687 and 5,500,321 disclose toner particles produced by dispersion polymerization. In such a method, monomers (typically styrenic and acrylate monomers) and additives such as pigment, charge control agent and wax are mixed together to form a monomer dispersion. This is then further dispersed into an aqueous or a non-aqueous medium and the monomer is reacted to form toner particles. This method has the advantage over the aforementioned milling methods that spherical toner particles with a small mean diameter can be prepared. However, the polymerization involves a substantial volume contraction and it results in entrapment of the dispersion medium inside the resulting particles. Furthermore, the polymerization is difficult to complete and a substantial portion of the monomers remain in the toner particles. The residual monomers and the entrapped dispersion solvent are difficult to remove from the particles. Further, agents employed, such as dispersion-stabilizing agent and surface active agent, cause the charging characteristics and preservability of the toner particles to deteriorate by remaining on the surface of the toner particles and are difficult to remove. Another so-called chemical method for forming small toner particles is the emulsion aggregation method disclosed in U.S. Pat. Nos. 5,916,735 and 6,268,103. In a typical emulsion aggregation method, emulsion particles of sub-micron size are first formed using an emulsion polymerization process and toner particles are produced by aggregating the emulsion particles and subsequent drying. The method consists of many delicate process steps including the aggregation step and an extensive drying step. Additionally, the above-described chemical methods of manufacturing toner particles are applicable only for resins such as styrenic copolymer resins that are polymerized by an addition reaction. The methods therefore cannot be used for a polyester resin which is polymerized by a condensation reaction. U.S. Pat. No. 6,132,919 discloses a high-resolution toner composition with a core-shell structure, prepared by a suspension polymerization process. In this case, core particles are first prepared by polymerizing a suspension of monomer for core resin containing a colorant and toner particles and toner particles are then prepared by polymerizing shell monomer on the surface of the core particles that are dispersed in a liquid medium. There are several important limitations with such a core-shell toner. First, the core resin is required to have a lower glass transition temperature than that of the shell resin. The amount of colorant that one can incorporate is limited. Lastly, the process is impractically complex. There is continuing interest in developing improved toner composition including particles which have a novel arrangement of the component compounds and enabling methods of producing the toner particles with such a unique structure and properties for high-resolution color electrophotography. | <SOH> SUMMARY OF THE INVENTION <EOH>There is provided in accordance with the present invention color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, D p , and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, d p , wherein the ratio of D p /d p is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. Typically, the ratio of the volume average diameter of the core toner particles to the volume average diameter of the colorant powder particles is at least about 10, preferably at least about 50, and in some cases, at least about 100. The weight fraction of colorant powder particles usually is at least about 0.025 based on the combined weight of core toner particles and colorant particles, preferably the weight fraction of colorant powder particles is at least about 0.05 based on the combined weight of core toner particles and colorant particles. In preferred cases, the weight fraction of colorant powder particles is from about 0.3 to about 3 times the product, (ρ p /ρ r ) (d/r) (1+d/r) 2 , where ρ p is the density of the colorant powder particles, ρ r the density of the core resin particles, d, the volumetric mean diameter of the colorant powder particles and r the volumetric mean radius of the toner core resin particles. So also, it is preferred that 80 vol. % of the core toner particles are in the diameter range of about 0.5 to 1.5 times of the volumetric average diameter. The resin core particles may further comprise a wax, and include a polymer selected from the group consisting of polyester resins and styrenic copolymer resins. Typically, if a wax is present, it is selected from a group consisting of paraffinic wax, ester wax, amide wax, polyethylene wax, polypropylene wax, Canauba wax and bee's wax, and the core includes a wax in the amount of from about 0 to about 30 weight percent parts of the toner composition. Optionally included is a charge control agent selected from a group consisting of negative and positive charge control agents. The colorant powder particles typically incude a pigment selected from the group consisting of cyan, magenta, yellow and black pigments, and the toner composition may further include one or more particle flow agents selected from the group consisting of hydrophobic silica, hydrophilic silica, titanium oxide, zinc stearate, magnesium stearate, alumina, calcium titanate, polymethylmethacrylate particles, polyester particles and silicon polymer particles, as an external additive. In one preferred embodiment, there is a particulate toner composition for development of latent electrostatic images comprising: toner particles consisting of a resin core consisting of a resin with the weight average molecular weight in the range of about 5,000 and about 40,000 g/mol and the glass transition temperature in the range of about 40° C. and about 90° C.; a colorant particle in the amount of about 3 to about 30 weight % embedded in the peripheral region of the core to form powder coated toner particles; and, optionally, a protective resin layer overcoated over the powder coated toner particles, wherein a volume average diameter of the toner particles is in the range of 3 and 12 microns with 80 vol. % of the particles in the diameter range of from about 0.5 to 1.5 times that of the volumetric average diameter. In another preferred embodiment, there is provided a color toner composition for developing latent electrostatic images comprising powder-coated toner particles, the toner particles being characterized in that each comprises a core toner particle having a volume average diameter, D p , the toner particles having affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, d p , as well as a melt-fused protective polymer operative to secure the powder to the core toner particles, wherein the ratio of D p /d p is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles, colorant particles and protective resin. A method of producing a toner composition of the present invention includes: admixing toner core particles having a volume average diameter, D p , with a powder colorant composition having a volume average particle diameter, d p , the ratio D p /d p being at least about 5; and dispersing the powder colorant composition over the surfaces of the toner core particles under conditions effective to affix the powder to the surfaces of the core particles such that the core particles have a plurality of discrete toner particles of lesser size affixed to their surfaces. The method may be carried out under substantially dry conditions. Another method of producing a toner composition of the present invention includes: admixing toner core particles having a volume average diameter, D p , with a powder colorant composition having a volume average particle diameter, d p , the ratio D p /d p being at least about 5, and with a powder resin component having a volume average particle diameter, d p′ , the ratio of D p /d p′ also being at least about 5; dispersing the powder colorant composition and the powder resin component over the surfaces of the toner core particles under conditions effective to affix the powders to the surfaces of the core particles such that the core particles have a plurality of discrete powder particles of resin and colorant of lesser size than the core toner particles affixed to their surfaces; and melting the powder resin component to further secure the powder colorant composition to the resin core particles. Further details will become apparent from the appended Figures and Examples. | 20040422 | 20070424 | 20050630 | 75028.0 | 0 | GOODROW, JOHN L | POWDER-COATED TONER PARTICLES AND METHOD OF MAKING SAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,830,242 | ACCEPTED | Method and system for secure content distribution | A system on a chip (SOC) device is disclosed comprising external outputs, and external inputs. A first secure storage location is operably decoupled from all of the external outputs of the SOC device during a normal mode of operation. By being decoupled from all external outputs, representations of the data stored at the first secure device are prevented from being provided to the external outputs. The decryption engine is also included on the system on a chip, comprising a first data input, and a private key input coupled to a first portion of the first secure storage location, and an output coupled to a second secure location. The decryption engine is operable to determine decrypted data from data received at the first data input based upon a private key received at the private key input. The decryption engine is further operable to write the decrypted data only to the first secure memory location and the second secure location. | 1. A system on a chip (SOC) device comprising: external output interfaces to provide information from the SOC device; external input interfaces to provide information to the SOC device; a first secure storage location operably de-coupled from all external output nodes of the SOC device during a normal mode of operation to prevent representations of data to be stored at the first secure storage location from being provided at an external output interface; and a decryption engine comprising a first data input, a private key input coupled to a first portion of the first secure storage location, and an output coupled to a second secure storage location, the decryption engine operable to determine decrypted data from data received at the first data input based on a private key received at the private key input, and further operable to write the decrypted data only to the first secure memory location and the second secure storage location. 2. The system of claim 1, wherein the first storage location is operably decoupled from all external devices by preventing access to the first storage location. 3. The system of claim 1, wherein the first storage location is operably decoupled from all external devices by destroying the data at the first storage location in response to being accessed. 4. The system of claim 1, wherein a second secure storage location coupled to the output of the decryption engine is operably de-coupled from all external output nodes of the SOC device during a normal mode of operation to prevent data stored at the second secure storage location from being provided at an external output interface. 5. The method of claim 4, wherein a first portion of the first secure storage location is a write-once storage location. 6. The method of claim 4, wherein the first portion of the first secure storage location is a write-many storage location. 7. The system of claim 4, wherein a first portion of the first secure storage location comprises a non-volatile storage location for a first private key storage location. 8. The system of claim 7, wherein the first secure storage location comprises a plurality of private key storage locations. 9. The system of claim 8, wherein the plurality of private key storage locations are part of the first portion of the first secure storage location. 10. The system of claim 1, wherein the decryption engine is operable to execute a decryption algorithm in parallel in hardware. 11. The system of claim 1 further comprising a unique SOC identifier. 12. The system of claim 4 further comprising: a descrambler comprising a first data input, a control word input coupled to a first portion of the second secure storage location during normal operation, and an output, the descrambler operable to access a control word only from the second secured storage location, wherein the control word is used by the descrambler to descramble scrambled data. 13. The system of claim 12 further comprising a random number generator comprising an output, the random number generator operable to provide a random number at the output. 14. The system of claim 13, wherein the output of the random number generator is coupled to the second secure storage location. 15. The system of claim 14, wherein the output of the random number generator is operably coupled to have exclusive write access to a predefined location of the second secure storage location during normal operation. 16. The system of claim 15 further comprising: an encryption engine comprising a first data input coupled to the second secure storage location, a public key input to receive a public key, and an output to provide an encrypted representation of data received at the first data input. 17. The system of claim 16, where in the encryption engine is operable to provide the encrypted representation to an external output interface. 18. The system of claim 17, where in the first secure storage location being operably de-coupled from all external output nodes of the SOC device further comprises the first secure storage location being de-coupled from the data input and the public key input of the encryption engine. 19. The system of claim 18 further comprising a transcoder operably coupled to the output of the descrambler to receive a first image having a first resolution and to provide a second image, based on the first image, having a second resolution, the second resolution being less than the first resolution. 20. The system of claim 18 further comprising a transcoder operably coupled to the output of the descrambler to receive a first image at a first bit rate and to provide a second image, based on the first image, having a second bit rate, the second resolution being less than the first resolution. 21. The system of claim 18 further comprising a watermark module coupled to the output of the de-scrambler, the watermark module operable to provide a watermark to image data from the output of the de-scrambler. 22. The system of claim 21 further comprising: a scrambler comprising a first data input, a control word input coupled to a second portion of the second secure storage location, and an output, the scrambler operable to access a control word only from the second secured storage location, wherein the control word is used by the scrambler to scramble data received at the first input. 23. A system comprising: a source system comprising a system on a chip device operable exclusively in a blind encryption mode during a normal mode of operation, wherein no private key of the source system is observable external the system on a chip; a destination system coupled to the source system, the destination system device operable exclusively in the blind encryption mode during the normal mode of operation, wherein no private key of the destination system is observable external the system on a chip. 24. The system of claim 23, wherein the source system is operable only in a double-blind-securing mode, wherein the destination system is operable in the blind encryption mode. 25. A method comprising: when in a normal mode of operation allowing observability of a private key stored at a first secured storage location of the system on a chip to a decryption engine of a system on a chip while not allowing observability of the private key external the system on a chip; allowing write access to a second secured storage location of the system on a chip to the decryption engine, where the second location is not observable external the system on a chip. 26. The method of claim 25, wherein the second secured storage location of the system on a chip is read accessible during normal operation only by a scrambling engine of the system on a chip. 27. The method of claim 25 further comprising: erasing information stored at the first secured storage location in response to a first access request during normal operation. 28. The method of claim 27, wherein the first access request would make data stored at the first secured location observable. 29. The method of claim 27 further comprising: erasing information stored at the second secured storage location in response to the first access request during normal operation. 30. The method of claim 29, wherein the first access request would make data stored at the second secured location observable. 31. The method of claim 27 further comprising: erasing information stored at the second secured storage location in response to a second access request during normal operation. 32. The method of claim 25 further comprising: ignoring an access request to the first secured storage location during normal operation. 33. The method of claim 32, wherein the access request would make data stored at the first secured location observable. 34. The method of claim 25 further comprising: providing dummy data in response to an access request to the first secured storage location during normal operation. 35. The method of claim 25, wherein providing access only to a second secured storage location of the system on a chip for a value decrypted by the decryption engine, where the second location is not observable external the system on a chip. 36. The method of claim 25 further comprising: erasing information stored at the first secured storage location in response to a request to enter a test mode of operation. 37. The method of claim 25 further comprising: erasing information stored at the second secured storage location in response to the request to enter the test mode of operation. 38. The system of claim 1, wherein the decryption engine is further operable to provide the decrypted data only to the second secure storage location during a normal mode of operation. | CROSS-REFERENCE TO RELATED APPLICATION(S) The present application claims priority from U.S. Provisional Application No. 60/545,089, filed Feb. 17, 2004, entitled “METHODS AND PROCESSES FOR SECURE CONTENT DISTRIBUTION AND RIGHTS MANAGEMENT,” naming inventor Paul Ducharme, which application is incorporated by reference herein in its entirety. FIELD OF THE DISCLOSURE The present disclosure relates generally to providing secure communications and more particularly to a device and methods of protecting data used in secure communications. BACKGROUND Several forms of digital audio and video content are available to consumers. Audio and video content can be provided through media, such as compact disks (CD) or digital versatile disks (DVD). Service providers can be used to present audio and video content by broadcasting digital audio and video content to consumers, such as through broadband network services, digital cable broadcasts, or digital satellite and terrestrial transmissions. Generally, there are ownership rights associated with the audio and video content and consumers pay for services to receive the audio and video content. To protect ownership rights, several methods are undertaken to secure audio and video content and ensure only valid consumers receive the content. For example, video associated with DVDs is generally scrambled to prevent undesired copying of DVD video content. Similarly, video content transmitted through digital satellite or digital cable broadcasts can be scrambled to only allow paying consumers to descramble the video content. Encryption and scrambling techniques use secret key or codeword values that are supposed to only be available to a device associated with the consumer, such as a digital cable, or digital satellite, set-top box. Once the secret key and/or codeword values become public knowledge, an unauthorized consumer is capable of descrambling protected audio and video content. From the above discussion, it should be apparent that systems and methods of providing secured key and codeword protection would be useful. BRIEF DESCRIPTION OF THE DRAWINGS Specific embodiments of the present disclosure are shown and described in the drawings presented herein. Various advantages, features and characteristics of the present disclosure, as well as methods, operations and functions of related elements of structure, and the combination of parts and economies of manufacture, will become apparent upon consideration of the following description and claims with reference to the accompanying drawings, all of which form a part of this specification, and wherein: FIG. 1 is a block diagram illustrating a system for processing scrambled information according to one embodiment of the present disclosure; FIG. 2 is a block diagram illustrating a decoupling between a protected storage device that can be decoupled from external interfaces of a system on a chip according to one embodiment of the present disclosure; FIG. 3 is a block diagram illustrating a a private key storage device that can be decoupled from external interfaces of a system on a chip according to one embodiment of the present disclosure; FIG. 4 is a diagram illustrating a method of providing content between a service provider and a consumer according to one embodiment of the present disclosure; FIGS. 5 and 6 are flow diagrams illustrating specific embodiment of decoupling protected memory from external interfaces of a system on a chip. DETAILED DESCRIPTION OF THE FIGURES At least one embodiment of the present disclosure provides a system on a chip (SOC) for processing secure data. The SOC includes external output interfaces for providing information from the SOC to an external component or device. The SOC also includes external input interfaces for providing information to the SOC device from the external component or device. The SOC includes a first storage location that is operably de-coupled from all external nodes of the SOC. The first storage location is operably de-coupled so as to prevent representations of data stored in the first storage location from being provided at an external output interface. The SOC also includes a decryption engine having a first data input, and a private key input coupled to a first portion of the first secure storage location. In one embodiment, a sensitive decryption key, such as the private key, is stored in the first portion of the first secure storage location. The decryption engine is capable of decrypting data received through the first data input based on the sensitive decryption key and the decryption engine is further capable of storing decrypted data only to secure memory. In one embodiment of the present disclosure, the SOC is capable of performing decryption and descrambling using sensitive decryption key and codeword values stored in storage locations internal to the SOC. Accordingly, access to sensitive decryption and descrambling values can be limited to the decryption engine and descrambler, and cannot be accessed external to the SOC. An advantage of at least one embodiment of the present disclosure is that sensitive values can be protected from malicious attacks designed to pirate protected audio or video content. For purposes of discussion, the following terms are described. Content pertains to audio or video or other data that is interchanged between components, such as a service provider, consumer or gateway. A medium for the transfer of content can include, but is not limited to, satellite, cable or terrestrial broadcasts, CD, DVD, network, Internet, telephone line transmission or other mediums. A service provider includes a company or party that produces or distributes content or provides a service that facilitates the transfer of content. A consumer includes a device or party that receives and consumes content, typically as part of an agreement with the service provider. A gateway represents a device or party that provides an interface for the transfer of content between a service provider and a consumer. In one embodiment, a gateway may also operate as a consumer. A pirate includes a party or device that uses illegal or fraudulent methods to receive, duplicate, or re-distribute content, provided by a service provider, intended for a consumer. Several methods for protecting transferred content from being intercepted by pirates exist. For the purposes of discussion, general methods used will be discussed and described; however, it should be appreciated that more specific methods are known in the art and the specific method used can be selected without departing from the scope of the present disclosure. Scrambling is an algorithm that uses a seed value, referred to as a codeword, to modify large amounts of data in such a way that the data can be de-scrambled using the same codeword. Without the value of the codeword, the scrambled data is not sensible. Examples of scrambling techniques used in the art include, but are not limited to, the Data Encryption Standard (DES), the Triple Data Encryption Standard (3DES), the Advanced Encryption Standard (AES), and the Digital Video Broadcast (DVB) encryption standard. The codeword includes a binary value, generally in multiples of 64 bits, that is used to scramble content. It should be noted that codewords can also include multiple binary values, such as initial vectors and sets of system keys, and that the codeword can change for a given set of content. As compared to scrambling, encryption is a computationally complex operation that is used in public/private key pairs systems to conceal a small amount of data, which may only be decrypted using an alternate key. Specific examples of encryption include, but are not limited to, the Rivest, Shamir and Adleman (RSA) encryption standard, or the Elliptical Curve Cryptography (ECC) standard. A public key includes a binary value that is used as a seed value in an encryption algorithm. The public key is generally used to encrypt/decrypt messages or values, such as codeword values. A public key is not considered secret and is freely transmitted to others. Generally, messages encrypted using a specific device's public key can only be decrypted using the specific device's private key. The private key includes a binary value that is used as a seed value in encryption/decryption algorithms. The private key is considered secret and not to be distributed to other devices. Referring now to FIG. 1, a block diagram illustrating a system for processing scrambled information, such as video content, is shown according to one embodiment of the present disclosure. A system 100 is shown acting as a gateway for communication between a service provider 102 and a consumer 106. The service provider 102 provides scrambled content, at interface 171 or 177, containing content to be received by the consumer 106. System 100 ensures security by handling authentication, scrambling/descrambling of the content, and encryption/decryption of sensitive values used to scramble content before re-transmission to the consumer 106. The system 100 includes a system on a chip (SOC), such as SOC 120, which is capable of internally storing and generating sensitive values, such as codeword 155, and private key 175. To prevent descrambling of scrambled content, such as scrambled content transmitted over interfaces 171, 173, 174, 177 and 178, from pirates, sensitive values, such as private key 175 are kept internal to SOC 120 in a secure storage location 170 and can not be accessed external to SOC 120. In one embodiment of the present disclosure, a network interface 104 provides the transfer of information, such as authentication and service requests, or the transfer of scrambled content or data between the service provider 102, the system 100 and the consumer 106. The network interface 104 can represent one of a plurality of different network interfaces, including but not limited to an Ethernet interface, a wireless broadcast interface or a modem and a telephone line, where the type of network interface can be chosen without departing from the scope of the present disclosure. The system 100 includes the SOC 120, used to securely process scrambled content, such as content received at interfaces 171 or 173, dynamic storage 110 used to store unscrambled content, a system decoder 115 used to decode the content for display, and a local bus 105 used to transfer scrambled content, such as scrambled content and messages provided over interfaces 173, 177 and 179 between the system 100 and the network interface 104 and external storage 108. In one embodiment of the present disclosure, external storage 108 is used by system 100 for the storage of scrambled content 179. In one embodiment of the present disclosure, SOC 120 includes codeword generator 180, a secure storage location (private key storage) 170 having at least one private key 175, a secure storage location (protected storage) 150 having at least one codeword 155, an encryption/decryption block 160, a scrambler/descrambler 130, content receiver 140, public storage (other memory) 125 having a unique identifier (ID) 126 and a public key 127, a transcoder 135, internal decoder 137 and watermark block 134. The scrambler/descrambler 130 includes a codeword input 131 for interfacing with protected storage 150, a data input 132 for interfacing with content receiver 140 and a data output for interfacing with local bus 105. SOC 120 is used to process security associated with the handling of scrambled content, such as scrambled content received over interfaces 171 or 174, provided from service provider 102. Note that service provider 102 is illustrated as providing content over both the interface 171 and the interface 174. It will be appreciated that the service providers 102 may be a common service provider, or different service providers. For example, the service provider 102 could be a service provider whereby the content received at interface 171 is received over a terrestrial or cable connection, whereas the service provider 102 may be the same or a different service provider that is shown to provide scrambled content to alternate interface 174, such as the Internet. In addition, even though the scrambled content at interface 177 to the local bus 105 is not illustrated as being receivable at the data-in port 132, it will be appreciated that the interfaces illustrated as providing scrambled content within the SOC 120 may actually be common or shared interfaces or interfaces that can otherwise share data amongst themselves. However, in accordance with the present disclosure, the interfaces, whether shared or individual, need to remain decoupled from the protected storage locations 150 and 170 as further described herein. In one embodiment, system 100 includes a watermark module 134. Watermark module 134 can be used to encode content stored in dynamic storage 110 with a value associated with system 100 or SOC 120, such as unique ID 126. The value is encoded into the content in a manner so that the value can be extracted from the content at a later time. Accordingly, the watermark can be used to track which system or SOC was compromised to extract the content should the content be pirated. It will be appreciated that while the watermark 134 is not specifically illustrated to be connected to any specific component, that the watermark module 134 could be connected in a variety of embodiments. In one embodiment, the watermark module 134 would be connected to the interface 183 between the scrambler/descrambler 130 to insert watermark encoding into the content prior to its being stored in dynamic storage 110. In alternate embodiments, the watermark could be connected to the interconnects 181 or 182 to allow for insertion of the watermark encoding after transcoding of information by the transcoder 135, or after the internal decoding by internal decoder 137 of the content received over interface 181. Scrambled content is secured through the use of secret values, such as codeword 155 and private key 175. In one embodiment of the present disclosure, system 100 and SOC 120 operate in a blind encryption scheme where the secret values represented by the private keys are not observable outside of SOC 120 by controlling access to the portions of memory used to store those values. A system where a source and destination system each operate in blind encryption mode is referred to as a double-blind encryption system, or a double-blind security system, or a double-blind decryption system. In a specific embodiment, before a source will provide protected content to a destination it will need to verify that the destination is a blind encryption system, thereby ensuring double-blind operation. Likewise, the destination can verify that a source is a blind encryption system to ensure double-blind operation. Encryption/decryption block 160 includes an encryption engine 161 and a decryption engine 162. The encryption engine 162 uses a provided public key, such as public key 107 to encrypt a value to be transmitted external to SOC 120. It should be noted that the values of the public keys used by the encryption engine 161 can be accessed from protected storage 150 or from other memory associated with system 100 or SOC 120, such as memory 125. Public keys are typically known outside of SOC 120 and do not need to be protected. The decryption engine 162 uses private key 175 to decrypt encrypted information provided to SOC 120. It should be noted that data decrypted by decryption engine 162 should be stored in a secured location, such as protected storage 150 or private key storage 170. Secret values, such as codeword 155 should not be provided external to SOC 120 before being encrypted by encryption engine 161. Interfaces between SOC 120 and local bus 105, dynamic storage 110, system decoder 115 and service provider 102 represent input interfaces allowing information to be provided to SOC 120 and output interfaces allowing information to be provided from SOC 120. SOC 120 ensures the integrity of scrambled content at interface 173 by protecting secret values and secure storage locations, such private key storage 170 and protected storage 150, from access at any of the interfaces. In one embodiment of the present disclosure, SOC 120 performs tighter security on more critical, or sensitive, information. For example, Table 1 shows a list of different types of information associated with the secure transport of content. TABLE 1 Values Associated with Secure Content Vs. Security Criticality Information Type Security Criticality Comment Private Key 1 Most Critical Group Key 2 Service Key 3 CW 4 Digital HD 5 Content Digital SD 6 content Analog Content 7 Encrypted Key 8 Encrypted CW 9 Public key 10 Scrambled 11 Least Critical Content Etc . . . As shown, in Table 1, some values associated with the processing of secure content are considered more critical to security, such as private key 175 and codeword 155, than others. A measurement of security criticality presented is meant to illustrate a ranking of how valuable a particular information type is to the integrity of a secure system. Information types having a lower valve security criticality ranking, i.e., 1, would be more damaging to the integrity of a secure system if discovered than information types having a higher security criticality ranking. The criticality of an information type, in relation to security, can be lessened by altering the associated information, so it is unusable, such as by encrypting a codeword value or scrambling content. It should be appreciated that while Table 1 provides unique security criticality rankings for each information type, several information types may be assigned to a same security criticality ranking. A security criticality ranking as provided in Table 1 can allow for system definitions that may dictate how information types at or below a particular security criticality value would be protected. For example, an information type having a security criticality ranking of ‘1’ can indicate that neither data nor a representation of the data associated with the information type be provided at an output associated with a secure system, such as SOC 120. In one embodiment of the present disclosure, private key storage 170 and protected storage 150 represent storage locations operably de-coupled from external interfaces of SOC 120 during a normal operating mode. Accordingly, SOC 120 protects private key 175 and codeword 155 from external access. Referring now to FIG. 2, a block diagram illustrates storage 150 (FIG. 1) to be decoupled from external input and output interfaces associated with SOC 120, according to one embodiment of the present disclosure. In one embodiment of the present disclosure, SOC 120 includes external interfaces 210 and 220, and decoupling modules 215 and 225. External output interface 210 is used to interface to external components of system 100, such as local bus 105, and provide information, such as scrambled content over interface 173, from SOC 120 to the external components. Similarly, external input interface 220 can be used to provide information from the external components to SOC 120. Decoupling modules 215 and 225 may provide an interface between protected storage 150 and external output interface 210 and external input interface 220, respectively, to provide access to the protected storage in limited circumstances. In one embodiment, decoupling modules 215 and 225 provide access to portions of protected storage 150 during a test mode of SOC 120. Decoupling module 225 can provide write access to protected storage 150, through data line 222 and address line 224, allowing external input interface 220 to store information in protected storage 150 for the purposes of testing or loading initial values. Decoupling module 215 can be used to provide read access to protected storage 150 to external output interface 210 during a test mode of SOC 120, thereby providing data through data line 212. In one embodiment, external interfaces 210 and 220 include test interfaces associated with SOC 120, such as a JTAG test interface, or other data interfaces. Accordingly, decoupling modules 210 and 220 can be used to store and read values into protected storage 150 during the test mode. When operating in a secure mode, the decoupling modules 210 and 220 will prevent information stored in protected storage 150, such as the code word 155, from being provided to the external output interface 210. As a result, it will not be possible either through the execution of internal instructions, or by accessing external interfaces 210 and 220 to retrieve data stored within protected storage 150. This is accomplished in one embodiment, by disabling logic in the decoupling module 215 after test mode and/or module 225 through the assertion of specific control bits to disable logic associated with accessing stored information. Alternatively, a physical destruction of a fuse, or fuse-type connection can also be implemented to disable the logic coupling of protected storage 150 from the external output interface 210. In an alternate embodiment, the decoupling module 225 operates to destroy any data stored at protected storage 150 as part of entering a test mode. In this embodiment, once the data is destroyed and test mode is fully entered, the user would be able to store and read information from protected storage 150. However, the information being stored and read would be information provided solely by the user. Information stored during test mode in protected storage 150 would not be observable external the system once test mode is exited. Data stored during test mode may or may not be observable during test mode, depending upon specific implementations. In yet another alternate embodiment, any access to the protected storage 150 during a mode other than test mode, would result in the data being destroyed prior to it being read. A further embodiment would result in indeterminate, or predetermined value to be returned when an address request of protected storage 150 is made to decoupling module 225. For example, in response to receiving an address as part of a read request to protected storage 150, the decoupling module 225 can communicate with decoupling module 215 to provide a dummy data to the external output interface 210, thereby bypassing the protected storage 150. This communication can be through protected storage 150, or bypass protected storage 150. Based upon these embodiments, it will be appreciated that both the decoupling module 215 and the decoupling module 225 can be disabled, or that in an alternative implementation, the decoupling module 225 may remain enabled, and possibly not even exist. It will be further appreciated, that the decoupling modules 215 and 225 may actually represent the lack of specific circuitry implementing the ability to provide information within protected storage 150 to the output interface 210. In other words, even during a test mode, or any other mode of operation, the decoupling module 215 could represent the lack of interface connections prohibiting protected data, such as the code word 155 from ever being provided to an output interface of the SOC. It would be appreciated in such an implementation, that the functionality of the protected storage 150 would need to be verified using alternative test methods, such as providing specific coded data to be descrambled and sent external for verification. Note that where a test mode of operation, and a secure mode of operation (also referred to as a normal mode of operation) exists, the decoupling modules 215 and 225 are designed as such to implement a one-way security enable, whereby after implemented, it is not possible to disable the security measures which prohibit observability of the protected storage 150, which is external SOC 120. In one embodiment, write access to codeword 155 during normal operation is only allowed through encryption/decryption block 160 and codeword generator 180. Once decoupling modules 215 and 225 are disabled, direct access to protected storage 150 is no longer available to external interfaces 210 and 220. Accordingly, the value of codeword 155 is read accessible only internal to SOC 120, for use at the codeword input 131 of scrambler/descrambler 130 and at a data input of encryption engine 161. The SOC is designed so that the only representation of the value of codeword 155 is only provided external to SOC 120 by first encrypting the value of codeword 155. Referring now to FIG. 3, a block diagram illustrating a decoupling of private key storage 170 (FIG. 1) from external input and output interfaces associated with SOC 120, according to one embodiment of the present disclosure. In one embodiment, during a test mode, decoupling module 320 provides write access of private key storage 170 to external input interface 220. Similarly, during the test mode, decoupling module 310 can provide read access of information at private key storage 170 to external output interfaces 210. In an alternate embodiment, no read access is provided to storage 170 during any mode of operation. During the test mode, or an initialization of SOC 120, decoupling module 320 can also be used to store a private key value into a portion of private key storage 170, such as private keys 175 and/or 176. In one embodiment, once the test mode or initialization mode are completed, decoupling modules 310 and 320 are disabled to decouple the storage location 170 from the external output interface 210, and/or to external input interface 220 to prevent further access to private key storage 170. In one embodiment, decoupling modules 310 and 320 are permanently disabled, and only the decryption engine 162 of the encryption/decryption block 160 has access to private key storage 170 at the private key input of the decryption engine 161. In one embodiment, write access to private key storage 170 is provided to the decryption engine 162 of encryption/decryption block 160 to allow encrypted private keys, decrypted by the decryption engine 162 using private key 175, to be written into private key storage 170, such as to private key 176. In an alternate embodiment, only read access of private key storage 170 is allowed and values of private keys, such as private keys 175 and 176, cannot be read accessed by other components of SOC 120 or external to SOC 120. Accordingly, more critical values are kept internal to SOC 120 and only less critical values, such as public key 127, scrambled or encrypted values, are provided external to SOC 120. Decoupling modules 320 and 310 may operate in a manner similar to modules 215 and 225 of FIG. 2. Referring back to FIG. 1, in one embodiment of the present disclosure, SOC 120 receives scrambled content 171 provided by a service provider, such as service provider 102, intended for a particular consumer, such as consumer 106, connected to network interface 104. The scrambled content 171 is typically scrambled using a codeword generated by the service provider 102. The service provider codeword is encrypted using a public key 127 associated with SOC 102. The decryption engine 162 of encryption/decryption block 160 is capable of decrypting the encrypted value of the received codeword using the value of private key 175. The decrypted codeword value is then stored in protected storage 150 and used by scrambler/descrambler 130 to descramble the scrambled content. The codeword is only accessible by scrambler/descrambler 130 for descrambling scrambled content. It should be noted that additional codewords could be stored in protected storage 150. Furthermore, access to some of the additional codeword portions of protected storage 150 can be made inaccessible by the encryption/decryption block 160. In one embodiment, a portion of protected storage 150, used to store data provided by the decryption engine 162, is secured so that the data is not provided external to SOC 120 in an unencrypted or scrambled form. For example, it may be desirable for codewords from external sources in storage 150, such as codewords from service provider 102, to not be accessible by the encryption/decryption module 160. In one embodiment of the present disclosure, private key 175 is stored into private key storage 170 as part of a write-once function associated with test or initialization, in which the value of private key 175 can no longer be altered. Furthermore, the value of private key 175 can be uniquely assigned to SOC 120 and other chips similar to SOC 120 will be assigned a different private key value. Similarly, the values of public key 127 and unique ID 126 are uniquely assigned to SOC 120. In one embodiment of the present disclosure, a method of authentication referred to as digital signing, is disabled in encryption/decryption block 160 by not allowing the decryption engine 162 of encryption/decryption block 160 to send decrypted messages to any external output interface. Digital signing can be exploited, such as through the use of a Trojan Horse attack, to uncover the value of a secret codeword, such as codeword 155. By disabling and/or preventing digital signing, SOC 120 can be protected from such an attack. In one embodiment of the present disclosure, encryption/decryption block 160 is further capable of performing encryption operations in parallel with other functions of system 100. Serial execution of decryption code generates measurable changes in current draw that can be detected external to SOC 120 to exploit private keys, such as private key 175. In comparison to serial execution of decryption code, parallel execution of decryption code by the decryption engine 162 cannot be as readily detected. Accordingly, encryption operations can be hidden from external monitoring of system 100. In one embodiment, the descrambled content is stored in dynamic storage 110, prior to display. In another embodiment, the descrambled content is re-scrambled using an internal codeword, codeword 155, which may be a codeword provided by service provider 102 or generated by the codeword generator 180, prior to storage in dynamic storage 110. Re-scrambled content can be stored, along with an encrypted value of codeword 155, external to system 100, such as in storage 108. As identified in Table 1, scrambled content is not considered critical. By being scrambled with a particular codeword value, such as codeword 155, the scrambled content cannot be unscrambled without the knowledge of the codeword. Accordingly, scrambled content is generally stored with an encrypted version of the codeword used to scramble the content. In one embodiment, a codeword used to scramble stored data is encrypted using public key 127, associated with SOC 120 and stored with the scrambled content. It should be noted that more than one codeword can be used by SOC 120. In one embodiment, stored content can be associated with a time in which the content can be decrypted, such as a content expiration date. Such an expiration date can be a timecode used by the encryption/decryption block 160 or scrambler/descrambler 130 to determine if the stored content is valid. Alternatively, system 100 can be used to clear stored content based on a timecode associated with the stored content. In another embodiment, codeword values stored with the stored content expire as old codeword values are replaced by new values generated by codeword generator 180. Similar to scrambled content stored by SOC 120, scrambled content sent to consumer 106 is sent with a codeword encrypted using the consumer's public key 107, associated with chip 103 of consumer 106. Accordingly, only consumer 106 can decrypt the codeword, using a private key 105 known only internal to chip 103 of consumer 106, and then descramble the scrambled content. In one embodiment, codeword generator 180 is used to generate random values and stores the random values as codeword 155 for use by the scrambling engine of the scrambler/descrambler 130. When multiple codewords are generated, new content is scrambled using the newly generated codeword values, the prior value of the codeword is no longer useful for descrambling newly scrambled content. In one embodiment, access to a portion of protected storage 150 used for storing codeword 155 is only accessible by codeword generator 180 to assure that no external devices are allowed to dictate and/or alter the values of codeword 155. In one embodiment of the present disclosure, transcoder 135 modifies the received content that is stored in dynamic storage 110. Transcoder 135 is capable of altering a bit-rate and/or resolution associated with content stored in dynamic memory 110. For example, the bit-rate and/or resolution associated with the content stored in dynamic memory 110 can be reduced to only a portion of the maximum bit-rate or resolution associated with the content, such as to a standard bit-rate and/or resolution, or can be reduced to match a lower bit-rate or resolution accepted by consumer 106. By reducing the bit-rate and/or resolution associated with content stored in dynamic memory 110, an overall value of the stored content can be reduced. For example, if a pirate compromises the content, the value of the compromised content is lowered due to the quality of the content being degraded from a maximum quality associated with the content. In one embodiment of the present disclosure, the internal decoder 137, associated with the SOC 120, is used to provide decoded content to the portion of system 100 external chip 120. In one embodiment of the present disclosure, other secure systems interfacing with system 100, such as consumer 106 include chips similar to SOC 120, such as chip 103. Accordingly, a double-blind encryption scheme can be incorporated in which neither a source system nor a destination system has direct or indirect observability to the value of its own private key for export directly or as an encoded representation. Accordingly, the values of the private keys can be protected from attacks made on the systems to determine the values of the private keys. The ability of a source system to communicate with a destination system can be based upon the ability of both systems being blind systems, thereby assuring a double blind encryption scheme is used. Referring now to FIG. 4, a flow diagram illustrating a method of providing content between a service provider, such as service provider 102 (FIG. 1), and a consumer, such as consumer 106 (FIG. 1) is shown, according to one embodiment of the present disclosure. In the illustrated embodiment, the consumer 106 is associated with an ID 101, a public key 107, and includes chip 103, having a protected private key 105. System 100 (FIG. 1) is associated with a unique ID 126, a public key 127 and includes SOC 120 having a protected private key 175 associated with the system 100. Service provider 102 is associated with a public key 109. System 100 operates as a gateway and provides authentication and content between the service provider 102 and the consumer 106. In step 410, the consumer 106 provides an authentication request to the system 100. The authentication request includes the ID 101, associated with the consumer 106. In step 420, the system 100 provides an authentication request, for consumer 106, to the service provider 102. The authentication request provided by system 100 includes an encrypted representation of ID 101 and ID 126, associated with system 100. The representations of Ids 101 and 126 are encrypted using public key 109. In step 430, once the service provider 102 has validated Ids 101 and 126, the service provider 102 sends a validation response, indicating authentication was successful, to the system 100. The validation response includes an encrypted representation of public codeword 109. The encrypted representation of public codeword 109 is encrypted using public key 127. In step 440, system 100 provides a validation response to consumer 106. The validation response includes an encrypted representation of public key 127. The encrypted representation of public key 127 is encrypted using public codeword 109. In step 450, the consumer 106 sends a service request to the system 100. The service request is encrypted by consumer 106 using public key 127. In step 460, response to the service request of step 450, the system 100 sends the consumer 106 an acceptance. The acceptance includes a codeword value, which is encrypted using public codeword 109. In one embodiment, the codeword value is randomly generated by SOC 120, such as through codeword generator 180 (FIG. 1). In step 470, the system 100 provides scrambled content to the consumer 106. The content is scrambled using the codeword provided to the consumer 106 in step 460. FIGS. 5 and 6 illustrate specific embodiments of the present disclosure relating to decoupling of protected memory from external interfaces of an SOC. In FIG. 5, at step 501, an unauthorized access to protected memory is requested. In one embodiment, an unauthorized access is any access of a private key location by a device other than the decryption engine. In another embodiment, an unauthorized access is a request that would provide information to a location that would potentially make data at the protected location observable external the system. At step 502, the protected memory is erased in response to the request. Either some or all of the protected memory can be erased in response to any and all requests. In one embodiment, only the specific location being accessed is erased. At step 503, access to the protected memory is allowed after it has been erased. In this manner, the protected memory is decoupled from external interfaces in that the contents of the protected memory cannot be provided to external interfaces. In FIG. 6, at step 601, an access to protected memory is requested. At step 602, a determination is made whether the system is in a test mode. If not in test mode, flow proceeds to step 608, where the access request is denied. As indicated in block 611, the access can be denied by disabling access to the protected memory, or by providing dummy data in response to the request. By denying the request for data stored at the protected memory when not in test mode, it remains decoupled from the external interface. When in test mode, the flow proceeds from step 602 to step 603. At step 603, the protected memory is erased in response to being in test mode. Block 612 indicates that the protected memory can all be erased in response to merely entering test mode. Alternatively, protected memory can be erased as it is requested during test mode. In this manner, the protected memory remains decoupled from the external interfaces of the Soc. At step 604, externally observable accesses are allowed after the protected memory is erased. In the preceding detailed description of the embodiments, reference has been made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit or scope of the disclosure. To avoid detail not necessary to enable those skilled in the art to practice the disclosure, the description may omit certain information known to those skilled in the art. Furthermore, many other varied embodiments that incorporate the teachings of the disclosure may be easily constructed by those skilled in the art. Accordingly, the present disclosure is not intended to be limited to the specific form set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the disclosure. The preceding detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined only by the appended claims. | <SOH> BACKGROUND <EOH>Several forms of digital audio and video content are available to consumers. Audio and video content can be provided through media, such as compact disks (CD) or digital versatile disks (DVD). Service providers can be used to present audio and video content by broadcasting digital audio and video content to consumers, such as through broadband network services, digital cable broadcasts, or digital satellite and terrestrial transmissions. Generally, there are ownership rights associated with the audio and video content and consumers pay for services to receive the audio and video content. To protect ownership rights, several methods are undertaken to secure audio and video content and ensure only valid consumers receive the content. For example, video associated with DVDs is generally scrambled to prevent undesired copying of DVD video content. Similarly, video content transmitted through digital satellite or digital cable broadcasts can be scrambled to only allow paying consumers to descramble the video content. Encryption and scrambling techniques use secret key or codeword values that are supposed to only be available to a device associated with the consumer, such as a digital cable, or digital satellite, set-top box. Once the secret key and/or codeword values become public knowledge, an unauthorized consumer is capable of descrambling protected audio and video content. From the above discussion, it should be apparent that systems and methods of providing secured key and codeword protection would be useful. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Specific embodiments of the present disclosure are shown and described in the drawings presented herein. Various advantages, features and characteristics of the present disclosure, as well as methods, operations and functions of related elements of structure, and the combination of parts and economies of manufacture, will become apparent upon consideration of the following description and claims with reference to the accompanying drawings, all of which form a part of this specification, and wherein: FIG. 1 is a block diagram illustrating a system for processing scrambled information according to one embodiment of the present disclosure; FIG. 2 is a block diagram illustrating a decoupling between a protected storage device that can be decoupled from external interfaces of a system on a chip according to one embodiment of the present disclosure; FIG. 3 is a block diagram illustrating a a private key storage device that can be decoupled from external interfaces of a system on a chip according to one embodiment of the present disclosure; FIG. 4 is a diagram illustrating a method of providing content between a service provider and a consumer according to one embodiment of the present disclosure; FIGS. 5 and 6 are flow diagrams illustrating specific embodiment of decoupling protected memory from external interfaces of a system on a chip. detailed-description description="Detailed Description" end="lead"? | 20040422 | 20080729 | 20050818 | 58956.0 | 1 | PEESO, THOMAS R | METHOD AND SYSTEM FOR SECURE CONTENT DISTRIBUTION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,830,346 | ACCEPTED | Method for displaying an image, image display apparatus, method for driving an image display apparatus and apparatus for driving an image display panel | A method of displaying an image using an image display device in which the image display device has an artificial light source includes inputting primary image signals to the image display device, determining chroma state of the primary image signals for each image frame, and determining gray-scale state of the primary image signals for each image frame. The primary image signals are transformed to multi-color image signals and luminance of the artificial light source is controlled, in response to the determined chroma state and gray-scale state of the primary image signals. | 1. A method of displaying an image using an image display device, the image display device comprising an artificial light source, the method comprising: inputting primary image signals to the image display device; determining chroma state of the primary image signals for each image frame; determining gray-scale state of the primary image signals for each image frame; and transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source, in response to the determined chroma state and gray-scale state of the primary image signals. 2. The method of claim 1, wherein the step of determining chroma state of the primary image signals comprises determining whether the primary signals are in a low chroma state, a middle chroma state or a high chroma state. 3. The method of claim 2, wherein the step of determining gray-scale state of the primary image signals comprises determining whether the primary signals are in a low gray-scale state, a middle gray-scale state or a high gray-scale state. 4. The method of claim 3, wherein, when the primary image signals are in a high chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the primary image signals and normally operating the artificial light source. 5. The method of claim 3, wherein, when the primary image signals are in a high chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the luminance of the artificial light source. 6. The method of claim 3, wherein, when the primary image signals are in a low chroma state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises normally operating the artificial light source. 7. The method of claim 3, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a low gray-scale state and primary image signals in a low chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and normally operating the artificial light source. 8. The method of claim 3, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a low gray-scale state and primary image signals in a low chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and normally operating the artificial light source. 9. The method of claim 3, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a high gray-scale state and primary image signals in a low chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises normally operating the artificial light source or increasing the luminance of the artificial light source. 10. The method of claim 3, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a high gray-scale state and primary image signals in a low chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises decreasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and increasing the luminance of the artificial light source. 11. The method of claim 1, wherein the step of determining the chroma state comprises: extracting a minimum gray scale and a maximum gray scale from the primary image signals; dividing the minimum gray scale by the maximum gray scale of the primary image signals to output divided data; outputting a high chroma state or a low chroma state in response to the divided data; counting the number of high and low chroma states; and comparing the number of high chroma states with the number of low chroma states to determine the chroma state of the present frame. 12. The method of claim 2, wherein the step of determining the gray-scale state comprises: determining the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale states and the number of primary image signals in a low gray-scale state; and comparing the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale state and the number of primary image signals in a low gray-scale state to determine the gray-scale state of the present frame. 13. An image display apparatus comprising: a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals; a data driver that outputs data signals in response to the multi-color image signals; a scan driver that successively outputs scan signals; a display panel that displays an image corresponding to the data signals in response to the scan signals; and a light source that supplies light to the display panel in response to the luminance control signal. 14. The image display apparatus of claim 13, wherein the transformation controller comprises: a gray-scale discriminator that discriminates a gray-scale state of each of the primary signals to output a gray-scale state signal; a chroma discriminator that discriminate a chroma state of each of the primary signals to output a chroma state signal; a multi-color transformer that transforms primary image signals to multi-color image signals in response to the gray-scale state signal and the chroma state signal; and a backlight controller that outputs the luminance control signal in response to the gray-scale state signal and the chroma state signal. 15. The image display apparatus of claim 14, wherein the chroma discriminator comprises: an extractor that extracts a minimum gray scale and a maximum gray scale from the primary image signals; a divider that divides the minimum gray scale by the maximum gray scale of the primary image signals to output divided data; a chroma comparator that outputs a high chroma state or a low chroma state in response to the divided data; a counter that counts the number of high and low chroma states; and a summer that compares the number of high chroma states with the number of low chroma states to output the chroma state signal. 16. The image display apparatus of claim 14, wherein the gray-scale discriminator comprises: a first summer that determines the number of primary image signals in a high gray-scale state; a second summer that determines the number of primary image signals in a middle gray-scale states; a third summer that determines the number of primary image signals in a low gray-scale state; and a comparator that compares the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale state and the number of primary image signals in a low gray-scale state to determine the gray-scale state of the present frame. 17. The image display apparatus of claim 14, wherein the multi-color transformer comprises: a color expander that transforms the primary image signals to primary multi-color image signals; and a luminance compensator that compensates luminance of the primary multi-color image signals in response to the gray-scale state signal and the chroma-state signal to output multi-color image signals. 18. A method for driving an image display apparatus, the image display apparatus comprising a display panel and a light source, the method comprising: inputting primary image signals to the image display apparatus; determining chroma state of the primary image signals for each image frame; determining gray-scale state of the primary image signals for each image frame; transforming the primary image signals to multi-color image signals and outputting a luminance control signal, in response to the determined chroma state and gray-scale state of the primary image signals; applying image data to the display panel in response to the multi-color image signals; and controlling the light source in response to the luminance control signal to output light to the display panel. 19. The method of claim 18, wherein the step of determining chroma state of the primary image signals comprises determining whether the primary signals are in a low chroma state, a middle chroma state or a high chroma state. 20. The method of claim 19, wherein the step of determining gray-scale state of the primary image signals comprises determining whether the primary signals are in a low gray-scale state, a middle gray-scale state or a high gray-scale state. 21. The method of claim 20, wherein, when the primary image signals are in a high chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the primary image signals and normally operating the artificial light source. 22. The method of claim 20, wherein, when the primary image signals are in a high chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the luminance of the artificial light source. 23. The method of claim 20, wherein, when the primary image signals are in a low chroma state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises normally operating the artificial light source. 24. The method of claim 20, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a low gray-scale state and primary image signals in a low chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and normally operating the artificial light source. 25. The method of claim 20, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a low gray-scale state and primary image signals in a low chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises increasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and normally operating the artificial light source. 26. The method of claim 20, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a high gray-scale state and primary image signals in a low chroma state and a low gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises normally operating the artificial light source or increasing the luminance of the artificial light source. 27. The method of claim 20, wherein, when the primary image signals include a mixture of primary image signals in a high chroma state and a high gray-scale state and primary image signals in a low chroma state and a high gray-scale state, the step of transforming the primary image signals to multi-color image signals and controlling luminance of the artificial light source comprises decreasing the gray-scale of gray-scale data corresponding to the high chroma state image signals and increasing the luminance of the artificial light source. 28. The method of claim 18, wherein the step of determining the chroma state comprises: extracting a minimum gray scale and a maximum gray scale from the primary image signals; dividing the minimum gray scale by the maximum gray scale of the primary image signals to output divided data; outputting a high chroma state or a low chroma state in response to the divided data; counting the number of high and low chroma states; and comparing the number of high chroma states with the number of low chroma states to determine the chroma state of the present frame. 29. The method of claim 19, wherein the step of determining the gray-scale state comprises: determining the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale states and the number of primary image signals in a low gray-scale state; and comparing the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale state and the number of primary image signals in a low gray-scale state to determine the gray-scale state of the present frame. 30. An apparatus for driving an image display panel, the image display panel comprising a plurality of gate lines, a plurality of data lines, a switching element electrically connected to one of the gate lines and one of the data lines, and a pixel electrode electrically connected to the switching element, the display panel displaying an image corresponding to data signals in response to scan signals, the apparatus comprising: a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals; a data driver that outputs the data signals to the plurality of data lines in response to the multi-color image signals; a scan driver that successively outputs the scan signals to the plurality of gate lines; and a light source that supplies light to the display panel in response to the luminance control signal. 31. The apparatus of claim 30, wherein the transformation controller comprises: a gray-scale discriminator that discriminates a gray-scale state of each of the primary image signals to output a gray-scale state signal; a chroma discriminator that discriminate a chroma state of each of the primary signals to output a chroma state signal; a multi-color transformer that transforms primary image signals to multi-color image signals in response to the gray-scale state signal and the chroma state signal; and a backlight controller that outputs the luminance control signal in response to the gray-scale state signal and the chroma state signal. 32. The apparatus of claim 31, wherein the chroma discriminator comprises: an extractor that extracts a minimum gray scale and a maximum gray scale from the primary image signals; a divider that divides the minimum gray scale by the maximum gray scale of the primary image signals to output divided data; a chroma comparator that outputs a high chroma state or a low chroma state in response to the divided data; a counter that counts the number of high and low chroma states; and a summer that compares the number of high chroma states with the number of low chroma states to output the chroma state signal. 33. The apparatus of claim 31, wherein the gray-scale discriminator comprises: a first summer that determines the number of primary image signals in a high gray-scale state; a second summer that determines the number of primary image signals in a middle gray-scale states; a third summer that determines the number of primary image signals in a low gray-scale state; and a comparator that compares the number of primary image signals in a high gray-scale state, the number of primary image signals in a middle gray-scale state and the number of primary image signals in a low gray-scale state to determine the gray-scale state of the present frame. 34. The apparatus of claim 31, wherein the multi-color transformer comprises: a color expander that transforms the primary image signals to primary multi-color image signals; and a luminance compensator that compensates luminance of the primary multi-color image signals in response to the gray-scale state signal and the chroma-state signal to output multi-color image signals. | BACKGROUND 1. Technical Field The present disclosure relates to a method and apparatus for displaying an image, and a method and apparatus for driving a display apparatus. More particularly, the present disclosure relates to a method and apparatus for displaying an image with adaptive color-transformation and increased luminance, and a method and apparatus for driving the display apparatus. 2. Discussion of Related Art In an image display apparatus, additional colors may be added to three primary colors of each pixel to increase luminance and improve image display quality. The three primary colors include red (R), green (G) and blue (B). FIGS. 1A to 1C are plan views showing a conventional arrangement of pixels. FIG. 1A is a plan view showing R, G and B subpixels. FIG. 1B is a plan view showing R, G, B and white (W) subpixels. FIG. 1C is a plan view showing R, G, B, cyan (C), magenta (M) and yellow (Y) subpixels. Referring to FIG. 1B, the W subpixel is added to the three primary colored subpixels to increase the luminance of the display apparatus. Referring to FIG. 1C, C, M and Y colored subpixels are added to the three primary colored subpixels to increase the color gamut of the display apparatus. When one of the primary colors having a high chroma is displayed by a display apparatus, the luminance of the display apparatus may be decreased. In addition, although a display apparatus having RGBW subpixels displays an achromatic color with increased luminance, the luminance of the primary colors may be decreased. For example, when an image of flowers having various colors are displayed on a white background using RGBW subpixels, the luminance of the background increases in inverse proportion to the luminance of the flowers that have the primary colors. Therefore, the image display quality of the flower may be deteriorated. When the same image is displayed using RGBCMY subpixels, the luminance of the background also increases in inverse proportion to the luminance of the flowers that have the primary colors. Further, the luminance of the primary colors in the RGBCMY type display apparatus decreases in proportion to the area of the RGB subpixels. In addition to using subpixels having divided areas, multi-color images may also be displayed using divided time periods during which the subpixels are activated. However, the problems discussed above are also associated with images displayed using divided time periods. Accordingly, there is a need for an image display apparatus in which the luminance and color transformation are controlled to improve image quality. SUMMARY OF THE INVENTION A method of displaying an image using an image display device in which the image display device has an artificial light source according to an exemplary embodiment of the invention includes inputting primary image signals to the image display device, determining chroma state of the primary image signals for each image frame, and determining gray-scale state of the primary image signals for each image frame. The primary image signals are transformed to multi-color image signals and luminance of the artificial light source is controlled, in response to the determined chroma state and gray-scale state of the primary image signals. An image display apparatus according to an exemplary embodiment of the invention includes a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals. A data driver outputs data signals in response to the multi-color image signals and a scan driver successively outputs scan signals. A display panel displays an image corresponding to the data signals in response to the scan signals. A light source supplies light to the display panel in response to the luminance control signal. A method for driving an image display apparatus in which the image display apparatus has a display panel and a light source according to exemplary embodiment of the invention includes inputting primary image signals to the image display apparatus, determining chroma state of the primary image signals for each image frame, and determining gray-scale state of the primary image signals for each image frame. The primary image signals are transformed to multi-color image signals and a luminance control signal is output, in response to the determined chroma state and gray-scale state of the primary image signals. Image data is applied to the display panel in response to the multi-color image signals. The light source is controlled in response to the luminance control signal to output light to the display panel. An apparatus for driving an image display panel according to an exemplary embodiment of the invention, in which the image display panel has a plurality of gate lines, a plurality of data lines, a switching element electrically connected to one of the gate lines and one of the data lines, and a pixel electrode electrically connected to the switching element, the display panel displaying an image corresponding to data signals in response to scan signals, includes a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals. A data driver outputs the data signals to the plurality of data lines in response to the multi-color image signals. A scan driver successively outputs the scan signals to the plurality of gate lines. A light source supplies light to the display panel in response to the luminance control signal. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments of the present invention will be described in detail with reference to the attached drawings in which: FIGS. 1A to 1C are plan views showing conventional arrangements of pixels; FIG. 2 is a schematic view showing an LCD apparatus in accordance with an exemplary embodiment of the present invention; FIG. 3 is a chromaticity diagram showing an expanded color region in accordance with an exemplary embodiment of the present invention; FIGS. 4A to 4G are graphs showing relationships between gray-scale and chroma in accordance with an exemplary embodiment of the present invention; FIGS. 5A to 5C are flow charts showing a method of driving an LCD apparatus in accordance with an exemplary embodiment of the present invention; FIG. 6 is a schematic view showing the transformation controller of FIG. 2; FIG. 7 is a schematic view showing the gray-scale discriminator of FIG. 6; FIG. 8 is a schematic view showing the chroma discriminator of FIG. 6; and FIG. 9 is a schematic view showing the multi-color transformer of FIG. 2. DESCRIPTION OF PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the invention, an example of which is illustrated in the accompanying drawings, in which like reference characters refer to corresponding elements. FIG. 2 is a schematic view showing an LCD apparatus in accordance with an exemplary embodiment of the present invention. The LCD apparatus may display a multi-color image. The multi-color image may be displayed using pixels each including at least four subpixels that have different color coordinates from one another. The multi-color image may include four primary colors. Primary image signals define a triangle in a visible color gamut of x-y color coordinates. Multi-color image signals define a polygon including the triangle in the visible color gamut of the x-y color coordinates. The polygon includes at least four sides. Red (R), green (G) and blue (B) primary colors corresponds to wavelengths of about 650 nm, about 550 nm and about 450 nm, respectively. Referring to FIG. 2, the LCD apparatus according to the present embodiment of the invention includes a transformation controller 100, a data driver 200, a backlight 300, a scan driver 400 and an LCD panel 500. The transformation controller 100 includes a discriminating part 110, a multi-color-transformer 120 and a backlight controller 130. The transformation controller 100 receives primary image signals (R, G and B) to output multi-color image signals (R1, G1, B1, C, M and Y) in response to a chroma of each of the primary image signals (R, G and B) and a gray-scale of each of the primary image signals (R, G and B). The transformation controller 100 outputs the multi-color image signals (R1, G1, B1, C, M and Y) to the data driver 200. The chroma of a color is measured relative to an achromatic color. For example, if the chroma of an achromatic color is 0, the chroma of a primary color is 10. The transformation controller 100 outputs a first control signal to the data driver 200. The first control signal controls output of the multi-color image signals (R1, G1, B1, C, M, Y) in response to a vertical synchronizing signal (Vsync), a horizontal synchronizing signal (Hsync), a data enable signal (DE) and a main clock (MCLK) that are provided together with the primary image signals (R, G and B). The first control signal includes a horizontal synchronizing start signal (STH) and a load signal (LOAD). The horizontal synchronizing start signal (STH) controls storage of normal data or predetermined data. The load signal (LOAD) controls output of the stored multi-color image signals (R1, G1, B1, C, M and Y). The transformation controller 100 outputs a second control signal to the scan driver 400 during 1 H period. The second control signal controls an image signal display in response to the multi-color image signals (R1, G1, B1, C, M and Y). The second control signal includes a gate clock (GATE CLK) and a vertical synchronizing start signal (STV). The gate clock (GATE CLK) corresponds to a next scan line. The vertical synchronizing start signal (STV) corresponds to a first scan line. The data driver 200 receives the horizontal synchronizing start signal (STH), and stores the multi-color image signals (R1, G1, B1, C, M and Y). The data driver 200 outputs analog-transformed data (D) that is transformed from the stored multi-color image signals (R1, G1, B1, C, M and Y) in response to the load signal (LOAD). The data driver 200 outputs the analog-transformed data (D) to the LCD panel 500. The backlight 300 includes a lamp unit and an inverter supplying power to the lamp unit. The backlight 300 supplies light to the LCD panel 500 in response to a luminance control signal 131. When the luminance control signal 131 is high level, the backlight 300 supplies a light having high intensity to the LCD panel 500. When the luminance control signal 131 is low level, the backlight 300 supplies a light having low intensity to the LCD panel. Therefore, the luminance of the LCD apparatus may be adjusted. The scan driver 400 successively outputs a scan signal (S) in response to the gate clock (GATE CLK) and the vertical synchronizing start signal (STV). The LCD panel 500 includes a plurality of pixel electrodes that are arranged in a matrix shape. The matrix is made of m×n pixel electrodes. When the scan signal (S) is applied to each of the pixels, the pixel electrode is operated in response to the data signal (D). The data driver 200 supplies the data signal (D) to the LCD panel 500. Therefore, the LCD panel 500 displays the image using the light generated from the backlight 300. The colors which can be matched by combining a given set of three primary colors such as the blue, green, and red are represented on a chromaticity diagram by a triangle joining the coordinates for the three colors. When the primary image signal is applied to the LCD apparatus, the LCD apparatus displays a color that is matched from the triangular region formed by the R, G and B primary colors so that the multi-color image signal defines a polygon including the triangle. The polygon includes at least four sides. FIG. 3 is a chromaticity diagram showing an expanded color region in accordance with an exemplary embodiment of the present invention. Referring to FIG. 3, the 1943 CIE color coordinates corresponding to the primary image signals (R, G and B) are graphed at positions different from one another to form the triangle in the chromaticity diagram. A color of an image which can be matched by combining R, G, and B falls within the triangle joining the coordinates for R, G, and B. The difference between the color coordinates corresponding to the primary image signals (R, G and B) satisfies equation 1. (Δx2+Δy2)1/2<0.15 Equation 1 A polygon formed by the color coordinates corresponding to the multi-color image signals (R1, G1, B1, C, M and Y) includes the triangle so that the image display quality may be improved. The difference between the color coordinates corresponding to the multi-color image signals (R1, G1, B1, C, M and Y) also satisfies equation 1. Therefore, the area corresponding to the multi-color image signals (R1, G1, B1, C, M and Y) is larger than the area corresponding to the triangular image signals (R, G and B). FIGS. 4A to 4G are graphs showing relationships between gray-scale and chroma in accordance with an exemplary embodiment of the present invention. Table 1 represents primary image signals and methods for processing gray-scale. TABLE 1 Characteristics of Operation of Case Primary Image Compensation During Multi-Color Luminance of (FIG.) Signal transformation Backlight I (4A) High Chroma & Low Increasing Gray-Scale Normal Operation Gray-Scale II (4B) High Chroma & High Normal Multi-Color-transformation Increasing Luminance Gray-Scale III (4C) Low Chroma Normal Multi-Color-transformation Normal Operation IV (4D) (High Chroma & Low Increasing Gray-Scale for High Normal Operation Gray-Scale) + Chroma Data (Low Chroma & Normal Multi-Color transformation Low Gray-Scale) for Low Chroma Data V (4E) (High Chroma & Low Increasing Gray-Scale for High Normal Operation Gray-Scale) + Chroma Data (Low Chroma & Normal Multi-Color transformation High Gray-Scale) for Low Chroma Data VI (4F) (High Chroma & Normal Multi-Color transformation Normal Operation or High Gray-Scale) + Increasing Luminance (Low Chroma & Low Gray-Scale) VII (4G) (High Chroma & Decreasing Gray-Scale for High Increasing Luminance High Gray-Scale) + Chroma Data (Low Chroma & Normal Multi-Color transformation High Gray-Scale) for Low Chroma Data Referring to FIGS. 4A to 4G, in case I of this exemplary embodiment, when the primary image signals include high chroma and low gray-scale, the gray-scale of the primary image signals is increased to output the multi-color image signals, and the backlight is normally operated. That is, the luminance of the backlight is not increased, although the primary image signals include high chroma. Therefore, the image display quality is improved. Although the primary image signals corresponding to one frame have high chroma, the luminance of the backlight may not be increased, because the power consumption of the backlight increases in proportion to the luminance of the backlight. In case II of this exemplary embodiment, when the primary image signals include high chroma corresponding to high gray-scale, the multi-color transformation may be insufficient for the compensation. Therefore, the primary image signals are normally multi-color transformed, and the luminance of the backlight is increased to improve the image display quality. When the primary image signals include a mixture of high chroma and low chroma, luminance of a color image signal may be decreased, resulting in deterioration of the image display quality. For example, when the primary image signals include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to high gray-scale, the color luminance corresponding to the high chroma is decreased, resulting in deterioration of the image display quality. For example, when red flowers are displayed in a white background, the luminance of the red flowers may be decreased so that brownish red flowers may be displayed. When the luminance of the backlight is increased, the luminance of the background increases in proportion to the luminance of the entire LCD panel, thereby deteriorating the display quality. In case VII of the exemplary embodiment, although the primary image signals include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to high gray-scale, the luminance of the achromatic color is decreased, and the luminance of the backlight is not increased so as to improve the image display quality. FIGS. 5A to 5C are flow charts showing a method of driving an LCD apparatus in accordance with an exemplary embodiment of the present invention. Referring to FIGS. 5A to 5C, reception of the primary image signals (R, G and B) is checked (Step S110). When the primary image signals (R, G and B) are received, the chroma and the gray-scale are checked with respect to reference primary image signals (R′, G′ and B′) (Step S112). The reference primary image signals (R′, G′ and B′) may be determined in response to the primary image signals (R, G and B). The reference primary image signals (R′, G′ and B′) may also be primary image signals corresponding to a previous frame. The primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of one frame include high chroma corresponding to low gray-scale (Step S120). When the primary image signals (R, G and B) of the frame include high chroma corresponding to low gray-scale, the primary image signals (R, G and B) are color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y), and the gray-scale of all the gray-scale data corresponding to the multi-color image signals (R1, G1, B1, C, M and Y) is increased during the color-transformation (Step S122). The backlight is normally operated (Step S124), and the process is feed backed to the step S110. In other exemplary embodiments of the invention, the step S124 may be performed prior to the step S122. When the primary image signals (R, G and B) of the frame do not include high chroma corresponding to low gray-scale, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include high chroma corresponding to high gray-scale (Step S130). When the primary image signals (R, G and B) of the frame include high chroma corresponding to high gray-scale, the gray-scale of all the gray-scale data corresponding to the primary image signals (R, G and B) are color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y) (Step S132), and the luminance of the backlight is increased (Step S134). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame do not include high chroma corresponding to high gray-scale, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include low chroma (Step S140). When the primary image signals (R, G and B) of the frame include low chroma, the gray-scale of all the gray-scale data corresponding to the primary image signals (R, G and B) are color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y) (Step S142), and the backlight is normally operated (Step S144). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame do not include low chroma, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to low gray-scale (Step S150). When the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to low gray-scale, the gray-scale of the gray-scale data corresponding to the low chroma is normally color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y), and the gray-scale corresponding to the high chroma is increased during the color-transformation (Step S152). The backlight is normally operated (Step S154). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame do not include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to low gray-scale, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to high gray-scale (Step S160). When the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to high gray-scale, the gray-scale of the gray-scale data corresponding to the low chroma is color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y), and the gray-scale corresponding to the high chroma is increased during the color-transformation (Step S162). The backlight is normally operated (Step S164). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame do not include a mixture of high chroma corresponding to low gray-scale and low chroma corresponding to high gray-scale, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to low gray-scale (Step S170). When the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to low gray-scale, the gray-scale of all the gray-scale data corresponding to the primary image signals (R, G and B) are color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y) (Step S172). The backlight is normally operated, or the luminance of the backlight is increased (Step S174). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to low gray-scale, the primary image signals (R, G and B) are compared with the reference primary image signals (R′, G′ and B′) to determine whether the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to high gray-scale (Step S180). When the primary image signals (R, G and B) of the frame include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to high gray-scale, the gray-scale of all the gray-scale data corresponding to the low chroma is color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y), and the gray-scale of the high chroma is decreased (Step S182). The luminance of the backlight is increased (Step S184). The process is feed backed to the step S110. When the primary image signals (R, G and B) of the frame do not include a mixture of high chroma corresponding to high gray-scale and low chroma corresponding to high gray-scale, the gray-scale of all the gray-scale data corresponding to the primary image signals (R, G and B) are normally color-transformed to the multi-color image signals (R1, G1, B1, C, M and Y) (Step S192), and the backlight is normally operated (Step S194). The process is feed backed to the step S110. FIG. 6 is a schematic view showing the transformation controller of FIG. 2. Referring to FIG. 6, the transformation controller 100 includes a discriminating part 110, a multi-color transformer 120 and a backlight controller 130. The transformation controller 100 receives the primary image signals (R, G and B) to output the luminance control signal 131 in response to the chroma and the gray-scale of the primary image signals (R, G and B). The discriminating part 110 includes a gray-scale discriminator 112 and a chroma discriminator 114. The discriminating part 110 discriminates the chroma and the gray-scale of the primary image signals (R, G and B) to output a gray-scale state signal 111a and a chroma state signal 111b to the multi-color transformer 120 and the backlight controller 130. The gray-scale discriminator 112 discriminates a gray-scale state of each of the primary image signals (R, G and B) to output the gray-scale state signal 111a corresponding to a low gray-scale, a middle gray-scale or a high gray-scale to the multi-color transformer 120 and the backlight controller 130. For example, when a full gray-scale is 256, and the primary image signals (R, G and B) are 10, 10 and 255, respectively, the gray-scale state signal corresponding to the R primary image signal and the gray-scale state signal corresponding to the G primary image signal are in low gray-scale states, and the gray-scale state signal corresponding to the B primary image signal is in a high gray-scale state. The chroma discriminator 114 discriminates a chroma state of each of the primary image signals (R, G and B) to output the chroma state signal 111b corresponding to a low chroma, a middle chroma or a high chroma to the multi-color transformer 120 and the backlight controller 130. The chroma state is a ratio of a minimum gray-scale to a maximum gray-scale among the gray-scales of the primary image signals (R, G and B). The chroma state signal is a rational number that is about 0 to 1. The high chroma state is about 0 to 0.3, and the low chroma state is about 0.7 to 1. For example, when a full gray-scale is 256, and the primary image signals (R, G and B) are 10, 10 and 255, respectively, the minimum and maximum gray-scales are 10 and 255, respectively. Therefore, the ratio of the minimum to maximum gray-scale is about 0.039, and the chroma state signal is in a high chroma state. In addition, when the primary image signals (R, G and B) are 200, 200 and 200, respectively, the minimum and maximum gray-scales are 200. Therefore, the ratio of the minimum to maximum gray-scale is 1, and the chroma state signal is in a low chroma state. The multi-color transformer 120 transforms the primary image signals (R, G and B) to the multi-color image signals (R1, G1, B1, C, M and Y) in response to the gray-scale state signal 111a and the chroma state signal 111b to output the multi-color image signals (R1, G1, B1, C, M and Y) to the data driving part 200. The backlight controller 130 outputs the luminance control signal 131 to the backlight 300 in response to the gray-scale state signal 111a and the chroma state signal 111b. FIG. 7 is a schematic view showing the gray-scale discriminator of FIG. 6. Referring to FIG. 7, the gray-scale discriminator 112 includes a first gray-scale discriminator 610, a second gray-scale discriminator 620, a third gray-scale discriminator 630, a first summer 640, a second summer 650, a third summer 660 and a comparator 670. The first gray-scale discriminator 610 includes a data discriminator 612, a first counter 614, a second counter 616 and a third counter 618. The first gray-scale discriminator 610 counts the number of high, middle and low gray-scale states corresponding to the R primary image signal and outputs the count data to the first, second and third summers 640, 650 and 660, respectively. The data discriminator 612 discriminates the R primary image signal to output the gray-scale state to the first, second and third counters 614, 616 and 618. That is, when the R primary image signal is in a high gray-scale state (RH), the data discriminator 612 outputs the high gray-scale state (RH) to the first counter 614. When the R primary image signal is in a middle gray-scale state (RM), the discriminator 612 outputs the middle gray-scale state (RM) to the second counter 616. When the R primary image signal is in a low gray-scale state (RL), the discriminator 612 outputs the low gray-scale state (RL) to the third counter 618. When the R primary image signal including the high gray-scale state (RH) is applied to the first counter 614, the number of the R primary image signal including the high gray-scale state (RH) is counted so that the first counter 614 outputs first R count data (GRH) to the first summer 640. When the R primary image signal including the middle gray-scale state (RM) is applied to the second counter 616, the number of the R primary image signal including the middle gray-scale state (RM) is counted so that the second counter 616 outputs second R count data (GRM) to the second summer 650. When the R primary image signal including the low gray-scale state (RL) is applied to the third counter 618, the number of the R primary image signal including the low gray-scale state (RL) is counted so that the third counter 618 outputs third R count data (GRL) to the third summer 660. The second gray-scale discriminator 620 includes a G data discriminator (not shown), a first G counter (not shown), a second G counter (not shown) and a third G counter (not shown). The second gray-scale discriminator 620 counts the number of high, middle and low gray-scale states corresponding to the G primary image signal and outputs the count data to the first, second and third summers 640, 650 and 660, respectively. The second gray-scale discriminator 620 counts the numbers of the G primary image signals including the high, middle and low gray-scale states (GH, GM and GL) to output first G count data (GGH), second G count data (GGM) and third G count data (GGL) to the first, second and third summers 640, 650 and 660, respectively. The third gray-scale discriminator 630 includes a B data discriminator (not shown), a first B counter (not shown), a second B counter (not shown) and a third B counter (not shown). The third gray-scale discriminator 630 counts the number of high, middle and low gray-scale states corresponding to the B primary image signal and outputs the count data to the first, second and third summers 640, 650 and 660, respectively. The third gray-scale discriminator 630 counts the numbers of the B primary image signals including the high, middle and low gray-scale states (BH, BM and BL) to output first B count data (GBH), second B count data (GBM) and third B count data (GBL) to the first, second and third summers 640, 650 and 660, respectively. The first summer 640 outputs first summation data 641 that is a summation of the first R count data (GRH), the first G count data (GGH) and the first B count data (GBH) to the comparator 670. The second summer 650 outputs second summation data 651 that is a summation of the second R count data (GRM), the second G count data (GGM) and the second B count data (GBM) to the comparator 670. The third summer 660 outputs third summation data 661 that is a summation of the third R count data (GRL), the third G count data (GGL) and the third B count data (GBL) to the comparator 670. The comparator 670 compares the first, second and third summation data 641, 651 and 661 to output the gray-scale state signal 111a. FIG. 8 is a schematic view showing the chroma discriminator of FIG. 6. Referring to FIG. 8, the chroma discriminator 114 includes an extractor 710, a divider 720, a chroma comparator 730, a counting part 740 and a summer 750. The extractor 710 extracts a maximum primary image signal (GMAX) and a minimum primary image signal (GMIN) from the first to third primary image signals to output the maximum and minimum primary image signals (GMAX and GMIN) to the divider 720. The divider 720 divides the minimum primary image signal (GMIN) by the maximum primary image signal (GMAX) to output the divided data (GMIN/GMAX) to the chroma comparator 730. The chroma comparator 730 outputs a high chroma state (H) or a low chroma state (L) to the counting part 740 in response to the divided data (GMIN/GMAX). The counting part 740 includes a high counter 742 and a low counter 744. The high and low counters 742 and 744 count the numbers of the high and low chroma states (H and L) to output counted numbers (CH and CL) corresponding to the high and low chroma states (H and L) to the summer 750. The summer 750 compares the counted number (CH) corresponding to the high chroma state (H) with the counted number (CL) corresponding to the low chroma state (L) during a frame to output the chroma state signal 111b corresponding to the high chroma state (H) or the low chroma state (L) to the multi-color transformer 120 and the backlight controller 130. The frame is determined by the vertical synchronizing signal (Vsync) that is provided to the chroma discriminator 114. For example, when the counted number (CH) corresponding to the high chroma state (H) is about twice the counted number (CL) corresponding to the low chroma state (L), the summer 750 outputs the chroma state signal 111b corresponding to the high chroma state (H) to the multi-color transformer 120 and the backlight controller 130. When the counted number (CH) corresponding to the high chroma state (H) is about a half of the counted number (CL) corresponding to the low chroma state (L), the summer 750 outputs the chroma state signal 111b corresponding to the low chroma state (L) to the multi-color transformer 120 and the backlight controller 130. When the counted numbers (CH and CL) corresponding to the high and low chroma states (H and L) are substantially the same, the summer 750 outputs the chroma state signal 111b corresponding to the middle chroma state (M) to the multi-color transformer 120 and the backlight controller 130. FIG. 9 is a schematic view showing the multi-color-transformer of FIG. 2. Referring to FIG. 9, the multi-color transformer 120 includes a color expander 122 and a luminance compensator 124. The multi-color transformer 120 transforms the primary image signals (R, G and B) to the multi-color image signals (R1, G1, B1, C, M and Y) in response to the gray-scale state signal 111a and the chroma state signal 111b to output the multi-color image signals (R1, G1, B1, C, M and Y) to the data driver 200. The color expander 122 transforms the primary image signals (R, G and B) to primary multi-color image signals (R2, G2, B2, C1, M1 and Y1) to output the primary multi-color image signals (R2, G2, B2, C1, M1 and Y1) to the luminance compensator 124. The luminance compensator 124 compensates luminance of the primary multi-color image signals (R2, G2, B2, C1, M1 and Y1) in response to the gray-scale state signal 111a and the chroma state signal 111b to output the multi-color image signals (R1, G1, B1, C, M and Y) to the data driver 200. The display apparatus according to various exemplary embodiments of the present invention is operated using an adaptive color-transformation and a luminance control so that the color reproducibility of the LCD apparatus is increased even when the primary image signals include high chroma, low chroma or a mixture thereof. The gray-scales of multi-color signals are adjusted in response to the gray-scale state and the chroma state of the primary image signals, and the intensity of a backlight is controlled in response to the primary image signals to display the multi-colored image. Therefore, the image display quality is improved. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | <SOH> BACKGROUND <EOH>1. Technical Field The present disclosure relates to a method and apparatus for displaying an image, and a method and apparatus for driving a display apparatus. More particularly, the present disclosure relates to a method and apparatus for displaying an image with adaptive color-transformation and increased luminance, and a method and apparatus for driving the display apparatus. 2. Discussion of Related Art In an image display apparatus, additional colors may be added to three primary colors of each pixel to increase luminance and improve image display quality. The three primary colors include red (R), green (G) and blue (B). FIGS. 1A to 1 C are plan views showing a conventional arrangement of pixels. FIG. 1A is a plan view showing R, G and B subpixels. FIG. 1B is a plan view showing R, G, B and white (W) subpixels. FIG. 1C is a plan view showing R, G, B, cyan (C), magenta (M) and yellow (Y) subpixels. Referring to FIG. 1B , the W subpixel is added to the three primary colored subpixels to increase the luminance of the display apparatus. Referring to FIG. 1C , C, M and Y colored subpixels are added to the three primary colored subpixels to increase the color gamut of the display apparatus. When one of the primary colors having a high chroma is displayed by a display apparatus, the luminance of the display apparatus may be decreased. In addition, although a display apparatus having RGBW subpixels displays an achromatic color with increased luminance, the luminance of the primary colors may be decreased. For example, when an image of flowers having various colors are displayed on a white background using RGBW subpixels, the luminance of the background increases in inverse proportion to the luminance of the flowers that have the primary colors. Therefore, the image display quality of the flower may be deteriorated. When the same image is displayed using RGBCMY subpixels, the luminance of the background also increases in inverse proportion to the luminance of the flowers that have the primary colors. Further, the luminance of the primary colors in the RGBCMY type display apparatus decreases in proportion to the area of the RGB subpixels. In addition to using subpixels having divided areas, multi-color images may also be displayed using divided time periods during which the subpixels are activated. However, the problems discussed above are also associated with images displayed using divided time periods. Accordingly, there is a need for an image display apparatus in which the luminance and color transformation are controlled to improve image quality. | <SOH> SUMMARY OF THE INVENTION <EOH>A method of displaying an image using an image display device in which the image display device has an artificial light source according to an exemplary embodiment of the invention includes inputting primary image signals to the image display device, determining chroma state of the primary image signals for each image frame, and determining gray-scale state of the primary image signals for each image frame. The primary image signals are transformed to multi-color image signals and luminance of the artificial light source is controlled, in response to the determined chroma state and gray-scale state of the primary image signals. An image display apparatus according to an exemplary embodiment of the invention includes a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals. A data driver outputs data signals in response to the multi-color image signals and a scan driver successively outputs scan signals. A display panel displays an image corresponding to the data signals in response to the scan signals. A light source supplies light to the display panel in response to the luminance control signal. A method for driving an image display apparatus in which the image display apparatus has a display panel and a light source according to exemplary embodiment of the invention includes inputting primary image signals to the image display apparatus, determining chroma state of the primary image signals for each image frame, and determining gray-scale state of the primary image signals for each image frame. The primary image signals are transformed to multi-color image signals and a luminance control signal is output, in response to the determined chroma state and gray-scale state of the primary image signals. Image data is applied to the display panel in response to the multi-color image signals. The light source is controlled in response to the luminance control signal to output light to the display panel. An apparatus for driving an image display panel according to an exemplary embodiment of the invention, in which the image display panel has a plurality of gate lines, a plurality of data lines, a switching element electrically connected to one of the gate lines and one of the data lines, and a pixel electrode electrically connected to the switching element, the display panel displaying an image corresponding to data signals in response to scan signals, includes a transformation controller that transforms primary image signals to multi-color image signals and outputs a luminance control signal, in response to determined chroma state and gray-scale state of the primary image signals. A data driver outputs the data signals to the plurality of data lines in response to the multi-color image signals. A scan driver successively outputs the scan signals to the plurality of gate lines. A light source supplies light to the display panel in response to the luminance control signal. | 20040422 | 20070123 | 20050825 | 63173.0 | 0 | AMIN, JWALANT B | METHOD FOR DISPLAYING AN IMAGE, IMAGE DISPLAY APPARATUS, METHOD FOR DRIVING AN IMAGE DISPLAY APPARATUS AND APPARATUS FOR DRIVING AN IMAGE DISPLAY PANEL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,830,862 | ACCEPTED | Method for mapping a logic circuit to a programmable look up table (LUT) | The method for mapping a logic circuit to a plurality of interconnectable, programmable look up tables (LUT) elements includes forming logic element groups including individual logic elements and/or previously formed logic element groups that are capable of being accommodated within the fanin and/or fanout capacity of a target LUT. The method further includes mapping the formed logic element group to the target LUT, and repeating the process for forming logic element groups and mapping to target LUTs for the entire network in a manner such that at each stage only the unmapped logic element/elements and mapped logic element groups of the previous stage are considered for mapping. | 1-3. (canceled). 4. A method for mapping a logic circuit to a plurality of interconnectable, programmable look up table (LUT) elements, the method comprising: forming logic element groups including at least one of individual logic elements and previously formed logic element groups that are within at least one of a fanin and fanout capacity of a target LUT; mapping the formed logic element group to the target LUT; and repeating forming and mapping for the entire logic circuit in a manner such that at each stage unmapped logic elements and mapped logic element groups of the previous stage are considered for mapping. 5. A method as claimed in claim 4 wherein mapping to the target LUT includes using mapped logic element groups of any selected previous stage. 6. A method as claimed in claim 4 wherein forming logic element groups includes inputting information about the logic elements to be mapped. 7. A method for mapping a logic circuit, including a network of logic elements and nodes, to a plurality of interconnectable, programmable look up table (LUT) elements, the method comprising: forming logic element groups including at least one of individual logic elements and previously formed logic element groups that are within at least one of a fanin and fanout capacity of a target LUT; mapping the formed logic element group to the target LUT; and repeating forming and mapping for the entire logic circuit in a manner that at each stage unmapped logic elements and mapped logic element groups of the previous stage are considered for mapping. 8. A method as claimed in claim 7 wherein mapping to the target LUT includes using mapped logic element groups of any selected previous stage. 9. A method as claimed in claim 7 wherein forming logic element groups includes inputting information about the logic elements to be mapped. 10. A method as claimed in claim 9 wherein forming logic element groups further includes generating a sub-network at a selected node including the selected node and transitive fanins of the selected node up to nodes in a cut set of immediate input nodes of the selected node. 11. A method as claimed in claim 10 wherein forming logic element groups further includes searching the sub-network starting from the selected node to find a feasible cut. 12. A method for mapping a logic circuit, including a network of logic elements and nodes, to a plurality of interconnectable, programmable look up table (LUT) elements, the method comprising: forming logic element groups including at least one of individual logic elements and previously formed logic element groups that are within at least one of a fanin and fanout capacity of a target LUT; and mapping the formed logic element group to the target LUT; wherein forming and mapping include using unmapped logic elements and mapped logic element groups of a previous mapping stage. 13. A method as claimed in claim 12 wherein mapping to the target LUT includes using mapped logic element groups of any selected previous mapping stage. 14. A method as claimed in claim 12 wherein forming logic element groups includes inputting information about the logic elements to be mapped. 15. A method as claimed in claim 12 wherein forming logic element groups includes generating a sub-network at a selected node including the selected node and transitive fanins of the selected node up to nodes in a cut set of immediate input nodes of the selected node. 16. A method as claimed in claim 15 wherein forming logic element groups further includes searching the sub-network starting from the selected node to find a feasible cut. | FIELD OF THE INVENTION The present invention relates to Field Programmable Gate Arrays (FPGA), and, more particularly, to methods for mapping a logic circuit to a programmable look up table. BACKGROUND OF THE INVENTION A programmable logic array device has a plurality of logic elements connected through an interconnect architecture. Electrical circuits are mapped over these logic elements to allow the device to perform desired operations. Mapping of an electrical circuit to an FPGA is a time consuming process, and thus it is desired to increase the speed of the mapping process. The important objectives during mapping of an electrical circuit over an FPGA are, to map the maximum number of circuit elements over a single logic element and to achieve the smallest possible tree of logic elements to realize the electrical circuit. Different technologies propose different methods for achieving these objectives. For example, R. J. Francis et al. in “Chortle-crf: Fast Technology Mapping for Lookup Table-Based FPGAs”, University of Toronto, CA 28th ACM/IEEE Design Automation Conference, 1991, pp. 227-233, proposes a mapping algorithm that reduces delay by using bin packing to determine the gate level decomposition of every node in the network. Another method suggested by K. C. Chen et al. in “DAG-Map: Graph-Based FPGA Technology Mapping for Delay Optimization”, IEEE Design and Test of Computers, September 1992, pp. 7-20, uses a graph based technology mapping package for delay optimization in logic elements. In this technology mapping is carried out in three main parts, transformation of an arbitrary network into a two input network technology mapping for delay minimization, and area optimization in the mapping approach through a direct acyclic graph (DAG). A polynomial time technology mapping algorithm has been proposed by K. C. Chen, J. Cong, and Y. Ding in “DAG-Map: Graph-Based FPGA Technology Mapping for Delay Optimization”, IEEE Design and Test of Computers, September 1992, pp. 7-20, in which a Flow-Map that optimally maps an electrical circuit on an FPGA for depth minimization by computing a minimum height for k-feasible cut in a network. This process is commonly used for technology mapping. The process can be better understood by referring to the flowchart shown in FIG. 1. FIG. 1 shows a flow diagram of the process. According to this process, in the first step, the gate level Net-list 1.1 containing information about the logic gates is inserted for mapping onto the LUTs in the FPGA. Now supposing that N denotes the given network of logic gates contained in the Net-list and Nt(v) denotes a sub-network generated at a node v, the next step is to generate sub-network Nt(v) at each node v 1.2 of the network N. The sub-network Nt(v) contains the node v itself along with all the transitive fanins of node v including the primary inputs. Next, k-distinct paths are found in the sub-network Nt(v) by applying known techniques such as depth first, breadth first search and the like. Subsequently, a minimum height k-feasible cut is found in the sub-network Nt(v) 1.3 starting from v until the primary inputs and LUTs are formed. The next step followed in the process is to level each gate of the design 1.4 and subsequently, map the given design starting from the primary output towards the primary inputs 1.5 onto a LUT. FIG. 2 shows the generation of sub-networks Nt(v) using the process discussed above. In this process at each node v of the network N, in the given figure, sub-network Nt(12) generated at the node 12 starts from node 12 and continues until the primary nodes 1, 2, 3, 4 and 5. Thus, the sub-network can be mathematically represented as Nt(12)={12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1} as it includes all the transitive fanins of node v, including the primary inputs. A four input LUT is formed at node 12 for the sub-network Nt(v). Nodes inside the cone are 10, 11 and 12, while the fanin nodes of the cone are 6, 7, 8 and 9. Another research article by J. Cong et al. in “On Area/Depth Trade-off in LUT-Based FPGA Technology Mapping”, UCLA Computer Science Dept., 30th ACM/IEEE Design Automation Conference (DAC), 1993, pp. 213-218, suggests a process for FPGA mapping technology. In this technique a number of depth relaxation operations are performed to obtain a new network with bounded increase in depth and is advantageous to subsequent re-mapping for area minimization by gradually increasing depth bound. An integrated approach for synthesizing and mapping has been disclosed by Francis, et. al. in “Technology Mapping of Lookup Table-Based FPGAs for Performance”, Dept. of Electrical Engineering, University of Toronto, CA, IEEE February 1991, pp. 568-571. This process uses a global combinatorial optimization technique to guide the Boolean synthesis process during depth minimization. The combinatorial optimization is achieved by computing a series of minimum cuts of fixed heights in a network based on fast network computation, and the Boolean optimization is achieved by efficient Ordered Binary Decision Diagrams (OBDD) based implementation of functional decomposition. In another approach by Francis, et al., a process has been discussed for technology mapping including a new method for choosing gate level decompositions based on binary packing. Several other approaches have also been applied to achieve these objectives. However, most of these approaches result in either local optimal or exponential time complexity. Hence, these approaches are too expensive and cannot be applied for all designs. One of the ways for achieving this reduction of sub-network includes: Starting from the node v and including all nodes until the k-feasible cut is found; and Considering node v as 0th level node, including all nodes up to a certain level, e.g. 4 or 5. Such reduction techniques do not give an optimal solution or even a near optimal solution. The Flow-diagram process described above suffers from a drawback, that the runtime of the process gets increased while constructing sub-networks and finding a cut for each node of the circuit. This increase becomes even more prominent when the delay of a circuit increases. SUMMARY OF THE INVENTION An object of this invention is to overcome the above drawbacks in the prior art and provide a method for LUT based mapping for reducing computation time taken and providing a near depth optimal mapping approach. To achieve the above and other objects, the invention provides a method for mapping a logic circuit to a plurality of interconnectable, programmable look up table (LUT) elements comprising: forming logic element groups including individual logic elements and/or previously formed logic element groups that are capable of being accommodated within the fanin and/or fanout capacity of a target LUT; mapping the formed logic element group to the target LUT, and; repeating the process for forming logic element groups and mapping to target LUTs for the entire network in a manner such that at each stage only the unmapped logic element/elements and mapped logic element groups of the previous stage are considered for mapping. The invention also provides a method that provides an ability to incorporate mapped logic elements groups up to any desired previous levels for the mapping to the target LUT. BRIEF DESCRIPTION OF THE DRAWINGS The objects and advantages of the invention will become more apparent with reference to the following description and accompanying drawings, wherein: FIG. 1 is a flowchart depicting steps in the conventional process for LUT mapping. FIG. 2 is a schematic diagram showing the generation of sub-networks at each node v of the network N representing all logic gates to be mapped in accordance with the process of FIG. 1. FIG. 3 is a flowchart for use in describing the process of the present invention for LUT mapping. FIG. 4 is a schematic diagram showing the generation of sub-networks according to the method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1, and FIG. 2 have already been described in the background of the invention. FIG. 3 shows the process/algorithm depicting the steps provided by the present invention for LUT mapping. First, the gate level Net-list is input for providing information about the logic gates to be mapped 4.1. The next step 4.2 is the generation of the sub-network Nt(v) at node v containing the node v itself along with all the transitive fanins of v until the nodes which are in the cut sets of immediate input nodes of v. This step is an improvement over the conventional mapping methods as it significantly reduces the number of nodes to be considered for mapping each time a new node is to be mapped. Further, in step 4.3 the k-feasible cut is found out for the sub-network Nt(v) by searching the sub-network starting from node v. In the present method for constructing sub-network Nt(v) for each node v of the network N, let v1 be a node for which all fanins are primary inputs. Sub-network Nt(v) includes primary inputs, which have a path to v and v itself. For constructing sub-network Nt(v) at any node v of the network N, Let X={x1, x2, . . . , xm} be the set of immediate fanin nodes of a node v. Let Ci={xi1, xi2, . . . , xik} (i=1, 2, . . . , m) be the k-feasible cut of the sub-network Nt(xi) generated at the node xi. Then Nt(v) includes of all nodes in C1, C2, . . . , Cm and all transitive fanouts of nodes in C1, C2, . . . , Cm which have path to v as shown in FIG. 4. In FIG. 4, suppose sub-networks Nt(18), Nt(19), Nt(20) have already been constructed and the sub-network Nt(26) has to be generated next at node 26. Further, suppose that number of inputs to each LUT is 4. The sets of fanin nodes for the sub-networks Nt(18), Nt(19), Nt(20) are {9, 10, 11, 12}, {4, 5, 6, 13} and {12, 13, 17, 21} respectively. If the sub-network Nt(26) is generated by following the steps of the conventional mapping process, then Nt(26) will contain all nodes till the primary inputs. In mathematical terms Nt(26)={1, 2, 3, . . . 24, 25, 26}. On the other hand, when the sub-network Nt(26) is generated using the method of the present invention, then it starts from node 26 and spans up to nodes for which the set of immediate fanins is the set: {9, 10, 11, 12}∪{4, 5, 6, 13}∪{12, 13, 17, 21}={9, 10, 11, 12, 4, 5, 6, 13, 17, 21}. Therefore, according to this invention, the set of nodes that are not required to construct Nt(26) is {1, 2, 3, 4, 5, 6, 7, 8, 22, 23, 24, 25}. As a result of this reduction in the number of nodes, the computational time taken gets reduced by about 50% as compared to the conventional method. At the same time, this method provides a near depth optimal mapping solution. Moreover, for a circuit having delay, the execution time saving will be even more. This execution time saving may vary from x to 4x times. Results of this invention on a few benchmark circuits for LUT formation have been tabulated in Table 1. Columns 2 and 3 of Table 1 are results for the conventional Flow-map process, while Columns 4 and 5 are results for the method of the present invention. TABLE 1 Flow-map Time Proposed method Design Depth (seconds) Depth Time Alu2 11 4.61 11 1.25 Alu4 7 27.68 7 19.59 Apex2 8 51.505 8 27.39 Apex3 7 10.485 7 5.39 B12 6 3.49 6 2.6 C1355 4 33.848 5 3.4 C499 4 11.847 5 1.4 Count 6 .5 6 .2 Duke2 5 1.8 5 1.05 Ex5p 7 35.53 7 9.93 i8 6 27.87 6 18.7 i9 5 12.99 6 4.5 Misex3 7 46.03 7 37.99 S1196 7 4.19 7 2.16 S1423 18 7.98 18 1.96 S838 14 2.82 14 1.31 S8381 6 2.96 6 1.16 S1238 7 4.14 7 2.06 Dalu-opt 6 3.22 6 1.66 Vg2 5 1.39 5 .14 X3 6 6.609 6 5.5 Table5 7 7.01 7 2.8 Table3 6 7.1 6 2.9 TOTAL 315.604 152.14 The description of the present invention has been presented for purposes of illustration and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. | <SOH> BACKGROUND OF THE INVENTION <EOH>A programmable logic array device has a plurality of logic elements connected through an interconnect architecture. Electrical circuits are mapped over these logic elements to allow the device to perform desired operations. Mapping of an electrical circuit to an FPGA is a time consuming process, and thus it is desired to increase the speed of the mapping process. The important objectives during mapping of an electrical circuit over an FPGA are, to map the maximum number of circuit elements over a single logic element and to achieve the smallest possible tree of logic elements to realize the electrical circuit. Different technologies propose different methods for achieving these objectives. For example, R. J. Francis et al. in “Chortle-crf: Fast Technology Mapping for Lookup Table-Based FPGAs”, University of Toronto, CA 28 th ACM/IEEE Design Automation Conference, 1991, pp. 227-233, proposes a mapping algorithm that reduces delay by using bin packing to determine the gate level decomposition of every node in the network. Another method suggested by K. C. Chen et al. in “DAG-Map: Graph-Based FPGA Technology Mapping for Delay Optimization”, IEEE Design and Test of Computers, September 1992, pp. 7-20, uses a graph based technology mapping package for delay optimization in logic elements. In this technology mapping is carried out in three main parts, transformation of an arbitrary network into a two input network technology mapping for delay minimization, and area optimization in the mapping approach through a direct acyclic graph (DAG). A polynomial time technology mapping algorithm has been proposed by K. C. Chen, J. Cong, and Y. Ding in “DAG-Map: Graph-Based FPGA Technology Mapping for Delay Optimization”, IEEE Design and Test of Computers, September 1992, pp. 7-20, in which a Flow-Map that optimally maps an electrical circuit on an FPGA for depth minimization by computing a minimum height for k-feasible cut in a network. This process is commonly used for technology mapping. The process can be better understood by referring to the flowchart shown in FIG. 1 . FIG. 1 shows a flow diagram of the process. According to this process, in the first step, the gate level Net-list 1.1 containing information about the logic gates is inserted for mapping onto the LUTs in the FPGA. Now supposing that N denotes the given network of logic gates contained in the Net-list and N t (v) denotes a sub-network generated at a node v, the next step is to generate sub-network N t (v) at each node v 1.2 of the network N. The sub-network N t (v) contains the node v itself along with all the transitive fanins of node v including the primary inputs. Next, k-distinct paths are found in the sub-network N t (v) by applying known techniques such as depth first, breadth first search and the like. Subsequently, a minimum height k-feasible cut is found in the sub-network N t (v) 1.3 starting from v until the primary inputs and LUTs are formed. The next step followed in the process is to level each gate of the design 1.4 and subsequently, map the given design starting from the primary output towards the primary inputs 1.5 onto a LUT. FIG. 2 shows the generation of sub-networks N t (v) using the process discussed above. In this process at each node v of the network N, in the given figure, sub-network N t ( 12 ) generated at the node 12 starts from node 12 and continues until the primary nodes 1 , 2 , 3 , 4 and 5 . Thus, the sub-network can be mathematically represented as N t ( 12 )={12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1} as it includes all the transitive fanins of node v, including the primary inputs. A four input LUT is formed at node 12 for the sub-network N t (v). Nodes inside the cone are 10, 11 and 12, while the fanin nodes of the cone are 6, 7, 8 and 9. Another research article by J. Cong et al. in “On Area/Depth Trade-off in LUT-Based FPGA Technology Mapping”, UCLA Computer Science Dept., 30 th ACM/IEEE Design Automation Conference (DAC), 1993, pp. 213-218, suggests a process for FPGA mapping technology. In this technique a number of depth relaxation operations are performed to obtain a new network with bounded increase in depth and is advantageous to subsequent re-mapping for area minimization by gradually increasing depth bound. An integrated approach for synthesizing and mapping has been disclosed by Francis, et. al. in “Technology Mapping of Lookup Table-Based FPGAs for Performance”, Dept. of Electrical Engineering, University of Toronto, CA, IEEE February 1991, pp. 568-571. This process uses a global combinatorial optimization technique to guide the Boolean synthesis process during depth minimization. The combinatorial optimization is achieved by computing a series of minimum cuts of fixed heights in a network based on fast network computation, and the Boolean optimization is achieved by efficient Ordered Binary Decision Diagrams (OBDD) based implementation of functional decomposition. In another approach by Francis, et al., a process has been discussed for technology mapping including a new method for choosing gate level decompositions based on binary packing. Several other approaches have also been applied to achieve these objectives. However, most of these approaches result in either local optimal or exponential time complexity. Hence, these approaches are too expensive and cannot be applied for all designs. One of the ways for achieving this reduction of sub-network includes: Starting from the node v and including all nodes until the k-feasible cut is found; and Considering node v as 0 th level node, including all nodes up to a certain level, e.g. 4 or 5. Such reduction techniques do not give an optimal solution or even a near optimal solution. The Flow-diagram process described above suffers from a drawback, that the runtime of the process gets increased while constructing sub-networks and finding a cut for each node of the circuit. This increase becomes even more prominent when the delay of a circuit increases. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of this invention is to overcome the above drawbacks in the prior art and provide a method for LUT based mapping for reducing computation time taken and providing a near depth optimal mapping approach. To achieve the above and other objects, the invention provides a method for mapping a logic circuit to a plurality of interconnectable, programmable look up table (LUT) elements comprising: forming logic element groups including individual logic elements and/or previously formed logic element groups that are capable of being accommodated within the fanin and/or fanout capacity of a target LUT; mapping the formed logic element group to the target LUT, and; repeating the process for forming logic element groups and mapping to target LUTs for the entire network in a manner such that at each stage only the unmapped logic element/elements and mapped logic element groups of the previous stage are considered for mapping. The invention also provides a method that provides an ability to incorporate mapped logic elements groups up to any desired previous levels for the mapping to the target LUT. | 20040423 | 20070313 | 20050217 | 63723.0 | 1 | GARBOWSKI, LEIGH M | METHOD FOR MAPPING A LOGIC CIRCUIT TO A PROGRAMMABLE LOOK UP TABLE (LUT) | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,830,972 | ACCEPTED | 2-Nitratoethyl oxirane, poly(2-nitratoethyl oxirane) and preparation method thereof | A synthesis of an energetic prepolymer used as a high-energy binder for an insensitive and high performance explosive is disclosed. More specifically, provided are a novel compound 2-nitratoethyl oxirane expressed by formula III, a novel compound poly(2-nitratoethyl oxirane) expressed by formula IV, obtained by polymerization of 2-nitratoethyl oxirane used as a monomer and a preparation method thereof. The compound, used as an energetic prepolymer and a monomer for preparation thereof can substitute for existing poly(glycidyl nitrate) (PGN) which has been known to be a promising one having the best performance among existing energetic prepolymers, but which has a problem to be self-decomposed after synthesis of polyurethane elastomer, to solve this problem. | 1. 2-nitratoethyl oxirane expressed by formula III. 2. Poly(2-nitratoethyl oxirane) expressed by formula IV. 3. Poly(2-nitratoethyl oxirane) of claim 2, used as an energetic prepolymer needed to prepare an insensitive and high performance explosive. 4. A method for preparing poly(2-nitratoethyl oxirane) expressed by formula IV of claim 2, comprising the following steps: synthesizing 1,4-dinitrato-2-butanol of formula II from 1,2,4-butanetriol of formula I, as shown in the following reaction scheme 3-1; synthesizing 2-nitratoethyl oxirane of formula III from the obtained 1,4-dinitrato-2-butanol of formula II, as shown in the following reaction scheme 3-2; and polymerizing poly(2-nitratoethyl oxirane) of formula IV from the obtained 2-nitratoethyl oxirane of formula III, as shown in following reaction scheme 3-3. | PRIORITY CLAIM This application claims priority from Korean patent application no. 27805/2003 filed Apr. 30, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthesis of an energetic prepolymer used as a high-energy binder for an insensitive and high performance explosive. 1. Description of the Background Art Currently, HTPB (Hydroxyl-Terminated Polybutadiene), a prepolymer for a binder for Plastic-Bonded Explosives(PBX's) is being widely used as a binder for polyurethane groups. This binder is included in PBX in the amount of about 15% to improve mechanical properties of PBX's. However, this binder is an inert material, and thereby causing reduction of energy of PBX's. Therefore, many efforts are made to develop a high-energy contained binder (an energetic binder) for increasing the energy of PBX's. Among energetic binders developed as a result of such efforts, poly(glycidyl nitrate) (PGN) expressed as the following formula 1 is a representative one. A monomer structure of the PGN is shown in following formula 2. However, as shown in following reaction scheme 1, after a polyurethane elastomer has been synthesized, the PGN of Formula 1 is self-decomposed in the polyurethane elastomer. As shown in reaction scheme 1, when the polyurethane elastomer is synthesized by using the PGN of Formula 1, hydrogen bonding to carbon to which a nitrate group bonds is chemically acidified thus to easily cause a decomposition reaction as shown in reaction scheme 1, thereby causing a decomposition of the main chain of polyurethane. Nevertheless, since the PGN has been known as a material having the best performance among existing energetic prepolymers, many researches are made in order to solve such problems. However, outstanding results have not been obtained yet. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a monomer, 2-nitratoethyl oxirane expressed as formula III, which has energy equal to PGN and an excellent storage stability, and poly(2-nitratoethyl oxirane) expressed as formula IV, which is polymerized therefrom. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The present invention relates to a synthesis of an energetic prepolymer used as a high-energy binder for an insensitive and high performance explosive. More particularly, the present invention provides a novel compound, 2-nitratoethyl oxirane expressed as formula III and poly(2-nitratoethyl oxirane) expressed as formula IV, which is polymerized therefrom. 2-nitratoethyl oxirane of formula III is used as a monomer for a synthesis of poly(2-nitratoethyl oxirane) of formula IV. In addition, poly(2-nitratoethyl oxirane) of formula IV has a chemical structure similar to the PGN of formula 1 which is a prepolymer conventionally used as a high energy binder, and also shows performance as a high-energetic prepolymer similar to the PGN. As shown in reaction scheme 1, the existing PGN is self-decomposed since hydrogen bonding to carbon to which a nitrate group bonds is unstable and a urethane group attacks the unstable hydrogen, thereby being rearranged. However, unlike the existing PGN, as shown in following reaction scheme 2, the compound IV in accordance with the present invention includes one more methylene group, whereby the unstable hydrogen is not spatially attacked by the polyurethane group, and thus the compound IV is not self-decomposed in a polyurethane elastomer. Accordingly, the compound IV is very useful as a high-energetic prepolymer capable of solving the problem in using the PGN. A synthesis of 2-nitratoethyl oxirane of formula III and a synthesis process of poly(2-nitraoethyl oxirane) of formula IV are shown in following reaction scheme 3. Said reaction scheme will now be explained in more detail. First, nitric acid is added to 1, 2, 4-butanetriol of the formula I and reacted at a room temperature. The reaction mixture is extracted with methylene chloride (MC), washed with water and dried. The solvent is removed to obtain 1,4-dinitrato-2-butanol of formula II (reaction scheme 3-1). Then, sodium hydroxide is added to the obtained 1,4-dinitrato-2-butanol and reacted. The reaction mixture is extracted with MC, washed with water and dried. The solvent is removed, to obtain 2-nitratoethyl oxirane of formula III (reaction scheme 3-2). Then, boron trifluoride (BF3) and 1,4-butandiol are reacted to the obtained 2-nitratoethyl oxirane of formula III and the polymerization thereof is performed to obtain poly(2-nitraoethyl oxirane) of formula IV (reaction scheme 3-3). The obtained poly(2-nitratoethyle oxirane) is equal to PGN, an existing energetic prepolymer, in an energy aspect but is not self-decomposed, which has been pointed out as a problem of the PGN. Accordingly, poly(2-nitratoethyl oxirane) is a very useful material as a new energetic prepolymer which is used as a high energy binder for an insensitive and high performance explosive. Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples. EXAMPLE 1 Synthesis of 1,4-dinitrato-2-butanol 31.8 g (0.3 mol) of 1,2,4-butanetriol of formula I was put in a 3-neck flask of 250 ml equipped with a thermometer, a reflux condenser and a dropping funnel, and the temperature was controlled to be 0° C. or below. 100.2 g (1.59 mol) of 98% nitric acid was put in the dropping funnel, and the nitric acid was dropped to a solution, controlling the temperature of the reaction solution so as not to be over 10° C. After the nitric acid had been all dropped, the reaction mixture was left at a room temperature for about one hour to complete the reaction. Then, the obtained reaction solution was slowly added to 150 ml of ice water. The reaction mixture was extracted with 100 ml of methylene chloride. Then, the resulting material was washed three times with 150 ml of 10% sodium hydrogen carbonate, washed twice with 150 ml of a sodium chloride saturated solution, and dehydrated with anhydrous magnesium sulfate. Then, the solid was removed by filtering the solution, and volatile matter was removed by evacuating the solution for five hours at 10 mmHg/60° C., to obtain 39.9 g of 1,4-dinitrato-2-butanol (yield: 70%). NMR (CDCl3, δfor TMS):4.40, 4.20(m, 2H), 4.06(m, 1H), 2.50, 2.19(m, 2H) EXAMPLE 2 Synthesis of 2-nitratoethyl oxirane 39.9 g (0.205 mol) of 1,4-dinitrato-2-butanol obtained in example 1 was put in a 250 ml 3-neck flask and distilled water was added thereto. The temperature of a reaction solution was controlled to be 10° C. or below, then 24.6 g (0.306 mol) of 50% sodium hydroxide was injected thereto using a dropping funnel, controlling the temperature of the reaction solution so as not to be over 10° C. After the injection, a reaction was additionally made for three hours at a room temperature and completed. Then, the reaction solution was extracted three times with 60 ml of methylene chloride. The resulting material was washed twice with 150 ml of sodium chloride saturated solution, and dehydrated with anhydrous magnesium sulfate. The obtained solution was filtered to remove the solid and then evacuated for five hours at 10 mmHg/60 □ to completely remove volatile matter. In order to obtain pure 2-nitratoethyl oxirane which could be polymerized to a prepolymer, the resulting product was purified using a Kugelrohr distillation apparatus (Aldrich, Z40, 11405) to obtain 14.2 g of pure 2-nitratoethyl oxirane of formula III (yield: 52%). NMR(CDCl3, δfor TMS):4.58(t, 2H), 3.00(m,1 H), 2.61, 2.53(m, 2H), 2.03,1.85(m, 2H) EXAMPLE 3 Synthesis of poly(2-nitratoethyl oxirane) 0.18 g (2mol) of 1,4-butandiol was added to 0.28g (2mol) of boron trifluoride etherate (BF3OEt2) and evacuated for about two hours to completely remove ether. Then,10 ml of methylene chloride was added thereto. A solution of 6.65 g (50 mol) of 2-nitratoethyl oxirane obtained in example 2 dissolved in methylene chloride was injected to the resulting solution for about three hours to perform polymerization. After polymerization, 50 ml of water and 30 ml of methylene chloride were additionally put therein for washing. Then, the resulting material was washed twice with 50 ml of saturated sodium chloride solution and dehydrated with anhydrous magnesium sulfate. 20 ml of ethanol was added to the obtained polymer and stirred to wash non-reaction organic matter. Then, volatile matter was completely removed by evacuating the resulting material for five hours at 1mmHg/80 □ to obtain polymer poly(2-nitratoethyl oxirane) expressed by formula IV. A yield of the obtained polymer was approximately 91%, a numeric average of the molecular weight 2,380, a polydispersity 1.18, a hydroxyl group 0.586eq/kg, a glass transition temperature −43° C., and a thermal decomposition onset temperature 180° C. EXAMPLE 4 Hardness change of poly(2-nitratoethyl oxirane) group polyurethane elastomer After synthesizing a polyurethane elastomer with each of poly(2-nitratoethyl oxirane) obtained in a manner described in example 3 and existing poly(glycidyl nitrate) (PGN) by using N-100 curing agent, a change of hardness (Shore D hardness) was examined and the result was shown in the following table 1. TABLE 1 Changes of hardness (shore D hardness) of polyurethane elastomer formed by using poly(2-nitratoethyl oxirane) and existing PGN over time 15 30 3 time 3 days 5 days 7 days 10 days days days months 6 months poly(2- 2.0 3.0 3.5 3.5 3.5 3.5 3.6 3.6 nitraoethyl- oxirane) PGN 2.0 3.0 2.5 complet- — — — — ely de- composed As shown in Table 1, in case of polyurethane elastomer formed by using an existing PGN, a polymer began decomposed from solid of gum-stock to liquid after about 1 week. However, in case of polyurethane elastomer formed by using poly(2-nitratoethyl oxirane) in accordance with the present invention, a physical property was maintained even after 6 months. The compound of the present invention, used as an energetic prepolymer or a monomer for preparation thereof can substitute for existing poly(glycidyl nitrate) (PGN) which has been known to be a promising one having the best performance among existing energetic prepolymers, but which has a problem to be self-decomposed after the synthesis of polyurethane elastomer, to solve this problem. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a synthesis of an energetic prepolymer used as a high-energy binder for an insensitive and high performance explosive. 1. Description of the Background Art Currently, HTPB (Hydroxyl-Terminated Polybutadiene), a prepolymer for a binder for Plastic-Bonded Explosives(PBX's) is being widely used as a binder for polyurethane groups. This binder is included in PBX in the amount of about 15% to improve mechanical properties of PBX's. However, this binder is an inert material, and thereby causing reduction of energy of PBX's. Therefore, many efforts are made to develop a high-energy contained binder (an energetic binder) for increasing the energy of PBX's. Among energetic binders developed as a result of such efforts, poly(glycidyl nitrate) (PGN) expressed as the following formula 1 is a representative one. A monomer structure of the PGN is shown in following formula 2. However, as shown in following reaction scheme 1, after a polyurethane elastomer has been synthesized, the PGN of Formula 1 is self-decomposed in the polyurethane elastomer. As shown in reaction scheme 1, when the polyurethane elastomer is synthesized by using the PGN of Formula 1, hydrogen bonding to carbon to which a nitrate group bonds is chemically acidified thus to easily cause a decomposition reaction as shown in reaction scheme 1, thereby causing a decomposition of the main chain of polyurethane. Nevertheless, since the PGN has been known as a material having the best performance among existing energetic prepolymers, many researches are made in order to solve such problems. However, outstanding results have not been obtained yet. | <SOH> SUMMARY OF THE INVENTION <EOH>Therefore, an object of the present invention is to provide a monomer, 2-nitratoethyl oxirane expressed as formula III, which has energy equal to PGN and an excellent storage stability, and poly(2-nitratoethyl oxirane) expressed as formula IV, which is polymerized therefrom. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. detailed-description description="Detailed Description" end="lead"? | 20040422 | 20071030 | 20050106 | 57484.0 | 0 | JACKSON, SHAWQUIA | 2-NITRATOETHYL OXIRANE, POLY(2-NITRATOETHYL OXIRANE) AND PREPARATION METHOD THEREOF | SMALL | 0 | ACCEPTED | 2,004 |
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10,831,070 | ACCEPTED | Lactobacillus acidophilus nucleic acid sequences encoding cell surface protein homologues and uses therefore | Cell wall, cell surface and secreted protein nucleic acid molecules and polypeptides and fragments and variants thereof are disclosed in the current invention. In addition, cell wall, cell surface and secreted fusion proteins, antigenic peptides, and anti-cell wall, cell surface and secreted antibodies are encompassed. The invention also provides recombinant expression vectors containing a nucleic acid molecule of the invention and host cells into which the expression vectors have been introduced. Methods for producing the polypeptides of the invention and methods for their use are further disclosed. | 1. An isolated nucleic acid molecule selected from the group consisting of: a) a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; b) a nucleic acid molecule comprising a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said nucleotide sequence encodes a polypeptide that retains activity; c) a nucleic acid molecule that encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; and, d) a nucleic acid molecule that encodes a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said nucleotide sequence encodes a polypeptide that retains activity; and, e) a complement of any of a)-d). 2. A vector comprising the nucleic acid molecule of claim 1. 3. The vector of claim 2, further comprising a nucleic acid molecule encoding a heterologous polypeptide. 4. A host cell that contains the vector of claim 2. 5. The host cell of claim 4 that is a bacterial host cell. 6. An isolated polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide that is encoded by a nucleotide sequence that is at least 80% identical to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 7. The polypeptide of claim 6 further comprising a heterologous amino acid sequence. 8. An antibody that selectively binds to the polypeptide of claim 6. 9. A method for producing a polypeptide comprising culturing the host cell of claim 4 under conditions in which a nucleic acid molecule encoding the polypeptide is expressed, said polypeptide being selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 10. A method for detecting the presence of a polypeptide in a sample comprising contacting the sample with a compound that selectively binds to a polypeptide and determining whether the compound binds to the polypeptide in the sample; wherein said polypeptide is selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 11. The method of claim 10, wherein the compound that binds to the polypeptide is an antibody. 12. A method for detecting the presence of a nucleic acid molecule of claim 1 in a sample, comprising the steps of: a) contacting the sample with a nucleic acid probe or primer that selectively hybridizes to the nucleic acid molecule; and, b) determining whether the nucleic acid probe or primer binds to a nucleic acid molecule in the sample. 13. The method of claim 12, wherein the sample comprises mRNA molecules and is contacted with a nucleic acid probe. 14. A method for modulating the immune system of a host, comprising introducing into said host a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 15. The method of claim 14, wherein the modulation of said immune system comprises altering the production of host cytokines. 16. The method of claim 15, wherein the modulation of said immune system comprises altering the anti-inflammatory activity. 17. A method for modulating the immune system of a host, comprising introducing into said host a microorganism that expresses a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 18. A method for altering the expression of a host protein or compound, comprising introducing into said host a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 19. The method of claim 18, wherein the host protein to be altered is selected from the group consisting of a cell surface protein, a protein involved in mucin production, a protein involved in cell-cell signaling, a protein involved in host tolerance of commensal bacteria, and a protein that has antimicrobial activity. 20. A method for altering the expression of a host protein or compound, comprising introducing into said host a microorganism that expresses a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 21. A method for treating a gastrointestinal disorder in a subject, comprising introducing into said subject a microorganism comprising a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 22. The method of claim 21, wherein the gastrointestinal disorder is selected from the group consisting of inflammatory bowel disease, Crohn's disease, ulcerative colitis, irritable bowel syndrome, diarrhea, antibiotic associated diarrhea, constipation, and small bowel bacterial overgrowth. 23. A method for treating a gastrointestinal disorder in a subject comprising introducing into said subject a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 24. A method for preventing or reducing the occurrence of an infection in a host, comprising introducing into said subject a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 25. The method of claim 24, wherein the infection is caused by a pathogen selected from the group consisting of a food-borne pathogen, an opportunistic pathogen, and Helicobacter pylori. 26. The method of claim 24, wherein the infection is selected from the group consisting of vaginosis, a yeast infection, and an HIV infection. 27. The method for preventing or reducing the occurrence of an infection in a host, comprising introducing into said subject a microorganism expressing a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 28. A method for removing a detrimental compound from the gastrointestinal tract of a subject, comprising introducing into said subject a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 1202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 29. The method of claim 28, wherein said compound is selected from the group consisting of a toxin, a mutagen, a bile salt, a fat, and a cholesterol. 30. A method for removing a detrimental compound from the gastrointestinal tract of a subject, comprising introducing into said subject a microorganism expressing a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 31. The method of claim 30, wherein the compound is selected from the group consisting of a toxin, a mutagen, a bile salt, a fat, and a cholesterol. 32. A method for enhancing the stability of a microorganism comprising introducing a vector into said organism, wherein the vector comprises at least one nucleotide sequence selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35., 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 33. The method of claim 32, wherein said enhanced stability allows said microorganism an increased ability to survive passage through the stomach, small intestine, and/or gastrointestinal tract. 34. The method of claim 32, wherein said enhanced stability allows said microorganism to resist acid and bile in the stomach, small intestine, and/or gastrointestinal tract. 35. The method of claim 32, wherein said enhanced stability allows said microorganism to persist in the gastrointestinal tract. 36. The method of claim 32, wherein said enhanced stability allows said microorganism to withstand stressful conditions that occur during storage. 37. The method of claim 36, wherein said conditions are selected from the group consisting of culturing, freezing, lyophilizing, and drying. 38. The method of claim 36, wherein said enhanced stability allows said microorganism to withstand stressful conditions that occur during production and processing. 39. The method of claim 38, wherein said conditions are selected from the group consisting of changes in temperature, changes in pH, changes is osmolarity, changes in oxidation state, desiccation, mechanical manipulation, and changes in pressure. 40. A method for enabling a microorganism to possess modified adherence properties, comprising introducing into said microorganism a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 41. The method of claim 40, wherein said microorganism is able to adhere to an epithelial cell. 42. A method for protecting food from contamination by a microorganism, comprising contacting said food with a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; b) a polypeptide encoded by the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; c) a polypeptide comprising an amino acid sequence having at least 80% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306, wherein said polypeptide retains activity; and, d) a polypeptide encoded by a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity. 43. A method for modifying the texture of a food product produced by a lactic acid bacteria, comprising introducing into said lactic acid bacteria a vector comprising a nucleic acid sequence selected from the group consisting of: a) the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307; b) a nucleotide sequence having at least 80% sequence identity to the nucleotide sequence of SEQ ID NO:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 or 307, wherein said polypeptide retains activity; c) a nucleotide sequence encoding a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306; and, d) a nucleotide sequence encoding a polypeptide comprising an amino acid sequence having at least 90% sequence identity to the amino acid sequence of SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 44. The method of claim 43, wherein said modifying of said texture comprises viscosifying, thickening, emulsifying, or gelling. 45. A Lactobacillus acidophilus bacterial strain with a modified ability for modulating the immune system of a host, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 46. A Lactobacillus acidophilus bacterial strain with a modified ability for altering the expression of a host protein or compound, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 47. A Lactobacillus acidophilus bacterial strain with a modified ability for treating a gastrointestinal disorder in a subject, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 48. A Lactobacillus acidophilus bacterial strain with a modified ability for preventing or reducing the occurrence of an infection in a host, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 49. A Lactobacillus acidophilus bacterial strain with a modified ability for removing a detrimental compound from the gastrointestinal tract of a subject, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 50. A Lactobacillus acidophilus bacterial strain with a modified ability for enhancing the stability of a microorganism, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 51. A Lactobacillus acidophilus bacterial strain with modified adherence properties, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 52. A Lactobacillus acidophilus bacterial strain with a modified ability for protecting food from contamination by a microorganism, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. 53. A Lactobacillus acidophilus bacterial strain with a modified ability for modifying the texture of a food product produced by a lactic acid bacteria, as compared to a wild-type Lactobacillus acidophilus, wherein said modified ability is due to expression of at least one polypeptide as found in SEQ ID NO:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 or 306. | CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application Ser. No. 60/465,621, filed Apr. 25, 2003, the contents of which are herein incorporated by reference in their entirety. FIELD OF THE INVENTION This invention relates to polynucleotides isolated from lactic acid bacteria, namely Lactobacillus acidophilus, and polypeptides encoded by them as well as methods for using the polypeptides and microorganisms expressing them. BACKGROUND OF THE INVENTION Lactobacillus acidophilus is a Gram-positive, rod-shaped, non-spore forming, homofermentative bacterium that is a normal inhabitant of the gastrointestinal and genitourinary tracts. Since its original isolation by Moro (1900) from infant feces, the “acid loving” organism has been found in the intestinal tract of humans, breast-fed infants, and persons consuming high milk, lactose, or dextrin diets. Historically, L. acidophilus is the Lactobacillus species most often implicated as an intestinal probiotic capable of eliciting beneficial effects on the microflora of the gastrointestinal tract (Klaenhammer and Russell (2000) “Species of the Lactobacillus acidophilus complex,” Encyclopedia of Food Microbiology, Volume 2, pp. 1151-1157. Robinson et al., eds. (Academic Press, San Diego, Calif.). L. acidophilus can ferment hexoses, including lactose and more complex oligosaccharides, to produce lactic acid and lower the pH of the environment where the organism is cultured. Acidified environments (e.g., food, vagina, and regions within the gastrointestinal tract) can interfere with the growth of undesirable bacteria, pathogens, and yeasts. The organism is well known for its acid tolerance, survival in cultured dairy products, and viability during passage through the stomach and gastrointestinal tract. Lactobacilli and other commensal bacteria, some of which are considered as probiotic bacteria that “favor life,” have been studied extensively for their effects on human health, particularly in the prevention or treatment of enteric infections, diarrheal disease, prevention of cancer, and stimulation of the immune system. The cell wall of Gram-positive bacteria consists of a peptidoglycan macromolecule, with attached accessory molecules such as teichoic acids, teichuronic acids, lipoteichoic acids, lipoglycans, polyphosphates, and carbohydrates (Hancock (1997) Biochem. Soc. Trans. 25:183-187; Salton (1994) The bacterial cell envelope—a historical perspective, p. 1-22. In J.-M. Ghuysen and R. Hakenbeck (ed.) Bacterial cell wall. Elsevier Science BV, Amsterdam, The Netherlands). Proteins associated with the cell surface of Gram-positive bacteria include hydrolases and proteases, polysaccharides, surface exclusion proteins and aggregation-promoting proteins (thought to be involved in mating), S-layer proteins (subunits of crystalline arrays covering the outer surface of many single-celled organisms), sortase (a transpeptidase responsible for cleaving surface proteins at the LPXTG-like (SEQ ID NO:308) motifs), proteins with LPXTG-like motifs, and MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) such as fibronectin-binding proteins, fibrinogen-binding proteins, and mucus-binding proteins. Cell wall, cell surface, and secreted proteins of Gram-positive bacteria serve many diverse functions, including adhering to other cells or compounds, providing structural stability, and responding to environmental stimuli. Surface proteins of bacteria are important for survival within a host, and for cell growth and division. Furthermore, surface proteins are often recognized by a host's immune system to initiate immuno-stimulation, -modulation, or -enhancement. The isolation and characterization of these proteins will aid in developing essential probiotic products with numerous applications, including those that benefit human or animal health, and those concerned with food production and safety. BRIEF SUMMARY OF THE INVENTION Compositions and methods for modifying Lactobacillus organisms are provided. Compositions of the invention include isolated nucleic acid molecules from Lactobacillus acidophilus encoding cell wall, cell surface, and secreted proteins. Specifically, the present invention provides for isolated nucleic acid molecules comprising the nucleotide sequences found in SEQ ID NOS:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 and 307, and isolated nucleic acid molecules encoding the amino acid sequences found in SEQ ID NOS:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 and 306. Also provided are isolated or recombinant polypeptides having an amino acid sequence encoded by a nucleic acid molecule described herein. Variant nucleic acid molecules and polypeptides sufficiently identical to the nucleotide and amino acid sequences set forth in the sequence listings are encompassed by the present invention. Additionally, fragments and sufficiently identical fragments of the nucleotide and amino acid sequences are encompassed. Nucleotide sequences that are complementary to a nucleotide sequence of the invention, or that hybridize to a sequence of the invention, are also encompassed. Compositions further include vectors and host cells for recombinant expression of the nucleic acid molecules described herein, as well as transgenic microbial populations comprising the vectors. Also included in the invention are methods for making the vectors and host cells described herein, as well as methods for the recombinant production of the polypeptides of the invention, and methods for their use. Further included are methods and kits for detecting the presence of a nucleic acid or polypeptide sequence of the invention in a sample, and antibodies that bind to a polypeptide of the invention. The cell wall, cell surface, and secreted polypeptides encoded by the inventive sequences, and the transgenic microbes expressing them, have health-related benefits. The microbes transformed with these polynucleotide sequences may be taken internally as a pharmaceutical or probiotic composition or alternatively, the microbes or their encoded polypeptides may be administered separately or added to products to provide health-related benefits. The nucleic acid molecules of the invention may also enhance the stability of microorganisms expressing them, and therefore may be useful in the production and processing of various foods. DESCRIPTION OF FIGURES FIG. 1 shows the percent adhesion of wild-type L. acidophilus NCFM versus mutant bacteria lacking FpbA (SEQ ID NO:58), Mub (SEQ ID NO:18), SlpA (SEQ ID NO: 60), or streptococcal R28 proteins (SEQ ID NO:76 and SEQ ID NO:78, designated as ORF 1633 and ORF 1634, respectively). DETAILED DESCRIPTION OF THE INVENTION The present invention relates to cell wall, cell surface and secreted molecules from Lactobacillus acidophilus. Nucleotide and amino acid sequences of the molecules are provided. The sequences find use in modifying organisms to have enhanced benefits. By “cell wall, cell surface and secreted molecules” is intended novel cell wall, cell surface and secreted proteins from L. acidophilus. By “cell wall” is intended a protein found in association with the cell wall of a bacterial cell. By “cell surface” as it relates to a polypeptide or polynucleotide of the current invention is intended a protein found in association with the bacterial cell membrane. By “secreted” is intended a protein that is released from the cell it is expressed in. A protein of the invention may be classified as either a cell wall, a cell surface or a secreted protein, or may be included in more than one of these classifications. Furthermore, the term “cell wall, cell surface, or secreted” may be used to describe a single protein as well as more than one protein. See Table I for specific cell wall, cell surface and secreted protein molecules of the present invention. These novel cell wall, cell surface and secreted proteins include cell components selected from the group consisting of peptidoglycans; teichoic acids; lipoteichoic acids; polysaccharides, including homopolysaccharides and heteropolysaccharides; adhesion proteins; secreted proteins; surface (s)-layer proteins; collagen-binding proteins and other cell surface proteins, and may include steroid binding proteins; lemA-like proteins; aggregation-promoting proteins; surface-exclusion proteins; myosin cross-reactive proteins; mucus binding precursors and proteins; fibronectin-binding proteins; sortases; biofilm-associated surface proteins; fibrinogen-binding proteins; tropomyosin-like proteins; FmtB-like surface proteins; psaA-like adhesins; lysM-like proteins; autolysins; cell shape-determining proteins; and rod shape-determining proteins. The full-length gene sequences are referred to as “cell wall, cell surface and secreted molecule sequences,” indicating that they have similarity to cell wall, cell surface and secreted genes. The invention further provides fragments and variants of these cell wall, cell surface and secreted sequences, which can also be used to practice the methods of the present invention. As used herein, the terms “gene” and “recombinant gene” refer to nucleic acid molecules comprising an open reading frame, particularly those encoding a cell wall, cell surface or secreted protein. Isolated nucleic acid molecules of the present invention comprise nucleic acid sequences encoding cell wall, cell surface and secreted proteins, nucleic acid sequences encoding the amino acid sequences set forth in SEQ ID NOS:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 and 306 (hereinafter designated “even SEQ ID NOS:1-307”), the nucleic acid sequences set forth in SEQ ID NOS:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 and 307 (hereinafter designated “odd SEQ ID NOS:1-307”), and variants and fragments thereof. The present invention also encompasses antisense nucleic acid molecules, as described below. In addition, isolated polypeptides and proteins associated with the cell wall, cell surface or that are secreted, and variants and fragments thereof, are encompassed. For purposes of the present invention, the terms “protein” and “polypeptide” are used interchangeably. The compositions and methods of the present invention can be used to modulate the function of the cell wall, cell surface and secreted molecules of L. acidophilus. By “modulate,” “alter,” or “modify” is intended the up- or down-regulation of a target biological activity. Proteins of the invention are useful in modifying the biological activities of lactic acid bacteria, and also in modifying the nutritional or health-promoting characteristics of foods fermented by lactic acid bacteria. Nucleotide molecules of the invention are useful in modulating cell wall, cell surface and secreted protein expression by lactic acid bacteria. Up- or down-regulation of expression from a polynucleotide of the present invention is encompassed. Up-regulation may be accomplished by providing multiple gene copies, modulating expression by modifying regulatory elements, promoting transcriptional or translational mechanisms, or other means. Down-regulation may be accomplished by using known antisense and gene silencing techniques. Thus, proteins of the invention are useful in modulating the immune system, expression of host proteins, therapeutic benefits, stability, and other activities of lactic acid bacteria. By “lactic acid bacteria” is intended bacteria from a genus selected from the following: Aerococcus, Carnobacterium, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Melissococcus, Alloiococcus, Dolosigranulum, Lactosphaera, Tetragenococcus, Vagococcus, and Weissella (Holzapfel et al. (2001) Am. J. Clin. Nutr. 73:365S-373S; Bergey's Manual of Systematic Bacteriology, Vol. 2 (Williams and Wilkins, Baltimore (1986) pp. 1075-1079). The polypeptides of the present invention or microbes expressing them are useful as nutritional additives or supplements, and as additives in dairy and fermentation processing. The polynucleotide sequences, encoded polypeptides, and microorganisms expressing them are useful in the manufacture of milk-derived products, such as cheeses, yogurt, fermented milk products, sour milks, and buttermilk. Microorganisms that express polypeptides of the invention may be probiotic organisms. By “probiotic” is intended a live microorganism that survives passage through the gastrointestinal tract and has a beneficial effect on the host. By “host” is intended an organism that comes into contact with a polypeptide disclosed in the present invention or a microorganism expressing such a protein. Host may refer to humans and other animals as well as bacteria. The polynucleotides and polypeptides of the present invention are useful in modifying the health-related benefits of milk-derived products. These uses include, but are not limited to modulating the immune system of a host; altering the expression of a host protein or compound; treating a gastrointestinal disorder; preventing or reducing the occurrence of an infection; binding, inactivating, removing, sequestering, degrading, digesting, cleaving or modifying detrimental compounds in a subject; enabling a microorganism to possess modified adherence properties; reducing the occurrence of dental caries in a subject; increasing feed conversion in production animals; enabling microorganisms or polypeptides to antagonize other microorganisms; protecting food from contamination; treating a wound; modulating the antibiotic sensitivity of a microorganism; enabling a microorganism to form a biofilm, or interfering with such an ability; treating or preventing cancer; treating heart disease; and lowering cholesterol. The uses also include modifying the texture of a food product produced by a lactic acid bacteria. The polynucleotides and polypeptides of the present invention are also useful in enhancing the stability of a microorganism during industrial fermentation processes including storage, where exposure to various stresses can lead to reduced microbial viability, impaired metabolic activity and sub-optimal fermentation conditions. Stresses are also present in the gastrointestinal tract. Possible stresses include oxidative stress, pH, osmotic stress, dehydration, carbon starvation, phosphate starvation, nitrogen starvation, amino acid starvation, mechanical stress, altered pressure, heat or cold shock and mutagenic stress. The nucleic acid molecules of the invention encode cell wall, cell surface and secreted proteins. They encode transcripts having the DNA sequences set forth in odd SEQ ID NOS:1-307. The amino acid sequences encoded by the nucleotide sequences of the invention are set forth in even SEQ ID NOS:1-307. In addition to the cell wall, cell surface and secreted nucleotide sequences disclosed herein, and fragments and variants thereof, the isolated nucleic acid molecules of the current invention also encompass homologous DNA sequences identified and isolated from other organisms or cells by hybridization with entire or partial sequences obtained from the cell wall, cell surface and secreted nucleotide sequences disclosed herein, or variants and fragments thereof. The nucleic acid and protein compositions encompassed by the present invention are isolated or substantially purified. By “isolated” or “substantially purified” is intended that the nucleic acid or protein molecules, or biologically active fragments or variants, are substantially or essentially free from components normally found in association with the nucleic acid or protein in its natural state. Such components include other cellular material, culture media from recombinant production, and various chemicals used in chemically synthesizing the proteins or nucleic acids. Preferably, an “isolated” nucleic acid of the present invention is free of nucleic acid sequences that flank the nucleic acid of interest in the genomic DNA of the organism from which the nucleic acid was derived (such as coding sequences present at the 5′ or 3′ ends). However, the molecule may include some additional bases or moieties that do not deleteriously affect the basic characteristics of the composition. For example, in various embodiments, the isolated nucleic acid contains less than 5 kb, 4 kb, 3 kb, 2 kb, 1 kb, 0.5 kb, or 0.1 kb of nucleic acid sequence normally associated with the genomic DNA in the cells from which it was derived. Similarly, a substantially purified protein has less than about 30%, 20%, 10%, 5%, or 1% (by dry weight) of contaminating protein, or non-cell wall, cell surface or secreted protein. When the protein is recombinantly produced, preferably culture medium represents less than 30%, 20%, 10%, or 5% of the volume of the protein preparation, and when the protein is produced chemically, preferably the preparations have less than about 30%, 20%, 10%, or 5% (by dry weight) of chemical precursors, or non-cell wall, cell surface or secreted protein chemicals. Fragments and Variants The invention provides isolated nucleic acid molecules comprising nucleotide sequences encoding cell wall, cell surface and secreted proteins, as well as the cell wall, cell surface and secreted proteins encoded thereby. By “cell wall, cell surface and secreted proteins” is intended proteins having the amino acid sequences set forth in even SEQ ID NOS:1-307. Fragments and variants of these nucleotide sequences and encoded proteins are also provided. By “fragment” of a nucleotide sequence or protein is intended a portion of the nucleotide or amino acid sequence. Fragments of the nucleic acid molecules disclosed herein can be used as hybridization probes to identify cell wall, cell surface and secreted protein-encoding nucleic acids, or can be used as primers in PCR amplification or mutation of cell wall, cell surface and secreted protein nucleic acid molecules. Fragments of nucleic acids can also be bound to a physical substrate to comprise what may be considered a macro- or microarray (see, for example, U.S. Pat. No. 5,837,832; U.S. Pat. No. 5,861,242; WO 89/10977; WO 89/11548; WO 93/17126; U.S. Pat. No. 6,309,823). Such arrays of nucleic acids may be used to study gene expression or to identify nucleic acid molecules with sufficient identity to the target sequences. By “polynucleotide” or “nucleic acid molecule” is intended both sense and antisense strands of DNA molecules (e.g., cDNA or genomic DNA) and RNA molecules (e.g., mRNA) and analogs of the DNA or RNA generated using nucleotide analogs. The nucleic acid molecule can be single-stranded or double-stranded, but preferably is double-stranded DNA. A fragment of a nucleic acid molecule encoding a cell wall, cell surface and secreted protein may encode a protein fragment that is biologically active, or it may be used as a hybridization probe or PCR primer as described below. A biologically active fragment of a polypeptide disclosed herein can be prepared by isolating a portion of one of the nucleotide sequences of the invention, expressing the encoded portion of the cell wall, cell surface or secreted protein (e.g., by recombinant expression in vitro), and assessing the activity of the encoded portion of the cell wall, cell surface or secreted protein. Fragments of nucleic acid molecules encoding cell wall, cell surface and secreted proteins comprise at least about 15, 20, 50, 75, 100, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 nucleotides or up to the total number of nucleotides present in a full-length cell wall, cell surface or secreted nucleotide sequence as disclosed herein (for example, 918 for SEQ ID NO:1, 573 for SEQ ID NO:3, 7617 for SEQ ID NO:5, etc.). Fragments of the nucleotide sequences of the present invention will encode protein fragments that retain the biological activity of the cell surface, cell membrane or secreted protein and, hence, retain cell surface, cell membrane or secreted protein activity. By “retains activity” is intended that the fragment will have at least about 30%, preferably at least about 50%, more preferably at least about 70%, even more preferably at least about 80% of the activity of the cell surface, cell membrane or secreted protein disclosed in even SEQ ID NOS:1-307. Methods for measuring cell surface, cell membrane or secreted activity are well known in the art. See, for example, the Example section below as well as the section entitled “Methods of Use” for examples of functional assays. Fragments of amino acid sequences include polypeptide fragments suitable for use as immunogens to raise anti-cell wall, cell surface and secreted antibodies. Fragments include peptides comprising amino acid sequences sufficiently identical to or derived from the amino acid sequence of a cell wall, cell surface or secreted protein, or partial-length protein, of the invention and exhibiting at least one activity of a cell wall, cell surface or secreted protein, but which include fewer amino acids than the full-length cell wall, cell surface and secreted proteins disclosed herein. Typically, biologically active portions comprise a domain or motif with at least one activity of the cell wall, cell surface or secreted protein. A biologically active portion of a cell wall, cell surface or secreted protein can be a polypeptide that is, for example, 10, 25, 50, 100, 150, 200 contiguous amino acids in length, or up to the total number of amino acids present in a full-length cell wall, cell surface or secreted protein of the current invention (for example, 306 for SEQ ID NO:2, 191 for SEQ ID NO:4, 2539 for SEQ ID NO:6, etc.). Such biologically active portions can be prepared by recombinant techniques and evaluated for one or more of the functional activities of a native cell wall, cell surface or secreted protein. As used herein, a fragment comprises at least 5 contiguous amino acids of any of even SEQ ID NOS:1-307. The invention encompasses other fragments, however, such as any fragment in the protein greater than 6, 7, 8, or 9 amino acids. Variants of the nucleotide and amino acid sequences are encompassed in the present invention. By “variant” is intended a sufficiently identical sequence. Accordingly, the invention encompasses isolated nucleic acid molecules that are sufficiently identical to the nucleotide sequences encoding cell wall, cell surface and secreted proteins in even SEQ ID NOS:1-307, or nucleic acid molecules that hybridize to a nucleic acid molecule of odd SEQ ID NOS:1-307, or a complement thereof, under stringent conditions. Variants also include polypeptides encoded by the variant nucleotide sequences of the present invention. In addition, polypeptides of the current invention have an amino acid sequence that is sufficiently identical to an amino acid sequence put forth in even SEQ ID NOS:1-307. By “sufficiently identical” is intended that one amino acid or nucleotide sequence contains a sufficient or minimal number of equivalent or identical amino acid residues as compared to a second amino acid or nucleotide sequence, thus providing a common structural domain and/or indicating a common functional activity. By “sufficiently identical” is intended an amino acid or nucleotide sequence that has at least about 45%, 55%, or 65% identity, preferably at least about 70% or 75% identity, more preferably at least about 80%, 85% or 90%, most preferably at least about 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acid sequence set forth in even SEQ ID NOS:1-307, or a nucleotide sequences set forth in odd SEQ ID NOS:1-307 using one of the alignment programs described herein using standard parameters. One of skill in the art will recognize that these values can be appropriately adjusted to determine corresponding identity of proteins encoded by two nucleotide sequences by taking into account codon degeneracy, amino acid similarity, reading frame positioning, and the like. Variant proteins encompassed by the present invention are biologically active, that is they retain the desired biological activity of the native protein, that is, one or more of the functional activities of a native cell wall, cell surface or secreted protein as described herein. By “retains activity” is intended that the variant will have at least about 30%, preferably at least about 50%, more preferably at least about 70%, even more preferably at least about 80% of the activity of the cell surface, cell membrane or secreted protein disclosed in even SEQ ID NOS:1-307. Methods for measuring cell surface, cell membrane or secreted activity are well known in the art. See, for example, the Example section below as well as the section entitled “Methods of Use” for examples of functional assays. A biologically active variant of a protein of the invention may differ from that protein by as few as 1-15 amino acid residues, as few as 1-10, such as 6-10, as few as 5, as few as 4, 3, 2, or even 1 amino acid residue. Naturally occurring variants may exist within a population (e.g., the L. acidophilus population). Such variants can be identified by using well-known molecular biology techniques, such as the polymerase chain reaction (PCR), and hybridization as described below. Synthetically derived nucleotide sequences, for example, sequences generated by site-directed mutagenesis or PCR-mediated mutagenesis that still encode a cell wall, cell surface or secreted protein, are also included as variants. One or more nucleotide or amino acid substitutions, additions, or deletions can be introduced into a nucleotide or amino acid sequence disclosed herein, such that the substitutions, additions, or deletions are introduced into the encoded protein. The additions (insertions) or deletions (truncations) may be made at the N-terminal or C-terminal end of the native protein, or at one or more sites in the native protein. Similarly, a substitution of one or more nucleotides or amino acids may be made at one or more sites in the native protein. For example, conservative amino acid substitutions may be made at one or more predicted, preferably nonessential amino acid residues. A “nonessential” amino acid residue is a residue that can be altered from the wild-type sequence of a protein without altering the biological activity, whereas an “essential” amino acid is required for biological activity. A “conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue with a similar side chain. Families of amino acid residues having similar side chains are known in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Such substitutions would not be made for conserved amino acid residues, or for amino acid residues residing within a conserved motif, where such residues are essential for protein activity. Alternatively, mutations can be made randomly along all or part of the length of the cell wall, cell surface or secreted coding sequence, such as by saturation mutagenesis. The mutants can be expressed recombinantly, and screened for those that retain biological activity by assaying for one or more of the functional activities of a native cell wall, cell surface or secreted protein using standard assay techniques. Methods for mutagenesis and nucleotide sequence alterations are known in the art. See, for example, Kunkel (1985) Proc. Natl. Acad. Sci. USA 82:488-492; Kunkel et al. (1987) Methods in Enzymol. Molecular Biology (MacMillan Publishing Company, New York) and the references sited therein. Obviously the mutations made in the DNA encoding the variant must not disrupt the reading frame and preferably will not create complimentary regions that could produce secondary mRNA structure. See, EP Patent Application Publication No. 75,444. Guidance as to appropriate amino acid substitutions that do not affect biological activity of the protein of interest may be found in the model of Dayhoff et al. (1978) Atlas of Protein Sequence and Structure (Natl. Biomed. Res. Found., Washington, D.C.), herein incorporated by reference. The deletions, insertions, and substitutions of the protein sequences encompassed herein are not expected to produce radical changes in the characteristics of the protein. However, when it is difficult to predict the exact effect of the substitution, deletion, or insertion in advance of doing so, one skilled in the art will appreciate that the effect will be evaluated by routine screening assays. That is, the activity can be evaluated by comparing the activity of the modified sequence with the activity of the original sequence. For example, the modification of gusA has produced alterations in enzyme activity and enzyme stability. (see, Matsumura and Ellington (2001) J. Mol. Biol. 305:331-9; Flores and Ellington (2002) J. Mol. Biol., 315:325-37). Similar work has been done with lactase. Variant nucleotide and amino acid sequences of the present invention also encompass sequences derived from mutagenic and recombinogenic procedures such as DNA shuffling. With such a procedure, one or more different cell wall, cell surface and secreted protein coding regions can be used to create a new cell wall, cell surface or secreted protein possessing the desired properties. In this manner, libraries of recombinant polynucleotides are generated from a population of related sequence polynucleotides comprising sequence regions that have substantial sequence identity and can be homologously recombined in vitro or in vivo. For example, using this approach, sequence motifs encoding a domain of interest may be shuffled between the cell wall, cell surface or secreted gene of the invention and other known cell wall, cell surface or secreted genes to obtain a new gene coding for a protein with an improved property of interest, such as an increased Km in the case of an enzyme. Strategies for such DNA shuffling are known in the art. See, for example, Stemmer (1994) Proc. Natl. Acad. Sci. USA 91:10747-10751; Stemmer (1994) Nature 370:389-391; Crameri et al. (1997) Nature Biotech. 15:436-438; Moore et al. (1997) J. Mol. Biol. 272:336-347; Zhang et al. (1997) Proc. Natl. Acad. Sci. USA 94:4504-4509; Crameri et al. (1998) Nature 391:288-291; and U.S. Pat. Nos. 5,605,793 and 5,837,458. Variants of the cell wall, cell surface and secreted proteins can function as either cell wall, cell surface or secreted protein agonists (mimetics) or as cell wall, cell surface or secreted protein antagonists. An agonist of a cell wall, cell surface or secreted protein can retain substantially the same, or a subset, of the biological activities of a naturally occurring form of the cell wall, cell surface or secreted protein. An antagonist of a cell wall, cell surface or secreted protein can inhibit one or more of the activities of a naturally occurring form of the cell wall, cell surface or secreted protein by, for example, competitively binding to a downstream or upstream member of a cellular signaling cascade that includes the cell wall, cell surface or secreted protein. Variants of a cell wall, cell surface or secreted protein that function as either agonists or antagonists can be identified by screening combinatorial libraries of mutants, e.g., truncation mutants, of cell wall, cell surface and secreted proteins for cell wall, cell surface and secreted protein agonist or antagonist activity. In one embodiment, a variegated library of cell wall, cell surface and secreted variants is generated by combinatorial mutagenesis at the nucleic acid level and is encoded by a variegated gene library. A variegated library of cell wall, cell surface and secreted variants can be produced by, for example, enzymatically ligating a mixture of synthetic oligonucleotides into gene sequences such that a degenerate set of potential cell wall, cell surface and secreted sequences is expressible as individual polypeptides, or alternatively, as a set of larger fusion proteins (e.g., for phage display) containing the set of cell wall, cell surface and secreted sequences therein. There are a variety of methods that can be used to produce libraries of potential cell wall, cell surface and secreted variants from a degenerate oligonucleotide sequence. Chemical synthesis of a degenerate gene sequence can be performed in an automatic DNA synthesizer, and the synthetic gene then ligated into an appropriate expression vector. Use of a degenerate set of genes allows for the provision, in one mixture, of all of the sequences encoding the desired set of potential cell wall, cell surface or secreted protein sequences. Methods for synthesizing degenerate oligonucleotides are known in the art (see, e.g., Narang (1983) Tetrahedron 39:3; Itakura et al. (1984) Annu. Rev. Biochem. 53:323; Itakura et al. (1984) Science 198:1056; Ike et al. (1983) Nucleic Acid Res. 11:477). In addition, libraries of fragments of cell wall, cell surface and secreted protein coding sequences can be used to generate a variegated population of cell wall, cell surface and secreted fragments for screening and subsequent selection of variants of cell wall, cell surface and secreted proteins. In one embodiment, a library of coding sequence fragments can be generated by treating a double-stranded PCR fragment of a cell wall, cell surface or secreted coding sequence with a nuclease under conditions wherein nicking occurs only about once per molecule, denaturing the double-stranded DNA, renaturing the DNA to form double-stranded DNA which can include sense/antisense pairs from different nicked products, removing single-stranded portions from reformed duplexes by treatment with S1 nuclease, and ligating the resulting fragment library into an expression vector. By this method, one can derive an expression library that encodes N-terminal and internal fragments of various sizes of cell wall, cell surface and secreted proteins. Several techniques are known in the art for screening gene products of combinatorial libraries made by point mutations or truncation and for screening cDNA libraries for gene products having a selected property. Such techniques are adaptable for rapid screening of the gene libraries generated by the combinatorial mutagenesis of cell wall, cell surface and secreted proteins. The most widely used techniques, which are amenable to high through-put analysis, for screening large gene libraries typically include cloning the gene library into replicable expression vectors, transforming appropriate cells with the resulting library of vectors, and expressing the combinatorial genes under conditions in which detection of a desired activity facilitates isolation of the vector encoding the gene whose product was detected. Recursive ensemble mutagenesis (REM), a technique that enhances the frequency of functional mutants in the libraries, can be used in combination with the screening assays to identify cell wall, cell surface or secreted variants (Arkin and Yourvan (1992) Proc. Natl. Acad. Sci. USA 89:7811-7815; Delgrave et al. (1993) Protein Engineering 6(3):327-331). Sequence Identity The cell wall, cell surface and secreted sequences of Gram-positive bacteria, even though they have a diverse range of functions, and are from multiple protein families, have several common themes in their design (see, Navarre and Schneewind (1999) Micro. Mol. Biol. Rev. 63:174-229). N-terminal domains, which usually contain binding or catalytic activities are often followed by a number of repeat domains of various sizes, which may or may not have activity (Navarre and Schneewind (1999) Micro. Mol. Biol. Rev. 63:174-229). A proline-rich stretch of amino acid residues that may introduce random coils in the protein structure, and aid in traversing the peptidoglycan complex, is frequently found immediately preceding the LPXTG motif (SEQ ID NO:308, Navarre and Schneewind (1999) Micro. Mol. Biol. Rev. 63:174-229). By “family” is intended two or more proteins or nucleic acid molecules having sufficient nucleotide or amino acid sequence identity. By “sequence identity” is intended the nucleotide or amino acid residues that are the same when aligning two sequences for maximum correspondence over a specified comparison window. By “comparison window” is intended a contiguous segment of the two nucleotide or amino acid sequences for optimal alignment, wherein the second sequence may contain additions or deletions (i.e., gaps) as compared to the first sequence. Generally, for nucleic acid alignments, the comparison window is at least 20 contiguous nucleotides in length, and optionally can be 30, 40, 50, 100, or longer. For amino acid sequence alignments, the comparison window is at least 6 contiguous amino acids in length, and optionally can be 10, 15, 20, 30, or longer. Those of skill in the art understand that to avoid a high similarity due to inclusion of gaps, a gap penalty is typically introduced and is subtracted from the number of matches. Family members may be from the same or different species, and can include homologues as well as distinct proteins. Often, members of a family display common functional characteristics. Homologues can be isolated based on their identity to the Lactobacillus acidophilus cell wall, cell surface or secreted protein nucleic acid sequences disclosed herein using the cDNA, or a portion thereof, as a hybridization probe according to standard hybridization techniques under stringent hybridization conditions as disclosed below. To determine the percent identity of two amino acid or nucleotide sequences, an alignment is performed. Percent identity of the two sequences is a function of the number of identical residues shared by the two sequences in the comparison window (i.e., percent identity=number of identical residues/total number of residues×100). In one embodiment, the sequences are the same length. Methods similar to those mentioned below can be used to determine the percent identity between two sequences. The methods can be used with or without allowing gaps. Alignment may also be performed manually by inspection. When amino acid sequences differ in conservative substitutions, the percent identity may be adjusted upward to correct for the conservative nature of the substitution. Means for making this adjustment are known in the art. Typically the conservative substitution is scored as a partial, rather than a full mismatch, thereby increasing the percentage sequence identity. Mathematical algorithms can be used to determine the percent identity of two sequences. Non-limiting examples of mathematical algorithms are the algorithm of Karlin and Altschul (1990) Proc. Natl. Acad. Sci. USA 87:2264, modified as in Karlin and Altschul (1993) Proc. Natl. Acad. Sci. USA 90:5873-5877; the algorithm of Myers and Miller (1988) CABIOS 4:11-17; the local alignment algorithm of Smith et al. (1981) Adv. Appl. Math. 2:482; the homology alignment algorithm of Needleman and Wunsch (1970) J. Mol. Biol. 48:443-453; and the search-for-similarity-method of Pearson and Lipman (1988) Proc. Natl. Acad. Sci. USA 85:2444-2448. Various computer implementations based on these mathematical algorithms have been designed to enable the determination of sequence identity. The BLAST programs of Altschul et al. (1990) J. Mol. Biol. 215:403 are based on the algorithm of Karlin and Altschul (1990) supra. Searches to obtain nucleotide sequences that are homologous to nucleotide sequences of the present invention can be performed with the BLASTN program, score=100, wordlength=12. To obtain amino acid sequences homologous to sequences encoding a protein or polypeptide of the current invention, the BLASTX program may be used, score=50, wordlength=3. Gapped alignments may be obtained by using Gapped BLAST as described in Altschul et al. (1997) Nucleic Acids Res. 25:3389. To detect distant relationships between molecules, PSI-BLAST can be used. See, Altschul et al. (1997) supra. For all of the BLAST programs, the default parameters of the respective programs can be used. See, www.ncbi.nlm.nih.gov. Another program that can be used to determine percent sequence identity is the ALIGN program (version 2.0), which uses the mathematical algorithm of Myers and Miller (1988) supra. A PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4 can be used with this program when comparing amino acid sequences. In addition to the ALIGN and BLAST programs, the BESTFIT, GAP, FASTA and TFASTA programs are part of the Wisconsin Genetics Software Package (from GCG, Madison, Wis.), and can be used for performing sequence alignments. The preferred program is GAP version 10, which used the algorithm of Needleman and Wunsch (1970) supra. Unless otherwise stated the sequence identity similarity values provided herein refer to the value obtained using GAP Version 10 with the following parameters: % identity and % similarity for a nucleotide sequence using GAP Weight of 50 and Length Weight of 3, and the nwsgapdna.cmp scoring matrix; % identity and % similarity for an amino acid sequence using GAP Weight of 8 and Length Weight of 2, and the BLOSUM62 scoring matrix; or any equivalent program. By “equivalent program” is intended any sequence comparison program that, for any two sequences in question, generates an alignment having identical nucleotide or amino acid residue matches and an identical percent sequence identity when compared to the corresponding alignment generated by GAP Version 10. Identification and Isolation of Homologous Sequences Cell wall, cell surface and secreted nucleotide sequences identified based on their sequence identity to the cell wall, cell surface and secreted nucleotide sequences set forth herein or to fragments and variants thereof are encompassed by the present invention. Methods such as PCR or hybridization can be used to identify sequences from a cDNA or genomic library, for example, that are substantially identical to a sequence of the invention. See, for example, Sambrook et al. (1989) Molecular Cloning: Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Plainview, N.Y.) and Innis, et al. (1990) PCR Protocols: A Guide to Methods and Applications (Academic Press, New York). Methods for construction of such cDNA and genomic libraries are generally known in the art and are also disclosed in the above reference. In hybridization techniques, the hybridization probes may be genomic DNA fragments, cDNA fragments, RNA fragments, or other oligonucleotides, and may consist of all or part of a known nucleotide sequence disclosed herein. In addition, they may be labeled with a detectable group such as 32p, or any other detectable marker, such as other radioisotopes, a fluorescent compound, an enzyme, or an enzyme co-factor. Probes for hybridization can be made by labeling synthetic oligonucleotides based on the known cell wall, cell surface and secreted nucleotide sequences disclosed herein. Degenerate primers designed on the basis of conserved nucleotides or amino acid residues in a known cell wall, cell surface and secreted nucleotide sequence or encoded amino acid sequence can additionally be used. The hybridization probe typically comprises a region of nucleotide sequence that hybridizes under stringent conditions to at least about 10, preferably about 20, more preferably about 50, 75, 100, 125, 150, 175, 200, 250, 300, 350, or 400 consecutive nucleotides of a cell wall, cell surface or secreted protein nucleotide sequence of the invention or a fragment or variant thereof. To achieve specific hybridization under a variety of conditions, such probes include sequences that are unique among cell wall, cell surface or secreted protein sequences. Preparation of probes for hybridization is generally known in the art and is disclosed in Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Plainview, N.Y.), herein incorporated by reference. In one embodiment, the entire nucleotide sequence encoding a cell wall, cell surface or secreted protein is used as a probe to identify novel cell wall, cell surface or secreted sequences and messenger RNAs. In another embodiment, the probe is a fragment of a nucleotide sequence disclosed herein. In some embodiments, the nucleotide sequence that hybridizes under stringent conditions to the probe can be at least about 300, 325, 350, 375, 400, 425, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10,000, 11,000, 12,000, or 12,500 nucleotides in length. Substantially identical sequences will hybridize to each other under stringent conditions. By “stringent conditions” is intended conditions under which a probe will hybridize to its target sequence to a detectably greater degree than to other sequences (e.g., at least 2-fold over background). Generally, stringent conditions encompass those conditions for hybridization and washing under which nucleotides having at least about 60%, 65%, 70%, preferably 75% sequence identity typically remain hybridized to each other. Stringent conditions are known in the art and can be found in Current Protocols in Molecular Biology (John Wiley & Sons, New York (1989)), 6.3.1-6.3.6. Hybridization typically occurs for less than about 24 hours, usually about 4 to about 12 hours. Stringent conditions are sequence-dependent and will differ in different circumstances. Full-length or partial nucleic acid sequences may be used to obtain homologues and orthologs encompassed by the present invention. By “orthologs” is intended genes derived from a common ancestral gene and which are found in different species as a result of speciation. Genes found in different species are considered orthologs when their nucleotide sequences and/or their encoded protein sequences share substantial identity as defined elsewhere herein. Functions of orthologs are often highly conserved among species. When using probes, stringent conditions will be those in which the salt concentration is less than about 1.5 M Na ion, typically about 0.01 to 1.0 M Na ion concentration (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 30° C. for short probes (e.g., 10 to 50 nucleotides) and at least about 60° C. for long probes (e.g., greater than 50 nucleotides). The post-hybridization washes are instrumental in controlling specificity. The two critical factors are ionic strength and temperature of the final wash solution. For the detection of sequences that hybridize to a full-length or approximately full-length target sequence, the temperature under stringent conditions is selected to be about 5° C. lower than the thermal melting point (Tm) for the specific sequence at a defined ionic strength and pH. However, stringent conditions would encompass temperatures in the range of 1° C. to 20° C. lower than the Tm, depending on the desired degree of stringency as otherwise qualified herein. For DNA-DNA hybrids, the Tm can be determined using the equation of Meinkoth and Wahl (1984) Anal. Biochem. 138:267-284: Tm=81.5° C.+16.6 (logM)+0.41 (% GC)-0.61 (% form)-500/L; where M is the molarity of monovalent cations, % GC is the percentage of guanosine and cytosine nucleotides in the DNA, % form is the percentage of formamide in the hybridization solution, and L is the length of the hybrid in base pairs. The Tm is the temperature (under defined ionic strength and pH) at which 50% of a complementary target sequence hybridizes to a perfectly matched probe. The ability to detect sequences with varying degrees of homology can be obtained by varying the stringency of the hybridization and/or washing conditions. To target sequences that are 100% identical (homologous probing), stringency conditions must be obtained that do not allow mismatching. By allowing mismatching of nucleotide residues to occur, sequences with a lower degree of similarity can be detected (heterologous probing). For every 1% of mismatching, the Tm is reduced about 1° C.; therefore, hybridization and/or wash conditions can be manipulated to allow hybridization of sequences of a target percentage identity. For example, if sequences with ≧90% sequence identity are preferred, the Tm can be decreased by 10° C. Two nucleotide sequences could be substantially identical, but fail to hybridize to each other under stringent conditions, if the polypeptides they encode are substantially identical. This situation could arise, for example, if the maximum codon degeneracy of the genetic code is used to create a copy of a nucleic acid. Exemplary low stringency conditions include hybridization with a buffer solution of 30-35% formamide, 1 M NaCl, 1% SDS (sodium dodecyl sulfate) at 37° C., and a wash in 1× to 2×SSC (20×SSC=3.0 M NaCl/0.3 M trisodium citrate) at 50 to 55° C. Exemplary moderate stringency conditions include hybridization in 40 to 45% formamide, 1.0 M NaCl, 1% SDS at 37° C., and a wash in 0.5× to 1×SSC at 55 to 60° C. Exemplary high stringency conditions include hybridization in 50% formamide, 1 M NaCl, 1% SDS at 37° C., and a wash in 0.1×SSC at 60 to 65° C. Optionally, wash buffers may comprise about 0.1% to about 1% SDS. Duration of hybridization is generally less than about 24 hours, usually about 4 to about 12 hours. An extensive guide to the hybridization of nucleic acids is found in Tijssen (1993) Laboratory Techniques in Biochemistry and Molecular Biology—Hybridization with Nucleic Acid Probes, Part I, Chapter 2 (Elsevier, New York); and Ausubel et al., eds. (1995) Current Protocols in Molecular Biology, Chapter 2 (Greene Publishing and Wiley-Interscience, New York). See Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual (2d ed.; Cold Spring Harbor Laboratory Press, Plainview, N.Y.). In a PCR approach, oligonucleotide primers can be designed for use in PCR reactions to amplify corresponding DNA sequences from cDNA or genomic DNA extracted from any organism of interest. PCR primers are preferably at least about 10 nucleotides in length, and most preferably at least about 20 nucleotides in length. Methods for designing PCR primers and PCR cloning are generally known in the art and are disclosed in Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Plainview, N.Y.). See also Innis et al., eds. (1990) PCR Protocols: A Guide to Methods and Applications (Academic Press, New York); Innis and Gelfand, eds. (1995) PCR Strategies (Academic Press, New York); and Innis and Gelfand, eds. (1999) PCR Methods Manual (Academic Press, New York). Known methods of PCR include, but are not limited to, methods using paired primers, nested primers, single specific primers, degenerate primers, gene-specific primers, vector-specific primers, partially-mismatched primers, and the like. Assays Diagnostic assays to detect expression of the disclosed polypeptides and/or nucleic acid molecules as well as their disclosed activity in a sample are disclosed. An exemplary method for detecting the presence or absence of a disclosed nucleic acid or protein comprising the disclosed polypeptide in a sample involves obtaining a sample from a food/dairy/feed product, starter culture (mother, seed, bulk/set, concentrated, dried, lyophilized, frozen), cultured food/dairy/feed product, dietary supplement, bioprocessing fermentate, or a subject that has ingested a probiotic material and contacting the sample with a compound or an agent capable of detecting the disclosed polypeptides or nucleic acids (e.g., an mRNA or genomic DNA comprising the disclosed nucleic acid or fragment thereof) such that the presence of the disclosed sequence is detected in the sample. Results obtained with a sample from the food, supplement, culture, product, or subject may be compared to results obtained with a sample from a control culture, product, or subject. One agent for detecting the mRNA or genomic DNA comprising a disclosed nucleotide sequence is a labeled nucleic acid probe capable of hybridizing to the disclosed nucleotide sequence of the mRNA or genomic DNA. The nucleic acid probe can be, for example, a disclosed nucleic acid molecule, such as the nucleic acid of odd SEQ ID NOS:1-307, or a portion thereof, such as a nucleic acid molecule of at least 15, 30, 50, 100, 250, or 500 nucleotides in length and sufficient to specifically hybridize under stringent conditions to the mRNA or genomic DNA comprising the disclosed nucleic acid sequence. Other suitable probes for use in the diagnostic assays of the invention are described herein. One agent for detecting a protein comprising a disclosed polypeptide sequence is an antibody capable of binding to the disclosed polypeptide, preferably an antibody with a detectable label. Antibodies can be polyclonal, or more preferably, monoclonal. An intact antibody, or a fragment thereof (e.g., Fab or F(ab′)2) can be used. The term “labeled,” with regard to the probe or antibody, is intended to encompass direct labeling of the probe or antibody by coupling (i.e., physically linking) a detectable substance to the probe or antibody, as well as indirect labeling of the probe or antibody by reactivity with another reagent that is directly labeled. Examples of indirect labeling include detection of a primary antibody using a fluorescently labeled secondary antibody and end labeling of a DNA probe with biotin such that it can be detected with fluorescently labeled streptavidin. The term “sample” is intended to include tissues, cells, and biological fluids present in or isolated from a subject, as well as cells from starter cultures or food products carrying such cultures, or derived from the use of such cultures. That is, the detection method of the invention can be used to detect mRNA, protein, or genomic DNA comprising a disclosed sequence in a sample both in vitro and in vivo. In vitro techniques for detection of mRNA comprising a disclosed sequence include Northern hybridizations and in situ hybridizations. In vitro techniques for detection of a protein comprising a disclosed polypeptide include enzyme linked immunosorbent assays (ELISAs), Western blots, immunoprecipitations, and immunofluorescence. In vitro techniques for detection of genomic DNA comprising the disclosed nucleotide sequences include Southern hybridizations. Furthermore, in vivo techniques for detection of a protein comprising a disclosed polypeptide include introducing into a subject a labeled antibody against the disclosed polypeptide. For example, the antibody can be labeled with a radioactive marker whose presence and location in a subject can be detected by standard imaging techniques. In one embodiment, the sample contains protein molecules from a test subject that has consumed a probiotic material. Alternatively, the sample can contain mRNA or genomic DNA from a starter culture. The invention also encompasses kits for detecting the presence of disclosed nucleic acids or proteins comprising disclosed polypeptides in a sample. Such kits can be used to determine if a microbe expressing a specific polypeptide of the invention is present in a food product or starter culture, or in a subject that has consumed a probiotic material. For example, the kit can comprise a labeled compound or agent capable of detecting a disclosed polypeptide or mRNA in a sample and means for determining the amount of a disclosed polypeptide in the sample (e.g., an antibody that recognizes the disclosed polypeptide or an oligonucleotide probe that binds to DNA encoding a disclosed polypeptide, e.g., any of even SEQ ID NOS:1-307. Kits can also include instructions detailing the use of such compounds. For antibody-based kits, the kit can comprise, for example: (1) a first antibody (e.g., attached to a solid support) that binds to a disclosed polypeptide; and, optionally, (2) a second, different antibody that binds to the disclosed polypeptide or the first antibody and is conjugated to a detectable agent. For oligonucleotide-based kits, the kit can comprise, for example: (1) an oligonucleotide, e.g., a detectably labeled oligonucleotide, that hybridizes to a disclosed nucleic acid sequence or (2) a pair of primers useful for amplifying a disclosed nucleic acid molecule. The kit can also comprise, e.g., a buffering agent, a preservative, or a protein-stabilizing agent. The kit can also comprise components necessary for detecting the detectable agent (e.g., an enzyme or a substrate). The kit can also contain a control sample or a series of control samples that can be assayed and compared to the test sample contained. Each component of the kit is usually enclosed within an individual container, and all of the various containers are within a single package along with instructions for use. In one embodiment, the kit comprises multiple probes in an array format, such as those described, for example, in U.S. Pat. Nos. 5,412,087 and 5,545,531, and International Publication No. WO 95/00530, herein incorporated by reference. Probes for use in the array may be synthesized either directly onto the surface of the array, as disclosed in International Publication No. WO 95/00530, or prior to immobilization onto the array surface (Gait, ed. (1984) Oligonucleotide Synthesis a Practical Approach IRL Press, Oxford, England). The probes may be immobilized onto the surface using techniques well known to one of skill in the art, such as those described in U.S. Pat. No. 5,412,087. Probes may be a nucleic acid or peptide sequence, preferably purified, or an antibody. The arrays may be used to screen organisms, samples, or products for differences in their genomic, cDNA, polypeptide, or antibody content, including the presence or absence of specific sequences or proteins, as well as the concentration of those materials. Binding to a capture probe is detected, for example, by signal generated from a label attached to the nucleic acid molecule comprising the disclosed nucleic acid sequence, a polypeptide comprising the disclosed amino acid sequence, or an antibody. The method can include contacting the molecule comprising the disclosed nucleic acid, polypeptide, or antibody with a first array having a plurality of capture probes and a second array having a different plurality of capture probes. The results of each hybridization can be compared to analyze differences in expression between a first and second sample. The first plurality of capture probes can be from a control sample, e.g., a wild type lactic acid bacteria, or control subject, e.g., a food, dietary supplement, starter culture sample, or a biological fluid. The second plurality of capture probes can be from an experimental sample, e.g., a mutant type lactic acid bacteria, or subject that has consumed a probiotic material, e.g., a starter culture sample or a biological fluid. These assays may be especially useful in microbial selection and quality control procedures where the detection of unwanted materials is essential. The detection of particular nucleotide sequences or polypeptides may also be useful in determining the genetic composition of food, fermentation products, or industrial microbes, or microbes present in the digestive system of animals or humans that have consumed probiotics. Antisense Nucleotide Sequences The present invention also encompasses antisense nucleic acid molecules, i.e., molecules that are complementary to a sense nucleic acid encoding a protein, e.g., complementary to the coding strand of a double-stranded cDNA molecule, or complementary to an mRNA sequence. Accordingly, an antisense nucleic acid can hydrogen bond to a sense nucleic acid. The antisense nucleic acid can be complementary to an entire cell wall, cell surface or secreted protein coding strand, or to only a portion thereof, e.g., all or part of the protein-coding region (or open reading frame). An antisense nucleic acid molecule can be antisense to a noncoding region of the coding strand of a nucleotide sequence encoding a cell wall, cell surface or secreted protein. The noncoding regions are the 5′ and 3′ sequences that flank the coding region and are not translated into amino acids. Antisense nucleotide sequences are useful in disrupting the expression of the target gene. Antisense constructions having 70%, preferably 80%, more preferably 85% sequence identity to the corresponding sequence may be used. Given the coding-strand sequence encoding a cell wall, cell surface or secreted protein disclosed herein (e.g., odd SEQ ID NOS:1-307), antisense nucleic acids of the invention can be designed according to the rules of Watson and Crick base pairing. The antisense nucleic acid molecule can be complementary to the entire coding region of cell wall, cell surface or secreted protein mRNA, but more preferably is an oligonucleotide that is antisense to only a portion of the coding or noncoding region of cell wall, cell surface or secreted protein mRNA. For example, the antisense oligonucleotide can be complementary to the region surrounding the translation start site of cell wall, cell surface or secreted protein mRNA. An antisense oligonucleotide can be, for example, about 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 nucleotides in length, or it can be 100, 200 nucleotides, or greater in length. An antisense nucleic acid of the invention can be constructed using chemical synthesis and enzymatic ligation procedures known in the art. For example, an antisense nucleic acid (e.g., an antisense oligonucleotide) can be chemically synthesized using naturally occurring nucleotides or variously modified nucleotides designed to increase the biological stability of the molecules or to increase the physical stability of the duplex formed between the antisense and sense nucleic acids, including, but not limited to, for example e.g., phosphorothioate derivatives and acridine substituted nucleotides. Alternatively, the antisense nucleic acid can be produced biologically using an expression vector into which a nucleic acid has been subcloned in an antisense orientation (i.e., RNA transcribed from the inserted nucleic acid will be of an antisense orientation to a target nucleic acid of interest). An antisense nucleic acid molecule of the invention can be an α-anomeric nucleic acid molecule. An α-anomeric nucleic acid molecule forms specific double-stranded hybrids with complementary RNA in which, contrary to the usual β-units, the strands run parallel to each other (Gaultier et al. (1987) Nucleic Acids Res. 15:6625-6641). The antisense nucleic acid molecule can also comprise a 2′-o-methylribonucleotide (Inoue et al. (1987) Nucleic Acids Res. 15:6131-6148) or a chimeric RNA-DNA analogue (Inoue et al. (1987) FEBS Lett. 215:327-330). The invention also encompasses ribozymes, which are catalytic RNA molecules with ribonuclease activity that are capable of cleaving a single-stranded nucleic acid, such as an mRNA, to which they have a complementary region. Ribozymes (e.g., hammerhead ribozymes (described in Haselhoff and Gerlach (1988) Nature 334:585-591)) can be used to catalytically cleave cell wall, cell surface and secreted mRNA transcripts to thereby inhibit translation of cell wall, cell surface and secreted mRNA. A ribozyme having specificity for a cell wall, cell surface or secreted protein-encoding nucleic acid can be designed based upon the nucleotide sequence of a cell wall, cell surface or secreted protein cDNA disclosed herein (e.g., odd SEQ ID NOS:1-307). See, e.g., U.S. Pat. No. 4,987,071; and U.S. Pat. No. 5,116,742. Alternatively, cell wall, cell surface and secreted protein mRNA can be used to select a catalytic RNA having a specific ribonuclease activity from a pool of RNA molecules. See, e.g., Bartel and Szostak (1993) Science 261:1411-1418. The invention also encompasses nucleic acid molecules that form triple helical structures. For example, cell wall, cell surface or secreted protein gene expression can be inhibited by targeting nucleotide sequences complementary to the regulatory region of the cell wall, cell surface or secreted protein (e.g., the cell wall, cell surface or secreted promoters and/or enhancers) to form triple helical structures that prevent transcription of the cell wall, cell surface or secreted protein gene in target cells. See generally Helene (1991) Anticancer Drug Des. 6(6):569; Helene (1992) Ann. N.Y. Acad. Sci. 660:27; and Maher (1992) Bioassays 14(12):807. In some embodiments, the nucleic acid molecules of the invention can be modified at the base moiety, sugar moiety, or phosphate backbone to improve, e.g., the stability, hybridization, or solubility of the molecule. For example, the deoxyribose phosphate backbone of the nucleic acids can be modified to generate peptide nucleic acids (see Hyrup et al. (1996) Bioorganic & Medicinal Chemistry 4:5). As used herein, the terms “peptide nucleic acids” or “PNAs” refer to nucleic acid mimics, e.g., DNA mimics, in which the deoxyribose phosphate backbone is replaced by a pseudopeptide backbone and only the four natural nucleobases are retained. The neutral backbone of PNAs has been shown to allow for specific hybridization to DNA and RNA under conditions of low ionic strength. The synthesis of PNA oligomers can be performed using standard solid-phase peptide synthesis protocols as described, for example, in Hyrup et al. (1996) supra; Perry-O'Keefe et al. (1996) Proc. Natl. Acad. Sci. USA 93:14670. PNAs can be used as antisense or antigene agents for sequence-specific modulation of gene expression by, e.g., inducing transcription or translation arrest or inhibiting replication. PNAs of the invention can also be used, e.g., in the analysis of single base pair mutations in a gene by, e.g., PNA-directed PCR clamping; as artificial restriction enzymes when used in combination with other enzymes, e.g., S1 nucleases (Hyrup (1996) supra); or as probes or primers for DNA sequence and hybridization (Hyrup (1996) supra; Perry-O'Keefe et al. (1996) supra). In another embodiment, PNAs of a cell wall, cell surface or secreted molecule can be modified, e.g., to enhance their stability, specificity, or cellular uptake, by attaching lipophilic or other helper groups to PNA, by the formation of PNA-DNA chimeras, or by the use of liposomes or other techniques of drug delivery known in the art. The synthesis of PNA-DNA chimeras can be performed as described in Hyrup (1996) supra; Finn et al. (1996) Nucleic Acids Res. 24(17):3357-63; Mag et al. (1989) Nucleic Acids Res. 17:5973; and Peterson et al. (1975) Bioorganic Med. Chem. Lett. 5:1119. Fusion Proteins The invention also includes cell wall, cell surface and secreted chimeric or fusion proteins. A cell wall, cell surface or secreted “chimeric protein” or “fusion protein” comprises a cell wall, cell surface or secreted polypeptide operably linked to a non-cell wall, cell surface or secreted polypeptide. A “cell wall, cell surface or secreted polypeptide” refers to a polypeptide having an amino acid sequence corresponding to a cell wall, cell surface or secreted protein, whereas a “non-cell wall, cell surface or secreted polypeptide” refers to a polypeptide having an amino acid sequence corresponding to a protein that is not substantially identical to the cell wall, cell surface or secreted protein, and which is derived from the same or a different organism. Within a cell wall, cell surface or secreted fusion protein, the (cell wall, cell surface or secreted polypeptide can correspond to all or a portion of a cell wall, cell surface or secreted protein, preferably including at least one biologically active portion of a cell wall, cell surface or secreted protein. Within the fusion protein, the term “operably linked” is intended to indicate that the cell wall, cell surface or secreted polypeptide and the non-cell wall, cell surface or secreted polypeptide are fused in-frame to each other. The non-cell wall, cell surface or secreted polypeptide can be fused to the N-terminus or C-terminus of the cell wall, cell surface or secreted polypeptide. Expression of the linked coding sequences results in two linked heterologous amino acid sequences that form the fusion protein. The carrier sequence (the non-cell wall, cell surface or secreted polypeptide) can encode a carrier polypeptide that potentiates or increases expression of the fusion protein in the bacterial host. The portion of the fusion protein encoded by the carrier sequence, i.e., the carrier polypeptide, may be a protein fragment, an entire functional moiety, or an entire protein sequence. The carrier region or polypeptide may additionally be designed to be used in purifying the fusion protein, either with antibodies or with affinity purification specific for that carrier polypeptide. Likewise, physical properties of the carrier polypeptide can be exploited to allow selective purification of the fusion protein. Particular carrier polypeptides of interest include superoxide dismutase (SOD), maltose-binding protein (MBP), glutathione-S-transferase (GST), an N-terminal histidine (His) tag, and the like. This list is not intended to be limiting, as any carrier polypeptide that potentiates expression of the cell wall, cell surface or secreted protein as a fusion protein can be used in the methods of the invention. In one embodiment, the fusion protein is a GST-cell wall, cell surface or secreted fusion protein in which the cell wall, cell surface or secreted sequence is fused to the C-terminus of the GST sequence. In another embodiment, the fusion protein is a cell wall, cell surface or secreted-immunoglobulin fusion protein in which all or part of a cell wall, cell surface or secreted protein is fused to sequences derived from a member of the immunoglobulin protein family. The cell wall, cell surface or secreted protein-immunoglobulin fusion proteins of the invention can be used as immunogens to produce anti-cell wall, cell surface or secreted antibodies in a subject, to purify cell wall, cell surface or secreted protein ligands, and in screening assays to identify molecules that inhibit the interaction of a cell wall, cell surface or secreted protein with a cell wall, cell surface or secreted protein ligand. One of skill in the art will recognize that the particular carrier polypeptide is chosen with the purification scheme in mind. For example, His tags, GST, and maltose-binding protein represent carrier polypeptides that have readily available affinity columns to which they can be bound and eluted. Thus, where the carrier polypeptide is an N-terminal His tag such as hexahistidine (His6 tag), the cell wall, cell surface or secreted fusion protein can be purified using a matrix comprising a metal-chelating resin, for example, nickel nitrilotriacetic acid (Ni-NTA), nickel iminodiacetic acid (Ni-IDA), and cobalt-containing resin (Co-resin). See, for example, Steinert et al. (1997) QIAGEN News 4:11-15, herein incorporated by reference in its entirety. Where the carrier polypeptide is GST, the cell wall, cell surface or secreted fusion protein can be purified using a matrix comprising glutathione-agarose beads (Sigma or Pharmacia Biotech); where the carrier polypeptide is a maltose-binding protein (MBP), the cell wall, cell surface or secreted fusion protein can be purified using a matrix comprising an agarose resin derivatized with amylose. Preferably, a chimeric or fusion protein of the invention is produced by standard recombinant DNA techniques. For example, DNA fragments coding for the different polypeptide sequences may be ligated together in-frame, or the fusion gene can be synthesized, such as with automated DNA synthesizers. Alternatively, PCR amplification of gene fragments can be carried out using anchor primers that give rise to complementary overhangs between two consecutive gene fragments, which can subsequently be annealed and re-amplified to generate a chimeric gene sequence (see, e.g., Ausubel et al., eds. (1995) Current Protocols in Molecular Biology (Greene Publishing and Wiley-Interscience, New York). Moreover, a cell wall, cell surface or secreted protein-encoding nucleic acid can be cloned into a commercially available expression vector such that it is linked in-frame to an existing fusion moiety. The fusion protein expression vector is typically designed for ease of removing the carrier polypeptide to allow the cell wall, cell surface or secreted protein to retain the native biological activity associated with it. Methods for cleavage of fusion proteins are known in the art. See, for example, Ausubel et al., eds. (1998) Current Protocols in Molecular Biology (John Wiley & Sons, Inc.). Chemical cleavage of the fusion protein can be accomplished with reagents such as cyanogen bromide, 2-(2-nitrophenylsulphenyl)-3-methyl-3′-bromoindolenine, hydroxylamine, or low pH. Chemical cleavage is often accomplished under denaturing conditions to cleave otherwise insoluble fusion proteins. Where separation of the cell wall, cell surface or secreted polypeptide from the carrier polypeptide is desired and a cleavage site at the junction between these fused polypeptides is not naturally occurring, the fusion construct can be designed to contain a specific protease cleavage site to facilitate enzymatic cleavage and removal of the carrier polypeptide. In this manner, a linker sequence comprising a coding sequence for a peptide that has a cleavage site specific for an enzyme of interest can be fused in-frame between the coding sequence for the carrier polypeptide (for example, MBP, GST, SOD, or an N-terminal His tag) and the coding sequence for the cell wall, cell surface or secreted polypeptide. Suitable enzymes having specificity for cleavage sites include, but are not limited to, factor Xa, thrombin, enterokinase, remin, collagenase, and tobacco etch virus (TEV) protease. Cleavage sites for these enzymes are well known in the art. Thus, for example, where factor Xa is to be used to cleave the carrier polypeptide from the cell wall, cell surface or secreted polypeptide, the fusion construct can be designed to comprise a linker sequence encoding a factor Xa-sensitive cleavage site, for example, the sequence IEGR (see, for example, Nagai and Thøgersen (1984) Nature 309:810-812, Nagai and Thøgersen (1987) Meth. Enzymol. 153:461-481, and Pryor and Leiting (1997) Protein Expr. Purif. 10(3):309-319, herein incorporated by reference). Where thrombin is to be used to cleave the carrier polypeptide from the cell wall, cell surface and secreted polypeptide, the fusion construct can be designed to comprise a linker sequence encoding a thrombin-sensitive cleavage site, for example the sequence LVPRGS or VIAGR (see, for example, Pryor and Leiting (1997) Protein Expr. Purif. 10(3):309-319, and Hong et al. (1997) Chin. Med. Sci. J. 12(3):143-147, respectively, herein incorporated by reference). Cleavage sites for TEV protease are known in the art. See, for example, the cleavage sites described in U.S. Pat. No. 5,532,142, herein incorporated by reference in its entirety. See also the discussion in Ausubel et al., eds. (1998) Current Protocols in Molecular Biology (John Wiley & Sons, Inc.), Chapter 16. Fusion proteins of the invention can utilize all or part of the “cell wall, cell surface or secreted protein” to target foreign peptides and proteins to the cell wall, cell surface or for secretion. Targeting to the cell wall, cell surface or for secretion by the cell results from signal sequences, secretion signals, or LPXTG-like (SEQ ID NO:308) motifs in the cell wall, cell surface or secreted protein. The functional region which allows the native cell wall, cell surface or secreted protein to be secreted or bound at the cell wall or cell surface can be fused as described below in such a way as to enable a non-cell wall, cell surface or secreted protein to be secreted or bound to the cell wall or cell surface of the same or a different organism. Antibodies An isolated polypeptide of the present invention can be used as an immunogen to generate antibodies that specifically bind cell wall, cell surface or secreted proteins, or stimulate production of antibodies in vivo. The full-length cell wall, cell surface or secreted protein can be used as an immunogen or, alternatively, antigenic peptide fragments of cell wall, cell surface or secreted proteins as described herein can be used. The antigenic peptide of a cell wall, cell surface or secreted protein comprises at least 8, preferably 10, 15, 20, or 30 amino acid residues of the amino acid sequence shown in any of even SEQ ID NOS:1-307, and encompasses an epitope of a cell wall, cell surface or secreted protein such that an antibody raised against the peptide forms a specific immune complex with the cell wall, cell surface or secreted protein. Preferred epitopes encompassed by the antigenic peptide are regions of a cell wall, cell surface or secreted protein that are located on the surface of the protein, e.g., hydrophilic regions. Recombinant Expression Vectors and Host Cells The nucleic acid molecules of the present invention may be included in vectors, preferably expression vectors. “Vector” refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. Expression vectors include one or more regulatory sequences and direct the expression of genes to which they are operably linked. By “operably linked” is intended that the nucleotide sequence of interest is linked to the regulatory sequence(s) such that expression of the nucleotide sequence is allowed (e.g., in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell). The term “regulatory sequence” is intended to include controllable transcriptional promoters, operators, enhancers, transcriptional terminators, and other expression control elements such as translational control sequences (e.g., Shine-Dalgamo consensus sequence, initiation and termination codons). These regulatory sequences will differ, for example, depending on the host cell being used. The vectors can be autonomously replicated in a host cell (episomal vectors), or may be integrated into the genome of a host cell, and replicated along with the host genome (non-episomal mammalian vectors). Integrating vectors typically contain at least one sequence homologous to the bacterial chromosome that allows for recombination to occur between homologous DNA in the vector and the bacterial chromosome. Integrating vectors may also comprise bacteriophage or transposon sequences. Episomal vectors, or plasmids are circular double-stranded DNA loops into which additional DNA segments can be ligated. Plasmids capable of stable maintenance in a host are generally the preferred form of expression vectors when using recombinant DNA techniques. The expression constructs or vectors encompassed in the present invention comprise a nucleic acid construct of the invention in a form suitable for expression of the nucleic acid in a host cell. Expression in prokaryotic host cells is encompassed in the present invention. It will be appreciated by those skilled in the art that the design of the expression vector can depend on such factors as the choice of the host cell to be transformed, the level of expression of protein desired, etc. The expression vectors of the invention can be introduced into host cells to thereby produce proteins or peptides, including fusion proteins or peptides, encoded by nucleic acids as described herein (e.g., cell wall, cell surface and secreted proteins, mutant forms of cell wall, cell surface and secreted proteins, fusion proteins, etc.). Regulatory sequences include those that direct constitutive expression of a nucleotide sequence as well as those that direct inducible expression of the nucleotide sequence only under certain environmental conditions. A bacterial promoter is any DNA sequence capable of binding bacterial RNA polymerase and initiating the downstream (3′) transcription of a coding sequence (e.g., structural gene) into mRNA. A promoter will have a transcription initiation region, which is usually placed proximal to the 5′ end of the coding sequence. This transcription initiation region typically includes an RNA polymerase binding site and a transcription initiation site. A bacterial promoter may also have a second domain called an operator, which may overlap an adjacent RNA polymerase binding site at which RNA synthesis begins. The operator permits negative regulated (inducible) transcription, as a gene repressor protein may bind the operator and thereby inhibit transcription of a specific gene. Constitutive expression may occur in the absence of negative regulatory elements, such as the operator. In addition, positive regulation may be achieved by a gene activator protein binding sequence, which, if present is usually proximal (5′) to the RNA polymerase binding sequence. An example of a gene activator protein is the catabolite activator protein (CAP), which helps initiate transcription of the lac operon in Escherichia coli (Raibaud et al. (1984) Annu. Rev. Genet. 18:173). Regulated expression may therefore be positive or negative, thereby either enhancing or reducing transcription. Other examples of positive and negative regulatory elements are well known in the art. Various promoters that can be included in the protein expression system include, but are not limited to, a T7/LacO hybrid promoter, a trp promoter, a T7 promoter, a lac promoter, and a bacteriophage lambda promoter. Any suitable promoter can be used to carry out the present invention, including the native promoter or a heterologous promoter. Heterologous promoters may be constitutively active or inducible. A non-limiting example of a heterologous promoter is given in U.S. Pat. No. 6,242,194. Sequences encoding metabolic pathway enzymes provide particularly useful promoter sequences. Examples include promoter sequences derived from sugar metabolizing enzymes, such as galactose, lactose (lac) (Chang et al. (1987) Nature 198:1056), and maltose. Additional examples include promoter sequences derived from biosynthetic enzymes such as tryptophan (trp) (Goeddel et al. (1980) Nucleic Acids Res. 8:4057; Yelverton et al. (1981) Nucleic Acids Res. 9:731; U.S. Pat. No. 4,738,921; EPO Publication Nos. 36,776 and 121,775). The beta-lactamase (bla) promoter system (Weissmann, (1981) “The Cloning of Interferon and Other Mistakes,” in Interferon 3 (ed. I. Gresser); bacteriophage lambda PL (Shimatake et al. (1981) Nature 292:128); the arabinose-inducible araB promoter (U.S. Pat. No. 5,028,530); and T5 (U.S. Pat. No. 4,689,406) promoter systems also provide useful promoter sequences. See also Balbas (2001) Mol. Biotech. 19:251-267, where E. coli expression systems are discussed. In addition, synthetic promoters that do not occur in nature also function as bacterial promoters. For example, transcription activation sequences of one bacterial or bacteriophage promoter may be joined with the operon sequences of another bacterial or bacteriophage promoter, creating a synthetic hybrid promoter (U.S. Pat. No. 4,551,433). For example, the tac (Amann et al. (1983) Gene 25:167; de Boer et al. (1983) Proc. Natl. Acad. Sci. 80:21) and trc (Brosius et al. (1985) J. Biol. Chem. 260:3539-3541) promoters are hybrid trp-lac promoters comprised of both trp promoter and lac operon sequences that are regulated by the lac repressor. The tac promoter has the additional feature of being an inducible regulatory sequence. Thus, for example, expression of a coding sequence operably linked to the tac promoter can be induced in a cell culture by adding isopropyl-1-thio-β-D-galactoside (IPTG). Furthermore, a bacterial promoter can include naturally occurring promoters of non-bacterial origin that have the ability to bind bacterial RNA polymerase and initiate transcription. A naturally occurring promoter of non-bacterial origin can also be coupled with a compatible RNA polymerase to produce high levels of expression of some genes in prokaryotes. The bacteriophage T7 RNA polymerase/promoter system is an example of a coupled promoter system (Studier et al. (1986) J. Mol. Biol. 189:113; Tabor et al. (1985) Proc. Natl. Acad. Sci. 82:1074). In addition, a hybrid promoter can also be comprised of a bacteriophage promoter and an E. coli operator region (EPO Publication No. 267,851). The vector may additionally contain a gene encoding the repressor (or inducer) for that promoter. For example, an inducible vector of the present invention may regulate transcription from the Lac operator (LacO) by expressing the gene encoding the LacI repressor protein. Other examples include the use of the lexa gene to regulate expression of pRecA, and the use of trpO to regulate ptrp. Alleles of such genes that increase the extent of repression (e.g., lacIq) or that modify the manner of induction (e.g., .lambda.CI857, rendering .lambda.pL thermo-inducible, or .lambda.CI+, rendering .lambda.pL chemo-inducible) may be employed. In addition to a functioning promoter sequence, an efficient ribosome-binding site is also useful for the expression of the fusion construct. In prokaryotes, the ribosome binding site is called the Shine-Dalgamo (SD) sequence and includes an initiation codon (ATG) and a sequence 3-9 nucleotides in length located 3-11 nucleotides upstream of the initiation codon (Shine et al. (1975) Nature 254:34). The SD sequence is thought to promote binding of mRNA to the ribosome by the pairing of bases between the SD sequence and the 3′ end of bacterial 16S rRNA (Steitz et al. (1979) “Genetic Signals and Nucleotide Sequences in Messenger RNA,” in Biological Regulation and Development: Gene Expression (ed. R. F. Goldberger, Plenum Press, NY). Cell wall and cell surface proteins can also be secreted from the cell by creating chimeric DNA molecules that encode a protein comprising a signal peptide sequence fragment that provides for secretion of the cell wall or cell surface polypeptides in bacteria (U.S. Pat. No. 4,336,336). The signal sequence fragment typically encodes a signal peptide comprised of hydrophobic amino acids that direct the secretion of the protein from the cell. The protein is either secreted into the growth media (Gram-positive bacteria) or into the periplasmic space, located between the inner and outer membrane of the cell (Gram-negative bacteria). Preferably there are processing sites, which can be cleaved either in vivo or in vitro, encoded between the signal peptide fragment and the cell wall, cell surface and secreted protein. DNA encoding suitable signal sequences can be derived from genes for secreted bacterial proteins, such as the E. coli outer membrane protein gene (ompA) (Masui et al. (1983) FEBS Lett. 151(1):159-164; Ghrayeb et al. (1984) EMBO J. 3:2437-2442) and the E. coli alkaline phosphatase signal sequence (phoA) (Oka et al. (1985) Proc. Natl. Acad. Sci. 82:7212). Other prokaryotic signals include, for example, the signal sequence from penicillinase, Ipp, or heat stable enterotoxin II leaders. Bacteria such as L. acidophilus generally utilize the start codon ATG, which specifies the amino acid methionine (which is modified to N-formylmethionine in prokaryotic organisms). Bacteria also recognize alternative start codons, such as the codons GTG and TTG, which code for valine and leucine, respectively. When they are used as the initiation codon, however, these codons direct the incorporation of methionine rather than of the amino acid they normally encode. Lactobacillus acidophilus NCFM recognizes these alternative start sites and incorporates methionine as the first amino acid. Typically, transcription termination sequences recognized by bacteria are regulatory regions located 3′ to the translation stop codon and thus, together with the promoter, flank the coding sequence. These sequences direct the transcription of an mRNA that can be translated into the polypeptide encoded by the DNA. Transcription termination sequences frequently include DNA sequences (of about 50 nucleotides) that are capable of forming stem loop structures that aid in terminating transcription. Examples include transcription termination sequences derived from genes with strong promoters, such as the trp gene in E. coli as well as other biosynthetic genes. The expression vectors will have a plurality of restriction sites for insertion of the cell wall, cell surface or secreted protein sequence so that it is under transcriptional regulation of the regulatory regions. Selectable marker genes that ensure maintenance of the vector in the cell can also be included in the expression vector. Preferred selectable markers include those that confer resistance to drugs such as ampicillin, chloramphenicol, erythromycin, kanamycin (neomycin), and tetracycline (Davies et al. (1978) Annu. Rev. Microbiol. 32:469). Selectable markers may also allow a cell to grow on minimal medium, or in the presence of toxic metabolite and may include biosynthetic genes, such as those in the histidine, tryptophan, and leucine biosynthetic pathways. The regulatory regions may be native (homologous), or may be foreign (heterologous) to the host cell and/or the nucleotide sequence of the invention. The regulatory regions may also be natural or synthetic. Where the region is “foreign” or “heterologous” to the host cell, it is intended that the region is not found in the native cell into which the region is introduced. Where the region is “foreign” or “heterologous” to the cell wall, cell surface or secreted protein nucleotide sequence of the invention, it is intended that the region is not the native or naturally occurring region for the operably linked cell wall, cell surface or secreted protein nucleotide sequence of the invention. For example, the region may be derived from phage. While it may be preferable to express the sequences using heterologous regulatory regions, native regions may be used. Such constructs would be expected in some cases to alter expression levels of cell wall, cell surface or secreted proteins in the host cell. Thus, the phenotype of the host cell could be altered. In preparing the expression cassette, the various DNA fragments may be manipulated, so as to provide for the DNA sequences in the proper orientation and, as appropriate, in the proper reading frame. Toward this end, adapters or linkers may be employed to join the DNA fragments or other manipulations may be involved to provide for convenient restriction sites, removal of superfluous DNA, removal of restriction sites, or the like. For this purpose, in vitro mutagenesis, primer repair, restriction, annealing, resubstitutions, e.g., transitions and transversions, may be involved. The invention further provides a recombinant expression vector comprising a DNA molecule of the invention cloned into the expression vector in an antisense orientation. That is, the DNA molecule is operably linked to a regulatory sequence in a manner that allows for expression (by transcription of the DNA molecule) of an RNA molecule that is antisense to a cell wall, cell surface or secreted protein mRNA. Regulatory sequences operably linked to a nucleic acid cloned in the antisense orientation can be chosen to direct the continuous or inducible expression of the antisense RNA molecule. The antisense expression vector can be in the form of a recombinant plasmid or phagemid in which antisense nucleic acids are produced under the control of a high efficiency regulatory region, the activity of which can be determined by the cell type into which the vector is introduced. For a discussion of the regulation of gene expression using antisense genes see Weintraub et al. (1986) Reviews—Trends in Genetics, Vol. 1(1). Alternatively, some of the above-described components can be put together in transformation vectors. Transformation vectors are typically comprised of a selectable market that is either maintained in a replicon or developed into an integrating vector, as described above. Microbial or Bacterial Host Cells The production of bacteria containing the nucleic acid sequences or proteins designated, the preparation of starter cultures of such bacteria, and methods of fermenting substrates, particularly food substrates such as milk, may be carried out in accordance with known techniques. By “introducing” as it pertains to nucleic acid molecules is intended introduction into prokaryotic cells via conventional transformation or transfection techniques, or by phage-mediated infection. As used herein, the terms “transformation,” “transduction,” “conjugation,” and “protoplast fusion” are intended to refer to a variety of art-recognized techniques for introducing foreign nucleic acid (e.g., DNA) into a host cell, including calcium phosphate or calcium chloride co-precipitation, DEAE-dextran-mediated transfection, lipofection, or electroporation. Suitable methods for transforming or transfecting host cells can be found in Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Plainview, N.Y.) and other laboratory manuals. By “introducing” as it pertains to polypeptides or microorganisms of the invention, is intended introduction into a host by ingestion, topical application, nasal, suppository, urogenital, or oral application of the polypeptide or microorganism. Bacterial cells used to produce the cell wall, cell surface and secreted polypeptides of this invention are cultured in suitable media, as described generally in Sambrook et al. (1989) Molecular Cloning, A Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Plainview, N.Y.). Function and Assays Assays to measure binding activity of proteins such as periplasmic solute binding proteins (PFAM Accession PF01297) are well known in the art (see, for example, Hosie et al. (2001) Mol. Microbiol. 40: 1449-59; Hazlett et al. (2003) J. Biol. Chem. 278:20687-20694). Periplasmic solute binding proteins of the present invention include that in SEQ ID NO:2. Glycosyl hydrolases, such as the O-Glycosyl hydrolases (EC 3.2.1.-) are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. Glycosyl hydrolase family 32 (PFAM Accession PF00251) comprises enzymes with several known activities; invertase (EC:3.2.1.26); inulinase (EC:3.2.1.7); levanase (EC:3.2.1.65); exo-inulinase (EC:3.2.1.80); sucrose:sucrose 1-fructosyltransferase (EC:2.4.1.99); and fructan:fructan 1-fructosyltransferase (EC:2.4.1.100). Glycosyl hydrolase family 32 proteins of the present invention include that in SEQ ID NO:10. Glycoside hydrolase family 31 (PFAM Accession PF01055) comprises enzymes with several known activities; -glucosidase (EC:3.2.1.20), -galactosidase (EC:3.2.1.22); glucoamylase (EC:3.2.1.3), sucrase-isomaltase (EC:3.2.1.48) (EC:3.2.1.10); -xylosidase (EC:3.2.1); -glucan lyase (EC:4.2.2.13). Glycosyl hydrolase family 31 proteins of the present invention include those in SEQ ID NOS:262, 264, and 268. Assays to measure hydrolase activity are well known in the art (see, for example, Avigad and Bauer (1966) Methods Enzymol. 8:621-628; Neumann and Lampen (1967) Biochemistry 6:468-475; Henry and Darbyshire (1980) Phytochemistry 19:1017-1020). Alpha amylase (PFAM Accession PF00128) is classified as family 13 of the glycosyl hydrolases. The structure of the alpha amylases consists of an 8 stranded alpha/beta barrel containing the active site, interrupted by an about 70 amino acid calcium-binding domain protruding between beta strand 3 and alpha helix 3, and a carboxyl-terminal Greek key beta-barrel domain. Assays to measure alpha-amylase activity are well known in the art (see, for example, Das et al. (2004) Biotechnol. Appl. Biochem. Mar 25; Grzybowska et al. (2004) Mol. Biotechnol. 26:101-110). Alpha amylase proteins of the present invention include those in SEQ ID NOS:260, 266, 270, 272, 274, 276, and 278. Enzymes containing the Alpha amylase, N-terminal ig-like domain belong to family 13 of the glycosyl hydrolases (PFAM Accession PF02903). The maltogenic-amylase is an enzyme which catalyses hydrolysis of (1-4)-D-glucosidic linkages in polysaccharides so as to remove successive maltose residues from the non-reducing ends of the chains in the conversion of starch to maltose. Other enzymes include neopullulanase, which hydrolyses pullulan to panose, and cyclomaltodextrinase, which hydrolyses cyclodextrins. Alpha amylase, N-terminal ig-like domain proteins of the present invention include that in SEQ ID NO:274. Enzymes containing the Isoamylase N-terminal domain belong to family 13 of the glycosyl hydrolases (PFAM Accession PF02922). This domain is found in a range of enzymes that act on branched substrates, ie. isoamylase, pullulanase and branching enzyme. Isoamylase hydrolyses 1,6-D-glucosidic branch linkages in glycogen, amylopectin and dextrin; 1,4-glucan branching enzyme functions in the formation of 1,6-glucosidic linkages of glycogen; and pullulanase is a starch-debranching enzyme. Isoamylase N-terminal domain proteins of the present invention include that in SEQ ID NO:272. Surface layer proteins, which are glycoproteins forming a layer on the outermost cell envelope component of bacteria, may function as attachment structures for extracellular enzymes, or as cell shape determinants. Assays for measuring structure-function relationships of s-layer proteins are well known in the art (see, for example, Sleytr et al. (1997) Trends Biotechnol. 15:20-26; Olabarria et al. (1996) J. Bacteriol. 178:4765-4772). Surface layer proteins of the present invention include that in SEQ ID NO:62. The N-acetylmuramoyl-L-alanine amidase family of proteins (PFAM Accession PF01510) includes zinc amidases that have N-acetylmuramoyl-L-alanine amidase activity (EC:3.5.1.28). This enzyme domain cleaves the amide bond between N-acetylmuramoyl and L-amino acids in bacterial cell walls (preferentially: D-lactyl-L-Ala). Methods to measure amidase activity are well known in the art (see, for example, Wang et al. (2003) J. Biol. Chem. 278:49044-52; Gelius et al. (2003) Biochem Biophys Res Commun. 306:988-94). N-acetylmuramoyl-L-alanine amidase proteins of the present invention include that in SEQ ID NO:82. Proteins such as FtsW, RodA, and SpoVE are integral membrane proteins involved in cell cycle processes (PFAM Accession PF01098). Methods to assay activity of cell cycle proteins are well known in the art (see, for example, Vinella et al. (1993) J. Bacteriol. 175:6704-6710). Cell cycle proteins of the present invention include those in SEQ ID NOS:92 and 286. Mur ligase family proteins contain a number of related ligase enzymes which have EC numbers 6.3.2.-. This family includes: MurC, MurD, MurE, MurF, Mpl and FolC. MurC, MurD, MurE and MurF catalyse consecutive steps in the synthesis of peptidoglycan. Peptidoglycan consists of a sheet of two sugar derivatives, with one of these N-acetylmuramic acid attaching to a small pentapeptide. The pentapeptide is made of L-alanine, D-glutamic acid, Meso-diaminopimelic acid and D-alanyl alanine. The peptide moiety is synthesized by successively adding these amino acids to UDP-N-acetylmuramic acid. MurC transfers the L-alanine; MurD transfers the D-glutamate; MurE transfers the diaminopimelic acid; and MurF transfers the D-alanyl alanine. This family also includes Folylpolyglutamate synthase that transfers glutamate to folylpolyglutamate. Assays to measure ligase enzyme activity are well known in the art (see, for example, Bouhss et al. (1997) Biochemistry. 36:11556-11563; Hesse et al. (2003) J. Bacteriol. 185:6507-6512). Mur ligase family proteins of the present invention include those in SEQ ID NOS:94, 96, 98, 100, and 116. Glycosyltransferases are enzymes that catalyse the transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. The glycosyltransferase family 28 N-terminal domain (PFAM Accession PF03033) includes monogalactosyldiacylglycerol synthase (P93115, EC 2.4.1.46), 1,2-diacylglycerol 3-galactosyltransferase (EC:2.4.1.46), 1,2-diacylglycerol 3-glucosyltransferase (EC:2.4.1.157), and UDP-N-acetylglucosamine transferase (MURG_SYNY3, EC 2.4.1.-). The N-terminal domain contains the acceptor binding site and likely membrane association site. Glycosyltransferase family 28 N-terminal domain proteins of the present invention include that in SEQ ID NO:102. The glycosyl transferases (PFAM Accession PF00953) are a family of UDP-GlcNAc/MurNAc:polyisoprenol-P GlcNAc/MurNAc-1-P transferases. Members of the family include eukaryotic N-acetylglucosamine-1-phosphate transferases, which catalyze the conversion of UDP-N-acteyl-D-glucosamine and dolichyl phosphate to UMP and N-acetyl-D-glucosaminyl-diphosphodolichol in the glycosylation pathway; and bacterial phospho-N-acetylmuramoyl-pentapeptide-transferases, which catalyze the first step of the lipid cycle reactions in the biosynthesis of cell wall peptidoglycan. Glycosyltransferase proteins (PFAM Accession PF00953) of the present invention include those in SEQ ID NOS:104 and 126. The Glycosyl transferase family (PFAM Accession PF00535) is a diverse family of a variety of glycosyl transferases that transfer the sugar from UDP-glucose, UDP-N-acetyl-galactosamine, GDP-mannose or CDP-abequose, to a range of substrates including cellulose, dolichol phosphate and teichoic acids. Glycosyltransferase proteins (PFAM Accession PF00535) of the present invention include those in SEQ ID NOS:164, 170, 236, and 252. Members of the Glycosyl transferases group 1 family (PFAM Accession PF00534) transfer activated sugars to a variety of substrates, including glycogen, fructose-6-phosphate and lipopolysaccharides. Members of this family transfer UDP, ADP, GDP or CMP linked sugars to a variety of substrates, including glycogen, fructose-6-phosphate and lipopolysaccharides. The bacterial enzymes are involved in various biosynthetic processes that include exopolysaccharide biosynthesis, lipopolysaccharide core biosynthesis and the biosynthesis of the slime polysaccaride colanic acid. Glycosyl transferases group 1 family proteins of the present invention include those in SEQ ID NOS:242, 250, and 258. Assays to measure glycosyltransferase activity are well known in the art (see, for example, Mengin-Lecreulx et al. (1991) J. Bacteriol. 173:4625-4636). The mannosyl-glycoprotein endo-beta-N-acetylglucosamidase family includes enzymes in EC:3.2.1.96, which cause endohydrolysis of the di-N-acetylchitobiosyl unit in high-mannose glycopeptides and glycoproteins containing the -[Man(GlcNAc)2]Asn-structure. Assays to measure amidase activity are well known in the art (see, for example, Pierce et al. (1980) Biochem. J. 185:261-264; Koide and Muramatsu (1974) J. Biol. Chem. 249:4897-4904). Mannosyl-glycoprotein endo-beta-N-acetylglucosamidase proteins of the present invention include those in SEQ ID NOS:106 and 108. The LysM domain is found in a variety of enzymes involved in bacterial cell wall degradation (Bateman and Bycroft (2000) J. Mol. Biol. 299:1113-1119). This domain may have a general peptidoglycan binding function. The structure of this domain is known (Joris et al. (1992) FEMS Microbiol. Lett. 70:257-264). LysM domain proteins of the present invention include that in SEQ ID NO:110. The D-ala D-ala ligase N terminus family (PFAM Accession PF01820) includes D-alanine-D-alanine ligase (EC:6.3.2.4), a bacterial enzyme involved in cell-wall biosynthesis. It participates in forming UDP-N-acetylmuramyl pentapeptide, the peptidoglycan precursor. These enzymes are proteins of 300 to 360 amino acids containing many conserved regions. The N-terminal Gly-rich region could be involved in ATP-binding. Methods for measuring D-alanine-D-alanine ligase activity are well known in the art (see, for example, Ito and Strominger (1962) J. Biol. Chem. 237:2696-2703; Marshall et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94:6480-6483). D-ala D-ala ligase N terminus proteins of the present invention include that in SEQ ID NO:112). D-alanyl-D-alanine carboxypeptidases (PFAM Accession PF00768) are serine peptidases belonging to Merops peptidase family S11 (D-Ala-D-Ala carboxypeptidase A family, clan SE). D-Ala-D-Ala carboxypeptidase A is involved in the metabolism of cell components. There are three families of serine-type D-Ala-D-Ala peptidase, which are also known as low molecular weight penicillin-binding proteins (S11, S12, S13). Family S11 contains only D-Ala-D-Ala peptidases, unlike families S12 and S13, which contain other enzymes, such as class C-lactamases and D-amino-peptidases (Rawlings and Barrett (1994) Methods Enzymol. 244:19-61). Assays for measuring serine carboxypeptidase activity are well known in the art (see, for example, Chang et al. (1990) Proc. Natl. Acad. Sci. U.S.A. 87:2823-7). D-alanyl-D-alanine carboxypeptidase proteins of the present invention include that in SEQ ID NO:118. EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) (EC:2.5.1.19) catalyzes the sixth step in the biosynthesis from chorismate of the aromatic amino acids (the shikimate pathway) in bacteria (gene aroA), plants and fungi (where it is part of a multifunctional enzyme which catalyzes five consecutive steps in this pathway). The sequence of EPSP from various biological sources shows that the structure of the enzyme has been well conserved throughout evolution. Two strongly conserved regions are well defined. The first one corresponds to a region that is part of the active site and which is also important for the resistance to glyphosate. The second second one is located in the C-terminal part of the protein and contains a conserved lysine which seems to be important for the activity of the enzyme. Assays for measuring EPSP synthase activity are well known in the art (see, for example, Okunuki et al. (2003) Shokuhin Eiseigaku Zasshi. 44:77-82; Oliveira et al. (2001) Protein Expr. Purif. 22:430-435). EPSP synthase proteins of the present invention include that in SEQ ID NO:120. The bacterial transferase hexapeptide (three repeats) family (PFAM Accession PF00132) contains a repeat structure composed of tandem repeats of a [LIV]-G-X(4) hexapeptide, which, in the tertiary structure of LpxA (UDP N-acetylglucosamine acyltransferase), has been shown to form a left-handed parallel helix (Raetz and Roderick (1995) Science 270:997-1000). Bacterial transferase hexapeptide proteins of the present invention include that in SEQ ID NO:122. Members of the Putative undecaprenyl diphosphate synthase family (PFAM Accession PF01255) include Di-trans-poly-cis-decaprenylcistransferase (EC:2.5.1.31) (UPP synthetase), which generates undecaprenyl pyrophosphate (UPP) from isopentenyl pyrophosphate (IPP). Methods for measuring Upp synthetase activity are well known in the art (see, for example, Apfel et al. (1999) J. Bacteriol. 181:483-492). Undecaprenyl diphosphate synthase proteins of the present invention include that in SEQ ID NO:124. The penicillin-binding proteins are bifunctional proteins consisting of transglycosylase and transpeptidase in the N- and C-terminus respectively. The transglycosylase domain catalyses the polymerisation of murein glycan chains (Lefevre et al. (1997) J. Bacteriol. 179:4761-4767). Members of the Transglycosylase family (PFAM Accession PF00912) include the bifunctional penicillin-binding proteins that have a transglycosylase (N-terminus) and transpeptidase (C-terminus) domain and the monofunctional biosynthetic peptidoglycan transglycosylases. Methods to measure the catalytic activity of these proteins are well known in the art (see, for example, Di Guilmi et al. (2003) J. Bacteriol. 185:4418-4423). Penicillin-binding transglycosylase proteins of the present invention include those in SEQ ID NOS:134 and 138. Members of the Penicillin binding protein transpeptidase domain family (PFAM Accession PF00905) have an active site serine (residue 337 in PBPX_STRPN) that is conserved in all members of the family. These proteins are responsible for the final stages of peptidoglycan biosynthesis for cell wall formation. The proteins synthesize cross-linked peptidoglycan from lipid intermediates, and contain a penicillin-sensitive transpeptidase carboxy-terminal domain. Assays for measuring transpeptidase activity are well known in the art (see, for example, Zijderveld et al. (1995) J. Bacteriol. 177:6290-6293). Penicillin-binding transpeptidase proteins of the present invention include those in SEQ ID NOS:132, 134, 138, and 146. Members of the AMP-binding enzyme family (PFAM Accession PF00501) appear to act via an ATP-dependent covalent binding of AMP to their substrate, and share a region of sequence similarity. This region is a Ser/Thr/Gly-rich domain that is further characterised by a conserved Pro-Lys-Gly triplet. Assays for measuring the catalytic activity of these proteins are well known in the art (see, for example, Weimar et al. (2002) J. Biol. Chem. 277:29369-29376. AMP-binding proteins of the present invention include that in SEQ ID NO:148. Many members of the Polysaccharide biosynthesis protein family (PFAM Accession PF01943) are implicated in production of polysaccharide. Assays for measuring polysaccharide biosynthesis are well known in the art (see, for example, Yao and Valvano (1994) J. Bacteriol. 176:4133-4143). Polysaccharide biosynthesis proteins of the present invention include those in SEQ ID NOS:156 and 238. Members of the UDP-galactopyranose mutase family (PFAM Accession PF03275) (EC:5.4.99.9) are involved in the conversion of UDP-GALP into UDP-GALF through a 2-keto intermediate, and contain FAD as a cofactor. Assays for measuring UDP-galactopyranose mutase activity are well known in the art (see, for example, Lee et al. (1996) Anal. Biochem. 242:1-7). UDP-galactopyranose mutase proteins of the present invention include that in SEQ ID NO:158. The Bacterial sugar transferase family (PFAM Accession PF02397) represents a conserved region from a number of different bacterial sugar transferases, involved in diverse biosynthesis pathways. Examples include galactosyl-P—P-undecaprenol synthetase (EC:2.7.8.6), which transfers galatose-1-phosphate to the lipid precursor undecaprenol phosphate in the first steps of O-polysaccharide biosynthesis; UDP-galactose-lipid carrier transferase, which is involved in the biosynthesis of amylovoran; and galactosyl transferase CpsD, which is essential for assembly of the group B Streptococci (GBS) type III capsular polysaccharide. Methods for assaying for transferase activity are well known in the art (see, for example, Osborn and Yuan Tze-Yuen (1968) J. Biol. Chem. 243:5145-5152; Wright et al. (1967) Proc. Natl. Acad. Sci. USA 57:1798-1803). Bacterial sugar transferase proteins of the present invention include that in SEQ ID NO:174. The Chain length determinant protein family (PFAM Accession PF02706) includes proteins involved in lipopolysaccharide (LSP) biosynthesis. Methods for measuring lipopolysaccharide biosynthesis are well known in the art (see, for example, Franco et al. (1998) J. Bacteriol. 180:2670-5). Chain length determinant proteins of the present invention include that in SEQ ID NO:180. NlpC/P60 (PFAM Accession PF00877) is a family containing cell-wall peptidases, some members of which are known to hydrolyze D-gamma-glutamyl-meso-diaminopimelate or N-acetylmuramate-L-alanine linkages (Anantharaman and Aravind (2003) Genome Biol. 4:R11). NlpC/P60 proteins of the present invention include those in SEQ ID NOS:190, 194, and 196. Ribonucleotide reductase (EC:1.17.4.1) provides the precursors necessary for DNA synthesis. This enzyme catalyzes the reductive synthesis of deoxyribonucleotides from their corresponding ribonucleotides: 2′-deoxyribonucleoside diphosphate+oxidized thioredoxin+H2O=ribonucleoside diphosphate+reduced thioredoxin. Ribonucleotide reductase is an oligomeric enzyme composed of a large subunit (700 to 1000 residues) and a small subunit (300 to 400 residues)—class II RNRs are less complex, using the small molecule B 12 in place of the small chain. The small chain binds two iron atoms (three Glu, one Asp, and two His are involved in metal binding) and contains an active site tyrosine radical. The regions of the sequence that contain the metal-binding residues and the active site tyrosine are conserved in ribonucleotide reductase small chain from prokaryotes, eukaryotes and viruses. Assays for measuring ribonucleoside-diphosphate reductase activity are well known in the art (see, for example, Nilsson et al. (1988) Biochem. Soc. Trans. 16:91-94; Reichard (1993) Science 260:1773-1777). Ribonucleotide reductase proteins of the present invention include that in SEQ ID NO:208. ABC transporters (PFAM Accession PF00005) form a large family of proteins responsible for translocation of a variety of compounds across biological membranes. They are minimally composed of four domains, with two transmembrane domains (TMDs) responsible for allocrite binding and transport and two nucleotide-binding domains (NBDs) responsible for coupling the energy of ATP hydrolysis to conformational changes in the TMDs. Both NBDs are capable of ATP hydrolysis, and inhibition of hydrolysis at one NBD effectively abrogates hydrolysis at the other. The proteins belonging to this family also contain one or two copies of the ‘A’ consensus sequence (Walker et al. (1982) EMBO J. 1:945-951) or the ‘P-loop’ (Saraste et al. (1990) Trends Biochem Sci. 15:430-434). Methods for measuring ATP-binding and transport are well known in the art (see, for example, Hung et al. (1998) Nature 396:703-707; Higgins et al. (1990) J. Bioenerg. Biomembr. 22:571-592). ABC transporters proteins of the present invention include those in SEQ ID NOS:218 and 226. Members of the UDP-N-acetylglucosamine 2-epimerase family (PFAM Accession PF02350) consist of UDP-N-acetylglucosamine 2-epimerases (EC:5.1.3.14). This enzyme catalyzes the production of UDP-ManNAc from UDP-GlcNAc. Assays to measure UDP-N-acetylglucosamine 2-epimerase activity are well known in the art (see, for example, Stasche et al. (1997) J. Biol. Chem. 272:24319-24324). UDP-N-acetylglucosamine 2-epimerase proteins of the present invention include those in SEQ ID NOS:244 and 246. The tRNA (Guanine-1)-methyltransferase (PFAM Accession PF01746) family consists of tRNA (Guanine-1)-methyltransferases (EC:2.1.1.31). In E. coli K12 this enzyme catalyses the conversion of a guanosine residue to N1-methylguanine in position 37, next to the anticodon, in tRNA (Hjalmarsson et al. (1983) J. Biol. Chem 258:1343-1351. tRNA (guanine-N-1-)-methyltransferasecatalyses the reaction: S-adenosyl-L-methionine+tRNA->S-adenosyl-L-homocysteine+tRNA containing N1-methylguanine. In the process, guanosine(G) is methylated to N1-methylguanine (1-methylguanosine (m1G)) at position 37 of tRNAs that read CUN (leucine), CCN (proline), and CGG (arginine) codons. The presence of ml G improves the cellular growth rate and the polypeptide steptime and also prevents the tRNA from shifting the reading frame (Hagervall et al. (1990) Biochim. Biophys. Acta. 1050:263-266). Assays for measuring tRNA methyltransferase activity are well known in the art (see, for example, Hjalmarsson et al. (1983) J. Biol. Chem. 258:1343-1351). tRNA (Guanine-1)-methyltransferase proteins of the present invention include that in SEQ ID NO:294. The aminoacyl-tRNA synthetases (EC:6.1.1) catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. The 20 aminoacyl-tRNA synthetases are divided into two classes, I and II (PFAM Accession PF00587). Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold and are mostly monomeric, while class II aminoacyl-tRNA synthetases share an anti-parallel-sheet formation, flanked by -helices (Perona et al. (1993) Biochemistry 32:8758-8771), and are mostly dimeric or multimeric. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2′-hydroxyl of the tRNA, while, in class II reactions, the 3′-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases. Assays to measure aminoacyl-tRNA synthetases activity are well known in the art (see, for example, Augustine and Francklyn (1997) Biochemistry 36:3473-3482). Aminoacyl-tRNA synthetase proteins of the present invention include that in SEQ ID NO:296. The LuxS protein family (LuxS) (PFAM Accession PF02664) consists of the LuxS protein involved in autoinducer A12 synthesis and its hypothetical relatives. In bacteria, the regulation of gene expression in response to changes in cell density is called quorum sensing. Quorum-sensing bacteria produce, release, and respond to hormone-like molecules (autoinducers) that accumulate in the external environment as the cell population grows. The LuxS protein is involved in quorum sensing and is a autoinducer-production protein (Surette et al. (1999) Proc. Natl. Acad. Sci. USA. 96:1639-1644). Methods to detect quorum sensing are well known in the art (see, for example, Surette et al. (1999) Proc. Natl. Acad. Sci. U.S.A. 96:1639-1644). LuxS proteins of the present invention include that in SEQ ID NO:304. Methods of Use In one embodiment, polypeptides of the present invention, as well as microbes expressing them may alter the immune system of a host, including alteration of the humoral, cellular, and nonspecific immune responses, both locally and systemically. Immune system alteration by probiotic bacteria may occur, for example, by augmentation of non-specific or antigen-specific defenses against infection and tumors, by increased mucosal immunity, by providing an adjuvant effect in an antigen-specific immune response, or by regulation of Th1/Th2 cells and their cytokine production (See, for example, U.S. Application No. 2002/0159976). By “adjuvant” is intended a substance that increases the immune response to an antigen when introduced together with the antigen. Humoral immunity may be augmented by increased IgA production and stimulation of B lymphocyte production after consumption of probiotic bacteria. Methods used to study the mucosal immune system, including assays to measure the type and concentration of immunoglobulins and assays to assess the number and type of immune cells, are well known in the art (see, for example; Erickson and Hubbard (2000) J. Nutr. 130:403S-409S). Modification of non-specific immunity may result in altered production of cytokines such as IL-1β, IL-6, IL-10, TNFα, IL-12, IFN-γ, and IL-18, and enhanced phagocytic activity; assays to detect the type and amount of cytokines released from cells after stimulation with probiotic bacteria, and other assays to measure non-specific immunity are known in the art (see, for example, Miettinen et al. (1996) Infect. Immun. 64:5403-5405; Marin et al. (1998) J. Food Prot. 61:859-864; Schiffrin et al. (1994) J. Dairy Sci. 78:491-497). Alteration of cellular immunity may result in the increased production of macrophages, or altered cytokine production. Proteases from probiotic supplements can degrade the casein in cow milk, generating peptides that suppress lymphocyte proliferation (Sutas et al. (1996) J. Allergy Clin. Immunol. 98:216-224). Assays to measure the cellular immune response, such as lymphocyte proliferation assays, are well known in the art (see, for example, Erickson and Hubbard (2000) J. Nutr. 130:403S-409S; De Simone et al. (1993) J. Immunother. 9:23-28); Perdigón et al. (1986) Infect. Immun. 53:404-410). Probiotic bacteria may also enhance the immune response to oral vaccines (see Chin et al. (2000) Immunol. Cell Biol. 78:55-66; Isolauri et al. (1995) Vaccine 13:310-312), have anti-inflammatory properties (Pessi et al. (1999) Appl. Environ. Microbiol. 65:475-478; Isolauri et al. (2001) Am. J. Clin. Nutr. 73:444S-450S; Antonopoulou et al. (1996) J. Agric. Food Chem. 44:3047-3051), and stabilize intestinal permeability to macromolecules (Heyman (2000) J. Am. College Nutr. 19:137S-146S; Isolauri et al. (1993) Ped. Res. 33:548-553). This effect on intestinal permeability may result from the maintenance or repair of tight junctions between the mucosal epithelial cells. Assays to measure these properties are known in the art, and examples can be found in the references cited. In another embodiment, polypeptides of the present invention as well as microbes expressing them may alter the expression of various host proteins or compounds. These proteins and compounds include, but are not limited to, cell surface proteins (i.e. cell adhesion molecules), proteins involved in mucin production (i.e., MUC1 and MUC2), cell signaling proteins (i.e., tyrosine kinases, protein kinase C, mitogen-activated protein kinases, and nuclear factor kappa B (NF-κB)), proteins involved in host tolerance of commensal bacteria, and antimicrobial proteins or compounds (i.e., hydrogen peroxide (Hawes et al. (1996) J. Infect. Dis 174:1058-1063) or nitric oxide (Korhonen et al. (2002) Inflammation 26:207-214)). By “cell surface” as it relates to an altered host protein is intended a protein found in association with a cell membrane. By “mucin” is intended a protein secreted by mucous glands or mucous cells. By “cell signaling protein” is intended a protein involved in cell signaling. By “host tolerance” is intended the decrease in, or loss of, the ability of an animal to produce an immune response upon the administration of a particular antigen. By “commensal bacteria” is intended a bacterium that exists in close physical association with another organism, where neither organism benefits nor is harmed as a result of the association. By “antimicrobial” is intended a compound that prevents the growth of or kills a microorganism. Altered expression of cell adhesion molecules, or regions/domains/fragments thereof, may enable a microorganism to have modified adherence properties. Alternatively, proteins involved in mucin production may prevent the ability of pathogenic organisms to attach to intestinal epithelial cells (Mack et al. (1999) Am. J. Physiol. 276:G941-G950). The composition, quality and quantity of mucin production could be affected, leading to altered pathogen-mucin interactions. Assays to measure altered expression of host proteins or compounds are well known in the art, and include Northern blots and Western blots. See, for example, Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory Press, Plainview, N.Y.). In yet another embodiment, the polypeptides and microorganisms expressing them may be useful for the treatment or prevention of gastrointestinal disorders, including, but not limited to, inflammatory bowel disease, Crohn's disease, ulcerative colitis, irritable bowel syndrome, diarrhea, antibiotic associated diarrhea, constipation, and small bowel bacterial overgrowth. By “treatment or prevention” is intended a reduction in or prevention of any of the symptoms associated with a disease that occurs following administration of a polypeptide or microorganism of the present invention. This reduction includes any decrease in intensity or duration of symptoms in the subject receiving therapy. As used herein, an “effective amount” of a polypeptide or microorganism of the present invention will be sufficient to prevent, reduce, or lessen the clinical symptoms of the disease being treated. Probiotic bacteria may be effective in treating or preventing gastrointestinal disorders by acting as an immunomodulator, as mentioned above, by influencing the gut-associated lymphoid tissue, or may attach to the epithelium forming a protective layer, preventing invasion by pathogenic bacteria (Kasper (1998) Int. J. Food Micro. 41:127 131). Probiotic bacteria have been administered to patients with Crohn's disease, a chronic inflammatory bowel disease, with resultant immunological improvement (Malin et al. (1996) Ann. Nutr. Metab. 40:137-145). Positive effects have also been seen when treating constipation (Kasper (1998) Int. J. Food Micro. 41:127-131), enteric rotavirus-associated infection in children (Isolauri et al. (1991) Pediatrics 88:90-97; Boudraa et al. (1990) Gastroenterol. Nutr. 11:509-512), travelers' diarrhea (Hilton et al. (1997) J. Travel Med. 4:41-43), small bowel bacterial overgrowth (Vanderhoof et al. (1998) J. Pediatr. Gastroenterol. Nutr. 27:155-160), and antibiotic associated diarrhea (Biller et al. (1995) J. Pediatr. Gastr. Nutr. 21:224-226). Assays to determine the clinical effectiveness of using probiotic bacteria to treat or prevent a gastrointestinal disorder are known in the art (see, for example, Guandalini et al. (2000) J. Pediatr. Gastroenterol. Nutr. 30:54-60; Saavedra et al. (1994) Lancet 344:1046-1049). In yet another embodiment, a polypeptide or a microorganism expressing a polypeptide of the current invention may prevent or reduce the occurrence of an infection in a host. By “reduce the occurrence of” is intended a reduction in the probability of a subject becoming infected with an organism and subsequently exhibiting symptoms of a disease caused by that organism. Infections that can be prevented or treated by probiotic bacteria include, but are not limited to, those caused by a food-borne pathogen (i.e., enterotoxigenic Escherichia coli (ETEC), Salmonella typhimurium, Listeria monocytogenes, and Vibrio cholerae) (see Boris et al. (1998) Infect. Immun. 66:1985-1989; Silva et al. (2001) J. Med. Microbiol. 50:161-164; Strus et al. (2001) Med. Dosw. Mikrobiol. 53:133-142; Tannock (1999) Probiotics: a critical review. Horizon Scientific Press, 161 pp; Salminen, S, and von Wright, A. 1998. Lactic acid bacteria: microbiology and functional aspects. Marcel Dekker, Inc. NY. 617 pp.), infections caused by an opportunistic pathogen, infections caused by Helicobacter pylori (Cremonini et al. (2001) Dig. Dis. 19:144-147; Lorca et al. (2001) Current Micro. 42:39-44), urogenital diseases such as vaginosis or vaginitis (Reid et al. (2001) FEMS Immunol. Med. Micro. 30:49-52), and HIV infection (Hashemi et al. (2000) J. Infect. Dis. 181:1574-1580). Methods to determine whether probiotic bacteria are effective at treating or preventing infections are well known in the art, and examples may be found in the above references. In another embodiment, the polypeptides may enable a microorganism to bind and remove detrimental compounds in the gastrointestinal tract, including toxins, mutagens, bile salts, fats, cholesterol, and currently unidentified proteins or compounds. The compounds may also be inactivated, sequestered, degraded, digested, cleaved or modified. The compounds may be produced by the host, for instance as a result of the digestion of a food product with mutagenic compounds (i.e., heterocyclic amines formed during the cooking of meat), or may be produced by microorganisms that are present in the gastrointestinal tract (i.e., microbial metabolites that possess genotoxic, mutagenic or carcinogenic activity). Bacterial enzymes such as NAD(P)H dehydrogenase (azoreductase), nitroreductase, β-glucoronidase, β-glucosidase, and 7-α-dehydroxylase may increase the carcinogenic effect of toxic compounds. Bacteria such as lactobacilli have lower activities of these xenobiotic-metabolizing enzymes, and administration of some strains decreased the activity of nitroreductase and β-glucoronidase (Goldin and Gorbach (1984) Am. J. Clin. Nutr. 39:756-761; Goldin et al. (1992) Dig. Dis. Sci. 37:121-128; Benno and Mitsuoka (1992) Microbiol. Immunol. 36:683-694; Bouhnik et al. (1996) Eur. J. Clin. Nutr. 50:269-273). The polypeptides themselves may also possess these activities. Thus, the proteins of the invention or probiotic bacteria expressing them may find use in the treatment or prevention of cancer, particularly colon cancer. Anticarcinogenic effects of probiotic bacteria have been noted (Wollowski et al. (2001) Am. J. Clin. Nutr. 73:451 S-455S; Hayatsu and Hayatsu (1993) Cancer Lett. 73:173-179), and the physical binding of various mutagenic compounds to lactic acid bacteria has been shown (Orrhage et al. (1994) Mutation Res. 311:239-248). Assays to measure various anticarcinogenic effects of probiotic bacteria are well known in the art (see, for example, Wollowski et al. (2001) Am. J. Clin. Nutr. 73:451S-455S; Goldin and Gorbach (1980) J. Natl. Cancer Inst. 64:263-265; Goldin and Gorbach (1984) J. Natl. Cancer Inst. 73:689-695). In addition to cancer prevention, polypeptides of the invention or microorganisms expressing them may lower serum cholesterol levels and aid in the prevention of heart disease. Lactic acid bacteria can remove cholesterol from culture medium (Klayer and van der Meer (1993) Appl. Environ. Microbiol. 59:1120-1124) and some studies have shown a decrease in serum cholesterol in humans after consumption of probiotic bacteria (Lin et al. (1989) J Dairy Res. 72:2885-2899; Khedkar et al. (1993) J. Dairy Foods Home Sci. 12:33-38). Cholesterol levels may be lowered by probiotic bacteria through the deconjugation of bile acids, since cholesterol is converted to bile acids to replace those lost by excretion (Sanders (2000) J. Nutr. 130:384S-390S). In another embodiment, a polypeptide of the present invention, or a variant thereof, may enhance the stability of a microorganism. This enhanced stability may enable a microorganism to survive passage through the stomach, small intestine and/or gastrointestinal tract, to resist acid and bile in those areas, or to persist in the gastrointestinal tract after ingestion by a host. Enhanced stability might also allow the microorganism to withstand stressful conditions that occur during production and processing of a fermented product, including storage of the microorganism. These stresses include, but are not limited to, oxidative stress, pH, pressure, osmotic stress, dehydration, carbon starvation, phosphate starvation, nitrogen starvation, amino acid starvation, mechanical manipulation such as centrifugation, heat or cold shock, mutagenic stress, and the stresses associated with various storage conditions, including cell culture, freezing, lyophilization, and drying (see Girgis et al. (2002) Stress adaptations of lactic acid bacteria. In Microbial adaptation to stress and safety of new-generation foods. Yousef, A. E. and Juneja, V. K. (Eds.) Technomic Publishing Co. Inc.). A polypeptide of the invention could provide protection against one or more stresses. Assays to measure the stability of microorganisms are well known in the art (for example, Klaenhammer and Kleeman (1981) Appl. Environ. Microbiol. 41:1461-1467; Wright and Klaenhammer (1983) J. Food Sci. 48:773-777). Sequences that may be useful in enhancing stability include, but are not limited to, those set forth in SEQ ID NOS:60, 62, 286, 270, 294, 300, 302, 304 and 306. In another embodiment, a polypeptide of the current invention, or a variant thereof, may enable a microorganism to have modified adherence properties. These adherence properties could allow the microorganism to bind with an increased or decreased ability to a specific cell type, such as an intestinal epithelial cell or to another bacterial cell, or to a compound, such as a mucin (see, for example, Ouwehand et al. (2000) Lett. Appl. Microbiol. 30:10-13; Tuomola et al. (1999) FEMS Immunol. Med. Microbiol. 26:137-142). An increased ability to adhere to other bacterial cells may result in aggregation. Assays to measure bacterial adhesion are well known in the art (see, for example, Jin et al. (2000) Appl. Environ. Microbiol. 66:4200-4204; Coconnier et al. (1992) Appl. Environ. Microbiol. 58:2034-2039; Greene and Klaenhammer (1994) Appl. Environ. Microbiol. 60:4487-4494; Lorca et al. (2002) FEMS Microbiol Lett 206:31-37; Antikainen et al. (2002) Mol. Microbiol. 46:381-94). In another embodiment, a polypeptide of the invention may enable a microorganism to reduce the occurrence of dental caries after oral administration to a subject. Methods to assess the ability of probiotic bacteria to reduce dental caries are known in the art (see, for example, Nase et al. (2001) Caries Res. 35:412-420). In another embodiment, a polypeptide of the invention may enable a microorganism to increase feed conversion in a production animal. Methods of measuring increased feed conversion in a production animal are known in the art (see, for example, Fuller (1998) Priobiotics for farm animals. In: Probiotics: A Critical Review (Tannock, G. W., ed.). Horizon Scientific Press, Wymondham, UK. In another embodiment, the polynucleotides and polypeptides of the invention may enable a microorganism to antagonize or kill another microorganism, including a pathogen. By “antagonizing” is intended an interaction between two biologically active substances, such that one partially or completely inhibits an activity of the other. The polypeptides may enable a microorganism expressing them to bind to another microorganism, to have antimicrobial activity towards another microorganism, or to lyse another microorganism. Expression of the polypeptide may result in the first microorganism competing with the second microorganism for essential binding sites or essential nutrients, for example in the gastrointestinal tract of a host that has ingested the microorganism (see, for example, Jin et al. (2000) Appl. Environ. Microbiol. 66:4200-4204). In different embodiments, isolated polypeptides themselves may antagonize or kill microorganisms, by the same mechanisms as mentioned above. Assays to measure antimicrobial activity, including the lysis or death of a microorganism are known in the art (see Methods for General and Molecular Bacteriology. 1994. Gerhardt, P., Murray, R. G. E., Wood, W. A. Krieg, N. R. (Eds.) American Society for Microbiology, 791 pp.). Assays to measure bacterial adhesion are well known in the art (see, for example, Jin et al., above). Assays to measure competition for binding sites or nutrients are known in the art (see, for example, Edelman et al. (2003) Vet. Microbiol. 91:41-56; Gan et al. (2002) J. Infect. Dis. 185:1369-1372; Horie et al. (2002) J. Appl. Microbiol. 92:396-403). In another embodiment, the polypeptides may have antimicrobial activity and provide use in various applications, including food protection and wound treatment, such as for a topical treatment. Methods for detecting antimicrobial activity in a protein are well known in the art (Allison and Klaenhammer (1999) Genetics of bacteriocins produced by lactic acid bacteria and their use in novel industrial applications. pp789-808. In Manual of Industrial Microbiology and Biotechnology. A. L. DeMain and J. E. Davies. (eds.) ASM Press, Washington, D.C.). In another embodiment, the polypeptides of the invention may modulate the antibiotic sensitivity of a microorganism, or the polypeptides may modulate the sensitivity of a microorganism to other compounds with antimicrobial activity. Methods for detecting the antibiotic sensitivity of a microorganism or the sensitivity of a microorganism to a compound with antimicrobial activity are well known in the art. In another embodiment, a polypeptide may enable a microorganism to aggregate or form a biofilm, or enable a first microorganism to interfere with a second microorganisms' ability to form a biofilm. The polypeptides themselves may also interfere with a microorganisms' ability to form a biofilm. By “biofilm” is intended a microbially derived sessile community characterized by cells that are irreversibly attached to a substratum or interface or to each other, are embedded in a matrix of extracellular polymeric substances that they have produced, and exhibit an altered phenotype with respect to growth rate and gene transcription. Assays to measure biofilm formation are well known in the art (see, for example, O'Toole and Kolter (1998) Mol. Microbiol. 28:449-461; Yoshida and Kuramitsu (2002) Appl Environ Microbiol 68:6283-6291). In another embodiment, a sorting signal sufficient for cell wall anchoring isolated from a polypeptide of the present invention may be fused to a heterologous protein (Schneewind et al. (1993) EMBO J. 12:4803-4811; Schneewind et al. (1992) Cell 70:267-281). The LPXTG (SEQ ID NO:308) motif has been identified as characteristic of surface proteins in Gram-positive bacteria (Navarre and Schneewind (1994) Molecular Microbiology 14:115-121; Fischetti et al. (1990) Mol. Microbiol. 4:1603-1605). Assays to measure expression of heterologous proteins on the surface of a cell are well known in the art (see, for example, Steidler et al. (1998) Appl. Env. Micro. 64:342-345). The polypeptides of the invention may modulate the texture or other physical properties of a food product produced using a lactic acid bacteria. Exopolysaccharides may act as stabilizers, thickeners, gelling agents, viscosifying agents, and emulsifiers in various food products (De Vuyst and Degeest (1999) FEMS Microbiol. Rev. 153-177). The increased viscosity of foods containing exopolysaccharides may be beneficial for probiotic bacterial colonization in the gastrointestinal tract (German et al. (1999) Trends Biotechnol. 17:491-499; Jolly et al. (2002) Antonie van Leeuwenhoek 82:367-374). Methods for measuring texture of a food product are known in the art (see, for example, van den Berg et al. (1995) Appl. Envir. Microbiol. 61:2840-2844). TABLE 1 SEQ ID NO: IDENTITY/FUNCTION 1, 2 ABC-type metal ion transport system, periplasmic component/surface adhesin 3, 4 lemA protein 5, 6 FmtB surface protein 7, 8 67 kDa Myosin-crossreactive streptococcal antigen 9, 10 Myosin-crossreactive antigen 11, 12 Sortase 13, 14 Mucus binding protein precursor 15, 16 Mucus binding protein precursor 17, 18 Mucus binding protein precursor (Mub) 19, 20 Mucus binding protein precursor (Mub) 21, 22 Mucus binding protein precursor (Mub) 23, 24 Mucus binding protein precursor 25, 26 Mucus binding protein 27, 28 Mucus binding protein 29, 30 Mucus binding protein 31, 32 Mucus binding protein 33, 34 Mucus binding protein 35, 36 Mucus binding protein precursor 37, 38 Mucus binding protein precursor 39, 40 Steroid binding protein 41, 42 Surface exclusion protein 43, 44 Tropomyosin-like protein 45, 46 Biofilm-associated surface protein 47, 48 Aggregation promoting protein 49, 50 Aggregation promoting protein 51, 52 Fibrinogen-binding protein 53, 54 Fibrinogen-binding protein 55, 56 Fibrinogen-binding protein 57, 58 Fibronectin-binding protein 59, 60 Surface layer protein 61, 62 Surface layer protein 63, 64 Surface layer Protein 65, 66 Surface layer protein 67, 68 Surface layer protein 69, 70 Surface layer protein 71, 72 Surface layer protein 73, 74 Surface layer protein 75, 76 Surface protein 77, 78 Surface protein 79, 80 Surface protein 81, 82 Autolysin; amidase 83, 84 Cell shape-determining protein (MreB) 85, 86 Cell shape-determining protein (MreB) 87, 88 Cell shape-determining protein (MreC) 89, 90 Cell shape-determining protein (MreD) 91, 92 Rod shape-determining protein (RodA) 93, 94 UDP-N-acetylmuramate-alanine ligase 95, 96 UDP-N-acetylmuramyl tripeptide synthetase 97, 98 UDP-N-acetylmuramoyl-L-alanyl-D-glutamyl-lysine ligase 99, 100 UDP-N-acetylmuramoylalanine-D-glutamate ligase 101, 102 p-N-acetylmuramoyl-pentapeptide-transferase 103, 104 p-N-acetylmuramoyl-pentapeptide-transferase 105, 106 N-acetylmuramidase 107, 108 N-acetylmuramidase 109, 110 N-acetylmuramidase 111, 112 d-alanine-d-alanine ligase 113, 114 Permease 115, 116 d-ala-d-ala adding enzyme 117, 118 d-alanyl-d-alanine carboxypeptidase 119, 120 UDP-N-acetylglucosamine 1-carboxyvinyltransferase 121, 122 UDP-N-acetylglucosamine pyrophosphorylase 123, 124 Undecaprenyl pyrophosphate synthetase 125, 126 Undecaprenyl-phosphate N-acetyl-glucosaminyltransferase 127, 128 Penicillin binding protein 129, 130 Penicillin binding protein 131, 132 Penicillin binding protein 133, 134 Penicillin binding protein 135, 136 Penicillin binding protein 137, 138 Penicillin binding protein 1A 139, 140 Penicillin binding protein-related factor A 141, 142 Penicillin binding protein 143, 144 Penicillin binding protein 145, 146 Penicillin binding protein 2B 147, 148 DltA D-alanine-D-alanyl carrier protein ligase 149, 150 DltB basic membrane protein 151, 152 DltC D-alanyl carrier protein 153, 154 DltD extramembranal transfer protein 155, 156 Oligosaccharide repeat unit transporter (EpsI) 157, 158 UDP-galactopyranose mutase 159, 160 UDP-galactopyranose mutase 161, 162 Polysaccharide polymerase 163, 164 Glycosyltransferase 165, 166 Cell surface, cell membrane or secreted protein 167, 168 Cell surface, cell membrane or secreted protein 169, 170 Glycosyltransferase 171, 172 Galactosyl transferase 173, 174 Phospho-glucosyltransferase (EpsE) 175, 176 EpsD 177, 178 EpsC 179, 180 EpsB 181, 182 EpsA 183, 184 GTP-binding protein 185, 186 Cell surface, cell membrane or secreted protein 187, 188 Cell surface protein 189, 190 Cell wall-associated hydrolase 191, 192 Cell surface, cell membrane or secreted protein 193, 194 Cell wall-associated hydrolase 195, 196 Glycosidase 197, 198 Guanylate kinase 199, 200 Cell surface, cell membrane or secreted protein 201, 202 Membrane protein 203, 204 Cell surface, cell membrane or secreted protein 205, 206 Ribonucleotide reductase (NrdI) 207, 208 Ribonucleotide reductase 209, 210 Cell surface, cell membrane or secreted protein 211, 212 Cell surface, cell membrane or secreted protein 213, 214 Cell surface, cell membrane or secreted protein 215, 216 ABC transporter component 217, 218 ABC transporter 219, 220 Cell surface, cell membrane or secreted protein 221, 222 Membrane protein 223, 224 Membrane protein 225, 226 ATPase component of ABC transporter 227, 228 Cell surface, cell membrane or secreted protein 229, 230 Acetyltransferase 231, 232 Transcriptional regulator 233, 234 Polysaccharide transporter 235, 236 EpsV 237, 238 EpsU 239, 240 EpsA 241, 242 Capsular polysaccharide biosynthesis protein J (capJ) 243, 244 Cap5P 245, 246 Cap5P 247, 248 CpsIVN 249, 250 Lipopolysaccharide biosynthesis protein 251, 252 Cellulose synthase 253, 254 Sucrose phosphorylase 255, 256 Polysaccharide transporter 257, 258 LPS biosynthesis protein 259, 260 Oligo-1,6-glucosidase 261, 262 Alpha-glucosidase 263, 264 Alpha-glucosidase 265, 266 Glucan 1,6-alpha-glucosidase 267, 268 Alpha-glucosidase II 269, 270 Dextran glucosidase 271, 272 1,4-alpha-glucan branching enzyme 273, 274 Neopullulanase 275, 276 Pullulanase 277, 278 Amylopullulanase 279, 280 Cyclomaltodextrin transport membrane protein 281, 282 Cell surface, cell membrane or secreted protein 283, 284 Cell surface protein 285, 286 Cell surface protein (bacterial cell division membrane protein) 287, 288 Membrane protein 289, 290 Membrane protein 291, 292 DNA methylase 293, 294 tRNA (guanine-N1)-methyltransferase 295, 296 Theronyl-tRNA synthetase 297, 298 Surface protein 299, 300 Transport accessory protein 301, 302 Methionine synthase 303, 304 Autoinducer-2 production protein (LuxS) 305, 306 Cell division protein (cdpA) 307 Biofilm-associated surface protein The following examples are offered by way of illustration and not by way of limitation. EXAMPLE 1 Gapped BlastP Results for Amino Acid Sequences A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:2 (306 amino acids) has about 73% identity from amino acids 7-304 with a protein from Lactobacillus gasseri that is a ABC-type metal ion transport system, periplasmic component/surface adhesin (Accession No. ZP—00046648.1), about 71% identity from amino acids 9-304 with a protein from Lactobacillus johnsonii that is an ABC transporter solute-binding component (Accession No. NP—965678.1), about 62% identity from amino acids 18-306 with a protein from Lactobacillus gasseri that is an ABC-type metal ion transport system, periplasmic component/surface adhesin (Accession No. ZP—00046208.1), about 62% identity from amino acids 26-306 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964756.1), and about 45% identity from amino acids 18-306 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an ABC-type metal ion transport system, periplasmic component/surface adhesin (Accession No. ZP—00064315.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:4 (191 amino acids) has about 75% identity from amino acids 29-191 with an uncharacterized conserved protein from Lactobacillus gasseri (Accession No. ZP—00047066.1), about 76% identity from amino acids 29-191 with a protein from Lactobacillus johnsonii that is a LemA-like protein (Accession No. NP—964093.1), about 68% identity from amino acids 29-191 with an unknown protein from Lactobacillus plantarum (Accession No. NP—784295.1), about 65% identity from amino acids 29-191 with a protein from Streptococcus mutans that is a LemA-like protein (Accession No. NP—722235.1), and about 61% identity from amino acids 29-191 with a protein from Streptococcus pneumoniae that is a lemA protein (Accession No. NP—345748.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:6 (2539 amino acids) has about 41% identity from amino acids 1-2501 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964984.1), about 27% identity from amino acids 797-2209 with a protein from Abiotrophia defectiva that is an extracellular matrix binding protein (Accession No. pir∥T31110), about 20% identity from amino acids 4-2521 with a protein from Staphylococcus epidermidis that is a FmtB protein (Accession No. NP—764984.1), about 21% identity from amino acids 1-2529 with a protein from Staphylococcus aureus subsp. aureus that is homologous to a streptococcal adhesin emb (Accession No. NP—374548.1), and about 20% identity from amino acids 1-2529 with a hypothetical protein from Staphylococcus aureus subsp. aureus (Accession No. NP—371958.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:8 (591 amino acids) has about 84% identity from amino acids 1-591 with a protein from Lactobacillus gasseri that is a myosin-crossreactive antigen (Accession No. ZP—00047333.1), about 83% identity from amino acids 1-591 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964681.1), about 70% identity from amino acids 1-591 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a myosin-crossreactive antigen (Accession No. ZP—00063735.1), about 67% identity from amino acids 1-591 with a protein from Streptococcus pyogenes that is a 67 kDa myosin-crossreactive streptococcal antigen (Accession No. NP—268761.1), and about 67% identity from amino acids 1-591 with a protein from Streptococcus pyogenes that is a 67 kDa myosin-crossreactive streptococcal antigen (Accession No. NP—664136.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:10 (590 amino acids) has about 79% identity from amino acids 1-590 with a protein from Lactobacillus gasseri that is a myosin-crossreactive antigen (Accession No. ZP—00046024.1), about 71% identity from amino acids 1-590 with a protein from Streptococcus mutans that is homologous to a 67 kDa myosin-crossreactive streptococcal antigen (Accession No. NP—721921.1), about 60% identity from amino acids 1-590 with a protein from Staphylococcus aureus subsp. aureus that is homologous to a 67 kDa myosin-crossreactive streptococcal antigen (Accession No. NP—644896.1), about 59% identity from amino acids 1-590 with a protein from Staphylococcus aureus subsp. aureus that is homologous to a 67 kDa myosin-crossreactive streptococcal antigen (Accession No. NP—370630.1), and about 58% identity from amino acids 1-590 with a protein from Staphylococcus epidermidis that is a 67 kDa myosin-crossreactive streptococcal antigen-like protein (Accession No. NP—764331.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:12 (229 amino acids) has about 61% identity from amino acids 1-229 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965278.1), about 65% identity from amino acids 31-229 with a protein from Lactobacillus gasseri that is a sortase (surface protein transpeptidase) (Accession No. ZP—00046569.1), about 38% identity from amino acids 31-229 with a protein from Enterococcus faecalis that is a sortase family protein (Accession No. NP—816668.1), about 37% identity from amino acids 31-210 with a protein from Lactobacillus plantarum that is a sortase (Accession No. NP—784294.1), and about 36% identity from amino acids 31-229 with a hypothetical protein from Lactococcus lactis subsp. lactis (Accession No. NP—267269.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:14 (643 amino acids) has about 34% identity from amino acids 1-643 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046128.1), about 38% identity from amino acids 2-456 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046781.1), about 38% identity from amino acids 2-456 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964064.1), about 34% identity from amino acids 124-602 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046133.1), and about 33% identity from amino acids 11-428 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964062.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:16 (1017 amino acids) has about 27% identity from amino acids 299-865 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1), about 22% identity from amino acids 273-848 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1), about 23% identity from amino acids 420-862 with a protein from Lactobacillus reuteri that is a mucus binding protein precursor (Mub) (Accession No. gb|AAF25576.1), about 25% identity from amino acids 487-859 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964063.1), and about 25% identity from amino acids 537-865 with a protein from Lactobacillus plantarum that is a cell surface protein precursor (Accession No. NP—786417.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:18 (4326 amino acids) has about 29% identity from amino acids 2234-4165 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1), about 23% identity from amino acids 650-3974 with a protein from Lactobacillus reuteri that is a mucus binding protein precursor (Mub) (Accession No. gb|AAF25576.1), about 24% identity from amino acids 1778-4164 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1), about 27% identity from amino acids 1673-2994 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1), and about 25% identity from amino acids 1388-2974 with a protein from Lactobacillus plantarum that is a cell surface protein precursor (Accession No. NP—785232.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:20 (1208 amino acids) has about 64% identity from amino acids 725-1060 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964063.1), about 29% identity from amino acids 7-999 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1), about 29% identity from amino acids 159-999 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965681.1), about 35% identity from amino acids 456-1060 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1), and about 35% identity from amino acids 504-1060 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:22 (1174 amino acids) has about 30% identity from amino acids 662-1000 with a protein from Lactobacillus plantarum that is a cell surface protein precursor (Accession No. NP—784891.1), about 30% identity from amino acids 641-985 with a hypothetical protein from Lactococcus lactis subsp. lactis (Accession No. NP—268337.1), about 30% identity from amino acids 658-1000 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046308.1), about 26% identity from amino acids 672-1000 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965614.1), and about 29% identity from amino acids 636-974 with a protein from Lactobacillus reuteri that is a mucus binding protein precursor (Mub) (Accession No. gb|AAF25576.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:24 (697 amino acids) has about 25% identity from amino acids 135-649 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046316.1), about 24% identity from amino acids 185-681 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965614.1), about 23% identity from amino acids 86-697 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1), about 22% identity from amino acids 185-615 with a protein from Lactobacillus reuteri that is a mucus binding protein precursor (Mub) (Accession No. gb|AAF25576.1), and about 22% identity from amino acids 190-630 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046308.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:26 (2319 amino acids) has about 53% identity from amino acids 10-2010 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964063.1), about 40% identity from amino acids 10-1552 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1), about 49% identity from amino acids 1154-2119 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1), about 33% identity from amino acids 1263-2118 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965818.1), and about 31% identity from amino acids 1270-2112 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:28 (2650 amino acids) has about 36% identity from amino acids 1-2373 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1), about 40% identity from amino acids 310-2086 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964063.1), about 42% identity from amino acids 1702-2463 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1), about 30% identity from amino acids 1504-2513 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965818.1), and about 32% identity from amino acids 1987-2513 with a protein from Bos taurus that is a bovine homologue of human Hr44 (Accession No. emb|CAC16354.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:30 (346 amino acids) has about 33% identity from amino acids 2-204 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046067.1), about 34% identity from amino acids 56-231 with a protein from Lactobacillus reuteri that is a mucus binding protein precursor (Mub) (Accession No. gb|AAF25576.1), about 26% identity from amino acids 1-346 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964510.1), about 24% identity from amino acids 2-344 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964406.1), and about 29% identity from amino acids 2-182 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046945.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:32 (294 amino acids) has about 34% identity from amino acids 6-294 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046131.1), about 29% identity from amino acids 6-293 with a protein from Lactobacillus gasseri that is an RTX toxin and related Ca2+-binding protein (Accession No. ZP—00046947.1), about 29% identity from amino acids 6-293 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046945.1), about 30% identity from amino acids 6-284 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046130.1), and about 30% identity from amino acids 3-279 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964510.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:34 (185 amino acids) has about 42% identity from amino acids 3-179 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964510.1), about 33% identity from amino acids 10-176 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046067.1), about 30% identity from amino acids 10-177 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046946.1), about 30% identity from amino acids 10-177 with a protein from Lactobacillus gasseri that is an RTX toxin and related Ca2+-binding protein (Accession No. ZP—00046947.1), and about 30% identity from amino acids 12-177 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046945.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:36 (508 amino acids) has about 30% identity from amino acids 4-474 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046128.1), about 31% identity from amino acids 9-409 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046781.1), about 30% identity from amino acids 9-362 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964064.), about 29% identity from amino acids 13-399 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046779.1), and about 31% identity from amino acids 13-385 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964062.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:38 (339 amino acids) has about 31% identity from amino acids 79-286 with a protein from Lactobacillus plantarum that is a cell surface protein precursor (Accession No. NP—784891.1), about 32% identity from amino acids 86-285 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965614.1), about 34% identity from amino acids 112-284 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046316.1), about 42% identity from amino acids 178-293 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046308.1), and about 29% identity from amino acids 79-282 with a protein from Lactobacillus fermentum that is an Mlp protein (Accession No. gb|AAP41738.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:40 (76 amino acids) has about 47% identity from amino acids 4-75 with a protein from Lactobacillus plantarum (Accession No. NP—786269.1), about 43% identity from amino acids 2-73 with a protein from Clostridium acetobutylicum that is a HypQ3 protein (Accession No. gb|AAK11585.1), about 43% identity from amino acids 2-73 with a protein from Clostridium acetobutylicum that is homologous to a steroid binding protein (Accession No. NP—149307.1), about 44% identity from amino acids 1-73 with a conserved hypothetical protein from Methanosarcina acetivorans (Accession No. NP—618599.1), and about 42% identity from amino acids 1-73 with a hypothetical protein from Clostridium perfringens (Accession No. NP—563415.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:42 (355 amino acids) has about 26% identity from amino acids 99-340 with a protein from Streptococcus pyogenes that is homologous to a surface exclusion protein (Accession Nos. NP—606538.1; NC—003485), about 26% identity from amino acids 99-340 with a protein from Streptococcus pyogenes that is homologous to a surface exclusion protein (Accession No. NP—664001.1), about 26% identity from amino acids 99-340 with a protein from Streptococcus pyogenes that is homologous to a surface exclusion protein (Accession Nos. NP—268623.1; NC—002737), about 23% identity from amino acids 116-319 with a protein from Enterococcus faecalis that is a surface exclusion protein (seal) precursor (Accession No. pir∥S22452), and about 23% identity from amino acids 116-319 with a protein from Enterococcus faecalis that is a surface exclusion protein (Seal) (Accession No. NP—816976.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:44 (111 amino acids) has about 27% identity from amino acids 1-107 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965479.1), about 27% identity from amino acids 1-102 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046710.1), about 26% identity from amino acids 31-108 with a protein from Salmo trutta that is a cardiac tropomyosin (Accession No. emb|CAA91434.1), about 31% identity from amino acids 31-94 with a hypothetical protein from Homo sapiens (Accession No. NP—653299.2), and about 25% identity from amino acids 33-108 with a protein from Mus musculus that is a testis-expressed gene 9 (Accession Nos. NP—033385.1; NM—009359). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:46 (66 amino acids) has about 58% identity from amino acids 15-62 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1), about 58% identity from amino acids 12-60 with a protein from Lactobacillus gasseri that is a type V secretory pathway adhesin (AidA) (Accession No. ZP—00046948.1), about 61% identity from amino acids 15-53 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964984.1), about 58% identity from amino acids 16-54 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046307.1), and about 63% identity from amino acids 15-52 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965682.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:48 (231 amino acids) has about 44% identity from amino acids 66-231 with a protein from Lactobacillus gasseri that is an Apf1 protein (Accession No. gb|AAO86515.1), about 44% identity from amino acids 66-231 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00047488.1), about 44% identity from amino acids 66-231 with a protein from Lactobacillus johnsonii that is an aggregation promoting factor (Accession No. gb|AAN78451.1), about 40% identity from amino acids 66-231 with a protein from Lactobacillus johnsonii that is a surface protein, aggregation promoting factor (Accession No. NP—965551.1), and about 40% identity from amino acids 66-231 with a protein from Lactobacillus johnsonii that is a surface protein (Apf1) (Accession No. gb|AAN63951.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:50 (120 amino acids) has about 61% identity from amino acids 26-120 with a protein from Lactobacillus plantarum that is an extracellular protein (Accession No. NP—786365.1), about 54% identity from amino acids 14-120 with a protein from Lactobacillus plantarum that is an extracellular protein (Accession No. NP—786209.1), about 52% identity from amino acids 24-120 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00047488.1), about 54% identity from amino acids 24-120 with a protein from Lactobacillus johnsonii that is an aggregation promoting factor (Accession No. gb|AAN78450.1), and about 55% identity from amino acids 26-120 with a protein from Lactobacillus johnsonii that is an aggregation promoting factor (Accession No. gb|AAN64914.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:52 (264 amino acids) has about 27% identity from amino acids 1-94 with a protein from Staphylococcus aureus subsp. aureus that is a ser-asp rich fibrinogen-binding, bone sialoprotein-binding protein (Accession No. NP—373774.1), about 27% identity from amino acids 1-94 with a protein from Staphylococcus aureus subsp. aureus that is a ser-asp rich fibrinogen-binding, bone sialoprotein-binding protein (Accession No. NP—371087.1), and about 27% identity from amino acids 1-94 with a protein from Staphylococcus aureus that is homologous to a fibrinogen-binding protein (Accession No. pir∥T28680). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:54 (991 amino acids) has about 24% identity from amino acids 97-477 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—701725.1), about 22% identity from amino acids 270-510 with a hypothetical protein from Dictyostelium discoideum (Accession No. gb|AAO51593.1), about 23% identity from amino acids 47-452 with a protein from Plasmodium falciparum that is a starp antigen (Accession No. NP—703988.1), about 19% identity from amino acids 13-401 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—704588.1), and about 23% identity from amino acids 44-403 with a protein from Fusobacterium nucleatum subsp. nucleatum that is a hemolysin (Accession No. NP—602617.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:56 (906 amino acids) has about 70% identity from amino acids 1-888 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964984.1), about 24% identity from amino acids 1-760 with a protein from Lactobacillus gasseri that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00046780.1), about 23% identity from amino acids 1-645 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964063.1), about 29% identity from amino acids 1-248 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046645.1), and about 17% identity from amino acids 27-869 with a protein from Staphylococcus epidermidis that is a streptococcal hemagglutinin protein (Accession No. NP—765804.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:58 (566 amino acids) has about 69% identity from amino acids 4-564 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965038.1), about 66% identity from amino acids 4-564 with a protein from Lactobacillus gasseri that is a predicted RNA-binding protein homologous to a eukaryotic snRNP (Accession No. ZP—00045959.1), about 41% identity from amino acids 4-566 with a protein from Enterococcus faecium that is a predicted RNA-binding protein homologous to a eukaryotic snRNP (Accession No. ZP—00037499.1), about 41% identity from amino acids 4-566 with a protein from Enterococcus faecalis that is homologous to a fibronectin/fibrinogen-binding protein (Accession No. NP—814975.1), and about 41% identity from amino acids 4-557 with a protein from Lactobacillus plantarum that is an adherence protein (Accession No. NP—785358.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:60 (444 amino acids) has about 90% identity from amino acids 49-444 with a protein from Lactobacillus acidophilus that is an S-layer protein precursor (Accession No. sp|P35829|SLAP_LACAC), about 67% identity from amino acids 49-443 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession No. emb|CAA62606.1), about 67% identity from amino acids 49-443 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession Nos. emb|CAB46984.1; AJ388558), 66% identity from amino acids 49-443 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession No. emb|CAB46985.1), and 66% identity from amino acids 49-443 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession No. emb|CAB46986.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:62 (457 amino acids) has about 88% identity from amino acids 1-457 with a protein from Lactobacillus acidophilus that is an SB-protein (Accession Nos. CAA61561.1; X89376), about 51% identity from amino acids 1-457 with a protein from Lactobacillus acidophilus that is an s-layer protein precursor (Accession No. sp|P35829|SLAP_LACAC), about 44% identity from amino acids 1-456 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession Nos. emb|CAB46985.1; AJ388559), about 44% identity from amino acids 1-456 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession No. emb|CAA62606.1), and about 44% identity from amino acids 1-456 with a protein from Lactobacillus helveticus that is a surface layer protein (Accession No. emb|CAA63409.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:64 (567 amino acids) has about 35% identity from amino acids 163-311 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession Nos. gb|AAB58734.1; AF001313), about 37% identity from amino acids 182-311 with a protein from Lactobacillus acidophilus that is an SB-protein (Accession Nos. emb|CAA61561.1; X89376), about 34% identity from amino acids 163-304 with a protein from Lactobacillus helveticus that is a proteinase(Accession Nos. dbj|BAB72065.1; AB061775), about 25% identity from amino acids 27-311 with a protein from Lactobacillus acidophilus that is a surface layer protein precursor (Accession No. sp|P35829|SLAP_LACAC), and about 34% identity from amino acids 44-104 with a protein from Homo sapiens that is a myomesin 1 (Accession Nos. NP—003794.1; NM—003803). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:66 (177 amino acids) has about 28% identity from amino acids 13-170 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession No. gb|AAB58734.1), about 26% identity from amino acids 9-170 with a protein from Lactobacillus crispatus that is homologous to a silent surface layer protein (Accession No. gb|AAF68972.1), about 26% identity from amino acids 42-162 with a protein from Clostridium acetobutylicum that is homologous to an enterotoxin (Accession No. NP—347713.1), about 26% identity from amino acids 62-166 with a protein from Lactobacillus gasseri that is a glycerophosphoryl diester phosphodiesterase (Accession No. ZP—00046260.1), and about 25% identity from amino acids 40-162 with a protein from Chromobacterium violaceum that is homologous to an rhs-related protein (Accession No. NP—900908.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:68 (173 amino acids) has about 32% identity from amino acids 68-135 with a protein from Lama glama that is an immunoglobulin heavy chain variable region (Accession No. emb|CAD22470.1), about 33% identity from amino acids 107-171 with a protein from Rattus norvegicus that is homologous to an olfactory receptor-like protein F3 (Accession No. XP—216832.2), about 27% identity from amino acids 71-165 with a protein from Arabidopsis thaliana (Accession No. NP—191860.1), about 29% identity from amino acids 71-160 with an environmental sequence (Accession No. gb|EAD49084.1), and about 26% identity from amino acids 80-157 with a protein from Dictyostelium discoideum (Accession No. gb|AA051562.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:70 (292 amino acids) has about 66% identity from amino acids 2-292 with a protein from Lactobacillus acidophilus that is a surface layer protein (Accession Nos. gb|AAF65561.1; AF250229), about 28% identity from amino acids 8-291 with a protein from Lactobacillus acidophilus that is an S-layer protein precursor (Accession Nos. sp|P35829; SLAP_LACAC), about 42% identity from amino acids 178-291 with a protein from Lactobacillus acidophilus that is an SB-protein (Accession Nos. emb|CAA61561.1; X89376), about 37% identity from amino acids 137-291 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession Nos. gb|AAB58734.1; AF001313), and about 32% identity from amino acids 90-291 with a protein from Lactobacillus crispatus that is homologous to a silent surface layer protein (Accession Nos. gb|AAF68972.1; AF253044). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:72 (216 amino acids) has about 27% identity from amino acids 35-128 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession Nos. gb|AAB58734.1; AF001313), about 27% identity from amino acids 35-128 with a protein from Lactobacillus crispatus that is a silent surface layer protein (Accession No. dbj|BAC76687.1), about 28% identity from amino acids 35-128 with a protein from Lactobacillus crispatus that is homologous to a silent surface layer protein (Accession No. gb|AAF68972.1), about 31% identity from amino acids 41-126 with an environmental sequence (Accession No. gb|EAG77017.1), and about 28% identity from amino acids 45-169 with an environmental sequence (Accession No. gb|EAC33545.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:74 (359 amino acids) has about 27% identity from amino acids 34-228 with a hypothetical protein from Cytophaga hutchinsonii (Accession No. ZP—00118765.1), about 28% identity from amino acids 3-160 with a protein from Lactobacillus crispatus that is a silent surface layer protein (Accession No. dbj|BAC76687.1), about 26% identity from amino acids 98-256 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is a lactocepin (EC 3.4.21.96) precursor (Accession No. pir∥JC6032), about 27% identity from amino acids 4-160 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession No. gb|AAB58734.1), and about 28% identity from amino acids 3-160 with a protein from Lactobacillus crispatus that is homologous to a silent surface layer protein (Accession No. gb|AAF68972.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:76 (1676 amino acids) has about 42% identity from amino acids 926-1528 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965634.1), about 40% identity from amino acids 839-1528 with a protein from Streptococcus pyogenes that is a surface protein R28 (Accession Nos. gb|AAD39085.1; AF091393), about 39% identity from amino acids 839-1528 with a protein from Streptococcus agalactiae that is a surface protein Rib (Accession No. NP—687467.1), about 39% identity from amino acids 839-1528 with a protein from Streptococcus agalactiae that is a rib protein (Accession No. pir∥T28681), and about 33% identity from amino acids 752-1528 with a protein from Enterococcus faecium that is homologous to a surface protein precursor (Accession No. emb|CAD32315.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:78 (1924 amino acids) has about 44% identity from amino acids 921-1796 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965634.1), about 29% identity from amino acids 807-1923 with a protein from Streptococcus pyogenes that is a surface protein R28 (Accession No. gb|AAD39085.1), about 30% identity from amino acids 807-1923 with a protein from Streptococcus agalactiae that is a surface protein Rib (Accession No. NP—687467.1), about 30% identity from amino acids 807-1923 with a protein from Streptococcus agalactiae that is a rib protein (Accession No. pir∥T28681), and about 31% identity from amino acids 984-1812 with a protein from Lactobacillus fermentum that is an Rlp protein (Accession No. gb|AAP41737.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:80 (353 amino acids) has about 22% identity from amino acids 128-344 with a protein from Haemophilus somnus that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00133279.1), about 22% identity from amino acids 128-344 with a protein from Haemophilus somnus that is a large exoprotein involved in heme utilization or adhesion (Accession No. ZP—00133280.1), about 26% identity from amino acids 137-278 with an environmental sequence (Accession No. gb|EAC64082.1), and about 27% identity from amino acids 84-250 with an environmental sequence (Accession No. gb|EAJ12295.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:82 (364 amino acids) has about 46% identity from amino acids 33-222 with a protein from Listeria innocua that is an autolysin, amidase (Accession No. NP—472032.1), about 45% identity from amino acids 49-237 with a protein from Listeria monocytogenes that is an autolysin, amidase (Accession No. gb|AAC46384.1), about 45% identity from amino acids 49-237 with a protein from Listeria monocytogenes that is an autolysin, amidase (Accession No. NP—466081.1), about 45% identity from amino acids 49-237 with a protein from Listeria monocytogenes that is an AMI protein (Accession No. gb|AAC45605.1), and about 39% identity from amino acids 49-299 with a protein from Listeria monocytogenes that is an Ami 4b protein (Accession No. emb|CAC20640.1; AJ276390). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:84 (334 amino acids) has about 87% identity from amino acids 1-333 with a protein from Lactobacillus johnsonii that is a rod shape-determining protein (MreB) (Accession No. NP—964817.1), about 86% identity from amino acids 23-333 with a protein from Lactobacillus gasseri that is an actin-like ATPase involved in cell morphogenesis (Accession No. ZP—00047434.1), about 75% identity from amino acids 1-331 with a protein from Lactobacillus plantarum that is a cell shape determining protein (MreB) (Accession No. NP—785793.1), about 66% identity from amino acids 2-331 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an actin-like ATPase involved in cell morphogenesis (Accession No. ZP—00063690.1), and about 66% identity from amino acids 1-333 with a protein from Listeria innocua that is homologous to a cell-shape determining protein (MreB) (Accession No. NP—470919.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:86 (329 amino acids) has about 86% identity from amino acids 1-329 with a protein from Lactobacillus johnsonii that is an mreB-like protein (Accession No. NP—964798.1), about 86% identity from amino acids 1-329 with a protein from Lactobacillus gasseri that is an actin-like ATPase involved in cell morphogenesis (Accession No. ZP—00046248.1), about 65% identity from amino acids 1-325 with a protein from Lactobacillus plantarum that is a cell shape determining protein (MreB) (Accession No. NP—785826.1), about 65% identity from amino acids 1-328 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an actin-like ATPase involved in cell morphogenesis (Accession No. ZP—00063606.1), and about 64% identity from amino acids 2-328 with a protein from Bacillus anthracis that is an mbl protein (Accession No. NP—847679.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:88 (283 amino acids) has about 64% identity from amino acids 1-281 with a protein from Lactobacillus gasseri that is a cell shape-determining protein (Accession No. ZP—00047435.1), about 63% identity from amino acids 1-281 with a protein from Lactobacillus johnsonii that is a rod shape-determining protein (MreC) (Accession No. NP—964818.1), about 42% identity from amino acids 1-279 with a protein from Lactobacillus plantarum that is a cell-shape determining protein (MreC) (Accession No. NP—785792.1), about 38% identity from amino acids 1-279 with a protein from Enterococcus faecium that is a cell shape-determining protein (Accession No. ZP—00037396.1), and about 41% identity from amino acids 33-281 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a cell shape determining protein (Accession No. ZP—00063689.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:90 (179 amino acids) has about 42% identity from amino acids 1-171 with a protein from Lactobacillus johnsonii that is a rod-shape determining protein (MreD) (Accession No. NP—964819.1), about 39% identity from amino acids 15-171 with a protein from Lactobacillus gasseri that is a cell shape determining protein (Accession No. ZP—00047436.1), about 26% identity from amino acids 6-159 with a protein from Lactobacillus plantarum that is a cell shape determining protein (MreD) (Accession No. NP—785791.1), about 28% identity from amino acids 3-122 with a protein from Oceanobacillus iheyensis that is a cell-shape determining protein (Accession No. NP—692972.1), and about 29% identity from amino acids 11-132 with a protein from Lactococcus lactis subsp. lactis that is a cell shape determining protein (Accession No. NP—268387.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:92 (397 amino acids) has about 61% identity from amino acids 1-397 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964801.1), about 60% identity from amino acids 1-397 with a protein from Lactobacillus gasseri that is a cell division membrane protein (Accession No. ZP—00046251.1), about 50% identity from amino acids 13-392 with a protein from Lactobacillus plantarum that is a rod shape-determining protein (Accession No. NP—785823.1), about 41% identity from amino acids 5-384 with a protein from Enterococcus faecalis that is a cell division protein in the FtsW/RodA/SpoVE family (Accession Nos. NP—816148.1), and about 41% identity from amino acids 16-368 with a protein from Lactobacillus plantarum that is a rod-shape determining protein (Accession No. NP—785596.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:94 (437 amino acids) has about 91% identity from amino acids 1-437 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramate-alanine ligase (Accession No. ZP—00046723.1), about 91% identity from amino acids 1-437 with a protein from Lactobacillus johnsonii that is a UDP-N-acetyl muramate-alanine ligase (Accession No. NP—965470.1), about 56% identity from amino acids 2-434 with a protein from Lactobacillus plantarum that is a UDP-N-acetylmuramate-alanine ligase (Accession No. NP—785073.1), about 56% identity from amino acids 5-437 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a UDP-N-acetylmuramate-alanine ligase (Accession No. ZP—00064100.1), and about 51% identity from amino acids 4-437 with a protein from Enterococcus faecalis that is a UDP-N-acetylmuramate-alanine ligase (Accession No. NP—815590.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:96 (452 amino acids) has about 87% identity from amino acids 3-452 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramyl tripeptide synthase (Accession No. ZP—00046234.1), about 86% identity from amino acids 3-452 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964783.1), about 55% identity from amino acids 3-452 with a protein from Lactobacillus plantarum that is homologous to a UDP-N-acetylmuramyl tripeptide synthase (Accession No. NP—785844.1), about 50% identity from amino acids 3-452 with a protein from Enterococcus faecalis that is a mur ligase family protein (Accession No. NP—816226.1), and about 51% identity from amino acids 3-451 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a UDP-N-acetylmuramyl tripeptide synthase (Accession No. ZP—00063654.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:98 (532 amino acids) has about 83% identity from amino acids 11-528 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylmuramoyl-L-alanyl-D-glutamate-lysine ligase (Accession No. NP—965690.1), about 83% identity from amino acids 11-528 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramyl tripeptide synthase (Accession No. ZP—00046637.1), about 44% identity from amino acids 10-524 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a UDP-N-acetylmuramyl tripeptide synthase (Accession No. ZP—00062837.1), about 43% identity from amino acids 24-522 with a protein from Enterococcus faecium that is a UDP-N-acetylmuramyl tripeptide synthase (Accession No. ZP—00036035.1), and about 42% identity from amino acids 10-522 with a protein from Enterococcus faecalis that is homologous to a UDP-N-acetylmuramoylalanyl-D-glutamate-2,6-diaminopimelate ligase (Accession No. NP—814420.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:100 (459 amino acids) has about 78% identity from amino acids 1-459 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylmuramoylalanine-D-glutamate ligase (Accession No. NP—964826.1), about 80% identity from amino acids 89-459 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramoylalanine-D-glutamate ligase (Accession No. ZP—00046265.1), about 49% identity from amino acids 1-456 with a protein from Bacillus anthracis that is a UDP-N-acetylmuramoylalanine-D-glutamate ligase (Accession No. NP—846291.1), about 49% identity from amino acids 1-456 with a protein from Bacillus cereus that is a UDP-N-acetylmuramoylalanine-D-glutamate ligase (Accession No. NP—980253.1), and about 49% identity from amino acids 1-456 with a protein from Bacillus cereus that is a UDP-N-acetylmuramoylalanine-D-glutamate ligase (Accession No. NP—833632.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:102 (368 amino acids) has about 79% identity from amino acids 1-364 with a protein from Lactobacillus gasseri that is a UDP-N-acetylglucosamine:LPS N-acetylglucosamine transferase (Accession No. ZP—00046266.1), about 78% identity from amino acids 1-366 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylglucosamine-N-acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (Accession No. NP—964827.1), about 49% identity from amino acids 1-366 with a protein from Lactobacillus plantarum that is a UDP-N-acetylglucosamine-N-acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (Accession No. NP—785692.1), about 46% identity from amino acids 1-368 with a protein from Bacillus halodurans that is a UDP-N-acetylglucosamine-N-acetylmuramyl-(pentapeptide) pyrophos (Accession No. NP—243431.1), and about 47% identity from amino acids 1-366 with a protein from Enterococcus hirae that is a UDP-N-acetylglucosamine-N-acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (Accession No. sp|O076701|MURG_ENTHR). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:104 (322 amino acids) has about 67% identity from amino acids 4-322 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramyl pentapeptide phosphotransferase/UDP-N-acetylglucosamine-1-phosphate transferase (Accession No. ZP—00047442.1), about 67% identity from amino acids 4-322 with a protein from Lactobacillus johnsonii that is a phospho-N-acetylmuramoyl-pentapeptide-transferase (Accession No. NP—964825.1), about 49% identity from amino acids 11-319 with a protein from Lactobacillus plantarum that is a phospho-N-acetylmuramoyl-pentapeptide-transferase (Accession No. NP—785694.1), about 47% identity from amino acids 9-320 with a protein from Enterococcus faecium that is a UDP-N-acetylmuramyl pentapeptide phosphotransferase/UDP-N-acetylglucosamine-1-phosphate transferase (Accession No. ZP—00037828.1), and about 47% identity from amino acids 9-320 with a protein from Enterococcus faecalis that is a phospho-N-acetylmuramoyl-pentapeptide-transferase (Accession No. NP—814728.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:106 (215 amino acids) has about 54% identity from amino acids 15-214 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965527.1), about 54% identity from amino acids 15-214 with a protein from Lactobacillus gasseri that is a muramidase (flagellum-specific) (Accession No. ZP—00046365.1), about 42% identity from amino acids 1-215 with a protein from Listeria monocytogenes that is homologous to an N-acetylmuramoyl-L-alanine amidase (autolysin) (Accession No. NP—464740.1), about 42% identity from amino acids 1-215 with a protein from Listeria innocua that is homologous to an N-acetylmuramoyl-L-alanine amidase (autolysin) (Accession Nos. NP—470515.1; NC—003212), and about 53% identity from amino acids 71-215 with a protein from Lactococcus lactis subsp. lactis that is an N-acetylmuramidase (Accession No. NP—267521.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:108 (409 amino acids) has about 43% identity from amino acids 1-262 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964171.1), about 39% identity from amino acids 26-257 with a protein from Listeria monocytogenes that is homologous to an autolysin (EC 3.5.1.28) (N-acetylmuramoyl-L-alanine amidase) (Accession No. NP—464601.1), about 38% identity from amino acids 16-236 with a protein from Listeria innocua that is homologous to an autolysin, N-acetylmuramidase (Accession No. NP—472166.1), about 34% identity from amino acids 16-274 with a protein from Listeria monocytogenes that is homologous to an autolysin, N-acetylmuramidase (Accession No. NP—466213.1), and about 39% identity from amino acids 40-222 with a protein from Enterococcus faecium that is homologous to a glycosidase (GlyA) (Accession No. gb|AAK72496.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:110 (153 amino acids) has about 47% identity from amino acids 105-152 with a protein from Oenococcus oeni that is a muramidase (flagellum-specific) (Accession No. ZP—00069384.1), about 53% identity from amino acids 108-150 with a protein from Bacillus subtilis that is an N-acetylmuramoyl-L-alanine amidase (Accession Nos. NP—389164.1; NC—000964), about 48% identity from amino acids 104-150 with a hypothetical protein from Chloroflexus aurantiacus (Accession No. ZP—00019741.1), about 54% identity from amino acids 107-152 with a protein from Deinococcus radiodurans that is homologous to a cell wall protein (Accession No. NP—294634.1), and about 47% identity from amino acids 109-152 with a protein from Lactococcus lactis subsp. lactis that is an N-acetylmuramidase (Accession No. NP—266697.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:112 (360 amino acids) has about 71% identity from amino acids 1-360 with a protein from Lactobacillus gasseri that is a D-alanine-D-alanine ligase and related ATP-grasp enzyme (Accession No. ZP—00047036.1), about 71% identity from amino acids 1-360 with a protein from Lactobacillus johnsonii that is a D-alanine-D-alanine ligase (Accession No. NP—964124.1), about 41% identity from amino acids 3-348 with a protein from Escherichia coli that is a D-alanine-D-alanine ligase A (Accession No. NP—308458.1), about 41% identity from amino acids 3-348 with a protein from Escherichia coli that is a D-alanine-D-alanine ligase A (Accession Nos. NP—752421.1), and about 39% identity from amino acids 4-348 with a protein from Oceanobacillus iheyensis that is a D-alanine-D-alanine ligase A (Accession No. NP—692227.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:114 (327 amino acids) has about 41% identity from amino acids 29-326 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965730.1), about 43% identity from amino acids 79-326 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046598.1), about 43% identity from amino acids 58-165 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046597.1), and about 38% identity from amino acids 141-187 with a protein from Clostridium perfringens that is homologous to a cell division protein (Accession No. NP—561266.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:116 (455 amino acids) has about 77% identity from amino acids 1-454 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylmuramoylalanyl-D-glutamyl-2,6-diaminopimelate-D-alanyl-D-alanyl ligase (Accession No. NP—964286.1), about 79% identity from amino acids 150-454 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramyl pentapeptide synthase (Accession No. ZP—00047007.1), about 54% identity from amino acids 1-454 with a protein from Lactobacillus plantarum that is a UDP-N-acetylmuramoylalanyl-D-glutamyl-2,6-diaminopimelate-D-alanyl-D-alanine ligase (Accession No. NP—784298.1), about 46% identity from amino acids 1-454 with a protein from Enterococcus faecalis that is a UDP-N-acetylmuramoylalanyl-D-glutamyl-2,6-diaminopimelate-D-alanyl-D-alanyl ligase (Accession No. NP—814587.1), and about 43% identity from amino acids 1-454 with a protein from Streptococcus pyogenes that is homologous to a D-Ala-D-Ala adding enzyme (Accession No. NP—269511.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:118 (432 amino acids) has about 40% identity from amino acids 1-426 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—786467.1), about 51% identity from amino acids 37-317 with a protein from Lactobacillus johnsonii that is a D-alanyl-D-alanine carboxypeptidase (Accession No. NP—964537.1), about 49% identity from amino acids 37-317 with a protein from Lactobacillus gasseri that is a D-alanyl-D-alanine carboxypeptidase (Accession No. ZP—00047293.1), about 38% identity from amino acids 5-430 with a protein from Bacillus subtilis that is a D-alanyl-D-alanine carboxypeptidase (penicillin-binding protein 5) (Accession No. NP—387891.1), and about 40% identity from amino acids 56-430 with a protein from Bacillus subtilis that is a penicillin binding protein 5 (Accession No. gb|AAA22375.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:120 (441 amino acids) has about 88% identity from amino acids 11-430 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1 (Accession No. NP—964240.1), about 90% identity from amino acids 1-382 with a protein from Lactobacillus gasseri that is a UDP-N-acetylglucosamine enolpyruvyl transferase (Accession No. ZP—00047072.1), about 64% identity from amino acids 11-435 with a protein from Lactobacillus plantarum that is a UDP-N-acetylglucosamine 1-carboxyvinyltransferase (Accession No. NP—784290.1), about 62% identity from amino acids 11-429 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a UDP-N-acetylglucosamine enolpyruvyl transferase (Accession No. ZP—00063218.1), and about 58% identity from amino acids 11-436 with a protein from Enterococcus faecalis that is a UDP-N-acetylglucosamine 1-carboxyvinyltransferase 2 (Accession No. NP—814899.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:122 (459 amino acids) has about 82% identity from amino acids 1-459 with a protein from Lactobacillus johnsonii that is a UDP-N-acetylglucosamine-1-phosphate uridyltransferase (Accession No. NP—964224.1), about 81% identity from amino acids 1-459 with a protein from Lactobacillus gasseri that is an N-acetylglucosamine-1-phosphate uridyltransferase (Accession No. ZP—00047088.1), about 62% identity from amino acids 3-453 with a protein from Lactobacillus plantarum that is a UDP-N-acetylglucosamine pyrophosphorylase (Accession No. NP—784257.1), about 61% identity from amino acids 3-457 with a protein from Enterococcus faecalis that is a UDP-N-acetylglucosamine pyrophosphorylase (Accession No. NP—813869.1), and about 56% identity from amino acids 1-453 with a protein from Streptococcus agalactiae that is a UDP-N-acetylglucosamine pyrophosphorylase (Accession No. NP—688532.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:124 (244 amino acids) has about 69% identity from amino acids 1-239 with a protein from Lactobacillus johnsonii that is an undecaprenyl pyrophosphate synthetase (Accession No. NP—965298.1), about 68% identity from amino acids 1-239 with a protein from Lactobacillus gasseri that is an undecaprenyl pyrophosphate synthase (Accession No. ZP—00046589.1), about 57% identity from amino acids 10-242 with a protein from Oenococcus oeni that is an undecaprenyl pyrophosphate synthase (Accession No. ZP—00070158.1), about 59% identity from amino acids 10-237 with a protein from Listeria innocua that is homologous to an undecaprenyl diphosphate synthase (Accession No. NP—470688.1), and about 56% identity from amino acids 10-242 with a protein from Enterococcus faecalis that is an undecaprenyl diphosphate synthase (Accession No. NP—816141.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:126 (389 amino acids) has about 72% identity from amino acids 1-377 with a protein from Lactobacillus gasseri that is a UDP-N-acetylmuramyl pentapeptide phosphotransferase/UDP-N-acetylglucosamine-1-phosphate transferase (Accession No. ZP—00046896.1), about 72% identity from amino acids 1-377 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964696.1), about 72% identity from amino acids 1-375 with a protein from Lactobacillus delbrueckii that is an RgpG protein (Accession No. gb|AAK00329.1), about 54% identity from amino acids 2-355 with a protein from Lactobacillus plantarum that is an undecaprenyl-phosphate N-acetyl-glucosaminyl transferase (Accession No. NP—784485.1), and about 51% identity from amino acids 1-358 with a protein from Enterococcus faecalis that is a glycosyl transferase, group 4 family protein (Accession No. NP—815860.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:128 (313 amino acids) has about 38% identity from amino acids 51-311 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965759.1), about 38% identity from amino acids 51-311 with a protein from Lactobacillus gasseri that is in the beta-lactamase class C and other penicillin binding protein family (Accession No. ZP—00046847.1), about 31% identity from amino acids 30-296 with a protein from Enterococcus faecalis that is homologous to a penicillin-binding protein (Accession No. NP—814494.1), about 31% identity from amino acids 12-290 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—785548.1), and about 33% identity from amino acids 38-289 with a protein from Enterococcus faecium that is in the beta-lactamase class C and other penicillin binding protein family (Accession No. ZP—00035472.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:130 (374 amino acids) has about 51% identity from amino acids 49-304 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is a conserved hypothetical penicillin-binding protein (Accession No. gb|AAM22482.1), about 30% identity from amino acids 67-362 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—784838.1), about 24% identity from amino acids 46-371 with a protein from Streptococcus agalactiae (Accession No. NP—735091.1), about 24% identity from amino acids 46-371 with a protein from Streptococcus agalactiae that is homologous to a lipoprotein (Accession No. NP—687676.1), and about 27% identity from amino acids 48-346 with a protein from Enterococcus faecalis that is homologous to a penicillin-binding protein (Accession No. NP—814494.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:132 (702 amino acids) has about 69% identity from amino acids 1-699 with a protein from Lactobacillus johnsonii that is a penicillin-binding protein 2B (Accession No. NP—965426.1), about 71% identity from amino acids 22-699 with a protein from Lactobacillus gasseri that is a cell division protein FtsI/penicillin-binding protein 2 (Accession No. ZP—00046928.1), about 44% identity from amino acids 1-700 with a protein from Lactobacillus plantarum that is a penicillin binding protein 2B (Accession No. NP—785166.1), about 39% identity from amino acids 19-699 with a protein from Enterococcus faecalis that is a penicillin-binding protein 2B (Accession No. NP—816479.1), and about 37% identity from amino acids 12-702 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a cell division protein FtsI/penicillin-binding protein 2 (Accession No. ZP—00063639.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:134 (704 amino acids) has about 75% identity from amino acids 34-704 with a protein from Lactobacillus johnsonii that is a penicillin-binding protein IF (Accession No. NP—965485.1), about 74% identity from amino acids 34-704 with a protein from Lactobacillus gasseri that is a membrane carboxypeptidase (penicillin-binding protein) (Accession No. ZP—00046704.1), about 53% identity from amino acids 34-703 with a protein from Lactobacillus plantarum that is a penicillin-binding protein 2a (Accession No. NP—785034.1), about 47% identity from amino acids 24-699 with a protein from Enterococcus faecalis that is a penicillin-binding protein 2a (Accession No. NP—814430.1), and about 47% identity from amino acids 61-704 with a protein from Listeria monocytogenes that is homologous to a penicillin-binding protein (Accession No. NP—465753.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:136 (343 amino acids) has about 68% identity from amino acids 26-337 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965496.1), about 67% identity from amino acids 26-338 with a protein from Lactobacillus gasseri that is in the beta-lactamase class C and other penicillin binding protein family (Accession No. ZP—00046698.1), about 67% identity from amino acids 27-178 with a protein from Lactobacillus reuteri that is homologous to a penicillin-binding protein class C fmt-like protein (Accession No. gb|AAP97059.1), about 29% identity from amino acids 27-343 with a protein from Streptococcus mutans that is homologous to a penicillin-binding protein class C, fmt-like protein (Accession No. NP—721297.1), and about 30% identity from amino acids 39-323 with a protein from Streptococcus agalactiae that is homologous to a lipoprotein (Accession No. NP—687676.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:138 (776 amino acids) has about 71% identity from amino acids 1-679 with a protein from Lactobacillus gasseri that is a membrane carboxypeptidase (penicillin-binding protein) (Accession No. ZP—00045945.1), about 71% identity from amino acids 1-680 with a protein from Lactobacillus johnsonii that is a penicillin binding protein 1A (Accession No. NP—965052.1), about 45% identity from amino acids 19-688 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a membrane carboxypeptidase (penicillin-binding protein) (Accession No. ZP—00064357.1), about 45% identity from amino acids 1-688 with a protein from Lactobacillus plantarum that is a penicillin-binding protein 1 a (Accession No. NP—785323.1), and about 45% identity from amino acids 20-651 with a protein from Enterococcus faecium that is a membrane carboxypeptidase (penicillin-binding protein) (Accession No. ZP—00035508.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:140 (218 amino acids) has about 72% identity from amino acids 7-217 with a protein from Lactobacillus gasseri that is a penicillin-binding protein-related factor A that is homologous to a recombinase (Accession No. ZP—00045946.1), about 74% identity from amino acids 7-212 with a protein from Lactobacillus johnsonii that is a recombination protein (RecU) (Accession No. NP—965051.1), about 53% identity from amino acids 7-213 with a protein from Enterococcus hirae that is a penicillin binding protein-related factor A (Accession No. emb|CAC21567.1), about 57% identity from amino acids 7-212 with a protein from Lactobacillus plantarum that is a recombination protein (RecU) (Accession No. NP—785324.1), and about 52% identity from amino acids 7-213 with a protein from Enterococcus faecium that is a penicillin-binding protein-related factor A that is homologous to a recombinase (Accession No. ZP—00035507.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:142 (364 amino acids) has about 46% identity from amino acids 48-290 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is a conserved hypothetical penicillin binding protein (Accession No. gb|AAM22482.1), about 30% identity from amino acids 37-337 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—784838.1), about 27% identity from amino acids 19-336 with a protein from Enterococcus faecalis that is homologous to a penicillin-binding protein (Accession No. NP—814494.1), about 31% identity from amino acids 78-299 with a protein from Streptococcus mutans that is homologous to a penicillin-binding protein class C, fmt-like protein (Accession No. NP—721297.1), and about 27% identity from amino acids 48-336 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—785548.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:144 (369 amino acids) has about 46% identity from amino acids 46-299 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is a conserved hypothetical penicillin binding protein (Accession No. gb|AAM22482.1), about 30% identity from amino acids 16-350 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—784838.1), about 29% identity from amino acids 26-362 with a protein from Staphylococcus aureus subsp. aureus that is an autolysis and methicillin resistant-related protein (Accession No. NP—371581.1), about 28% identity from amino acids 22-304 with a protein from Staphylococcus epidermidis that is an autolysis and methicillin resistant-related protein (Accession No. NP—764309.1), and about 28% identity from amino acids 16-341 with a protein from Lactobacillus plantarum that is a serine-type D-Ala-D-Ala carboxypeptidase (Accession No. NP—785548.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:146 (720 amino acids) has about 60% identity from amino acids 14-719 with a protein from Lactobacillus gasseri that is a cell division protein FtsI/penicillin-binding protein 2 (Accession No. ZP—00047441.1), about 60% identity from amino acids 14-719 with a protein from Lactobacillus johnsonii that is a penicillin-binding protein 2B (Accession No. NP—964824.1), about 43% identity from amino acids 42-719 with a protein from Lactobacillus plantarum that is a penicillin-binding protein 2B (Accession No. NP—785695.1), about 39% identity from amino acids 42-718 with a protein from Listeria innocua that is homologous to a penicillin-binding protein 2B (Accession No. NP—471479.1), and about 38% identity from amino acids 42-718 with a protein from Listeria monocytogenes that is homologous to a penicillin-binding protein 2B (Accession No. NP—465563.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:148 (504 amino acids) has about 74% identity from amino acids 1-503 with a protein from Lactobacillus johnsonii that is a D-alanine-activating enzyme (Accession No. NP—965763.1), about 73% identity from amino acids 1-503 with a protein from Lactobacillus gasseri that is in the non-ribosomal peptide synthetase module and related protein family (Accession No. ZP—00046843.1), about 53% identity from amino acids 1-503 with a protein from Lactobacillus plantarum that is a D-alanine-activating enzyme (DltA) (Accession No. NP—785546.1), about 51% identity from amino acids 1-503 with a protein from Lactobacillus rhamnosus that is a D-alanine-poly (phosphoribitol) ligase subunit I (D-alanine-activating enzyme) (Accession No. sp|P35854|DLTA_LACRH), and about 49% identity from amino acids 1-504 with a protein from Streptococcus agalactiae that is a D-alanine-activating enzyme (Accession No. NP—688780.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:150 (412 amino acids) has about 70% identity from amino acids 6-412 with a protein from Lactobacillus gasseri that is a predicted membrane protein involved in D-alanine export (Accession No. ZP—00046844.1), about 70% identity from amino acids 6-412 with a protein from Lactobacillus johnsonii that is a DltB protein (Accession No. NP—965762.1), about 58% identity from amino acids 6-410 with a protein from Lactobacillus plantarum that is a D-alanyl transfer protein (DltB) (Accession No. NP—785545.1), about 55% identity from amino acids 4-409 with a protein from Enterococcus faecalis that is a basic membrane protein (DltB) (Accession No. NP—816377.1), and about 51% identity from amino acids 6-409 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a predicted membrane protein involved in D-alanine export (Accession No. ZP—00064054.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:152 (79 amino acids) has about 81% identity from amino acids 1-79 with a protein from Lactobacillus johnsonii that is a D-alanyl carrier protein (Accession No. NP—965761.1), about 79% identity from amino acids 1-79 with a protein from Lactobacillus gasseri that is an acyl carrier protein (Accession No. ZP—00046845.1), about 63% identity from amino acids 1-73 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an acyl carrier protein (Accession No. ZP—00064053.1), about 67% identity from amino acids 2-77 with a protein from Lactobacillus plantarum that is a D-alanyl carrier protein (DltC) (Accession No. NP—785544.1), and about 64% identity from amino acids 2-77 with a protein from Lactobacillus plantarum that is a D-alanyl carrier protein (DltC) (Accession No. NP—785028.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:154 (428 amino acids) has about 58% identity from amino acids 1-428 with a protein from Lactobacillus johnsonii that is a DltD precursor (Accession No. NP—965760.1), about 58% identity from amino acids 1-428 with a protein from Lactobacillus gasseri that is a protein involved in D-alanine esterification of lipoteichoic acid and wall teichoic acid (D-alanine transfer protein) (Accession No. ZP—00046846.1), about 50% identity from amino acids 1-409 with a protein from Lactobacillus plantarum that is a D-alanyl transfer protein DltD (Accession No. NP—785543.1), about 46% identity from amino acids 1-410 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a protein involved in D-alanine esterification of lipoteichoic acid and wall teichoic acid (D-alanine transfer protein) (Accession No. ZP—00064052.1), and about 45% identity from amino acids 5-408 with a protein from Streptococcus mutans that is homologous to an extramembranal protein (DltD) (Accession No. NP—722019.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:156 (477 amino acids) has about 74% identity from amino acids 1-473 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964890.1), about 74% identity from amino acids 1-474 with a protein from Lactobacillus gasseri that is a membrane protein involved in the export of O-antigen and teichoic acid (Accession No. ZP—00045854.1), about 46% identity from amino acids 1-470 with a protein from Streptococcus thermophilus that is a cpsU protein (Accession No. gb|AAM93406.1), about 46% identity from amino acids 1-470 with a protein from Streptococcus thermophilus that is an EpsI protein (Accession No. gb|AAK61904.1), and about 46% identity from amino acids 1-470 with a protein from Streptococcus thermophilus that is an EpsU protein (Accession No. emb|CAB52225.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:158 (174 amino acids) has about 83% identity from amino acids 1-174 with a protein from Lactobacillus gasseri that is a UDP-galactopyranose mutase (Accession No. ZP—00045853.1), about 83% identity from amino acids 1-172 with a protein from Lactobacillus johnsonii that is a UDP-galactopyranose mutase (Accession No. NP—964888.1), about 74% identity from amino acids 1-169 with a protein from Lactobacillus plantarum that is a UDP-galactopyranose mutase (Accession No. NP—784842.1), about 69% identity from amino acids 1-172 with a protein from Lactobacillus plantarum that is a UDP-galactopyranose mutase (Accession No. NP—784882.1), and about 63% identity from amino acids 1-172 with a protein from Streptococcus thermophilus that is an EpsJ protein (Accession No. gb|AAK61905.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:160 (133 amino acids) has about 88% identity from amino acids 2-133 with a protein from Lactobacillus johnsonii that is a UDP-galactopyranose mutase (Accession No. NP—964888.1), about 79% identity from amino acids 4-133 with a protein from Lactobacillus plantarum that is a UDP-galactopyranose mutase (Accession No. NP—784842.1), about 78% identity from amino acids 4-133 with a protein from Lactobacillus plantarum that is a UDP-galactopyranose mutase (Accession No. NP—784882.1), about 73% identity from amino acids 1-133 with a protein from Streptococcus pneumoniae that is a Glf-like protein (Accession No. gb|AAL68431.1), and about 70% identity from amino acids 1-133 with a protein from Streptococcus thermophilus that is an EpsJ protein (Accession No. gb|AAK61905.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:162 (431 amino acids) has about 22% identity from amino acids 1-375 with a protein from Streptococcus pneumoniae that is homologous to a polysaccharide polymerase (Accession No. gb|AAC44966.1), about 22% identity from amino acids 1-368 with a protein from Streptococcus pneumoniae that is a polysaccharide polymerase (Cps19aI) (Accession No. gb|AAC78671.1), about 24% identity from amino acids 4-376 with a protein from Streptococcus pneumoniae that is a Wzy protein (Accession No. gb|AAK20689.1), about 24% identity from amino acids 4-376 with a protein from Streptococcus pneumoniae that is homologous to a polysaccharide polymerase (Cps6aI) (Accession No. gb|AAL68424.1), and about 24% identity from amino acids 4-376 with a protein from Streptococcus pneumoniae that is homologous to a polysaccharide polymerase (Cps6aI) (Accession No. gb|AAL82786.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:164 (346 amino acids) has about 35% identity from amino acids 35-251 with a protein from Streptococcus pneumoniae that is a glycosyltransferase (Accession Nos. emb|CAAO7401.1; AJ006986), about 32% identity from amino acids 36-305 with a protein from Streptococcus pneumoniae that is homologous to a glycosyltransferase (Accession Nos. emb|CAB59291.1; AJ131984), about 33% identity from amino acids 4-272 with a protein from Clostridium acetobutylicum that is a glycosyltransferase involved in cell wall biogenesis (Accession Nos. NP—348116.1; NC—003030), about 31% identity from amino acids 4-254 with a protein from Bifidobacterium longum that is homologous to a glycosyltransferase (Accession No. NP—695639.1), and about 31% identity from amino acids 4-254 with a protein from Bifidobacterium longum that is a glycosyltransferase involved in cell wall biogenesis (Accession No. ZP—00120907.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:166 (218 amino acids) has about 29% identity from amino acids 8-151 with an environmental sequence (Accession No. gb|EAF15712.1), about 26% identity from amino acids 38-139 with a hypothetical protein from Helicobacter hepaticus (Accession No. NP—860377.1), about 24% identity from amino acids 13-166 with an environmental sequence (Accession No. gb|EAB88932.1), about 27% identity from amino acids 51-155 with an environmental sequence (Accession No. gb|EAD88260.1), and about 24% identity from amino acids 2-167 with an environmental sequence (Accession No. gb|EAF01752.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:168 (173 amino acids) has about 29% identity from amino acids 30-108 with an environmental sequence (Accession No. gb|EAJ18143.1), about 29% identity from amino acids 30-108 with an environmental sequence (Accession No. gb|EAK67508.1), about 23% identity from amino acids 8-134 with an environmental sequence (Accession No. gb|EAD63991.1), about 23% identity from amino acids 38-173 with a protein from Arabidopsis thaliana that is an F-box family protein (Accession No. NP—178986.1), and about 25% identity from amino acids 47-155 with a protein from Photorhabdus luminescens subsp. laumondii that is a maltodextrin phosphorylase (Accession No. NP—927823.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:170 (293 amino acids) has about 39% identity from amino acids 3-293 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964886.1), about 38% identity from amino acids 5-293 with a protein from Oenococcus oeni that is homologous to a glycosyltransferase (Accession No. ZP—00069921.1), about 36% identity from amino acids 3-290 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is homologous to a glycosyltransferase (Accession No. ZP—00064030.1), about 33% identity from amino acids 4-292 with a protein from Thermoanaerobacterium thermosaccharolyticum that is homologous to a glycosyltransferase (Accession No. gb|AAR85515.1), and about 32% identity from amino acids 4-265 with a hypothetical protein from Pyrococcus horikoshii (Accession No. NP—142407.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:172 (257 amino acids) has about 75% identity from amino acids 1-257 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964882.1), about 49% identity from amino acids 1-257 with a protein from Lactobacillus plantarum that is a polysaccharide biosynthesis protein (Accession No. NP—784889.1), about 51% identity from amino acids 1-249 with a protein from Lactobacillus plantarum that is a glycosyltransferase (Accession No. NP—784846.1), about 44% identity from amino acids 1-249 with a hypothetical protein from Oenococcus oeni (Accession No. ZP—00069922.1), and about 46% identity from amino acids 2-228 with a protein from Streptococcus thermophilus that is an EpsF protein (Accession No. gb|AAK61900.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:174 (217 amino acids) has about 73% identity from amino acids 1-217 with a protein from Lactobacillus gasseri that is a sugar transferase involved in lipopolysaccharide synthesis (Accession No. ZP—00045843.1), about 71% identity from amino acids 1-217 with a protein from Lactobacillus johnsonii that is an undecaprenyl-phosphate galactosephosphotransferase (Accession No. NP—964881.1), about 70% identity from amino acids 9-215 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is a phospho-glucosyltransferase (EpsE) (Accession No. gb|AAG44709.1), about 66% identity from amino acids 18-217 with a protein from Lactobacillus rhamnosus that is homologous to an undecaprenyl-phosphate glycosyl-1-phosphate transferase (Accession No. gb|AAK63832.1), and about 60% identity from amino acids 7-217 with a protein from Lactobacillus plantarum that is priming glycosyltransferase (Accession No. NP—784894.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:176 (256 amino acids) has about 68% identity from amino acids 1-255 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is an EpsD protein (Accession Nos. gb|AAG44708.1; AF267127), about 67% identity from amino acids 1-256 with a protein from Lactobacillus gasseri that is a capsular polysaccharide biosynthesis protein (Accession No. ZP—00045842.1), about 66% identity from amino acids 1-256 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964880.1), about 57% identity from amino acids 3-250 with a protein from Lactobacillus rhamnosus that is an EpsB protein (Accession No. gb|AAK64289.1), and about 45% identity from amino acids 3-256 with a protein from Lactobacillus plantarum that is an exopolysaccharide biosynthesis protein (Accession No. NP—784865.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:178 (260 amino acids) has about 66% identity from amino acids 5-225 with a protein from Lactobacillus johnsonii that is homologous to a tyrosine-protein kinase (Accession No. NP—964879.1), about 65% identity from amino acids 5-225 with a protein from Lactobacillus gasseri that is an ATPase involved in chromosome partitioning (Accession No. ZP—00045840.1), about 57% identity from amino acids 1-228 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is an EpsC protein (Accession No. gb|AAG44707.1), about 51% identity from amino acids 1-226 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an ATPase involved in chromosome partitioning (Accession No. ZP—00063784.1), and about 46% identity from amino acids 5-230 with a protein from Oceanobacillus iheyensis that is a capsular polysaccharide biosynthesis protein (Accession No. NP—693822.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:180 (291 amino acids) has about 51% identity from amino acids 1-288 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964878.1), about 50% identity from amino acids 2-289 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is an EpsB protein (Accession No. gb|AAG44706.1), about 51% identity from amino acids 74-291 with a protein from Lactobacillus gasseri that is a capsular polysaccharide biosynthesis protein (Accession No. ZP—00045839.1), about 35% identity from amino acids 9-279 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a capsular polysaccharide biosynthesis protein (Accession No. ZP—00063785.1), and about 31% identity from amino acids 8-284 with a protein from Lactobacillus plantarum that is an exopolysaccharide biosynthesis protein (Accession No. NP—784863.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:182 (351 amino acids) has about 52% identity from amino acids 45-340 with a protein from Lactobacillus delbrueckii subsp. bulgaricus that is an EpsA protein (Accession Nos. gb|AAG44705.1; AF267127), about 51% identity from amino acids 26-335 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964877.1), about 43% identity from amino acids 58-335 with a protein from Lactobacillus plantarum that is a transcription regulator (Accession No. NP—784704.1), about 37% identity from amino acids 59-335 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a transcriptional regulator (Accession No. ZP—00063495.1), and about 37% identity from amino acids 26-335 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a transcriptional regulator (Accession No. ZP—00063643.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:184 (421 amino acids) has about 76% identity from amino acids 1-417 with a protein from Lactobacillus gasseri that is a GTPase (Accession No. ZP—00046671.1), about 76% identity from amino acids 1-417 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965656.1), about 51% identity from amino acids 10-421 with a protein from Listeria monocytogenes that is homologous to an ATP/GTP-binding protein (Accession No. NP—464289.1), about 51% identity from amino acids 13-421 with a protein from Listeria innocua that is homologous to an ATP/GTP-binding protein (Accession No. NP—470098.1), and about 48% identity from amino acids 4-421 with a protein from Lactobacillus plantarum that is a GTPase (Accession No. NP—784620.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:186 (336 amino acids) has about 41% identity from amino acids 25-331 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964123.1), about 39% identity from amino acids 2-331 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00047037.1), about 20% identity from amino acids 6-310 with a hypothetical protein from Clostridium thermocellum (Accession No. ZP—00059706.1), about 45% identity from amino acids 162-194 with an environmental sequence (Accession No. gb|EAD87497.1), and about 24% identity from amino acids 215-324 with an environmental sequence (Accession No. gb|EAB36127.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:188 (1382 amino acids) has about 24% identity from amino acids 132-1035 with a hypothetical protein from Enterococcus faecalis (Accession No. NP—815907.1), about 27% identity from amino acids 456-931 with a protein from Lactobacillus plantarum that is homologous to a cell surface protein (Accession No. NP—786384.1), about 31% identity from amino acids 491-925 with a protein from Vibrio vulnificus that is a membrane associated lipoprotein precursor (Accession No. NP—935020.1), about 28% identity from amino acids 408-926 with a hypothetical protein from Helicobacter hepaticus (Accession No. NP—859581.1), and about 23% identity from amino acids 24-795 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964510.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:190 (250 amino acids) has about 52% identity from amino acids 126-249 with a protein from Lactobacillus gasseri that is a cell wall-associated hydrolase (invasion-associated protein) (Accession No. ZP—00046669.1), about 50% identity from amino acids 126-249 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965658.1), about 54% identity from amino acids 131-249 with a protein from Clostridium acetobutylicum that has an N-terminal domain intergin-like repeat and a c-terminal cell wall-associated hydrolase domain (Accession No. NP—349545.1), about 46% identity from amino acids 126-250 with a protein from Oenococcus oeni that is a cell wall-associated hydrolase (invasion-associated protein) (Accession No. ZP—00070605.1), and about 33% identity from amino acids 72-246 with a protein from Lactobacillus plantarum that is homologous to an extracellular protein, gamma-D-glutamate-meso-diaminopimelate muropeptidase (Accession No. NP—785666.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:194 (262 amino acids) has about 54% identity from amino acids 145-260 with a protein from Lactobacillus gasseri that is a cell wall-associated hydrolase (invasion-associated protein) (Accession No. ZP—00046669.1), about 51% identity from amino acids 145-260 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965658.1), about 53% identity from amino acids 143-261 with a conserved hypothetical protein from Clostridium perfringens (Accession No. NP—561194.1), about 50% identity from amino acids 145-261 with a protein from Oenococcus oeni that is a cell wall-associated hydrolase (invasion-associated protein) (Accession No. ZP—00070605.1), and about 51% identity from amino acids 143-260 with a protein from Clostridium acetobutylicum that is a cell wall-associated hydrolase (Accession No. NP—346949.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:196 (184 amino acids) has about 43% identity from amino acids 48-182 with a protein from Lactobacillus gasseri that is a cell wall-associated hydrolase (invasion-associated protein) (Accession No. ZP—00046669.1), about 43% identity from amino acids 47-182 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965658.1), about 48% identity from amino acids 66-182 with a protein from Enterococcus faecium that is a surface antigen (Accession No. ZP—00036908.1), about 48% identity from amino acids 66-182 with a protein from Enterococcus faecium that is homologous to a glycosidase (GlyA) (Accession No. gb|AAK72496.1), and about 41% identity from amino acids 46-171 with a hypothetical protein from Lactococcus lactis subsp. lactis (Accession No. NP—267092.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:198 (149 amino acids) has about 52% identity from amino acids 1-146 with a protein from Lactobacillus gasseri that is a guanylate kinase (Accession No. ZP—00046668.1), about 54% identity from amino acids 1-145 with a protein from Lactobacillus johnsonii that is a guanylate kinase (Accession No. NP—965659.1), about 43% identity from amino acids 1-148 with a protein from Lactobacillus plantarum that is a guanylate kinase (Accession No. NP—784598.1), about 40% identity from amino acids 1-145 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a guanylate kinase (Accession No. ZP—00063506.1), and about 38% identity from amino acids 1-145 with a protein from Oenococcus oeni that is a guanylate kinase (Accession No. ZP—00070365.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:200 (99 amino acids) has about 71% identity from amino acids 1-80 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046667.1), about 70% identity from amino acids 1-80 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965660.1), about 40% identity from amino acids 8-69 with a hypothetical protein from Leuconostoc mesenteroides subsp. mesenteroides (Accession No. ZP—00063600.1), about 33% identity from amino acids 5-75 with a protein from Lactobacillus plantarum (Accession No. NP—785013.1), and about 39% identity from amino acids 4-69 with a protein from Lactobacillus plantarum (Accession No. NP—786559.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:202 (503 amino acids) has about 40% identity from amino acids 1-497 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965661.1), about 40% identity from amino acids 214-502 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046666.1), about 22% identity from amino acids 105-477 with a protein from Bacillus cereus that is homologous to a membrane protein (Accession No. NP—977301.1), about 19% identity from amino acids 4-497 with a hypothetical protein from Bacillus anthracis (Accession No. NP—653890.1), and about 19% identity from amino acids 4-497 with a protein from Bacillus anthracis that is homologous to a membrane protein (Accession No. NP—847818.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:204 (206 amino acids) has about 43% identity from amino acids 4-205 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965662.1), about 42% identity from amino acids 4-205 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046665.1), about 33% identity from amino acids 41-203 with a protein from Lactobacillus plantarum (Accession No. NP—786135.1), about 26% identity from amino acids 71-177 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—701622.1), and about 27% identity from amino acids 62-145 with an environmental sequence (Accession No. gb|EAH10085.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:206 (148 amino acids) has about 60% identity from amino acids 1-147 with a protein from Lactobacillus johnsonii that is an NrdI protein (Accession No. NP—965663.1), about 60% identity from amino acids 1-147 with a protein from Lactobacillus gasseri that is a protein involved in ribonucleotide reduction (Accession No. ZP—00046664.1), about 38% identity from amino acids 4-123 with a protein from Enterococcus faecalis that is a NrdI protein (Accession No. NP—814256.1), about 33% identity from amino acids 4-124 with a protein from Lactococcus lactis that is a NrdI protein (Accession No. sp|Q48709|NRDI_LACLC), and about 33% identity from amino acids 4-124 with a protein from Lactococcus lactis subsp. lactis that is a ribonucleotide reductase (Accession No. NP—267132.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:208 (311 amino acids) has about 53% identity from amino acids 3-310 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965664.1), about 53% identity from amino acids 3-311 with a protein from Lactobacillus gasseri that is a ribonucleotide reductase, beta subunit (Accession No. ZP—00046663.1), about 42% identity from amino acids 5-296 with a protein from Streptococcus pyogenes that is a ribonucleotide diphosphate reductase small subunit (Accession No. NP—607484.1), about 42% identity from amino acids 5-296 with a protein from Streptococcus pyogenes that is a ribonucleotide diphosphate reductase small subunit (Accession No. NP—269482.1), and about 42% identity from amino acids 5-296 with a protein from Streptococcus agalactiae that is a ribonucleoside-diphosphate reductase 2, beta subunit (Accession No. NP—687833.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:210 (177 amino acids) has about 58% identity from amino acids 1-152 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046662.1), about 57% identity from amino acids 1-152 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965665.1), about 33% identity from amino acids 1-132 with a protein from Lactobacillus plantarum (Accession No. NP—786047.1), about 29% identity from amino acids 23-144 with a hypothetical protein from Pyrococcus horikoshii (Accession No. NP—142266.1), and about 33% identity from amino acids 1-67 with an environmental sequence (Accession No. gb|EAC37753.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:212 (240 amino acids) has about 63% identity from amino acids 7-240 with a protein from Lactobacillus gasseri (Accession No. ZP—00047171.1), about 66% identity from amino acids 20-240 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965638.1), about 41% identity from amino acids 7-239 with a protein from Lactobacillus plantarum (Accession No. NP—786183.1), about 44% identity from amino acids 51-239 with a protein from Listeria monocytogenes that is homologous to a YvpB protein (Accession No. NP—464251.1), and about 42% identity from amino acids 52-240 with a protein from Bacillus subtilis that is a YvpB protein (Accession No. NP—391374.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:214 (105 amino acids) has about 60% identity from amino acids 4-105 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964999.1), about 50% identity from amino acids 4-104 with a hypothetical protein from Lactococcus lactis subsp. lactis (Accession No. NP—267039.1), about 50% identity from amino acids 3-104 with a protein from Enterococcus faecium that is homologous to a metal-sulfur cluster biosynthetic enzyme (Accession No. ZP—00036555.1), about 46% identity from amino acids 4-104 with a conserved hypothetical protein from Enterococcus faecalis (Accession No. NP—815231.1), and about 56% identity from amino acids 16-105 with a protein from Lactobacillus plantarum (Accession No. NP—784773.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:216 (98 amino acids) has about 81% identity from amino acids 3-98 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964998.1), about 72% identity from amino acids 3-98 with a protein from Lactobacillus plantarum that is homologous to an ABC transporter component, iron regulated (Accession No. NP—785081.1), about 67% identity from amino acids 3-98 with a protein from Oenococcus oeni that is an ABC-type transport system involved in Fe-S cluster assembly, permease component (Accession No. ZP—00069298.1), about 64% identity from amino acids 4-98 with a conserved hypothetical protein from Streptococcus pneumoniae (Accession No. NP—358369.1), and about 64% identity from amino acids 4-98 with a conserved hypothetical intein-containing protein from Streptococcus pneumoniae (Accession No. NP—345358.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:218 (76 amino acids) has about 80% identity from amino acids 1-73 with a protein from Lactobacillus johnsonii that is an ABC transporter ATPase component (Accession No. NP—964994.1), about 73% identity from amino acids 1-73 with a protein from Lactobacillus plantarum that is an ABC transporter, ATP-binding protein (Accession No. NP—785077.1), about 71% identity from amino acids 1-73 with a protein from Streptococcus mutans that is homologous to an ABC transporter, ATP-binding protein (Accession No. NP—720711.1), about 65% identity from amino acids 1-73 with a protein from Enterococcus faecium that is an ABC-type transport system involved in Fe-S cluster assembly, ATPase component (Accession No. ZP—00037285.1), and about 69% identity from amino acids 1-72 with a protein from Streptococcus pneumoniae that is an ABC transporter, ATP-binding protein (Accession No. NP—345354.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:220 (52 amino acids) has about 32% identity from amino acids 5-47 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—700844.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:222 (161 amino acids) has about 59% identity from amino acids 1-146 with a protein from Lactobacillus gasseri (Accession No. ZP—00046659.1), about 60% identity from amino acids 1-146 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965668.1), about 44% identity from amino acids 7-151 with a protein from Listeria innocua (Accession No. NP—469929.1), about 39% identity from amino acids 7-161 with a protein from Enterococcus faecalis that is homologous to a membrane protein (Accession No. NP—814929.1), and about 40% identity from amino acids 11-137 with a protein from Lactobacillus plantarum that is an integral membrane protein (Accession No. NP—784703.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:224 (256 amino acids) has about 64% identity from amino acids 12-235 with a protein from Lactobacillus gasseri (Accession No. ZP—00046658.1), about 63% identity from amino acids 12-235 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965669.1), about 48% identity from amino acids 12-216 with a protein from Lactobacillus sakei that is a LabL protein (Accession No. gb|AAL00959.1), about 45% identity from amino acids 13-235 with a conserved membrane protein from Listeria innocua (Accession No. NP—469930.1), and about 45% identity from amino acids 13-235 with a conserved membrane protein from Listeria monocytogenes (Accession No. NP—464106.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:226 (513 amino acids) has about 81% identity from amino acids 1-513 with a protein from Lactobacillus gasseri that is an ATPase component of ABC transporters with duplicated ATPase domains (Accession No. ZP—00046657.1), about 81% identity from amino acids 1-513 with a protein from Lactobacillus johnsonii that is an ABC transporter ATPase component (Accession No. NP—965670.1), about 52% identity from amino acids 1-513 with a protein from Lactobacillus plantarum that is an ABC transporter, ATP-binding protein (Accession No. NP—785961.1), about 52% identity from amino acids 1-512 with a protein from Enterococcus faecalis that is an ABC transporter, ATP-binding protein (Accession No. NP—815740.1), and about 49% identity from amino acids 1-513 with a protein from Oenococcus oeni that is an ATPase component of ABC transporters with duplicated ATPase domains (Accession No. ZP—00070366.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:228 (124 amino acids) has about 50% identity from amino acids 3-124 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965671.1), about 51% identity from amino acids 3-121 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00046656.1), and about 48% identity from amino acids 53-81 with a hypothetical protein from Pyrococcus furiosus (Accession No. NP—578913.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:230 (73 amino acids) has about 39% identity from amino acids 8-58 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is an acetyltransferase (Accession No. ZP—00063180.1), about 36% identity from amino acids 7-58 with a protein from Oenococcus oeni that is an acetyltransferase (Accession No. ZP—00069032.1), about 36% identity from amino acids 7-56 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965082.1), about 36% identity from amino acids 15-55 with an environmental sequence (Accession No. gb|EAI00330.1), and about 37% identity from amino acids 12-54 with a protein from Bacillus anthracis that is an acetyltransferase in the GNAT family (Accession No. NP—658716.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:232 (424 amino acids) has about 58% identity from amino acids 8-375 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965673.1), about 58% identity from amino acids 8-375 with a protein from Lactobacillus gasseri that is a transcriptional regulator (Accession No. ZP—00046655.1), about 41% identity from amino acids 42-383 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964188.1), about 42% identity from amino acids 42-370 with a protein from Lactobacillus gasseri that is a transcriptional regulator (Accession No. ZP—00047236.1), and about 46% identity from amino acids 78-350 with a protein from Lactobacillus plantarum that is a transcription regulator (Accession No. NP—784105.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:234 (538 amino acids) has about 30% identity from amino acids 5-527 with a protein from Lactobacillus gasseri that is a membrane protein involved in the export of O-antigen and teichoic acid (Accession No. ZP—00047298.1), about 29% identity from amino acids 5-527 with a protein from Lactobacillus johnsonii that is an export protein for polysaccharides and teichoic acids (Accession No. NP—964533.1), about 31% identity from amino acids 1-457 with a protein from Enterococcus faecalis that is a polysaccharide biosynthesis family protein (Accession No. NP—814328.1), about 33% identity from amino acids 3-450 with a protein from Enterococcus faecalis that is a polysaccharide biosynthesis family protein (Accession No. NP—814421.1), and 28% identity from amino acids 3-526 with a protein from Streptococcus mutans that is homologous to a membrane protein (Accession No. NP—722009.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:236 (271 amino acids) has about 58% identity from amino acids 1-271 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964116.1), about 58% identity from amino acids 1-271 with a protein from Lactobacillus gasseri that is a glycosyltransferase involved in cell wall biogenesis (Accession No. ZP—00047045.1), about 31% identity from amino acids 7-234 with a protein from Bacillus cereus that is a glycosyltransferase (Accession No. NP—834930.1), about 28% identity from amino acids 2-250 with a protein from Streptococcus thermophilus that is an EpsV protein (Accession No. emb|CAB52224.1), and 31% identity from amino acids 2-222 with a protein from Lactobacillus plantarum that is a glycosyltransferase (Accession No. NP—786160.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:238 (476 amino acids) has about 75% identity from amino acids 1-475 with a protein from Lactobacillus gasseri that is a membrane protein involved in the export of O-antigen and teichoic acid (Accession No. ZP—00047223.1), about 74% identity from amino acids 1-475 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965532.1), about 30% identity from amino acids 7-460 with a protein from Streptococcus thermophilus that is a cpsU protein (Accession No. gb|AAM93406.1), about 30% identity from amino acids 7-460 with a protein from Streptococcus thermophilus that is an EpsU protein (Accession No. emb|CAB52225.1), and 30% identity from amino acids 7-460 with a protein from Streptococcus thermophilus that is an EpsI protein (Accession No. gb|AAK61904.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:240 (367 amino acids) has about 54% identity from amino acids 3-364 with a protein from Lactobacillus gasseri that is a transcriptional regulator (Accession No. ZP—00047236.1), about 53% identity from amino acids 3-364 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964188.1), about 42% identity from amino acids 22-360 with a protein from Lactobacillus gasseri that is a transcription regulator (Accession No. ZP—00046655.1), about 41% identity from amino acids 21-360 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965673.1), and 0.44% identity from amino acids 33-338 with a protein from Lactobacillus plantarum that is a transcription regulator (Accession No. NP—784704.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:242 (246 amino acids) has about 46% identity from amino acids 1-242 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965126.1), about 37% identity from amino acids 77-234 with a protein from Clostridium thermocellum that is a glycosyltransferase (Accession No. ZP—00060425.1), about 33% identity from amino acids 10-220 with a protein from Helicobacter pylori that is a type I capsular polysaccharide biosynthesis protein J (capJ) (Accession No. NP—207219.1), about 32% identity from amino acids 17-225 with a protein from Bifidobacterium longum that is a glycosyltransferase (Accession No. ZP—00120944.1), and 32% identity from amino acids 17-225 with a protein from Bifidobacterium longum that is homologous to a glycosyltransferase (Accession No. NP—696276.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:244 (380 amino acids) has about 88% identity from amino acids 1-380 with a protein from Lactobacillus gasseri that is a UDP-N-acetylglucosamine 2-epimerase (Accession No. ZP—00046464.1), about 84% identity from amino acids 1-379 with a protein from Lactobacillus johnsonii that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—965402.1), about 70% identity from amino acids 1-379 with a protein from Streptococcus mutans that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—721794.1), about 68% identity from amino acids 4-364 with a protein from Lactobacillus plantarum that is a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—784839.1), and 64% identity from amino acids 1-379 with a protein from Listeria innocua that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—472010.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:246 (399 amino acids) has about 85% identity from amino acids 7-398 with a protein from Lactobacillus gasseri that is a UDP-N-acetylglucosamine 2-epimerase (Accession No. ZP—00046464.1), about 84% identity from amino acids 20-398 with a protein from Lactobacillus johnsonii that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—965402.1), about 70% identity from amino acids 20-398 with a protein from Streptococcus mutans that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—721794.1), about 68% identity from amino acids 23-383 with a protein from Lactobacillus plantarum that is a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—784839.1), and 64% identity from amino acids 20-398 with a protein from Listeria innocua that is homologous to a UDP-N-acetylglucosamine 2-epimerase (Accession No. NP—472010.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:248 (232 amino acids) has about 74% identity from amino acids 1-232 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965530.1), about 74% identity from amino acids 1-232 with a protein from Lactobacillus gasseri that is in the mannosyltransferase OCH1 and related enzyme family (Accession No. ZP—00047224.1), about 40% identity from amino acids 1-208 with a protein from Clostridium thermocellum that is in the mannosyltransferase OCH1 and related enzyme family (Accession No. ZP—00060271.1), about 35% identity from amino acids 2-213 with a protein from Lactobacillus gasseri that is in the mannosyltransferase OCH 1 and related enzyme family (Accession No. ZP—00045846.1), and 38% identity from amino acids 1-211 with a protein from Lactococcus lactis subsp. cremoris that is an EpsQ protein (Accession No. gb|AAP32730.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:250 (387 amino acids) has about 70% identity from amino acids 1-379 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965577.1), about 77% identity from amino acids 1-315 with a protein from Lactobacillus gasseri that is a glycosyltransferase (Accession No. ZP—00047202.1), about 53% identity from amino acids 1-374 with a protein from Lactobacillus plantarum that is a glycosyltransferase (Accession No. NP—784929.1), about 49% identity from amino acids 1-386 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a glycosyltransferase (Accession No. ZP—00063751.1), and 48% identity from amino acids 1-374 with a protein from Enterococcus faecium that is a glycosyltransferase (Accession No. ZP—00036762.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:252 (156 amino acids) has about 62% identity from amino acids 26-152 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964097.1), about 52% identity from amino acids 1-152 with a protein from Lactobacillus gasseri that is a glycosyltransferase (Accession No. ZP—00047062.1), about 56% identity from amino acids 50-152 with a protein from Streptococcus mutans that is homologous to a glycosyltransferase (Accession No. NP—721791.1), about 40% identity from amino acids 36-149 with a protein from Clostridium tetani that is an N-acetylglucosaminyltransferase (Accession No. NP—781499.1), and 37% identity from amino acids 44-152 with a protein from Bacillus subtilis that is homologous to a cellulose synthase (Accession No. NP—388311.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:254 (490 amino acids) has about 100% identity from amino acids 11-490 with a protein from Lactobacillus acidophilus that is a sucrose phosphorylase (Accession No. gb|AAO21861.1), about 69% identity from amino acids 11-490 with a protein from Lactobacillus acidophilus that is a sucrose phosphorylase (Accession No. gb|AA021868.1), about 68% identity from amino acids 11-490 with a protein from Lactobacillus johnsonii that is a sucrose phosphorylase (Accession No. NP—964279.1), about 63% identity from amino acids 11-490 with a protein from Streptococcus mutans that is a sucrose phosphorylase (EC 2.4.1.7) (Accession No. pir∥A27626), and 63% identity from amino acids 11-489 with a protein from Streptococcus mutans that is a gtfA protein (Accession No. pir∥BWSOGM). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:256 (548 amino acids) has about 69% identity from amino acids 8-546 with a protein from Lactobacillus gasseri that is a membrane protein involved in the export of O-antigen and teichoic acid (Accession No. ZP—00047298.1), about 67% identity from amino acids 8-546 with a protein from Lactobacillus johnsonii that is an export protein for polysaccharides and teichoic acids (Accession No. NP—964533.1), about 42% identity from amino acids 5-546 with a protein from Enterococcus faecalis that is a polysaccharide biosynthesis family protein (Accession Nos. NP—814421.1), about 42% identity from amino acids 17-546 with a protein from Lactobacillus plantarum that is an integral membrane protein (Accession No. NP—784959.1), and 38% identity from amino acids 13-547 with a protein from Streptococcus mutans that is homologous to a membrane protein (Accession No. NP—722009.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:258 (363 amino acids) has about 64% identity from amino acids 1-363 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965541.1), about 62% identity from amino acids 1-363 with a protein from Lactobacillus gasseri that is a glycosyltransferase (Accession No. ZP—00047215.1), about 41% identity from amino acids 1-363 with a protein from Bacillus anthracis that is a glycosyltransferase, group 1 family protein (Accession No. NP—847817.1), about 40% identity from amino acids 1-363 with a protein from Bacillus anthracis that is a glycosyltransferase group I protein (Accession No. NP—653889.1), and 39% identity from amino acids 1-363 with a protein from Bacillus cereus that is a glycosyltransferase (Accession No. NP—835081.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:260 (556 amino acids) has about 74% identity from amino acids 6-555 with a protein from Lactobacillus gasseri that is a glycosidase (Accession No. ZP—00047085.1), about 73% identity from amino acids 6-553 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964227.1), about 50% identity from amino acids 8-553 with a protein from Lactobacillus plantarum that is an alpha-glucosidase (Accession No. NP—784006.1), about 35% identity from amino acids 7-556 with a protein from Bacillus halodurans that is an oligo-1,6-glucosidase (Accession No. NP—243769.1), and 34% identity from amino acids 9-553 with a protein from Bacillus cereus that is an oligo-1,6-glucosidase (oligosaccharide alpha-1,6-glucosidase) (Accession No. sp|P21332|O16G_BACCE). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:262 (759 amino acids) has about 75% identity from amino acids 1-757 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964589.1), about 52% identity from amino acids 1-732 with a protein from Clostridium acetobutylicum that is an alpha-glucosidase (Accession No. NP—347719.1), about 51% identity from amino acids 1-726 with a protein from Thermotoga maritima that is an alpha-xylosidase (Accession No. NP—228120.1), about 49% identity from amino acids 1-724 with a protein from Bacillus halodurans (Accession No. NP—242771.1), and 47% identity from amino acids 1-727 with a hypothetical protein from Escherichia coli (Accession No. NP—418113.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:264 (767 amino acids) has about 69% identity from amino acids 3-766 with a protein from Lactobacillus johnsonii that is an alpha-glucosidase (Accession No. NP—965686.1), about 69% identity from amino acids 3-766 with a protein from Lactobacillus gasseri that is an alpha-glucosidase (Accession No. ZP—00046641.1), about 64% identity from amino acids 5-761 with a protein from Lactobacillus plantarum that is an alpha-glucosidase (Accession No. NP—786738.1), about 41% identity from amino acids 15-720 with a protein from Thermoanaerobacter tengcongensis that is an alpha-glucosidase (Accession No. NP—621719.1), and 40% identity from amino acids 20-717 with a protein from Bacillus thermoamyloliquefaciens that is an alpha-glucosidase II (Accession No. sp|Q9F234|AGL2_BACTQ). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:266 (544 amino acids) has about 78% identity from amino acids 6-541 with a protein from Lactobacillus gasseri that is a glycosidase (Accession No. ZP—00047077.1), about 77% identity from amino acids 6-541 with a protein from Lactobacillus johnsonii that is a glucan 1,6-alpha-glucosidase (Accession No. NP—964235.1), about 63% identity from amino acids 2-542 with a protein from Enterococcus faecium that is a glycosidase (Accession No. ZP—00037211.1), about 62% identity from amino acids 9-542 with a protein from Enterococcus faecalis that is homologous to a glucan 1,6-alpha-glucosidase (Accession No. NP—815069.1), and 61% identity from amino acids 9-543 with a protein from Streptococcus pneumoniae that is a glucan 1,6-alpha-glucosidase (Accession No. NP—344876.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:268 (1004 amino acids) has about 48% identity from amino acids 4-1003 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964131.1), about 48% identity from amino acids 1-1003 with a protein from Lactobacillus gasseri that is an alpha-glucosidase (Accession No. ZP—00047030.1), about 32% identity from amino acids 12-1001 with a protein from Enterococcus faecalis that is a glycosyl hydrolase (Accession No. NP—815521.1), about 30% identity from amino acids 98-1000 with a protein from Bacteroides thetaiotaomicron that is an alpha-xylosidase (Accession No. NP—812081.1), and 25% identity from amino acids 11-995 with a hypothetical protein from Clostridium perfringens (Accession No. NP—561962.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:270 (570 amino acids) has about 77% identity from amino acids 17-568 with a protein from Lactobacillus gasseri that is a glycosidase (Accession No. ZP—00045981.1), about 77% identity from amino acids 17-568 with a protein from Lactobacillus johnsonii that is a trehalose-6-phosphate hydrolase (Accession No. NP—964610.1), about 66% identity from amino acids 18-566 with a protein from Lactobacillus plantarum that is an alpha, alpha-phosphotrehalase (Accession No. NP—784081.1), about 57% identity from amino acids 23-568 with a protein from Streptococcus pneumoniae that is a dextran glucosidase (Accession No. NP—359290.1), and 57% identity from amino acids 23-568 with a protein from Streptococcus pneumoniae that is homologous to a dextran glucosidase (DexS) (Accession No. NP—346315.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:272 (638 amino acids) has about 56% identity from amino acids 8-621 with a protein from Streptococcus mutans that is homologous to a 1,4-alpha-glucan branching enzyme (Accession No. NP—721883.1), about 57% identity from amino acids 8-619 with a protein from Streptococcus agalactiae that is a 1,4-alpha-glucan branching enzyme (Accession No. sp|Q8E5V8|GLGB_STRA3), about 57% identity from amino acids 8-619 with a protein from Streptococcus agalactiae that is a 1,4-alpha-glucan branching enzyme (Accession No. NP—687868.1), about 56% identity from amino acids 8-621 with a protein from Streptococcus pneumoniae that is a 1,4-alpha-glucan branching enzyme (Accession No. NP—345592.1), and 56% identity from amino acids 8-621 with a protein from Streptococcus pneumoniae that is a 1,4-alpha-glucan branching enzyme (Accession No. NP—358623.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:274 (573 amino acids) has about 76% identity from amino acids 1-572 with a protein from Lactobacillus johnsonii that is a maltogenic amylase or neopullulanase (Accession No. NP—964228.1), about 75% identity from amino acids 1-572 with a protein from Lactobacillus gasseri that is a glycosidase (Accession No. ZP—00047084.1), about 54% identity from amino acids 56-571 with a protein from Enterococcus faecium that is a glycosidase (Accession No. ZP—00036988.1), about 49% identity from amino acids 1-570 with a protein from Enterococcus faecalis that is a glycosyl hydrolase (Accession No. NP—815068.1), and 50% identity from amino acids 1-540 with a protein from Lactococcus lactis subsp. lactis that is a neopullulanase (Accession No. NP—267838.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:276 (1185 amino acids) has about 39% identity from amino acids 284-1008 with a protein from Bacillus cereus that is a pullulanase (Accession No. NP—832487.1), about 40% identity from amino acids 284-1008 with a protein from Bacillus cereus that is homologous to a pullulanase (Accession No. NP—979065.1), about 40% identity from amino acids 284-1008 with a protein from Bacillus anthracis that is homologous to a pullulanase (Accession No. NP—845079.1), about 41% identity from amino acids 306-1008 with a protein from Bacillus anthracis that is an alpha-amylase (Accession No. NP—656611.1), and 38% identity from amino acids 284-976 with a protein from Anaerobranca horikoshii that is a pullulanase (Accession No. gb|AAP45012.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:278 (589 amino acids) has about 42% identity from amino acids 5-548 with a protein from Lactococcus lactis subsp. lactis that is an amylopullulanase (Accession Nos. NP—266857.1; NC—002662), about 41% identity from amino acids 1-546 with a protein from Lactobacillus plantarum that is an alpha-amylase (Accession No. NP—783889.1), about 38% identity from amino acids 3-558 with a protein from Clostridium perfringens that is an amylopullulanase (Accession No. NP—560982.1), about 70% identity from amino acids 198-441 with a protein from Lactobacillus delbrueckii subsp. lactis that is a glycosyl hydrolase (Accession No. gb|AAQ06973.1), and 37% identity from amino acids 73-547 with a protein from Desulfitobacterium hafniense that is a glycosidase (Accession No. ZP—00100175.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:280 (435 amino acids) has about 22% identity from amino acids 78-384 with an environmental sequence (Accession No. gb|EAH69409.1), about 23% identity from amino acids 53-387 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—701320.1), about 22% identity from amino acids 59-382 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—701961.1), about 22% identity from amino acids 56-386 with a hypothetical protein from Plasmodium falciparum (Accession No. NP—473199.1), and about 24% identity from amino acids 61-336 with a protein from Plasmodium yoelii yoelii that is homologous to a CCAAT-box DNA binding protein subunit B (Accession No. gb|EAA22696.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:282 (382 amino acids) has about 54% identity from amino acids 1-382 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965524.1), about 60% identity from amino acids 115-382 with a protein from Lactobacillus gasseri that is a protein involved in sex pheromone biosynthesis (Accession No. ZP—00046368.1), about 41% identity from amino acids 1-382 with a protein from Lactobacillus plantarum that is a lipoprotein precursor (Accession No. NP—784816.1), about 38% identity from amino acids 53-374 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a protein involved in sex pheromone biosynthesis (Accession No. ZP—00063694.1), and 35% identity from amino acids 1-379 with a protein from Listeria innocua (Accession No. NP—471203.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:284 (173 amino acids) has about 52% identity from amino acids 1-161 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964736.1), about 51% identity from amino acids 1-161 with a hypothetical protein from Lactobacillus gasseri (Accession No. ZP—00047405.1), about 25% identity from amino acids 21-159 with a hypothetical protein from Oenococcus oeni (Accession No. ZP—00010369.1), about 28% identity from amino acids 4-74 with an environmental sequence (Accession No. gb|EAF86579.1), and 24% identity from amino acids 63-160 with a protein from Listeria innocua that is homologous to a cell surface protein (Accession No. NP—471613.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:286 (414 amino acids) has about 65% identity from amino acids 21-404 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—964852.1), about 64% identity from amino acids 21-404 with a protein from Lactobacillus gasseri that is a bacterial cell division membrane protein (Accession No. ZP—00046289.1), about 39% identity from amino acids 23-407 with a protein from Lactobacillus plantarum that is a cell division protein FtsW (Accession No. NP—785648.1), about 36% identity from amino acids 48-411 with a protein from Enterococcus faecalis that is a cell division protein in the FtsW/RodA/SpoVE family (Accession No. NP—816105.1), and 35% identity from amino acids 48-404 with a protein from Enterococcus faecium that is a bacterial cell division membrane protein (Accession No. ZP—00035664.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:288 (151 amino acids) has about 53% identity from amino acids 1-149 with a protein from Lactobacillus plantarum that is an integral membrane protein (Accession No. NP—785439.1), about 58% identity from amino acids 18-146 with a protein from Listeria monocytogenes (Accession No. NP—465093.1), about 58% identity from amino acids 18-146 with a protein from Listeria innocua (Accession No. NP—470939.1), about 48% identity from amino acids 1-149 with a protein from Enterococcus faecium that is homologous to a membrane protein (Accession No. ZP—00036546.1), and 49% identity from amino acids 1-147 with a protein from Enterococcus faecalis (Accession No. NP—814972.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:290 (451 amino acids) has about 62% identity from amino acids 13-450 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965202.1), about 61% identity from amino acids 13-450 with a protein from Lactobacillus gasseri (Accession No. ZP—00046546.1), about 53% identity from amino acids 6-451 with a protein from Lactobacillus plantarum that is an integral membrane protein (Accession No. NP—783922.1), about 51% identity from amino acids 13-451 with a protein from Leuconostoc mesenteroides subsp. mesenteroides (Accession No. ZP—00062829.1), and 51% identity from amino acids 19-451 with a protein from Oenococcus oeni (Accession No. ZP—00070095.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:292 (374 amino acids) has about 75% identity from amino acids 1-374 with a protein from Lactobacillus gasseri that is homologous to a DNA methylase (Accession No. ZP—00045949.1), about 74% identity from amino acids 1-374 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965048.1), about 53% identity from amino acids 1-373 with a protein from Lactobacillus plantarum (Accession No. NP—785327.1), about 52% identity from amino acids 2-373 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is homologous to a DNA methylase (Accession No. ZP—00062777.1), and 50% identity from amino acids 2-373 with a conserved hypothetical protein from Enterococcus faecalis (Accession No. NP—814882.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:294 (242 amino acids) has about 79% identity from amino acids 1-238 with a protein from Lactobacillus johnsonii that is a tRNA (guanine-N1)-methyltransferase (Accession No. NP—965315.1), about 52% identity from amino acids 1-241 with a protein from Lactobacillus plantarum that is a tRNA (guanine-N1)-methyltransferase (Accession No. NP—785229.1), about 46% identity from amino acids 1-238 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a tRNA methyltransferase (Accession No. ZP—00064008.1), 51% identity from amino acids 1-238 with a protein from Bacillus cereus that is a tRNA (guanine-N1)-methyltransferase (Accession No. NP—833560.1), and 51% identity from amino acids 1-236 with a protein from Bacillus anthracis that is a tRNA (guanine-N1)-methyltransferase (Accession No. NP—657810.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:296 (667 amino acids) has about 83% identity from amino acids 24-666 with a protein from Lactobacillus johnsonii that is a threonyl-tRNA synthetase (Accession No. NP—965452.1), about 83% identity from amino acids 24-666 with a protein from Lactobacillus gasseri that is a threonyl-tRNA synthetase (Accession No. ZP—00046734.1), about 61% identity from amino acids 25-665 with a protein from Lactobacillus plantarum that is a threonine-tRNA ligase 1 (Accession No. NP—785120.1), about 57% identity from amino acids 28-665 with a protein from Streptococcus mutans that is homologous to a threonyl-tRNA synthetase (Accession No. NP—721923.1), and 56% identity from amino acids 28-665 with a protein from Lactococcus lactis subsp. lactis that is a threonyl-tRNA synthetase (Accession No. NP—268068.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:298 (706 amino acids) has about 24% identity from amino acids 123-511 with a protein from Lactobacillus plantarum that is a cell surface protein precursor (Accession No. NP—786268.1), about 29% identity from amino acids 220-510 with a protein from Enterococcus faecium that is an autotransporter adhesin (Accession No. ZP—00035995.1), about 23% identity from amino acids 181-503 with a protein from Fusobacterium nucleatum subsp. nucleatum that is a hemolysin (Accession No. NP—603198.1), about 19% identity from amino acids 26-260 with a protein from Staphylococcus aureus subsp. aureus that is a fibrinogen-binding protein (Accession No. NP—645581.1), and 25% identity from amino acids 383-509 with a hypothetical protein from Microbulbifer degradans (Accession No. ZP—00064879.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:300 (438 amino acids) has about 31% identity from amino acids 116-297 with a hypothetical protein from Streptococcus mutans (Accession No. NP—722210.1), about 50% identity from amino acids 116-188 with a protein from Lactobacillus salivarius subsp. salivarius (Accession No. gb|AAM61773.1), about 29% identity from amino acids 126-220 with a protein from Streptococcus agalactiae that is homologous to a bacteriocin transport accessory protein (Accession No. NP—687482.1), 24% identity from amino acids 125-338 with a protein from Bradyrhizobium japonicum that is a thioredoxin (Accession No. NP—767234.1), and 27% identity from amino acids 123-201 with a protein from Bacillus anthracis (Accession No. NP—052783.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:302′ (372 amino acids) has about 55% identity from amino acids 11-371 with a protein from Leuconostoc mesenteroides subsp. mesenteroides that is a methionine synthase II (cobalamin-independent) protein (Accession No. ZP—00064070.1), about 47% identity from amino acids 5-372 with a protein from Lactobacillus gasseri that is a methionine synthase II (cobalamin-independent) protein (Accession No. ZP—00046311.1), about 46% identity from amino acids 7-372 with a hypothetical protein from Chlamydophila pneumoniae (Accession No. NP—224351.1), 44% identity from amino acids 4-372 with a hypothetical protein from Lactobacillus johnsonii (Accession No. NP—965623.1), and 45% identity from amino acids 9-372 with a protein from Oenococcus oeni that is a methionine synthase II (cobalamin-independent) protein (Accession No. ZP—00069898.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:304 (157 amino acids) has about 87% identity from amino acids 1-157 with a protein from Lactobacillus johnsonii that is an autoinducer-2 production protein LuxS (Accession No. NP—965624.1), about 87% identity from amino acids 1-157 with a protein from Lactobacillus gasseri that is a LuxS protein involved in autoinducer A12 synthesis (Accession No. ZP—00046310.1), about 76% identity from amino acids 4-157 with a protein from Streptococcus bovis that is a LuxS autoinducer 2 synthase (Accession No. dbj|BAD06876.1), 77% identity from amino acids 1-157 with a protein from Lactobacillus plantarum that is an autoinducer production protein (Accession No. NP—784522.1), and 73% identity from amino acids 4-157 with a protein from Streptococcus pyogenes that is an autoinducer-2 production protein (Accession No. NP—269689.1). A Gapped BlastP amino acid sequence alignment showed that SEQ ID NO:306 (599 amino acids) has about 37% identity from amino acids 225-343 with a protein from Lactobacillus crispatus that is an S-layer protein (Accession No. emb|CAA07708.1), about 34% identity from amino acids 225-343 with a protein from Lactobacillus crispatus that is a surface layer protein (Accession No. gb|AAB58734.1), about 33% identity from amino acids 225-343 with a protein from Lactobacillus crispatus that is a silent surface layer protein (Accession No. dbj|BAC76687.1), about 34% identity from amino acids 225-343 with a protein from Lactobacillus crispatus that is homologous to a silent surface layer protein (Accession No. gb|AAF68972.1), and about 30% identity from amino acids 137-284 with a protein from Lactobacillus helveticus that is an extracellular proteinase (EC 3.4.21.-) (prtY) (Accession No. pir∥JC7306). EXAMPLE 2 PFAM Results for Amino Acid Sequences SEQ ID NO:2 contains a predicted Lipoprotein—4 domain located from about amino acids 25 to 306, and is a member of the Periplasmic solute binding protein family (SBP_bac—9)(PFAM Accession PF01297). SEQ ID NO:10 contains a predicted Glyco_hydro—32 domain located from about amino acids 24 to 409, and is a member of the Glycosyl hydrolases family 32 (Glyco_hydro—32)(PFAM Accession PF00251). SEQ ID NO:62 contains a predicted SLAP domain located from about amino acids 1 to 456, and is a member of the Bacterial surface layer protein family (SLAP) (PFAM Accession PF03217). SEQ ID NO:82 contains a predicted Amidase—2 domain located from about amino acids 59 to 208, and is a member of the N-acetylmuramoyl-L-alanine amidase (Amidase—2) family (PFAM Accession PF01510). SEQ ID NO:92 contains a predicted FTSW_RODA_SPOVE domain located from about amino acids 15 to 388, and is a member of the Cell cycle protein family (FTSW_RODA_SPOVE) (PFAM Accession PF01098). SEQ ID NO:94 contains a predicted Mur_ligase domain located from about amino acids 43 to 293, and a predicted Mur_ligase_C domain from about amino acids 301-390, and is a member of the Mur ligase, catalytic domain family (Mur_ligase) (PFAM Accession PF01225) and the Mur ligase, glutamate ligase domain family (Mur_ligase_C) (PFAM Accession PF02875). SEQ ID NO:98 contains a predicted Mur_ligase C domain located from about amino acids 365 to 454, and is a member of the Mur_ligase, glutamate ligase domain family (Mur_ligase_C) (PFAM Accession PF02875). SEQ ID NO:100 contains a predicted Mur_ligase domain located from about amino acids 48 to 309, and a predicted Mur_ligase_C domain from about amino acids 317-394, and is a member of the Mur ligase, catalytic domain family (Mur_ligase) (PFAM Accession PF01225) and the Mur ligase, glutamate ligase domain family (Mur_ligase_C) (PFAM Accession PF02875). SEQ ID NO:102 contains a predicted Glyco_transf—28 domain located from about amino acids 2 to 287, and is a member of the Glycosyltransferase family 28 N-terminal domain (Glyco_transf—28) (PFAM Accession PF03033). SEQ ID NO:104 contains a predicted Glycos_transf—4 domain located from about amino acids 82 to 254, and is a member of the Glycosyl transferase family (Glycos_transf—4) (PFAM Accession PF00953). SEQ ID NO:106 contains a predicted Amidase—4 domain located from about amino acids 63 to 212, and is a member of the Mannosyl-glycoprotein endo-beta-N-acetylglucosamidase family (Amidase—4) (PFAM Accession PF01832). SEQ ID NO:108 contains a predicted Amidase—4 domain located from about amino acids 43 to 196, and is a member of the Mannosyl-glycoprotein endo-beta-N-acetylglucosamidase family (Amidase—4) (PFAM Accession PF01832). SEQ ID NO:110 contains a predicted LysM domain located from about amino acids 110 to 153, and is a member of the LysM domain family (LysM) (PFAM Accession PF01476). SEQ ID NO:112 contains a predicted Dala_Dala_ligas (Dala_Dala_lig_N) domain located from about amino acids 5 to 343, and is a member of the D-ala D-ala ligase N terminus family (Dala_Dala_lig_N) (PFAM Accession PF01820). SEQ ID NO: 116 contains a predicted Mur ligase domain located from about amino acids 36 to 303, and is a member of the Mur ligase, catalytic domain family (Mur_ligase) (PFAM Accession PF01225). SEQ ID NO: 118 contains a predicted Peptidase_S 11 domain located from about amino acids 25 to 321, and is a member of the D-alanyl-D-alanine carboxypeptidase family (Peptidase_S11) (PFAM Accession PF00768). SEQ ID NO:120 contains a predicted EPSP_synthase domain located from about amino acids 16 to 419, and is a member of the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) family (EPSP_synthase) (PFAM Accession PF00275). SEQ ID NO:122 contains a predicted NTP_transferase domain located from about amino acids 4 to 233, and is a member of the Bacterial transferase hexapeptide (three repeats) family (Hexapep) (PFAM Accession PF00132). SEQ ID NO:124 contains a predicted Prenyltransf (UPP_synthetase) domain located from about amino acids 14 to 238, and is a member of the Putative undecaprenyl diphosphate synthase family (Prenyltransf) (PFAM Accession PF01255). SEQ ID NO:126 contains a predicted Glycos_transf—4 domain located from about amino acids 74 to 240, and is a member of the Glycosyl transferase family (Glycos_transf—4) (PFAM Accession PF00953). SEQ ID NO:132 contains a predicted Transpeptidase domain located from about amino acids 331 to 693, and is a member of the Penicillin binding protein transpeptidase domain family (Transpeptidase) (PFAM Accession PF00905). SEQ ID NO:134 contains a predicted Transglycosyl domain located from about amino acids 82 to 251, and a predicted Transpeptidase domain located from about amino acids 336 to 640, and is a member of the Transglycosylase family (Transgly)(Transglycosyl) (PFAM Accession PF00912), as well as the Penicillin binding protein transpeptidase domain family (Transpeptidase) (PFAM Accession PF00905). SEQ ID NO:138 contains a predicted Transglycosyl domain located from about amino acids 70 to 242, and a predicted Transpeptidase domain located from about amino acids 324 to 629, and is a member of the Transglycosylase family (Transgly)(Transglycosyl) (PFAM Accession PF00912), as well as the Penicillin binding protein transpeptidase domain family (Transpeptidase) (PFAM Accession PF00905). SEQ ID NO:146 contains a predicted Transpeptidase domain located from about amino acids 259 to 593, and is a member of the Penicillin binding protein transpeptidase domain family (Transpeptidase) (PFAM Accession PF00905). SEQ ID NO:148 contains a predicted AMP-binding domain located from about amino acids 30 to 426, and is a member of the AMP-binding enzyme family (AMP-binding) (PFAM Accession PF00501). SEQ ID NO:156 contains a predicted Polysacc_synt domain located from about amino acids 3 to 269, and is a member of the Polysaccharide biosynthesis protein family (Polysacc_synt) (PFAM Accession PF01943). SEQ ID NO:158 contains a predicted GLF domain located from about amino acids 1 to 154, and is a member of the UDP-galactopyranose mutase family (GLF) (PFAM Accession PF03275). SEQ ID NO:164 contains a predicted Glycos_transf—2 domain located from about amino acids 7 to 179, and is a member of the Glycosyl transferase family (Glycos_transf—2) (PFAM Accession PF00535). SEQ ID NO:170 contains a predicted Glycos_transf—2 domain located from about amino acids 5 to 171, and is a member of the Glycosyl transferase family (Glycos_transf—2) (PFAM Accession PF00535). SEQ ID NO:174 contains a predicted Bac_transf (Bact_transf) domain located from about amino acids 24 to 217, and is a member of the Bacterial sugar transferase family (Bac_transf) (Bact_transf) (PFAM Accession PF02397). SEQ ID NO:180 contains a predicted Wzz domain located from about amino acids 9 to 186, and is a member of the Chain length determinant protein family (Wzz) (PFAM Accession PF02706). SEQ ID NO:190 contains a predicted NLPC_P60 domain located from about amino acids 141 to 249, and is a member of the NlpC/P60 family (NLPC_P60) (PFAM Accession PF00877). SEQ ID NO:194 contains a predicted NLPC_P60 domain located from about amino acids 152 to 260, and is a member of the NlpC/P60 family (NLPC_P60) (PFAM Accession PF00877). SEQ ID NO:196 contains a predicted NLPC_P60 domain located from about amino acids 77 to 182, and is a member of the NlpC/P60 family (NLPC_P60) (PFAM Accession PF00877). SEQ ID NO:208 contains a predicted Ribonuc_red_sm domain located from about amino acids 1 to 283, and is a member of the Ribonucleotide reductase, small chain family (Ribonuc_red_sm) (PFAM Accession PF00268). SEQ ID NO:214 contains a predicted DUF59 domain located from about amino acids 9 to 83, and is a member of the Domain of unknown function DUF59 family (DUF59) (PFAM Accession PF01883). SEQ ID NO:216 contains a predicted UPF0051 domain located from about amino acids 2 to 73, and is a member of the Uncharacterized protein family (UPF0051) (PFAM Accession PF01458). SEQ ID NO:218 contains a predicted ABC_tran domain located from about amino acids 35 to 73, and is a member of the ABC transporter family (ABC_tran) (PFAM Accession PF00005). SEQ ID NO:226 contains predicted ABC_tran domains located from about amino acids 29 to 232, and from about amino acids 347 to 512, and is a member of the ABC transporter family (ABC_tran) (PFAM Accession PF00005). SEQ ID NO:236 contains a predicted Glycos_transf—2 domain located from about amino acids 8 to 171, and is a member of the Glycosyl transferase family (Glycos_transf—2) (PFAM Accession PF00535). SEQ ID NO:238 contains a predicted Polysacc_synt domain located from about amino acids 4 to 273, and is a member of the Polysaccharide biosynthesis protein family (Polysacc_synt) (PFAM Accession PF01943). SEQ ID NO:242 contains a predicted Glycos_transf—1 domain located from about amino acids 57 to 233, and is a member of the Glycosyl transferases group 1 family (Glycos_transf—1) (PFAM Accession PF00534). SEQ ID NO:244 contains a predicted Epimerase—2 domain located from about amino acids 45 to 365, and is a member of the UDP-N-acetylglucosamine 2-epimerase family (Epimerase—2) (PFAM Accession PF02350). SEQ ID NO:246 contains a predicted Epimerase—2 domain located from about amino acids 64 to 384, and is a member of the UDP-N-acetylglucosamine 2-epimerase family (Epimerase—2) (PFAM Accession PF02350). SEQ ID NO:250 contains a predicted Glycos_transf—1 domain located from about amino acids 189 to 359, and is a member of the Glycosyl transferases group 1 family (Glycos_transf 1) (PFAM Accession PF00534). SEQ ID NO:252 contains a predicted Glycos_transf—2 domain located from about amino acids 51 to 152, and is a member of the Glycosyl transferase family (Glycos_transf—2) (PFAM Accession PF00535). SEQ ID NO:258 contains a predicted Glycos_transf—1 domain located from about amino acids 174 to 341, and is a member of the Glycosyl transferases group 1 family (Glycos_transf—1) (PFAM Accession PF00534). SEQ ID NO:260 contains a predicted Alpha-amylase domain located from about amino acids 18 to 412, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:262 contains a predicted Glyco_hydro—31 domain located from about amino acids 110 to 757, and is a member of the Glycosyl hydrolases family 31 (Glyco_hydro—31) (PFAM Accession PF01055). SEQ ID NO:264 contains a predicted Glyco_hydro—31 domain located from about amino acids 83 to 757, and is a member of the Glycosyl hydrolases family 31 (Glyco_hydro—31) (PFAM Accession PF01055). SEQ ID NO:266 contains a predicted Alpha-amylase domain located from about amino acids 18 to 410, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:268 contains a predicted Glyco_hydro—31 domain located from about amino acids 68 to 682, and is a member of the Glycosyl hydrolases family 31 (Glyco_hydro—31) (PFAM Accession PF01055). SEQ ID NO:270 contains a predicted Alpha-amylase domain located from about amino acids 28 to 429, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:272 contains a predicted Isoamylase_N domain located from about amino acids 23 to 109, and an Alpha-amylase domain located from about amino acids 145 to 495, and is a member of the Isoamylase N-terminal domain family (Isoamylase_N) (PFAM Accession PF02922) and the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:274 contains a predicted Alpha-amylase_N domain located from about amino acids 1 to 121, and an Alpha-amylase domain located from about amino acids 140 to 503, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128) and the Alpha amylase, N-terminal ig-like domain family (Alpha-amylase_N) (PFAM Accession PF02903). SEQ ID NO:276 contains a predicted Alpha-amylase domain located from about amino acids 548 to 926, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:278 contains a predicted Alpha-amylase domain located from about amino acids 133 to 505, and is a member of the Alpha amylase, catalytic domain family (Alpha-amylase) (PFAM Accession PF00128). SEQ ID NO:286 contains a predicted FTSW_RODA_SPOVE domain located from about amino acids 29 to 405, and is a member of the Cell cycle protein family (FTSW_RODA_SPOVE) (PFAM Accession PF01098). SEQ ID NO:292 contains a predicted UPF0020 domain located from about amino acids 163 to 368, and is a member of the Putative RNA methylase family UPF0020 (UPF0020) (PFAM Accession PF01170). SEQ ID NO:294 contains a predicted tRNA_m1G_MT domain located from about amino acids 21 to 226, and is a member of the tRNA (Guanine-1)-methyltransferase (tRNA_m1G_MT) (PFAM Accession PF01746). SEQ ID NO:296 contains a predicted TGS domain located from about amino acids 22 to 85, a predicted tRNA-synt—2b domain located from about amino acids 283 to 438, and a predicted HGTP_anticodon domain located from about amino acids 562 to 659, and is a member of the tRNA synthetase class II core domain family (G, H, P, S and T)(tRNA-synt—2b) (PFAM Accession PF00587), the Anticodon binding domain family (HGTP_anticodon) (PFAM Accession PF03129), and the TGS domain family (TGS) (PFAM Accession PF02824). SEQ ID NO:304 contains a predicted LuxS domain located from about amino acids 2 to 155, and is a member of the LuxS protein family (LuxS) (PFAM Accession PF02664). EXAMPLE 3 Identification of Sequences Involved in Cell Adhesion The ability of microorganisms to adhere to mucosal surfaces can provide a distinct advantage when establishing residence in the gastrointestinal tract. Lactobacilli are normal components of the intestinal microbiota, although the molecular mechanisms by which these organisms attach to the epithelium have not yet been fully characterized. In order to identify genes potentially involved with adhesion in L. acidophilus NCFM, the complete genomic sequence was analyzed and open reading frames (ORFs) similar to genes previously shown to be involved with adhesion were selected, including two streptococcal R28 homologs (SEQ ID NO:76 and SEQ ID NO:78, designated as ORF 1633 and ORF 1634, respectively in FIG. 1), a fibronectin binding protein (FpbA)(SEQ ID NO:58), and a mucin binding protein (Mub) (SEQ ID NO:18). To determine their impact on adhesion, these genes were targeted for insertional inactivation using the integration tools and strategy described by (Russell and Klaenhammer (2001) Appl. Environ. Microbiol. 67:4361-4364). Due to the interactive nature of bacterial surface components with adhesion, a strain containing an inactivated surface layer protein (SlpA) (SEQ ID NO:60) was also evaluated for adhesive properties. All mutants were assessed for their adhesive properties on Caco-2 cells in comparison to L. acidophilus NCFM LacL− which was used as an antibiotic control and designated as wild type. Caco-2 cells express many of the markers associated with normal small intestine villus cells and are commonly used to study bacterial adherence. The two R28 homolog mutants, SEQ ID NO:76 and SEQ ID NO:78, did not show reproducible decreases in adhesion (see FIG. 1). SlpA (SEQ ID NO:60), the surface layer mutant, showed the highest decrease in adhesion while the fibronectin (SEQ ID NO:58) and mucin binding (SEQ ID NO:18) mutants both had significant decreases in adhesion when compared to the wild type. These data suggest that fibronectin binding protein, surface layer protein, and mucin binding protein contribute to attachment or adherence processes. Adhesion Assays Caco-2 cells were grown on cell-culture treated coverslips for 15 days to achieve proper differentiation and expression of intestinal markers. The monolayers were then treated with a bacterial suspension at a concentration of about 4×108 bacteria/ml. Middle log-phase bacterial populations were used grown in MRS with 2.5 μg/ml Em to maintain selection. Bacteria were incubated on the monolayers for 1.5 hr at 37° C. in a mixture of MRS and cell line culture medium (Minimum Essential Medium supplemented with 20% Fetal Bovine Serum). Following incubation, the monolayers were washed five times with phosphate-buffered saline (PBS), fixed in methanol, and Gram-stained. The coverslips were then transferred to a microscope slide where the cells were enumerated. For statistical purposes, 17 fields were enumerated in a fixed grid for each coverslip; duplicate coverslips were counted for each experiment. Total counts for each coverslip were used and adhesion was expressed as percent (%) of the control. L. acidophilus, NCFM::lacL, harboring pOR128 integrated into the β-galactosidase gene. Integration into lacL was not found to influence adhesion and the control could be propagated under the same antibiotic selection conditions as all the other integrants. All publications and patent applications mentioned in the specification are indicative of the level of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Lactobacillus acidophilus is a Gram-positive, rod-shaped, non-spore forming, homofermentative bacterium that is a normal inhabitant of the gastrointestinal and genitourinary tracts. Since its original isolation by Moro (1900) from infant feces, the “acid loving” organism has been found in the intestinal tract of humans, breast-fed infants, and persons consuming high milk, lactose, or dextrin diets. Historically, L. acidophilus is the Lactobacillus species most often implicated as an intestinal probiotic capable of eliciting beneficial effects on the microflora of the gastrointestinal tract (Klaenhammer and Russell (2000) “Species of the Lactobacillus acidophilus complex,” Encyclopedia of Food Microbiology , Volume 2, pp. 1151-1157. Robinson et al., eds. (Academic Press, San Diego, Calif.). L. acidophilus can ferment hexoses, including lactose and more complex oligosaccharides, to produce lactic acid and lower the pH of the environment where the organism is cultured. Acidified environments (e.g., food, vagina, and regions within the gastrointestinal tract) can interfere with the growth of undesirable bacteria, pathogens, and yeasts. The organism is well known for its acid tolerance, survival in cultured dairy products, and viability during passage through the stomach and gastrointestinal tract. Lactobacilli and other commensal bacteria, some of which are considered as probiotic bacteria that “favor life,” have been studied extensively for their effects on human health, particularly in the prevention or treatment of enteric infections, diarrheal disease, prevention of cancer, and stimulation of the immune system. The cell wall of Gram-positive bacteria consists of a peptidoglycan macromolecule, with attached accessory molecules such as teichoic acids, teichuronic acids, lipoteichoic acids, lipoglycans, polyphosphates, and carbohydrates (Hancock (1997) Biochem. Soc. Trans. 25:183-187; Salton (1994) The bacterial cell envelope—a historical perspective, p. 1-22. In J.-M. Ghuysen and R. Hakenbeck (ed.) Bacterial cell wall. Elsevier Science BV, Amsterdam, The Netherlands). Proteins associated with the cell surface of Gram-positive bacteria include hydrolases and proteases, polysaccharides, surface exclusion proteins and aggregation-promoting proteins (thought to be involved in mating), S-layer proteins (subunits of crystalline arrays covering the outer surface of many single-celled organisms), sortase (a transpeptidase responsible for cleaving surface proteins at the LPXTG-like (SEQ ID NO:308) motifs), proteins with LPXTG-like motifs, and MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) such as fibronectin-binding proteins, fibrinogen-binding proteins, and mucus-binding proteins. Cell wall, cell surface, and secreted proteins of Gram-positive bacteria serve many diverse functions, including adhering to other cells or compounds, providing structural stability, and responding to environmental stimuli. Surface proteins of bacteria are important for survival within a host, and for cell growth and division. Furthermore, surface proteins are often recognized by a host's immune system to initiate immuno-stimulation, -modulation, or -enhancement. The isolation and characterization of these proteins will aid in developing essential probiotic products with numerous applications, including those that benefit human or animal health, and those concerned with food production and safety. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>Compositions and methods for modifying Lactobacillus organisms are provided. Compositions of the invention include isolated nucleic acid molecules from Lactobacillus acidophilus encoding cell wall, cell surface, and secreted proteins. Specifically, the present invention provides for isolated nucleic acid molecules comprising the nucleotide sequences found in SEQ ID NOS:1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255, 257, 259, 261, 263, 265, 267, 269, 271, 273, 275, 277, 279, 281, 283, 285, 287, 289, 291, 293, 295, 297, 299, 301, 303, 305 and 307, and isolated nucleic acid molecules encoding the amino acid sequences found in SEQ ID NOS:2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 302, 304 and 306. Also provided are isolated or recombinant polypeptides having an amino acid sequence encoded by a nucleic acid molecule described herein. Variant nucleic acid molecules and polypeptides sufficiently identical to the nucleotide and amino acid sequences set forth in the sequence listings are encompassed by the present invention. Additionally, fragments and sufficiently identical fragments of the nucleotide and amino acid sequences are encompassed. Nucleotide sequences that are complementary to a nucleotide sequence of the invention, or that hybridize to a sequence of the invention, are also encompassed. Compositions further include vectors and host cells for recombinant expression of the nucleic acid molecules described herein, as well as transgenic microbial populations comprising the vectors. Also included in the invention are methods for making the vectors and host cells described herein, as well as methods for the recombinant production of the polypeptides of the invention, and methods for their use. Further included are methods and kits for detecting the presence of a nucleic acid or polypeptide sequence of the invention in a sample, and antibodies that bind to a polypeptide of the invention. The cell wall, cell surface, and secreted polypeptides encoded by the inventive sequences, and the transgenic microbes expressing them, have health-related benefits. The microbes transformed with these polynucleotide sequences may be taken internally as a pharmaceutical or probiotic composition or alternatively, the microbes or their encoded polypeptides may be administered separately or added to products to provide health-related benefits. The nucleic acid molecules of the invention may also enhance the stability of microorganisms expressing them, and therefore may be useful in the production and processing of various foods. | 20040423 | 20080325 | 20050526 | 76848.0 | 0 | NAVARRO, ALBERT MARK | LACTOBACILLUS ACIDOPHILUS NUCLEIC ACID SEQUENCES ENCODING CELL SURFACE PROTEIN HOMOLOGUES AND USES THEREFORE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,831,258 | ACCEPTED | Suppression of router advertisement | In an embodiment, an apparatus for detecting a router advertisement, includes: a network device configured to generate a response when a router advertisement is received in a port in the network device. In another embodiment, a method for detecting a router advertisement, includes: generating a response when a router advertisement is received in a port in the network device. | 1. An apparatus for suppressing a router advertisement, the apparatus comprising: a network device configured to filter a router advertisement from an unauthorized device. 2. The apparatus of claim 1, wherein the network device prevents a client from routing packets to the unauthorized device. 3. The apparatus of claim 1, wherein the network device comprises a network switch. 4. The apparatus of claim 1, wherein the network switch comprises: a port module including a first port and a second port; and a switch control configured to permit the first port to process the advertisement if the first port is connected to the router and to permit the second port to filter the advertisement if the second port is not connected to the router. 5. The apparatus of claim 1, wherein the first port is coupled to a designated router; and wherein the second port is coupled to the unauthorized device. 6. The apparatus of claim 1, wherein the unauthorized device comprises a router. 7. The apparatus of claim 1, wherein the network device is in a communication network based upon the Internet Protocol version 6 (IPV6) protocol. 8. A method for suppressing a router advertisement, the method comprising: filtering a router advertisement from an unauthorized device. 9. The method of claim 8, wherein the act of filtering comprises: designating a port to receive a router advertisement and designating another port to filter a router advertisement. 10. The method of claim 8, further comprising: preventing a client from routing packets to the unauthorized device. 11. The method of claim 8, wherein the act of filtering is performed by a network device. 12. The method of claim 11, wherein the network device comprises a network switch. 13. The method of claim 9, wherein the port is coupled to a designated router; and wherein the other port is coupled to the unauthorized device. 14. The method of claim 13, wherein the unauthorized device comprises a router. 15. The method of claim 11, wherein the network device is in a communication network based upon the Internet Protocol version 6 (IPV6) protocol. 16. An apparatus for detecting a router advertisement, the apparatus comprising: a network device configured to generate a response when a router advertisement is received in a port in the network device. 17. The apparatus of claim 16, wherein the response comprises: filtering of the router advertisement. 18. The apparatus of claim 16, wherein the response comprises: creating of a flag to indicate receipt of the router advertisement in a port. 19. The apparatus of claim 16, wherein the response comprises: transmitting an SNMP report to indicate receipt of the router advertisement in a port. 20. A method for detecting a router advertisement, the method comprising: generating a response when a router advertisement is received in a port in the network device. 21. The method of claim 20, wherein the response comprises: filtering of the router advertisement. 22. The method of claim 16, wherein the response comprises: creating of a flag to indicate receipt of the router advertisement in a port. 23. The method of claim 16, wherein the response comprises: transmitting an SNMP report to indicate receipt of the router advertisement in a port. 24. An apparatus for detecting a router advertisement, the apparatus comprising: means for generating a response when a router advertisement is received in a port in the network device. 25. An article of manufacture, comprising: a machine-readable medium having stored thereon instructions to: generate a response when a router advertisement is received in a port in the network device. | TECHNICAL FIELD Embodiments of the invention relate generally to communication networks, and more particularly to the suppression of IPV6 router advertisement in a communication network. BACKGROUND Routing is a function associated with the Network Layer (layer 3) in the Open Systems Interconnection (OSI) model which is the standard model of network programming. On a communication network (e.g., the Internet), a router is typically a device that determines the next network point to which a packet should be forwarded so that the packet can reach its destination. The router is located at any gateway of at least two different networks and permits the connected different networks to communicate with each other. A router creates and maintains a table of the available routes and their conditions, and use this information (along with distance and cost algorithms) to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. In an environment where IPV6 stateless address autoconfiguration is used, an IPV6 router is required to advertise its presences in a network, by transmitting an advertisement that has information about the network. The router advertises at periodic time intervals in order to indicate that it is the dedicated router for that particular network or which network addresses are associated with the link. Additionally, the dedicated router can answer to a query from a client by responding with an advertisement to the client. The advertisement function is typically performed by the central processing unit (CPU) of the router. In an IPV6 (Internet Protocol Version 6) network, any device that can access a physical port (on a network device in the network) can intentionally or unintentionally become the designated router for a particular network. The IPV6 standard is described in, for example, <http://asg.web.cmu.edu/rfc/rfc2462.html> which is hereby fully incorporated herein by reference. If the client on an IPV6 network uses stateless address autoconfiguration (RFC 2462) to obtain network related information, a security issue arises. Stateless address autoconfiguration (RFC 2462) requires no manual configuration of hosts, minimal configuration of routers, and no additional servers. The stateless mechanism allows a host to generate its own addresses using a combination of locally available information and information advertised by routers. Routers advertise prefixes that identify the subnet associated with a link, while hosts generate an interface identifier that uniquely identifies an interface on a subnet. An address is formed by combining the two (prefix and interface identifier). Assuming the unauthorized device is an IPV6 routing capable device, then that unauthorized device can become the designated router by plugging that unauthorized device to a physical port on the network device. This scenario can be a potential network security problem and may cause networking problems in general. The unauthorized device can also advertise additional network prefixes and any client configured for autoconfiguration will automatically become a member of this network. The unauthorized device intentionally becomes the designated router if a hacker connects that unauthorized device to a network port on the network device, and the unauthorized device advertises itself as the best route for the network. The clients will erroneously learn that the unauthorized device is the designated router for the network, based upon the advertisements from the unauthorized device, and the clients will then change their routes to go through the unauthorized device. Therefore, all packet traffic for a network segment is diverted to this unauthorized device that is acting as the designated router. This unauthorized device can then examine all packets through a monitor port and forward the packets to a particular destination that permits sniffing of the packet content. The sniffing of the packet contents can permit a hacker to obtain passwords, credit card information, and/or other confidential information of a network user or can permit the hacker to otherwise disrupt the operation of the network. The unauthorized device unintentionally becomes the designated router if the unauthorized device is connected to the network device for purposes of testing, or is unintentionally connected to a port (of the network device) where the port is not configured. The unauthorized device can potentially become the default gateway for the network, but will not have any routes to the rest of the network because the unauthorized device is not the proper designated router. The host node (client) will use this unauthorized device as the designated router, but the host user will receive back a message from the unauthorized device, where the message indicates that the network is unreachable. Therefore, in this manner, the unauthorized device will disrupt the normal operation of the network, and this disruption will persist until the unauthorized device is removed from the network or the entries regarding this unauthorized device are aged out (i.e., the entries are automatically deleted after a particular amount of time). In one possible approach for network security, RFC (Request For Comment) 2462 mentions that IPSEC (Internet Protocol Security) could be used for authentication in network communication. Only devices in the network that could pass this authentication can become part of the network. IPSEC is a framework for a set of protocols for security at the network or packet processing layer of network communication. IPSEC provides two choices of security service: Authentication Header (AH), which essentially allows authentication of the sender of data, and Encapsulating Security Payload (ESP), which supports both authentication of the sender and encryption of data as well. The specific information associated with each of these services is inserted into the packet in a header that follows the IP packet header. Separate key protocols can be selected, such as the ISAKMP/Oakley protocol. However, IPSEC is not yet widely used and is not available for all devices. In one possible approach for network security, 802.1x (port based network access control) authentication may be used in network communication. However, this standard may not function in an IPV6 (Internet Protocol Version 6) network. Therefore, the current technology is limited in its capabilities and suffers from at least the above constraints and deficiencies. SUMMARY OF EMBODIMENTS OF THE INVENTION In one embodiment of the invention, an apparatus for suppressing a router advertisement includes a network device configured to filter a router advertisement from an unauthorized device. In another embodiment of the invention, an apparatus for detecting a router advertisement includes a network device configured to generate a response when a router advertisement is received in a particular port in the network device. The response may be, for example, the filtering of the router advertisement, creation of a flag to indicate receipt of the router advertisement in the particular port, or transmission of an SNMP report to indicate receipt of the router advertisement in the particular port. In another embodiment of the invention, an apparatus for detecting a router advertisement, includes: a network device configured to generate a response when a router advertisement is received in a port in the network device. In another embodiment of the invention, a method for detecting a router advertisement, includes: generating a response when a router advertisement is received in a port in the network device. In another embodiment of the invention, a method for suppressing a router advertisement includes filtering a router advertisement from an unauthorized device. These and other features of an embodiment of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. FIGS. 1A-1E are diagrams of a network system and system operation, in accordance with an embodiment of the invention. FIGS. 2A-2D are diagrams of a network system and system operation, in accordance with an embodiment of the invention. FIG. 3 is a block diagram of a network system, in accordance with an embodiment of the invention. FIG. 4 is a block diagram of a network device, in accordance with an embodiment of the invention. FIG. 5 is a flowchart of a method in accordance with an embodiment of the invention. FIG. 6 is a flowchart of a method used in the Internet Protocol version 6 (IPV6). DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of embodiments of the invention. An embodiment of the invention advantageously provides security and maintainability of IPV6 networks. As a result, a network administrator can better control the resources on the network. An embodiment of the invention provides a network device that can filter advertisements from an unauthorized device. The network device uses a pre-defined filter to filter the advertisements from the unauthorized device. As a result, the network device can prevent an authorized device on the network to become the default gateway and also can prevent a host(s) (clients) from creating unwanted virtual interfaces to the default gateway. Therefore, a host is prevented from creating an excessive number of virtual interfaces that can cause the host to crash. Referring initially to FIG. 3, there is shown a block diagram of a network system 100 with a network device 105, in accordance with an embodiment of the invention. As discussed below, one example of the network device 105 is an embodiment of a switch 105A in FIG. 4. At least one host node 115 is connected to a segment 120 that is connected to the router 110 via network device 105. The node 115 can send queries 120 to determine the designated router for the network. In a flat layer 2 network, hundreds of host nodes 115 may be connected to the segment 120. A host node 115 may typically be an end point node such as a client device. As known to those skilled in the art, a segment is a portion of a network and is separated by a bridge or router from other parts of the network. Within a network segment, data can flow between any two points without having to pass through switches, routers, bridges, or hubs. The size of a segment may be defined by the number of nodes within it, or by the amount of network traffic carried by the segment. Typically, a segment is a single continuous link or may be multiple links connected by repeaters. A link may be, for example, a suitable communication media such as copper, fibre, and/or air (wireless media). FIG. 1A is a diagram of a network system 40, in accordance with an embodiment of the invention, where the network device 105 is in a switch embodiment. In the example of FIG. 1, Host A1 goes through its normal autoconfiguration process when it is booted. This process is listed below, and the configuration information 50 in the switch A2 is shown in FIG. 1B. Step 1: Interface (in the Host A1) creates a link-local address 52. Step 2: Interface joins a multicast group. Step 3: Interface checks for a duplicate address. Step 4: Interface assigns itself the link-local address 52. Step 5: Host A1 receives Router advertisement with prefix(es) from router (Cisco1) A3. Step 6: Host A1 creates, tests, and assigns address to the interface. The MAC address 53 is also shown in FIG. 1B. The router A3 may be, for example, of the type commercially available from Cisco Systems, Inc., San Jose, Calif. FIG. 1C illustrates the configuration information 54 for a Host A1 with no IPV6 network connection. The link local address 55 is shown in the configuration information 54. In FIG. 1D, the router A3 will send out a router advertisement message 58 that is received by the host A1. The message 58 will include an advertised network prefix 60. In FIG. 1E, the host A1 has received the router advertisement 58. The host A1 becomes a member of an advertised network and a default gateway is sent to the link local address of the router A3, as shown by the configuration data 62 n FIG. 2A, router (Cisco2) A4 is inserted into the network 40 and the router A4 advertises the same prefix 60 (in a router advertisement 62) as the prefix 60 from router A3. The host A1 receives router advertisements 58 and 62 of the router 58 and router 62, respectively, and adds the router A4 as a default gateway (in this case, router A4 is preferred). As shown in the configuration Information 64 of FIG. 2B, the configuration data 65 shows that host A1 now has two default gateways, with router A4 as the preferred default gateway. All traffic originating from Host A1 destined to a host that is not on the local network would go to router A4, where packets could be spoofed and sent on to the packets' final destination. Another example would be that router A4 advertises additional networks, which Host A1 automatically becomes a member of. Host A1 now becomes vulnerable to attacks. Table 1 shows the Router Advertisement 62 of router A4 with additional network prefix of 3ffe:2002:1:aaaa::/64. FIG. 2C shows a portion 66 of the advertisement 62, where the advertised prefix are shown in portions 67 and 68. TABLE 1 Frame decode: Frame 10 (150 bytes on wire, 150 bytes captured) Arrival Time: Mar 23, 2004 14:20:28.191136000 Time delta from previous packet: 2.350486000 seconds Time since reference or first frame: 40.013390000 seconds Frame Number: 10 Packet Length: 150 bytes Capture Length: 150 bytes Ethernet II, Src: 00:0e:d7:dc:e4:a0, Dst: 33:33:00:00:00:01 Destination: 33:33:00:00:00:01 (IPv6-Neighbor- Discovery_00:00:00:01) Source: 00:0e:d7:dc:e4:a0 (Cisco_dc:e4:a0) Type: IPv6 (0x86dd) Internet Protocol Version 6 Version: 6 Traffic class: 0xe0 Flowlabel: 0x00000 Payload length: 96 Next header: ICMPv6 (0x3a) Hop limit: 255 Source address: fe80::20e:d7ff:fedc:e4a0 Destination address: ff02::1 Internet Control Message Protocol v6 Type: 134 (Router advertisement) Code: 0 Checksum: 0xd108 (correct) Cur hop limit: 64 Flags: 0x00 0... .... = Not managed .0.. .... = Not other ..0. .... = Not Home Agent ...0 0... = Router preference: Medium Router lifetime: 1800 Reachable time: 0 Retrans time: 0 ICMPv6 options Type: 1 (Source link-layer address) Length: 8 bytes (1) Link-layer address: 00:0e:d7:dc:e4:a0 ICMPv6 options Type: 5 (MTU) Length: 8 bytes (1) MTU: 1500 ICMPv6 options Type: 3 (Prefix information) Length: 32 bytes (4) Prefix length: 64 Flags: 0xc0 1... .... = Onlink .1.. .... = Auto ..0. .... = Not router address ...0 .... = Not site prefix Valid lifetime: 0x00278d00 Type: 3 (Prefix information) Length: 32 bytes (4) Prefix length: 64 Flags: 0xc0 1... .... = Onlink .1.. .... = Auto ..0. .... = Not router address ...0 .... = Not site prefix Valid lifetime: 0x00015180 FIG. 2D shows the configuration 70 of Host Al after it received advertisement 62 from router A4. The Host A1 automatically became a member of network 3FF3:2002:1:AAA as shown in data portion 71. FIG. 4 is a block diagram of a network device 105A in a switch embodiment, in accordance with an embodiment of the invention. In networks, a switch is a device that filters and forwards packets between Local Area Network (LAN) segments. Switches operate at the data link layer (layer 2) and sometimes at the network layer (layer 3) of the OSI Reference Model and therefore support any packet protocol. The switch's processor 205 performs overall configuration and control of the operation of the switch 105A. The The port module 220 has the multiple network ports (generally ports 221) of the switch 105A. In the example of FIG. 4, the port module 220 has ports 221a, 221b, and 221c. In practice, the port module 220 typically has additional ports. Each of the ports 221 typically includes an inbound buffer and an outbound buffer. For example, the port 221a has inbound buffer 222a and outbound buffer 224a, while the port 221b has inbound buffer 222b and outbound buffer 224b. The inbound buffer 222a is configured to receive packets from the network medium connected to the port module 220 and the outbound buffer 224a is configured to queue data associated with the transmission of packets to be sent to the network medium. The inbound buffer 222b and outbound buffer 224b perform these same functions. The port module 220 includes circuits (not specifically shown in FIG. 4) to connect its ports 221 to the switch bus 215 which is connected to a switch control 210 which includes inbound buffer 212 and outbound buffer 214 for exchanged data over a switch bus 215 and port module 220. The switch control 210 may be implemented in, for example, application specific integrated circuit (ASIC). A memory 230 will hold received packets for processing by the processor 205. The network device 105 (e.g., switch 105A in the example of FIG. 4) can filter out router advertisements from an unauthorized device 155 and provide improved security and better control of the network 100 (FIG. 3), based upon the following method. A network administrator (who controls the network infrastructure) can control which particular network devices will be used as routers on the network 100. The network administrator can specify the particular ports 221 in the switch 105A that are permitted to process router advertisements and specify particular ports 221 that are not permitted to process (i.e., are required to filter) router advertisements. Typically, the network administrator can send port configuration commands 240 from, for example, a host node 115, in order to specify the particular port 221 that will be permitted to process the router advertisements and to specify the particular ports 221 that will be required to filter the router advertisements. As described in the example below, the commands 240 can be the command 240a and the command 240b. Typically, the port configuration commands 240 are received by a port (e.g., port 221c) from the host node 115. A command software 245 (which is typically stored in the memory 230) can process the port configuration commands 240. Alternatively, the network administrator can directly input the port configuration commands 240 into the switch 105A, by manually entering the port configuration commands 240 into a user interface (if available) of the switch 105A. The command software 245 can then process the port configuration commands 240. Based upon the port configurations commands 240, the switch control 210 can configure a particular port 221 to accept router advertisements for further processing, and can configure the other ports 221 to filter (drop) router advertisements. An example of the filtering process for router advertisements is now described below. Assume that the network administrator is aware that the port 221a (i.e., “port 1”) is connected to a router 110 (with processor 135) which is the proper designated router for the network 130. Assume further that an unauthorized device has been connected to the port 221b (i.e., “port 2”). Of course, the unauthorized device can also be connected to the port 221 (i.e., “port 3”) or other additional ports of the switch 105A, in another example. The network administrator can then permit the transmission of command 240a (command #1) which is processed by the command software 245. The command 240a indicates the function “allow router-advertisement port 1” which allows router advertisements to port 221a to be processed. In other words, the command 240a permits the switch control 210 to configure the port 221a so that all router advertisements 140 received by port 221a is forwarded to all ports 221 for transmission. For example, the router advertisement 140 is received in the inbound buffer 222a of port 221a. The switch control 210 identifies a received packet as a router advertisement 140 on port 221a based upon a predefined address in field 260 (see FIG. 2) in the router advertisement 140. When the switch control 210 identifies a router advertisement 140 that is received by the inbound buffer 222a in the port 221a, the switch control 210 will accept the router advertisement 140 in the inbound buffer 212 and transmit the router advertisement 140 from the outbound buffer 214. As a result, the switch control 210 permits the advertisement 140 to be transmitted from the outbound buffers 224b and 224c of ports 221b and 221c, respectively, to other hosts 115 in the network 130 (FIG. 3). The switch control 210 will also permit the router advertisement 140 to be transmitted from the outbound buffers of any additional ports 221 in the port module 220. As a result, all hosts 115 in the network 130 will receive the router advertisements 140. Based upon the router advertisements 140, all hosts 115 will learn that the router 110 is their default gateway to network 125 (FIG. 1) and will obtain additional configuration data related to the router 110. The network administrator also permits the transmission of command 240b (command #2) which is processed by the command software 245. The command 240b indicates the function “disable router-advertisement port 2-3” which would disable router advertisements 150 to ports 221b and 221c. In other words, the command 240b permits the switch control 210 to configure the port 221b and 221c so that all router advertisements 150 received by port 221b and port 221 are filtered (dropped), and the hosts 115 are prohibited from adding the unauthorized device 155 (connected to port 221b and/or port 221c) as a designated router. These router advertisements 150 originate from an unauthorized device 155. As an example, the router advertisement 150 is received in the inbound buffer 222b of port 221b. The switch control 210 identifies a received packet as a router advertisement 150 on port 221b based upon a predefined address in field 265 (see FIG. 4) in the router advertisement 150. When the switch control 210 identifies a router advertisement 150 that is received by the inbound buffer 222b in the port 221b, the switch control 210 will not accept the router advertisement 150 in the inbound buffer 212 and will not transmit the router advertisement 150 from the outbound buffer 214. As a result, the switch control 210 does not permit the advertisement 150 to be transmitted from the outbound buffers 224c and 224a of ports 221c and 221a, respectively, to other hosts 115 in the network 130 (FIG. 1). The switch control 210 will also not permit the router advertisement 150 to be transmitted from the outbound buffers of any additional ports 221 in the port module 220. As a result, the switch 105A is able to filter the router advertisement 150 from an authorized device 155, and all hosts 115 in the network 130 will not receive the router advertisements 150. Therefore, all hosts 115 will not erroneously learn the unauthorized device 155 as the default gateway to the network 125 (FIG. 3). Therefore, an embodiment of the invention allows an implementation of IPV6 in networks to have improved security and better control of devices that can impact network functionality. Therefore, in the above embodiment of the invention, the network switch 105A generates a response when a router advertisement 150 is received in the port 221b or 221c. This response is the filtering of the router advertisement 150 after the router advertisement 150 is received in the filtered ports (i.e., ports 221b and 221c which are not connected to the proper designated router 110 in the above example). Another response to the receipt of a router advertisement 150 in the filtered ports (i.e., ports 221b and 221c which are not connected to the proper designated router 110 in the above example) may be the creation of a flag 270 by the command software 245 after the router advertisement 150 is received in the port 221b or 221c. The command software 245 has a logging function that can generate a flag 270 whenever a router advertisement 150 is received in the filtered ports. This flag 270 is recorded by the command software 245 in log data 275. The log data 275 may be stored in memory such as memory 230. The processor 205 can then format the log data 275 into a packet 280 and the switch control 210 can permit transmission of the packet 280 to a host 115. As a result, the flag 270 in the log data 275 can be viewed by the network administrator via a suitable user interface in, for example, a host 115. Therefore, the flag 270 alerts the network administrator that a router advertisement 150 has been received by the ports 221b or 221c which are not connected to a designate router 110. Another response to the receipt of a router advertisement 150 in the filtered ports (e.g., ports 221b and 221c in the above example) may be the transmission of an SNMP report 285 to indicate receipt of the router advertisement 150 in a filtered port. The SNMP report 285 can be viewed by the network administrator via a suitable user interface in, for example, a host 115. Therefore, the SNMP report 285 alerts the network administrator that a router advertisement 150 has been received by the ports 221b or 221c which are not connected to a designate router 110. An SNMP engine 290 generates the SNMP report 285. As known to those skilled in the art, SNMP (Simple Network Management Protocol is an Internet standard developed for managing nodes on an IP network. SNMP is a widely used network-monitoring protocol that is supported on most major platforms. SNMP manages and monitors various types of network equipment (including computers, routers, and hubs) by passing data from SNMP agents to workstations, and reporting activity in each network device. An example of a command syntax to accomplish the above operation could be as follows, as shown in Table 2. TABLE 2 On the switch CLI (in configuration mode): Interface 1> Permit ipv6 router-advertisements Interface 2-24 Deny ipv6 router-advertisements The above commands would influence the packet processing of the inbound interface. As the packets enter the port, the packets would be permitted or denied by the above filtering rules. The software or engines shown in FIG. 4 can be implemented in hardware, software, firmware, or a combination of hardware, software, and firmware. The various components shown in FIG. 4, such as, for example, the processor 205, memory 230, switch control 210, port module 220, and switch bus 215 can be implemented in hardware or other suitable known component structures. FIG. 5 is a flowchart of a method 300 in accordance with an embodiment of the invention. In step (305), a port coupled to a designated router is configured to receive and process a router advertisement, and all port(s) not coupled to the designated router are configured to filter a received router advertisement. The ports are in a network device such as, for example, a network switch. In step (310), when the port coupled to the designated router receives a router advertisement, then the router advertisement is forwarded to other ports, in order to transmit the router advertisement to all hosts in the network. The router advertisement is transmitted to all hosts in the network. In step (315), when the port(s) not coupled to the designated router receives a router advertisement, then a response is generated. The response may be, for example, a filtering of the router advertisement, a creation of a flag, or a transmission of an SNMP report. It is understood that step (310) and step (315) may occur concurrently, or step (315) may occur before step (310), or step (310) may occur before step (315). In step (320), all host(s) learns about the designated router, based upon the router advertisement. Since the method 300 limits the number of advertisements that are sent to the hosts, the number of virtual interfaces (created for each network that will use a particular router) that a host will create will be limited. This limiting feature advantageously prevents denial of service attacks or other types of attacks that can negatively affect the host. FIG. 6 is a flowchart of a method 400 used in the Internet Protocol version 6 (IPV6), shown for background purposes. In step (405), an interface (driver) of a host creates a Link-Local address (tentative address) which is an internal address that is used on a link that is coupled to the host. In step (410), the interface joins the multicast groups, by using the Link-local address to communicate with multicast addresses. In step (415), while sending out multicast packets, the host interface checks for duplicate address, in order to determine if another device already has the Link-Local address. If another device does not have the Link-Local address, then in step (420), the interface assigns itself the Link-Local address (which is a unique address on the link). In step (425), the host sends a router solicitation message, in order to determine the default gateway for the link. In step (430), the host receives router advertisement messages (from one or more routers on the link). In step (435), the host creates, tests, and assigns a unique address to interface, based upon the information in the advertisement message that is received from the router. If multiple routers respond to the host with different prefixes, multiple interfaces are created to be a member on each network. In step (440), the host will add the router as a default gateway. If multiple routers responded for the same network, one of the multiple router will be chosen based upon parameters such as, for example, lifetime, reliability and/or other parameters. If all parameters are the same (e.g., default parameters), multiple entries for the default gateway will be present and the host will either choose the first router or will use a router that permits load balancing (depending on the implementation on the host). The method of certain embodiments of the invention may be implemented in hardware, software, firmware, or a combination thereof. In one embodiment, the method is executed by software or firmware that is stored in a memory and that is executed by a suitable instruction execution system. If implemented in hardware, as in an alternative embodiment, the method can be implemented with any suitable technology that is well known in the art. The various engines or software discussed herein may be, for example, computer software, firmware, commands, data files, programs, code, instructions, or the like, and may also include suitable mechanisms. Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment”, “in an embodiment”, or “in a specific embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Other variations and modifications of the above-described embodiments and methods are possible in light of the foregoing disclosure. Further, at least some of the components of an embodiment of the invention may be implemented by using a programmed general purpose digital computer, by using application specific integrated circuits, programmable logic devices, or field programmable gate arrays, or by using a network of interconnected components and circuits. Connections may be wired, wireless, and the like. It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. It is also within the scope of an embodiment of the present invention to implement a program or code that can be stored in a machine-readable medium to permit a computer to perform any of the methods described above. Additionally, the signal arrows in the drawings/Figures are considered as exemplary and are not limiting, unless otherwise specifically noted. Furthermore, the term “or” as used in this disclosure is generally intended to mean “and/or” unless otherwise indicated. Combinations of components or steps will also be considered as being noted, where terminology is foreseen as rendering the ability to separate or combine is unclear. As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. It is also noted that the various functions, variables, or other parameters shown in the drawings and discussed in the text have been given particular names for purposes of identification. However, the function names, variable names, or other parameter names are only provided as some possible examples to identify the functions, variables, or other parameters. Other function names, variable names, or parameter names may be used to identify the functions, variables, or parameters shown in the drawings and discussed in the text. While the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments and equivalents falling within the scope of the appended claims. | <SOH> BACKGROUND <EOH>Routing is a function associated with the Network Layer (layer 3 ) in the Open Systems Interconnection (OSI) model which is the standard model of network programming. On a communication network (e.g., the Internet), a router is typically a device that determines the next network point to which a packet should be forwarded so that the packet can reach its destination. The router is located at any gateway of at least two different networks and permits the connected different networks to communicate with each other. A router creates and maintains a table of the available routes and their conditions, and use this information (along with distance and cost algorithms) to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. In an environment where IPV6 stateless address autoconfiguration is used, an IPV6 router is required to advertise its presences in a network, by transmitting an advertisement that has information about the network. The router advertises at periodic time intervals in order to indicate that it is the dedicated router for that particular network or which network addresses are associated with the link. Additionally, the dedicated router can answer to a query from a client by responding with an advertisement to the client. The advertisement function is typically performed by the central processing unit (CPU) of the router. In an IPV6 (Internet Protocol Version 6) network, any device that can access a physical port (on a network device in the network) can intentionally or unintentionally become the designated router for a particular network. The IPV6 standard is described in, for example, <http://asg.web.cmu.edu/rfc/rfc2462.html> which is hereby fully incorporated herein by reference. If the client on an IPV6 network uses stateless address autoconfiguration (RFC 2462) to obtain network related information, a security issue arises. Stateless address autoconfiguration (RFC 2462) requires no manual configuration of hosts, minimal configuration of routers, and no additional servers. The stateless mechanism allows a host to generate its own addresses using a combination of locally available information and information advertised by routers. Routers advertise prefixes that identify the subnet associated with a link, while hosts generate an interface identifier that uniquely identifies an interface on a subnet. An address is formed by combining the two (prefix and interface identifier). Assuming the unauthorized device is an IPV6 routing capable device, then that unauthorized device can become the designated router by plugging that unauthorized device to a physical port on the network device. This scenario can be a potential network security problem and may cause networking problems in general. The unauthorized device can also advertise additional network prefixes and any client configured for autoconfiguration will automatically become a member of this network. The unauthorized device intentionally becomes the designated router if a hacker connects that unauthorized device to a network port on the network device, and the unauthorized device advertises itself as the best route for the network. The clients will erroneously learn that the unauthorized device is the designated router for the network, based upon the advertisements from the unauthorized device, and the clients will then change their routes to go through the unauthorized device. Therefore, all packet traffic for a network segment is diverted to this unauthorized device that is acting as the designated router. This unauthorized device can then examine all packets through a monitor port and forward the packets to a particular destination that permits sniffing of the packet content. The sniffing of the packet contents can permit a hacker to obtain passwords, credit card information, and/or other confidential information of a network user or can permit the hacker to otherwise disrupt the operation of the network. The unauthorized device unintentionally becomes the designated router if the unauthorized device is connected to the network device for purposes of testing, or is unintentionally connected to a port (of the network device) where the port is not configured. The unauthorized device can potentially become the default gateway for the network, but will not have any routes to the rest of the network because the unauthorized device is not the proper designated router. The host node (client) will use this unauthorized device as the designated router, but the host user will receive back a message from the unauthorized device, where the message indicates that the network is unreachable. Therefore, in this manner, the unauthorized device will disrupt the normal operation of the network, and this disruption will persist until the unauthorized device is removed from the network or the entries regarding this unauthorized device are aged out (i.e., the entries are automatically deleted after a particular amount of time). In one possible approach for network security, RFC (Request For Comment) 2462 mentions that IPSEC (Internet Protocol Security) could be used for authentication in network communication. Only devices in the network that could pass this authentication can become part of the network. IPSEC is a framework for a set of protocols for security at the network or packet processing layer of network communication. IPSEC provides two choices of security service: Authentication Header (AH), which essentially allows authentication of the sender of data, and Encapsulating Security Payload (ESP), which supports both authentication of the sender and encryption of data as well. The specific information associated with each of these services is inserted into the packet in a header that follows the IP packet header. Separate key protocols can be selected, such as the ISAKMP/Oakley protocol. However, IPSEC is not yet widely used and is not available for all devices. In one possible approach for network security, 802.1x (port based network access control) authentication may be used in network communication. However, this standard may not function in an IPV6 (Internet Protocol Version 6) network. Therefore, the current technology is limited in its capabilities and suffers from at least the above constraints and deficiencies. | <SOH> SUMMARY OF EMBODIMENTS OF THE INVENTION <EOH>In one embodiment of the invention, an apparatus for suppressing a router advertisement includes a network device configured to filter a router advertisement from an unauthorized device. In another embodiment of the invention, an apparatus for detecting a router advertisement includes a network device configured to generate a response when a router advertisement is received in a particular port in the network device. The response may be, for example, the filtering of the router advertisement, creation of a flag to indicate receipt of the router advertisement in the particular port, or transmission of an SNMP report to indicate receipt of the router advertisement in the particular port. In another embodiment of the invention, an apparatus for detecting a router advertisement, includes: a network device configured to generate a response when a router advertisement is received in a port in the network device. In another embodiment of the invention, a method for detecting a router advertisement, includes: generating a response when a router advertisement is received in a port in the network device. In another embodiment of the invention, a method for suppressing a router advertisement includes filtering a router advertisement from an unauthorized device. These and other features of an embodiment of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims. | 20040423 | 20090728 | 20051027 | 69388.0 | 1 | RUTKOWSKI, JEFFREY M | SUPPRESSION OF ROUTER ADVERTISEMENT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,831,397 | ACCEPTED | Recombinant separator | A heterogeneous, cellulose battery separator made of a mixture of cellulose and a polymer with hydrogen permeability for use in zinc-based batteries exhibiting increased hydrogen transport through the membrane while maintaining low electrical impedance and exhibiting resistance to zinc ion transport preventing zinc dendrite formation. | 1-23. (canceled) 24. A battery according to claim 26 in which the cellulose is crosslinked with a hydrocarbon bridge containing from 2 to 12 carbon atoms between cellulose chains. 25. A battery according to claim 24 in which the bridge is an alkylene bridge containing from 4 to 8 carbon atoms. 26. A secondary, zinc ion battery comprising in combination; a battery case containing; a body of alkaline electrolyte; a zinc electrode disposed in said body of electrolyte; a counter-electrode disposed in said body of electrolyte; and a cellulose separator film having a thickness from 10 microns to 250 microns, being resistant to alkaline electrolyte, being impermeable to zinc ions containing a dispersion of discrete domains of polymer having a hydrogen permeability of at least 1×10−13 cm3cm−1s−1Pa−1, said film being impermeable to hydrogen except where said polymer is present in said film in an amount of 10 to 60 parts by weight to 100 parts of the cellulose film disposed in said body of electrolyte between said electrodes. 27. A secondary zinc battery according to claim 26 in which the counter-electrode comprises silver. 28. A secondary zinc battery according to claim 26 in which the polymer is present in said separator in an amount of 10 to 60 parts by weight to 100 parts by weight of cellulose. 29. A secondary zinc battery according to claim 28 in which the polymer is cellulose ether. 30. A secondary battery according to claim 29 in which the polymer is alkyl cellulose. 31. A secondary battery according to claim 30 in which the polymer is ethyl cellulose. | TECHNICAL FIELD This invention relates to a separator for an alkaline battery and, more particularly, this invention relates to a cellulosic separator for a secondary zinc ion battery such as a silver-zinc battery. BACKGROUND OF THE INVENTION Separators play a crucial role in alkaline batteries. They keep the positive and negative sides of the battery separate while letting certain ions go through and blocking others. The separator is a passive element that has to perform the same task unchanged for the life of the battery. Meanwhile, it must be able to withstand a strongly alkaline environment both at ambient and elevated temperatures. In addition, it must be capable of resisting oxidative attacks. In an alkaline battery, a separator should conduct hydroxyl ions at a sufficiently rapid rate to meet the increasingly high current demands of modern electronics. Films of cellulose in the form of regenerated cellulose have been used since World War II as the separator of choice for this purpose because of its superior ability to conduct hydroxyl ions in strongly alkaline media. Its low electrical resistance of 10 milliohm-in2 has also led to its favor for use in zinc-based batteries, such as silver-zinc, zinc-nickel, and zinc manganese dioxide batteries. Additionally, it acts as a physical barrier to migration of other ions in the battery, such as that of zincate ions and silver ions in a silver-zinc battery. Despite its advantages as a battery separator, regenerated cellulose has some intrinsic limitations. During overcharge, an alkaline battery tends to break down water and evolve hydrogen in sufficient quantities as to materially affect the internal impedance of the battery. Unless this hydrogen is removed efficiently, a parasitic feedback results in which the battery continues to be overcharged with resultant pressure buildup and venting of hydrogen or catastrophic rupture of the battery case. Regenerated cellulose, however, exhibits one of the lowest hydrogen permeability coefficients of known polymers, reported in the Polymer Handbook as 2.044×10−15 cm3cm−1s−1Pa−1. DESCRIPTION OF THE PRIOR ART Prior batteries incorporate in recombinant separators comprising porous melt-blown polymer fibers that incorporate surfactants or lubricants that facilitate gas transport within a battery. U.S. Pat. No. 6,054,084 describes separators for lead-acid batteries made of polytetrafluoroethylene (PTFE) fibril matrix incorporating particulate silica filler and non-evaporative lubricant as gas transport agents. Zucker in U.S. Pat. No. 5,962,161 describes a recombinant separator for lead-acid batteries that comprises melt-blown polypropylene made wettable by a surfactant agent thus enabling transport of oxygen. In U.S. Pat. No. 4,919,865 Nelson teaches a method for making a composite membrane made from a mixture of polymethyl methacrylate and a cellulosic derivative, such as cellulose acetate. A gas stream containing hydrogen is selectively cleaned of the hydrogen by the presence of the methyl methacrylate. Polymethyl methacrylate is, however, unsuitable as a battery separator capable of handling high currents because of its high electrical resistance. SUMMARY OF THE INVENTION The separator provided by the present invention consists of a membrane having both high hydroxyl conductivity and high hydrogen transport. When the separator is placed in a silver-zinc battery, hydrogen buildup in the battery is diminished. The present invention relates to a recombinant separator that is able to transport hydrogen while conducting hydroxyl ions. The separator of the invention help maintain low electrical impedance and exhibit resistance against formation of zinc dendrites. A preferred battery separator according to the inventor contains a solution of cellulose having of a degree of polymerization between 200 and 1200 that is mixed with particles of a polymer having a hydrogen permeability greater than 1×10−13 cm3cm−1s−1Pa−1. The resulting mixture is then coagulated under controlled environmental conditions to produce a heterogeneous gel that when dehydrated yields a membrane useful as a recombinant battery separator. These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic drawing of the heterogeneous recombinant separator of the invention. FIG. 2 is a spectra of cellulose. FIG. 3 is a spectra of ethyl cellulose; and FIG. 4 is a line scan view of the separator of the invention. DETAILED DESCRIPTION OF THE INVENTION The recombinant separator of the invention is formed of a mixture of a hydrophilic polymer, cellulose and hydrophobic agents. The hydrophilic polymers preferably have relatively high hydrogen permeability. The mixture is then coagulated under controlled conditions to yield a membrane that maintains the macroscopic properties of the two substituents. Cellulose, with a degree of polymerization from 200 to 1200, in the form of, but not limited to, microcrystalline cellulose, cotton fiber, paper and microgranular cellulose, is dissolved using a variety of different solvents. These solvents include, but are not limited to, LiCl/DMAC, trifluoroacetic acid and N-morpholine N-oxide. The applicable range in the case of LiCl/DMAC solution for the percent weight of the solution of cellulose to the solvent is 1 to 11%. The cellulose may be crosslinked with standard methods and then dissolved. A polymer having a hydrogen permeability greater than 1×10−13 cm3cm−1s−1Pa−1 can include, but is not limited to, ethyl cellulose, polyphenyl oxide, polymethyl siloxane, cellulose acetate, and gutta percha. The polymer is dissolved in a solvent that is miscible with the solvent that dissolves the cellulose, and is added either concurrently or separately. Whether mixed concurrently or separately, a preferable concentration range of 2 to 10% weight of solvent is used. A softener, such as glycerol or decane, may be added at this point, as long as it is soluble in the solvent. Hydrophilic fibers may also be added at this point. The solution containing both cellulose and the high hydrogen permeability polymer is then cast into a film using a variety of techniques known to those skilled in the art of membrane fabrication. These techniques include extrusion of the solution onto a conveyor belt, casting onto a glass plate with a casting knife or casting onto a well-leveled glass plate. An important aspect of the invention is that the controlled introduction of into the film or to the atmosphere above the solution in film form induces the formation of macroscopic domains and phase separation for both the hydrophobic and hydrophilic constituents in the cast solution. A properly formed-heterogeneous gel exhibits intertwined domains. These separate domains include one that is mostly the cellulose material and one that is mostly the hydrophobic agent. In the final film the hydrophobic regions are sufficiently large as to exhibit macroscopic transport characteristic of the bulk hydrophobic polymer. A schematic representation is shown in FIG. 1 which illustrates a recombinant film 10 having a continuous cellulose phase 12 and discontinuous regions 14 that are permeable to hydrogen. It has been observed via local measurements that hydrogen readily permeates through the hydrophobic rich regions, but not the cellulose regions. Nevertheless, cellulose molecules surround the hydrophobic regions, giving the film the zinc dendrite resistance, mechanical strength and ionic conductivity required for high performance. The rate of introduction of water to the cast mixture cannot be too slow or too fast. If it is too slow, no gel will form in a meaningful amount of time. If it is too fast, the gel formed will not be cohesive, and the film will not be strong. The solution can be coagulated with conventional techniques, either be exposure to ambient moisture, exposure to an alcohol atmosphere or by direct application of a water stream or alcohol stream to the resulting solution. It has been observed that an ambient atmosphere having a relative humidity range of 35 to 80% at a temperature range of 15 to 30 degrees Celsius yields acceptable gels within a 1 to 3 hour range. The coagulated cellulose material, in the form of a cohesive gel, is washed to remove the solvent and the salt. It is possible to employ alcohols mixed with water, but it is preferable that the percentage of alcohol be kept below a 50% volume ratio. After thorough washing of the resulting gel, the gel may be dried with any conventional technique such as air drying, vacuum drying or press drying. EXAMPLE 1 40 grams of microcrystalline cellulose (MCC, Aldrich 31,069-7) is placed in a solution of 2 kg of 5% LiCl/DMAC and heated to 120 degrees Celsius for 15 minutes. The cooled solution affords a clear solution of MCC. 5 grams of ethyl cellulose (EC) is dissolved in 100 ml DMAC separately. The MCC and EC solutions are combined in a 60/40 weight ratio by polymer weight. 40 ml of the combined solution is placed on a glass tray. Exposure to ambient moisture at 21 degrees Celsius at 55-60% relative humidity yields a cohesive gel in approximately 2 hours. This gel contains phases of MCC and EC. The gel is then washed with water repeatedly until all DMAC and LiCl are removed. The gel is then dried with a press-dry, affording a film useful as a separator. The separator film is tested for hydrogen transport using an assembly containing a mass spectrometer. A cavity whose walls are made of a hydrogen impermeable material is filled with hydrogen on one side is capped with a separator film to form a tight seal around the cavity. A mass spectrometer equipped with an external probe is placed on the exposed part of the separator and the partial pressure of hydrogen is read after a suitable amount of time. Representative data after 1 minute follows: Base H2 pressure Measured H2 pressure Membrane ID (×10e − 10 Torr) (×10e − 10 Torr) Cellulose 1.5 1.5 Recombinant 685b 1.5 20.9 Recombinant 959c 1.5 89 The separators were presoaked in 50% by weight KOH for 2 minutes and placed in the above apparatus. Similar differentiation in hydrogen transport properties was obtained between regenerated cellulose and recombinant separators. The recombinant separators were placed in silver-zinc batteries with the result that the batteries were fast charged, and their impedance was indistinguishable from regenerated cellulose. Further confirmation of phase separation was obtained by performing a scanning reflective Fourier Transform Infrared spectrograms of the film surface over a region 2500 microns in length. A Perkin Elmer Autoimage FTIR microscope was used to collect the data. For illustrative purposes a scan of plain cellulose and of plain ethyl cellulose is shown in FIGS. 2 and 3, respectively. The most obvious differentiation between the two spectra is the presence of a peak at 2970 cm−1 in the EC spectrum corresponding to a C—H stretch of the ethyl group. FIG. 4 shows a plot of 100 IR scans where each scan is taken every 25 microns along a particular direction. It is observed from the spectra that agglomerated regions of EC are juxtaposed to regions that are comprised mostly of cellulose. Furthermore, a microprobe attached to a mass spectrometer as described above, when placed on the ethyl cellulose-rich regions, detected transport of hydrogen through these regions, whereas the probe, when placed over a cellulose-rich region, failed to detect any passage of hydrogen. EXAMPLE 2 20 g of microgranular cellulose (Aldrich C6413) is dissolved in 22 kg of 5% LiCl/DMAC and heated to 130 degrees Celsius for 1 hour. The solution is cooled and then mixed with 5% by weight EC in DMAC in a 60/40 weight ratio cellulose/EC. 45 g of solution is cast and gelled with a humidifier over the glass tray. A thermohygrometer close to the tray registered 20 degrees Celsius and 65% relative humidity. After 1 hour, a cohesive gel forms, which is then rinsed to yield a solvent and salt-free gel. The gel is dried under vacuum to yield a separator that is 75 microns in thickness. EXAMPLE 3 20 g. cellulose of powder form (International Filler Corporation) of degree of polymerization 1200 is dissolved in 2 kg of 3% LiCl/DMAC. Cellulose is crosslinked by reacting with NaOH and 1,6 diiodohexane. The resulting cellulose solution is mixed with 4% polyphenyl oxide in DMAC and both solutions are heated to 70 degrees Celsius and then cooled. Solutions are cast onto a conveyor belt and allowed to gel on the conveyor belt. Gel is moved to a different section where it is washed and rinsed along another belt and then taken to a drying drum. EXAMPLE 4 The procedure of example was repeated except washing was performed with 50% methanol, 50% water. It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Separators play a crucial role in alkaline batteries. They keep the positive and negative sides of the battery separate while letting certain ions go through and blocking others. The separator is a passive element that has to perform the same task unchanged for the life of the battery. Meanwhile, it must be able to withstand a strongly alkaline environment both at ambient and elevated temperatures. In addition, it must be capable of resisting oxidative attacks. In an alkaline battery, a separator should conduct hydroxyl ions at a sufficiently rapid rate to meet the increasingly high current demands of modern electronics. Films of cellulose in the form of regenerated cellulose have been used since World War II as the separator of choice for this purpose because of its superior ability to conduct hydroxyl ions in strongly alkaline media. Its low electrical resistance of 10 milliohm-in 2 has also led to its favor for use in zinc-based batteries, such as silver-zinc, zinc-nickel, and zinc manganese dioxide batteries. Additionally, it acts as a physical barrier to migration of other ions in the battery, such as that of zincate ions and silver ions in a silver-zinc battery. Despite its advantages as a battery separator, regenerated cellulose has some intrinsic limitations. During overcharge, an alkaline battery tends to break down water and evolve hydrogen in sufficient quantities as to materially affect the internal impedance of the battery. Unless this hydrogen is removed efficiently, a parasitic feedback results in which the battery continues to be overcharged with resultant pressure buildup and venting of hydrogen or catastrophic rupture of the battery case. Regenerated cellulose, however, exhibits one of the lowest hydrogen permeability coefficients of known polymers, reported in the Polymer Handbook as 2.044×10 −15 cm 3 cm −1 s − 1 Pa −1 . | <SOH> SUMMARY OF THE INVENTION <EOH>The separator provided by the present invention consists of a membrane having both high hydroxyl conductivity and high hydrogen transport. When the separator is placed in a silver-zinc battery, hydrogen buildup in the battery is diminished. The present invention relates to a recombinant separator that is able to transport hydrogen while conducting hydroxyl ions. The separator of the invention help maintain low electrical impedance and exhibit resistance against formation of zinc dendrites. A preferred battery separator according to the inventor contains a solution of cellulose having of a degree of polymerization between 200 and 1200 that is mixed with particles of a polymer having a hydrogen permeability greater than 1×10 −13 cm 3 cm −1 s −1 Pa −1 . The resulting mixture is then coagulated under controlled environmental conditions to produce a heterogeneous gel that when dehydrated yields a membrane useful as a recombinant battery separator. These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. | 20040423 | 20060418 | 20050901 | 71686.0 | 0 | WILLS, MONIQUE M | RECOMBINANT SEPARATOR | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,831,412 | ACCEPTED | Elimination of write head plating defects using high activation chemically amplified resist | Methods of forming a component of a thin film magnetic head and improving the plating of a component of a thin film magnetic head are provided. The methods include the use of a high activation energy chemically amplified photoresist (CARS) that is contacted with a low pH high saturation magnetic moment plating solution to form a magnetic head component that is essentially free of plating defects. The methods find utility in hard disk drive applications, such as in the manufacture of magnetic poles for the write head of a hard disk drive. | 1. A method of forming a component of a thin film magnetic head, wherein the magnetic head is formed from a structure that includes a substrate layer, a seedlayer deposited on the substrate layer, and a photoresist composition layer deposited on the seedlayer, comprising: providing a high activation energy chemically amplified photoresist composition as said photoresist composition layer; patternwise exposing said photoresist composition layer to an imaging radiation source to form a latent, patterned image in the photoresist composition layer; developing the latent image in the photoresist composition layer with a developer to form a patterned photoresist; and, performing a plating process to form the thin film magnetic head component by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. 2. The method according to claim 1, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 70° C. 3. The method according to claim 2, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 90° C. 4. The method according to claim 3, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 120° C. 5. The method according to claim 1, wherein the high activation energy chemically amplified photoresist is a positive-tone photoresist. 6. The method according to claim 5, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having acid-cleavable substituent groups selected from acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate, orthoester, and a combination thereof. 7. The method according to claim 6, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having polar functional groups selected from hydroxyl, carboxyl, anhydride, lactone, imide, fluoroalcohol, sulfonamide, and a combination thereof. 8. The method according to claim 1, further comprising a post-exposure bake at a temperature of at least about 90° C. 9. The method according to claim 1, wherein the plating process solution comprises a high saturation magnetic moment plating material selected from NiFe, CoNiFe and CoFe. 10. The method according to claim 9, wherein the high saturation magnetic moment plating material has a saturation magnetic moment of at least about 2.4 T. 11. The method according to claim 1, wherein the plating process solution has a pH of less than about 2.5. 12. The method according to claim 1, wherein the plating process is a frame plating process. 13. A method of improving the plating of a component of a thin film magnetic head, comprising forming a frame plating patterned photoresist layer from a layer of a high activation energy chemically amplified photoresist composition coated on a substrate layer, and directly contacting the patterned photoresist layer with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. 14. The method according to claim 13, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 70° C. 15. The method according to claim 14, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 90° C. 16. The method according to claim 15, wherein the high activation energy chemically amplified photoresist has an activation temperature of at least about 120° C. 17. The method according to claim 13, wherein the high activation energy chemically amplified photoresist is a positive-tone photoresist. 18. The method according to claim 17, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having acid-cleavable substituent groups selected from acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate, orthoester, and a combination thereof. 19. The method according to claim 18, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having polar functional groups selected from hydroxyl, carboxyl, anhydride, lactone, imide, fluoroalcohol, sulfonamide, and a combination thereof. 20. The method according to claim 13, wherein the plating process solution comprises a high saturation magnetic moment plating material selected from NiFe, CoNiFe and CoFe. 21. The method according to claim 20, wherein the high saturation magnetic moment plating material has a saturation magnetic moment of at least about 2.4 T. 22. The method according to claim 13, wherein the plating process solution has a pH of less than about 2.5. 23. In a method of plating a component of a thin film magnetic head, wherein a photoresist composition is layered on a substrate layer, formed into a patterned photoresist composition layer and contacted with a plating process solution having a pH of less than about 3.0 in order to form a component of the thin film magnetic head, the improvement which comprises employing a high activation energy chemically amplified photoresist composition as said photoresist composition such that the plated thin film magnetic head component is essentially free of plating defects arising from contact of the photoresist composition layer with the plating process solution. 24. The method according to claim 23, wherein the high activation energy chemically amplified photoresist is a positive-tone photoresist having an activation temperature of at least about 90° C. 25. The method according to claim 24, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having acid-cleavable substituent groups selected from acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate, orthoester, and a combination thereof. 26. The method according to claim 23, wherein the plating process solution comprises a high saturation magnetic moment plating material having a saturation magnetic moment of at least about 2.4 T selected from NiFe, CoNiFe and CoFe. 27. A frame plating method, comprising: forming a pattern in a photoresist composition comprising a high activation energy chemically amplified photoresist, or in a layer of said photoresist composition formed on a substrate, by patternwise exposing said photoresist composition to an imaging radiation source to form a latent, patterned image in the photoresist composition; developing the latent image in the photoresist composition with a developer to form a patterned photoresist; performing a plating process using the patterned photoresist as a frame by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, and removing the patterned photoresist. 28. The method according to claim 27, wherein the high activation energy chemically amplified photoresist is a positive-tone photoresist having an activation temperature of at least about 90° C. 29. The method according to claim 28, wherein the high activation energy chemically amplified photoresist contains an aqueous base soluble polymer resin having acid-cleavable substituent groups selected from acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate, orthoester, and a combination thereof. 30. The method according to claim 27, wherein the plating process solution comprises a high saturation magnetic moment plating material having a saturation magnetic moment of at least about 2.4 T selected from NiFe, CoNiFe and CoFe. | FIELD OF THE INVENTION This invention relates to an improved method for making certain components for magnetic storage hard disc drives. More particularly, the invention relates to the reduction or elimination of plating defects in components of a magnetic head, such as in a write head of a thin film magnetic head for use in hard disk drives. BACKGROUND OF THE INVENTION The need for increased storage capacity and improved read and write access to information stored on magnetic disk drives has produced a large number of improvements in hard disk drive technology. The general trend has been toward increased areal density of information stored on magnetic disk drives, accomplished in part by improvements in the magnetic storage characteristics of materials used to store magnetic information on hard disks and by improved designs and methods of making read and write heads for hard disks. In a thin film write (recording) head, for example, such improvements have resulted in reductions in the width of the pole tips of the write heads in order to increase the track density of the recording medium to which the head writes information. Since higher track densities resulting from narrower pole tip widths allow for more information to be stored on a hard disk, the need to provide further improvements by reducing track width presents a continuing challenge. Write heads for hard disk drives also desirably benefit from the use of high magnetic fields for writing information on a hard disk. In order for a high magnetic field to be provided by a write head, the magnetic flux density needs to be high in the write head. In turn, higher saturation magnetic moments for write heads are necessary to provide higher flux densities so that areal densities of the magnetic media may thereby also be increased. Materials with high saturation magnetic moments allow for the generation of higher magnetic fields in the magnetic media, increased field gradients, faster effective rise times, narrower pulse widths, smaller erase bands and improved over-write characteristics on the magnetic media. For this reason, it is desirable that the pole tips of a thin film magnetic write head be formed from a high saturation magnetic moment material. The fabrication of a thin film magnetic head, as well as the various components of the magnetic head, requires that certain submicrometer structures be formed. An example of such a structure is the pole tip of a write head. One method of making pole structures is to fabricate a mask using a photoresist according to a frame plating method in conjunction with a plating process. A typical general sequence for frame plating a pole structure includes depositing a seedlayer on a wafer, spin coating a layer of photoresist on the wafer, imagewise patterning of the photoresist through a mask to expose areas of the photoresist intended to be removed (for a positive-tone resist, or areas intended to be not removed for a negative-tone resist), removal of areas intended to be removed by developing the photoresist to thereby provide a framed opening in the photoresist corresponding to a pole structure, and plating the framed opening to form the pole structure by a conventional plating process. Resist frame plating methods are also described in the literature. In U.S. Pat. No. 6,547,975 (to Kobrin), for example, a magnetic pole fabrication process is described in which a seedlayer material is sputtered onto the vertical sidewall portion of a polymer layer used to form a submicrometer structure. A “resist frame for plating” method is also referred to in Kobrin based on the disclosure of U.S. Pat. No. 5,665,251. In U.S. Pat. Nos. 6,635,408 and 6,641,984 and U.S. Patent Application Publication No. 2001/0035343 (all to Kamijima) and U.S. Pat. No. 6,358,674 (to Kamijima et al.), frame plating methods are also described using a resist that may be a chemically amplified resist. The resist is described as being coated with a covering layer of a water-soluble crosslinking agent capable of being crosslinked in the presence of acid and a resin material containing at least a water-soluble resin on the water-soluble crosslinking agent. The covering layer, rather than the resist, appears to be described as functioning as the frame in contact with the plating solution. As is known in the art, chemically amplified resists (CARS) may be categorized as positive-tone or negative-tone resists. Positive-tone resists generally contain two major components: an aqueous base soluble polymer resin and a photoacid generator (PAG). The aqueous base soluble polymer of such chemically amplified resists typically contains polar functional groups protected by acid-cleavable protecting groups (also known in the art as acid labile, or blocking groups). The presence of such protecting groups converts the aqueous base soluble polymer into an insoluble resin. Acid catalyzed deprotection of the protected sites converts the polymer back into an aqueous base soluble polymer. Development of the positive-tone resist selectively removes the exposed regions of the photoresist. The acid-cleavable groups used with the aqueous base soluble polymer resins can be classified into two distinct groups: a) high activation energy protecting groups such as t-butyl ester or t-butyl carbonyl groups; and b) low activation energy protecting groups such as acetal, ketal or silylether groups. Hybrid resists are also described in the art in which a combination of high and low activation energy groups is included in the resist (see, e.g., U.S. Pat. No. 6,303,263 to Chen et al.). Although a wide variety of photoresists are known in the art, the requirements of a specific application may govern the suitability of using a particular resist in that application. For example, in contacting a resist frame with certain plating process solutions, defects such as cracks and “worms” (i.e., localized fractures or irregular defects in the resist) may be introduced into the resist depending on the type of resist, the plating solution and/or the plating conditions used. Such defects, in turn, may lead to irregularities and defects in the plated structures obtained from the plating process. Thus it is desirable to have a method for making plated components for hard disk drive magnetic heads, particularly the write head poles of a magnetic head, which are essentially free of plating defects. It is further desirable for such a method to provide a means for reducing or eliminating such defects through compatible modifications to existing methods for making plated components for magnetic heads. Accordingly, the present invention addresses such needs in part by providing an improved method of forming a component of a magnetic head, that, in one embodiment, is suitable for making a plated magnetic component of a write head for use in a hard disk drive. SUMMARY OF THE INVENTION It is a general object of the invention to provide a method of forming a component of a thin film magnetic head, a method of improving the plating of a component of a thin film magnetic head, and a frame plating method, whereby a plated component is formed that is essentially free of plating defects. One aspect of the invention therefore relates to a method of forming a component of a thin film magnetic head, wherein the magnetic head is formed from a structure that includes a substrate layer, a seedlayer deposited on the substrate layer, and a photoresist composition layer deposited on the seedlayer, comprising: providing a high activation energy chemically amplified photoresist composition as said photoresist composition layer; patternwise exposing said photoresist composition layer to an imaging radiation source to form a latent, patterned image in the photoresist composition layer; developing the latent image in the photoresist composition layer with a developer to form a patterned photoresist; and, performing a plating process to form the thin film magnetic head component by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. Another aspect of the invention pertains to a method of improving the plating of a component of a thin film magnetic head, comprising forming a frame plating patterned photoresist layer from a layer of a high activation energy chemically amplified photoresist composition coated on a substrate layer, and directly contacting the patterned photoresist layer with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. A further aspect of the invention concerns an improvement in a method of plating a component of a thin film magnetic head, wherein a photoresist composition is layered on a substrate layer, formed into a patterned photoresist composition layer and contacted with a plating process solution having a pH of less than about 3.0 in order to form a component of the thin film magnetic head, the improvement comprising employing a high activation energy chemically amplified photoresist composition as said photoresist composition such that the plated thin film magnetic head component is essentially free of plating defects arising from contact of the photoresist composition layer with the plating process solution. Yet another aspect of the inventions relates to a frame plating method, comprising: forming a pattern in a photoresist composition comprising a high activation energy chemically amplified photoresist, or in a layer of said photoresist composition formed on a substrate, by patternwise exposing said photoresist composition to an imaging radiation source to form a latent, patterned image in the photoresist composition; developing the latent image in the photoresist composition with a developer to form a patterned photoresist; performing a plating process using the patterned photoresist as a frame by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, and, removing the patterned photoresist. Additional aspects, advantages and novel features of the invention will be set forth in part in the figures and detailed description that follow, and will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention through routine experimentation. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a plated high activation energy CARS (Shipley UV26®) plated with 22/78 NiFe plating as described in Example 1. FIGS. 2A and 2B, collectively referred to as FIG. 2, show fractures in KRS-Xe® resist (a low activation energy resist) after immersion in a 22/78 NiFe plating bath as described in Example 2. FIG. 3 shows fractures in ShinEtsu I036® resist (a hybrid resist containing low and high activation energy groups) at the edge of a wafer after immersion in CoFe plating bath as described in Example 3. DETAILED DESCRIPTION OF THE INVENTION Definitions and Overview The definitions set forth herein apply only to the terms as they are used in this patent and may not be applicable to the same terms as used elsewhere, for example in scientific literature or other patents or applications including other applications by these inventors or assigned to common owners. The following description of embodiments and examples are provided by way of explanation and illustration. As such, they are not to be viewed as limiting the scope of the invention as defined by the claims. Additionally, when examples are provided, they are intended to be exemplary only and not to be restrictive. As well, when an example is said to “include” a specific feature, it is intended to imply that it may have that feature but not that such examples are limited to those that include such features. As used in this specification and in the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Similarly, the phrase “a combination thereof” includes mixtures of one or more of the same category of referent, as well as mixtures of different referents. More particularly, the combination of acid-cleavable substituent groups for an aqueous base soluble polymer is intended to include mixtures of one or more acid-cleavable substituent groups with one or more aqueous base soluble polymers, in addition to a mixture of one polymer having an acid-cleavable substituent group with one or more other polymers having the same or different acid-cleavable substituent group(s). The same understanding also applies for other combinations; in particular, for the aqueous base soluble polymers having polar functional groups. In describing and claiming the present invention, the following terminology is used in accordance with the definitions set out below. The term “high activation energy” refers to chemically activated resists having protecting groups that require a comparatively high activation energy in order to deprotect the blocking groups in the resist. In this sense, the term “high” is intended to be descriptive of a known class of chemically activated resists rather than indicative of a particular degree or quantity of activation energy required. As a class of resists, high activation energy resists are distinguished from low activation energy and hybrid resists since they are not activated at room or low to moderate temperatures. Typically, temperatures of about 70° C. or above are required to activate such high activation energy resists. Similarly, the term “high saturation magnetic moment” refers to plating materials having a comparatively high magnetic moment. Here, the term “high” is also intended to be descriptive of a class of magnetic materials rather than indicative of a particular degree of saturation magnetic moment. Typically, however, such materials have saturation magnetic moments above about 2.3 T. The term “activation temperature,” as used in reference to chemically amplified photoresists (CARS), refers to the temperature at which a chemical amplification reaction occurs due to the temperature induced, acid-catalyzed deprotection of acid-cleavable (blocking) groups in the resist resin. The phrase “essentially free of plating defects” is generally intended to mean that most or all plating defects that arise due to contacting a photoresist with a plating solution are eliminated. Minor defects not adversely affecting the performance of the plated component, such as a write head of a thin film magnetic head for use in hard disk drive applications, may still remain. By the term “directly contacted,” as used in reference to the plating of the patterned photoresist using the plating solution, it is intended that the photoresist is not further treated, such as by coating or sputtering an additional layer of a material onto the photoresist, prior to contacting the photoresist with the plating solution. In this sense, the photoresist itself is contacted with the plating solution rather than a surface treated or coated photoresist being contacted with the plating solution. The “directly contacted” patterned photoresist of the present invention may be distinguished in part from processes described in the literature, such as the Kamijima and Kamijima et al. patents mentioned above, since coatings and surface treatments of the photoresist are not used. The term “acid-cleavable” refers to a molecular segment containing at least one covalent bond that is cleaved upon exposure to acid. Typically, the reaction of acid-cleavable groups herein with photogenerated acid occurs only, or is promoted greatly by, the application of heat. Those skilled in the art will recognize the various factors that influence the rate and ultimate degree of cleavage of acid-cleavable groups as well as the issues surrounding integration of the cleavage step into a viable manufacturing process. The product of the cleavage reaction is generally an acidic group, which, when present in sufficient quantities, imparts solubility to resist polymers in basic aqueous solutions. Analogously, the term “acid-inert” refers to a substituent that is not cleaved or otherwise chemically modified upon contact with photogenerated acid. The terms “photogenerated acid” and “photoacid” are used interchangeably herein to refer to the acid that is created upon exposure of the present photoresist compositions to radiation, by virtue of the photoacid generator contained in the compositions. Unless otherwise indicated, the term “hydrocarbyl” is to be interpreted as including substituted and/or heteroatom-containing hydrocarbyl moieties. “Hydrocarbyl” refers to univalent hydrocarbyl radicals containing 1 to about 30 carbon atoms, preferably 1 to about 18 carbon atoms, most preferably 1 to about 12 carbon atoms, including linear, branched, cyclic, alicyclic, and aromatic species. “Substituted hydrocarbyl” refers to hydrocarbyl substituted with one or more substituent groups, and the term “heteroatom-containing hydrocarbyl” refers to hydrocarbyl in which at least one carbon atom is replaced with a heteroatom. For additional information concerning terms used in the field of lithography and lithographic compositions, see Introduction to Microlithography, Eds. Thompson et al. (Washington, D.C.: American Chemical Society, 1994). High Activation Energy Chemically Amplified Photoresist High activation energy chemically amplified photoresists suitable for use in the present invention are generally known in the art, and are available from various manufacturers. Such resists generally contain an aqueous base soluble polymer resin having acid-cleavable substituent groups selected from acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate, orthoester, and combinations thereof. Although negative-tone resists may in principle be utilized, the high activation energy chemically amplified photoresist is preferably a positive-tone photoresist. The aqueous base soluble polymer resins employed in the present invention are generally well known to those skilled in the resist material art. Suitable aqueous base soluble polymer resins employed include homopolymers containing one monomeric repeating unit or higher polymers, i.e. copolymers, terpolymers, etc., containing two or more monomeric repeating units that are soluble in an alkaline solution. The polymer may also be formed from a mixture of two or more different first monomers and may further include at least one additional olefinic comonomer, e.g., thereby forming ter-, tetra- or multi-monomer polymers. While not strictly limited, such additional monomers include monomers containing an acid-cleavable substituent, monomers containing an acid-inert, polar substituent, monomers containing an acid-inert, nonpolar substituent, and combinations thereof. The aqueous soluble base polymer resins employed in the present invention are those that contain polar functional groups that readily ionize. Generally such groups are hydroxyl or carboxyl functionalities, although other polar functional groups, such as anhydride, lactone, imide, fluoroalcohol, sulfonamide, and combinations thereof may also be used. Illustrative examples of suitable homopolymers that can be utilized in the present invention include, but are not limited to: phenolic-containing resins such as poly(hydroxystyrene) including the para-, meta-, and ortho-substituted forms and phenol formaldehydes; polymers having an acid or an anhydride group, e.g. polyacrylic acid or polymethacrylic acid; or acrylamide, imide or hydroxyimide group polymers. Preferred homopolymers generally have a weight average molecular weight within the range of about 1000 to about 250,000, and preferably within the range of about 2000 to about 25,000. Examples of suitable higher polymer resins that can be employed in the present invention are those which contain at least two of the following monomers: styrene, hydroxystyrene, acrylic acid, methacrylic acid, acrylate, methacrylate, vinylcyclohexanol, phenol formaldehyde, acrylamide, maleic anhydride, and maleimide. The molecular weight for such higher polymer resins employed in the present invention is generally in the same ranges noted previously for the homopolymers. A preferred higher polymer employed in the present invention is one which contains at least two of the following monomeric units: styrene, hydroxystyrene, acrylic acid, methacrylic acid, vinylcyclohexanol, acrylate, and methacrylate. The aqueous base soluble polymer resins employed in the present invention also contain a polymeric backbone such as, but not limited to: polyolefins, polyolefin sulfones, polysulfones, polyketones, polycyclic olefins, polycarbonates, polyimides, polyethers and the like. The acid-cleavable substituent (protecting) groups are desirably selected such that the high activation energy chemically amplified photoresist has an activation temperature of at least about 70° C., preferably at least about 90° C., more preferably at least about 120° C. In addition, the photoresist polymer should be stable in low pH plating solutions, preferably such that defects do not occur in the photoresist and plated components arising from contact of the photoresist with the plating solution. As noted, representative such groups include acid-cleavable cyclic and branched aliphatic carbonyls, ester, oligomeric ester, ether, carbonate and orthoester groups. Illustrative examples of cyclic or branched aliphatic carbonyls that may be employed in the present invention include, but are not limited to: phenolic carbonates; t-alkoxycarbonyloxys such as t-butoxylcarbonyloxy; and isopropyloxycarbonyloxy. A preferred carbonate that may be employed in the present invention is t-butoxylcarbonyloxy. Examples of cyclic and branched ethers that may be employed in the present invention include, but are not limited to: benzyl ether and t-alkyl ethers, such as t-butyl ether. Of the ethers, t-butyl ether is preferred. Examples of cyclic and branched esters that can be employed in the present invention are carboxylic esters having a cyclic or branched aliphatic substituent such as t-butyl ester, isobornyl ester, 2-methyl-2-admantyl ester, benzyl ester, 3-oxocyclohexanyl ester, dimethylpropylmethyl ester, mevalonic lactonyl ester, 3-hydroxy-.gamma.-butyrolactonyl ester, 3-methyl-.gamma.-butylrolactonyl ester, bis(trimethylsilyl)isopropyl ester, trimethylsilylethyl ester, tris(trimethylsilyl)silylethyl ester and cumyl ester. In another aspect, the polymer resin may contain at least one acid-inert, non-polar substituent. Exemplary such groups, without limitation, may be selected from C1-C18 hydrocarbyl and substituted C1-C18 hydrocarbyl, e.g., fluorinated C1-C18 hydrocarbyl. Suitable acid-inert moieties include, for example, C1-C18 alkyl, C1-C18 hydroxyalkyl, fluorinated C1-C18 alkyl, and fluorinated C1-C18 hydroxyalkyl. Photoresist Compositions The high activation energy photoresist is generally used in the form of a photoresist composition that comprises the photoresist polymer, as described in detail above, and a photoacid generator, with the polymer representing up to about 99 wt. % of the solids included in the composition, and the photoacid generator representing approximately 0.1 to 25 wt. % of the solids contained in the composition. Other components and additives may also be present, e.g., dissolution modifying additives such as dissolution inhibitors. The photoacid generator may be any compound that, upon exposure to radiation, generates a strong acid and is compatible with the other components of the photoresist composition. Such compounds are commonly employed herein as well as in the prior art for the deprotection of the acid-cleavable protecting groups. Examples of preferred photochemical acid generators (PAGs) include, but are not limited to, sulfonates, onium salts, aromatic diazonium salts, sulfonium salts, diaryliodonium salts and sulfonic acid esters of N-hydroxyamides or N-hydroxyimides, as disclosed in U.S. Pat. No. 4,731,605. Any PAG(s) incorporated into the present photoresists should have high thermal stability, i.e., stable to at least 140° C., so they are not degraded during pre-exposure processing. The specific photoacid generator selected will depend on the irradiation source being used for patterning the resist. Photoacid generators are currently available for a variety of different wavelengths of light from the visible range to the X-ray range; thus, imaging of the resist can be performed using mid-UV, deep-UV, extreme-UV, e-beam, X-ray or any other irradiation source deemed useful. Any suitable photoacid generator can be used in the photoresist compositions of the invention. Typical photoacid generators include, without limitation: sulfonium salts, such as triphenylsulfonium perfluoromethanesulfonate (triphenylsulfonium triflate), triphenylsulfonium perfluorobutanesulfonate, triphenylsulfonium perfluoropentanesulfonate, triphenylsulfonium perfluorooctanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium bromide, triphenylsulfonium chloride, triphenylsulfonium iodide, 2,4,6-trimethylphenyldiphenylsulfonium perfluorobutanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium benzenesulfonate, tris(t-butylphenyl)sulfonium perfluorooctane sulfonate, diphenylethylsulfonium chloride, and phenacyldimethylsulfonium chloride; halonium salts, particularly iodonium salts, including diphenyliodonium perfluoromethanesulfonate (diphenyliodonium triflate), diphenyliodonium perfluorobutanesulfonate, diphenyliodonium perfluoropentanesulfonate, diphenyliodonium perfluorooctanesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroarsenate, bis-(t-butylphenyl)iodonium triflate, and bis-(t-butylphenyl)-iodonium camphanylsulfonate; α,α′-bis-sulfonyl-diazomethanes such as bis(p-toluenesulfonyl)diazomethane, methylsulfonyl p-toluenesulfonyldiazomethane, 1-cyclohexylsulfonyl-1-(1,1-dimethylethylsulfonyl) diazomethane, and bis(cyclohexylsulfonyl)diazomethane; trifluoromethanesulfonate esters of imides and hydroxyimides, e.g., α-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (MDT); nitrobenzyl sulfonate esters such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzyl p-trifluoromethylbenzene sulfonate; sulfonyloxynaphthalimides such as N-camphorsulfonyloxynaphthalimide and N-pentafluorophenylsulfonyloxynaphthalimide; pyrogallol derivatives (e.g., trimesylate of pyrogallol); naphthoquinone-4-diazides; alkyl disulfones; s-triazine derivatives, as described in U.S. Pat. No. 4,189,323; and miscellaneous sulfonic acid generators including t-butylphenyl-α-(p-toluene-sulfonyloxy)-acetate, t-butyl-α-(p-toluenesulfonyloxy)acetate, and N-hydroxy-naphthalimide dodecane sulfonate (DDSN), and benzoin tosylate. Other suitable photoacid generators are disclosed in Reichmanis et al. (1991), Chemistry of Materials 3:395, and in U.S. Pat. No. 5,679,495 to Yamachika et al. Additional suitable acid generators useful in conjunction with the compositions and methods provided herein will be known to those skilled in the art and/or are described in the pertinent literature. A dissolution modifying additive, generally although not necessarily a dissolution inhibitor, is typically included. If a dissolution inhibitor is present, it will typically represent in the range of about 1 wt. % to 40 wt. %, preferably about 5 wt. % to 30 wt. %, of the total solids. Preferred dissolution inhibitors have high solubility in the resist composition and in the solvent used to prepare solutions of the resist composition (e.g., propylene glycol methyl ether acetate, or “PGMEA”), exhibit strong dissolution inhibition, have a high exposed dissolution rate, are substantially transparent at the wavelength of interest, may exhibit a moderating influence on Tg, strong etch resistance, and display good thermal stability (i.e., stability at temperatures of about 140° C. or greater). Suitable dissolution inhibitors include, but are not limited to, bisphenol A derivatives, e.g., wherein one or both hydroxyl moieties are converted to a t-butoxy substituent or a derivative thereof such as a t-butoxycarbonyl or t-butoxycarbonylmethyl group; fluorinated bisphenol A derivatives such as CF3-bisphenol A-OCH2(CO)—O-tBu (6F-bisphenol A protected with a t-butoxycarbonylmethyl group); normal or branched chain acetal groups such as 1-ethoxyethyl, 1-propoxyethyl, 1-n-butoxyethyl, 1-isobutoxy-ethyl, 1-t-butyloxyethyl, and 1-t-amyloxyethyl groups; and cyclic acetal groups such as tetrahydrofuranyl, tetrahydropyranyl, and 2-methoxytetrahydro-pyranyl groups; androstane-17-alkylcarboxylates and analogs thereof, wherein the 17-alkylcarboxylate at the 17-position is typically lower alkyl. Examples of such compounds include lower alkyl esters of cholic, ursocholic and lithocholic acid, including methyl cholate, methyl lithocholate, methyl ursocholate, t-butyl cholate, t-butyl lithocholate, t-butyl ursocholate, and the like (see, e.g., Allen et al. (1995) J. Photopolym. Sci. Technol., cited supra); hydroxyl-substituted analogs of such compounds (ibid.); and androstane-17-alkylcarboxylates substituted with one to three C1-C4 fluoroalkyl carbonyloxy substituents, such as t-butyl trifluoroacetyllithocholate (see, e.g., U.S. Pat. No. 5,580,694 to Allen et al.). The remainder of the resist composition is composed of a solvent and may additionally, if necessary or desirable, include customary additives such as dyes, sensitizers, additives used as stabilizers, dissolution modifying additives, and acid-diffusion controlling agents, basic compounds, coating aids such as surfactants or anti-foaming agents, crosslinking agents, photospeed control agents, adhesion promoters and plasticizers. The choice of solvent is governed by many factors not limited to the solubility and miscibility of resist components, the coating process, and safety and environmental regulations. Additionally, inertness to other resist components is desirable. It is also desirable that the solvent possess the appropriate volatility to allow uniform coating of films yet also allow significant reduction or complete removal of residual solvent during the post-application bake process. See, e.g., Introduction to Microlithography, Eds. Thompson et al., cited previously. In addition to the above components, the photoresist compositions provided herein generally include a casting solvent to dissolve the other components so that the overall composition may be applied evenly on the substrate surface to provide a defect-free coating. Where the photoresist composition is used in a multilayer imaging process, the solvent used in the imaging layer photoresist is preferably not a solvent to the underlayer materials, otherwise unwanted intermixing may occur. The invention is not limited to selection of any particular solvent. Suitable casting solvents may generally be chosen from ether-, ester-, hydroxyl-, and ketone-containing compounds, or mixtures of these compounds. Examples of appropriate solvents include carbon dioxide, cyclopentanone, cyclohexanone, ethyl 3-ethoxypropionate (EEP), a combination of EEP and γ-butyrolactone (GBL), lactate esters such as ethyl lactate, alkylene glycol alkyl ether esters such as PGMEA, alkylene glycol monoalkyl esters such as methyl cellosolve, butyl acetate, and 2-ethoxyethanol. Preferred solvents include ethyl lactate, propylene glycol methyl ether acetate, ethyl 3-ethoxypropionate and their mixtures. The above list of solvents is for illustrative purposes only and should not be viewed as being comprehensive nor should the choice of solvent be viewed as limiting the invention in any way. Those skilled in the art will recognize that any number of solvents or solvent mixtures may be used. Greater than 50 percent of the total mass of the resist composition is typically composed of the solvent, preferably greater than 80 percent. Other customary additives include dyes that may be used to adjust the optical density of the formulated resist and sensitizers which enhance the activity of photoacid generators by absorbing radiation and transferring it to the photoacid generator. Examples include aromatics such as functionalized benzenes, pyridines, pyrimidines, biphenylenes, indenes, naphthalenes, anthracenes, coumarins, anthraquinones, other aromatic ketones, and derivatives and analogs of any of the foregoing. A wide variety of compounds with varying basicity may be used as stabilizers and acid-diffusion controlling additives. They may include nitrogenous compounds such as aliphatic primary, secondary, and tertiary amines, cyclic amines such as piperidines, pyrimidines, morpholines, aromatic heterocycles such as pyridines, pyrimidines, purines, imines such as diazabicycloundecene, guanidines, imides, amides, and others. Ammonium salts may also be used, including ammonium, primary, secondary, tertiary, and quaternary alkyl- and arylammonium salts of alkoxides including hydroxide, phenolates, carboxylates, aryl and alkyl sulfonates, sulfonamides, and others. Other cationic nitrogenous compounds including pyridinium salts and salts of other heterocyclic nitrogenous compounds with anions such as alkoxides including hydroxide, phenolates, carboxylates, aryl and alkyl sulfonates, sulfonamides, and the like may also be employed. Surfactants may be used to improve coating uniformity, including a wide variety of ionic and non-ionic, monomeric, oligomeric, and polymeric species. Likewise, various anti-foaming agents may be employed to suppress coating defects, adhesion promoters, and monomeric, oligomeric, and polymeric plasticizers such as oligo- and polyethyleneglycol ethers, cycloaliphatic esters, and non-acid reactive steroidally derived materials may be used, if desired. However, neither the classes of compounds nor the specific compounds mentioned above are intended to be comprehensive and/or limiting. The skilled artisan will recognize the wide spectrum of commercially available products that may be used to carry out the types of functions that these customary additives perform. Typically, the sum of all customary additives will comprise less than 20 percent of the solids included in the resist formulation, preferably, less than 5 percent. The photoresist compositions of the invention may also contain polymers selected to provide or increase certain properties, such as transparency at a predetermined, desired wavelength, increase dry etch resistance, and/or improve aqueous base development. Representative such polymers are disclosed in the patent literature. Polymers that are non-fluorine-containing or fluorine-containing may be used. Plating Process Solution The plating process solutions useful in the invention are comprised of one or more high saturation magnetic moment materials. In general, such materials are metal compounds or alloys wherein the high saturation magnetic moment plating material has a saturation magnetic moment of at least about 2.3 T, preferably at least about 2.4 T, and more preferably at least about 2.5 T. Representative such materials include, without limitation, NiFe, CoFeNi and CoFe alloys, although other materials may also be used. Preferred materials include CoFe and CoFeNi with an Fe content greater than about 60% having a magnetic moment in the range of about 2.4 T to 2.45 T. CoFeNi materials are noted as being generally more robust against corrosion but require low pH plating baths having a pH of about 1.85 or less. In general, the plating solution has a relatively low pH due to the solubility requirements of the metal compounds in the plating solution. Typically, the plating solution comprising the high saturation magnetic moment material has a pH of less than about 3.0, preferably less than about 2.5, and more preferably less than 1.85, depending of the plating material. A variety of components may be present in the plating solution, including metal compounds such as metal salts (e.g. sulfates such as cobalt sulfate, nickel sulfate, and ferrous sulfate), stabilizers, reducing agents, complexing agents, buffers, accelerators, surfactants etc. Additives such as saccharin sodium may also be included for stress relaxation to prevent peeling off of a plated film. The amounts and concentrations of the various components of the plating solution may be within ranges generally utilized in the art. Metal compounds such as cobalt sulfate, nickel sulfate, and ferrous sulfate, for example, are typically present in amounts ranging from 0 to about 100 g/liter. Methods of Use Various methods for making components of magnetic heads such as write heads for thin film magnetic heads have been described in the art. In U.S. Pat. No. 6,693,769 to Hsu et al., for example, a general frame plating technique for making a magnetic pole tip of a write head is mentioned. In the method, a photoresist is employed to provide the frame while a seedlayer is used to provide a return path for the plating operation. The sequence of steps mentioned at column 2, line 6 et seq., includes: sputter cleaning of a wafer, sputter depositing of a seedlayer on the wafer, spinning of a photoresist layer on the wafer, light-imaging of the photoresist layer through a mask to expose areas of the photoresist that are to be removed, developing the photoresist to remove the light-exposed areas to provide an opening in the photoresist at the pole tip region, and plating the pole tip in the opening up to a desired height. The present invention may be applied to such methods of making magnetic head components, particularly write heads for hard disk drive applications. For example, in one embodiment, the plating process is a frame plating process used in making a magnetic pole of a write head of a hard disk drive. A high activation energy chemically amplified photoresist as described above is used as the resist material for forming the frame. Plating of the magnetic pole, or other magnetic head component structures, using a high saturation magnetic moment material having a low pH (e.g., less than about 3.0), also as described herein, is then performed, resulting in a plated structure that is essentially free of plating defects. Suitable substrate and seedlayer materials are generally known in the art. For example, substrates may be formed from non-magnetic ceramic materials, including but not limited to oxides, nitrides, carbides, borides and mixtures of oxides, nitrides, carbides and borides. Aluminum oxide-titanium carbide non-magnetic ceramic materials may be used. The substrate is desirably formed with appropriate dimensions such that the substrate may be fabricated into a slider employed within a magnetic data storage device such as a hard disk drive. Seedlayer materials include, for example, copper or aluminum containing materials and conductive magnetic seed materials such as permalloy magnetic materials and other conventional materials. The seedlayer may also be desirably formed from Rh, NiFe, CoFe, CoFeN and Au seedlayer materials. Methods for forming the seedlayer include without limitation any of several known in the art, such as plating deposition methods, chemical vapor deposition methods, physical vapor deposition methods and sputtering methods. The method may further comprise a post-exposure bake at a temperature of at least about 70° C., preferably at least about 70° C., and more preferably at least about 120° C. Such post-exposure bake conditions may be utilized, for example, to activate the deprotection of a high activation energy CARS. While the process of the present invention has been described in terms of a microfabrication technique for forming plated components of thin film magnetic heads, it may also be generally applied to the formation of other submicrometer structures. For example, the process of the present invention may also be utilized to form micro-electro-mechanical systems (“MEMS”) in which plated MEMS components are essentially free of plating defects, particularly those defects arising from contact of a resist with a low pH plating solution. Other adaptations and uses will be evident to the skilled artisan or may be determined through practice of the invention. EXAMPLES The following examples are included so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the compositions and methods of the invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some experimental error and deviations should, of course, be allowed for. Unless indicated otherwise, proportions are percent by weight, temperature is measured in degrees centigrade and pressure is at or near atmospheric. All components were obtained from commercially-available sources unless otherwise indicated. Example 1 22/78 NiFe Plating High Activation Energy Cars A high activation energy CARS (Shipley UV26®, an acrylic polymer resist) was contacted with a 22/78 NiFe plating bath with a pH value of 2.5. The seedlayer was CoFeN and the plating was preceded by a 2 minutes hydrogen-based plasma ashing. The resist thickness was 3.5 μm and the post plating NiFe thickness was 3 μm. FIG. 1 is a micrograph of the plated structures for this example with the UV26® resist intact. As shown in FIG. 1, the plated UV26® resist was free of defects such as cracks and “worms.” Example 2 NiFe Plating with Low Activation Energy Resist A low activation energy CARS (KRS-Xe® from JSR) was contacted with a 22/78 NiFe plating bath having a pH value of 2.5. The seedlayer was CoFeN and the plating was preceded by a 2 minutes hydrogen-based plasma ashing. The resist thickness was 3.5 μm and the post plating NiFe thickness was 3 μm. As shown in FIG. 2A and FIG. 2B, the plated KRS resist contained defects such as cracks and “worms.” Similar results were also seen in ShinEtsu I036® hybrid resist under the same conditions. Example 3 CoFe Plating with Hybrid Activation Energy Resist A hybrid activation energy CARS (ShinEtsu I036®) was patterned by DUV at 248 nm wavelength. The exposed resist was contacted with a CoFe plating bath having a pH value of 3.0 for 30 minutes (please note the resist was not developed, and there was no plating; the immersion time in the plating solution is equivalent to the length of time required to plate 3 μm thick of CoFe). The resist thickness was 3.5 μm. As shown in FIG. 3, the latent image was visible after exposure. Tensile stress in the resist induced by the plating solution resulted in cracks, especially between corners of the latent image. Example 4 CoFeN Seedlayer/CoNiFe Plating Plating of a magnetic write head pole formed by CoNiFe plating on a CoFeN seedlayer was performed. The resist used was a 3.5 μm thick layer of Shipley UV26®. Exposure of the write head pole pattern was performed using electron-beam lithography at 100 kV. The plating conditions were: 2 min H2/N2 pre-plate ash, plating solution pH=1.5, plating time 2 hrs, plating thickness=3 μm. Following plating, no cracks, worms or under-plating were observed, indicating the UV26® resist was successfully applied and plated. Similar results were obtained using other high activation energy resists (e.g., TOK EP-TF 005 EL resist). Example 5 Rh Seedlayer/CoFe Plating Plating of a magnetic write head pole formed by CoFe plating on an Rh seedlayer was performed. The resist used was a 3.5 μm thick layer of UV26®. Exposure of the write head pole pattern was performed using electron-beam lithography at 100 kV. The plating conditions were: 2 min H2/N2 pre-plate ash, plating solution pH=3, plating time ˜20 min. Following plating, no cracks, worms or under-plating were observed, indicating the UV26® resist was successfully applied and plated. Similar results were obtained using other high activation energy resists (e.g., TOK EP-TF 005 EL resist). Example 6 CoFeN Seedlayer/NiFe Plating Plating of a magnetic write head pole formed by 22/78 NiFe plating on a CoFeN seedlayer was performed with PMGI (polydimethylglutarimide) underlayer. The resist used was a 3.5 μm thick layer of UV26®. Exposure of the write head pole pattern was performed using electron-beam lithography at 100 kV. The plating conditions were: 2 min H2/N2 pre-plate ash, plating solution pH=2.5, plating time ˜30 min, plating thickness=3 μm. Following plating, no cracks, worms or under-plating were observed, indicating the UV26® resist was successfully applied and plated. Similar results were obtained using other high activation energy resists (e.g., TOK EP-TF 005 EL resist). All patents, publications, and other published documents mentioned or referred to herein are incorporated by reference in their entireties. It is to be understood that while the invention has been described in conjunction with the certain specific embodiments thereof, that the foregoing description as well as the examples, are intended to illustrate and not limit the scope of the invention. It should be further understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention, and further that other aspects, advantages and modifications will be apparent to those skilled in the art to which the invention pertains. | <SOH> BACKGROUND OF THE INVENTION <EOH>The need for increased storage capacity and improved read and write access to information stored on magnetic disk drives has produced a large number of improvements in hard disk drive technology. The general trend has been toward increased areal density of information stored on magnetic disk drives, accomplished in part by improvements in the magnetic storage characteristics of materials used to store magnetic information on hard disks and by improved designs and methods of making read and write heads for hard disks. In a thin film write (recording) head, for example, such improvements have resulted in reductions in the width of the pole tips of the write heads in order to increase the track density of the recording medium to which the head writes information. Since higher track densities resulting from narrower pole tip widths allow for more information to be stored on a hard disk, the need to provide further improvements by reducing track width presents a continuing challenge. Write heads for hard disk drives also desirably benefit from the use of high magnetic fields for writing information on a hard disk. In order for a high magnetic field to be provided by a write head, the magnetic flux density needs to be high in the write head. In turn, higher saturation magnetic moments for write heads are necessary to provide higher flux densities so that areal densities of the magnetic media may thereby also be increased. Materials with high saturation magnetic moments allow for the generation of higher magnetic fields in the magnetic media, increased field gradients, faster effective rise times, narrower pulse widths, smaller erase bands and improved over-write characteristics on the magnetic media. For this reason, it is desirable that the pole tips of a thin film magnetic write head be formed from a high saturation magnetic moment material. The fabrication of a thin film magnetic head, as well as the various components of the magnetic head, requires that certain submicrometer structures be formed. An example of such a structure is the pole tip of a write head. One method of making pole structures is to fabricate a mask using a photoresist according to a frame plating method in conjunction with a plating process. A typical general sequence for frame plating a pole structure includes depositing a seedlayer on a wafer, spin coating a layer of photoresist on the wafer, imagewise patterning of the photoresist through a mask to expose areas of the photoresist intended to be removed (for a positive-tone resist, or areas intended to be not removed for a negative-tone resist), removal of areas intended to be removed by developing the photoresist to thereby provide a framed opening in the photoresist corresponding to a pole structure, and plating the framed opening to form the pole structure by a conventional plating process. Resist frame plating methods are also described in the literature. In U.S. Pat. No. 6,547,975 (to Kobrin), for example, a magnetic pole fabrication process is described in which a seedlayer material is sputtered onto the vertical sidewall portion of a polymer layer used to form a submicrometer structure. A “resist frame for plating” method is also referred to in Kobrin based on the disclosure of U.S. Pat. No. 5,665,251. In U.S. Pat. Nos. 6,635,408 and 6,641,984 and U.S. Patent Application Publication No. 2001/0035343 (all to Kamijima) and U.S. Pat. No. 6,358,674 (to Kamijima et al.), frame plating methods are also described using a resist that may be a chemically amplified resist. The resist is described as being coated with a covering layer of a water-soluble crosslinking agent capable of being crosslinked in the presence of acid and a resin material containing at least a water-soluble resin on the water-soluble crosslinking agent. The covering layer, rather than the resist, appears to be described as functioning as the frame in contact with the plating solution. As is known in the art, chemically amplified resists (CARS) may be categorized as positive-tone or negative-tone resists. Positive-tone resists generally contain two major components: an aqueous base soluble polymer resin and a photoacid generator (PAG). The aqueous base soluble polymer of such chemically amplified resists typically contains polar functional groups protected by acid-cleavable protecting groups (also known in the art as acid labile, or blocking groups). The presence of such protecting groups converts the aqueous base soluble polymer into an insoluble resin. Acid catalyzed deprotection of the protected sites converts the polymer back into an aqueous base soluble polymer. Development of the positive-tone resist selectively removes the exposed regions of the photoresist. The acid-cleavable groups used with the aqueous base soluble polymer resins can be classified into two distinct groups: a) high activation energy protecting groups such as t-butyl ester or t-butyl carbonyl groups; and b) low activation energy protecting groups such as acetal, ketal or silylether groups. Hybrid resists are also described in the art in which a combination of high and low activation energy groups is included in the resist (see, e.g., U.S. Pat. No. 6,303,263 to Chen et al.). Although a wide variety of photoresists are known in the art, the requirements of a specific application may govern the suitability of using a particular resist in that application. For example, in contacting a resist frame with certain plating process solutions, defects such as cracks and “worms” (i.e., localized fractures or irregular defects in the resist) may be introduced into the resist depending on the type of resist, the plating solution and/or the plating conditions used. Such defects, in turn, may lead to irregularities and defects in the plated structures obtained from the plating process. Thus it is desirable to have a method for making plated components for hard disk drive magnetic heads, particularly the write head poles of a magnetic head, which are essentially free of plating defects. It is further desirable for such a method to provide a means for reducing or eliminating such defects through compatible modifications to existing methods for making plated components for magnetic heads. Accordingly, the present invention addresses such needs in part by providing an improved method of forming a component of a magnetic head, that, in one embodiment, is suitable for making a plated magnetic component of a write head for use in a hard disk drive. | <SOH> SUMMARY OF THE INVENTION <EOH>It is a general object of the invention to provide a method of forming a component of a thin film magnetic head, a method of improving the plating of a component of a thin film magnetic head, and a frame plating method, whereby a plated component is formed that is essentially free of plating defects. One aspect of the invention therefore relates to a method of forming a component of a thin film magnetic head, wherein the magnetic head is formed from a structure that includes a substrate layer, a seedlayer deposited on the substrate layer, and a photoresist composition layer deposited on the seedlayer, comprising: providing a high activation energy chemically amplified photoresist composition as said photoresist composition layer; patternwise exposing said photoresist composition layer to an imaging radiation source to form a latent, patterned image in the photoresist composition layer; developing the latent image in the photoresist composition layer with a developer to form a patterned photoresist; and, performing a plating process to form the thin film magnetic head component by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. Another aspect of the invention pertains to a method of improving the plating of a component of a thin film magnetic head, comprising forming a frame plating patterned photoresist layer from a layer of a high activation energy chemically amplified photoresist composition coated on a substrate layer, and directly contacting the patterned photoresist layer with a plating process solution having a pH of less than about 3.0, wherein the plated thin film magnetic head component is essentially free of plating defects. A further aspect of the invention concerns an improvement in a method of plating a component of a thin film magnetic head, wherein a photoresist composition is layered on a substrate layer, formed into a patterned photoresist composition layer and contacted with a plating process solution having a pH of less than about 3.0 in order to form a component of the thin film magnetic head, the improvement comprising employing a high activation energy chemically amplified photoresist composition as said photoresist composition such that the plated thin film magnetic head component is essentially free of plating defects arising from contact of the photoresist composition layer with the plating process solution. Yet another aspect of the inventions relates to a frame plating method, comprising: forming a pattern in a photoresist composition comprising a high activation energy chemically amplified photoresist, or in a layer of said photoresist composition formed on a substrate, by patternwise exposing said photoresist composition to an imaging radiation source to form a latent, patterned image in the photoresist composition; developing the latent image in the photoresist composition with a developer to form a patterned photoresist; performing a plating process using the patterned photoresist as a frame by directly contacting the patterned photoresist with a plating process solution having a pH of less than about 3.0, and, removing the patterned photoresist. Additional aspects, advantages and novel features of the invention will be set forth in part in the figures and detailed description that follow, and will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention through routine experimentation. | 20040423 | 20080819 | 20051027 | 93334.0 | 0 | SULLIVAN, CALEEN O | ELIMINATION OF WRITE HEAD PLATING DEFECTS USING HIGH ACTIVATION CHEMICALLY AMPLIFIED RESIST | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,831,722 | ACCEPTED | Section divider ensemble for roller grill for cooking human food | A roller grill for cooking human food is disclosed which comprises a housing having a plurality of tubular cooking members rotatably mounted within the housing and a section divider ensemble for sectioning the tubular cooking members into a first cooking area and a second cooking area. | 1. A roller grill for cooking human food comprising: a housing having a plurality of tubular cooking members rotatably mounted within the housing; and a section divider ensemble for sectioning the tubular cooking members into a first cooking area and a second cooking area. 2. The roller grill of claim 1 wherein the divider comprises a first mounting brace positioned toward a front of the housing, a second mounting brace positioned toward a back of the housing, and a divider member shaped to be supported by the braces in a position above the tubular cooking members to section the tubular cooking members into a first cooking area and a second cooking area. 3. The roller grill of claim 1 wherein the divider ensemble comprises a first mounting brace having a plurality of openings and being positioned toward a front of the housing, a second mounting brace having a plurality of openings and being positioned towards a back of the housing, and a divider member shaped to be inserted into an opening of the first brace and into an opening of the second brace so that the first and second brace support the divider member at a position above the tubular cooking members to section the tubular cooking members into a first cooking area and a second cooking area. 4. The roller grill of claim 2 further comprising a second divider member that is shaped to be supported by the braces to section the tubular cooking members into a third cooking area. 5. The roller grill of claim 3 further comprising a second divider member shaped to be inserted into an opening of the first brace and into an opening of the second brace so that the first and second brace support the second divider member at a position above the tubular cooking members to section the tubular cooking members into a third cooking area. 6. The roller grill of claim 3 wherein the section divider ensemble further comprises a pair of front brackets that are attached to the housing, the brackets being shaped to engage and hold the first mounting brace to the housing. 7. The roller grill of claim 6 wherein each of the front brackets comprises a pair of projections shaped to engage and support the first brace. 8. The roller grill of claim 7 wherein the first brace has a pair of flanges with each of the flanges having a pair of notches that are shaped to receive the pair of projections so that the front brackets support the first brace. 9. The roller grill of claim 3 wherein the section divider ensemble further comprises a pair of back brackets that are attached toward the back of the housing, the back brackets being shaped to engage and hold the second mounting brace to the housing. 10. The roller grill of claim 9 wherein each of the back brackets comprises a pair of projections shaped to engage and support the second brace. 11. The roller grill of claim 9 wherein the second mounting brace has a pair of flanges with each of the flanges having a pair of notches that are shaped to receive the pair of projections. 12. The roller grill of claim 1 further comprising a product identifier label constructed to being positioned on the section divider ensemble for identifying what product is being cooked in the first cooking area. 13. A divider ensemble for a roller grill assembly for cooking a first food product having a first length or being of a first type and a second food product having a second length or being of a second type, the roller grill assembly comprising a housing and a plurality of rotatable tubular cooking members, the divider ensemble comprising: a first mounting brace having a series of openings positioned toward a front of the housing, a second mounting brace having a series of openings positioned toward a back of the housing, the series of openings in the first mounting brace being aligned with the series of openings in the second mounting brace; the first mounting brace having a pair of flanges with each of the flanges having a pair of notches; the second mounting brace having a pair of flanges with each of the flanges having a pair of notches; a pair of front brackets that are attached to the housing toward the front of the housing, the front brackets each comprising a pair of projections shaped to be received by the notches of each of the flanges of the first mounting brace, to support the first brace; a pair of back brackets that are attached to the housing toward the back of the housing, the back brackets each comprising a pair of projections shaped to be received by the notches of the flanges of the second mounting brace to support the second brace; and a divider member shaped to be inserted into the openings of the first and second mounting braces so that the divider member is supported above the tubular members to divide the tubular cooking members into a first cooking area for cooking the food product having the first length or being of the first type and a second cooking area for cooking the food product having the second length or being of a second type. 14. The divider ensemble of claim 13 wherein the divider ensemble further comprises a second divider member that is shaped to be inserted into the openings of the first and second mounting brace to be supported above the tubular members to section the tubular cooking members into a third cooking area. 15. The divider ensemble of claim 14 further comprising a product identifier label adapted to being positioned on the first mounting brace for identifying what product is being cooked in the first cooking area. 16. The divider ensemble of claim 15 further comprising a second product identifier label adapted to being positioned on the first mounting brace for identifying what product is being cooked in the second cooking area. 17. In a roller grill assembly for cooking food, the roller grill assembly having a housing with a front, a back, a pair of sidewalls and a plurality of tubular cooking members, a divider ensemble comprising: a first mounting brace for attaching toward the front of the housing, and a second mounting brace for attaching toward the back of the housing; and a divider member, the divider member and the first and second braces being shaped so that the divider member is supported by the braces in a position above the tubular cooking members to section the tubular cooking members into a first cooking area and a second cooking area. 18. In the roller grill assembly of claim 17, wherein the section divider ensemble further comprises the first mounting brace and the second mounting brace each having a plurality of aligned openings, and the divider member having a first end and a second end, with the openings in the first brace being sized to receive the first end of the divider member, and the openings in the second brace being sized to receive the second end of the divider member. 19. In the roller grill assembly of claim 17, further comprising a pair of front brackets that are attached toward the front of the housing, and a pair of back brackets that are attached toward the back of the housing, the first brace having its ends shaped and the front brackets being shaped so that the ends of the first brace fit with the front brackets to be supported by the front brackets, the second brace having its ends shaped and the front brackets being shaped so that the ends of the second brace fit with the rear brackets to be supported by the rear brackets. 20. In the roller grill assembly of claim 19, wherein the front pair of brackets have a pair of projections shaped to engage and support the first brace, and wherein the back brackets comprise a pair of projections shaped to engage and support the second brace. 21. In the roller grill assembly of claim 20, wherein the first brace has a pair of flanges with each of the flanges having a pair of notches shaped to receive the pair of projections of the front brackets, and the second brace has a pair of flanges with each of the flanges having a pair of notches shaped to receive the pair of projections of the back brackets. 22. In a roller grill assembly for cooking food, the roller grill assembly having a housing with a front and back, a pair of sidewalls and a plurality of tubular cooking members, a divider ensemble comprising: a first pair of brackets for mounting to the sidewalls at the front of the housing, the pair of brackets having a pair of projections; a second pair of brackets for mounting to the sidewalls at the back of the housing, the pair of brackets having a pair of projections; a first mounting brace having a series of openings, and a pair of flanges each having a pair of notches that mate with the projections of the first pair of brackets to be supported by the first pair of brackets; a second mounting bracket having a series of openings for alignment with the openings of the first brace, and a pair of flanges each having a pair of notches that mate with the projections of the second pair of brackets to be supported by the second pair of brackets; and a divider member for positioning in the openings in the first and second mounting braces to support the divider member above the tubular members to section the tubular cooking members into a first cooking area and a second cooking area. 23. The divider ensemble of claim 22 further comprising a product identifier label constructed to being positioned on the first mounting brace for identifying what food is being cooked in the first cooking area. 24. The divider ensemble of claim 23 further comprising a second divider member for positioning in the openings in the first and second mounting braces to support the divider member above the tubular members to section the tubular cooking members into a third cooking area. 25. The roller grill of claim 1 wherein the divider ensemble comprises a wall member positioned on the tubular members, the wall member having a plurality of openings with each of the openings having a bearing assembly shaped to receive one of the tubular cooking members. 26. The roller grill of claim 25 wherein the bearing assembly comprises a bearing member and a sealing member. 27. The roller grill of claim 26 wherein the bearing member comprises a pair of annular rim sections with an annular notch positioned there between, each of the annular rim sections having an outer surface, a cylindrical bore, and a bore section with the bore section shaped to receive the sealing member. 28. The roller grill of claim 27 wherein the divider ensemble comprises an upper wall section and a lower wall section movably connected to each other, each of the wall sections having a plurality of semi-circular notches, and each of the notches having a bearing seal shaped to be received by the notch. 29. The roller grill of claim 28 wherein each of the bearing seals comprises a semi-annular bearing section. 30. The roller grill of claim 28 further comprising a latch assembly to hold the upper and lower wall sections in a closed position. 31. The roller grill of claim 28 wherein each of the bearing seals comprises a semi-annular tapered gripping lip. 32. The roller grill of claim 1 wherein the divider ensemble is positioned on the tubular members and comprises an upper wall section and a lower wall section pivotally connected to each other, each of the wall sections having a plurality of semi-circular notches, and each of the notches having a bearing seal shaped to be received by the notch. 33. The roller grill of claim 1 wherein the divider ensemble is positioned on the tubular members and comprises a divider partition wall having a pair of opposite ends with each end having an inwardly slanted leg, a plurality of bearing sub-assemblies, and a pair of end sub-assemblies. 34. The roller grill of claim 33 wherein each of the bearing sub-assemblies comprises a bearing seal and the pair of end bearing sub-assemblies comprises a bearing seal. 35. The roller grill of claim 33 wherein the bearing sub-assemblies are integral with the divider partition wall. 36. The roller grill of claim 33 wherein the bearing sub-assemblies and the divider partition wall are a unitary construction. 37. The roller grill of claim 33 wherein the bearing sub-assemblies each have a semi-annular tapered gripping lip. 38. In a roller grill assembly for cooking a first food product having a first length and a second food product having a second length, the roller grill assembly comprising a plurality of rotatable tubular cooking members, a divider ensemble comprising: a wall member having a plurality of openings with each of the openings having a bearing assembly shaped to receive one of the tubular cooking members, the wall member for sectioning the tubular cooking members into a first cooking area and a second cooking area. 39. The divider ensemble of claim 38 wherein the bearing assembly comprises a bearing member and a sealing member. 40. In a roller grill assembly for cooking human food, the roller grill assembly having a plurality of rotatable tubular cooking members, a divider ensemble comprising: an upper wall section and a lower wall section movably connected to each other, each of the wall sections having a plurality of semi-circular notches, and each of the notches having a bearing seal shaped to be received by the notch; and a latch assembly for holding the wall sections in a closed position. 41. The divider ensemble of claim 40 wherein each of the bearing seals comprises a semi-annular tapered gripping lip. 42. The divider ensemble of claim 40 wherein each of the wall sections have first and second ends, and the wall sections are pivotally connected to each other near their ends. 43. The divider ensemble of claim 42 further comprising each wall section having an opening near one of its ends, with the openings being aligned with each other, and a member for extending through the aligned openings for pivotal connection. 44. The divider ensemble of claim 40 wherein the upper wall section and the lower wall section each have a conforming bore and the latch assembly comprises a pair of tong sections with each of the sections having a distal end and each of the distal ends having an inwardly projecting circular nib with the nibs shaped to fit snugly into the conforming bores. 45. In a roller grill assembly for cooking food, the roller grill assembly having a plurality of rotatable tubular cooking members, a divider ensemble comprising: a divider partition wall having a pair of opposite ends, a plurality of bearing sub-assemblies for receiving and sealing about corresponding roller tubes, and a pair of end sub-assemblies for receiving and sealing about corresponding roller tubes. 46. The divider ensemble of claim 45 wherein each of the plurality of bearing sub-assemblies comprises a bearing seal and the pair of end bearing sub-assemblies comprises a bearing seal. 47. The divider ensemble of claim 46 wherein the bearing seals are integral with the divider partition wall. 48. The divider ensemble of claim 46 wherein the bearing seals and the divider partition wall are a unitary construction. 49. The divider ensemble of claim 46 wherein the bearing seals each have a semi-annular tapered gripping lip. | CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 10/284,609, which was filed on Oct. 31, 2002. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable. BACKGROUND OF THE INVENTION This invention relates generally to a roller grill for cooking human food, and more particularly to a roller grill for cooking human food having a section divider ensemble. Roller food grill assemblies are used in commercial establishments to quickly cook food products for customers. Such roller food grill assemblies typically have rotatable roller tubes for heating and cooking food. Roller tube cooking is especially adaptable to heating and cooking products that have an elongated shape, such as hot dogs, brats, and wieners. In this manner, the food product is placed on the heating surface of the roller tubes. As the roller tubes rotate, the food product is in constant contact with the roller tubes and the food product is evenly cooked and heated. However, due to the construction of these roller food grill assemblies it is difficult to cook food products having varying or differing lengths. Further, it may not be desirable to cook different food products on the same surface due to juices or tastes cooked from one product being absorbed onto another dissimilar product. For example, a hot dog may end up tasting like a brat. Additionally, it may be desirable to cook a relatively short food product, such as an egg roll, while at the same time it would be desirable to cook a relatively long food product, such as a foot long hotdog. In such situation the known food grill assemblies are not capable of being adjusted to compensate for food products having different lengths. The present invention is designed to obviate and overcome many of the disadvantages and shortcomings experienced with roller food grill assemblies discussed hereinbefore and with other food grill assemblies used in the past, and to provide a roller food grill assembly which can be easily utilized to cook foods having differing or varying lengths. Moreover, the roller food grill assembly of the present invention is more advantageous than the roller food grill assemblies previously used in that it is capable of separately cooking foods that have different lengths. Further, the present roller food grill assembly segregates and prevents against the transfer of juices or tastes from one food product to another dissimilar food product. Also, the present section divider ensemble for a roller food grill may be a kit that can be employed to retrofit existing roller food grill assemblies. SUMMARY OF THE INVENTION In one form of the present invention, a roller grill for cooking human food comprises a housing having a plurality of tubular cooking members rotatably mounted within the housing, and a section divider ensemble for sectioning the tubular cooking members into a first cooking area and a second cooking area. In another form of the present invention, a divider ensemble for a roller grill assembly for cooking a first food product having a first length or being of a first type, and a second food product having a second length, or being of a second type, the roller grill assembly comprising a housing and a plurality of rotatable tubular cooking members. The divider ensemble comprises a first mounting bracket having a plurality of openings positioned on a front of the housing, a second mounting bracket having a plurality of openings positioned at a back of the housing, and a divider member adapted to being inserted into the openings of the first and second mounting brackets to divide the tubular cooking members into a first cooking area for cooking the food product having the first length, or being of the first type, and a second cooking area for cooking the food product having the second length, or being of the second type. In yet another form of the present invention, a divider ensemble for a roller grill assembly for cooking food, the roller grill assembly having a housing having a pair of sidewalls and a plurality of tubular cooking members, the divider ensemble comprises a first pair brackets mounted to the sidewalls at a front of the housing, the pair of brackets having a pair of projections, a second pair of brackets mounted to the sidewalls at a back of the housing, the pair of brackets having a pair of projections, a first mounting bracket having a series of openings and a pair of flanges each having a pair of notches that mate with the projections of the first pair of brackets, a second mounting bracket having a series of openings and a pair of flanges each having a pair of notches that mate with the projections of the second pair of brackets, and a divider member for positioning in the openings in the first and second mounting brackets for sectioning the tubular cooking members into a first cooking area and a second cooking area. Features obtained by the invention as covered by one or more of the claims include one or more of the following: to provide an improved roller grill for cooking human food with the roller grill having a section divider ensemble; to provide a roller grill assembly for cooking human food having a section divider ensemble which is of simple construction and design and which can be easily employed with highly reliable results; to provide a roller grill assembly that is capable of cooking foods that have different lengths; to provide a roller grill assembly that is capable of preventing the transfer of juices or tastes from one food product to another food product when both of the products are being cooked at the same time; to provide a roller grill assembly in which foods having the same length may be cooked on one section of the roller grill assembly and foods having a different length may be cooked on another section of the roller grill assembly; to provide a roller grill assembly for cooking human food having a section divider ensemble which is removable; to provide a roller grill assembly for cooking human food having a number of divider ensembles for partitioning the roller grill assembly into various cooking areas; to provide a roller grill assembly for cooking human food with a section divide ensemble that is adjustable relative to the roller grill; to provide a divider ensemble for a roller grill assembly that can be easily installed; to provide a divider ensemble for a roller grill assembly that can be retrofitted to an existing roller grill assembly; to provide a divider ensemble for a roller grill assembly that has indicia that indicate what food product is being cooked in a particular section of the roller grill assembly; and to provide a divider ensemble for a roller grill assembly that can be easily removed from the roller grill assembly. These and other objects and advantages of the present invention will become apparent after considering the following detailed specification in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The objects of the invention are achieved as set forth in the illustrative embodiments shown in the drawings which form a part of the specification. In the drawings: FIG. 1 is an orthogonal projection of a roller grill assembly having a section divider ensemble constructed according to the present invention; FIG. 2 is an exploded view of the section divider ensemble for the roller grill assembly of FIG. 1; FIG. 3 is a top view of a divider mounting bracket of the section divider ensemble; FIG. 4 is a rear view of the divider mounting bracket of the section divider ensemble; FIG. 5 is a side view of the divider mounting bracket of the section divider ensemble; FIG. 6 is a front view of a short bracket of the section divider ensemble; FIG. 7 is a side view of the short bracket shown in FIG. 6; FIG. 8 is a front view of a long bracket of the section divider ensemble; FIG. 9 is a side view of the long bracket shown in FIG. 8; FIG. 10 is a partial cross-sectional view the roller grill assembly having a section divider ensemble taken along the plane of line 10-10 of FIG. 1; FIG. 11 is an orthogonal projection of a roller grill assembly having a section divider constructed according to the present invention; FIG. 12 is a front elevation of the divider for the roller grill assembly of FIG. 11; FIG. 13 is a top plan view of the assembly of FIG. 11 showing the divider; FIG. 14 is a section of part of the assembly of FIG. 11 showing a roller tube extending through a sealing member mounted about a hole in the divider; FIG. 15 is an exploded view of the sealing assembly of FIG. 14; FIG. 16 is a view of a roller tube extending through an alternate sealing member assembly mounted about a hole in the divider; FIG. 17 is an exploded view of the sealing assembly of FIG. 15; FIG. 18 is a section of the assembly taken on the line 18-18 of FIG. 13; FIG. 19 is a side elevation of the left side of the assembly as viewed to the left of FIG. 11, with the geartrain cover and heating element connections removed; FIG. 20 is an orthogonal projection of a roller grill assembly having a modified section divider of the invention; FIG. 21 is a side elevation of the alternate divider of FIG. 20, shown in the closed position with one of the bearing/sealing sub-assemblies shown removed; FIG. 22 is a side elevation of the modified divider of FIG. 10, shown in the open position; FIG. 23 is a section of the modified divider of FIGS. 20-22, taken on the line 23-23 of FIG. 21; FIG. 24 is a section of the modified divider of FIGS. 20-22, taken on the line 24-24 of FIG. 21, and depicting an enlarged view of the latching ensemble; FIG. 24A is a side elevation of an isolated latching tong of the latching ensemble; FIG. 25 is an orthogonal projection of a roller grill assembly having yet another modified divider of the invention; FIG. 26 is a side elevation of the divider of FIG. 25, with one of the bearing sub-assemblies shown removed; FIG. 27 is a section of the divider of FIGS. 25-26, taken on the line 27-27 of FIG. 26, but not showing the lower right end of the divider as seen in FIG. 26; FIG. 27A is a section of a modification of the divider of FIG. 27, wherein the partition wall of the divider is a separate component from the bearing/sealing member; FIG. 28 is an exploded view showing a tool for mounting a roller tube with the divider; FIG. 29 is a broken side elevation of the divider of FIG. 11; FIG. 30 is a side elevation of an isolated bearing/sealing subassembly of FIGS. 14 and 15; and FIG. 31 is a broken side view of the divider of FIG. 11 showing a section of an installed bearing/sealing subassembly. Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF INVENTION The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what we presently believe is the best mode of carrying out the invention. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the following description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. General Review Of Housing With reference now to FIGS. 1 and 2, a roller grill assembly for cooking human food having a section divider ensemble is generally designated by numeral 20. The assembly 20 generally comprises a main housing 22, upon which are mounted a plurality of rotatable tubular cooking members 24 which are adapted to being heated. The assembly 20 further comprises a section divider ensemble 26 for separating the cooking tubes 24 into cooking areas or sections such as sections 28, 30, and 32. The section divider ensemble 26 can be used with roller tube assemblies of various types wherein the tubes rotate relative to a housing to which they are mounted. The housing 22 can vary in size and configuration. A detailed example of such a roller grill assembly is shown in U.S. Pat. No. 6,393,971, which is assigned to the assignee of this application, and said patent is incorporated herein by this reference. The various manners or constructions in which the cooking tubes 24 are rotated, heated, or operated are also described in detail in such referenced patent. The housing 22 comprises two generally rectangular side support frames 34 and 36. Each of the side support frames 34 and 36 are fabricated from a rigid material such as stainless steel and can be stamped so that they each have an interior sidewall 38 and 40, respectively. A separate grease drip tray 42 is provided beneath the roller tubes 24 to catch grease and fluids dripping there from. Towards its front, the housing 22 comprises a control panel 44 that has a middle wall section 46 that extends rearwardly at an angle of about 15° to 20°. A control assembly 48 is positioned on the control panel 44 and comprises a pair of temperature control knobs 50 and 52, which are rotatable for selectively controlling the temperature of the roller tubes 24. A power switch 54 is also mounted to the control panel 44 and is used to power the roller grill 20. Each of the frame sidewalls 34 and 36 has a plurality of holes 56 for mounting the rotatable cooking tubes 24 into tube sealing sub-assemblies 58. Each of the side support frames 34 and 36 has a front 60 and 62, respectively, and a back 64 and 66, respectively. General Overview Of Section Divider Ensemble As a general overview, the section divider ensemble 26 comprises a first or front divider mounting brace 68 that is configured to be positioned on a pair of side brackets 70 and 72. The front divider mounting brace 68 has a series of slots or openings 74 formed therein. The section divider ensemble 26 further comprises a second or back divider mounting brace 76 that is configured to be positioned on a pair of side brackets 78 and 80. The back divider mounting brace 76 has a series of slots or openings 82 formed therein that are aligned with the openings 74 of the front divider mounting brace 68. One or more divider bars or members 84 can be inserted into aligned slots 74 and 82 to form the cooking areas 28, 30, and 32. The divider members 84 are generally rectangular and sized and shaped to fit within the slots 74 and 82. The dividers 84 are long enough to span the distance between the front and back mounting braces 68 and 76. The positioning of the mounting braces 68 and 76 are such that the divider members 84 are positioned above the roller tubes 24. The front mounting brace 68 also includes a product identifier label 86 attached thereto to display or identify what product is being cooked within each of the cooking areas 28, 30, or 32. For example, the label 86 may have printed thereon the words “hot dog”. The label 86 can be attached to the front mounting brace 68 using any suitable method, such as the label 86 being magnetized. More Detailed Descriptions Of Divider Ensemble Now a more detailed description is given of the divider ensemble 26. Referring now to FIGS. 3 and 4, the divider mounting brace 68 is illustrated. Although the mounting brace 68 is shown, it is to be understood that the divider mounting brace 76 is constructed in the same manner. The divider mounting brace 68 has a top wall 100 with a back wall 101 depending from the rear edge thereof. The series of slots or openings 78 are formed in the walls 100 and 101. The series of openings 78 are shown to have three series of seven openings. However, it is also contemplated that the brace 68 can have other series or number of openings. The top wall 100 is slanted forwarded and downwardly into a midsection 102. Midsection wall 102 ends into a ledge wall 104. The ledge wall 104 bends downwardly into a front wall 106. The divider mounting brace 68 also has a pair of ends 110 and 112. At the ends 110 and 112, a pair of mounting flanges 114 and 116, respectively extend from the outer edges of the front wall 106. The divider mounting brace 68 may be constructed or formed from metal such as stainless steel, and can be formed by stamping to be one unitary piece. From the different perspective of FIG. 5, there is shown a side view of the divider mounting brace 68. The end 110 is depicted in FIG. 5. FIG. 5 shows the divider mounting brace 68 with the top wall 100 extending into the downwardly slanting midwall 102. The midwall 102 extends into the ledge wall 104. The front wall portion 106 depends from ledge wall 104. The top wall 100 is also shown to depend from the back wall 101. FIG. 5 also shows the mounting flange 114 having a pair of notches or keyholes 116 and 118 formed therein. The flange 114 and the notches 116 and 118 are used to secure or hold the divider mounting brace 68 to the housing 22, as will be explained more fully herein. With reference now to FIGS. 6 and 7, the mounting bracket 70 is depicted. The bracket 70 has a rectangular shaped body 120. A pair of nubs or projections 122 and 124 extend from the inwardly facing bracket surface 123. The projections 122 and 124 are sized and shaped to be received in the notches 116 and 118 of the flanges 114 and 116 of divider mounting brace 68. The bracket has an outwardly facing surface 125. The bracket 72 is constructed in a similar manner. FIGS. 8 and 9 illustrate the bracket 78. The bracket 78 has a rectangular shaped body 126 that is longer than the rectangular body 120 of the bracket 70. The body 126 has an inwardly facing surface 127 from which a pair of projections 128 and 130 project. The bracket has an outwardly facing surface 129. The projections 128 and 130 are received within the notches 116 and 118 in the flanges 114 and 116 of mounting brace 76. Once the notches 116 and 118 receive the projections 128 and 130, the divider mounting brace 76 is held in place. Also, the bracket 80 is constructed in a similar manner. The outwardly facing bracket surfaces 123 and 129 can be secured to the frame side walls 38 and 40, respectively. The brackets 70, 72, 78 and 80 can both be constructed or formed from metal such as stainless steel. The brackets 70, 72, 78 and can be secured to the housing 22 such as by use of an adhesive, or by spot welding. For factory assembly, spot welding of the brackets to the side walls is preferred. For installation of the ensemble 26 in the field to an existing roller grill, use of adhesive to the bracket surfaces 123 and 129 is preferred to secure the brackets to the side walls 38 and 40. The preferred embodiment has been described as the mounting braces having end flanges with notches to receive projections of support brackets. However, the support of the mounting braces and brackets can take on other configurations, such as the ends of the mounting braces having flanges with projections such as have been described for the brace, which projections are received within notches or grooves of support brackets associated with the housing. From the foregoing, it can be seen that the assembly 20 comprises the section divider ensemble 26 comprising the front divider mounting brace 68, the back divider mounting brace 76, the side bracket a 72, 74, 78 and 80, and at least one divider member 84. The section divider ensemble 26 can be used with two divider numbers 84 to separate the cooking tubes 24 into the cooking areas 28, 30, and 32. Further Description Of Housing FIG. 10 illustrates a partial cross-sectional view of the roller grill assembly 20 taken along the plane of line 10-10 of FIG. 1. The roller grill assembly 20 comprises the main housing 22, upon which are mounted the plurality of rotatable tubular cooking members 24 which are adapted to being heated by heating elements 200. Further, the heating elements 200 can take the form of the heating elements shown and disclosed in U.S. Pat. No. 6,393,971. Although not shown in detail, the heating elements 200 can comprise a pair of elements within each of the cooking members 24 with such members being individually controlled. One of the heating elements can extend into one end of a roller tube 24, while a second heating element extends into the other end of the same roller tube. The temperature control knob 52 may control the heating elements in the cooking area 32 and the temperature control knob 50 (not shown) may control the heating elements in the cooking area 28. The knobs 50 and 52 and the related circuitry can therefore control the two heating elements so that the temperature of one heating element differs from that of the other heating element. Hence, the temperature in the cooking area or section 28 can be at a different temperature than that in the cooking area or section 32, to suit the temperature needs for cooking two different kinds of food. The grease drip tray 42 is provided which rests on a floor section 202 beneath the roller tubes 24 to catch grease and fluids dripping therefrom. The drip tray 42 may be easily grasped and slid along the floor section 202 to be removed from the housing 22. The tray 42 can then be emptied and cleaned. The clearance beneath the roller tubes 24 allows the drip tray 42 to then be slid along the floor section 202 back into a position to capture grease and other droppings. The housing 22 further comprises an integral L-shaped member 204, formed of rigid material, illustrated in this embodiment to be of stainless steel. The L-member 204 has a rear wall 206 that extends downward into a horizontal flanged foot 208 that is secured to the bottom of a base channel 210 by screws 212. The L-shaped housing member 204 further comprises a horizontal wall 214 that extends forward from the top of the rear wall 206. At the front of the horizontal wall 214 is an integral U-shaped channel 216. The housing also comprises a central horizontal base sheet 218 with the front end of the base sheet 218 extending into an integral U-shaped channel 220. The rear of the base sheet 218 extends into the base channel 210. The housing 22 may be provided with legs 222. The roller tubes 24 have cylindrical end sections at one end and at the other end a sprocket or gear (not shown). The roller tubes 24 are rotated by use of a roller tube drive assembly (not shown). The drive assembly may include a driving sprocket (also not shown) that is drivingly engaged with a shaft of a motor 224. The motor 224 is mounted by any known means in the housing 22. The drive assembly may further include other components such as an idler sprocket or gear and a drive chain. Further operation and construction of the drive assembly is shown and described in the previously cited patent. Additionally, the manner in which the roller tubes 24 are heated and the circuitry employed for such heating is also described in such patent. Operation Of Divider Ensemble With Roller Grill As noted, the section divider ensemble can be assembled in a production facility such as a factory or plant, by securing the brackets 70, 72, 78 and 80 to the side walls 38 and 40 by spot welding for example. However, the section divider ensemble 26 also lends itself to being retrofitted on existing roller grills, such as existing in the field. For installation in the field, the brackets 70, 72, 78 and 80 can be attached to the side walls 38 and 40 such as by adhesive. Once the brackets 70, 72, 78, and 80 are attached, the front and back mounting braces 68 and 76 are positioned so that the notches 116 and 118 are manipulated to receive the projections 122, 124, 128 and 130. When the front and back mounting braces 68 and 76 are in place, one or more of the divider members 84 can be positioned into aligned brace slots 74 and 82. Further, a label 86 can be placed on the front mounting brace 68 to indicate to an operator or a customer what product is being cooked or warmed in the particular cooking area 28, 30, or 32. The label 86 can be a magnetized piece of material that can be releasably held in place on the front mounting brace 68. This allows different labels 86 to be used interchangeably as the types of foods being cooked varies. However, other attaching methods can be employed for the labels such as releasable adhesive, glue, or cards with the product description placed in slotted support brackets. As can be appreciated, in operation of the roller grill assembly 20 one type of food product, such as hot dogs, can be placed on the roller tubes 24 located in cooking area 28 and a separate type of food product, e.g., corn dogs, egg rolls, hamburgers and sausages that have a tubular shape, food wrapped in tortillas, and tubular pastry rolls, can be placed on the roller tubes 24 located in the cooking area 30. This allows an operator to initially place the same type of food products, such as hot dogs, in the cooking area 28 and then remove them when cooked. Once the cooked hot dogs are removed, the operator can place additional uncooked hot dogs in the same cooking area 28. When two divider members 84 are used, another type of food can be cooked in the separate cooking area 32. The divider ensemble 26 thus helps keep juices and particles from food cooked in cooking area 28 from contacting foods cooked in the other cooking areas 30 and 32, and vice versa. The operator will thus be able to cook the hot dogs in the cooking area 28 without being concerned about the drippings or portions of the food in the cooking area 30 or 32 from contacting or being imparted upon the hot dogs to alter their flavor. An operator can cook two entirely different flavors of food in the separate cooking areas 28 and 32, while keeping the juices and particles of those foods from altering or modifying the flavor of each other, or likewise use the third cooking area 30. The divider ensemble 26 allows the operator to easily remember which cooking area is being used for the particular food product, and thus to prevent the operator from mistakenly placing one of the types of food products to be cooked on area 28 and area 32, and vice versa, or area 30 when two divider members 84 are used. Also, the product identifying labels 86 help another operator know what food product was being cooked in each of the cooking areas 28, 30, or 32. As can be appreciated from the foregoing, although one divider ensemble 26 has been discussed that divides the assembly 20 into three cooking areas, it should be recognized and understood that additional divider members 84 can also be placed about the roller tubes 24 in the same fashion as shown and spaced from the other divider members 84 so as to divide the assembly into many separate cooking areas. Further, only one divider member 84 could be used to divide the cooking area into two large cooking areas. It is also contemplated and possible that the cooking areas 28, 30, and 32 may be sectioned into equal areas or that one cooking area will be larger than the other cooking area. The mounting braces 68 and 76 may also be constructed each having only one opening 74. In this manner, the roller grill will only be separated into two cooking areas. As can be further appreciated, the divider ensemble 26 can be easily moved, installed, or repositioned. It is also possible that the divider ensemble 26 can be produced in a kit form in order to be used with existing roller grill assemblies. Although the series of roller tubes 24 are shown mounted at an angle relative to the housing 22 it should be understood that the roller tubes 24 may also be aligned parallel to each other and on a horizontal plane or with roller tubes 24 that angle downwardly from the front to the rear of the housing 22 and the ensemble 26 can be used equally well with such orientations of the roller tubes 24. Other Embodiments Turning now to other embodiments, with reference now to FIGS. 11-13, a roller grill assembly for cooking human food is generally designated by numeral 320. The assembly 320 generally comprises a main housing 322, upon which are mounted a plurality of rotatable tubular cooking members 324 which are adapted to being heated, as will be explained fully herein. The assembly 320 further comprises a divider ensemble 326 comprising a divider partition wall member 328 for separating the cooking tubes 324 into two cooking areas or sections 330 and 332. The divider ensemble 326 also comprises roller tube bearing/sealing sub-assemblies 334 for providing a seal of the partition wall 328 about the tubes 324. The section divider ensemble 326 can be used with roller tube assemblies of various types wherein the tubes rotate relative to a housing to which they are mounted. The housing 322 can vary in size and configuration. A detailed example of such a roller grill assembly is shown in U.S. Pat. No. 6,393,971, which is assigned to the assignee of this application, and said patent is incorporated herein by this reference. The various manners or constructions in which the cooking tubes 324 are rotated or operated are also described in detail in such referenced patent. The housing 322 comprises two generally rectangular side support frames 336 and 338. Each of the side support frames 336 and 338 are fabricated from a rigid material such as stainless steel and can be stamped so that they each have an interior sidewall 340 and 342, respectively. A separate grease drip tray 344 is provided which rests on a floor section 346 beneath the roller tubes 324 to catch grease and fluids dripping there from. Towards its front, the housing 322 comprises a control panel 348 that has a middle wall section 350 that extends rearwardly at an angle of about 15° to 20°. A control assembly 352 is positioned on the control panel 348 and comprises a pair of temperature control knobs 354 and 356, which are rotatable for selectively controlling the temperature of the roller tubes 324. A power switch 358 is also mounted to the control panel 348 and is used to power the roller grill 320. Each of the frame sidewalls 336 and 338 has a plurality of holes 360 for mounting the rotatable cooking tubes 324 into tube sealing sub-assemblies 362. The construction and composition of the tube sealing sub-assemblies 362 will be described in more detail herein. Further, the partition wall member 328 of the divider ensemble 326 may be constructed of or formed from metal such as stainless steel, or other suitable material such as polytetrafluoroethylene. The partition 328 is elongated and has a front or distal end 364, and a rear or proximal end 366, both of which are illustrated as having a generally semicircular shape. The ends 364 and 366 can have other shapes, but curved ends are preferred. Referring now to FIGS. 14 and 15, the construction of one of the roller tube bearing/sealing sub-assemblies 334 is now described. The sub-assembly 334 comprises a bearing seal 368 and a sealing member or an O-ring 370. The bearing seal 368 may be constructed of any suitable plastic material such as polytetrafluoroethylene. The O-ring 370 may be formed from any rubber-like material such as silicone rubber. Each bearing seal 368 has a pair of annular rim sections 372 and 374 with an annular notch 376 positioned there between. The annular notch 376 has a pair of generally flat inwardly facing side walls 378 and 380 and an annular notch floor 382 that extends generally perpendicular to the side walls 378 and 380. Each annular rim section 372 and 374 has an annular outer surface 384 and 386, respectively, that extend generally perpendicular to the side walls 378 and 380, respectively. Further, each rim 372 and 374 has an outwardly facing tapered surface 388 and 390 which slopes inwardly from the outer surfaces 384 and 386, respectively. The bearing seal 368 has a generally cylindrical bore 392 and a bore section 394. The bore section 394 has an annular semi-circular surface 396 that is sized and shaped to receive the outer curved surface of the O-ring 370. The bearing seal 368 further includes a cylindrical lip section 398 that is about the same diameter as the bore 392 and is used to help retain the O-ring 370 in place. In the installed position of FIG. 14, the tube 324 extends through the cylindrical bore 392 and through the O-ring 370. The inner surface of the O-ring 370 fits snugly against the outer surface of the tube 324 to thus provide a seal there against to resist the flow of juice, grease, and food particles from one side of the O-ring 370 to the other side thereof. Thus, the seal of the O-ring 370 helps to resist the flow of grease and the like through the bearing seal 368. As can be appreciated, in operation of the roller grill assembly 320 one type of food product, such as hot dogs, can be placed on the roller tubes 324 located in cooking area 330 and a separate type of food product, e.g., corn dogs, egg rolls, hamburgers and sausages that have a tubular shape, food wrapped in tortillas, and tubular pastry rolls, can be placed on the roller tubes 324 located in the cooking area 332. This allows an operator to initially place the same type of food products, such as hot dogs, in the cooking area 330 and then remove them when cooked. Once the cooked hot dogs are removed, the operator can place additional uncooked hot dogs in the same cooking area 330. The divider ensemble 326 resists or prevents the flow of juices and particles from food cooked in cooking area 330 from flowing or moving along the tubes 324 into the other cooking area 332 and vice versa. The operator will thus be able to cook the hot dogs in the cooking area 330 without being concerned about the drippings or portions of the food in the cooking area 332 from contacting or being imparted upon the hot dogs to alter their flavor. Likewise, the divider ensemble 326 with its sealing sub-assemblies 334 and the partition wall 328 resists the flow of juice and particles from the hot dogs in the cooking area 330 along the surfaces of tubes 324 into the cooking area 332, so that the food flavor in the cooking area 332 is not altered thereby. Therefore, an operator can cook two entirely different flavors of food in the separate cooking areas 330 and 332, while keeping the juices and particles of those foods from altering or modifying the flavor of each other. The divider ensemble 326 allows the operator to easily remember which cooking area is being used for the particular food product, and thus to prevent the operator from mistakenly placing one of the types of food products to be cooked on area 330 in area 332, and vice versa. FIGS. 16 and 17 show an alternate embodiment of a sealing sub-assembly 400 to fit with a partition wall 402 of a divider ensemble 404. Each sealing sub-assembly 400 fits about a corresponding roller tube 406, such as shown in FIG. 16. As seen more clearly in the exploded view of FIG. 17, the alternate sub-assembly 400 comprises a bearing seal 408 and an O-ring 410. The bearing seal 408 can be of plastic, such as polytetrafluoroethylene, and the O-ring 410 can be of rubber-like material, such as silicon rubber. The bearing seal 408 has an outer cylindrical sleeve 412 that has an annular flange 414 with the flange 414 having a notch 416. The wall 402 has an integral nib 418 that projects outwardly from the wall surface 402. The notch 416 is sized to snugly receive the nib 418 to prevent rotation of the bearing seal 408 relative to the divider wall 402 when the tube 406 rotates. The cylindrical sleeve 412 extends into an annular rim section 420, which has a flat annular outer surface 422, a substantially flat left side surface 424, and a curved tapered right side surface 426. The bearing seal 408 further has a cylindrical bore 428. The cylindrical bore 428 extends into a bore section 430 that has an arcuate semi-circular surface 432 shaped to receive the outer curved surface of the O-ring 410. The bore section 430 then extends into a bore lip section 434 which has about the same diameter as the cylindrical bore 428. FIG. 18 illustrates a partial cross-sectional view of the roller grill assembly 320 taken along the plane of line 18-18 of FIG. 13. The roller grill assembly 320 comprises the main housing 322, upon which are mounted the plurality of rotatable tubular cooking members 324 which are adapted to being heated by heating elements 500. Further, the heating elements 500 can take the form of the heating elements shown and disclosed in U.S. Pat. No. 6,393,971. Although not shown in detail, the heating elements 500 can comprise a pair of elements within each of the cooking members with such members being individually controlled. One of the heating elements can extend into one end of a roller tube 324, while a second heating element extends into the other end of the same roller tube. The position to which each such element extends can be the same for each of the roller tubes 324 so that the section divider ensemble 326 can be placed at a location approximately between the distal ends of those heating elements. The temperature control knob 354 may control the heating elements in the cooking area 330 and the temperature control knob 356 may control the heating elements in the cooking area 332. The knobs 354 and 356 and the related circuitry can therefore control the two heating elements so that the temperature of one heating element differs from that of the other heating element. Hence, the temperature in the cooking area or section 330 can be at a different temperature than that in the cooking area or section 332, to suit the temperature needs for cooking two different kinds of food. The assembly 320 further comprises the divider ensemble 326 comprising a divider partition wall member 328 for separating the cooking tubes 324 into the two cooking areas. The divider ensemble 326 also comprises roller tube bearing/sealing sub-assemblies 334 for providing a seal of the partition wall 328 about the tubes 324. The grease drip tray 344 is provided which rests on the floor section 346 beneath the roller tubes 324 to catch grease and fluids dripping there from. In the installed position, the lower edge of the divider partition wall 328 is spaced a sufficient clearance distance, preferably such as about 1-¼ to 1-{fraction (3/4)} inches, above the drip tray 344. The lowest point of the divider wall 328 preferably has about 1-½ to 2 inches clearance above the floor section 346. Such clearance allows drip tray 344 to be easily grasped and slid along the upper surface of the floor section 346 to be removed from the housing 322. The tray 344 can then be emptied and cleaned. The clearance beneath the roller tubes 324 allows the drip tray 344 to then be slid along the floor section 346 back into a position to capture grease and other droppings. The housing 322 further comprises an integral L-shaped member 502, formed of rigid material, illustrated in this embodiment to be of stainless steel. The L-member 502 has a rear wall 504 which extends downward into a horizontal flanged foot 506 that is secured to the bottom of a base channel 508 by screws 510. The L-shaped housing member 502 further comprises a horizontal wall 512 that extends forward from the top of the rear wall 504. At the front of the horizontal wall 512 is an integral U-shaped channel 514. The housing also comprises a central horizontal base sheet 516 with the front end of the base sheet 516 extending into an integral U-shaped channel 518. The rear of the base sheet 516 extends into the base channel 508. Turning now to FIG. 19, the side frame 338 of the housing 322 is further shown to have a front facing frame wall 520 and a rear facing frame wall 522. The front frame wall 520 and the rear frame wall 522 each have projecting from their outer edges a channel 524 and 526, respectively, with inwardly extending lip flanges 528 and 530 projecting respectively from the channels 524 and 526 at their ends. A floor frame wall 532 has at its outer end an upwardly extending flange 534. The floor frame wall 532 may have feet 536 attached thereto. A frame top wall 538 has a vertical flange that depends there from. The roller tubes 324 have cylindrical end sections at their left ends as viewed looking at FIGS. 11-13, while at their right ends, each of the roller tubes has formed integrally therewith a sprocket or gear 542 which is part of a roller tube drive assembly 544. The drive assembly 544 further comprises a driving sprocket 546 that is drivingly engaged with a shaft of a motor 548. The motor 548 is mounted by any known means in the housing 322. The drive assembly 544 further comprises an idler sprocket or gear 550 and a drive chain 552. The drive chain 552 extends from the drive sprocket 546 on to the idler sprocket 550 and thence to the tube sprockets 542. Further operation and construction of the drive assembly 544 is shown and described in the previously cited patent. Additionally, the manner in which the roller tubes 324 are heated and the circuitry employed for such heating is also described in such patent. Another embodiment of a roller grill for cooking human food having a section divider ensemble is depicted in FIGS. 20-24A. With particular reference to FIGS. 20-22, a roller grill assembly 600 has an ensemble 602 which is mounted to a plurality of roller tubes 604. The ensemble 602 has a divider partition wall 606 formed of an upper wall section 608 and a lower wall section 610. The wall sections 608 and 610 can be of stainless steel. At the left side of FIGS. 20-22, a pair of proximal ends 612 and 614 of the walls 608 and 610 is pivotally connected as by a rivet 616 that extends through aligned openings (not shown) in the walls 608 and 610. The rivet 616 allows the wall sections 608 and 610 to be pivoted away from one another to an open position, such as shown in FIG. 22. The wall sections 608 and 610 have inner edges 618 and 620, respectively. The edges 618 and 620 have formed therealong a plurality of semi-circular notches 622 and 624, respectively, as seen more clearly for the third opening from the left in FIG. 21. When the wall sections 608 and 610 are closed together as in FIG. 21, the inner edges 618 and 620 are in approximate contact, and the notches 622 and 624 are joined together so that a plurality of circular bores 626 extend along the partition wall 606. The ensemble 602 has a plurality of bearing seals 628 that fit with each of the pairs of semi-circular notches 622 and 624. Each bearing seal 628 comprises an upper semi-annular bearing section or upper bearing/sealing member 630 and a lower semi-annular bearing section or lower bearing/sealing member 632. The upper semi-annular sections 630 have a pair of flat edges 634 and the lower sections 632 have a pair of flat edges 636. The edges 634 are adapted to abut the flat edges 636 of the lower semi-annular section 632 when the ensemble 602 is in the closed position as is illustrated in FIG. 21. With particular reference now to FIG. 23, each of the sections 630 and 632 have a semi-circular notch 638 and 640, respectively, that extends along the outside thereof to receive the edges of semi-circular notches 622 and 624 in the partition walls 608 and 610. The upper semi-annular section 630 and the lower semi-annular section 632 each have semi-circular passageways 642 and 644, respectively, that together form a closed opening 646 which can receive a tube 604. Each of the bearing sections 630 and 632 also has semi-annular sloped outer surfaces 648 and 650, respectively. The passageways 642 and 644 have central semi-cylindrical bores 652 and 654, respectively, that when joined together in the closed position of FIGS. 21 and 23, form a cylindrical bore section 656. The bore sections 652 and 654 further extend, as seen in FIG. 23, into a pair of bore sections 658 and 660, respectively. The bore sections 658 and 660 are tapered to have a smaller radius at their outer edge than at their inner edge so that the outer parts of the bearing sections 630 and 632 that extend thereabout have semi-annular tapered gripping lips 662 and 664, which together have an annular shape. When the partition wall sections 608 and 610 are closed about the tubes 604, the gripping lips 662 and 664 press against each outer surface 666 (FIG. 20) of the tubes 604 to prevent the passage of drippings and particles from food products being cooked on either side of the divider ensemble 602. Referring again to FIGS. 20 and 21, a latch assembly 668 is employed to hold the two wall sections 608 and 610 together in the closed or locked position. With particular reference now to FIGS. 24 and 24A, the latch assembly 668 comprises a pair of latch tongs 670 and 672. As seen in FIG. 24, and in the isolated view of the tong 672 in FIG. 24A, each of the latch tongs 670 and 672 has a proximal section 674 and 676, respectively. Each of the proximal sections 674 and 676 has a flat inner surface (shown as 678 for the tong 672 in FIG. 24A) that fits substantially flush against the substantially flat outer surfaces of the divider wall sections 608 and 610 when the latch assembly 668 is in the closed position. The tong sections 670 and 672 can be secured or held in place by spot welding the tong sections 670 and 672 to the wall section 608. Each of the tongs 670 and 672 has a distal end 680 and 682, respectively, and each of the distal ends 680 and 682 has an inwardly projecting circular nib 684 and 686, respectively. The nibs 684 and 686 are adapted to fit snugly into a conforming circular bore 688 that is formed in the wall section 610 and is further depicted in FIG. 22. Each of the tongs 670 and 672 has a distal leg portion 690 and 692, respectively, which are positioned beneath each of the nibs 684 and 686. The distal leg portions 690 and 692 are adapted to abut or contact the wall section 610 when the two wall sections 608 and 610 are in the closed position. The nibs 684 and 686 further have outer edges 694 and 696, respectively, which are chamfered to facilitate opening or closing of the wall sections 608 and 610. For example, when the wall sections 608 and 610 are moved toward each other into the locked position, the chamfered surfaces 694 and 696 of the nibs 684 and 686 are wedged apart by the wall section 610. When the nibs 684 and 686 become aligned with the bore 688, the spring action of the tongs 670 and 672 moves the nibs 684 and 686 into a locked position within bore 688, as shown in FIG. 24, to hold the walls 608 and 610 together. To disengage the latch assembly 668, the leg portions 690 and 692 are pried away from the wall section 610 to move the nibs 684 and 686 away from one another. The wall sections 608 and 610 can then be pivoted away from each other so that the chamfered surfaces 694 and 696 of the nibs 684 and 686 assist or allow the nibs 684 and 686 to be disengaged from bore 688. In this manner, the ensemble 602 lends itself to easy installation with the assembly 600 without having to disengage the tubes 604 from the assembly 600. As can be appreciated, for installation of the ensemble 602, the upper divider wall section 608 is pivoted away from the lower wall section 610 so that the section 610 can be slid beneath the tubes 604. Each of the lower bearing/seal members 632 is then aligned with a corresponding tube 604. The wall section 610 is then moved so that the corresponding tubes 604 are received within the bearing/seal members 632 with the bearing/sealing members 632 are pressed against the tube surfaces 666. The divider wall 608 is then pivoted downwardly until the bearing/seals 630 press against the tube surfaces 666 and the nibs 684 and 686 of latch tongs 670 and 672 are received in latching arrangement within the bore 688 of the lower wall 610. To disengage the ensemble 602, the latch 668 can be opened by pivoting the upper wall section 608 upwardly so that the lower wall section 610 can be removed from underneath the tubes 604. Now attention is directed to another embodiment of a roller grill for cooking human food having a section divider ensemble that is illustrated in FIGS. 25-27. A roller grill assembly 700 is shown having a divider ensemble 702 mounted to a plurality of heated roller tubes 704. The ensemble 702 is used to divide the roller grill assembly 700 into two different cooking areas 706 and 708. In particular, the cooking area 706 may be used to cook food products having a particular length. The cooking area 708 may be used to cook food products having a different length than those of the food products being cooked in the cooking area 706. The ensemble 702 comprises a divider partition wall 710 having bearing sub-assemblies 712. The bearing sub-assemblies 712 are adapted to fit on cooking surfaces 714 of the roller tubes 704. In this particular embodiment, the ensemble 702 is described as being an integral piece of plastic, such as polytetrafluoroethylene, made such as by injection molding or other molding process. Referring now in particular to FIG. 26, the partition wall 710 has a pair of opposite ends 716 and 718 each having an inwardly slanted leg 720 and 722, respectively. The leg 720 has a generally semi-circular end 724 having an inner edge 726. The other leg 722 also has a generally semi-circular end 728 and an inner edge 730. The ensemble 702 further comprises the bearing sub-assemblies 712 which are preferably unitary with the partition wall 710. The ensemble 702 further comprises two end bearing sub-assemblies 732 and 734 with the sub-assembly 732 being at the end 724 and the sub-assembly 734 being at the end 728. The bearing sub-assemblies 712 are positioned between the end sub-assemblies 732 and 734. The sub-assemblies 712 each comprise a bearing/seal 736. The end sub-assembly 732 has a bearing/seal 738 and the end sub-assembly 734 has a bearing/seal 740. A sectional view of the bearing seal 736 of the sub-assembly 712 is shown in FIG. 27. The bearing seal 736 is preferably molded to be unitary or one piece with the partition wall 710. The bearing seal 736 has a semi-circular passageway 742 which can receive the roller tube 704. Each of the bearing/sealing members 736 has semi-annular sloped outer surfaces 744 and the passageway 742 has a central semi-cylindrical bore 746. The bore 746 extends outwardly into semi-circular bore sections 748. The bore sections 748 are tapered to be of smaller radius at their outer edge than at their inner edge where the bore sections 748 join the bore section 746. The bearing 736 further has semi-annular tapered gripping lips or flanges 750. When the ensemble 702 is placed about the tubes 704 the gripping lips 750 press against the outer surface 714 of the tubes 704 to prevent the passage of drippings and particles from food products cooked in the cooking areas 706 and 708 from passing from one side of the divider ensemble 702 to the other side. The end bearing assembly 732 has the bearing/seal 738 which has the same cross-sectional configuration as the bearing members 712, except that the bearing/seal 738 has a curvature greater than a semi-circular shape, as can be seen in FIG. 26, to extend along the inside edge 726 of the leg 720. Further, the end bearing assembly 734 has the bearing/seal 740 constructed similar to the bearing/seal 738. The end bearing assembly 734 also extends along the inside edge 730 of the leg 722. In installation, the ensemble 702 can be placed above the roller tubes 704 and then the ensemble 702 can then be tilted either so that its rear leg 720 or its forward leg 722 is lowered. For purposes of illustration, the installation of the ensemble 702 will be given assuming that the front leg 722 is being tilted down. The leg 722 can be moved to a position forward of the front most tube 704 of the assembly 700. The ensemble 702 can then be moved at an angle so that the forward most tube 704 is moved to be received within bearing/seal 740 so that its gripping flanges 750 rest against the forward most tube. The ensemble 702 can then be pivoted to lower the other leg 720 so that the other tubes 704 are received within the bearing/seals 736 with the rearmost tube 704 being received within bearing/seal 732 so that the gripping lips 750 of the bearing/seals 736 and 750 press against the tubes 704. This ensemble 702 lends itself to installation to assemblies 700 that are in the field, as it can be installed without having to disengage the roller tubes 704 from the assembly 700. The ensemble can also be constructed with the bearing component being separate from the partition wall 710. This particular construction is illustrated in FIG. 27A. With reference now to FIG. 27A, a bearing/assembly or bearing member 760 has a semi-circular notch 762 to receive edges of semi-circular notches in a partition wall 764. The partition wall 764 in this embodiment would be constructed from stainless steel and the bearing member 760 would be constructed from any suitable plastic material such as polytetrafluoroethylene. In FIG. 27A, the bearing/seal 760 likewise has a semi-circular passageway 766″, semi-annular sloped outer surfaces 768, and a central semi-cylindrical bore 770 that extends outwardly into semi-circular bore sections 772. The bore sections 772 are likewise tapered to be of smaller radius at their outer edges than at their inner edges, and gripping lips 774 are provided at the openings of the bore sections 772. The lips 774 are capable of pressing against the outer tube surfaces, for example outer tube surfaces 714 of the roller tubes 704 of the assembly 700 to prevent passage of drippings and particles from food products. FIG. 28 shows a tool 800 which may be used to mount the roller tube 324 to or through the ensemble 326. The tool 800 is elongated with an arcuate cross section and is illustrated having a generally cylindrical shape, with a slot 802 separating two longitudinal edges 804 and 806. The tool 800 has a first end 808, and a second end 810, both of which are of arcuate shape, and illustrated as generally being of a partially circular shape. The tool 800 can be constructed of spring steel. For purposes of illustration in FIG. 28, a portion of the divider ensemble 326 is shown. The bearing sealing assembly 334, positioned at the front of the ensemble 326, is shown axially aligned with tool 800 with an O-ring 370 in place. Whereas, for purposes of illustration, the tool 800 is shown to the left of the divider ensemble 326, the tool 800 can be inserted through the bearing fitting 368 and the O-ring 370 from the right side of the divider ensemble 326 as well. The tool 800 can be compressed by the hand so as to pass through the O-ring 370 and the bearing 368, such as about ¼ to ½ inch past the bearing 368. The tool 800 can then be released by the hand so that it expands outwardly to stretch the O-ring 370 to press it firmly into its conforming bore section 396 (not shown in FIG. 28). In such position the tool 800 is in a compressed state and has a generally cylindrical shape and its ends 808 and 810 have a generally circular shape. With the tool 800 so positioned, the roller tube 324 can be inserted from the position in which it is shown in FIG. 28, to pass into the tool end 808. The tube 324 can continue to be inserted through the tool 800 and through bearing fitting 368 to extend about ½ inch beyond the inside of bearing fitting 368. The tube 324 could be inserted a lesser or farther distance if desired. After insertion to such point, the tool 800 can be grasped by the operator and slid away from the tube 324 and the ensemble 326 to thus become disengaged from the tube 324 and from the bearing 368 and the O-ring 370. The tube 324 is thus positioned to continue pressing the O-ring 370 outwardly into its conforming bearing bore 396. The roller tube 324 can thence be moved through the bearing fitting 368 and the O-ring 370 until the divider ensemble 326 is located in the desired position relative to the tube 324 to provide for the desired amount of space for cooking areas 330 and 332. The process or method can then be repeated for inserting the tool 800 through the bearing fittings 368 and the O-rings 370 in the remaining sealing assemblies 334 to give the desired amount of space for the cooking areas 330 and 332. Referring now to FIG. 29, a partial view of the divider partition wall member 328 is depicted to illustrate the construction thereof. In particular, the wall 328 has a plurality of circular openings 850, of which only one is illustrated, sized to allow a corresponding roller tube 324 to extend there through. Each opening 850 has at its lower edge a tab 852 that projects radially inwardly. The tab 852 is integral with the partition wall member 328. The tab 852 also has a radially extending left wall 854 and a radially extending right end wall 856. The partition wall 328 has a lower edge 858 and an upper edge 460 which are preferably approximately straight and parallel with each other. The edges 458 and 860 extend into the lower and upper edges of the curved ends 364 and 366, shown in FIGS. 11 and 13, respectively. The partition 328 also has a pair of side surfaces 862, of which only one such surface 862 is shown in FIG. 29. The roller tube sealing sub-assemblies 334 fit with the partition 328 and are adapted to mate with the tab 852, as will be described herein. With reference now to FIG. 30, a side view of a bearing 368 is depicted. The bearing 368 has a radial slit 870 that separates the bearing 368. The slit 870 extends from the bearing outer edges 384 and 386 (not shown) to the bore 392. The slit 870 separates the bearing 368 so that it has first and second ends 872 and 874, which can be pulled apart or away from each other when the bearing 368 is in the isolated position of FIG. 30. The ends 872 and 874 of the slit 870 may be pulled part far enough to fit or mate with the tab 852. FIG. 31 illustrates the bearing 368 fitted within the opening 850 of the wall 328. To install the bearing seal 368 with the partition 328, the bearing seal 368, in its isolated position of FIG. 30, is grasped and the ends 872 and 874 are pulled apart. The bearing seal 368 is inserted into the circular opening 850 and the ends 872 and 874 contact or abut the tab 852. Once the bearing seal 368 is installed, the O-ring 370 can then be installed within bearing 368. With the bearing seal 368 mounted in the partition wall 328, the annular wall opening 850 of the wall 328 fits approximately flush against the annular surface of the bearing seal 368. The radially extending left wall 854 and the radially extending right end wall 856 engage the bearing 368 to resist rotation of the bearing 368 relative to the partition wall 328 regardless of the direction of rotation of the tube 324. The anti-rotation action of the tab 852 in conjunction with the ends 872 and 874 of the bearing 368 help to resist wear and tear of the bearing 368. As can be appreciated from the foregoing, although one divider ensemble 326, 602, or 702 has been discussed that divides the assembly 320, 600, or 700 into two cooking areas, it should be recognized and understood that an additional divider ensemble can also be placed about the roller tubes 324 in the same fashion as shown and spaced from the other divider ensemble so as to divide the assembly into three separate cooking areas. Further, additional ensembles could be used to divide the cooking area into a larger number of sections, for example, four or more cooking areas. It is also contemplated and possible that the cooking areas 330 and 332 may be sectioned into equal areas or that one cooking area will be larger than the other cooking area. As can be further appreciated, the divider ensembles 326, 602, and 702 can be easily moved, installed, or repositioned on the tubular cooking members. It is also possible and contemplated that the divider ensembles 326, 602, and 702 may be used on the same roller grill assembly. Although the series of roller tubes 324 are shown mounted at an angle relative to the housing 322 it should be understood that the roller tubes 324 may also be aligned parallel to each other and on a horizontal plane or with roller tubes 324 that angle downwardly from the front to the rear of the housing 322 and the ensembles 326, 602, or 702 can be used equally well with such orientations of the roller tubes 324. In either case, there preferably are at least about 1-¼ to 1-{fraction (3/4)} inches of clearance between the lowest point of the divider wall 328 and the uppermost point of the grease tray 344. From all that has been said, it will be clear that there has been shown and described herein a roller grill for cooking human food having a section divider ensemble which fulfills the various objects and advantages sought therefore. It will be apparent to those skilled in the art, however, that many changes, modifications, variations, and other uses and applications of the subject roller grill for cooking human food having a section divider ensemble are possible and contemplated. All changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates generally to a roller grill for cooking human food, and more particularly to a roller grill for cooking human food having a section divider ensemble. Roller food grill assemblies are used in commercial establishments to quickly cook food products for customers. Such roller food grill assemblies typically have rotatable roller tubes for heating and cooking food. Roller tube cooking is especially adaptable to heating and cooking products that have an elongated shape, such as hot dogs, brats, and wieners. In this manner, the food product is placed on the heating surface of the roller tubes. As the roller tubes rotate, the food product is in constant contact with the roller tubes and the food product is evenly cooked and heated. However, due to the construction of these roller food grill assemblies it is difficult to cook food products having varying or differing lengths. Further, it may not be desirable to cook different food products on the same surface due to juices or tastes cooked from one product being absorbed onto another dissimilar product. For example, a hot dog may end up tasting like a brat. Additionally, it may be desirable to cook a relatively short food product, such as an egg roll, while at the same time it would be desirable to cook a relatively long food product, such as a foot long hotdog. In such situation the known food grill assemblies are not capable of being adjusted to compensate for food products having different lengths. The present invention is designed to obviate and overcome many of the disadvantages and shortcomings experienced with roller food grill assemblies discussed hereinbefore and with other food grill assemblies used in the past, and to provide a roller food grill assembly which can be easily utilized to cook foods having differing or varying lengths. Moreover, the roller food grill assembly of the present invention is more advantageous than the roller food grill assemblies previously used in that it is capable of separately cooking foods that have different lengths. Further, the present roller food grill assembly segregates and prevents against the transfer of juices or tastes from one food product to another dissimilar food product. Also, the present section divider ensemble for a roller food grill may be a kit that can be employed to retrofit existing roller food grill assemblies. | <SOH> SUMMARY OF THE INVENTION <EOH>In one form of the present invention, a roller grill for cooking human food comprises a housing having a plurality of tubular cooking members rotatably mounted within the housing, and a section divider ensemble for sectioning the tubular cooking members into a first cooking area and a second cooking area. In another form of the present invention, a divider ensemble for a roller grill assembly for cooking a first food product having a first length or being of a first type, and a second food product having a second length, or being of a second type, the roller grill assembly comprising a housing and a plurality of rotatable tubular cooking members. The divider ensemble comprises a first mounting bracket having a plurality of openings positioned on a front of the housing, a second mounting bracket having a plurality of openings positioned at a back of the housing, and a divider member adapted to being inserted into the openings of the first and second mounting brackets to divide the tubular cooking members into a first cooking area for cooking the food product having the first length, or being of the first type, and a second cooking area for cooking the food product having the second length, or being of the second type. In yet another form of the present invention, a divider ensemble for a roller grill assembly for cooking food, the roller grill assembly having a housing having a pair of sidewalls and a plurality of tubular cooking members, the divider ensemble comprises a first pair brackets mounted to the sidewalls at a front of the housing, the pair of brackets having a pair of projections, a second pair of brackets mounted to the sidewalls at a back of the housing, the pair of brackets having a pair of projections, a first mounting bracket having a series of openings and a pair of flanges each having a pair of notches that mate with the projections of the first pair of brackets, a second mounting bracket having a series of openings and a pair of flanges each having a pair of notches that mate with the projections of the second pair of brackets, and a divider member for positioning in the openings in the first and second mounting brackets for sectioning the tubular cooking members into a first cooking area and a second cooking area. Features obtained by the invention as covered by one or more of the claims include one or more of the following: to provide an improved roller grill for cooking human food with the roller grill having a section divider ensemble; to provide a roller grill assembly for cooking human food having a section divider ensemble which is of simple construction and design and which can be easily employed with highly reliable results; to provide a roller grill assembly that is capable of cooking foods that have different lengths; to provide a roller grill assembly that is capable of preventing the transfer of juices or tastes from one food product to another food product when both of the products are being cooked at the same time; to provide a roller grill assembly in which foods having the same length may be cooked on one section of the roller grill assembly and foods having a different length may be cooked on another section of the roller grill assembly; to provide a roller grill assembly for cooking human food having a section divider ensemble which is removable; to provide a roller grill assembly for cooking human food having a number of divider ensembles for partitioning the roller grill assembly into various cooking areas; to provide a roller grill assembly for cooking human food with a section divide ensemble that is adjustable relative to the roller grill; to provide a divider ensemble for a roller grill assembly that can be easily installed; to provide a divider ensemble for a roller grill assembly that can be retrofitted to an existing roller grill assembly; to provide a divider ensemble for a roller grill assembly that has indicia that indicate what food product is being cooked in a particular section of the roller grill assembly; and to provide a divider ensemble for a roller grill assembly that can be easily removed from the roller grill assembly. These and other objects and advantages of the present invention will become apparent after considering the following detailed specification in conjunction with the accompanying drawings. | 20040423 | 20080226 | 20050310 | 94388.0 | 2 | ALEXANDER, REGINALD | SECTION DIVIDER ENSEMBLE FOR ROLLER GRILL FOR COOKING HUMAN FOOD | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,831,734 | ACCEPTED | Evap canister purge prediction for engine fuel and air control | In a system and a method for purging a vapor storage canister having adsorbed fuel vapor (or hydrocarbon vapor) by drawing air through the storage canister the storage canister being coupled with an engine having a system for controlling the amount of fuel provided to the engine, the amount of fuel vapor in the purge is estimated using a model that predicts fuel vapor concentration in the purge vapor. The engine controller uses the estimated amount of fuel vapor and air brought into the engine from the evaporative vapor storage canister for better control of engine air and fuel during purging. | 1. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor, comprising the steps of: providing an initial value, CHC0, for the concentration of hydrocarbon vapor in the canister containing adsorbed hydrocarbon vapor; drawing air into the canister containing adsorbed hydrocarbon vapor and withdrawing from the canister a volume of purge vapor containing desorbed hydrocarbon vapor; calculating a concentration of desorbed hydrocarbon vapor in the purge vapor; and using purge vapor volume and concentration of hydrocarbon vapor in the purge vapor to calculate the amounts of purge hydrocarbon vapor and purge air and adjusting an amount of fuel to be taken from the fuel tank and an amount of intake air based on the amounts of purge hydrocarbon vapor and purge air. 2. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein CHC0 is measured by monitoring the fuel injection rate with and without canister purge at steady state engine operation. 3. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein CHC0 is estimated from purge canister and/or vehicle conditions. 4. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein the concentration of desorbed hydrocarbon vapor in the purge vapor is calculated using a curve fitted to experimentally measured values for hydrocarbon concentration in the purge vapor as a function of commanded purge vapor volume for a specific vehicle, purge canister, absorbent, and purge conditions. 5. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein the concentration of desorbed hydrocarbon vapor in the purge vapor is calculated using a model that predicts exponential decrease for hydrocarbon concentration in the purge vapor from the initial hydrocarbon concentration with continuing purge. 6. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein the concentration of hydrocarbon in the purge vapor, CHC, is calculated from an equation: CHC═CHC0EXP(−(αCHC0+β)V), in which V is the cubic feet of commanded purge volume; CHC0 is the initial concentration of hydrocarbon vapor in the purge; CHC is the concentration of hydrocarbon vapor in the purge after V cubic feet of commanded purge volume; and α and β are constants, the values of which depend on the particular engine and make of vehicle. 7. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein the concentration of hydrocarbon in the purge vapor, CHC, is calculated using a model combining material balance and isotherm equations. 8. A method for controlling amounts of air and fuel introduced to an engine during purge of hydrocarbon vapor from a canister containing adsorbed hydrocarbon vapor according to claim 1, wherein the concentration fraction of hydrocarbon CHC in the purge vapor is determined from a ratio of its partial pressure P to the atmospheric pressure Patm using the equation CHC=P/Patm, wherein P = - b + b 2 - 4 ac 2 a wherein a=KBb, b=K−QBb+QmBb, and c=−Q, and K=ΔV/(kckf(1-ε)VcRT) where ΔV is the volume of purge vapor, kc is a correction factor for carbon utilization, kf is a correction factor for partial fill, (1-ε)Vc is the volume of the carbon in the evap canister, ε is the porosity of the adsorbent in the evap canister, and Vc is the evap canister volume, R is the gas law constant, and T is the air temperature in Kelvin, Q is the initial adsorbed amount of hydrocarbon per unit volume of carbon, Q1 is the final adsorbed amount of hydrocarbon per unit volume of carbon after ΔV volume of purge vapor wherein Q1=QmBbP÷(1+QmBbP), and Qm and Bb are isotherm constants in which Qm=A+B/T and Bb=EXP(C+D/T), with A, B, C, and D being characteristic constants of the adsorbent in the evap canister. 9. A method of operating a vehicle having an internal combustion engine with an air induction system, a fuel tank connected to the engine to supply fuel to the engine, an electronic engine control module comprising a programmed microprocessor controlling fuel delivery to the engine and intake air to the engine, and a canister to adsorb vapor from the fuel tank comprising a vapor inlet coupled to the fuel tank and a purge outlet coupled to the air induction system, comprising steps of: adsorbing fuel vapor from the fuel tank into the canister through the vapor inlet; desorbing fuel vapor from the canister through the purge outlet by opening the purge valve through a signal from the electronic engine control module and drawing air through the canister into the air induction system; calculating the concentration of desorbed hydrocarbon vapor in the purge vapor; using the concentration of desorbed hydrocarbon vapor and purge vapor volume to calculate the amounts of purge hydrocarbon vapor and purge air and using the electronic engine control module to adjust fuel delivery from the fuel tank to the engine and/or the amount of intake air in response to the calculated amounts of purge hydrocarbon vapor and purge air. 10. A controller having an algorithm for determining the concentration of hydrocarbon vapor in purge vapor drawn from a canister containing adsorbed hydrocarbon vapor, said algorithm including steps for providing an initial concentration of hydrocarbon in purge vapor; steps for determining commanded purge volume and purge vapor composition; and steps for calculating purge air correction and purge hydrocarbon correction and applying the corrections in engine air and fuel intake calculations. 11. A controller according to claim 10, wherein the purge vapor composition is determined using a curve fitted to experimentally measured values for hydrocarbon concentration in the purge vapor as a function of commanded purge vapor volume for a specific vehicle, purge canister, absorbent, and purge conditions. 12. A controller according to claim 10, wherein the purge vapor composition is determined using a model that predicts exponential decrease for hydrocarbon concentration in the purge vapor from the initial hydrocarbon concentration with continuing purge. 13. A controller according to claim 10, wherein the purge vapor composition is determined using a model combining material balance and isotherm equations. 14. A vehicle having an internal combustion engine with an air induction system, a fuel tank connected to the engine to supply fuel to the engine, an electronic engine control module comprising a programmed microprocessor controlling fuel and air delivery to the engine, and a canister to adsorb vapor from the fuel tank comprising a vapor inlet coupled to the fuel tank, a purge outlet coupled to the air induction system, and an air inlet, wherein the microprocessor is programmed to estimate concentration of hydrocarbon vapor in purge air drawn from the canister from an equation that predicts a decrease of fuel vapor concentration in the purge air from an initial fuel vapor concentration in the purge air and further wherein the electronic engine control module adjusts fuel and air delivery to the engine in response to the estimated concentration of hydrocarbon vapor in the purge air. 15. A vehicle according to claim 14, wherein the equation predicts exponential decrease for hydrocarbon concentration in the purge vapor from the initial hydrocarbon concentration with continuing purge. 16. A vehicle according to claim 14, wherein the equation combines material balance and isotherm equations. | FIELD OF THE INVENTION The present invention relates generally to systems and methods connected with vapor storage canisters. In particular, the present invention concerns estimating hydrocarbon vapor and air drawn into an engine from purge of an evap canister and using the estimate for engine air and fuel control. BACKGROUND OF THE INVENTION The automotive industry has actively sought improved emissions reduction, including reduction in emissions due to gasoline evaporation. Gasoline includes a mixture of hydrocarbons ranging from higher volatility butanes (C4) to lower volatility C8 to C10 hydrocarbons. When vapor pressure increases in the fuel tank due to conditions such as higher ambient temperature or displacement of vapor during filling of the tank, fuel vapor flows through openings in the fuel tank. To prevent fuel vapor loss into the atmosphere, the fuel tank is vented into a canister called an “evap canister” that contains an adsorbent material such as activated carbon granules. As the fuel vapor enters an inlet of the canister, the fuel vapor diffuses into the carbon granules and is temporarily adsorbed. The size of the canister and the volume of the adsorbent material are selected to accommodate the expected fuel vapor generation. One exemplary evaporative control system is described in U.S. Pat. No. 6,279,548 to Reddy, which is hereby incorporated by reference. After the engine is started, the control system uses engine intake vacuum to draw air through the adsorbent to desorb the fuel. An engine control system may use an engine control module (ECM), a powertrain control module (PCM), or other such controller to optimize fuel efficiency and minimize regulated emissions. The desorbed fuel vapor is directed into an air induction system of the engine as a secondary air/fuel mixture to consume the desorbed fuel vapor. To optimize fuel efficiency it is desirable to take this secondary air/fuel source into account. Presently, however, canister purge fuel and air are not metered, and so the ECM has no data to use in adjusting the fuel and air to the engine. Exhaust oxygen sensor feedback control is used to adjust fuel control during canister purge. Feedback control, as it is after the fact, is not very effective in exhaust emissions control. Stringent exhaust emission regulations, however, require ever more careful control of the air/fuel ratio in the engine. On the other hand, more stringent evap emissions regulations require increased purge air rates, meaning even more un-metered air entering the engine. Additionally, the amount of adsorbed fuel vapor in the canister varies during the desorption process. The rate at which fuel vapor is drawn from the canister will decrease as more and more is removed until finally all of the fuel will have been desorbed from the canister. It would be desirable to enable the engine or powertrain control module (“controller”) to take into account the amount of fuel vapor drawn from the storage container in optimizing fuel efficiency and minimizing emissions and to be able to adjust for the decrease in fuel vapor from the storage canister as the adsorbed fuel is depleted. One way to provide to the controller the information of fuel vapor and purge air drawn from the storage container would be to measure directly the amount of hydrocarbon and air being drawn from the storage canister using a purge hydrocarbon sensor so that the engine controller can reduce the fuel from the fuel tank injected into the engine and air intake of the engine accordingly. This approach will result in feed forward control that is very effective in exhaust emission control, but would require adding an expensive purge sensor to the engine. It would thus be useful to have a method of predicting the amount of hydrocarbon in the air drawn through the canister into the engine for better feed forward fuel control without adding expensive equipment to the engine. SUMMARY OF THE INVENTION The present invention provides a method and an apparatus for controlling the engine air and fuel ratio during purging of an evaporative vapor storage canister. The apparatus includes a controller programmed to use a calculation to estimate the amount of hydrocarbon and air in purge vapor from an evaporative vapor storage canister to reduce the amount of metered fuel and air entering the engine. The canister contains adsorbent material capable of adsorbing fuel vapor from a fuel tank storing a volatile fuel. The canister includes a vapor inlet coupled to the fuel tank, a purge outlet coupled to an air induction system of an engine, and fuel vapor generated in the fuel tank from diurnal and refueling events that is stored in the canister. During purging, the air induction system draws air through the canister. Desorbed fuel vapor (also referred to herein as hydrocarbon vapor) enters the air as it is drawn through the canister. The hydrocarbon vapor in the withdrawn hydrocarbon vapor/air mix will decrease through the purging operation. The initial concentration of desorbed hydrocarbon vapor in the purge vapor, if not known, may be estimated from relevant factors such as the fuel level change since the last purge, the interval of time since refueling (i.e., since increasing the fuel level), ambient temperature, seasonal RVP of the fuel, and the adsorption capacity and quantity of the adsorbent in the evaporative vapor storage canister. The controller calculates the amount of hydrocarbon and air in purge vapor from an evaporative vapor storage canister using an estimate or determination of initial concentration of hydrocarbon vapor in the purge and an equation that predicts the decrease with time of the amount of hydrocarbon in the purge from the evaporative vapor storage canister. The equation is preferably based on Langmuir adsorption isotherm equations. The invention further provides a method for purging a vapor storage canister having adsorbed fuel (or hydrocarbon) vapor coupled with an engine having a system for controlling the amount of fuel provided to the engine, e.g. an electronic engine control module. In the method, the amount of fuel vapor and air in the purge is estimated using an estimate or determination of initial concentration of hydrocarbon vapor in the purge an equation that predicts the decrease with time of the amount of hydrocarbon in the purge from the evaporative vapor storage canister. The equation is preferably based on Langmuir adsorption isotherm equations. An initial concentration of hydrocarbon vapor in the purge air may be measured or estimated based on known factors such as engine temperature, time since refueling, seasonal RVP of the fuel, and the adsorption capacity and quantity of the adsorbent in the evaporative vapor storage canister. An ECM or PCM uses the calculation of fuel vapor flow from the canister during purging to improve fuel efficiency and/or reduce exhaust emissions. The amount of fuel drawn from the fuel tank and/or intake air can be reduced by the known amount of fuel vapor and air in the purge stream. In a further embodiment, when an engine starts and purging of the canister starts the initial concentration of hydrocarbons in purge vapor is determined or is estimated from how much vapor may be stored in the canister based on indicators of time since the engine was last on and how hot the canister is (e.g., whether heated by heat released from vapor adsorption during refueling). Next, decrease of hydrocarbon vapor in the purge vapor is determined using an equation. The equation may be modeled from Langmuir adsorption isotherm equations. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. In describing the present invention, “engine control module,” “ECM,” “powertrain control module,” “PCM,” and “controller” are used interchangeably to refer to a control module that can adjust the amount of fuel and air provided to the engine. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a functional block diagram of an engine and evaporative control system for a vehicle; FIGS. 2A and 2B together are a flow chart illustrating the steps by which the vehicle controller estimates the amount of fuel vapor in the purge from the evaporative vapor storage container; and FIG. 3 is a graph showing measured and calculated purge hydrocarbon volume percents. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Referring now to FIG. 1, an engine 12 having an intake manifold 80 and exhaust manifold 10 is illustrated. The vehicle may be a conventional (non-hybrid) vehicle including an internal combustion engine or a hybrid vehicle including an internal combustion engine and an electric motor (not shown). The engine 12 is preferably an internal combustion engine that is controlled by a controller 14. The engine 12 typically burns gasoline, ethanol, and other volatile hydrocarbon-based fuels. The controller 14 may be a separate controller or may form part of an engine control module (ECM), a powertrain control module (PCM), or another vehicle controller. When the engine 12 is started, the controller 14 receives signals from one or more engine sensors, transmission control devices, and/or emissions control devices. Line 16 from the engine 12 to the controller 14 schematically depicts the flow of sensor signals. During engine operation, gasoline 21 is delivered from a fuel tank 18 by a fuel pump 20 through a filter 28 and fuel lines 33 and 22 to a fuel rail (not shown). Fuel injectors inject gasoline into cylinders of the engine 12 or to ports that supply groups of cylinders. FIG. 1 shows one such fuel injector 26. The timing and operation of the fuel injectors and the amount of fuel injected are managed by the fuel controller 24. Fuel controller 24 is controlled by controller 14 (control line not shown). Air controller 82 in intake manifold 80 manages the amount of air entering engine 12 and is also controlled by controller 14 by control line 75. The fuel tank 18 is often made of blow-molded, high-density polyethylene provided with one or more gasoline impermeable interior layer(s). The fuel tank contains a fuel sender module 32. Fuel pump 20 pumps gasoline 21 through filter 28 and fuel line 33 to pressure regulator 34, where the unused fuel is returned to the tank. By-pass line 31 returns unused gasoline to the fuel pump inlet. The fuel tank 18 includes a vent line 30 that extends from the fuel tank 18 to a fuel vapor adsorbent canister 62. Fuel vapor pressure increases as the temperature of the gasoline increases. Vapor flows under pressure through the vent line 30 to the fuel vapor adsorbent canister 62. The vapor enters the canister 62 and is captured by suitable adsorbent material (not shown), such as activated carbon materials, on either side of a center wall 64. The fuel vapor adsorbent canister 62 is formed of any suitable material. For example, molded thermoplastic polymers such as nylon are typically used. After the fuel vapor is adsorbed in the canister, the air exits through vent line 66. Vent line 66 provides air during purging of adsorbed fuel vapor from the canister 62. A stream of purge air and fuel vapor exit the canister through the purge line 70. The purge line 70 contains valve 72 that selectively closes the canister 62 off from engine 12. Purge valve 72 is operated by the controller 14 through a signal lead 74 when the engine 12 is running. Purge valve 72 is closed when the engine 12 is not operating, but is opened after the engine 12 warms up when the engine 12 is operating for purging adsorbed vapor. Purge flow is controlled by ECM 14 by pulse width modulation (PWM) of purge valve 72. For example, purge flow is reduced during idle and/or when the purge vapor has a high concentration of hydrocarbon. The air becomes laden with desorbed hydrocarbon fuel vapor desorbed from canister 62. The fuel-laden air is drawn through the purge line 70 and into intake manifold 80. Controller 14 estimates the amount of fuel vapor in the purge air from purge line 70 and adjusts both the amount of fuel injected into the engine and air taken into the engine by the fuel controller 24 and the air controller 82 using a model that predicts the change in hydrocarbon concentration as a function of controller-commanded purge volume. The controller uses an algorithm that may have three major steps. In a first step, the controller determines the status of the canister to estimate how much vapor is stored and how hot the canister is. The canister may be heated from refueling vapor adsorption heat release. Alternatively, an actual measurement of initial hydrocarbon concentration in the purge vapor may be made. In an embodiment illustrated in FIGS. 2A and 2B, steps 102-109 are used for estimating initial hydrocarbon concentration in the purge vapor; steps 111 to 113 are used for determining actual initial hydrocarbon concentration in the purge vapor. In a second major step, the controller computes the decrease in hydrocarbon concentration in the purge vapor as the engine draws air through the canister. In FIGS. 2A and 2B, steps 114 to 117 represent this computation. In a third major step, using purge vapor volume and concentration of hydrocarbon vapor in the purge vapor, the amounts of purge hydrocarbon vapor and air are used by the controller in engine air and fuel calculations to determine an amount of fuel to be taken from the fuel tank and an amount of intake air for improved fuel efficiency and exhaust emission control. This is step 118 of algorithm 100 in FIG. 2B. (The individual steps of algorithm 100 of FIGS. 2A and 2B are described in more detail below.) The model for predicting change in hydrocarbon concentration as a function of controller-commanded purge volume may use an initial hydrocarbon concentration that is estimated from purge canister and/or vehicle conditions or may use an initial hydrocarbon concentration that is measured. An initial hydrocarbon concentration in purge vapor may be estimated based on factors such as the fuel level change since the last purge, the interval of time since refueling (i.e., since increasing the fuel level), ambient temperature, seasonal RVP of the fuel, and the adsorption capacity and quantity of the adsorbent in the evaporative vapor storage canister. An initial hydrocarbon concentration in purge vapor may be measured by monitoring the fuel injection rate with and without canister purge at steady state engine operation. The controller then uses the initial hydrocarbon concentration (predicted or measured) and a model to estimate hydrocarbon concentration in the purge vapor as a function of commanded purge vapor volume. In one embodiment, a suitable model can be made by fitting a curve to experimentally measured values for hydrocarbon concentration in the purge vapor as a function of commanded purge vapor volume for a specific vehicle, purge canister, absorbent, and purge conditions. In another embodiment, a model may be of a form that predicts exponential decrease for hydrocarbon concentration in the purge vapor from the initial hydrocarbon concentration with continuing purge. In this embodiment, the concentration of hydrocarbon in the purge vapor, CHC, may be estimated from an equation: CHC═CHC0EXP(−((αCHC0+β)V), in which V is the cubic feet of commanded purge volume; CHC0 is the initial concentration of hydrocarbon vapor in the purge; CHC is the concentration of hydrocarbon vapor in the purge after V cubic feet of commanded purge volume; and α and β are constants, the values of which depend on the particular engine and make of vehicle. The constants are given values to adjust the predictive curve to fit experimentally determined data to a desired extent. A perfect fit is not required for a commercially useful equation. In a preferred embodiment, a combination of material balance and isotherm equation is used to compute purge hydrocarbon concentration as a function of commanded purge volume. Commanded purge volume is computed from the purge valve pulse width modulation, or length of time that the purge valve is open. The isotherm-based model for predicting canister purge air and hydrocarbon flow uses a relationship that the amount of hydrocarbon purged from the evap canister equals the initial amount of hydrocarbon adsorbed in the evap canister when purging starts minus the final amount of hydrocarbon adsorbed in the evap canister after purging ends. The total amount of purge vapor sent to the engine is defined as ΔV. The volume of carbon contained in the evap canister is (1-ε)Vc, where ε is the porosity of the adsorbent (e.g., activated carbon) and Vc is the evap canister volume. Using these relationships in an isotherm model, (1-ε)Vc(Q)−(1-ε)Vc(Q1)=(ΔVP)÷(RT) and Q1=QmBbP÷(1+QmBbP), where (1-ε)Vc is the volume of the carbon in the evap canister, Q is the initial adsorbed amount of hydrocarbon per unit volume of carbon, ΔV is the volume of purge vapor, Q1 is the final adsorbed amount of hydrocarbon per unit volume of carbon after ΔV volume of purge vapor, R is the gas law constant, P is the partial pressure of the hydrocarbon vapor in the purge vapor, T is the air temperature in Kelvin, and Qm and Bb are isotherm constants in which Qm=A+B/T and Bb=EXP(C+D/T), with A, B, C, and D being characteristic constants of the adsorbent (e.g., the carbon) in the evap canister. For example, when the adsorbent is 15BWC carbon and the hydrocarbon is butane, A, B, C, and D are 0.00368, 0.365200, −8.6194, and 3102, respectively. The equation may be rearranged into a quadratic equation to solve for P: KBbP2+(K−QBb+QmBb)P−Q=0, where K=(ΔV)÷((1-ε)VcRT). The quadratic equation is solved for P: P = - b + b 2 - 4 ac 2 a where a=KBb, b=K−QBb+QmBb, and c=−Q. Correction factors are needed to account for the incomplete utilization of the adsorbent (e.g., carbon bed) and for partial fills. In most cases, even during fill ups of the fuel tank, only a part of the adsorbent in the evap canister is saturated with hydrocarbons. Some parts of the adsorbent bed may be partially saturated while other parts may remain clean to prevent breakthrough loss. Typically, only about 50% of a 2.1L canister adsorbent bed may be saturated with vapor after a complete refueling. The correction for the adsorbent utilization may be determined experimentally for the particular vehicle and equipment. In one example, correction factor kc for carbon utilization and correction factor kf for partial fill are included in an equation: K=ΔV/(kckf(1-ε)VcRT). A controller algorithm using the model may also take into account that usually during normal vehicle operation the concentration of purge hydrocarbon is less than about 5%. Further, for canister purging following one or two diurnal hydrocarbon vapor loadings of the evap canister at summer temperatures (temperatures greater than 50° F.), initial purge hydrocarbon concentration can be estimated to be about 10% and decrease slowly as purging continues. Diurnal hydrocarbon vapor loading of the evap canister at winter temperatures (less than 50° F.) is negligible. Finally, immediately after refueling an initial hydrocarbon vapor in the purge vapor can be estimated at about 35%, which decreases exponentially as purging continues. Vehicle refueling results in a nearly saturated, warm canister at both summer and winter ambient temperatures. The algorithm may also take into account two exceptional conditions for butane loading of the evap canister and hot fuel handling. First, if refueling has not taken place (no fuel level change detected) but a vehicle oxygen sensor detects high purge hydrocarbon concentration at an ambient temperature less than about 90° F., then the algorithm may assume a butane-loaded canister in estimating decay of hydrocarbon concentration in the purge vapor with continued purging. Secondly, if refueling has not taken place (no fuel level change detected) but a vehicle oxygen sensor detects high purge hydrocarbon concentration at an ambient temperature of about 90° F. or higher, then the algorithm may assume a hot fuel handling situation (high fuel vapor pressure) in which there is little or no air in the purge vapor. Returning now to the figures, FIGS. 2A and 2B together are a flow chart illustrating a preferred embodiment of the method by which the vehicle controller 14 estimates the amount of fuel vapor in the purge from the evaporative vapor storage container 62 using a preferred embodiment of a predictive model. Algorithm 100 begins with step 101 with engine start of the vehicle. At step 102, the controller (e.g., ECM or PCM) reads the engine soak time t (that is, how long it has been since the engine was last running), the fuel level F1 and ambient temperature TF1 at the end of the time the engine was last running (i.e., at the beginning of the soak or the end of the last trip), and the fuel level F2 and ambient temperature TF2 at the current engine start. At step 103 the controller makes a decision whether the engine start was a cold start—e.g., if t is more than about five hours. If the engine start was not a cold start, the algorithm proceeds to step 105 to treat the stop as a refueling stop. If the engine start was a cold start, the algorithm proceeds to step 104 and tests for a diurnal purge condition. At step 104, the algorithm compares fuel level F1 to fuel level F2. If the fuel level has not changed, the algorithm assumes a diurnal purge condition. In the case of a diurnal purge, if TF1 and TF2 are less than about 50° F. the initial hydrocarbon concentration in the purge vapor (CHC0) is set to zero; otherwise, the algorithm assumes an initial purge vapor with approximately 10% by volume hydrocarbon vapor and 90% by volume air, and the initial hydrocarbon concentration (CHC0) is set to 10% by volume hydrocarbon vapor in the purge. If F2 is greater than F1, the algorithm assumes a refueling vapor purge in which the initial purge vapor will have approximately 10% by volume hydrocarbon vapor and 90% by volume air, and the initial hydrocarbon concentration (CHC0) is set to 10% by volume hydrocarbon vapor in the purge. The algorithm then proceeds to step 109 to begin closed-loop fuel control. If the algorithm determined at step 103 that the purge comes after refueling, then at step 105 the algorithm asks whether F2 is greater than F1 (fuel level has increased) and if the stopping time t is less than about 10 minutes. If these conditions are both met, then the algorithm moves to step 106, assumes 35% hydrocarbon vapor in the purge vapor, and sets CHC0 to 35, and proceeds to step 108. If, on the other hand, refueling is followed by a soak period of t hours in which the canister has cooled, CHC0 will be less than 35, and CHC0 is estimated in step 107 to drop exponentially with time. CHC0 may be estimated using the equation: CHC0=10+25EXP(−0.9t) The algorithm then proceeds to step 108. In step 108, the algorithm calculates a partial fill factor kf using F1 and F2, then moves on to step 109 to begin closed-loop fuel control. In closed loop fuel control, the ECM or PCM uses oxygen sensor feedback for fuel control. Canister purge is enabled, or purging starts once the engine goes into closed loop operation. Proceeding now to step 109, the algorithm enters a closed-loop fuel control segment. In step 110, the algorithm determines whether it is possible to measure the initial fuel vapor concentration in the purge (CHC0) intrusively. It is possible to measure intrusively if the engine is operating at a steady state (e.g., if the engine is at idle or cruising at constant speed). If CHC0 can be measured intrusively, the algorithm proceeds to step 111; if it is not, the algorithm continues to step 114. In step 111, the controller turns the canister purge off, then stores a value for either tank fuel consumption rate or the injector pulse width (INJPW1). In step 112 the canister purge is turned on, and the controller algorithm stores a second value for tank fuel consumption rate or injector pulse width (INJPW2) with canister purge on. Finally, in step 113, the initial purge hydrocarbon concentration CHC0 is determined using the values of tank fuel consumption rate or injector pulse width that were determined in steps 112 and 113. The algorithm then continues to step 114. At step 114, the algorithm computes the isotherm constants Qm and Bb at air temperature T, where T is air temperature in kelvin. The algorithm also calculates the hydrocarbon vapor partial pressure P in the purge vapor by multiplying atmospheric pressure (which may be taken as 1 atmosphere) by the initial concentration fraction of hydrocarbon vapor in the purge vapor. Finally, Qm, Bb, and P are used to calculate Q using the equation Q=QmBbP÷(1+QmBbP). The algorithm then continues with step 115. In step 115, the algorithm computes the commanded purge volume ΔV from the purge valve PWM (pulse width modulation). In step 116, the algorithm computes the purge vapor composition using the isotherm-based model described above. K is determined using the equation K=(ΔV)÷((1-ε)VcRT). The quadratic equation for pressure P is solved P = - b + b 2 - 4 ac 2 a where a=KBb, b=K−QBb+QmBb, and c=−Q, and Q has the value determined in step 114. When P has been calculated, then the concentration fraction of hydrocarbon CHC in the purge vapor is determined from the ratio of its partial pressure P to the atmospheric pressure Patm: CHC=P/Patm Finally, the algorithm computes purge hydrocarbon flow ΔVCHC and purge air flow ΔV(1-CHC) in step 118 for engine fuel and air calculations. FIG. 3 is a graph showing measured and calculated purge hydrocarbon volume percents for a 2004 Buick Rendezvous having an 1850 cc evap canister containing 15BWC carbon. The hydrocarbon vapor is measured using an NGK hydrocarbon sensor. The vehicle used a Delphi purge valve having a 28L/min purge flow at 100% PWM (pulse width modulation). The data was taken following a refuel after a 10-mile city drive. The refuel was 14 gallons of fuel at an ambient temperature of 55° F. The vehicle was driven on the highway following the refuel, with purge hydrocarbon concentration being measured as a functional of cubic feet of commanded purge. A curve showing the isotherm-based model prediction shows a close fit to the experimentally determined data. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>The automotive industry has actively sought improved emissions reduction, including reduction in emissions due to gasoline evaporation. Gasoline includes a mixture of hydrocarbons ranging from higher volatility butanes (C 4 ) to lower volatility C 8 to C 10 hydrocarbons. When vapor pressure increases in the fuel tank due to conditions such as higher ambient temperature or displacement of vapor during filling of the tank, fuel vapor flows through openings in the fuel tank. To prevent fuel vapor loss into the atmosphere, the fuel tank is vented into a canister called an “evap canister” that contains an adsorbent material such as activated carbon granules. As the fuel vapor enters an inlet of the canister, the fuel vapor diffuses into the carbon granules and is temporarily adsorbed. The size of the canister and the volume of the adsorbent material are selected to accommodate the expected fuel vapor generation. One exemplary evaporative control system is described in U.S. Pat. No. 6,279,548 to Reddy, which is hereby incorporated by reference. After the engine is started, the control system uses engine intake vacuum to draw air through the adsorbent to desorb the fuel. An engine control system may use an engine control module (ECM), a powertrain control module (PCM), or other such controller to optimize fuel efficiency and minimize regulated emissions. The desorbed fuel vapor is directed into an air induction system of the engine as a secondary air/fuel mixture to consume the desorbed fuel vapor. To optimize fuel efficiency it is desirable to take this secondary air/fuel source into account. Presently, however, canister purge fuel and air are not metered, and so the ECM has no data to use in adjusting the fuel and air to the engine. Exhaust oxygen sensor feedback control is used to adjust fuel control during canister purge. Feedback control, as it is after the fact, is not very effective in exhaust emissions control. Stringent exhaust emission regulations, however, require ever more careful control of the air/fuel ratio in the engine. On the other hand, more stringent evap emissions regulations require increased purge air rates, meaning even more un-metered air entering the engine. Additionally, the amount of adsorbed fuel vapor in the canister varies during the desorption process. The rate at which fuel vapor is drawn from the canister will decrease as more and more is removed until finally all of the fuel will have been desorbed from the canister. It would be desirable to enable the engine or powertrain control module (“controller”) to take into account the amount of fuel vapor drawn from the storage container in optimizing fuel efficiency and minimizing emissions and to be able to adjust for the decrease in fuel vapor from the storage canister as the adsorbed fuel is depleted. One way to provide to the controller the information of fuel vapor and purge air drawn from the storage container would be to measure directly the amount of hydrocarbon and air being drawn from the storage canister using a purge hydrocarbon sensor so that the engine controller can reduce the fuel from the fuel tank injected into the engine and air intake of the engine accordingly. This approach will result in feed forward control that is very effective in exhaust emission control, but would require adding an expensive purge sensor to the engine. It would thus be useful to have a method of predicting the amount of hydrocarbon in the air drawn through the canister into the engine for better feed forward fuel control without adding expensive equipment to the engine. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a method and an apparatus for controlling the engine air and fuel ratio during purging of an evaporative vapor storage canister. The apparatus includes a controller programmed to use a calculation to estimate the amount of hydrocarbon and air in purge vapor from an evaporative vapor storage canister to reduce the amount of metered fuel and air entering the engine. The canister contains adsorbent material capable of adsorbing fuel vapor from a fuel tank storing a volatile fuel. The canister includes a vapor inlet coupled to the fuel tank, a purge outlet coupled to an air induction system of an engine, and fuel vapor generated in the fuel tank from diurnal and refueling events that is stored in the canister. During purging, the air induction system draws air through the canister. Desorbed fuel vapor (also referred to herein as hydrocarbon vapor) enters the air as it is drawn through the canister. The hydrocarbon vapor in the withdrawn hydrocarbon vapor/air mix will decrease through the purging operation. The initial concentration of desorbed hydrocarbon vapor in the purge vapor, if not known, may be estimated from relevant factors such as the fuel level change since the last purge, the interval of time since refueling (i.e., since increasing the fuel level), ambient temperature, seasonal RVP of the fuel, and the adsorption capacity and quantity of the adsorbent in the evaporative vapor storage canister. The controller calculates the amount of hydrocarbon and air in purge vapor from an evaporative vapor storage canister using an estimate or determination of initial concentration of hydrocarbon vapor in the purge and an equation that predicts the decrease with time of the amount of hydrocarbon in the purge from the evaporative vapor storage canister. The equation is preferably based on Langmuir adsorption isotherm equations. The invention further provides a method for purging a vapor storage canister having adsorbed fuel (or hydrocarbon) vapor coupled with an engine having a system for controlling the amount of fuel provided to the engine, e.g. an electronic engine control module. In the method, the amount of fuel vapor and air in the purge is estimated using an estimate or determination of initial concentration of hydrocarbon vapor in the purge an equation that predicts the decrease with time of the amount of hydrocarbon in the purge from the evaporative vapor storage canister. The equation is preferably based on Langmuir adsorption isotherm equations. An initial concentration of hydrocarbon vapor in the purge air may be measured or estimated based on known factors such as engine temperature, time since refueling, seasonal RVP of the fuel, and the adsorption capacity and quantity of the adsorbent in the evaporative vapor storage canister. An ECM or PCM uses the calculation of fuel vapor flow from the canister during purging to improve fuel efficiency and/or reduce exhaust emissions. The amount of fuel drawn from the fuel tank and/or intake air can be reduced by the known amount of fuel vapor and air in the purge stream. In a further embodiment, when an engine starts and purging of the canister starts the initial concentration of hydrocarbons in purge vapor is determined or is estimated from how much vapor may be stored in the canister based on indicators of time since the engine was last on and how hot the canister is (e.g., whether heated by heat released from vapor adsorption during refueling). Next, decrease of hydrocarbon vapor in the purge vapor is determined using an equation. The equation may be modeled from Langmuir adsorption isotherm equations. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. In describing the present invention, “engine control module,” “ECM,” “powertrain control module,” “PCM,” and “controller” are used interchangeably to refer to a control module that can adjust the amount of fuel and air provided to the engine. | 20040423 | 20071211 | 20051027 | 64206.0 | 0 | GIMIE, MAHMOUD | EVAP CANISTER PURGE PREDICTION FOR ENGINE FUEL AND AIR CONTROL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,831,780 | ACCEPTED | Metapneumovirus strains and their use in vaccine formulations and as vectors for expression of antigenic sequences and methods for propagating virus | The present invention provides an isolated mammalian negative strand RNA virus, metapneumovirus (MPV), within the sub-family Pneumoviridae, of the family Paramyxoviridae. The invention also provides isolated mammalian negative strand RNA viruses identifiable as phylogenetically corresponding or relating to the genus Metapneumovirus and components thereof. In particular the invention provides a mammalian MPV, subgroups and variants thereof. The invention relates to genomic nucleotide sequences of different isolates of mammalian metapneumoviruses, in particular human metapneumoviruses. The invention relates to the use of the sequence information of different isolates of mammalian metapneumoviruses for diagnostic and therapeutic methods. The present invention relates to nucleotide sequences encoding the genome of a metapneumovirus or a portion thereof, including both mammalian and avian metapneumovirus. The invention further encompasses chimeric or recombinant viruses encoded by said nucleotide sequences. The invention also relates to chimeric and recombinant mammalian MPV that comprise one or more non-native or heterologous sequences. The invention further relates to vaccine formulations comprising mammalian or avian metapneumovirus, including recombinant and chimeric forms of said viruses. The vaccine preparations of the invention encompass multivalent vaccines, including bivalent and trivalent vaccine preparations. The invention also provide methods for propagating virus. | 1. A method for producing a metapneumovirus (MPV) comprising: a) introducing into a host cell expressing a heterologous RNA polymerase: a DNA molecule comprising the cDNA of the MPV wherein the DNA molecule is transcribed by the heterologous RNA polymerase; and b) isolating the virus produced by the host cell. 2. A method for producing a metapneumovirus comprising: a) introducing into a host cell expressing a T7 RNA polymerase: a DNA molecule comprising the cDNA of the MPV wherein the DNA molecule is transcribed by the T7 RNA polymerase; b) isolating the virus produced by the host cell. 3. A method for producing a metapneumovirus comprising: (a) introducing into a host cell expressing a pol I and pol II polymerase a DNA molecule comprising the cDNA of the MPV in the positive orientation wherein the DNA molecule is transcribed by the pol I polymerase; and (b) isolating the virus produced by the host cell. 4. The method of claim 1, 2, or 3 wherein the method further comprises: introducing into a host cell expressing a pol I and pol II polymerase: one or more DNA molecules encoding viral N, P and L proteins operably linked to a transcriptional regulatory sequence. 5. The method of claim 1, 2, or 3 wherein the metapneumovirus is a mammalian metapneumovirus. 6. The method of claim 1, 2, or 3 wherein the metapneumovirus is a human metapneumovirus. 7. The method of claim 1, 2, or 3 wherein the host cell further comprises a DNA molecule encoding M2-1. 8. The method of claim 1, 2, or 3 wherein the host cell is a BHK cell line. 9. The method of claim 1, 2, or 3 wherein the host cell is a 293T cell. 10. The method of claim 1, 2, or 3 wherein the host cell is a Vero cell. 11. A method of producing a virus comprising: introducing into a host cell one or more DNA molecules encoding viral N, P and L proteins operably linked to a transcriptional regulatory sequence, wherein the N, P, and L proteins are from a viral species other than the viral species that is to be rescued. 12. An isolated mammalian metapneumovirus, wherein the mammalian metapneumovirus is a negative-sense single stranded RNA virus belonging to the sub-family Pneumovirinae of the family Paramyxoviridae and wherein the mammalian metapneumovirus is phylogenetically closer related to a virus isolate deposited as I-2614 with CNCM, Paris than it is related to turkey rhinotracheitis virus (TRTV), wherein (i) at least one region of the virus is replaced with an analogous region from a different isolate of mammalian metapneumovirus; or (ii) wherein at least one regions of the virus is deleted; or (iii) at least one region of the virus is replaced with an analogous region from a different isolate of mammalian metapneumovirus and at least one regions of the virus is deleted. 13. The virus of claim 12, wherein the region is at least 3 nucleotides in length, at least 5 nucleotides (nt), at least 10 nt, at least 25 nt, at least 50 nt, at least 75 nt, at least 100 nt, at least 250 nt, at least 500 nt, at least 750 nt, at least 1 kb, at least 1.5 kb, at least 2 kb, at least 2.5 kb, at least 3 kb, at least 4 kb, or at least 5 kb in length. 14. The virus of claim 12, wherein the region is a fragment of the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene, the L-gene, the leader region, the trailer region, or a noncoding region. 15. The virus of claim 12, wherein the region is the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene, the L-gene, the leader region, the trailer region, or a noncoding region. 16. The virus of claim 12, 13, or 14, wherein the virus is attenuated. 17. An attenuated hMPV, wherein the virus comprises at least one genetic modification resulting in at least one alteration at one or more of the following amino acid positions: the RQSR at amino acid positions 99 to 102 of the F protein; Phe at amino acid position 456 of the L protein; Glu at amino acid position 749 of the L protein; Tyr at amino acid position 1246 of the L protein; Met at amino acid position 1094 of the L protein, and Lys at amino acid position 746 of the L protein. 18. The attenuated virus of claim 17, wherein the genetic modification is a deletion, a substitution or an addition. 19. The attenuated virus of claim 17, wherein at least one of the genetic alterations consists of 2 or 3 nucleotide substitutions or deletions per codon. 20. An attenuated mammalian metapneumovirus, wherein the position of at least one open reading frame in the genome of the mammalian metapneumovirus has been altered. 21. The attenuated mammalian metapneumovirus of claim 20, wherein the open reading frame encodes N protein; P protein; M protein; F protein; M2 protein; SH protein; G protein or L protein. 22. A method for propagating virus, wherein the method comprises culturing cells that are infected with the virus at a temperature that is lower than the temperature that is optimal for growth of the cells. 23. A method for propagating virus, wherein the method comprises (i) culturing cells at a first temperature before infection with the virus; (ii) infecting the cells with the virus; and (iii) culturing the cells at a second temperature after infection of the cells with the virus, wherein the second temperature is lower than the first temperature. 24. A method for propagating virus, wherein the method comprises culturing cells that are infected with the virus in the absence of serum. 25. A method for propagating virus, wherein the method comprises (i) culturing cells in the presence of serum before infection with the virus; (ii) infecting the cells with the virus; and (iii) culturing the cells in the absence of serum after infection of the cells with the virus. 26. A method for propagating virus, wherein the method comprises culturing cells that are infected with the virus without serum at a temperature lower than the temperature that is optimal for growth of the cells. 27. The method of claim 22, 23, 24, 25, or 26, wherein the virus is a negative strand RNA virus. 28. The method of claim 22, 23, 24, 25, or 26, wherein the virus is a metapneumovirus. 29. The method of claim 22, 23, 24, 25, or 26, wherein the virus is a mammalian metapneumovirus. 30. The method of claim 22, 23, 24, 25, or 26, wherein the virus is a human metapneumovirus. 31. A method of inhibiting the infection of a cell with mammalian metapneumovirus, said method comprising contacting the cell with a heptad repeat, wherein the heptad repeat is at least 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or at least 99.5% identical to a HR of the mammalian metapneumovirus. 32. A method of preventing, treating, or managing the infection of a mammal with mammalian metapneumovirus, said method comprising administering to the mammal a therapeutically effective amount of a heptad repeat, wherein the heptad repeat is at least 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or at least 99.5% identical to a HR of the mammalian metapneumovirus. 33. The method of claim 31 or 32, wherein the heptad repeat is HRA, HRB or a combination thereof. 34. The method of claim 31 or 32, wherein the mammalian metapneumovirus is a human metapneumovirus 35. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent hybridization conditions to a second nucleic acid selected, wherein the second nucleic acid sequence is SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20 or SEQ ID NO:21. 36. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent hybridization conditions to a second nucleic acid, that encodes a protein, wherein the protein sequence is SEQ ID NO: 322, SEQ ID NO: 366, SEQ ID NO: 374, SEQ ID NO: 358, SEQ ID NO: 314, SEQ ID NO: 338, SEQ ID NO: 346, SEQ ID NO: 382, SEQ ID NO: 330, SEQ ID NO: 325, SEQ ID NO: 369, SEQ ID NO: 377, SEQ ID NO: 361, SEQ ID NO: 317, SEQ ID NO: 341, SEQ ID NO: 349, SEQ ID NO: 385, SEQ ID NO: 333, SEQ ID NO: 323, SEQ ID NO: 367, SEQ ID NO: 375, SEQ ID NO: 359, SEQ ID NO: 315, SEQ ID NO: 339, SEQ ID NO: 347, SEQ ID NO: 383, SEQ ID NO: 331, SEQ ID NO: 324, SEQ ID NO: 368, SEQ ID NO: 376, SEQ ID NO: 360, SEQ ID NO: 316, SEQ ID NO: 340, SEQ ID NO: 348, SEQ ID NO: 384 or SEQ ID NO: 332. 37. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent hybridization conditions to a second nucleic acid that encodes a protein that is at least 90% identical to SEQ ID NO: 366; is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382. 38. The method of claim 36 or 37, wherein said first nucleic acid specifically hybridizes to the genome of subtypes A1, B1, A2 or B2 of hMPV. 39. The method of claim 36 or 37, wherein said first nucleic acid is at least 12, at least 15, at least 20, or at least 25 nucleotides in length. 40. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with an antibody, or a fragment thereof, that specifically recognizes a protein or a fragment of a protein, wherein the protein sequence is SEQ ID NO: 374, SEQ ID NO: 358, SEQ ID NO: 314, SEQ ID NO: 338, SEQ ID NO: 346, SEQ ID NO: 330, SEQ ID NO: 322, SEQ ID NO: 382, SEQ ID NO: 366, SEQ ID NO: 324, SEQ ID NO: 368, SEQ ID NO: 376, SEQ ID NO: 360, SEQ ID NO: 316, SEQ ID NO: 340, SEQ ID NO: 348, SEQ ID NO: 384, SEQ ID NO: 332, SEQ ID NO: 325, SEQ ID NO: 369, SEQ ID NO: 377, SEQ ID NO: 361, SEQ ID NO: 317, SEQ ID NO: 341, SEQ ID NO: 349, SEQ ID NO: 385, SEQ ID NO: 333, SEQ ID NO: 323. SEQ ID NO: 367, SEQ ID NO: 375, SEQ ID NO: 359, SEQ ID NO: 315, SEQ ID NO: 339, SEQ ID NO: 347, SEQ ID NO: 383 or SEQ ID NO: 331. 41. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with an antibody or a fragment thereof, that specifically recognizes a protein or a fragment of a protein that is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382; is at least 90% identical to SEQ ID NO: 366. 42. A method for serologically diagnosing a MPV infection in a mammal, wherein said method comprises detecting in a sample from the mammal the presence of an antibody or a fragment thereof, that is specifically directed against an MPV or component thereof, wherein the virus is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), by reacting said sample with a protein or a fragment of a protein that is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382; is at least 90% identical to SEQ ID NO: 366. 43. A method for serologically diagnosing a MPV infection in a mammal, wherein said method comprises detecting in a sample from the mammal the presence of an antibody or a fragment thereof, that is specifically directed against an MPV or component thereof, wherein the virus is phylogenetically more closely related to a virus isolate deposited as 1-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), by reacting said sample with a MPV or component thereof. 44. A method for detecting a variant B1 mammalian MPV in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent conditions to a second nucleic acid, that encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). 45. A method for detecting a variant A1 mammalian MPV in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent conditions to a second nucleic acid, that encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). 46. A method for detecting a variant B2 mammalian MPV in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent conditions to a second nucleic acid, that encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377); (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). 47. A method for detecting a variant A2 mammalian MPV in a sample, wherein the method comprises contacting the sample with a first nucleic acid that hybridizes under stringent conditions to a second nucleic acid, that encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331). 48. The method of any one of claims 44, 45, 46, or 47, wherein said first nucleic acid is at least 12, at least 15, at least 20, or at least 25 nucleotides in length. 49. A method for detecting a variant B1 mammalian MPV in a sample, wherein said method comprises contacting the sample with an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F p protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). 50. A method for detecting a variant A1 mammalian MPV in a sample, wherein said method comprises contacting the sample with an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). 51. A method for detecting a variant B2 mammalian MPV in a sample, wherein said method comprises contacting the sample with an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377); (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). 52. A method for detecting a variant A2 mammalian MPV in a sample, wherein said method comprises contacting the sample with an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 96% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331). 53. A method for detecting an MPV in a sample, said method comprising contacting the sample with a nucleic acid or a fragment thereof, wherein the nucleic acid is SEQ ID NO: 378, SEQ ID NO: 362, SEQ ID NO: 318, SEQ ID NO: 342, SEQ ID NO: 350; SEQ ID NO: 326, SEQ ID NO: 334, SEQ ID NO: 386, SEQ ID NO: 370, SEQ ID NO: 379, SEQ ID NO: 363, SEQ ID NO: 319, SEQ ID NO: 343, SEQ ID NO: 351, SEQ ID NO: 327, SEQ ID NO: 335, SEQ ID NO: 387, SEQ ID NO: 371, SEQ ID NO: 380, SEQ ID NO: 364, SEQ ID NO: 320, SEQ ID NO: 344, SEQ ID NO: 352, SEQ ID NO: 328, SEQ ID NO: 336, SEQ ID NO: 388, SEQ ID NO: 372, SEQ ID NO: 381, SEQ ID NO: 365, SEQ ID NO: 321, SEQ ID NO: 345, SEQ ID NO: 353, SEQ ID NO: 329, SEQ ID NO: 337, SEQ ID NO: 389, SEQ ID NO: 373, or SEQ ID NO:357. 54. A method for detecting an MPV in a sample, said method comprising contacting the sample with a nucleic acid or a fragment thereof, wherein the nucleic acid is selected from the group consisting of SEQ ID NO:84-118; SEQ ID NO:154-233; SEQ ID NO:318-321; SEQ ID NO:326-329; SEQ ID NO:334-337; SEQ ID NO:342-345; SEQ ID NO:350-357; SEQ ID NO:362-365; SEQ ID NO:370-373; SEQ ID NO:378-381; and SEQ ID NO:386-389. 55. The method of claim 53 or 54, wherein the fragment is at least 10, at least 15, at least 20, at least 25, at least 50, at least 75, at least 100, at least 150, at least 250, at least 500, at least 750, or at least 1000 nucleotides in length. 56. A method for detecting a mammalian metapneumovirus in a sample, comprising (i) contacting the sample with a cell that comprises a minireplicon encoding a reporter gene; and (ii) measuring the expression of the reporter gene. 57. The method of claim 56, wherein the minireplicon is packaged into a viral particle of mammalian metapneumovirus that is amplified in the cell. 58. The method of claim 56, wherein expression of the reporter gene is stimulated in the presence of the mammalian metapneumovirus. 59. A method of detecting a mammalian metapneumovirus in a sample, wherein the method comprises contacting the sample with a first nucleic acid and a second nucleic acid that each hybridize under stringent hybridization conditions to a third nucleic acid, wherein the third nucleic acid is SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20 and SEQ ID NO: 21, or a fragment thereof. 60. A method of detecting a mammalian metapneumovirus in a sample, said method comprising: a) contacting said sample with a first nucleic acid that specifically hybridizes to SEQ ID NO: 18, SEQ ID NO:19, SEQ ID NO: 20, or SEQ ID NO: 21; and b) amplifying a fragment of an MPV nucleic acid from the position where the first nucleic acid sequence hybridizes, wherein the fragment is at least 89%, at least 95%, at least 98%, at least 99% identical to SEQ ID NO: 18, SEQ ID NO:19, SEQ ID NO: 20, or SEQ ID NO: 21; at least 90% identical to SEQ ID NO:366; at least 70% identical to SEQ ID NO:374; at least 90% identical to SEQ ID NO:358; at least 82% identical to SEQ ID NO:314; at least 85% identical to SEQ ID NO:338; at least 60% identical to SEQ ID NO:346; at least 85% identical to SEQ ID NO:330; at least 20% identical to SEQ ID NO:322; or at least 30% identical to SEQ ID NO:382 over the entire length of the fragment. 61. The method of claim 60, wherein the fragment is at least 90%, 95%, 98%, 99%, 99.5% or 100% identical to SEQ ID NO:366; SEQ ID NO:374; SEQ ID NO:358; SEQ ID NO:314; SEQ ID NO:338; SEQ ID NO:346; SEQ ID NO:330; SEQ ID NO:322; or SEQ ID NO:382 over the entire length of the fragment. 62. The method of claim 60, wherein said first nucleic acid is at least 10, at least 12, at least 15, at least 20, or at least 25 nucleotides in length. 63. The method of claim 60, wherein said fragment is at least 10, at least 12, at least 15, at least 20, at least 25, at least 50, at least 75, at least 100, at least 150, at least 250, at least 500, or at least 1000 nucleotides in length. 64. The method of claim 60, wherein said first nucleic acid comprises the nucleic acid sequence of a nucleic acid sequence selected from the group consisting of SEQ ID NOs:22-83. 65. The method of claim 60, wherein (i) a second nucleic acid that specifically hybridizes to SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO: 20, or SEQ ID NO: 21 is contacted with said sample; and (ii) said first and second nucleic acids each hybridize under stringent hybridization conditions within at least 50 nucleotides, at least 100 nucleotides, at least 200 nucleotides, at least 300 nucleotides or at least 400 nucleotides, at least 500 nucleotides, at least 1000 nucleotides, at least 2000 nucleotides, at least 3000 nucleotides or at least 4000 nucleotides of each other, to a third nucleic acid sequence, wherein said third nucleic acid sequence is selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO:84-118; SEQ ID NO:154-233; SEQ ID NO:318-321; SEQ ID NO:326-329; SEQ ID NO:334-337; SEQ ID NO:342-345; SEQ ID NO:350-357; SEQ ID NO:362-365; SEQ ID NO:370-373; SEQ ID NO:378-381; and SEQ ID NO:386-389. 66. The method of claim 60, further comprising, detecting the amplified fragment. 67. A method for diagnosing an MPV infection of a mammal comprising determining in a sample of said mammal the presence of MPV or a component thereof by contacting the sample with an antibody that specifically recognizes an MPV protein selected from the group consisting of F, L, N, M, P, M2, G and SH. 68. A method for diagnosing an MPV infection of a human comprising determining in a sample of human the presence of MPV or a component thereof by contacting the sample with an antibody that specifically recognizes an hMPV protein selected from the group consisting of F, L, N, M, P, M2, G and SH. 69. A kit for the detection of MPV, wherein the virus is phylogenetically more closely related to a virus isolate deposited as 1-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), comprising in one or more containers a protein that is at least 90% identical to SEQ ID NO: 366; is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382. 70. The kit of claim 69, further comprises means to detect the protein. 71. A kit for the detection of MPV, wherein the virus is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), comprising in one or more containers an antibody, wherein the antibody specifically binds to a protein that is at least 90% identical to SEQ ID NO: 366; is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382. 72. The kit of claim 71, further comprising means to detect the antibody. 73. A kit for the detection of MPV, wherein the virus is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), comprising in one or more containers a nucleic acid or a fragment thereof, wherein the nucleic acids encodes a protein that is at least 90% identical to SEQ ID NO: 366; is at least 70% identical to SEQ ID NO: 374; is at least 90% identical to SEQ ID NO: 358; is at least 82% identical to SEQ ID NO: 314; is at least 85% identical to SEQ ID NO: 338; is at least 60% identical to SEQ ID NO: 346; is at least 85% identical to SEQ ID NO: 330; is at least 20% identical to SEQ ID NO: 322; is at least 30% identical to SEQ ID NO: 382. 74. A kit for the detection of MPV, wherein the virus is phylogenetically more closely related to a virus isolate deposited as 1-2614 with CNCM, Paris, than it is related to turkey rhinotracheitis virus (TRTV), comprising one or more nucleic acids or fragments thereof, wherein the nucleic acid is at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to a nucleic acid selected from the group of nucleic acids consisting of SEQ ID NO: 378, SEQ ID NO: 362, SEQ ID NO: 318, SEQ ID NO: 342, SEQ ID NO: 350, SEQ ID NO: 326, SEQ ID NO: 334, SEQ ID NO: 386, SEQ ID NO: 370, SEQ ID NO: 379, SEQ ID NO: 363, SEQ ID NO: 319, SEQ ID NO: 343, SEQ ID NO: 351, SEQ ID NO: 327, SEQ ID NO: 335, SEQ ID NO: 387, SEQ ID NO: 371, SEQ ID NO: 380, SEQ ID NO: 364, SEQ ID NO: 320, SEQ ID NO: 344, SEQ ID: 352, SEQ ID NO: 328, SEQ ID NO: 336, SEQ ID NO: 388, SEQ ID NO: 372, SEQ ID NO: 381, SEQ ID NO: 365, SEQ ID NO: 321, SEQ ID NO: 345, SEQ ID NO: 353, SEQ ID NO: 329, SEQ ID NO: 337, SEQ ID NO: 389, SEQ ID NO: 373, SEQ ID NO:357, SEQ ID NO:314; and SEQ ID NOs:22-83. 75. The kit of claim 73 or 74, further comprising means to detect the nucleic acid or fragment thereof. 76. The kit of claim 73, wherein the fragment is at least 10, at least 15, at least 20, or at least 25 nucleotides in length. | RELATED APPLICATIONS This application claims the benefit of priority of U.S. provisional application Nos. 60/465,811 filed Apr. 25, 2003; 60/466,776 filed Apr. 30, 2003; 60/480,658 filed Jun. 20, 2003; 60/498,640 filed Aug. 28, 2003; and 60/550,911 filed Mar. 5, 2004, the entire disclosures of which are incorporated by reference herein in their entireties. 1. INTRODUCTION The invention relates to an isolated mammalian negative strand RNA virus, metapneumovirus (MPV), within the sub-family Pneumoviridae, of the family Paramyxoviridae. The present invention also relates to isolated mammalian negative strand RNA viruses identifiable as phylogenetically corresponding or relating to the genus Metapneumovirus and components thereof. The invention relates to genomic nucleotide sequences of different isolates of mammalian metapneumoviruses, in particular human metapneumoviruses. The invention relates to the use of the sequence information of different isolates of mammalian metapneumoviruses for diagnostic and therapeutic methods. The present invention relates to nucleotide sequences encoding the genome of a metapneumovirus or a portion thereof, including both mammalian and avian metapneumovirus. The invention further encompasses chimeric or recombinant viruses encoded by said nucleotide sequences. The invention also relates to chimeric and recombinant mammalian MPV that comprise one or more non-native or heterologous sequences. The invention further relates to vaccine formulations comprising mammalian or avian metapneumovirus, including recombinant and chimeric forms of said viruses. The vaccine preparations of the invention encompass multivalent vaccines, including bivalent and trivalent vaccine preparations. A copy of the Sequence Listing is herein described in this application as Table 15. 2. BACKGROUND OF THE INVENTION Classically, as devastating agents of disease, paramyxoviruses account for many animal and human deaths worldwide each year. The Paramyxoviridae form a family within the order of Mononegavirales (negative-sense single stranded RNA viruses), consisting of the sub-families Paramyxovirinae and Pneumovirinae. The latter sub-family is at present taxonomically divided in the genera Pneumovirus and Metapneumovirus (Pringle, 1999, Arch. Virol. 144/2, 2065-2070). Human respiratory syncytial virus (hRSV), a species of the Pneumovirus genus, is the single most important cause of lower respiratory tract infections during infancy and early childhood worldwide (Domachowske, & Rosenberg, 1999, Clin. Microbio. Rev. 12(2): 298-309). Other members of the Pneumovirus genus include the bovine and ovine respiratory syncytial viruses and pneumonia virus of mice (PVM). In the past decades several etiological agents of mammalian disease, in particular of respiratory tract illnesses (RTI), in particular of humans, have been identified (Evans, In: Viral Infections of Humans, Epidemiology and Control. 3th edn. (ed. Evans, A. S) 22-28 (Plenum Publishing Corporation, New York, 1989)). Classical etiological agents of RTI with mammals are respiratory syncytial viruses belonging to the genus Pneumovirus found with humans (hRSV) and ruminants such as cattle or sheep (bRSV and/or oRSV). In human RSV differences in reciprocal cross neutralization assays, reactivity of the G proteins in immunological assays and nucleotide sequences of the G gene are used to define two hRSV antigenic subgroups. Within the subgroups the amino acid sequences show 94% (subgroup A) or 98% (subgroup B) identity, while only 53% amino acid sequence identity is found between the subgroups. Additional variability is observed within subgroups based on monoclonal antibodies, RT-PCR assays and RNAse protection assays. Viruses from both subgroups have a worldwide distribution and may occur during a single season. Infection may occur in the presence of pre-existing immunity and the antigenic variation is not strictly required to allow re-infection. See, for example Sullender, 2000, Clinical Microbiology Reviews 13(1): 1-15; Collins et al. Fields Virology, ed. B. N. Knipe, Howley, P. M. 1996, Philadelphia: Lippencott-Raven. 1313-1351; Johnson et al., 1987, (Proc Natl Acad Sci USA, 84(16): 5625-9; Collins, in The Paramyxoviruses, D. W. Kingsbury, Editor. 1991, Plenum Press: New York. p. 103-153. Another classical Pneumovirus is the pneumonia virus of mice (PVM), in general only found with laboratory mice. However, a proportion of the illnesses observed among mammals can still not be attributed to known pathogens. 2.1 Avian Metapneumovirus Respiratory disease caused by an avian pneumovirus (APV) was first described in South Africa in the late 1970s (Buys et al., 1980, Turkey 28:36-46) where it had a devastating effect on the turkey industry. The disease in turkeys was characterized by sinusitis and rhinitis and was called turkey rhinotracheitis (TRT). The European isolates of APV have also been strongly implicated as factors in swollen head syndrome (SHS) in chickens (O'Brien, 1985, Vet. Rec. 117:619-620). Originally, the disease appeared in broiler chicken flocks infected with Newcastle disease virus (NDV) and was assumed to be a secondary problem associated with Newcastle disease (ND). Antibody against European APV was detected in affected chickens after the onset of SHS (Cook et al., 1988, Avian Pathol. 17:403-410), thus implicating APV as the cause. Avian pneumovirus (APV) also known as turkey rhinotracheitis virus (TRTV), the aetiological agent of avian rhinotracheitis, an upper respiratory tract infection of turkeys (Giraud et al., 1986, Vet. Res. 119:606-607), is the sole member of the recently assigned Metapneumovirus genus, which, as said was until now not associated with infections, or what is more, with disease of mammals. Serological subgroups of APV can be differentiated on the basis of nucleotide or amino acid sequences of the G glycoprotein and neutralization tests using monoclonal antibodies that also recognize the G glycoprotein. However, other differences in the nucleotide and amino acid sequences can be used to distinguish serological subgroups of APV. Within subgroups A, B and D, the G protein shows 98.5 to 99.7% aa sequence identity within subgroups while between the subgroups only 31.2-38% aa identity is observed. See for example Collins et al., 1993, Avian Pathology, 22: p. 469-479; Cook et al., 1993, Avian Pathology, 22: 257-273; Bayon-Auboyer et al., J Gen Virol, 81(Pt 11): 2723-33; Seal, 1998, Virus Res, 58(1-2): 45-52; Bayon-Auboyer et al., 1999, Arch Virol, 144(6): 91-109; Juhasz, et al., 1994, J Gen Virol, 75(Pt 11): 2873-80. A further serotype of APV is provided in WO00/20600, incorporated by reference herein, which describes the Colorado isolate of APV and compared it to known APV or TRT strains with in vitro serum neutralization tests. First, the Colorado isolate was tested against monospecific polyclonal antisera to recognized TRT isolates. The Colorado isolate was not neutralized by monospecific antisera to any of the TRT strains. It was, however, neutralized by a hyperimmune antiserum raised against a subgroup A strain. This antiserum neutralized the homologous virus to a titre of 1:400 and the Colorado isolate to a titer of 1:80. Using the above method, the Colorado isolate was then tested against TRT monoclonal antibodies. In each case, the reciprocal neutralization titer was <10. Monospecific antiserum raised to the Colorado isolate was also tested against TRT strains of both subgroups. None of the TRT strains tested were neutralized by the antiserum to the Colorado isolate. The Colorado strain of APV does not protect SPF chicks against challenge with either a subgroup A or a subgroup B strain of TRT virus. These results suggest that the Colorado isolate may be the first example of a further serotype of avian pneumovirus (See, Bayon-Auboyer et al., 2000, J. Gen. Vir. 81:2723-2733). The avian pneumovirus is a single stranded, non-segmented RNA virus that belongs to the sub-family Pneumovirinae of the family Paramyxoviridae, genus metapneumovirus (Cavanagh and Barrett, 1988, Virus Res. 11:241-256; Ling et al., 1992, J. Gen. Virol. 73:1709-1715; Yu et al., 1992, J. Gen. Virol. 73:1355-1363). The Paramyxoviridae family is divided into two sub-families: the Paramyxovirinae and Pneumovirinae. The subfamily Paramyxovirinae includes, but is not limited to, the genera: Paramyxovirus, Rubulavirus, and Morbillivirus. Recently, the sub-family Pneumovirinae was divided into two genera based on gene order, and sequence homology, i.e. pneumovirus and metapneumovirus (Naylor et al., 1998, J. Gen. Virol., 79:1393-1398; Pringle, 1998, Arch. Virol. 143:1449-1159). The pneumovirus genus includes, but is not limited to, human respiratory syncytial virus (hRSV), bovine respiratory syncytial virus (bRSV), ovine respiratory syncytial virus, and mouse pneumovirus. The metapneumovirus genus includes, but is not limited to, European avian pneumovirus (subgroups A and B), which is distinguished from hRSV, the type species for the genus pneumovirus (Naylor et al., 1998, J. Gen. Virol., 79:1393-1398; Pringle, 1998, Arch. Virol. 143:1449-1159). The US isolate of APV represents a third subgroup (subgroup C) within metapneumovirus genus because it has been found to be antigenically and genetically different from European isolates (Seal, 1998, Virus Res. 58:45-52; Senne et al., 1998, In: Proc. 47th WPDC, California, pp. 67-68). Electron microscopic examination of negatively stained APV reveals pleomorphic, sometimes spherical, virions ranging from 80 to 200 nm in diameter with long filaments ranging from 1000 to 2000 nm in length (Collins and Gough, 1988, J. Gen. Virol. 69:909-916). The envelope is made of a membrane studded with spikes 13 to 15 nm in length. The nucleocapsid is helical, 14 nm in diameter and has 7 nm pitch. The nucleocapsid diameter is smaller than that of the genera Paramyxovirus and Morbillivirus, which usually have diameters of about 18 nm. Avian pneumovirus infection is an emerging disease in the USA despite its presence elsewhere in the world in poultry for many years. In May 1996, a highly contagious respiratory disease of turkeys appeared in Colorado, and an APV was subsequently isolated at the National Veterinary Services Laboratory (NVSL) in Ames, Iowa (Senne et al., 1997, Proc. 134th Ann. Mtg., AVMA, pp. 190). Prior to this time, the United States and Canada were considered free of avian pneumovirus (Pearson et al., 1993, In: Newly Emerging and Re-emerging Avian Diseases: Applied Research and Practical Applications for Diagnosis and Control, pp. 78-83; Hecker and Myers, 1993, Vet. Rec. 132:172). Early in 1997, the presence of APV was detected serologically in turkeys in Minnesota. By the time the first confirmed diagnosis was made, APV infections had already spread to many farms. The disease is associated with clinical signs in the upper respiratory tract: foamy eyes, nasal discharge and swelling of the sinuses. It is exacerbated by secondary infections. Morbidity in infected birds can be as high as 100%. The mortality can range from 1 to 90% and is highest in six to twelve week old poults. Avian pneumovirus is transmitted by contact. Nasal discharge, movement of affected birds, contaminated water, contaminated equipment; contaminated feed trucks and load-out activities can contribute to the transmission of the virus. Recovered turkeys are thought to be carriers. Because the virus is shown to infect the epithelium of the oviduct of laying turkeys and because APV has been detected in young poults, egg transmission is considered a possibility. 2.2 PIV Infections Parainfluenza viral infection results in serious respiratory tract disease in infants and children. (Tao et al., 1999, Vaccine 17: 1100-08). Infectious parainfluenza viral infections account for approximately 20% of all hospitalizations of pediatric patients suffering from respiratory tract infections worldwide. Id. PIV is a member of the genus respirovirus (PIV1, PIV3) or rubulavirus (PIV2, PIV4) of the paramyxoviridae family. PIV is made up of two structural modules: (1) an internal ribonucleoprotein core, or nucleocapsid, containing the viral genome, and (2) an outer, roughly spherical lipoprotein envelope. Its genome is a single strand of negative sense RNA, approximately 15,456 nucleotides in length, encoding at least eight polypeptides. These proteins include, but are not limited to, the nucleocapsid structural protein (NP, NC, or N depending on the genera), the phosphoprotein (P), the matrix protein (M), the fusion glycoprotein (F), the hemagglutinin-neuraminidase glycoprotein (HN), the large polymerase protein (L), and the C and D proteins of unknown function. Id. The parainfluenza nucleocapsid protein (NP, NC, or N) consists of two domains within each protein unit including an amino-terminal domain, comprising about two-thirds of the molecule, which interacts directly with the RNA, and a carboxyl-terminal domain, which lies on the surface of the assembled nucleocapsid. A hinge is thought to exist at the junction of these two domains thereby imparting some flexibility to this protein (see Fields et al. (ed.), 1991, Fundamental Virology, Second Edition, Raven Press, New York, incorporated by reference herein in its entirety). The matrix protein (M), is apparently involved with viral assembly and interacts with both the viral membrane as well as the nucleocapsid proteins. The phosphoprotein (P), which is subject to phosphorylation, is thought to play a regulatory role in transcription, and may also be involved in methylation, phosphorylation and polyadenylation. The fusion glycoprotein (F) interacts with the viral membrane and is first produced as an inactive precursor, then cleaved post-translationally to produce two disulfide linked polypeptides. The active F protein is also involved in penetration of the parainfluenza virion into host cells by facilitating fusion of the viral envelope with the host cell plasma membrane. Id. The glycoprotein, hemagglutinin-neuraminidase (HN), protrudes from the envelope allowing the virus to contain both hemagglutinin and neuraminidase activities. HN is strongly hydrophobic at its amino terminal which functions to anchor the HN protein into the lipid bilayer. Id. Finally, the large polymerase protein (L) plays an important role in both transcription and replication. Id. 2.3 RSV Infections Respiratory syncytial virus (RSV) is the leading cause of serious lower respiratory tract disease in infants and children (Feigen et al., eds., 1987, In: Textbook of Pediatric Infectious Diseases, W B Saunders, Philadelphia at pages 1653-1675; New Vaccine Development, Establishing Priorities, Vol. 1, 1985, National Academy Press, Washington D.C. at pages 397-409; and Ruuskanen et al., 1993, Curr. Probl. Pediatr. 23:50-79). The yearly epidemic nature of RSV infection is evident worldwide, but the incidence and severity of RSV disease in a given season vary by region (Hall, 1993, Contemp. Pediatr. 10:92-110). In temperate regions of the northern hemisphere, it usually begins in late fall and ends in late spring. Primary RSV infection occurs most often in children from 6 weeks to 2 years of age and uncommonly in the first 4 weeks of life during nosocomial epidemics (Hall et al., 1979, New Engl. J. Med. 300:393-396). Children at increased risk for RSV infection include, but are not limited to, preterm infants (Hall et al., 1979, New Engl. J. Med. 300:393-396) and children with bronchopulmonary dysplasia (Groothuis et al., 1988, Pediatrics 82:199-203), congenital heart disease (MacDonald et al., New Engl. J. Med. 307:397-400), congenital or acquired immunodeficiency (Ogra et al., 1988, Pediatr. Infect. Dis. J. 7:246-249; and Pohl et al., 1992, J. Infect. Dis. 165:166-169), and cystic fibrosis (Abman et al., 1988, J. Pediatr. 113:826-830). The fatality rate in infants with heart or lung disease who are hospitalized with RSV infection is 3%-4% (Navas et al., 1992, J. Pediatr. 121:348-354). RSV infects adults as well as infants and children. In healthy adults, RSV causes predominantly upper respiratory tract disease. It has recently become evident that some adults, especially the elderly, have symptomatic RSV infections more frequently than had been previously reported (Evans, A. S., eds., 1989, Viral Infections of Humans. Epidemiology and Control, 3rd ed., Plenum Medical Book, New York at pages 525-544). Several epidemics also have been reported among nursing home patients and institutionalized young adults (Falsey, A. R., 1991, Infect. Control Hosp. Epidemiol. 12:602-608; and Garvie et al., 1980, Br. Med. J. 281:1253-1254). Finally, RSV may cause serious disease in immunosuppressed persons, particularly bone marrow transplant patients (Hertz et al., 1989, Medicine 68:269-281). Treatment options for established RSV disease are limited. Severe RSV disease of the lower respiratory tract often requires considerable supportive care, including administration of humidified oxygen and respiratory assistance (Fields et al., eds, 1990, Fields Virology, 2nd ed., Vol. 1, Raven Press, New York at pages 1045-1072). While a vaccine might prevent RSV infection, and/or RSV-related disease, no vaccine is yet licensed for this indication. A major obstacle to vaccine development is safety. A formalin-inactivated vaccine, though immunogenic, unexpectedly caused a higher and more severe incidence of lower respiratory tract disease due to RSV in immunized infants than in infants immunized with a similarly prepared trivalent parainfluenza vaccine (Kim et al., 1969, Am. J. Epidemiol. 89:422-434; and Kapikian et al., 1969, Am. J. Epidemiol. 89:405-421). Several candidate RSV vaccines have been abandoned and others are under development (Murphy et al., 1994, Virus Res. 32:13-36), but even if safety issues are resolved, vaccine efficacy must also be improved. A number of problems remain to be solved. Immunization would be required in the immediate neonatal period since the peak incidence of lower respiratory tract disease occurs at 2-5 months of age. The immaturity of the neonatal immune response together with high titers of maternally acquired RSV antibody may be expected to reduce vaccine immunogenicity in the neonatal period (Murphy et al., 1988, J. Virol. 62:3907-3910; and Murphy et al., 1991, Vaccine 9:185-189). Finally, primary RSV infection and disease do not protect well against subsequent RSV disease (Henderson et al., 1979, New Engl. J. Med. 300:530-534). Currently, the only approved approach to prophylaxis of RSV disease is passive immunization. Initial evidence suggesting a protective role for IgG was obtained from observations involving maternal antibody in ferrets (Prince, G. A., Ph.D. diss., University of California, Los Angeles, 1975) and humans (Lambrecht et al, 1976, J. Infect. Dis. 134:211-217; and Glezen et al., 1981, J. Pediatr. 98:708-715). Hemming et al. (Morell et al., eds., 1986, Clinical Use of Intravenous Immunoglobulins, Academic Press, London at pages 285-294) recognized the possible utility of RSV antibody in treatment or prevention of RSV infection during studies involving the pharmacokinetics of an intravenous immune globulin (IVIG) in newborns suspected of having neonatal sepsis. In this study, it was noted that one infant, whose respiratory secretions yielded RSV, recovered rapidly after IVIG infusion. Subsequent analysis of the IVIG lot revealed an unusually high titer of RSV neutralizing antibody. This same group of investigators then examined the ability of hyperimmune serum or immune globulin, enriched for RSV neutralizing antibody, to protect cotton rats and primates against RSV infection (Prince et al., 1985, Virus Res. 3:193-206; Prince et al., 1990, J. Virol. 64:3091-3092; Hemming et al., 1985, J. Infect. Dis. 152:1083-1087; Prince et al., 1983, Infect. Immun. 42:81-87; and Prince et al., 1985, J. Virol. 55:517-520). Results of these studies indicate that IVIG may be used to prevent RSV infection, in addition to treating or preventing RSV-related disorders. Recent clinical studies have demonstrated the ability of this passively administered RSV hyperimmune globulin (RSV IVIG) to protect at-risk children from severe lower respiratory infection by RSV (Groothius et al., 1993, New Engl. J. Med. 329:1524-1530; and The PREVENT Study Group, 1997, Pediatrics 99:93-99). While this is a major advance in preventing RSV infection, this treatment poses certain limitations in its widespread use. First, RSV IVIG must be infused intravenously over several hours to achieve an effective dose. Second, the concentrations of active material in hyperimmune globulins are insufficient to treat adults at risk or most children with comprised cardiopulmonary function. Third, intravenous infusion necessitates monthly hospital visits during the RSV season. Finally, it may prove difficult to select sufficient donors to produce a hyperimmune globulin for RSV to meet the demand for this product. Currently, only approximately 8% of normal donors have RSV neutralizing antibody titers high enough to qualify for the production of hyperimmune globulin. One way to improve the specific activity of the immunoglobulin would be to develop one or more highly potent RSV neutralizing monoclonal antibodies (MAbs). Such MAbs should be human or humanized in order to retain favorable pharmacokinetics and to avoid generating a human anti-mouse antibody response, as repeat dosing would be required throughout the RSV season. Two glycoproteins, F and G, on the surface of RSV have been shown to be targets of neutralizing antibodies (Fields et al., 1990, supra; and Murphy et al., 1994, supra). A humanized antibody directed to an epitope in the A antigenic site of the F protein of RSV, SYNAGIS®, is approved for intramuscular administration to pediatric patients for prevention of serious lower respiratory tract disease caused by RSV at recommended monthly doses of 15 mg/kg of body weight throughout the RSV season (November through April in the northern hemisphere). SYNAGIS® is a composite of human (95%) and murine (5%) antibody sequences. See, Johnson et al., 1997, J. Infect. Diseases 176:1215-1224 and U.S. Patent No. 5,824,307, the entire contents of which are incorporated herein by reference. The human heavy chain sequence was derived from the constant domains of human IgG1 and the variable framework regions of the VH genes of Cor (Press et al., 1970, Biochem. J. 117:641-660) and Cess (Takashi et al., 1984, Proc. Natl. Acad. Sci. USA 81:194-198). The human light chain sequence was derived from the constant domain of Ck and the variable framework regions of the VL gene K104 with Jk-4 (Bentley et al., 1980, Nature 288:5194-5198). The murine sequences derived from a murine monoclonal antibody, Mab 1129 (Beeler et al., 1989, J. Virology 63:2941-2950), in a process which involved the grafting of the murine complementarity determining regions into the human antibody frameworks. A significant portion of human respiratory disease is caused by members of the viral sub-families Paramyxovirinae and Pneumovirinae. The identification of another mammalian Pneumovirinae that infects humans, hMPV, is described for the first time herein. There still remains a need for an effective vaccine to confer protection against a variety of viruses that result in respiratory tract infection. 2.4 Virus Entry Into Host Cell It is emerging that some of the enveloped viruses, e.g., retrovirus, orthomyxovirus, filovirus, and paramyxovirus, might use a fusion mechanism to gain entry into a host cell (Eckert et. al., 2001, Annu. Rev. Biochem. 70:777-810; Weissenhorn et. al., 1999, Mol. Membr. Biol. 16:3-9; Lamb et. al., 1999, Mol. Membr. Biol. 16:11-19; Skehel et. al., 2000, Annu. Rev. Biochem. 69:531-569; Bentz, J., 2000, Biophys J. 78:886-900; Peisajovich et. al., 2002, Trends Biochem. Sci. 27:183-190). Under this model, fusion proteins undergo conformational changes and the fusion peptide located at the N-terminus of the F protein of paramyxovirus, for example, is exposed to insert into the cell membrane (Wang et. al., 2003, Biochem. Biophys. Res. Comm. 302:469-475). The highly conserved heptad repeat (HR) regions have been implicated in facilitation of the fusion process (Wang et. al., 2003, Biochem. Biophys. Res. Comm. 302:469-475). Therefore, the heptad repeats are an attractive target for the prevention of virus infection and/or propagation through the inhibition of fusion with a host cell. Citation or discussion of a reference herein shall not be construed as an admission that such is prior art to the present invention. 3. SUMMARY OF THE INVENTION The invention relates to an isolated mammalian negative strand RNA virus, metapneumovirus (MPV), within the sub-family Pneumovirinae, of the family Paramyxoviridae. The present invention also relates to isolated mammalian negative strand RNA viruses identifiable as phylogenitically corresponding or relating to the genus Metapneumovirus and components thereof. In particular, the invention relates to a mammalian MPV that is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris than it is related to APV type C. In more specific embodiments, the mammalian MPV can be a variant A1, A2, B1 or B2 mammalian MPV. However, the mammalian MPVs of the present invention may encompass additional variants yet to be identified, and are not limited to variants A1, A2, B1 or B2. The invention relates to genomic nucleotide sequences of different isolates of mammalian metapneumoviruses, in particular human metapneumoviruses. The invention relates to the use of the sequence information of different isolates of mammalian metapneumoviruses for diagnostic and therapeutic methods. The present invention relates to the differences of the genomic nucleotide sequences among the different metapneumovirus-isolates, and their use in the diagnostic and therapeutic methods of the invention. In specific embodiments, the nucleotide sequence of a mammalian MPV that encodes for the N, M, F, L, P, M2-1, M2-2, SH or G ORFs may be used to identify a virus of the invention. In other specific embodiments, the nucleotide sequence of mammalian MPV that encodes for the N, M, F, L, P, M2-1, M2-2, SH or G ORFs used to classify a mammalian MPV into variant A1, A2, B1 or B2. In a specific embodiment, the invention relates to the use of the single nucleotide polymorphisms (SNPs) among different metapneumovirus isolates for diagnostic purposes. The invention relates to recombinant and chimeric viruses that are derived from a mammalian MPV or avian pneumovirus (APV). In accordance with the present invention, a recombinant virus is one derived from a mammalian MPV or an APV that is encoded by endogenous or native genomic sequences or non-native genomic sequences. In accordance with the invention, a non-native sequence is one that is different from the native or endogenous genomic sequence due to one or more mutations, including, but not limited to, point mutations, rearrangements, insertions, deletions etc., to the genomic sequence that may or may not result in a phenotypic change. In accordance with the invention, a chimeric virus of the invention is a recombinant MPV or APV which further comprises a heterologous nucleotide sequence. In accordance with the invention, a chimeric virus may be encoded by a nucleotide sequence in which heterologous nucleotide sequences have been added to the genome or in which endogenous or native nucleotide sequences have been replaced with heterologous nucleotide sequences. In certain embodiments, a chimeric virus of the invention is derived from a MPV or APV in which one or more of the ORFs or a portion thereof is replaced by a homologous ORF or a portion thereof from another strain of metapneumovirus. In an exemplary embodiment, the ORF of the F gene of a mammalian MPV is replaced by the ORF of the F gene of an APV. In certain other embodiments, a chimeric virus of the invention is derived from an APV in which one or more of the ORFs is replaced by a homologous ORF of a mammalian MPV. The present invention relates to nucleotide sequences encoding the genome of a metapneumovirus (including mammalian and avian strains) or a portion thereof. The present invention relates to nucleotide sequences encoding gene products of a metapneumovirus. In particular, the invention relates to, but is not limited to, nucleotide sequences encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a MPV. In particular the invention relates to nucleotide sequences encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a variant of mammalian MPV, such as but not limited to variant A1, A2, B1 or B2 of a MPV. The present invention further relates to a cDNA or RNA that encodes the genome or a portion thereof of a metapneumovirus, including both mammalian and avian, in addition to a nucleotide sequence which is heterologous or non-native to the viral genome. The invention further encompasses chimeric or recombinant viruses encoded by said cDNAs or RNAs. The invention further relates to polypeptides and amino acid sequences of an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a mammalian MPV and different variants of mammalian MPV. The invention further relates to antibodies against an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a mammalian MPV and different variants of mammalian MPV. The antibodies can be used for diagnostic and therapeutic methods. In certain more specific embodiments, the antibodies are specific to mammalian MPV. In certain embodiments, the antibodies are specific to a variant of mammalian MPV. The invention further relates to vaccine formulations and immunogenic compositions comprising one or more of the following: an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, and/or an L protein of a mammalian MPV. The invention further relates to vaccine formulations and immunogenic compositions comprising mammalian or avian metapneumovirus, including recombinant and chimeric forms of said viruses. In particular, the present invention encompasses vaccine preparations comprising recombinant or chimeric forms of MPV and/or APV. The invention further relates to vaccines comprising chimeric MPV wherein the chimeric MPV encodes one or more APV proteins and wherein the chimeric MPV optionally additionally expresses one or more heterologous or non-native sequences. The invention also relates to vaccines comprising chimeric APV wherein the chimeric APV encodes one or more hMPV proteins and wherein the chimeric APV optionally additionally expresses one or more heterologous or non-native sequences. The present invention also relates to multivalent vaccines, including bivalent and trivalent vaccines. In particular, multivalent vaccines of the invention encompass two or more antigenic polypeptides expressed by the same or different pneumoviral vectors. The antigenic polypeptides of the multivalent vaccines include but are not limited to, antigenic polypeptides of MPV, APV, PIV, RSV, influenza or another negative strand RNA virus, or another virus, such as morbillivirus. The invention further relates to methods for treating a respiratory tract infection in a subject. In certain embodiments, the invention relates to treating a respiratory tract infection in a subject by administering to the subject a vaccine formulation comprising a mammalian MPV. In specific embodiments, the methods for treating a respiratory tract infection in a subject comprise administering to the subject a vaccine formulation or an immunogenic composition comprising a recombinant or a chimeric mammalian MPV or APV. In more specific embodiments, the recombinant or chimeric mammalian MPV is attenuated. In a specific embodiment, the invention relates to treating a respiratory tract infection in a human patient comprising administering to the human patient a vaccine formulation comprising a recombinant or chimeric APV, or a nucleotide sequence encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of APV. The invention provides an isolated negative-sense single stranded RNA virus MPV belonging to the sub-family Pneumovirinae of the family Paramyxoviridae and identifiable as phylogenetically corresponding to the genus Metapneumovirus, wherein the virus is phylogenetically more closely related to a virus isolate comprising the nucleotide sequence of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 than it is related to turkey rhinotracheitis virus, the etiological agent of avian rhinotracheitis. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:18. In certain embodiments, the invention providesa n isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:19. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:20. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:21. In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid has a nucleotide sequence that is at least 70% identical to SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20 or SEQ ID NO:21, wherein sequence identity is determined over the entire length of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20 or SEQ ID NO:21. In certain embodiments, the invention providesa n isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338) (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). In certain embodiments, the invention provides n isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:332); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377); (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361) (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid hybridizes specifically under high stringency, medium stringency, or low stringency conditions to a nucleic acid of a mammalian MPV. In certain embodiments, the invention provides a virus comprising the nucleotide sequence of SEQ ID NO: 18-21 or a fragment thereof. In certain embodiments, the invention provides an isolated protein, wherein the protein comprises (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316) (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an isolated protein, wherein the protein comprises: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338) (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330) In certain embodiments, the invention provides isolated protein, wherein the protein comprises (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375) (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315) (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix)an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2(SEQ ID NO:331). In certain embodiments, the invention provides an isolated protein, wherein the protein comprises: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377) (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376) (iv an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340) (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). In certain embodiments, the invention providesa n antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 96% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315) (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331) In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377) (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides a method for detecting a variant B1 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody of specific to a variant B1. In certain embodiments, the invention provides method for detecting a variant A1 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to variant A1. In certain embodiments, the invention provides a method for detecting a variant A2 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to variant A2. In certain embodiments, the invention provides a method for detecting a variant B2 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to B2. In certain embodiments, the invention provides a method for identifying a viral isolate as a mammalian MPV, wherein said method comprises contacting said isolate or a component thereof with the antibody specific to a mammalian MPV. In certain embodiments, the invention provides method for virologically diagnosing a MPV infection of a mammal comprising determining in a sample of said mammal the presence of a viral isolate or component thereof by contacting the sample with the antibody specific to a MPV. In certain embodiments, the invention provides method for virologically diagnosing a mammalian MPV infection of a subject, wherein said method comprises obtaining a sample from the subject and contacting the sample with an antibody specific to MPV wherein if the antibody binds to the sample the subject is infected with mammalian MPV. In certain embodiments, the invention provides an infectious recombinant virus, wherein the recombinant virus comprises the genome of a mammalian MPV and further comprises a non-native MPV sequence. In certain embodiments, the invention provides a recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV A1 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV A2 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides s recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV B1 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides a recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV B2 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV of a first variant, wherein one or more of the open reading frames in the genome of the mammalian MPV of the first variant have been replaced by the analogous open reading frame from a mammalian MPV of a second variant. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV of a first variant, wherein one or more of open reading frames of a mammalian MPV of a second variant are inserted into the genome of the mammalian MPV of the first variant. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV, wherein one or more of the open reading frames in the genome of the mammalian MPV have been replaced by an ORF which encodes one or more of an avian MPV F protein; an avian MPV G protein (iii) an avian MPV SH protein; (iv) an avian MPV N protein (v) an avian MPV P protein; (vi) an avian MPV M2 protein; (vii) an avian MPV M2-1 protein; (viii) an avian MPV M2-2 protein; or (ix) an avian MPV L protein. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of an avian MPV, wherein one or more of the open reading frames in the genome of the avian MPV have been replaced by an ORF which encodes one or more of (i) a mammalian MPV F protein (ii) a mammalian MPV G protein; (iii) a mammalian MPV SH protein; (iv) a mammalian MPV N protein; (v) a mammalian MPV P protein; (vi) a mammalian MPV M2 protein; (vii) a mammalian MPV M2-1 protein; (viii) a mammalian MPV M2-2 protein; or (ix) a mammalian MPV L protein. In certain embodiments, the invention provides an infectious chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using an interspecies or intraspecies polymerase. In one embodiment, the invention provides a chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using MPV polymerase. In one embodiment, the invention uses a polymerase from a virus different from the polymerase of the virus to be rescued, i.e., from a different clade, subtype, or other species. In another embodiment, the invention provides an infectious chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using the polymerase from another virus, including, but not limited to the polymerase of PIV, APV or RSV. By way of example, and not meant to limited the possible combinations, RSV polymerase can be used to rescue MPV; MPV polymerase can be used to rescue RSV; or PIV polymerase can be used to rescue MPV. In yet another embodiment of the invention, the polymerase complex that is used to rescue the recombinant virus is encoded by polymerase proteins from different viruses. By way of example, and not meant to limit the possible combinations, in one embodiment, the polymerase complex proteins are encoded by the N gene of MPV, the L gene of PIV, the P gene of RSV and the M2-1 gene of MPV. In other embodiments, the M2-1 gene is not a component of the polymerase complex. In another embodiment of the invention, and meant by way of example, the polymerase complex proteins are encoded by the N gene of RSV, the L gene of RSV, the P gene of APV, and the M2-1 gene of RSV. In another embodiment of the invention, the M2-1 gene is not required to rescue the recombinant virus of the invention. One skilled in the art would be familiar with the types of combinations that can be used to encode the polymerase complex proteins so that the recombinant chimeric virus of the invention is rescued. In certain embodiments, the invention provides an immunogenic composition, wherein the immunogenic composition comprises the infectious recombinant virus of the invention. In certain embodiments, the invention provides a method for detecting a mammalian MPV in a sample, wherein the method comprises contacting the sample with a nucleic acid sequence of the invention. In certain embodiments, the invention provides a pharmaceutical composition, wherein the pharmaceutical composition comprises the infectious recombinant virus of the invention. In certain embodiments, the invention provides a method for detecting a mammalian MPV in a sample, wherein the method comprises amplifying or probing for MPV related nucleic acids, processed products, or derivatives thereof. In a more specific embodiment, the invention provides polymerase chain reaction based methods for the detection of MPV in a sample. In an even further embodiment, the invention provides oligonucleotide probes that can be used to specifically detect the presence of MPV related nucleic acids, processed products, or derivatives thereof. In yet another embodiment, the invention provides diagnostic methods for the detection of MPV antibodies in a host that is infected with the virus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising a mammalian metapneumovirus. In certain embodiments, the invention provides an method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising the recombinant mammalian metapneumovirus of the invention. In certain embodiments, the invention provides an method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising avian metapneumovirus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a human, said method comprising administering a vaccine comprising avian metapneumovirus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a subject, said method comprising administering to the subject the composition of the invention. In certain embodiments, the invention provides a method for identifying a compound useful for the treatment of infections with mammalian MPV, wherein the method comprises: (a) infecting an animal with a mammalian MPV; (b) Administering to the animal a test compound; and (c) determining the effect of the test compound on the infection of the animal, wherein a test compound that reduces the extent of the infection or that ameliorates the symptoms associated with the infection is identified as a compound useful for the treatment of infections with mammalian MPV. In certain embodiments, the invention provides a method for identifying a compound useful for the treatment of infections with mammalian MPV, wherein the method comprises (a) infecting a cell culture with a mammalian MPV (b) incubating the cell culture with a test compound; and (c) determining the effect of the test compound on the infection of the cell culture, wherein a test compound that reduces the extent of the infection is identified as a compound useful for the treatment of infections with mammalian MPV. In certain embodiments, the invention provides a method for diagnosing a mammalian MPV infection of an animal, wherein the method comprises determining in a sample of said animal the presence of a viral isolate or component thereof by reacting said sample with a nucleic acid or an antibody reactive with a component of an avian pneumovirus, said nucleic acid or antibody being cross-reactive with a component of MPV. In certain embodiments, the invention provides a method for serologically diagnosing a mammalian MPV infection of an animal, wherein the method comprises contacting a sample from the animal with the protein of the invention. In certain embodiments, the invention provides a method for serologically diagnosing a mammalian MPV infection of an animal, wherein the method comprises contacting a sample from the animal with a protein of an APV. In certain embodiments, the invention provides an method for diagnosing an APV infection of a bird comprising contacting a sample from the animal with the protein of the invention. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA virus MPV belonging to the sub-family Pneumovirinae of the family Paramyxoviridae and identifiable as phylogenetically corresponding to the genus Metapneumovirus, wherein the virus is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris than to turkey rhinotracheitis virus, the etiological agent of avian rhinotracheitis. 3.1 Conventions and Abbreviations cDNA complementary DNA L large protein M matrix protein (lines inside of envelope) F fusion glycoprotein HN hemagglutinin-neuraminidase glycoprotein N, NP or NC nucleoprotein (associated with RNA and required for polymerase activity) P Phosphoprotein MOI multiplicity of infection NA neuraminidase (envelope glycoprotein) PIV parainfluenza virus hPIV human parainfluenza virus hPIV3 human parainfluenza virus type 3 APV/hMPV recombinant APV with hMPV sequences hMPV/APV recombinant hMPV with APV sequences Mammalian MPV mammalian metapneumovirus nt nucleotide RNP ribonucleoprotein rRNP recombinant RNP vRNA genomic virus RNA cRNA antigenomic virus RNA hMPV human metapneumovirus APV avian pneumovirus MVA modified vaccinia virus Ankara FACS Fluorescence Activated Cell Sorter CPE cytopathic effects Position 1 Position of the first gene of the viral genome to be transcribed Position 2 Position between the first and the second open reading frame of the native viral genome, or alternatively, the position of the second gene of the viral genome to be transcribed Position 3 Position between the second and the third open reading frame of the native viral genome, or alternatively, the position of the third gene of the viral genome to be transcribed. Position 4 Position between the third and the fourth open reading frame of the native viral genome, or alternatively, the position of the fourth gene of the viral genome to be transcribed. Position 5 Position between the fourth and the fifth open reading frame of the native viral genome, or alternatively, the position of the fifth gene of the viral genome to be transcribed. Position 6 Position between the fifth and the sixth open reading frame of the native viral genome, or alternatively, the position of the sixth gene of the viral genome to be transcribed. dpi (days post-infection); F (fusion); HAI (hemagglutination-inhibition); HN (hemagglutinin-neuraminidase); hpi (hours post-infection); MOI (multiplicity of infection); POI (point of infection); bPIV-3 (bovine parainfluenza virus type 3); hPIV-3 (human parainfluenza virus type 3); RSV (respiratory syncytial virus); SFM (serum-free medium); TCID50 (50% tissue culture infective dose) 4. DESCRIPTION OF THE FIGURES FIG. 1: Percentage homology found between the amino acid sequence of isolate 00-1 and other members of the Pneumovirinae. Percentages (×100) are given for the amino acid sequences of N, P, M, F and two RAP-PCR fragments in L (8 and 9/10). FIG. 2: Seroprevalence of MPV in humans categorized by age group, using immunofluorescence and virus neutralisation assays. FIG. 3: Schematic representation of the genome of APV with the location and size of the fragments obtained with RAP-PCR and RT-PCR on virus isolate 00-1 (A1). Fragments 1 to 10 were obtained using RAP-PCR. Fragment A was obtained with a primer in RAP-PCR fragment 1 and 2 and a primer that was designed based on alignment of leader and trailer sequences of APV and RSV (Randhawa et al., 1997, J.Virol. 71:9849-9854). Fragment B was obtained using primers designed in RAP-PCR fragment 1 and 2 and RAP-PCR fragment 3. Fragment C was obtained with primers designed in RAP-PCR fragment 3 and RAP-PCR fragments 4, 5, 6, and 7. FIG. 4: Comparison of the N, P, M and F ORFs of members of the subfamily Pneumovirinae and virus isolate 00-1 (A1). The alignment shows the amino acid sequence of the complete N, F, M and P proteins and partial L proteins of virus isolate 00-1 (A1). Amino acids that differ between isolate 00-1 (A1) and the other viruses are shown, identical amino acids are represented by periods. Gaps are represented as dashes. Numbers correspond to amino acid positions in the proteins. Abbreviations are as follows: APV-A, B or C: Avian Pneumovirus type A, B or C; hRSV: bovine or human respiratory syncytial virus; PVM: pneumonia virus of mice. L8: fragment 8 obtained with RAP-PCR located in L, L 9/10: consensus of fragment 9 and 10 obtained with RAP-PCR, located in L. For the L alignment only bRSV, hRSV and APV-A sequences were available. FIG. 5: Alignment of the predicted amino acid sequence of the nucleoprotein of MPV with those of other pneumoviruses. The conserved regions are represented by boxes and labeled A, B, and C. The conserved region among pneumoviruses is shown in gray and shaded. Gaps are represented by dashes, periods indicate the positions of identical amino acid residues compared to MPV. FIG. 6: Amino acid sequence comparison of the phosphoprotein of MPV with those of other pneumoviruses. The region of high similarity is boxed, and the glutamate rich region is in grey and shaded. Gaps are represented by dashes. Periods indicate the position of identical amino acid residues compared to MPV. FIG. 7: Comparison of the deduced amino acid sequence of the matrix protein of MPV with those of other pneumoviruses. The conserved hexapeptide sequence is in grey and shaded. Gaps are represented by dashes. Periods indicate the position of identical amino acid residues relative to MPV. FIG. 8: Genomic map of MPV isolate 00-1 (A1). The nucleotide positions of the start and stop codons are indicated under each ORF. The double lines which cross the L ORF indicate the shortened representation of the L gene. The three reading frames below the map indicate the primary G ORF (nt 6262-6972) and overlapping potential secondary ORFs. FIG. 9: Alignment of the predicted amino acid sequence of the fusion protein of MPV with those of other pneumoviruses. The conserved cysteine residues are boxed. N-linked glycosylation sites are underlined. The cleavage site of F0 is double underlined; the fusion peptide, signal peptide, and membrane anchor domain are shown in grey and shaded. Gaps are represented by dashes, and periods indicate the position of identical amino acids relative to MPV. FIG. 10: Comparison of amino acid sequences of the M2 ORFs of MPV with those of other pneumoviruses. The alignment of M2-1 ORFs is shown in panel A, with the conserved amino terminus shown in grey and shaded. The three conserved cysteine residues are printed bold face and indicated by #. The alignment of the M2-2 ORFs is shown in panel B. Gaps are represented by dashes and periods indicate the position of identical amino acids relative to MPV. FIG. 11: Amino acid sequence analyses of the SH ORF of MPV. (A) Amino acid sequence of the SH ORF of MPV, with the serine and threonine residues in grey and shaded, cysteine residues in bold face, and the hydrophobic region doubly underlined. Potential N-linked glycosylation sites are single underlined. Arrows indicate the positions of the basic amino acids flanking the hydrophobic domain. (B) Alignment of the hydrophobicity plots of the SH proteins of MPV, APV-A and hRSV-B. A window of 17 amino acids was used. Arrows indicate a strong hydrophobic domain. Positions within the ORF are given on the X-axis. FIG. 12: Amino acid sequence analyses of the G ORF of MPV. (A) Amino acid sequence of the G ORF of MPV, with serine, threonine, and proline residues in grey and shaded. The cysteine residue is in bold face, and the hydrophobic region is doubly underlined. The potential N-linked glycosylation sites are singly underlined. (B) Alignment of the hydrophobicity plots of the G proteins of MPV, APV-A and hRSV-B. A window of 17 amino acids was used. Arrows indicate the hydrophobic region, and positions within the ORF are given at the X-axis. FIG. 13: Comparison of the amino acid sequences of a conserved domain of the polymerase gene of MPV and other paramyxoviruses. Domain III is shown with the four conserved polymerase motifs (A, B, C, D) in domain III (Poch et al., 1989 EMBO J 8:3867-74; Poch et al., 1990, J. Gen. Virol 71:1153-62) boxed. Gaps are represented by dashes and periods indicate the position of identical amino acid residues relative to MPV. Abbreviations used are as follows: hPIV-3: human parainfluenza virus type 3; SV: sendai virus; hPIV-2: human parainfluenza virus type 2; NDV: New castle disease virus; MV: measles virus; nipah: Nipah virus. FIG. 14: Phylogenetic analyses of the N, F, M, and F ORFs of members of the genus Pneumovirinae and virus isolate 00-1 (A1). Phylogenetic analysis was performed on viral sequences from the following genes: F (panel A), N (panel B), M (panel C), and P (panel D). The phylogenetic trees are based on maximum likelihood analyses using 100 bootstraps and 3 jumbles. The scale representing the number of nucleotide changes is shown for each tree. FIG. 15: Phylogenetic analyses of the M2-1 and L ORFs of MPV and selected paramyxoviruses. The M2-1 ORF was aligned with the M2-1 ORFs of other members of the genus Pneumovirinae (A) and the L ORF was aligned with L ORFs members of the genus pneumovirinae and selected other paramyxoviruses as described in the legend of FIG. 13. Phylogenetic trees were generated by maximum likelihood analyses using 100 bootstraps and 3 jumbles. The scale representing the number of nucleotide changes is shown for each tree. Numbers in the trees represent bootstrap values based on the consensus trees. FIG. 16: Phylogenetic relationship for parts of the F (panel A), N (panel B), M (panel C) 20 and L (panel D) ORFs of nine of the primary MPV isolates with APV-C, its closest relative genetically. The phylogenetic trees are based on maximum likelihood analyses. The scale representing the number of nucleotide changes is shown for each tree. Accession numbers for APV-C: panel A: D00850; panel B: U39295; panel C: X58639; and panel D: U65312. FIG. 17: Alignment of the F genes of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2. FIG. 18: Alignment of the F proteins of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2. FIG. 19: Alignment of the G genes of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2. FIG. 20: Alignment of the G proteins of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2. FIG. 21: Phylogenetic tree based on the F gene sequences showing the phylogenetic relationship of the different hMPV isolates with the respective variants of hMPV. FIG. 22: Phylogenetic tree based on the G gene sequences showing the phylogenetic relationship of the different hMPV isolates with the respective variants of hMPV is shown in FIG. 13. FIG. 23: Growth curve of hMPV isolate 00-1 (A1) in Vero cells. The Vero cells were infected at a MOI of 0.1. FIG. 24: Sequence of CAT-hMPV minireplicon construct. The function encoded by a segment of sequence is indicated underneath the sequence. FIG. 25: Expression of CAT from the CAT-hMPV minireplicon. The different constructs used for transfection are indicated on the x-axis; the amount of CAT expression is indicated on the y-axis. The Figure shows CAT expression 24 hours after transfection and CAT expression 48 hours after transfection. Standards were dilutions of CAT protein. FIG. 26: Leader and Trailer Sequence Comparison: Alignments of the leader and trailer sequences of different viruses as indicated are shown. FIG. 27: hMPV genome analysis: PCR fragments of hMPV genomic sequence relative to the hMPV genomic organization are shown. The position of mutations are shown underneath the vertical bars indicating the PCR fragments. FIG. 28: Restriction maps of hMPV isolate 00-1 (A1) and hMPV isolate 99-1 (B1). Restriction sites in the respective isolates are indicated underneath the diagram showing the genomic organization of hMPV. The scale on top of the diagram indicates the position in the hMPV genome in kb. FIG. 29A and 29B: hMPV cDNA assembly. The diagram on top shows the genomic organization of hMPV, the bars underneath indicate the PCR fragments (see FIG. 27) that are assembled to result in a full length cDNA encoding the virus. The numbers on top of the bars representing the PCR fragments indicate the position in the viral genome in basepairs. FIG. 30: Nucleotide and amino acid sequence information from the 3′ end of the genome of MPV isolate 00-1 (A1). ORFs are given. N: ORF for nucleoprotein; P: ORF for phosphoprotein; M: ORF for matrix protein; F: ORF for fusion protein; GE: gene end; GS: gene start. FIG. 31 A and B: Nucleotide and amino acid sequence information from obtained fragments in the polymerase gene (L) of MPV isolates 00-1 (A1). Positioning of the fragments in L is based on protein homologies with APV-A (accession number U65312). The translated fragment 8 (FIG. 31 A) is located at amino acid number 8 to 243, and the consensus of fragments 9 and 10 (FIG. 31 B) is located at amino acid number 1358 to 1464 of the APV-A L ORF. FIG. 32: Results of RT-PCR assays on throat and nose swabs of 12 guinea pigs 15 inoculated with ned/00/01 (A1) and/or ned/99/01 (B1). FIG. 33A: IgG response against ned/00/01 (A1) and ned/99/01 (B1) for guinea pigs infected with ned/00/01 (A1) and re-infected with ned/00/01 (A1) (GP 4, 5 and 6) or ned/99/01 (B1) (GP 1 and 3). FIG. 33B: IgG response against ned/00/01 (A1) and ned/99/01 (B1) for guinea pigs infected with ned/99/01 and re-infected with either ned/00/01 (A1) (GP's 8 and 9) or with ned/99/01 (B1) (GP's 10, 11, 12). FIG. 34: Specificity of the ned/00/01 (A1) and ned/99/01 (B1) ELISA on sera taken from guinea pigs infected with either ned/00/01 (A1) or ned/99/01 (B1). FIG. 35: Mean IgG response against ned/00/01 (A1) and ned/99/01 (B1) ELISA of 3 homologous (00-1/00-1), 2 homologous (99-1/99-1), 2 heterologous (99-1/00-1) and 2 heterologous (00-1/99-1) infected guinea pigs. FIG. 36: Mean percentage of APV inhibition of hMPV infected guinea pigs. FIG. 37: Virus neutralization titers of ned/00/01 (A1) and ned/99/01 (B1) infected guinea pigs against ned/00/01 (A1), ned/99/01 (B1) and APV-C. FIG. 38: Results of RT-PCR assays on throat swabs of cynomolgous macaques inoculated (twice) with ned/00/01 (A1). FIG. 39A (top two panels): IgA, IgM and IgG response against ned/00/01 (A1) of 2 cynomologous macaques (re)infected with ned/00/01 (A1). FIG. 39B (bottom panels): IgG response against APV of 2 Cynomologous macaques infected with ned/00/01 (A1). FIG. 40: Comparison of the use of the hMPV ELISA and the APV inhibition ELISA for the detection of IgG antibodies in human sera. FIG. 41: Comparison of two prototypic hMPV isolates with APV-A and APV-C; DNA similarity matrices for nucleic acids encoding the various viral proteins. FIG. 42: Comparison of two prototypic hMPV isolates with APV-A and APV-C; protein similarity matrices for the various viral proteins. FIG. 42b: Comparison of the coding sequences of four prototypes of mammalian MPV. The left column shows nucleic acid sequence comparisons and the right column shows amino acid sequence comparisons. NL/1/00 is the prototype of variant A1 (SEQ ID NO: 19). NL/17/00 is the prototype of variant A2 (SEQ ID NO:20). NL/1/99 the prototype of variant B1 (SEQ ID NO:18). NL/1/94 is the prototype of variant B2 (SEQ ID NO:21). FIG. 43: Amino acid alignment of the nucleoprotein of two prototype hMPV isolates. FIG. 44: Amino acid alignment of the phosphoprotein of two prototype hMPV isolates. FIG. 45: Amino acid alignment of the matrix protein of two prototype hMPV isolates. FIG. 46: Amino acid alignment of the fusion protein of two prototype hMPV isolates. FIG. 47: Amino acid alignment of the M2-1 protein of two prototype hMPV isolates. FIG. 48: Amino acid alignment of the M2-2 protein of two prototype hMPV isolates. FIG. 49: Amino acid alignment of the short hydrophobic protein of two prototype hMPV isolates. FIG. 50: Amino acid alignment of the attachment glycoprotein of two prototype hMPV isolates. FIG. 51: Amino acid alignment of the N-terminus of the polymerase protein of two prototype hMPV isolates. FIG. 52: Noncoding sequences of hMPV isolate 00-1 (A1). (A) The noncoding sequences between the ORFs and at the genomic termini are shown in the positive sense. From left to right, stop codons of indicated ORFs are shown, followed by the noncoding sequences, the gene start signals and start codons of the indicated subsequent ORFs. Numbers indicate the first position of start and stop codons in the hMPV map. Sequences that display similarity to published gene end signals are underlined and sequences that display similarity to UAAAAAU/A/C are represented with a line above the sequence. (B) Nucleotide sequences of the genomic termini of hMPV. The genomic termini of hMPV are aligned with each other and with those of APV. Underlined regions represent the primer sequences used in RT-PCR assays which are based on the 3′ and 5′ end sequences of APV and RSV. Bold italicized nucleotides are part of the gene start signal of the N gene. Le: leader, Tr: trailer. FIG. 53: Sequence comparison of the genomic sequence of hMPV isolate 00-1 (A1) with hMPV isolate 99-1 (B1). FIG. 54: Leader sequences of human metapneumovirus (hMPV) NL/1/00 (A1) genomic RNA was determined using a combination of polyadenylation and 3′ RACE methods. FIG. 55: Sequencing analyses on PCR products directly and on PCR clones both indicated that the leader region of hMPV consisted of 5′ ACG CGA AAA AAA CGC GTA TA (expressed as positive sense cDNA orientation) at the 3′ most proximal 20 nucleotides in the leader sequence. The two newly identified nucleotides are underlined. FIG. 56: Plaque formation resulting from successful rescue of infectious virus from the recombinant hMPV clone #2 which has the APV leader and trailer. FIG. 57: Immunostaining of rescued recombinant hMPV. Guinea pig polyclonal antibody followed by anti-guinea pig HRP and the DAKO AEC substrate was used for immunostaining. Positive immunostaining was evident for hMPV from various clades, i.e., A1, A2, B1, and B2, indicating that successful rescue was achieved in all subgroups. (pI=post infection) FIG. 58: Results of RT-PCR and DNA blotting assay used to detect the presence of hMPV in a sample. RT-PCR products using primers specific for the L and N genes of hMPV were transferred to a membrane and subsequently probed with an oligonucleotide specific for the L gene or the N gene respectively. Hydbridization was detected using streptavidinperoxidase. The results indicate that the assay was sensitive for the detection of both the L and N genes of hMPV. FIG. 59: Taqman assay results used to detect hMPV. A) NL-N Taqman assay on titrated viral RNA from the four hMPV prototype virus strains showing the equivalent sensitivity of the assay for all four prototype strains of hMPV. B) Quantitation of RNA transcripts demonstrated that as low as 5 RNA copies yielded a positive signal in the Taqman RT-PCR assay. C) Entropy plots of oligonucleotide-annealing sites for the four prototype hMPV strains for the different primer/probe sets tested. D) Amplification of viral cDNA of the four prototype cDNA strains using previously published assays showed lower sensitivity than the NL-N assay for the hMPV A viruses, and a lack of detection for the hMPV B viruses. FIG. 60: Attenuation of human metapneumovirus resulting from substitution of different viral genes. A) Shows the levels of CAT enzyme in different chimeric forms of hMPV that were generated by substituting different genes of the isolate 99-1 of hMPV (SEQ ID NO:18) with the respective analogous gene of isolate 00-1 of hMPV (SEQ ID NO:19). B) Shows the levels of CAT enzyme in different chimeric forms of hMPV that were generated by substituting different genes of the isolate 00-1 of hMPV (SEQ ID NO:19) with the respective analogous gene of isolate 99-1 of hMPV (SEQ ID NO:18). FIG. 61: Generation of M2 deletion mutants. FIG. 62: A: Shows plaques in Vero cells of wild type hMPV (wt hMPV/NL/1/00), recombinant hMPV with proline at the 101 position of the F protein (rec hMPV/101P), and recombinant hMPV with serine at the 101 position of the F protein (rec hMPV/101S). Growth of the virus was either in the presence or the absence of Trypsin. B: Shows plaques 6 days after infection under methyl cellulose of wild type hMPV, recombinant hMPV with proline at the 101 position of the F protein, and recombinant hMPV with serine at the 101 position of the F protein. Growth of the virus was either in the presence or the absence of Trypsin. FIG. 63: Shows growth curves of wild type hMPV (wt hMPV), recombinant hMPV with proline at the 101 position of the F protein (rec hMPV), and recombinant hMPV with serine at the 101 position of the F protein (P101S in F). Presence or the absence of Trypsin during different phases of the experiment are indicated on top of the graphs. FIG. 64 Western blot analysis of the supernatant (A) or cells (B) of Vero cells infected with wild type hMPV (wt Pro), recombinant hMPV with proline at the 101 position of the F protein (#5 Pro), and recombinant hMPV with serine at the 101 position of the F protein (#7 Ser) grown either in the presence or absence of Trypsin. The uncleaved F0 protein and the cleavage product F1 are indicated by arrows. FIG. 65. Growth curves of recombinant hMPV/NL/1/00 in the presence and absence of Trypsin. wt hMPV=wild type hMPV/NL/1/00; rec hMPV (#21)=recombinant virus with the sequence of hMPV/NL/1/00; rec hMPV (C4A)(#5) recombinant virus with the sequence of hMPV/NL/1/00. FIG. 66. Replication of wild type and recombinant hMPV in the upper and lower respiratory tract of hamsters. FIG. 67. Growth curves of recombinant hMPV/NL/1/00 in the presence and absence of Trypsin. wt hMPV=wild type hMPV/NL/1/00; rec hMPV (#21)=recombinant virus with the sequence of hMPV/NL/1/00; rec hMPV (C4A)(#5) recombinant virus with the sequence of hMPV/NL/1/00. FIG. 68. Linear Correlation Between Plaque Reduction and Microneutralization using hMPV/GFP2. 5. DETAILED DESCRIPTION OF THE INVENTION The invention relates to an isolated mammalian negative strand RNA virus, metapneumovirus (MPV) and variants thereof, within the sub-family Pneumovirinae, of the family Paramyxoviridae. The present invention also relates to isolated mammalian negative strand RNA viruses identifiable as phylogenetically corresponding or relating to the genus metapneumovirus and components thereof. The mammalian MPVs of the invention can be a variant A1, A2, B1 or B2 mammalian MPV. However, the mammalian MPVs of the present invention may encompass additional variants of MPV yet to be identified, and are not limited to variants A1, A2, B1 or B2. The invention relates to genomic nucleotide sequences of different variants of isolates of mammalian metapneumoviruses (MPV), in particular human metapneumoviruses including isolates of variants A1, A2, B1 and B2. The invention relates to the use of the sequence information of different isolates of mammalian metapneumoviruses for diagnostic and therapeutic methods. The present invention relates to the differences of the genomic nucleotide sequences among the different metapneumovirus-isolates, and their use in the diagnostic and therapeutic methods of the invention. In particular, the invention relates to the use of the single nucleotide polymorphisms (SNPs) among different metapneumovirus isolates for diagnostic and therapeutic methods. The present invention also relates to the use serological characterization of the different isolates of mammalian metapneumoviruses, alone or in combination with the sequence information of the different isolates, for diagnostic and therapeutic methods. The present invention relates to nucleotide sequences encoding the genome of a metapneumovirus or a portion thereof, including both mammalian and avian metapneumovirus (APV). The present invention relates to nucleotide sequences encoding gene products of a metapneumovirus, including both mammalian and avian metapneumoviruses. The present invention further relates to nucleic acids, including DNA and RNA, that encodes the genome or a portion thereof of a metapneumovirus, including both mammalian and avian, in addition to a nucleotide sequence which is heterologous or non-native to the viral genome. The invention further encompasses recombinant or chimeric viruses encoded by said nucleotide sequences. In accordance with the present invention, a recombinant virus is one derived from a mammalian MPV or an APV that is encoded by endogenous or native genomic sequences or non-native genomic sequences. In accordance with the invention, a non-native sequence is one that is different from the native or endogenous genomic sequence due to one or more mutations, including, but not limited to, point mutations, rearrangements, insertions, deletions etc., the genomic sequence that may or may not result in a phenotypic change. In accordance with the invention, a chimeric virus is a recombinant MPV or APV which further comprises a heterologous nucleotide sequence. In accordance with the invention, a chimeric virus may be encoded by a nucleotide sequence in which heterologous nucleotide sequences have been added to the genome or in which endogenous or native nucleotide sequences have been replaced with heterologous nucleotide sequences. The invention further relates to vaccine formulations comprising mammalian or avian metapneumovirus, including recombinant forms of said viruses. In particular, the present invention encompasses vaccine preparations comprising recombinant or chimeric forms of MPV or APV that express antigenic glycoproteins, including glycoproteins of MPV, or APV and/or non-native MPV or APV glycoproteins. The invention also encompasses vaccine preparations comprising recombinant forms of MPV or APV that encode antigenic sequences of another negative strand RNA virus, including PIV or RSV, or a heterologous glycoprotein of another species or strain of metapneumovirus. The invention further relates to vaccines comprising chimeric hMPV wherein the chimeric hMPV encodes one or more APV proteins and wherein the chimeric hMPV optionally additionally expresses one or more heterologous or non-native sequences. The invention also relates to vaccines comprising chimeric APV wherein the chimeric APV encodes one or more hMPV proteins and wherein the chimeric APV optionally additionally expresses one or more heterologous or non-native sequences. The present invention also relates to multivalent vaccines, including bivalent and trivalent vaccines. In particular, the bivalent and trivalent vaccines of the invention encompass two or more antigenic polypeptides expressed by the same or different pneumoviral vectors encoding antigenic proteins of MPV, APV, PIV, RSV, influenza or another negative strand RNA virus, or morbillivirus. 5.1 Mammalian Metapneumovirus Structural Characteristics of a Mammalian Metapneumovirus The invention provides a mammalian MPV. The mammalian MPV is a negative-sense single stranded RNA virus belonging to the sub-family Pneumovirinae of the family Paramyxoviridae. Moreover, the mammalian MPV is identifiable as phylogenetically corresponding to the genus Metapneumovirus, wherein the mammalian MPV is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris (SEQ ID NO:19) than to turkey rhinotracheitis virus, the etiological agent of avian rhinotracheitis. A virus is identifiable as phylogenetically corresponding to the genus Metapneumovirus by, e.g., obtaining nucleic acid sequence information of the virus and testing it in phylogenetic analyses. Any technique known to the skilled artisan can be used to determine phylogenetic relationships between strains of viruses. For exemplary methods see section 5.9. Other techniques are disclosed in International Patent Application PCT/NL02/00040, published as WO 02/057302, which is incorporated by reference in its entirety herein. In particular, PCT/NL02/00040 discloses nucleic acid sequences that are suitable for phylogenetic analysis at page 12, line 27 to page 19, line 29, which are incorporated by reference herein. A virus can further be identified as a mammalian MPV on the basis of sequence similarity as described in more detail below. In addition to phylogenetic relatedness and sequence similarity of a virus to a mammalian MPV as disclosed herein, the similarity of the genomic organization of a virus to the genomic organization of a mammalian MPV disclosed herein can also be used to identify the virus as a mammalian MPV. For a representative genomic organization of a mammalian MPV see FIG. 27. In certain embodiments, the genomic organization of a mammalian MPV is different from the genomic organization of pneumoviruses within the sub-family Pneumovirinae of the family Paramyxoviridae. The classification of the two genera, metapneumovirus and pneumovirus, is based primarily on their gene constellation; metapneumoviruses generally lack non-structural proteins such as NS1 or NS2 (see also Randhawa et al., 1997, J. Virol. 71:9849-9854) and the gene order is different from that of pneumoviruses (RSV: ‘3-NS1-NS2-N-P-M-SH-G-F-M2-L-5’, APV: ‘3-N-P-M-F-M2-SH-G-L-5’) (Lung, et al., 1992, J. Gen. Virol. 73:1709-17 15; Yu, et al., 1992, Virology 186:426-434; Randhawa, et al., 1997, J. Virol. 71:9849-9854). Further, a mammalian MPV of the invention can be identified by its immunological properties. In certain embodiments, specific anti-sera can be raised against mammalian MPV that can neutralize mammalian MPV. Monoclonal and polyclonal antibodies can be raised against MPV that can also neutralize mammalian MPV. (See, PCT WO 02/057302 at pages ______ to ______, which is incorporated by reference herein. The mammalian MPV of the invention is further characterized by its ability to infect a mammalian host, i.e., a mammalian cultured cell or a mammal. Unlike APV, mammalian MPV does not replicate or replicates only at low levels in chickens and turkeys. Mammalian MPV replicates, however, in mammalian hosts, such as cynomolgous macaques. In certain, more specific, embodiments, a mammalian MPV is further characterized by its ability to replicate in a mammalian host. In certain, more specific embodiments, a mammalian MPV is further characterized by its ability to cause the mammalian host to express proteins encoded by the genome of the mammalian MPV. In even more specific embodiments, the viral proteins expressed by the mammalian MPV are inserted into the cytoplasmic membranes of the mammalian host. In certain embodiments, the mammalian MPV of the invention can infect a mammalian host and cause the mammalian host to produce new infectious viral particles of the mammalian MPV. For a more detailed description of the functional characteristics of the mammalian MPV of the invention, see section 5.1.2. In certain embodiments, the appearance of a virus in an electron microscope or its sensitivity to chloroform can be used to identify the virus as a mammalian MPV. The mammalian MPV of the invention appears in an electron microscope as paramyxovirus-like particle. Consistently, a mammalian MPV is sensitive to treatment with chloroform; a mammalian MPV is cultured optimally on tMK cells or cells functionally equivalent thereto and it is essentially trypsine dependent in most cell cultures. Furthermore, a mammalian MPV has a typical cytopathic effects (CPE) and lacks haemagglutinating activity against species of red blood cells. The CPE induced by MPV isolates are similar to the CPE induced by hRSV, with characteristic syncytia formation followed by rapid internal disruption of the cells and subsequent detachment from the culture plates. Although most paramyxoviruses have haemagglutinating activity, most of the pneumoviruses do not (Pringle, C. R. In: The Paramyxoviruses; (ed. D. W. Kingsbury) 1-39 (Plenum Press, New York, 1991)). A mammalian MPV contains a second overlapping ORF (M2-2) in the nucleic acid fragment encoding the M2 protein. The occurrence of this second overlapping ORF occurs in other pneumoviruses as shown in Ahmadian et al., 1999, J Gen. Vir. 80:2011-2016. In certain embodiments, the invention provides methods to identify a viral isolate as a mammalian MPV. A test sample can, e.g., be obtained from an animal or human. The sample is then tested for the presence of a virus of the sub-family Pneumovirinae. If a virus of the sub-family Pneumovirinae is present, the virus can be tested for any of the characteristics of a mammalian MPV as discussed herein, such as, but not limited to, phylogenetic relatedness to a mammalian MPV, nucleotide sequence identity to a nucleotide sequence of a mammalian MPV, amino acid sequence identity/homology to a amino acid sequence of a mammalian MPV, and genomic organization. Furthermore, the virus can be identified as a mammalian MPV by cross-hybridization experiments using nucleic acid sequences from a MPV isolate, RT-PCR using primers specific to mammalian MPV, or in classical cross-serology experiments using antibodies directed against a mammalian MPV isolate. In certain other embodiments, a mammalian MPV can be identified on the basis of its immunological distinctiveness, as determined by quantitative neutralization with animal antisera. The antisera can be obtained from, e.g., ferrets, pigs or macaques that are infected with a mammalian MPV (see, e.g., Example 8). In certain embodiments, the serotype does not cross-react with viruses other than mammalian MPV. In other embodiments, the serotype shows a homologous-to-heterologous titer ratio >16 in both directions If neutralization shows a certain degree of cross-reaction between two viruses in either or both directions (homologous-to-heterologous titer ration of eight or sixteen), distinctiveness of serotype is assumed if substantial biophysical/biochemical differences of DNA sequences exist. If neutralization shows a distinct degree of cross-reaction between two viruses in either or both directions (homologous-to-heterologous titer ratio of smaller than eight), identity of serotype of the isolates under study is assumed. Isolate I-2614, herein also known as MPV isolate 00-1, can be used as prototype. In certain embodiments, a virus can be identified as a mammalian MPV by means of sequence homology/identity of the viral proteins or nucleic acids in comparison with the amino acid sequence and nucleotide sequences of the viral isolates disclosed herein by sequence or deposit. In particular, a virus is identified as a mammalian MPV when the genome of the virus contains a nucleic acid sequence that has a percentage nucleic acid identity to a virus isolate deposited as 1-2614 with CNCM, Paris which is higher than the percentages identified herein for the nucleic acids encoding the L protein, the M protein, the N protein, the P protein, or the F protein as identified herein below in comparison with APV-C (see Table 1). (See, PCT WO 02/05302, at pp. 12 to 19, which is incorporated by reference herein. Without being bound by theory, it is generally known that viral species, especially RNA virus species, often constitute a quasi species wherein the members of a cluster of the viruses display sequence heterogeneity. Thus, it is expected that each individual isolate may have a somewhat different percentage of sequence identity when compared to APV-C. The highest amino sequence identity between the proteins of MPV and any of the known other viruses of the same family to date is the identity between APV-C and human MPV. Between human MPV and APV-C, the amino acid sequence identity for the matrix protein is 87%, 88% for the nucleoprotein, 68% for the phosphoprotein, 81% for the fusion protein and 56-64% for parts of the polymerase protein, as can be deduced when comparing the sequences given in FIG. 30, see also Table 1. Viral isolates that contain ORFs that encode proteins with higher homology compared to these maximum values are considered mammalian MPVs. It should be noted that, similar to other viruses, a certain degree of variation is found between different isolated of mammalian MPVs. TABLE 1 Amino acid sequence identity between the ORFs of MPV and those of other paramyxoviruses. N P M F M2-1 M2-2 L APV A 69 55 78 67 72 26 64 APV B 69 51 76 67 71 27 −2 APV C 88 68 87 81 84 56 −2 hRSV A 42 24 38 34 36 18 42 hRSV B 41 23 37 33 35 19 44 bRSV 42 22 38 34 35 13 44 PVM 45 26 37 39 33 12 −2 others3 7-11 4-9 7-10 10-18 −4 −4 13-14 Footnotes: 1No sequence homologies were found with known G and SH proteins and were thus excluded 2Sequences not available. 3others: human parainfluenza virus type 2 and 3, Sendai virus, measles virus, nipah virus, phocine distemper virus, and New Castle Disease virus. 4ORF absent in viral genome. In certain embodiments, the invention provides a mammalian MPV, wherein the amino acid sequence of the SH protein of the mammalian MPV is at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of SEQ ID NO:382 (SH protein of isolate NL/1/00; see Table 14). The isolated negative-sense single stranded RNA metapneumovirus that comprises the SH protein that is at least 30% identical to SEQ ID NO:382 (SH protein of isolate NL/1/00; see Table 14) is capable of infecting a mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the SH protein that is at least 30% identical to SEQ ID NO:382 (SH protein of isolate NL/1/00; see Table 14) is capable of replicating in a mammalian host. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a SH protein that is at least 30% identical to SEQ ID NO:382 (SH protein of isolate NL/1/00; see Table 14). In certain embodiments, the invention provides a mammalian MPV, wherein the amino acid sequence of the G protein of the mammalian MPV is at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of SEQ ID NO:322 (G protein of isolate NL/1/00; see Table 14). The isolated negative-sense single stranded RNA metapneumovirus that comprises the G protein that is at least 20% identical to SEQ ID NO:322 (G protein of isolate NL/1/00; see Table 14) is capable of infecting a mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the G protein that is at least 20% identical to SEQ ID NO:322 (G protein of isolate NL/1/00; see Table 14) is capable of replicating in a mammalian host. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a G protein that is at least 20% identical to SEQ ID NO:322 (G protein of isolate NL/1/00; see Table 14). In certain embodiments, the invention provides a mammalian MPV, wherein the amino acid sequence of the L protein of the mammalian MPV is at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of SEQ ID NO:330 (L protein of isolate NL/1/00; see Table 14). The isolated negative-sense single stranded RNA metapneumovirus that comprises the L protein that is at least 85% identical to SEQ ID NO:330 (L protein of isolate NL/1/00; see Table 14) is capable of infecting a mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the L protein that is at least 85% identical to SEQ ID NO:330 (L protein of isolate NL/1/00; see Table 14) is capable of replicating in a mammalian host. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a L protein that is at least 20% identical to SEQ ID NO:330 (L protein of isolate NL/1/00; see Table 14). In certain embodiments, the invention provides a mammalian MPV, wherein the amino acid sequence of the N protein of the mammalian MPV is at least 90%, at least 95%, or at least 98% identical to the amino acid sequence of SEQ ID NO:366. The isolated negative-sense single stranded RNA metapneumovirus that comprises the N protein that is at least 90% identical in amino acid sequence to SEQ ID NO:366 is capable of infecting mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the N protein that is 90% identical in amino acid sequence to SEQ ID NO:366 is capable of replicating in a mammalian host. The amino acid identity is calculated over the entire length of the N protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a N protein that is at least 90%, at least 95%, or at least 98% identical to the amino acid sequence of SEQ ID NO:366. The invention further provides mammalian MPV, wherein the amino acid sequence of the P protein of the mammalian MPV is at least 70%, at least 80%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:374. The mammalian MPV that comprises the P protein that is at least 70% identical in amino acid sequence to SEQ ID NO:374 is capable of infecting a mammalian host. In certain embodiments, the mammalian MPV that comprises the P protein that is at least 70% identical in amino acid sequence to SEQ ID NO:374 is capable of replicating in a mammalian host. The amino acid identity is calculated over the entire length of the P protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a P protein that is at least 70%, at least 80%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:374. The invention further provides, mammalian MPV, wherein the amino acid sequence of the M protein of the mammalian MPV is at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:358. The mammalian MPV that comprises the M protein that is at least 90% identical in amino acid sequence to SEQ ID NO:358 is capable of infecting mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the M protein that is 90% identical in amino acid sequence to SEQ ID NO:358 is capable of replicating in a mammalian host. The amino acid identity is calculated over the entire length of the M protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a M protein that is at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:358. The invention further provides mammalian MPV, wherein the amino acid sequence of the F protein of the mammalian MPV is at least 85%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:314. The mammalian MPV that comprises the F protein that is at least 85% identical in amino acid sequence to SEQ ID NO:314 is capable of infecting a mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the F protein that is 85% identical in amino acid sequence to SEQ ID NO:314 is capable of replicating in mammalian host. The amino acid identity is calculated over the entire length of the F protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a F protein that is at least 85%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:314. The invention further provides mammalian MPV, wherein the amino acid sequence of the M2-1 protein of the mammalian MPV is at least 85%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:338. The mammalian MPV that comprises the M2-1 protein that is at least 85% identical in amino acid sequence to SEQ ID NO:338 is capable of infecting a mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the M2-1 protein that is 85% identical in amino acid sequence to SEQ ID NO:338 is capable of replicating in a mammalian host. The amino acid identity is calculated over the entire length of the M2-1 protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a M2-1 protein that is at least 85%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:338. The invention further provides mammalian MPV, wherein the amino acid sequence of the M2-2 protein of the mammalian MPV is at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:346 The isolated mammalian MPV that comprises the M2-2 protein that is at least 60% identical in amino acid sequence to SEQ ID NO:346 is capable of infecting mammalian host. In certain embodiments, the isolated negative-sense single stranded RNA metapneumovirus that comprises the M2-2 protein that is 60% identical in amino acid sequence to SEQ ID NO:346 is capable of replicating in a mammalian host. The amino acid identity is calculated over the entire length of the M2-2 protein. In certain embodiments, a mammalian MPV contains a nucleotide sequence that encodes a M2-1 protein that is is at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or at least 98% identical to the amino acid sequence of SEQ ID NO:346. In certain embodiments, the invention provides mammalian MPV, wherein the negative-sense single stranded RNA metapneumovirus encodes at least two proteins, at least three proteins, at least four proteins, at least five proteins, or six proteins selected from the group consisting of (i) a N protein with at least 90% amino acid sequence identity to SEQ ID NO:366; (ii) a P protein with at least 70% amino acid sequence identity to SEQ ID NO:374 (iii) a M protein with at least 90% amino acid sequence identity to SEQ ID NO:358 (iv) a F protein with at least 85% amino acid sequence identity to SEQ ID NO:314 (v) a M2-1 protein with at least 85% amino acid sequence identity to SEQ ID NO:338; and (vi) a M2-2 protein with at least 60% amino acid sequence identity to SEQ ID NO:346. The invention provides two subgroups of mammalian MPV, subgroup A and subgroup B. The invention also provides four variants A1, A2, B1 and B2. A mammalian MPV can be identified as a member of subgroup A if it is phylogenetically closer related to the isolate 00-1 (SEQ ID NO:19) than to the isolate 99-1 (SEQ ID NO:18). A mammalian MPV can be identified as a member of subgroup B if it is phylogenetically closer related to the isolate 99-1 (SEQ ID NO:18) than to the isolate 00-1 (SEQ ID NO:19). In other embodiments, nucleotide or amino acid sequence homologies of individual ORFs can be used to classify a mammalian MPV as belonging to subgroup A or B. The different isolates of mammalian MPV can be divided into four different variants, variant A1, variant A2, variant B1 and variant B2 (see FIGS. 21 and 22). The isolate 00-1 (SEQ ID NO:19) is an example of the variant A1 of mammalian MPV. The isolate 99-1 (SEQ ID NO:18) is an example of the variant B1 of mammalian MPV. A mammalian MPV can be grouped into one of the four variants using a phylogenetic analysis. Thus, a mammalian MPV belongs to a specific variant if it is phylogenetically closer related to a known member of that variant than it is phylogenetically related to a member of another variant of mammalian MPV. The sequence of any ORF and the encoded polypeptide may be used to type a MPV isolate as belonging to a particular subgroup or variant, including N, P, L, M, SH, G, M2 or F polypeptides. In a specific embodiment, the classification of a mammalian MPV into a variant is based on the sequence of the G protein. Without being bound by theory, the G protein sequence is well suited for phylogenetic analysis because of the high degree of variation among G proteins of the different variants of mammalian MPV. In certain embodiments of the invention, sequence homology may be determined by the ability of two sequences to hybridize under certain conditions, as set forth below. A nucleic acid which is hybridizable to a nucleic acid of a mammalian MPV, or to its reverse complement, or to its complement can be used in the methods of the invention to determine their sequence homology and identities to each other. In certain embodiments, the nucleic acids are hybridized under conditions of high stringency. It is well-known to the skilled artisan that hybridization conditions, such as, but not limited to, temperature, salt concentration, pH, formamide concentration (see, e.g., Sambrook et al., 1989, Chapters 9 to 11, Molecular Cloning, A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., incorporated herein by reference in its entirety). In certain embodiments, hybridization is performed in aqueous solution and the ionic strength of the solution is kept constant while the hybridization temperature is varied dependent on the degree of sequence homology between the sequences that are to be hybridized. For DNA sequences that 100% identical to each other and are longer than 200 basebairs, hybridization is carried out at approximately 15-25° C. below the melting temperature (Tm) of the perfect hybrid. The melting temperature (Tm) can be calculated using the following equation (Bolton and McCarthy, 1962, Proc. Natl. Acad. Sci. USA 84:1390): Tm=81.5° C.−16.6(log 10[Na+])+(% G+C)−0.63(% formamide)−(600/l) Wherein (Tm) is the melting temperature, [Na+] is the sodium concentration, G+C is the Guanine and Cytosine content, and l is the length of the hybrid in basepairs. The effect of mismatches between the sequences can be calculated using the formula by Bonner et al. (Bonner et al., 1973, J. Mol. Biol. 81:123-135): for every 1% of mismatching of bases in the hybrid, the melting temperature is reduced by 1-1.5° C. Thus, by determining the temperature at which two sequences hybridize, one of skill in the art can estimate how similar a sequence is to a known sequence. This can be done, e.g., by comparison of the empirically determined hybridization temperature with the hybridization temperature calculated for the know sequence to hybridize with its perfect match. Through the use of the formula by Bonner et al., the relationship between hybridization temperature and per cent mismatch can be exploited to provide information about sequence similarity. By way of example and not limitation, procedures using such conditions of high stringency are as follows. Prehybridization of filters containing DNA is carried out for 8 h to overnight at 65 C in buffer composed of 6×SSC, 50 mM Tris-HCl (pH 7.5), 1 mM EDTA, 0.02% PVP, 0.02% Ficoll, 0.02% BSA, and 500 μg/ml denatured salmon sperm DNA. Filters are hybridized for 48 h at 65 C in prehybridization mixture containing 100 μg/ml denatured salmon sperm DNA and 5-20×106 cpm of 32P-labeled probe. Washing of filters is done at 37 C for 1 h in a solution containing 2×SSC, 0.01% PVP, 0.01% Ficoll, and 0.01% BSA. This is followed by a wash in 0.1×SSC at 50 C for 45 min before autoradiography. Other conditions of high stringency which may be used are well known in the art. In other embodiments of the invention, hybridization is performed under moderate of low stringency conditions, such conditions are well-known to the skilled artisan (see e.g., Sambrook et al., 1989, Molecular Cloning, A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; see also, Ausubel et al., eds., in the Current Protocols in Molecular Biology series of laboratory technique manuals, 1987-1997 Current Protocols,© 1994-1997 John Wiley and Sons, Inc., each of which is incorporated by reference herein in their entirety). An illustrative low stringency condition is provided by the following system of buffers: hybridization in a buffer comprising 35% formamide, 5×SSC, 50 mM Tris-HCl (pH 7.5), 5 mM EDTA, 0.02% PVP, 0.02% Ficoll, 0.2% BSA, 100 g/ml denatured salmon sperm DNA, and 10% (wt/vol) dextran sulfate for 18-20 hours at 40?C, washing in a buffer consisting of 2×SSC, 25 mM Tris-HCl (pH 7.4), 5 mM EDTA, and 0.1% SDS for 1.5 hours at 55?C, and washing in a buffer consisting of 2×SSC, 25 mM Tris-HCl (pH 7.4), 5 mM EDTA, and 0.1% SDS for 1.5 hours at 60?C. In certain embodiments, a mammalian MPV can be classified into one of the variant using probes that are specific for a specific variant of mammalian MPV. Such probes include primers for RT-PCR and antibodies. Illustrative methods for identifying a mammalian MPV as a member of a specific variant are described in section 5.9 below. In certain embodiments of the invention, the different variants of mammalian MPV can be distinguished from each other by way of the amino acid sequences of the different viral proteins (see, e.g., FIG. 42b). In other embodiments, the different variants of mammalian MPV can be distinguished from each other by way of the nucleotide sequences of the different ORFs encoded by the viral genome (see, e.g., FIG. 42b). A variant of mammalian MPV can be, but is not limited to, A1, A2, B1 or B2. The invention, however, also contemplates isolates of mammalian MPV that are members of another variant yet to be identified. The invention also contemplates that a virus may have one or more ORF that are closer related to one variant and one or more ORFs that are closer phylogenetically related to another variant. Such a virus would be classified into the variant to which the majority of its ORFs are closer phylogenetically related. Non-coding sequences may also be used to determine phylogenetic relatedness. An isolate of mammalian MPV is classified as a variant B1 if it is phylogenetically closer related to the viral isolate NL/1/99 (SEQ ID NO:18) than it is related to any of the following other viral isolates: NL/1/00 (SEQ ID NO:19), NL/17/00 (SEQ ID NO:20) and NL/1/94 (SEQ ID NO:21). One or more of the ORFs of a mammalian MPV can be used to classify the mammalian MPV into a variant. A mammalian MPV can be classified as an MPV variant B1, if the amino acid sequence of its G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:324); if the amino acid sequence of its N proteint is at least 98.5% or at least 99% or at least 99.5% identical to the N protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:368); if the amino acid sequence of its P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:376); if the amino acid sequence of its M protein is identical to the M protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:360); if the amino acid sequence of its F protein is at least 99% identical to the F protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:316); if the amino acid sequence of its M2-1 protein is at least 98% or at least 99% or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:340); if the amino acid sequence of its M2-2 protein is at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:348); if the amino acid sequence of its SH protein is at least 83%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:384); and/or if the amino acid sequence of its L protein is at least 99% or at least 99.5% identical to the L protein a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:332). An isolate of mammalian MPV is classified as a variant A1 if it is phylogenetically closer related to the viral isolate NL/1/00 (SEQ ID NO:19) than it is related to any of the following other viral isolates: NL/1/99 (SEQ ID NO:18), NL/17/00 (SEQ ID NO:20) and NL/1/94 (SEQ ID NO:21). One or more of the ORFs of a mammalian MPV can be used to classify the mammalian MPV into a variant. A mammalian MPV can be classified as an MPV variant A1, if the amino acid sequence of its G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:322); if the amino acid sequence of its N protein is at least 99.5% identical to the N protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:366); if the amino acid sequence of its P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:374); if the amino acid sequence of its M protein is at least 99% or at least 99.5% identical to the M protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:358); if the amino acid sequence of its F protein is at least 98% or at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:314); if the amino acid sequence of its M2-1 protein is at least 99% or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:338); if the amino acid sequence of its M2-2 protein is at least 96% or at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:346); if the amino acid sequence of its SH protein is at least 84%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:382); and/or if the amino acid sequence of its L protein is at least 99% or at least 99.5% identical to the L protein of a virus of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:330). An isolate of mammalian MPV is classified as a variant A2 if it is phylogenetically closer related to the viral isolate NL/17/00 (SEQ ID NO:20) than it is related to any of the following other viral isolates: NL/1/99 (SEQ ID NO:18), NL/1/00 (SEQ ID NO:19) and NL/1/94 (SEQ ID NO:21). One or more of the ORFs of a mammalian MPV can be used to classify the mammalian MPV into a variant. A mammalian MPV can be classified as an MPV variant A2, if the amino acid sequence of its G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:323); if the amino acid sequence of its N protein is at least 99.5% identical to the N protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:367); if the amino acid sequence of its P protein is at least 96%, at least 98%, at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:375); if the amino acid sequence of its M protein is at least 99%, or at least 99.5% identical to the M protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:359); if the amino acid sequence of its F protein is at least 98%, at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:315); if the amino acid sequence of its M2-1 protein is at least 99%, or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO: 339); if the amino acid sequence of its M2-2 protein is at least 96%, at least 98%, at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:347); if the amino acid sequence of its SH protein is at least 84%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:383); if the amino acid sequence of its L protein is at least 99% or at least 99.5% identical to the L protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:331). An isolate of mammalian MPV is classified as a variant B2 if it is phylogenetically closer related to the viral isolate NL/1/94 (SEQ ID NO:21) than it is related to any of the following other viral isolates: NL/1/99 (SEQ ID NO:18), NL/1/00 (SEQ ID NO:19) and NL/17/00 (SEQ ID NO:20). One or more of the ORFs of a mammalian MPV can be used to classify the mammalian MPV into a variant. A mammalian MPV can be classified as an MPV variant B2, if the amino acid sequence of its G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:325); if the amino acid sequence of its N protein is at least 99% or at least 99.5% identical to the N protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:369); if the amino acid sequence of its P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:377); if the amino acid sequence of its M protein is identical to the M protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:361); if the amino acid sequence of its F protein is at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:317); if the amino acid sequence of the M2-1 protein is at least 98% or at least 99% or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:341); if the amino acid sequence that is at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:349); if the amino acid sequence of its SH protein is at least 84%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:385); and/or if the amino acid sequence of its L protein is at least 99% or at least 99.5% identical to the L protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:333). In certain embodiments, the percentage of sequence identity is based on an alignment of the full length proteins. In other embodiments, the percentage of sequence identity is based on an alignment of contiguous amino acid sequences of the proteins, wherein the amino acid sequences can be 25 amino acids, 50 amino acids, 75 amino acids, 100 amino acids, 125 amino acids, 150 amino acids, 175 amino acids, 200 amino acids, 225 amino acids, 250 amino acids, 275 amino acids, 300 amino acids, 325 amino acids, 350 amino acids, 375 amino acids, 400 amino acids, 425 amino acids, 450 amino acids, 475 amino acids, 500 amino acids, 750 amino acids, 1000 amino acids, 1250 amino acids, 1500 amino acids, 1750 amino acids, 2000 amino acids or 2250 amino acids in length. 5.2 Functional Characteristics of a Mammalian MPV In addition to the structural definitions of the mammalian MPV, a mammalian MPV can also be defined by its functional characteristics. In certain embodiments, the mammalian MPV of the invention is capable of infecting a mammalian host. The mammalian host can be a mammalian cell, tissue, organ or a mammal. In a specific embodiment, the mammalian host is a human or a human cell, tissue or organ. Any method known to the skilled artisan can be used to test whether the mammalian host has been infected with the mammalian MPV. In certain embodiments, the virus is tested for its ability to attach to a mammalian cell. In certain other embodiments, the virus is tested for its ability to transfer its genome into the mammalian cell. In an illustrative embodiment, the genome of the virus is detectably labeled, e.g., radioactively labeled. The virus is then incubated with a mammalian cell for at least 1 minute, at least 5 minutes at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours, or at least 1 day. The cells are subsequently washed to remove any viral particles from the cells and the cells are then tested for the presence of the viral genome by virtue of the detectable label. In another embodiment, the presence of the viral genome in the cells is detected using RT-PCR using mammalian MPV specific primers. (See PCT WO 02/057302 at pp. 37 to 44, which is incorporated by reference herein). In certain embodiments, the mammalian virus is capable to infect a mammalian host and to cause proteins of the mammalian MPV to be inserted into the cytoplasmic membrane of the mammalian host. The mammalian host can be a cultured mammalian cell, organ, tissue or mammal. In an illustrative embodiment, a mammalian cell is incubated with the mammalian virus. The cells are subsequently washed under conditions that remove the virus from the surface of the cell. Any technique known to the skilled artisan can be used to detect the newly expressed viral protein inserted in the cytoplasmic membrane of the mammalian cell. For example, after infection of the cell with the virus, the cells are maintained in medium comprising a detectably labeled amino acid. The cells are subsequently harvested, lysed, and the cytoplasmic fraction is separated from the membrane fraction. The proteins of the membrane fraction are then solubilized and then subjected to an immunoprecipitation using antibodies specific to a protein of the mammalian MPV, such as, but not limited to, the F protein or the G protein. The immunoprecipitated proteins are then subjected to SDS PAGE. The presence of viral protein can then be detected by autoradiography. In another embodiment, the presence of viral proteins in the cytoplasmic membrane of the host cell can be detected by immunocytochemistry using one or more antibodies specific to proteins of the mammalian MPV. In even other embodiments, the mammalian MPV of the invention is capable of infecting a mammalian host and of replicating in the mammalian host. The mammalian host can be a cultured mammalian cell, organ, tissue or mammal. Any technique known to the skilled artisan can be used to determine whether a virus is capable of infecting a mammalian cell and of replicating within the mammalian host. In a specific embodiment, mammalian cells are infected with the virus. The cells are subsequently maintained for at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours, at least 1 day, or at least 2 days. The level of viral genomic RNA in the cells can be monitored using Northern blot analysis, RT-PCR or in situ hybridization using probes that are specific to the viral genome. An increase in viral genomic RNA demonstrates that the virus can infect a mammalian cell and can replicate within a mammalian cell. In even other embodiments, the mammalian MPV of the invention is capable of infecting a mammalian host, wherein the infection causes the mammalian host to produce new infectious mammalian MPV. The mammalian host can be a cultured mammalian cell or a mammal. Any technique known to the skilled artisan can be used to determine whether a virus is capable of infecting a mammalian host and cause the mammalian host to produce new infectious viral particles. In an illustrative example, mammalian cells are infected with a mammalian virus. The cells are subsequently washed and incubated for at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours, at least 1 day, at least 2 days, at least one week, or at least twelve days. The titer of virus can be monitored by any method known to the skilled artisan. For exemplary methods see section 5.8. In certain, specific embodiments, the mammalian MPV is a human MPV. The tests described in this section can also be performed with a human MPV. In certain embodiments, the human MPV is capable of infecting a mammalian host, such as a mammal or a mammalian cultured cell. In certain embodiments, the human MPV is capable to infect a mammalian host and to cause proteins of the human MPV to be inserted into the cytoplasmic membrane of the mammalian host. In even other embodiments, the human MPV of the invention is capable of infecting a mammalian host and of replicating in the mammalian host. In even other embodiments, the human MPV of the invention is capable of infecting a mammalian host and of replicating in the mammalian host, wherein the infection and replication causes the mammalian host to produce and package new infectious human MPV. In certain embodiments, the mammalian MPV, even though it is capable of infecting a mammalian host, is also capable of infecting an avian host, such as a bird or an avian cultured cell. In certain embodiments, the mammalian MPV is capable to infect an avian host and to cause proteins of the mammalian MPV to be inserted into the cytoplasmic membrane of the avian host. In even other embodiments, the mammalian MPV of the invention is capable of infecting an avian host and of replicating in the avian host. In even other embodiments, the mammalian MPV of the invention is capable of infecting an avian host and of replicating in the avian host, wherein the infection and replication causes the avian host to produce and package new infectious mammalian MPV. 5.3 Recombinant and Chimeric Metapneumovirus The present invention encompasses recombinant or chimeric viruses encoded by viral vectors derived from the genomes of metapneumovirus, including both mammalian and avian variants. In accordance with the present invention a recombinant virus is one derived from a mammalian MPV or an APV that is encoded by endogenous or native genomic sequences or non-native genomic sequences. In accordance with the invention, a non-native sequence is one that is different from the native or endogenous genomic sequence due to one or more mutations, including, but not limited to, point mutations, rearrangements, insertions, deletions etc., to the genomic sequence that may or may not result in a phenotypic change. The recombinant viruses of the invention encompass those viruses encoded by viral vectors derived from the genomes of metapneumovirus, including both mammalian and avian variants, and may or may not, include nucleic acids that are non-native to the viral genome. In accordance with the present invention, a viral vector which is derived from the genome of a metapneumovirus is one that contains a nucleic acid sequence that encodes at least a part of one ORF of a mammalian metapneumovirus, wherein the polypeptides encoded by the ORF have amino acid sequence identity as set forth in Section 5.1. supra, and Table 1. In accordance with the present invention, the recombinant viruses of the invention encompass those viruses encoded by viral vectors derived from the genome of a mammalian metapneumovirus (MPV), in particular a human metapneumovirus. In particular embodiments of the invention, the viral vector is derived from the genome of a metapneumovirus A1, A2, B1 or B2 variant. In accordance with the present invention, these viral vectors may or may not include nucleic acids that are non-native to the viral genome In accordance with the present invention, the recombinant viruses of the invention encompass those viruses encoded by viral vectors derived from the genome of an avian pneumovirus (APV), also known as turkey rhinotracheitis virus (TRTV). In particular embodiments of the invention, the viral vector is derived from the genome of an APV subgroup A, B, C or D. In a preferred embodiment, a viral vector derived from the genome of an APV subgroup C. In accordance with the present invention these viral vectors may or may not include nucleic acids that are non-native to the viral genome. In another preferred embodiment of the invention, the recombinant viruses of the invention encompass those viruses encoded by a viral vector derived from the genome of an APV that contains a nucleic acid sequence that encodes a F-ORF of APV subgroup C. In certain embodiments, a viral vector derived from the genome of an APV is one that contains a nucleic acid sequence that encodes at least a N-ORF, a P-ORF, a M-ORF, a F-ORF, a M2-1-ORF, a M2-2-ORF or a L-ORF of APV. In accordance with the invention, a chimeric virus is a recombinant MPV or APV which further comprises a heterologous nucleotide sequence. In accordance with the invention, a chimeric virus may be encoded by a nucleotide sequence in which heterologous nucleotide sequences have been added to the genome or in which endogenous or native nucleotide sequences have been replaced with heterologous nucleotide sequences. In accordance with the invention, the chimeric viruses are encoded by the viral vectors of the invention which further comprise a heterologous nucleotide sequence. In accordance with the present invention a chimeric virus is encoded by a viral vector that may or may not include nucleic acids that are non-native to the viral genome. In accordance with the invention a chimeric virus is encoded by a viral vector to which heterologous nucleotide sequences have been added, inserted or substituted for native or non-native sequences. In accordance with the present invention, the chimeric virus may be encoded by nucleotide sequences derived from different strains of mammalian MPV. In particular, the chimeric virus is encoded by nucleotide sequences that encode antigenic polypeptides derived from different strains of MPV. In accordance with the present invention, the chimeric virus may be encoded by a viral vector derived from the genome of an APV, in particular subgroup C, that additionally encodes a heterologous sequence that encodes antigenic polypeptides derived from one or more strains of MPV. A chimeric virus may be of particular use for the generation of recombinant vaccines protecting against two or more viruses (Tao et al., J. Virol. 72, 2955-2961; Durbin et al., 2000, J.Virol. 74, 6821-6831; Skiadopoulos et al., 1998, J. Virol. 72, 1762-1768; Teng et al., 2000, J.Virol. 74, 9317-9321). For example, it can be envisaged that a MPV or APV virus vector expressing one or more proteins of another negative strand RNA virus, e.g., RSV or a RSV vector expressing one or more proteins of MPV will protect individuals vaccinated with such vector against both virus infections. A similar approach can be envisaged for PIV or other paramyxoviruses. Attenuated and replication-defective viruses may be of use for vaccination purposes with live vaccines as has been suggested for other viruses. (See, PCT WO 02/057302, at pp. 6 and 23, incorporated by reference herein). In accordance with the present invention the heterologous sequence to be incorporated into the viral vectors encoding the recombinant or chimeric viruses of the invention include sequences obtained or derived from different strains of metapneumovirus, strains of avian pneumovirus, and other negative strand RNA viruses, including, but not limited to, RSV, PIV and influenza virus, and other viruses, including morbillivirus. In certain embodiments of the invention, the chimeric or recombinant viruses of the invention are encoded by viral vectors derived from viral genomes wherein one or more sequences, intergenic regions, termini sequences, or portions or entire ORF have been substituted with a heterologous or non-native sequence. In certain embodiments of the invention, the chimeric viruses of the invention are encoded by viral vectors derived from viral genomes wherein one or more heterologous sequences have been added to the vector. In certain embodiments, the virus of the invention contains heterologous nucleic acids. In a preferred embodiment, the heterologous nucleotide sequence is inserted or added at Position 1 of the viral genome. In another preferred embodiment, the heterologous nucleotide sequence is inserted or added at Position 2 of the viral genome. In even another preferred embodiment, the heterologous nucleotide sequence is inserted or added at Position 3 of the viral genome. Insertion or addition of nucleic acid sequences at the lower-numbered positions of the viral genome results in stronger or higher levels of expression of the heterologous nucleotide sequence compared to insertion at higher-numbered positions due to a transcriptional gradient across the genome of the virus. Thus, inserting or adding heterologous nucleotide sequences at lower-numbered positions is the preferred embodiment of the invention if high levels of expression of the heterologous nucleotide sequence is desired. Without being bound by theory, the position of insertion or addition of the heterologous sequence affects the replication rate of the recombinant or chimeric virus. The higher rates of replication can be achieved if the heterologous sequence is inserted or added at Position 2 or Position 1 of the viral genome. The rate of replication is reduced if the heterologous sequence is inserted or added at Position 3, Position 4, Position 5, or Position 6. Without being bound by theory, the size of the intergenic region between the viral gene and the heterologous sequence further determines rate of replication of the virus and expression levels of the heterologous sequence. In certain embodiments, the viral vector of the invention contains two or more different heterologous nucleotide sequences. In a preferred embodiment, one heterologous nucleotide sequence is at Position 1 and a second heterologous nucleotide sequence is at Position 2 of the viral genome. In another preferred embodiment, one heterologous nucleotide sequence is at Position 1 and a second heterologous nucleotide sequence is at Position 3 of the viral genome. In even another preferred embodiment, one heterologous nucleotide sequence is at Position 2 and a second heterologous nucleotide sequence is at Position 3 of the viral genome. In certain other embodiments, a heterologous nucleotide sequence is inserted at other, higher-numbered positions of the viral genome. In accordance with the present invention, the position of the heterologous sequence refers to the order in which the sequences are transcribed from the viral genome, e.g., a heterologous sequence at Position 1 is the first gene sequence to be transcribed from the genome. The selection of the viral vector may depend on the species of the subject that is to be treated or protected from a viral infection. If the subject is human, then an attenuated mammalian metapneumovirus or an avian pneumovirus can be used to provide the antigenic sequences. In accordance with the present invention, the viral vectors can be engineered to provide antigenic sequences which confer protection against infection by a metapneumovirus, including sequences derived from mammalian metapneumovirus, human metapneumovirus, MPV variants A1, A2, B1 or B2, sequences derived from avian pneumovirus, including APV subgroups A, B, C or D, although C is preferred. The viral vectors can be engineered to provide antigenic sequences which confer protection against infection or disease by another virus, including negative strand RNA virus, including influenza, RSV or PIV, including PIV3. The viral vectors may be engineered to provide one, two, three or more antigenic sequences. In accordance with the present invention the antigenic sequences may be derived from the same virus, from different strains or variants of the same type of virus, or from different viruses, including morbillivirus. In certain embodiments of the invention, the heterologous nucleotide sequence to be inserted into the genome of the virus of the invention is derived from a metapneumovirus. In certain specific embodiments of the invention, the heterologous nucleotide sequence is derived from a human metapneumovirus. In another specific embodiment, the heterologous nucleotide sequence is derived from an avian pneumovirus. More specifically, the heterologous nucleotide sequence of the invention encodes a F gene of a human metapneumovirus. More specifically, the heterologous nucleotide sequence of the invention encodes an G gene of a human metapneumovirus. More specifically, the heterologous nucleotide sequence of the invention encodes a F gene of an avian pneumovirus. More specifically, the heterologous nucleotide sequence of the invention encodes a G gene of an avian pneumovirus. In specific embodiments, a heterologous nucleotide sequences can be any one of SEQ ID NO:1 through SEQ ID NO:5, SEQ ID NO:14, and SEQ ID NO:15. In certain specific embodiments, the nucleotide sequence encodes a protein of any one of SEQ ID NO:6 through SEQ ID NO:13, SEQ ID NO:16, and SEQ ID NO:17. In a specific embodiment of the invention, the heterologous nucleotide sequence encodes a chimeric F protein. In an illustrative embodiment, the ectodomain of the chimeric F-protein is the ectodomain of a human MPV and the transmembrane domain and the luminal domain are derived from the F-protein of an avian metapneumovirus. Without being bound by theory, a chimeric human MPV that encodes the chimeric F-protein consisting of the human ectodomain and the avian luminol/transmembrane domain is attenuated because of the avian part of the F-protein, yet highly immunogenic against hMPV because of the human ectodomain. In certain embodiments, two different heterologous nucleotide sequences are inserted or added to the viral vectors of the invention, derived from metapneumoviral genomes, including mammalian and avian. For example, the heterologous nucleotide sequence is derived from a human metapneumovirus, an avian pneumovirus, RSV, PIV, or influenza. In a preferred embodiment, the heterologous sequence encodes the F-protein of human metapneumovirus, avian pneumovirus, RSV or PIV respectively. In another embodiment, the heterologous sequence encodes the HA protein of influenza. In certain embodiments, the viral vector of the invention contains two different heterologous nucleotide sequences wherein a first heterologous nucleotide sequence is derived from a metapneumovirus, such as a human metapneumovirus or an avian pneumovirus, and a second nucleotide sequence is derived from a respiratory syncytial virus (see Table 2). In specific embodiments, the heterologous nucleotide sequence derived from respiratory syncytial virus is a F gene of a respiratory syncytial virus. In other specific embodiments, the heterologous nucleotide sequence derived from respiratory syncytial virus is a G gene of a respiratory syncytial virus. In a specific embodiment, the heterologous nucleotide sequence derived from a metapneumovirus is inserted at a lower-numbered position than the heterologous nucleotide sequence derived from a respiratory syncytial virus. In another specific embodiment, the heterologous nucleotide sequence derived from a metapneumovirus is inserted at a higher-numbered position than the heterologous nucleotide sequence derived from a respiratory syncytial virus. In certain embodiments, the virus of the invention contains two different heterologous nucleotide sequences wherein a first heterologous nucleotide sequence is derived from a metapneumovirus, such as a human metapneumovirus or an avian pneumovirus, and a second nucleotide sequence is derived from a parainfluenza virus, such as, but not limited to PIV3 (see Table 2). In specific embodiments, the heterologous nucleotide sequence derived from PIV is a F gene of PIV. In other specific embodiments, the heterologous nucleotide sequence derived from PIV is a G gene of a PIV. In a specific embodiment, the heterologous nucleotide sequence derived from a metapneumovirus is inserted at a lower-numbered position than the heterologous nucleotide sequence derived from a PIV. In another specific embodiment, the heterologous nucleotide sequence derived from a metapneumovirus is inserted at a higher-numbered position than the heterologous nucleotide sequence derived from a PIV. The expression products and/or recombinant or chimeric virions obtained in accordance with the invention may advantageously be utilized in vaccine formulations. The expression products and chimeric virions of the present invention may be engineered to create vaccines against a broad range of pathogens, including viral and bacterial antigens, tumor antigens, allergen antigens, and auto antigens involved in autoimmune disorders. In particular, the chimeric virions of the present invention may be engineered to create vaccines for the protection of a subject from infections with PIV, RSV, and/or metapneumovirus. In another embodiment, the chimeric virions of the present invention may be engineered to create anti-HIV vaccines, wherein an immunogenic polypeptide from gp 160, and/or from internal proteins of HIV is engineered into the glycoprotein HN protein to construct a vaccine that is able to elicit both vertebrate humoral and cell-mediated immune responses. In yet another embodiment, the invention relates to recombinant metapneumoviral vectors and viruses which are engineered to encode mutant antigens. A mutant antigen has at least one amino acid substitution, deletion or addition relative to the wild-type viral protein from which it is derived. In certain embodiments, the invention relates to trivalent vaccines comprising a recombinant or chimeric virus of the invention. In specific embodiments, the virus used as backbone for a trivalent vaccine is a chimeric avian-human metapneumovirus or a chimeric human-avian metapneumovirus containing a first heterologous nucleotide sequence derived from a RSV and a second heterologous nucleotide sequence derived from PIV. In an exemplary embodiment, such a trivalent vaccine will be specific to (a) the gene products of the F gene and/or the G gene of the human metapneumovirus or avian pneumovirus, respectively, dependent on whether chimeric avian-human or chimeric human-avian metapneumovirus is used; (b) the protein encoded by the heterologous nucleotide sequence derived from a RSV; and (c) the protein encoded by the heterologous nucleotide sequence derived from PIV. In a specific embodiment, the first heterologous nucleotide sequence is the F gene of the respiratory syncytial virus and is inserted in Position 1, and the second heterologous nucleotide sequence is the F gene of the PIV and is inserted in Position 3. Many more combinations are encompassed by the present invention and some are shown by way of example in Table 2. Further, nucleotide sequences encoding chimeric F proteins could be used (see supra). In some less preferred embodiments, the heterologous nucleotide sequence can be inserted at higher-numbered positions of the viral genome. TABLE 2 Exemplary arrangements of heterologous nucleotide sequences in the viruses used for trivalent vaccines. Combination Position 1 Position 2 Position 3 1 F-gene of PIV F-gene of RSV — 2 F-gene of RSV F-gene of PIV — 3 — F-gene of PIV F-gene of RSV 4 — F-gene of RSV F-gene of PIV 5 F-gene of PIV — F-gene of RSV 6 F-gene of RSV — F-gene of PIV 7 HN-gene of PIV G-gene of RSV — 8 G-gene of RSV HN-gene of PIV — 9 — HN-gene of PIV G-gene of RSV 10 — G-gene of RSV HN-gene of PIV 11 HN-gene of PIV — G-gene of RSV 12 G-gene of RSV — HN-gene of PIV 13 F-gene of PIV G-gene of RSV — 14 G-gene of RSV F-gene of PIV — 15 — F-gene of PIV G-gene of RSV 16 — G-gene of RSV F-gene of PIV 17 F-gene of PIV — G-gene of RSV 18 G-gene of RSV — F-gene of PIV 19 HN-gene of PIV F-gene of RSV — 20 F-gene of RSV HN-gene of PIV — 21 — HN-gene of PIV F-gene of RSV 22 — F-gene of RSV HN-gene of PIV 23 HN-gene of PIV — F-gene of RSV 24 F-gene of RSV — HN-gene of PIV In certain embodiments, the expression products and recombinant or chimeric virions of the present invention may be engineered to create vaccines against a broad range of pathogens, including viral antigens, tumor antigens and auto antigens involved in autoimmune disorders. One way to achieve this goal involves modifying existing metapneumoviral genes to contain foreign sequences in their respective external domains. Where the heterologous sequences are epitopes or antigens of pathogens, these chimeric viruses may be used to induce a protective immune response against the disease agent from which these determinants are derived. Thus, the present invention relates to the use of viral vectors and recombinant or chimeric viruses to formulate vaccines against a broad range of viruses and/or antigens. The viral vectors and chimeric viruses of the present invention may be used to modulate a subject's immune system by stimulating a humoral immune response, a cellular immune response or by stimulating tolerance to an antigen. As used herein, a subject means: humans, primates, horses, cows, sheep, pigs, goats, dogs, cats, avian species and rodents. The invention may be divided into the following stages solely for the purpose of description and not by way of limitation: (a) construction of recombinant cDNA and RNA templates; (b) expression of heterologous gene products using recombinant cDNA and RNA templates; (c) rescue of the heterologous gene in recombinant virus particles; and (d) generation and use of vaccines comprising the recombinant virus particles of the invention. 5.4 Construction of the Recombinant cDNA and RNA In certain embodiments, the viral vectors are derived from the genomes of human or mammalian metapneumovirus of the invention. In other embodiments, the viral vectors are derived from the genome of avian pneumovirus. In certain embodiments, viral vectors contain sequences derived from mammalian MPV and APV, such that a chimeric human MPV/APV virus is encoded by the viral vector. In an exemplary embodiment, the F-gene and/or the G-gene of human metapneumovirus have been replaced with the F-gene and/or the G-gene of avian pneumovirus to construct chimeric hMPV/APV virus. In other embodiments, viral vectors contain sequences derived from APV and mammalian MPV, such that a chimeric APV/hMPV virus is encoded by the viral vector. In more exemplary embodiments, the F-gene and/or the G-gene of avian pneumovirus have been replaced with the F-gene and/or the G-gene of human metapneumovirus to construct the chimeric APV/hMPV virus. The present invention also encompasses recombinant viruses comprising a viral vector derived from a mammalian MPV or APV genome containing sequences endogenous or native to the viral genome, and may or may not contain sequences non-native to the viral genome. Non-native sequences include those that are different from native or endogenous sequences which may or may not result in a phenotypic change. The recombinant viruses of the invention may contain sequences which result in a virus having a phenotype more suitable for use in vaccine formulations, e.g., attenuated phenotype or enhanced antigenicity. The mutations and modifications can be in coding regions, in intergenic regions and in the leader and trailer sequences of the virus. In certain embodiments the viral vectors of the invention comprise nucleotide sequences derived from hMPV, APV, hMPV/APV or APV/hMPV, in which native nucleotide sequences have been substituted with heterologous sequences or in which heterologous sequences have been added to the native metapneumoviral sequences. In a more specific embodiment, a chimeric virus comprises a viral vector derived from MPV, APV, APV/hMPV, or hMPV/APV in which heterologous sequences derived from PIV have been added. In a more specific embodiment, a recombinant virus comprises a viral vector derived from MPV, APV, APV/hMPV, or hMPV/APV in which sequences have been replaced by heterologous sequences derived from PIV. In other specific embodiments, a chimeric virus comprises a viral vector derived from MPV, APV, APV/hMPV, or hMPV/APV in which heterologous sequences derived from RSV have been added. In a more specific embodiment, a chimeric virus comprises a viral vector derived from MPV, APV, APV/hMPV, or hMPV/APV in which sequences have been replaced by heterologous sequences derived from RSV. Heterologous gene coding sequences flanked by the complement of the viral polymerase binding site/promoter, e.g., the complement of 3′-hMPV virus terminus of the present invention, or the complements of both the 3′- and 5′-hMPV virus termini may be constructed using techniques known in the art. In more specific embodiments, a recombinant virus of the invention contains the leader and trailer sequence of hMPV or APV. In certain embodiments, the intergenic regions are obtained from hMPV or APV. The resulting RNA templates may be of the negative-polarity and contain appropriate terminal sequences which enable the viral RNA-synthesizing apparatus to recognize the template. Alternatively, positive-polarity RNA templates which contain appropriate terminal sequences which enable the viral RNA-synthesizing apparatus to recognize the template, may also be used. Recombinant DNA molecules containing these hybrid sequences can be cloned and transcribed by a DNA-directed RNA polymerase, such as bacteriophage T7, T3, the SP6 polymerase or eukaryotic polymerase such as polymerase I and the like, to produce in vitro or in vivo the recombinant RNA templates which possess the appropriate viral sequences that allow for viral polymerase recognition and activity. In a more specific embodiment, the RNA polymerase is fowlpox virus T7 RNA polymerase or a MVA T7 RNA polymerase. An illustrative approach for constructing these hybrid molecules is to insert the heterologous nucleotide sequence into a DNA complement of a hMPV, APV, APV/hMPV or hMPV/APV genome, so that the heterologous sequence is flanked by the viral sequences required for viral polymerase activity; i.e., the viral polymerase binding site/promoter, hereinafter referred to as the viral polymerase binding site, and a polyadenylation site. In a preferred embodiment, the heterologous coding sequence is flanked by the viral sequences that comprise the replication promoters of the 5′ and 3′ termini, the gene start and gene end sequences, and the packaging signals that are found in the 5′ and/or the 3′ termini. In an alternative approach, oligonucleotides encoding the viral polymerase binding site, e.g., the complement of the 3′-terminus or both termini of the virus genomic segment can be ligated to the heterologous coding sequence to construct the hybrid molecule. The placement of a foreign gene or segment of a foreign gene within a target sequence was formerly dictated by the presence of appropriate restriction enzyme sites within the target sequence. However, recent advances in molecular biology have lessened this problem greatly. Restriction enzyme sites can readily be placed anywhere within a target sequence through the use of site-directed mutagenesis (e.g., see, for example, the techniques described by Kunkel, 1985, Proc. Natl. Acad. Sci. U.S.A. 82;488). Variations in polymerase chain reaction (PCR) technology, described infra, also allow for the specific insertion of sequences (i.e., restriction enzyme sites) and allow for the facile construction of hybrid molecules. Alternatively, PCR reactions could be used to prepare recombinant templates without the need of cloning. For example, PCR reactions could be used to prepare double-stranded DNA molecules containing a DNA-directed RNA polymerase promoter (e.g., bacteriophage T3, T7 or SP6) and the hybrid sequence containing the heterologous gene and the PIV polymerase binding site. RNA templates could then be transcribed directly from this recombinant DNA. In yet another embodiment, the recombinant RNA templates may be prepared by ligating RNAs specifying the negative polarity of the heterologous gene and the viral polymerase binding site using an RNA ligase. In addition, one or more nucleotides can be added in the untranslated region to adhere to the “Rule of Six” which may be important in obtaining virus rescue. The “Rule of Six” applies to many paramyxoviruses and states that the RNA nucleotide genome must be divisible by six to be functional. The addition of nucleotides can be accomplished by techniques known in the art such as using a commercial mutagenesis kits such as the QuikChange mutagenesis kit (Stratagene). After addition of the appropriate number of nucleotides, the correct DNA fragment can then be isolated by digestion with appropriate restriction enzyme and gel purification. Sequence requirements for viral polymerase activity and constructs which may be used in accordance with the invention are described in the subsections below. Without being bound by theory, several parameters affect the rate of replication of the recombinant virus and the level of expression of the heterologous sequence. In particular, the position of the heterologous sequence in hMPV, APV, hMPV/APV or APV/hMPV and the length of the intergenic region that flanks the heterologous sequence determine rate of replication and expression level of the heterologous sequence. In certain embodiments, the leader and or trailer sequence of the virus are modified relative to the wild type virus. In certain more specific embodiments, the lengths of the leader and/or trailer are altered. In other embodiments, the sequence(s) of the leader and/or trailer are mutated relative to the wild type virus. For more detail, see section 5.7. The production of a recombinant virus of the invention relies on the replication of a partial or full-length copy of the negative sense viral RNA (vRNA) genome or a complementary copy thereof (cRNA). This vRNA or cRNA can be isolated from infectious virus, produced upon in-vitro transcription, or produced in cells upon transfection of nucleic acids. Second, the production of recombinant negative strand virus relies on a functional polymerase complex. Typically, the polymerase complex of pneumoviruses consists of N, P, L and possibly M2 proteins, but is not necessarily limited thereto. Polymerase complexes or components thereof can be isolated from virus particles, isolated from cells expressing one or more of the components, or produced upon transfection of specific expression vectors. Infectious copies of MPV can be obtained when the above mentioned vRNA, cRNA, or vectors expressing these RNAs are replicated by the above mentioned polymerase complex 16 (Schnell et al., 1994, EMBO J 13: 4195-4203; Collins, et al., 1995, PNAS 92: 11563-11567; Hoffmann, et al., 2000, PNAS 97: 6108-6113; Bridgen, et al., 1996, PNAS 93: 15400-15404; Palese, et al., 1996, PNAS 93: 11354-11358; Peeters, et al., 1999, J. Virol. 73: 5001-5009; Durbin, et al., 1997, Virology 235: 323-332). The invention provides a host cell comprising a nucleic acid or a vector according to the invention. Plasmid or viral vectors containing the polymerase components of MPV (presumably N, P, L and M2, but not necessarily limited thereto) are generated in prokaryotic cells for the expression of the components in relevant cell types (bacteria, insect cells, eukaryotic cells). Plasmid or viral vectors containing full-length or partial copies of the MPV genome will be generated in prokaryotic cells for the expression of viral nucleic acids in-vitro or in-vivo. The latter vectors may contain other viral sequences for the generation of chimeric viruses or chimeric virus proteins, may lack parts of the viral genome for the generation of replication defective virus, and may contain mutations, deletions or insertions for the generation of attenuated viruses. Infectious copies of MPV (being wild type, attenuated, replication-defective or chimeric) can be produced upon co-expression of the polymerase components according to the state-of-the-art technologies described above. In addition, eukaryotic cells, transiently or stably expressing one or more full-length or partial MPV proteins can be used. Such cells can be made by transfection (proteins or nucleic acid vectors), infection (viral vectors) or transduction (viral vectors) and may be useful for complementation of mentioned wild type, attenuated, replication-defective or chimeric viruses. 5.4.1 Heterologous Gene Sequences to be Inserted In accordance with the present invention the viral vectors of the invention may be further engineered to express a heterologous sequence. In an embodiment of the invention, the heterologous sequence is derived from a source other than the viral vector. By way of example, and not by limitation, the heterologous sequence encodes an antigenic protein, polypeptide or peptide of a virus belonging to a different species, subgroup or variant of metapneumovirus than the species, subgroup or variant from which the viral vector is derived. By way of example, and not by limitation, the heterologous sequence encodes an antigenic protein, polypeptide or peptide of a virus other than a metapneumovirus. By way of example, and not by limitation, the heterologous sequence is not viral in origin. In accordance with this embodiment, the heterologous sequence may encode a moiety, peptide, polypeptide or protein possessing a desired biological property or activity. Such a heterologous sequence may encode a tag or marker. Such a heterologous sequence may encode a biological response modifier, examples of which include, lymphokines, interleukines, granulocyte macrophage colony stimulating factor and granulocyte colony stimulating factor. In certain embodiments, the heterologous nucleotide sequence to be inserted is derived from a metapneumovirus. More specifically, the heterologous nucleotide sequence to be inserted is derived from a human metapneumovirus and/or an avian pneumovirus. In certain embodiments, the heterologous sequence encodes PIV nucleocapsid phosphoprotein, PIV L protein, PIV matrix protein, PIV HN glycoprotein, PIV RNA-dependent RNA polymerase, PIV Y1 protein, PIV D protein, PIV C protein, PIV F protein or PIV P protein. In certain embodiments, the heterologous nucleotide sequence encodes a protein that is at least 90%, at least 95%, at least 98%, or at least 99% homologous to PIV nucleocapsid phosphoprotein, PIV L protein, PIV matrix protein, PIV HN glycoprotein, PIV RNA-dependent RNA polymerase, PIV Y1 protein, PIV D protein, PIV C protein, PIV F protein or PIV P protein. The heterologous sequence can be obtained from PIV type 1, PIV type 2, or PIV type 3. In more specific embodiments, the heterologouse sequence is obtained from human PIV type 1, PIV type 2, or PIV type 3. In other embodiments, the heterologous sequence encodes RSV nucleoprotein, RSV phosphoprotein, RSV matrix protein, RSV small hydrophobic protein, RSV RNA-dependent RNA polymerase, RSV F protein, RSV G protein, or RSV M2-1 or M2-2 protein. In certain embodiments, the heterologous sequence encodes a protein that is at least 90%, at least 95%, at least 98%, or at least 99% homologous to RSV nucleoprotein, RSV phosphoprotein, RSV matrix protein, RSV small hydrophobic protein, RSV RNA-dependent RNA polymerase, RSV F protein, or RSV G protein. The heterologous sequence can be obtained from RSV subtype A and RSV subtype B. In more specific embodiments, the heterologouse sequence is obtained from human RSV subtype A and RSV subtype B. In other embodiments, the heterologous sequence encodes APV nucleoprotein, APV phosphoprotein, APV matrix protein, APV small hydrophobic protein, APV RNA-dependent RNA polymerase, APV F protein, APV G protein or APV M2-1 or M2-2 protein. In certain embodiments, the heterologous sequence encodes a protein that is at least 90%, at least 95%, at least 98%, or at least 99% homologous to APV nucleoprotein, APV phosphoprotein, APV matrix protein, APV small hydrophobic protein, APV RNA-dependent RNA polymerase, APV F protein, or APV G protein. The avian pneumovirus can be APV subgroup A, APV subgroup B, or APV subgroup C. In other embodiments, the heterologous sequence encodes hMPV nucleoprotein, hMPV phosphoprotein, hMPV matrix protein, hMPV small hydrophobic protein, hMPV RNA-dependent RNA polymerase, hMPV F protein, hMPV G protein or hMPV M2-1 or M2-2. In certain embodiments, the heterologous sequence encodes a protein that is at least 90%, at least 95%, at least 98%, or at least 99% homologous to hMPV nucleoprotein, hMPV phosphoprotein, hMPV matrix protein, hMPV small hydrophobic protein, hMPV RNA-dependent RNA polymerase, hMPV F protein, or hMPV G protein. The human metapneumovirus can be hMPV variant A1, hMPV variant A2, hMPV variant B1, or hMPV variant B2. In certain embodiments, any combination of different heterologous sequence from PIV, RSV, human metapneumovirus, or avian pneumovirus can be inserted into the virus of the invention. In certain preferred embodiments of the invention, the heterologous nucleotide sequence to be inserted is derived from a F gene from RSV, PIV, APV or hMPV. In certain embodiments, the heterologous nucleotide sequence encodes a chimeric protein. In more specific embodiments, the heterologous nucleotide sequence encodes a chimeric F protein of RSV, PIV, APV or hMPV. A chimeric F protein can comprise parts of F proteins from different viruses, such as a human metapneumovirus, avian pneumovirus, respiratory syncytial virus, and parainfluenza virus. In certain other embodiments, the heterologous sequence encodes a chimeric G protein. A chimeric G protein comprises parts of G proteins from different viruses, such as a human metapneumovirus, avian pneumovirus, respiratory syncytial virus, and parainfluenza virus. In a specific embodiment, the F protein comprises an ectodomain of a F protein of a metapneumovirus, a transmembrane domain of a F protein of a parainfluenza virus, and luminal domain of a F protein of a parainfluenza virus. In certain specific embodiments, the heterologous nucleotide sequence of the invention is any one of SEQ ID NO:1 through SEQ ID NO:5, SEQ ID NO:14, and SEQ ID NO:15. In certain specific embodiments, the nucleotide sequence encodes a protein of any one of SEQ ID NO:6 through SEQ ID NO:13, SEQ ID NO:16, and SEQ ID NO:17. For heterologous nucleotide sequences derived from respiratory syncytial virus see, e.g., PCT/US98/20230, which is hereby incorporated by reference in its entirety. In a preferred embodiment, heterologous gene sequences that can be expressed into the recombinant viruses of the invention include but are not limited to antigenic epitopes and glycoproteins of viruses which result in respiratory disease, such as influenza glycoproteins, in particular hemagglutinin H5, H7, respiratory syncytial virus epitopes, New Castle Disease virus epitopes, Sendai virus and infectious Laryngotracheitis virus (ILV). In a preferred embodiment, the heterologous nucleotide sequences are derived from a RSV or PIV. In yet another embodiment of the invention, heterologous gene sequences that can be engineered into the chimeric viruses of the invention include, but are not limited to, viral epitopes and glycoproteins of viruses, such as hepatitis B virus surface antigen, hepatitis A or C virus surface glycoproteins of Epstein Barr virus, glycoproteins of human papilloma virus, simian virus 5 or mumps virus, West Nile virus, Dengue virus, glycoproteins of herpes viruses, VPI of poliovirus, and sequences derived from a lentivirus, preferably, but not limited to human immunodeficiency virus (HIV) type 1 or type 2. In yet another embodiment, heterologous gene sequences that can be engineered into chimeric viruses of the invention include, but are not limited to, Marek's Disease virus (MDV) epitopes, epitopes of infectious Bursal Disease virus (IBDV), epitopes of Chicken Anemia virus, infectious laryngotracheitis virus (ILV), Avian Influenza virus (AIV), rabies, feline leukemia virus, canine distemper virus, vesicular stomatitis virus, and swinepox virus (see Fields et al., (ed.), 1991, Fundamental Virology, Second Edition, Raven Press, New York, incorporated by reference herein in its entirety). Other heterologous sequences of the present invention include antigens that are characteristic of autoimmune disease. These antigens will typically be derived from the cell surface, cytoplasm, nucleus, mitochondria and the like of mammalian tissues, including antigens characteristic of diabetes mellitus, multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, pernicious anemia, Addison's disease, scleroderma, autoimmune atrophic gastritis, juvenile diabetes, and discold lupus erythromatosus. Antigens that are allergens generally include proteins or glycoproteins, including antigens derived from pollens, dust, molds, spores, dander, insects and foods. In addition, antigens that are characteristic of tumor antigens typically will be derived from the cell surface, cytoplasm, nucleus, organelles and the like of cells of tumor tissue. Examples include antigens characteristic of tumor proteins, including proteins encoded by mutated oncogenes; viral proteins associated with tumors; and glycoproteins. Tumors include, but are not limited to, those derived from the types of cancer: lip, nasopharynx, pharynx and oral cavity, esophagus, stomach, colon, rectum, liver, gall bladder, pancreas, larynx, lung and bronchus, melanoma of skin, breast, cervix, uterine, ovary, bladder, kidney, uterus, brain and other parts of the nervous system, thyroid, prostate, testes, Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma and leukemia. In one specific embodiment of the invention, the heterologous sequences are derived from the genome of human immunodeficiency virus (HIV), preferably human immunodeficiency virus-1 or human immunodeficiency virus-2. In another embodiment of the invention, the heterologous coding sequences may be inserted within a gene coding sequence of the viral backbone such that a chimeric gene product is expressed which contains the heterologous peptide sequence within the metapneumoviral protein. In such an embodiment of the invention, the heterologous sequences may also be derived from the genome of a human immunodeficiency virus, preferably of human immunodeficiency virus-1 or human immunodeficiency virus-2. In instances whereby the heterologous sequences are HIV-derived, such sequences may include, but are not limited to sequences derived from the env gene (i.e., sequences encoding all or part of gp160, gp120, and/or gp41), the pol gene (i.e., sequences encoding all or part of reverse transcriptase, endonuclease, protease, and/or integrase), the gag gene (i.e., sequences encoding all or part of p7, p6, p55, p17/18, p24/25) tat, rev, nef, vif, vpu, vpr, and/or vpx. In yet another embodiment, heterologous gene sequences that can be engineered into the chimeric viruses include those that encode proteins with immunopotentiating activities. Examples of immunopotentiating proteins include, but are not limited to, cytokines, interferon type 1, gamma interferon, colony stimulating factors, and interleukin-1, -2, -4, -5, -6, -12. In addition, other heterologous gene sequences that may be engineered into the chimeric viruses include antigens derived from bacteria such as bacterial surface glycoproteins, antigens derived from fungi, and antigens derived from a variety of other pathogens and parasites. Examples of heterologous gene sequences derived from bacterial pathogens include, but are not limited to, antigens derived from species of the following genera: Salmonella, Shigella, Chlamydia, Helicobacter, Yersinia, Bordatella, Pseudomonas, Neisseria, Vibrio, Haemophilus, Mycoplasma, Streptomyces, Treponema, Coxiella, Ehrlichia, Brucella, Streptobacillus, Fusospirocheta, Spirillum, Ureaplasma, Spirochaeta, Mycoplasma, Actinomycetes, Borrelia, Bacteroides, Trichomoras, Branhamella, Pasteurella, Clostridium, Corynebacterium, Listeria, Bacillus, Erysipelothrix, Rhodococcus, Escherichia, Klebsiella, Pseudomanas, Enterobacter, Serratia, Staphylococcus, Streptococcus, Legionella, Mycobacterium, Proteus, Campylobacter, Enterococcus, Acinetobacter, Morganella, Moraxella, Citrobacter, Rickettsia, Rochlimeae, as well as bacterial species such as: P. aeruginosa; E. coli, P. cepacia, S. epidermis, E. faecalis, S. pneumonias, S. aureus, N. meningitidis, S. pyogenes, Pasteurella multocida, Treponema pallidum, and P. mirabilis. Examples of heterologous gene sequences derived from pathogenic fungi, include, but are not limited to, antigens derived from fungi such as Cryptococcus neoformans; Blastomyces dermatitidis; Aiellomyces dermatitidis; Histoplasma capsulatum; Coccidioides immitis; Candida species, including C. albicans, C. tropicalis, C. parapsilosis, C. guilliermondii and C. krusei, Aspergillus species, including A. fumigatus, A. flavus and A. niger, Rhizopus species; Rhizomucor species; Cunninghammella species; Apophysomyces species, including A. saksenaea, A. mucor and A. absidia; Sporothrix schenckii, Paracoccidioides brasiliensis; Pseudallescheria boydii, Torulopsis glabrata; Trichophyton species, Microsporum species and Dermatophyres species, as well as any other yeast or fungus now known or later identified to be pathogenic. Finally, examples of heterologous gene sequences derived from parasites include, but are not limited to, antigens derived from members of the Apicomplexa phylum such as, for example, Babesia, Toxoplasma, Plasmodium, Eimeria, Isospora, Atoxoplasma, Cystoisospora, Hammondia, Besniotia, Sarcocystis, Frenkelia, Haemoproteus, Leucocytozoon, Theileria, Perkinsus and Gregarina spp.; Pneumocystis carinii; members of the Microspora phylum such as, for example, Nosema, Enterocytozoon, Encephalitozoon, Septata, Mrazekia, Amblyospora, Ameson, Glugea, Pleistophora and Microsporidium spp.; and members of the Ascetospora phylum such as, for example, Haplosporidium spp., as well as species including Plasmodium falciparum, P. vivax, P. ovale, P. malaria; Toxoplasma gondii; Leishmania mexicana, L. tropica, L. major, L. aethiopica, L. donovani, Trypanosoma cruzi, T brucei, Schistosoma mansoni, S. haematobium, S. japonium; Trichinella spiralis; Wuchereria bancrofti; Brugia malayli; Entamoeba histolytica; Enterobius vermiculoarus; Taenia solium, T. saginata, Trichomonas vaginatis, T. hominis, T. tenax; Giardia lamblia; Cryptosporidium parvum; Pneumocytis carinii, Babesia bovis, B. divergens, B. microti, Isospora belli, L hominis; Dientamoeba fragilis; Onchocerca volvulus; Ascaris lumbricoides; Necator americanis; Ancylostoma duodenale; Strongyloides stercoralis; Capillaria philippinensis; Angiostrongylus cantonensis; Hymenolepis nana; Diphyllobothrium latum; Echinococcus granulosus, E. multilocularis; Paragonimus westermani, P. caliensis; Chlonorchis sinensis; Opisthorchis felineas, G. Viverini, Fasciola hepatica, Sarcoptes scabiei, Pediculus humanus; Phthirlus pubis; and Dermatobia hominis, as well as any other parasite now known or later identified to be pathogenic. 5.4.2 Insertion of the Heterologous Gene Sequence Insertion of a foreign gene sequence into a viral vector of the invention can be accomplished by either a complete replacement of a viral coding region with a heterologous sequence or by a partial replacement or by adding the heterologous nucleotide sequence to the viral genome. Complete replacement would probably best be accomplished through the use of PCR-directed mutagenesis. Briefly, PCR-primer A would contain, from the 5′ to 3′ end: a unique restriction enzyme site, such as a class IIS restriction enzyme site (i.e., a “shifter” enzyme; that recognizes a specific sequence but cleaves the DNA either upstream or downstream of that sequence); a stretch of nucleotides complementary to a region of the gene that is to be replaced; and a stretch of nucleotides complementary to the carboxy-terminus coding portion of the heterologous sequence. PCR-primer B would contain from the 5′ to 3′ end: a unique restriction enzyme site; a stretch of nucleotides complementary to the gene that is to be replaced; and a stretch of nucleotides corresponding to the 5′ coding portion of the heterologous or non-native gene. After a PCR reaction using these primers with a cloned copy of the heterologous or non-native gene, the product may be excised and cloned using the unique restriction sites. Digestion with the class IIS enzyme and transcription with the purified phage polymerase would generate a RNA molecule containing the exact untranslated ends of the viral gene that carries now a heterologous or non-native gene insertion. In an alternate embodiment, PCR-primed reactions could be used to prepare double-stranded DNA containing the bacteriophage promoter sequence, and the hybrid gene sequence so that RNA templates can be transcribed directly without cloning. A heterologous nucleotide sequence can be added or inserted at various positions of the virus of the invention. In one embodiment, the heterologous nucleotide sequence is added or inserted at position 1. In another embodiment, the heterologous nucleotide sequence is added or inserted at position 2. In another embodiment, the heterologous nucleotide sequence is added or inserted at position 3. In another embodiment, the heterologous nucleotide sequence is added or inserted at position 4. In another embodiment, the heterologous nucleotide sequence is added or inserted at position 5. In yet another embodiment, the heterologous nucleotide sequence is added or inserted at position 6. As used herein, the term “position” refers to the position of the heterologous nucleotide sequence on the viral genome to be transcribed, e.g., position 1 means that it is the first gene to be transcribed, and position 2 means that it is the second gene to be transcribed. Inserting heterologous nucleotide sequences at the lower-numbered positions of the virus generally results in stronger expression of the heterologous nucleotide sequence compared to insertion at higher-numbered positions due to a transcriptional gradient that occurs across the genome of the virus. However, the transcriptional gradient also yields specific ratios of viral mRNAs. Insertion of foreign genes will perturb these ratios and result in the synthesis of different amounts of viral proteins that may influence virus replication. Thus, both the transcriptional gradient and the replication kinetics must be considered when choosing an insertion site. Inserting heterologous nucleotide sequences at lower-numbered positions is the preferred embodiment of the invention if strong expression of the heterologous nucleotide sequence is desired. In a preferred embodiment, the heterologous sequence is added or inserted at position 1, 2 or 3. When inserting a heterologous nucleotide sequence into the virus of the invention, the intergenic region between the end of the coding sequence of the heterologous gene and the start of the coding sequence of the downstream gene can be altered to achieve a desired effect. As used herein, the term “intergenic region” refers to nucleotide sequence between the stop signal of one gene and the start codon (e.g., AUG) of the coding sequence of the next downstream open reading frame. An intergenic region may comprise a non-coding region of a gene, i.e., between the transcription start site and the start of the coding sequence (AUG) of the gene. This non-coding region occurs naturally in some viral genes. In various embodiments, the intergenic region between the heterologous nucleotide sequence and the downstream gene can be engineered, independently from each other, to be at least 10 nt in length, at least 20 nt in length, at least 30 nt in length, at least 50 nt in length, at least 75 nt in length, at least 100 nt in length, at least 125 nt in length, at least 150 nt in length, at least 175 nt in length or at least 200 nt in length. In certain embodiments, the intergenic region between the heterologous nucleotide sequence and the downstream gene can be engineered, independently from each other, to be at most 10 nt in length, at most 20 nt in length, at most 30 nt in length, at most 50 nt in length, at most 75 nt in length, at most 100 nt in length, at most 125 nt in length, at most 150 nt in length, at most 175 nt in length or at most 200 nt in length. In various embodiments, the non-coding region of a desired gene in a virus genome can also be engineered, independently from each other, to be at least 10 nt in length, at least 20 nt in length, at least 30 nt in length, at least 50 nt in length, at least 75 nt in length, at least 100 nt in length, at least 125 nt in length, at least 150 nt in length, at least 175 nt in length or at least 200 nt in length. In certain embodiments, the non-coding region of a desired gene in a virus genome can also be engineered, independently from each other, to be at most 10 nt in length, at most 20 nt in length, at most 30 nt in length, at most 50 nt in length, at most 75 nt in length, at most 100 nt in length, at most 125 nt in length, at most 150 nt in length, at most 175 nt in length or at most 200 nt in length. When inserting a heterologous nucleotide sequence, the positional effect and the intergenic region manipulation can be used in combination to achieve a desirable effect. For example, the heterologous nucleotide sequence can be added or inserted at a position selected from the group consisting of position 1, 2, 3, 4, 5, and 6, and the intergenic region between the heterologous nucleotide sequence and the next downstream gene can be altered (see Table 3). Some of the combinations encompassed by the present invention are shown by way of example in Table 3. TABLE 3 Examples of mode of insertion of heterologous nucleotide sequences Position 1 Position 2 Position 3 Position 4 Position 5 Position 6 IGRa 10-20 10-20 10-20 10-20 10-20 10-20 IGR 21-40 21-40 21-40 21-40 21-40 21-40 IGR 41-60 41-60 41-60 41-60 41-60 41-60 IGR 61-80 61-80 61-80 61-80 61-80 61-80 IGR 81-100 81-100 81-100 81-100 81-100 81-100 IGR 101-120 101-120 101-120 101-120 101-120 101-120 IGR 121-140 121-140 121-140 121-140 121-140 121-140 IGR 141-160 141-160 141-160 141-160 141-160 141-160 IGR 161-180 161-180 161-180 161-180 161-180 161-180 IGR 181-200 181-200 181-200 181-200 181-200 181-200 IGR 201-220 201-220 201-220 201-220 201-220 201-220 IGR 221-240 221-240 221-240 221-240 221-240 221-240 IGR 241-260 241-260 241-260 241-260 241-260 241-260 IGR 261-280 261-280 261-280 261-280 261-280 261-280 IGR 281-300 281-300 281-300 281-300 281-300 281-300 aIntergenic Region, measured in nucleotide. Depending on the purpose (e.g., to have strong immunogenicity) of the inserted heterologous nucleotide sequence, the position of the insertion and the length of the intergenic region of the inserted heterologous nucleotide sequence can be determined by various indexes including, but not limited to, replication kinetics and protein or mRNA expression levels, measured by following non-limiting examples of assays: plaque assay, fluorescent-focus assay, infectious center assay, transformation assay, endpoint dilution assay, efficiency of plating, electron microscopy, hemagglutination, measurement of viral enzyme activity, viral neutralization, hemagglutination inhibition, complement fixation, immunostaining, immunoprecipitation and immunoblotting, enzyme-linked immunosorbent assay, nucleic acid detection (e.g., Southern blot analysis, Northern blot analysis, Western blot analysis), growth curve, employment of a reporter gene (e.g., using a reporter gene, such as Green Fluorescence Protein (GFP) or enhanced Green Fluorescence Protein (eGFP), integrated to the viral genome the same fashion as the interested heterologous gene to observe the protein expression), or a combination thereof. Procedures of performing these assays are well known in the art (see, e.g., Flint et al., PRINCIPLES OF VIROLOGY, MOLECULAR BIOLOGY, PATHOGENESIS, AND CONTROL, 2000, ASM Press pp 25-56, the entire text is incorporated herein by reference), and non-limiting examples are given in the Example sections, infra. For example, expression levels can be determined by infecting cells in culture with a virus of the invention and subsequently measuring the level of protein expression by, e.g., Western blot analysis or ELISA using antibodies specific to the gene product of the heterologous sequence, or measuring the level of RNA expression by, e.g., Northern blot analysis using probes specific to the heterologous sequence. Similarly, expression levels of the heterologous sequence can be determined by infecting an animal model and measuring the level of protein expressed from the heterologous sequence of the recombinant virus of the invention in the animal model. The protein level can be measured by obtaining a tissue sample from the infected animal and then subjecting the tissue sample to Western blot analysis or ELISA, using antibodies specific to the gene product of the heterologous sequence. Further, if an animal model is used, the titer of antibodies produced by the animal against the gene product of the heterologous sequence can be determined by any technique known to the skilled artisan, including but not limited to, ELISA. As the heterologous sequences can be homologous to a nucleotide sequence in the genome of the virus, care should be taken that the probes and the antibodies are indeed specific to the heterologous sequence or its gene product. In certain specific embodiments, expression levels of F-protein of hMPV from chimeric avian-human metapneumovirus can be determined by any technique known to the skilled artisan. Expression levels of the F-protein can be determined by infecting cells in a culture with the chimeric virus of the invention and measuring the level of protein expression by, e.g., Western blot analysis or ELISA using antibodies specific to the F-protein and/or the G-protein of hMPV, or measuring the level of RNA expression by, e.g., Northern blot analysis using probes specific to the F-gene and/or the G-gene of human metapneumovirus. Similarly, expression levels of the heterologous sequence can be determined using an animal model by infecting an animal and measuring the level of F-protein and/or G-protein in the animal model. The protein level can be measured by obtaining a tissue sample from the infected animal and then subjecting the tissue sample to Western blot analysis or ELISA using antibodies specific to F-protein and/or G-protein of the heterologous sequence. Further, if an animal model is used, the titer of antibodies produced by the animal against F-protein and/or G-protein can be determined by any technique known to the skilled artisan, including but not limited to, ELISA. The rate of replication of a recombinant virus of the invention can be determined by any technique known to the skilled artisan. In certain embodiments, to facilitate the identification of the optimal position of the heterologous sequence in the viral genome and the optimal length of the intergenic region, the heterologous sequence encodes a reporter gene. Once the optimal parameters are determined, the reporter gene is replaced by a heterologous nucleotide sequence encoding an antigen of choice. Any reporter gene known to the skilled artisan can be used with the methods of the invention. For more detail, see section 5.8. The rate of replication of the recombinant virus can be determined by any standard technique known to the skilled artisan. The rate of replication is represented by the growth rate of the virus and can be determined by plotting the viral titer over the time post infection. The viral titer can be measured by any technique known to the skilled artisan. In certain embodiments, a suspension containing the virus is incubated with cells that are susceptible to infection by the virus. Cell types that can be used with the methods of the invention include, but are not limited to, Vero cells, LLC-MK-2 cells, Hep-2 cells, LF 1043 (HEL) cells, MRC-5 cells, WI-38 cells, tMK cells, 293 T cells, QT 6 cells, QT 35 cells, or chicken embryo fibroblasts (CEF). Subsequent to the incubation of the virus with the cells, the number of infected cells is determined. In certain specific embodiments, the virus comprises a reporter gene. Thus, the number of cells expressing the reporter gene is representative of the number of infected cells. In a specific embodiment, the virus comprises a heterologous nucleotide sequence encoding for eGFP, and the number of cells expressing eGFP, i.e., the number of cells infected with the virus, is determined using FACS. In certain embodiments, the replication rate of the recombinant virus of the invention is at most 20% of the replication rate of the wild type virus from which the recombinant virus is derived under the same conditions. The same conditions refer to the same initial titer of virus, the same strain of cells, the same incubation temperature, growth medium, number of cells and other test conditions that may affect the replication rate. For example, the replication rate of APV/hMPV with PIV's F gene in position 1 is at most 20% of the replication rate of APV. In certain embodiments, the replication rate of the recombinant virus of the invention is at most 5%, at most 10%, at most 20%, at most 30%, at most 40%, at most 50%, at most 75%, at most 80%, at most 90% of the replication rate of the wild type virus from which the recombinant virus is derived under the same conditions. In certain embodiments, the replication rate of the recombinant virus of the invention is at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 75%, at least 80%, at least 90% of the replication rate of the wild type virus from which the recombinant virus is derived under the same conditions. In certain embodiments, the replication rate of the recombinant virus of the invention is between 5% and 20%, between 10% and 40%, between 25% and 50%, between 40% and 75%, between 50% and 80%, or between 75% and 90% of the replication rate of the wild type virus from which the recombinant virus is derived under the same conditions. In certain embodiments, the expression level of the heterologous sequence in the recombinant virus of the invention is at most 20% of the expression level of the F-protein of the wild type virus from which the recombinant virus is derived under the same conditions. The same conditions refer to the same initial titer of virus, the same strain of cells, the same incubation temperature, growth medium, number of cells and other test conditions that may affect the replication rate. For example, the expression level of the heterologous sequence of the F-protein of PIV3 in position 1 of hMPV is at most 20% of the expression level of the F-protein of hMPV. In certain embodiments, the expression level of the heterologous sequence in the recombinant virus of the invention is at most 5%, at most 10%, at most 20%, at most 30%, at most 40%, at most 50%, at most 75%, at most 80%, at most 90% of the expression level of the F-protein of the wild type virus from which the recombinant virus is derived under the same conditions. In certain embodiments, the expression level of the heterologous sequence in the recombinant virus of the invention is at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 75%, at least 80%, at least 90% of the expression level of the F-protein of the wild type virus from which the recombinant virus is derived under the same conditions. In certain embodiments, the expression level of the heterologous sequence in the recombinant virus of the invention is between 5% and 20%, between 10% and 40%, between 25% and 50%, between 40% and 75%, between 50% and 80%, or between 75% and 90% of the expression level of the F-protein of the wild type virus from which the recombinant virus is derived under the same conditions. 5.4.3 Insertion of the Heterologous Gene Sequence Into the G Gene The G protein is a transmembrane protein of metapneumoviruses. In a specific embodiment, the heterologous sequence is inserted into the region of the G-ORF that encodes for the ectodomain, such that it is expressed on the surface of the viral envelope. In one approach, the heterologous sequence may be inserted within the antigenic site without deleting any viral sequences. In another approach, the heterologous sequences replaces sequences of the G-ORF. Expression products of such constructs may be useful in vaccines against the foreign antigen, and may indeed circumvent problems associated with propagation of the recombinant virus in the vaccinated host. An intact G molecule with a substitution only in antigenic sites may allow for G function and thus allow for the construction of a viable virus. Therefore, this virus can be grown without the need for additional helper functions. The virus may also be attenuated in other ways to avoid any danger of accidental escape. Other hybrid constructions may be made to express proteins on the cell surface or enable them to be released from the cell. 5.4.4 Construction of Bicistronic RNA Bicistronic MRNA could be constructed to permit internal initiation of translation of viral sequences and allow for the expression of foreign protein coding sequences from the regular terminal initiation site. Alternatively, a bicistronic mRNA sequence may be constructed wherein the viral sequence is translated from the regular terminal open reading frame, while the foreign sequence is initiated from an internal site. Certain internal ribosome entry site (IRES) sequences may be utilized. The IRES sequences which are chosen should be short enough to not interfere with MPV packaging limitations. Thus, it is preferable that the IRES chosen for such a bicistronic approach be no more than 500 nucleotides in length. In a specific embodiment, the IRES is derived from a picornavirus and does not include any additional picornaviral sequences. Specific IRES elements include, but are not limited to the mammalian BiP IRES and the hepatitis C virus IRES. Alternatively, a foreign protein may be expressed from a new internal transcriptional unit in which the transcriptional unit has an initiation site and polyadenylation site. In another embodiment, the foreign gene is inserted into a MPV gene such that the resulting expressed protein is a fusion protein. 5.5 Expression of Heterologous Gene Products Using Recombinant cDNA and RNA Templates The viral vectors and recombinant templates prepared as described above can be used in a variety of ways to express the heterologous gene products in appropriate host cells or to create chimeric viruses that express the heterologous gene products. In one embodiment, the recombinant cDNA can be used to transfect appropriate host cells and the resulting RNA may direct the expression of the heterologous gene product at high levels. Host cell systems which provide for high levels of expression include continuous cell lines that supply viral functions such as cell lines superinfected with APV or MPV, respectively, cell lines engineered to complement APV or MPV functions, etc. In an alternate embodiment of the invention, the recombinant templates may be used to transfect cell lines that express a viral polymerase protein in order to achieve expression of the heterologous gene product. To this end, transformed cell lines that express a polymerase protein such as the L protein may be utilized as appropriate host cells. Host cells may be similarly engineered to provide other viral functions or additional functions such as G or N. In another embodiment, a helper virus may provide the RNA polymerase protein utilized by the cells in order to achieve expression of the heterologous gene product. In yet another embodiment, cells may be transfected with vectors encoding viral proteins such as the N, P, L, and M2-1 proteins. 5.6 Rescue of Recombinant Virus Particles In order to prepare the chimeric and recombinant viruses of the invention, a cDNA encoding the genome of a recombinant or chimeric virus of the invention in the plus or minus sense may be used to transfect cells which provide viral proteins and functions required for replication and rescue. Alternatively, cells may be transfected with helper virus before, during, or after transfection by the DNA or RNA molecule coding for the recombinant virus of the invention. The synthetic recombinant plasmid DNAs and RNAs of the invention can be replicated and rescued into infectious virus particles by any number of techniques known in the art, as described, e.g., in U.S. Pat. No. 5,166,057 issued Nov. 24, 1992; in U.S. Pat. No. 5,854,037 issued Dec. 29, 1998; in European Patent Publication EP 0702085A1, published Feb. 20, 1996; in U.S. patent application Serial No. 09/152,845; in International Patent Publications PCT WO97/12032 published Apr. 3, 1997; WO96/34625 published Nov. 7, 1996; in European Patent Publication EP-A780475; WO 99/02657 published Jan. 21, 1999; WO 98/53078 published Nov. 26, 1998; WO 98/02530 published Jan. 22, 1998; WO 99/15672 published Apr. 1, 1999; WO 98/13501 published Apr. 2, 1998; WO 97/06270 published Feb. 20, 1997; and EPO 780 47SA1 published Jun. 25, 1997, each of which is incorporated by reference herein in its entirety. In one embodiment, of the present invention, synthetic recombinant viral RNAs may be prepared that contain the non-coding regions (leader and trailer) of the negative strand virus RNA which are essential for the recognition by viral polymerases and for packaging signals necessary to generate a mature virion. There are a number of different approaches which may be used to apply the reverse genetics approach to rescue negative strand RNA viruses. First, the recombinant RNAs are synthesized from a recombinant DNA template and reconstituted in vitro with purified viral polymerase complex to form recombinant ribonucleoproteins (RNPs) which can be used to transfect cells. In another approach, a more efficient transfection is achieved if the viral polymerase proteins are present during transcription of the synthetic RNAs either in vitro or in vivo. With this approach the synthetic RNAs may be transcribed from cDNA plasmids which are either co-transcribed in vitro with cDNA plasmids encoding the polymerase proteins, or transcribed in vivo in the presence of polymerase proteins, i.e., in cells which transiently or constitutively express the polymerase proteins. In additional approaches described herein, infectious chimeric or recombinant virus may be replicated in host cell systems that express a metapneumoviral polymerase protein (e.g., in virus/host cell expression systems; transformed cell lines engineered to express a polymerase protein, etc.), so that infectious chimeric or recombinant virus are replicated and rescued. In this instance, helper virus need not be utilized since this function is provided by the viral polymerase proteins expressed. In accordance with the present invention, any technique known to those of skill in the art may be used to achieve replication and rescue of recombinant and chimeric viruses. One approach involves supplying viral proteins and functions required for replication in vitro prior to transfecting host cells. In such an embodiment, viral proteins may be supplied in the form of wildtype virus, helper virus, purified viral proteins or recombinantly expressed viral proteins. The viral proteins may be supplied prior to, during or post transcription of the synthetic cDNAs or RNAs encoding the chimeric virus. The entire mixture may be used to transfect host cells. In another approach, viral proteins and functions required for replication may be supplied prior to or during transcription of the synthetic cDNAs or RNAs encoding the chimeric virus. In such an embodiment, viral proteins and functions required for replication are supplied in the form of wildtype virus, helper virus, viral extracts, synthetic cDNAs or RNAs which express the viral proteins are introduced into the host cell via infection or transfection. This infection/transfection takes place prior to or simultaneous to the introduction of the synthetic cDNAs or RNAs encoding the chimeric virus genome. In a particularly desirable approach, cells engineered to express all viral genes or chimeric or recombinant virus of the invention, i.e., APV, MPV, MPV/APV or APV/MPV, may result in the production of infectious virus which contain the desired genotype; thus eliminating the need for a selection system. Theoretically, one can replace any one of the ORFs or part of any one of the ORFs encoding structural proteins of MPV with a foreign sequence. However, a necessary part of this equation is the ability to propagate the defective virus (defective because a normal viral gene product is missing or altered). A number of possible approaches exist to circumvent this problem. In one approach a virus having a mutant protein can be grown in cell lines which are constructed to constitutively express the wild type version of the same protein. By this way, the cell line complements the mutation in the virus. Similar techniques may be used to construct transformed cell lines that constitutively express any of the MPV genes. These cell lines which are made to express the viral protein may be used to complement the defect in the chimeric or recombinant virus and thereby propagate it. Alternatively, certain natural host range systems may be available to propagate chimeric or recombinant virus. In yet another embodiment, viral proteins and functions required for replication may be supplied as genetic material in the form of synthetic cDNAs or RNAs so that they are co-transcribed with the synthetic cDNAs or RNAs encoding the chimeric virus. In a particularly desirable approach, plasmids which express the chimeric virus and the viral polymerase and/or other viral functions are co-transfected into host cells. For example, plasmids encoding the genomic or antigenomic APV, MPV, MPV/APV or APV/MPV RNA, with or without one or more heterologous sequences, may be co-transfected into host cells with plasmids encoding the metapneumoviral polymerase proteins N, P, L, or M2-1. Alternatively, rescue of the recombinant viruses of the invention may be accomplished by the use of Modified Vaccinia Virus Ankara (MVA) encoding T7 RNA polymerase, or a combination of MVA and plasmids encoding the polymerase proteins (N, P, and L). For example, MVA-T7 or Fowl Pox-T7 can be infected into Vero cells, LLC-MK-2 cells, HEp-2 cells, LF 1043 (HEL) cells, tMK cells, LLC-MK2, HUT 292, FRHL-2 (rhesus), FCL-1 (green monkey), WI-38 (human), MRC-5 (human) cells, 293 T cells, QT 6 cells, QT 35 cells and CEF cells. After infection with MVA-T7 or Fowl Pox-T7, a full length antigenomic or genomic cDNA encoding the recombinant virus of the invention may be transfected into the cells together with the N, P, L, and M2-1 encoding expression plasmids. Alternatively, the polymerase may be provided by plasmid transfection. The cells and cell supernatant can subsequently be harvested and subjected to a single freeze-thaw cycle. The resulting cell lysate may then be used to infect a fresh Vero cell monolayer in the presence of 1-beta-D-arabinofuranosylcytosine (ara C), a replication inhibitor of vaccinia virus, to generate a virus stock. The supernatant and cells from these plates can then be harvested, freeze-thawed once and the presence of recombinant virus particles of the invention can be assayed by immunostaining of virus plaques using antiserum specific to the particular virus. Another approach to propagating the chimeric or recombinant virus may involve co-cultivation with wild-type virus. This could be done by simply taking recombinant virus and co-infecting cells with this and another wild-type virus. The wild-type virus should complement for the defective virus gene product and allow growth of both the wild-type and recombinant virus. Alternatively, a helper virus may be used to support propagation of the recombinant virus. In another approach, synthetic templates may be replicated in cells co-infected with recombinant viruses that express the metapneumovirus polymerase protein. In fact, this method may be used to rescue recombinant infectious virus in accordance with the invention. To this end, the metapneumovirus polymerase protein may be expressed in any expression vector/host cell system, including but not limited to viral expression vectors (e.g., vaccinia virus, adenovirus, baculovirus, etc.) or cell lines that express a polymerase protein (e.g., see Krystal et al., 1986, Proc. Natl. Acad. Sci. USA 83: 2709-2713). Moreover, infection of host cells expressing all metapneumovirus proteins may result in the production of infectious chimeric virus particles. It should be noted that it may be possible to construct a recombinant virus without altering virus viability. These altered viruses would then be growth competent and would not need helper functions to replicate. In order to recombinantly generate viruses in accordance with the methods of the invention, the genetic material encoding the viral genome must be transcribed (transcription step). This step can be accomplished either in vitro (outside the host cell) or in vivo (in a host cell). The viral genome can be transcribed from the genetic material to generate either a positive sense copy of the viral genome (antigenome copy) or a negative sense copy of the viral genome (genomic copy). The next step requires replication of the viral genome and packaging of the replicated genome into viral particles (replication and packaging step). This step occurs intracellularly in a host cell which has been engineered to provide sufficient levels of viral polymerase and structural proteins necessary for viral replication and packaging. When the transcription step occurs in vitro, it is followed by intracellular replication and packaging of the viral genome. When the transcription step occurs in vivo, transcription of the viral genome can occur prior to, concurrently or subsequently to expression of the viral genetic material encoding the viral genome can be obtained or generated from a variety of sources and using a variety of methods known to one skilled in the art. The genetic material may be isolated from the virus itself. For example, a complex of the viral RNA genome and the polymerase proteins, ribonucleoprotein complexes (RNP), may be isolated from whole virus. The viral RNA genome is then stripped of the associated proteins, e.g., viral RNA polymerase and nuclear proteins. The genetic material encoding the viral genome can be generated using standard recombinant techniques. The genetic material may encode the full length viral genome or a portion thereof. Alternatively, the genetic material may code for a heterologous sequence flanked by the leader and/or trailer sequences of the viral genome. A full-length viral genome can be assembled from several smaller PCR fragments using techniques known in the art. Restriction maps of different isolates of hMPV are shown in FIG. 28. The restriction sites can be used to assemble the full-length construct. In certain embodiments, PCR primers are designed such that the fragment resulting from the PCR reaction has a restriction site close to its 5′ end and a restriction site close to it 3′ end. The PCR product can then be digested with the respective restriction enzymes and subsequently ligated to the neighboring PCR fragments. In order to achieve replication and packaging of the viral genome, it is important that the leader and trailer sequences retain the signals necessary for viral polymerase recognition. The leader and trailer sequences for the viral RNA genome can be optimized or varied to improve and enhance viral replication and rescue. Alternatively, the leader and trailer sequences can be modified to decrease the efficiency of viral replication and packaging, resulting in a rescued virus with an attenuated phenotype. Examples of different leader and trailer sequences, include, but are not limited to, leader and trailer sequences of a paramyxovirus. In a specific embodiment of the invention, the leader and trailer sequence is that of a wild type or mutated hMPV. In another embodiment of the invention, the leader and trailer sequence is that of a PIV, APV, or an RSV. In yet another embodiment of the invention, the leader and trailer sequence is that of a combination of different virus origins. By way of example and not meant to limit the possible combination, the leader and trailer sequence can be a combination of any of the leader and trailer sequences of hMPV, PIV, APV, RSV, or any other paramyxovirus. Examples of modifications to the leader and trailer sequences include varying the spacing relative to the viral promoter, varying the sequence, e.g., varying the number of G residues (typically 0 to 3), and defining the 5′ or 3′ end using ribozyme sequences, including, Hepatitis Delta Virus (HDV) ribozyme sequence, Hammerhead ribozyme sequences, or fragments thereof, which retain the ribozyme catalytic activity, and using restriction enzymes for run-off RNA produced in vitro. In an alternative embodiment, the efficiency of viral replication and rescue may be enhanced if the viral genome is of hexamer length. In order to ensure that the viral genome is of the appropriate length, the 5′ or 3′ end may be defined using ribozyme sequences, including, Hepatitis Delta Virus (HDV) ribozyme sequence, Hammerhead ribozyme sequences, or fragments thereof, which retain the ribozyme catalytic activity, and using restriction enzymes for run-off RNA produced in vitro. In order for the genetic material encoding the viral genome to be transcribed, the genetic material is engineered to be placed under the control of appropriate transcriptional regulatory sequences, e.g., promoter sequences recognized by a polymerase. In preferred embodiments, the promoter sequences are recognized by a T7, Sp6 or T3 polymerase. In yet another embodiment, the promoter sequences are recognized by cellular DNA dependent RNA polymerases, such as RNA polymerase I (Pol I) or RNA polymerase II (Pol II). The genetic material encoding the viral genome may be placed under the control of the transcriptional regulatory sequences, so that either a positive or negative strand copy of the viral genome is transcribed. The genetic material encoding the viral genome is recombinantly engineered to be operatively linked to the transcriptional regulatory sequences in the context of an expression vector, such as a plasmid based vector, e.g. a plasmid with a pol II promoter such as the immediate early promoter of CMV, a plasmid with a T7 promoter, or a viral based vector, e.g., pox viral vectors, including vaccinia vectors, MVA-T7, and Fowl pox vectors. The genetic material encoding the viral genome may be modified to enhance expression by the polymerase of choice, e.g., varying the number of G residues (typically 0 to 3) upstream of the leader or trailer sequences to optimize expression from a T7 promoter. Replication and packaging of the viral genome occurs intracellularly in a host cell permissive for viral replication and packaging. There are a number of methods by which the host cell can be engineered to provide sufficient levels of the viral polymerase and structural proteins necessary for replication and packaging, including, host cells infected with an appropriate helper virus, host cells engineered to stably or constitutively express the viral polymerase and structural proteins, or host cells engineered to transiently or inducibly express the viral polymerase and structural proteins. Protein function required for MPV viral replication and packaging includes, but not limited to, the polymerase proteins P, N, L, and M2-1. In one embodiment, the proteins expressed are native or wild type MPV proteins. In another embodiment, the proteins expressed may be modified to enhance their level of expression and/or polymerase activity, using standard recombinant techniques. Alternatively, fragments, derivatives, analogs or truncated versions of the polymerase proteins that retain polymerase activity may be expressed. In yet another embodiment, analogous polymerase proteins from other pneumoviruses, such as APV, or from any other paramyxovirus may be expressed. Moreover, an attenuated virus can be produced by expressing proteins of one strain of MPV along with the genome of another strain. For example, a polymerase protein of one strain of MPV can be expressed with the genome of another strain to produce an attenuated phenotype. The viral polymerase proteins can be provided by helper viruses. Helper viruses that may be used in accordance with the invention, include those that express the polymerase viral proteins natively, such as MPV or APV. Alternatively, helper viruses may be used that have been recombinantly engineered to provide the polymerase viral proteins Alternatively the viral polymerase proteins can be provided by expression vectors. Sequences encoding the viral polymerase proteins are engineered to be placed under the control of appropriate transcriptional regulatory sequences, e.g., promoter sequences recognized by a polymerase. In preferred embodiments, the promoter sequences are recognized by a T7, Sp6 or T3 polymerase. In yet another embodiment, the promoter sequences are recognized by a Pol I or Pol II polymerase. Alternatively, the promoter sequences are recognized by a viral polymerase, such as CMV. The sequences encoding the viral polymerase proteins are recombinantly engineered to be operatively linked to the transcriptional regulatory sequences in the context of an expression vector, such as a plasmid based vector, e.g. a CMV driven plasmid, a T7 driven plasmid, or a viral based vector, e.g., pox viral vectors, including vaccinia vectors, MVA-T7, and Fowl pox vectors. In order to achieve efficient viral replication and packaging, high levels of expression of the polymerase proteins is preferred. Such levels are obtained using 100-200 ng L/pCITE, 200-400 ng N/pCITE, 200-400 ng P/pCITE, and 100-200 ng M2-1/pCITE plasmids encoding paramyxovirus proteins together with 2 -4 ug of plasmid encoding the full-length viral cDNA transfected into cells infected with MVA-T7. In another embodiment, 0.1-2.0 μg of pSH25 (CAT expressing), 0.1-3.0 μg of pRF542 (expressing T7 polymerase), 0.1-0.8 μg pCITE vector with N cDNA insert, and 0.1-1.0 μg of each of three pCITE vectors containing P, L and M2-1 cDNA insert are used. Alternatively, one or more polymerase and structural proteins can be introduced into the cells in conjunction with the genetic material by transfecting cells with purified ribonucleoproteins. Host cells that are permissive for MPV viral replication and packaging are preferred. Examples of preferred host cells include, but are not limited to, 293T, Vero, tMK, and BHK. Other examples of host cells include, but are not limited to, LLC-MK-2 cells, Hep-2 cells, LF 1043 (HEL) cells, LLC-MK2, HUT 292, FRHL-2 (rhesus), FCL-1 (green monkey), WI-38 (human), MRC-5 (human) cells, QT 6 cells, QT 35 cells and CEF cells. In alternative embodiments of the invention, the host cells can be treated using a number of methods in order to enhance the level of transfection and/or infection efficiencies, protein expression, in order to optimize viral replication and packaging. Such treatment methods, include, but are not limited to, sonication, freeze/thaw, and heat shock. Furthermore, standard techniques known to the skilled artisan can be used to optimize the transfection and/or infection protocol, including, but are not limited to, DEAE-dextran-mediated transfection, calcium phosphate precipitation, lipofectin treatment, liposome-mediated transfection and electroporation. The skilled artisan would also be familiar with standard techniques available for the optimization of transfection/infection protocols. By way of example, and not meant to limit the available techniques, methods that can be used include, manipulating the timing of infection relative to transfection when a virus is used to provide a necessary protein, manipulating the timing of transfections of different plasmids, and affecting the relative amounts of viruses and transfected plasmids. In another embodiment, the invention relates to the rescue or production of live virus from cDNA using polymerase from a virus other than the one being rescued. In certain embodiments, hMPV is rescued from a cDNA using any of a number of polymerases, including, but not limited to, interspecies and intraspecies polymerases. In a certain embodiment, hMPV is rescued in a host cell expressing the minimal replication unit necessary for hMPV replication. For example, hMPV can be rescued from a cDNA using a number of polymerases, including, but not limited to, the polymerase of RSV, APV, MPV, or PIV. In a specific embodiment of the invention, hMPV is rescued using the polymerase of an RNA virus. In a more specific embodiment of the invention, hMPV is rescued using the polymerase of a negative stranded RNA virus. In an even more specific embodiment of the invention, hMPV is rescued using RSV polymerase. In another embodiment of the invention, hMPV is rescued using APV polymerase. In yet another embodiment of the invention, hMPV is rescued using an MPV polymerase. In another embodiment of the invention, hMPV is rescued using PIV polymerase. In a more certain embodiment of the invention, hMPV is rescued from a cDNA using a complex of hMPV polymerase proteins. For example, the hMPV minireplicon can be rescued using a polymerase complex consisting of the L, P, N, and M2-1 proteins. In another embodiment of the invention, the polymerase complex consists of the L, P, and N proteins. In yet another embodiment of the invention, hMPV can be rescued from a cDNA using a polymerase complex consisting of polymerase proteins from other viruses, such as, but not limited to, RSV, PIV, and APV. In particular, hMPV can be rescued from a cDNA using a polymerase complex consisting of the L, P, N, and M2-1 proteins of RSV, PIV, APV, MPV, or any combination thereof. In yet another embodiment of the invention, the polymerase complex used to rescue hMPV from a cDNA consists of the L, P, and N proteins of RSV, PIV, APV, MPV, or any combination thereof. In even another embodiment of the invention, different polymerase proteins from various viruses can be used to form the polymerase complex. In such an embodiment, the polymerase used to rescue hMPV can be formed by different components of the RSV, PIV, APV, or MPV polymerases. By way of example, and not meant to limit the possible combination in forming a complex, the N protein can be encoded by the N gene of RSV, APV, PIV or MPV while the L protein is encoded by the L gene of RSV, APV, PIV or MPV and the P protein can be encoded by the P gene of RSV, APV, PIV or MPV. One skilled in the art would be able to determine the possible combinations that may be used to form the polymerase complex necessary to rescue the hMPV from a cDNA. In certain embodiments, conditions for the propagation of virus are optimized in order to produce a robust and high-yielding cell culture (which would be beneficial, e.g., for manufacture the virus vaccine candidates of the invention). Critical parameters can be identified, and the production process can be first optimized in small-scale experiments to determine the scalability, robustness, and reproducibility and subsequently adapted to large scale production of virus. In certain embodiments, the virus that is propagated using the methods of the invention is hMPV. In certain embodiments, the virus that is propagated using the methods of the invention is a recombinant or a chimeric hMPV. In certain embodiments, the virus that is propagated using the methods of the invention is a virus of one of the following viral families Adenoviridae, Arenaviridae, Astroviridae, Baculoviridae, Bunyaviridae, Caliciviridae, Caulimovirus, Coronaviridae, Cystoviridae, Filoviridae, Flaviviridae, Hepadnaviridae, Herpesviridae, Hypoviridae, Idaeovirus, Inoviridae, Iridoviridae, Leviviridae, Lipothrixviridae, Luteovirus, Machlomovirus, Marafivirus, Microviridae, Myoviridae, Necrovirus, Nodaviridae, Orthomyxoviridae, Papovaviridae, Paramyxoviridae, Partitiviridae, Parvoviridae, Phycodnaviridae, Picomaviridae, Plasmaviridae, Podoviridae, Polydnaviridae, Potyviridae, Poxviridae, Reoviridae, Retroviridae, Rhabdoviridae, Sequiviridae, Siphoviridae, Sobemovirus, Tectiviridae, Tenuivirus, Tetraviridae, Tobamovirus, Tobravirus, Togaviridae, Tombusviridae, Totiviridae, Trichovirus, Mononegavirales. In certain embodiments, the virus that is propagated with the methods of the invention is an RNA virus. In certain embodiments, the virus is not a virus of the family Herpesviridae. In certain embodiments, the virus is not HSV. In certain embodiments, a cell culture infected with a virus or a viral construct of interest is incubated at a lower post-infection incubation temperature as compared to the standard incubation temperature for the cells in culture. In a specific embodiment, a cell culture infected with a viral construct of interest is incubated at 33° C. or about 33° C. (e.g., 33±1° C.). In certain embodiments, the post-infection incubation temperature is about 25° C., 26° C., 27° C., 28° C., 29° C., 30° C., 31° C., 32° C., 33° C., 34° C., 35° C., 36° C. or 37° C. In certain embodiments, virus is propagated by incubating a cells before infection with the virus at a temperature optimized for the growth of the cells and subsequent to infection of the cells with the virus, i.e., post-infection, the temperature is shifted to a lower temperature. In certain embodiments the shift is at least 1° C., 2° C., 3° C., 4° C., 5° C., 6° C., 7° C., 8° C., 8° C., 9° C., 10° C., 11° C., or at least 12° C. In certain embodiments the shift is at most 1° C., 2° C., 3° C., 4° C., 5° C., 6° C., 7° C., 8° C., 9° C., 10° C., 11° C., or at most 12° C. In a specific embodiment, the shift is 4° C. In certain embodiments, the cells are cultured in a medium containing serum before infection with a virus or a viral construct of interest and the cells are cultured in a medium without serum after infection with the virus or viral construct. For a more detailed description of growing infected cells without serum, see the section entitled “Plasmid-Only Recovery of Virus in Serum Free Media.” In a specific embodiment, the serum is fetal bovine serum and is present a concentration of 5% of culture volume, 2% of culture volume, or 0.5% of culture volume. In certain embodiments, virus is propagated by incubating cells that are infected with the virus in the absence of serum. In certain embodiments, virus is propagated by incubating cells that are infected with the virus in a culture medium containing less than 5% of serum, less than 2.5% of serum, less than 1% of serum, less than 0.1 % of serum, less than 0.01% of serum, or less than 0.001% of serum. In certain embodiments, the cells are incubated before infection with the virus in medium containing serum. In certain embodiments, subsequent to infection of the cells with the virus, the cells are incubated in the absence of serum. In other embodiments, the cells are first incubated in medium containing serum; the cells are then transferred into medium without serum; and subsequently, the cells are infected with the virus and further incubated in the absence of virus. In certain embodiments, the cells are transferred from medium containing serum into medium in the absence of serum, by removing the serum-containing medium from the cells and adding the medium without serum. In other embodiments, the cells are centrifuged and the medium containing serum is removed and medium without serum is added. In certain embodiments, the cells are washed with medium without serum to ensure that cells once infected with the virus are incubated in the absence of serum. In certain, more specific embodiments, the cells are washed with medium without serum at least one time, two times, three times, four times, five times, or at least ten times. In yet other embodiments, cells are cultured in a medium containing serum and at a temperature that is optimal for the growth of the cells before infection with a virus or a viral construct, and the cell culture is incubated at a lower temperature (relative to the standard incubation temperature for the corresponding virus or viral vector) after infection with the viral construct of interest. In a specific embodiment, cells are cultured in a medium containing serum before infection with a viral construct of interest at 37° C., and the cell culture is incubated at 33° C. or about 33° C. (e.g., 33±1° C.) after infection with the viral construct of interest. In even other embodiments, cells are cultured in a medium containing serum and at a temperature that is optimal for the growth of the cells before infection with a virus or a viral construct, and the cell culture is incubated without serum at a lower temperature (relative to the standard incubation temperature for the corresponding virus or viral vector) after infection with the viral construct of interest. In a specific embodiment, cells are cultured in a medium containing serum before infection with a viral construct of interest at 37° C., and the cell culture is incubated without serum at 33° C. or about 33° C. (e.g., 33±1° C.) after infection with the viral construct of interest. The viral constructs and methods of the present invention can be used for commercial production of viruses, e.g., for vaccine production. For commercial production of a vaccine, it is preferred that the vaccine contains only inactivated viruses or viral proteins that are completely free of infectious virus or contaminating viral nucleic acid, or alternatively, contains live attenuated vaccines that do not revert to virulence. Contamination of vaccines with adventitious agents introduced during production should also be avoided. Methods known in the art for large scale production of viruses or viral proteins can be used for commercial production of a vaccine of the invention. In one embodiment, for commercial production of a vaccine of the invention, cells are cultured in a bioreactor or fermenter. Bioreactors are available in volumes from under 1 liter to in excess of 100 liters, e.g., Cyto3 Bioreactor (Osmonics, Minnetonka, Minn.); NBS bioreactors (New Brunswick Scientific, Edison, N.J.); and laboratory and commercial scale bioreactors from B. Braun Biotech International (B. Braun Biotech, Melsungen, Germany). In another embodiment, small-scale process optimization studies are performed before the commercial production of the virus, and the optimized conditions are selected and used for the commercial production of the virus. Plasmid-Rescue in Serum-Free Medium In certain embodiments of the invention, virus can be recovered without helper virus. More specifically, virus can be recovered by introducing into a cell a plasmid encoding the viral genome and plasmids encoding viral proteins required for replication and rescue. In certain embodiments, the cell is grown and maintained in serum-free medium. In certain embodiments, the plasmids are introduced into the cell by electroporation. In a specific embodiment, a plasmid encoding the antigenomic cDNA of the virus under the control of the T7 promoter, a plasmid encoding the T7 RNA polymerase, and plasmids encoding the N protein, P protein, and L protein, respectively, under control of the T7 promoter are introduced into SF Vero cells by electroporation. Vero cells were obtained from ATCC and adapted to grow in serum-free media according to the following steps (developed by Mike Berry's laboratory). 1. Thaw ATCC CCL-81 Vial in DMEM+5% v/v FBS in T-25 flask P121; 2. Expand 5 passages in DMEM+5% v/v FBS P126; 3. Directly transfer FBS grown cells to OptiPRO (Invitrogen Corporation) in T-225 flasks; 4. Expand 7 passages in OptiPRO; 5. Freeze down Pre-Master Cell Bank Stock at Passage 133-7; 6. Expand 4 passages in OptiPRO; 7. Freeze down Master Cell Bank Stock at Passage 137; 8. Expand 4 passages in OptiPRO; 9. Freeze down Working Cell Bank Stock at Passage 141; and 10. Thaw and expand for electroporation and virus amplification. Methods for the rescue of viral particles are described in section 5.6 entitled “Rescue Of Recombinant Virus Particles”. In certain embodiments, the cells used for viral rescue are cells that can be grown and/or maintained without the addition of components derived from animals or humans. In certain embodiments, the cells used for viral rescue are cells that are adapted to growth without serum. In a specific embodiment, SF Vero cells are used for the rescue of virus. In certain embodiments, the cells are grown and/or maintained in OptiPRO SFM (Invitrogen Corporation) supplemented with 4 mM L-glutamine. In certain embodiments, the cells are grown in medium that is supplemented with serum but for rescue of viral particles the cells are transferred into serum-free medium. In a specific embodiment, the cells are washed in serum-free medium to ensure that the viral rescue takes place in a serum-free environment. The plasmids are introduced into the cells by any method known to the skilled artisan that can be used with the cells, e.g., by calcium phosphate transfection, DEAE-Dextran transfection, electroporation or liposome mediated transfection (see Chapter 9 of Short Protocols in Molecular Biology, Ausubel et al. (editors), John Wiley & Sons, Inc., 1999). In specific embodiments, electroporation is used to introduce the plasmid DNA into the cells. SF Vero cells are resistant to lipofection. To select cells that have been transfected with the required plasmids, the plasmids can also carry certain markers. Such markers include, but are not limited to, resistancy to certain antibiotics (e.g., kanamycin, blasticidin, ampicillin, Hygromycin B, Puromycin and Zeocin™), makers that confer certain autotrophic properties on a cell that lacks this property without the marker, or a marker can also be a gene that is required for the growth of a cell but that is mutated in the cells into which the plasmid is introduced. The transcription of the viral genome and/or the viral genes are under transcriptional control of a promoter. Thus, the sequences encoding the viral genome or the viral proteins are operatively linked to the promoter sequence. Any promoter/RNA polymerase system known to the skilled artisan can be used with the methods of the present invention. In certain embodiments, the promoter can be a promoter that allows transcription by an RNA polymerase endogenous to the cell, e.g., a promoter sequences that are recognized by a cellular DNA dependent RNA polymerases, such as RNA polymerase I (Pol I) or RNA polymerase II (Pol 11). In certain embodiments, the promoter can be an inducible promoter. In certain embodiments, the promoter can be a promoter that allows transcription by an RNA polymerase that is not endogenous to the cell. In certain, more specific embodiments, the promoter is a T3 promoter, T7 promoter, SP6 promoter, or CMV promoter. Depending on the type of promoter used, a plasmid encoding the RNA polymerase that recognizes the promoter is also introduced into the cell to provide the appropriate RNA polymerase. In specific embodiments, the RNA polymerase is T3 RNA polymerase, T7 RNA polymerase, SP6 RNA polymerase, or CMV RNA polymerase. In a specific embodiment, the viral genes and the viral genome are transcribed under the control of a T7 promoter and a plasmid encoding the T7 RNA polymerase is introduced to provide the T7 RNA polymerase. The transcription of the polymerase can be under the control of any promoter system that would function in the cell type used. In a specific embodiment, the CMV promoter is used. The viral genome can be in the plus or minus orientation. Thus, the viral genome can be transcribed from the genetic material to generate either a positive sense copy of the viral genome (antigenome copy) or a negative sense copy of the viral genome (genomic copy). In certain embodiments, the viral genome is a recombinant, chimeric and/or attenuated virus of the invention. In certain embodiments, the efficiency of viral replication and rescue may be enhanced if the viral genome is of hexamer length. In order to ensure that the viral genome is of the appropriate length, the 5′ or 3′ end may be defined using ribozyme sequences, including, Hepatitis Delta Virus (HDV) ribozyme sequence, Hammerhead ribozyme sequences, or fragments thereof, which retain the ribozyme catalytic activity. In certain embodiments, the viral proteins required for replication and rescue include the N, P, and L gene. In certain, more specific, embodiments, the viral proteins required for replication and rescue include the N, P, M2-1 and L gene. 5.7 Attenuation of Recombinant Viruses The recombinant viruses of the invention can be further genetically engineered to exhibit an attenuated phenotype. In particular, the recombinant viruses of the invention exhibit an attenuated phenotype in a subject to which the virus is administered as a vaccine. Attenuation can be achieved by any method known to a skilled artisan. Without being bound by theory, the attenuated phenotype of the recombinant virus can be caused, e.g., by using a virus that naturally does not replicate well in an intended host (e.g., using an APV in human), by reduced replication of the viral genome, by reduced ability of the virus to infect a host cell, or by reduced ability of the viral proteins to assemble to an infectious viral particle relative to the wild type strain of the virus. The viability of certain sequences of the virus, such as the leader and the trailer sequence can be tested using a minigenome assay (see section 5.8). The attenuated phenotypes of a recombinant virus of the invention can be tested by any method known to the artisan (see, e.g., section 5.8). A candidate virus can, for example, be tested for its ability to infect a host or for the rate of replication in a cell culture system. In certain embodiments, a mimi-genome system is used to test the attenuated virus when the gene that is altered is N, P, L, M2, F, G, M2-1, M2-2 or a combination thereof. In certain embodiments, growth curves at different temperatures are used to test the attenuated phenotype of the virus. For example, an attenuated virus is able to grow at 35° C., but not at 39° C. or 40° C. In certain embodiments, different cell lines can be used to evaluate the attenuated phenotype of the virus. For example, an attenuated virus may only be able to grow in monkey cell lines but not the human cell lines, or the achievable virus titers in different cell lines are different for the attenuated virus. In certain embodiments, viral replication in the respiratory tract of a small animal model, including but not limited to, hamsters, cotton rats, mice and guinea pigs, is used to evaluate the attenuated phenotypes of the virus. In other embodiments, the immune response induced by the virus, including but not limited to, the antibody titers (e.g., assayed by plaque reduction neutralization assay or ELISA) is used to evaluate the attenuated phenotypes of the virus. In a specific embodiment, the plaque reduction neutralization assay or ELISA is carried out at a low dose. In certain embodiments, the ability of the recombinant virus to elicit pathological symptoms in an animal model can be tested. A reduced ability of the virus to elicit pathological symptoms in an animal model system is indicative of its attenuated phenotype. In a specific embodiment, the candidate viruses are tested in a monkey model for nasal infection, indicated by mucous production. The viruses of the invention can be attenuated such that one or more of the functional characteristics of the virus are impaired. In certain embodiments, attenuation is measured in comparison to the wild type strain of the virus from which the attenuated virus is derived. In other embodiments, attenuation is determined by comparing the growth of an attenuated virus in different host systems. Thus, for a non-limiting example, an APV is said to be attenuated when grown in a human host if the growth of the APV in the human host is reduced compared to the growth of the APV in an avian host. In certain embodiments, the attenuated virus of the invention is capable of infecting a host, is capable of replicating in a host such that infectious viral particles are produced. In comparison to the wild type strain, however, the attenuated strain grows to lower titers or grows more slowly. Any technique known to the skilled artisan can be used to determine the growth curve of the attenuated virus and compare it to the growth curve of the wild type virus. For exemplary methods see Example section, infra. In a specific embodiment, the attenuated virus grows to a titer of less than 105 pfu/ml, of less than 104 pfu/ml, of less than 103 pfu/ml, or of less than 102 pfu/ml in Vero cells under conditions as described in, e.g., Example 22. In certain embodiments, the attenuated virus of the invention (e.g., a chimeric mammalian MPV) cannot replicate in human cells as well as the wild type virus (e.g., wild type mammalian MPV) does. However, the attenuated virus can replicate well in a cell line that lack interferon functions, such as Vero cells. In other embodiments, the attenuated virus of the invention is capable of infecting a host, of replicating in the host, and of causing proteins of the virus of the invention to be inserted into the cytoplasmic membrane, but the attenuated virus does not cause the host to produce new infectious viral particles. In certain embodiments, the attenuated virus infects the host, replicates in the host, and causes viral proteins to be inserted in the cytoplasmic membrane of the host with the same efficiency as the wild type mammalian virus. In other embodiments, the ability of the attenuated virus to cause viral proteins to be inserted into the cytoplasmic membrane into the host cell is reduced compared to the wild type virus. In certain embodiments, the ability of the attenuated mammalian virus to replicate in the host is reduced compared to the wild type virus. Any technique known to the skilled artisan can be used to determine whether a virus is capable of infecting a mammalian cell, of replicating within the host, and of causing viral proteins to be inserted into the cytoplasmic membrane of the host. For illustrative methods see section 5.8. In certain embodiments, the attenuated virus of the invention is capable of infecting a host. In contrast to the wild type mammalian MPV, however, the attenuated mammalian MPV cannot be replicated in the host. In a specific embodiment, the attenuated mammalian virus can infect a host and can cause the host to insert viral proteins in its cytoplasmic membranes, but the attenuated virus is incapable of being replicated in the host. Any method known to the skilled artisan can be used to test whether the attenuated mammalian MPV has infected the host and has caused the host to insert viral proteins in its cytoplasmic membranes. In certain embodiments, the ability of the attenuated mammalian virus to infect a host is reduced compared to the ability of the wild type virus to infect the same host. Any technique known to the skilled artisan can be used to determine whether a virus is capable of infecting a host. For illustrative methods see section 5.8. In certain embodiments, mutations (e.g., missense mutations) are introduced into the genome of the virus to generated a virus with an attenuated phenotype. Mutations (e.g., missense mutations) can be introduced into the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene of the recombinant virus. Mutations can be additions, substitutions, deletions, or combinations thereof. In specific embodiments, a single amino acid deletion mutation for the N, P, L, F, G, M2-1, M2-2 or M2 proteins is introduced, which can be screened for functionality in the mini-genome assay system and be evaluated for predicted functionality in the virus. In more specific embodiments, the missense mutation is a cold-sensitive mutation. In other embodiments, the missense mutation is a heat-sensitive mutation. In one embodiment, major phosphorylation sites of P protein of the virus is removed. In another embodiment, a mutation or mutations are introduced into the L gene of the virus to generate a temperature sensitive strain. In yet another embodiment, the cleavage site of the F gene is mutated in such a way that cleavage does not occur or occurs at very low efficiency. In certain, more specific embodiments, the motif with the amino acid sequence RQSR at amino acid postions 99 to 102 of the F protein of hMPV is mutated (see FIG. 9). A mutation can be, but is not limited to, a deletion of one or more amino acids, an addition of one or more amino acids, a substitution (conserved or non-conserved) of one or more amino acids or a combination thereof. In some strains of hMPV, the cleavage site is RQPR (see Example “P101S”). In certain embodiments, the cleavage site with the amino acid sequence is RQPR is mutated. In more specific embodiments, the cleavage site of the F protein of hMPV is mutated such that the infectivity of hMPV is reduced. In certain embodiments, the infectivity of hMPV is reduced by a factor of at least 5, 10, 50, 100, 500, 103, 5×103, 104, 5×104, 105, 5×105, or at least 106. In certain embodiments, the infectivity of hMPV is reduced by a factor of at most 5, 10, 50, 100, 500, 103, 5×103, 104, 5×104, 105, 5×105, or at most 106. In other embodiments, deletions are introduced into the genome of the recombinant virus. In more specific embodiments, a deletion can be introduced into the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene of the recombinant virus. In specific embodiments, the deletion is in the M2-gene of the recombinant virus of the present invention. In other specific embodiments, the deletion is in the SH-gene of the recombinant virus of the present invention. In yet another specific embodiment, both the M2-gene and the SH-gene are deleted. In certain embodiments, the intergenic region of the recombinant virus is altered. In one embodiment, the length of the intergenic region is altered. In another embodiment, the intergenic regions are shuffled from 5′ to 3′ end of the viral genome. In other embodiments, the genome position of a gene or genes of the recombinant virus is changed. In one embodiment, the F or G gene is moved to the 3′ end of the genome. In another embodiment, the N gene is moved to the 5′ end of the genome. In certain embodiments, attenuation of the virus is achieved by replacing a gene of the wild type virus with the analogous gene of a virus of a different species (e.g., of RSV, APV, PIV3 or mouse pneumovirus), of a different subgroup, or of a different variant. In illustrative embodiments, the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene of a mammalian MPV is replaced with the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene, respectively, of an APV. In other illustrative embodiments, the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene of APV is replaced with the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene or the L-gene, respectively, of a mammalian MPV. In a preferred embodiment, attenuation of the virus is achieved by replacing one or more polymerase associated genes (e.g., N, P, L or M2) with genes of a virus of a different species. In certain embodiments, attenuation of the virus is achieved by replacing one or more specific domains of a protein of the wild type virus with domains derived from the corresponding protein of a virus of a different species. In an illustrative embodiment, the ectodomain of a F protein of APV is replaced with an ectodomain of a F protein of a mammalian MPV. In a preferred embodiment, one or more specific domains of L, N, or P protein are replaced with domains derived from corresponding proteins of a virus of a different species. In certain other embodiments, attenuation of the virus is achieved by deleting one or more specific domains of a protein of the wild type virus. In a specific embodiment, the transmembrane domain of the F-protein is deleted. In certain embodiments of the invention, the leader and/or trailer sequence of the recombinant virus of the invention can be modified to achieve an attenuated phenotype. In certain, more specific embodiments, the leader and/or trailer sequence is reduced in length relative to the wild type virus by at least 1 nucleotide, at least 2 nucleotides, at least 3 nucleotides, at least 4 nucleotides, at least 5 nucleotides or at least 6 nucleotides. In certain other, more specific embodiments, the sequence of the leader and/or trailer of the recombinant virus is mutated. In a specific embodiment, the leader and the trailer sequence are 100% complementary to each other. In other embodiments, 1 nucleotide, 2 nucleotides, 3 nucleotides, 4 nucleotides, 5 nucleotides, 6 nucleotides, 7 nucleotides, 8 nucleotides, 9 nucleotides, or 10 nucleotides are not complementary to each other where the remaining nucleotides of the leader and the trailer sequences are complementary to each other. In certain embodiments, the non-complementary nucleotides are identical to each other. In certain other embodiments, the non-complementary nucleotides are different from each other. In other embodiments, if the non-complementary nucleotide in the trailer is purine, the corresponding nucleotide in the leader sequence is also a purine. In other embodiments, if the non-complementary nucleotide in the trailer is pyrimidine, the corresponding nucleotide in the leader sequence is also a purine. In certain embodiments of the invention, the leader and/or trailer sequence of the recombinant virus of the invention can be replaced with the leader and/or trailer sequence of a another virus, e.g., with the leader and/or trailer sequence of RSV, APV, PIV3, mouse pneumovirus, or with the leader and/or trailer sequence of a human metapneumovirus of a subgroup or variant different from the human metapneumovirus from which the protein-encoding parts of the recombinant virus are derived. When a live attenuated vaccine is used, its safety must also be considered. The vaccine must not cause disease. Any techniques known in the art that can make a vaccine safe may be used in the present invention. In addition to attenuation techniques, other techniques may be used. One non-limiting example is to use a soluble heterologous gene that cannot be incorporated into the virion membrane. For example, a single copy of the soluble RSV F gene, a version of the RSV gene lacking the transmembrane and cytosolic domains, can be used. Since it cannot be incorporated into the virion membrane, the virus tropism is not expected to change. Various assays can be used to test the safety of a vaccine. See section 5.8, infra. Particularly, sucrose gradients and neutralization assays can be used to test the safety. A sucrose gradient assay can be used to determine whether a heterologous protein is inserted in a virion. If the heterologous protein is inserted in the virion, the virion should be tested for its ability to cause symptoms even if the parental strain does not cause symptoms. Without being bound by theory, if the heterologous protein is incorporated in the virion, the virus may have acquired new, possibly pathological, properties. In certain embodiments, one or more genes are deleted from the hMPV genome to generate an attenuated virus. In more specific embodiments, the M2-2 ORF, the M2-1 ORF, the M2 gene, the SH gene and/or the G2 gene is deleted. In other embodiments, small single amino acid deletions are introduced in genes involved in virus replication to generate an attenuated virus. In more specific embodiments, a small single amino acid deletion is introduced in the N, L, or the P gene. In certain specific embodiments, one or more of the following amino acids are mutated in the L gene of a recombinant hMPV: Phe at amino acid position 456, Glu at amino acid position 749, Tyr at amino acid position 1246, Met at amino acid position 1094 and Lys at amino acid position 746 to generate an attenuated virus. A mutation can be, e.g., a deletion or a substitution of an amino acid. An amino acid substitution can be a conserved amino acid substitution or a non-conserved amino acid substitution. Illustrative examples for conserved amino acid exchanges are amino acid substitutions that maintain structural and/or functional properties of the amino acids' side-chains, e.g., an aromatic amino acid is substituted for another aromatic amino acid, an acidic amino acid is substituted for another acidic amino acid, a basic amino acid is substituted for another basic amino acid, and an aliphatic amino acid is substituted for another aliphatic amino acid. In contrast, examples of non-conserved amino acid exchanges are amino acid substitutions that do not maintain structural and/or functional properties of the amino acids' side-chains, e.g., an aromatic amino acid is substituted for a basic, acidic, or aliphatic amino acid, an acidic amino acid is substituted for an aromatic, basic, or aliphatic amino acid, a basic amino acid is substituted for an acidic, aromatic or aliphatic amino acid, and an aliphatic amino acid is substituted for an aromatic, acidic or basic amino acid. In even more specific embodiments Phe at amino acid position 456 is replaced by a Leu. In certain embodiments, one nucleic acid is substituted to encode one amino acid exchange. In other embodiments, two or three nucleic acids are substituted to encode one amino acid exchange. It is preferred that two or three nucleic acids are substituted to reduce the risk of reversion to the wild type protein sequence. In other embodiments, small single amino acid deletions are introduced in genes involved in virus assembly to generate an attenuated virus. In more specific embodiments, a small single amino acid deletion is introduced in the M gene or the M2 gene. In a preferred embodiment, the M gene is mutated. In even other embodiments, the gene order in the genome of the virus is changed from the gene order of the wild type virus to generate an attenuated virus. In a more specific embodiment, the F, SH, and/or the G gene is moved to the 3′ end of the viral genome. In another embodiment, the N gene is moved to the 5′ end of the viral genome. In other embodiments, one or more gene start sites (for locations of gene start sites see, e.g., Table 8) are mutated or substituted with the analogous gene start sites of another virus (e.g., RSV, PIV3, APV or mouse pneumovirus) or of a human metapneumovirus of a subgroup or a variant different from the human metapneumovirus from which the protein-encoding parts of the recombinant virus are derived. In more specific embodiments, the gene start site of the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene and/or the L-gene is mutated or replaced with the start site of the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene and/or the L-gene, respectively, of another virus (e.g., RSV, PIV3, APV or mouse pneumovirus) or of a human metapneumovirus of a subgroup or a variant different from the human metapneumovirus from which the protein-encoding parts of the recombinant virus are derived. 5.7.1 Attenuation by Substitution of Viral Genes In certain embodiments of the invention, attenuation is achieved by replacing one or more of the genes of a virus with the analogous gene of a different virus, different strain, or different viral isolate. In certain embodiments, one or more of the genes of a metapneumovirus, such as a mammalian metapneumovirus, e.g., hMPV, or APV, is replaced with the analogous gene(s) of another paramyxovirus. In a more specific embodiment, the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene or the L-gene or any combination of two or more of these genes of a mammalian metapneumovirus, e.g., hMPV, is replaced with the analogous gene of another viral species, strain or isolate, wherein the other viral species can be, but is not limited to, another mammalian metapneumovirus, APV, or RSV. In more specific embodiments, one or more of the genes of human metapneumovirus are replaced with the analogous gene(s) of another isolate of human metapneumovirus. E.g., the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene or the L-gene or any combination of two or more of these genes of isolate NL/1/99 (99-1), NL/1/00 (00-1), NL/17/00, or NL/1/94 is replaced with the analogous gene or combination of genes, i.e., the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene or the L-gene, of a different isolate, e.g., NL/1/99 (99-1), NL/1/00 (00-1), NL/17/00, or NL/1/94. In certain embodiments, one or more regions of the genome of a virus is/are replaced with the analogous region(s) from the genome of a different viral species, strain or isolate. In certain embodiments, the region is a region in a coding region of the viral genome. In other embodiments, the region is a region in a non-coding region of the viral genome. In certain embodiments, two regions of two viruses are analogous to each other if the two regions support the same or a similar function in the two viruses. In certain other embodiments, two regions of two viruses are analogous if the two regions provide the same of a similar structural element in the two viruses. In more specific embodiments, two regions are analogous if they encode analogous protein domains in the two viruses, wherein analogous protein domains are domains that have the same or a similar function and/or structure. In certain embodiments, one or more of regions of a genome of a metapneumovirus, such as a mammalian metapneumovirus, e.g., hMPV, or APV, is/are replaced with the analogous region(s) of the genome of another paramyxovirus. In certain embodiments, one or more of regions of the genome of a paramyxovirus is/are replaced with the analogous region(s) of the genome of a mammalian metapneumovirus, e.g., hMPV, or APV. In more specific embodiments, a region of the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene or the L-gene or any combination of two or more regions of these genes of a mammalian metapneumovirus, e.g., hMPV, is replaced with the analogous region of another viral species, strain or isolate. Another viral species can be, but is not limited to, another mammalian metapneumovirus, APV, or RSV. In more specific embodiments, one or more regions of human metapneumovirus are replaced with the analogous region(s) of another isolate of human metapneumovirus. E.g., one or more region(s) of the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the M2-1 ORF, the M2-2 ORF, the SH-gene, the G-gene or the L-gene or any combination of two or more regions of isolate NL/1/99 (99-1), NL/1/00 (00-1), NL/17/00, or NL/1/94 is replaced with the analogous region(s) of a different isolate of hMPV, e.g., NL/1/99 (99-1), NL/1/00 (00-1), NL/17/00, or NL/1/94. In certain embodiments, the region is at least 5 nucleotides (nt) in length, at least 10 nt, at least 25 nt, at least 50 nt, at least 75 nt, at least 100 nt, at least 250 nt, at least 500 nt, at least 750 nt, at least 1 kb, at least 1.5 kb, at least 2 kb, at least 2.5 kb, at least 3 kb, at least 4 kb, or at least 5 kb in length. In certain embodiments, the region is at most 5 nucleotides (nt) in length, at most 10 nt, at most 25 nt, at most 50 nt, at most 75 nt, at most 100 nt, at most 250 nt, at most 500 nt, at most 750 nt, at most I kb, at most 1.5 kb, at most 2 kb, at most 2.5 kb, at most 3 kb, at most 4 kb, or at most 5 kb in length. 5.8 Assays for Use With the Invention A number of assays may be employed in accordance with the present invention in order to determine the rate of growth of a chimeric or recombinant virus in a cell culture system, an animal model system or in a subject. A number of assays may also be employed in accordance with the present invention in order to determine the requirements of the chimeric and recombinant viruses to achieve infection, replication and packaging of virions. The assays described herein may be used to assay viral titre over time to determine the growth characteristics of the virus. In a specific embodiment, the viral titre is determined by obtaining a sample from the infected cells or the infected subject, preparing a serial dilution of the sample and infecting a monolayer of cells that are susceptible to infection with the virus at a dilution of the virus that allows for the emergence of single plaques. The plaques can then be counted and the viral titre express as plaque forming units per milliliter of sample. In a specific embodiment of the invention, the growth rate of a virus of the invention in a subject is estimated by the titer of antibodies against the virus in the subject. Without being bound by theory, the antibody titer in the subject reflects not only the viral titer in the subject but also the antigenicity. If the antigenicity of the virus is constant, the increase of the antibody titer in the subject can be used to determine the growth curve of the virus in the subject. In a preferred embodiment, the growth rate of the virus in animals or humans is best tested by sampling biological fluids of a host at multiple time points post-infection and measuring viral titer. The expression of heterologous gene sequence in a cell culture system or in a subject can be determined by any technique known to the skilled artisan. In certain embodiments, the expression of the heterologous gene is measured by quantifying the level of the transcript. The level of the transcript can be measured by Northern blot analysis or by RT-PCR using probes or primers, respectively, that are specific for the transcript. The transcript can be distinguished from the genome of the virus because the virus is in the antisense orientation whereas the transcript is in the sense orientation. In certain embodiments, the expression of the heterologous gene is measured by quantifying the level of the protein product of the heterologous gene. The level of the protein can be measured by Western blot analysis using antibodies that are specific to the protein. In a specific embodiment, the heterologous gene is tagged with a peptide tag. The peptide tag can be detected using antibodies against the peptide tag. The level of peptide tag detected is representative for the level of protein expressed from the heterologous gene. Alternatively, the protein expressed from the heterologous gene can be isolated by virtue of the peptide tag. The amount of the purified protein correlates with the expression level of the heterologous gene. Such peptide tags and methods for the isolation of proteins fused to such a peptide tag are well known in the art. A variety of peptide tags known in the art may be used in the modification of the heterologous gene, such as, but not limited to, the immunoglobulin constant regions, polyhistidine sequence (Petty, 1996, Metal-chelate affinity chromatography, in Current Protocols in Molecular Biology, volume 1-3 (1994-1998). Ed. by Ausubel, F. M., Brent, R., Kunston, R. E., Moore, D. D., Seidman, J. G., Smith, J. A. and Struhl, K. Published by John Wiley and sons, Inc., USA, Greene Publish. Assoc. & Wiley Interscience), glutathione S-transferase (GST; Smith, 1993, Methods Mol. Cell Bio. 4:220-229), the E. coli maltose binding protein (Guan et al., 1987, Gene 67:21-30), various cellulose binding domains (U.S. Pat. Nos. 5,496,934; 5,202,247; 5,137,819; Tomme et al., 1994, Protein Eng. 7:117-123), and the FLAG epitope (Short Protocols in Molecular Biology, 1999, Ed. Ausubel et al., John Wiley & Sons, Inc., Unit 10.11) etc. Other peptide tags are recognized by specific binding partners and thus facilitate isolation by affinity binding to the binding partner, which is preferably immobilized and/or on a solid support. As will be appreciated by those skilled in the art, many methods can be used to obtain the coding region of the above-mentioned peptide tags, including but not limited to, DNA cloning, DNA amplification, and synthetic methods. Some of the peptide tags and reagents for their detection and isolation are available commercially. Samples from a subject can be obtained by any method known to the skilled artisan. In certain embodiments, the sample consists of nasal aspirate, throat swab, sputum or broncho-alveolar lavage. 5.8.1 Minireplicon Constructs The production of live virus from cDNA provides a means for characterizing hMPV and also for producing attenuated vaccine strains and immunogenic compounds. In order to accomplish this goal, cDNA or minireplicon constructs that encode vRNAs containing a reporter gene can be used to rescue virus and also to identify the nucleotide sequences and proteins involved in amplification, expression, and incorporation of RNAs into virions. Any reporter gene known to the skilled artisan can be used with the invention (see section 5.8.2). For example, reporter genes that can be used include, but are not limited to, genes that encode GFP, HRP, LUC, and AP. (Also see section 5.8.2 for a more extensive list of examples of reporters) In one specific embodiment, the reporter gene that is used encodes CAT. In another specific embodiment of the invention, the reporter gene is flanked by leader and trailer sequences. The leader and trailer sequences that can be used to flank the reporter genes are those of any negative-sense virus, including, but not limited to, MPV, RSV, and APV. For example, the reporter gene can be flanked by the negative-sense hMPV or APV leader linked to the hepatitis delta ribozyme (Hep-d Ribo) and T7 polymerase termination (T-T7) signals, and the hMPV or APV trailer sequence preceded by the T7 RNA polymerase promoter. In certain embodiments, the plasmid encoding the minireplicon is transfected into a host cell. In a more specific embodiment of the invention, hMPV is rescued in a host cell expressing T7 RNA polymerase, the N gene, the P gene, the L gene, and the M2. 1 gene. In certain embodiments, the host cell is transfected with plasmids encoding T7 RNA polymerase, the N gene, the P gene, the L gene, and the M2.1 gene. In other embodiments, the plasmid encoding the minireplicon is transfected into a host cell and the host cell is infected with a helper virus. The hMPV minireplicon can be rescued using a number of polymerases, including, but not limited to, interspecies and intraspecies polymerases. In a certain embodiment, the hMPV minireplicon is rescued in a host cell expressing the minimal replication unit necessary for hMPV replication. For example, hMPV can be rescued from a cDNA using a number of polymerases, including, but not limited to, the polymerase of RSV, APV, MPV, or PIV. In a specific embodiment of the invention, hMPV is rescued using the polymerase of an RNA virus. In a more specific embodiment of the invention, hMPV is rescued using the polymerase of a negative stranded RNA virus. In an even more specific embodiment of the invention, hMPV is rescued using RSV polymerase. In another embodiment of the invention, hMPV is rescued using APV polymerase. In yet another embodiment of the invention, hMPV is rescued using an MPV polymerase. In another embodiment of the invention, hMPV is rescued using PIV polymerase. In another embodiment of the invention, hMPV is rescued from a cDNA using a complex of hMPV polymerase proteins. For example, the hMPV minireplicon can be rescued using a polymerase complex consisting of the L, P, N, and M2-1 proteins. In another embodiment of the invention, the polymerase complex consists of the L, P, and N proteins. In yet another embodiment of the invention, the hMPV minireplicon can be rescued using a polymerase complex consisting of polymerase proteins from other viruses, such as, but not limited to, RSV, PIV, and APV. In particular, the hMPV minireplicon can be rescued using a polymerase complex consisting of the L, P, N, and M2-1 proteins of RSV, PIV, or APV. In yet another embodiment of the invention, the polymerase complex used to rescue the hMPV minireplicon consists of the L, P, and N proteins of RSV, PIV, or APV. In even another embodiment of the invention, different polymerase proteins from various viruses can be used to form the polymerase complex. In such an embodiment, the polymerase used to rescue the hMPV minireplicon can be formed by different components of the RSV, PIV, or APV polymerases. By way of example, and not meant to limit the possible combination, in forming a complex, the N protein can be encoded by the N gene of RSV, APV, or PIV, while the L protein is encoded by the L gene of RSV, APV, or PIV, and P protein can be encoded by the P gene of RSV, APV, or PIV. One skilled in the art would be able to determine the possible combinations that may be used to form the polymerase complex necessary to rescue the hMPV minireplicon. In the minireplicon system, the expression of a reporter gene is measured in order to confirm the successful rescue of the virus and also to characterize the virus. The expression level of the reporter gene and/or its activity can be assayed by any method known to the skilled artisan, such as, but not limited to, the methods described in section 5.8.2. In certain, more specific, embodiments, the minireplicon comprises the following elements, in the order listed: T7 RNA Polymerase or RNA polymerase I, leader sequence, gene start, GFP, trailer sequence, Hepatitis delta ribozyme sequence or RNA polymerase I termination sequence. If T7 is used as RNA polymerase, Hepatitis delta ribozyme sequence should be used as termination sequence. If RNA polymerase I is used, RNA polymerase I termination sequence may be used as a termination signal. Dependent on the rescue system, the sequence of the minireplicon can be in the sense or antisense orientation. In certain embodiments, the leader sequence can be modified relative to the wild type leader sequence of hMPV. The leader sequence can optionally be preceded by an AC. The T7 promoter sequence can be with or without a G-doublet or triplet, where the G-doublet or triplet provides for increased transcription. In a specific embodiment, a cell is infected with hMPV at T0. 24 hours later, at T24, the cell is transfected with a minireplicon construct. 48 hours after T0 and 72 hours after T0, the cells are tested for the expression of the reporter gene. If a fluorescent reporter gene product is used (e.g., GFP), the expression of the reporter gene can be tested using FACS. In another embodiment, a cell is transfected with six plasmids at T=0 hours. Cells are then harvested at T=40 hours and T=60 hours and analyzed for CAT or GFP expression. (See FIG. 25.) In another specific embodiment, a cell is infected with MVA-T7 at T0. 1 hour later, at T1, the cell is transfected with a minireplicon construct. 24 hours after T0, the cell is infected with hMPV. 72 hours after T0, the cells are tested for the expression of the reporter gene. If a fluorescent reporter gene product is used (e.g., GFP), the expression of the reporter gene can be tested using FACS. 5.8.2 Reporter Genes In certain embodiments, assays for measurement of reporter gene expression in tissue culture or in animal models can be used with the methods of the invention. The nucleotide sequence of the reporter gene is cloned into the virus, such as APV, hMPV, hMPV/APV or APV/hMPV, wherein (i) the position of the reporter gene is changed and (ii) the length of the intergenic regions flanking the reporter gene are varied. Different combinations are tested to determine the optimal rate of expression of the reporter gene and the optimal replication rate of the virus comprising the reporter gene. In certain embodiments, minireplicon constructs are generated to include a reporter gene. The construction of minireplicon constructs is described herein. The abundance of the reporter gene product can be determined by any technique known to the skilled artisan. Such techniques include, but are not limited to, Northern blot analysis or Western blot analysis using probes or antibodies, respectively, that are specific to the reporter gene. In certain embodiments, the reporter gene emits a fluorescent signal that can be detected in a FACS. FACS can be used to detect cells in which the reporter gene is expressed. Techniques for practicing the specific aspect of this invention will employ, unless otherwise indicated, conventional techniques of molecular biology, microbiology, and recombinant DNA manipulation and production, which are routinely practiced by one of skill in the art. See, e.g., Sambrook et al., Molecular cloning, a laboratory manual, second ed., vol. 1-3. (Cold Spring Harbor Laboratory, 1989), A Laboratory Manual, Second Edition; DNA Cloning, Volumes I and II (Glover, Ed. 1985); and Transcription and Translation (Hames & Higgins, Eds. 1984). The biochemical activity of the reporter gene product represents the expression level of the reporter gene. The total level of reporter gene activity depends also on the replication rate of the recombinant virus of the invention. Thus, to determine the true expression level of the reporter gene from the recombinant virus, the total expression level should be divided by the titer of the recombinant virus in the cell culture or the animal model. Reporter genes that can be used with the methods of invention include, but are not limited to, the genes listed in the Table 4 below: TABLE 4 Reporter genes and the biochemical properties of the respective reporter gene products Reporter Gene Protein Activity & Measurement CAT Transfers radioactive acetyl groups to (chloramphenicol chloramphenicol or detection by thin layer acetyltransferase) chromatography and autoradiography GAL (b-galactosidase) Hydrolyzes colorless galactosides to yield colored products. GUS (b-glucuronidase) Hydrolyzes colorless glucuronides to yield colored products. LUC (luciferase) Oxidizes luciferin, emitting photons GFP (green fluorescent fluorescent protein without substrate protein) SEAP (secreted luminescence reaction with suitable substrates alkaline phosphatase) or with substrates that generate chromophores HRP (horseradish in the presence of hydrogen oxide, oxidation peroxidase) of 3,3′,5,5′-tetramethylbenzidine to form a colored complex AP (alkaline luminescence reaction with suitable substrates phosphatase) or with substrates that generate chromophores The abundance of the reporter gene can be measured by, inter alia, Western blot analysis or Northern blot analysis or any other technique used for the quantification of transcription of a nucleotide sequence, the abundance of its mRNA its protein (see Short Protocols in Molecular Biology, Ausubel et al., (editors), John Wiley & Sons, Inc., 4th edition, 1999). In certain embodiments, the activity of the reporter gene product is measured as a readout of reporter gene expression from the recombinant virus. For the quantification of the activity of the reporter gene product, biochemical characteristics of the reporter gene product can be employed (see Table 4). The methods for measuring the biochemical activity of the reporter gene products are well-known to the skilled artisan. A more detailed description of illustrative reporter genes that can be used with the methods of the invention is set forth below. 5.8.3 Measurement of Incidence of Infection Rate The incidence of infection can be determined by any method well-known in the art, for example, but not limited to, clinical samples (e.g., nasal swabs) can be tested for the presence of a virus of the invention by immunofluorescence assay (IFA) using an anti-APV-antigen antibody, an anti-hMPV-antigen antibody, an anti-APV-antigen antibody, and/or an antibody that is specific to the gene product of the heterologous nucleotide sequence, respectively. In certain embodiments, samples containing intact cells can be directly processed, whereas isolates without intact cells should first be cultured on a permissive cell line (e.g. HEp-2 cells). In an illustrative embodiments, cultured cell suspensions should be cleared by centrifugation at, e.g., 300×g for 5 minutes at room temperature, followed by a PBS, pH 7.4 (Ca++ and Mg++ free) wash under the same conditions. Cell pellets are resuspended in a small volume of PBS for analysis. Primary clinical isolates containing intact cells are mixed with PBS and centrifuged at 300×g for 5 minutes at room temperature. Mucus is removed from the interface with a sterile pipette tip and cell pellets are washed once more with PBS under the same conditions. Pellets are then resuspended in a small volume of PBS for analysis. Five to ten microliters of each cell suspension are spotted per 5 mm well on acetone washed 12-well HTC supercured glass slides and allowed to air dry. Slides are fixed in cold (−20° C.) acetone for 10 minutes. Reactions are blocked by adding PBS—1% BSA to each well followed by a 10 minute incubation at room temperature. Slides are washed three times in PBS—0.1% Tween-20 and air dried. Ten microliters of each primary antibody reagent diluted to 250 ng/ml in blocking buffer is spotted per well and reactions are incubated in a humidified 37° C. environment for 30 minutes. Slides are then washed extensively in three changes of PBS—0.1% Tween-20 and air dried. Ten microliters of appropriate secondary conjugated antibody reagent diluted to 250 ng/ml in blocking buffer are spotted per respective well and reactions are incubated in a humidified 37° C. environment for an additional 30 minutes. Slides are then washed in three changes of PBS—0.1% Tween-20. Five microliters of PBS—50% glycerol—10 mM Tris pH 8.0-1 mM EDTA are spotted per reaction well, and slides are mounted with cover slips. Each reaction well is subsequently analyzed by fluorescence microscopy at 200× power using a B-2A filter (EX 450-490 nm). Positive reactions are scored against an autofluorescent background obtained from unstained cells or cells stained with secondary reagent alone. Positive reactions are characterized by bright fluorescence punctuated with small inclusions in the cytoplasm of infected cells. 5.8.4 Measurement of Serum Titer Antibody serum titer can be determined by any method well-known in the art, for example, but not limited to, the amount of antibody or antibody fragment in serum samples can be quantitated by a sandwich ELISA. Briefly, the ELISA consists of coating microtiter plates overnight at 4° C. with an antibody that recognizes the antibody or antibody fragment in the serum. The plates are then blocked for approximately 30 minutes at room temperature with PBS-Tween—0.5% BSA. Standard curves are constructed using purified antibody or antibody fragment diluted in PBS-TWEEN-BSA, and samples are diluted in PBS-BSA. The samples and standards are added to duplicate wells of the assay plate and are incubated for approximately 1 hour at room temperature. Next, the non-bound antibody is washed away with PBS-TWEEN and the bound antibody is treated with a labeled secondary antibody (e.g., horseradish peroxidase conjugated goat-anti-human IgG) for approximately 1 hour at room temperature. Binding of the labeled antibody is detected by adding a chromogenic substrate specific for the label and measuring the rate of substrate turnover, e.g., by a spectrophotometer. The concentration of antibody or antibody fragment levels in the serum is determined by comparison of the rate of substrate turnover for the samples to the rate of substrate turnover for the standard curve at a certain dilution. 5.8.5 Serological Tests In certain embodiments of the invention, the presence of antibodies that bind to a component of a mammalian MPV is detected. In particular the presence of antibodies directed to a protein of a mammalian MPV can be detected in a subject to diagnose the presence of a mammalian MPV in the subject. Any method known to the skilled artisan can be used to detect the presence of antibodies directed to a component of a mammalian MPV. In another embodiment, serological tests can be conducted by contacting a sample, from a host suspected of being infected with MPV, with an antibody to an MPV or a component thereof, and detecting the formation of a complex. In such an embodiment, the serological test can detect the presence of a host antibody response to MPV exposure. The antibody that can be used in the assay of the invention to detect host antibodies or MPV components can be produced using any method known in the art. Such antibodies can be engineered to detect a variety of epitopes, including, but not limited to, nucleic acids, amino acids, sugars, polynucleotides, proteins, carbohydrates, or combinations thereof. In another embodiment of the invention, serological tests can be conducted by contacting a sample from a host suspected of being infected with MPV, with an a component of MPV, and detecting the formation of a complex. Examples of such methods are well known in the art, including but are not limited to, direct immunofluoresence, ELISA, western blot, immunochromatography. In an illustrative embodiment, components of mammalian MPV are linked to a solid support. In a specific embodiment, the component of the mammalian MPV can be, but is not limited to, the F protein or the G protein. Subsequently, the material that is to be tested for the presence of antibodies directed to mammalian MPV is incubated with the solid support under conditions conducive to the binding of the antibodies to the mammalian MPV components. Subsequently, the solid support is washed under conditions that remove any unspecifically bound antibodies. Following the washing step, the presence of bound antibodies can be detected using any technique known to the skilled artisan. In a specific embodiment, the mammalian MPV protein-antibody complex is incubated with detectably labeled antibody that recognizes antibodies that were generated by the species of the subject, e.g., if the subject is a cotton rat, the detectably labeled antibody is directed to rat antibodies, under conditions conducive to the binding of the detectably labeled antibody to the antibody that is bound to the component of mammalian MPV. In a specific embodiment, the detectably labeled antibody is conjugated to an enzymatic activity. In another embodiment, the detectably labeled antibody is radioactively labeled. The complex of mammalian MPV protein-antibody-detectably labeled antibody is then washed, and subsequently the presence of the detectably labeled antibody is quantified by any technique known to the skilled artisan, wherein the technique used is dependent on the type of label of the detectably labeled antibody. 5.8.6 BIAcore Assay Determination of the kinetic parameters of antibody binding can be determined for example by the injection of 250 μL of monoclonal antibody (“mAb”) at varying concentration in HBS buffer containing 0.05% Tween-20 over a sensor chip surface, onto which has been immobilized the antigen. The antigen can be any component of a mammalian MPV. In a specific embodiment, the antigen can be, but is not limited to, the F protein or the G protein of a mammalian MPV. The flow rate is maintained constant at 75uL/min. Dissociation data is collected for 15 min, or longer as necessary. Following each injection/dissociation cycle, the bound mAb is removed from the antigen surface using brief, 1 min pulses of dilute acid, typically 10-100 mM HCl, though other regenerants are employed as the circumstances warrant. More specifically, for measurement of the rates of association, kon, and dissociation, koff, the antigen is directly immobilized onto the sensor chip surface through the use of standard amine coupling chemistries, namely the EDC/NHS method (EDC═N-diethylaminopropyl)-carbodiimide). Briefly, a 5-100 nM solution of the antigen in 10 mM NaOAc, pH 4 or pH 5 is prepared and passed over the EDC/NHS-activated surface until approximately 30-50 RU's (Biacore Resonance Unit) worth of antigen are immobilized. Following this, the unreacted active esters are “capped” off with an injection of 1M Et-NH2. A blank surface, containing no antigen, is prepared under identical immobilization conditions for reference purposes. Once a suitable surface has been prepared, an appropriate dilution series of each one of the antibody reagents is prepared in HBS/Tween-20, and passed over both the antigen and reference cell surfaces, which are connected in series. The range of antibody concentrations that are prepared varies depending on what the equilibrium binding constant, KD, is estimated to be. As described above, the bound antibody is removed after each injection/dissociation cycle using an appropriate regenerant. Once an entire data set is collected, the resulting binding curves are globally fitted using algorithms supplied by the instrument manufacturer, BIAcore, Inc. (Piscataway, N.J.). All data are fitted to a 1:1 Langmuir binding model. These algorithm calculate both the kon and the koff, from which the apparent equilibrium binding constant, KD, is deduced as the ratio of the two rate constants (i.e. koff/kon). More detailed treatments of how the individual rate constants are derived can be found in the BIAevaluation Software Handbook (BIAcore, Inc., Piscataway, N.J.). 5.8.7 Microneutralization Assay The ability of antibodies or antigen-binding fragments thereof to neutralize virus infectivity is determined by a microneutralization assay. This microneutralization assay is a modification of the procedures described by Anderson et al., (1985, J. Clin. Microbiol. 22:1050-1052, the disclosure of which is hereby incorporated by reference in its entirety). The procedure is also described in Johnson et al., 1999, J. Infectious Diseases 180:35-40, the disclosure of which is hereby incorporated by reference in its entirety. Antibody dilutions are made in triplicate using a 96-well plate. 106 TCID50 of a mammalian MPV are incubated with serial dilutions of the antibody or antigen-binding fragments thereof to be tested for 2 hours at 37_C in the wells of a 96-well plate. Cells susceptible to infection with a mammalian MPV, such as, but not limited to Vero cells (2.5×104) are then added to each well and cultured for 5 days at 37_C in 5% CO2. After 5 days, the medium is aspirated and cells are washed and fixed to the plates with 80% methanol and 20% PBS. Virus replication is then determined by viral antigen, such as F protein expression. Fixed cells are incubated with a biotin-conjugated anti-viral antigen, such as anti-F protein monoclonal antibody (e.g., pan F protein, C-site-specific MAb 133-1H) washed and horseradish peroxidase conjugated avidin is added to the wells. The wells are washed again and turnover of substrate TMB (thionitrobenzoic acid) is measured at 450 nm. The neutralizing titer is expressed as the antibody concentration that causes at least 50% reduction in absorbency at 450 nm (the OD450) from virus-only control cells. The microneutralization assay described here is only one example. Alternatively, standard neutralization assays can be used to determine how significantly the virus is affected by an antibody. 5.8.8 Viral Fusion Inhibition Assay This assay is in principle identical to the microneutralization assay, except that the cells are infected with the respective virus for four hours prior to addition of antibody and the read-out is in terms of presence of absence of fusion of cells (Taylor et al., 1992, J. Gen. Virol. 73:2217-2223). 5.8.9 Isothermal Titration Calorimetry Thermodynamic binding affinities and enthalpies are determined from isothermal titration calorimetry (ITC) measurements on the interaction of antibodies with their respective antigen. Antibodies are diluted in dialysate and the concentrations were determined by UV spectroscopic absorption measurements with a Perkin-Elmer Lambda 4B Spectrophotometer using an extinction coefficient of 217,000 M−1 cm−1 at the peak maximum at 280 nm. The diluted mammalian MPV-antigen concentrations are calculated from the ratio of the mass of the original sample to that of the diluted sample since its extinction coefficient is too low to determine an accurate concentration without employing and losing a large amount of sample. ITC Measurements The binding thermodynamics of the antibodies are determined from ITC measurements using a Microcal, Inc. VP Titration Calorimeter. The VP titration calorimeter consists of a matched pair of sample and reference vessels (1.409 ml) enclosed in an adiabatic enclosure and a rotating stirrer-syringe for titrating ligand solutions into the sample vessel. The ITC measurements are performed at 25° C. and 35° C. The sample vessel contained the antibody in the phosphate buffer while the reference vessel contains just the buffer solution. The phosphate buffer solution is saline 67 mM PO4 at pH 7.4 from HyClone, Inc. Five or ten μl aliquots of the 0.05 to 0.1 mM RSV-antigen, PIV-antigen, and/or hMPV-antigen solution are titrated 3 to 4 minutes apart into the antibody sample solution until the binding is saturated as evident by the lack of a heat exchange signal. A non-linear, least square minimization software program from Microcal, Inc., Origin 5.0, is used to fit the incremental heat of the i-th titration (ΔQ (i)) of the total heat, Qt, to the total titrant concentration, Xt, according to the following equations (I), Qt=nCtΔHboV{1+Xt/nCt+1/nKbCt−[(1+Xt/nCt+1/nKbCt)2−4Xt/nCt]1/2}/2 (1a) ΔQ(i)=Q(i)+dVi/2V{Q(i)+Q(i−1)}−Q(i−1) (1b) where Ct is the initial antibody concentration in the sample vessel, V is the volume of the sample vessel, and n is the stoichiometry of the binding reaction, to yield values of Kb, ΔHbo, and n. The optimum range of sample concentrations for the determination of Kb depends on the value of Kb and is defined by the following relationship. CtKbn≦500 (2) so that at 1 μM the maximum Kb that can be determined is less than 2.5×108 M−1. If the first titrant addition does not fit the binding isotherm, it was neglected in the final analysis since it may reflect release of an air bubble at the syringe opening-solution interface. 5.8.10 Immunoassays Immunoprecipitation protocols generally comprise lysing a population of cells in a lysis buffer such as RIPA buffer (I % NP-40 or Triton X-100, 1% sodium deoxycholate, 0.1% SDS, 0.15 M NaCl, 0.01 M sodium phosphate at pH 7.2, 1% Trasylol) supplemented with protein phosphatase and/or protease inhibitors (e.g., EDTA, PMSF, 159 aprotinin, sodium vanadate), adding the antibody of interest to the cell lysate, incubating for a period of time (e.g., to 4 hours) at 4 degrees C., adding protein A and/or protein G sepharose beads to the cell lysate, incubating for about an hour or more at 4 degrees C., washing the beads in lysis buffer and re-suspending the beads in SDS/sample buffer. The ability of the antibody of interest to immunoprecipitate a particular antigen can be assessed by, e.g., western blot analysis. One of skill in the art would be knowledgeable as to the parameters that can be modified to increase the binding of the antibody to an antigen and decrease the background (e.g., pre-clearing the cell lysate with sepharose beads). For further discussion regarding immunoprecipitation protocols see, e.g., Ausubel et al., eds., 1994, Current Protocols in Molecular Biology, Vol. 1, John Wiley & Sons, Inc., New York at pages 10, 16, 1. Western blot analysis generally comprises preparing protein samples, electrophoresis of the protein samples in a polyacrylamide gel (e.g., 8%-20% SDS-PAGE depending on the molecular weight of the antigen), transferring the protein sample from the polyacrylamide get to a membrane such as nitrocellulose, PVDF or nylon, blocking the membrane, in blocking solution (e.g., PBS with 3% BSA or non-fat milk), washing the membrane in washing buffer (e.g., PBSTween20), incubating the membrane with primary antibody (the antibody of interest) diluted in blocking buffer, washing the membrane in washing buffer, incubating the membrane with a secondary antibody (which recognizes the primary antibody, e.g., an anti-human antibody) conjugated to an enzymatic substrate (e.g., horseradish peroxidase or alkaline phosphatase) or radioactive molecule (e.g., 12P or 121I) diluted in blocking buffer, washing the membrane in wash buffer, and detecting the presence of the antigen. One of skill in the art would be knowledgeable as to the parameters that can be modified to increase the signal detected and to reduce the background noise. For further discussion regarding western blot protocols see, e.g., Ausubel et al., eds, 1994, GinTent Protocols in Molecular Biology, Vol. 1, John Wiley & Sons, Inc., New York at 10.8.1. ELISAs comprise preparing antigen, coating the well of a 96-well microtiter plate with the antigen, washing away antigen that did not bind the wells, adding the antibody of interest conjugated to a detectable compound such as an enzymatic substrate (e.g., horseradish peroxidase or alkaline phosphatase) to the wells and incubating for a period of time, washing away unbound antibodies or non-specifically bound antibodies, and detecting the presence of the antibodies specifically bound to the antigen coating the well. In ELISAs the antibody of interest does not have to be conjugated to a detectable compound; instead, a second antibody (which recognizes the antibody of interest) conjugated to a detectable compound may be added to the well. Further, instead of coating the well with the antigen, the antibody may be coated to the well. In this case, the detectable molecule could be the antigen conjugated to a detectable compound such as an enzymatic substrate (e.g., horseradish peroxidase or alkaline phosphatase). The parameters that can be modified to increase signal detection and other variations of ELISAs are well known to one of skill in the art. For further discussion regarding ELISAs see, e.g., Ausubel et al., eds, 1994, Current Protocols in Molecular Biology, Vol. 1, John Wiley & Sons, Inc., New York at 11.2.1. The binding affinity of an antibody (including a scFv or other molecule comprising, or alternatively consisting of, antibody fragments or variants thereof) to an antigen and the off-rate of an antibody-antigen interaction can be determined by competitive binding assays. One example of a competitive binding assay is a radioimmunoassay comprising the incubation of labeled antigen (e.g., 3H or 121I) with the antibody of interest in the presence of increasing amounts of unlabeled antigen, and the detection of the antibody bound to the labeled antigen. 5.8.11 Sucrose Gradient Assay The question of whether the heterologous proteins are incorporated into the virion can be further investigated by use of any biochemical assay known to the skilled artisan. In a specific embodiment, a sucrose gradient assay is used to determine whether a heterologous protein is incorporated into the virion. Infected cell lysates can be fractionated in 20-60% sucrose gradients, various fractions are collected and analyzed for the presence and distribution of heterologous proteins and the vector proteins by, e.g., Western blot analysis. The fractions and the virus proteins can also be assayed for peak virus titers by plaque assay. If the heterologous protein co-migrates with the virion the heterologous protein is associated with the virion. 5.9 Methods to Identify New Isolates of MPV The present invention relates to mammalian MPV, in particular hMPV. While the present invention provides the characterization of two serological subgroups of MPV, A and B, and the characterization of four variants of MPV A1, A2, B1 and B2, the invention is not limited to these subgroups and variants. The invention encompasses any yet to be identified isolates of MPV, including those which are characterized as belonging to the subgroups and variants described herein, or belonging to a yet to be characterized subgroup or variant. Immunoassays can be used in order to characterize the protein components that are present in a given sample. Immunoassays are an effective way to compare viral isolates using peptides components of the viruses for identification. For example, the invention provides herein a method to identify further isolates of MPV as provided herein, the method comprising inoculating an essentially MPV-uninfected or specific-pathogen-free guinea pig or ferret (in the detailed description the animal is inoculated intranasally but other was of inoculation such as intramuscular or intradermal inoculation, and using an other experimental animal, is also feasible) with the prototype isolate I-2614 or related isolates. Sera are collected from the animal at day zero, two weeks and three weeks post inoculation. The animal specifically seroconverted as measured in virus neutralization (VN) assay (For an example of a VN assay, see Example 16) and indirect IFA (For an example of IFA, see Example 11 or 14) against the respective isolate I-2614 and the sera from the seroconverted animal are used in the immunological detection of said further isolates. As an example, the invention provides the characterization of a new member in the family of Paramyxoviridae, a human metapneumovirus or metapneumovirus-like virus (since its final taxonomy awaits discussion by a viral taxonomy committee the MPV is herein for example described as taxonomically corresponding to APV) (MPV) which may cause severe RTI in humans. The clinical signs of the disease caused by MPV are essentially similar to those caused by hRSV, such as cough, myalgia, vomiting, fever broncheolitis or pneumonia, possible conjunctivitis, or combinations thereof. As is seen with hRSV infected children, specifically very young children may require hospitalization. As an example an MPV which was deposited Jan. 19, 2001 as I-2614 with CNCM, Institute Pasteur, Paris or a virus isolate phylogenetically corresponding therewith is herewith provided. Therewith, the invention provides a virus comprising a nucleic acid or functional fragment phylogenetically corresponding to a nucleic acid sequence of SEQ. ID NO:19, or structurally corresponding therewith. In particular the invention provides a virus characterized in that after testing it in phylogenetic tree analysis wherein maximum likelihood trees are generated using 100 bootstraps and 3 jumbles it is found to be more closely phylogenetically corresponding to a virus isolate deposited as I-2614 with CNCM, Paris than it is related to a virus isolate of avian pnuemovirus (APV) also known as turkey rhinotracheitis virus (TRTV), the aetiological agent of avian rhinotracheitis. It is particularly useful to use an AVP-C virus isolate as outgroup in said phylogenetic tree analysis, it being the closest relative, albeit being an essentially non-mammalian virus. 5.9.1 Bioinformatics Alignment of Sequences Two or more amino acid sequences can be compared by BLAST (Altschul, S. F. et al., 1990, J. Mol. Biol. 215:403-410) to determine their sequence homology and sequence identities to each other. Two or more nucleotide sequences can be compared by BLAST (Altschul, S. F. et al., 1990, J. Mol. Biol. 215:403-410) to determine their sequence homology and sequence identities to each other. BLAST comparisons can be performed using the Clustal W method (MacVector(tm)). In certain specific embodiments, the alignment of two or more sequences by a computer program can be followed by manual re-adjustment. The determination of percent identity between two sequences can be accomplished using a mathematical algorithm. A preferred, non-limiting example of a mathematical algorithm utilized for the comparison of two sequences is the algorithm of Karlin and Altschul, 1990, Proc. Natl. Acad. Sci. USA 87:2264-2268, modified as in Karlin and Altschul, 1993, Proc. Natl. Acad. Sci. USA 90:5873-5877. Such an algorithm is incorporated into the NBLAST and XBLAST programs of Altschul et al., 1990, J. Mol. Biol. 215:403-410. BLAST nucleotide comparisons can be performed with the NBLAST program. BLAST amino acid sequence comparisons can be performed with the XBLAST program. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al., 1997, Nucleic Acids Res.25:3389-3402. Alternatively, PSI-Blast can be used to perform an iterated search which detects distant relationships between molecules (Altschul et al., 1997, supra). When utilizing BLAST, Gapped BLAST, and PSI-Blast programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used (see http://www.ncbi.nlm.nih.gov). Another preferred, non-limiting example of a mathematical algorithm utilized for the comparison of sequences is the algorithm of Myers and Miller, 1988, CABIOS 4:11-17. Such an algorithm is incorporated into the ALIGN program (version 2.0) which is part of the GCG sequence alignment software package. When utilizing the ALIGN program for comparing amino acid sequences, a PAM120 weight residue table can be used. The gap length penalty can be set by the skilled artisan. The percent identity between two sequences can be determined using techniques similar to those described above, with or without allowing gaps. In calculating percent identity, typically only exact matches are counted. 5.9.2 Hybridization Conditions A nucleic acid which is hybridizable to a nucleic acid of a mammalian MPV, or to its reverse complement, or to its complement can be used in the methods of the invention to determine their sequence homology and identities to each other. In certain embodiments, the nucleic acids are hybridized under conditions of high stringency. By way of example and not limitation, procedures using such conditions of high stringency are as follows. Prehybridization of filters containing DNA is carried out for 8 h to overnight at 65 C in buffer composed of 6×SSC, 50 mM Tris-HCl (pH 7.5), 1 mM EDTA, 0.02% PVP, 0.02% Ficoll, 0.02% BSA, and 500 μg/ml denatured salmon sperm DNA. Filters are hybridized for 48 h at 65 C in prehybridization mixture containing 100 μg/ml denatured salmon sperm DNA and 5-20×106 cpm of 32P-labeled probe. Washing of filters is done at 37 C for 1 h in a solution containing 2×SSC, 0.01% PVP, 0.01% Ficoll, and 0.01% BSA. This is followed by a wash in 0.1×SSC at 50 C for 45 min before autoradiography. Other conditions of high stringency which may be used are well known in the art. In other embodiments of the invention, hybridization is performed under moderate of low stringency conditions, such conditions are well-known to the skilled artisan (see e.g., Sambrook et al., 1989, Molecular Cloning, A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; see also, Ausubel et al., eds., in the Current Protocols in Molecular Biology series of laboratory technique manuals, 1987-1997 Current Protocols,© 1994-1997 John Wiley and Sons, Inc.). 5.9.3 Phylogenetic Analysis This invention relates to the inference of phylogenetic relationships between isolates of mammalian MPV. Many methods or approaches are available to analyze phylogenetic relationship; these include distance, maximum likelihood, and maximum parsimony methods (Swofford, D L., et. al., Phylogenetic Inference. In Molecular Systematics. Eds. Hillis, D M, Mortiz, C, and Mable, B K. 1996. Sinauer Associates: Massachusetts, USA. pp. 407-514; Felsenstein, J., 1981, J. Mol. Evol. 17:368-376). In addition, bootstrapping techniques are an effective means of preparing and examining confidence intervals of resultant phylogenetic trees (Felsenstein, J., 1985, Evolution. 29:783-791). Any method or approach using nucleotide or peptide sequence information to compare mammalian MPV isolates can be used to establish phylogenetic relationships, including, but not limited to, distance, maximum likelihood, and maximum parsimony methods or approaches. Any method known in the art can be used to analyze the quality of phylogenetic data, including but not limited to bootstrapping. Alignment of nucleotide or peptide sequence data for use in phylogenetic approaches, include but are not limited to, manual alignment, computer pairwise alignment, and computer multiple alignment. One skilled in the art would be familiar with the preferable alignment method or phylogenetic approach to be used based upon the information required and the time allowed. In one embodiment, a DNA maximum likehood method is used to infer relationships between hMPV isolates. In another embodiment, bootstrapping techniques are used to determine the certainty of phylogenetic data created using one of said phylogenetic approaches. In another embodiment, jumbling techniques are applied to the phylogenetic approach before the input of data in order to minimize the effect of sequence order entry on the phylogenetic analyses. In one specific embodiment, a DNA maximum likelihood method is used with bootstrapping. In another specific embodiment, a DNA maximum likelihood method is used with bootstrapping and jumbling. In another more specific embodiment, a DNA maximum likelihood method is used with 50 bootstraps. In another specific embodiment, a DNA maximum likelihood method is used with 50 bootstraps and 3 jumbles. In another specific embodiment, a DNA maximum likelihood method is used with 100 bootstraps and 3 jumbles. In one embodiment, nucleic acid or peptide sequence information from an isolate of hMPV is compared or aligned with sequences of other hMPV isolates. The amino acid sequence can be the amino acid sequence of the L protein, the M protein, the N protein, the P protein, or the F protein. In another embodiment, nucleic acid or peptide sequence information from an hMPV isolate or a number of hMPV isolates is compared or aligned with sequences of other viruses. In another embodiment, phylogenetic approaches are applied to sequence alignment data so that phylogenetic relationships can be inferred and/or phylogenetic trees constructed. Any method or approach that uses nucleotide or peptide sequence information to compare hMPV isolates can be used to infer said phylogenetic relationships, including, but not limited to, distance, maximum likelihood, and maximum parsimony methods or approaches. Other methods for the phylogenetic analysis are disclosed in International Patent Application PCT/NL02/00040, published as WO 02/057302, which is incorporated in its entirety herein. In particular, PCT/NL02/00040 discloses nucleic acid sequences that are suitable for phylogenetic analysis at page 12, line 27 to page 19, line 29, which is incorporated herein by reference. For the phylogenetic analyses it is most useful to obtain the nucleic acid sequence of a non-MPV as outgroup with which the virus is to be compared, a very useful outgroup isolate can be obtained from avian pneumovirus serotype C (APV-C), see, e.g., FIG. 16. Many methods and programs are known in the art and can be used in the inference of phylogenetic relationships, including, but not limited to BioEdit, ClustalW, TreeView, and NJPlot. Methods that would be used to align sequences and to generate phylogenetic trees or relationships would require the input of sequence information to be compared. Many methods or formats are known in the art and can be used to input sequence information, including, but not limited to, FASTA, NBRF, EMBL/SWISS, GDE protein, GDE nucleotide, CLUSTAL, and GCG/MSF. Methods that would be used to align sequences and to generate phylogenetic trees or relationships would require the output of results. Many methods or formats can be used in the output of information or results, including, but not limited to, CLUSTAL, NBRF/PIR, MSF, PHYLIP, and GDE. In one embodiment, ClustalW is used in conjunction with DNA maximum likelihood methods with 100 bootstraps and 3 jumbles in order to generate phylogenetic relationships. 5.10 Generation of Antibodies The invention also relates to the generation of antibodies against a protein encoded by a mammalian MPV. In particular, the invention relates to the generation of antibodies against all MPV antigens, including the F protein, N protein, M2-1 protein, M2-2 protein, G protein, or P protein of a mammalian MPV. According to the invention, any protein encoded by a mammalian MPV, derivatives, analogs or fragments thereof, may be used as an immunogen to generate antibodies which immunospecifically bind such an immunogen. Antibodies of the invention include, but are not limited to, polyclonal, monoclonal, multispecific, human, humanized or chimeric antibodies, single chain antibodies, Fab fragments, F(ab′) fragments, fragments produced by a Fab expression library, anti-idiotypic (anti-Id) antibodies (including, e.g., anti-Id antibodies to antibodies of the invention), and epitope-binding fragments. The term “antibody,” as used herein, refers to immunoglobulin molecules and immunologically active portions of immunoglobulin molecules, i.e., molecules that contain an antigen binding site that immunospecifically binds an antigen. The immunoglobulin molecules of the invention can be of any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass of immunoglobulin molecule. Examples of immunologically active portions of immunoglobulin molecules include F(ab) and F(ab′)2 fragments which can be generated by treating the antibody with an enzyme such as pepsin or papain. In a specific embodiment, antibodies to a protein encoded by human MPV are produced. In another embodiment, antibodies to a domain a protein encoded by human MPV are produced. Various procedures known in the art may be used for the production of polyclonal antibodies against a protein encoded by a mammalian MPV, derivatives, analogs or fragments thereof. For the production of antibody, various host animals can be immunized by injection with the native protein, or a synthetic version, or derivative (e.g., fragment) thereof, including but not limited to rabbits, mice, rats, etc. Various adjuvants may be used to increase the immunological response, depending on the host species, and including but not limited to Freund's (complete and incomplete), mineral gels such as aluminum hydroxide, surface active substances such as lysolecithin, pluronic polyols, polyanions, peptides, oil emulsions, keyhole limpet hemocyanins, dinitrophenol, and potentially useful human adjuvants such as BCG (bacille Calmette-Guerin) and corynebacterium parvum. For preparation of monoclonal antibodies directed toward a protein encoded by a mammalian MPV, derivatives, analogs or fragments thereof, any technique which provides for the production of antibody molecules by continuous cell lines in culture may be used. For example, the hybridoma technique originally developed by Kohler and Milstein (1975, Nature 256:495-497), as well as the trioma technique, the human B-cell hybridoma technique (Kozbor et al., 1983, Immunology Today 4:72), and the EBV-hybridoma technique to produce human monoclonal antibodies (Cole et al., 1985, in Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96). In an additional embodiment of the invention, monoclonal antibodies can be produced in germ-free animals utilizing recent technology (PCT/US90/02545). According to the invention, human antibodies may be used and can be obtained by using human hybridomas (Cote et al., 1983, Proc. Natl. Acad. Sci. U.S.A. 80:2026-2030) or by transforming human B cells with EBV virus in vitro (Cole et al., 1985, in Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, pp. 77-96). In fact, according to the invention, techniques developed for the production of“chimeric antibodies” (Morrison et al., 1984, Proc. Natl. Acad. Sci. U.S.A. 81:6851-6855; Neuberger et al., 1984, Nature 312:604-608; Takeda et al., 1985, Nature 314:452-454) by splicing the genes from a mouse antibody molecule specific for a protein encoded by a mammalian MPV, derivatives, analogs or fragments thereof together with genes from a human antibody molecule of appropriate biological activity can be used; such antibodies are within the scope of this invention. According to the invention, techniques described for the production of single chain antibodies (U.S. Pat. No. 4,946,778) can be adapted to produce specific single chain antibodies. An additional embodiment of the invention utilizes the techniques described for the construction of Fab expression libraries (Huse et al., 1989, Science 246:1275-1281) to allow rapid and easy identification of monoclonal Fab fragments with the desired specificity for a protein encoded by a mammalian MPV, derivatives, analogs or fragments thereof. Antibody fragments which contain the idiotype of the molecule can be generated by known techniques. For example, such fragments include but are not limited to: the F(ab′)2 fragment which can be produced by pepsin digestion of the antibody molecule; the Fab′ fragments which can be generated by reducing the disulfide bridges of the F(ab′)2 fragment, the Fab fragments which can be generated by treating the antibody molecule with papain and a reducing agent, and Fv fragments. In the production of antibodies, screening for the desired antibody can be accomplished by techniques known in the art, e.g. ELISA (enzyme-linked immunosorbent assay). For example, to select antibodies which recognize a specific domain of a protein encoded by a mammalian MPV, one may assay generated hybridomas for a product which binds to a fragment of a protein encoded by a mammalian MPV containing such domain. The antibodies provided by the present invention can be used for detecting MPV and for therapeutic methods for the treatment of infections with MPV. The specificity and binding affinities of the antibodies generated by the methods of the invention can be tested by any technique known to the skilled artisan. In certain embodiments, the specificity and binding affinities of the antibodies generated by the methods of the invention can be tested as described in sections 5.8.5, 5.8.6, 5.8.7, 5.8.8 or 5.8.9. 5.11 Screening Assays to Identify Antiviral Agents The invention provides methods for the identification of a compound that inhibits the ability of a mammalian MPV to infect a host or a host cell. In certain embodiments, the invention provides methods for the identification of a compound that reduces the ability of a mammalian MPV to replicate in a host or a host cell. Any technique well-known to the skilled artisan can be used to screen for a compound that would abolish or reduce the ability of a mammalian MPV to infect a host and/or to replicate in a host or a host cell. In a specific embodiment, the mammalian MPV is a human MPV. In certain embodiments, the invention provides methods for the identification of a compound that inhibits the ability of a mammalian MPV to replicate in a mammal or a mammalian cell. More specifically, the invention provides methods for the identification of a compound that inhibits the ability of a mammalian MPV to infect a mammal or a mammalian cell. In certain embodiments, the invention provides methods for the identification of a compound that inhibits the ability of a mammalian MPV to replicate in a mammalian cell. In a specific embodiment, the mammalian cell is a human cell. For a detailed description of assays that can be used to determine virus titer see section 5.7. In certain embodiments, a cell is contacted with a test compound and infected with a mammalian MPV. In certain embodiments, a control culture is infected with a mammalian virus in the absence of a test compound. The cell can be contacted with a test compound before, concurrently with, or subsequent to the infection with the mammalian MPV. In a specific embodiment, the cell is a mammalian cell. In an even more specific embodiment, the cell is a human cell. In certain embodiments, the cell is incubated with the test compound for at least 1 minute, at least 5 minutes at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours, or at least 1 day. The titer of the virus can be measured at any time during the assay. In certain embodiments, a time course of viral growth in the culture is determined. If the viral growth is inhibited or reduced in the presence of the test compound, the test compound is identified as being effective in inhibiting or reducing the growth or infection of a mammalian MPV. In a specific embodiment, the compound that inhibits or reduces the growth of a mammalian MPV is tested for its ability to inhibit or reduce the growth rate of other viruses to test its specificity for mammalian MPV. In certain embodiments, a test compound is administered to a model animal and the model animal is infected with a mammalian MPV. In certain embodiments, a control model animal is infected with a mammalian virus in without the administration of a test compound. The test compound can be administered before, concurrently with, or subsequent to the infection with the mammalian MPV. In a specific embodiment, the model animal is a mammal. In an even more specific embodiment, the model animal can be, but is not limited to, a cotton rat, a mouse, or a monkey. The titer of the virus in the model animal can be measured at any time during the assay. In certain embodiments, a time course of viral growth in the culture is determined. If the viral growth is inhibited or reduced in the presence of the test compound, the test compound is identified as being effective in inhibiting or reducing the growth or infection of a mammalian MPV. In a specific embodiment, the compound that inhibits or reduces the growth of a mammalian MPV in the model animal is tested for its ability to inhibit or reduce the growth rate of other viruses to test its specificity for mammalian MPV. 5.12 Formulations of Vaccines, Antibodies and Antivirals In a preferred embodiment, the invention provides a proteinaceous molecule or metapneumovirus-specific viral protein or functional fragment thereof encoded by a nucleic acid according to the invention. Useful proteinaceous molecules are for example derived from any of the genes or genomic fragments derivable from a virus according to the invention. Such molecules, or antigenic fragments thereof, as provided herein, are for example useful in diagnostic methods or kits and in pharmaceutical compositions such as sub-unit vaccines. Particularly useful are the F, SH and/or G protein or antigenic fragments thereof for inclusion as antigen or subunit immunogen, but inactivated whole virus can also be used. Particularly useful are also those proteinaceous substances that are encoded by recombinant nucleic acid fragments that are identified for phylogenetic analyses, of course preferred are those that are within the preferred bounds and metes of ORFs useful in phylogenetic analyses, in particular for eliciting MPV specific antibody or T cell responses, whether in vivo (e.g. for protective purposes or for providing diagnostic antibodies) or in vitro (e.g. by phage display technology or another technique useful for generating synthetic antibodies). Also provided herein are antibodies, be it natural polyclonal or monoclonal, or synthetic (e.g. (phage) library-derived binding molecules) antibodies that specifically react with an antigen comprising a proteinaceous molecule or MPV-specific functional fragment thereof according to the invention. Such antibodies are useful in a method for identifying a viral isolate as an MPV comprising reacting said viral isolate or a component thereof with an antibody as provided herein. This can for example be achieved by using purified or non-purified MPV or parts thereof (proteins, peptides) using ELISA, RIA, FACS or different formats of antigen detection assays (Current Protocols in Immunology). Alternatively, infected cells or cell cultures may be used to identify viral antigens using classical immunofluorescence or immunohistochemical techniques. A pharmaceutical composition comprising a virus, a nucleic acid, a proteinaceous molecule or fragment thereof, an antigen and/or an antibody according to the invention can for example be used in a method for the treatment or prevention of a MPV infection and/or a respiratory illness comprising providing an individual with a pharmaceutical composition according to the invention. This is most useful when said individual comprises a human, specifically when said human is below 5 years of age, since such infants and young children are most likely to be infected by a human MPV as provided herein. Generally, in the acute phase patients will suffer from upper respiratory symptoms predisposing for other respiratory and other diseases. Also lower respiratory illnesses may occur, predisposing for more and other serious conditions. The compositions of the invention can be used for the treatment of immuno-compromised individuals including cancer patients, transplant recipients and the elderly. The invention also provides methods to obtain an antiviral agent useful in the treatment of respiratory tract illness comprising establishing a cell culture or experimental animal comprising a virus according to the invention, treating said culture or animal with an candidate antiviral agent, and determining the effect of said agent on said virus or its infection of said culture or animal. An example of such an antiviral agent comprises a MPV-neutralising antibody, or functional component thereof, as provided herein, but antiviral agents of other nature are obtained as well. The invention also provides use of an antiviral agent according to the invention for the preparation of a pharmaceutical composition, in particular for the preparation of a pharmaceutical composition for the treatment of respiratory tract illness, specifically when caused by an MPV infection or related disease, and provides a pharmaceutical composition comprising an antiviral agent according to the invention, useful in a method for the treatment or prevention of an MPV infection or respiratory illness, said method comprising providing an individual with such a pharmaceutical composition. In certain embodiments of the invention, the vaccine of the invention comprises mammalian metapneumovirus as defined herein. In certain, more specific embodiments, the mammalian metapneumovirus is a human metapneumovirus. In a preferred embodiment, the mammalian metapneumovirus to be used in a vaccine formulation has an attenuated phenotype. For methods to achieve an attenuated phenotype, see section 5.6. The invention provides vaccine formulations for the prevention and treatment of infections with PIV, RSV, APV, and/or hMPV. In certain embodiments, the vaccine of the invention comprises recombinant and chimeric viruses of the invention. In certain embodiments, the virus is attenuated. In a specific embodiment, the vaccine comprises APV and the vaccine is used for the prevention and treatment for hMPV infections in humans. Without being bound by theory, because of the high degree of homology of the F protein of APV with the F protein of hMPV, infection with APV will result in the production of antibodies in the host that will cross-react with hMPV and protect the host from infection with hMPV and related diseases. In another specific embodiment, the vaccine comprises hMPV and the vaccine is used for the prevention and treatment for APV infection in birds, such as, but not limited to, in turkeys. Without being bound by theory, because of the high degree of homology of the F protein of APV with the F protein of hMPV, infection with hMPV will result in the production of antibodies in the host that will cross-react with APV and protect the host from infection with APV and related diseases. In a specific embodiment, the invention encompasses the use of recombinant and chimeric APV/hMPV viruses which have been modified in vaccine formulations to confer protection against APV and/or hMPV. In certain embodiments, APV/hMPV is used in a vaccine to be administered to birds, to protect the birds from infection with APV. Without being bound by theory, the replacement of the APV gene or nucleotide sequence with a hMPV gene or nucleotide sequence results in an attenuated phenotype that allows the use of the chimeric virus as a vaccine. In other embodiments the APV/hMPV chimeric virus is administered to humans. Without being bound by theory the APV viral vector provides the attenuated phenotype in humans and the expression of the hMPV sequence elicits a hMPV specific immune response. In a specific embodiment, the invention encompasses the use of recombinant and chimeric hMPV/APV viruses which have been modified in vaccine formulations to confer protection against APV and/or hMPV. In certain embodiments, hMPV/APV is used in a vaccine to be administered to humans, to protect the human from infection with hMPV. Without being bound by theory, the replacement of the hMPV gene or nucleotide sequence with a APV gene or nucleotide sequence results in an attenuated phenotype that allows the use of the chimeric virus as a vaccine. In other embodiments the hMPV/APV chimeric virus is administered to birds. Without being bound by theory the hMPV backbone provides the attenuated phenotype in birds and the expression of the APV sequence elicits an APV specific immune response. In certain preferred embodiments, the vaccine formulation of the invention is used to protect against infections by a metapneumovirus and related diseases. More specifically, the vaccine formulation of the invention is used to protect against infections by a human metapneumovirus and/or an avian pneumovirus and related diseases. In certain embodiments, the vaccine formulation of the invention is used to protect against infections by (a) a human metapneumovirus and a respiratory syncytial virus; and/or (b) an avian pneumovirus and a respiratory syncytial virus. In certain embodiments, the vaccine formulation of the invention is used to protect against infections by (a) a human metapneumovirus and a human parainfluenza virus; and/or (b) an avian pneumovirus and a human parainfluenza virus, and related diseases. In certain embodiments, the vaccine formulation of the invention is used to protect against infections by (a) a human metapneumovirus, a respiratory syncytial virus, and a human parainfluenza virus; and/or (b) an avian pneumovirus, a respiratory syncytial virus, and a human parainfluenza virus, and related diseases. In certain embodiments, the vaccine formulation of the invention is used to protect against infections by a human metapneumovirus, a respiratory syncytial virus, and a human parainfluenza virus and related diseases. In certain other embodiments, the vaccine formulation of the invention is used to protect against infections by an avian pneumovirus, a respiratory syncytial virus, and a human parainfluenza virus and related diseases. Due to the high degree of homology among the F proteins of different viral species, for exemplary amino acid sequence comparisons see FIG. 9, the vaccine formulations of the invention can be used for protection from viruses different from the one from which the heterologous nucleotide sequence encoding the F protein was derived. In a specific exemplary embodiment, a vaccine formulation contains a virus comprising a heterologous nucleotide sequence derived from an avian pneumovirus type A, and the vaccine formulation is used to protect from infection by avian pneumovirus type A and avian pneumovirus type B. The invention encompasses vaccine formulations to be administered to humans and animals which are useful to protect against APV, including APV-C and APV-D, hMPV, PIV, influenza, RSV, Sendai virus, mumps, laryngotracheitis virus, simianvirus 5, human papillomavirus, measles, mumps, as well as other viruses and pathogens and related diseases. The invention further encompasses vaccine formulations to be administered to humans and animals which are useful to protect against human metapneumovirus infections and avian pneumovirus infections and related diseases. In one embodiment, the invention encompasses vaccine formulations which are useful against domestic animal disease causing agents including rabies virus, feline leukemia virus (FLV) and canine distemper virus. In yet another embodiment, the invention encompasses vaccine formulations which are useful to protect livestock against vesicular stomatitis virus, rabies virus, rinderpest virus, swinepox virus, and further, to protect wild animals against rabies virus. Attenuated viruses generated by the reverse genetics approach can be used in the vaccine and pharmaceutical formulations described herein. Reverse genetics techniques can also be used to engineer additional mutations to other viral genes important for vaccine production—i.e., the epitopes of useful vaccine strain variants can be engineered into the attenuated virus. Alternatively, completely foreign epitopes, including antigens derived from other viral or non-viral pathogens can be engineered into the attenuated strain. For example, antigens of non-related viruses such as HIV (gp160, gp120, gp41) parasite antigens (e.g., malaria), bacterial or fungal antigens or tumor antigens can be engineered into the attenuated strain. Alternatively, epitopes which alter the tropism of the virus in vivo can be engineered into the chimeric attenuated viruses of the invention. Virtually any heterologous gene sequence may be constructed into the chimeric viruses of the invention for use in vaccines. Preferably moieties and peptides that act as biological response modifiers. Preferably, epitopes that induce a protective immune response to any of a variety of pathogens, or antigens that bind neutralizing antibodies may be expressed by or as part of the chimeric viruses. For example, heterologous gene sequences that can be constructed into the chimeric viruses of the invention include, but are not limited to influenza and parainfluenza hemagglutinin neuraminidase and fusion glycoproteins such as the HN and F genes of human PIV3. In yet another embodiment, heterologous gene sequences that can be engineered into the chimeric viruses include those that encode proteins with immuno-modulating activities. Examples of immuno-modulating proteins include, but are not limited to, cytokines, interferon type 1, gamma interferon, colony stimulating factors, interleukin-1, -2, -4, -5, -6, -12, and antagonists of these agents. In addition, heterologous gene sequences that can be constructed into the chimeric viruses of the invention for use in vaccines include but are not limited to sequences derived from a human immunodeficiency virus (HIV), preferably type 1 or type 2. In a preferred embodiment, an immunogenic HIV-derived peptide which may be the source of an antigen may be constructed into a chimeric PIV that may then be used to elicit a vertebrate immune response. Such HIV-derived peptides may include, but are not limited to sequences derived from the env gene (i.e., sequences encoding all or part of gp160, gp120, and/or gp41), the pol gene (i.e., sequences encoding all or part of reverse transcriptase, endonuclease, protease, and/or integrase), the gag gene (i.e., sequences encoding all or part of p7, p6, p55, p17/1 8, p24/25), tat, rev, nef, vif, vpu, vpr, and/or vpx. Other heterologous sequences may be derived from hepatitis B virus surface antigen (HBsAg); hepatitis A or C virus surface antigens, the glycoproteins of Epstein Barr virus; the glycoproteins of human papillomavirus; the glycoproteins of respiratory syncytial virus, parainfluenza virus, Sendai virus, simianvirus 5 or mumps virus; the glycoproteins of influenza virus; the glycoproteins of herpesviruses; VP1 of poliovirus; antigenic determinants of non-viral pathogens such as bacteria and parasites, to name but a few. In another embodiment, all or portions of immunoglobulin genes may be expressed. For example, variable regions of anti-idiotypic immunoglobulins that mimic such epitopes may be constructed into the chimeric viruses of the invention. Other heterologous sequences may be derived from tumor antigens, and the resulting chimeric viruses be used to generate an immune response against the tumor cells leading to tumor regression in vivo. These vaccines may be used in combination with other therapeutic regimens, including but not limited to chemotherapy, radiation therapy, surgery, bone marrow transplantation, etc. for the treatment of tumors. In accordance with the present invention, recombinant viruses may be engineered to express tumor-associated antigens (TAAs), including but not limited to, human tumor antigens recognized by T cells (Robbins and Kawakami, 1996, Curr. Opin. Immunol. 8:628-636, incorporated herein by reference in its entirety), melanocyte lineage proteins, including gp100, MART-1/MelanA, TRP-1 (gp75), tyrosinase; Tumor-specific widely shared antigens, MAGE-1, MAGE-3, BAGE, GAGE-1, GAGE-1, N-acetylglucosaminyltransferase-V, p15; Tumor-specific mutated antigens, β-catenin, MUM-1, CDK4; Nonmelanoma antigens for breast, ovarian, cervical and pancreatic carcinoma, HER-2/neu, human papillomavirus-E6, -E7, MUC-1. In even other embodiments, a heterologous nucleotide sequence is derived from a metapneumovirus, such as human metapneumovirus and/or avian pneumovirus. In even other embodiments, the virus of the invention contains two different heterologous nucleotide sequences wherein one is derived from a metapneumovirus, such as human metapneumovirus and/or avian pneumovirus, and the other one is derived from a respiratory syncytial virus. The heterologous nucleotide sequence encodes a F protein or a G protein of the respective virus. In a specific embodiment, a heterologous nucleotide sequences encodes a chimeric F protein, wherein the chimeric F protein contains the ectodomain of a F protein of a metapneumovirus and the transmembrane domain as well as the luminal domain of a F protein of a parainfluenza virus. Either a live recombinant viral vaccine or an inactivated recombinant viral vaccine can be formulated. A live vaccine may be preferred because multiplication in the host leads to a prolonged stimulus of similar kind and magnitude to that occurring in natural infections, and therefore, confers substantial, long-lasting immunity. Production of such live recombinant virus vaccine formulations may be accomplished using conventional methods involving propagation of the virus in cell culture or in the allantois of the chick embryo followed by purification. In a specific embodiment, the recombinant virus is non-pathogenic to the subject to which it is administered. In this regard, the use of genetically engineered viruses for vaccine purposes may desire the presence of attenuation characteristics in these strains. The introduction of appropriate mutations (e.g., deletions) into the templates used for transfection may provide the novel viruses with attenuation characteristics. For example, specific missense mutations which are associated with temperature sensitivity or cold adaption can be made into deletion mutations. These mutations should be more stable than the point mutations associated with cold or temperature sensitive mutants and reversion frequencies should be extremely low. Alternatively, chimeric viruses with “suicide” characteristics may be constructed. Such viruses would go through only one or a few rounds of replication within the host. When used as a vaccine, the recombinant virus would go through limited replication cycle(s) and induce a sufficient level of immune response but it would not go further in the human host and cause disease. Recombinant viruses lacking one or more of the genes of wild type APV and hMPV, respectively, or possessing mutated genes as compared to the wild type strains would not be able to undergo successive rounds of replication. Defective viruses can be produced in cell lines which permanently express such a gene(s). Viruses lacking an essential gene(s) will be replicated in these cell lines but when administered to the human host will not be able to complete a round of replication. Such preparations may transcribe and translate—in this abortive cycle—a sufficient number of genes to induce an immune response. Alternatively, larger quantities of the strains could be administered, so that these preparations serve as inactivated (killed) virus vaccines. For inactivated vaccines, it is preferred that the heterologous gene product be expressed as a viral component, so that the gene product is associated with the virion. The advantage of such preparations is that they contain native proteins and do not undergo inactivation by treatment with formalin or other agents used in the manufacturing of killed virus vaccines. Alternatively, recombinant virus of the invention made from cDNA may be highly attenuated so that it replicates for only a few rounds. In certain embodiments, the vaccine of the invention comprises an attenuated mammalian MPV. Without being bound by theory, the attenuated virus can be effective as a vaccine even if the attenuated virus is incapable of causing a cell to generate new infectious viral particles because the viral proteins are inserted in the cytoplasmic membrane of the host thus stimulating an immune response. In another embodiment of this aspect of the invention, inactivated vaccine formulations may be prepared using conventional techniques to “kill” the chimeric viruses. Inactivated vaccines are “dead” in the sense that their infectivity has been destroyed. Ideally, the infectivity of the virus is destroyed without affecting its immunogenicity. In order to prepare inactivated vaccines, the chimeric virus may be grown in cell culture or in the allantois of the chick embryo, purified by zonal ultracentrifugation, inactivated by formaldehyde or β-propiolactone, and pooled. The resulting vaccine is usually inoculated intramuscularly. Inactivated viruses may be formulated with a suitable adjuvant in order to enhance the immunological response. Such adjuvants may include but are not limited to mineral gels, e.g., aluminum hydroxide; surface active substances such as lysolecithin, pluronic polyols, polyanions; peptides; oil emulsions; and potentially useful human adjuvants such as BCG, Corynebacterium parvum, ISCOMS and virosomes. Many methods may be used to introduce the vaccine formulations described above, these include but are not limited to oral, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, percutaneous, and intranasal and inhalation routes. It may be preferable to introduce the chimeric virus vaccine formulation via the natural route of infection of the pathogen for which the vaccine is designed. In certain embodiments, the invention relates to immunogenic compositions. The immunogenic compositions comprise a mammalian MPV. In a specific embodiment, the immunogenic composition comprises a human MPV. In certain embodiments, the immunogenic composition comprises an attenuated mammalian MPV or an attenuated human MPV. In certain embodiments, the immunogenic composition further comprises a pharmaceutically acceptable carrier. 5.13 Dosage Regimens, Administration and Formulations The present invention provides vaccines and immunogenic preparations comprising MPV and APV, including attenuated forms of the virus, recombinant forms of MPV and APV, and chimeric MPV and APV expressing one or more heterologous or non-native antigenic sequences. The vaccines or immunogenic preparations of the invention encompass single or multivalent vaccines, including bivalent and trivalent vaccines. The vaccines or immunogenic formulations of the invention are useful in providing protections against various viral infections. Particularly, the vaccines or immunogenic formulations of the invention provide protection against respiratory tract infections in a host. A recombinant virus and/or a vaccine or immunogenic formulation of the invention can be administered alone or in combination with other vaccines. Preferably, a vaccine or immunogenic formulation of the invention is administered in combination with other vaccines or immunogenic formulations that provide protection against respiratory tract diseases, such as but not limited to, respiratory syncytial virus vaccines, influenza vaccines, measles vaccines, mumps vaccines, rubella vaccines, pneumococcal vaccines, rickettsia vaccines, staphylococcus vaccines, whooping cough vaccines or vaccines against respiratory tract cancers. In a preferred embodiment, the virus and/or vaccine of the invention is administered concurrently with pediatric vaccines recommended at the corresponding ages. For example, at two, four or six months of age, the virus and/or vaccine of the invention can be administered concurrently with DtaP (IM), Hib (IM), Polio (IPV or OPV) and Hepatitis B (IM). At twelve or fifteen months of age, the virus and/or vaccine of the invention can be administered concurrently with Hib (IM), Polio (IPV or OPV), MMRII®(SubQ); Varivax®(SubQ), and hepatitis B (IM). The vaccines that can be used with the methods of invention are reviewed in various publications, e.g., The Jordan Report 2000, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, United States, the content of which is incorporated herein by reference in its entirety. A vaccine or immunogenic formulation of the invention may be administered to a subject per se or in the form of a pharmaceutical or therapeutic composition. Pharmaceutical compositions comprising an adjuvant and an immunogenic antigen of the invention (e.g., a virus, a chimeric virus, a mutated virus) may be manufactured by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes. Pharmaceutical compositions may be formulated in conventional manner using one or more physiologically acceptable carriers, diluents, excipients or auxiliaries which facilitate processing of the immunogenic antigen of the invention into preparations which can be used pharmaceutically. Proper formulation is, amongst others, dependent upon the route of administration chosen. When a vaccine or immunogenic composition of the invention comprises adjuvants or is administered together with one or more adjuvants, the adjuvants that can be used include, but are not limited to, mineral salt adjuvants or mineral salt gel adjuvants, particulate adjuvants, microparticulate adjuvants, mucosal adjuvants, and immunostimulatory adjuvants. Examples of adjuvants include, but are not limited to, aluminum hydroxide, aluminum phosphate gel, Freund's Complete Adjuvant, Freund's Incomplete Adjuvant, squalene or squalane oil-in-water adjuvant formulations, biodegradable and biocompatible polyesters, polymerized liposomes, triterpenoid glycosides or saponins (e.g., QuilA and QS-21, also sold under the trademark STIMULON, ISCOPREP), N-acetyl-muramyl-L-threonyl-D-isoglutamine (Threonyl-MDP, sold under the trademark TERMURTIDE), LPS, monophosphoryl Lipid A (3D-MLA sold under the trademark MPL). The subject to which the vaccine or an immunogenic composition of the invention is administered is preferably a mammal, most preferably a human, but can also be a non-human animal, including but not limited to, primates, cows, horses, sheep, pigs, fowl (e.g., chickens, turkeys), goats, cats, dogs, hamsters, mice and rodents. Many methods may be used to introduce the vaccine or the immunogenic composition of the invention, including but not limited to, oral, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, percutaneous, intranasal and inhalation routes, and via scarification (scratching through the top layers of skin, e.g., using a bifurcated needle). For topical administration, the vaccine or immunogenic preparations of the invention may be formulated as solutions, gels, ointments, creams, suspensions, etc. as are well-known in the art. For administration intranasally or by inhalation, the preparation for use according to the present invention can be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, e.g., gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch. For injection, the vaccine or immunogenic preparations may be formulated in aqueous solutions, preferably in physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. The solution may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the proteins may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. Determination of an effective amount of the vaccine or immunogenic formulation for administration is well within the capabilities of those skilled in the art, especially in light of the detailed disclosure provided herein. An effective dose can be estimated initially from in vitro assays. For example, a dose can be formulated in animal models to achieve an induction of an immunity response using techniques that are well known in the art. One having ordinary skill in the art could readily optimize administration to all animal species based on results described herein. Dosage amount and interval may be adjusted individually. For example, when used as an immunogenic composition, a suitable dose is an amount of the composition that when administered as described above, is capable of eliciting an antibody response. When used as a vaccine, the vaccine or immunogenic formulations of the invention may be administered in about 1 to 3 doses for a 1-36 week period. Preferably, 1 or 2 doses are administered, at intervals of about 2 weeks to about 4 months, and booster vaccinations may be given periodically thereafter. Alternate protocols may be appropriate for individual animals. A suitable dose is an amount of the vaccine formulation that, when administered as described above, is capable of raising an immunity response in an immunized animal sufficient to protect the animal from an infection for at least 4 to 12 months. In general, the amount of the antigen present in a dose ranges from about 1 pg to about 100 mg per kg of host, typically from about 10 pg to about 1 mg, and preferably from about 100 pg to about 1 μg. Suitable dose range will vary with the route of injection and the size of the patient, but will typically range from about 0.1 mL to about 5 mL. In a specific embodiment, the viruses and/or vaccines of the invention are administered at a starting single dose of at least 103 TCID50, at least 104 TCID50, at least 105 TCID50, at least 106 TCID50. In another specific embodiment, the virus and/or vaccines of the invention are administered at multiple doses. In a preferred embodiment, a primary dosing regimen at 2, 4, and 6 months of age and a booster dose at the beginning of the second year of life are used. More preferably, each dose of at least 105 TCID50, or at least 106 TCID50 is given in a multiple dosing regimen. 5.13.1 Challenge Studies This assay is used to determine the ability of the recombinant viruses of the invention and of the vaccines of the invention to prevent lower respiratory tract viral infection in an animal model system, such as, but not limited to, cotton rats or hamsters. The recombinant virus and/or the vaccine can be administered by intravenous (IV) route, by intramuscular (IM) route or by intranasal route (IN). The recombinant virus and/or the vaccine can be administered by any technique well-known to the skilled artisan. This assay is also used to correlate the serum concentration of antibodies with a reduction in lung titer of the virus to which the antibodies bind. On day 0, groups of animals, such as, but not limited to, cotton rats (Sigmodon hispidis, average weight 100 g) cynomolgous macacques (average weight 2.0 kg) are administered the recombinant or chimeric virus or the vaccine of interest or BSA by intramuscular injection, by intravenous injection, or by intranasal route. Prior to, concurrently with, or subsequent to administration of the recombinant virus or the vaccine of the invention, the animals are infected with wild type virus wherein the wild type virus is the virus against which the vaccine was generated. In certain embodiments, the animals are infected with the wild type virus at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, 1 week or 1 or more months subsequent to the administration of the recombinant virus and/or the vaccine of the invention. After the infection, cotton rats are sacrificed, and their lung tissue is harvested and pulmonary virus titers are determined by plaque titration. Bovine serum albumin (BSA) 10 mg/kg is used as a negative control. Antibody concentrations in the serum at the time of challenge are determined using a sandwich ELISA. Similarly, in macacques, virus titers in nasal and lung lavages can be measured. 5.13.2 Target Populations In certain embodiments of the invention, the target population for the therapeutic and diagnostic methods of the invention is defined by age. In certain embodiments, the target population for the therapeutic and/or diagnostic methods of the invention is characterized by a disease or disorder in addition to a respiratory tract infection. In a specific embodiment, the target population encompasses young children, below 2 years of age. In a more specific embodiment, the children below the age of 2 years do not suffer from illnesses other than respiratory tract infection. In other embodiments, the target population encompasses patients above 5 years of age. In a more specific embodiment, the patients above the age of 5 years suffer from an additional disease or disorder including cystic fibrosis, leukaemia, and non-Hodgkin lymphoma, or recently received bone marrow or kidney transplantation. In a specific embodiment of the invention, the target population encompasses subjects in which the hMPV infection is associated with immunosuppression of the hosts. In a specific embodiment, the subject is an immunocompromised individual. In certain embodiments, the target population for the methods of the invention encompasses the elderly. In a specific embodiment, the subject to be treated or diagnosed with the methods of the invention was infected with hMPV in the winter months. 5.13.3 Clinical Trials Vaccines of the invention or fragments thereof tested in in vitro assays and animal models may be further evaluated for safety, tolerance and pharmacokinetics in groups of normal healthy adult volunteers. The volunteers are administered intramuscularly, intravenously or by a pulmonary delivery system a single dose of a recombinant virus of the invention and/or a vaccine of the invention. Each volunteer is monitored at least 24 hours prior to receiving the single dose of the recombinant virus of the invention and/or a vaccine of the invention and each volunteer will be monitored for at least 48 hours after receiving the dose at a clinical site. Then volunteers are monitored as outpatients on days 3, 7, 14, 21, 28, 35, 42, 49, and 56 postdose. Blood samples are collected via an indwelling catheter or direct venipuncture using 10 ml red-top Vacutainer tubes at the following intervals: (1) prior to administering the dose of the recombinant virus of the invention and/or a vaccine of the invention; (2) during the administration of the dose of the recombinant virus of the invention and/or a vaccine of the invention; (3) 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 12 hours, 24 hours, and 48 hours after administering the dose of the recombinant virus of the invention and/or a vaccine of the invention; and (4) 3 days, 7 days 14 days, 21 days, 28 days, 35 days, 42 days, 49 days, and 56 days after administering the dose of the recombinant virus of the invention and/or a vaccine of the invention. Samples are allowed to clot at room temperature and serum will be collected after centrifugation. The amount of antibodies generated against the recombinant virus of the invention and/or a vaccine of the invention in the samples from the patients can be quantitated by ELISA. T-cell immunity (cytotoxic and helper responses) in PBMC and lung and nasal lavages can also be monitored. The concentration of antibody levels in the serum of volunteers are corrected by subtracting the predose serum level (background level) from the serum levels at each collection interval after administration of the dose of recombinant virus of the invention and/or a vaccine of the invention. For each volunteer the pharmacokinetic parameters are computed according to the model-independent approach (Gibaldi et al., eds., 1982, Pharmacokinetics, 2nd edition, Marcel Dekker, New York) from the corrected serum antibody or antibody fragment concentrations. 5.14 Methods for Detecting and Diagnosing Mammalian MPV The invention provides means and methods for the diagnosis and/or detection of MPV, said means and methods to be employed in the detection of MPV, its components, and the products of its transcription, translation, expression, propagation, and metabolic processes. More specifically, this invention provides means and methods for the diagnosis of an MPV infection in animals and in humans, said means and methods including but not limited to the detection of components of MPV, products of the life cycle of MPV, and products of a host's response to MPV exposure or infection. The methods that can be used to detect MPV or its components, and the products of its transcription, translation, expression, propagation and metabolic processes are well known in the art and include, but are not limited to, molecular based methods, antibody based methods, and cell-based methods. Examples of molecular based methods include, but are not limited to polymerase chain reaction (PCR), reverse transcriptase PCR (RT-PCR), real time RT-PCR, nucleic acid sequence based amplification (NASBA), oligonucleotide probing, southern blot hybridization, northern blot hybridization, any method that involves the contacting of a sample with a nucleic acid that is complementary to an MPV or similar or identical to an MPV, and any combination of these methods with each other or with those in the art. Identical or similar nucleic acids that can be used are described herein, and are also well known in the art to be able to allow one to distinguish between MPV and the genomic material or related products of other viruses and organisms. Examples of antibody based methods include, but are not limited to, the contacting of an antibody with a sample suspected of containing MPV, direct immunofluorescence (DIF), enzyme linked immunoabsorbent assay (ELISA), western blot, immunochromatography. Examples of cell-based methods include, but are not limited to, reporter assays that are able to emit a signal when exposed to MPV, its components, or products thereof. In another embodiment, the reporter assay is an in vitro assay, whereby the reporter is expressed upon exposure to MPV, its components, or products thereof. Examples of the aforementioned methods are well-known in the art and also described herein. In a more specific embodiment, NASBA is used to amplify specific RNA or DNA from a pool of total nucleic acids. In one embodiment, the invention provides means and methods for the diagnosis and detection of MPV, said means and methods including but not limited to the detection of genomic material and other nucleic acids that are associated with or complimentary to MPV, the detection of transcriptional and translational products of MPV, said products being both processed and unprocessed, and the detection of components of a host response to MPV exposure or infection. In one embodiment, the invention relates to the detection of MPV through the preparation and use of oligonucleotides that are complimentary to nucleic acid sequences and transcriptional products of nucleic acid sequences that are present within the genome of MPV. Furthermore, the invention relates to the detection of nucleic acids, or sequences thereof, that are present in the genome of MPV and its transcription products, using said oligonucleotides as primers for copying or amplification of specific regions of the MPV genome and its transcripts. The regions of the MPV genome and its transcripts that can be copied or amplified include but are not limited to complete and incomplete stretches of one or more of the following: the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene, and the L-gene. In a specific embodiment, oligonucleotides are used as primers in conjunction with methods to copy or amplify the N-gene of MPV, or transcripts thereof, for identification purposes. Said methods include but are not limited to, PCR assays, RT-PCR assays, real time RT-PCR assays, primer extension or run on assays, NASBA and other methods that employ the genetic material of MPV or transcripts and compliments thereof as templates for the extension of nucleic acid sequences from said oligonucleotides. In another embodiment, a combination of methods is used to detect the presence of MPV in a sample. One skilled in the art would be familiar with the requirements and applicability of each assay. For example, PCR and RT-PCR would be useful for the amplification or detection of a nucleic acid. In a more specific embodiment, real time RT-PCR is used for the routine and reliable quantitation of PCR products. In another embodiment, the invention relates to detection of MPV through the preparation and use of oligonucleotides that are complimentary to nucleic acid sequences and transcriptional products of nucleic acid sequences that are present within the genome of MPV. Furthermore, the invention relates to the detection of nucleic acids, or sequences thereof, that are present in or complimentary to the genome of MPV and its transcription products, using said oligonucleotide sequences as probes for hybridization to and detection of specific regions within or complimentary to the MPV genome and its transcripts. The regions of the MPV genome and its transcripts that can be detected using hybridization probes include but are not limited to complete and incomplete stretches of one or more of the following: the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene, and the L-gene. In a specific embodiment, oligonucleotides are used as probes in conjunction with methods to detect, anneal, or hybridize to the N-gene of MPV, or transcripts thereof, for identification purposes. Said methods include but are not limited to, Northern blots, Southern blots and other methods that employ the genetic material of MPV or transcripts and compliments thereof as targets for the hybridization, annealing, or detection of sequences or stretches of sequences within or complimentary to the MPV genome. A nucleic acid which is hybridizable to a nucleic acid of a mammalian MPV, or to its reverse complement, or to its complement can be used in the methods of the invention to detect the presence of a mammalian MPV. In certain embodiments, the nucleic acids are hybridized under conditions of high stringency. By way of example and not limitation, procedures using such conditions of high stringency are as follows. Prehybridization of filters containing DNA is carried out for 8 h to overnight at 65 C in buffer composed of 6×SSC, 50 mM Tris-HCl (pH 7.5), 1 mM EDTA, 0.02% PVP, 0.02% Ficoll, 0.02% BSA, and 500 μg/ml denatured salmon sperm DNA. Filters are hybridized for 48 h at 65 C in prehybridization mixture containing 100 μg/ml denatured salmon sperm DNA and 5-20×106 cpm of 32P-labeled probe. Washing of filters is done at 37 C for 1 h in a solution containing 2×SSC, 0.01% PVP, 0.01% Ficoll, and 0.01% BSA. This is followed by a wash in 0.1×SSC at 50 C for 45 min before autoradiography. Other conditions of high stringency which may be used are well known in the art. In other embodiments of the invention, hybridization is performed under moderate of low stringency conditions, such conditions are well-known to the skilled artisan (see e.g., Sambrook et al., 1989, Molecular Cloning, A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; see also, Ausubel et al., eds., in the Current Protocols in Molecular Biology series of laboratory technique manuals, 1987-1997 Current Protocols,© 1994-1997 John Wiley and Sons, Inc.). Any size oligonucleotides can be used in the methods of the invention. As described herein, such oligonucleotides are useful in a variety of methods, e.g., as primer or probes in various detection or analysis procedures. In preferred embodiments, oligonucleotide probes and primers are at least 5, at least 8, at least 10, at least 12, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 70, at least 80, at least 100, at least 200, at least 300 at least 400, at least 500, at least 1000, at least 2000, at least 3000, at least 4000 or at least 5000 bases. In another more certain embodiments, oligonucleotide probes and primers comprise at least 5, at least 8, at least 10, at least 12, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 70, at least 80, at least 100, at least 200, at least 300 at least 400, at least 500, at least 1000, at least 2000, at least 3000, at least 4000 or at least 5000 bases, that are at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 99%, at least 99.5% homologous to a target sequence, such as an MPV genomic sequence or complement thereof. In a another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 8 of its most 3′ terminal bases to a target sequence. In another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 10 of its most 3′ terminal bases to a target sequence. In another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 12 of its most 3′ terminal bases to a target sequence. In another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 15 of its most 3′ terminal bases to a target sequence. In another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 20 of its most 3′ terminal bases to a target sequence. In another specific embodiment, the oligonucleotide that is used as a primer or a probe is of any length, and specifically hybridizes under stringent conditions through at least 25 of its most 3′ terminal bases to a target sequence. In another embodiment, a degenerate set of oligos is used so that a specific position or nucleotide is subsituted. The degeneracy can occur at any position or at any number of positions, most preferably, at least at one position, but also at least at two positions, at least at three positions, at least ten positions, in the region that hybridizes under stringent conditions to the target sequence. One skilled in the art would be familiar with the structural requirements imposed upon oligonucleotides by the assays known in the art. It is also possible to design oligonucleotide primers and probes using more systematic approaches. For example, one skilled in the art would be able to determine the appropriate length and sequence of an oligonucleotide primer or probe based upon preferred assay or annealing temperatures and the structure of the oligo, i.e., sequence. In addition, one skilled in the art would be able to determine the specificity of the assay employing an oligonucleotide primer or probe, by adjusting the temperature of the assay so that the specificity of the oligo for the target sequence is enhanced or diminished, depending upon the termpeature. In a preferred embodiment, the annealing temperature of the primer or probe is determined, using methods known in the art, and the assay is performed at said annealing temperature. One skilled in the art would be familiar with methods to calculate the annealing tempeature associated with an oligonucleotide for its specific target sequence. For example, annealing temperatures can be roughly calculated by, assigning 4° C. to the annealing temperature for each G or C nucleotide in the oligonucleotide that hybridizes to the target sequence. In another example, annealing temperatures can be roughly calculated by, assigning 2° C. to the annealing temperature for each A or T nucleotide in the oligonucleotide that hybridizes to the target sequence. The annealing temperature of the oligonucleotide is necessarily dependent upon the length and sequence of the oligonucleotide, as well as upon the complimentarity of the oligo for the target sequence, so that only binding events between the oligo primer or probe are factored into the annealing temperature. The examples described herein for the calculation of annealing temperature are meant to be examples and are not meant to limit the invention from other methods of determination for the annealing temperature. One skilled in the art would be familiar with other methods that can be used, and in addition, other more sophisticated methods of calculating annealing or melting temperatures for an oligonucleotide have been described herein. In a more specific embodiment, oligonucleotide probes and primers are annealed at a temperature of at least 30° C., at least 35° C., at least 40° C., at least 45° C., at least 50° C., at least 55° C., at least 60° C., at least 65° C., at least 70° C., at least 80° C., at least 90° C. or at least 99° C. The invention provides cell-based and cell-free assays for the identification or detection of MPV in a sample. A variety of methods can be used to conduct the cell-based and cell-free assays of the invention, including but not limited to, those using reporters. Examples of reporters are described herein and can be used for the identification or detection of MPV using high-throughput screening and for any other purpose that would be familiar to one skilled in the art. There are a number of methods that can be used in the reporter assays of the invention. For example, the cell-based assays may be conducted by contacting a sample with a cell containing a nucleic acid sequence comprising a reporter gene, wherein the reporter gene is linked to the promoter of an MPV gene or linked to a promoter that is recognized by an MPV gene product, and measuring the expression of the reporter gene, upon exposure to MPV or a component of MPV. In a further embodiment of the cell-based assay, a host cell that is able to be infected by MPV, is transfected with a nucleic acid construct that encodes one or more reporter genes, such that expression from the reporter gene occurs in the presence of an MPV or an MPV component. In such an embodiment, expression of the reporter gene is operably linked to a nucleic acid sequence that is recognized by MPV or a component thereof, thereby causing expression of the reporter gene. The presence of MPV in the sample induces expression of the reporter gene that can be detected using any method known in the art, and also described herein (section 5.8.2). Examples of host cells that can be transfected and used in the cell-based detection assay, include, but are not limited to, Vero, tMK, COS7 cells. In another embodiment, the host cell is any cell that can be infected with MPV. The expression of the reporter gene is thereby indicative of the presence of an MPV or a component thereof. In a cell-free assay, a sample is contacted with a nucleic acid comprising a reporter gene that is operably linked to a nucleic acid sequence so that the presence of an MPV or a component thereof induces expression of the reporter gene in vitro. For example, the cell-free assay may be conducted by contacting a sample suspected of containing an MPV or a component thereof, with a nucleic acid that comprises a reporter gene, wherein the reporter gene is linked to the promoter of an MPV gene or linked to a promoter that is recognized by an MPV gene product, and measuring the expression of the reporter gene, upon exposure to MPV or a component of MPV. The expression of the reporter gene is thereby indicative of the presence of an MPV or a component thereof. While a large number of reporter compounds are known in the art, a variety of examples are provided herein (see, e.g., section 5.8.2). In another embodiment, the invention relates to the detection of MPV infection using a minireplicon system. For example, a host cell can be transfected with an hMPV minireplicon construct that encodes one or more reporter genes, such that expression from the reporter gene occurs in the presence of hMPV or hMPV polymerase. Examples of reporter genes are described herein, in section 5.8.2. In such an embodiment, hMPV acts as a helper virus to promote the expression of the reporter gene or genes encoded by the minireplicon system. Without being bound by limitation, hMPV provides polymerase that drives rescue of the minireplicon system and therefore drives expression of the reporter gene or genes. In a certain embodiment, a host cell, that has been transfected with an hMPV minireplicon, encoding a reporter gene, is contacted with a sample suspected to contain hMPV. The presence of hMPV in the sample induces expression of the reporter gene that can be detected using any method known in the art, and also described herein (section 5.8.2). Examples of the host cell, include, but are not limited to, Vero, tMK, COS7 cells. In another embodiment, the host cell is any cell that can be infected with hMPV. In another embodiment, the invention relates to the detection of an MPV infection in an animal or human host through the preparation and use of antibodies, e.g., monoclonal antibodies (MAbs), that are specific to and can recognize peptides or nucleic acids that are characteristic of MPV or its gene products. The epitopes or antigenic determinants recognized by said MAbs include but are not limited to proteinaceous and nucleic acid products that are synthesized during the life cycle and metabolic processes involved in MPV propagation. The proteinaceous or nucleic acid products that can be used as antigenic determinants for the generation of suitable antibodies include but are not limited to complete and incomplete transcription and expression products of one or more of the following components of MPV: the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene, and the L-gene. In one specific embodiment, MAbs raised against proteinaceous products of the G-gene or portions thereof are used in conjunction with other methods to detect or confirm the presence of the MPV expressed G peptide in a biological sample, e.g. body fluid. Said methods include but are not limited to ELISA, Radio-Immuno or Competition Assays, Immuno-precipitation and other methods that employ the transcribed or expressed gene products of MPV as targets for detection by MAbs raised against said targets or portions and relatives thereof. In another embodiment of the invention, the antibodies that can be used to detect hMPV, recognize the F, G, N, L, M, M2-1, P, and SH proteins of all four subtypes. In another embodiment, the invention relates to the detection of factors that are associated with and characteristic of a host's immunologic response to MPV exposure or infection. Upon exposure or infection by MPV, a host's immune system illicits a response to said exposure or infection that involves the generation by the host of antibodies directed at eliminating or attenuating the effects and/or propagation of virus. This invention provides means and methods for the diagnosis of MPV related disease through the detection of said antibodies that may be produced as a result of MPV exposure to or infection of the host. The epitopes recognized by said antibodies include but are not limited to peptides and their exposed surfaces that are accessible to a host immune response and that can serve as antigenic determinants in the generation of an immune response by the host to the virus. Some of the proteinaceous and nuclear material used by a host immune response as epitopes for the generation of antibodies include but are not limited to products of one or more of the following components of MPV: the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene, and the L-gene. In one embodiment, antibodies to partially or completely accessible portions of the N-gene encoded peptides of MPV are detected in a host sample. In a specific embodiment, proteinaceous products of the G-gene or portions thereof are used in conjunction with other methods to detect the presence of the host derived antibodies in a biological sample, e.g. body fluid. Said methods include but are not limited to ELISA, Radio-Immuno or Competition Assays, and other methods that employ the transcribed or expressed gene products of MPV as targets for detection by host antibodies that recognize said products and that are found in biological samples. This invention also provides means and methods for diagnostic assays or test kits and for methods to detect agents of an MPV infection from a variety of sources including but not limited to biological samples, e.g., body fluids. In one embodiment, this invention relates to assays, kits, protocols, and procedures that are suitable for identifying an MPV nucleic acid or a compliment thereof. In another embodiment, this invention relates to assays, kits, protocols, and procedures that are suitable for identifying an MPV expressed peptide or a portion thereof. In another embodiment, this invention relates to assays, kits, protocols, and procedures that are suitable for identifying components of a host immunologic response to MPV exposure or infection. In addition to diagnostic confirmation of MPV infection of a host, the present invention also provides for means and methods to classify isolates of MPV into distinct phylogenetic groups or subgroups. In one embodiment, this feature can be used advantageously to distinguish between the different variant of MPV, variant A1, A2, B1 and B2, in order to design more effective and subgroup specific therapies. Variants of MPV can be differentiated on the basis of nucleotide or amino acid sequences of one or more of the following: the N-gene, the P-gene, the M-gene, the F-gene, the M2-gene, the SH-gene, the G-gene, and the L-gene. In a specific embodiment, MPV can be differentiated into a specific subgroup using the nucleotide or amino acid sequence of the G gene or glycoprotein and neutralization tests using monoclonal antibodies that also recognize the G glycoprotein. In one embodiment, the diagnosis of an MPV infection in a human is made using any technique well known to one skilled in the art, e.g., immunoassays. Immunoassays which can be used to analyze immunospecific binding and cross-reactivity include, but are not limited to, competitive and non-competitive assay systems using techniques such as western blots, radioimmunoassays, ELISA (enzyme linked immunosorbent assay), sandwich immunoassays, immunoprecipitation assays, precipitin reactions, gel diffusion precipitation reactions, immunodiffusion assays, agglutination assays, complement-fixation assays, and fluorescent immunoassays, to name but a few. Such assays are routine and well known in the art (see, e.g., Ausubel et al., eds, 1994, Current Protocols in Molecular Biology, Vol. 1, John Wiley & Sons, Inc., New York, which is incorporated by reference herein in its entirety) and non-limiting examples of immunoassays are described in section 5.8. In one embodiment, the invention relates to the detection of an MPV infection using oligonucleotides in conjunction with PCR or primer extension methods to copy or amplify regions of the MPV genome, said regions including but not limited to genes or parts of genes, e.g., the N, M, F, G, L, M, P, and M2 genes. In a specific embodiment, oligonucleotides are used in conjunction with RT-PCR methods. In a further embodiment, the amplification products and/or genetic material can be probed with oligonucleotides that are complimentary to specific sequences that are either conserved between various hMPV strains or are distinct amongst various hMPV strains. The latter set of oligonucletides would allow for identification of the specific strain of hMPV responsible for the infection of the host. The invention provides methods for distinguishing between different subgroups and variants of hMPV that are capable of infecting a host. In one specific embodiment, the hMPV that is responsible for a host infection is classified into a specific subgroup, e.g., subgroup A or subgroup B. In another specific embodiment, the hMPV that is responsible for a host infection is classified as a specific variant of a subgroup, e.g., variant A1, A2, B1 , or B2. In another embodiment, the invention provides means and methods for the classification of an hMPV that is responsible for a host infection into a new subgroup and/or into a new variant of a new or existing subgroup. The methods that are able to distinguish hMPV strains into subgroups and/or variant groups would be known to one skilled in the art. In one embodiment, a polyclonal antibody is used to identify the etiological agent of an infection as a strain of hMPV, and a secondary antibody is used to distinguish said strain as characteristic of a new or known subgroup and/or new or known variant of hMPV. In one embodiment, antibodies that are selective for hMPV are used in conjunction with immunoreactive assays, e.g. ELISA or RIA, to identify the presence of hMPV exposure or infection in biological samples. In a further embodiment, secondary antibodies that are selective for specific epitopes in the peptide sequence of hMPV proteins are used to further classify the etiological agents of said identified hMPV infections into subgroups or variants. In one specific embodiment, an antibody raised against peptide epitopes that are shared between all subgroups of hMPV is used to identify the etioligical agent of an infection as an hMPV. In a further specific embodiment, antibodies raised against peptide epitopes that are unique to the different subgroups and/or variants of hMPV are used to classify the hMPV that is responsible for the host infection into a known or new subgroup and/or variant. In one specific embodiment, the antibody that is capable of distinguishing between different subgroups and/or variants of hMPV recognizes segments of hMPV peptides that are unique to the subgroup or variant, said peptides including but not limited to those encoded by the N, M, F, G, L, M, P, and M2 genes. The peptides or segments of peptides that can be used to generate antibodies capable of distinghishing between different hMPV sugroups or variants can be selected using differences in known peptide sequences of various hMPV proteins in conjunction with hydrophillicity plots to identify suitable peptide segments that would be expected to be solvent exposed or accessible in a diagnostic assay. In one embodiment, the antibody that is capable of distinguishing between the different subgroups of hMPV recongnizes differences in the F protein that are unique to different subgroups of hMPV, e.g. the amino acids at positions 286, 296, 312, 348, and 404 of the full length F protein. In another specific embodiment, the antibody that is capable of distinguishing between different subgroups and/or variants of hMPV recognizes segments of the G protein of hMPV that are unique to specific subgroups or variants, e.g., the G peptide sequence corresponding to amino acids 50 through 60 of SEQ ID:119 can be used to distinguish between subgroups A and B as well as between variants A1, A2, B1, and B2. In another embodiment of the invention, the nucleotide sequence of hMPV isolates are used to distinguish between different subgroups and/or different variants of hMPV. In one embodiment, oligonucleotide sequences, primers, and/or probes that are complimentary to sequences in the hMPV genome are used to classify the etiological agents of hMPV infections into distinct subgroups and/or variants in conjunction with methods known to one skilled in the art, e.g. RT-PCR, PCR, primer run on assays, and various blotting techniques. In one specific embodiment, a biological sample is used to copy or amplify a specific segment of the hMPV genome, using RT-PCR. In a further embodiment, the sequence of said segment is obtained and compared with known sequences of hMPV, and said comparison is used to classify the hMPV strain into a distinct subgroup or variant or to classify the hMPV strain into a new subgroup or variant. In another embodiment, the invention relates to diagnostic kits that can be used to distinguish between different subgroups and/or variants of hMPV. In a preferred embodiment, diagnosis and/or treatment of a specific viral infection is performed with reagents that are most specific for said specific virus causing said infection. In this case this means that it is preferred that said diagnosis and/or treatment of an MPV infection is performed with reagents that are most specific for MPV. This by no means however excludes the possibility that less specific, but sufficiently crossreactive reagents are used instead, for example because they are more easily available and sufficiently address the task at hand. Herein it is for example provided to perform virological and/or serological diagnosis of MPV infections in mammals with reagents derived from APV, in particular with reagents derived from APV-C, in the detailed description herein it is for example shown that sufficiently trustworthy serological diagnosis of MPV infections in mammals can be achieved by using an ELISA specifically designed to detect APV antibodies in birds. A particular useful test for this purpose is an ELISA test designed for the detection of APV antibodies (e.g in serum or egg yolk), one commercially available version of which is known as APV-Ab SVANOVIR® which is manufactured by SVANOVA Biotech AB, Uppsal Science Park Glunten SE-751 83 Uppsala Sweden. The reverse situation is also the case, herein it is for example provided to perform virological and/or serological diagnosis of APV infections in mammals with reagents derived from MPV, in the detailed description herein it is for example shown that sufficiently trustworthy serological diagnosis of APV infections in birds can be achieved by using an ELISA designed to detect MPV antibodies. Considering that antigens and antibodies have a lock-and-key relationship, detection of the various antigens can be achieved by selecting the appropriate antibody having sufficient cross-reactivity. Of course, for relying on such cross-reactivity, it is best to select the reagents (such as antigens or antibodies) under guidance of the amino acid homologies that exist between the various (glyco)proteins of the various viruses, whereby reagents relating to the most homologous proteins will be most useful to be used in tests relying on said cross-reactivity. For nucleic acid detection, it is even more straightforward, instead of designing primers or probes based on heterologous nucleic acid sequences of the various viruses and thus that detect differences between the essentially mammalian or avian Metapneumoviruses, it suffices to design or select primers or probes based on those stretches of virus-specific nucleic acid sequences that show high homology. In general, for nucleic acid sequences, homology percentages of 90% or higher guarantee sufficient cross-reactivity to be relied upon in diagnostic tests utilizing stringent conditions of hybridisation. The invention for example provides a method for virologically diagnosing a MPV infection of an animal, in particular of a mammal, more in particular of a human being, comprising determining in a sample of said animal the presence of a viral isolate or component thereof by reacting said sample with a MPV specific nucleic acid a or antibody according to the invention, and a method for serologically diagnosing an MPV infection of a mammal comprising determining in a sample of said mammal the presence of an antibody specifically directed against an MPV or component thereof by reacting said sample with a MPV-specific proteinaceous molecule or fragment thereof or an antigen according to the invention. The invention also provides a diagnostic kit for diagnosing an MPV infection comprising an MPV, an MPV-specific nucleic acid, proteinaceous molecule or fragment thereof, antigen and/or an antibody according to the invention, and preferably a means for detecting said MPV, MPV-specific nucleic acid, proteinaceous molecule or fragment thereof, antigen and/or an antibody, said means for example comprising an excitable group such as a fluorophore or enzymatic detection system used in the art (examples of suitable diagnostic kit format comprise IF, ELISA, neutralization assay, RT-PCR assay). To determine whether an as yet unidentified virus component or synthetic analogue thereof such as nucleic acid, proteinaceous molecule or fragment thereof can be identified as MPV-specific, it suffices to analyse the nucleic acid or amino acid sequence of said component, for example for a stretch of said nucleic acid or amino acid, preferably of at least 10, more preferably at least 25, more preferably at least 40 nucleotides or amino acids (respectively), by sequence homology comparison with known MPV sequences and with known non-MPV sequences APV-C is preferably used) using for example phylogenetic analyses as provided herein. Depending on the degree of relationship with said MPV or non-MPV sequences, the component or synthetic analogue can be identified. The invention also provides method for virologically diagnosing an MPV infection of a mammal comprising determining in a sample of said mammal the presence of a viral isolate or component thereof by reacting said sample with a cross-reactive nucleic acid derived from APV (preferably serotype C) or a cross-reactive antibody reactive with said APV, and a method for serologically diagnosing an MPV infection of a mammal comprising determining in a sample of said mammal the presence of a cross-reactive antibody that is also directed against an APV or component thereof by reacting said sample with a proteinaceous molecule or fragment thereof or an antigen derived from APV. Furthermore, the invention provides the use of a diagnostic kit initially designed for AVP or AVP-antibody detection for diagnosing an MPV infection, in particular for detecting said MPV infection in humans. The invention also provides methods for virologically diagnosing an APV infection in a bird comprising determining in a sample of said bird the presence of a viral isolate or component thereof by reacting said sample with a cross-reactive nucleic acid derived from MPV or a cross-reactive antibody reactive with said MPV, and a method for serologically diagnosing an APV infection of a bird comprising determining in a sample of said bird the presence of a cross-reactive antibody that is also directed against an MPV or component thereof by reacting said sample with a proteinaceous molecule or fragment thereof or an antigen derived from MPV. Furthermore, the invention provides the use of a diagnostic kit initially designed for MPV or MPV-antibody detection for diagnosing an APV infection, in particular for detecting said APV infection in poultry such as a chicken, duck or turkey. For diagnosis as for treatment, use can be made of the high degree of homology among different mammalian MPVs and between MPV and other viruses, such as, e.g., APV, in particular when circumstances at hand make the use of the more homologous approach less straightforward. Vaccinations that can not wait, such as emergency vaccinations against MPV infections can for example be performed with vaccine preparations derived from APV(preferably type C) isolates when a more homologous MPV vaccine is not available, and, vice versa, vaccinations against APV infections can be contemplated with vaccine preparations derived from MPV. Also, reverse genetic techniques make it possible to generate chimeric APV-MPV virus constructs that are useful as a vaccine, being sufficiently dissimilar to field isolates of each of the respective strains to be attenuated to a desirable level. Similar reverse genetic techniques will make it also possible to generate chimeric paramyxovirus-metapneumovirus constructs, such as RSV-MPV or P13-MPV constructs for us in a vaccine preparation. Such constructs are particularly useful as a combination vaccine to combat respiratory tract illnesses. Since MPV CPE was virtually indistinguishable from that caused by hRSV or hPIV-1 in tMK or other cell cultures, the MPV may have well gone unnoticed until now. tMK (tertiary monkey kidney cells, i.e. MK cells in a third passage in cell culture) are preferably used due to their lower costs in comparison to primary or secondary cultures. The CPE is, as well as with some of the classical Paramyxoviridae, characterized by syncytium formation after which the cells showed rapid internal disruption, followed by detachment of the cells from the monolayer. The cells usually (but not always) displayed CPE after three passages of virus from original material, at day 10 to 14 post inoculation, somewhat later than CPE caused by other viruses such as hRSV or hPIV-1. As an example, the invention provides a not previously identified paramyxovirus from nasopharyngeal aspirate samples taken from 28 children suffering from severe RTI. The clinical symptoms of these children were largely similar to those caused by hRSV. Twenty-seven of the patients were children below the age of five years and half of these were between 1 and 12 months old. The other patient was 18 years old. All individuals suffered from upper RTI, with symptoms ranging from cough, myalgia, vomiting and fever to broncheolitis and severe pneumonia. The majority of these patients were hospitalised for one to two weeks. The virus isolates from these patients had the paramyxovirus morphology in negative contrast electron microscopy but did not react with specific antisera against known human and animal paramyxoviruses. They were all closely related to one another as determined by indirect immunofluorescence assays (IFA) with sera raised against two of the isolates. Sequence analyses of nine of these isolates revealed that the virus is somewhat related to APV. Based on virological data, sequence homology as well as the genomic organisation we propose that the virus is a member of Metapneumovirus genus. Serological surveys showed that this virus is a relatively common pathogen since the seroprevalence in the Netherlands approaches 100% of humans by the age of five years. Moreover, the seroprevalence was found to be equally high in sera collected from humans in 1958, indicating this virus has been circulating in the human population for more than 40 years. The identification of this proposed new member of the Metapneumovirus genus now also provides for the development of means and methods for diagnostic assays or test kits and vaccines or serum or antibody compositions for viral respiratory tract infections, and for methods to test or screen for antiviral agents useful in the treatment of MPV infections. Methods and means provided herein are particularly useful in a diagnostic kit for diagnosing a MPV infection, be it by virological or serological diagnosis. Such kits or assays may for example comprise a virus, a nucleic acid, a proteinaceous molecule or fragment thereof, an antigen and/or an antibody according to the invention. Use of a virus, a nucleic acid, a proteinaceous molecule or fragment thereof, an antigen and/or an antibody according to the invention is also provided for the production of a pharmaceutical composition, for example for the treatment or prevention of MPV infections and/or for the treatment or prevention of respiratory tract illnesses, in particular in humans. Attenuation of the virus can be achieved by established methods developed for this purpose, including but not limited to the use of related viruses of other species, serial passages through laboratory animals or/and tissue/cell cultures, site directed mutagenesis of molecular clones and exchange of genes or gene fragments between related viruses. Four distinct subtypes of hMPV have been described, referred to as subtypes A1, A2, B1 and B2. The invention relates to the detection of hMPV in a host using a single assay that is sensitive for all four subtypes. Any method known in the art can be used to detect the presence of hMPV in a host. In a more specific embodiment of the invention, a sensitive Taqman assay is used to detect the presence of hMPV in a host. One skilled in the art would be familiar with the requirements for the design of olignoucleotides and probes for use in such assays. Such oligonucleotides and probes can be designed to specifically recognize any region of the hMPV genome, transcripts or processed and unprocessed products thereof. In a more specific embodiment of the invention, the oligonucleotides and probes of the invention are complementary to or identical to, or similar to a sequence in all subtypes of hMPV, its transcripts, or processed and unprocessed products thereof, e.g., A1, B1, A2, and B2. In particular, the oligonucleotides and probes are at least 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or 99.5% identical to a negative or positive copy of the sequence in all four subtypes of hMPV, a transcript or processed and unprocessed products thereof. In another embodiment, it is complimentary to the negative or positive copy of the sequence in all four subtypes of hMPV. Any length oligonucleotides and probes can be used in the detection of assay of invention. Typical hybridization and washing conditions that may be used are known in the art. Preferably, the conditions are such as to enable the probe to bind specifically and to prevent the binding or easy removal of nonspecific binding. In yet another more specific embodiment of the invention, the oligonucleotides and probes of the invention are complementary to any of the open reading frames within the hMPV genome, including, but not limited to, the N-gene, P-gene, F-gene, M-gene, M2-gene, SH-gene, G-gene, and L-gene, or processed and unprocessed products thereof. In an even more specific embodiment of the invention, the oligonucleotides and probes of the invention recognize the N-gene, its transcipts, or processed and unprocessed products thereof. In yet another embodiment hMPV from all four subtypes are recognized with equal specificity. Virus can be isolated from any biological sample obtainable from a host. In a more specific embodiment of the invention, nasopharyngeal samples are collected from a host for use in the detection assays of the invention. Virus can be propagated for detection purposes in a variety of cell lines that are able to support hMPV, including, but not limited to, Vero and tMK cells. The detection of viral RNA can be performed using a number of methods known to the skilled artisan. In one specific embodiment, viral RNA detection is performed using a Taqman PCR based method. 5.15 Compositions of the Invention and Components of Mammalian Metapneumovirus The invention relates to nucleic acid sequences of a mammalian MPV, proteins of a mammalian MPV, and antibodies against proteins of a mammalian MPV. The invention further relates to homologs of nucleic acid sequences of a mammalian MPV and homologs of proteins of a mammalian MPV. The invention further relates to nucleic acid sequences encoding fusion proteins, wherein the fusion protein contains a protein of a mammalian MPV or a fragment thereof and one or more peptides or proteins that are not derived from mammalian MPV. In a specific embodiment, a fusion protein of the invention contains a protein of a mammalian MPV or a fragment thereof and a peptide tag, such as, but not limited to a polyhistidine tag. The invention further relates to fusion proteins, wherein the fusion protein contains a protein of a mammalian MPV or a fragment thereof and one or more peptides or proteins that are not derived from mammalian MPV. The invention also relates to derivatives of nucleic acids encoding a protein of a mammlian MPV. The invention also relates to derivatives of proteins of a mammalian MPV. A derivative can be, but is not limited to, mutant forms of the protein, such as, but not limited to, additions, deletions, truncations, substitutions, and inversions. A derivative can further be a chimeric form of the protein of the mammalian MPV, wherein at least one domain of the protein is derived from a different protein. A derivative can also be a form of a protein of a mammalian MPV that is covalently or non-covalently linked to another molecule, such as, e.g., a drug. The viral isolate termed NL/1/00 (also 00-1) is a mammalian MPV of variant A1 and its genomic sequence is shown in SEQ ID NO:19. The viral isolate termed NL/17/00 is a mammalian MPV of variant A2 and its genomic sequence is shown in SEQ ID NO:20. The viral isolate termed NL/1/99 (also 99-1) is a mammalian MPV of variant B1 and its genomic sequence is shown in SEQ ID NO:18. The viral isolate termed NL/1/94 is a mammalian MPV of variant B2 and its genomic sequence is shown in SEQ ID NO:21. A list of sequences disclosed in the present application and the corresponding SEQ ID Nos is set forth in Table 14. The protein of a mammalian MPV can be a an N protein, a P protein, a M protein, a F protein, a M2-1 protein or a M2-2 protein or a fragment thereof. A fragment of a protein of a mammlian MPV can be can be at least 25 amino acids, at least 50 amino acids, at least 75 amino acids, at least 100 amino acids, at least 125 amino acids, at least 150 amino acids, at least 175 amino acids, at least 200 amino acids, at least 225 amino acids, at least 250 amino acids, at least 275 amino acids, at least 300 amino acids, at least 325 amino acids, at least 350 amino acids, at least 375 amino acids, at least 400 amino acids, at least 425 amino acids, at least 450 amino acids, at least 475 amino acids, at least 500 amino acids, at least 750 amino acids, at least 1000 amino acids, at least 1250 amino acids, at least 1500 amino acids, at least 1750 amino acids, at least 2000 amino acids or at least 2250 amino acids in length. A fragment of a protein of a mammlian MPV can be can be at most 25 amino acids, at most 50 amino acids, at most 75 amino acids, at most 100 amino acids, at most 125 amino acids, at most 150 amino acids, at most 175 amino acids, at most 200 amino acids, at most 225 amino acids, at most 250 amino acids, at most 275 amino acids, at most 300 amino acids, at most 325 amino acids, at most 350 amino acids, at most 375 amino acids, at most 400 amino acids, at most 425 amino acids, at most 450 amino acids, at most 475 amino acids, at most 500 amino acids, at most 750 amino acids, at most 1000 amino acids, at most 1250 amino acids, at most 1500 amino acids, at most 1750 amino acids, at most 2000 amino acids or at most 2250 amino acids in length. In certain embodiments of the invention, the protein of a mammalian MPV is a N protein, wherein the N protein is phylogenetically closer related to a N protein of a mammalian MPV, such as the N protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, (see also Table 14 for a description of the SEQ ID Nos) than it is related to the N protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a P protein, wherein the P protein is phylogenetically closer related to a P protein of a mammalian MPV, such as the P protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to the N protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a M protein, wherein the M protein is closer related to a M protein of a mammalian MPV, such as the M protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to the M protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a F protein, wherein the F protein is phylogenetically closer related to a F protein of a mammalian MPV, such as the F protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to the F protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a M2-1 protein, wherein the M2-1 protein is phylogenetically closer related to a M2-1 protein of a mammalian MPV, such as the M2-1 protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to the M2-1 protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a M2-2 protein, wherein the M2-2 protein is phylogenetically closer related to a M2-2 protein of a mammalian MPV, such as the M2-2 protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to the M2-2 protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a G protein, wherein the G protein is phylogenetically closer related to a G protein of a mammalian MPV, such as the G protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to any protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a SH protein, wherein the SH protein is phylogenetically closer related to a SH protein of a mammalian MPV, such as the SH protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to any protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a L protein, wherein the L protein is phylogenetically closer related to a L protein of a mammalian MPV, such as the SH protein encoded by, e.g., the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, than it is related to any protein of APV type C. In certain embodiments of the invention, the protein of a mammalian MPV is a N protein, wherein the N protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a N protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective N proteins are disclosed in SEQ ID NO:366-369; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a N protein, wherein the P protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a P protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective P proteins are disclosed in SEQ ID NO:374-377; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a M protein, wherein the M protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a M protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective M proteins are disclosed in SEQ ID NO:358-361; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a F protein, wherein the F protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a F protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective F proteins are disclosed in SEQ ID NO:314-317; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a M2-1 protein, wherein the M2-1 protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a M2-1 protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective M2-1 proteins are disclosed in SEQ ID NO:338-341; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a M2-2 protein, wherein the M2-2 protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a M2-2 protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective M2-2 proteins are disclosed in SEQ ID NO:346-349; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a G protein, wherein the G protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a G protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective G proteins are disclosed in SEQ ID NO:322-325; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a SH protein, wherein the SH protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a SH protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective SH proteins are disclosed in SEQ ID NO:382-385; see also Table 14). In certain embodiments of the invention, the protein of a mammalian MPV is a L protein, wherein the L protein is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the amino acid sequence of a L protein encoded by the viral genome of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective L proteins are disclosed in SEQ ID NO:330-333; see also Table 14). A fragment of a protein of mammalian MPV is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the homologous protein encoded by the virus of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 over the portion of the protein that is homologous to the fragment. In a specific, illustrative embodiment, the invention provides a fragment of the F protein of a mammalian MPV that contains the ectodomain of the F protein and homologs thereof. The homolog of the fragment of the F protein that contains the ectodomain is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the corresponding fragment containing the ectodomain of the F protein encoded by a virus of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 (the amino acid sequences of the respective F proteins are disclosed in SEQ ID NO:314-317; see also Table 14). In certain embodiments, the invention provides a protein of a mammalian MPV of subgroup A and fragments thereof. The invention provides a N protein of a mammalian MPV of subgroup A, wherein the N protein is phylogenetically closer related to the N protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the N protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a G protein of a mammalian MPV of subgroup A, wherein the G protein is phylogenetically closer related to the G protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the G protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a P protein of a mammalian MPV of subgroup A, wherein the P protein is phylogenetically closer related to the P protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the P protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a M protein of a mammalian MPV of subgroup A, wherein the M protein is phylogenetically closer related to the M protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the M protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a N protein of a mammalian MPV of subgroup A, wherein the F protein is phylogenetically closer related to the F protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the F protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a M2-1 protein of a mammalian MPV of subgroup A, wherein the M2-1 protein is phylogenetically closer related to the M2-1 protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the M2-1 protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a M2-2 protein of a mammalian MPV of subgroup A, wherein the M2-2 protein is phylogenetically closer related to the M2-2 protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the M2-2 protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a SH protein of a mammalian MPV of subgroup A, wherein the SH protein is phylogenetically closer related to the SH protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the SH protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. The invention provides a L protein of a mammalian MPV of subgroup A, wherein the L protein is phylogenetically closer related to the L protein encoded by a virus of SEQ ID NO:19 or SEQ ID NO:20 than it is related to the L protein encoded by a virus encoded by SEQ ID NO:18 or SEQ ID NO:21. In other embodiments, the invention provides a protein of a mammalian MPV of subgroup B or fragments thereof. The invention provides a N protein of a mammalian MPV of subgroup B, wherein the N protein is phylogenetically closer related to the N protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the N protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a G protein of a mammalian MPV of subgroup A, wherein the G protein is phylogenetically closer related to the G protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the G protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a P protein of a mammalian MPV of subgroup A, wherein the P protein is phylogenetically closer related to the P protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the P protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a M protein of a mammalian MPV of subgroup A, wherein the M protein is phylogenetically closer related to the M protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the M protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a N protein of a mammalian MPV of subgroup A, wherein the F protein is phylogenetically closer related to the F protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the F protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a M2-1 protein of a mammalian MPV of subgroup A, wherein the M2-1 protein is phylogenetically closer related to the M2-1 protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the M2-1 protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a M2-2 protein of a mammalian MPV of subgroup A, wherein the M2-2 protein is phylogenetically closer related to the M2-2 protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the M2-2 protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a SH protein of a mammalian MPV of subgroup A, wherein the SH protein is phylogenetically closer related to the SH protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the SH protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention provides a L protein of a mammalian MPV of subgroup A, wherein the L protein is phylogenetically closer related to the L protein encoded by a virus of SEQ ID NO:18 or SEQ ID NO:21 than it is related to the L protein encoded by a virus encoded by SEQ ID NO:19 or SEQ ID NO:20. The invention further provides proteins of a mammalian MPV of variant A1, A2, B1 or B2. In certain embodiments of the invention, the proteins of the different variants of mammalian MPV can be distinguished from each other by way of their amino acid sequence identities (see, e.g., FIG. 42b). A variant of mammalian MPV can be, but is not limited to, A1, A2, B1 or B2. The invention, however, also contemplates isolates of mammalian MPV that are members of another variant. The invention provides a G protein of a mammalian MPV variant B 1, wherein the G protein of a mammalian MPV variant B1 is phylogenetically closer related to the G protein of the prototype of variant B1, isolate NL/1/99, than it is related to the G protein of the prototype of variant A1, isolate NL/1/00, the G protein of the prototype of A2, isolate NL/17/00, or the G protein of the prototype of B2, isolate NL/1/94. The invention provides a G protein of a mammalian MPV variant B1, wherein the amino acid sequence of the G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:324). The invention provides a N protein of a mammalian MPV variant B1, wherein the N protein of a mammalian MPV variant B1 is phylogenetically closer related to the N protein of the prototype of variant B1, isolate NL/1/99, than it is related to the N protein of the prototype of variant A1, isolate NL/1/00, the N protein of the prototype of A2, isolate NL/17/00, or the N protein of the prototype of B2, isolate NL/1/94. The invention provides a N protein of a mammalian MPV variant B1, wherein the amino acid sequence of the N proteint is at least 98.5% or at least 99% or at least 99.5% identical to the N protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:368). The invention provides a P protein of a mammalian MPV variant B1, wherein the P protein of a mammalian MPV variant B1 is phylogenetically closer related to the P protein of the prototype of variant B1, isolate NL/1/99, than it is related to the P protein of the prototype of variant A1, isolate NL/1/00, the P protein of the prototype of A2, isolate NL/17/00, or the P protein of the prototype of B2, isolate NL/1/94. The invention provides a P protein of a mammalian MPV variant B1, wherein the amino acid sequence of the P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical the P protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:376). The invention provides a M protein of a mammalian MPV variant B1, wherein the M protein of a mammalian MPV variant B1 is phylogenetically closer related to the M protein of the prototype of variant B1, isolate NL/1/99, than it is related to the M protein of the prototype of variant A1, isolate NL/1/00, the M protein of the prototype of A2, isolate NL/17/00, or the M protein of the prototype of B2, isolate NL/1/94. The invention provides a M protein of a mammalian MPV variant B1, wherein the amino acid sequence of the M protein is identical the M protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:360). The invention provides a F protein of a mammalian MPV variant B1, wherein the F protein of a mammalian MPV variant B1 is phylogenetically closer related to the F protein of the prototype of variant B1, isolate NL/1/99, than it is related to the F protein of the prototype of variant A1, isolate NL/1/00, the F protein of the prototype of A2, isolate NL/17/00, or the F protein of the prototype of B2, isolate NL/1/94. The invention provides a F protein of a mammalian MPV variant B1, wherein the amino acid sequence of the F protein is at least 99% identical to the F protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:316). The invention provides a M2-1 protein of a mammalian MPV variant B1, wherein the M2-1 protein of a mammalian MPV variant B1 is phylogenetically closer related to the M2-1 protein of the prototype of variant B1, isolate NL/1/99, than it is related to the M2-1 protein of the prototype of variant A1, isolate NL/1/00, the M2-1 protein of the prototype of A2, isolate NL/17/00, or the M2-1 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-1 protein of a mammalian MPV variant B1, wherein the amino acid sequence of the M2-1 protein is at least 98% or at least 99% or at least 99.5% identical the M2-1 protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:340). The invention provides a M2-2 protein of a mammalian MPV variant B1, wherein the M2-2 protein of a mammalian MPV variant B1 is phylogenetically closer related to the M2-2 protein of the prototype of variant B1, isolate NL/1/99, than it is related to the M2-2 protein of the prototype of variant A1, isolate NL/1/00, the M2-2 protein of the prototype of A2, isolate NL/17/00, or the M2-2 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-2 protein of a mammalian MPV variant B1, wherein the amino acid sequence of the M2-2 protein is at least 99% or at least 99.5% identical the M2-2 protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:348). The invention provides a SH protein of a mammalian MPV variant B1, wherein the SH protein of a mammalian MPV variant B1 is phylogenetically closer related to the SH protein of the prototype of variant B1, isolate NL/1/99, than it is related to the SH protein of the prototype of variant A1, isolate NL/1/00, the SH protein of the prototype of A2, isolate NL/17/00, or the SH protein of the prototype of B2, isolate NL/1/94. The invention provides a SH protein of a mammalian MPV variant B1, wherein the amino acid sequence of the SH protein is at least 83%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical the SH protein of a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:384). The invention provides a L protein of a mammalian MPV variant B1, wherein the L protein of a mammalian MPV variant B1 is phylogenetically closer related to the L protein of the prototype of variant B1, isolate NL/1/99, than it is related to the L protein of the prototype of variant A1, isolate NL/1/00, the L protein of the prototype of A2, isolate NL/17/00, or the L protein of the prototype of B2, isolate NL/1/94. The invention provides a L protein of a mammalian MPV variant B1, wherein the amino acid sequence of the L protein is at least 99% or at least 99.5% identical the L protein a mammalian MPV variant B1 as represented by the prototype NL/1/99 (SEQ ID NO:332). The invention provides a G protein of a mammalian MPV variant A1, wherein the G protein of a mammalian MPV variant A1 is phylogenetically closer related to the G protein of the prototype of variant A1, isolate NL/1/00, than it is related to the G protein of the prototype of variant B1, isolate NL/1/99, the G protein of the prototype of A2, isolate NL/17/00, or the G protein of the prototype of B2, isolate NL/1/94. The invention provides a G protein of a mammalian MPV variant A1, wherein the amino acid sequence of the G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:322). The invention provides a N protein of a mammalian MPV variant A1, wherein the N protein of a mammalian MPV variant A1 is phylogenetically closer related to the N protein of the prototype of variant A1, isolate NL/1/00, than it is related to the N protein of the prototype of variant B1, isolate NL/1/99, the N protein of the prototype of A2, isolate NL/17/00, or the N protein of the prototype of B2, isolate NL/1/94. The invention provides a N protein of a mammalian MPV variant A1, wherein the amino acid sequence of the N protein is at least 99.5% identical to the N protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:366). The invention provides a P protein of a mammalian MPV variant A1, wherein the P protein of a mammalian MPV variant A1 is phylogenetically closer related to the P protein of the prototype of variant A1, isolate NL/1/00, than it is related to the P protein of the prototype of variant B1, isolate NL/1/99, the P protein of the prototype of A2, isolate NL/17/00, or the P protein of the prototype of B2, isolate NL/1/94. The invention provides a P protein of a mammalian MPV variant A1, wherein the amino acid sequence of the P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:374). The invention provides a M protein of a mammalian MPV variant A1, wherein the M protein of a mammalian MPV variant A1 is phylogenetically closer related to the M protein of the prototype of variant A1, isolate NL/1/00, than it is related to the M protein of the prototype of variant B1, isolate NL/1/99, the M protein of the prototype of A2, isolate NL/17/00, or the M protein of the prototype of B2, isolate NL/1/94. The invention provides a M protein of a mammalian MPV variant A1, wherein the amino acid sequence of the M protein is at least 99% or at least 99.5% identical to the M protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:358). The invention provides a F protein of a mammalian MPV variant A1, wherein the F protein of a mammalian MPV variant A1 is phylogenetically closer related to the F protein of the prototype of variant A1, isolate NL/1/00, than it is related to the F protein of the prototype of variant B1, isolate NL/1/99, the F protein of the prototype of A2, isolate NL/17/00, or the F protein of the prototype of B2, isolate NL/1/94. The invention provides a F protein of a mammalian MPV variant A1, wherein the amino acid sequence of the F protein is at least 98% or at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:314). The invention provides a M2-1 protein of a mammalian MPV variant A1, wherein the M2-1 protein of a mammalian MPV variant A1 is phylogenetically closer related to the M2-1 protein of the prototype of variant A1, isolate NL/1/00, than it is related to the M2-1 protein of the prototype of variant B1, isolate NL/1/99, the M2-1 protein of the prototype of A2, isolate NL/17/00, or the M2-1 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-1 protein of a mammalian MPV variant A1, wherein the amino acid sequence of the M2-1 protein is at least 99% or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:338). The invention provides a M2-2 protein of a mammalian MPV variant A1, wherein the M2-2 protein of a mammalian MPV variant A1 is phylogenetically closer related to the M2-2 protein of the prototype of variant A1, isolate NL/1/00, than it is related to the M2-2 protein of the prototype of variant B1, isolate NL/1/99, the M2-2 protein of the prototype of A2, isolate NL/17/00, or the M2-2 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-2 protein of a mammalian MPV variant A1, wherein the amino acid sequence of the M2-2 protein is at least 96% or at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:346). The invention provides a SH protein of a mammalian MPV variant A1, wherein the SH protein of a mammalian MPV variant A1 is phylogenetically closer related to the SH protein of the prototype of variant A1, isolate NL/1/00, than it is related to the SH protein of the prototype of variant B1, isolate NL/1/99, the SH protein of the prototype of A2, isolate NL/17/00, or the SH protein of the prototype of B2, isolate NL/1/94. The invention provides a SH protein of a mammalian MPV variant A1, wherein the amino acid sequence of the SH protein is at least 84%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:382). The invention provides a L protein of a mammalian MPV variant A1, wherein the L protein of a mammalian MPV variant A1 is phylogenetically closer related to the L protein of the prototype of variant A1, isolate NL/1/00, than it is related to the L protein of the prototype of variant B1, isolate NL/1/99, the L protein of the prototype of A2, isolate NL/17/00, or the L protein of the prototype of B2, isolate NL/1/94. The invention provides a L protein of a mammalian MPV variant A1, wherein the amino acid sequence of the L protein is at least 99% or at least 99.5% identical to the L protein of a virus of a mammalian MPV variant A1 as represented by the prototype NL/1/00 (SEQ ID NO:330). The invention provides a G protein of a mammalian MPV variant A2, wherein the G protein of a mammalian MPV variant A2 is phylogenetically closer related to the G protein of the prototype of variant A2, isolate NL/17/00, than it is related to the G protein of the prototype of variant B1, isolate NL/1/99, the G protein of the prototype of A1, isolate NL/1/00, or the G protein of the prototype of B2, isolate NL/1/94. The invention provides a G protein of a mammalian MPV variant A2, wherein the amino acid sequence of the G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:332). The invention provides a N protein of a mammalian MPV variant A2, wherein the N protein of a mammalian MPV variant A2 is phylogenetically closer related to the N protein of the prototype of variant A2, isolate NL/17/00, than it is related to the N protein of the prototype of variant B1, isolate NL/1/99, the N protein of the prototype of A1, isolate NL/1/00, or the N protein of the prototype of B2, isolate NL/1/94. The invention provides a N protein of a mammalian MPV variant A2, wherein the amino acid sequence of the N protein at least 99.5% identical to the N protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:367). The invention provides a P protein of a mammalian MPV variant A2, wherein the P protein of a mammalian MPV variant A2 is phylogenetically closer related to the P protein of the prototype of variant A2, isolate NL/17/00, than it is related to the P protein of the prototype of variant B1, isolate NL/1/99, the P protein of the prototype of A1, isolate NL/1/00, or the P protein of the prototype of B2, isolate NL/1/94. The invention provides a P protein of a mammalian MPV variant A2, wherein the amino acid sequence of the P protein is at least 96%, at least 98%, at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00(SEQ ID NO:375). The invention provides a M protein of a mammalian MPV variant A2, wherein the M protein of a mammalian MPV variant A2 is phylogenetically closer related to the M protein of the prototype of variant A2, isolate NL/17/00, than it is related to the M protein of the prototype of variant B1, isolate NL/1/99, the M protein of the prototype of A1, isolate NL/1/00, or the M protein of the prototype of B2, isolate NL/1/94. The invention provides a M protein of a mammalian MPV variant A2, wherein the the amino acid sequence of the M protein is at least 99%, or at least 99.5% identical to the M protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00(SEQ ID NO:359). The invention provides a F protein of a mammalian MPV variant A2, wherein the F protein of a mammalian MPV variant A2 is phylogenetically closer related to the F protein of the prototype of variant A2, isolate NL/17/00, than it is related to the F protein of the prototype of variant B1, isolate NL/1/99, the F protein of the prototype of A1, isolate NL/1/00, or the F protein of the prototype of B2, isolate NL/1/94. The invention provides a F protein of a mammalian MPV variant A2, wherein the amino acid sequence of the F protein is at least 98%, at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:315). The invention provides a M2-1 protein of a mammalian MPV variant A2, wherein the M2-1 protein of a mammalian MPV variant A2 is phylogenetically closer related to the M2-1 protein of the prototype of variant A2, isolate NL/17/00, than it is related to the M2-1 protein of the prototype of variant B1, isolate NL/1/99, the M2-1 protein of the prototype of A1, isolate NL/1/00, or the M2-1 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-1 protein of a mammalian MPV variant A2, wherein the amino acid sequence of the M2-1 protein is at least 99%, or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO: 339). The invention provides a M2-2 protein of a mammalian MPV variant A2, wherein the M2-2 protein of a mammalian MPV variant A2 is phylogenetically closer related to the M2-2 protein of the prototype of variant A2, isolate NL/17/00, than it is related to the M2-2 protein of the prototype of variant B1, isolate NL/1/99, the M2-2 protein of the prototype of A1, isolate NL/1/00, or the M2-2 protein of the prototype of B2, isolate NL/1/94. The invention provides a M2-2 protein of a mammalian MPV variant A2, wherein the amino acid sequence of the M2-2 protein is at least 96%, at least 98%, at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:347). The invention provides a SH protein of a mammalian MPV variant A2, wherein the SH protein of a mammalian MPV variant A2 is phylogenetically closer related to the SH protein of the prototype of variant A2, isolate NL/17/00, than it is related to the SH protein of the prototype of variant B1, isolate NL/1/99, the SH protein of the prototype of A1, isolate NL/1/00, or the SH protein of the prototype of B2, isolate NL/1/94. The invention provides a SH protein of a mammalian MPV variant A2, wherein the amino acid sequence of the SH protein is at least 84%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00(SEQ ID NO:383). The invention provides a L protein of a mammalian MPV variant A2, wherein the L protein of a mammalian MPV variant A2 is phylogenetically closer related to the L protein of the prototype of variant A2, isolate NL/17/00, than it is related to the L protein of the prototype of variant B1, isolate NL/1/99, the L protein of the prototype of A1, isolate NL/1/00, or the L protein of the prototype of B2, isolate NL/1/94. The invention provides a L protein of a mammalian MPV variant A2, wherein the amino acid sequence of the L protein is at least 99% or at least 99.5% identical to the L protein of a mammalian MPV variant A2 as represented by the prototype NL/17/00 (SEQ ID NO:331). The invention provides a G protein of a mammalian MPV variant B2, wherein the G protein of a mammalian MPV variant B2 is phylogenetically closer related to the G protein of the prototype of variant B2, isolate NL/1/94, than it is related to the G protein of the prototype of variant B1, isolate NL/1/99, the G protein of the prototype of A1, isolate NL/1/00, or the G protein of the prototype of A2, isolate NL/17/00. The invention provides a G protein of a mammalian MPV variant B2, wherein the amino acid sequence of the G protein is at least 66%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the G protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:325). The invention provides a N protein of a mammalian MPV variant B2, wherein the N protein of a mammalian MPV variant B2 is phylogenetically closer related to the N protein of the prototype of variant B2, isolate NL/1/94, than it is related to the N protein of the prototype of variant B1, isolate NL/1/99, the N protein of the prototype of A1, isolate NL/1/00, or the N protein of the prototype of A2, isolate NL/17/00. The invention provides a N protein of a mammalian MPV variant B2, wherein the amino acid sequence of the N protein is at least 99% or at least 99.5% identical to the N protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:369). The invention provides a P protein of a mammalian MPV variant B2, wherein the P protein of a mammalian MPV variant B2 is phylogenetically closer related to the P protein of the prototype of variant B2, isolate NL/1/94, than it is related to the P protein of the prototype of variant B1, isolate NL/1/99, the P protein of the prototype of A1, isolate NL/1/00, or the P protein of the prototype of A2, isolate NL/17/00. The invention provides a P protein of a mammalian MPV variant B2, wherein the amino acid sequence of the P protein is at least 96%, at least 98%, or at least 99% or at least 99.5% identical to the P protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:377). The invention provides a M protein of a mammalian MPV variant B2, wherein the M protein of a mammalian MPV variant B2 is phylogenetically closer related to the M protein of the prototype of variant B2, isolate NL/1/94, than it is related to the M protein of the prototype of variant B3, isolate NL/1/99, the M protein of the prototype of A1, isolate NL/1/00, or the M protein of the prototype of A2, isolate NL/17/00. The invention provides a M protein of a mammalian MPV variant B2, wherein the amino acid sequence of its M protein is identical to the M protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:361). The invention provides a F protein of a mammalian MPV variant B2, wherein the F protein of a mammalian MPV variant B2 is phylogenetically closer related to the F protein of the prototype of variant B2, isolate NL/1/94, than it is related to the F protein of the prototype of variant B1, isolate NL/1/99, the F protein of the prototype of A1, isolate NL/1/00, or the F protein of the prototype of A2, isolate NL/17/00. The invention provides a F protein of a mammalian MPV variant B2, wherein the amino acid sequence of the F protein is at least 99% or at least 99.5% identical to the F protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:317). The invention provides a M2-1 protein of a mammalian MPV variant B2, wherein the M2-1 protein of a mammalian MPV variant B2 is phylogenetically closer related to the M2-1 protein of the prototype of variant B2, isolate NL/1/94, than it is related to the M2-1 protein of the prototype of variant B1, isolate NL/1/99, the M2-1 protein of the prototype of A1, isolate NL/1/00, or the M2-1 protein of the prototype of A2, isolate NL/17/00. The invention provides a M2-1 protein of a mammalian MPV variant B2, wherein the amino acid sequence of the M2-1 protein is at least 98% or at least 99% or at least 99.5% identical to the M2-1 protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:341). The invention provides a M2-2 protein of a mammalian MPV variant B2, wherein the M2-2 protein of a mammalian MPV variant B2 is phylogenetically closer related to the M2-2 protein of the prototype of variant B2, isolate NL/1/94, than it is related to the M2-2 protein of the prototype of variant B1, isolate NL/1/99, the M2-2 protein of the prototype of A1, isolate NL/1/00, or the M2-2 protein of the prototype of A2, isolate NL/17/00. The invention provides a M2-2 protein of a mammalian MPV variant B2, wherein the amino acid sequence is at least 99% or at least 99.5% identical to the M2-2 protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:349). The invention provides a SH protein of a mammalian MPV variant B2, wherein the SH protein of a mammalian MPV variant B2 is phylogenetically closer related to the SH protein of the prototype of variant B2, isolate NL/1/94, than it is related to the SH protein of the prototype of variant B1, isolate NL/1/99, the SH protein of the prototype of A1, isolate NL/1/00, or the SH protein of the prototype of A2, isolate NL/17/00. The invention provides a SH protein of a mammalian MPV variant B2, wherein the amino acid sequence of the SH protein is at least 84%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% or at least 99.5% identical to the SH protein of a mammalian MPV. variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:385). The invention provides a L protein of a mammalian MPV variant B2, wherein the L protein of a mammalian MPV variant B2 is phylogenetically closer related to the L protein of the prototype of variant B2, isolate NL/1/94, than it is related to the L protein of the prototype of variant B1, isolate NL/1/99, the L protein of the prototype of A1, isolate NL/1/00, or the L protein of the prototype of A2, isolate NL/17/00. The invention provides a L protein of a mammalian MPV variant B2, wherein the and/or if the amino acid sequence of the L protein is at least 99% or at least 99.5% identical to the L protein of a mammalian MPV variant B2 as represented by the prototype NL/1/94 (SEQ ID NO:333). In certain embodiments, the percentage of sequence identity is based on an alignment of the full length proteins. In other embodiments, the percentage of sequence identity is based on an alignment of contiguous amino acid sequences of the proteins, wherein the amino acid sequences can be 25 amino acids, 50 amino acids, 75 amino acids, 100 amino acids, 125 amino acids, 150 amino acids, 175 amino acids, 200 amino acids, 225 amino acids, 250 amino acids, 275 amino acids, 300 amino acids, 325 amino acids, 350 amino acids, 375 amino acids, 400 amino acids, 425 amino acids, 450 amino acids, 475 amino acids, 500 amino acids, 750 amino acids, 1000 amino acids, 1250 amino acids, 1500 amino acids, 1750 amino acids, 2000 amino acids or 2250 amino acids in length. In certain, specific embodiments, the invention provides a G protein of a mammalian MPV wherein the G protein has one of the amino acid sequences set forth in SEQ ID NO:119-153; SEQ ID NO:322-325 or a fragment thereof. In certain, specific embodiments, the invention provides a F protein of a mammalian MPV wherein the F protein has one of the amino acid sequences set forth in SEQ ID NO:234-317. In certain, specific embodiments, the invention provides a L protein of a mammalian MPV wherein the L protein has one of the amino acid sequences set forth in SEQ ID NO:330-333 or a fragment thereof. In certain, specific embodiments, the invention provides a M2-1 protein of a mammalian MPV wherein the M2-1 protein has one of the amino acid sequences set forth in SEQ ID NO:338-341 or a fragment thereof. In certain, specific embodiments, the invention provides a M2-2 protein of a mammalian MPV wherein the M2-2 protein has one of the amino acid sequences set forth in SEQ ID NO:346-349 or a fragment thereof. In certain, specific embodiments, the invention provides a M protein of a mammalian MPV wherein the M protein has one of the amino acid sequences set forth in SEQ ID NO:358-361 or a fragment thereof. In certain, specific embodiments, the invention provides a N protein of a mammalian MPV wherein the N protein has one of the amino acid sequences set forth in SEQ ID NO:366-369 or a fragment thereof. In certain, specific embodiments, the invention provides a P protein of a mammalian MPV wherein the P protein has one of the amino acid sequences set forth in SEQ ID NO:374-377 or a fragment thereof. In certain, specific embodiments, the invention provides a SH protein of a mammalian MPV wherein the SH protein has one of the amino acid sequences set forth in SEQ ID NO:382-385 or a fragment thereof. In certain embodiments of the invention, a fragment is at least 25 amino acids, 50 amino acids, 75 amino acids, 100 amino acids, 125 amino acids, 150 amino acids, 175 amino acids, 200 amino acids, 225 amino acids, 250 amino acids, 275 amino acids, 300 amino acids, 325 amino acids, 350 amino acids, 375 amino acids, 400 amino acids, 425 amino acids, 450 amino acids, 475 amino acids, 500 amino acids, 750 amino acids, 1000 amino acids, 1250 amino acids, 1500 amino acids, 1750 amino acids, 2000 amino acids or 2250 amino acids in length. In certain embodiments of the invention, a fragment is at most 25 amino acids, 50 amino acids, 75 amino acids, 100 amino acids, 125 amino acids, 150 amino acids, 175 amino acids, 200 amino acids, 225 amino acids, 250 amino acids, 275 amino acids, 300 amino acids, 325 amino acids, 350 amino acids, 375 amino acids, 400 amino acids, 425 amino acids, 450 amino acids, 475 amino acids, 500 amino acids, 750 amino acids, 1000 amino acids, 1250 amino acids, 1500 amino acids, 1750 amino acids, 2000 amino acids or 2250 amino acids in length. The invention further provides nucleic acid sequences derived from a mammalian MPV. The invention also provides derivatives of nucleic acid sequences derived from a mammalian MPV. In certain specific embodiments the nucleic acids are modified. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of subgroup A of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of subgroup B of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of variant A1 of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of variant A2 of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of variant B1 of a mammalian MPV as defined above. In certain embodiments, a nucleic acid of the invention encodes a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of variant B2 of a mammalian MPV as defined above. In certain embodiments, the invention provides a nucleotide sequence that is at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to the nucleotide sequence of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21. In certain embodiments, the nucleic acid sequence of the invention, is at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% identical to a fragment of the nucleotide sequence of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21, wherein the fragment is at least 25 nucleotides, at least 50 nucleotides, at least 75 nucleotides, at least 100 nucleotides, at least 150 nucleotides, at least 200 nucleotides, at least 250 nucleotides, at least 300 nucleotides, at least 400 nucleotides, at least 500 nucleotides, at least 750 nucleotides, at least 1,000 nucleotides, at least 1,250 nucleotides, at least 1,500 nucleotides, at least 1,750 nucleotides, at least 2,000 nucleotides, at least 2,00 nucleotides, at least 3,000 nucleotides, at least 4,000 nucleotides, at least 5,000 nucleotides, at least 7,500 nucleotides, at least 10,000 nucleotides, at least 12,500 nucleotides, or at least 15,000 nucleotides in length. In a specific embodiment, the nucleic acid sequence of the invention is at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or at least 99.5% or 100% identical to one of the nucleotide sequences of SEQ ID NO:84-118; SEQ ID NO:154-233; SEQ ID NO:318-321; SEQ ID NO:326-329; SEQ ID NO:334-337; SEQ ID NO:342-345; SEQ ID NO:350-353; SEQ ID NO:354-357; SEQ ID NO:362-365; SEQ ID NO:370-373; SEQ ID NO:378-381; or SEQ ID NO:386-389. In specific embodiments of the invention, a nucleic acid sequence of the invention is capable of hybridizing under low stringency, medium stringency or high stringency conditions to one of the nucleic acid sequences of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21. In specific embodiments of the invention, a nucleic acid sequence of the invention is capable of hybridizing under low stringency, medium stringency or high stringency conditions to one of the nucleic acid sequences of SEQ ID NO:84-118; SEQ ID NO:154-233; SEQ ID NO:318-321; SEQ ID NO:326-329; SEQ ID NO:334-337; SEQ ID NO:342-345; SEQ ID NO:350-353; SEQ ID NO:354-357; SEQ ID NO:362-365; SEQ ID NO:370-373; SEQ ID NO:378-381; or SEQ ID NO:386-389. In certain embodiments, a nucleic acid hybridizes over a length of at least 25 nucleotides, at least 50 nucleotides, at least 75 nucleotides, at least 100 nucleotides, at least 150 nucleotides, at least 200 nucleotides, at least 250 nucleotides, at least 300 nucleotides, at least 400 nucleotides, at least 500 nucleotides, at least 750 nucleotides, at least 1,000 nucleotides, at least 1,250 nucleotides, at least 1,500 nucleotides, at least 1,750 nucleotides, at least 2,000 nucleotides, at least 2,00 nucleotides, at least 3,000 nucleotides, at least 4,000 nucleotides, at least 5,000 nucleotides, at least 7,500 nucleotides, at least 10,000 nucleotides, at least 12,500 nucleotides, or at least 15,000 nucleotides with the nucleotide sequence of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21. The invention further provides antibodies and antigen-binding fragments that bind specifically to a protein of a mammalian MPV. An antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a mammalian MPV. In specific embodiments, the antibody is a human antibody or a humanized antibody. In certain embodiments, an antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of subgroup A of a mammalian MPV. In certain other embodiments, an antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of subgroup B of a mammalian MPV. In certain, more specific, embodiments, an antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of variant A1 of a mammalian MPV. In other embodiments, the antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of subgroup A2 of a mammalian MPV. In certain embodiments, an antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of subgroup B1 of a mammalian MPV. In certain other embodiments, an antibody of the invention binds specifically to a G protein, a N protein, a P protein, a M protein, a F protein, a M2-1 protein, a M2-2 protein, a SH protein, or a L protein of a virus of subgroup B2 of a mammalian MPV. 5.16 Inhibition of Virus Cell Fusion using Heptad Repeats Virus-host cell fusion is a necessary step in the infectious life cycle of many enveloped viruses, including MPV. As such, the inhibition of virus cell fusion represents a new approach toward the control of these viruses. This method of inhibition represents an alternative means of preventing the propagation of MPV in a host and the infection by MPV of a host. The inhibition of virus-cell fusion is dependent upon the type of attachment protein required. Wang et al., Biochem Biophys Res Comm 302 (2003) 469-475. Consequently, in one embodiment of the invention, an assay is used to identify the dependency of virus cell fusion on various attachment proteins. In certain embodiments, the invention provides methods for preventing, treating, or managing an hMPV infection in a subject, the method comprising administering a pharmaceutically effective amount of a heptad repeat (HR) peptide. In certain embodiments, a pharmaceutically effective amount reduces virus host cell fusion by at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, at least 99.5%. In a specific embodiment, the HR is an HR of the virus that causes the infection in the subject. In a certain embodiment, the HR is that of an hMPV of the subtype A1. In a more specific embodiment, the HR sequence is one of the HR sequences of the F protein of hMPV, designated HRA or HRB, where HRA is the heptad repeat sequence near the N terminus of the peptide and HRB is near the C terminus. In certain embodiments, the HR that is administered to treat, prevent, or manage hMPV infection in the subject is an HR of hMPV subtype of A1, B1, A2, or B2. In certain embodiments, the HR is at least 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or at least 99.5% identical to a HR of the virus that causes the infection in the subject. In certain embodiments, a derivative of a HR can be used to prevent viral fusion. Such derivatives include, but are not limited to, HR peptides that have been substituted with non native amino acids, truncated so that stretches of amino acids are removed, or lengthened, so that single amino acids or stretches thereof have been added. In yet another embodiment, single HR peptides are used to treat, manage, or prevent hMPV infection. In an even further embodiment, a combination of HR peptides is administered to treat, manage, or prevent hMPV infection. The tests set forth below can be used to determine the effectiveness of a HR in preventing the fusion of an hMPV with a cell and can thus be used to determine which HRs or analogs or derivatives thereof are best suited for treating, preventing, or managing and hMPV infection in a subject. In another embodiment of the invention, soluble synthesized HR peptides are assayed to determine whether the peptides are able to prevent viral-cell fusion. Any HR sequence can be used to inhibit hMPV viral-cell fusion, including but not limited to, HR sequences against RSV, PIV, APV, and hMPV. In a preferred embodiment, the HR sequence is that of hMPV. In a more specific embodiment, the HR sequence is one of the HR sequences of the F protein of hMPV, designated HRA or HRB, where HRA is the heptad repeat sequence near the N terminus of the peptide and HRB is near the C terminus. In another embodiment of the invention, the HRA and HRB derived peptides that are used to inhibit hMPV viral-cell fusion, include, but are not limited to HRA and HRB peptides from RSV, APV, and PIV. In even another embodiment of the invention, derivatives of HRA and HRB peptides are used to inhibit hMPV viral-cell fusion. For example, derivatives that are made by mutation of at least one amino acid residue in an HRA or HRB peptide are used to inhibit hMPV viral-cell fusion. In another embodiment of the invention, derivatives are made by truncation or resection of specific regions of an HRA or HRB peptide. In yet even another embodiment, the HRA or HRB peptide that is used is lengthened with respect to the endogenous HR sequence. In an even further embodiment, groups of short peptides that consist of sequences of different regions of an HRA or HRB peptide are used to inhibit hMPV viral-cell fusion. In another embodiment of the invention, hMPV HRA and HRB derived peptides are used against homologous strains of hMPV or against heterologous strains of hMPV. In yet another embodiment of the invention, HRA and HRB peptides, or analogs or derivatives thereof, are used together to inhibit viral-cell fusion. In a more preferred embodiment, either an HRA or HRB peptide or analog or derivative thereof is used alone. In another embodiment, the derivative of an HRA or HRB peptide that is used is at least 90%, 80%, 70%, 60%, or 50% identical to the endogenous HR peptide. In order to examine the ability of the heptad repeat sequences to inhibit viral fusion, heptad repeat peptides can be expressed and purified so that they may be tested for their viral fusion inhibition ability. Soluble heptad repeat peptides can be expressed and purified and subsequently used in an assay to compete with endogenous heptad repeats in order to test for the blocking of viral fusion. In one embodiment of the invention, synthetic recombinant DNAs may be prepared that encode the heptad repeat sequences of the F protein of hMPV, designated HRA and HRB respectively. In another embodiment of the invention, synthetic recombinant DNAs may be prepared that encode heptad repeat peptides that also contain sequence tags useful in facilitating purification. In a preferred embodiment of the invention, the tag that facilitates purification of the heptad repeat peptide does not interfere with its activity. In yet another embodiment of the invention, the tag is composed of a series of histidine residues, e.g., six consecutive histidines at one of the peptide's termini, and is referred to as a histidine tag. There are a number of different approaches that can be used to express and purify soluble HRA and HRB. First, DNA vectors encoding the HRA and HRB are prepared using methods known to one skilled in the art. The plasmids are subsequently transformed into an appropriate expression host cell, such as, e.g., E. coli strain BL21 (DE3), and the protein is expressed and purified using methods routine in the art. For example, expression of a gene encoding an HR peptide with a histidine tag can be induced from a pET vector using IPTG. Cells can then be lysed and the expressed peptide can be isolated after immobilization on a Ni-chelated Sepharose affinity column following elution with a counter charged species, for e.g., imidazole. In order to determine the potential effectiveness of the expressed heptad repeat peptides in inhibiting viral fusion, an assay can be used to confirm the assembly of a complex between HR peptides. This method would be advantageous over cell based assays in that it would allow for cell-free screening of peptides in order to determine efficacy in viral fusion inhibition. In one embodiment of the invention, HR peptides are incubated simultaneously for a period of time sufficient to allow complex formation. In a more specific embodiment, the amount of time allowed for complex formation is 1 h at 28° C. Complex formation can be detected using any method known in the art, including but not limited to, chromatogaphy, Uv-vis spectroscopy, NMR spectroscopy, X-ray crystallography, centrifugation, or electrophoresis. In another specific embodiment of the invention, complex formation is detected using gel filtration methods coupled with electrophoresis in order to determine the molecular weight of the complex. In yet another embodiment of the invention, this complex formation assay is used to identify candidates that are useful in inhibiting viral fusion, e.g., the effectiveness of mutated HR peptides in the inhibition of viral fusion is determined. In yet even another embodiment of the invention, the effectiveness of derivatives of HR peptides in the inhibition of viral fusion is measured using this complex formation assay. It is known that the heptad repeat segments of the peptides are helical in nature. For this reason, a number of methods can be used to determine whether expressed HR peptides form alpha helices in order to identify appropriate candidates for use in viral fusion inhibition. Such methods, include, but are not limited to, spectroscopy, X-ray crystallography, and microscopy. In one embodiment of the invention, CD (circular dichroism) spectroscopy is used to determine the structural features of the HR peptides. A cell based assay can be used to determine the effectiveness of HR peptides in the inhibition of viral fusion. Any cell that can be infected with MPV can be used in the assay, including, but not limited to: tMK, Hep2, or Vero cells. In a specific embodiment, the type of cells that are used are Hep2 cells. Upon infection of a host cell with MPV, the cells are incubated with HR protein preparations and scored for fusion after incubation for an appropriate period of time. Cells are subsequently stained for synctium/polykaryon formation in order to determine whether viral-cell fusion was successful. 6. Virus Isolation and Characterization 6.1 EXAMPLE 1 Specimen Collection, Virus Isolation, Virus Characterization Samples of nasopharyngeal aspirates were obtained from hosts to assay for the presence of viruses, and also to characterize those identified. Nasopharyngeal aspirates were collected from children suffering from respiratory tract infection (RTI). In order to determine the identity of the cause of illness, all nasopharyngeal aspirates were tested by direct immmunofluorescence assays (DIF) (See method in Example 9), using fluorescence labeled antibodies against influenza virus types A and B, hRSV, and human parainfluenza virus (hPIV) types 1, 2, and 3. Viruses were also isolated from nasopharyngeal aspirates using rapid shell vial techniques, (Rothbarth et. al., 1999, J of Virol. Methods 78:163-169) on various cell lines, including VERO cells, tertiary cynomolgous monkey kidney (tMK) cells, human endothelial lung (HEL) cells and marbin dock kidney (MDCK) cells. Samples showing cytopathic effects (CPE) after two to three passages, that were negative in DIF assays, were tested by indirect immunofluorescence assays (IFA) (See method in Example 11), using virus specific antibodies against influenza virus types A, B and C, hRSV types A and B, measles virus, mumps virus, human parainfluenza virus (hPIV) types 1 to 4, sendai virus, simian virus type 5, and New-Castle disease virus. Although for many cases the aetiological agent could be identified, some specimens were negative for all of the viruses tested. These 28 unidentified virus isolates grew slowly in tMK cells, poorly in VERO cells and A549 cells and barely in MDCK or chicken embryonated fibroblast cells. Most of the virus isolates induced CPE on tMK cells, between days ten and fourteen. This was somewhat later than the CPE caused by other viruses such as hRSV or hPIV. The CPE were virtually indistinguishable from that caused by hRSV or hPIV in tMK or other cell cultures, and were characterized by syncytium formation. Some of the effects observed on the cells included rapid internal disruption, followed by detachment of the cells from the monolayer. The supernatants of infected tMK cells were used for Electron Microscopy (EM) analysis, and they revealed the presence of paramyxovirus-like virus particles ranging from 150 to 600 nanometers in diameter, with short envelope projections ranging from 13 to 17 nanometers. Consistent with the biochemical properties of enveloped viruses such as the Paramyxoviridae family of viruses, standard chloroform or ether treatment (Osterhaus et. al., 1985, Arch. of Virol. 86:239-25) resulted in a greater than 104 TCID50 reduction in infectivity of tMK cells. Virus-infected tMK cell culture supernatants did not display heamagglutinating activity with turkey, chicken and guinea pig erythrocytes. During culture, the virus replication appeared to be trypsin dependent. These combined virological data demonstrated that the newly identified virus was a taxonomic member of the Paramyxoviridae family. RNA from tMK cells infected with 15 of the unidentified virus isolates was extracted for use in reverse transcription and polymerase chain reaction (RT-PCR) analyses, using primer-sets specific for Paramyxovirinae (K. B. Chua et al., 2000, Science 288:1432-1435) such as: hP-IV 1-4, sendai virus, simian virus type 5, New-Castle disease virus, hRSV, morbilli, mumps, Nipah, Hendra, Tupaia and Mapuera viruses. RT-PCR assays were performed under conditions of low stringency in order to detect potentially related viruses. RNA isolated from homologous virus stocks was used as a control. Whereas the available controls reacted positive with the respective virus-specific primers, the newly identified virus isolates did not react with any primer set, indicating the virus was not closely related to the viruses tested. Two of the virus-infected tMK cell culture supernatants were used to inoculate guinea pigs and ferrets intranasally. Sera samples were collected from these animals at day zero, two weeks, and three weeks post inoculation. The animals displayed no clinical symptoms, however, the seroconversion of all of the animals was detected and measured in virus neutralization (VN) (See method in Example 16) assays and indirect IFA against the homologous viruses. The sera did not react in indirect IFA with any of the known paramyxoviruses described above or with pneumovirus of mice (PVM). The so far unidentified virus isolates were screened, using the guinea pig and ferret pre- and post-infection sera. Of these, 28 were clearly positive by indirect IFA, with the post-infection sera suggesting that, the thus far unidentified viral isolates, were closely related or identical. In order further characterize the virus, the phenotypic effects of virus infection on a cell line was examined. In short, tMK cells were cultured in 24 well plates containing glass slides (Costar, Cambridge, UK), with the medium described below supplemented with 10% fetal bovine serum (BioWhittaker, Vervier, Belgium). Before inoculation, the plates were washed with PBS and supplied with Eagle's MEM with Hanks' salt (ICN, Costa mesa, Calif.), of which 0.5 L was supplemented with 0.26 g of NaHCO3, 0.025 M Hepes (Biowhittaker), 2 mM L-glutamine (Biowhittaker), 100 units penicillin, 100 μg streptomycin (Biowhittaker), 0.5 g lactalbumin (Sigma-Aldrich, Zwijndrecht, The Netherlands), 1.0 g D-glucose (Merck, Amsterdam, The Netherlands), 5.0 g peptone (Oxoid, Haarlem, The Netherlands) and 0.02% trypsin (Life Technologies, Bethesda, Md.). The plates were inoculated with the supernatant of the nasopharyngeal aspirate samples (0.2 ml per well in triplicate), followed by centrifuging at 840×g for one hour. After inoculation, the plates were incubated at 37° C. for a maximum of 14 days, and the medium was changed once a week while cultures were checked daily for CPE. After 14 days, the cells were scraped from the second passage and incubated for 14 days. This step was repeated for the third passage. The glass slides were used to demonstrate the presence of the virus by indirect IFA as described below. CPE were generally observed after the third passage, between days 8 to 14, depending on the isolate. The CPE were virtually indistinguishable from that caused by hRSV or hPIV in tMK or other cell cultures, except that hRSV induces CPE at around day 4. CPE were characterized by syncytia formation, after which the cells showed rapid internal disruption, followed by detachment of the cells from the monolayer. For some isolates, CPE were difficult to observe, and IFA was used to confirm the presence of the virus in these cultures. The observation that the CPE were indistinghuishable from those of other viruses indicated that diagnosis could not be made from a visual examination of clinical symptoms. 6.2 EXAMPLE 2 Seroprevalence in the Human Population To study the seroprevalence of this virus in the human population, sera from humans in different age categories were analyzed by indirect IFA using tMK cells infected with one of the unidentified virus isolates. Studies revealed that antibodies to the virus could be detected in 25% of the children between six and twelve months. Furthermore, by the age of five, nearly 100% of the children were seropositive. In total, 56 sera samples examined by indirect IFA and by VN assay. For 51 of the samples or 91%, the results of the VN assay, i.e., a titer greater than 8, coincided with the results obtained with indirect IFA, i.e., a titer greater than 32. Four samples that were found to be positive by IFA, were negative by the VN assay, i.e., titer less than 8, whereas one serum sample was negative by IFA, i.e., titer less than 32, and was positive by the VN test, i.e., a titer of 16 (FIG. 2). IFA conducted on 72 sera samples taken from humans in 1958, with ages ranging from 8-99 years, revealed a 100% seroprevalence rate, indicating the virus has been circulating in the human population for more than 40 years. In addition, a number of these sera samples were used in VN assays to confirm the IFA data (FIG. 2). The seroprevalence data indicate that the virus has been a significant source of infection in the human population for many years. The repeated isolation of this virus from clinical samples from children with severe RTI indicates that the clinical and economic impact of MPV may be high. New diagnostic assays based on virus detection and serology would yield a more detailed analysis of the incidence rate and also of the clinical and economical impact of this viral pathogen. The slight differences between the IFA and VN results (5 samples) may have been due to the fact that in the IFA, only IgG serum antibodies were detected, whereas the VN assay detects both classes and sub-classes of antibodies. Alternatively, differences may have been due to the differences in sensitivity between both assays. For IFA, a threshold value of 16 was used, whereas for VN a value of 8 was used. Differences between results in the IFA and VN assays may also indicate possible differences between serotypes of this newly identified virus. Since MPV seems to be most closely related to APV, it was speculated that the human virus may have originated from birds. Analysis of serum samples taken from humans in 1958 revealed that MPV has been widespread in the human population for more then 40 years, indicating that a tentative zoonosis event must have taken place long before 1958. 6.3 EXAMPLE 3 Genomic Sequence of hMPV Isolate 00-1 In order to obtain sequence information for the unknown virus isolates, a random PCR amplification strategy known as RAP-PCR (Welsh et. al., 1992, NAR 20:4965-4970) (See Example 21). In short, tMK cells were infected with one of the virus isolates (isolate 00-1) as well as with hPIV-1 that served as a positive control. After both cultures displayed similar levels of CPE, virus in the culture supernatants was purified on continuous 20-60% sucrose gradients. The gradient fractions were inspected for virus-like particles by EM, and RNA was isolated from the fraction that contained approximately 50% sucrose, in which nucleocapsids were observed. Equivalent amounts of RNA isolated from both virus fractions were used for RAP-PCR, after which samples were run side by side on a 3% NuSieve agarose gel. Twenty differentially displayed bands specific for the unidentified virus were subsequently purified from the gel, cloned in plasmid pCR2.1 (Invitrogen) and sequenced (See Example 22) with vector-specific primers. A search for homologies against sequences in the Genbank database, using the BLAST program available through the National Library of Medicine, found that 10 out of 20 fragments displayed resemblance to APV/TRTV sequences. These 10 fragments were located in the genes coding for the nucleoprotein (N; fragment 1 and 2), the matrix protein (M; fragment 3), the fusion protein (F; fragment 4, 5, 6, 7) and the polymerase protein (L; fragment 8, 9, 10) (FIG. 3). PCR primers were designed to complete the sequence information for the 3′ end of the viral genome based on our RAP PCR fragments as well as published leader and trailer sequences for the Pneumovirinae (Randhawa, et.al., 1997, J. Virol. 71:9849-9854). Three fragments were amplified, of which fragment A spanned the extreme 3′ end of the N open reading frame (ORF), fragment B spanned the phosphoprotein (F) ORF and fragment C closed the gap between the M and F ORFs (FIG. 16). Sequence analyses of these three fragments revealed the absence of NS1 and NS2 ORFs at the extreme 3′ end of the viral genome and positioning of the F ORF immediately adjacent to the M ORF. This genomic organization resembled that of the metapneumovirus APV, which was also consistent with the sequence homology. Relation between different viruses could be deduced by comparing the amino acid sequence of FIG. 4 with the amino acid sequence of the respective N proteins of other viruses. Overall the translated sequences for the N, P, M and F ORFs showed an average of 30-33% homology with members of the genus Pneumovirus and 66-68% with members of the genus Metapneumovirus. For the SH and G ORFs, no discernable homology was found with members of either genera. The amino acid homologies found for the amino acid sequence of the N ORF showed about 40% homology with HRSV and 88% with APV-C, its closest relative genetically. The amino acid sequence for the P ORF showed about 25% homology with hRSV and about 66-68% with APV-C, the M ORF showed about 36-39% with hRSV and about 87-89% with APV-C, the F ORF showed about 40% homology with hRSV and about 81% with APV-C, the M2-1 ORF showed about 34-36% homology with pneumoviruses and 84-86% with APV-C, the M2-2 ORF showed 15-17% homology with pneumoviruses and 56% with APV-C and the fragments obtained from the L ORF showed an average of 44% with pneumoviruses and 64% with APV-C. Genetic analyses of the N, M, P and F genes revealed that MPV has higher sequence homology to the recently proposed genus Metapneumovirinae as compared to the genus Pneumovirinae and thus demonstrates a genomic organization similar to and resembling that of APV/TRTV. In contrast to the genomic organization of the RSVs (‘3-NS1-NS2-N-P-M-SH-G-F-M2-L-5’), metapneumoviruses lack NS1 and NS2 genes and also have a different genomic organization, specifically between the M and L (‘3-N-P-M-F-M2-SH-G-L-5’) genes. The lack of ORFs between the M and F genes in the virus isolates of the invention, the lack of NS1 and NS2 adjacent to N, and the high amino acid sequence homology found within APV led to the proposed classification of MPV isolated from humans as the first member of the Metapneumovirus genus of mammals, and more specifically of humans. Phylogenetic analyses revealed that the nine MPV isolates, from which sequence information was obtained, are closely related. Although sequence information was limited, they appeared to be more closely related to one another than to any of the avian metapneumoviruses. Of the four serotypes of APV that have been described, serotype C appeared to be most closely related to MPV. This conclusion was based upon the nucleotide sequence similarities of the N, P, M and F genes. It should be noted however, that for serotype D, only partial sequences of the F gene were available from Genbank, and for serotype B, only M, N, and F sequences were available. Our MPV isolates formed two clusters in phylogenetic trees. For both hRSV and APV, different genetic and serological subtypes have been described. Whether the two genetic clusters of MPV isolates represent serogical subgroups that are also functionally different remains unknown at present. Our serological surveys showed that MPV is a common human pathogen. 6.4 EXAMPLE 4 Further Characterization of Associated Genes Sequence analyses of the nucleoprotein (N), phosphoprotein (P), matrixprotein (M) and fusion protein (F) genes of MPV revealed the highest degree of sequence homology with APV serotype C, the avian pneumovirus found primarily in birds in the United States. These analyses also revealed the absence of non-structural proteins NS1 and NS2 at the 3′end of the viral genome and positioning of the fusion protein immediately adjacent to the matrix protein. The sequences of the 22K (M2) gene, the small hydrophobic (SH) gene, the attachment (G) gene, the polymerase (L) gene, the intergenic regions, and the trailer sequences were determined. In combination with the sequences described previously, the sequences presented here completed the genomic sequence of MPV with the exception of the extreme 12-15 nucleotides of the genomic termini and establish the genomic organization of MPV. Side by side comparisons of the sequences of the MPV genome with those of APV subtype A, B and C, RSV subtype A and B, PVM and other paramyxoviruses provides strong evidence for the classification of MPV in the Metapneumovirus genus. GENE ENCODING THE NUCLEOPROTEIN (N): As shown above, the first gene in the genomic map of MPV codes for a 394 amino acid (aa) protein and shows extensive homology with the N protein of other pneumoviruses. The length of the N ORF is identical to the length of the N ORF of APV-C (Table 5) and is smaller than those of other paramyxoviruses (Barr et al., 1991, J Gen Virol 72:677-85). Analysis of the amino acid sequence revealed the highest homology with APV-C (88%), and only 7-11% with other paramyxoviruses (Table 6). Three regions of similarity between viruses belonging to the order Mononegavirales were identified: A, B and C (FIG. 22) (Barr et al., 1991, J Gen Virol 72: 677-85). Although similarities are highest within a virus family, these regions are highly conserved between virus families observed. In all three regions MPV revealed 97% aa sequence identity with APV-C, 89% with APV-B, 92% with APV-A, and 66-73% with RSV and PYM. The region between aa residues 160 and 340 appears to be highly conserved among metapneumoviruses and to a somewhat lesser extent the Pneumovirinae (Miyahara et al., 1991, Arch Viral 124:255-68; Li et al., 1996, Virus Res 41:185-91; Barr, 1991, J Gen Virol 72:677-85). GENE ENCODING THE PHOSPHOPROTEIN (P): The second ORF in the genome map codes for a 294 aa protein which shares 68% aa sequence homology with the P protein of APV-C, and only 22-26% with the P protein of RSV (Table 7). The P gene of MPV contains one substantial ORF and in that respect is similar to P from many other paramyxoviruses (Reviewed in Lamb et. al., Fields virology, (B. N. Knipe, Hawley, P. M., ed., LippencottRaven), Philadelphia, 1996; Sedlmeier et al., 1998, Adv Virus Res 50:101-39). In contrast to APV A and B and PVM and similar to RSV and APV-C the MPV P ORF lacks cysteine residues. A region of high similarity between all pneumoviruses (amino acids 185-241) plays a role in either the RNA synthesis process or in maintaining the structural integrity of the nucleocapsid complex (Ling et al., 1995, Virus Res 36:247-57). This region of high similarity is also found in MPV (FIG. 6) especifically when conservative substitutions are taken into account, showing 100% similarity with APYC, 93% with APV-A and B, and approximately 81% with RSV. The C-terminus of the MPV P protein is rich in glutamate residues as has been described for APVs (Ling, et al., 1995, Virus Res 36:247-57). GENE ENCODING THE MATRIX (M) PROTEIN: The third ORF of the MPV genome encodes a 254 aa protein, which resembles the M ORFs of other pneumoviruses. The M ORF of MPV has exactly the same size as the M ORFs of other metapneumoviruses and shows high aa sequence homology with the matrix proteins of APV (78-87%), lower homology with those of iRSV and PVM (37-38%), and 10% or less homology with those of other paramyxoviruses (Table 6). The sequences of matrix proteins of all pneumoviruses were compared and a conserved heptadpeptide at residue 14 to 19 was found to also conserved in MPV (FIG. 7) (Easton et al. 1997, Virus Res, 48:27-33). For RSV, PVM and APV, small secondary ORFs within or overlapping with the major ORF of M have been identified (52 aa and 51 aa in bRSV, 75 aa in RSV, 46 aa in PVM and 51 aa in APV) (Yu et al., 1992, Virology 186:426-34; Easton et al., 1997, Virus Res 48:27-33; Samal et al., 1991, J Gen Virol 72:715-20; Satake et al., 1995, J Virol 50:92-9). One small ORF of 54 aa residues was found within the major M ORF (fragment 1, FIG. 8), starting at nucleotide 2281 and one small ORF of 33 aa residues was found overlapping with the major ORF of M starting at nucleotide 2893 (fragment 2, FIG. 8). Similar to the secondary ORFs of RSV and APV there is no significant homology between these secondary ORFs and secondary ORFs of the other pneumoviruses, and apparent start or stop signals are lacking. Furthermore, there have not been any report of protein synthesis occurring from these secondary ORFs. GENE ENCODING THE FUSION PROTEIN: The F ORF of MPV is located adjacent to the M ORF, a feature that is characteristic of members of the Metapneumovirus genus. The F gene of MPV encodes a 539 aa protein, which is two aa residues longer than F of APV-C. Analysis of the aa sequence revealed 81% homology with APV-C, 67% with APV-A and B, 33-39% with pneumovirus F proteins and only 10-18% with other paramyxoviruses (Table 6). One of the conserved features among F proteins of paramyxoviruses, and also seen in MPV is the distribution of cysteine residues (Morrison et al., 1988, Virus Res 10:113-35; Yu et al., 1991, J. Gen Virol 72:75-81). The metapneumoviruses share 12 cysteine residues in E1 (7 are conserved among all paramyxoviruses), and two in E2 (1 is conserved among all paramyxoviruses). Of the 3 potential N-linked glycosylation sites present in the F ORF of MPV, none are shared with RSV and two (position 74 and 389) are shared with APV. The third, unique, potential N-linked glycosylation site for MPV is located at position 206 (FIG. 9). Despite the low sequence homology with other paramyxoviruses, the F protein of MPV revealed typical fusion protein characteristics consistent with those described for the F proteins of other Paramyxoviridae family members (Morrison et. al., 1988, Virus Res 10:113-35). F proteins of Paramyxoviridae members are synthesized as inactive precursors (F0) that are cleaved by host cell proteases which generate amino terminal E2 subunits and large carboxy terminal F1 subunits. The proposed cleavage site (Collins et al., Fields virology, (B. N. Knipe, Howley, P. M., ed., Lippencott-Raven), Philadelphia, 1996) is conserved among all members of the Paramyxoviridae family. The cleavage site of MPV contains the residues RQSR. Both arginine (R) residues are shared with APV and RSV, but the glutamine (Q) and serine (S) residues are shared with other paramyxoviruses such as human parainfluenza virus type 1, Sendai virus and morbilliviruses. The hydrophobic region at the amino terminus of F1 is thought to function as the membrane fusion domain and shows high sequence similarity among paramyxoviruses and morbilliviruses and to a lesser extent the pneumoviruses (Morrison et al., 1988, Virus Res 10:113-35). These 26 residues (position 137-163, FIG. 9) are conserved between MPV and APV-C, which is in agreement with this region being highly conserved among the metapneumoviruses (Naylor et al., 1998, J. Gen Virol 79:1393-1398; Seal et al., 2000, Virus Res 66:139-47). As is seen for the F2 subunits of APV and other paramyxoviruses, MPV revealed a deletion of 22 aa residues compared with RSV (position 107-128, FIG. 9). Furthermore, for RSV and APV, the signal peptide and anchor domain were found to be conserved within subtypes and displayed high variability between subtypes (Plows et al., 1995, Virus Genes 11:37-45; Naylor et al., 1998, J. Gen Virol 79:1393-1398). The signal peptide of MPV (aa 10-35, FIG. 9) at the amino terminus of F2 exhibits some sequence similarity with APV-C (18 out of 26 aa residues are similar), and less conservation with other APVs or RSV. Much more variability between subtypes is seen in the membrane anchor domain at the carboxy terminus of E1, although some homology is still seen with APV-C. GENE ENCODING THE M2 PROTEIN: The M2 gene is unique to the Pneumovirinae and two overlapping ORFs have been observed in all pneumoviruses. The first major ORF represents the M2-1 protein which enhances the processivity of the viral polymerase (Collins et al., 1995, Proc Natl Acad Sci U S A 92:11563-7; Collins et. al., Fields virology (B. N. Knipe, Howley, P. M., ed., Lippencott-Raven), Philadelphia, 1996) and its readthrough of intergenic regions (Hardy et al., 1998, J Virol 72:520-6; Fearns et al., 1999, J Virol 73:5852-64). The M2-1 gene for MPV, located adjacent to the F gene, encodes a 187 aa protein, and reveals the highest (84%) homology with M2-1 of APV-C. Comparison of all pneumovirus M2-1 proteins revealed the highest conservation in the amino-terminal half of the protein (Collins et al., 1990, J. Gen Virol 71:3015-20; Zamora et al., 1992, J. Gen Virol 73:737-41; Ahmadian et al., 1999, J. Gen Virol 80:2011-6), which is in agreement with the observation that MPV displays 100% similarity with APV-C in the first 80 aa residues of the protein (FIG. 10). The MPV M2-1 protein contains 3 cysteine residues located within the first 30 aa residues that are conserved among all pneumoviruses. Such a concentration of cysteines is frequently found in zinc-binding proteins (Cuesta et al., 2000, Gen Virol:74, 9858-67). The secondary ORFs (M2-2) that overlap with the M2-1 ORFs of pneumoviruses are conserved in location but not in sequence and are thought to be involved in the control of the switch between virus RNA replication and transcription (Collins et al., 1985, J Virol 54:65-71; Elango et al., 1985, J Virol 55:101-10; Baybutt et. al., 1987, J Gen Virol 68:2789-96; Collins et al., 1990, J. Gen Virol 71:3015-20; Ling et al., 1992, J. Gen Virol 73:1709-15; Zamora et al., 1992, J. Gen Virol 73:737-41; Alansari et al., 1994, J. Gen Virol:75:401-404; Ahmadian et al., 1999, J. Gen Virol 80: 2011-6). For MPV, the M2-2 ORF starts at nucleotide 512 in the M2-1 ORF (FIG. 8), which is exactly the same start position as for APV-C. The length of the M2-2 ORFs are the same for APV-C and MPV, 71 aa residues. Sequence comparison of the M2-2 ORF (FIG. 10) revealed 64% aa sequence homology between MPV and APV-C and only 44-48% aa sequence homology between MPV and APV-A and B. SMALL HYROPHOBIC (SH) GENE ORF: The gene located adjacent to M2 of hMPV probably encodes a 183 aa SH protein (FIG. 8). There is no discernible sequence identity between this ORF and other RNA virus genes or gene products. This is not surprising since sequence similarity between pneumovirus SH proteins is generally low. The aa composition of the SH ORF is relatively similar to that of APV, RSV and PVM, with a high percentage of threonine and serune residues (22%, 18%, 19%, 20.0%, 21% and 28% for hMPV, APV, RSV A, RSV B, bRSV and PVM respectively). The SH ORF of hMPV contains 10 cysteine residues, whereas APV SH contains 16 cysteine residues. The SH ORF of hMPV contains two potential N-linked glycosylation sites (aa 76 and 121), whereas APV has one, RSV has two or three and PVM has four. The hydrophilicity profiles for the putative hMPV SH protein and SH of APV and RSV revealed similar characteristics (FIG. 1B). The SH ORFs of APV and hMPV have a hydrophilic N-terminus, a central hydrophobic domain which can serve as a potential membrane spanning domain (aa 30-53 for hMPV), a second hydrophobic domain (aa 155-170) and a hydrophilic C-terminus. In contrast, RSV SH appears to lack the C-terminal part of the APV and hMPV ORFs. In all pneumovirus SH proteins the hydrophobic domain is flanked by basic aa residues, which are also found in the SH ORF for hMPV (aa 29 and 54). GENE ENCODING THE ATTACHMENT GLYCOPROTEIN (G): The putative G ORF of hMPV is located adjacent to the putative SH gene and encodes a 236 as protein (nt 6262-6972, FIG. 8). A secondary small ORF is found immediately following this ORF, potentially coding for 68 aa residues (nt 6973-7179) but lacking a start codon. A third potential ORF in the second reading frame of 194 aa residues is overlapping with both of these ORFs but also lacks a start codon (nt 6416-7000). This ORF is followed by a potential fourth ORF of 65 aa residues in the same reading frame (nt 7001-7198), again lacking a start codon. Finally, a potential ORF of 97 aa residues (but lacking a start codon) is found in the third reading frame (nt 6444-6737, FIG. 8). Unlike the first ORF, the other ORFs do not have apparent gene start or gene end sequences (see below). Although the 236 aa G ORF probably represents at least a part of the hMPV attachment protein it can not be excluded that the additional coding sequences are expressed as separate proteins or as part of the attachment protein through some RNA editing event. It should be noted that for APV and RSV no secondary ORFs after the primary G ORF have been identified but that both APV and RSV have secondary ORFs within the major ORF of G. However, evidence for expression of these ORFs is lacking and there is no sequence identity between the predicted aa sequences for different viruses (Ling et al., 1992, J Gen Virol 73:1709-15). The secondary ORFs in hMPV G do not reveal characteristics of other G proteins and whether the additional ORFs are expressed requires further investigation. BLAST analyses with all ORFs revealed no discernible sequence identity at the nucleotide or aa sequence level with other known virus genes or gene products. This is in agreement with the low percentage sequence identity found for other G proteins such as those of hRSV A and B (53%) (Johnson et al., 1987, J Virol 61:163-6) and APV A and B (38%) (Juhasz and Easton, 1994, J Gen Virol 75:2873-80). Whereas most of the hMPV ORFs resemble those of APV both in length and sequence, the putative G ORF of 236 aa residues of hMPV is considerably smaller than the G ORF of APV (Table 4). The aa sequence revealed a serine and threonine content of 34%, which is even higher than the 32% for RSV and 24% for APV. The putative G ORF also contains 8.5% proline residues, which is higher than the 8% for RSV and 7% for APV. The unusual abundance of proline residues in the G proteins of APV, RSV and hMPV has also been observed in glycoproteins where it is a major determinant of the proteins three dimensional structure (Collins and Wertz, 1983, PNAS 80:3208-12; Wertz et al., 1985, PNAS 82:4075-9; Jentoft, 1990, Trends Biochem Sci 15:291-4.). The G ORF of hMPV contains five potential N-linked glycosylation sites, whereas hRSV has seven, bRSV has five and APV has three to five. The predicted hydrophilicity profile of hMPV G revealed characteristics similar to the other pneumoviruses. The N-terminus contains a hydrophilic region followed by a short hydrophobic area (aa 33-53 for hMPV) and a mainly hydrophilic C-terminus (FIG. 12B). This overall organization corresponds well with regions in the G protein of APV and RSV. The putative G ORF of hMPV contains only 1 cysteine residue in contrast to RSV and APV (5 and 20 respectively). Of note, only two of the four secondary ORFs in the G gene contained one additional cysteine residue and these four potential ORFs revealed 12-20% serine and threonine residues and 6-11% proline residues. POLYMERASE GENE (L): In analogy to other negative strand viruses, the last ORF of the MPV genome is the RNA-dependent RNA polymerase component of the replication and transcription complexes. The L gene of MPV encodes a 2005 aa protein, which is one residue longer than the APV-A protein (Table 5). The L protein of MPV shares 64% homology with APV-A, 42-44% with RSV, and approximately 13% with other paramyxoviruses (Table 6). Six conserved domains within the L proteins of non-segmented negative strand RNA viruses were identified; it was found that the domain three contained the four core polymerase motifs that are thought to be essential for polymerase function (Poch et al., 1990, J Gen Virol 71:1153-62; Poch et al., 1989, EMBO J 8:3867-74). These motifs (A, B, C and D) are well conserved in the MPV L protein: in motifs A, B and C: MPV shares 100% similarity with all pneumoviruses and in motif D MPV shares 100% similaritywith APV and 92% with RSVs. For all of domain III (aa 627-903 in the L ORF), MPV shares 77% identity with APV, 61-62% with RSV and 23-27% with other paramyxoviruses (FIG. 13). In addition to the polymerase motifs the pneumovirus L proteins contain a sequence which conforms to a consensus ATP binding motif K(X)21GEGAGN(X)20K (Stec et al., 1991, Virology 183:273-87). The MPV L ORF contains a similar motif as APV, in which the spacing of the intermediate residues is shifted by one residue: K(X)22GEGAGN(X)19K. TABLE 5 LENGTHS OF THE ORFs OF MPV AND OTHER PARAMYXOVIRUSES N1 P M F M2-1 M2-2 SH G L MPV 394 294 254 539 187 71 183 236 2005 APV A 391 278 254 538 186 73 174 391 2004 APV B 391 279 254 538 186 73 ** 414 ** APV C 394 294 254 537 184 71 ** ** ** APV D ** ** ** ** ** ** ** 389 ** hRSV A 391 241 256 574 194 90 64 298 2165 hRSV B 391 241 249 574 195 93 65 299 2166 bRSV 391 241 256 569 186 93 81 257 2162 PVM 393 295 257 537 176 77 92 396 ** others3 418-542 225-709 335-393 539-565 **** **** **** **** 2183-2262 Legend for Table 5: * = length in amino acid residues, ** = sequences not available, *** = others: human parainfluenza virus 2, 3. Sendai virus, measles virus, nipah virus, phocine distemper virus, and New Castle Disease virus, **** = ORF not present in viral genome. TABLE 6 AMINO ACID SEQUENCE IDENTITY BETWEEN THE ORFs OF MPV AND THOSE OF OTHER PARAMYXOVIRUSES N P M F M2-1 M2-2 L APV A 69 55 78 67 72 26 64 APV B 69 51 76 67 71 27 ** APV C 88 68 87 81 84 56 ** hRSV A 42 24 38 34 36 18 42 hRSV B 41 23 37 33 35 19 44 bRSV 42 22 38 34 35 13 44 PVM 45 26 37 39 33 12 ** others3 7-11 4-9 7-10 10-18 **** **** 13-14 Legend for Table 6: * = No sequence homologies were found with known G and SH proteins and were thus excluded, ** = Sequences not available, *** = See list in table 4, denoted by same (***), **** = ORF absent in viral genome. 6.5 EXAMPLE 5 Genomic Sequence of hMPV Isolate 1-99 Another isolate of hMPV (1-99) was also identified and sequenced. In order to do so, the hMPV isolate 1-99 was propagated on tertiary monkey kidney cells exactly as described before (van den Hoogen et al., 2001, Nature Medicine 7(6):719-724). Viral RNA was isolated using the MagnaPure LC isolation system (Roche Applied Science) and the total nucleic acid kit protocol. RNA was converted into cDNA using standard protocols, with random hexamers (Progema Inc. Leiden) as primers. This cDNA was kept at −20 ° C. or lower until used for sequence analysis. Primers used throughout this project were based on the sequences available from the prototype hMPV 1-00 strain, or obtained after sequence analysis using the hMPV strain 1-99. PCR fragments were made ranging in size up to 1600 base-pairs to generate overlapping fragments. Sequence analysis was performed on the PCR fragments using standard technology and an ABI 3100 capillary sequence instrument (Applied Biosystems, Nieuwerkerk Issel). The nucleotide sequences generated were compared initially with the prototype hMPV strain 1-00 for comparison. Blast software was used for comparison with related sequences in the GenBank database. For further analysis of the sequences, DNASTAR software was used (DNASTAR Inc, Madison Wis., U.S.A.) and for phylogenetic analysis, the ClustalW software program was used. Initially, sequences for the 1-99 isolate were obtained using primers that were designed based on sequence information from the 1-00 isolate. However, since some parts of the genome could not be sequenced based on the information from the 1-00 isolate, new primers based on sequence information from the 1-99 isolate, as well from information made available through the sequencing of the 3′and 5′end of the 1-00 isolate, were used. The prototype sequence of the hMPV isolate 1-99 contained 13,223 base-pairs, sequenced in a total of 227 individual sequences, with an average length of 404 base-pairs. The sequence is SEQ ID NO:18. The length of the open reading frames of hMPV 1-99 and other Paramyxoviruses, both in absolute size and percentage amino acid identity are shown in Table 7. Most identity between the 1-99 and 1-00 strains was observed in the genes coding for N protein (95.2%), M (97.3%), F (93.7%), L (94.1%) and M2-1 (94.1%) with percentages homology of over 90%. The homology of the P and M2-2 genes between both strains was found to be 86.1 and 88.9% respectively. Also, the isolate is mostly related to the subtype C of the avian Metapneumovirus, with amino acid identities in the N protein (88.6%), M protein (87.1%) and M2-1 protein (84.3%). The identity with the P and M2-2 proteins is lower at 67.8% and 56.9% respectively. The genes of the prototype 1-00 and 1-99 strains are identical on the genomic map, with the same number of amino acids for N, P, M, F, M21 and M2-2 protein. The putative SH gene is 6 amino acids shorter, the G protein is 12 amino acids shorter, and the L gene of the 1-00 and 1-99 strain are the same size. Finally, the start of the genes on the genomic map and the non-coding sequences located between the genes, have been summarized in Table 8. In summary, the sequence information of the 1-99 strain of the human Metapneumovirus clearly demonstrates the genetic relation of 1-99 with the prototype strain 1-00, sharing identical genomic map organization. Less phylogenetic relation is observed with the subtype C of APV. TABLE 7 LENGTH OF THE ORFS OF HMPV 1-99 AND OTHER PARAMYXOVIRUSES (NO. OF AMINO ACID RESIDUES) N P M F M21 M22 SH G L 1-99 394 294 254 539 187 71 177 224 1937 1-00 394 294 254 539 187 71 183 236 2005 APV-A 391 278 254 538 186 73 174 391 2004 APV-B 391 279 254 538 186 73 414 APV-C 394 294 254 537 184 71 hRSV-A 391 241 256 574 194 90 64 298 2165 hRSV-B 391 241 256 574 195 90 65 299 2166 bRSV 391 241 256 574 186 90 81 257 2162 PVM 393 295 257 537 176 98 92 396 PERCENTAGE OF THE AMINO ACID SEQUENCE IDENTITY BETWEEN HMPV 1-99 AND OTHER PARAMYXOVIRUSES N P M F M21 M22 SH G L 1-00 95,2 86,1 97,3 93,7 94,1 88,9 59 32,4 94,1 APV-A 68,9 58,1 76,1 67,5 69 25 13,1 14,2 63,7 APV-B 69,1 53,9 76,5 66,8 65,8 26,4 APV-C 88,6 67,8 87,1 80,5 84,3 56,9 bRSV 41,1 28,1 36,9 35 32,6 9,7 12,2 15,6 46,5 hRSV-A 41,1 26 37,6 32,2 35,6 6,2 16 46,9 hRSV-B 40,6 26 36,9 34,4 34 13,9 21,2 15,6 47 PVM 43,7 22,4 39,2 38,8 5,4 8 TABLE 8 SUMMARY OF GENE START SEQUENCES ON THE GENOMIC MAP AND THE NON-CODING SEQUENCES LOCATED BETWEEN THE GENES. Pos. ORF Stop Non-coding sequence Gene start Start Pos ORF 1 Le ACGAGAAAAAAACGCGUAUAAAUU GGGACAAAUAAAA AUG 54 N AAAUUCCAAACAAAAC 1238 N UAA UUAAAAAACU GGGACAAGUCAAA AUG 1262 P 2146 P UAG UUUAAUAAAAAUAAACAAU GGGACAAGUCAAG AUG 2179 M 2943 M UAA AAAUAACUGUCUUAAUCAAUAAUU GGGACAAAUAAAA AUG 3065 F GCUUAUAUAACUCUAG AGAUUAAUAAGCUUAUUAUUAUAG UUAUAUAAAAAUAAAU UAGAAUUAGAAGGGCAUCAAUAGA AAGC 4684 F UAG UUAAUUAAAAAAU GGGACAAAUCAUC AUG 4711 M2 5437 M2 UAG UAAAAAAUAAAAAUAGAAU GGGAUAAAUGACA AUG 5470 SH 6003 SH UAA AAUAACACGGSUUUSAACAUUAAA GGGACAAGUGGCU AUG 6210 G AUSAGAACAACCUCCA CCCAGGUCUAUCAAUACAGUGGUU UAGCCAUUUAAAAACC GAAUAUUAUCUAGGCUGCACGACA CUUUGCAAUAAUAUGC AAUAGUCAAUAGUUAAACCACUGC UGCAAACUCAUCCAUA AUAUAAUCACUGAGUAAUACAAAA CAAGAAAAU 6884 G UAG AGAGGUGCAAAACUCAAAUGAGCA GGGAUAAAUGACA AUG 7124 L CAACACACAAACAUYC CAUCCAAGUAGUUAACAAAAAACC ACAAAAUAACCUUGAA AACCAAAAAACCAAAACAUAAACC CAGACCCAGAAAAACA UAGACACCAUAUGGAAGGUUCUAG CAUAUGCACCAAUGAG AUGGCAUCUGUUCAUGUAUCAAUA GCACCACCAUCAUUCA AGGAAUAAGAAGAGGCGAAAAUUU AA 13009 L UGA AUUAAACUAUGAUUUCUUUGAAGC AUG 13243 Tr AUUAGAGAACACAUAC CCCAAUAUGAUCAAGCUUAUAGAU AAUUUGGGAAAUGCAG AAAUAAAGAAACUAAUCMAGGUCM CUGGGUAUAUGCUUGU GAGUAAGAAGUAAUAAUAAUGAUA AUGAUUAACCAUAAUC UCMCMCMACUGAGAAAAUAAUCGU CUAACAGUUUAGUUGA UCAUUAGUUAUUUAAAAUUAUAAA AUAGUAACUA 6.6 EXAMPLE 6 Phylogenetic Relationships Phylogenetic approaches can be used in order to identify the relationships among groups of viruses, i.e. between MPV and other viruses. Additionally, phylogenetic relationships can be determined for different isolates of the same type of virus. Phylogenetic trees were determined to determine relationships between MPV and other viruses, and also to determine relationships between the different isolates of hMPV. For example, phylogenetic trees can be generated, using nucleotide or protein sequence data, in order to illustrate the relationship between MPV and different viruses. Alternatively, phylogenetic trees can be generated, using nucleotide or protein sequence data, in order to illustrate the relationship between various isolates of hMPV. PHYLOGENETIC RELATIONSHIPS BETWEEN hMPV AND DIFFERENT VIRUSES: Although BLAST searches using nucleotide sequences obtained from the unidentified virus isolates revealed homologies primarily with members of Pneumovirinae, homologies that were based on protein sequences revealed some resemblance with other paramyxoviruses as well. As an indication of the relationship between the newly identified virus isolates and members of Pneumovirinae, phylogenetic trees were constructed based on the N, P, M and F ORFs of these viruses. In all four phylogenetic trees, the newly identified virus isolate was most closely related to APV (FIG. 14). From the four serotypes of APV that have been described (Bayon-Auboyer et al., 2000, J Gen. Virol 81:2723-2733), APV serotype C, the metapneumovirus found primarily in birds in the USA, showed the closest resemblance to the newly identified virus. It should be noted however, that only partial sequence information for APV serotype D is available. For all phylogenetic trees, DNA sequences were aligned using the ClustalW software package and maximum likelihood trees were generated using the DNA-ML software package of the Phylip 3.5 program using 50 or 100 bootstraps and 3 jumbles (Brandenburg et al., 1997, J Med Virol 52:97-104). Previously published sequences that were used for the generation of phylogenetic trees are available from Genbank under accessions numbers: For all ORFs: hRSV: NC001781; bRSV: NC001989; For the F ORF: PYM, D11128; MV-A, D00850; MV-B, Y14292; MV-C, AF187152; For the N ORF: PVM, D10331; MV-A, U39295; MV-B, U39296; MV-C, M176590; For the M ORF: PMV,U66893; MV-A, X58639; MV-B, U37586; MV-C, AE262571; For the P ORF: PVM, 09649; MV-A, U22110, MV-C, AF176591. As an indicator of the relationship between MPV and members of the Pneumovirinae, phylogenetic trees based on the N, P, M, and F ORFs were constructed previously (van den Hoogen et al., 2001, Nat Med 7(6):19-24) and revealed a close relationship between MPV and APV-C. Because of the low homology of the MPV SH and G genes with those genes of other paramyxoviruses, reliable phylogenetic trees for these genes cannot be constructed. In addition, the distinct genomic organization between members of the Pneumovirus and Metapneumovirus genera make it impossible to generate phylogenetic trees based on the entire genomic sequence. Trees for the M2 and L genes were constructed in addition to those previously published. Both these trees confirmed the close relation between APV and MPV within the Pneumovirinae subfamily (FIG. 15). To construct phylogenetic trees, DNA sequences were aligned using the ClustalW software package and maximum likelihood trees were generated using the DNA-ML software package of the Phylip 3.5 program using 100 bootstraps and 3 jumbles. Bootstrap values were computed for consensus trees created with the PHYLIP consensus package. Based upon phylogenetic analyses of the different isolates of hMPV obtained so far, two major genotypes have been identified with virus isolate 00-1 being the prototype of genotype A and isolate 99-1 the prototype of genotype B. It is hypothesized that the genotypes are related to subtypes and that re-infection with viruses from both subgroups occur in the presence of pre-existing immunity and the antigenic variation may not be strictly required to allow re-infection. Furthermore, hMPV appears to be closely related to avian pneumovirus, a virus primarily found in poultry. The nucleotide sequences of both viruses show high percentages of homology, with the exception of the SH and G proteins. The viruses appear to cross-react in tests that are based primarily on the nucleoprotein and matrixprotein, however, they respond differently in tests that are based on the attachment proteins. The differences in virus neutralization titer provide further proof that the two genotypes of hMPV are two different serotypes of one virus, where APV is a different virus. PHYLOGENETIC RELATIONSHIPS BETWEEN DIFFERENT hMPV ISOLATES: Phylogenetic approaches can also be used in order to identify the relationships among different isolates of MPV. For example, phylogenetic trees can be generated, using nucleotide or protein sequence data of MPV, in order to illustrate the relationship between a number of MPV isolates that are obtained from different subjects. This approach is useful in understanding the differences that occur within the population of MPV viruses. To determine the relationship of our various newly identified virus isolates, phylogenetic trees were constructed based on sequence information obtained from eight to nine isolates (8 for F, 9 for N, M and L). RT-PCR was used with primers designed to amplify short fragments in the N, M, F, P, SH and L ORFs, that were subsequently sequenced directly. The nine virus isolates that were previously found to be related in serological terms (see above) were also found to be closely related genetically. In fact, all nine isolates were more closely related to one another than to APV. Although the sequence information used for these phylogenetic trees was limited, it appears that the nine isolates can be divided in two groups, with isolate 94-1, 99-1 and 99-2 clustering in one group and the other six isolates (94-2; 93-1; 93-2; 93-3; 93-4; 00-1) in the other (FIG. 16). An alignment of the F genes of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2, is shown in FIG. 17. An alignment of the F proteins of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2, is shown in FIG. 18. An alignment of the G genes of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2, is shown in FIG. 19. An alignment of the G proteins of different isolates of hMPV of all four variants, variant A1, A2, B1, or B2, is shown in FIG. 20. A phylogenetic tree based on the F gene sequences showing the phylogenetic relationship of the different hMPV isolates and their association with the respective variants of hMPV is shown in FIG. 21. Further, a phylogenetic tree based on the G gene sequences showing the phylogenic relationship of the different hMPV isolates and their association with the respective variants of hMPV is shown in FIG. 22. The phylogenetic trees were calculated using DNA maximum likelihood with 50 bootstraps and 3 jumbles. Sequence identities between different genes of hMPV isolate 00-1 with different genes of hMPV isolate 99-1, APV serotype C, and APV serotype A are listed in Table 9. TABLE 9 ORF SEQUENCE IDENTITY BETWEEN HMPV ISOLATE 00-1 AND OTHER VIRUSES N P M F M2.1 M2.2 SH G L hMPV isolate 95 86 98 94 95 90 57 33 94 99-1 APV serotype C 88 68 87 81 84 56 N.A. N.A. N.A. APV serotype A 69 55 78 68 72 25 18 9 64 Originally, phylogenetic relationships were inferred for only nine different isolates. Two potential genetic clusters were identified by analyses of partial nucleotide sequences in the N, M, F and L ORFs of virus isolates. Nucleotide identity of 90-100% was observed within a cluster, and 81-88% identity was observed between the clusters. Sequence information obtained on more virus isolates confirmed the existence of two genotypes. Virus isolate 00-1, as a prototype of cluster A, and virus isolate 99-1 as a prototype of cluster B, have been used in cross neutralization assays to test whether the genotypes are related to different serotypes or subgroups. Using RT-PCR assays with primers located in the polymerase gene, thirty additional virus isolates were identified from nasopharyngeal aspirate samples. Sequence information of parts of the matrix and polymerase genes of these new isolates together with those of the previous nine isolates were used to construct phylogenetic trees (FIG. 15). Analyses of these trees confirmed the presence of two genetic clusters, with virus isolate 00-1, as the prototype virus in group A and virus isolate 99-1 as the prototype virus in group B. The nucleotide sequence identity within a group was more than 92%, while between the clusters the identity was 81-85%. 6.7 EXAMPLE 7 Leader Sequences of Human Metapneumovirus (hMPV) NL/1/00 Genomic RNA While the majority of genomic composition was determined, the authentic terminal sequences at the extreme ends were lacking. Using ligation of the viral RNA and subsequent PCR amplification of the ligated junction and a combination of polyadenylation and 3′ RACE methods, the authentic nucleotide sequences were determined (FIG. 54). The sequence analysis of PCR fragments generated by ligation of viral RNA ends revealed the Leader and Trailer sequences displayed in FIG. 26 (See, SEQ IDs 18-21). The trailer sequences obtained this way were consistent with the sequences expected from the trailer sequences of other pramyxoviruses, including APV. However, the leader sequence of only 2 out of 71 clones sequenced, contained AC as the terminal nucleotide residues that are found in all paramyxoviruses to date. Therefore, the terminal nucleotide sequences of the hMPV/NL/1/00 leader were subsequently confirmed using a combination of polyadenylation and 3′ RACE methods. Furthermore, two extra nucleotides at the 3′ leader terminus of hMPV NL/1/00 were identified. Vero-grown hMPV NL/1/00 virus was used in this study. As a control, a related negative sense RNA virus, respiratory syncytial virus (RSV) A2, that has a similar genomic size with identified terminal sequences, was included. Viral RNA was isolated using the QIAamp Viral RNA Mini Kit (Qiagen), following the manufacturer's instructions. Viral RNA was polyadenylated by incubating the viral RNA with poly (A) polymerase (Ambion) at 37° C. for 1 hr, followed by clean up using a NucAway spin column (Ambion). The viral RNA was then reverse transcribed using a primer complementary to the poly (A) tail region and the reverse transcriptase, Superscript I (Invitrogen). PCR and Nested PCR reactions were carried out using hMPV specific primers, juxtaposed to the terminal ends, to amplify the desired products with expected sizes for sequencing analysis. PCR products were further cloned into pCRII vector using a TA cloning kit (Invitrogen). To reveal the authentic nucleotide sequences for the terminus, direct sequencing of PCR DNA as well as the cloned PCR products were conducted. Only hMPV data are shown in FIG. 55. Control experiments, using RSV-A2 RNA, indicated that the leader sequences of RSV-A2 remained intact and detectible with the same approach. Sequencing analyses on PCR products directly (FIG. 55) and on PCR clones both indicated that the leader region of hMPV consisted of 5′ ACG CGA AAA AAA CGC GTA TA (expressed as positive sense cDNA orientation) at the 3′ most proximal 20 nucleotides in the leader sequence. The two newly identified nucleotides are underlined in FIG. 101. 6.8 EXAMPLE 8 Serotyping and Subgrouping of MPV Isolates Virus neutralization assays (See, e.g., Example 16) were used to determine if the virus isolates of hMPV could be distingushed by serotype or genotype. Virus isolates 00-1 and 99-1 were used to inoculate ferrets in order to raise virus-specific antisera. For the 00-1 isolate, ferret and guinea pig specific antisera for the virus were generated by experimental intranasal infection of two specific pathogen free ferrets and two guinea pigs, housed in separate pressurized glove boxes. Two to three weeks later all the animals were bled by cardiac puncture, and their sera were used as reference sera. The sera were tested for all previous described viruses with indirect IFA as described below. These antisera, along with antisera prepared using the 99-1 isolate, were used in virus neutralization assays with both viruses (Table 10). TABLE 10 VIRUS NEUTRALIZATION TITERS ISOLATE ISOLATE 00-1 99-1 PRESERUM FERRET A 2 2 (00-1) FERRET A 22 DPI (00-1) 64 2 PRESERUM FERRET B 2 2 (99-1) FERRET B 22 DPI 4 64 (99-1) For isolate 00-1 the titer differs 32 (64/2) fold For isolate 99-1 the titer differs 16 (64/4) fold In addition, six guinea pigs were inoculated with either one of the viruses, i.e., 00-1 and 99-1). RT-PCR assays on nasophyeal aspirate samples showed virus replication from day 2 through day 10 post infection. At day 70 post infection the guinea pigs were challenged with either the homologous or the heterologous virus, and in all four cases virus replication was noticed. Virus neutralization assays with anti sera after the first challenge showed essentially the same results as in the VN assays performed with the ferrets (>16-fold difference in VN titer). The results presented in this example confirm the existence of two genotypes, that correspond to two serotypes of MPV, and show the possibility of repeated infection with heterologous and homologous virus (Table 11). TABLE 11 primary virus secondary virus infection replication infection replication guinea pig 1-3 00-1 2 out of 3 99-1 1 out of 2 guinea pig 4-6 00-1 3 out of 3 00-1 1 out of 3 guinea pig 7-9 99-1 3 out of 3 00-1 2 out of 2 guinea pig 10-12 99-1 3 out of 3 99-1 1 out of 3 Note: for the secondary infection guinea pig 2 and 9 were not there any more. 7 Diagnostic Assays/Detection Methods 7.1 EXAMPLE 9 Direct Immunofluoresence Assay (DIF) Method Nasopharyngeal aspirateples from patients suffering from RTI were analyzed by DIF as described (Rothbarth et. al., 1999, J. of Virol. Methods 78:163-169). Samples were stored at −70° C. In short, nasopharyngeal aspirates were diluted with 5 ml Dulbecco MEM (BioWhittaker, Walkersville, Md.) and thoroughly mixed on a vortex mixer for one minute. The suspension was centrifuged for ten minutes at 840×g. The sediment was spread on a multispot slide (Nutacon, Leimuiden, The Netherlands) and the supernatant was used for virus isolation. After drying, the cells were fixed in acetone for one minute at room temperature. After the slides were washed, they were incubated for 15 minutes at 37° C. with commercially available FITC-labeled anti-sera specific for viruses such as influenza A and B, hRSV and hPIV 1 to 3 (Dako, Glostrup, Denmark). After three washings in PBS and one in tap water, the slides were submerged in a glycerol/PBS solution (Citifluor, UKO, Canterbury, UK) and covered. The slides were then analyzed using a Axioscop fluorescence microscope. 7.2 EXAMPLE 10 Virus Culture of MPV The detection of the virus in a cultivated sample from a host is a direct indication of the host's current and/or past exposure or infection with the virus. Samples that displayed CPE after the first passage were used to inoculate sub-confluent mono-layers of tMK cells in media in 24 well plates. Cultures were checked for CPE daily and the media was changed once a week. Since CPE differed for each isolate, all cultures were tested at day 12 to 14 with indirect IFA using ferret antibodies against the new virus isolate. Positive cultures were freeze-thawed three times, after which the supernatants were clarified by low-speed centrifugation, aliquoted and stored frozen at −70° C. The 50% tissue culture infectious doses (TCID50) of virus in the culture supernatants were determined as described (Lennette, D. A. et al. In: DIAGNOSTIC PROCEDURES FOR VIRAL, RICKETTSIAL, AND CHLAMYDIAL INFECTIONS, 7th ed. (eds. Lennette, E. H., Lennette, D.A. & Lennette, E. T.) 3-25; 37-138; 431-463; 481-494; 539-563 (American Public Health Association, Washington, 1995)). 7.3 EXAMPLE 11 Antigen Detection by Indirect Immunofluoresence Assays (IFA) Antibodies can be used to visualize viral proteins in infected cells or tissues. Indirect immunofluorescence assay (IFA) is a sensitive approach in which a second antibody coupled to a fluorescence indicator recognizes a general epitope on the virus-specific antibody. IFA is more advantageous than DIF because of its higher level of sensitivity. In order to perform the indirect IFA, collected specimens were diluted with 5 ml Dulbecco MEM medium (BioWhittaker, Walkersville, Md.) and thoroughly mixed on a vortex mixer for one minute. The suspension was then centrifuged for ten minutes at 840×g. The sediment was spread on a multispot slide. After drying, the cells were fixed in acetone for 1 minute at room temperature. Alternatively, virus was cultured on tMK cells in 24 well slides containing glass slides. These glass slides were washed with PBS and fixed in acetone for 1 minute at room temperature. Two indirect IFAs were performed. In the first indirect IFA, slides containing infected tMK cells were washed with PBS, and then incubated for 30 minutes at 37° C. with virus specific antisera. Monoclonal antibodies against influenza A, B and C, hPIV type 1 to 3, and hRSV were used. For hPIV type 4, mumps virus, measles virus, sendai virus, simian virus type 5, and New-Castle Disease virus, polyclonal antibodies (RIVM) and ferret and guinea pig reference sera were used. After three washings with PBS and one wash with tap water, the slides were stained with secondary antibodies directed against the sera used in the first incubation. Secondary antibodies for the polyclonal antisera were goat-anti-ferret (KPL, Guilford, UK, 40 fold diluted), mouse-anti-rabbit (Dako, Glostrup, Denmark, 20 fold diluted), rabbit-anti-chicken (KPL, 20 fold dilution) and mouse-anti-guinea pig (Dako, 20 fold diluted). In the second IFA, after washing with PBS, the slides were incubated for 30 minutes at 37° C. with 20 polyclonal antibodies at a dilution of 1:50 to 1:100 in PBS. Immunized ferrets and guinea pigs were used to obtain polyclonal antibodies, but these antibodies can be raised in various animals, and the working dilution of the polyclonal antibody can vary for each immunization. After three washes with PBS and one wash with tap water, the slides were incubated at 37° C. for 30 minutes with FITC labeled goat-anti-ferret antibodies (KPL, Guilford, UK, 40 fold diluted). After three washes in PBS and one in tap water, the slides were included in a glycerol/PBS solution (Citifluor, UKO, Canterbury, UK) and covered. The slides were analyzed using an Axioscop fluorescence microscope (Carl Zeiss B. V., Weesp, the Netherlands). 7.4 EXAMPLE 12 Haemagglutination Assays, Chloroform Sensitivity Tests and Electron Microscopy Different characteristics of a virus can be utilized for the detection of the virus. For example, many virus contain proteins that can bind to erythrocytes resulting in a lattice. This property is called hemagglutination and can be used in hemagglutination assays for detection of the virus. Virus may also be visualized under an electron microscope (EM) or detected by PCR techniques. Hemagglutination assays and chloroform sensitivity tests were performed as described (Osterhaus et al., 1985, Arch. of Virol 86:239-25; Rothbarth et al., J of Virol Methods 78:163-169). For EM analyses, virus was concentrated from infected cell culture supernatants in a micro-centrifuge at 4° C. at 17000×g, after which the pellet was resuspended in PBS and inspected by negative contrast EM. 7.5 EXAMPLE 13 Detection of hMPV/AVP Antibodies of IgC, IgA and IgM Classes Specific antibodies to viruses rise during the course of infection/illness. Thus, detection of virus-specific antibodies in a host is an indicator of current and/or past infections of the host with that virus. The indirect enzyme immunoassay (EIA) was used to detect the IgG class of hMPV antibodies. This assay was performed in microtitre plates essentially as described previously (Rothbarth et al., 1999, J. of Vir. Methods 78:163-169). Briefly, concentrated hMPV was solubilized by treatment with 1% Triton X-100. After determination of the optimal working dilution by checkerboard titration, it was coated for 16 hr at room temperature into microtitre plates in PBS. Subsequently, 100 ul volumes of 1:100 diluted human serum samples in EIA buffer were added to the wells and incubated for 1 hour at 37° C. Binding of human IgG was detected by adding a goat anti-human IgG peroxidase conjugate (Biosource, USA), adding TMB as substrate developed plates and Optical Density (OD) was measured at 450 nm. The results were expressed as the S(ignal)/N(egative) ratio of the OD. A serum was considered positive for IgG if the S/N ratio was beyond the negative control plus three times the standard. The hMPV antibodies of the IgM and IgA classes were detected in sera by capture EIA essentially as described previously (Rothbarth et al., 1999, J Vir Methods 78:163-169). For the detection of IgA and IgM, commercially available microtiter plates coated with anti human IgM or IgA specific monoclonal antibodies were used. Sera were diluted 1:100. After incubation of 1 hour at 37° C., an optimal working dilution of hMPV was added to each well (100 μl) before incubation for 1 hour at 37° C. After washing, polyclonal anti-hMPV antibody labeled with peroxidase was added, and the plate was incubated 1 hour at 37° C. Adding TMB as a substrate the plates were developed, and OD was measured at 450 rim. The results were expressed as the S(ignal)/N(egative) ratio of the OD. A positive result was indicated for IgG when the S/N ratio was beyond the negative control plus three times the standard. AVP antibodies were detected in an AVP inhibition assay. The protocol for the APV inhibition test is included in the APV-Ab SVANOVIR® enzyme immunoassay that is manufactured by SVANOVA Biotech AB, Uppsala Science Park Glunten SE-751 83 Uppsala Sweden. The results were expressed as the S(ignal)/N(egative ratio of the OD. A serum was considered positive for IgG, if the S/N ratio was beyond the negative control plus three times the standard. 7.6 EXAMPLE 14 Detection of Antibodies in Humans, Mammals, Ruminants or Other Animals by Indirect IFA For the detection of virus specific antibodies, infected tMK cells with MPV were fixed with acetone on coverslips (as described above), washed with PBS and incubated 30 minutes at 37° C. with serum samples at a 1 to 16 dilution. After two washes with PBS and one with tap water, the slides were incubated for 30 minutes at 37° C. with FITC-labeled secondary antibodies to the species used (Dako). Slides were processed as described above. Antibodies can be labeled directly with a fluorescent dye, which will result in a direct immunofluorescence assay. FITC can be replaced with any fluorescent dye. 7.7 EXAMPLE 15 Detection of Antibodies in Humans, Mammals, Ruminants or Other Animals by ELISA In Paramyxoviridae, the N protein is the most abundant protein, and the immune response to this protein occurs early in infection. For these reasons, a recombinant source of the N proteins is preferably used for developing an ELISA assay for detection of antibodies to MPV. Antigens suitable for antibody detection include any MPV protein that combines with any MPV-specific antibody of a patient exposed to or infected with MPV virus. Preferred antigens of the invention include those that predominantly engender the immune response in patients exposed to MPV, thus, typically are recognized most readily by antibodies of a patient. Particularly preferred antigens include the N, F, M and G proteins of MPV. Antigens used for immunological techniques can be native antigens or can be modified versions thereof. Well known techniques of molecular biology can be used to alter the amino acid sequence of a MPV antigen to produce modified versions of the antigen that may be used in immunologic techniques. Methods for cloning genes, for manipulating the genes to and from expression vectors, and for expressing the protein encoded by the gene in a heterologous host are well-known, and these techniques can be used to provide the expression vectors, host cells, and the for expressing cloned genes encoding antigens in a host to produce recombinant antigens for use in diagnostic assays. See e.g., MOLECULAR CLONING, A LABORATORY MANUAL AND CURRENT PROTOCOLS IN MOLECULAR BIOLOGY. A variety of expression systems may be used to produce MPV antigens. For instance, a variety of expression vectors suitable to produce proteins in E. Coli, B. subtilis, yeast, insect cells, and mammalian cells have been described, any of which might be used to produce a MPV antigen suitable to detect anti-MPV antibodies in exposed patients. The baculovirus expression system has the advantage of providing necessary processing of proteins, and is therefor preferred. The system utilizes the polyhedrin promoter to direct expression of MPV antigens. (Matsuura et al., 1987, J. Gen. Virol. 68:1233-1250). Antigens produced by recombinant baculo-viruses can be used in a variety of immunological assays to detect anti-MPV antibodies in a patient. It is well established that recombinant antigens can be used instead of natural virus in practically any immunological assay for detection of virus specific antibodies. The assays include direct and indirect assays, sandwich assays, solid phase assays such as those using plates or beads among others, and liquid phase assays. Assays suitable include those that use primary and secondary antibodies, and those that use antibody binding reagents such as protein A. Moreover, a variety of detection methods can be used in the invention, including calorimetric, fluorescent, phosphorscent, chemiluminescent, luminescent and radioactive methods. For example, an indirect IgG EIA using a recombinant N protein (produced with recombinant baculo-vuus in insect (Sf9) cells) as antigen can be performed. For antigen preparation, Sf9 cells are infected with the recombinant baculovirus and harvested 3-7 days post infection. The cell suspension is washed twice in PBS, pH 7.2, adjusted to a cell density of 5.0×106 cells/ml, and freeze-thawed three times. Large cellular debris is pelleted by low speed centrifugation (500×g for 15 minutes) and the supernatant is collected and stored at −70° C. until use. Uninfected cells are processed similarly for negative control antigen. Once the antigen is prepared, 100 μl of a freeze-thaw lysate is used to coat microtiter plates at dilutions ranging from 1:50 to 1:1000. An uninfected cell lysate is run in duplicate wells and serves as a negative control. After incubation overnight, plates are washed twice with PBS/0.05% Tween. Test sera are diluted 1:50 to 1:200 in ELISA buffer (PBS, supplemented to 2% with normal goat sera, and with 0.5% bovine serum albumin and 0.1% milk), followed by incubation wells for 1 hour at 37° C. Plates are washed two times with PBS/0.05% Tween. Horseradish peroxidase labeled goat anti-human (or against other species) IgG, diluted 1:3000 to 1:5000 in ELISA buffer, is added to wells, and incubated for 1 hour at 37° C. The plates are then washed two times with PBS/0.05% Tween and once with tap water, incubated for 15 minutes at room temperature with the enzyme substrate TMB, 3,3′,5,5′ tetramethylbenzidine, such as that obtained from Sigma, and the reaction is stopped with 100 μl of 2 M phosphoric acid. Colorimetric readings are measured at 450 nm using an automated microtiter plate reader. 7.8 EXAMPLE 16 Virus Neutralization Assay When a subject is infected with a virus, an array of antibodies against the virus are produced. Some of these antibodies can bind virus particles and neutralize their infectivity. Virus neutralization assays (VN) are usually conducted by mixing dilutions of serum or monoclonal antibody with virus, incubating them, and assaying for remaining infectivity with cultured cells, embryonated eggs, or animals. Neutralizing antibodies can be used to define type-specific antigens on the virus particle, e.g., neutralizing antibodies could be used to define serotypes of a virus. Additionally, broadly neutralizing antibodies may also exist. VN assays were performed with serial two-fold dilutions of human and animal sera starting at an eight-fold dilution. Diluted sera were incubated for one hour with 100 TCID50 of virus before inoculation of tMK cells grown in 96 well plates, after which the plates were centrifuged at 840×g. The media was changed after three and six days and IFA was conducted with FTIC-labeled ferret antibodies against MPV 8 days after inoculation. The VN titre was defined as the lowest dilution of the serum sample resulting in negative IFA and inhibition of CPE in cell cultures. 7.9 EXAMPLE 17 RNA Isolation The presence of viruses in a host can also be diagnosed by detecting the viral nucleic acids in samples taken from the host (See e.g., RT-PCR in Example 18 and RAP-PCR in Example 21). RNA was isolated from the supernatants of infected cell cultures or sucrose gradient fractions using a High Pure RNA Isolation kit, according to instructions from the manufacturer (Roche Diagnostics, Ahnere, The Netherlands). RNA can also be isolated following other procedures known in the art (see, e.g., CURRENT PROTOCOLS IN MOLECULAR BIOLOGY, volume 1-3 (1994-1998). Ed. by Ausubel, F. M. et al., Published by John Wiley and sons, Inc., USA). 7.10 EXAMPLE 18 RT-PCR to Detect/Diagnose MPV Detection of the virus in a biological sample can be done using methods that copy or amplify the genomic material of the virus. Virus-specific oligonucleotide sequences for RT-PCR assays on known paramyxoviruses are described below in this Example. A one-step RT-PCR was performed in 50 μl reactions containing 50 mM Tris.HCl pH 8.5, 50 mM NaCl, 4 mM MgCl2, 2 mM dithiotreitol, 200 μM each dNTP, 10 units recombinant RNAsin (Promega, Leiden, the Netherlands), 10 units AMV RT (Promega, Leiden, The Netherlands), 5 units Amplitaq Gold DNA polymerase (PE Biosystems, Nieuwerkerk aan de Ijssel, The Netherlands) and 5 μl RNA. Cycling conditions were 45 min. at 42° C. and 7 min. at 95° C. once, 1 min at 95° C., 2 min. at 42° C. and 3 min. at 72° C. repeated 40 times and 10 min. at 72° C. once. Primers sequences are provided in the sequence listing. More specifically, the primers used for the nucleoprotein gene were N3 and N4, having nucleotide sequences corresponding to SEQ ID NOs:28 and 29 respectively, and were used to amplify a 151 nucleotide fragment. The primers used for the matrix protein gene were M3 and M4, having nucleotide sequences corresponding to SEQ ID NOs: 30 and 31 respectively, and were used to amplify a 252 nucleotide fragment. The primers used for the polymerase protein gene were L6 and L7, corresponding to SEQ ID NOs: 34 and 35 respectively, and were used to amplify a 173 nucleotide fragment. The primers used for the F protein gene were F7 and F8, corresponding to SEQ IS NOs: 32 and 33 respectively, and were used to amplify a 221 nucleotide fragment. Furthermore, probes were used to confirm the presence of hMPV genome sequences. The probe used to detect the M gene had a nucleotide sequence corresponding to SEQ ID NO: 36. The probe used to detect the N gene had a nucleotide sequence corresponding to SEQ ID NO: 37. The probe used to detect the L gene had a nucleotide sequence corresponding to SEQ ID NO:38. In another example, primers and probes can be designed based on MPV sequences that are known or obtained through sequencing. Likewise, different sequences of primers and difference buffer and assay conditions to be used for specific purposes would be known to one skilled in the art. RT-PCR was used for the detection of known paramyxoviruses as well. Primers for hPIV-1 to 4, mumps, measles, Tupsia, Mapuera, and Hendra were developed in house and based on alignments of available sequences. Primers for New Castle Disease Virus were taken from Seal, J., J. et al; Clin. Microb., 2624-2630, 1995. Primers for Nipah and general paramyxovirus-PCR were taken from Chua, et al., 2000, Science, 288. The primers used to detect other known paramyxoviruses were as follows: hPIV-1 was detected with primers corresponding to the sequences of SEQ ID NO: 58 and 59 for the forward and reverse primers respectively, hPIV-2 was detected with primers corresponding to the sequences of SEQ ID NO: 60 and 61 for the forward and reverse primers respectively, hPIV-3 was detected with primers corresponding to the sequences of SEQ ID NO: 62 and 63 for the forward and reverse primers respectively, hPIV-4 was detected with primers corresponding to the sequences of SEQ ID NO: 64 and 65 for the forward and reverse primers respectively, Mumps was detected with primers corresponding to the sequences of SEQ ID NO: 66 and 67 for the forward and reverser primers respectively, NDV was detected with primers corresponding to the sequences of SEQ ID NO: 68 and 69 for the forward and reverse primers respectively, Tupaia was detected with primers corresponding to the sequences of SEQ ID NO: 70 and 71 for the forward and reverse primers respectively, Mapuera was detected with primers corresponding to the sequences of SEQ ID NO: 72 and 73 for the forward and reverse primers respectively, Hendra was detected with primers corresponding to the sequences of SEQ ID NO: 74 and 75 for the forward and reverse primers respectively, Nipah was detected with primers corresponding to the sequences of SEQ ID NO: 76 and 77 for the forward and reverse primers respectively, hRSV was detected with primers corresponding to the sequences of SEQ ID NO: 78 and 79 for the forward and reverse primers respectively, Measles was detected with primers corresponding to the sequences of SEQ ID NO: 80 and 81 for the forward and reverse primers respectively, and general Paramyxoviridae viruses were detected with primers corresponding to the sequences of SEQ ID NO: 82 and 83 for the forward and reverse primers respectively. 7.11 EXAMPLE 19 Detection of hMPV Using PCR In order to detect the presence of hMPV in a sample, a rapid and simple PCR based assay was developed. Regular RT-PCR assays targeting L and N sequences of hMPV were performed with the following primer sets: L-forward (5′-CACCCCAGTCTTTCTTGAAA-3′) and L-reverse (5′-CATGCCCACTATAAAAGGTCAG-3′) and the primers N-forward (5′-CATGCTATATTAAAAGAGTCTC-3′) and N-reverse (5′-TCTGCAGCATATTTGTAATCA-3′). The reaction mixture (total volume 50 μl) contained 5 μl RNA, 200 nM of each primer, AmpliTaq Gold buffer (Applied Biosystems, Nieuwerkerk a/d IJssel, The Netherlands), 600 μM dNTPs, 2 μM DTT, 2 mM MgCl2, 20 U RNAsin, 5 U Taq polymerase and 10 U AMV reverse transcriptase (all enzymes supplied by Promega). The RT-PCR parameters were: 60 min at 42° C. and 7 min at 95° C., followed by 40 cycles of 1 min at 95° C., 2 min at 45° C. and 3 min at 72° C. A final incubation at 72° C. for 10 min was included to ensure that elongation of all new DNA strands was completed. Detection of PCR products was perfomed by transferring a 10 μl PCR reaction sample to a Hybond N+ membrane (Amersham Pharmacia biotech) and subsequent hybridization with a biotin-labeled probe (for both assays resp. N-probe (5′-ACAACTGCAGTGACACCTTCATCATTGCA-3′) and L-probe(5′-CTGTTAATATCCCACACCAGTGGCATGC-3′)). Then the conjugate streptavidinperoxidase was bound to the probe and the detection reagent ECL (Amersham Pharmacia biotech) added. DNA fragments were visualized by exposing the blot to a x-ray film (FIG. 58). The results demonstrate that this RT-PCR based assay can be used to detect MPV strains from all four clades using one set of oligonucleotides for either the N or the L sequences. 7.12 EXAMPLE 20 Development of a Single Assay for the Detection of all Four Human Metapneumovirus Subtypes In order to allow for the detection of all hMPV subtypes, A1, A2, B1, and B2, a single sensitive assay was developed. This assay was advantageous because it allowed for the detection of hMPV strains from the various subtypes to be detected using a uniform set of diagnostic equipment and reagents. This new and sensitive Taqman assay was determined to be equally sensitive for all four subtypes. Two sets of Taqman primers and probe were designed to identify all four subclades of hMPV on the basis of sequence information of the hMPV nucleocapsid gene from 53 clinical isolates. All four subtypes of hMPV were present within this panel of isolates. The selected primers and probes were located within the most conserved sequences in all subtypes. Designed Taqman primers for assay were Medi-N-forward (5′-CAACAACATAATGCTAGGACATGTATC-3′), Medi-N-reverse (5′-CCGAGAACAACACTAGCAAAGTTG-3′) and probe Medi-N-probe (5′-FAM-TGGTGCGAGAAATGGGTCCTGAATCTGG-TAMRA-3′). For assay NL-N the designed primers were RF930 (5′-CATATAAGCATGCTATATTAAAAGAGTCTC-3′) and RF931 (5′-CCTATTTCTGCAGCATATTTGTAATCAG-3′) and probe RF928 (5′-FAM-TGYAATGATGAGGGTGTCACTGCGGTTG-TAMRA-3′) in which Y is either a C or a T residue. HMPV isolates were obtained from frozen diagnostic nasopharyngeal samples. Viruses were grown on tMK cells and stored at −70° C. From all clinical hMPV isolates, four were chosen as prototype isolates, one for each subtype, to test the designed primers and probes. Full sequences of these prototype viruses can be obtained from the GenBank database: Prototype virus for hMPV subtype A1 (strain NL/01/00; accession number AF371337), A2 (strain NL/17/00; to be submitted), B1 (strain NL/99/01; to be submitted) and B2 (strain NL/94/01; to be submitted). RNA runoff transcripts were made for generating a standard curve to be able to quantitate viral genomic copy numbers. The N sequence of the hMPV A1 prototype virus was cloned into a modified pCITE vector under the control of a T7 promoter. Runoff transcripts were generated using the Riboprobe System -T7 system (Promega), according to the manufacturer's instructions. Purity of the RNA runoff transcripts were checked by gel electrophoresis and quantitated by measuring A260 in a photospectrometer. RNA was isolated with a high pure RNA isolation kit (Roche Diagnostics, Almere, The Netherlands) according to the manufacturers instructions. A 0.2 ml sample was used for RNA isolation. After binding to the column, DNase I digestion and washing, the RNA was eluted in 50 l nuclease-free double-distilled water. A 5 μl RNA sample was used for generation of cDNA with specific primers using the superscript III reverse-transcriptase enzyme (Invitrogen) in a final volume of 20 μl according to the manufacturers instruction. Aliquots of 5 μl cDNA were used for each real time PCT reaction. Detection of viral RNA was performed using the Taqman universal PCR master mix (Applied Biosystems, Nieuwerkerk a/d IJessel, The Netherlands) following a separate RT step and according to the manufacturer's instructions. For the one step reactions the EZ RT-PCR kit (Applied Biosystems) was used. Amplification and detection were performed in the ABI Prism 7000 Taqman machine (Applied Biosystems). Each reaction mix contained 500 nm of forward primer (RF930), 250 nm reverse primer (RF931) and 500 nM endonuclease probe (RF928) labeled at the 5′ end with FAM (6-carboxy-fluorescein) and at the 3′ end with TAMRA (6-carboxy-tetramethyl-rhodamine). Amplification parameters were 5 min naturation/activation at 95° C. and 45 cycles of 30 sec at 95° C. and 1 min at 60° C. For the one-step reaction these cycle conditions were preceded by 2 min at 50° C. and 30 min at 60° C. for the RT step. Two sets of primers and probe (for assays Medi-N and NL-N) were designed to detect all four subclades of hMPV. Primers and probes were targeted at the mostly conserved sequences within the nucleocapsid gene of hMPV and designed to hybridize with all four subclades of hMPV. Both assays were tested for their sensitivity to detect target sequences of the four prototype hMPV viruses. Runoff transcripts from the N sequences of the prototype virus strains were used to determine the sensitivity of both assays. A comparison between both assays (Medi-N and NL-N) revealed that both assays were able to detect target sequences from all four subclades of hMPV. Serial dilutions of runoff transcripts and virus isolates showed that the assay NL-N had a higher sensitivity in detecting target sequences of the A1 and A2 prototype virus strains. Therefore, the assay NL-N was chosen for further development and testing. To test whether the primers and probe designed for assay NL-N were specific for hMPV, template RNA from 15 other common respiratory viral agents were used for real time RT-PCR analysis. These templates were isolated from virus stocks including RNA from measles virus, mumps, SV5, NDV, RSV A and B, APV-A, B, and C, HPIV-1, 2, 3, and 4, and Influenza virus A and B. The positive control sample was an hMPV A1 RNA template. None of the RNA templates isolated from the non hMPV virus stocks gave a positive signal, confirming that the designed primers and probe were specific for hMPV. Different amounts of forward and reverse primers and of the probe were tested to obtain an optimal amplification signal. Preliminary experiments revealed that an asymmetric mix with twice the amount of forward primer (RF930) as compared to the reverse primer (RF931) give the most sensitive reaction mixture. To determine the sensitivity of our assay, serial dilutions of viral RNA from all four prototype viruses of hMPV were tested. Serial dilutions from the hMPV A1 and B1 prototype strains gave a positive result up to a dilution of 104, while RNA from the higher titered virus stocks from the hMPV A2 and B2 prototype strains could be diluted as far as 105 times (FIG. 59A). The assay proved to be equally sensitive for all four prototype viruses with a detection limit of at least 0.006 TCID50 for the hMPV A2 prototype virus and 0.01 TCID50 for the other prototype viruses. As a standard, RNA run-off transcripts from the hMPV A1 N sequence were generated. Upon quantitation of these RNA transcripts and making serial dilutions, as low as 5 RNA copies yielded a positive signal in our Taqman RT-PCR assay (FIG. 59 B). Primers and probe for our new RT-PCR assay were based on sequences of the N gene from all four hMPV subtypes. Previously described assays, targeting the N (MacKay et. al., J. Clin. Microbiol. 41:100-105) or L (Van Den Hoogen, 2003 in press) sequences of hMPV, however used primers based on the sequence of the hMPV A1 prototype virus only. In FIG. 59 C, entropy plots of oligonucleotide annealing sites for the four prototype hMPV strains are shown for the different primer/probe sets tested. These assays were tested to determine whether they were able to detect all four subtypes of hMPV. The results from these assays on serial RNA dilutions of the prototype viruses showed that they did pick up the hMPV A viruses, albeit with a lower sensitivity than assay NL-N, but not the viruses from the B clades (FIG. 59 D). 7.13 EXAMPLE 21 RAP-PCR The genetic material of MPV or another virus can be detected or amplified using primers that hybridize to regions within the genome and that extend in a particular direction so that the genetic material is amplified. This type of technique is useful when specific sequence information is unavailable or when performing an initial amplification of genetic material in a sample. One such technique is called RAP-PCR. RAP-PCR was performed essentially as described (Welsh et al., 1992, NAR 20:4965-4970). For the RT reaction, 2 μl of RNA was used in a 10 μl reaction containing 10 ng/μl oligonucleotide, 10 mM dithiotreitol, 500 μm each dNTP, 25 mM Tris-HCl pH 8.3, 75 mM KCl and 3 mM MgCl2. The reaction mixture was incubated for 5 minutes at 70° C. and 5 minutes at 37° C., after which 200 units Superscript RT enzyme (LifeTechnologies) were added. The incubation at 37 ° C. was continued for 55 minutes and the reaction was terminated by a 5 minute incubation at 72 ° C. The RT mixture was diluted to give a 50 μl PCR reaction containing 8 ng/μl oligonucleotide, 300 μl each dNTP, 15 mM Tris-HCl pH 8.3, 65 mM KCl, 3.0 mM MgCL2 and 5 units Taq DNA polymerase (FE Biosystems). Cycling conditions were 5 minutes at 94° C., 5 minutes at 40° C., and 1 minute at 72° C. once, followed by 1 minute at 94° C., 2 minutes at 56° C. and 1 minute at 72° C. repeated 40 times, and 5 minutes at 72° C. once. Primers used for RAP-PCR were: primer ZF1 with a nucleotide sequence corresponding to SEQ ID NO: 46, primer ZF4 with a nucleotide sequence corresponding to SEQ ID NO: 47, primer ZF7 with a nucleotide sequence corresponding to SEQ ID NO: 48, primer ZF10 with a nucleotide sequence corresponding to SEQ ID NO: 49, primer ZF13 with a nucleotide sequence corresponding to SEQ ID NO: 50, primer ZF16 with a nucleotide sequence corresponding to SEQ ID NO: 51, primer CS1 with a nucleotide sequence corresponding to SEQ ID NO: 52, CS4 with a nucleotide sequence corresponding to SEQ ID NO: 53, primer CS7 with a nucleotide sequence corresponding to SEQ ID NO: 54, primer CS10 with a nucleotide sequence corresponding to SEQ ID NO: 55, primer CS13 with a nucleotide sequence corresponding to SEQ ID NO: 56, and primer CS16 with a nucleotide sequence corresponding to SEQ ID NO: 57. Products were run side by side on a 3% NuSieve agarose gel (FMC BioProducts, Heerhugowaard, The Netherlands). Differentially displayed fragments specific for MPV were purified from the gel with a Qiaquick Gel Extraction kit (Qiagen, Leusden, The Netherlands) and cloned in pCR2.1 vector (Invitrogen, Groningen, The Netherlands), according to instructions from the manufacturer. Twenty fragments were successfully purified and sequenced. Sequence homology to APV was found in ten fragments, i.e. fragment 1 isolated using the ZF7 primer yielded a 335 bp fragment with homology to the N gene, fragment 2 isolated using the ZF10 primer yielded a 235 bp fragment with homology to the N gene, fragment 3 isolated using the ZF10 primer yielded a 800 bp fragment with homology to the M gene, fragment 4 isolated using the CS1 primer yielded a 1250 bp fragment with homology to the F gene, fragment 5 isolated using the CS10 primer yielded a 400 bp fragment with homology to the F gene, fragment 6 isolated using the CS13 primer yielded a 1450 bp fragment with homology to the F gene, fragment 7 isolated using primer CS13 yielded a 750 bp fragment with homology to the F gene, fragment 8 isolated using the ZF4 primer yielded a 780 bp fragment with homology to the L gene (protein level), fragment 9 isolated using the ZF10 primer yielded a 330 bp fragment with homology to the L gene (protein level), and fragment 10 isolated using the ZF10 primer yielded a 250 bp fragment with homology to the L gene (protein level). TaqMan assays can be used to measure the level of expression of a gene. TaqMan assays were adapted to examine the expression of the L-gene and the N-gene. The primers that were used in these assays are not required to be specific to any one of the hMPV groups, however, examples are shown below. Reactions were carried out with a 500 nM concentration of a forward primer, 250 nM concentration of a reverse primer, 250 nM concentration of an oligonucleotide probe, 25 μl of a universal PCR mastermix (available from ABI), and 5 μl of cDNA in a 50 μl total reaction volume. Cycling conditions were: a first step of 10 minutes at 95° C., followed by a second step of 45 cycles consisting of 30 seconds at 95° C. and 60 seconds at 60° C. on an ABI 7000 sequence detection system. Other examples of primers for the N gene of hMPV to be used in TaqMan assays are as follows: For isolates NL/1/00, BI/1/01, FI/4/01, NL/8/01, and FI/2/01, all of the subgroup A1, primers with the nucleotide sequence of SEQ ID NO: 39 could be used. For isolate NL/30/01, of the subgroup A1, a primer with the nucleotide sequence of SEQ ID NO: 40 could be used. For isolates NL/22/01 and NL/23/01, of the subgroup A2, a primer with the nucleotide sequence of SEQ ID NO: 41 could be used. For isolates NL/17/01, of the subgroup A2, a primer with the nucleotide sequence of SEQ ID NO: 42 could be used. For isolate NL/17/00, of the subgroup A2, a primer with the nucleotide sequence of SEQ ID NO: 43 could be used. For isolates NL/1/99, NL/5/01, NL/21/01, and NL/9/01, of the subgroup B1, a primer with the nucleotide sequence of SEQ ID NO: 44. For isolates FI/1/01 and FI/10/01, of subgroup B1, a primer with the nucleotide sequence of SEQ ID NO: 45 could be used. A potential probe that can be used for the A1 subgroup corresponds to SEQ ID NO:390, a probe that can be used for the B1 subgroup corresponds to SEQ ID NO:391, and a probe that can be used for the B2 subgroup corresponds to SEQ ID NO:392. 7.14 EXAMPLE 22 Sequence Analysis of RAP-PCR Products After segments are amplified using RAP-PCR, sequence information can be obtained on the amplfied segments. In order to do so, it is advantageous to clone the generated fragments into vectors before sequencing. RAP-PCR products cloned in vector pCR2.1 (Invitrogen) were sequenced with M13-specific oligonucleotides. DNA fragments obtained by RT-PCR were purified from agarose gels using Qiaquick Gel Extraction kit (Qiagen, Leusden, The Netherlands), and sequenced directly with the same oligonucleotides used for PCR. Sequence analyses were performed using a Dyenamic ET terminator sequencing kit (Amersham Pharmacia Biotech, Roosendaal, The Netherlands) and an ABI 373 automatic DNA sequencer (PE Biosystem). All techniques were performed according to the instructions of the manufacturer. 7.15 EXAMPLE 23 Generating Genomic Fragments by RT-PCR The RAP-PCR method can leave gaps in the sequence that have not be amplified or copied. In order to obtain a complete sequence, the sequence information of the gaps can be obtained using RT-PCR. To generate PCR fragments spanning gaps A, B and C between the RAP-PCR fragments (FIG. 3), RT-PCR assays were used as described previously on RNA samples isolated from virus isolate 00-1. The following primers were used to generate fragment A: TR1 designed in the leader, corresponding to the nucleotide sequence of SEQ ID NO:22 and N1 designed at the 3′ end of the RAP-PCR fragments obtained in N and corresponding to the sequence of SEQ ID NO:23. The following primers were used to generate fragment B: N2 designed at the 5′ end of the RAP-PCR fragments obtained in N and corresponding to the nucleotide sequence of SEQ ID NO:24 and M1 designed at the 3′ end of the RAP-PCR fragments obtained in M and corresponding to the nucleotide sequence of SEQ ID NO:25. The following primers were used to generate fragment C: M2 designed at the 5′ end of the RAP-PCR fragment obtained in M and corresponding to the nucleotide sequence of SEQ ID NO:26 and F1 designed at the 3′ end of the RAP-PCR fragments obtained in F and corresponding to the nucleotide sequence of SEQ ID NO: 27. Fragments were purified after gel electrophoresis and cloned and sequenced as described previously. 7.16 EXAMPLE 24 Capture Anti-MPV IgM EIA Using a Recombinant Nucleoprotein In order to detect the hMPV virus, an immunological assay that detects the presence of the antibodies in a variety of hosts. In one example, antibodies to the N protein are used because it is the most abundant protein that is produced. This feature is due the transciptional gradient that occurs across the genome of the virus. A capture IgM EIA using the recombinant nucleoprotein or any other recombinant protein as antigen can be performed by modification of assays as previously described by Erdman et al., 1990, J.Clin.Microb. 29: 1466-1471. Affinity purified anti-human IgM capture antibody (or against other species), such as that obtained from Dako, is added to wells of a microtiter plate in a concentration of 250 ng per well in 0.1 M carbonate buffer pH 9.6. After overnight incubation at room temperature, the plates are washed two times with PBS/0.05% Tween. 100 μl of test serum diluted 1:200 to 1:1000 in ELISA buffer is added to triplicate wells and incubated for 1 hour at 37° C. The plates are then washed two times with in PBS/0.05% Tween. The freeze-thawed (infected with recombinant virus) Sf21 cell lysate is diluted 1:100 to 1:500 in ELISA buffer is added to the wells and incubated for 2 hours at 37° C. Uninfected cell lysate serves as a negative control and is run in duplicate wells. The plates are then washed three times in PBS/0.05% Tween and incubated for 1 hour at 37° C. with 100 μl of a polyclonal antibody against MPV in a optimal dilution in ELISA buffer. After 2 washes with PBS/0.05% Tween, the plates are incubated with horseradish peroxide labeled secondary antibody (such as rabbit anti ferret), and the plates are incubated 20 minutes at 37° C. The plates are then washed five times in PBS/0/05% Tween, incubated for 15 minutes at room temperature with the enzyme substrate TMB, 3,3,5,5 tetramethylbenzidine, as, for instance obtained from “Sigma”, and the reaction is stopped with 100 μl of 2M phosphoric acid. Colormetric readings are measured at 450 nm using automated microtiter plate reader. The sensitivities of the capture IgM EIAs using the recombinant nucleoprotein (or other recombinant protein) and whole MPV virus are compared using acute-and convalescent-phase serum pairs form persons with clinical MPV virus infection. The specificity of the recombinant nucleoprotein capture EIA is determined by testing serum specimens from healthy persons and persons with other paramyxovirus infections. Potential for EIAs for using recombinant MPV fusion and glycoprotein proteins produced by the baculovirus expression. The glycoproteins G and F are the two transmembraneous envelope glycoproteins of the MPV virion and represent the major neutralisation and protective antigens. The expression of these glycoproteuns in a vector virus system sych as a baculovinus system provides a source of recombinant antigens for use in assays for detection of MPV specific antibodies. Moreover, their use in combination with the nucleoprotein, for instance, further enhances the sensitivity of enzyme immunoassays in the detection of antibodies against MPV. A variety of other immunological assays (Current Protocols in Immunology, volume 1-3. Ed. by Coligan, J. E., Kruisbeek, A. M., Margulies, D. H., Shevach, E. M. and Strobe, W. Published by John Wiley and sons, Inc., USA) may be used as alternative methods to those described here. In order to find virus isolates nasopharyngeal aspirates, throat and nasal swabs, broncheo alveolar lavages and throat swabs preferable from but not limited to humans, carnivores (dogs, cats, seals etc.), horses, ruminants (cattle, sheep, goats etc.), pigs, rabbits, birds (poultry, ostridges, etc) can be examined. From birds, cloaca and intestinal swabs and droppings can be examined as well. For all samples, serology (antibody and antigen detection etc.), virus isolation and nucleic acid detection techniques can be performed for the detection of virus. Monoclonal antibodies can be generated by immunizing mice (or other animals) with purified MPV or parts thereof (proteins, peptides) and subsequently using established hybridoma technology (Current Protocols in Immunology, Published by John Wiley and sons, Inc., USA). Alternatively, phage display technology can be used for this purpose (Current Protocols in Immunology, Published by John Wiley and sons, Inc., USA). Similarly, polyclonal antibodies can be obtained from infected humans or animals, or from immunised humans or animals (Current Protocols in Immunology, Published by John Wiley and sons, Inc., USA). The detection of the presence or absence of NS1 and NS2 proteins can be performed using western-blotting, IFA, immuno precipitation techniques using a variety of antibody preparations. The detection of the presence or absence of NS1 and NS2 genes or homologues thereof in virus isolates can be performed using PCR with primer sets designed on the basis of known NS1 and/or NS2 genes as well as with a variety of nucleic acid hybridisation techniques. To determine whether NS1 and NS2 genes are present at the 3′ end of the viral genome, a PCR can be performed with primers specific for this 3′ end of the genome. In our case, we used a primer specific for the 3′ untranslated region of the viral genome and a primer in the N ORF. Other primers may be designed for the same purpose. The absence of the NS1/NS2 genes is revealed by the length and/or nucleotide sequence of the PCR product. Primers specific for NS1 and/or NS2 genes may be used in combination with primers specific for other parts of the 3′ end of the viral genome (such as the untranslated region or N, M or F ORFs) to allow a positive identification of the presence of NS1 or NS2 genes. In addition to PCR, a variety of techniques such as molecular cloning, nucleic acid hybridisation may be used for the same purpose. 8. Cell Culture Systems and Animal Models for MPV and Recombinant Engineering of MPV 8.1 EXAMPLE 25 hMPV Growth in Different Cell Lines Virus isolates can be cultured in different cell lines in order to examine characteristics of each virus. For example, the infectivity of different virus isolates can be characterized and distinguished on the basis of titer levels measured in culture. Alternatively, cells can be used to propagate or amplify strains of the virus in culture for further analysis. In one example, tertiary monkey kidney cells were used to amplify hMPV. However, tertiary monkey kidney cells are derived from primary cells which may only be passaged a limited number of times and have been passaged three times in vivo. It was not known which kind of immortalized cell line would support hMPV virus growth to high titers. A number of monkey cell lines such as Vero, LLC-MK2, HEp-2, and lung fibroblast (LF1043) cells, were tested to see whether they could support hMPV virus replication (Table 12). Trypsin used was TPCK-trypsin (Worthington) at a concentration of 0.001 mg/ml. The growth of this virus in fertilized 10 day old chicken eggs was also tested. The infected eggs were incubated for 2 and 3 days at 37° C. prior to AF harvest. Virus titers were determined by plaque assay of infected cell lysates on Vero cells without trypsin, incubated for 10 days at 35° C., and immunostained using the guinea pig hMPV antiserum. The results showed that Vero cells and LLC-MK2 cells were the cell substrates most suitable for hMPV virus replication, resulting in virus stock titers of 106-107 pfu/ml. These titers were similar to those obtained from tMK cells. The addition of trypsin at a concentration of 0.01 mg/ml did not increase virus titers appreciably (Table 12). TABLE 12 HMPV VIRUS GROWTH IN DIFFERENT CELL LINES Virus titers on Trypsin used to Vero cells Cell Substrate grow virus (pfu/ml) Vero yes 2.1 × 107 no 1.1 × 107 LLC-MK2 yes 2.3 × 105 Hep-2 yes cells died LF 1043 (HEL) yes no virus recovered no no virus recovered tMK yes 1.0 × 107 eggs (10 days) no no virus recovered In order to study the virus kinetics of hMPV viral growth in Vero cells, a growth curve was performed using an MOI of 0.1 (FIG. 23). Cells and cell supernatants were harvested every 24 hours, and analyzed by plaque assay for quantification of virus titers. The results showed that at day 5, near peak titers of hMPV were observed. The absolute peak titer of 5.4 log10 pfu/ml was achieved on Day 8. The virus titer was very stable up to day 10. A growth curve carried out at the same time with solely the cell supernatants, showed only very low virus titers. This data demonstrated that hMPV replication, under the conditions used (MOI of 0.1) peaked on day 8 post-infection and that hMPV was largely, a cell-associated RNA virus. TRANSFECTION OF 293 CELLS: 293 cells (human kidney epithelial cells) were passed in DMEM and supplemented with FCS (10%), L-Glutamine (1:100) and Pen/Strep (1:100) and split 1:10 every 3-4 days. Care was taken not to let the cells grow to confluency in order to enhance transfectability. Cells were not very adherent; a very brief (2 min. or less) incubation in Trypsin-EDTA was usually sufficient to release them from plastic surfaces. Cells were diluted in culture media immediately after trypsin-treatment. Cells were split the day before transfection. Cell confluency approximated 50-75% when transfected. Gelatinized plasticware was used to prevent cells from detaching throughout the transfection procedure. Plates or flasks were covered with 0.1% gelatinin (1:20 dilution of 2% stock) for 10 minuted and rinsed one time with PBS once. To achieve the correct cell density; cells were used at a concentration of 1×107 cells per T75 flask or 100 mm plate (in 10 ml) or 1×106 cells per well of a 6-well plate (in 2 ml). Transfection lasted for a minimum of 7 hours, however, it was preferable to allow the transfection to occur overnight. The following were combined in a sterile tube: 30 mg DNA with 62 ml 2 M CaCl2 and H2O to 500 ml (T75) or 3 mg DNA with 6.2 ml 2 M CaCl2 and H2O to 50 ml (6-well plate); with brief mixing. Addition of 500 or 50 ml 2×HBS occurred dropwise and the solutions were allowed to mix for 5 minutes until a precipitate formed. Gentle care was used, i.e. no vortexing was applied. The old media was replaced with fresh prewarmed media (10 ml per T75 flask or 1 ml per well of a 6-well plate. The DNA was mixed carefully by blowing airbubles through the tube with a Gilson pipet and the precipitate was added dropwise to the media covering the cells. The cells were incubated in a 37C CO2 atmosphere. The cells appeared to be covered with little specks (the precipitate). The transfection media was removed from the cells, and the cells were rinsed carefully with PBS, and then replaced with fresh media. The cells were incubated in a 37C CO2 atmosphere until needed, usually between 8-24 hours. A 10× stock of HBS was prepared with with 8.18% NaCl, 5.94% Hepes and 0.2% Na2HPO4 (all w/v). The solution was filter sterilized and stored at 4C. A 2× solution was prepared by diluting the 10× stock with H2O and adjusting the pH to 7.12 with 1 M NaOH. The solution was stored in aliquots at −20C. Care was taken to exactly titrate the pH of the solution. The pH was adjusted immediately before the solution was used for the transfection procedure. 8.2 EXAMPLE 26 Minireplicon Construct of MPV Minireplicon constructs can be generated to contain an antisense reporter gene. An example of a minireplicon, CAT-hMPV, is shown in FIG. 24. The leader and trailer sequences that were used for the generation of the minireplicon construct are shown in FIG. 26. For comparison, an alignment of APV, RSV and PIV3 leader and trailer sequences are also shown in FIG. 26. Two versions of the minireplicon constructs were tested: one with terminal AC residues at the leader end (Le+AC), and one without terminal AC residues at the leader end (Le-AC). The two constructs were both functional in the assay (FIG. 25). It can be seen in FIG. 25 that much higher CAT expression occurred after 48 hours than after 24 hours. After 48 hours, around 14 ng CAT per 500,000 cells transfected was observed. This experiment was entirely plasmid driven: the minireplicon was cotransfected with a T7 polymerase plasmid, and the N, P, L, M2.1 genes were expressed from pCITE-2a/3a (the pCite plasmids have a T7 promoter followed by the IRES element derived from the encephalomyocarditis virus (EMCV)). The CAT expression was completely abolished when L, P and N were excluded. A significant reduction in CAT expression was noted when M2.1 expression was excluded from the vector. The specificity (attributes to heterologous viruses) and the effect of the terminal residues of the leader (attributes to homologous virus) of the minireplicon system can also be tested by superinfecting the minireplicon-transfected cells with hMPV polymerase components (NL/1/00 and NL/1/99) or polymerase components from APV-A, APV-C, RSV or PIV. The different amount of each of the six plasmids can also be tested in order to determine the optimal conditions. Other reporter genes can be used instead of CAT. In other examples, GFP can be inserted into the minireplicon construct instead of CAT. 8.3 EXAMPLE 27 Rescue of hMPV from a Minireplicon using RSV APV, MPV, or PIV Polymerase In order to rescue hMPV, minireplicon constructs can be generated to contain a reporter gene. An example of a minireplicon, CAT-hMPV, is shown in FIG. 24. A cDNA encoding the reporter protein chloramphenicol acetyltransferase (CAT) can be cloned in negative-sense orientation between the 5′ and 3′ noncoding viral sequences. A T7 RNA polymerase promoter sequence and a recognition sequence for a restriction enzyme can flank the construct. In vitro transcription will yield virus-like RNA that will form reconstituted RNP complexes when mixed with purified polymerase proteins. The RNPs can be transfected into eucaryotic cells, for example, with helper virus. Alternatively, the rescue can be entirely plasmid driven, i.e., the minireplicon can be co-transfected with a T7 polymerase plasmid, and the N, P, L, and M2-1 genes expressed from pCITE-2a/3a. The polymerase components used to rescue hMPV can be those of RSV, APV, PIV, MPV, or any combination thereof (see section 5.8.1). Virus can be detected using any of a number of assays capable of detecting CAT activity. (See Example 24). In another alternative, rescue of hMPV using a minireplicon system can also be performed by superinfecting the minireplicon-transfected cells with hMPV polymerase components (NL/1/00 and NL/1/99) or polymerase components from MPV, APV, RSV, PIV, or any combination thereof. In more detail, a cDNA of the leader region and the adjoining gene can be modified by mutagenesis using synthetic oligonucleotides. Similarly, a cDNA of the downstream end of another hMPV gene, e.g., the L gene, and adjoining trailer region, can be modified to contain an adjacent T7 RNA polymerase promoter. The leader and trailer fragments can be cloned into an expression vector, e.g., pUC19, on either side of an insert of the CAT gene. cDNAs encoding additional hMPV viral analogs can be constructed in the same way. Construct structures can be confirmed using sequencing. Examples of the leader and trailer sequences that can be used for the generation of the minireplicon construct are shown in FIG. 26. For comparison, an alignment of APV, RSV and PIV3 leader and trailer sequences are also shown in FIG. 26. 8.4 EXAMPLE 28 Generation of Full Length Infectious cDNA Full length cDNAs that express the genes of the hMPV virus can be constructed so that infectious viruses can be produced. For example, a cDNA encoding all of the genes or all of the essential genes of hMPV can be constructed; the genome can then be expressed to produce infectious viruses. In order to genetically manipulate hMPV, the genome of this RNA virus was cloned. For the 00-1 isolate of hMPV, eight PCR fragments varying in length from 1-3 kb were generated (FIG. 27). The PCR fragments were sequenced and analyzed for sequence errors by comparison to the hMPV sequence deposited in Genbank. Two silent mutations (nucleotide 5780 ile:ile in the SH gene, nucleotide 12219 cys:cys in the L gene) were not corrected. Another change in the L gene at nucleotide 8352 (trp:leu) was not changed since this mutation was observed in two independently generated PCR fragments (C and H), as well as in the hMPV 99-1 sequence. Similarly, a 5 nucleotide insertion at nucleotide 4715 in the F-M2 intergenic region was not corrected. Both of these changes may be reflected in the wild type sequence of hMPV. In contrast, at nucleotide 1242, a single A residue was removed in the N-P intergenic region; at nucleotide 3367, a ser:pro was corrected in the F gene; at nucleotide 6296, an asp:val was changed in the G gene; and at nucleotide 7332 a stop codon was changed to a glu in the L gene. Restriction maps of different isolates of hMPV are shown in FIG. 28. The restriction sites can be used to assemble the full-length construct. The eight corrected PCR fragments were then assembled in sequence, taking advantage of unique restriction enzyme sites (FIG. 29). A genetic marker was introduced at nucleotide 75 generating an AfIII restriction enzyme site without altering the amino acid sequence. A unique restriction enzyme site, XhoI, was added at the 3′ end of the hMPV sequence. A phage T7 polymerase promoter followed by two G residues was also added to the 3′ end of the hMPV sequence. At the 5′ end of the hMPV genome, a Hepatitis delta ribozyme sequence and BssHII restriction enzyme site were added. Helper plasmids encoding the hMPV L, N, P and M2-1 proteins in a pCITE plasmid were also generated. Once the full-length hMPV cDNA is generated, virus recovery by reverse genetics can be performed in Vero cells using fowl-pox T7 or MVA-T7 as a source of T7 RNA polymerase, or a cell line or a plasmid expressing T7 RNA polymerase. 8.5 EXAMPLE 29 hMPV Recovery Employing the Pol I-Pol II Promoter System Unlike the reverse genetics systems for non segmented RNA viruses which are based on plasmids with T7-promoter for expression of genomic RNA, systems employing the cellular transcription machinery may be more efficient and do not require the coexpression of the RNA polymerase derived from the bacteriophage T7. A unidirectional or bi-directional pol I-pol II transcription system can be used to express viral RNA molecule intracellularly. This systems proved to be very efficient for the generation of influenza virus from cloned cDNA (Hoffmann et. al., PNAS, 97 6108-6113 (2000). Unlike RNA polymerase II transcripts, RNA polymerase I transcripts do not contain cap structures at their 5′-end and do not have poly A tails at the 3′-end. Thus, systems employing the cellular transcription machinery are designed to express proteins from a pol II promoter and viral (−)vRNA or (+) cRNA which do not have a cap structure or a polyA tail from a pol I promoter. To provide virus-like primary transcripts which do not contain additional non viral sequences is critical because the terminal structures are crucial for viral replication and transcription. In order to evaluate whether (−)vRNA or (+)cRNA transcription of hMPV cDNAs by RNA polymerase I is more efficient, a minigenome system may be designed to compare the replication efficiency of each. Replication efficiency can be measured by the transcription of a reporter molecule expressed by the minigenome, e.g., a CAT gene. In this approach, plasmids expressing the L, N, P, and M2-1 genes of hMPV, under the control of a pol II promoter, are cotransfected into a host cell together with a CAT-minigenome-plasmid. The relative efficiency of replication is measured by determining the relative level of expression of the CAT reporter molecule. For example, RNA pol I can be used to synthesize positive strand copies of the hMPV viral genome (cRNA). In brief, the viral cDNA is inserted between an RNA pol I promoter and a terminator sequence. The whole pol I transcription unit is inserted in the positive-sense orientation between an RNA pol II promoter and a polyadenylation site. Two types of positive-sense RNAs are synthesized. From the pol II promoter, an mRNA with a 5′-cap structure is transcribed. From the pol I promoter full-length, positive-sense hMPV cRNA with a triphosphate group at the 5′end is transcribed by cellular RNA polymerase I. A cloning vector can be used for the insertion of arbitrary cDNA fragments, e.g., pHW 11 (Hoffmann & Webster, J. Gen Virol. 2000 December 81(Pt 12):2843-7) This plasmid contains the pol II promoter (immediate early promoter of the human cytomegalovirus) and the human pol I promoter that are upstream of a pol I terminator sequence and a poly(A) site. In order to replicate the primary transcript representing viral cRNA, the viral polymerase proteins are provided by plasmid vectors with a pol II promoter, such as the immediate early promoter of human cytomegalovirus. These plasmids contain the cDNAs representing four gene segments of hMPV, i.e., the L-gene, the N-gene, the P-gene, and the M2-1 gene. Those four plasmids (1-5 μg) are cotransfected with the pol I/pol II plasmid (1-5 μg) representing the full length genome of hMPV into 106-107 293T cells, COS-7 or Vero cells. To improve the efficiency and reliability of the system, 293T cells can be cocultured with cells permissive for MPV, such as Vero or tMK cells. The addition of trypsin to the cell culture medium results in the generation of infectious virus particles. The coculturing of primate cells with MDCK cells was employed for the efficient rescue of influenza A virus (Hoffmann et. al., PNAS, 97 6108-6113 (2000). The supernatant after different times after transfection (i.e., 3 d to 10 d) is titrated and transferred to fresh Vero cells to determine the virus titer. The coexpression of all viral structural proteins (i.e., M, M2-2, SH, F, and G) from a pol II promoter may improve the efficiency of virus recovery. Because from the the pol I/pol II plasmids with the full length cDNA a capped and non-capped RNA is produced, it is expected that the first open reading frame representing the N-gene is translated into N-protein. Thus, by employing the pol I/pol II approach only four plasmids are needed for virus rescue: Three pol II-plasmids expressing L, P, and M2-1 protein and one pol I/pol II plasmid expressing the N-protein and the full length RNA of MPV. 8.6 EXAMPLE 30 Cell-Lines Expressing T7 RNA Polymerase for Recovery of Negative Strand Viruses A cell line expressing T7 RNA polymerase can be used for replication and packaging of recombinant MPV genomes. For example, Vero cells can be engineered to express T7 RNA polymerase under the control of a CMV promoter. This approach is useful because it eliminates the need for co-infection with a helper virus, such as a pox-virus expressing T7 RNA polymerase. Another advantage of this method is the elimination of the need for selection systems required to remove the helper virus. In brief, cDNA encoding the L, N, P and M2-1 genes of hMPV are cloned and recombinantly engineered into expression vectors under the control of T7 promoter sequences. cDNA encoding the genome of the MPV, in either the positive or negative orientation, is cloned and recombinantly engineered into an expression vector under the control of T7 promoter sequences. These expression vectors may be concurrently transfected into the T7 expressing cell line, e.g., a BHK cell line that expresses T7 polymerase. The in vivo transcription of these cDNA constructs is mediated by T7 RNA polymerase. Viral titers can be determined by plaque assay of infected cell lysates. 8.7 EXAMPLE 31 Use of a Plasmid to Transiently Express T7 RNA Polymerase from a CMV or SV40 Promoter for hMPV Rescue A plasmid expressing T7 RNA polymerase under the control of a CMV or SV40 promoter can be engineered and transiently transfected into cells where it is used for replication and packaging of recombinant MPV genomes. For example, Vero and 293T cells can be engineered to express T7 RNA polymerase under the control of a CMV promoter. In one specific embodiment, a plasmid carrying the gene encoding T7 RNA polymerase under the control of the CMV MIE promoter can be used in combination with a selectable marker (e.g. Neomycin) driven by the T7 promoter. This would enable efficient selection of a cell line expressing T7 RNA polymerase. The approach using a cell line expressing T7 RNA polymerase is useful because it eliminates the need for co-infection with a helper virus, such as a poxvirus expressing T7 polymerase. Another advantage of this method is that eliminates the need for selection systems to eliminate contamination with the helper virus. Also, this approach allows the use of cell lines with high transfection efficiencies, such as 293T and COS-7 cells. Thus, cells transfected have multiple copies of T7-polymerase expressing plasmids resulting in a higher quantity of T7-polymerase protein per cell than transiently transfected cells compared to stable cell lines which only one copy In brief, cDNA encoding the L, N, P and M2-1 genes of hMPV are cloned and recombinantly engineered into expression vectors under the control of T7 promoter sequences. Alternatively, those four genes are expressed under the control of a RNA polymerase II promoter, such as the immediate early promoter of human cytomegalovirus. cDNA encoding the genome of the MPV, in either the positive or negative orientation, is cloned and recombinantly engineered into an expression vector under the control of T7 promoter sequences. These expression vectors are co-transfected together with the plasmid expressing T7 polymerase into cells that support hMPV replication, e.g., a Vero cell line, a tMK cell line, a 293T cell line, or a coculture of multiple cell lines. The in vivo transcription of these cDNA constructs is mediated by T7 RNA polymerase. Viral titers can be determined by plaque assay of infected cell lysates. An alternative approach to supply T7, T3 or SP6 RNA polymerase consists of transfecting the T7 polymerase protein into cells before, concomitantly or after transfecting the cells with N, P, L, M2-1 and full-length genomic or antigenomic cDNA plasmids under the control of T7, T3 or SP6 promoters using lipid transfection reagents. 8.8 EXAMPLE 32 Rescue of hMPV A successful system was developed to rescue recombinant hMPV. In brief, expression plasmids, encoding various polymerase proteins, were co-transfected with the cloned hMPV to be rescued into appropriate host cells. Upon collection and treatment, the cells and supernatant were then used to inoculate Vero cells. Infectious rescued virus was detected using immunostaining methods. In order to rescue hMPV, confluent monolayers of 293T cells in a TC6-well plate were inoculated with fowl pox virus at a MOI (multiplicity of infection)=0.5. The cells were then incubated at 35C for 1 hour. The expression plasmids and the cloned hMPV to be rescued were mixed in 100 μl optiMEM (per well) in the following amounts: 0.4 μg of plasmid encoding the hMPV P gene (in pCITE 2a/3a, designated clone #41-6), 0.4 μg of plasmid encoding the hMPV N gene (in pCITE 2a/3a, designated clone #35-11), 0.3 μg of plasmid encoding the hMPV M2 gene (in pCITE 2a/3a, designated clone #25-6), 0.2 μg of plasmid encoding the L gene (in pCITE 2a/3a, designated clone #2), and 4 μg of hMPV plasmid clone #2 which has the leader and trailer like APV or clone #10 which has hMPV leader and trailer sequences. It is noteworthy that the expression plasmids used have the wild type sequence restored in the second amino acid position. In the next step, the transfection reagent Lipofectamine 2000 (8 μl) was mixed into 100 μl of optiMEM and then added to the plasmid mixture. This combined mixture was applied to the 293T cells. Six days after transfection, the cells and supernatant were collected, frozen, thawed, and used to inoculate Vero cells. Nine days post inoculation, the infected cells were fixed in methanol, immunostained with a guinea pig polyclonal antibody followed by anti-guinea pig HRP and the DAKO AEC substrate. Plaque formation indicated that the rescued virus was infectious (FIG. 56). Positive red immunostaining was evident in the wells with both clone #2 and #10, though more immunostained cells were in the well with hMPV clone #2 which has the APV leader and trailer compared to the clone #10 with the hMPV leader and trailer. Positive immunostains are show in in FIG. 57. RT-PCR will be done on the virus that will be collected 10 days post infection to confirm the rescued sequence. These results indicate that recombinant hMPV was successfully rescued and that infectious virus was produced. 8.9 EXAMPLE 33 Infection of Animal Hosts with Subtypes of hMPV Animal hosts can be infected in order to characterize the virulence of MPV strains. For example, different hosts can be used in order to determine how infectious each strain is in an organism. A small animal model for hMPV had not been identified. Balb/c mice, cotton rats, and Syrian Golden hamsters were infected with hMPV using a dose of 1.3×106 pfu/animal. The animals were inoculated intranasally with 1.3×106 pfu of hMPV in a 0.1 ml volume. The tissue samples were quantified by plaque assays that were immunostained on Day 9 with the hMPV guinea pig antiserum. Four days post-infection, the animals were sacrificed, and the nasal turbinates and lungs were isolated and quantified for hMPV titers by plaque assays that were immunostained (Table 13). TABLE 13 HMPV TITERS IN INFECTED ANIMALS Mean virus titer on day 4 post-infection (log10PFU/g Number of tissue +/− Standard Error Animals animals Nasal turbinates Lungs mice (Balb c) 6 2.7 +/− 0.4 2.2 +/− 0.6 cotton rats 5 <1.7 +/− 0.0 <1.8 +/− 0.0 Syrian Golden 6 5.3 +/− 0.2 2.3 +/− 0.6 hamsters The results showed that hMPV replicated to high titers in Syrian Golden hamsters. Titers of 5.3 and 2.3 log 10 pfu/g tissue were obtained in the nasal turbinates and lungs, respectively. hMPV did not replicate to any appreciable titer levels in the respiratory tracts of cotton rats. Mice showed titers of 2.7 and 2.2 log10 pfu/g tissue in the upper and lower respiratory tracts, respectively. These results suggested that Syrian Golden hamsters would be a suitable small animal model to study hMPV replication and immunogenicity as well as to evaluate hMPV vaccine candidates. INFECTION OF GUINEA PIGS. Two virus isolates, 00-1 (subtype A) and 99-1 (subtype B), were used to inoculate six guinea pigs per subtype (intratracheal, nose and eyes). Six guinea pigs were infected with hMPV 00-1 (10e6,5 TCID50). Six guinea pigs were infected with hMPV 99-1 (10e4,1 TCID50). The primary infection was allowed to progress for fifty-four days when the guinea pigs were inoculated with the homologous and heterologous subtypes (10e4 TCID50/ml), i.e., two guinea pigs had a primary infection with 00-1 and a secondary infection with 99-1 in order to achieve a heterologous infection, three guinea pigs had a primary infection with 00-1 and a secondary infection with 00-1 to achieve a homologous infection, two guinea pigs had a primary infection with 99-1 and a secondary infection with 00-1 to achieve a heterologous infection and three guinea pigs had a primary infection with 99-1 and a secondary infection with 99-1 to achieve a homologous infection. Throat and nose swabs were collected for 12 days (primary infection) or 8 days (secondary infection) post infection, and were tested for the presence of the virus by RT-PCR assays. The results (FIG. 32) of the RT-PCR assays showed that guinea pigs inoculated with virus isolate 00-1 showed infection of the upper respiratory tract on days 1 through 10 post infection. Guinea pigs inoculated with 99-1 showed infection of the upper respiratory tract day 1 to 5 post infection. Infection of guinea pigs with 99-1 appeared to be less severe than infection with 00-1. A second inoculation of the guinea pigs with the heterologous virus, as commented on above, resulted in re-infection in 3 out of 4 of the guinea pigs. Likewise, reinfection in the case of the homologous virus occurred in 2 out of 6 guinea pigs. Little or no clinical symptoms were noted in those animals that became re-infected, and no clinical symptoms were seen in those animals that were protected against the re-infections, demonstrating that even with the wild-type virus, a protective effect due to the first infection may have occurred. This also showed that heterologous and homologous isolates could be used as a vaccine. Both subtypes of hMPV were able to infect guinea pigs, although infection with subtype B (99-1) seemed less severe, i.e., the presence of the virus in nose and throat was for a shorter period than infection with subtype A (00-1). This may have been due to the higher dose given for subtype A, or to the lower virulence of subtype B. Although the presence of pre-existing immunity did not completely protect against re-infection with both the homologous and heterologous virus, the infection appeared to be less prominent, in that a shorter period of presence of virus was noted and not all animals became virus positive. The serology of guinea pigs that were infected with both subtypes of hMPV was examined. At days 0, 52, 70, 80, 90, 110, 126 and 160, sera were collected from the guinea pigs and tested at a 1:100 dilution in a whole virus ELISA against 00-1 and 99-1 antigens. (See FIGS. 33A and B showing the IgG response against 00-1 and 99-1 for each individual guinea pig. See also FIG. 34 showing the specificity of the 00-1 and 99-1 ELISA but note that only data from homologous reinfected guinea pigs was used. See also FIG. 35 showing the mean IgG response against 00-1 and 99-1 ELISA of three homologous, i.e. 00-1 and 00-1, two homologous, i.e., 99-1 and 99-1, two heterologous, i.e., 99-1 and 00-1, and 2 heterologous, i.e., 00-1 and 99-1 infected guinea pigs). Only a minor difference in response to the two different ELISAs was observed. Whole virus ELISA against 00-1 or 99-1 could not be used to discriminate between the two subtypes. The reactivity of sera raised against hMPV in guinea pigs with APV antigen was examined. Sera were collected from the infected guinea pigs and tested with an APV inhibition ELISA. (See FIG. 36, showing the mean percentage of APV inhibition of hMPV infected guinea pigs). Sera raised against hMPV in guinea pigs reacted in the APV inhibition test in a manner similar to their reaction in the hMPV IgG ELISA's. Sera raised against 99-1 revealed a lower percentage of inhibition in the APV inhibition ELISA than sera raised against 00-1. Guinea pigs infected with 99-1 may have had a lower titer than that seen in the hMVP ELISAs. Alternatively, the cross-reaction of 99-1 with APV could have been less than that of 00-1. Nevertheless, the APV Ab inhibition ELISA could be used to detect hMPV antibodies in guinea pigs. Virus neutralization assays were performed with sera raised against hMPV in guinea pigs. Sera were collected at day 0, day 52, day 70 and day 80 post infection and used in a virus cross-neutralization assay with 00-1, 99-1, and APV-C. The starting dilution used was 1 to 10 and 100 TCID50 virus per well. After neutralization, the virus was exposed to tMK cells (15 mm.) and centrifuged at 3500 RPM, after which the media was refreshed. The APV cultures were grown for 4 days and the hMPV cultures were grown for 7 days. Cells were fixed with 80% acetone, and IFAs were conducted with labeled monkey-anti hMPV. Wells that were negative upon staining were defined as the neutralizing titer. For each virus, a 10-log titration of the virus stock and a 2 fold titration of the working solution was included. (See FIG. 37 showing the virus neutralization titers of 00-01 and 99-1 infected guinea pigs against 00-1, 99-1, and APV-C). INFECTION OF CYNOMOLOGOUS MACAGUES. Virus isolates 00-1 (subtype A) and 99-1 (subtype B) (1e5 TCID50) was used to inoculate two cynomologous macaques per subtype (intratracheal, nose and eyes). Six months after the primary infection, the macaques were inoculated for the second time with 00-1. Throat swabs were collected for 14 days (primary infection) or 8 days (secondary infection) post infection, and were tested for presence of the virus by RT-PCR assays (FIG. 38). Cynomologous macaques inoculated with virus isolate 00-1 showed infection of the upper respiratory tract day 1 to 10 post infection. Clinical symptoms included a suppurative rhinitis. A second inoculation of the macaques with the homologous virus results in re-infection, as demonstrated by PCR, however, no clinical symptoms were seen. Sera were collected from the macaques that received 00-1 during six months after the primary infection (re-infection occurred at day 240 for monkey 3 and day 239 for monkey 6). Sera were used to test for the presence of IgG (FIG. 39B) antibodies against either 00-1 or APV, and for the presence of IgA and IgM antibodies against 00-1 (FIG. 39A). Two macaques were succesfully infected with 00-1 and in the presence of antibodies against 00-1 were reinfected with the homologous virus. The response to IgA and IgM antibodies showed the raise in IgM antibodies after the first infection, and the absence of it after the reinfection. IgA antibodies were only detected after the re-infection, showing the immediacy of the immune response after a first infection. Sera raised against hMPV in macaques that were tested in an APV inhibition ELISA showed a similar response as to the hMPV IgG ELISA. Antibodies to hMPV in cynomologous macaques were detected with the APV inhibition ELISA using a similar sensitivity as that with the hMPV ELISA, and therefore the APV inhibition EIA was suitable for testing human samples for the presence of hMPV antibodies. Virus cross-neutralization assays were preformed on sera collected from hMPV infected cynomologous macaques. The sera were taken from day 0 to day 229 post primary infection and showed only low virus neutralization titers against 00-1 (0-80), the sera taken after the secondary infection showed high neutralisation titers against 00-1, i.e., greater than 1280. Only sera taken after the secondary infection showed neutralization titers against 99-1 (80-640), and none of the sera were able to neutralize the APV C virus. There was no cross reaction between APV-C and hMPV in virus cross-neutralization assays, however, there was a cross reaction between 00-1 and 99-1 after a boost of the antibody response. INFECTION OF HUMANS. The sera of patients ranging in ages under six months or greater than twenty years of age were previously tested using IFA and virus neutralization assays against 00-1. These sera were tested for the presence of IgG, IgM and IgA antibodies in an ELISA against 00-1. The samples were also tested for their ability to in inhibit the APV ELISA. A comparison of the use of the hMPV ELISA and the APV inhibition ELISA for the detection of IgG antibodies in human sera was made and a strong correlation between the IgG hMPV test and the APV-Ab test was noted, therefore the APV-Ab test was essentially able to detect IgG antibodies to hMPV in humans (FIG. 40). INFECTION OF POULTRY. The APV inhibition ELISA and the 00-1 ELISA were used to test chickens for the presence of IgG antibodies against APV. Both the hMPV ELISA and the APV inhibition ELISA detected antibodies against APV. 8.10 EXAMPLE 34 APV as a Vaccine in Humans APV can be used as a vaccine in humans to prevent infection by a human MPV, or to reduce the infectivity of human MPV in human hosts. The vaccine can be a whole APV or a chimeric or recombinant version or derivative thereof, that is comprised of heterologous sequences of another metapneumovirus in addition to sequences of APV. The genome of APV can be used as a backbone to create a recombinant virus vaccine. For example, a vaccine can be made where the F-gene and/or the G-gene of APV is substituted by the F-gene or the G-gene of human MPV. Alternatively, a vaccine can be made that includes sequences from PIV substituted for or added to sequences of an APV backbone. For more on the construction of a recombinant/chimeric vaccine, see, e.g., Construction of the Recombinant cDNA and RNA. The vaccine can be administered to a candidate by a variety of methods known to those skilled in the art, (see, Section 5.13, infra) including but not limited to, subcutaneous injection, intranasal administration, or inhalation. The viruses and/or vaccines of the invention are administered at a starting dosage of at least between 103 TCID50 and 106 TCID50. The viruses and/or vaccines are administered in either single or multiple dosages, e.g., a primary dose can be administered with one or more subsequent or booster doses administered at periodic time intervals throughout the host life. In a clinical trial, the replication rate of the virus can be used as an index to adjust the dosage of the vaccine so that an effective dosage regimen can be determined. A comparison can be made between the replication rate of the virus in the study population and a predetermined rate that is known to be effective. The present invention is not to be limited in scope by the specific described embodiments that are intended as single illustrations of individual aspects of the invention, and any constructs, viruses or enzymes that are functionally equivalent are within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims. 8.11 EXAMPLE 35 MPV as a Vaccine in Birds Human MPV can be used as a vaccine in birds to prevent infection by an APV, or to reduce the infectivity of APV in avian hosts. The vaccine can be a whole MPV or a chimeric or recombinant version or derivative thereof, that is comprised of heterologous sequences of another metapneumovirus in addition to sequences of MPV. The genome of human MPV can be used as a backbone to create a recombinant virus vaccine. For example, a vaccine can be made where the F-gene and/or the G-gene of human MPV is substituted by the F-gene or the G-gene of APV. For more on the construction of a recombinant/chimeric vaccine, see, e.g., Construction of the Recombinant cDNA and RNA. The vaccine can be administered to a candidate by a variety of methods, including but not limited to, subcutaneous injection, intranasal administration, or inhalation. The viruses and/or vaccines of the invention are administered at a starting dosage of at least between 103 TCID50 and 106 TCID50. The viruses and/or vaccines are administered in either single or multiple dosages, e.g., a primary dose can be administered with one or more subsequent or booster doses administered at periodic time intervals throughout the host life. In a clinical trial, the replication rate of the virus can be used as an index to adjust the dosage of the vaccine so that an effective dosage regimen can be determined. A comparison can be made between the replication rate of the virus in the study population and a predetermined rate that is known to be effective. Various publications are cited herein, the disclosures of which are incorporated by reference in their entireties. 8.12 EXAMPLE 36 Inhibiting hMPV Fusion using hMPV F Protein Heptad Repeats Inhibition of virus cell fusion represents a new approach toward the control of enveloped viruses. This approach would be advantageous in order to prevent the infection and/or propagation of the hMPV virus. During the fusion process, heptad repeat (HR) segments of the F protein are exposed. If soluble HR peptides are added to compete during the fusion process, then viral fusion will be blocked. Inhibition of hMPV-cell fusion by the HR peptides of the F protein is expected to show strong virus-cell fusion inhibition activity. In order to examine the ability of hMPV F protein heptad repeats to inhibit viral fusion, HR peptides can be purified and used in a variety of assays to determine their effect on viral fusion. Genes encoding the HR segments of the hMPV F protein, i.e. designated HRA and HRB (see below) are cloned into expression vectors, e.g., pET 30a (Novagen). This cloning strategy would yield fusion proteins that correspond to the HR segments of the F protein of hMPV. For four isolates, the sequences of the HR segment near the amino terminal end of hMPV F protein, designated HRA, are postulated to be: NL1/00: KTIRLESEVTAIKNALKKTNEAVSTLGNGVRVLATAVRELKDFVSK NL17/00: KTIRLESEVTAIKNALKTTNEAVSTLGNGVRVLATAVRELKDFVSK NL1/99: KTIRLESEVNAIKGALKQTNEAVSTLGNGVRVLATAVRELKEFVSK NL1/94: KTIRLESEVNAIKGALKTTNEAVSTLGNGVRVLATAVRELKEFVSK Likewise, the sequences of the HR segment near the carboxy terminal end of the hMPV F protein, designated HRB, are postulated to be: NL1/00: NVALDQVFESIENSQALVDQSNRILSSAE NL17/00: NVALDQVFENIENSQALVDQSNRILSSAE NL1/99: NVALDQVFESIENSQALVDQSNKILNSAE NL1/94: NVALDQVFESIENSQALVDQSNKILNSAE Protein Expression and Purification In order to examine the ability of the heptad repeat sequences to inhibit viral fusion, heptad repeat peptides can be expressed and purified so that they may be tested for their viral fusion inhibition ability. The recombinant expression vectors are transformed into a suitable bacterial host, e.g. E. Coli BL21 (DE3) and expression is induced at an optical density of 0.8-1.0 at 600 nm. Induction, using 1.0 mM IPTG, for 5 h at 25° C. is followed by harvesting and lysis of the bacterial cells by sonication in phosphate buffered saline. Triton X-100 is then added to a final concentration of 3% and the lysate is incubated for 30 min on ice and subsequently clarified by centrifugation at 12,000×g for 15 min at 4° C. The expressed HR proteins are subsequently purified. Assembly of Complex and Analysis by Gel Filtration In order to determine the potential effectiveness of the expressed heptad repeat peptides in inhibiting viral fusion, an assay can be used to confirm the assembly of a complex between HR peptides. In order to do so, equal molar amounts of HRA and HRB are mixed and incubated at room temperature for 1 h. The formation of the HRA/B complex with both HRA and HRB in the form of fusion proteins is evaluated. For gel filtration, samples are loaded on a Hiload Superdex G75 column (Pharmacia) running on Akta Explorer FPLC system (Amersham-Pharmacia). The fractions of the peak are collected and run on Tris-tricine SDS-PAGE. The peak molecular weight was estimated by comparison with the protein standards (Pharmacia) running on the same column. CD Spectroscopy It is known that the heptad repeat segments of the peptides are helical in nature. For this reason, a number of methods can be used to determine whether expressed HR peptides form alpha helices in order to identify appropriate candidates for use in viral fusion inhibition. CD spectra are performed on a spectrophotometer with proteins in PBS (10 mM sodium phosphate, pH 7.3; 150 mM NaCl). Wavelength spectra are recorded at 37° C. using a 0.1 cm path length cuvette. A protein concentration of approximately 20 μg/ml is used for the analysis. Cell Fusion Assay A cell based assay can be used to determine the effectiveness of HR peptides in the inhibition of viral fusion. In order to test for the inhibition of viral-cell fusion by the HRA and HRB peptides, an inhibition test is performed. Monolayers of Vero cells are infected with hMPV at 10-100 TCID50. Two hours post-infection, the supernatant is aspirated and the cells are washed in phosphate-buffered saline (PBS) to remove virus inoculum. Fresh medium (Iscove's Modified Dulbecco's Medium (IMDM) containing L-glutamine (2 mM), penicillin (100 U/ml), streptomycin (100 μg/ml) and 0.3% bovine serum albumin) is added and the cells are incubated at 37° C. HRA and HRB peptides are incubated individually with hMPV infected cells. Alternatively, different amounts of HRA and HRB peptides are incubated together with hMPV infected cells. Corresponding HR peptides from APV, RSV, or PIV, can also be used to inhibit hMPV viral fusion by incubation with hMPV infected cells. The cells are scored 24-72 hrs after incubation using immune fluorescence analysis (IFA). Staining for IFA is performed by incubating infected cells with guinea pig anti-hMPV serum in PBS for 1 hour, followed by a FITC-labeled rabbit anti-guinea pig polyclonal antibody preparation in PBS for 1 hour. Background staining is finally performed with eriochrome black before analysis under an immune fluorescence microscope. Infected cells were counted in 5 fields under high power magnification (320×) Alternatively, cells are scored for cell to cell fusion an appropriate time after infection. After staining with crystal violet, cell fusion is measured by synctium/polykaryon formation and recorded as percentage of nuclei numbers in polykaryons to numbers of total nuclei. Five random different fields under a light microscope are counted and IC50 are calculated according to Reed-Muench method. 9. Attenuated Viruses 9.1 EXAMPLE 36 Attenuation Resulting from Substitution of Viral Genes Open reading frames of different viral genes are substituted in the cloned cDNA of the viral genome using standard recombinant DNA technology. For CAT activity of the different viral constructs see FIG. 60. 9.2 EXAMPLE 37 M2 Deletion Mutants A map of the M2 gene of hMPV strain hMPV/NL/1/00 is shown in FIG. 61. In order to generate a deletion of the M2 gene, a Bsp E1 site is constructed at nucleotide position 4741 and a second Bsp E1 site is constructed at nucleotide position 5444. The restriction sites are constructed by site-specific mutagenesis. Restriction digestion of the recombinant genome at the two Bsp E1 sites using the restriction endonuclease Bsp E1 and subsequent ligation results in a deletion of the sequence between nucleotide position 4741 and nucleotide position 5444. In order to generate a deletion of the M2-1 open reading frame of the M2 gene, Nhe I sites are introduced at nucleotide positions 4744 and 5241. The restriction sites are constructed by site-specific mutagenesis. Restriction digestion of the recombinant genome at the two Nhe I sites using the restriction endonuclease Nhe I and subsequent ligation results in a deletion of the sequence between nucleotide position 4744 and nucleotide position 5241. In order to generate a deletion of the M2-2 open reading frame of the M2 gene, Swa I sites are introduced at nucleotide positions 5311 and 5453. The restriction sites are constructed by site-specific mutagenesis. Restriction digestion of the recombinant genome at the two Swa I sites using the restriction endonuclease Swa I and subsequent ligation results in a deletion of the sequence between nucleotide position 5311 and nucleotide position 5453. The following primer sets were used: primers used to introduce the restriction enzyme sites: For putting BspEI into hMPV/NL/1/00 to make M2 deletion from 4741 to 5444: primer set “hMPV, BspEI, +4741” gga caa atc ata acg t tcc gga ag gc tcc gtg c “hMPV, BspEI, −4741” g cac gga gc ct tcc gga acgt tat gat ttg tcc and primer set “hMPV, BspEI, +5444” cat agaaat tat at atg tcc gga ct ta ctt a agt tag “hMPV, Bsp EI, −5444” cta act t aa g ta ag tcc gga cat at ata att tc For putting Nhe I sites into hMPV to make M2-1 deletion from 4744 to 5241 and change the start site from atg to acg at nt 4742: primer set “hMPV, Nhe I, +4744” gga caa atc ata ac g g ct agc aag gc t ccg tgc “hMPV, NheI, −4744 gca cgg agc ctt gct agc cgt tat gat ttg tcc primer set “hMPV, NheI, +5241 ctt atc agc agg t gctagc a atg act ctt cat a tg c “hMPV, Nhe I, −5241 gcat atg aa g ag t ca t t gct a gc a cct gct gat aag For putting SwaI sites into hMPV to make M2-2 deletion from 5311 to 5453: primer set “hMPV, SwaI, +5311” c agt gag cat ggt cca att taa att act ata gag g “hMPV, SwaI, −5311” c ctc tat agt aat tta aat tgg acc atg ctc act g and primers “hMPV, SwaI, +5453” c ata gaa att ata tat gtc aag gct tat tta aat tag “hMPV, SwaI, −5453” cta att taa ata agc ctt gac ata tat aat ttc tat g For the generation of hMPV (strain hMPV/NL/1/00) with a deletion in SH, cloned with deletion from 5472 to 6026, has been recovered and grows well in Vero cell culture. The primer sets for cloning the hMPV/NL/1/00 virus with the SH deletion are as follows: Primer set hMPV SacII +5472 ggc tta ctt aag tta gta aaa aca ccg cgg agt ggg ata aat gac hMPV SacII −5472 gtc att tat ccc act ccg cgg tgt ttt tac taa ctt aag taa gcc primer set hMPV SacII +6026 ct atc att acc caa ccgcgg aa acc caa tcc taa atg tta ac r hMPV SacII −6026 gt taa cat tta gga ttg ggt tt ccgcgg ttg ggt aat gat ag 10. EXAMPLE: Plasmid-Only Recovery of hMPV in Serum Free Vero Cells by Electroporation Introduction This process allows recovery of recombinant hMPV using plasmids only, in the absence of helper viruses. The recovery of hMPV is carried out using SF Vero cells, which are propagated in the absence of animal and human derived products. This process allows recovery of recombinant hMPV with similar efficiency to previous methods using helper viruses (recombinant vaccinia or fowl-pox viruses expressing T7 polymerase). Because no helper viruses are needed in the recovery process, the vaccine viruses are free of contaminating agents, simplifying downstream vaccine production. The cells used for vaccine virus recovery are grown in media containing no animal or human derived products. This eliminates concerns about transmissible spongiform encephalopathies (e.g. BSE), for product end users. This method enables generation of a recombinant vaccine seed that is completely free of animal or human derived components. The seed is also free of contaminating helper viruses. Plasmid-based expression systems for rescue of viruses from cDNA are described, e.g., in R A Lerch et al., Wyeth Vaccines, Pearl River NY, USA (Abstract 206 from XII International Conference on Negative Strand Viruses, June 14th-19th 2003, Pisa Italy) and G. Neumann et. al., J. Virol., 76, pp 406-410. Methods and Results hMPV N plasmids (4 μg; marker: kanamycin resistancy), hMPV P plasmids (4 μg; marker: kanamycin resistancy), hMPV L plasmids (2 μg; marker: kanamycin resistancy), cDNA encoding hMPV antigenomic cDNA (5 μg; marker: kanamycin resistancy) and pADT7(N)DpT7 encoding T7 RNA polymerase (5 μg; marker: blasticidin) are introduced into SF Vero cells using electroporation in serum-free medium. For the rescue of hMPV virus, 4 expression plasmids are used. They are for the genes N, P, L and also M2 of hMPV. In particular the following plasmids are used: 4 ug hMPV N pCITE plasmid, 4 ug hMPV P pCITE plasmid, 3 ug hMPV M2 pCITE plasmid, 2 ug hMPV L pCITE plasmid 5 ug T7 RNA polymerase plasmid, and 5 ug of the viral cDNA encoding the viral genome to be be rescued. The pCITE plasmid has an internal ribosomal entry site that functions in the cytoplasm of the Vero cell so that the proteins for the N, P, M2 and L are made in the cytoplasm. These proteins form the viral polymerase complex. The viral genome to be rescued is in a full length plasmid with a T7 promoter. Without being bound by theory, T7 DNA-dependent RNA polymerase transcribes a full length viral RNA genome using this full length plasmid. After the viral genome is made, the viral polymerase complex will transcribe the viral genome and generate viral messenger RNAs and virus is subsequently recovered. The pulse for the electroporation is 220V and 950 microfarads. 5.5×106 SF Vero cells are used per electroporation. The electroporated cells are allowed to recover at 33° C. in the presence of OptiC (a custom formulation from GIBCO Invitrogen Corporation) overnight. Recovered cells are washed twice with 1 mL of PBS containing calcium and magnesium and overlayed with 2 mL of OptiC. Electroporated cells are further incubated at 33° C. for 5-7 days. At the end of the incubation period, cells are scraped into the media and total cell lysate is analyzed for presence of hMPV. Virus recovery is confirmed by immunostaining of plaque assays using hMPV specific polyclonal antibodies. 11. EXAMPLE A Proline to Serine Change in the Human Metapneumovirus F Protein Cleavage Site Abrogates Cleavage and Infectivity in Vero Cells Human metapneumovirus (hMPV), a recently described paramyxovirus, causes respiratory illness, which can include severe cough, bronchiolitis and pneumonia. Analogous to other members of.he Pneumovirus subfamily, avian metapneumovirs (APV) and respiratory syncytiai virus (RSV), hMPV expresses two surface glycoproteins: an attachment glycoprotein (G) and a fusion protein (F). Although binding and entry studies of hMPV have not yet been reported, sequence alignment with other paramyxovirus F proteins have revealed conserved functional domains (see, e.g., FIG. 9). Without being bound by theory, cleavage of full-length fusion protein F0 into F1 and F2 exposes a fusion peptide at the N terminus of the F1 fragment, a prerequisite for fusion of the virus membrane with the host cell membrane. While the strain hMPV/NL/1/00 (SEQ ID NO: 19) contains the sequence RQPR at the cleavage site of the F protein, the majority of other hMPV strains contain the amino acid sequence RQSR at the cleavage site of the F protein. The full-length hMPV/NL/1/00 with either proline or serine at amino acid position 101 of the F protein was cloned. Both viruses were rescued and amplified as described in Example 32 in the presence of trypsin (FIGS. 62 and 63). However, in the absence of trypsin, the serine substitution abrogated cleavage of the F protein (FIG. 64) and inhibited virus infectivity. Cleavage and subsequent infectivity could be restored with the addition of trypsin, albeit the plaque size of the 101S mutant was smaller than the 101P virus. These results demonstrate that cleavage of F is a prerequisite for infectivity of hMVP/NL/1/00. Many other strains of hMPV that have been sequenced have serine at position 101 in the F protein and are likely to be cleaved. For example, the F protein of the strain CAN 99-81 has been shown to be cleaved using Western blot. 12. EXAMPLE Growth Behavior of Recombinant hMPV Several recombinant hMPV were constructed as described in Example 28. The different recombinant hMPV were rescued as described in Example 32. Growth curves of recombinant hMPV/NL/1/00 in the presence and absence of Trypsin are shown in FIG. 65. The cells (Vero cells) were infected at a MOI of 0.1. Replication of wild type hMPV/NL/1/00 and recombinant hMPV/NL/1/00 in the upper and lower respiratory tract of hamsters are shown in FIG. 66. Hamsters were infected as described in Example 33. A growth curve of a recombinant hMPV/NL/1/00 with an amino acid exchange of a glutamic acid to valine at amino acid position 93 of the F protein in the presence and absence of Trypsin are shown in FIG. 67. The cells (Vero cells) were infected at a MOI of 1. 13. Microneutralization Assay using hMPV/GFP2 When viruses are inoculated into an animal, an array of antibodies against the virus are produced. Some of these antibodies can bind virus particles and neutralize the infectivity of the viruses. In this example, a microneutralization assay was used to analyze the remaining infectivity of the viruses after the viruses were incubated with dilutions of serum containing antibodies. For serial dilutions, a 96-well plate is divided (i) into rows A (dilution 1:32); B (1:64); C (1:128); D (1:256); E (1:512); F (1:1024); G (1:2048); and H (No Antibody) and (ii) into columns 1 to 12 for the different samples (first sample: columns 1 to 3; second sample: columns 4 to 6; third sample: columns 7 to 9; and fourth sample: columns 10 to 12). 230 μl of sample dilution are added to row A. 115 μl of Opti-MEM are added to rows B-H. Then 115 μl of the 1:32 dilution of the first sample are added to wells 1B, 2B, and 3B, the second sample to wells 4B, 5B, and 6B, the third sample to wells 7B, 8B, and 9B, and the fourth sample to 10B, 11B, and 12B. Sera and medium are mixed gently by pipetting up and down three times. The steps are repeated for rows B to C, rows C to D, rows D to E, rows E to G. After diluted sample is added to row G and mixed, 115 μl are removed from row G and discarded. Microneutralization assay was performed as follows: sera were serially diluted. Each test sample and each control was diluted by 1:32 by adding 22.5 μl of sera to 697.5 μl of Opti-MEM Medium (1×). Serum and medium were mixed gently by inversion three times and place on ice. Each dilution of serum was incubated with the virus hMPV/GFP2. Cells were washed with phosphate buffered saline (“PBS”). Vero cells from ATCC are maintained in MEM (JRH Biosciences) supplemented with 10% fetal bovine serum, 2 mM L-glutamine, nonessential amino acids, and 100 units/ml penicillin G, 100 μg/ml streptomycin sulfate. The virus/sera mixtures were added to cells and incubated for one hour at 35° C. All of the medium, which contained the virus, were removed, and cells were washed with PBS. Opti-MEM medium was added to the cells and the cell cultures were incubated for three days. Opti-MEM I Reduced-Serum Medium (1×) (GIBCO 31985-070) contains, among others, HEPES buffer, 2400 mg/L sodium bicarbonate, hypoxanthine, thymidine, sodium pyruvate, L-glutamine, trace elements, growth factors, and phenol red reduced to 1.1 mg/L. The remaining infectivity of the viruses was measured by quantifying eGFP green foci on the images captured with fluorescence microscope. Plaque reduction assay (see Example 16) using a wildtype virus, e.g., wildtype hMPV/NL/1/00, was also performed for comparing the sensitivity of the microneutralization assay. The results are presented in Table 16, Table 17, Table 18, Table 19 and FIG. 68. The results demonstrate that the microneutralization assay using hMPV/GFP2 provides reliable and reproducible results. The use of hMPV-GFP in the microneutralization assay facilitates the high throughput screening of different vaccines and antibodies in animal model systems such as ferrets and monkeys. This technique also provides efficient means for diagnosing and monitoring infections in humans. TABLE 16 Titers of ferret sera using hMPV/GFP2 microneutralization assay and plaque reduction assay. Complement from Guinea pig (add 100 ul in 20 ml of Opti-MEM) was used for plaque reduction assay. NT50 is 1/dilution that confers 50% neutralization of input virus. The numbers in the table indicate the titers of sera. Plaque (NT50) Microneutralization (NT50) − trypsin − trypsin + trypsin + complement − complement − complement Ferret sera Wildtype hMPV/NL/1/00 hMPV/GFP2 hMPV/GFP2 1 5.9 8.2 8.3 2 3.3 8.7 6.9 3 4.1 6.8 7.1 4 3.6 8.5 5.1 5 2.9 6.0 7.9 TABLE 17 Titers of Monkey sera using hMPV/GFP2 microneutralization assay and plaque reduction assay. Plaque (NT50) Microneutralization − trypsin (NT 50) + complement + trypsin Wildtype − complement Monkey sera hMPV/NL/1/00 hMPV/GFP2 PreC23606M 3.8 <5 PreC23611F 2.1 <5 PreC23614F 2.9 <5 Day28C23606M 7 10 Day28C23611F 10 9 Day28C23614F 8 8.5 Day35C23606M NA 10 Day35C23611F NA 9.5 Day35C23614F NA 10 Day42C23606M NA 9.5 Day42C23611F NA 10 TABLE 18 Linear Correlation between plaque reduction assay and microneutralization assay using hMPV/GFP2 (see also, FIG. 68) Serum Correlation (no trypsin) Correlation (with trypsin) Ferret 1 0.924 0.911 Ferret 3 0.935 0.992 Ferret 5 0.943 0.87 Ferret 6 0.773 0.910 TABLE 19 Titers of Hamster sera using plaque reduction assay and microneutralization assay. Challenge with Plaque Reduction Microneutralization 50% Neutralization Mean reciprocal Mean reciprocal titer log2 ± SE log2 ± SE Assay Virus hMPV/NL/1/00 hMPV/NL/1/00/GFP2 b/h PIV3/hMPV-F2 7.4 ± 1.5 9.7 ± 0.6 Assay Virus hMPV/NL/1/00 hMPV 99/1 hMPV/NL/1/00/GFP2 hMPV99-1 4.3 + 1.1 11.0 ± 2.1 10.6 ± 0.2 hMPV001 na na 9.7 ± 0.4 14. EXAMPLE Evaluating the Efficacy and Immunogenicity of b/h PIV3 Expressing an Antigenic Protein of MPV in African Green Monkeys Bivalent MPV/RSV vaccine candidates, e.g., hMPV expressing an antigenic protein of RSV such as a soluble form of the F protein of human RSV (“hMPV/RSV FSOL”), wherein the soluble form of the RSV F protein lacks the transmembrane and the luminal domains, are evaluated for efficacy and immunogenicity in a non-human primate model, such as African green monkeys. Vero cells are maintained in Modified Eagle's Medium (MEM) (JRH Biosciences) supplemented with 2 mM L-glutamine, non-essential amino acids (NEAA), antibiotics, and 10% FBS. hMPV expressing an antigenic protein of RSV, e.g., hMPV/RSV FSOL, wildtype MPV, e.g., hMPV/NL/100, and a wildtype RSV, e.g., wildtype RSV A2, are propagated in Vero cells. Cells are infected with the viruses at a multiplicity of infection (MOI) of 0.1 PFU/cell. Three to five days post-infection the cells and supernatant are collected and stabilized by adding 10×SPG (10×SPG is 2.18 M Sucrose, 0.038 M KH2PO4, 0.072 M K2HPO4, 0.054 M L-Glutamate) to a final concentration of 1×. The virus stocks are stored at −70° C. The virus titers are determined by plaque assays on Vero cells. Plaques are quantified after immunoperoxidase staining using PIV3 (VMRD) or MPV goat polyclonal antisera (Biogenesis). MPV- and RSV-seronegative African Green monkeys (Cercopithecus aethiops) (3.5 to 6.5 years old, 2.6 to 5.8 kg) are identified using an MPV F IgG ELISA (Immuno-Biological Laboratories) and an RSV F IgG ELISA (Immuno-Biological Laboratories) for primate pre-sera collected on day 14 prior to the study start date. MPV F IgG ELISA is performed as follows: the primate sera from days 1, 28 and 56 from the vaccinated animals are analyzed for the presence of MPV F IgG using an ELISA kit (Immuno-Biological Laboratories, Hamburg, Germany) according to the manufacturer's instructions. The secondary monkey antiserum (Rockland Inc.) is used at a 1:1000 dilution. The MPV F IgG antibody titers are expressed as log2 IgG U/ml. The primate sera from days 1, 28 and 56 from the vaccinated animals are analyzed for the presence of RSV F IgG using an ELISA kit (Immuno-Biological Laboratories, Hamburg, Germany) according to the manufacturer's instructions. The secondary monkey antiserum (Rockland Inc.) is used at a 1:1000 dilution. The RSV F IgG antibody titers are plotted as log2 IgG U/ml. The primates are housed in individual micro-isolator cages. The monkeys are anesthetized with a ketamine-valium mixture and infected intranasally and intratracheally with a hMPV vector expressing an antigenic protein of RSV, e.g., hMPV/RSV FSOL, wildtype MPV, e.g., hMPV/NL/100, and a wildtype RSV, e.g., wildtype RSV A2, respectively. The nasal dose volume is 0.5 ml per nostril, and the intratracheal dose volume is 1 ml. On Day 1, each animal receives a dose of 2 ml containing 2-3×105 PFU of virus. The placebo animal group receives the same dose volume of Opti-MEM. On Day 28, all animals are challenged intratracheally and intranasally with 7×105 PFU of wildtype RSV A2 (1 ml at each site). Nasopharyngeal (NP) swabs are collected daily for 11 days and tracheal lavage (TL) specimens are collected on Days 1, 3, 5, 7 and 9 post-immunization and post-challenge. Blood samples obtained from the femoral vein are collected on Days 0, 7, 14, 21, 28, 35, 42, 49 and 56 for serological analysis. The animals are monitored for body temperature changes indicating a fever, signs of a cold, runny nose, sneezing, loss of appetite, and body weight. Virus present in the primate NP and TL specimens is quantitated by plaque assays using Vero cells that are immunostained with MPV goat polyclonal antiserum. Mean peak virus titers represent the mean of the peak virus titer measured for each animal on any of the 11 days following immunization or challenge. Plaque reduction neutralization assays (PRNAs) are carried out for sera obtained on days 1, 28, and 56 post-dose from primates infected with a hMPV/RSV FSOL. The primate sera are two-fold serially diluted, and incubated with 100 PFU of wildtype RSV A2 or wildtype MPV, e.g., hMPV/NL/100, respectively, in the presence of guinea pig complement for one hour at 4° C. The virus-serum mixtures are transferred to Vero cell monolayers and overlaid with 1% methyl cellulose in EMEM/L-15 medium (JRH Biosciences; Lenexa, Kans.) containing 2% FBS and 1% antibiotics. After 6 days of incubation at 35° C., the monolayers are immunostained using RSV goat polyclonal antiserum or hMPV goat polyclonal antiserum, respectively, for quantitation. Neutralization titers are expressed as the reciprocal log2 of the highest serum dilution that inhibits 50% of viral plaques. hMPV microneutralization assays and RSV A2 microneutralization assays, respectively, are performed on Vero cells. Serial two-fold dilutions of primate serum, starting at 1:4, are incubated at 37° C. for 60 min with 100 TCID50 of hMPV or RSV A2, respectively. Subsequently, virus-serum mixtures are transferred to cell monolayers in 96-well plates and incubated at 37° C. for six days, after which all wells are observed for CPE. Neutralization titers are expressed as the reciprocal of the highest serum dilution that inhibited CPE. Neutralization antibody titers of ≦1:4 (the lowest serum dilution tested) are assigned a reciprocal log2 titer of 2. To study the replication efficiency of the bivalent MPV/RSV vaccine candidates, the experiment is designed as follows. On Day 1, MPV and RSV sero-negative African green monkeys, eight animals per group, are immunized intranasally and intratracheally with a MPV vaccine candidate, e.g., hMPV/RSV FSOL, with a dose of 2-3×105 PFU. One positive control group is infected with wildtype MPV, e.g., hMPV/NL/100, another positive control group is infected with wildtype RSV A2, and the negative control group is administered placebo medium. On Day 28, each group is split into two sections, all animals of one section of each group are challenged intranasally and intratracheally with 7×105 PFU of wildtype MPV, e.g., hMPV/NL/100. All animals of the other section of each group are challenged intranasally and intratracheally with 7×105 PFU wildtype RSV A2. The animals are housed in micro-isolator cages for the duration of this study. Nasopharyngeal swabs are collected daily for 11 days post-immunization and post-challenge, and tracheal lavage samples are obtained on days 2, 4, 6, 8, and 10 post-immunization and post-challenge. Serum samples for antibody analyses are collected every seven days throughout the duration of the study. In order to evaluate immune protection from MPV infection and RSV infection, respectively, the vaccinated primates are challenged with a high dose of wildtype MPV, e.g., hMPV/NL/100, and a high dose wildtype RSV A2, respectively, four weeks post-immunization. Efficacy is measured as a reduction in shed MPV challenge virus titer in the URT and LRT of the infected animals. Efficacy of the MPV/RSV bivalent vaccine candidates is further evaluated by the levels of MPV neutralizing antibody titers and RSV F IgG serum antibody titers produced four weeks post-immunization. The MPV neutralizing antibody titers are determined using a 50% plaque reduction neutralization assay (PRNA). The immune responses elicited by the MPV/RSV bivalent vaccine candidates are also analyzed by measuring RSV F protein specific IgG levels at pre-dose (Day 1), four weeks post-dose (Day 28), and four weeks post-challenge (Day 56). The presence of RSV F IgG serum antibodies is determined using ELISA. The presence of MPV neutralizing activity in the serum can also be determined using an hMPV microneutralization assay. In order to evaluate whether the MPV/RSV bivalent vaccines can protect from RSV infection, primate sera are also analyzed for the presence of RSV neutralization using a plaque reduction neutralization assay or a microneutralization assay. TABLE 14 LEGEND FOR SEQUENCE LISTING SEQ ID NO: 1 Human metapneumovirus isolate 00-1 matrix protein (M) and fusion protein (F) genes SEQ ID NO: 2 Avian pneumovirus fusion protein gene, partial cds SEQ ID NO: 3 Avian pneumovirus isolate 1b fusion protein mRNA, complete cds SEQ ID NO: 4 Turkey rhinotracheitis virus gene for fusion protein (F1 and F2 subunits), complete cds SEQ ID NO: 5 Avian pneumovirus matrix protein (M) gene, partial cds and Avian pneumovirus fusion glycoprotein (F) gene, complete cds SEQ ID NO: 6 paramyxovirus F protein hRSV B SEQ ID NO: 7 paramyxovirus F protein hRSV A2 SEQ ID NO: 8 human metapneumovirus01-71 (partial sequence) SEQ ID NO: 9 Human metapneumovirus isolate 00-1 matrix protein(M) and fusion protein (F) genes SEQ ID NO: 10 Avian pneumovirus fusion protein gene, partial cds SEQ ID NO: 11 Avian pneumovirus isolate 1b fusion protein mRNA, complete cds SEQ ID NO: 12 Turkey rhinotracheitis virus gene for fusion protein (F1 and F2 subunits), complete cds SEQ ID NO: 13 Avian pneumovirus fusion glycoprotein (F) gene, complete cds SEQ ID NO: 14 Turkey rhinotracheitis virus (strain CVL14/1)attachment protien (G) mRNA, complete cds SEQ ID NO: 15 Turkey rhinotracheitis virus (strain 6574) attachment protein (G), complete cds SEQ ID NO: 16 Turkey rhinotracheitis virus (strain CVL14/1)attachment protein (G) mRNA, complete cds SEQ ID NO: 17 Turkey rhinotracheitis virus (strain 6574) attachment protein (G), complete cds SEQ ID NO: 18 isolate NL/1/99 (99-1) HMPV (Human Metapneumovirus)cDNA sequence SEQ ID NO: 19 isolate NL/1/00 (00-1) HMPV cDNA sequence SEQ ID NO: 20 isolate NL/17/00 HMPV cDNA sequence SEQ ID NO: 21 isolate NL/1/94 HMPV cDNA sequence SEQ ID NO: 22 RT-PCR primer TR1 SEQ ID NO: 23 RT-PCR primer N1 SEQ ID NO: 24 RT-PCR primer N2 SEQ ID NO: 25 RT-PCR primer M1 SEQ ID NO: 26 RT-PCR primer M2 SEQ ID NO: 27 RT-PCR primer F1 SEQ ID NO: 28 RT-PCR primer N3 SEQ ID NO: 29 RT-PCR primer N4 SEQ ID NO: 30 RT-PCR primer M3 SEQ ID NO: 31 RT-PCR primer M4 SEQ ID NO: 32 RT-PCR primer F7 SEQ ID NO: 33 RT-PCR primer F8 SEQ ID NO: 34 RT-PCR primer L6 SEQ ID NO: 35 RT-PCR primer L7 SEQ ID NO: 36 Oligonucleotide probe M SEQ ID NO: 37 Oligonucleotide probe N SEQ ID NO: 38 Oligonucleotide probe L SEQ ID NO: 39 TaqMan primer and probe sequences for isolates NL/1/00, BI/1/01, FI/4/01, NL/8/01, FI/2/01 SEQ ID NO: 40 TaqMan primer and probe sequences for isolates NL/30/01 SEQ ID NO: 41 TaqMan primer and probe sequences for isolates NL/22/01 and NL/23/01 SEQ ID NO: 42 TaqMan primer and probe sequences for isolate NL/17/01 SEQ ID NO: 43 TaqMan primer and probe sequences for isolate NL/17/00 SEQ ID NO: 44 TaqMan primer and probe sequences for isolates NL/9/01, NL/21/01, and NL/5/01 SEQ ID NO: 45 TaqMan primer and probe sequences for isolates FI/1/01 and FI/10/01 SEQ ID NO: 46 Primer ZF1 SEQ ID NO: 47 Primer ZF4 SEQ ID NO: 48 Primer ZF7 SEQ ID NO: 49 Primer ZF10 SEQ ID NO: 50 Primer ZF13 SEQ ID NO: 51 Primer ZF16 SEQ ID NO: 52 Primer CS1 SEQ ID NO: 53 Primer CS4 SEQ ID NO: 54 Primer CS7 SEQ ID NO: 55 Primer CS10 SEQ ID NO: 56 Primer CS13 SEQ ID NO: 57 Primer CS16 SEQ ID NO: 58 Forward primer for amplification of HPIV-1 SEQ ID NO: 59 Reverse primer for amplification of HPIV-1 SEQ ID NO: 60 Forward primer for amplification of HPIV-2 SEQ ID NO: 61 Reverse primer for amplification of HPIV-2 SEQ ID NO: 62 Forward primer for amplification of HPIV-3 SEQ ID NO: 63 Reverse primer for amplification of HPIV-3 SEQ ID NO: 64 Forward primer for amplification of HPIV-4 SEQ ID NO: 65 Reverse primer for amplification of HPIV-4 SEQ ID NO: 66 Forward primer for amplification of Mumps SEQ ID NO: 67 Reverse primer for amplification of Mumps SEQ ID NO: 68 Forward primer for amplification of NDV SEQ ID NO: 69 Reverse primer for amplification of NDV SEQ ID NO: 70 Forward primer for amplification of Tupaia SEQ ID NO: 71 Reverse primer for amplification of Tupaia SEQ ID NO: 72 Forward primer for amplification of Mapuera SEQ ID NO: 73 Reverse primer for amplification of Mapuera SEQ ID NO: 74 Forward primer for amplification of Hendra SEQ ID NO: 75 Reverse primer for amplification of Hendra SEQ ID NO: 76 Forward primer for amplification of Nipah SEQ ID NO: 77 Reverse primer for amplification of Nipah SEQ ID NO: 78 Forward primer for amplification of HRSV SEQ ID NO: 79 Reverse primer for amplification of HRSV SEQ ID NO: 80 Forward primer for amplification of Measles SEQ ID NO: 81 Reverse primer for amplification of Measles SEQ ID NO: 82 Forward primer to amplify general paramyxoviridae viruses SEQ ID NO: 83 Reverse primer to amplify general paramyxoviridae viruses SEQ ID NO: 84 G-gene coding sequence for isolate NL/1/00 (A1) SEQ ID NO: 85 G-gene coding sequence for isolate BR/2/01 (A1) SEQ ID NO: 86 G-gene coding sequence for isolate FL/4/01 (A1) SEQ ID NO: 87 G-gene coding sequence for isolate FL/3/01 (A1) SEQ ID NO: 88 G-gene coding sequence for isolate FL/8/01 (A1) SEQ ID NO: 89 G-gene coding sequence for isolate FL/10/01 (A1) SEQ ID NO: 90 G-gene coding sequence for isolate NL/10/01 (A1) SEQ ID NO: 91 G-gene coding sequence for isolate NL/2/02 (A1) SEQ ID NO: 92 G-gene coding sequence for isolate NL/17/00 (A2) SEQ ID NO: 93 G-gene coding sequence for isolate NL/1/81 (A2) SEQ ID NO: 94 G-gene coding sequence for isolate NL/1/93 (A2) SEQ ID NO: 95 G-gene coding sequence for isolate NL/2/93 (A2) SEQ ID NO: 96 G-gene coding sequence for isolate NL/3/93 (A2) SEQ ID NO: 97 G-gene coding sequence for isolate NL/1/95 (A2) SEQ ID NO: 98 G-gene coding sequence for isolate NL/2/96 (A2) SEQ ID NO: 99 G-gene coding sequence for isolate NL/3/96 (A2) SEQ ID NO: 100 G-gene coding sequence for isolate NL/22/01 (A2) SEQ ID NO: 101 G-gene coding sequence for isolate NL/24/01 (A2) SEQ ID NO: 102 G-gene coding sequence for isolate NL/23/01 (A2) SEQ ID NO: 103 G-gene coding sequence for isolate NL/29/01 (A2) SEQ ID NO: 104 G-gene coding sequence for isolate NL/3/02 (A2) SEQ ID NO: 105 G-gene coding sequence for isolate NL/1/99 (B1) SEQ ID NO: 106 G-gene coding sequence for isolate NL/11/00 (B1) SEQ ID NO: 107 G-gene coding sequence for isolate NL/12/00 (B1) SEQ ID NO: 108 G-gene coding sequence for isolate NL/5/01 (B1) SEQ ID NO: 109 G-gene coding sequence for isolate NL/9/01 (B1) SEQ ID NO: 110 G-gene coding sequence for isolate NL/21/01 (B1) SEQ ID NO: 111 G-gene coding sequence for isolate NL/1/94 (B2) SEQ ID NO: 112 G-gene coding sequence for isolate NL/1/82 (B2) SEQ ID NO: 113 G-gene coding sequence for isolate NL/1/96 (B2) SEQ ID NO: 114 G-gene coding sequence for isolate NL/6/97 (B2) SEQ ID NO: 115 G-gene coding sequence for isolate NL/9/00 (B2) SEQ ID NO: 116 G-gene coding sequence for isolate NL/3/01 (B2) SEQ ID NO: 117 G-gene coding sequence for isolate NL/4/01 (B2) SEQ ID NO: 118 G-gene coding sequence for isolate UK/5/01 (B2) SEQ ID NO: 119 G-protein sequence for isolate NL/1/00 (A1) SEQ ID NO: 120 G-protein sequence for isolate BR/2/01 (A1) SEQ ID NO: 121 G-protein sequence for isolate FL/4/01 (A1) SEQ ID NO: 122 G-protein sequence for isolate FL/3/01 (A1) SEQ ID NO: 123 G-protein sequence for isolate FL/8/01 (A1) SEQ ID NO: 124 G-protein sequence for isolate FL/10/01 (A1) SEQ ID NO: 125 G-protein sequence for isolate NL/10/01 (A1) SEQ ID NO: 126 G-protein sequence for isolate NL/2/02 (A1) SEQ ID NO: 127 G-protein sequence for isolate NL/17/00 (A2) SEQ ID NO: 128 G-protein sequence for isolate NL/1/81 (A2) SEQ ID NO: 129 G-protein sequence for isolate NL/1/93 (A2) SEQ ID NO: 130 G-protein sequence for isolate NL/2/93 (A2) SEQ ID NO: 131 G-protein sequence for isolate NL/3/93 (A2) SEQ ID NO: 132 G-protein sequence for isolate NL/1/95 (A2) SEQ ID NO: 133 G-protein sequence for isolate NL/2/96 (A2) SEQ ID NO: 134 G-protein sequence for isolate NL/3/96 (A2) SEQ ID NO: 135 G-protein sequence for isolate NL/22/01 (A2) SEQ ID NO: 136 G-protein sequence for isolate NL/24/01 (A2) SEQ ID NO: 137 G-protein sequence for isolate NL/23/01 (A2) SEQ ID NO: 138 G-protein sequence for isolate NL/29/01 (A2) SEQ ID NO: 139 G-protein sequence for isolate NL/3/02 (A2) SEQ ID NO: 140 G-protein sequence for isolate NL/1/99 (B1) SEQ ID NO: 141 G-protein sequence for isolate NL/11/00 (B1) SEQ ID NO: 142 G-protein sequence for isolate NL/12/00 (B1) SEQ ID NO: 143 G-protein sequence for isolate NL/5/01 (B1) SEQ ID NO: 144 G-protein sequence for isolate NL/9/01 (B1) SEQ ID NO: 145 G-protein sequence for isolate NL/21/01 (B1) SEQ ID NO: 146 G-protein sequence for isolate NL/1/94 (B2) SEQ ID NO: 147 G-protein sequence for isolate NL/1/82 (B2) SEQ ID NO: 148 G-protein sequence for isolate NL/1/96 (B2) SEQ ID NO: 149 G-protein sequence for isolate NL/6/97 (B2) SEQ ID NO: 150 G-protein sequence for isolate NL/9/00 (B2) SEQ ID NO: 151 G-protein sequence for isolate NL/3/01 (B2) SEQ ID NO: 152 G-protein sequence for isolate NL/4/01 (B2) SEQ ID NO: 153 G-protein sequence for isolate NL/5/01 (B2) SEQ ID NO: 154 F-gene coding sequence for isolate NL/1/00 SEQ ID NO: 155 F-gene coding sequence for isolate UK/1/00 SEQ ID NO: 156 F-gene coding sequence for isolate NL/2/00 SEQ ID NO: 157 F-gene coding sequence for isolate NL/13/00 SEQ ID NO: 158 F-gene coding sequence for isolate NL/14/00 SEQ ID NO: 159 F-gene coding sequence for isolate FL/3/01 SEQ ID NO: 160 F-gene coding sequence for isolate FL/4/01 SEQ ID NO: 161 F-gene coding sequence for isolate FL/8/01 SEQ ID NO: 162 F-gene coding sequence for isolate UK/1/01 SEQ ID NO: 163 F-gene coding sequence for isolate UK/7/01 SEQ ID NO: 164 F-gene coding sequence for isolate FL/10/01 SEQ ID NO: 165 F-gene coding sequence for isolate NL/6/01 SEQ ID NO: 166 F-gene coding sequence for isolate NL/8/01 SEQ ID NO: 167 F-gene coding sequence for isolate NL/10/01 SEQ ID NO: 168 F-gene coding sequence for isolate NL/14/01 SEQ ID NO: 169 F-gene coding sequence for isolate NL/20/01 SEQ ID NO: 170 F-gene coding sequence for isolate NL/25/01 SEQ ID NO: 171 F-gene coding sequence for isolate NL/26/01 SEQ ID NO: 172 F-gene coding sequence for isolate NL/28/01 SEQ ID NO: 173 F-gene coding sequence for isolate NL/30/01 SEQ ID NO: 174 F-gene coding sequence for isolate BR/2/01 SEQ ID NO: 175 F-gene coding sequence for isolate BR/3/01 SEQ ID NO: 176 F-gene coding sequence for isolate NL/2/02 SEQ ID NO: 177 F-gene coding sequence for isolate NL/4/02 SEQ ID NO: 178 F-gene coding sequence for isolate NL/5/02 SEQ ID NO: 179 F-gene coding sequence for isolate NL/6/02 SEQ ID NO: 180 F-gene coding sequence for isolate NL/7/02 SEQ ID NO: 181 F-gene coding sequence for isolate NL/9/02 SEQ ID NO: 182 F-gene coding sequence for isolate FL/1/02 SEQ ID NO: 183 F-gene coding sequence for isolate NL/1/81 SEQ ID NO: 184 F-gene coding sequence for isolate NL/1/93 SEQ ID NO: 185 F-gene coding sequence for isolate NL/2/93 SEQ ID NO: 186 F-gene coding sequence for isolate NL/4/93 SEQ ID NO: 187 F-gene coding sequence for isolate NL/1/95 SEQ ID NO: 188 F-gene coding sequence for isolate NL/2/96 SEQ ID NO: 189 F-gene coding sequence for isolate NL/3/96 SEQ ID NO: 190 F-gene coding sequence for isolate NL/1/98 SEQ ID NO: 191 F-gene coding sequence for isolate NL/17/00 SEQ ID NO: 192 F-gene coding sequence for isolate NL/22/01 SEQ ID NO: 193 F-gene coding sequence for isolate NL/29/01 SEQ ID NO: 194 F-gene coding sequence for isolate NL/23/01 SEQ ID NO: 195 F-gene coding sequence for isolate NL/17/01 SEQ ID NO: 196 F-gene coding sequence for isolate NL/24/01 SEQ ID NO: 197 F-gene coding sequence for isolate NL/3/02 SEQ ID NO: 198 F-gene coding sequence for isolate NL/3/98 SEQ ID NO: 199 F-gene coding sequence for isolate NL/1/99 SEQ ID NO: 200 F-gene coding sequence for isolate NL/2/99 SEQ ID NO: 201 F-gene coding sequence for isolate NL/3/99 SEQ ID NO: 202 F-gene coding sequence for isolate NL/11/00 SEQ ID NO: 203 F-gene coding sequence for isolate NL/12/00 SEQ ID NO: 204 F-gene coding sequence for isolate NL/1/01 SEQ ID NO: 205 F-gene coding sequence for isolate NL/5/01 SEQ ID NO: 206 F-gene coding sequence for isolate NL/9/01 SEQ ID NO: 207 F-gene coding sequence for isolate NL/19/01 SEQ ID NO: 208 F-gene coding sequence for isolate NL/21/01 SEQ ID NO: 209 F-gene coding sequence for isolate UK/11/01 SEQ ID NO: 210 F-gene coding sequence for isolate FL/1/01 SEQ ID NO: 211 F-gene coding sequence for isolate FL/2/01 SEQ ID NO: 212 F-gene coding sequence for isolate FL/5/01 SEQ ID NO: 213 F-gene coding sequence for isolate FL/7/01 SEQ ID NO: 214 F-gene coding sequence for isolate FL/9/01 SEQ ID NO: 215 F-gene coding sequence for isolate UK/10/01 SEQ ID NO: 216 F-gene coding sequence for isolate NL/1/02 SEQ ID NO: 217 F-gene coding sequence for isolate NL/1/94 SEQ ID NO: 218 F-gene coding sequence for isolate NL/1/96 SEQ ID NO: 219 F-gene coding sequence for isolate NL/6/97 SEQ ID NO: 220 F-gene coding sequence for isolate NL/7/00 SEQ ID NO: 221 F-gene coding sequence for isolate NL/9/00 SEQ ID NO: 222 F-gene coding sequence for isolate NL/19/00 SEQ ID NO: 223 F-gene coding sequence for isolate NL/28/00 SEQ ID NO: 224 F-gene coding sequence for isolate NL/3/01 SEQ ID NO: 225 F-gene coding sequence for isolate NL/4/01 SEQ ID NO: 226 F-gene coding sequence for isolate NL/11/01 SEQ ID NO: 227 F-gene coding sequence for isolate NL/15/01 SEQ ID NO: 228 F-gene coding sequence for isolate NL/18/01 SEQ ID NO: 229 F-gene coding sequence for isolate FL/6/01 SEQ ID NO: 230 F-gene coding sequence for isolate UK/5/01 SEQ ID NO: 231 F-gene coding sequence for isolate UK/8/01 SEQ ID NO: 232 F-gene coding sequence for isolate NL/12/02 SEQ ID NO: 233 F-gene coding sequence for isolate HK/1/02 SEQ ID NO: 234 F-protein sequence for isolate NL/1/00 SEQ ID NO: 235 F-protein sequence for isolate UK/1/00 SEQ ID NO: 236 F-protein sequence for isolate NL/2/00 SEQ ID NO: 237 F-protein sequence for isolate NL/13/00 SEQ ID NO: 238 F-protein sequence for isolate NL/14/00 SEQ ID NO: 239 F-protein sequence for isolate FL/3/01 SEQ ID NO: 240 F-protein sequence for isolate FL/4/01 SEQ ID NO: 241 F-protein sequence for isolate FL/8/01 SEQ ID NO: 242 F-protein sequence for isolate UK/1/01 SEQ ID NO: 243 F-protein sequence for isolate UK/7/01 SEQ ID NO: 244 F-protein sequence for isolate FL/10/01 SEQ ID NO: 245 F-protein sequence for isolate NL/6/01 SEQ ID NO: 246 F-protein sequence for isolate NL/8/01 SEQ ID NO: 247 F-protein sequence for isolate NL/10/01 SEQ ID NO: 248 F-protein sequence for isolate NL/14/01 SEQ ID NO: 249 F-protein sequence for isolate NL/20/01 SEQ ID NO: 250 F-protein sequence for isolate NL/25/01 SEQ ID NO: 251 F-protein sequence for isolate NL/26/01 SEQ ID NO: 252 F-protein sequence for isolate NL/28/01 SEQ ID NO: 253 F-protein sequence for isolate NL/30/01 SEQ ID NO: 254 F-protein sequence for isolate BR/2/01 SEQ ID NO: 255 F-protein sequence for isolate BR/3/01 SEQ ID NO: 256 F-protein sequence for isolate NL/2/02 SEQ ID NO: 257 F-protein sequence for isolate NL/4/02 SEQ ID NO: 258 F-protein sequence for isolate NL/5/02 SEQ ID NO: 259 F-protein sequence for isolate NL/6/02 SEQ ID NO: 260 F-protein sequence for isolate NL/7/02 SEQ ID NO: 261 F-protein sequence for isolate NL/9/02 SEQ ID NO: 262 F-protein sequence for isolate FL/1/02 SEQ ID NO: 263 F-protein sequence for isolate NL/1/81 SEQ ID NO: 264 F-protein sequence for isolate NL/1/93 SEQ ID NO: 265 F-protein sequence for isolate NL/2/93 SEQ ID NO: 266 F-protein sequence for isolate NL/4/93 SEQ ID NO: 267 F-protein sequence for isolate NL/1/95 SEQ ID NO: 268 F-protein sequence for isolate NL/2/96 SEQ ID NO: 269 F-protein sequence for isolate NL/3/96 SEQ ID NO: 270 F-protein sequence for isolate NL/1/98 SEQ ID NO: 271 F-protein sequence for isolate NL/17/00 SEQ ID NO: 272 F-protein sequence for isolate NL/22/01 SEQ ID NO: 273 F-protein sequence for isolate NL/29/01 SEQ ID NO: 274 F-protein sequence for isolate NL/23/01 SEQ ID NO: 275 F-protein sequence for isolate NL/17/01 SEQ ID NO: 276 F-protein sequence for isolate NL/24/01 SEQ ID NO: 277 F-protein sequence for isolate NL/3/02 SEQ ID NO: 278 F-protein sequence for isolate NL/3/98 SEQ ID NO: 279 F-protein sequence for isolate NL/1/99 SEQ ID NO: 280 F-protein sequence for isolate NL/2/99 SEQ ID NO: 281 F-protein sequence for isolate NL/3/99 SEQ ID NO: 282 F-protein sequence for isolate NL/11/00 SEQ ID NO: 283 F-protein sequence for isolate NL/12/00 SEQ ID NO: 284 F-protein sequence for isolate NL/1/01 SEQ ID NO: 285 F-protein sequence for isolate NL/5/01 SEQ ID NO: 286 F-protein sequence for isolate NL/9/01 SEQ ID NO: 287 F-protein sequence for isolate NL/19/01 SEQ ID NO: 288 F-protein sequence for isolate NL/21/01 SEQ ID NO: 289 F-protein sequence for isolate UK/11/01 SEQ ID NO: 290 F-protein sequence for isolate FL/1/01 SEQ ID NO: 291 F-protein sequence for isolate FL/2/01 SEQ ID NO: 292 F-protein sequence for isolate FL/5/01 SEQ ID NO: 293 F-protein sequence for isolate FL/7/01 SEQ ID NO: 294 F-protein sequence for isolate FL/9/01 SEQ ID NO: 295 F-protein sequence for isolate UK/10/01 SEQ ID NO: 296 F-protein sequence for isolate NL/1/02 SEQ ID NO: 297 F-protein sequence for isolate NL/1/94 SEQ ID NO: 298 F-protein sequence for isolate NL/1/96 SEQ ID NO: 299 F-protein sequence for isolate NL/6/97 SEQ ID NO: 300 F-protein sequence for isolate NL/7/00 SEQ ID NO: 301 F-protein sequence for isolate NL/9/00 SEQ ID NO: 302 F-protein sequence for isolate NL/19/00 SEQ ID NO: 303 F-protein sequence for isolate NL/28/00 SEQ ID NO: 304 F-protein sequence for isolate NL/3/01 SEQ ID NO: 305 F-protein sequence for isolate NL/4/01 SEQ ID NO: 306 F-protein sequence for isolate NL/11/01 SEQ ID NO: 307 F-protein sequence for isolate NL/15/01 SEQ ID NO: 308 F-protein sequence for isolate NL/18/01 SEQ ID NO: 309 F-protein sequence for isolate FL/6/01 SEQ ID NO: 310 F-protein sequence for isolate UK/5/01 SEQ ID NO: 311 F-protein sequence for isolate UK/8/01 SEQ ID NO: 312 F-protein sequence for isolate NL/12/02 SEQ ID NO: 313 F-protein sequence for isolate HK/1/02 SEQ ID NO: 314 F protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 315 F protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 316 F protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 317 F protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 318 F-gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 319 F-gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 320 F-gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 321 F-gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 322 G protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 323 G protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 324 G protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 325 G protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 326 G-gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 327 G-gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 328 G-gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 329 G-gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 330 L protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 331 L protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 332 L protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 333 L protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 334 L-gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 335 L-gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 336 L-gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 337 L-gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 338 M2-1 protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 339 M2-1 protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 340 M2-1 protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 341 M2-1 protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 342 M2-1 gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 343 M2-1 gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 344 M2-1 gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 345 M2-1 gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 346 M2-2 protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 347 M2-2 protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 348 M2-2 protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 349 M2-2 protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 350 M2-2 gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 351 M2-2 gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 352 M2-2 gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 353 M2-2 gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 354 M2 gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 355 M2 gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 356 M2 gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 357 M2 gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 358 M protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 359 M protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 360 M protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 361 M protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 362 M gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 363 M gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 364 M gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 365 M gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 366 N protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 367 N protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 368 N protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 369 N protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 370 N gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 371 N gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 372 N gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 373 N gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 374 P protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 375 P protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 376 P protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 377 P protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 378 P gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 379 P gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 380 P gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 381 P gene sequence for HMPV isolate NL/1/94 SEQ ID NO: 382 SH protein sequence for HMPV isolate NL/1/00 SEQ ID NO: 383 SH protein sequence for HMPV isolate NL/17/00 SEQ ID NO: 384 SH protein sequence for HMPV isolate NL/1/99 SEQ ID NO: 385 SH protein sequence for HMPV isolate NL/1/94 SEQ ID NO: 386 SH gene sequence for HMPV isolate NL/1/00 SEQ ID NO: 387 SH gene sequence for HMPV isolate NL/17/00 SEQ ID NO: 388 SH gene sequence for HMPV isolate NL/1/99 SEQ ID NO: 389 SH gene sequence for HMPV isolate NL/1/94 | <SOH> 2. BACKGROUND OF THE INVENTION <EOH>Classically, as devastating agents of disease, paramyxoviruses account for many animal and human deaths worldwide each year. The Paramyxoviridae form a family within the order of Mononegavirales (negative-sense single stranded RNA viruses), consisting of the sub-families Paramyxovirinae and Pneumovirinae. The latter sub-family is at present taxonomically divided in the genera Pneumovirus and Metapneumovirus (Pringle, 1999, Arch. Virol. 144/2, 2065-2070). Human respiratory syncytial virus (hRSV), a species of the Pneumovirus genus, is the single most important cause of lower respiratory tract infections during infancy and early childhood worldwide (Domachowske, & Rosenberg, 1999, Clin. Microbio. Rev. 12(2): 298-309). Other members of the Pneumovirus genus include the bovine and ovine respiratory syncytial viruses and pneumonia virus of mice (PVM). In the past decades several etiological agents of mammalian disease, in particular of respiratory tract illnesses (RTI), in particular of humans, have been identified (Evans, In: Viral Infections of Humans, Epidemiology and Control. 3th edn. (ed. Evans, A. S) 22-28 (Plenum Publishing Corporation, New York, 1989)). Classical etiological agents of RTI with mammals are respiratory syncytial viruses belonging to the genus Pneumovirus found with humans (hRSV) and ruminants such as cattle or sheep (bRSV and/or oRSV). In human RSV differences in reciprocal cross neutralization assays, reactivity of the G proteins in immunological assays and nucleotide sequences of the G gene are used to define two hRSV antigenic subgroups. Within the subgroups the amino acid sequences show 94% (subgroup A) or 98% (subgroup B) identity, while only 53% amino acid sequence identity is found between the subgroups. Additional variability is observed within subgroups based on monoclonal antibodies, RT-PCR assays and RNAse protection assays. Viruses from both subgroups have a worldwide distribution and may occur during a single season. Infection may occur in the presence of pre-existing immunity and the antigenic variation is not strictly required to allow re-infection. See, for example Sullender, 2000, Clinical Microbiology Reviews 13(1): 1-15; Collins et al. Fields Virology, ed. B. N. Knipe, Howley, P. M. 1996, Philadelphia: Lippencott-Raven. 1313-1351; Johnson et al., 1987, (Proc Natl Acad Sci USA, 84(16): 5625-9; Collins, in The Paramyxoviruses, D. W. Kingsbury, Editor. 1991, Plenum Press: New York. p. 103-153. Another classical Pneumovirus is the pneumonia virus of mice (PVM), in general only found with laboratory mice. However, a proportion of the illnesses observed among mammals can still not be attributed to known pathogens. | <SOH> 3. SUMMARY OF THE INVENTION <EOH>The invention relates to an isolated mammalian negative strand RNA virus, metapneumovirus (MPV), within the sub-family Pneumovirinae, of the family Paramyxoviridae. The present invention also relates to isolated mammalian negative strand RNA viruses identifiable as phylogenitically corresponding or relating to the genus Metapneumovirus and components thereof. In particular, the invention relates to a mammalian MPV that is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris than it is related to APV type C. In more specific embodiments, the mammalian MPV can be a variant A1, A2, B1 or B2 mammalian MPV. However, the mammalian MPVs of the present invention may encompass additional variants yet to be identified, and are not limited to variants A1, A2, B1 or B2. The invention relates to genomic nucleotide sequences of different isolates of mammalian metapneumoviruses, in particular human metapneumoviruses. The invention relates to the use of the sequence information of different isolates of mammalian metapneumoviruses for diagnostic and therapeutic methods. The present invention relates to the differences of the genomic nucleotide sequences among the different metapneumovirus -isolates, and their use in the diagnostic and therapeutic methods of the invention. In specific embodiments, the nucleotide sequence of a mammalian MPV that encodes for the N, M, F, L, P, M2-1, M2-2, SH or G ORFs may be used to identify a virus of the invention. In other specific embodiments, the nucleotide sequence of mammalian MPV that encodes for the N, M, F, L, P, M2-1, M2-2, SH or G ORFs used to classify a mammalian MPV into variant A1, A2, B1 or B2. In a specific embodiment, the invention relates to the use of the single nucleotide polymorphisms (SNPs) among different metapneumovirus isolates for diagnostic purposes. The invention relates to recombinant and chimeric viruses that are derived from a mammalian MPV or avian pneumovirus (APV). In accordance with the present invention, a recombinant virus is one derived from a mammalian MPV or an APV that is encoded by endogenous or native genomic sequences or non-native genomic sequences. In accordance with the invention, a non-native sequence is one that is different from the native or endogenous genomic sequence due to one or more mutations, including, but not limited to, point mutations, rearrangements, insertions, deletions etc., to the genomic sequence that may or may not result in a phenotypic change. In accordance with the invention, a chimeric virus of the invention is a recombinant MPV or APV which further comprises a heterologous nucleotide sequence. In accordance with the invention, a chimeric virus may be encoded by a nucleotide sequence in which heterologous nucleotide sequences have been added to the genome or in which endogenous or native nucleotide sequences have been replaced with heterologous nucleotide sequences. In certain embodiments, a chimeric virus of the invention is derived from a MPV or APV in which one or more of the ORFs or a portion thereof is replaced by a homologous ORF or a portion thereof from another strain of metapneumovirus. In an exemplary embodiment, the ORF of the F gene of a mammalian MPV is replaced by the ORF of the F gene of an APV. In certain other embodiments, a chimeric virus of the invention is derived from an APV in which one or more of the ORFs is replaced by a homologous ORF of a mammalian MPV. The present invention relates to nucleotide sequences encoding the genome of a metapneumovirus (including mammalian and avian strains) or a portion thereof. The present invention relates to nucleotide sequences encoding gene products of a metapneumovirus. In particular, the invention relates to, but is not limited to, nucleotide sequences encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a MPV. In particular the invention relates to nucleotide sequences encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a variant of mammalian MPV, such as but not limited to variant A1, A2, B1 or B2 of a MPV. The present invention further relates to a cDNA or RNA that encodes the genome or a portion thereof of a metapneumovirus, including both mammalian and avian, in addition to a nucleotide sequence which is heterologous or non-native to the viral genome. The invention further encompasses chimeric or recombinant viruses encoded by said cDNAs or RNAs. The invention further relates to polypeptides and amino acid sequences of an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a mammalian MPV and different variants of mammalian MPV. The invention further relates to antibodies against an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of a mammalian MPV and different variants of mammalian MPV. The antibodies can be used for diagnostic and therapeutic methods. In certain more specific embodiments, the antibodies are specific to mammalian MPV. In certain embodiments, the antibodies are specific to a variant of mammalian MPV. The invention further relates to vaccine formulations and immunogenic compositions comprising one or more of the following: an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, and/or an L protein of a mammalian MPV. The invention further relates to vaccine formulations and immunogenic compositions comprising mammalian or avian metapneumovirus, including recombinant and chimeric forms of said viruses. In particular, the present invention encompasses vaccine preparations comprising recombinant or chimeric forms of MPV and/or APV. The invention further relates to vaccines comprising chimeric MPV wherein the chimeric MPV encodes one or more APV proteins and wherein the chimeric MPV optionally additionally expresses one or more heterologous or non-native sequences. The invention also relates to vaccines comprising chimeric APV wherein the chimeric APV encodes one or more hMPV proteins and wherein the chimeric APV optionally additionally expresses one or more heterologous or non-native sequences. The present invention also relates to multivalent vaccines, including bivalent and trivalent vaccines. In particular, multivalent vaccines of the invention encompass two or more antigenic polypeptides expressed by the same or different pneumoviral vectors. The antigenic polypeptides of the multivalent vaccines include but are not limited to, antigenic polypeptides of MPV, APV, PIV, RSV, influenza or another negative strand RNA virus, or another virus, such as morbillivirus. The invention further relates to methods for treating a respiratory tract infection in a subject. In certain embodiments, the invention relates to treating a respiratory tract infection in a subject by administering to the subject a vaccine formulation comprising a mammalian MPV. In specific embodiments, the methods for treating a respiratory tract infection in a subject comprise administering to the subject a vaccine formulation or an immunogenic composition comprising a recombinant or a chimeric mammalian MPV or APV. In more specific embodiments, the recombinant or chimeric mammalian MPV is attenuated. In a specific embodiment, the invention relates to treating a respiratory tract infection in a human patient comprising administering to the human patient a vaccine formulation comprising a recombinant or chimeric APV, or a nucleotide sequence encoding an F protein, a G protein, an M protein, an SH protein, an N protein, a P protein, an M2 protein, or an L protein of APV. The invention provides an isolated negative-sense single stranded RNA virus MPV belonging to the sub-family Pneumovirinae of the family Paramyxoviridae and identifiable as phylogenetically corresponding to the genus Metapneumovirus, wherein the virus is phylogenetically more closely related to a virus isolate comprising the nucleotide sequence of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, or SEQ ID NO:21 than it is related to turkey rhinotracheitis virus, the etiological agent of avian rhinotracheitis. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:18. In certain embodiments, the invention providesa n isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:19. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:20. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA metapneumovirus, wherein the genome of the virus comprises a nucleotide sequence of SEQ ID NO:21. In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid has a nucleotide sequence that is at least 70% identical to SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20 or SEQ ID NO:21, wherein sequence identity is determined over the entire length of SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20 or SEQ ID NO:21. In certain embodiments, the invention providesa n isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338) (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). In certain embodiments, the invention provides n isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:332); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid encodes a protein comprising (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377); (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361) (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides an isolated nucleic acid, wherein the nucleic acid hybridizes specifically under high stringency, medium stringency, or low stringency conditions to a nucleic acid of a mammalian MPV. In certain embodiments, the invention provides a virus comprising the nucleotide sequence of SEQ ID NO: 18-21 or a fragment thereof. In certain embodiments, the invention provides an isolated protein, wherein the protein comprises (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376); (iv) an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316) (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340); (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); or (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an isolated protein, wherein the protein comprises: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338) (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330) In certain embodiments, the invention provides isolated protein, wherein the protein comprises (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375) (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315) (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); or (ix)an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2(SEQ ID NO:331). In certain embodiments, the invention provides an isolated protein, wherein the protein comprises: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377) (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B1 (SEQ ID NO:324); (ii) an amino acid sequence that is at least 98.5% identical to the N protein of a mammalian MPV variant B1 (SEQ ID NO:368); (iii) an amino acid sequence that is at least 96% identical the P protein of a mammalian MPV variant B1 (SEQ ID NO:376) (iv an amino acid sequence that is identical the M protein of a mammalian MPV variant B1 (SEQ ID NO:360); (v) an amino acid sequence that is at least 99% identical the F protein of a mammalian MPV variant B1 (SEQ ID NO:316); (vi) an amino acid sequence that is at least 98% identical the M2-1 protein of a mammalian MPV variant B1 (SEQ ID NO:340) (vii) an amino acid sequence that is at least 99% identical the M2-2 protein of a mammalian MPV variant B1 (SEQ ID NO:348); (viii) an amino acid sequence that is at least 83% identical the SH protein of a mammalian MPV variant B1 (SEQ ID NO:384); (ix) an amino acid sequence that is at least 99% identical the L protein a mammalian MPV variant B1 (SEQ ID NO:332). In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A1 (SEQ ID NO:322); (ii) an amino acid sequence that is at least 99.5% identical to the N protein of a mammalian MPV variant A1 (SEQ ID NO:366); (iii an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A1 (SEQ ID NO:374); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A1 (SEQ ID NO:358); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A1 (SEQ ID NO:314); (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A1 (SEQ ID NO:338); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A1 (SEQ ID NO:346); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A1 (SEQ ID NO:382); (ix) an amino acid sequence that is at least 99% identical to the L protein of a virus of a mammalian MPV variant A1 (SEQ ID NO:330). In certain embodiments, the invention providesa n antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant A2 (SEQ ID NO:323); (ii) an amino acid sequence that is at least 96% identical to the N protein of a mammalian MPV variant A2 (SEQ ID NO:367) (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant A2 (SEQ ID NO:375); (iv) an amino acid sequence that is at least 99% identical to the M protein of a mammalian MPV variant A2 (SEQ ID NO:359); (v) an amino acid sequence that is at least 98% identical to the F protein of a mammalian MPV variant A2 (SEQ ID NO:315) (vi) an amino acid sequence that is at least 99% identical to the M2-1 protein of a mammalian MPV variant A2 (SEQ ID NO: 339); (vii) an amino acid sequence that is at least 96% identical to the M2-2 protein of a mammalian MPV variant A2 (SEQ ID NO:347); (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant A2 (SEQ ID NO:383); (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant A2 (SEQ ID NO:331) In certain embodiments, the invention provides an antibody, wherein the antibody binds specifically to a protein consisting of: (i) an amino acid sequence that is at least 66% identical to the G protein of a mammalian MPV variant B2 (SEQ ID NO:325); (ii) an amino acid sequence that is at least 97% identical to the N protein of a mammalian MPV variant B2 (SEQ ID NO:369); (iii) an amino acid sequence that is at least 96% identical to the P protein of a mammalian MPV variant B2 (SEQ ID NO:377) (iv) an amino acid sequence that is identical to the M protein of a mammalian MPV variant B2 (SEQ ID NO:361); (v) an amino acid sequence that is at least 99% identical to the F protein of a mammalian MPV variant B2 (SEQ ID NO:317); (vi) an amino acid sequence that is at least 98% identical to the M2-1 protein of a mammalian MPV variant B2 (SEQ ID NO:341); (vii) an amino acid sequence that is at least 99% identical to the M2-2 protein of a mammalian MPV variant B2 (SEQ ID NO:349) (viii) an amino acid sequence that is at least 84% identical to the SH protein of a mammalian MPV variant B2 (SEQ ID NO:385); or (ix) an amino acid sequence that is at least 99% identical to the L protein of a mammalian MPV variant B2 (SEQ ID NO:333). In certain embodiments, the invention provides a method for detecting a variant B1 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody of specific to a variant B1. In certain embodiments, the invention provides method for detecting a variant A1 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to variant A1. In certain embodiments, the invention provides a method for detecting a variant A2 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to variant A2. In certain embodiments, the invention provides a method for detecting a variant B2 mammalian MPV in a sample, wherein said method comprises contacting the sample with the antibody specific to B2. In certain embodiments, the invention provides a method for identifying a viral isolate as a mammalian MPV, wherein said method comprises contacting said isolate or a component thereof with the antibody specific to a mammalian MPV. In certain embodiments, the invention provides method for virologically diagnosing a MPV infection of a mammal comprising determining in a sample of said mammal the presence of a viral isolate or component thereof by contacting the sample with the antibody specific to a MPV. In certain embodiments, the invention provides method for virologically diagnosing a mammalian MPV infection of a subject, wherein said method comprises obtaining a sample from the subject and contacting the sample with an antibody specific to MPV wherein if the antibody binds to the sample the subject is infected with mammalian MPV. In certain embodiments, the invention provides an infectious recombinant virus, wherein the recombinant virus comprises the genome of a mammalian MPV and further comprises a non-native MPV sequence. In certain embodiments, the invention provides a recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV A1 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV A2 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides s recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV B1 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides a recombinant nucleic acid, wherein the recombinant nucleic acid comprises (i) a nucleic acid encoding a G polypeptide of an MPV B2 variant; and (ii) a nucleic acid encoding a non-native MPV polypeptide. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV of a first variant, wherein one or more of the open reading frames in the genome of the mammalian MPV of the first variant have been replaced by the analogous open reading frame from a mammalian MPV of a second variant. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV of a first variant, wherein one or more of open reading frames of a mammalian MPV of a second variant are inserted into the genome of the mammalian MPV of the first variant. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of a mammalian MPV, wherein one or more of the open reading frames in the genome of the mammalian MPV have been replaced by an ORF which encodes one or more of an avian MPV F protein; an avian MPV G protein (iii) an avian MPV SH protein; (iv) an avian MPV N protein (v) an avian MPV P protein; (vi) an avian MPV M2 protein; (vii) an avian MPV M2-1 protein; (viii) an avian MPV M2-2 protein; or (ix) an avian MPV L protein. In certain embodiments, the invention provides an infectious chimeric virus, wherein the chimeric virus comprises the genome of an avian MPV, wherein one or more of the open reading frames in the genome of the avian MPV have been replaced by an ORF which encodes one or more of (i) a mammalian MPV F protein (ii) a mammalian MPV G protein; (iii) a mammalian MPV SH protein; (iv) a mammalian MPV N protein; (v) a mammalian MPV P protein; (vi) a mammalian MPV M2 protein; (vii) a mammalian MPV M2-1 protein; (viii) a mammalian MPV M2-2 protein; or (ix) a mammalian MPV L protein. In certain embodiments, the invention provides an infectious chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using an interspecies or intraspecies polymerase. In one embodiment, the invention provides a chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using MPV polymerase. In one embodiment, the invention uses a polymerase from a virus different from the polymerase of the virus to be rescued, i.e., from a different clade, subtype, or other species. In another embodiment, the invention provides an infectious chimeric or recombinant virus, wherein the chimeric or recombinant virus is rescued using the polymerase from another virus, including, but not limited to the polymerase of PIV, APV or RSV. By way of example, and not meant to limited the possible combinations, RSV polymerase can be used to rescue MPV; MPV polymerase can be used to rescue RSV; or PIV polymerase can be used to rescue MPV. In yet another embodiment of the invention, the polymerase complex that is used to rescue the recombinant virus is encoded by polymerase proteins from different viruses. By way of example, and not meant to limit the possible combinations, in one embodiment, the polymerase complex proteins are encoded by the N gene of MPV, the L gene of PIV, the P gene of RSV and the M2-1 gene of MPV. In other embodiments, the M2-1 gene is not a component of the polymerase complex. In another embodiment of the invention, and meant by way of example, the polymerase complex proteins are encoded by the N gene of RSV, the L gene of RSV, the P gene of APV, and the M2-1 gene of RSV. In another embodiment of the invention, the M2-1 gene is not required to rescue the recombinant virus of the invention. One skilled in the art would be familiar with the types of combinations that can be used to encode the polymerase complex proteins so that the recombinant chimeric virus of the invention is rescued. In certain embodiments, the invention provides an immunogenic composition, wherein the immunogenic composition comprises the infectious recombinant virus of the invention. In certain embodiments, the invention provides a method for detecting a mammalian MPV in a sample, wherein the method comprises contacting the sample with a nucleic acid sequence of the invention. In certain embodiments, the invention provides a pharmaceutical composition, wherein the pharmaceutical composition comprises the infectious recombinant virus of the invention. In certain embodiments, the invention provides a method for detecting a mammalian MPV in a sample, wherein the method comprises amplifying or probing for MPV related nucleic acids, processed products, or derivatives thereof. In a more specific embodiment, the invention provides polymerase chain reaction based methods for the detection of MPV in a sample. In an even further embodiment, the invention provides oligonucleotide probes that can be used to specifically detect the presence of MPV related nucleic acids, processed products, or derivatives thereof. In yet another embodiment, the invention provides diagnostic methods for the detection of MPV antibodies in a host that is infected with the virus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising a mammalian metapneumovirus. In certain embodiments, the invention provides an method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising the recombinant mammalian metapneumovirus of the invention. In certain embodiments, the invention provides an method for treating or preventing a respiratory tract infection in a mammal, said method comprising administering a vaccine comprising avian metapneumovirus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a human, said method comprising administering a vaccine comprising avian metapneumovirus. In certain embodiments, the invention provides a method for treating or preventing a respiratory tract infection in a subject, said method comprising administering to the subject the composition of the invention. In certain embodiments, the invention provides a method for identifying a compound useful for the treatment of infections with mammalian MPV, wherein the method comprises: (a) infecting an animal with a mammalian MPV; (b) Administering to the animal a test compound; and (c) determining the effect of the test compound on the infection of the animal, wherein a test compound that reduces the extent of the infection or that ameliorates the symptoms associated with the infection is identified as a compound useful for the treatment of infections with mammalian MPV. In certain embodiments, the invention provides a method for identifying a compound useful for the treatment of infections with mammalian MPV, wherein the method comprises (a) infecting a cell culture with a mammalian MPV (b) incubating the cell culture with a test compound; and (c) determining the effect of the test compound on the infection of the cell culture, wherein a test compound that reduces the extent of the infection is identified as a compound useful for the treatment of infections with mammalian MPV. In certain embodiments, the invention provides a method for diagnosing a mammalian MPV infection of an animal, wherein the method comprises determining in a sample of said animal the presence of a viral isolate or component thereof by reacting said sample with a nucleic acid or an antibody reactive with a component of an avian pneumovirus, said nucleic acid or antibody being cross-reactive with a component of MPV. In certain embodiments, the invention provides a method for serologically diagnosing a mammalian MPV infection of an animal, wherein the method comprises contacting a sample from the animal with the protein of the invention. In certain embodiments, the invention provides a method for serologically diagnosing a mammalian MPV infection of an animal, wherein the method comprises contacting a sample from the animal with a protein of an APV. In certain embodiments, the invention provides an method for diagnosing an APV infection of a bird comprising contacting a sample from the animal with the protein of the invention. In certain embodiments, the invention provides an isolated negative-sense single stranded RNA virus MPV belonging to the sub-family Pneumovirinae of the family Paramyxoviridae and identifiable as phylogenetically corresponding to the genus Metapneumovirus, wherein the virus is phylogenetically more closely related to a virus isolate deposited as I-2614 with CNCM, Paris than to turkey rhinotracheitis virus, the etiological agent of avian rhinotracheitis. | 20040423 | 20100427 | 20050127 | 57234.0 | 1 | HILL, MYRON G | METAPNEUMOVIRUS STRAINS AND THEIR USE IN VACCINE FORMULATIONS AND AS VECTORS FOR EXPRESSION OF ANTIGENIC SEQUENCES AND METHODS FOR PROPAGATING VIRUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,831,801 | ACCEPTED | Closure device providing visual confirmation of occlusion | A closure device providing a visual confirmation of occlusion. The closure device includes a first and a second interlocking fastening strips which are arranged to be interlocked over a predetermined length, at least one of the fastening strips having a surface alteration providing visual confirmation of occlusion of the closure device. The surface alteration may be a slit which opens or closes upon occlusion of said closure device. In one embodiment, the surface alteration may extend into a coextruded portion. The color of the coextruded portion is exposed when the surface alteration is open and hidden when the surface alteration is substantially closed. In another embodiment, the surface alteration may extend into an edge glow material which produces an edge glow effect when the surface alteration is open. In a third embodiment, the surface alteration may extend through an opaque side wall to expose the color of the base. The surface alteration may be located on the mating side, the non-mating side or both sides of one or both of the bases. In addition, the surface alteration may be located on the closure element. The opening or closing of the surface alteration may be achieved by a deformation in the closure device upon occlusion of the closure device. The deformation may be an inward deformation or an outward deformation on the fastening strip. This deformation may also allow a user to tactually confirm that the closure device has been occluded, even after the closure device has been occluded. The deformation may be on one or both of the fastening strips. In addition, the fastening strip may include multiple deformations. | 1. A closure device comprising first and second interlocking fastening strips arranged to be interlocked over a predetermined length, said first fastening strip has a surface alteration, said surface alteration opens or closes upon occlusion of said closure device to provide visual confirmation of occlusion of said closure device. 2. The invention as in claim 1 wherein said surface alteration is made of a fluorescent material and becomes brighter in appearance or weaker in appearance upon occlusion of said closure device. 3. The invention as in claim 2 wherein said fluorescent material is an edge glow material and said visual confirmation is an edge glow effect. 4. The invention as in claim 3 wherein said weaker in appearance includes no appearance. 5. The invention as in claim 1 wherein said closure device includes a first material and a second material, said surface alteration extends through said first material and into said second material. 6. The invention as in claim 5 wherein said second material is hidden substantially when viewing said surface alteration and said surface alteration is closed. 7. The invention as in claim 6 wherein said closure device includes a portion of a container sidewall, said first material is a portion of a container sidewall and said second material is another portion of said closure device. 8. The invention as in claim 6 wherein said first material substantially surrounds said second material. 9. The invention as in claim 6 wherein said first material and said second material are coextruded. 10. The invention as in claim 6 wherein said first material is opaque. 11. The invention as in claim 10 wherein said second fastening strip is translucent. 12. The invention as in claim 1 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said mating side of said first fastening strip. 13. The invention as in claim 1 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said non-mating side of said first fastening strip. 14. The invention as in claim 1 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said mating side of said first fastening strip and a second surface alteration is located on said non-mating side. 15. The invention as in claim 1 wherein said first fastening strip includes a plurality of said surface alterations. 16. The invention as in claim 15 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said mating side. 17. The invention as in claim 15 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said non-mating side. 18. The invention as in claim 15 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said mating side and said non-mating side. 19. The invention as in claim 1 wherein said second fastening strip includes a second surface alteration. 20. The invention as in claim 1 wherein said first fastening strip has a deformation upon occlusion of said closure device, said deformation causing said surface alteration to change from a first visual state to a second visual state. 21. The invention as in claim 1 wherein said first fastening strip has a deformation upon occlusion of said closure device, said deformation opening or closing said surface alteration. 22. The invention as in claim 1 wherein said first fastening strip includes a base and a closure element, said surface alteration is located in said base. 23. The invention as in claim 1 wherein said first fastening strip includes a base and a closure element, said surface alteration is located in said closure element. 24. The invention as in claim 1 wherein said first fastening strip including a first closure element and further including a first wing extending from said first fastening strip; said second fastening strip including a second closure element for mating with said first closure element, said second fastening strip further including a second wing for engaging with said first wing; whereby said first wing engages with said second wing such that at least a portion of said first fastening strip deflects when said first and second fastening strips interlock to thereby create a deformation in said first fastening strip causing said surface alteration to change from a first visual state to a second visual state. 25. The invention as in claim 1 wherein said first fastening strip including a pair of first wings integrally attached to said first fastening strip and extending therefrom, said first wings spaced apart on said first fastening strip, said second fastening strip including a pair of second wings integrally attached to said second fastening strip and extending therefrom, said second wings spaced apart on said second fastening strip so as to engage with said first wings. 26. The invention as in claim 24, wherein said first closure element comprises a pair of spaced-apart webs integrally attached to said first fastening strip and extending therefrom, said webs terminating in male hooks, said male hooks comprising male hook portions facing away from one another, and wherein said second closure element comprises a pair of spaced-apart webs integrally attached to said second fastening strip and extending therefrom, said webs terminating in female hooks, said female hooks comprising female hook portions facing towards one another to engage said male hooks. 27. The invention as in claim 26, wherein one of said fastening strips includes a spacing member. 28. The invention as in claim 1, wherein said first closure element comprises a first web integrally attached to said first fastening strip and extending therefrom, said first web terminating in an arrowhead. 29. The invention as in claim 20 wherein said deformation is an inward deformation. 30. The invention as in claim 20 wherein said deformation is an outward deformation. 31. The invention as in claim 1 wherein said first fastening strip includes a first closure element, said first closure element comprises a first web integrally attached to said first fastening strip and extending therefrom, said first web terminating in an arrowhead. 32. The invention as in claim 31 wherein said surface alteration is located in said arrowhead. 33. The invention as in claim 32 wherein said surface alteration opens upon occlusion of said closure device. 34. The invention as in claim 33 wherein said surface alteration is made of a fluorescent material and becomes brighter in appearance or weaker in appearance upon occlusion of said closure device. 35. The invention as in claim 34 wherein said fluorescent material is an edge glow material and said visual confirmation is an edge glow effect. 36. The invention as in claim 35 wherein said weaker in appearance includes no appearance. 37. The invention as in claim 32 wherein said first fastening strip includes a first material and a second material, said surface alteration extends through said first material and into said second material. 38. The invention as in claim 37 wherein said second material is hidden substantially when viewing said surface alteration and said surface alteration is closed. 39. The invention as in claim 38 wherein said closure device includes a portion of a container sidewall, said first material is a portion of a container sidewall and second material is another portion of said closure device. 40. The invention as in claim 38 wherein said first material substantially surrounds said second material. 41. The invention as in claim 38 wherein said first material and said second material are coextruded. 42. The invention as in claim 38 wherein said first material is opaque. 43. The invention as in claim 42 wherein said second fastening strip is translucent. 44. A container comprising first and second sidewalls, said first and second sidewalls including mating first and second fastening strips respectively, said first and second fastening strips comprising a closure device arranged to be interlocked over a predetermined length, said first fastening strip has a surface alteration, said surface alteration providing visual confirmation of occlusion of said closure device. 45. The invention as in claim 44 wherein said surface alteration is made of a fluorescent material and becomes brighter in appearance or weaker in appearance upon occlusion of said closure device. 46. The invention as in claim 45 wherein said fluorescent material is an edge glow material and said visual confirmation is an edge glow effect. 47. The invention as in claim 46 wherein said weaker in appearance includes no appearance. 48. The invention as in claim 44 wherein said closure device includes a first material and a second material, said surface alteration extends through said first material and into said second material. 49. The invention as in claim 48 wherein said second material is hidden substantially when viewing said surface alteration and said surface alteration is closed. 50. The invention as in claim 49 wherein said closure device includes a portion of said first sidewall, said first material is a portion of said first sidewall and said second material is another portion of said closure device. 51. The invention as in claim 49 wherein said first material substantially surrounds said second material. 52. The invention as in claim 49 wherein said first material and said second material are coextruded. 53. The invention as in claim 49 wherein said first material is opaque. 54. The invention as in claim 53 wherein said second fastening strip is translucent. 55. The invention as in claim 44 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said mating side of said first fastening strip. 56. The invention as in claim 44 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said non-mating side of said first fastening strip. 57. The invention as in claim 44 wherein said first fastening strip has a mating side and a non-mating side, said surface alteration is located on said mating side of said first fastening strip and a second surface alteration is located on said non-mating side. 58. The invention as in claim 44 wherein said first fastening strip includes a plurality of said surface alterations. 59. The invention as in claim 58 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said mating side. 60. The invention as in claim 58 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said non-mating side. 61. The invention as in claim 58 wherein said first fastening strip has a mating side and a non-mating side, said surface alterations are located on said mating side and said non-mating side. 62. The invention as in claim 44 wherein said second fastening strip includes a second surface alteration. 63. The invention as in claim 44 wherein said first fastening strip has a deformation upon occlusion of said closure device, said deformation causing said surface alteration to change from a first visual state to a second visual state. 64. The invention as in claim 44 wherein said first fastening strip has a deformation upon occlusion of said closure device, said deformation opening or closing said surface alteration. 65. The invention as in claim 44 wherein said first fastening strip includes a base and a closure element, said surface alteration is located in said base. 66. The invention as in claim 44 wherein said first fastening strip includes a base and a closure element, said surface alteration is located in said closure element. 67. The invention as in claim 44 wherein said first fastening strip including a first closure element and further including a first wing extending from said first fastening strip; said second fastening strip including a second closure element for mating with said first closure element, said second fastening strip further including a second wing for engaging with said first wing;. whereby said first wing engages with said second wing such that at least a portion of said first fastening strip deflects when said first and second fastening strips interlock to thereby create a deformation in said first-fastening strip causing said surface alteration to change from a first visual state to a second visual state. 68. The invention as in claim 44 wherein said first fastening strip including a pair of first wings integrally attached to said first fastening strip and extending therefrom, said first wings spaced apart on said first fastening strip, said second fastening strip including a pair of second wings integrally attached to said second fastening strip and extending therefrom, said second wings spaced apart on said second fastening strip so as to engage with said first wings. 69. The invention as in claim 67, wherein said first closure element comprises a pair of spaced-apart webs integrally attached to said first fastening strip and extending therefrom, said webs terminating in male hooks, said male hooks comprising male hook portions facing away from one another, and wherein said second closure element comprises a pair of spaced-apart webs integrally attached to said second fastening strip and extending therefrom, said webs terminating in female hooks, said female hooks comprising female hook portions facing towards one another to engage said male hooks. 70. The invention as in claim 69, wherein one of said fastening strips includes a spacing member. 71. The invention as in claim 44, wherein said first closure element comprises a first web integrally attached to said first fastening strip and extending therefrom, said first web terminating in an arrowhead. 72. The invention as in claim 63 wherein said deformation is an inward deformation. 73. The invention as in claim 63 wherein said deformation is an outward deformation. 74. The invention as in claim 44 wherein said first fastening strip includes a first closure element, said first closure element comprises a first web integrally attached to said first fastening strip and extending therefrom, said first web terminating in an arrowhead. 75. The invention as in claim 74 wherein said surface alteration is located in said arrowhead. 76. The invention as in claim 75 wherein said surface alteration opens upon occlusion of said closure device. 77. The invention as in claim 76 wherein said surface alteration is made of a fluorescent material and becomes brighter in appearance or weaker in appearance upon occlusion of said closure device. 78. The invention as in claim 77 wherein said fluorescent material is an edge glow material and said visual confirmation is an edge glow effect. 79. The invention as in claim 78 wherein said weaker in appearance includes no appearance. 80. The invention as in claim 75 wherein said first fastening strip includes a first material and a second material, said surface alteration extends through said first material and into said second material. 81. The invention as in claim 80 wherein said second material is hidden substantially when viewing said surface alteration and said surface alteration is closed. 82. The invention as in claim 81 wherein said closure device includes a portion of said first sidewall, said first material is a portion of said first sidewall and second material is another portion of said closure device. 83. The invention as in claim 81 wherein said first material substantially surrounds said second material. 84. The invention as in claim 81 wherein said first material and said second material are coextruded. 85. The invention as in claim 81 wherein said first material is opaque. 86. The invention as in claim 85 wherein said second fastening strip is translucent. | FIELD OF THE INVENTION The present invention pertains to an interlocking closure device, and, more particularly, to a closure device providing visual confirmation of occlusion. In addition, the closure device may also provide tactile confirmation of occlusion. The closure device of the present invention may be employed in traditional fastener areas, and is particularly suited for use as a fastener for storage containers, such as plastic bags. BACKGROUND OF THE INVENTION The use of fastening devices for the closure of containers, including plastic bag bodies, is generally known. Furthermore, the manufacture of fastening devices made of plastic materials is generally known to those skilled in the art relating to closure devices, as demonstrated by the numerous patents in this area. A particularly well-known use for fastening devices is in connection with flexible containers, such as bag bodies. The closure device and the associated container may be formed from thermoplastic materials, and the closure device and sidewalls of the container can be integrally formed by extrusion as a single piece. Alternatively, the closure device and sidewalls may be formed as separate pieces and then connected by heat sealing or any other suitable connecting process. The closure devices when incorporated as fasteners on bag bodies have been particularly useful in providing a closure means for retaining the contents within the bag body. Conventional closure devices utilize mating male and female closure elements which are occluded. When conventional closure devices are employed, it often is difficult to determine when the male and female closure elements are occluded. This problem is particularly acute when the closure devices are relatively narrow. Accordingly, when conventional closure devices are employed, there exists a reasonable likelihood that the closure device is at least partially open. The occlusion problem arises from the inability of a user to perceive when the male and female closure are occluded to form a seal between the contents of the bag and the environment external to the bag. A number of solutions to this problem have been attempted. For example, U.S. Pat. Nos. 4,186,786, 4,285,105, and 4,829,641, as well as in Japanese patent application No. 51-27719, disclose fasteners that provide a visual indication that the male and female closure elements are properly occluded. Specifically, a color change means for verifying the occlusion of the male and female members of the closure is provided wherein male and female members having different colors are employed, and, upon occlusion, provide yet a different color. For example, the female member of the closure may be opaque yellow and the male member of the closure may be translucent blue. Upon occlusion of the male member and female member a composite color with a green hue results. This use of a color change greatly improves the ability of the user of the interlocking closure device to determine when the male and female members are occluded. The change in color that is viewed when dissimilarly colored male and female members are occluded is demonstrated in a commercially available product sold under the trademark GLAD-LOCK (Glad-Lock is the registered trademark of The Glad Products Company, Oakland, Calif.). This color change effect may be enhanced by the incorporation of a color change enhancement member in the closure device, as disclosed in U.S. Pat. No. 4,829,641. However, if the first fastening strip is opaque and the second fastening strip is translucent, the color change can only be observed from the translucent side of the closure device. Therefore, one of the objects of this invention is to provide visual confirmation of occlusion from both sides of the closure device. In addition, another object of this invention is to provide a visual confirmation of occlusion wherein one of the fastening strips can be transparent. Furthermore, color-blind users may not be able to perceive the color change effect. Thus, a further object of the invention is to provide a visual confirmation of occlusion which does not rely upon color change. It is another object of the invention to provide a visual confirmation which appears or disappears upon occlusion of the closure device. The prior art includes references which have slits or notches to the surface. Such references include U.S. Pat. Nos. 5,070,584, 5,307,552, 5,363,540 and 5,403,094, and French Patent 2,022,865. However, these references do not use the slits or notches to show visual confirmation of occlusion or unocclusion. Another object of this invention is to combine visual confirmation of occlusion with a tactile and/or audible indication of occlusion. For example, the color-change effect is imperceptible in the dark, thus mooting the color-change advantage of the closure devices when they are used under such conditions. In addition, sight-impaired or color-blind people may not be able to perceive the color-change effect. Accordingly, it would be desirable to provide a closure device that affords other indications of occlusion. The prior art has attempted to furnish a fastener that provides a tactile or audible indication of occlusion. For example, U.S. Pat. Nos. 4,736,496, 5,138,750, 5,140,727, 5,403,094, and 5,405,478, as well as EP 510,797, disclose closure devices that allegedly provide a tactually or audibly perceptive indication of proper interlocking of the closure elements. It is said that, upon occlusion of the disclosed closure devices, a user is able to feel or hear that full closure is accomplished. For example, U.S. Pat. No. 4,736,946 discloses the use of additional ribs on either side of the closure elements. These ribs are said to give an improved “feel” to the closure, thus aiding a user in aligning the closure elements. The devices shown in these references are able only to provide a dynamic tactile indication of occlusion, that is, the user is able to tactually perceive that the closure device is functioning properly only at the time the user is manually closing the device. Such devices do not provide a static tactile indication of occlusion, that is, they do not “feel” closed after occlusion has been effected. Accordingly, if a plastic bag containing such a closure device is sealed by one person, a second person will not readily be able to tactually determine that the bag is sealed. The ability to make such a determination is desirable. It is a general object of the present invention to provide visual confirmation of occlusion for a closure device. It is a further general object of the present invention to provide a container that is closeable and sealable by means of such a closure device. BRIEF SUMMARY OF THE INVENTION The present invention satisfies these general objects by providing a closure device in which a user is able to visually determine that the closure device has been occluded. In addition, the user may be able to tactually determine that the closure device has been occluded. The closure device comprises first and second interlocking fastening strips arranged to be interlocked over a predetermined length, at least one of the fastening strips having a visual indication upon occlusion of the closure device. Thus, a user will be able to visually confirm that the closure device has been properly occluded, not only while the user is in the process of occluding the closure device, but also after the closure device has been occluded. In addition, one of the fastening strips may have a deformation upon occlusion. This deformation may provide tactile confirmation of occlusion of the closure device. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a container according to the present invention in the form of a plastic bag. FIG. 2 is an enlarged partial cross-sectional view taken along line 2-2 in FIG. 1 illustrating the female fastening strip of a closure device of the present invention. FIG. 3 is an enlarged partial cross-sectional view taken along line 2-2 in FIG. 1 illustrating the male fastening strip of a closure device of the present invention. FIG. 3A is a cross-sectional view of another embodiment of the fastening strips in FIGS. 2 and 3 in the unoccluded position. FIG. 3B is a cross-sectional view of the fastening strips in FIG. 3A in the occluded position. FIG. 3C is a cross-sectional view of another embodiment of the fastening strips in FIGS. 2 and 3 in the unoccluded position. FIG. 3D is a cross-sectional view of the fastening strips in FIG. 3C in the occluded position. FIG. 3E is a cross-sectional view of another embodiment of the fastening strips in FIGS. 2 and 3 in the unoccluded position. FIG. 3F is a cross-sectional view of the fastening strips in FIG. 3E in the occluded position. FIGS. 4A-4C are cross-sectional views of the male and female fastening strips illustrated in FIGS. 2 and 3 shown in various positions. FIG. 4D is a cross-sectional view of the fastening strip of FIGS. 2-3 in the occluded position, and illustrating the visual changing portion and the inward deformation of the male fastening strip upon occlusion. FIG. 5 is a perspective view of the female fastening strip illustrated in FIG. 2, including a female closure element and a pair of wings. FIG. 6 is a perspective view of the male fastening strip illustrated in FIG. 3, including a male closure element and a pair of wings. FIG. 7 is an enlarged perspective view of a closure device according to the present invention when occluded, illustrating the visual changing portion and the inward deformation formed upon occlusion of the closure device. FIG. 7A is a top view of the closure device when occluded showing the visually changing portion. FIG. 8 is a cross-sectional view of the male fastening strip of another embodiment of the closure device according to the present invention, including a male closure element and a pair of wings on each side of the male closure element. FIG. 9 is a cross-sectional view of the female fastening strip according to the present invention, complementary to the male fastening strip shown in FIG. 8, including visual changing portions, a female closure element and a pair of wings on each side of the female closure element. FIG. 10 is a cross-sectional view of the closure device formed by the male and female fastening strips illustrated in FIGS. 8 and 9 when occluded, illustrating in cross-section the visual changing portions and the deformation formed by flexure of the female closure element upon occlusion of the closure device. FIG. 10A is a cross-sectional view of another embodiment of the fastening strips in FIGS. 8 and 9 in the unoccluded position. FIG. 10B is a cross-sectional view of the closure device in FIG. 10A in the occluded position. FIG. 11 is a perspective view of the male fastening strip illustrated in FIG. 8, having a male closure element and a pair of wings on each side of the male closure element. FIG. 12 is a perspective view of the female fastening strip illustrated in FIG. 9, having visual changing portions, a female closure element and a pair of wings on each side of the female closure element. FIG. 13 is a cross-sectional view of a closure device according to the present invention wherein the female fastening strip includes visual changing portions, a female closure element, a pair of wings on each side of the female closure element, a plurality of protrusions between each wing and the female closure element, and a spacer member. FIG. 14 is a cross-sectional view of the closure device illustrated in FIG. 13 as it is in the process of becoming occluded. FIG. 15 is a cross-sectional view of the closure device illustrated in FIG. 13 when fully occluded. FIG. 15A is a cross-sectional view of another embodiment of the closure device in FIG. 13 in the unoccluded position. FIG. 15B is a cross-sectional view of the closure device in FIG. 15A in the occluded position. FIG. 16 is a cross-sectional view of another embodiment which includes visual changing portions and a spacer member. FIG. 17 is a cross-sectional view of another embodiment which includes visual changing portions and a plurality of protrusions. FIG. 18 illustrates a closure device according to the present invention in which the wings of the male fastening strip are Y-shaped. FIG. 19 is a cross-sectional view of another embodiment of a closure device of the present invention in which the notches are located on the non-mating side of the fastening strip. FIG. 19A is a cross-sectional view of another embodiment of a closure device of the present invention with coextruded portions and an inward deformation. FIG. 19B is a cross-sectional view of another embodiment of the closure device in FIG. 19A. FIG. 20 is a cross sectional view of another embodiment of the present invention which includes a notch between the webs. FIG. 21 is a cross-sectional view of another embodiment of the present invention which includes a notch between the webs. FIG. 22A is a cross-sectional view of another embodiment with a deformation in both the fastening strips. FIG. 22B is a cross-sectional view of another embodiment with coextruded portions and with a deformation in both fastening strips. FIG. 23A is a cross-sectional view of another embodiment in the unoccluded position illustrating visual changing portions on the non-mating side of the fastening strip. FIG. 23B is a cross-sectional view of the embodiment illustrated in FIG. 23A in the occluded position. FIG. 23C is a cross-sectional view of another embodiment of the closure device in FIG. 23A in the unoccluded position. FIG. 23D is a cross-sectional view of the closure device in FIG. 23C in the occluded position. FIG. 24 is a cross sectional view of another embodiment of the present invention which includes visually changing portions and a notch between the webs on the non-mating side of the fastening strip. FIG. 25 is a cross-sectional view of another embodiment which includes visually changing portions and notches on the non-mating sides of the fastening strips and a deformation on both fastening strips. FIG. 25A is a cross-sectional view of another embodiment of the closure device in FIG. 25 in the occluded position. FIG. 26 is a cross-sectional view of another embodiment which includes visually changing portions and another type of closure element. FIG. 27 is a cross-sectional view of another embodiment which includes the closure element in FIG. 26. FIG. 28A is a cross-sectional view of another embodiment with visually changing portions and a deformation in both fastening strips. FIG. 28B is a cross-sectional view of another embodiment with coextruded portions, with visual changing portions and with a deformation in both fastening strips. FIG. 28C is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 28D is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 29 is a cross-sectional view of another embodiment with visually changing portions and a deformation in one of the fastening strips. FIG. 30 is a cross-sectional view of another embodiment with visually changing portions and a deformation in one of the fastening strips. FIG. 31 is a cross-sectional view of another embodiment with visually changing portions and a deformation in both of the fastening strips. FIG. 32 is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in one of the fastening strips. FIG. 33 is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in one of the fastening strips. FIG. 34A is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in both of the fastening strips. FIG. 34B is a cross-sectional view of another embodiment with coextruded portions, with visually changing portions and an outward deformation in both of the fastening strips. FIG. 34C is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 34D is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 35 is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in one of the fastening strips. FIG. 36 is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in one of the fastening strips. FIG. 37 is a cross-sectional view of another embodiment with visually changing portions and an outward deformation in both of the fastening strips. FIG. 38A is a cross-sectional view of another embodiment of the closure device in the unoccluded position. FIG. 38B is a cross-sectional view of the closure device in FIG. 38A in the occluded position with an inward deformation on one of the fastening strips. FIG. 39A is a cross-sectional view of another embodiment of the closure device in the unoccluded position. FIG. 39B is a cross-sectional view of the closure device in FIG. 39A in the occluded position with an inward deformation on one of the fastening strips. FIG. 40A is a cross-sectional view of another embodiment of the closure device in the unoccluded position with visually changing portions. FIG. 40B is a cross-sectional view of the closure device in FIG. 40A in the occluded position with visually changing portions and an outward deformation on one of the fastening strips. FIG. 41A is a cross-sectional view of another embodiment of the closure device in the unoccluded position with visually changing portions. FIG. 41B is a cross-sectional view of the closure device in FIG. 41A in the occluded position with visually changing portions and an outward deformation on one of the fastening strips. FIG. 42 is a cross-sectional view of another embodiment of the closure device with visually changing portions and multiple deformations in one of the fastening strips. FIG. 42A is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 43 is a cross-sectional view of another embodiment of the closure device with visual changing portions and multiple deformations in one of the fastening strips. FIG. 43A is a cross-sectional view of another embodiment of the closure device in the occluded position. FIG. 44A is a cross-sectional view of another embodiment of the closure device in the unoccluded position with visually changing portions on one of the closure elements. FIG. 44B is a cross-sectional view of the closure device in FIG. 44A in the occluded position illustrating the visually changing portions. FIG. 45A is a cross-sectional view of another embodiment of the closure device in the unoccluded position with visually changing portions on one of the closure elements. FIG. 45B is a cross-sectional view of the closure device in FIG. 45A in the occluded position illustrating the visually changing portions. FIG. 46 illustrates a female fastening strip of a closure device according to the present invention. FIG. 47 illustrates a male fastening strip of a closure device according to the present invention. FIG. 48 is a perspective view of another embodiment of a container according to the present invention in the form of a plastic bag. FIG. 49A is a top view of the container shown in FIG. 48 in the unoccluded position. FIG. 49B is a top view of the container shown in FIG. 48 in the occluded position. FIG. 50A is a cross-sectional view taken along line 50-50 in FIG. 49 illustrating a first embodiment in the unoccluded position. FIG. 50B is a cross-sectional view of the embodiment in FIG. 50A in the occluded position. FIG. 50C is a cross-sectional view of a second embodiment in the unoccluded position. FIG. 50D is a cross-sectional view of the embodiment in FIG. 50C in the occluded position. DESCRIPTION OF THE EMBODIMENTS The present invention provides interlocking closure devices in which a visual indication occurs upon proper occlusion. In addition, the device may provide a deformation which is formed upon proper occlusion. A user thus is able to visually and, possibly tactually, perceive whether the closure device is properly occluded. In one embodiment, the closure device comprises interlocking male and female fastening strips arranged to be interlocked over a predetermined length. As used herein and as generally understood in the art, the terms “male” and “female” closure elements refer to closure elements wherein the element that interlocks into the other closure element and having outwardly projecting hooks is referred to as the “male closure element” and the outer element is referred to as the “female closure element” and has inwardly projecting hooks. Further, as used herein, the term “edge glow effect” refers to the appearance at a surface alteration which is different from the surrounding material and that is visually evident when the first and second closure fastening strips are in a non-occluded position or an occluded position. In accordance with this embodiment of the present invention, the male fastening strip flexes when the male and female fastening strips interlock. This flexure creates a deformation in the male fastening strip and the deformation is locked into place by the interlocking male and female closure elements. The deformation causes a surface alteration to open and/or close which provides a visual confirmation of occlusion. In addition, the deformation may provide tactile confirmation of occlusion of the closure device. FIG. 1 illustrates a container according to the present invention in the form of a plastic bag 20 having a sealable closure device 21. The bag 20 includes side walls 22 joined at seams 25 to form a compartment sealable by means of the closure device 21. The side walls 22 extend above the closure device 21 to form mouth portions 27. Mouth portions 27 enable a user to grip the plastic bag 20 in a fashion to more conveniently be able to deocclude or open the closure device 21 to thereby open the bag 20. FIGS. 2 and 3 together illustrate a closure device according to one embodiment of the present invention. The closure device comprises male and female fastening strips 30, 31. As shown in FIG. 2, the female fastening strip 31 includes a female closure element 34 and a pair of female wings 35 spaced apart on the female fastening strip 31 on each side of the female closure element 34. As illustrated in FIG. 3, the male fastening strip 30 comprises a male closure element 36 for engaging the female closure element 34, and further comprises a pair of male wings 37 spaced-apart on the male fastening strip on each side of the male closure element 36. The female closure element 34 comprises a base portion 38 having a pair of spaced-apart parallely disposed webs 40, 41 extending from the base portion 38. The webs 40, 41 include female hook portions 42, 44 extending from the webs 40, 41 respectively, and facing towards each other. The female hook portions 42, 44 include guide surfaces 46,47 which serve to guide the hook portions 42, 44 for occluding with the male hook portions of a mating closure element. The male closure element 36 comprises a base portion 47 including a pair of spaced-apart, parallely disposed webs 50, 51 extending from the base portion 47. The webs 50, 51 include male hook portions 52, 54 extending from the webs 50, 51 respectively and facing away from each other. The male hook portions 52, 54 include guide surfaces 45, 55, which generally serve to guide the hook portions 52, 54 for occlusion with the female hook portions 42, 44 of the mating female closure element. The guide surface 45 may also have a rounded crown surface 45. In addition, the hooks may be designed so that the hooks 44, 54 adjacent the interior of the container provide a greater resistance to opening of the closure device. Notches 56 may be provided in the base portion 47 of the male closure element to facilitate deflection of the base. The base 47 is made from a material which has a first color. In this embodiment, the first color would be opaque. The base 47 includes a coextruded portion 65 which has a second color. The second color may be surrounded by the first color in the base. For example, the first color may be yellow and the second color may be blue. A second example, the first color may be white and the second color may be red; A third example, the first color may be white and the second color may be black. A fourth example, the first color may be red and the second color may be green. The base 47 includes a surface alteration 63 which extends into the coextruded portion 65. The surface alteration 63 may also facilitate deflection of the base. While this embodiment has one surface alteration, the base 47 may include two, three, four or more surface alterations. In addition the coextruded portion may extend along each of the surface alterations or the base may include a separate coextruded portion for each surface alteration. Furthermore, the separate coextruded portions may have a different color than the second color of the first coextruded portion. In addition, the surface alteration may be on the mating side of the fastening strip or the non-mating side of the fastening strip or both sides of the fastening strip. In addition, the coextruded portion may be continuous along the length of the fastening strip or the coextruded portion may be discontinuous along the length to provide an intermittent visual effect. Furthermore, the surface alteration may be continuous along the length of the fastening strip or the surface alteration may be discontinuous along the length to provide an intermittent visual effect. Additionally, the depth of the surface alterations may vary depending upon the location of the surface alteration and the depth of any other surface alterations. Also, the surface alteration may be substantially closed to hide the color when the fastening strips are unoccluded and open to expose the color when the fastening strips are occluded. Conversely, the surface alteration may be open to expose the color when the fastening strips are unoccluded and substantially closed to hide the color when the fastening strips are occluded. The surface alteration can be substantially perpendicular to the surface, such as, the surface alteration 63 in FIG. 3 or the surface alteration can be at an angle to the surface. In addition, the surface alteration can be linear, such as surface alteration 63 in FIG. 3, or L-shaped, or Y-shaped, or curved, such as, a serpentine shape or any combination of shapes, curves or linear portions. The surface alteration and coextruded portion may be used with any embodiment described herein. In addition, the location of the surface alteration and coextruded portion is not limited to the base, and the surface alteration and coextruded portion may be positioned in other locations on the closure device. More specifically, the surface alteration and coextruded portion may be located in any location which flexes during occlusion and provides a viewing point. For example, referring to FIGS. 3A and 3B, the surface alteration and coextruded portion may be located in the hooks 42A, 44C, 52B, 54D or in the wings 35E, 35G, 37F, 37H. Specifically, a surface alteration 63A and coextruded portion 65A may be located in the hook 42A. The surface alteration 63A is open and exposing the coextruded portion 65A when the closure device is unoccluded. When the closure device is occluded, the hook 42A flexes and is retained in the flexed or deflected position. Thus, the surface alteration 63A is closed and hiding the coextruded portion 65A when the closure device is occluded. A similar example is surface alteration 63B and coextruded portion 65B in hook 52B. Conversely, a surface alteration and a coextruded portion may be located in a hook so that the surface alteration is closed when the closure device is unoccluded and the surface alteration is open when the closure device is occluded. Such examples are surface alteration 63C and coextruded portion 65C in hook 44C or surface alteration 63D and coextruded portion 65D in hook 54D. Similarly, a surface alteration 63E, 63F, 63G, 63H and coextruded portion 65E, 65F, 65G, 65H may be located in the wings 35E, 35F, 37G, 37H. Specifically, a surface alteration 63E and coextruded portion 65E may be located in the wing 35E. The surface alteration 63E is open and exposing the coextruded portion 65E when the closure device is unoccluded. When the closure device is occluded, the wing 35E flexes and is retained in the flexed or deflected position. Thus, the surface alteration 63E is closed and hiding the coextruded portion 65E when the closure device is occluded. A similar example is surface alteration 63F and coextruded portion 65F in wing 37F. Conversely, a surface alteration and a coextruded portion may be located in a wing so that the surface alteration is closed when the closure device is unoccluded and the surface alteration is open when the closure device is occluded. Such examples are surface alteration 63G and coextruded portion 65G in wing 35G or surface alteration 63H and coextruded portion 65H in wing 37H. The surface alteration and coextruded portion may be positioned in any, location on the closure device for any embodiment described herein. For example, the surface alteration and coextruded portion may be positioned in the spacing member 259 shown in FIGS. 13-15. In other embodiments, the base 471 is made from an edge glow material, such as, FIGS. 3C and 3D. The material provides an edge glow effect when the surface alteration 631 is open. The surface alteration 631 may be substantially closed to hide the edge glow effect when the fastening strips are unoccluded as in FIG. 3C and open to expose the edge glow effect when the fastening strips are occluded as in FIG. 3D. Conversely, in another embodiment, the surface alteration may be open to expose the edge glow effect when the fastening strips are unoccluded and substantially closed to hide the edge glow effect when the fastening strips are occluded. In addition, the surface alteration may be continuous along the length of the closure element or the surface alteration may be discontinuous along the length to provide an intermittent visual effect. Furthermore, in another embodiment, the coextruded portion may include a fluorescent material. The surface alteration and fluorescent material may be used with any embodiment described herein. In yet other embodiments, the surface alteration and the edge glow material may be positioned in other locations on the closure device. More specifically, the surface alteration and edge glow material may be located in any location which flexes during occlusion and provides a viewing point. For example, referring to FIGS. 3E and 3F, the surface alteration and edge glow material may be located in the hooks 42K, 44M, 52L, 54N or in the wings 35P, 35R, 37Q, 37S. Specifically, a surface alteration 63K may be located in the hook 42K. The surface alteration 63K is open and exposing the edge glow effect when the closure device is unoccluded. When the closure device is occluded, the hook 42K flexes and is retained in the flexed or deflected position. Thus, the surface alteration 63K is closed and hiding the edge glow effect when the closure device is occluded. A similar example is surface alteration 63L in hook 52L. Conversely, a surface alteration and an edge glow material may be located in a hook so that the surface alteration is closed when the closure device is unoccluded and the surface alteration is open when the closure device is occluded. Such examples are surface alteration 63M in hook 44M or surface alteration 63N in hook 54N. Similarly, a surface alteration 63P, 63R, 63Q, 63S may be located in the wings 35P, 35R, 37Q, 37S. Specifically, a surface alteration 63P may be located in the wing 35P. The surface alteration 63P is open and exposing the edge glow effect when the closure device is unoccluded. When the closure device is occluded, the wing 35P flexes and is retained in the flexed or deflected position. Thus, the surface alteration 63P is closed and hiding the edge glow effect when the closure device is occluded. A similar example is surface alteration 63Q in wing 37Q. Conversely, a surface alteration and an edge glow material may be located in a wing so that the surface alteration is closed when the closure device is unoccluded and the surface alteration is open when the closure device is occluded. Such examples are surface alteration 63R in wing 35R or surface alteration 63S in wing 37S. The surface alteration and the edge glow material may be positioned in any location on the closure device for any embodiment described herein. For example, the surface alteration and edge glow material may be positioned in the spacing member 259 shown in FIGS. 13-15. Furthermore, the entire fastening strip could be made of edge glow material or only the portions with surface alterations would be edge glow material coextruded with another material. For example, only the base would be edge glow material, or only the hook would be edge glow material or only the wing would be edge glow material or only a selected area in the base, hook or wing would be edge glow material, such as, the coextruded portions in FIGS. 3A and 3B. The fastening strips further include wings as shown in FIGS. 2 and 3. The male wings 37 shown in FIG. 3 are flexible and extend further from the base of the fastening strip than does the male closure element 30. Each wing terminates in an end portion 43 which projects outwardly from the wing 37. Although two wings are shown, a greater or lesser number of wings may be used, such as, one, three, four or more wings. A pair of female wings 35 is included with the female fastening strip in order to engage the male wings 37. The female wings 35 extend from the female fastening strip 31 and terminate in end portions 39 which project outwardly from the wings 35. The number of female wings may be equal to, greater than, or less than the number of male wings. FIGS. 4A-4D illustrate occlusion of the closure device. In accordance with the invention, compression forces are applied to the opposed fastening strips 30, 31 in the direction denoted by the arrows 60, 61 shown in FIGS. 4A-4C. These forces are typically applied as the user depresses or pinches his or her fingers along a desired length of the fastening strips 30, 31. As the user begins to occlude the fastening strips, the male wings 37 engage the base portions 62A, 62B as shown in FIG. 4B. In this position, the fastening strips are separated by distance 64A. As the user continues to apply the forces 60, 61, the male wings 37 slide towards the female wings 35 until the female wings 35 contact the male wings 37 as shown in FIG. 4C. In this position the fastening strips are separated by distance 64B which is less than distance 64 due to the movement of the wings 37. Also, the female hooks 42, 44 have contacted the male hooks 52, 54 as shown in FIG. 4C. In order to hold the fastening strips in an occluded position, the female hooks 42, 44 must engage the male hooks 52, 54. As the user continues to apply the forces 60, 61, the female webs 40, 41 deflect outwardly and the male webs 50, 51 deflect inwardly in order to allow the female hooks 42, 44 and the male hooks 52, 54 to pass each other. In addition, the hooks may also deflect during this process. As the user continues to apply the forces 60, 61, the female hooks 42, 44 engage the male hooks 52, 54 as shown in FIG. 4D. During this process, the base of the male fastening strip deflects inward and forms an inward deformation 57. The deformation 57 is retained because the male wings 37 are more rigid than the base and because the male wings 37 are prevented from further outward movement by the wings 35. In addition, the force exerted by the deflected base is less than the force required to disengage the hooks. In order to facilitate the deflection of the base, the fastening strip may include notches 56. As the base deflects inward, the surface alteration 63 opens and exposes the coextruded portion 65 as shown in FIG. 4D. The mating fastening strip 31 is translucent or transparent. Thus, the second color of the coextruded portion is visible to the user through the mating fastening strip 31 as shown in FIG. 7A. Prior to occlusion, the second color of the coextruded portion is not visible because the first color of the base surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 63 will be open and the second color will be visible. The fastening strips are separated a distance 66 near the male wings 37 and a distance 67 near the center of the fastening strips. The difference between distance 66 and distance 67 is the depth 68 of the deformation 57. With respect to the edge glow embodiment shown in FIGS. 3C and 3D, the occlusion occurs in a similar fashion. As the base deflects inward, the surface alteration 631 opens and exposes the edge glow material as shown in FIG. 3D. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip as shown in FIG. 7A. Prior to occlusion, the edge glow effect is not visible because the surface alteration 631 is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 631 will be open and the edge glow effect will be visible. The wings employed in this embodiment of the present invention have the additional advantage of serving as guide members. Guide members sometimes are incorporated into conventional closure devices to provide a further improved “feel” and further accuracy to such devices. Such guide members have been provided in the shape of triangles, rectangles or other suitable shapes and are generally provided by extrusion as integrally connected to one or both of the closure elements. In this embodiment of the present invention, the wings provide a funneling-type action as the fastening strips are brought together and the female closure element is brought into contact with the male closure element. FIG. 7 illustrates the inward deformation 57 formed by the flexure of the male fastening strip. This deformation 57 provides a tactile confirmation of occlusion of the closure device. Accordingly, a user need only run his or her finger along the male fastening strip to confirm that the container is properly sealed. In addition to the visual and tactile confirmations of occlusion noted above, other visual indications of occlusion may be provided. For example, the male and female fastening strips may include pigments so as to provide a visual indication of occlusion of the closure device. The conventional use of such pigments is known in the art and has been discussed above. For example, the male element may be translucent and the female element may be opaque. When the male and female element portions are occluded, a different color is provided for establishing visually the occlusion. The closure device may also include a color change closure as disclosed in U.S. Pat. No. 4,829,641. U.S. Pat. No. 4,829,641 is incorporated herein by reference. Thus, the closure device could have two visual indications of occlusion. The first visual indication would be the color from the opened surface alteration as noted above. The second visual indication would be the different color provided when the opaque female element is occluded with the translucent male element as noted above. FIGS. 8 and 9 illustrate male and female fastening strips according to another embodiment of the present invention. As shown in FIG. 8, the male fastening strip 130 includes a pair of female wings 153, whereas, as shown in FIG. 9, the female fastening strip 131 includes a pair of male wings 159. The function of the closure device formed by the fastening strips shown in FIGS. 8 and 9 is analogous to that of the closure device illustrated in FIGS. 2-6, except that the female fastening strip 131 flexes to form an inward deformation 157 when the closure device is occluded rather than the male fastening strip 130. In addition, the female fastening strip 131 has three surface alterations 163 which open to expose the coextruded portion 165. FIG. 10 illustrates the closure device formed by the fastening strip shown in FIGS. 8 and 9 in an occluded position. FIGS. 11 and 12 illustrate in further detail the fastening strips shown in FIGS. 8 and 9. Specifically, female fastening strip 131 includes a female closure element 134 similar to female closure element 34 in FIG. 2. The female fastening strip 131 also includes a pair of male wings 159 similar to male wings 37 in FIG. 3 described above. The male fastening strip 130 includes a male closure element 136 similar to male closure element 36 in FIG. 3. The male fastening strip 130 also includes a pair of female wings 153 similar to female wings 35 in FIG. 2. The female closure element 134 includes a base portion 138 similar to base portion 38 in FIG. 2 and includes webs 140, 141 similar to webs 40, 41 in FIG. 2. The webs 140, 141 include female hook portions 142, 144 similar to female hook portions 42, 44 in FIG. 2. The male closure element 136 includes a base portion 147 similar to base portion 47 in FIG. 3 and includes webs 150, 151 similar to webs 50, 51 in FIG. 3. The webs 150, 151 include male hook portions 152, 154 similar to male hook portions 52, 54 in FIG. 3. Finally, the base portion 138 may be provided with notches 156 which are similar to notches 56 in FIG. 3. The base portion 138 is provided with surface alterations 163 and coextruded portion 165 which are similar to surface alterations 63 and coextruded portion 65. However, the base could include any other surface alterations embodiment described herein. For example, as shown in FIGS. 10A and 10B, the base portion 138A may include an edge glow material and the surface alterations 163A would extend through the edge glow material. In this embodiment, the center surface alteration 163A extends further into the base than the outer surface alterations 163A. Thus, the center surface alteration 163A has a greater depth than the outside surface alterations 163A. As the base deflects inward, the surface alterations 163 open and expose the coextruded portion 165 as shown in FIG. 10. The mating fastening strip 130 is translucent or transparent. Thus, the second color of the coextruded portion is visible to the user through the mating fastening strip 130. Prior to occlusion, the second color of the coextruded portion 165 is not visible because the first color of the base surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 163 will be open and the second color will be visible. With respect to the edge glow embodiment shown in FIGS. 10A and 10B, the occlusion occurs in a similar fashion. As the base deflects inward, the surface alterations 163A open and expose the edge glow effect as shown in FIG. 10B. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip. Prior to occlusion, the edge glow effect is not visible because the surface alteration 163A is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 163A will be open and the edge glow effect will be visible. FIG. 13 illustrates yet another embodiment of the closure device of the present invention. In this embodiment, the closure device includes a plurality of protrusions which engage wings to provide a dynamically tactile indication of proper occlusion, in addition to the visual indication. Many of the components in FIGS. 13-15 are similar to FIGS. 2-6. Referring to FIG. 13, the closure device comprises male and female fastening strips 230, 231 similar to fastening strips 30, 31 in FIGS. 2 and 3. The female fastening strip 231 includes a female closure element 234 and a pair of wings 235 similar to female closure element 31 and wings 35 in FIG. 2. The male fastening strip 230 includes a male closure element 236 and a pair of wings 237 similar to male closure element 36 and wings 37 in FIG. 3. The female closure element 234 includes a base portion 238 and webs 240, 241 similar to base portion 38 and webs 40, 41 in FIG. 2. The webs 240, 241 include hook portions 242, 244 similar to hook portions 42, 44 in FIG. 2. The male closure element 236 includes a base portion 247 and webs 250, 251 similar to base portion 47 and webs 50, 51 in FIG. 3. The webs 250, 251 include hook portions 252, 254 similar to hook portions 52, 54 in FIG. 3. The base portion 247 is provided with surface alterations 263 and coextruded portions 265 which are similar to surface alteration 63 and coextruded portion 65. However, the base could include any other surface alteration embodiment described herein. For example, as shown in FIGS. 15A and 15B, the base 247A may include a fluorescent material and the surface alteration 263A would extend through the fluorescent material. As another example, one of the coextruded portions 265 may have a different color than the other coextruded portion 265. Furthermore, the base portion 247 may be provided with notches 256 which are similar to the notches 56 in FIG. 3. As the base deflects inward, the surface alterations 263 open and expose the coextruded portions 265 as shown in FIG. 15. The mating fastening strip 231 is translucent or transparent. Thus, the second color of the coextruded portion 265 is visible to the user through the mating fastening strip 231. Prior to occlusion, the second color of the coextruded portion 265 is not visible because the first color of the base 247 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 263 will be open and the second color will be visible. With respect to the edge glow embodiment shown in FIGS. 15A and 15B, the occlusion occurs in a similar fashion. As the base deflects inward, the surface alterations 263A open and expose the edge glow effect as shown in FIG. 15B. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip. Prior to occlusion, edge glow effect is not visible because the surface alteration 263A is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 263A will be open and the edge glow effect will be visible. In this embodiment shown in FIGS. 13-15, the female fastening strip 231 includes a plurality of protrusions 258 spaced apart along the fastening strip on each side of the female closure element 234. These protrusions 258 are spaced apart to engage the wings 237 of the male closure element. The wings 237 travel in increments along the length of the female fastening strip 231 as the male and female fastening strips are brought together. This discrete travel is tactually perceptible to a user. Thus, in addition to providing a visual indication and a deformation 257 when the closure device is occluded, the closure device affords a dynamically tactile indication of proper occlusion. A user is thus able to “feel” that the closure device is being properly closed. FIG. 14 illustrates the closure device of FIG. 13 when the wings of the male fastening strip have traversed across one protrusion 258 of the female fastening strip 231. FIG. 15 shows the closure device of FIG. 13 in a fully occluded position. As shown, the female fastening strip includes four protrusions 258, two on each side of the female closure element. However, the female closure element could include a greater or fewer number of protrusions, such as one, two three, four or more protrusions. The protrusions may have the same size or may be different sizes. For example, the protrusions may be sized such that the outermost protrusions are larger than the innermost protrusions, thus requiring slightly more force to push the wings over the outer protrusions. Alternatively, or in addition thereto, the protrusions may include colorants such as pigments. If the wings of the male fastening strip are opaque, the user will be able to see the protrusions when the closure device is deoccluded or partially occluded, but will not see the protrusions when the closure device is fully occluded. Thus, further visual indication of occlusion of the closure device will be provided. The innermost protrusions may be differently colored from the outermost protrusions which allows the user to visually observe the progression of occlusion of the closure device. The use of the protrusions and wings to provide a dynamically tactile indication of proper occlusion may be used with any of the embodiments in this application as appropriate. Another feature of the invention is the spacing member 259 which provides a predetermined spacing between the fastening strips and also a predetermined tension among the closure elements. Referring to FIGS. 13-15, the base 238 includes a spacing member 259 and the base 247 includes an engagement surface 260 for the spacing member. The spacing member 259 extends from the base a predetermined distance and is located between the webs 240, 241. The engagement surface 260 is located between the webs 250, 251 and includes a groove which engages the spacing member 259. Referring to FIG. 14, as the user applies forces to the fastening strips, the spacing member 259 contacts the engagement surface 260. In order to hold the fastening strips in an occluded position, the female hooks 242, 244 must engage the male hooks 252, 254. As the user continues to apply the forces, the female webs 240, 241 deflect outwardly and the male webs 250, 251 deflect inwardly in order to allow the female hooks 242, 244 and the male hooks 252, 254 to pass each other. In addition, the hooks may also deflect during this process. As the user continues to apply the forces, the female hooks 242, 244 engage the male hooks 252, 254 as shown in FIG. 15. During the process, the base of the male fastening strip deflects inward and forms an inward deformation 257. During the process, the spacing member 259 may also deflect as shown in FIG. 15. The spacing member performs several functions. The spacing member 259 maintains a predetermined distance between the fastening strips. The spacing member 259 also maintains a predetermined depth for the deformation 257 by preventing the deformation 257 from moving too close to the other fastening strip. The spacing member 259 also maintains tension between the female hooks 242, 244 and the male hooks 252, 254. The deformation 257 is retained because the male wings 237 are more rigid than the base and because the male wings 237 are prevented from further outward movement by the wings 235. In addition, the forces exerted by the deflected base and the deflected spacing member 259 are less than the force required to disengage the hooks. In order to facilitate the deflection of the base, the fastening strip may include notches 256. The spacing member 259 may be located on the male fastening strip 230 and the engagement surface 260 on the female fastening strip 231 as shown in FIGS. 13-15. Conversely, the spacing member may be located on the female fastening strip and the engagement surface on the male fastening strip. The spacing member 259 and the engagement surface 260 may also include color to provide the user with a visual indication that occlusion has occurred as noted above. In addition, the spacing member may be used with any of the embodiments in this application where appropriate. Furthermore, the spacing member 259 and the protrusions 258 can be used independently. For example, FIG. 16 illustrates a closure device which includes a spacing member 259A similar to FIGS. 13-15 but does not include protrusions. Conversely, FIG. 17 illustrates a closure device which includes protrusions 258A similar to FIGS. 13-15 but does not include a spacing member. In addition, FIG. 17 illustrates three separate coextrusions in the base portion. Other embodiments of the closure elements and wings may be provided. For example, FIG. 18 illustrates a closure device in which the wings 371 of the male fastening strip are Y-shaped. The wings 372 of the female fastening strip are spaced so as to engage the grooves 370 in the wings 371. Referring to FIG. 18, the female fastening strip 331 includes a female closure element 334 similar to female closure element 34 shown in FIG. 2. The female closure element 334 includes a base portion 338 and a pair of webs 340, 341 similar to base 38 and webs 40, 41 in FIG. 2. The webs 340, 341 include female hook portions 342, 344 similar to hooks 42, 44 in FIG. 2. The fastening strip 331 also includes a wing 372 on each side of the female closure element 334. The male fastening strip 330 includes a male closure element 336 similar to male closure element 36 in FIG. 3. The male closure element 336 includes a base portion 347 and a pair of webs 350, 351 similar to base 47 and webs 50, 51 in FIG. 3. The webs 350, 351 include male hook portions 352, 354 similar to hooks 52, 54 in FIG. 3. The fastening strip 330 also includes a wing 371 on each side of the male closure element 336. The wing 371 includes a groove 370 to engage the wing 372. The base portion 347 is provided with a surface alteration 363 and a coextruded portion 365 which are similar to the surface alteration 63 and the coextruded portion 65 in FIG. 3. Furthermore, the base could include any other surface alteration embodiment described herein. For example, the base may include a fluorescent material and the surface alterations extend through the fluorescent material. FIG. 18 shows the closure device in occluded position. As noted above, the user applies compression forces to the fastening strips in order to occlude the closure device. As the user occludes the fastening strips, the male wings 371 engage the female wings 372 as shown in FIG. 18. In order to hold the fastening strips in an occluded position, the female hooks 342, 344 must engage the male hooks 352, 354 as noted above for hooks 42, 44, 52, 54. During this process, the base of the male fastening strip deflects inward and forms an inward deformation 357. The deformation 357 is retained because the male wings 371 are more rigid than the base and because the male wings 371 are held in position by the groove 370 engaging the wings 372. The groove 370 prevents the wings 371 from moving laterally with respect to wings 372. In order to facilitate the deflection of the base, the fastening strip may include notches 356. As the base deflects inward, the surface alteration 363 opens and exposes the coextruded portion 365 as shown in FIG. 18. The mating fastening strip 331 is translucent or transparent. Thus, the second color of the coextruded portion 365 is visible to the user through the mating fastening strip 331. Prior to occlusion, the second color of the coextruded portion 365 is not visible because the first color of the base 347 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 363 will be open and the second color will be visible. In another embodiment of the present invention, the notches may be disposed on the other side of the male fastening strip. FIG. 19 illustrates such a male fastening strip 430 including the notches 456 which are disposed on the outside of male fastening strip 430. The notches 456 may also be formed into the side wall 22 of the plastic bag. Referring to FIG. 19, the female fastening strip 431 includes a female closure element 434 similar to female closure element 34 shown in FIG. 2. The female closure element 434 includes a base portion 438 and webs 440, 441 similar to base 38 and webs 40, 41 in FIG. 2. The webs 440, 441 include female hook portions 442, 444 similar to hooks 42, 44 in FIG. 2. The fastening strip 431 also includes wings 435 similar to wings 35 in FIG. 2. The male fastening strip 430 includes a male closure element 436 similar to male closure element 36 in FIG. 3. The male closure element 436 includes a base portion 447 and a pair of webs 450, 451 similar to base 47 and webs 50, 51 in FIG. 3. The webs 450, 451 include male hook portions 452, 454 similar to hooks 52, 54 in FIG. 3. The fastening strip 43 also includes a wing 437 on each side of the male closure element 436 similar to the wings 37 in FIG. 3. The base portion 447 is provided with a surface alteration 63 and a coextruded portion 465 which are similar to the surface alteration 63 and the coextruded portion 65 in FIG. 3. Furthermore, the base could include any other surface alteration embodiment described herein. For example, the base may include an edge glow material and the surface alterations extend through the edge glow material, as illustrated in FIGS. 3A, 3B, 10A, 10B, 15A and 15B. The fastening strip 430 includes notches 456 which are disposed on the non-mating side of the fastening strip 430. The notches are also formed into the side wall 22 of the plastic bag. During occlusion, the user applies compression forces to the fastening strips as noted above. As the user occludes the fastening strips, the male wings 437 engage the female wings 435 as shown in FIG. 19. In order to hold the fastening strips in an occluded position, the female hooks 442, 444 must engage the male hooks 452, 454 as noted above for hooks 42, 44, 52, 54. During this process, the base of the male fastening strip deflects inward and forms an inward deformation 457. The deformation 457 is retained because the male wings 437 are more rigid than the base and because the male wings 437 are prevented from further outward movement by the wings 435. In addition, the force exerted by the deflected base is less than the force required to disengage the hooks. The notches 456 facilitate the deflection of the base. As the base deflects inward, the surface alteration 463 opens and exposes the coextruded portion 465 as shown in FIG. 19. The mating fastening strip 431 is translucent or transparent. Thus, the second color of the coextruded portion 365 is visible to the user through the mating fastening strip 431. Prior to occlusion, the second color of the coextruded portion 365 is not visible because the first color of the base 347 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 463 will be open and the second color will be visible. In addition, the fastening strip 430 provides an additional tactile sensation. The notches 456 on each side of the deformation 457 assist the user in locating and maintaining contact with the deformation. Furthermore, depending upon the configuration of the notches, the notches may also provide tactile confirmation of the occlusion. For example, the notches may be narrow when the closure device is not occluded. When the closure device is occluded, the notches may become wide enough so that the user can tactilely determine the difference between the narrow notch (i.e. unoccluded) and the wide notch (i.e. occluded). The base flexes to create a deformation because at least a portion of the base is less rigid than the other portions of the fastening strip. The rigidity of the base can be reduced by having an area of reduced cross-section in the base. This area would be more likely to flex than the surrounding areas. An area of reduced cross-section can be achieved by using notches. In addition, an area of reduced cross-section can be achieved by chemical etching of at least a portion of the fastening strip. The chemical etching could be performed by using a chemical solvent. For example, chemical solvents for polyethylene are Decolin, a strong nitric acid or a strong base. The rigidity of the base can also be reduced by having an area in the base which is made of a different second material, such as, by coextrusion. Referring to FIG. 19A, the male fastening strip 430A includes a base 447A which is made of a first material and coextruded portions 456A which are made of a second material. The second material would be more likely to flex than the first material with the application of the same force, i.e. the first material would have a different modulus of elasticity than the second material. Therefore, the base would more likely flex at the location of the second material. Referring to FIG. 19A, the female fastening strip 431A includes a female closure element 434A similar to female closure element 434 shown in FIG. 19. The female closure element 434A includes a base portion 438A and webs 440A, 441A similar to base 438 and webs 440, 441 in FIG. 19. The webs 440A, 441A include female hook portions 442A, 444A similar to hooks 442, 444 in FIG. 19. The fastening strip 431A also includes wings 435A similar to wings 435 in FIG. 19. The male fastening strip 430A includes a male closure element 436A similar to male closure element 436 in FIG. 19. The male closure element 436A includes a base portion 447A and a pair of webs 450A, 451 A similar to base 447 and webs 450, 451 in FIG. 19. The webs 450A, 451A include male hook portions 452A, 454A similar to hooks 452, 454 in FIG. 19. The fastening strip 430A also includes a wing 437A on each side of the male closure element 436A similar to the wings 437 in FIG. 19. As noted above, the fastening strip 430A includes extruded portions 456A. The base portion 447A is provided with a surface alteration 463A and a coextruded portion 465A which are similar to the surface alteration 63 and the coextruded portion 65 in FIG. 3. Furthermore, the base could include any other surface alteration embodiment described herein. For example, as shown in FIG. 19B the base 447B may include an edge glow material and the surface alterations 463B extend through the edge glow material. During occlusion, the user applies compression forces to the fastening strips as noted above. As the user occludes the fastening strips, the male wings 437A engage the female wings 435A as shown in FIG. 19A. In order to hold the fastening strips in an occluded position, the female hooks 442A, 444A must engage the male hooks 452A, 454A as noted above for hooks 442, 444, 452, 454. During this process, the base of the male fastening strip deflects inward and forms an inward deformation 457A. The deformation 457A is retained because the male wings 437A are more rigid than the base and because the male wings 437A are prevented from further outward movement by the wings 435A. In addition, the force exerted by the deflected base is less than the force required to disengage the hooks. The coextruded portions 456A facilitate the deflection of the base. As the base deflects inward, the surface alteration 463A opens and exposes the coextruded portion 465A as shown in FIG. 19A. The mating fastening strip 431A is translucent or transparent. Thus, the second color of the coextruded portion 365A is visible to the user through the mating fastening strip 431A prior to occlusion, the second color of the coextruded portion 365A is not visible because the first color of the base 347A surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 463A will be open and the second color will be visible. With respect to the edge glow embodiment shown in FIG. 19B, the occlusion occurs in a similar fashion. As the base deflects inward, the surface alteration 463B opens and exposes the edge glow effect as shown in FIG. 19B. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip. Prior to occlusion, the edge glow effect is not visible because the surface alteration 463B is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 463B will be open and the edge glow effect will be visible. In addition, the coextruded portion 456A may be continuous along the length of the fastening strip or the coextruded portion may be discontinuous along the length to provide an intermittent deformation effect. Furthermore, the second material could be disposed parallel to the longitudinal axis of the fastening strip as in FIG. 19A. In other embodiments, the second material could be disposed perpendicular to the longitudinal axis of the fastening strip as in U.S. Pat. No. 5,138,750 which is incorporated herein by reference. Finally, FIGS. 22B, 28B and 34B illustrate other embodiments of closure devices with coextruded portions. As noted above, notches may be provided to facilitate deflection or deformation. The notch or notches may be placed in various locations on the fastening strip. Referring to FIG. 20, the male fastening strip 530 includes a notch 556A located between webs 550, 551. The notch 556A may be used in conjunction with one or more of the other notches 556B, 556C or the notch 556A may be used without the other notches 556B, 556C. The notch 556A will facilitate the deflection of the base to form the deformation. In addition, the fastening strip may include surface alterations 563 and coextruded portions 565. Conversely, notches may be included on the female fastening strip in order to form the deformation on the female fastening strip. Referring to FIG. 21, the female fastening strip 531 includes a notch 556D located between webs 540, 541. The notch 556D may be used in conjunction with one or more of the other notches 556E, 556F or the notch 556D may be used without the other notches. In addition, the fastening strip may include surface alterations 563 and coextruded portions 565. Furthermore, if a deformation or deformations are desired on both sides of the closure device, notches and or coextruded portions may be included on both the male fastening strip and the female fastening strip. For example, referring to FIG. 22A, the closure device includes the male fastening strip 530 from FIG. 20 and the female fastening strip 531 from FIG. 21 to form deformations 557A, 558B on each side of the closure device. As another example, referring to FIG. 22B, the closure device includes a male fastening strip with coextruded portions 556G and a female fastening strip with coextruded portions 556H to facilitate the formation of the deformations 557G, 557H on each side of the closure device. Notches in various locations on the male fastening strip and/or the female fastening strip may be used with any of the embodiments described herein as appropriate. For example, referring to FIGS. 23, 24 and 25, the fastening strips 630, 631 include notches 656 on the non-mating sides of the fastening strips. The notches may have various configurations. For example, the notches may be composed of arcuate and linear segments, such as, notch 56 in FIG. 3. As another example, the notch may be composed of arcuate segments, such as, notch 156 in FIG. 9 or notch 256 in FIG. 13. As a further example, the notch may be a surface alteration, such as, notches 956A, 956B, 1056A, 1056B in FIGS. 38A, 38B, 39A and 39B. For polyethylene the preferred notch depth should be no less than 15% of the base thickness to maintain the integrity of the base. In addition, the notch may be continuous along the length of the fastening strip or the notch may be discontinuous along the length to provide an intermittent deformation effect. FIGS. 23A-25 show fastening strips with surface alterations which are open when the closure device is unoccluded and substantially closed when the closure device is occluded. Referring to FIG. 23A, the base is provided with surface alterations 663 and coextruded portions 665 which are open when the closure device is unoccluded. However, the base could include any other surface alteration embodiment described herein. For example, as shown in FIGS. 23C, 23D and 25A, the base 647A may include an edge glow material and the surface alterations 663A extend through the edge glow material. Prior to occlusion, the second color of the extruded portion 665 is visible. As the base deflects inward, the surface alterations 663 close and substantially hide the coextruded portion 665 as shown in FIGS. 23B, 24 and 25. The coextrusion portion is not visible because the first color of the base 647 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 663 will be closed and the second color will not be visible. As shown in FIG. 25, the user is able to determine that occlusion has occurred from either side because the surface alteration 663 will be closed on both fastening strips. With respect to the edge glow embodiments shown in FIGS. 23C, 23D and 25A, the occlusion occurs in a similar fashion. Prior to occlusion, the edge glow effect is visible. As the base deflects inward, the surface alterations 663A close and substantially hide the edge glow effect as shown in FIG. 23D. The edge glow effect is not-visible because the surface alteration 663A is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 663A will be closed and the edge glow effect will not be visible. As shown in FIG. 25A, the user is able to determine that occlusion has occurred from either side because the surface alterations 663A will be closed on both fastening strips. In another embodiment, the closure device may include other types of closure elements. Referring to FIG. 26, a male fastening strip 730 includes a male closure element 736 and a female fastening strip 731 includes a female closure element 734. The closure elements 734, 736 are known and described in U.S. Pat. No. 3,198,228 (which was reissued as Re. 28,969), U.S. Pat. Nos. 4,736,496, 5,140,727 and 5,363,540 which are incorporated herein by reference. These closure elements 734, 736 are sometimes referred to as “arrowhead” closure elements. The remaining components of the fastening strips 730, 731, such as, the wings 735, 737, the bases 738, 747 and the notches 756, are similar to the similarly numbered components 35, 37, 38, 47, 56 in FIGS. 2 and 3. When the fastening strips 730, 731 are occluded, a deformation 757 is formed along the fastening strip 730. The base 747 is provided with surface alterations 763A-763C and coextruded portions 765. The surface alterations 763A, 763B on the mating side of the base are closed when the closure device is unoccluded and open when the closure device is occluded similar to surface alteration 63 and coextruded portion 65 in FIG. 3. Conversely, the surface alterations 763C on the non-mating side of the base are open when the closure device is unoccluded and closed when the closure device is occluded similar to surface alterations 663 and coextruded portions 665 in FIGS. 23-25. However, the base could include any other surface alteration embodiment described herein. For example, as shown in FIGS. 28C and 28D, the base 747G, 747H may include an edge glow material and the surface alterations 763G, 763H extend through the edge glow material. During occlusion, the user applies compression forces to the fastening strips as noted above. As the user occludes the fastening strips, the male wings 737 engage the female wings 735 as shown in FIG. 26. In order to hold the fastening strips in an occluded position, the female closure element 734 engages the male closure element 736. During this process, the base of the male fastening strip deflects inward and forms an inward deformation 757. The deformation is retained because the male wings 737 are more rigid than the base and because the male wings 737 are prevented from further outward movement by the female wings 735. In addition, the force exerted by the deflected base is less than the force required to disengage the closure elements. The notches 756 facilitate the deflection of the base. As the base deflects inward, the surface alterations 763A, 763B open and expose the coextruded portions 765 as shown in FIG. 26. The mating fastening strip 731 is translucent or transparent. Thus, the second color of the coextruded portion 765 is visible to the user through the mating fastening strip 731. Prior to occlusion, the second color of the coextruded portion 765 is not visible because the first color of the base 747 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 763A, 763B will be open and the second color will be visible. With respect to the surface alterations 763C, the second color of the extruded portion 765 is visible prior to occlusion. As the base deflects inward, the surface alterations 763C close and substantially hide the coextruded portion 765 as shown in FIG. 26. The coextrusion portion 765 is not visible because the first color of the base 747 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 763C will be closed and the second color will not be visible. As shown in FIG. 28, the user is able to determine that occlusion has occurred from either side because the surface alterations on the non-mating sides will be closed on both fastening strips. FIGS. 27-31 illustrate other embodiments of the invention using the arrowhead closure elements 734, 736 and having different locations for the deformations, surface alterations and notches. For example, FIG. 27 shows the surface alterations 763D and deformation 757D on the female fastening strip. FIG. 28A shows the notches 756E, the surface alterations 763E, the coextruded portions 765E and deformations 757E on both the fastening strips. FIG. 28B shows coextruded portions 756F, the deformations 757F, the surface alterations 763F and the coextruded portions 765F on both the fastening strips. FIG. 28C shows the edge glow embodiment wherein the base 747G includes an edge glow material and the surface alterations 763G extend through the edge glow material. The base 747G also includes notches 756G and the base forms deformations 757G. When the closure device is unoccluded, the surface alterations 763G are open and the edge glow effect will be visible on both sides of the closure device. FIG. 28D shows another edge glow embodiment with an edge glow base 747H, coextruded portions 756H and surface alterations 763H. When the closure device is unoccluded, the deformations 757H are created, the surface alterations 763H are opened and the edge glow effect will be visible on both sides of the closure device. FIGS. 29 and 30 show the surface alterations 763I, 763J and notches 7561, 756J on the non-mating side and the deformation 7571, 757J on only one of the fastening strips. FIG. 31 shows the surface alterations 763K and notches 756K on the non-mating sides and deformations 757K on both of the fastening strips. Referring to FIGS. 32-37, the closure device may also form an outward deformation when occluded. As shown in FIG. 32, the closure device 821 includes male and female fastening strips 830, 831 similar to fastening strips 230, 231 in FIG. 13. The female fastening strip 831 includes a female closure element 834 and a pair of wings 835 similar to female closure element 231 and wings 235 in FIG. 13. The male fastening strip 830 includes a male closure element 836 and a pair of wings 837 similar to male closure element 236 and wings 237 in FIG. 13. The female closure element 834 includes a base portion 838 and webs 840, 841 similar to base portion 238 and webs 240, 241 in FIG. 13. The webs 840, 841 include hook portions 842, 844 similar to hook portions 242, 244 in FIG. 13. The male closure element 836 includes a base portion 847 and webs 850, 851 similar to base portion 247 and webs 250, 251 in FIG. 13. The webs 850, 851 include hook portions 852, 854 similar to hook portions 252, 254 in FIG. 13. The base portion 847 may be provided with notches 856 which are similar to notches 256 in FIG. 13. The base 847 is provided with surface alterations 863A-863C and coextruded portions 865. The surface alterations 863A, 863B on the mating side of the base are open when the closure device is unoccluded and closed when the closure device is occluded similar to surface alterations 663 and coextruded portions 665 in FIGS. 23A-25. Conversely, the surface alterations 863C on the non-mating side of the base are closed when the closure device is unoccluded and open when the closure device is occluded similar to surface alterations 63 and coextruded portion 65 in FIG. 3. However, the base could include any other surface alterations embodiment described herein. For example, as shown in FIGS. 34C and 34D, the base 847G, 847H may include a fluorescent material and the surface alterations 863G, 863H extend through the fluorescent material. A spacing member 859 provides a predetermined spacing between the fastening strips and also a predetermined tension among the closure elements. Referring to FIG. 32, the base 838 includes a spacing member 859 and the base 847 includes an engagement surface 860 for the spacing member. The spacing member 859 extends from the base a predetermined distance and is located between the webs 840, 841. The engagement surface 860 is located between the webs 850, 851 and includes a groove which engages the spacing member 859. Referring to FIG. 32, as the user applies forces to the fastening strips, the spacing member 859 contacts the engagement surface 860. In order to hold the fastening strips in an occluded position, the female hooks 842, 844 must engage the male hooks 852, 854. As the user continues to apply the forces, the female webs 840, 841 deflect outwardly and the male webs 850, 851 deflect inwardly in order to allow the female hooks 842, 844 and the male hooks 852, 854 to pass each other. In addition, the hooks may also deflect during this process. As the user continues to apply the forces, the female hooks 842, 844 engage the male hooks 852, 854 as shown in FIG. 32. During the process, the base of the male fastening strip deflects outward and forms an outward deformation 857. During the process, the spacing member 859 may also deflect. The spacing member performs several functions. The spacing member 859 maintains a predetermined distance between the fastening strips. The spacing member 859 also maintains a predetermined height for the deformation 857. The spacing member 859 also maintains tension between the female hooks 842, 844 and the male hooks 852, 854. The deformation 857 is retained because the male wings 837 are more rigid than the base and because the male wings 837 are prevented from further outward movement by the wings 835. In addition, the forces exerted by the deflected base and the deflected spacing member 859 are less than the force required to disengage the hooks. In order to facilitate the deflection of the base, the fastening strip may include notches 856. As the base deflects outward, the surface alterations 863A, 863B close and substantially hide the coextruded portion 865 as shown in FIG. 32. The mating fastening strip 831 is translucent or transparent. Thus, the second color of the coextruded portion 865 is visible to the user through the mating fastening strip 831. After occlusion, the second color of the coextruded portion is not visible because the first color of the base 847 surrounds the second color. The user is able to determine that occlusion has occurred because the surface alterations 863A, 863B will be closed and the second color will not be visible. With respect to the surface alterations 863C, the second color of the extruded portion 865 is not visible prior to occlusion. As the base deflects outward, the surface alterations 863C open and expose the coextruded portion 865 as shown in FIG. 32. Prior to occlusion, the coextrusion portion 865 is not visible because the first color of the base 847 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 863C will be open and the second color will be visible. As shown in FIGS. 34A, 34B and 37, the user is able to determine that occlusion has occurred from either side because the surface alterations will be open on both fastening strips. The spacing member 859 and the engagement surface 860 may also include color to provide the user with a visual indication that occlusion has occurred as noted above. In addition, the spacing member may be used with any of the embodiments in this application where appropriate. FIGS. 33-37 illustrate other embodiments of the invention using the spacing member 859 and having different locations for the deformations, surface alterations and notches. For example, FIG. 33 shows the notches 856D, surface alterations 863D and outward deformation 857D on the female fastening strip. FIG. 34A shows the notches 856E, the surface alterations 863E, outward deformations 857E and the coextruded portions 865E on both the fastening strips. FIG. 34B shows the coextruded portions 856F, the outward deformations 857F and the coextruded portions 865F on both the fastening strips. FIG. 34C shows the edge glow embodiment wherein the base 847G includes an edge glow material and the surface alterations 863G extend through the edge glow material. The base 847G also includes notches 856G and the base forms deformations 857G. When the closure device is occluded, the surface alterations 863G are open and the edge glow effect will be visible on both sides of the closure device. FIG. 34D shows another edge glow embodiment with an edge glow base 847H, coextruded portions 856H and surface alterations 863H. When the closure device is occluded, the deformations 857H are created, the surface alterations 863H are opened and the edge glow effect will be visible on both sides of the closure device. FIGS. 35 and 36 show the notches 8561, 856J on the non-mating side and the deformation 8571, 857J and the surface alterations 8631, 863J on only one of the fastening strips. FIG. 37 shows the notches 856K on the non-mating sides, and the deformations 857K and the surface alterations 863K on both of the fastening strips. In addition, the closure device may include other closure elements, such as, the arrowhead closure elements, and form an outward deformation when occluded. FIGS. 38A and 38B illustrate another embodiment of a closure device which has an inward deformation when occluded. The closure device 921 includes a male fastening strip 930 and a female fastening strip 931. The female fastening strip 931 includes a female closure element 934. The female closure element 934 includes a base portion 938 and a pair of webs 940, 941 extending from the base portion 938. The webs 940, 941 include hook portions 942, 944 extending from the webs. The base 938 may also include surface alterations 963A on the mating side and surface alterations 963B on the non-mating side. The male fastening strip 930 includes a male closure element 936. The male closure element 936 includes a base portion 947 and a pair of webs 950, 951 extending from the base portion 947. The webs 950, 951 include hook portions 952, 954 extending from the webs. The male fastening strip 930 may also include wings 937 to guide the webs of the female closure element. In this embodiment, a portion of the side wall for the bag is used to provide the visual changing effect. Specifically, the portion 922 of the side wall 22 which contacts the fastening strip 931 is a first color. In this embodiment the first color is opaque. The base portion 938 has a second color and the first-color substantially hides the second color. The surface alterations 963B on the non-mating side extend through the side wall portion 922 and into the base portion 938. In this embodiment, the surface alterations 963B are substantially closed to hide the second color of the base portion 1047 when the fastening strips are occluded and open to expose the second color when the fastening strips are unoccluded. The combination of the first color for the side wall portion and the second color for the base achieves the visual change without the need for the coextruded portion. In another embodiment, the base could include edge an glow material and the first color of the side wall portion would not need to be opaque and could be transparent. FIG. 38B illustrates the closure device 921 in the occluded position with an inward deformation. As the user applies forces to the fastening strips, the webs 940, 941 deflect outwardly in order to allow the hooks to pass each other. In addition, the hooks may also deflect during this process. As the user continues to apply the forces, the hooks engage as shown in FIG. 38B. During this process, the base 938 deflects inward and forms an inward deformation 957. The deformation 957 is retained because the webs 940, 941, 950, 951 are more rigid than the base 938. Specifically, the distance between the hooks 952, 954 is greater than the distance between the webs 940, 941 when the fastening strip 931 is in the unoccluded position. The webs 940, 941 are urged away from each other in order to fit over the hooks 952, 954. The webs are rigid in comparison to the base 938 and thus the webs 940, 941 are permitted to be urged away from each other. In this embodiment, the base is less rigid due to the notches 956A, 956B. The notches allow the base to flex inward to form the deformation. Specifically, the notches 956A open to permit the mating surface of the base to increase and the notches 956B close to permit the non-mating surface of the base to decrease. The forces exerted by the deflected base are less than the force required to disengage the hooks. As the base deflects inward, the surface alterations 963B close and hide the base portion 938 as shown in FIG. 38B. Prior to occlusion, the second color of the base portion 938 is visible. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 963B will be closed and the second color will not be visible. In another embodiment, the base 938 includes an edge glow material. Prior to occlusion, the surface alterations 963B are open and the edge glow effect is visible as shown in FIG. 38A. As the base deflects inward, the surface alterations 963B close and substantially hide the edge glow effect as shown in FIG. 38B. The edge glow effect is not visible because the surface alteration 963B is closed. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 963B will be closed and the edge glow effect will not be visible. In addition, as the base 938 deflects inward, the surface alterations 963A open and expose the edge glow effect as shown in FIG. 38B. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip. Prior to occlusion, the edge glow effect is not visible because the surface alteration 963A is closed as shown in FIG. 38A. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 963A will be open and the edge glow effect will be visible. FIGS. 39A and 39B illustrate another embodiment of a closure device which is similar to the embodiment in FIGS. 38A and 38B. However, the closure device in FIGS. 39A and 39B includes a coextruded portion 965C. The coextruded portion 965C can provide a third color. In another embodiment, the combination of a coextruded portion with a third color and a base 938C with a second color, would allow the first color to be eliminated from the sidewall 922C. In a third embodiment, the combination of a coextruded portion with a third color and a sidewall with a first color, would allow the second color to be eliminated from the base. In addition, in a fourth embodiment, the first, second and/or third color could be a fluorescent material. FIGS. 40A and 40B illustrate another embodiment of a closure device which has an outward deformation when occluded. The closure device 1021 includes a male fastening strip 1030 and a female fastening strip 1031. The female fastening strip 1031 includes a female closure element 1034. The female closure element 1034 includes a base portion 1038 and a pair of webs 1040, 1041 extending from the base portion 1038. The webs 1040, 1041 include hook portions 1042, 1044 extending from the webs. The male fastening strip 1030 includes a male closure element 1036. The male closure element 1036 includes a base portion 1047 and a pair of webs 1050, 1051 extending from the base portion 1047. The webs 1050, 1051 include hook portions 1052, 1054 extending from the webs. The male fastening strip 1030 may also include wings 1037 to guide the webs of the female closure element. The base 1047 may also include surface alterations 1063A on the mating side and surface alteration 1063B on the non-mating side. In this embodiment, a portion of the side wall for the bag is used to provide the visual changing effect. Specifically, the portion 1022 of the side wall 22 which contacts the fastening strip 1030 is a first color. In this embodiment the first color is opaque. The base portion 1047 has a second color and the first color substantially hides the second color. The surface alterations 1063B on the non-mating side extend through the side wall portion 1022 and into the base portion 1047. In this embodiment, the surface alterations 1063B are substantially closed to hide the second color of the base portion 1047 when the fastening strips are unoccluded and open to expose the second color when the fastening strips are occluded. The combination of the first color for the side wall portion and the second color for the base achieves the visual change without the need for the coextruded portion. In another embodiment, the base could include an edge glow material and the first color of the side wall portion would not need to be opaque and could be transparent. FIG. 40B illustrates the closure device 1021 in the occluded position with an outward deformation. As the user applies forces to the fastening strips, the male webs 1050, 1051 deflect inwardly in order to allow the hooks to pass each other. In addition, the hooks may also deflect during this process. As the user continues to apply the forces, the hooks engage as shown in FIG. 40B. During this process, the base 1047 deflects outward and forms an outward deformation 1057. The deformation 1057 is retained because the webs 1040, 1041, 1050, 1051 are more rigid than the base 1047. Specifically, the distance between the hooks 1042, 1044 is less than the distance between the webs 1050, 1051 when the fastening strip 1030 is in the unoccluded position. The webs 1050, 1051 are urged closer to each other in order to fit between the hooks 1042, 1044. The webs are rigid in comparison to the base 1047 and thus the webs 1050, 1051 are permitted to be urged closer to each other. In this embodiment, the base is less rigid due to the notches 1056A, 1056B. The notches allow the base to flex outward to form the deformation. Specifically, the notches 1056B open to permit the non-mating surface of the base to increase and the notches 1056A close to permit the mating surface of the base to decrease. The forces exerted by the deflected base are less than the force required to disengage the hooks. As the base deflects outward, the surface alterations 1063B open and expose the base portion 1047 as shown in FIG. 40B. Prior to occlusion, the second color of the base portion 1047 is not visible because the first color of the sidewall portion 1022 hides the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 1063B will be open and the second color will be visible. In another embodiment, the base 1047 includes an edge glow material. Prior to occlusion, the surface alterations 1063B are closed and the edge glow effect is not visible as shown in FIG. 40A. As the base deflects outward, the surface alterations 1063B open and expose the edge glow effect as shown in FIG. 40B. The edge glow effect is visible because the surface alteration 1063B is open. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 1063B will be open and the edge glow effect will be visible. In addition, as the base 1047 deflects outward, the surface alterations 1063A close and hide the edge glow effect as shown in FIG. 40B. The mating fastening strip is translucent or transparent. Thus, the edge glow effect is visible to the user through the mating fastening strip. Prior to occlusion, the edge glow effect is visible because the surface alteration 1063A is open as shown in FIG. 40A. After occlusion, the user is able to determine that occlusion has occurred because the surface alteration 1063A will be closed and the edge glow effect will not be visible. FIGS. 41A and 41B illustrate another embodiment of a closure device which is similar to the embodiment in FIGS. 40A and 40B. However, the closure device in FIGS. 41A and 41B includes a coextruded portion 1065C. The coextruded portion 1065C can provide a third color. In another embodiment, the combination of a coextruded portion with a third color and a base 1047C with a second color, would allow the first color to be eliminated from the sidewall 1022C. In a third embodiment, the combination of a coextruded portion with a third color and a sidewall with a first color, would allow the second color to be eliminated from the base. In addition, in a fourth embodiment, the first, second and/or third color could be a fluorescent material. Referring to FIGS. 42 and 43, a closure device may also include multiple deformations upon occlusion of the closure device. In FIG. 42, the closure device 1121 includes two inward deformations 1157. The closure device 1121 is similar to the closure device in FIG. 16 except the closure device 1121 includes two additional notches 1156 to obtain additional flexibility in the base 1147. In addition, the closure device includes surface alterations 1163 and coextruded portion 1165. In FIG. 43, the closure device is similar to the closure device in FIG. 42 except the closure device 1221 uses two arrowhead closure elements 1234, 1236 versus the hook closure elements. The closure device includes surface alterations 1263 and a coextruded portion 1265. FIGS. 42A and 43A show one of the edge glow embodiments of FIGS. 42 and 43 wherein the base 1147A, 1247A includes an edge glow material and the surface alterations 1163A, 1263A extend through the edge glow material. When the closure device is occluded, the surface alterations 1163A, 1263A are open and the edge glow effect will be visible. Referring to FIGS. 44A-45B, the closure elements may include the surface alterations to achieve a visual changing effect. As shown in FIGS. 44A and 44B, the closure device includes a male fastening strip 1330 and a female fastening strip 1331. The male fastening strip 1330 includes a male closure element 1336 and the female fastening strip 1331 includes a female closure element 1334. These closure elements are similar to the closure elements 734, 736 in FIG. 26 except that the male closure element 1336 includes surface alterations 1363 and coextruded portion 1365. In addition, the female closure element 1334 may include protrusions 1335 which facilitate the opening of the surface alterations 1363. The male closure element is made from a material which has a first color. In this embodiment, the first color would be opaque. The male closure element 1336 includes a coextruded portion 1365 which has a second color. The second color may be surrounded by the first color in the closure element. The closure element includes surface alterations 1363 which extend into the coextruded portion 1365. While this embodiment has two surface alterations, the closure element may include one, three, four or more surface alterations. In addition, the coextruded portion may extend along each of the surface alterations or the closure element may include a separate coextruded portion for each surface alteration. Furthermore, the separate coextruded portions may have a different color than the second color of the first coextruded portion. In addition, the coextruded portion may be continuous along the closure element or the coextruded portion may be discontinuous along the length of the closure element. Similarly, the surface alteration may be continuous along the length of the closure element or the surface alteration may be discontinuous along the length of the closure element. The surface alteration 1363 is substantially closed to hide the color when the fastening strips are unoccluded as in FIG. 44A and open to expose the color when the fastening strips are occluded as in FIG. 44B. A closure element with a surface alteration may be used with any embodiment described herein. During occlusion, the user applies compression forces to the fastening strips as noted above. As the user occludes the fastening strips, the female closure element 1334 engages the male closure element 1336. The surface alterations 1363 open and expose the coextruded portion 1365 as shown in FIG. 44B. In this embodiment, the mating fastening strip 1331 is translucent or transparent. Thus, the second color of the coextruded portion 1365 is visible to the user through the mating fastening strip 1331. Prior to occlusion, the second color of the coextruded portion 1365 is not visible because the first color of the closure element 1336 surrounds the second color. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 1363 will be open and the second color will be visible. Referring to FIGS. 45A-45B, the closure elements include the surface alterations to achieve a visual changing effect. FIGS. 45A and 45B show one of the edge glow embodiments of FIGS. 44A and 44B wherein the male closure element 1336A is made of an edge glow material and the surface alterations 1363A extend through the edge glow material. The material provides an edge glow effect when the surface alteration 1363A is open. Prior to occlusion, the surface alterations 1363A are closed and the edge glow effect is not visible as shown in FIG. 45A. After occlusion, the surface alterations 1363A open and the edge glow effect is visible through the mating fastening strip as shown in FIG. 45B. Thus, the user is able to visually determine that occlusion has occurred because the edge glow effect will be visible. FIGS. 46 and 47 illustrate the female and male fastening strips respectively of one embodiment of the closure device of the present invention. The representative dimensions of the various parameters are given as follows: PARAMETER RANGE(mils) PREFERRED (mils) 1471 0.283-0.363 0.323 1472 0.007-0.047 0.027 1473 0.012-0.032 0.022 1474 0.024-0.094 0.059 1475 0.187-0.267 0.227 1476 0.010-0.016 0.013 1477 0.018-0.088 0.053 1478 0.016-0.086 0.051 1481 0.203-0.283 0.243 1482 0.029-0.099 0.064 1483 0.013-0.033 0.023 1484 0.015-0.065 0.040 1485 0.115-0.195 0.155 1486 0.022-0.052 0.037 1487 0.010-0.016 0.013 1488 0.023-0.053 0.038 1489 0.004-0.010 0.007 1490 0.010-0.016 0.013 Referring to FIGS. 48-50D, the closure elements may include surface alterations which are perpendicular to the longitudinal axis of the closure device. FIGS. 48-50D illustrate another embodiment of a container according to the present invention in the form of a plastic bag 1520 having a sealable closure device 1521. The bag 1520 includes side walls 1522 joined at seams 1525 to form a compartment sealable by means of the closure device 1521. The side walls 1522 extend above the closure device 1521 to form mouth portions 1527. Mouth portions 1527 enable a user to grip the plastic bag 1520 in a fashion to more conveniently be able to deocclude or open the closure device 1521 to thereby open the bag 1520. The closure device 1521 includes fastening strips 1530, 1531. As shown in FIGS. 48 and 49, the fastening strips 1530, 1531, the side walls 1522 near the fastening strips and the mouth portions 1527 are deformed outwardly away from each other when the closure device is unoccluded. As shown in FIG. 49B, the fastening strips 1530,. 1531, the side walls 1522 near the fastening strips and the mouth portions 1527 are relatively parallel to each other when the closure device is occluded. FIGS. 50A and 50B illustrate an embodiment of a closure device which has an outward deformation when unoccluded. The closure device 1521 includes a first fastening strip 1530 and a second fastening strip 1531. The first fastening strip 1530 includes a first closure element 1536. The first closure element 1536 includes a base portion 1547. The second fastening strip 1531 includes a second closure element 1534. The second closure element 1534 includes a base portion 1538. The closure elements 1534, 1536 can be any one of the embodiments described herein. The bases include surface alterations 1563 on the non-mating sides. In this embodiment, a portion of the side wall for the bag is used to provide the visual changing effect. Specifically, the portion of the side wall 1522 which contacts the fastening strip 1531 is a first color. In this embodiment the first color is opaque. The base portion 1538 has a second color and the first color substantially hides the second color. The surface alterations 1563 on the non-mating side extend through the side wall portion 1522 and into the base portion 1538. In this embodiment, the surface alterations 1563 are substantially closed to hide the second color of the base portion 1547 when the fastening strips are occluded and open to expose the second color when the fastening strips are unoccluded. The combination of the first color for the side wall portion and the second color for the base achieves the visual change. In another embodiment, the base could include an edge glow material and the first color of the side wall portion would not need to be opaque and could be transparent. FIG. 50A illustrates the closure device 1521 in the unoccluded position with an outward deformation. As the user applies forces to the fastening strips, the fastening strips 1530, 1531 move inward and become parallel with each other as in FIG. 50B. As the bases move inward, the surface alterations 1563 close and hide the base portions 1538, 1547 as shown in FIG. 50B. Prior to occlusion, the second color of the base portions 1538, 1547 were visible. After occlusion, the user is able to determine that occlusion has occurred because the surface alterations 1563 will be closed and the second color will not be visible. In another embodiment, the bases 1538, 1547 include an edge glow material. Prior to occlusion, the surface alterations 1563 are open and the edge glow effect is visible as shown in FIG. 50A. As the bases move inward, the surface alterations 1563 close and substantially hide the edge glow effect as shown in FIG. 50B. The edge glow effect is not visible because the surface alteration 1563 is closed. After occlusion, the user is able to determine that occlusion has occurred because the slits 1563 will be closed and the edge glow effect will not be visible. FIGS. 50C and 50D illustrate another embodiment of a closure device which is similar to the embodiment in FIGS. 50A and 50B. However, the closure device in FIGS. 50C and 50D includes a coextruded portion 1565C. The coextruded portion 1565C can provide a third color. In another embodiment, the combination of a coextruded portion with a third color and a base 1538C, 1547C with a second color, would allow the first color to be eliminated from the sidewall 1522C. In a third embodiment, the combination of a coextruded portion with a third color and a sidewall with a first color, would allow the second color to be eliminated from the base. In addition, in a fourth embodiment, the first, second and/or third color could be a fluorescent material. The fastening strips may be manufactured by extrusion through a die that has the approximate dimensions given above, although the die should be made somewhat larger than the desired final dimensions of the fastening strip, inasmuch as shrinkage of the extruded fastening strip is likely upon cooling. The fastening strips of the closure device should be manufactured to have approximately uniform cross-sections. This not only simplifies the manufacturing of a device, but also contributes to the physical flexibility of the device, which is a desirable property in any event, and which is necessary to form a deformation in the fastening strip. Generally, the closure elements of this invention may be formed from thermoplastic materials such as, for example, polyethylene, polypropylene, nylon, or the like, or from a combination thereof. Thus, resins or mixtures of resins such as high density polyethylene, medium density polyethylene and low density polyethylene may be employed to prepare the novel fastener of this invention. Preferably, the closure element is made from low density polyethylene. The selection of the thermoplastic material will be related to the closure design and its Young's Modulus and desired elasticity and flexibility correlated to provide the functionality of the closure as herein claimed. Regarding the fluorescent or luminescent material used in this invention, a wide variety of suitable materials may be used. In general, from the functional standpoint, any fluorescent material may be used which provides a fluorescent appearance in the environment of the particular closure device in which the fluorescent material is utilized. Of course, as may be appreciated, the selection for a particular application may well be influenced by the intended application. Fluorescent materials are generally described in Coloring of Plastics, by Thomas G. Webber, John Wiley & Sons, 1979, ISBN 0471-92327-3. In Coloring of Plastics, fluorescent materials are described as follows: “Fluorescence is the ability of a dye or pigment to absorb radiant energy at one set of wavelengths and to emit light at a longer wavelength. The process is essentially instantaneous. Measurement of fluorescence and its separation from ordinary reflectance requires special equipment. Certain types of fluorescent agents absorb ultraviolet light in the 300-400 nanometer region and emit in the blue at about 440 nanometers, acting as whitening agents. These are organic compounds, and they may be considered dyes.” Id. pages 207-208. Further, Coloring of Plastics states “[I]n contrast to the fluorescent brightening agents, we have the daylight fluorescent dyes and the pigments obtainable from them. These materials are colored in the ordinary sense. In addition, they absorb ultraviolet or shortwave daylight and emit in the visible. The result is a very high degree of reflectance; the colored material appears to glow. The two principal classes of dyes that are involved are the rhodamines, which reinforce the red region, and the greenish yellow aminonaphthalimide derivatives.” Id. Page 210. In general, useful fluorescent materials are sometimes referred to as fluorescent daylight materials. Such materials have the ability to not only reflect color light selectively, but to give off an extra glow of fluorescent light upon being excited by daylight or an equivalent white light. With a few exceptions, daylight fluorescent pigments consist of particles of colorless resins containing dyestuffs that not only have color but are capable of intense fluorescence in solution. The resin is truly a solvent for the dyes. For example, in one resin system, a thermoplastic resin is formed containing the dye. Upon cooling to room temperature, the resin mass becomes very brittle and is then pulverized to the proper fineness. In this context, the term “dye” applies to any organic substance that exhibits strong absorption of light in the visible region of the spectrum without regard to any affinity for the substrate. Of the dyes which have been used for years, the brilliant red and salmon dyes of the rhodamine and rosamine classes may be used as fluorescent pigments. As further illustrative examples of important dyestuffs used as daylight fluorescent pigments, the following are included: Xylene Red B, Fluorescent Yellow Y, Maxilon 10GFF Alberta Yellow, Potomac Yellow and Macrolex Fluorescent Yellow 10GN. When using the fluorescent material to achieve the edge glow effect for identifying the occluded or unoccluded position, the edge glow effect will be affected by a variety of variables including the particular optical properties of the closure elements and the physical characteristics of the material of construction, e.g., the selected plastic and any coloration ingredient or the like. The light scattering characteristics of the closure element are also important and are influenced by the depth of the channel of the closure element, the presence or absence of guide members, the width of the closure element and the like. The fluorescent material may be incorporated into the suitable element or portion of the closure element in any way desired. One suitable method is simply to incorporate the fluorescent material in the plastics material from which the closure element is to be made in a fashion similar to the inclusion of other additives such as antioxidants and the like. The following examples are illustrative, but not in limitation of, the present invention. One sample was made with C-62389A/PC Edge Glow Green supplied by Chroma Corporation of McHenry, Ill., U.S.A. Another sample was made with Lumogen F Red Dye from BASF Corporation of Rensselaer, New York, U.S.A. When the fastener of the present invention is used in a sealable bag, the fastener and the films that form the body of the bag can be made from heat sealable material. The bag thus can be formed economically by heat sealing the aforementioned components to form the bag using thermoplastics of a type aforementioned for formation of the closure elements. Preferably, the bag is made from a mixture of high pressure, low density polyethylene and linear low density polyethylene. The closure elements of the invention may be manufactured by extrusion or other known methods. The closure device can be manufactured as individual fastening strips for later attachment to a film, or the fastening strips can be manufactured integrally with a film. In addition, the closure elements can be manufactured with or without flange portions on one or both of the closure elements depending upon the intended use or expected additional manufacturing operations. Generally, the closure device of this invention can be manufactured in a variety of forms to suit the intended use. In the practice of the instant invention, the closure device may be integrally formed with the sidewalls of a container, or connected to a container, by the use of any of many known methods. For example, a thermoelectric device can be applied to a film in contact with a flange portion of a closure element or the thermoelectric device can be applied to a film in contact with the base portion of a closure element having no flange portion, to cause a transfer of heat through the film to produce melting at the interface of the film and a flange portion or base portion of the closure element. The thermoelectric device can be heated rotary discs, traveling heater bands, resistance-heated slide wires, or the like. The connection between the film and the closure element can also be established by the use of hot melt adhesives, hot jets of air to the interface, ultrasonic heating, or other known methods. The bonding of the closure element to the film stock may be carried out either before or after the film is U-folded to form a bag. In any event, such bonding is done prior to side sealing the bags at the edges by conventional thermal cutting. In addition, the male and female closure elements can be positioned on opposite sides of a film. Such an embodiment would be suited for wrapping an object or a collection of objects such as wires. The male and female closure elements on a film generally should be parallel to each other, but this will depend on the intended use. While particular embodiments of the invention have been shown, it will of course be understood that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the appended claims to cover any such modifications as incorporate those features which constitute the essential features of these improvements within the true spirit and scope of the invention. All references and copending applications cited herein are hereby incorporated by reference in their entireties. | <SOH> BACKGROUND OF THE INVENTION <EOH>The use of fastening devices for the closure of containers, including plastic bag bodies, is generally known. Furthermore, the manufacture of fastening devices made of plastic materials is generally known to those skilled in the art relating to closure devices, as demonstrated by the numerous patents in this area. A particularly well-known use for fastening devices is in connection with flexible containers, such as bag bodies. The closure device and the associated container may be formed from thermoplastic materials, and the closure device and sidewalls of the container can be integrally formed by extrusion as a single piece. Alternatively, the closure device and sidewalls may be formed as separate pieces and then connected by heat sealing or any other suitable connecting process. The closure devices when incorporated as fasteners on bag bodies have been particularly useful in providing a closure means for retaining the contents within the bag body. Conventional closure devices utilize mating male and female closure elements which are occluded. When conventional closure devices are employed, it often is difficult to determine when the male and female closure elements are occluded. This problem is particularly acute when the closure devices are relatively narrow. Accordingly, when conventional closure devices are employed, there exists a reasonable likelihood that the closure device is at least partially open. The occlusion problem arises from the inability of a user to perceive when the male and female closure are occluded to form a seal between the contents of the bag and the environment external to the bag. A number of solutions to this problem have been attempted. For example, U.S. Pat. Nos. 4,186,786, 4,285,105, and 4,829,641, as well as in Japanese patent application No. 51-27719, disclose fasteners that provide a visual indication that the male and female closure elements are properly occluded. Specifically, a color change means for verifying the occlusion of the male and female members of the closure is provided wherein male and female members having different colors are employed, and, upon occlusion, provide yet a different color. For example, the female member of the closure may be opaque yellow and the male member of the closure may be translucent blue. Upon occlusion of the male member and female member a composite color with a green hue results. This use of a color change greatly improves the ability of the user of the interlocking closure device to determine when the male and female members are occluded. The change in color that is viewed when dissimilarly colored male and female members are occluded is demonstrated in a commercially available product sold under the trademark GLAD-LOCK (Glad-Lock is the registered trademark of The Glad Products Company, Oakland, Calif.). This color change effect may be enhanced by the incorporation of a color change enhancement member in the closure device, as disclosed in U.S. Pat. No. 4,829,641. However, if the first fastening strip is opaque and the second fastening strip is translucent, the color change can only be observed from the translucent side of the closure device. Therefore, one of the objects of this invention is to provide visual confirmation of occlusion from both sides of the closure device. In addition, another object of this invention is to provide a visual confirmation of occlusion wherein one of the fastening strips can be transparent. Furthermore, color-blind users may not be able to perceive the color change effect. Thus, a further object of the invention is to provide a visual confirmation of occlusion which does not rely upon color change. It is another object of the invention to provide a visual confirmation which appears or disappears upon occlusion of the closure device. The prior art includes references which have slits or notches to the surface. Such references include U.S. Pat. Nos. 5,070,584, 5,307,552, 5,363,540 and 5,403,094, and French Patent 2,022,865. However, these references do not use the slits or notches to show visual confirmation of occlusion or unocclusion. Another object of this invention is to combine visual confirmation of occlusion with a tactile and/or audible indication of occlusion. For example, the color-change effect is imperceptible in the dark, thus mooting the color-change advantage of the closure devices when they are used under such conditions. In addition, sight-impaired or color-blind people may not be able to perceive the color-change effect. Accordingly, it would be desirable to provide a closure device that affords other indications of occlusion. The prior art has attempted to furnish a fastener that provides a tactile or audible indication of occlusion. For example, U.S. Pat. Nos. 4,736,496, 5,138,750, 5,140,727, 5,403,094, and 5,405,478, as well as EP 510,797, disclose closure devices that allegedly provide a tactually or audibly perceptive indication of proper interlocking of the closure elements. It is said that, upon occlusion of the disclosed closure devices, a user is able to feel or hear that full closure is accomplished. For example, U.S. Pat. No. 4,736,946 discloses the use of additional ribs on either side of the closure elements. These ribs are said to give an improved “feel” to the closure, thus aiding a user in aligning the closure elements. The devices shown in these references are able only to provide a dynamic tactile indication of occlusion, that is, the user is able to tactually perceive that the closure device is functioning properly only at the time the user is manually closing the device. Such devices do not provide a static tactile indication of occlusion, that is, they do not “feel” closed after occlusion has been effected. Accordingly, if a plastic bag containing such a closure device is sealed by one person, a second person will not readily be able to tactually determine that the bag is sealed. The ability to make such a determination is desirable. It is a general object of the present invention to provide visual confirmation of occlusion for a closure device. It is a further general object of the present invention to provide a container that is closeable and sealable by means of such a closure device. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention satisfies these general objects by providing a closure device in which a user is able to visually determine that the closure device has been occluded. In addition, the user may be able to tactually determine that the closure device has been occluded. The closure device comprises first and second interlocking fastening strips arranged to be interlocked over a predetermined length, at least one of the fastening strips having a visual indication upon occlusion of the closure device. Thus, a user will be able to visually confirm that the closure device has been properly occluded, not only while the user is in the process of occluding the closure device, but also after the closure device has been occluded. In addition, one of the fastening strips may have a deformation upon occlusion. This deformation may provide tactile confirmation of occlusion of the closure device. | 20040426 | 20090609 | 20060112 | 59932.0 | B65D3316 | 0 | LAVINDER, JACK W | CLOSURE DEVICE PROVIDING VISUAL CONFIRMATION OF OCCLUSION | UNDISCOUNTED | 0 | ACCEPTED | B65D | 2,004 |
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10,831,847 | ACCEPTED | System and method for facilitating network-to-network transitions | A system and method for facilitating network-to-network transitions of mobile stations comprising includes at least one access point (204). At least one receiver (202, 224 or 230) is coupled to the at least one access point. The at least one receiver (202, 224 or 230) determines information concerning a wide area network and provides the information to the access point (204). The access point (204) conveys the information to at least one mobile station (206). | 1. A system for facilitating network-to-network transitions of mobile stations comprising: a first receiver to provide access to a wide area network, wherein the first receiver is located at an access point; and at least one second receiver coupled to the first receiver, wherein the at least one second receiver is located at the access point and determines information concerning a wide area network and provides the information to the access point, and wherein the access point conveys the information to at least one mobile station. 2. The system of claim 1 wherein the access point is located near a transition region to the wide area network. 3. The system of claim 1 wherein the at least one mobile station comprises means for determining a preferred service provides from the information received from the at least one access point. 4. The system of claim 1 wherein the wide area network is chosen from a group comprising a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, a Universal Mobile Telecommunications System (UMTS) network, advanced mobile phone service (AMPS) network, and a time division multiple access (TDMA) network. 5. A method for facilitating network-to-network transitions of mobile stations comprising: scanning for and receiving information received from wide area network receiver located at an access point of a wireless local area network, wherein the information concerning at least one characteristic of a wide area network to provide received information; supplying the received information to a wireless local area network receiver located at the access point and wherein the wireless local area network receiver being coupled to the wide are network receiver; and forwarding information that corresponds to the receive information from the access point to at least one mobile station. 6. The method of claim 5 further comprising determining a strength measurement report at the access point and sending information that corresponds to the report to the at least one mobile station. 7. The method of claim 5 wherein scanning and receiving the information comprises scanning for the presence of a cellular network by decoding system information messages. 8. The method of claim 5 wherein scanning and receiving information comprises receiving information indicative of an available radio access technology (RAT) and available communication channels. 9. The method of claim 5 further comprising receiving the information at the at least one mobile station and transitioning to a wide area network determined at least in part based upon the information. 10. The method of claim 9 wherein transitioning from the service provider to a wide area network comprises transitioning to a network chosen from a group consisting of a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, a Universal Mobile Telecommunications System (UMTS) network, an advanced mobile phone service (AMPS) network, and a time division multiple access (TDMA) network. 11. A method of transitioning from a wireless local area network to a wide area network comprising: receiving information from a wide area network receiver, wherein the information concerning at least one characteristic of the wide area network, wherein the wide area network receiver located at an access point, to provide received information to a wireless local area network receiver located at the access point, wherein the wide are network receiver being coupled to the wireless local are network receiver; and determining a service option from the received information. 12. The method of claim 11 wherein receiving the information comprises receiving information indicative of an available radio access technology (RAT) available and an available communication channel. 13. The method of claim 11 wherein receiving the information includes receiving WAN system message content from the access point for the RAT of interest. 14. The method of claim 11 wherein receiving the information from an access point includes receiving the information from access point at an edge of a transition region to a wide area network. 15. The method of claim 11 wherein receiving the information includes receiving a signal strength report from the access point. 16. The method of claim 11 further comprising transitioning from a wireless local area network to a wide area network based at least in part upon the received information. 17. The method of claim 16 wherein transitioning from the service provider to a wide area network comprises transitioning to network chosen from a group consisting of a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, a Universal Mobile Telecommunications System (UMTS) network, an advanced mobile phone service (AMPS) network, and a time division multiple access (TDMA) network. | FIELD OF THE INVENTION The invention relates generally to communication systems and more particularly to communication devices that transition between networks. BACKGROUND OF THE INVENTION Systems and networks for transmitting information are well known and are often classified according to the size of the coverage area of the respective system or network. As one example, a wide area network (WAN) may provide coverage over a wide area, for example over an entire a city, state, or region of a country. Conventional cellular communication systems are one example of a WAN. Other networks may extend coverage only to smaller, localized regions and are referred to as local area networks (LANs). For example, a wireless local area network (WLAN) may provide wireless coverage to users within a particular building, or over a college or business campus. Mobile stations, for example cellular telephones, often need to operate in both types of networks and, therefore, must also have the ability to transition between different types of networks. For example, a mobile station may operate in a WLAN while within a specific room because it is more economical to use a WLAN in that particular setting. However, as the mobile station reaches the limit of the coverage area of the WLAN (e.g., at the edge of the room), the mobile station needs to transition to the WAN in order to maintain unbroken communications. Mobile stations often have a preferred network, service provider, and/or radio access technology (RAT). The preferred choice often depends upon the cost of the service or other service benefits. In one example, the mobile station may connect to the WLAN when inside an enclosed area, such as a room or office, but then transition to a WAN as the mobile station leaves the enclosed area. Conventional multimode mobile stations are almost always battery powered and can consume a great deal of energy searching for WAN service while still operating in a WLAN. The station must account for the possibility that it may be on the edge of WLAN coverage and should therefore be ready for a WLAN to WAN handoff at any time. Since initial acquisition is often a time consuming processing, taking many seconds per failed attempt and often multiple seconds for successful attempts, the station must continuously look for WAN service at a minimum across several different channels and possibly multiple RATs as well. In conventional systems, if the acquired RAT or service provider is not the first choice, the station often continues to scan, in hopes of finding a higher, more preferred choice. If the WLAN is the preferred system of the mobile station, even after WAN service has been found, the mobile station must do periodic scans to keep information updated until WLAN coverage degrades to the point where a handoff from the WLAN to the WAN occurs. Such constant scanning by the mobile station wastes the energy of the battery of the station and also consumes valuable processing time that could be used for other purposes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing mobile devices within a WLAN/WAN according to principles of the present invention; FIG. 2 is a block diagram of an access point according to principles of the present invention; FIG. 3 is a flowchart showing the operation of the system for transitioning between networks according to principles of the present invention; FIG. 4 is a call flow diagram showing the occurrence of a network-to-network transition according to principles of the present invention; and FIG. 5 is a call flow diagram showing the occurrence of a network-to-network transition without the use of a broadcast indicator bit according to principles of the present invention. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Pursuant to many of these embodiments, a system and method for facilitating network-to-network transitions of mobile stations allows mobile stations to transition seamlessly from a first network to a second network. To this end, the mobile stations receive information from an access point to allow the mobile station to quickly and easily transition from a first network to a second network. By using this approach, the mobile station itself does not have to constantly monitor for the information needed to complete a hand-off to the second network and a user does not notice that a transition has taken place. Pursuant to a preferred embodiment, a WLAN access point is coupled to at least one WAN receiver. The receiver determines information concerning a wide area network and provides the information to the access point. The access point then conveys the information to the mobile station. The mobile station determines a preferred service provider from the information received from the access point. The wide area network may be a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, an advanced mobile phone service (AMPS) network, a wideband code division multiple access (WCDMA) network, or a time division multiple access (TDMA) network. Pursuant to another preferred approach, multiple receivers are coupled to the access point. Each of the receivers may receive messages according to a particular type of RAT. For example, one receiver may be structured to receive CDMA messages, another receiver may receive GSM messages, a different receiver may receive AMPS messages, still another receiver may receive WCDMA messages, and yet another receiver may receive TDMA messages. The messages received by the receivers are all forwarded to the access point where they are processed into a format that can be used by mobile stations. The access point then conveys the information to a mobile station. In many of these embodiments, different types of information may be provided by the access point to the mobile station. For example, the information may include the RATs available, the channels on which service can be found and the network information associated with each RAT. For CDMA networks, pilot strength measurement reports for all or some of the neighbor list can be sent to the mobile station. In the case of GSM, the access point could convey the WLAN time at which the next Fast Associated Control Channel (FACCH) burst will occur on the GSM network, allowing the station to optimally time its scans on the WAN. Optionally, the WAN receivers coupled to the access point may assist the mobile to more rapidly acquire WAN network timing by enabling WAN/WLAN relative timing to be conveyed to the mobile by the access point. Additionally, contents of messages transmitted for general use by all mobiles can be passed on to the mobile to ease and speed the transition to the WAN. For example, a mobile cannot access the WAN until specific system parameters have been received. This could happen while the mobile still is on the WLAN, significantly shortening the transition time from WLAN to WAN. Thus, the access point and specifically the receivers at the access point perform functions previously performed exclusively by mobile stations shifting the burden from the battery-powered mobile to AC-powered access point. The mobile stations of the present system do not have to constantly monitor for a second network in anticipation of transitioning to that network. Instead, the stations only have to determine when they are near a transition point from a first network to a second network. In the present approach, the mobile station saves power because it does not have to constantly monitor for a second network. The information provided by the access point to the mobile station allows the mobile station to transition to its preferred RAT/service, provider in a minimum time and using a minimum amount of energy. Referring initially to FIG. 1, a system for facilitating transitions between networks includes a plurality of access points 104, 106, 108, and 110 as well as a grouping 112 of multiple access points, all disposed in a room 102. Two mobile stations 114 and 116 are also present in the room 102. The access points 104, 106, 108, 110 and within grouping 112 transmit and receive data. The access points 104, 106, 108, 110 and within grouping 112 also connect users to other users within the network and also can serve as the point of interconnection between the WLAN and a fixed wire network. Each access point can serve multiple users within a defined network area. As mobile stations move beyond the range of one access point, they are automatically handed over to the next access point. Although in the example of FIG. 1 multiple access points are shown, a small WLAN may only require a single access point. The number of access points required to provide coverage typically increases as a function of the number of network users and the physical size of the network. The access points 104, 106, 108 and 110 include receivers. The access points 104, 106, 108 and 110 having receivers are located on the border area between network coverage areas and where hand-offs between the coverage areas would occur. The receivers on these access points monitor for information involving specified RATs and/or service providers. In contrast, the access points within the grouping 112 do not include receivers. The information transmittal to the station 114 could include the RAT available, the channels on which the service can be found, and the operator/network information associated with each one allowing the station to go directly to its most preferred RAT/service provider combination. In the case of a CDMA network, strength measurement reports for some or all of the neighbor list may be sent, further reducing the need for the station to spend time accessing these measurements while using a boundary access point. For GSM networks, the access point could convey the WLAN time at which the next FACCH burst will occur on the GSM network, allowing the station to time its scans on the WAN system. The mobile stations 114 and 116 may be any type of mobile wireless device. For example, the wireless device may be a cellular telephone, personal digital assistant, or pager. The mobile devices 114 and 116 operate in different operating modes and across different types of networks. In operation, the mobile stations 114 and 116 are free to move inside and outside of the room 102. For example, if the mobile stations are cellular telephones a user may move in the room. However, the user may move outside the room 102. In one approach, the mobile station 116 remains in the room and does not approach any of the limits of the coverage area of the WLAN. Consequently, the station 116 stays on the WLAN and does not need to obtain network-to-network transition information. In other circumstances, the mobile station may near the coverage limits of the WLAN and, therefore, a network-to-network transition becomes required. For instance, as shown in FIG. 1, as the mobile station 114 nears the door it detects an indicator bit transmitted by the access points 104 or 106 which indicates that there is information available for the mobile station 114 to allow it to transition to another network. The mobile station can then query the access points 104 or 106 to obtain the information and make the transition. In this case, a query is sent and the access point 104 or 106 returns the requested information to the mobile station 114. Alternately, the mobile station could query for this information following each handoff automatically in the event that the access point does not broadcast the indicator bit. Referring now to FIG. 2, an access point coupled to a group of receivers is described. An access point 204 is coupled to three receivers 202, 224 and 230. Each of the receivers 202, 224 and 230 receives different types of communications. For instance, the receiver 202 may receive signals from GSM cellular system, the receiver 224 may receive signals from an AMPS system, and the receiver 230 may receive signals from the TDMA system. Although three receivers are shown in FIG. 2, it will be understood that any number of receivers may be used with each of the receivers scanning and processing from a different RAT. Further, the receivers 202, 224 and 230 are coupled to the access point 204 by cables 242, 246 and 248. The cables 242, 246 and 248 are conventional cables of any type used in telecommunication applications. The receivers 224, 202 and 230 include antennas 214, 208 and 250. The antenna 214 receives a GSM signal 236, the antenna 202 receives an AMPS signal 238 and the antenna 250 receives a TDMA signal 240. The receivers 224, 202 and 230 also include interfaces 226, 210 and 230. The function of the interfaces is to convert the received signals 236, 238 and 240 from RF signals to signals usable by a digital controller. In that regard, the interfaces 226, 210 and 232 are coupled to controllers 228, 212 and 234. The controllers 228, 212 and 234 are responsible for scanning for appropriate signals 236, 238 and 240 (from different networks) and obtaining the information from the appropriate interface 226, 210 or 232 and extracting relevant information from the received messages. The information extracted from the messages is then received at the access point 204 by a controller 216. The controller 216 converts the information into an appropriately formatted message to be sent to an interface 218 via an antenna 220. The interface 218 converts the information from a digital form to an analog/RF form to be sent as a signal 220 to a mobile station 206. The information sent to the mobile station 206 can include a number of different components in any type of format. For instance, the information may include the RAT(s) available, channels on which communication is available or signal strength measure reports (in the case of CDMA or WCDMA). Other types of information may also be sent to the mobile station 206. Once received, the mobile station 206 processes the message. In this regard, the mobile station 206 decides the RAT/service provider combination to use. For example, the mobile station may determine whether its preferred choice is available, and if not, determine an alternative network to which it can transition. Referring now to FIG. 3, an example of a method for facilitating network-to-network transitions is described. At step 302, a receiver coupled to an access point scans for available WAN systems. In this regard, a different receiver may be used for a specific RAT. For instance, one receiver may be used to scan for available CDMA systems, another receiver for TDMA systems, another receiver for WCDMA systems, still another for AMPS systems, and another GSM systems. The information concerning these systems is collected and provided to an access point at step 304. At step 306, the access point processes the received information. For example, the access point may determine the source RAT for the information, format the information and otherwise prepare the information for transmission to mobile stations. At step 308, the access point transmits the information to the mobile station. The transmission may be triggered by the access point having received a message that the mobile station was in the vicinity of the access point. In this regard, the access point may transmit an indicator bit. When a mobile station detects the indicator bit, it may respond by requesting the proper transition information from the access point. At step 310, the mobile station receives the information transmitted by the access point. From the information received, the mobile station determines the RAT/service provider combination to use. Other information may also be provided, for instance, allowing the mobile station to select the appropriate communication channel to use. Referring now to FIG. 4, one example of a call-flow diagram showing the network-to-network transition is described. At steps 402, 404 and 406, an access point having multiple receivers receives information from three systems having different RATs. Steps 402, 404 and 406 may occur either serially or in parallel. The access point, at step 408, sends an indicator bit that is received by a mobile station. In this case, the mobile station receives the indicator bit signal and responds by requesting information to allow the mobile station to make a network-to-network transition. The mobile station's response is placed in a response message and transmitted to the access point at step 410. The access point processes the information received at steps 402, 404 and 406 and sends this to the mobile station at step 412. The processing includes receiving information from systems having different RATs and formatting the information in a message. At step 414, the mobile station determines the RAT/service provider it wishes to use and the transition occurs. Referring now to FIG. 5, one example of a call-flow diagram showing the network-to-network transition without the use of a beacon is described. At steps 502, 504 and 506, an access point having multiple receivers receives information from three systems having different RATs. Steps 502, 504 and 506 may occur either serially or in parallel. The query determines if information on the WAN is available. The mobile station issues a query at step 510. The query determines if information on the WAN is available. The access point processes the information received at steps 502, 504 and 506 and sends this to the mobile station at step 512. The processing includes receiving information from systems having different RATs and formatting the information in a message. At step 514, the mobile station determines the RAT/service provider it wishes to use and the transition occurs. While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Systems and networks for transmitting information are well known and are often classified according to the size of the coverage area of the respective system or network. As one example, a wide area network (WAN) may provide coverage over a wide area, for example over an entire a city, state, or region of a country. Conventional cellular communication systems are one example of a WAN. Other networks may extend coverage only to smaller, localized regions and are referred to as local area networks (LANs). For example, a wireless local area network (WLAN) may provide wireless coverage to users within a particular building, or over a college or business campus. Mobile stations, for example cellular telephones, often need to operate in both types of networks and, therefore, must also have the ability to transition between different types of networks. For example, a mobile station may operate in a WLAN while within a specific room because it is more economical to use a WLAN in that particular setting. However, as the mobile station reaches the limit of the coverage area of the WLAN (e.g., at the edge of the room), the mobile station needs to transition to the WAN in order to maintain unbroken communications. Mobile stations often have a preferred network, service provider, and/or radio access technology (RAT). The preferred choice often depends upon the cost of the service or other service benefits. In one example, the mobile station may connect to the WLAN when inside an enclosed area, such as a room or office, but then transition to a WAN as the mobile station leaves the enclosed area. Conventional multimode mobile stations are almost always battery powered and can consume a great deal of energy searching for WAN service while still operating in a WLAN. The station must account for the possibility that it may be on the edge of WLAN coverage and should therefore be ready for a WLAN to WAN handoff at any time. Since initial acquisition is often a time consuming processing, taking many seconds per failed attempt and often multiple seconds for successful attempts, the station must continuously look for WAN service at a minimum across several different channels and possibly multiple RATs as well. In conventional systems, if the acquired RAT or service provider is not the first choice, the station often continues to scan, in hopes of finding a higher, more preferred choice. If the WLAN is the preferred system of the mobile station, even after WAN service has been found, the mobile station must do periodic scans to keep information updated until WLAN coverage degrades to the point where a handoff from the WLAN to the WAN occurs. Such constant scanning by the mobile station wastes the energy of the battery of the station and also consumes valuable processing time that could be used for other purposes. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a block diagram showing mobile devices within a WLAN/WAN according to principles of the present invention; FIG. 2 is a block diagram of an access point according to principles of the present invention; FIG. 3 is a flowchart showing the operation of the system for transitioning between networks according to principles of the present invention; FIG. 4 is a call flow diagram showing the occurrence of a network-to-network transition according to principles of the present invention; and FIG. 5 is a call flow diagram showing the occurrence of a network-to-network transition without the use of a broadcast indicator bit according to principles of the present invention. detailed-description description="Detailed Description" end="lead"? Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. | 20040426 | 20070703 | 20051027 | 95827.0 | 0 | JAIN, RAJ K | SYSTEM AND METHOD FOR FACILITATING NETWORK-TO-NETWORK TRANSITIONS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,028 | ACCEPTED | Integrated wireline and wireless end-to-end virtual private networking | An end-to-end virtual private networking system transports network packets securely through a public data network. A mobile device comprises an application client and a wireless roaming client managing data transfer from the mobile device to the public data network via one of a plurality of predetermined wireless links. A roaming gateway is located in a data center and is coupled to the public data network for tracking the plurality of predetermined wireless links and for managing data transfer from the public data network to the mobile device via one of the plurality of predetermined wireless links. An enterprise server is provided in a private enterprise for exchanging network packets with the application client in the mobile device. A CPE-VPN router in the private enterprise network is coupled to the enterprise server and to the public data network. A VPN router located in the data center is coupled to the roaming gateway and to the public data network, wherein the VPN router and the CPE-VPN router establish a VPN tunnel therebetween via the public data network. The CPE-VPN router transports the network packets between the enterprise server and the VPN tunnel. The VPN router transports the network packets between the roaming gateway and the VPN tunnel. | 1. An end-to-end virtual private networking system for transporting network packets securely through a public data network, comprising: a mobile device comprising an application client and a wireless roaming client managing data transfer from said mobile device to said public data network via one of a plurality of predetermined wireless links; a roaming gateway located in a data center and coupled to said public data network for tracking said plurality of predetermined wireless links and for managing data transfer from said public data network to said mobile device via one of said plurality of predetermined wireless links; an enterprise server in a private network for exchanging network packets with said application client in said mobile device; a CPE-VPN router in said private network coupled to said enterprise server and to said public data network; a VPN router located in said data center coupled to said roaming gateway and to said public data network, wherein said VPN router and said CPE-VPN router establish a VPN tunnel therebetween via said public data network; wherein said CPE-VPN router transports said network packets between said enterprise server and said VPN tunnel, and wherein said VPN router transports said network packets between said roaming gateway and said VPN tunnel. 2. The system of claim 1 wherein said plurality of predetermined wireless links include a wireless LAN link and a wireless WAN link, and wherein said wireless roaming client selects said one of said wireless LAN link or said wireless WAN link in response to availability thereof. 3. The system of claim 1 wherein said data transfer between said mobile device and said roaming gateway includes encryption of said network packets. 4. The system of claim 1 wherein said roaming gateway comprises a gateway router performing network address translation. 5. The system of claim 1 wherein said VPN tunnel comprises a site-to-site tunnel. 6. The system of claim 1 wherein said VPN tunnel comprises an application-specific tunnel. 7. A data center for providing an end-to-end virtual private networking system for transporting network packets between a mobile device and an enterprise server securely through a public data network, wherein said mobile device comprises an application client and a wireless roaming client managing data transfer from said mobile device to said public data network via one of a plurality of predetermined wireless links, wherein said enterprise server is located in a private network, and wherein a CPE-VPN router is located in said private network for coupling said enterprise server and to said public data network, said data center comprising: a roaming gateway located in a data center and coupled to said public data network for tracking said plurality of predetermined wireless links and for managing data transfer from said public data network to said mobile device via one of said plurality of predetermined wireless links; and a VPN router located in said data center coupled to said roaming gateway and to said public data network, wherein said VPN router and said CPE-VPN router establish a VPN tunnel therebetween via said public data network, wherein said VPN router transports said network packets between said roaming gateway and said VPN tunnel. 8. The system of claim 7 wherein said roaming gateway comprises a gateway router performing network address translation. 9. A method of transporting network packets from a mobile wireless device to an enterprise server in a private enterprise network via a wireless data network and a public wireline data network, said wireless data network and said public wireline data network each being coupled to a data center, said method comprising the steps of: generating a network packet in said mobile device, said network packet having an original destination address of said enterprise server and an original source address of said mobile wireless device; encapsulating said network packet with a public destination address and a public source address associated with said wireless data network; transporting said network packet via said wireless data network to said data center; removing said public destination and public source addresses from said network packet; processing said network packet via a gateway to an entry router for a virtual private network (VPN) tunnel so that said original destination and said original source addresses are hidden; transporting said network packet via said public wireline data network to an exit router for said VPN tunnel; restoring said original destination and said original source addresses in said network packet; and transporting said network packet from said exit router to said enterprise server via said private enterprise network. 10. The method of claim 9 further comprising the step of: selecting said wireless data network from a plurality of predetermined wireless links. 11. The method of claim 9 wherein said network packet is generated in said mobile wireless device by an application accessing said enterprise server. 12. The method of claim 11 further comprising the step of: labeling said network packet according to a Class of Service (CoS) associated to said application. 13. The method of claim 9 wherein said public destination address is comprised of a network address corresponding to a network-address translation (NAT) router located within said data center, and wherein said NAT router forwards said network packet to said gateway. 14. The method of claim 9 wherein said entry router is located within said data center. 15. The method of claim 9 wherein said exit router is located within said private enterprise network. 16. The method of claim 9 wherein said entry router encrypts said network packet and wherein said exit router decrypts said network packet. 17. A method of transporting network packets from an enterprise server in a private enterprise network to a remote application in a mobile wireless device via a public wireline data network and a wireless data network, said wireless data network and said public wireline data network each being coupled to a data center, said method comprising the steps of: generating a network packet in said enterprise server, said network packet having an original destination address of said mobile wireless device and an original source address of said enterprise server; processing said network packet in an entry router for a virtual private network (VPN) tunnel so that said original destination and said original source addresses are hidden; transporting said network packet via said public wireline data network to an exit router for said VPN tunnel; forwarding said network packet from said exit router to a wireless gateway; encapsulating said network packet with a public destination address and a public source address associated with said wireless data network; transporting said network packet via said wireless data network to a mobile wireless client in said mobile wireless device; removing said public destination and public source addresses from said network packet; restoring said original destination and said original source addresses in said network packet; and transporting said network packet from said mobile wireless client to said remote application. 18. The method of claim 17 further comprising the step of: selecting said wireless data network from a plurality of predetermined wireless links. 19. The method of claim 17 further comprising the step of: labeling said network packet according to a Class of Service (CoS) associated to said remote application. 20. The method of claim 17 wherein said public source address is comprised of a network address corresponding to a network-address translation (NAT) router located within said data center, and wherein said NAT router forwards said network packet to said mobile wireless device. 21. The method of claim 17 wherein said entry router is located within said private enterprise network. 22. The method of claim 17 wherein said exit router is located within said data center. 23. The method of claim 17 wherein said entry router encrypts said network packet and wherein said exit router decrypts said network packet. | CROSS REFERENCE TO RELATED APPLICATIONS Not Applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not Applicable. BACKGROUND OF THE INVENTION The present invention relates in general to virtual private networking, and, more specifically, to secure data network communications between a wireless networking device and an enterprise server within a private, wired data network. Large and small enterprises (such as businesses, government, non-profit institutions, and other organizations) increasingly rely on digital data communication networks to perform essential tasks. Private computer networks are usually deployed within the enterprise to provide access for enterprise personnel to resources necessary to perform their data processing tasks. Many data-processing related tasks may be performed at non-enterprise locations, e.g., employees working offsite at a customer location or while traveling to or from such sites. Some enterprise networks may provide remote access of certain network resources to offsite employees. Due to data security concerns when a data network is opened up to outside access, one common access method is via dial-up networking which uses the public telephone network to tie-in to relatively controlled (i.e., secure) digital networks. However, the convenience, availability, and speed of dial-up access are limited. Therefore, public Internet connections are sometimes used. To increase security of data transport over the public data network, virtual private networking (VPN) techniques can be employed to create a secure “tunnel” via the Internet, provided that a wire line connection to the Internet is available. The availability and use of wireless networking has proliferated as a result of various standards being adopted. Wireless systems include wireless local area networks (e.g., 802.11 networks), wireless cellular systems (e.g., CDMA) and general packet radio service (GPRS). Current wireless systems address the security of data within the wireless network, but have not provided end-to-end protection when sending network packets between a mobile wireless device to a private enterprise network when both a wireless and wireline link are required. SUMMARY OF THE INVENTION The present invention has the advantage of tying together a seamless wireless networking solution with a wired CPE-based IP VPN to provide an end-to-end secure connection. The invention provides a managed VPN system for mobile enterprise users who can roam between various wireless networks (e.g., CDMA, GPRS, or WLAN) while maintaining a connection to a central enterprise server over dedicated wireline circuits. Support for the use of Class of Service (CoS) is also provided. In one aspect of the invention, an end-to-end virtual private networking system transports network packets securely through a public data network. A mobile device comprises an application client and a wireless roaming client managing data transfer from the mobile device to the public data network via one of a plurality of predetermined wireless links. A roaming gateway is located in a data center and is coupled to the public data network for tracking the plurality of predetermined wireless links and for managing data transfer from the public data network to the mobile device via one of the plurality of predetermined wireless links. An enterprise server is provided in a private network for exchanging network packets with the application client in the mobile device. A CPE-VPN router in the private network is coupled to the enterprise server and to the public data network. A VPN router located in the data center is coupled to the roaming gateway and to the public data network, wherein the VPN router and the CPE-VPN router establish a VPN tunnel therebetween via the public data network. The CPE-VPN router transports the network packets between the enterprise server and the VPN tunnel. The VPN router transports the network packets between the roaming gateway and the VPN tunnel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a networking system of the present invention. FIG. 2 is a block diagram showing elements of the networking system in greater detail. FIG. 3 is a flowchart showing a preferred method for establishing a connection between a mobile wireless device and an enterprise server. FIG. 4 is a flowchart showing a preferred method for directing network packets from a mobile wireless device to an enterprise server. FIG. 5 is a flowchart showing a preferred method for directing network packets from an enterprise server to a mobile wireless device. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, a private enterprise network 10 serves enterprise facilities 11 and 12 and may include local area networks (LANs) and wide area networks (WANs). It is desired for a mobile wireless device 13 (such as a laptop computer or a data-enabled cellular phone) to remotely access resources within private enterprise network 10. Mobile device 13 may be traveling in an automobile 14, for example. Mobile device 13 may typically be capable of connecting with various wireless services depending upon their availability. For example, a CDMA system 15 connected to a wireless tower 16 may be preferentially selected by mobile device 13 when available. A GPRS system 17 connected to a tower 18 may alternatively be selected when in range and according to a predetermined priority scheme when multiple wireless services are available. CDMA system 15 and GPRS system 17 are examples of wireless wide area networks (WANs). Mobile device 13 may also connect to a wireless LAN, such as provided in a public area (e.g., an airport or a hotel lobby), that is provided for connecting users to the Internet. CDMA system 15 and GPRS system 17 are coupled to the public Internet 20. Although private enterprise network 10 is coupled (e.g., via a gateway) to public Internet 20, a direct connection passing network packets between CDMA system 15 or GPRS system 17 directly to private enterprise network 10 are not utilized due to security concerns. Instead, the present invention employs a data center 21 coupled to public Internet 20 for acting as an intermediary between the mobile wireless device and the resources of private enterprise network 10. The primary elements of the secure network system are shown in greater detail in FIG. 2. Mobile wireless device 13 comprises a digital-computing device for executing a remote application 25. During its operation, application 25 accesses an enterprise server 26 in private enterprise network 10. In order to support wireless roaming between various wireless services, a roaming client 27 is provided in mobile device 13 for interfacing to application 25 and to wireless transceivers 28 and 30, for example. Transceiver 28 is adapted to communicate with CDMA system 15 while transceiver 30 is adapted to communicate with a wireless LAN 31, which may be any wireless LAN deployed remotely from private enterprise network 10 which allows access by the mobile user and which is interconnected with Internet 20. CDMA system 15 and WLAN 31 are connected via Internet 20 to a router 32 in data center 21. Router 32 is coupled to a port address translation (PAT) router 34 via a switch 33. In order to obtain data security within the wireless link from mobile device 13 to router 34 in data center 21, a virtual private network tunnel is created. Router 34 is coupled to a roaming gateway 35. Roaming client 27 and roaming gateway 35 cooperate to provide seamless wireless roaming for data transport between remote application 25 and a router 36 connected to gateway 35. Roaming client 27 and gateway 35 may be comprised of the TotalRoam® software platform available from Padcom, Inc. of Bethlehem, Pa. In particular, roaming client 27 may utilize the TR6100 client from Padcom. The roaming gateway and roaming client manage the transfer of network packets therebetween in response to availability of various wireless links and a pre-configured priority between links. A VPN tunnel created between the roaming client and the roaming gateway may comprise a VPN tunnel using 3DES encryption, for example. In addition, gateway 35 may be protected by static network address translation or port address translation performed by router 34 as is known in the art. Router 36 comprises an entry router for a VPN tunnel 37 passing through a provider network 38 via Internet 20 to an exit router 39 located in the private enterprise network 10. In view of the bi-directional communication, routers 36 and 39 each perform the functions of entry and exit routers as appropriate. Router 39 is connected to enterprise server 26 for making enterprise server 26 accessible via the tunnel. VPN tunnel 37 may be created as a site-to-site tunnel that is available as long as there is at least one mobile device accessing it. Such a site-to-site tunnel may be created using IPSec protocols, for example. Alternatively, VPN tunnel 37 may be an application specific tunnel using the SSL protocol. A specific example of transport of a particular packet will now be described. Example IP addresses of network elements of FIG. 2 are shown in the following chart. Network Element IP Address Remote Application 25 192.168.9.3/24 Roaming Client 27 192.168.9.1/24 WLAN 31 144.230.98.XXX Router 32 144.230.96.1 Router 34 144.230.99.102 Gateway 35 NIC1 192.168.8.2/24 Gateway 35 NIC2 192.168.20.3 Router 36 192.168.20.1 Router 39 192.168.21.1/24 Enterprise Server 26 192.168.21.2/24 During transport of a network packet from application 25 to enterprise server 26, the network packet passes through a virtual private network tunnel between mobile device 13 and gateway 35. Addressing of the network packets is as shown in Table 1 beginning at sequence point ‘a’ wherein the visible source address is the IP address of remote application 25 and the visible destination address is the IP address of enterprise server 26. A packet moves from application 25 to roaming client 27 where it is encapsulated at sequence point ‘b’. After encapsulation, the visible source address becomes a public source address dynamically assigned within the CDMA system, for example. The visible destination address of the encapsulated packet at sequence point ‘b’ comprises the IP address of router 34, which is a PAT router. The actual source and destination addresses are encapsulated at sequence point ‘b’ as shown. After router 34 performs network address translations for a network packet, addressing is shown at sequence point ‘c’ wherein a visible destination address has been translated to the IP address of NIC1 of gateway 35. Gateway 35 de-encapsulates the network packet so that the original source and destination addresses are visible as shown at sequence point ‘d’. Thereafter, addressing of the network packet as it passes through the CPE-IP-VPN tunnel is determined according to the specific configuration of that tunnel. Thereafter, the network packet may be transported to enterprise server 26 within the private enterprise network 10. TABLE 1 Encapsulated Encapsulated Sequence Visible SA Visible DA SA DA a 192.168.9.3 192.168.21.2 b Public CDMA 144.230.99.102 192.168.9.3 192.168.21.2 c Public CDMA 192.168.8.2 192.168.9.3 192.168.21.2 d 192.168.9.3 192.168.21.2 Once a network packet reaches enterprise server 26, a response or return packet may typically be generated by enterprise server 26 destined for the remote application on the mobile wireless device. Initially, the return network packet is transported through CPE-IP-VPN tunnel 37, exits router 36, and enters gateway 35 at NIC2. The return network packet then passes through the VPN tunnel of the wireless link as shown in Table 2. The visible source and destination addresses correspond to the IP addresses of enterprise server 26 and application 25, respectively, as shown at sequence point ‘e’. Gateway 35 encapsulates the network packet providing a source address of gateway 35 NIC1 and a visible destination address corresponding to a public dynamically assigned address within the CDMA system at sequence point ‘f’. Next, the visible source address is altered at sequence point ‘g’ to the IP address of the router exposed to the public network. Once packets arrive at roaming client 27 in the wireless mobile device, the outer IP header having the encapsulating addresses is stripped off and the original source and destination addresses are restored at sequence point ‘h’. TABLE 2 Encapsulated Encapsulated Sequence Visible SA Visible DA SA DA e 192.168.21.2 192.168.9.3 f 192.168.8.2 Public CDMA 192.168.21.2 192.168.9.3 g 144.230.99.102 Public CDMA 192.168.21.2 192.168.9.3 h 192.168.21.2 192.168.9.3 Use of a digital link by the mobile wireless device of the present invention is shown in FIG. 3. In step 40, a user accesses the remote application, preferably in a manner supporting Class of Service (CoS). The use of CoS allows higher priority applications to receive an increased allocation of bandwidth of network transport, resulting in lower latency times. A CoS-enabled application labels its corresponding network packets with a CoS label, as is known in the art. A check is made in step 41 to determine whether one or more wireless networks are available to the mobile wireless device. If available, then the highest priority wireless network is selected, a VPN is established with the roaming gateway via that selected wireless network, and subsequent network packets from the remote application are diverted to the VPN to the roaming gateway and then to the CPE-IP-VPN tunnel traversing the public network to the private enterprise network and to the enterprise server. Preferably, the public network (such as network 38 and Internet 20) are CoS-enabled in order to support the preferred CoS-enabled remote application. If no available wireless network is found in step 41, then the mobile wireless device may instead dial out to the public switched telephone network (PSTN), if available, via a dial-up modem 24 in mobile device 13 (shown in FIG. 2). A preferred method for transporting network packets in the direction from mobile device 13 to enterprise server 26 is shown in FIG. 4. In step 45, the remote application generates a network packet destined for the enterprise server. In step 46, the network packet is encapsulated with public addresses for traversing the wireless link. The network packet is transported in step 47 to a router in the data center via the In the data center, network address translation is performed on the network packet in step 48 and then the public addresses are removed. In step 49, the network packet is processed through the roaming gateway to the entry router of the CPE-IP-VPN tunnel. In step 50, the network packet is transported in an encrypted form through the tunnel. The network packet is processed through the exit router of the tunnel to restore its original address information. Thereafter, in step 52, the network packet is transported to the enterprise server via the private enterprise network. A preferred method for transporting a return network packet from the enterprise server to the mobile device is shown in FIG. 5. In step 55, the enterprise server generates a network packet destined for the mobile device. The network packet is processed via the entry router to the CPE-IP-VPN tunnel in step 56. Processing into the VPN tunnel includes encryption as is known in the art. In step 57, the network packet is transported to the exit router and the data center via the tunnel and is then decrypted. The network packet is forwarded to the roaming gateway in step 58. In step 59, the network packet delivered to the roaming gateway is encapsulated with public addresses corresponding to the selected wireless link. The network packet is transported to the roaming client via the selected wireless link in step 60. Public addresses are removed and the original addresses restored in step 61. In step 62, the network packet is transported within the mobile wireless device to the remote application. In view of the foregoing description, the present invention has provided a secure end-to-end network transport solution between a mobile application and a fixed enterprise server using wireless and wireline public networks and a private wireline network. In particular, the functions performed by the data center provide a secure bridge between the wireless and wireline environments. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates in general to virtual private networking, and, more specifically, to secure data network communications between a wireless networking device and an enterprise server within a private, wired data network. Large and small enterprises (such as businesses, government, non-profit institutions, and other organizations) increasingly rely on digital data communication networks to perform essential tasks. Private computer networks are usually deployed within the enterprise to provide access for enterprise personnel to resources necessary to perform their data processing tasks. Many data-processing related tasks may be performed at non-enterprise locations, e.g., employees working offsite at a customer location or while traveling to or from such sites. Some enterprise networks may provide remote access of certain network resources to offsite employees. Due to data security concerns when a data network is opened up to outside access, one common access method is via dial-up networking which uses the public telephone network to tie-in to relatively controlled (i.e., secure) digital networks. However, the convenience, availability, and speed of dial-up access are limited. Therefore, public Internet connections are sometimes used. To increase security of data transport over the public data network, virtual private networking (VPN) techniques can be employed to create a secure “tunnel” via the Internet, provided that a wire line connection to the Internet is available. The availability and use of wireless networking has proliferated as a result of various standards being adopted. Wireless systems include wireless local area networks (e.g., 802.11 networks), wireless cellular systems (e.g., CDMA) and general packet radio service (GPRS). Current wireless systems address the security of data within the wireless network, but have not provided end-to-end protection when sending network packets between a mobile wireless device to a private enterprise network when both a wireless and wireline link are required. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has the advantage of tying together a seamless wireless networking solution with a wired CPE-based IP VPN to provide an end-to-end secure connection. The invention provides a managed VPN system for mobile enterprise users who can roam between various wireless networks (e.g., CDMA, GPRS, or WLAN) while maintaining a connection to a central enterprise server over dedicated wireline circuits. Support for the use of Class of Service (CoS) is also provided. In one aspect of the invention, an end-to-end virtual private networking system transports network packets securely through a public data network. A mobile device comprises an application client and a wireless roaming client managing data transfer from the mobile device to the public data network via one of a plurality of predetermined wireless links. A roaming gateway is located in a data center and is coupled to the public data network for tracking the plurality of predetermined wireless links and for managing data transfer from the public data network to the mobile device via one of the plurality of predetermined wireless links. An enterprise server is provided in a private network for exchanging network packets with the application client in the mobile device. A CPE-VPN router in the private network is coupled to the enterprise server and to the public data network. A VPN router located in the data center is coupled to the roaming gateway and to the public data network, wherein the VPN router and the CPE-VPN router establish a VPN tunnel therebetween via the public data network. The CPE-VPN router transports the network packets between the enterprise server and the VPN tunnel. The VPN router transports the network packets between the roaming gateway and the VPN tunnel. | 20040426 | 20080108 | 20051027 | 87589.0 | 0 | MONDESIR, ABDIAS | INTEGRATED WIRELINE AND WIRELESS END-TO-END VIRTUAL PRIVATE NETWORKING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,120 | ACCEPTED | Detection of herpes simplex virus types 1 and 2 by nucleic acid amplification | The present invention relates to a method of detecting the presence or absence of herpes simplex virus (HSV) in a sample based on amplifying a portion of the Glycoprotein G (US4) gene of HSV and detecting the presence of the amplified nucleic acid using primers and detector primers as described herewith. The method of the invention further identifies the type of HSV, either HSV-1 or HSV-2, in a sample. Also encompassed by the invention is a kit comprising the primers and detector primers which may be used with the amplification method described herewith. | 1. A method of detecting a Herpes Simplex Virus type 1 (HSV-1) or Herpes Simplex Virus type 2 (HSV-2) target sequence comprising: (a) hybridizing a polynucleotide comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 5-25 and 36-47; and (b) detecting the HSV-1 or HSV-2 target sequence. 2. A method of detecting a Herpes Simplex Virus type 1 (HSV-1) or Herpes Simplex Virus type 2 (HSV-2) target sequence comprising: (a) amplifying the Herpes Simplex Virus target sequence using a first amplification primer comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 7-8 and 38; (b) amplifying the target sequence using a second amplification primer comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 9-18 and 39-43; and (c) detecting the amplified HSV-1 or HSV-2 target sequence. 3. A method of detecting a Herpes Simplex Virus type 1 (HSV-1) or Herpes Simplex Virus type 2 (HSV-2) target sequence comprising: (a) amplifying the target sequence using a first amplification primer comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 7-8 and 38; (b) amplifying the target sequence using a second amplification primer comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 9-18 and 39-43; and (c) detecting the amplified HSV-1 or HSV-2 target sequence. 4. The method of claim 2, wherein the amplification reaction is a Strand Displacement Amplification (SDA) reaction. 5. The method of claim 2, wherein the detection method is selected from the group consisting of: direct detection, Polymerase Chain Reaction (PCR), Ligase Chain Reaction (LCR), in situ hybridization, Transcription Mediated Amplification (TMA), Self-Sustaining Sequence Replication (3SR), Rolling Circle Amplification (RCA), Qβ replicase system, and Nucleic Acid Sequence Based Amplification (NASBA). 6. The method of claim 2, wherein the first amplification primer further comprises a sequence selected from the group consisting of: a hairpin, a g-quartet, a restriction enzyme recognition sequence, and a sequence that binds to an assay probe. 7. The method of claim 2, wherein the first amplification primer further comprises a detectable label. 8. The method of claim 7, wherein the label is a fluorescent moiety. 9. The method of claim 2, wherein the first amplification primer comprises a sequence selected from the group consisting of: a restriction enzyme recognition site and a RNA polymerase promoter. 10. The method of claim 2, further comprising amplifying an Internal Amplification Control (IAC). 11. The method of claim 10, wherein the IAC is selected from the group consisting of: SEQ ID NOs: 26-27 and 48-49. 12. The method of claim 10, further comprising detecting amplified IAC. 13. The method of claim 12, wherein the amplified IAC is detected by a means different from the amplified target sequence. 14. A method of detecting a Herpes Simplex Virus type 1 (HSV-1) or Herpes Simplex Virus type 2 (HSV-2) target sequence comprising: (a) hybridizing one or more polynucleotides comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 7-18 and 38-43; (b) and detecting the HSV-1 or HSV-2 target sequence. 15. The method of claim 14, wherein said one or more polynucleotides further comprises a detectable label. 16. The method of claim 15, wherein the detectable label is a fluorescent moiety. 17. A polynucleotide comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 5-25 and 36-47. 18. The polynucleotide of claim 17, further comprising a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 7-18 and 38-43. 19. The polynucleotide of claim 17, further comprising a sequence selected from the group consisting of a hairpin, a g-quartet, a restriction enzyme recognition site, and a sequence that binds to an assay probe. 20. The polynucleotide of claim 18, wherein the polynucleotide is labeled with a detectable label. 21. The polynucleotide of claim 20, wherein the label is a fluorescent moiety. 22. A kit for detecting a sequence, comprising one or more primers having a sequence consisting essentially of a target binding sequence of any one of SEQ ID NOs: 7-18 and 38-43. 23. The kit of claim 22, further comprising bumper primers. 24. The kit of claim 23, wherein the bumper primers are selected from the group consisting of: SEQ ID NOs: 23-25 and 46-47. 25. The kit of claim 22, further comprising adapter primers. 26. The kit of claim 25, wherein the adapter primers are selected from the group consisting of: SEQ ID NOs: 19-22 and 44-45. 27. The kit of claim 22, further comprising detector primers: 28. The kit of claim 27, wherein the detector primers are selected from the group consisting of: SEQ ID NOs: 30-35. 29. A composition comprising one or more primers consisting essentially of a target binding sequence of any one of SEQ ID NOs: 5-25 and 36-47. 30. The composition of claim 29 comprising one or more primers consisting essentially of a target binding sequence of any one of SEQ ID NOs: 5-18, 23-25, 36-43, and 46-47. 31. The composition of claim 30, further comprising: (a) an adapter primer sequence capable of hybridizing to the target sequence through a target binding sequence located at the 3′ end of the adapter primer, wherein the adapter primer comprises a 5′ generic tail, and the adapter primer is selected from the group consisting of: SEQ ID NOs: 19-22; and (b) a detector primer sequence capable of hybridizing to a complement of the 5′ tail of the adapter primer through the 3′ portion of the detector primer, wherein the detector primer sequence comprises a 5′ restriction enzyme recognition site and a detectable label selected from the group consisting of: a fluorescent moiety, a radioisotope, a chemiluminescent agent, an enzyme substrate capable of developing a visible reaction product, and a ligand-detectably labeled ligand binding partner. 32. The composition of claim 31, wherein the detector primer sequence comprises a structural moiety selected from the group consisting of: a hairpin and g-quartet. 33. The composition of claim 31, wherein the detectable label is a fluorescent moiety. 34. The composition of claim 33, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 35. The composition of claim 34, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 36. A composition comprising one or more primers consisting essentially of the HSV-1 target binding sequence of any one of SEQ ID NOs: 5-18, and 23-25. 37. The composition of claim 36, further comprising: (a) an adapter primer sequence capable of hybridizing to the target sequence through a target binding sequence located at the 3′ end of the adapter primer, wherein the adapter primer comprises a 5′ generic tail, and the adapter primer is selected from the group consisting of: SEQ ID NOs: 19-22; and (b) a detector primer sequence capable of hybridizing to a complement of the 5′ tail of the adapter primer through the 3′ portion of the detector primer, wherein the detector primer sequence comprises a 5′ restriction enzyme recognition site and a detectable label selected from the group consisting of: a fluorescent moiety, a radioisotope, a chemiluminescent agent, an enzyme substrate capable of developing a visible reaction product, and a ligand-detectably labeled ligand binding partner. 38. The composition of claim 37, wherein the detector primer sequence comprises a structural moiety selected from the group consisting of: a hairpin and g-quartet. 39. The composition of claim 37, wherein the detectable label is a fluorescent moiety. 40. The composition of claim 39, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 41. The composition of claim 37, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 42. A composition comprising one or more primers consisting essentially of the HSV-2 target binding sequence of any one of SEQ ID NOs: 36-43 and 46-47. 43. The composition of claim 42, further comprising: (a) an adapter primer sequence capable of hybridizing to the target sequence through a target binding sequence located at the 3′ end of the adapter primer, wherein the adapter primer comprises a 5′ generic tail, and the adapter primer is selected from the group consisting of: SEQ ID NOs: 19-22; and (b) a detector primer sequence capable of hybridizing to the 5′ tail of the adapter primer through the 3′ portion of the detector primer, wherein the detector primer sequence comprises a 5′ restriction enzyme recognition site and a detectable label selected from the group consisting of: a fluorescent moiety, a radioisotope, a chemiluminescent agent, an enzyme substrate capable of developing a visible reaction product, and a ligand-detectably labeled ligand binding partner. 44. The composition of claim 43, wherein the detector primer sequence comprises a structural moiety selected from the group consisting of: a hairpin and g-quartet. 45. The composition of claim 43, wherein the detectable label is a fluorescent moiety. 46. The composition of claim 45, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 47. The composition of claim 43, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 48. A method of detecting the presence of HSV-1 target sequence in a sample, said method comprising: (a) adding the sample to a first amplification primer selected from the group consisting of: SEQ ID NOs: 7-8; and a second amplification primer selected from the group consisting of: SEQ ID NOs: 9-18, producing an amplified HSV-1 nucleic acid product; and (b) detecting the amplified HSV-1 nucleic acid product, wherein the detection of the amplified product indicates the presence of HSV-1 in the sample. 49. The method of claim 48, wherein the amplified HSV-1 nucleic acid product is detected by a method selected from the group consisting of: universal detection, gel electrophoresis, and quantitative hybridization. 50. The method of claim 48, further comprising: (c) Adding the sample to a first bumper primer of SEQ ID NO: 46 and a second bumper of SEQ ID NO: 47. 51. The method of claim 50, wherein the detecting step further comprises, (d) hybridizing the first amplification primer and an adapter primer selected from the group consisting of: SEQ ID NOs: 19-22 to the amplified HSV-1 target sequence, wherein the adapter primer hybridizes downstream of the first amplification primer; (e) extending the 3′ ends of the first amplification primer and the adapter primer producing an adapter primer extension product, wherein the extension of the first amplification primer displaces the adapter primer extension product; (f) hybridizing the second amplification primer to the adapter primer extension product; (g) extending the 3′ end of the second amplification primer, producing a double-stranded molecule comprising the adapter primer extension product and its complement, wherein each strand comprises a nickable restriction enzyme site; (h) nicking the double-stranded molecule, creating a 5′ portion and a 3′ portion, wherein the 5′ portion comprises a nicked tail and the 3′ portion comprises a nicked complement adapter primer extension product; (i) extending the 3′ end of the nicked tail, displacing the nicked complement adapter primer extension product, wherein the displaced nicked complement adapter primer extension product is single-stranded; (j) hybridizing a detector primer to the single-stranded complement adapter primer extension product, wherein the detector primer comprises a detectable label and detects the HSV-1 target sequence; (k) extending the 3′ ends of the detector primer and the complement adapter primer extension product, producing a double-stranded detection molecule comprising a detector primer extension product and its complement, wherein each strand comprises a cleavable restriction enzyme recognition site; (l) cleaving the double-stranded detection molecule; and (m) detecting the detectable label. 52. The method of claim 51, wherein the detectable label is a fluorescent moiety. 53. The method of claim 52, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 54. The method of claim 53, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 55. The method of claim 51, further comprising: (n) amplifying an Internal Amplification Control (IAC) target sequence selected from the group consisting of: SEQ ID NOs: 26-27; (o) hybridizing the first amplification primer and an IAC adapter primer selected from the group consisting of: SEQ ID NOs: 28-29 to the IAC, wherein the adapter primer hybridizes downstream of the first amplification primer; (p) extending the 3′ ends of the first amplification primer and the IAC adapter primer, producing an IAC adapter primer extension product, wherein the extension of the first amplification primer displaces the IAC adapter primer extension product; (q) hybridizing the second amplification primer to the IAC adapter primer extension product; (r) extending the 3′ end of the second amplification primer, producing a double-stranded molecule comprising the IAC adapter primer extension product and its complement, wherein each strand comprises a nickable restriction enzyme site; (s) nicking the double-stranded molecule; (t) extending the nicked tail end of the complement IAC adapter primer extension product, displacing the single-stranded nicked complement adapter primer extension product; (u) hybridizing an IAC detector primer to the single-stranded complement IAC adapter primer extension product, wherein the IAC detector primer comprises a detectable label and detects the IAC; (v) extending the 3′ ends of the IAC detector primer and the single-stranded complement IAC adapter primer extension product, producing a double-stranded detection molecule comprising a detector primer extension product and its complement, wherein each strand comprises a cleavable restriction enzyme site; (w) cleaving the double-stranded detection molecule; and (x) detecting the detectable label. 56. The method of claim 55, wherein the IAC detector primer sequence is selected from the group consisting of: SEQ ID NOs: 34-35; and the detector primer for detecting HSV-1 target sequence is selected from the group consisting of SEQ ID NOs: 30-33. 57. The method of claim 55, wherein the detectable label is a fluorescent moiety. 58. The method of claim 57, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 59. The method of claim 58, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 60. A method of detecting the presence of HSV-2 target sequence in a sample, said method comprising: (a) adding the sample to a first amplification primer of SEQ ID NO: 38; and a second amplification primer selected from the group consisting of: SEQ ID NOs: 39-43, producing an amplified HSV-2 nucleic acid product; and (b) detecting the amplified HSV-2 nucleic acid product, wherein the detection of the amplified product indicates the presence of HSV-2 in the sample. 61. The method of claim 60, wherein the amplified HSV-2 nucleic acid product is detected by a method selected from the group consisting of: universal detection, gel electrophoresis, and quantitative hybridization. 62. The method of claim 60, further comprising: (c) adding the sample to a first bumper primer of SEQ ID NO: 46 and a second bumper of SEQ ID NO: 47. 63. The method of claim 62, wherein the detecting step further comprises, (d) hybridizing the first amplification primer and an adapter primer selected from the group consisting of: SEQ ID NOs: 44-45 to the amplified HSV-2 target sequence, wherein the adapter primer hybridizes downstream of the first amplification primer; (e) extending the 3′ ends of the first amplification primer and the adapter primer producing an adapter primer extension product, wherein the extension of the first amplification primer displaces the adapter primer extension product; (f) hybridizing the second amplification primer to the adapter primer extension product; (g) extending the 3′ end of the second amplification primer, producing a double-stranded molecule comprising the adapter primer extension product and its complement, wherein each strand comprises a nickable restriction enzyme site; (h) nicking the double-stranded molecule, creating a 5′ portion and a 3′ portion, wherein the 5′ portion comprises a nicked tail and the 3′ portion comprises a nicked complement adapter primer extension product; (i) extending 3′ end of the nicked tail, displacing the nicked complement adapter primer extension product, wherein the displaced nicked complement adapter primer extension product is single-stranded; (j) hybridizing a detector primer to the complement adapter primer extension product, wherein the detector primer comprises a detectable label; (k) extending the 3′ ends of the detector primer and the complement adapter primer extension product, producing a double-stranded detection molecule comprising a detector primer extension product and its complement, wherein each strand comprises a cleavable restriction enzyme recognition site; (l) cleaving the double-stranded detection molecule; and (m) detecting the detectable label. 64. The method of claim 63, wherein the detectable label is a fluorescent moiety. 65. The method of claim 64, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 66. The method of claim 65, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 67. The method of claim 63, further comprising: (n) amplifying an internal amplification control (IAC) target sequence selected from the group consisting of: SEQ ID NOs: 47-48; (o) hybridizing the first amplification primer and an IAC adapter primer selected from the group consisting of: SEQ ID NOs: 50-51 to the IAC, wherein the adapter primer hybridizes downstream of the first amplification primer; (p) extending the 3′ ends of the first amplification primer and the IAC adapter primer, producing an IAC adapter primer extension product, wherein the extension of the first amplification primer displaces the IAC adapter primer extension product; (q) hybridizing the second amplification primer to the IAC adapter primer extension product; (r) extending the 3′ end of the second amplification primer, producing a double-stranded molecule comprising the IAC adapter primer extension product and its complement, wherein each strand comprises a nickable restriction enzyme site; (s) nicking the double-stranded molecule, creating a 5′ portion and a 3′ portion, wherein the 5′ portion comprises a nicked tail and the 3′ portion comprises a nicked complement IAC adapter primer extension product; (t) extending the 3′ end of the nicked tail, displacing the nicked complement IAC adapter primer extension product, wherein the displaced nicked complement adapter primer extension product is single-stranded; (u) hybridizing an IAC detector primer to the single-stranded complement IAC adapter primer extension product, wherein the IAC detector primer comprises a detectable label and detects the IAC target sequence; (v) extending the 3′ ends of the IAC detector primer and the complement IAC adapter primer extension product, producing a double-stranded detection molecule comprising a detector primer extension product and its complement, wherein each strand comprises a cleavable restriction enzyme site; (w) cleaving the double-stranded detection molecule; and (x) detecting the detectable label. 68. The method of claim 67, wherein the IAC detector primer sequence is selected from the group consisting of: SEQ ID NOs: 34-35; and the detector primer for detecting HSV-2 target sequence is selected from the group consisting of SEQ ID NOs: 30-33. 69. The method of claim 68, wherein the detectable label is a fluorescent moiety. 70. The method of claim 69, wherein the fluorescent moiety comprises a donor and quencher dye pair selected from the group consisting of: fluorescein (FAM)/rhodamine (ROX); FAM/P-(dimethyl aminophenylazo) benzoic acid (DABCYL); ROX/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™; FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). 71. The method of claim 67, wherein the detector primer is selected from the group consisting of: SEQ ID NOs: 30-35. 72. A composition comprising primers for the detection of HSV-1 target sequence in a sample by an amplification reaction comprising: (a) a first amplification primer sequence capable of hybridizing to the HSV-1 target sequence, wherein the first amplification primer is selected from the group consisting of: SEQ ID NO: 7-8; (b) a second amplification primer sequence capable of hybridizing to a complement of the HSV-1 target sequence, wherein the second amplification primer is selected from the group consisting of: SEQ ID NOs: 9-18; (c) a first bumper primer sequence capable of hybridizing to the HSV-1 target sequence upstream of the first amplification primer, wherein the first bumper primer is SEQ ID NO: 23; and (d) a second bumper primer sequence capable of hybridizing to a complement of the HSV-1 target sequence upstream of the second amplification primer, wherein the second amplification primer is selected from the group consisting of SEQ ID NOs: 24-25. 73. A composition comprising primers for the detection of an HSV-2 target sequence in a sample by an amplification reaction comprising: (a) a first amplification primer sequence that hybridizes to the HSV-2 target sequence, wherein the first amplification primer sequence is SEQ ID NO: 38; (b) a second amplification primer sequence that hybridizes to a complement of the HSV-2 target sequence, wherein the second amplification primer is selected from the group consisting of: SEQ ID NOs: 39-43; (c) a first bumper primer sequence that hybridizes to the HSV-2 target sequence upstream of the first amplification primer, wherein the first bumper primer is SEQ ID NO: 46; and (d) a second bumper primer sequence that hybridizes to a complement of the HSV-2 target sequence upstream of the second amplification primer, wherein the second amplification primer is SEQ ID NO: 47. 74. A method for detecting, in a sample, an HSV-1 target sequence, comprising: (a) hybridizing a first amplification primer, having a sequence selected from the group consisting of SEQ ID NOs: 7-8, to the HSV-1 target sequence; (b) hybridizing a first bumper primer of SEQ ID NO: 23 to the HSV-l target sequence, wherein the first bumper primer hybridizes to the HSV-1 target sequence upstream of the first amplification primer and the second bumper primer hybridizes to the complement HSV-1 target sequence upstream of the second amplification primer; (c) extending the 3′ ends of the first bumper primer and the first amplification primer, producing a first amplification primer extension product, wherein the extension of the first bumper primer displaces the first amplification primer extension product; (d) hybridizing a second amplification primer, having a sequence selected from the group consisting of SEQ ID NOs: 9-18, to the first amplification primer extension product; (e) hybridizing a second bumper primer, having a sequence selected from the group consisting of: SEQ ID NOs: 24-25, to the first amplification primer extension product; (f) extending the 3′ ends of the second bumper primer and the second amplification primer, producing a second amplification primer extension product, wherein the extension of the second bumper primer displaces the second amplification primer extension product; (g) hybridizing the first amplification primer to the second amplification primer extension product, (h) extending the 3′ end of the first amplification primer of step (g), producing a double-stranded molecule comprising the second amplification primer extension product and its complement,wherein each strand comprises a nickable restriction enzyme site; (i) nicking the double-stranded molecule; creating a 5′ portion and a 3′ portion, wherein the 5′ portion comprises a nicked tail and the 3′ portion comprises a nicked second amplification primer extension product, and its complement; (j) extending the 3′ end of the nicked tail, displacing the nicked second amplification primer extension product, wherein the nicked complement second amplification primer extension product is single-stranded; (k) extending the 3′ end of the nicked tail, displacing the nicked complement second amplification primer extension product, wherein the nicked complement second amplification primer extension product is single-stranded; (l) exponentially amplifying the two single-stranded molecules by separately hybridizing the first amplification primer and the second amplification primer to each single-stranded molecule, and repeating steps (h)-(k), thereby amplifying the HSV-1 target sequence; and (m) detecting the amplified HSV-1 target sequence. 75. A method for detecting, in a sample, an HSV-2 target sequence, comprising: (a) hybridizing a first amplification primer of SEQ ID NO: 38 to the HSV-2 target sequence; (b) hybridizing a first bumper primer of SEQ ID NO: 46 to the HSV-2 target sequence, wherein the first bumper primer hybridizes to the HSV-2 target sequence upstream of the first amplification primer and the second bumper primer hybridizes to the complement target sequence upstream of the second amplification primer; (c) extending the 3′ ends of the first bumper primer and the first amplification primer, producing a first amplification primer extension product, wherein the extension of the first bumper primer displaces the first amplification primer extension product; (d) hybridizing a second amplification primer, having a sequence selected from the group consisting of SEQ ID NOs: 39-43, to the first amplification primer extension product; (e) hybridizing a second bumper primer of SEQ ID NO: 47 to the first amplification primer extension product; (f) extending the 3′ ends of the second bumper primer and the second amplification primer, producing a second amplification primer extension product, wherein the extension of the second bumper primer displaces the second amplification primer extension product; (g) hybridizing the first amplification primer to the second amplification primer extension product, (h) extending the 3′ end of the first amplification primer of step (g), producing a double-stranded molecule comprising the second amplification primer extension product and its complement,wherein each strand comprises a nickable restriction enzyme site; (i) nicking the double-stranded molecule, creating a 5′ portion and a 3′ portion, wherein the 5′ portion comprises a nicked tail and the 3′ portion comprises a nicked second amplification primer extension product, and its complement; (j) extending the 3′ nicked tail, displacing the nicked second amplification primer extension product, wherein the nicked complement second amplification primer extension product is single-stranded; (k) extending the 3′ end of the nicked tail, displacing the nicked complement second amplification primer extension product, wherein the nicked complement second amplification primer extension product is single-stranded; (l) exponentially amplifying the two single-stranded molecules by separately hybridizing the first amplification primer and the second amplification primer to each single-stranded molecule, and repeating steps (h)-(k), thereby amplifying the HSV-2 target sequence; and (m) detecting the amplified HSV-2 target sequence. 76. A kit for the detection of HSV-1 target sequence, comprising one or more amplification primers selected from the group consisting of: SEQ ID NOs: 7-18; and bumper primers selected from the group consisting of SEQ ID NOs: 23-25. 77. The kit of claim 76, further comprising: one or more adapter primers selected from the group consisting of: SEQ ID NOs: 19-22; and one or more detector primer selected from the group consisting of: SEQ ID NOs: 30-35. 78. The kit of claim 77, further comprising: one or more IAC target sequences selected from the group consisting of: SEQ ID NOs: 26-27; and one or more IAC adapter primers selected from the group consisting of: SEQ ID NOs: 28-29. 79. A kit for the detection of HSV-2 target sequence, comprising one or more amplification primers selected from the group consisting of: 38-43; and bumper primers selected from the group consisting of SEQ ID NOs: 46-47. 80. The kit of claim 79, further comprising: one or more adapter primers selected from the group consisting of: SEQ ID NOs: 44-45; and one or more detector primer selected from the group consisting of: SEQ ID NOs: 30-35. 81. The kit of claim 80, further comprising: one or more IAC target sequences selected from the group consisting of: SEQ ID NOs: 48-49; and one or more IAC adapter primers selected from the group consisting of: SEQ ID NOs: 50-51. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Provisional Application No. 60/465,458, filed Apr. 25, 2003, entitled “Detection of Herpes Simplex 1 Virus by SDA” by David M. Wolfe. FIELD OF THE INVENTION The present invention relates to diagnostic methods and nucleic acid sequences for identifying Herpes Simplex Virus (HSV) by nucleic acid amplification methods. BACKGROUND OF THE INVENTION Herpes Simplex is an enveloped double-stranded DNA virus that is responsible for primary and recurrent infections in humans and is related to the viruses that cause infectious mononucleosis (Epstein-Barr Virus), chicken pox and shingles (Varicella Zoster Virus). Symptoms of Herpes Simplex Virus (HSV) infections include an eruption of tiny blisters on the skin or mucous membranes. After the eruption of blisters subsides, the virus remains in a dormant (latent) state inside the group of nerve cells (ganglia) that supply the nerve fibers to the infected area. Periodically, the virus reactivates, begins growing again, and travels through the nerve fibers back to the skin, thereby causing eruptions of blisters in the same area of skin as the earlier infection. Sometimes the virus may be present on the skin or mucous membranes even when there is no obvious blister. Herpes Simplex Virus (HSV) is classified into two types, HSV-1 and HSV-2. The complete genomes of human HSV-1 and HSV-2 have been sequenced (see, for example, NCBI Accession Nos. X14112 and Z86099, respectively). HSV has been shown to contribute to or cause a variety of disorders, including blindness and encephalitis. Besides causing local outbreaks, HSV-1 and HSV-2 are associated with encephalitis. The pathophysiology of this encephalitis is poorly understood in humans. Animal models suggest that the virus enters the central nervous system through peripheral nerves and causes inflammation of the brain. HSV-1 is the more common cause of adult encephalitis. HSV-2 is the more common cause of newborn encephalitis, which is associated with maternal genital infections. HSV-2 is one of the most common sexually transmitted diseases in society. HSV-related encephalitis has the highest fatality rate of all the types of encephalitis with an annual incidence of 1 to 4 per million. HSV encephalitis affects people of all ages and at any time of the year. In adults, HSV-related encephalitis is thought to be due to a reactivation of a latent virus. Symptoms may include fever, headaches, seizures, an altered level of consciousness and personality changes. The similarity of these symptoms to other maladies makes clinical diagnosis difficult. If left untreated, the mortality rate for herpes simplex encephalitis (HSE) is as high as seventy percent, compared with as low as nineteen percent among those who receive treatment. Of the treated patients, approximately thirty-eight percent are reported to eventually return to normal function. It is, therefore, very important to be able to diagnose HSV infection at an early stage. The diagnosis of HSV infection is commonly performed using cell culture on appropriate clinical specimens. However, the ability to isolate HSV in cell culture is reduced in old lesions, in the presence of a host immune response and in episodes of reactivation. Serologic diagnosis, particularly of HSV in cerebrospinal fluid (CSF), is not sufficiently sensitive or specific, and takes too much time to be of use in decisions involving choices for early therapeutic intervention of encephalitis. HSV is rarely detected in cerebral spinal fluid using cell culture, with only four percent of the cases being culture-positive. Serological methods are also inadequate for diagnosis of HSE due to delay between two and three weeks in appearance of antibody response after initial infection. The “gold standard” method of diagnosis involving brain biopsies is invasive and controversial with significant risk of long-term morbidity. Alternate techniques such as Computer-Assisted Tomography and Magnetic Resonance Imaging are not specific and lack sensitivity as diagnostic tools. At the present time, immunological methods for detection of HSV are unreliable and difficult to perform. Molecular methods of detection offer the potential for enhanced sensitivity and faster time to result than is possible by conventional means. There are instances in which rapid, sensitive, and specific diagnosis of HSV disease is imperative. There is therefore, a clinical need to develop a rapid and sensitive tool to aid in the diagnosis of HSV. There also remains a need for a tool for the typing of the HSV infection. Rapid identification of the specific etiological agent involved in a viral infection provides information which can be used to determine appropriate therapy within a short period of time. SUMMARY OF THE INVENTION The present invention relates to methods and compositions for determining the presence of Herpes Simplex Virus (HSV), specifically Herpes Simplex Virus type 1 (HSV-1) or type 2 (HSV-2) in mammals. The method involves using primers to amplify and detect Herpes Simplex Virus target sequence. One embodiment uses the amplification technique of Strand Displacement Amplification (SDA). The nucleic acid primers of the invention uniquely amplify the target sequence in HSV-1 or HSV-2, thereby allowing sensitive detection and type-identification of HSV. The present invention is also directed to a Strand Displacement Amplification (SDA) based method for the detection of HSV that involves real-time detection using a universal fluorescent energy transfer probe. The probes and primers of the present invention provide a direct, rapid, and sensitive detection of HSV nucleic acids and therefore offer an attractive alternative to immunological assays. The probes and primers of the invention may be used after culture of the sample as a means for confirming the identity of the cultured organism. Alternatively, they may be used prior to culture or in place of culture for detection and identification of HSV nucleic acids using known amplification methods. The inventive probes, primers, and compositions and assay methods using the probes, primers, and compositions, provide a means for rapidly discriminating between the nucleic acid target sequences of HSV-1 and HSV-2, allowing the practitioner to identify, diagnose, and treat the HSV type without resorting to the time-consuming immunological and biochemical procedures typically relied upon. BRIEF DESCRIPTION OF THE DRAWINGS The various objects, advantages and novel features of the present invention will be readily understood from the following detailed description when read in conjunction with the appended drawings in which: FIG. 1 shows a consensus sequence (SEQ ID NO: 1) of the Glycoprotein G (US4) gene of Herpes Simplex Virus Type 1 (HSV-1). FIG. 2 is a map showing a portion of the genomic sequence of the HSV-1 target region (SEQ ID NO: 2) and the location of primers, bumpers, and adapters designed for specific detection of HSV-1 DNA. FIG. 3 is a graph showing “MOTA” expression of results. FIG. 4 is a graph showing the “PAT” algorithm used with the BD ProbeTec™ ET System. FIG. 5 depicts the analytical sensitivity of the SDA method on dilutions of various HSV-1 strains. FIG. 6 is a consensus sequence (SEQ ID NO: 3) of a fragment of the Glycoprotein G (US4) gene of Herpes Simplex Virus Type 2 (HSV-2). FIG. 7 is a map showing the genomic sequence of the HSV-2 target region (SEQ ID NO: 4) and the location of primers, bumpers, and adapters designed for specific detection of HSV-2 DNA. DETAILED DESCRIPTION OF THE INVENTION The present invention provides isolated and purified nucleic acids, polynucleotides, amplification primers and assay probes which exhibit Herpes Simplex Virus (HSV) type specificity in nucleic acid amplification reactions. Also provided are methods for detecting and identifying HSV nucleic acids using the probes and primers of the invention. One embodiment of the present invention relates to an amplification method for detecting the presence of a target nucleic acid sequence using one or more amplification primers having a target binding sequence, producing an amplified target sequence, and detecting the target sequence. Non-limiting examples of amplification methods include Polymerase Chain Reaction (PCR; see Saiki et al., 1985, Science 230:1350-1354, herein incorporated by reference), Ligase Chain Reaction (LCR; see Wu et al., 1989, Genomics 4:560-569; Barringer et al., 1990, Gene 89:117-122; Barany, 1991, Proc. Natl. Acad. Sci. USA 88:189-193, all of which are incorporated herein by reference), in situ hybridization, Transcription Mediated Amplification (TMA; see Kwoh et al., 1989, Proc. Natl. Acad. Sci. USA 86:1173-1177, herein incorporated by reference), Self-Sustaining Sequence Replication (3SR; see Guatelli et al., 1990, Proc. Natl. Acad. Sci. USA 87:1874-1878, herein incorporated by reference), Rolling Circle Amplification (RCA), Nucleic Acid Sequence Based Amplification (NASBA), Qβ replicase system (Lizardi et al., 1988, BioTechnology 6:1197-1202, herein incorporated by reference) and Strand Displacement Amplification (SDA; see Walker et al., 1992, Proc. Natl. Acad. Sci. USA 89:392-396; Walker et al., 1992, Nuc. Acids. Res. 20:1691-1696; and EP 0 497 272, all of which are incorporated herein by reference)) including thermophilic SDA (tSDA). Another embodiment of the present invention relates to an isothermal Strand Displacement Amplification (SDA) method for detecting the presence of HSV nucleic acid sequences in a sample by exponential amplification of the HSV target sequence. In a further embodiment, SDA is performed at about 52° C as described in U.S. Pat. No. 5,648,211 using a selected detector primer to detect a target during amplification as described in U.S. Pat. Nos. 5,919,630; 5,928,869; 5,958,700; and 6,261,785, all of which are hereby incorporated by reference. As typical with SDA, reagents, primers, enzymes, such as restriction enzymes and polymerase, and other components are added to a reaction microwell, container, or receptacle. SDA amplifies a specific DNA sequence from a sample, where once all the components are mixed together, the reaction continues until a critical component is exhausted. In contrast to the polymerase chain reaction (PCR), SDA is an isothermal reaction process such that, once the reaction is initiated, there is no external control over the progress of the reaction. The SDA method of the present invention requires at least two HSV amplification primers and two bumper primers to initiate the amplification method. The amplification primers are designed to be highly specific for HSV-1 or HSV-2. The SDA method involves concurrent amplification reactions in a mixture and does not require separate phases or cycles for temperature cycling as is necessary in a PCR amplification method. A further advantage of the SDA of the present invention is exponential amplification. The steps of DNA polymerase extension, nicking, displacement, and regeneration of the nick site result in displaced single-stranded molecules with partial restriction enzyme sites (e.g., BsoBI sites) at either end which then circulate and are captured by amplification primers, thereby exponentially amplifying the HSV target sequence. The SDA method also provides an improved workflow, especially for high-throughput methods. SDA may be incorporated in a microarray-based application, where small volume amounts (nanoliters) of sample and reagents may be used to amplify HSV target DNA and detect the amplification products on a microchip array by performing multiple SDA assays on a single platform. The primary advantage of the SDA method for detecting HSV in a sample is the minimal labor requirement and high-throughput potential since the isothermal amplification process presents significantly fewer technical challenges in design and maintenance of the platform. The term “target” or “target sequence,” as used herein, refers to HSV nucleic acid sequences, HSV-1 or HSV-2, to be amplified and detected. These include the original HSV nucleic acid sequence to be amplified, the complementary second strand of the original HSV nucleic acid sequence to be amplified, and either strand of a copy of the original HSV sequence which is produced by the amplification reaction. These copies serve as amplifiable targets since they contain copies of the sequence to which the amplification primers anneal. Copies of the target sequence which are generated during the amplification reaction are referred to as amplification products, amplimers or amplicons. The HSV-1 and HSV-2 target sequences are located in the Glycoprotein G (US4) gene of the HSV-1 and HSV-2 genomic sequences. The HSV-1 target sequence is located between bases 555 and 680 of the consensus sequence of FIG. 1. The HSV-2 target sequence is located between bases 867 and 990 of the consensus sequence of FIG. 6. The Glycoprotein G (US4) gene is located between position 136,744 and 137,460 of the HSV-1 genomic sequence and between positions 137,878 to 139,977 of the HSV-2 genomic sequence of FIGS. 2 and 7, respectively. As used herein, an “amplification primer” is a primer that anneals to a target sequence and can be extended by amplification. The region of the amplification primer that binds to the target sequence is the target binding sequence. Amplification techniques include, but are not limited to, Strand Displacement Amplification (SDA), including thermophilic SDA (tSDA), Polymerase Chain Reaction (PCR), Ligase Chain Reaction (LCR), in situ hybridization, Self-Sustaining Sequence Replication (3SR), Rolling Circle Amplification (RCA), Nucleic Acid Sequence Based Amplification (NASBA), And Transcription Mediated Amplification (TMA). In one embodiment, an amplification primer may be used in a Strand Displacement Amplification (SDA) method. The amplification primer comprises at the 3′ end, a target binding sequence portion which binds to the HSV target sequence, and at the 5′ end, a portion that does not bind or anneal to the target sequence. The portion of the SDA amplification primer that does not bind the target sequence also comprises a tail and a recognition site for a restriction endonuclease upstream of the target binding sequence as described in U.S. Pat. No. 5,455,166 and U.S. Pat. No. 5,270,184, incorporated herein by reference. This recognition site is specific for a restriction endonuclease which will nick one strand of a DNA duplex when the recognition site is hemimodified, as described by Walker, et al. (1992. Proc. Natl. Acad. Sci. USA 89:392-396 and 1992 Nucl. Acids Res. 20:1691-1696). The tail is upstream of the restriction endonuclease recognition site sequence and functions as a polymerase repriming site when the remainder of the amplification primer is nicked and displaced during SDA. The repriming function of the tail sustains the SDA reaction and allows synthesis of multiple amplicons from a single target molecule. The length and sequence of the tail are generally not critical and can be routinely selected and modified. One embodiment of the invention is based on the target binding sequence conferring target specificity on the amplification primer, where it should be understood that the target binding sequences exemplified in the present invention may also be used in a variety of other ways for detection of HSV. For example, the target binding sequences disclosed herein may alternatively be used as hybridization probes for direct detection of HSV, either without prior amplification or in a post-amplification assay. Such hybridization methods are well known in the art and typically employ a detectable label associated with or linked to the target binding sequence to facilitate detection of hybridization. Furthermore, Tables 1 and 2 list primer sequences (SEQ ID NOs: 5-25 and 36-47, respectively) containing a target binding sequence which is indicated by capitalization and underlining. These target binding sequences may be used as primers in amplification reactions which do not require additional specialized sequences (such as, PCR) or appended to the appropriate specialized sequences for use in NASBA, in situ hybridization, TMA, 3SR, other transcription based amplification primers which require an RNA polymerase promoter linked to the target binding sequence of the primer, or any other primer extension amplification reactions. These amplification methods which require specialized non-target binding sequences in the primer are necessary for the amplification reaction to proceed and typically serve to append the specialized sequence to the target. For example, the restriction enzyme recognition site is necessary for exponential amplification to occur in SDA (see U.S. Pat. Nos. 5,455,166 and 5,270,184). Amplification primers for Self-sustained Sequence Replication (3SR) and Nucleic Acid Sequence-Based Amplification (NASBA), in contrast, comprise an RNA polymerase promoter near the 5′ end. (3SR assays are described in Guatelli et al., 1990, Proc. Natl. Acad. Sci. USA 87:1874-1878) The promoter is appended to the target binding sequence and serves to drive the amplification reaction by directing transcription of multiple RNA copies of the template. Linking such specialized sequences to a target binding sequence for use in a selected amplification reaction is routine and well known to one of ordinary skill in the art. In contrast, amplification methods such as PCR, which do not require specialized sequences at the ends of the target, generally employ amplification primers consisting of only target binding sequence. For detection purposes in these other amplification methods, the primers may be detectably labeled as understood by the skilled artisan. As nucleic acids do not require complete complementarity in order to anneal, one skilled in the art would understand that the probe and primer sequences disclosed herein may be modified to some extent without loss of utility as HSV-1-and HSV-2-specific primers and probes. The term “homology” refers to a degree of complementarity. There may be partial homology or complete homology, wherein complete homology is equivalent to identity. A partially complementary sequence that at least partially inhibits an identical sequence from hybridizing to a target nucleic acid is referred to as “substantially homologous.” The inhibition of hybridization of the completely complementary sequence to the target sequence may be examined using a hybridization assay (e.g., Southern or Northern blot, solution hybridization and the like) under conditions of low stringency. A substantially homologous sequence or probe will compete for and inhibit the binding (i.e., the hybridization) of a completely homologous sequence or probe to the target sequence under conditions of low stringency. Nonetheless, conditions of low stringency do not permit non-specific binding; low stringency conditions require that the binding of two sequences to one another be a specific (i.e., selective) interaction. As will be understood by those of skill in the art, the stringency of annealing may be altered in order to identify or detect identical or related polynucleotide sequences. As will be further appreciated by the skilled practitioner, the melting temperature, Tm, may be approximated by the formulas as known in the art, depending on a number of parameters, such as the length of the primer or probe in number of nucleotides, or annealing buffer ingredients and conditions (see, for example, T. Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1982 and J. Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1989; Current Protocols in Molecular Biology, Eds. F. M. Ausubel et al., Vol. 1, “Preparation and Analysis of DNA”, John Wiley and Sons, Inc., 1994-1995, Suppls. 26, 29, 35 and 42; pp. 2.10.7-2.10.16; G. M. Wahl and S. L. Berger (1987; Methods Enzymol. 152:399-407); and A. R. Kimmel, 1987; Methods of Enzymol. 152:507-511). As a general guide, Tm decreases approximately 1° C.-1.5° C. with every 1% decrease in sequence homology. Temperature ranges may vary between about 50° C. and 62° C., but the amplification primers may be designed to be optimal at 52° C. However, temperatures below 50° C. may result in primers lacking specificity, while temperatures over 62° C. may result in no hybridization. A further consideration when designing amplification primers is the guanine and cytosine content. Generally, the GC content for a primer may be about 60-70%, but may also be less and can be adjusted appropriately by one skilled in the art. The hybridizing region of the target binding sequence may have a Tm of about 42° C.-48° C. Annealing complementary and partially complementary nucleic acid sequences may be obtained by modifying annealing conditions to increase or decrease stringency (i.e., adjusting annealing temperature or salt content of the buffer). Such minor modifications of the disclosed sequences and any necessary adjustments of annealing conditions to maintain HSV-1 and HSV-2 specificity require only routine experimentation and are within the ordinary skill in the art. The amplification primers designed for detection of HSV-1 and HSV-2 target sequences are identified in Tables 1 and 2 as SEQ ID NOs: 7-18 and 38-43, respectively. These amplification primers are designed such that the target binding sequence anneals to a segment of the highly homologous consensus Glycoprotein G (US4) gene region (see, FIGS. 1-2 and 6-7). HSV target binding sequence regions within the amplification primers that anneal to or are complementary to HSV target DNA sequences, are underlined and capitalized (see, Tables 1 and 2). The remaining 5′ portion of the SDA detection primer sequences comprises the BsoBI restriction endonuclease recognition site (RERS) (as indicated in lowercase italics) that is required for the SDA reaction to proceed, as well as, a generic non-target-specific 5′ tail end sequence. HSV-1 and HSV-2 amplification primers of SEQ ID NOs: 7-8 and 38, respectively, are left hand (“first”) S1 amplification primers, and SEQ ID NOs: 9-18 and 39-43, respectively, are right hand (“second”) S2 amplification primers. For amplification purposes, a pair of HSV amplification primers of a specific type may be used alone (i.e., one HSV-1 left amplification primer and one HSV-1 right amplification primer) or in combination (i.e., one HSV-1 SDA left primer and two HSV-1 SDA right primers), such that there is at least one left and right hand primer pair in the reaction. Multiple amplification primers may be used to amplify several regions of the target sequence. The concentrations of primers may be adjusted appropriately, such that when an HSV-1 first amplification primer is used as the sole first amplification primer at a concentration of 500 nM, two HSV-1 right amplification primers may be used in conjunction, each have a concentration of 250 nM. The term “extension product” generally refers to the sequence produced by extending a primer or target sequence using an enzyme, such as polymerase. In one embodiment, hybridization of an amplification primer and extension of the amplification primer by polymerase using the HSV target sequence as a template produces an amplification primer extension product. A “bumper primer” or “external primer” is a primer that anneals to a target sequence upstream of the amplification primer such that extension of the bumper primer displaces the downstream amplification primer and its extension product. As used herein, the term “bumper primer” refers to a polynucleotide comprising an HSV target binding sequence. Useful bumper primers are identified in Tables 1 and 2 as SEQ ID NOs: 23-25 and 46-47, respectively. The left or first HSV-1 and HSV-2 bumper primers are SEQ ID NOs: 23 and 46, respectively, while the right or second HSV-1 and HSV-2 bumper primers are SEQ ID NOs: 24-25 and 47, respectively. Bumper primers are derived from conserved regions of sequence that flank the amplification primers at a position upstream of the amplification primers that is sufficiently close to the target binding site of the amplification primer to allow displacement of the amplification primer extension product after extension of the bumper primer. For example, the 5′ end of the HSV-1 first bumper primer of SEQ ID NO: 23 (HSV1GGLB1.0) is located at base 137,256 of the HSV-1 genomic sequence (FIG. 2). The 5′ end of the HSV-1 second bumper primer of SEQ ID NO: 25 (HSV1GGRB1.1) is located at base 137,382 of the HSV-1 genomic sequence (FIG. 2). During the initial round of SDA, the bumper primers hybridize to the HSV target sequence and displace by polymerase extension, the downstream amplification primer extension products, resulting in the generation of a single-stranded DNA that may undergo further rounds of replication and/or exponential amplification. The term “assay probe” refers to any nucleic acid used to facilitate detection or identification of a nucleic acid. For example, in an embodiment of the present invention, assay probes are used for detection or identification of HSV nucleic acids. Detector probes, detector primers, capture probes and primers as described below are examples of assay probes. In particular, “detector probes” useful in detecting and identifying specific HSV-types are labeled or tagged. The detectable label of the detector probe is a moiety that may be detected either directly or indirectly, indicating the presence of the target nucleic acid sequence. For direct detection, the assay or detector probe may be tagged with a radioisotope and detected by autoradiography or tagged with a fluorescent moiety and detected by fluorescence as known in the art. Alternatively, the assay probes may be indirectly detected by labeling with additional reagents that enable the detection. Indirectly detectable labels include, for example, chemiluminescent agents, enzymes that produce visible or colored reaction products, and a ligand-detectably labeled ligand binding partner, where a ligand (e.g., haptens, antibodies, or antigens) may be detected by binding to labeled ligand-specific binding partner. For detection of the amplification products, amplification primers comprising the target binding sequences disclosed herein may be labeled as is known in the art, or labeled detector primers comprising the disclosed target binding sequences may be used in conjunction with the amplification primers as described in U.S. Pat. No. 5,547,861; U.S. Patent No. 5,928,869; U.S. Pat. No. 5,593,867; U.S. Pat. No. 5,550,025; U.S. Pat. No. 5,935,791; U.S. Pat. No. 5,888,739; U.S. Pat. No. 5,846,726 for real-time homogeneous detection of amplification. Such detector primers may comprise a directly or indirectly detectable sequence which does not initially hybridize to the target but which facilitates detection of the detector primer once it has hybridized to the target and been extended. For example, such detectable sequences may be sequences which contain a restriction site, or sequences which form a secondary structure which brings fluorophore and quencher moieties in close proximity, such as, but not limited to hairpin and g-quartet sequences, or linear sequences which are detected by hybridization of their complements to a labeled oligonucleotide (sometimes referred to as a reporter probe) as is known in the art. Alternatively, the amplification products may be detected either in real-time or post-amplification through the use of intercalating dyes or post-amplification by hybridization of a probe selected from any of the target binding sequences disclosed herein which fall between a selected set of amplification primers. Terminal and internal labeling methods are known in the art and may be used to link the donor and acceptor dyes at their respective sites in the detector primer. Examples of 5′-terminal labeling methods include a) periodate oxidation of a 5′-to-5′ coupled ribonucleotide followed by reaction with an amine-containing label, b) condensation of ethylenediamine with a 5′-phosphorylated polynucleotide followed by reaction with an amine-reactive label, and c) introduction of an aliphatic amine substituent using an aminohexyl phosphite reagent in solid-phase DNA synthesis followed by reaction with an amine-reactive label. Labels may also be linked to synthetic DNA oligonucleotides at specific locations using special aliphatic amine-containing nucleotide phosphoramidite reagents. Selection of an appropriate method for linking the selected labels to the detector primer and performing the linking reactions are routine in the art. Another embodiment utilizes a detector primer that hybridizes to a specific target sequence resulting in the necessity for multiple detector primers depending on the target sequence being detected. However, an embodiment for the detection and identification of the specific HSV-type uses the Universal detection system, which is modified from the real-time SDA detection method described by Nadeau, et al. (1999). The Universal detection system permits the use of the same pair of fluorescent detector primers for multiple assays, offering several advantages such as cost, time, and reduced technical complexity. “Signal” or “adapter” primers have a target binding portion that hybridizes to the HSV target sequence and a tail portion that is generic and does not bind to the HSV target sequence. Adapter primers are used in conjunction with detector primers for Universal detection. The detector primer hybridizes to the tail portion (i.e., the non-target binding sequence) of the complement adapter primer. Signal or adapter primers are designed to hybridize to regions of the target sequence that lie at least partially in the intervening region between the first and second amplification primers so that the signal or adapter primers are displaced during the amplification reaction. HSV-1 and HSV-2 signal or adapter primers having SEQ ID NOs: 19-22 and 44-45 are shown in Tables 1 and 2, respectively. The detector probe may be a “universal detector primer” or “detector primer” which has a 5′ tail end portion that is detectably labeled and a 3′ end portion which binds to the complement adapter primer tail sequence. Generally, the 3′ end of the detector primer does not contain sequences with any significant complementarity to the HSV or Internal Amplification Control (IAC) target sequence. The detector primer also has a restriction enzyme recognition site at the 5′ end. Briefly, this Universal detection system can be used simultaneously and in the same reaction container as the SDA method for amplification. The Universal detection system involves the target-dependent extension of an unlabeled adapter primer. The adapter primer comprises an HSV-1 or HSV-2 target specific 3′ sequence and 5′ generic tail and is exemplified in SEQ ID NOs: 19-22 and SEQ ID NOs: 44-45, and its complement, respectively. The adapter primer hybridizes to the amplified HSV target sequence downstream of the S1 amplification primer. DNA polymerase extends from the 3′ ends of the adapter primer and the S1 amplification primer, where the extension of the amplification primer displaces the adapter primer extension product. The S2 amplification primer anneals to the adapter primer extension product. DNA polymerase extends the 3′ end of the S2 amplification primer, producing a double-stranded molecule comprising the adapter primer extension product and its complement, and has a nickable restriction enzyme recognition site. Nicking refers to breaking the phosphodiester bond of only one of two strands in a DNA duplex. A corresponding restriction enzyme nicks the double-stranded molecule at the restriction enzyme recognition site creating a 5′ portion comprising a short nicked tail and a 3′ portion comprising a long nicked complement adapter primer extension product. Nicking the restriction enzyme site with a corresponding restriction enzyme, such as, BsoBI enzyme, and extending the strand from the nicked site displaces a single-stranded copy of the adapter primer complement. DNA polymerase extends the 3′ end of the nicked tail, thereby displacing the single-stranded nicked complement adapter primer extension product. The S1 amplification primer extension product and extended HSV target sequence may be further amplified exponentially by SDA. The displaced complement adapter primer extension product is then captured by a detector primer, where the 3′ end of the detector primer anneals to the 5′ portion of the complement adapter primer extension product. The detector primer comprises a detectable label and detects target sequence. DNA polymerase extension from the 3′ ends of the detector primer and the complement adapter primer extension product results in opening the hairpin, if present, producing a double-stranded detection molecule comprising a detector primer extension product and its complement. Each strand comprises a cleavable restriction enzyme recognition site, which when cleaved separates the donor and, quencher dyes, separating the fluorophore and the quencher moieties, and generating target-specific fluorescence. Due to the separation, the quencher is no longer capable of suppressing the fluorescence emitted by the fluorophore. Complete cleavage of the double-stranded detector primer restriction enzyme recognition site increases the fluorescent signal by separating the fluorophore and quencher. In an embodiment of the invention, detector primers may be tagged for fluorescence detection with a fluorescent donor moiety (or fluorophore) and a quencher moiety where each moiety flanks the restriction enzyme recognition site. Tables 1 and 2 show detector primer sequences having SEQ ID NOs: 30-35. In Universal detection, the detector primers for detecting target sequence are generally used in conjunction with adapter primers. Detector primers that are labeled with a donor dye, rhodamine (ROX), and a quencher dye, P-(dimethyl aminophenylazo) benzoic acid (DABCYL) having SEQ ID NOs: 30-33 are used for HSV target sequence detection in an embodiment of the invention. Other donor and quencher dye pairs may be readily selected for use in the SDA by one skilled in the art, such that the quencher dye sufficiently absorbs the fluorescence emitted by the donor dye. For example, the donor and quencher dyes are readily detected and differentiated by absorption at different wavelengths. Depending on the donor and quencher dyes, the quencher dye may act as a quencher in one instance and as a donor dye in other. In this embodiment, the detector primer of SEQ ID NOs: 30-35 has a donor and quencher dye pair separated by a restriction enzyme recognition site located at the 5′ end of the detector primer. Furthermore, the detector primer of SEQ ID NO: 30 has a sequence comprising a hairpin structure sequence located between the donor and quencher moities, where the restriction enzyme recognition site lies therein. The hairpin structure brings the two dyes in close proximity such that the fluorescence emitted by the donor dye is suppressed by the quencher dye. However, the detector primers of SEQ ID NOs: 31-35 have a linear sequence between the two dyes which is short enough in length for the quencher to absorb any fluorescence emitted by the fluorophore. Many donor/quencher dye pairs known in the art are useful in embodiments of the present invention. These include, but are not limited to, fluorescein (FAM™; Glen Research; Sterling, Va.)/rhodamine (ROX™; Molecular Probes; Eugene, Oreg.); ROX/P-(dimethyl aminophenylazo) benzoic acid (DABCYL™; Glen Research); FAM/DABCYL; fluorescein isothiocyanate (FITC)/tetramethylrhodamine isothiocyanate (TRITC); FITC/Texas Red™ (Molecular Probes); FITC/N-hydroxysuccinimidyl 1-pyrenebutyrate (PYB); FITC/eosin isothiocyanate (EITC); N-hydroxysuccinimidyl 1-pentanesulfonate (PYS)/FITC; FITC/Rhodamine X; and FITC/tetramethylrhodamine (TAMRA). The selection of a particular donor/quencher pair is not critical. However, for energy transfer quenching mechanisms, it is only necessary that the emission wavelengths of the donor fluorophore overlap the excitation wavelengths of the quencher, i.e., there must be sufficient spectral overlap between the two dyes to allow efficient energy transfer, charge transfer or fluorescence quenching. ROX has an EMmax=608 nm and FAM has an EMmax of 520 nm. One skilled in the art would be knowledgeable in selecting the appropriate donor and quencher dye pair. P-(dimethyl aminophenylazo) benzoic acid (DABCYL) is a non-fluorescent quencher dye which effectively quenches fluorescence from an adjacent fluorophore, e.g., FAM or 5-(2′-aminoethyl) aminonaphthalene (EDANS). Certain donor/quencher pairs are exemplified in this disclosure; however, others will be apparent to those skilled in the art and are also useful in the invention. Any dye pair which produces fluorescence quenching in the detector primers of the invention are suitable for use in the methods of the invention, regardless of the mechanism by which quenching occurs. Non-limiting examples of other quenchers include Black Hole Quencher™ (Biosearch Technologies, Inc.; Novato, Calif.) and Iowa Black™ (Integrated DNA Technologies, Inc.; Corralville, Iowa). Fluorescence is measured during the course of the nucleic acid amplification reaction to monitor the accumulation of specific amplification products. The fluorescent signal is proportional to the amount of specific amplicon produced. In the presence of HSV target nucleic acid sequence, fluorescence will increase. In the absence of target, fluorescence will remain consistently low throughout the reaction. An increase in fluorescence or a failure of fluorescence to change substantially indicates the presence or absence of HSV target sequence, respectively. The fluorescence of the samples is typically measured over time to determine whether a sample contains HSV DNA. In one embodiment, fluorescence may be monitored for 60 passes over the course of one hour. Briefly, approximately every minute, data are collected regarding the amount of fluorescence measured in the sample container, a correction value (if necessary), and calibrators for each column. Data may be analyzed using the “MOTA” (Metric Other Than Acceleration) method of expressing results in terms of the area under a curve of a graph. The graph measures the number of passes (X-axis) versus relative fluorescent units (Y-axis) (see, FIG. 3). The greater the MOTA area, the more fluorescence generated and the more efficient the detection of amplified products. Yet another embodiment uses a Passes After Threshold (PAT) algorithm, which is shown in FIG. 4, and is particularly developed for use with the BD ProbeTec™ ET System. Similar to MOTA, a higher PAT score indicates a more efficient SDA reaction. When using the PAT algorithm, the time at which the background corrected signal of fluorescence intensity crosses a predetermined threshold is designated as T3 (“Time-To-Threshold”). This graph also measures the number of passes to relative fluorescent units. The same T3 threshold value is used for every sample. The PAT score is equal to 60 minus the T3 value. Negative samples do not achieve the minimum threshold of fluorescence and are therefore assigned a PAT value of zero. Positive samples have PAT values greater than 0, preferably between 1 and 60, more preferably between 40-55, depending on the assay and target level. Lower T3 scores and corresponding higher PAT values correlate with a more efficient SDA. The PAT algorithm utilizes only the region of the amplification curve that is the most reproducible. As a result, the PAT algorithm method minimizes discernable differences between wells or samples, and is more precise than other methods of comparison between detectors. PAT can be performed automatically by the BD ProbeTec™ ET System. The BD ProbeTec™ ET printout provides a PAT score and a reportable result. In yet a further embodiment, an “internal amplification control” (“IAC”) may be incorporated into the present method to verify negative results and to identify potential inhibitory specimens or to facilitate quantification of organism load in a sample, such as but not limited to viruses, bacteria, and fungi. For diagnostic applications, simultaneous amplification and detection of two different DNA sequences, i.e., the HSV target sequence and the IAC target sequence, enable the use of an IAC. The “IAC target sequence” or “IAC sequence” is similar to the HSV target sequence with the exception that the IAC target sequences of SEQ ID NOs: 26-27 and of SEQ ID NOs: 48-49 are mismatched by about 5-10 bases compared to the HSV-1 and HSV-2 target sequences. These modified bases are sufficient to allow specific annealing of IAC adapter primers. “IAC adapter primers” function similarly to the signal or adapter primers with the exception that the IAC adapter primers hybridize to an “IAC target sequence” or “IAC sequence” through an IAC target binding sequence. The IAC adapter primer also has a 5′ tail portion containing a generic sequence which does not hybridize to the IAC target sequence. Rather a detector primer may hybridize to the tail portion of the IAC adapter primer complement. The IAC adapter primers used in the HSV-1 and HSV-2 SDA assays may be selected from SEQ ID NOs: 28-29 and 50-51, respectively, and are useful in the amplification of IAC target sequences. The IAC target binding sequence located at the 3′ end of the IAC adapter primer differs from the HSV target sequence sufficiently such that the HSV-1 or HSV-2 adapter primers do not hybridize or interfere with the amplification of the IAC target sequence. In Tables 1 and 2, the IAC target binding sequence at the 3′ end of the IAC adapter primer is indicated by lowercase underlining. The IAC adapter primers are useful in verifying negative results and in monitoring for specimens that inhibit the reaction. For quantitative SDA, competition for rate-limiting reagents between an IAC and a native target sequence may also be useful (Nadeau, et al., 1999 Anal. Biochem. 276: 177-187). Detector primers of the invention may be used to detect either HSV target sequences or IAC target sequences. However, in one embodiment of the invention, detector primers used to detect the HSV-1 or HSV-2 target sequence are those of SEQ ID NOs: 30-33. The detector primers useful in detecting IAC target sequences are those selected from SEQ ID NOs: 34-35, where the donor and quencher dye pair is fluorescein (FAM) and DABCYL, respectively, and may be referred to herein as “IAC detector primers.” One skilled in the art would be knowledgeable in selecting the appropriate detector primers having labels, such that the identification of the IAC target sequence is distinguishable from the identification of the HSV-1 or HSV-2 target sequence. Therefore, the detector primers used in the detection of HSV target sequence and IAC target sequence may be exchanged such that detector primers of SEQ ID NOs: 30-33 and may be used in the detection of IAC target sequences and SEQ ID NOs: 34-35 may be used in the detection of HSV target sequences. Another embodiment of the invention relates to assaying multiple samples simultaneously in a high-throughput process. Samples include, but are not limited to those collected from cerebral spinal fluid (CSF), genital lesions, oral lesions, mucosal lesions, ocular specimens, dermal specimens, rectal swabs, vaginal swabs, vaginal secretions, urine, peripheral blood leukocytes, and tissue (such as from a brain biopsy). The samples may be assayed in plates, slides, wells, dishes, beads, particles, cups, strands, chips, and strips. In one embodiment, the methods are performed in 96 micro-well plates in a format consistent with that used in the BD ProbeTec™ ET CT/GC Amplified DNA Assay. The method is performed in a dried micro-well format, where the dried composition comprises all of the primers and probes necessary for carrying out SDA detection of HSV-1 or HSV-2 for use in simultaneously assaying multiple samples. Assays detecting the presence of a selected target sequence according to the methods of the invention may be performed in solution or on a solid phase. Real-time or endpoint homogeneous assays in which the detector nucleic acid functions as a primer are typically performed in solution. Hybridization assays using the detector primers of the invention may also be performed in solution (e.g., as homogeneous real-time assays) but are also particularly well-suited to solid phase assays for real-time or endpoint detection of target. In a solid phase assay, detector oligonucleotides may be immobilized on the solid phase (e.g., beads, membranes or the reaction vessel) via internal or terminal labels using methods known in the art. For example, a biotin-labeled detector oligonucleotide may be immobilized on an avidin-modified solid phase where it will produce a change in fluorescence when exposed to the target under appropriate hybridization conditions. Capture of the target in this manner facilitates separation of the target from the sample and allows removal of substances in the sample which may interfere with detection of the signal or other aspects of the assay. The primers and probes used for detecting and identifying HSV-1 target sequence are listed in Table 1. The specific HSV target binding sequences are underlined and capitalized, while the restriction enzyme endonuclease sites are indictated in lower case italics. For the IAC adapter primers, the IAC target binding sequence is indicated by lower case underlining. All primers are listed in the 5′→3′ direction. TABLE 1 PRIMER SEQUENCES FOR AMPLIFICATION AND DETECTION OF SEQ ID HERPES SIMPLEX VIRUS 1 DNA NO: PCR AMPLIFICATION PRIMERS FOR THE HSV-1 TARGET SEQUENCE PCRL1.0 GCGGAATTCGACCCTTGGTTCC 5 PCRR1.0 GCGGGATCCCCAACCACCACAC 6 LEFT (FIRST) AMPLIFICATION PRIMER HSV1GGLP1.0 ACCGCATCGAATGACTGTctcgggCTGTTCTCGTTCCTC 7 HSV1GGLP1.1 ACCGCATCGAATGACTGTctcgggCTGTTCTCGTTCCT 8 RIGHT (SECOND) AMPLIFICATION PRIMER HSV1GGRP1.0 CGATTCCGCTCCAGACTTctcgggCACCAATACACAAAAA 9 HSV1GGRP1.1 CGATTCCGCTCCAGACTTctcgggCAACAATACACACAAA 10 HSV1GGRP2.0 CGATTCCGCTCCAGACTTctcgggCACCAATACACAAAAAC 11 HSV1GGRP2.1 CGATTCCGCTCCAGACTTctcgggCAACAATACACACAAAC 12 HSV1GGRP3.0 CGATTCCGCTCCAGACTTctcgggCACCAATACACAAAAACG 13 HSV1GGRP3.1 CGATTCCGCTCCAGACTTctcgggCAACAATACACACAAACG 14 HSV1GGRP4.0 CGATTCCGCTCCAGACTTctcgggCAATACACAAAAACGAT 15 HSV1GGRP4.1 CGATTCCGCTCCAGACTTctcgggCAATACACACAAACGAT 16 HSV1GGRP4.2 CGATTCCGCTCCAGACTTctcgggCAATACACACAAATGAT 17 HSV1GGRP5.2 CGATTCCGCTCCAGACTTctcgggAAGGTGTGGATGAC 18 ADAPTER PRIMER HSV1GGAD1.0 ACGTTAGCCACCATACGGATCCGTCATCCACACCTTATC 19 HSV1GGAD2.1 ACGTTAGCCACCATACGGATGGACACCCTCTTCGTCGTC 20 HSV1GGAD3.0 ACGTTAGCCACCATACTTGAGGACACCCTCTTCGTCGTC 21 HSV1GGAD3.1 ACGTTAGCCACCATACTTGAGGACACCCTCTTCGTCG 22 LEFT (FIRST) BUMPER PRIMER HSV1GGLB1.0 GACGCCTCAACATAC 23 RIGHT (SECOND) BUMPER PRIMER HSV1GGRB1.0 GTGTGTCGCCATCG 24 HSV1GGRB1.1 AGGTGTGTCGCCAT 25 IAC TARGET SEQUENCE HSV1IAC8.1 CTGTTCTCGTTCCTCACTGCCTCCCCCGCCCTGGACACCCTC 26 TTGCTGCTGAGCACCGTCATCCACACCTT HSV1IAC8.7 CTGTTCTCGTTCCTCACTGCCTCCCCCGCCCTGGACACCCTC 27 TGTTCATCTAGCACCGTCATCCACACCTT IAC ADAPTER PRIMER HSV1 IACAD8.1 ACTGATCCGCACTAACGACTggacaccctcttgctgctg 28 HSV1 IACAD8.7 ACTGATCCGCACTAACGACTggacaccctctgttcatct 29 DETECTOR PRIMER TBD10.2 D/R (DABCYL)-TAGCGcccgagCGCT-(ROX)- 30 ACGTTAGCCACCATACGGAT TBD15 D/R (DABCYL)-TGcccgagT-(ROX)-ACGTTAGCCACCATACGGAT 31 TBD16 (D/R) (DABCYL)-TcccgagT-(ROX)-ACGTTAGCCACCATACGGAT 32 MPC.DR (DABCYL)-TCcccgagT-(ROX)-ACGTTAGCCACCATACTTGA 33 MPC2.FD (FAM)-TCcccgagT-(DABCYL)-ACTGATCCGCACTAACGACT 34 AltD8 (F/D) (FAM)-AcccgagT-(DABCYL)-AGCTATCCGCCATAAGCCAT 35 The primers and probes used for detecting and identifying HSV-2 target sequence are listed in Table 2. TABLE 2 PRIMER SEQUENCES FOR AMPLIFICATION AND DETECTION OF SEQ ID HERPES SIMPLEX VIRUS 2 DNA NO: PCR AMPLIFICATION PRIMERS FOR THE HSV-2 TARGET SEQUENCE HSV2PCRL GCGGAATTCATTCTTGGGCCGCT 36 HSV2PCRR GCGGGATCCACGTAACGCACGCT 37 LEFT (FIRST) AMPLIFICATION PRIMER HSV2GGLP1.0 ACCGCATCGAATGACTGTctcgggCTGTTCTGGTTCCTA 38 RIGHT (SECOND) AMPLIFICATION PRIMER HSV2GGRP1.0 CGATTCCGCTCCAGACTTctcgggCGACCAGACAAACGAA 39 HSV2GGRP1.1 CGATTCCGCTCCAGACTTctcgggACCAGACAAACGAAC 40 HSV2GGRP1.2 CGATTCCGCTCCAGACTTctcgggCGACCAGACAAACGAAC 41 HSV2GGRP2.0 CGATTCCGCTCCAGACTTctcgggAACGCCGCCGTGT 42 HSV2GGRP5.2 CGATTCCGCTCCAGACTTctcgggCCGTGTGGATGGT 43 ADAPTER PRIMER HSV2GGAD1.0 ACGTTAGCCACCATACGGATCCACCATCCACACGGCGGC 44 HSV2GGAD2.0 ACGTTAGCCACCATACTTGATGCTCTAGATATCCTCTTTATCAT 45 LEFT (FIRST) BUMPER PRIMER HSV2GGLB1.0 CACACCCCAACACAT 46 RIGHT (SECOND) BUMPER PRIMER HSV2GGRB1.0 TTGTGCTGCCAAGG 47 IAC TARGET SEQUENCE HSV2-IAC 5.2A1 CTGTTCTGGTTCCTAACGGCCTCCCCTGCTCTAGATATCCTCT 48 TTACTACCAGCACCACCATCCACACGG HSV2-IAC 5.2A2 CTGTTCTGGTTCCTAACGGCCTCCCCTGCTCTAGATATCCTCT 49 TAACTACCAGCACCACCATCCACACGG IAC ADAPTER PRIMER HSV2GG IAC ACTGATCCGCACTAACGATtgctctagatatcctctttactac 50 ADA1.0 HSV2GGIAC ACTGATCCGCACTAACGACTtgctctagatatcctcttaactac 51 ADA2.0 DETECTOR PRIMER TBD10.2 D/R (DABCYL)-TAGCGcccgagCGCT-(ROX)- 30 ACGTTAGCCACCATAC GGAT TBD15 D/R (DABCYL)-TGcccgagT-(ROX)-ACGTTAGCCACCATACGGAT 31 TBD16 (D/R) (DABCYL)-TcccgagT-(ROX)-ACGTTAGCCACCATACGGAT 32 MPC.DR (DABCYL)-TCcccgagT-(ROX)-ACGTTAGCCACCATACTTGA 33 MPC2.FD (FAM)-TCcccgagT-(DABCYL)-ACTGATCCGCACTAACGACT 34 ALTD8 (F/D) (FAM)-AcccgagT-(DABCYL)-AGCTATCCGCCATAAGCCAT 35 The nucleic acid primers of the present invention are designed based on a consensus sequence generated by analyzing the Glycoprotein G (US4) sequence region of the HSV gene for various strains. (See, FIGS. 1 and 6; Tables 1 and 2). Also shown are bumper primers, adapter primers, and detector primers for use in the SDA and universal detection methods. The designed HSV-1 primers specifically amplify an HSV-1 target sequence that is recognized in all strains as exemplified in Table 4. The HSV-2 primers are designed to specifically amplify an HSV-2 target sequence that is recognized in all strains as exemplified in Table 7. Since the homology between the HSV-1 and HSV-2 target sequences is about 90%, the primers are carefully designed to specifically distinguish between HSV-1 and HSV-2. Also contemplated in the invention, are sequences that substantially homologous to the target binding sequences and primers containing such substantially homologous target binding sequences listed in Tables 1 and 2. In one embodiment of the present invention, an HSV-1 target region is first selected from the complete HSV-1 genomic sequence of Human HSV-1, strain 17 (NCBI accession no. X14112) having 152,261 bases in length. The glycoprotein “US4” gene is located at 136,744-137,460 bases. The HSV-1 Left bumper primer (HSV1LB1.0) (5′ end) is located at nucleic acid 137,256. The HSV-1 Right bumper primer (HSV1RB1.1) (5′ end) is located at nucleic acid 137,382. Primers for all HSV-1 SDA systems are located within these bumper primer coordinates. Another embodiment of the invention relates to the complete HSV-2 genome sequence of Human HSV-2, strain HG52 (NCBI accession no. Z86099) having 154,746 bases in length. The glycoprotein G “US4” gene is located at 137,878-139,977 bases. The HSV-2 Left bumper primer (HSV2LB1.0) (5′ end) is located at position 139,773. The HSV-2 Right bumper primer (HSV2RB1.0) (5′ end) is located at position 139896. Primers for all IHSV-2 SDA systems are located within the bumper primer coordinates. PCR amplification primers are designed for cloning the HSV target DNA into a plasmid vector. The HSV-1 and HSV-2 PCR amplification primers of SEQ ID NOs: 5-6 and SEQ ID NOs: 36-37, respectively, are complementary to highly conserved target sequence regions of the HSV genome. The PCR amplification primers amplify an HSV target sequence region comprising a DNA fragment of the Glycoprotein G (US4) gene of HSV. The amplified fragment of the herpes simplex virus (HSV) genome containing the HSV target region is directionally cloned into a plasmid vector containing convenient restriction enzyme sites. Although the HSV fragment may be cloned into any plasmid vector as is understood by the skilled artisan, in one embodiment of the invention, the amplified HSV-1 and HSV-2 fragments are cloned into the Escherichia coli plasmid vectors, pUC19 (Genbank/EMBL Accession No. L09137) and pUC18 (Genbank/EMBL Accession No. L09136), respectively, using PCR amplification primers specific to the selected HSV target regions. The HSV fragment is referred to as the HSV target stock. The target HSV DNA may be quantified using the PicoGreen® double stranded DNA Quantitation Assay (Molecular Probes, Inc.). The presence of “L” or “R” in the primer name listed in Tables 1 and 2 indicates “left” or “right” primers, respectively, when used in amplification reactions. In one embodiment of the invention, PCR amplification primers SEQ ID NOs: 5-6 and 36-37 initially amplify a 152 and 254 base pair fragment of the Glycoprotein G gene of the HSV-1 and HSV-2 gene, respectively. The HSV-1 and HSV-2 Left PCR primer of SEQ ID NOs: 5 and 36, respectively, are each designed with an EcoRI restriction enzyme site. The HSV-1 and HSV-2 Right PCR primer of SEQ ID NOs: 6 and 37, respectively, each have a BamHI restriction enzyme site. This fragment is then positionally cloned into the pUC plasmid vector. The exemplified plasmid vector is pUC19 and pUC18 for HSV-1 and HSV-2, respectively, which have restriction enzyme sites EcoRI and BamHI. After purification and linearization by restriction enzyme digestion, the HSV target fragment is then exponentially amplified using HSV amplification primers and bumper primers. The target binding sequences and primers of the invention are useful in nucleic acid amplification. In one embodiment, the primers are particularly useful in strand displacement amplification (SDA). This is an isothermal method of nucleic acid amplification in which extension of primers, nicking of hemimodified restriction endonuclease recognition/cleavage site, displacement of single-stranded extension products, annealing of primers to the extension products (or the original target sequence) and subsequent extension of the primers occur concurrently in a reaction mixture. Furthermore, SDA allows for target sequence replication in excess of 1010 fold in less than 15 minutes. Whereas, in PCR, the steps of the reaction occur in separate phases or cycles as a result of temperature cycling in the reaction. Thermophilic Strand Displacement Amplification (tSDA) is performed essentially as the conventional SDA method described herein and by Walker, et al. (1992, Proc. Natl. Acad. Sci USA. USA 89:392-396 and 1992, Nucl. Acids Res. 20:1691-1696) with substitution of the thermostable polymerase and thermostable restriction endonuclease. The temperatures may be adjusted to the higher temperature appropriate for the substituted enzymes. An alternative method of detecting HSV amplification products or amplified target sequence may be by detecting a characteristic size by polyacrylamide or agarose gel electrophoresis, where the agarose is stained with ethidium bromide. The amplified products generated using the HSV-1 or HSV-2 amplification primers may also be detected by quantitative hybridization, or equivalent techniques for nucleic acid detection known to one skilled in the art of molecular biology (Sambrook et al, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring, N.Y. (1989)). The primers listed in Tables 1 and 2 are useful in the detection and identification of HSV-1 and HSV-2 in a sample. As used herein, the S1 and S2 amplification primers represent the first and second amplification primers, respectively; while the B1 and B2 bumper primers represent the first and second bumper primers, respectively. Briefly, in the SDA method, the S1 amplification primer hybridizes to a single-stranded HSV target sequence. Just upstream or 5′ of the S1 amplification primer, a first bumper primer, B1, hybridizes to the single-stranded HSV target sequence. DNA polymerase extends the 3′ ends of the B1 bumper primer and the S1 amplification primer, where the extension of the B1 bumper primer eventually displaces the S1 SDA extension product. The S1 SDA extension product is captured by the S2 amplification primer and B2 bumper primer which anneals upstream of the S2 amplification primer. DNA polymerase extends the 3′ ends of the S2 SDA and B2 bumper primers, where the extension of the B2 bumper primer displaces the downstream S2 SDA extension product. The S1 amplification primer anneals to the displaced S2 amplification primer extension product and DNA polymerase extends the 3′ end of the hybridized S1 amplification primer, producing a double-stranded molecule having the S2 amplification primer extension product and its complement strand. Each strand has a nickable restriction enzyme recognition site at either end. Upon addition of the corresponding restriction enzyme, the modified DNA strand, containing a thiolated cytosine, is nicked forming a short nicked tail and a long extension product 3′ of the nick site. DNA polymerase extends the short nicked tail from the 3′ end of the short nicked tail in a 5′→3′ direction displacing the single-stranded long extension product. Briefly, the nicked tail of the S2 amplification primer extension product and the nicked tail of its complement displace the single-stranded nicked S2 amplification primer extension product and single-stranded nicked complement S2 amplification primer extension product, respectively. In one embodiment, BsoBI enzyme is used to nick and cleave or cut each strand having a sequence of SEQ ID NOs: 52-53 and 54-55, respectively. The nick sites, indicated below, are incorporated into the amplification primer sequence and require a hemi-phosphorothiolated recognition sequence (dCsTP, thiolated cytosine). Although a nick site, SEQ ID NO: 53 is prone to double-stranded cleavage even in the presence of dCsTP and is not a preferred sequence in designing nickable amplification primers. Nick Sites: 5′-CTCGGG-3′ (SEQ ID NO: 52) and 5′-CCCGGG-3′ (SEQ ID NO: 53) Cut Sites: 5′-CTCGAG-3′ (SEQ ID NO: 54) and 5′-CCCGAG-3′ (SEQ ID NO: 55) In a further embodiment of the invention, a detector probe is useful in detecting the HSV target sequence. The S1 amplification primer and a detector primer specific for the HSV target sequence may be used, where the detector primer has a an HSV target binding sequence. DNA polymerase extends from the 3′ ends of the S1 primer and the detector primer. Extension of the S1 primer displaces the downstream detector primer extension product into solution, where it is captured and hybridizes to a complementary S2 amplification primer. DNA polymerase extends the 3′ end of the S2 amplification primer and opens up the secondary structure of the detector primer forming a double-stranded restriction enzyme site and separating the two dyes (fluorophore and quencher pair) to such a distance as to disable the quenching ability of the quencher and to generate fluorescence. Additional fluorescence is produced by cleaving the restriction enzyme recognition site and further separating the fluorophore and quencher. Enzymes useful in the SDA method are those that create a single-stranded nick in a hemi-phosphorothioated recognition sequence, where the incorporation of phosphorothioated nucleotides does not prevent further rounds of nicking and repair. Non-limiting examples of enzymes that possess these characteristics include: HincII, BsoBI, AvaI, NciI, and Fnu4HI. Useful DNA polymerases are those that initiate DNA synthesis at the single-stranded nick site, incorporate phosphorothioated nucleotides into the extending nucleic acid chain, and displace strands without 5′-3′ exonuclease activity. Cleavage refers to the breaking of the phosphodiester bond of the double-stranded or single-stranded DNA. Non-limiting examples of DNA polymerases that exhibit those characteristics include: exonuclease-deficient Klenow and exonuclease-deficient fragments of Bst polyermase and Bca polymerase. Although other DNA polymerases and restriction enzymes are suitable for SDA (Walker et al. Proc. Natl. Acad. Sci USA, Vol. 89, pp. 392-396, January 1992, Applied Biological Sciences), exo-Bst polymerase and BsoBI were chosen for their thermal characteristics and compatibility with one another. In one embodiment of the invention, BsoBI restriction endonuclease recognition sites are used and designated in italics (see, Tables 1 and 2). It will be readily apparent that the HSV target binding sequences may be used alone to amplify the HSV target in reactions which do not require specialized sequences or structures (e.g., PCR) and that other specialized sequences required by amplification reactions other than SDA (e.g., an RNA polymerase promoter) may be substituted in the system, for example for the RERS-containing sequence described herein. The target stock may then be amplified in the presence of amplification primers, alone or in combination with bumper primers, signal/adapter primers for universal detection, and a universal detector primer. For an amplification reaction, at least one pair comprising one “left” amplification primer is selected and one “right” amplification primer is selected to amplify each strand of the HSV target stock sequence. In addition to the left and right amplification primers, in the SDA reaction, one left and right bumper primer pair is initially used. Furthermore, for detection, a signal/adapter primer and a detection primer is selected and used to detect and identify the HSV target sequence. Several HSV systems that specifically amplify and detect either HSV-1 or HSV-2 DNA are embodied in the present invention. For example, HSV-1 systems may include the following primers: HSV1GGLP1.1, HSV1GGRP5.2, HSV1GGAD2.1, HSV1GGLB1.0, HSV1GGRB1.1, and TBD16 (D/R) or alternatively, HSV1GGLP1.1, HSV1GGRP5.2, HSV1GGAD3.0 or HSV1GGAD3.1, HSV1GGLB1.0, HSV1GGRB1.1, MPC.DR, HSV1IAC AD8.1 or HSV1IACAD8.7, MPC2.FD. In another embodiment, HSV-2 systems using various combinations of primers are listed in Table 3. Other combinations of primers are contemplated however, one skilled in the art would be knowledgeable in combining the primers in order to detect HSV-1 or HSV-2 in a sample. The primers may be selected from those listed in Tables 1 and 2, and tested in statistically designed experiments in order to identify HSV-1 or HSV-2 in a sample. Alternatively, primers that are specific fro HSV-1 or HSV-2 and substantially homologous to those listed in Tables 1 and 2 may also be used in the detection of HSV-1 or HSV-2 target sequences. TABLE 3 HSV-2 SDA SYSTEM DESIGNS HSV2 SDA SYSTEM PRIMERS USED IN SYSTEM HSV2GG 1.0 HSV2GGRP1.0 Right amplification primer HSV2GGLP1.0 Left amplification primer HSV2GGRB1.0 Right Bumper primer HSV2GGLB1.0 Left Bumper primer HSV2GGAD1.0 Adapter primer HSV2GG 1.1 HSV2GGRP1.1 Right amplification primer HSV2GGLP1.0 Left amplification primer HSV2GGRB1.0 Right Bumper primer HSV2GGLB1.0 Left Bumper primer HSV2GGAD1.0 Adapter primer HSV2GG 1.2 HSV2GGRP1.2 Right amplification primer HSV2GGLP1.0 Left amplification primer HSV2GGRB1.0 Right Bumper primer HSV2GGLB1.0 Left Bumper primer HSV2GGAD1.0 Adapter primer HSV2GG 2.0 HSV2GGRP2.0 Right amplification primer HSV2GGLP1.0 Left amplification primer HSV2GGRB1.0 Right Bumper primer HSV2GGLB1.0 Left Bumper primer HSV2GGAD2.0 Adapter primer HSV2GG 5.2 HSV2GGRP5.2 Right amplification primer HSV2GGLP1.0 Left amplification primer HSV2GGRB1.0 Right Bumper primer HSV2GGLB1.0 Left Bumper primer HSV2GGAD2.0 Adapter primer For commercial convenience, amplification primers for specific detection and identification of nucleic acids may be packaged in the form of a kit. Generally, such a kit contains at least one pair of HSV amplification primers. Reagents for performing a nucleic acid amplification reaction may also be included with the target-specific amplification primers, for example, buffers, additional primers, nucleotide triphosphates, enzymes, etc. The components of the kit are packaged together in a common container, optionally including instructions for performing a specific embodiment of the inventive methods. Other optional components may also be included in the kit, e.g., a primer tagged with a label suitable for use as an assay probe, and/or reagents or means for detecting the label. In one embodiment of the invention, a kit is provided that comprises a first amplification primer or S1 SDA amplification primer, and a second amplification primer or S2 SDA amplification primer. The kit may further comprise a first B1 bumper primer and second B2 bumper primer; an adapter primer; a detector primer; and optionally, reagents for simultaneously detecting an Internal Amplification Control (IAC) target sequence, including IAC adapter primers and an IAC target sequence. The kit may comprise of primers specifically for HSV1 or HSV-2, or the kit may comprise of primers directed to both HSV-1 and HSV-2, where one skilled in the art would understand that amplification reactions to detect and identify HSV-1 utilize the HSV-1 primers, and to detect and identify HSV-2 utilize HSV-2 primers. In order to identify whether a sample contains HSV-1 or HSV-2 DNA, primers for HSV-1 and HSV-2 should not be mixed. In yet another embodiment, the kit and primers of the invention may be used to detect and diagnose whether a clinical sample contains HSV-1 or HSV-2 DNA. The clinical sample may be amplified and detected using the SDA amplification primers, or may be used in an SDA reaction further comprising bumper primers, adapter primers, and detector primers. In an embodiment of the invention, IAC adapter primers may be used as an internal amplification control for the reactions, in addition to positive and negative controls for HSV-1 or HSV-2. One skilled in the art would understand, from reading the description herewith and from the general methods and techniques in the art, how to make and use the primers for the detection and identification of HSV-1 and HSV-2 in a sample. Furthermore, in a commercial embodiment, a composition comprising the primers of the invention and reagents for SDA may be provided in a dried or liquid format. The composition is more stable and easily manipulated when in a dried format. The dried composition may be added or pre-treated to a solid phase such as a microtiter plate, microarray, or other appropriate receptacle, where the sample and SDA buffer need only be added. This format facilitates assaying multiple samples simultaneously and is useful in high-throughput methods. In an embodiment of the invention, the BD ProbeTec™ ET instrument may be used. It is to be understood that a nucleic acid according to the present invention which consists of a target binding sequence and, optionally, either a sequence required for a selected amplification reaction or a sequence required for a selected detection reaction may also include certain other sequences which serve as spacers, linkers, sequences for labeling or binding of an enzyme, or other uses. Such additional sequences are typically known to be necessary to obtain optimum function of the nucleic acid in the selected reaction. The contents of all patents, patent applications, published PCT applications and articles, books, references, reference manuals and abstracts cited herein are hereby incorporated by reference in their entirety to more fully describe the state of the art to which the invention pertains. As various changes may be made in the above-described subject matter without departing from the scope and spirit of the present invention, it is intended that all subject matter contained in the above description, or defined in the appended claims, be interpreted as descriptive and illustrative of the present invention. Many modifications and variations of the present invention are possible in light of the above teachings. EXAMPLES The Examples herein are meant to exemplify the various aspects of carrying out the invention and are not intended to limit the scope of the invention in any way. The Examples do not include detailed descriptions for conventional methods employed, such as in the construction of vectors or the insertion of cDNA into such vectors. Such methods are well known to those skilled in the art and are described in numerous publications, for example, J. Sambrook and D. W. Russell, Molecular Cloning: a Laboratory Manual, 3rd Edition, Cold Spring Harbor Laboratory Press, USA, (2001). Example 1 Cloning of HSV-1 Glycoprotein-G Strand Displacement Amplification Target Region PCR was performed on DNA from the HSV-1 (strain ATCC: VR-539) using the PCR amplification primers of SEQ ID NO: 5 and SEQ ID NO: 6 identified in Table 1. These primers were designed to amplify a 152 base pair fragment within the Glycoprotein G (US4) gene of HSV-1. PCR amplified DNA was inserted into a pUC19 plasmid vector (Gibco BRL; Grand Island, N.Y.). The recombinant clone was named HSVIGG Plasmid #1. Plasmid #1 DNA was purified and linearized by digestion with BamH1 restriction enzyme. The DNA was then purified using QIAquick (Qiagen, Inc.; Valencia, Calif.) spin columns and quantified by analysis with fluorescent Picogreen® reagent. Dilutions of the target HSV-1 DNA for future experiments were prepared in water containing 10 ng/μl human DNA. Specific HSV1 strain dilutions and the results of HSV-1 detection in each dilution are shown in FIG. 5. A “plus” symbol indicates the presence of HSV-1 in the sample; a “minus” symbol indicates the absence of HSV-1 in the sample; and a question mark indicates the suspected contamination of the sample. All strains were positive at 1:10 dilution of Stock, except sample O-2526. At a 1:1,000 dilution of the stock, 20 of the 23 strains were positive. At a 1:100,000 dilution of the stock, 15 of 23 strains were positive. Example 2 Amplification of Cloned HSV-1 DNA As an initial step in the assay for detecting HSV-1 DNA, an SDA system for amplification of HSV-1 DNA was developed using the target nucleic acid method described in Example 1. The analytical senstivity of the DNA amplification assay was estimated using dilutions of the cloned plasmid. Eight replicate SDA reactions were performed at each target level. These eight reactions were equivalent to 100, 50, 25, 12.5, 6.25 and 0 copies of double stranded DNA per reaction. Amplification was conducted at 52° C. using a BD ProbeTec™ ET instrument (BD Diagnostic Systems; Sparks, Md.) with 50 nM each of HSV1GGLB1.0 and HSV1GGRB1.0 bumper primers, 100 nM of HSV1GGLP1.0 left amplification primer, 500 nM HSV1GGRP1.0 right amplification primer, 250 nM HSV1GGAD1.0 adapter primer, 500 nM TBD10.2 D/R detector primer. The sequences of these primers are listed in Table 1. Final buffer conditions were as follows: 143 mM Bicine, 82 mM KOH, 25MM KiPO4, 12.5% DMSO, 5 mM magnesium acetate, 500 mM 2′-deoxycytosine-5-o-(1-thiotriphosphate)(dCsTP), 100 nM each of dATP, dGTP, and dTTP, 100 ng/μl BSA, approximately 12 units of Bst polymerase and approximately 30 units of BsoBI restriction endonuclease. Fluorescence was monitored for 60 passes over the course of one hour. Results were expressed in terms of area under the curve or “MOTA” score. Positive MOTA scores can be readily determined by routine experimentation. For the purpose of the present invention, MOTA scores greater than or equal to 3500 were considered “positive.” The lowest level of HSV 1 GG target DNA at which the assay yielded 100% positive results was 100 copies per reaction. Seven of eight replicates (87.5%) were also positive at fifty copies of target DNA per reaction. Example 3 Detection of Herpes Simplex 1 Virus Particles by SDA To verify the ability of the primers and probes of the invention to detect HSV-1, SDA was performed on four strains of HSV-1 obtained from American Type Culture Collection (ATCC; Manassas, Va.), 10 strains obtained from Quest Diagnostic (Baltimore, Md.) and fourteen untyped HSV samples from Ohio State University (OSU). The untyped strains of HSV were characterized by amplifying a region of the DNA polymerase gene by PCR. One set of amplification primers was designed to amplify the same region in both HSV-1 and HSV-2. The two types of virus were distinguishable by the presence of an Apal restriction endonuclease recognition site in the HSV-2 PCR fragment that is not present in PCR products generated from strains of HSV-1. When incubated with the Apal restriction enzyme, the HSV-2-derived amplification products are cleaved into two shorter fragments while those obtained from HSV-1 remain intact. Restricted fragments were resolved on agarose gel electrophoresis with appropriate controls. The concentrations of the viral stocks used to evaluate the presence or absence of HSV in an SDA system were not known. The viral stocks were diluted 1:10 in phosphate buffered saline and 10 μL of this suspension was tested by SDA. Results are shown in Table 4. All strains of HSV-1 were detected using the HSV-1 amplification primers demonstrating the ability of disclosed primers and probes to detect strains of HSV-1 from a diversity of sources. Of the previously untyped 14 strains of HSV typed by Apal restriction digest, nine were determined to be HSV-1, four were determined to be HSV-2 and one did not amplify by PCR (see, Tables 4 and 5). TABLE 4 STRAINS OF HERPES SIMPLEX 1 VIRUS TESTED BY SDA HSV APA1 GEL HSV-1GG HSV-1GG TYPE SAMPLE # COMMENTS RESULTS (MOTA) (PAT) HSV-1 OSU 0-2021 previously untyped HSV-1 16970 45.91 HSV-1 OSU 0-450 previously untyped HSV-1 105400 50.07 HSV-1 OSU 0-1010 previously untyped HSV-1 156280 52.43 HSV-1 OSU 0-2526 previously untyped HSV-1 154715 51.96 HSV-1 OSU D-8-1973 previously untyped HSV-1 149720 54.73 HSV-1 OSU 7-370 previously untyped HSV-1 152600 54.56 HSV-1 OSU 0116-3 previously untyped HSV-1 175610 54.77 HSV-1 OSU 1136 previously untyped HSV-1 165410 53.36 HSV-1 OSU A.P. previously untyped HSV-1 225340 54.62 HSV-1 ATCC 260 VR ATCC HSV-1 148960 54.78 HSV-1 ATCC VR-733 ATCC HSV-1 248080 54.73 HSV-1 ATCC VR-735 ATCC HSV-1 153760 54.46 HSV-1 ATCC VR-539 ATCC HSV-1 173860 54.47 HSV-1 Clin1 Quest Diagnostics HSV-1 250570 54.33 HSV-1 Clin2 Quest Diagnostics HSV-1 222590 54.52 HSV-1 Clin3 Quest Diagnostics HSV-1 126780 51.51 HSV-1 Clin4 Quest Diagnostics HSV-1 262540 54.63 HSV-1 Clin5 Quest Diagnostics HSV-1 180530 54.44 HSV-1 Clin6 Quest Diagnostics HSV-1 12750 35.12 HSV-1 Clin7 Quest Diagnostics HSV-1 115500 50.31 HSV-1 Clin8 Quest Diagnostics HSV-1 184130 54.29 HSV-1 Clin9 Quest Diagnostics HSV-1 197860 52.98 HSV-1 Clin10 Quest Diagnostics HSV-1 160660 50.99 Example 4 Analytical Sensitivity of the SDA Method To determine the limit of detection of the HSV-1 assay using the primers and probes disclosed in the present invention, SDA reactions were performed on dilutions of cloned target nucleic acid and serial dilutions of viral particles. The stock of viral particles was enumerated by electron microscopy (Electron Microscopy Bioservices). Sixteen replicates were tested at each target level. To verify the sensitivity and specificity of the assay, 23 stains of HSV-1 from various geographical locations were tested at a 1:10, 1:1,000 and 1:100,000 dilution of the organism stock. The titer of the samples from the previously un-typed strains and from Quest Diagnostics was unknown. The titer of the two stocks of HSV-1 from ATCC were approximately as follows: VR260, 1.5×104 TCID/μL and VR-539, 2.0×105TCID/μl. Results are shown in FIG. 5. All strains were positive at 1:10 dilution of the stock suspension, except Strain #0-2526. Of the 23 strains, 20 tested positive at 1:1000 dilution of the stock, and 15 strains tested positive at dilution of 1 :100,000. Example 5 Specificity of SDA for HSV-1 DNA Sixteen strains of HSV-2 were tested with the HSV1GG SDA system. Ten microliters of each suspension of HSV-2 dilution were added per reaction. One of the 17 stocks tested positive with the HSV1GG system. The results are shown in Table 5. In addition, 23 other microorganisms were tested using the primers and probes of the disclosed inventive method. These microorganisms included bacteria, yeast and other viruses likely to be encountered in clinical specimens. None of the organisms tested positive for HSV-1. Results are shown in Table 6. TABLE 5 SPECIFICITY OF HSV-1 PRIMERS AND PROBES APAI GEL INTER- HSV-1GG HSV-1GG SAMPLE # COMMENTS PRETATION (MOTA) (PAT) 0-2053 previously HSV-2 680 0 untyped 0-1753 previously No Product 90 0 untyped D-8575 previously HSV-2 390 0 untyped C5 (S?) previously HSV-2 150 0 untyped July-67 previously HSV-2 740 0 untyped ATCC VR- ATCC HSV-2 30 0 734 ATCC VR- ATCC HSV-2 100 0 540 Clin11 Quest HSV-2 410 0 Diagnostics Clin12 Quest HSV-2 20 0 Diagnostics Clin13 Quest HSV-2 290 0 Diagnostics Clin14 Quest HSV-2 320 0 Diagnostics Clin15 Quest HSV-2 40 0 Diagnostics Clin16 Quest HSV-2 210 0 Diagnostics Clin17 Quest HSV-2 10 0 Diagnostics Clin18 Quest HSV-2 40 0 Diagnostics Clin19 Quest HSV-1* 145050 53.38 Diagnostics Clin20 Quest HSV-2 220 0 Diagnostics *Clin19 was typed as HSV-2 by Quest and typed HSV-1 by ApaI analysis. TABLE 6 SPECIFICITY OF HSV-1 PRIMERS AND PROBES HSV-1GG HSV-1GG SDA Organism Strain # (MOTA) (PAT) Adenovirus-5 ABI 74-070 180 0 Candida albicans ATCC 44808 0 0 Cryptococcus neoformans ATCC 36556 60 0 Cytomegalovirus (AD-169) ABi 68-125 10 0 Enterovirus (Echovirus-11) ABi 74-084 20 0 Epstein-Barr virus SIGMA 104HO854 240 0 Escherichia coli ATCC 11775 0 0 Fusobacterium nucleatum ATCC 25586 0 0 Group B Streptococcus ATCC 12386 130 0 Hameophilus influenzae ATCC 33533 320 0 Listeria moncytogenes ATCC 7644 40 0 Mycoplasma pneumoniae ATCC 63-030 300 0 Neisseria meningitidis ATCC 13077 10 0 Propioibacterium acnes ATCC 6919 0 0 Pseudomonas aeruginosa ATCC 27853 170 0 Resp. Synctial virus ABi 74-093 180 0 Staphylococcus. Aureus ATCC 25923 0 0 Staphylococcus epidermidis ATCC E155 0 0 Streptococcus mitis ATCC 6249 10 0 Streptococcus mutans ATCC 25175 20 0 Streptococcus pneumoniae ATCC 6303 0 0 Streptococcus pyogenes ATCC 19615 0 0 Rhiniovirus Clin 74 250 0 ATCC—American Type Culture Collection; ABi—Advanced Biotechnologies, Inc. Example 6 Cloning of HSV-2 Glycoprotein-G SDA Target Region PCR was performed on DNA from the HSV-2 strain ATCC VR-540 using the primers HSV2PCRR and HSV2PCRL with an annealing temperature of 69° C. These primers amplify a 254 base pair fragment within the Glycoprotein G (US4) gene of HSV-2. Amplified DNA was inserted into a pUC18 plasmid vector (Invitrogen). The recombinant clone was dubbed pHSV2-NT #9-1. Plasmid DNA was purified and linearized by digestion with BamHI restriction enzyme. The DNA was purified using QIAGEN QIAquick spin columns and quantified by analysis with fluorescent Picogreen® reagent. Dilutions of the target DNA for future experiments were prepared in water containing 7ng/μL salmon sperm DNA. Example 7 Amplification of Cloned HSV-2 DNA The analytical sensitivity of the DNA amplification assay was estimated using dilutions of the cloned plasmid. Eight replicate SDA reactions were performed at each target level using systems 2.0 and 5.2. These eight reactions were equivalent to 500, 250, 100, 50, 25, 10 and 0 copies of double stranded DNA per reaction. Amplification was conducted at 52° C. using a BD ProbeTec™ ET instrument with 50 nM each of HSV2GGLB1.0 and HSV2GGRB1.0, 100 nM of HSV2GGLP1.0, 500 nM HSV2GGRP2.0 or 5.2, 250 nM HSV2GGAD1.0, 500 nM MPC.D/R. The sequences of these primers are listed in Table 2. Final buffer conditions were as follows: 71 mM Bicine, 56.6 mM KOH, 23.9 mM KPO4, 15.4% DMSO, 5 mM magnesium acetate, 500 mM 2′-deoxycytosine-5-o-(1-thiotriphosphate)(dCsTP), 100 nM each of dATP, dGTP and dTTP, 100 μg/μL BSA, approximately 3.515 units of Bst polymerase and approximately 30 units of BsoBI restriction endonuclease. Fluorescence was monitored for 60 passes over the course of one hour. Results were expressed in terms of area under the curve or “MOTA” score, and as PAT scores (Passes After Threshold). For the purpose of the present invention, MOTA scores greater than or equal to 3500 and PAT scores greater than 0 were considered “positive.” The lowest level of HSV2GG target DNA at which the assay yielded 100% positive results was at 50 copies per reaction for both systems 2.0 and 5.2. Seven of eight replicates were positive for system 2.0 at 25 copies, and six of eight were positive for system 5.2 at 25 copies. Example 8 Detection of HSV-2 Virus Particles by SDA To verify the ability of the primers and probes of the invention to detect HSV-2, SDA was performed on two strains of HSV-2 obtained from American Type Culture Collection (ATCC), nine strains obtained from Quest Diagnostic (Baltimore, Md.) and five strains from Ohio State University (OSU) typed as HSV-2 by ApaI analysis. The strains from OSU were characterized by amplifying a region of the DNA polymerase gene by PCR. One set of PCR primers was designed to amplify the same region in both HSV-1 and HSV-2. The two types of virus were distinguishable by the presence of an ApaI restriction endonuclease recognition site in the HSV-2 PCR fragment that is not present in PCR products generated from strains of HSV-1. When incubated with the ApaI restriction enzyme, the HSV-2 derived PCR products are cleaved into two shorter fragments while those obtained from HSV-1 remain intact. Restricted fragments were resolved on agarose gel electrophoresis with appropriate controls. The concentrations of the viral stocks used to evaluate the SDA system were not known. The viral stocks were diluted 1:10 in phosphate buffered saline and 10 μL of this suspension was tested in SDA. Results are shown in Table 7. All strains of HSV-2 were detected using the amplification primers from systems 1.0, 2.0 and 5.2, demonstrating the ability of disclosed primers and probes to detect strains of HSV1 from a diversity of sources. TABLE 7 STRAINS OF HSV-2 TESTED IN THE HSV2GG SYSTEMS DILUTION HSV2GG HSV2GG HSV2GG FROM 1.0 HSV2GG 2.0 HSV2GG 5.2 HSV2GG STRAIN STOCK MOTA 1.0 PAT MOTA 2.0 PAT MOTA 5.2 PAT OSU 0- 1:10 5460 34 103902 52.2 104334 52.6 2053 OSU D- 1:10 59950 50 123676 52.6 129392 52.7 8575 OSU C5 1:10 34230 47 96845 52.4 103945 52.6 OSU 7- 1:10 135900 53 88932 52.4 86426 52.6 2667 ATCC 1.58E+9 TCID/μL 173220 54 108624 52.4 105501 52.6 VR-734 ATCC 1.58E+4 TCID/μL 183190 55 131364 52.5 128644 52.6 VR-540 Quest 1:10 157930 52 83950 52.4 86787 52.5 Clin 11 Quest 1:10 127670 51 129929 52.3 122640 52.4 Clin 12 Quest 1:10 136710 51 103652 52.2 101533 52.4 Clin 13 Quest 1:10 135660 53 106922 52.2 110146 52.5 Clin 14 Quest 1:10 8440 38 110309 51.1 141752 52.2 Clin 15 Quest 1:10 157960 53 125560 52.1 133232 52.4 Clin 16 Quest 1:10 203550 53 85670 51.4 81501 52.2 Clin 17 Quest 1:10 64690 48 153890 52.1 154132 52.4 Clin 18 Quest 1:10 225400 54 142087 52.4 119663 52.5 Clin 20 OSU = Ohio State University; ATCC = American Type Culture Collection; Quest = Quest Diagnostics Example 9 Specificity of SDA for HSV-2 DNA Twenty-five strains of HSV-1 were tested with HSV2GG SDA systems 1.0, 2.0 and 5.2. Ten microliters of each suspension of the HSV-1 dilution were added per reaction. None of the 25 strains were detected by the HSV-2 systems. Results are shown in Table 8. In addition, a panel of other microorganisms was tested using the primers and probes of the disclosed invention method. These microorganisms included bacteria, yeast and other viruses likely to be encountered in clinical specimens. None of the organisms tested positive for HSV-2. Results are shown in Table 9. TABLE 8 SPECIFICITY FOR HSV-2 STRAINS AGAINST HSV-1 STRAINS IN THE HSV2GG SYSTEMS Dilution HSV2 HSV2 HSV2 HSV2 HSV2 HSV2 HSV-1 from GG 1.0 GG 1.0 GG 2.0 GG 2.0 GG 5.2 GG 5.2 Strain Stock MOTA PAT MOTA PAT MOTA PAT 0-2021 1:10 250 0 2059 0 433 0 0-450 1:10 150 0 500 0 632 0 0-1010 1:10 580 0 1063 0 1733 0 OSU0-2526 1:10 330 0 988 0 816 0 OSU0-1753 1:10 250 0 16 0 4 0 OSUD-8- 1:10 90 0 1 0 433 0 1973 OSU7-370 1:10 110 0 612 0 102 0 OSU0116-3 1:10 290 0 25 0 45 0 OSU1136 1:10 390 0 88 0 61 0 OSUA.P. 1:10 470 0 No data No data No data No data ATCC 2.8E+6 TCID/μL 610 0 656 0 858 0 260VR ATCC VR- 15.8 TCID/μL 1270 0 No data No data No data No data 733 ATCC VR- 15.8 TCID/μL 130 0 0 0 1008 0 735 ATCC VR- 1000 vp/μL 480 0 926 0 1429 0 539 Quest Clin 1 1:10 990 0 1011 0 64 0 Quest Clin 2 1:10 190 0 0 0 68 0 Quest Clin 3 1:10 790 0 419 0 75 0 Quest Clin 4 1:10 310 0 No data No data No data No data Quest Clin 5 1:10 580 0 311 0 212 0 Quest Clin 6 1:10 370 0 0 0 0 0 Quest Clin 7 1:10 380 0 369 0 0 0 Quest Clin 8 1:10 520 0 1576 0 62 0 Quest Clin 9 1:10 770 0 2300 0 1138 0 Quest 1:10 440 0 1956 0 1500 0 Clin 10 Quest Clin 1:10 640 0 587 0 480 0 19 OSU = Ohio State University; ATCC = American Type Culture Collection; Quest = Quest Diagnostics TABLE 9 SPECIFICITY FOR HSV-2 AGAINST VARIOUS BACTERIA, VIRUSES AND YEASTS USING THE HSV2GG SYSTEMS HSV2 HSV2 HSV2 HSV2 HSV2G GG 1.0 GG 1.0 HSV2 GG GG 2.0 GG 5.2 G 5.2 Organism MOTA PAT 2.0 MOTA PAT MOTA PAT Adenovirus-5 50 0 0 0 581 0 Candida albicans 530 0 0 0 246 0 Cryptococcus 120 0 1344 0 1436 0 neoformans Cytomegalovirus 140 0 3 0 1 0 (AD-169) Enterovirus 680 0 491 0 15 0 (Echovirus-11) Epstein-Barr virus 530 0 No data No data No data No data Escherichia coli 20 0 1974 0 69 0 Fusobacterium 0 0 801 0 1560 0 nucleatum Group B 180 0 0 0 387 0 Streptococcus Haemophilus 340 0 618 0 1675 0 influenzae Pseudomonas 500 0 183 0 1303 0 aeruginosa Respiratory 350 0 4 0 236 0 Synctial Virus Staphylococcus 30 0 885 0 551 0 aureus Staphylococcus 10 0 84 0 831 0 epidermidis Streptococcus 190 0 8 0 226 0 mitis Streptococcus 510 0 294 0 1813 0 mutans Streptococcus 60 0 404 0 2006 0 pneumoniae Streptococcus 0 0 1063 0 3149 0 pyogenes Listeria 470 0 984 0 0 0 monocytogenes Mycoplasma 530 0 16 0 408 0 pneumoniae Neisseria 300 0 1661 0 134 0 meningitides Propionibacterium 40 0 1559 0 1022 0 acnes Rhinovirus 20 0 No data No data No data No data Rhinovirus 74 0 0 No data No data No data No data Rhinovirus 114 60 0 No data No data No data No data HIV-1 430 0 1335 0 2795 0 | <SOH> BACKGROUND OF THE INVENTION <EOH>Herpes Simplex is an enveloped double-stranded DNA virus that is responsible for primary and recurrent infections in humans and is related to the viruses that cause infectious mononucleosis (Epstein-Barr Virus), chicken pox and shingles (Varicella Zoster Virus). Symptoms of Herpes Simplex Virus (HSV) infections include an eruption of tiny blisters on the skin or mucous membranes. After the eruption of blisters subsides, the virus remains in a dormant (latent) state inside the group of nerve cells (ganglia) that supply the nerve fibers to the infected area. Periodically, the virus reactivates, begins growing again, and travels through the nerve fibers back to the skin, thereby causing eruptions of blisters in the same area of skin as the earlier infection. Sometimes the virus may be present on the skin or mucous membranes even when there is no obvious blister. Herpes Simplex Virus (HSV) is classified into two types, HSV-1 and HSV-2. The complete genomes of human HSV-1 and HSV-2 have been sequenced (see, for example, NCBI Accession Nos. X14112 and Z86099, respectively). HSV has been shown to contribute to or cause a variety of disorders, including blindness and encephalitis. Besides causing local outbreaks, HSV-1 and HSV-2 are associated with encephalitis. The pathophysiology of this encephalitis is poorly understood in humans. Animal models suggest that the virus enters the central nervous system through peripheral nerves and causes inflammation of the brain. HSV-1 is the more common cause of adult encephalitis. HSV-2 is the more common cause of newborn encephalitis, which is associated with maternal genital infections. HSV-2 is one of the most common sexually transmitted diseases in society. HSV-related encephalitis has the highest fatality rate of all the types of encephalitis with an annual incidence of 1 to 4 per million. HSV encephalitis affects people of all ages and at any time of the year. In adults, HSV-related encephalitis is thought to be due to a reactivation of a latent virus. Symptoms may include fever, headaches, seizures, an altered level of consciousness and personality changes. The similarity of these symptoms to other maladies makes clinical diagnosis difficult. If left untreated, the mortality rate for herpes simplex encephalitis (HSE) is as high as seventy percent, compared with as low as nineteen percent among those who receive treatment. Of the treated patients, approximately thirty-eight percent are reported to eventually return to normal function. It is, therefore, very important to be able to diagnose HSV infection at an early stage. The diagnosis of HSV infection is commonly performed using cell culture on appropriate clinical specimens. However, the ability to isolate HSV in cell culture is reduced in old lesions, in the presence of a host immune response and in episodes of reactivation. Serologic diagnosis, particularly of HSV in cerebrospinal fluid (CSF), is not sufficiently sensitive or specific, and takes too much time to be of use in decisions involving choices for early therapeutic intervention of encephalitis. HSV is rarely detected in cerebral spinal fluid using cell culture, with only four percent of the cases being culture-positive. Serological methods are also inadequate for diagnosis of HSE due to delay between two and three weeks in appearance of antibody response after initial infection. The “gold standard” method of diagnosis involving brain biopsies is invasive and controversial with significant risk of long-term morbidity. Alternate techniques such as Computer-Assisted Tomography and Magnetic Resonance Imaging are not specific and lack sensitivity as diagnostic tools. At the present time, immunological methods for detection of HSV are unreliable and difficult to perform. Molecular methods of detection offer the potential for enhanced sensitivity and faster time to result than is possible by conventional means. There are instances in which rapid, sensitive, and specific diagnosis of HSV disease is imperative. There is therefore, a clinical need to develop a rapid and sensitive tool to aid in the diagnosis of HSV. There also remains a need for a tool for the typing of the HSV infection. Rapid identification of the specific etiological agent involved in a viral infection provides information which can be used to determine appropriate therapy within a short period of time. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to methods and compositions for determining the presence of Herpes Simplex Virus (HSV), specifically Herpes Simplex Virus type 1 (HSV-1) or type 2 (HSV-2) in mammals. The method involves using primers to amplify and detect Herpes Simplex Virus target sequence. One embodiment uses the amplification technique of Strand Displacement Amplification (SDA). The nucleic acid primers of the invention uniquely amplify the target sequence in HSV-1 or HSV-2, thereby allowing sensitive detection and type-identification of HSV. The present invention is also directed to a Strand Displacement Amplification (SDA) based method for the detection of HSV that involves real-time detection using a universal fluorescent energy transfer probe. The probes and primers of the present invention provide a direct, rapid, and sensitive detection of HSV nucleic acids and therefore offer an attractive alternative to immunological assays. The probes and primers of the invention may be used after culture of the sample as a means for confirming the identity of the cultured organism. Alternatively, they may be used prior to culture or in place of culture for detection and identification of HSV nucleic acids using known amplification methods. The inventive probes, primers, and compositions and assay methods using the probes, primers, and compositions, provide a means for rapidly discriminating between the nucleic acid target sequences of HSV-1 and HSV-2, allowing the practitioner to identify, diagnose, and treat the HSV type without resorting to the time-consuming immunological and biochemical procedures typically relied upon. | 20040426 | 20071106 | 20050224 | 70836.0 | 0 | PANDE, SUCHIRA | DETECTION OF HERPES SIMPLEX VIRUS TYPES 1 AND 2 BY NUCLEIC ACID AMPLIFICATION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,172 | ACCEPTED | Method and system for customizing views of information associated with a social network user | A method, apparatus, and system are directed towards managing a view of a social network user's personal information based, in part, on user-defined criteria. The user-defined criteria may be applied towards a user's relationship with each prospective viewer. The user-defined criteria may include degrees of separation between members of the social network, a relationship to the prospective viewer, as well as criteria based, in part, on activities, such as dating, employment, hobbies, and the like. The user-defined criteria may also be based on a group membership, a strength of a relationship, and the like. Such user-defined relationship criteria may then be mapped against various categories of information associated with social network user to provide customized views of the social network user. | 1. A method of managing social network user information over a network, comprising: receiving a plurality of social network user information from a user; receiving a relationship criteria for viewing the social network user information from the user; receiving a request to view the social network user information from another user; and providing at least a portion of the social network user information to the other user based, in part, on a mapping of the relationship criteria against the plurality of social network user information. 2. The method of claim 1, wherein the relationship criteria further comprises at least one of a degree of separation, a category membership, a group membership, a relationship strength, and an activity. 3. The method of claim 1 wherein the relationship criteria further comprises a membership of the user in an activity. 4. The method of claim 3, wherein the activity further comprises at least one activity associated with dating, business, military, employment, help, advice, expertise, and alumni. 5. The method of claim 1, wherein mapping of the relationship criteria further comprises, determining if the request is from a member of a user-definable category. 6. The method of claim 1, wherein mapping of the relationship criteria further comprises, determining if the request is associated with a request for user information associated with at least one of an activity, and a group. 7. The method of claim 1, wherein providing at least a portion of the social network user information further comprises providing at least one of an age, a name, and an email address associated with the user. 8. A method of managing social network user information over a network, comprising: receiving a request to view social network user information associated with another user; if the request is from a user associated with a category, determining a user-definable set of social network user information; if the request is associated with an activity for which the other user is a member; determining an activity related set of social network user information; determining a basic set of social network user information; if the request is from the user that is associated with a group, determining a group set of social network user information; if the request is from the user that is associated with a predetermined relationship strength, determining a relationship strength set of social network user information; and providing at least one of the user-definable set, the activity related set, relationship strength, group, and the basic set of social network user information. 9. The method of claim 8, wherein if the request is from the user associated with the category, further comprises, determining a relationship between the between the user and the other user. 10. The method of claim 8, wherein the category further comprises a user-definable category. 11. The method of claim 8, wherein the activity further comprises a globally defined activity. 12. The method of claim 11, wherein the activity is selectable from at least one activity associated with dating, business, military, employment, help, advice, expertise, and alumni. 13. The method of claim 8, wherein determining the basic set of social network user information further comprises determining a globally defined set of information including at least one of an age, a name, an email address, and an alias. 14. The method of claim 8, wherein providing at least one further comprises: if at least two of the user-definable set, the activity related set, the group set, relationship strength set, and the basic set of social network user information are determined, removing redundant social network user information among the determined sets, and providing a reduced set of social network user information. 15. A client device adapted to managing social network user information over a network, comprising: a display configured to view social network user information; and a client application coupled to the display, that is configured to perform actions, including: requesting social network user information associated with another user; if the request is from a user associated with a user-definable category, receiving at least a user-definable set of social network user information, wherein the user-definable category and the user-definable set are defined by the other user; if the request is associated with an activity for which the other user is a member; receiving at least an activity related set of social network user information; and receiving a third set of social network user information. 16. The client device of claim 15, wherein receiving at least one of the user-definable set and the activity related set, and the third set of social network user information further comprises receiving a set of social network user information, wherein at least one redundant social network user information has been removed. 17. The client device of claim 15, wherein the client device further comprises a mobile device. 18. The client of claim 15, wherein if the request is from a user associated with a category, further comprises, determining a relationship between the user and the other user. 19. The client of claim 18, wherein determining the relationship further comprises determining a degree of separation between the user and the other user. 20. The client of claim 15, wherein the activity further comprises a globally defined activity selectable from at least one activity associated with dating, business, military, employment, help, advice, and alumni. 21. A server for managing social network user information over a network, comprising: a transceiver for receiving and sending information to a computing device; and a view manager that is configured to perform actions, including: receiving a request to view social network user information associated with another user; if the request is from a user associated with a category, determining a user-definable set of social network user information; if the request is associated with an activity for which the other user is a member; determining an activity related set of social network user information; determining a third set of social network user information; and providing at least one of the user-definable set, the activity related set, and the third set of social network user information. 22. The server claim 21, wherein the view manager is configure to perform further actions, comprising: if the request is from the user that is associated with a group, determining a group set of social network user information; if the request is from the user that is associated with a predetermined relationship strength, determining a relationship strength set of social network user information; and providing at least one of the group set, and the relationship strength set, and the third set of social network user information. 23. The server of claim 21, further comprising: a spam filter configured to employ at least one of the category, and the activity to determine whether a message is spam. 24. The server of claim 21, wherein if the request is from the user associated with the category further comprises determining a relationship between the user and the other user, wherein the category and the user-definable set of social network user information is definable by the other user. 25. The server of claim 21, wherein the activity further comprises a globally defined activity rather than a user-definable activity. 26. The server of claim 21, wherein the third set of social network user information comprises user information, including at least one of a name, an email address, an alias, and an age. 27. The server of claim 21, wherein providing at least one of the user-definable set, the activity related set, and the third set of social network user information further comprises providing the social network user information towards a mobile device. 28. A modulated data signal for managing social network user information over a network, the modulated data signal comprising the actions of: transferring a request to view social network user information associated with another user; if the request is from a user associated with a category, enabling a determination of a user-definable set of social network user information; if the request is associated with an activity for which the other user is a member; enabling a determination of an activity related set of social network user information; enabling a determination a third set of social network user information; and providing at least one of the user-definable set, the activity related set, and the third set of social network user information. 29. The modulated data signal of claim 28, wherein providing at least one of further comprises providing the at least one of the social network user information towards a mobile device. 30. An apparatus for managing social network user information, comprising: a means for receiving a plurality of social network user information; a means for receiving a relationship criteria for viewing the social network user information; a means for receiving a request to view the social network user information; and a means for providing at least a portion of the social network user information based, in part, on a means for mapping of the relationship criteria against the plurality of social network user information. | FIELD OF THE INVENTION The present invention relates generally to computing software for managing a social network view, and more particularly to a method and system for customizing views of a social network user. BACKGROUND OF THE INVENTION Social networking includes a concept that an individual's online personal network of friends, family colleagues, coworkers, and the subsequent connections within those networks, can be utilized to find more relevant connections for dating, job networking, service referrals, activity partners, and the like. Because individuals are more likely to trust and value the opinions from people they know than from complete strangers, social networking is typically directed towards mining these network relationships in a way that is often more difficult to do offline. Thus, there has been a flurry of companies launching services that help people to build and mine their personal networks. However, these efforts have been predominately directed towards dating and job opportunities. Many of these companies are struggling with developing additional services that will build customer loyalty. Without the ability to extend the value of the existing networks, social networking loses its appeal. Thus, there is a need in the industry for better mechanisms to manage, mine, and cultivate personal networks. Therefore, it is with respect to these considerations and others that the present invention has been made. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified. For a better understanding of the present invention, reference will be made to the following Detailed Description of the Invention, which is to be read in association with the accompanying drawings, wherein: FIG. 1 shows a functional block diagram illustrating one embodiment of an environment for practicing the invention; FIG. 2 shows one embodiment of a server device that may be included in a system implementing the invention; FIGS. 3A-3B illustrate a logical flow diagram generally showing one embodiment of a process for customizing a view of social network user information; and FIG. 4 illustrates a logical flow diagram generally showing one embodiment of a process for providing a customized view of social network user information, in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention now will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments by which the invention may be practiced. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as methods or devices. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense. The phrase “in one embodiment,” as used herein does not necessarily refer to the same embodiment, although it may. Similarly, the phrase “in another embodiment,” as used herein does not necessarily refer to a different embodiment, although it may. The term “based on” is not exclusive and provides for being based on additional factors not described, unless the context clearly dictates otherwise. Briefly stated, the present invention is directed towards providing a system, apparatus, and method for managing a view of a social network user's personal information based, in part, on user-defined criteria. The user-defined criteria may be applied towards a user's relationship with each prospective viewer. The user-defined criteria may include degrees of separation between members of the social network, a relationship to the prospective viewer, as well as criteria based, in part, on activities, such as dating, employment, hobbies, and the like. Such user-defined relationship criteria may then be mapped against various categories of information associated with social network user to provide customized views of the social network user. Such customized views may be employed to portray various personas to other users of the social network, and to enhance one's own overall value of the social networking experience. Moreover, employing such categories may minimize the likelihood of spam mailings. For example, a category may be employed for use in a spam filter, and the like, by determining whether the sending is a member of a category. In one embodiment, the user may establish a basic profile that includes a predetermined set of information about the user. A category may be established that has associated with it a set of user specified category profile information about the user. The category profile information and the basic profile information may then be employed to present a customized view of the user for that category. Additionally, the user may elect to join an activity, such as a job search activity, religious activity, and the like. Activity profile information may be established based, in part, on a globally defined set of social network user information, to encourage a community sharing of common information related to the activity. Profile information may then be provided that is employable to present potentially yet another view of the user. In another embodiment, the user may further rate a strength of a relationship between themselves and another social network user. The other social network user may then be permitted to view selected profile information based on the relationship strength. In still another embodiment, profile information may be made available based, in part, on an affiliation of the other social network user to an online group, such as a Yahoo! group, and the like, an offline group, such as a fishing club, and the like. Illustrative Operating Environment FIG. 1 illustrates one embodiment of an environment in which the present invention may operate. However, not all of these components may be required to practice the invention, and variations in the arrangement and type of the components may be made without departing from the spirit or scope of the invention. As shown in the figure, system 100 includes client devices 102-104, network 105, and social network server (SNS) 106. Network 105 is in communication with and enables communication between each of client devices 102-104, and SNS 106. Client devices 102-104 may include virtually any computing device capable of receiving and sending a message over a network, such as network 105, to and from another computing device, such as SNS 106, each other, and the like. The set of such devices may include devices that typically connect using a wired communications medium such as personal computers, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, and the like. The set of such devices may also include devices that typically connect using a wireless communications medium such as cell phones, smart phones, pagers, walkie talkies, radio frequency (RF) devices, infrared (IR) devices, CBs, integrated devices combining one or more of the preceding devices, or virtually any mobile device, and the like. Similarly, client devices 102-104 may be any device that is capable of connecting using a wired or wireless communication medium such as a PDA, POCKET PC, wearable computer, and any other device that is equipped to communicate over a wired and/or wireless communication medium. Each client device within client devices 102-104 may include a browser application that is configured to receive and to send web pages, and the like. The browser application may be configured to receive and display graphics, text, multimedia, and the like, employing virtually any web based language, including, but not limited to Standard Generalized Markup Language (SMGL), such as HyperText Markup Language (HTML), a wireless application protocol (WAP), a Handheld Device Markup Language (HDML), such as Wireless Markup Language (WML), WMLScript, JavaScript, and the like. Client devices 102-104 may be further configured to receive a message from the another computing device employing another mechanism, including, but not limited to email, Short Message Service (SMS), Multimedia Message Service (MMS), instant messaging (IM), internet relay chat (IRC), mIRC, Jabber, and the like. Client devices 102-104 may be further configured to enable a user to manage a user profile, category information, activity participation, and the like, which may in turn be saved at a remote location, such as SNS 106, and the like. As such, client devices 102-104 may further include a client application that is configured to manage various actions on behalf of the client device. For example, the client application may enable a user to interact with the browser application, email application, and the like, to customize how another social network user might view a persona, profile, or the like associated with the user. For example, the user may employ the client application, in part, to provide one customized view for family members, another customized view for poker members, yet another view for fishing buddies, and the like. The client application may interact with a process such as described below in conjunction with FIG. 3 to customize and manage such views. Network 105 is configured to couple one computing device to another computing device to enable them to communicate. Network 105 is enabled to employ any form of computer readable media for communicating information from one electronic device to another. Also, network 105 may include a wireless interface, and/or a wired interface, such as the Internet, in addition to local area networks (LANs), wide area networks (WANs), direct connections, such as through a universal serial bus (USB) port, other forms of computer-readable media, or any combination thereof. On an interconnected set of LANs, including those based on differing architectures and protocols, a router acts as a link between LANs, enabling messages to be sent from one to another. Also, communication links within LANs typically include twisted wire pair or coaxial cable, while communication links between networks may utilize analog telephone lines, full or fractional dedicated digital lines including T1, T2, T3, and T4, Integrated Services Digital Networks (ISDNs), Digital Subscriber Lines (DSLs), wireless links including satellite links, or other communications links known to those skilled in the art. Furthermore, remote computers and other related electronic devices could be remotely connected to either LANs or WANs via a modem and temporary telephone link. In essence, network 105 includes any communication method by which information may travel between client devices 102-104, and SNS 106. The media used to transmit information in communication links as described above illustrates one type of computer-readable media, namely communication media. Generally, computer-readable media includes any media that can be accessed by a computing device. Computer-readable media may include computer storage media, communication media, or any combination thereof. Additionally, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, data signal, or other transport mechanism and includes any information delivery media. The terms “modulated data signal,” and “carrier-wave signal” includes a signal that has one or more of its characteristics set or changed in such a manner as to encode information, instructions, data, and the like, in the signal. By way of example, communication media includes wired media such as twisted pair, coaxial cable, fiber optics, wave guides, and other wired media and wireless media such as acoustic, RF, infrared, and other wireless media. One embodiment of SNS 106 is described in more detail below in conjunction with FIG. 2. Briefly, however, SNS 106 may include any computing device capable of connecting to NETWORK 105 to manage a customization of a view associated with a social network user, such as a user of at least one of client devices 102-104. Devices that may operate as SNS 106 include personal computers desktop computers, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, servers, and the like. SNS 106 may be configured to receive information associated with a user and to enable the user to customize a view based in part, on the received information. The received information may include, but is not limited to, profile information, category information, an activity, membership information associated with a category, and the like. SNS 106 may further employ the received information to enable the user to customize a view associated with a social network perspective based, in part, on received criteria. By providing customized views, the user may put forth different online profiles, public personas, and the like, by sharing varying quantities of personal information with another social network user. The received criteria employed to enable customization of the views may include, but is not limited to, degrees of separation, category of relationship (such as friend, family, colleague, and the like), as well as any assessment of closeness, trust, and the like, based on information about the relationship between the user and the prospective viewer, and the like. The received criteria may further include a permission to view selected information based on a relationship strength, an offline group affiliation, an online group affiliation, and the like. SNS 106 may also enable another social network user, such as a user of one of client devices 102-104, to view the customized view based on the received criteria. SNS 106 may employ a web service, email service, and the like, to make the customized view available to the other social network user, as appropriate. SNS 106 may employ processes such as described in more detail below in conjunction with FIGS. 3-4 to manage the customized views. Illustrative Server Environment FIG. 2 shows one embodiment of a server, according to one embodiment of the invention. Server 200 may include many more components than those shown. The components shown, however, are sufficient to disclose an illustrative embodiment for practicing the invention. Server 200 includes processing unit 212, video display adapter 214, and a mass memory, all in communication with each other via bus 222. The mass memory generally includes RAM 216, ROM 232, and one or more permanent mass storage devices, such as hard disk drive 228, tape drive, optical drive, and/or floppy disk drive. The mass memory stores operating system 220 for controlling the operation of server 102. Any general-purpose operating system may be employed. Basic input/output system (“BIOS”) 218 is also provided for controlling the low-level operation of server 102. As illustrated in FIG. 2, server 200 also can communicate with the Internet, or some other communications network, such as network 105 in FIG. 1, via network interface unit 210, which is constructed for use with various communication protocols including the TCP/IP protocol. Network interface unit 210 is sometimes known as a transceiver, transceiving device, network interface card (NIC), and the like. The mass memory as described above illustrates another type of computer-readable media, namely computer storage media. Computer storage media may include volatile, nonvolatile, removable, and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computing device. The mass memory also stores program code and data. One or more applications 250 are loaded into mass memory and run on operating system 220. Examples of application programs include email programs, schedulers, calendars, web services, transcoders, database programs, word processing programs, spreadsheet programs, and so forth. Mass storage may further include applications such as view manager 254, category/activity store 256, and profile store 258. Category/activity store 256 may include a database, text, folder, file, and the like, that is configured to maintain and store information that identifies a category, activity, and the like. While category/activity store 256 may store identification information, profile store 258, described below, may store profile and criteria information for each social network user. A category may represent a classification of users within a user's social network, such as friends, co-workers, poker buddies, family, fishing buddies, and the like. Typically, social network users establish their own categories and profile information based on the category may be accessible to those identified by the creating social network user. However, the invention is not so limited, and global categories may be established that provide profile information about a social network user to virtually any other social network user. Each category may include a set of user-definable social network user information. When the category is user-definable, the set of social network user information (profile information) may also be user-definable. For example, the user may determine that social network user information associated with hobbies may be included in a category for sports, while it may be excluded from a category associated with religion, and the like. Category/activity store 256 may further include information associated with a group affiliation. For example, the user may establish groupings that enable another social network user to view selected profile information based on whether the other social network user is affiliated with a predetermined group. Such group affiliations may include, but are not limited to, online groups, such as a Yahoo! group, and the like, as well as an offline group, such as Fly Fishing club, a chess club, a bridge club, a bowling group, and the like. An activity may include virtually any way, manner, and the like, in which a social network user may select to employ their social network connections. For example, activities may include, but are not limited to, dating, careers, military, alumni, help, advice, expertise, and the like. Typically, an activity may be employed by other social network users, even though they are not a member of the activity. As such, it may be desired, although not required, that an activity be globally configured and managed. Additionally, at least a minimum set of profile information associated with the activity may be globally established. For example, if the activity includes dating, the minimum set of profile information, may include, but is not limited to age, sexual preference, information associated with one's physical appearance, and the like. If the activity includes job search, employment search, and the like, the minimum set of profile information may include, but is not limited to, job history, salary desired, job qualifications, experience, and the like. However, an activity may further include an optional set of profile information, such as achievements, hobbies, recommendations, and the like. Moreover, membership to an activity may also be employed to determine whether a message is spam. Profile store 258 may include a database, text, folder, file, and the like, that is configured to maintain and store a profile associated with a social network user. A profile may include information associated with the social network user. For example, the profile may include, but is not limited to such information as the social network user's name, alias, nickname, age, email address, and the like. In one embodiment, a collection of such information may be arranged to provide a basic profile for the social network user. Additional information may also be included in profile store 258 that includes category profile information, activity profile information, group profile information, relationship strength profile information, and the like. Such additional information may include, but is not limited, to a photograph, a hobby, a job history, a school history, career information, dating information, military information, sports information, religious information, sexual orientation, politics, interests, favorite sites, self-description, and the like. The additional information may further include such online status, including, but not limited to a current audio file being played, such as a current song, or the like, a favorite picture, a favorite group, blog, journal entry, file, update on a friend, and the like. In one embodiment, at least some information includes a Universal Resource Locator (URL). Virtually any information associated with the social network user may be included within profile store 258. Moreover, profile store 258 may store and maintain criteria associated with how profile information may be viewed by another social network user. For example, profile store 258 may include criteria indicating that only a member of a particular category may view a particular photograph, a subset of profile information, and the like. While information may be selected at a field by field level of granularity, the present invention however, is not so limited. For example, the present invention enables the social network user to establish criteria that is based on a relationship between the prospective viewer and the user. The relationship criteria may then be employed to map various collections, groupings, sets, and the like, of profile information, rather than merely toggling on/off individual viewers for all the profile information or individual profile fields. As such, the social network user, for example, may establish criteria such that any other social network user that is within some predetermined degrees of separation may view a predetermined set of profile information. Moreover, the social network user may further establish criteria that such that any other social network user that has a user-definable relationship strength may view a predetermined set of profile information. For example, the social network user may establish criteria that allow any other social network user with a relationship strength of “close friend,” to view more profile information, than a social network user that has a relationship strength of “acquaintance.” However, the invention is not limited to the examples for relationship strengths, and virtually any criteria, rating, and the like, may be employed to enable viewing of profile information based on relationship strength. The social network user may also establish criteria that enable viewing of another predetermined set of profile information based, in part, on a group affiliation. For example, criteria may be established that allows a member of a pre-defined group to view selected profile information. Such group affiliations may be determined employing any of a variety of mechanisms, including but not limited to, requesting such information from another social network user, examining a predetermined file, database, repository, and the like. View manager 254 is configured to enable a social network user to manage their information within profile store 258 and category/activity store 256. View manager 254 may further enable another social network user to view a profile based in part, on predetermined criteria as described above. As such, view manager 254 may employ processes such as described in more detail below in conjunction with FIGS. 3-4 to manage customized views of the social network user. Although illustrated in FIG. 2 as distinct components in server 200, view manager 254, category/activity store 256, and profile store 258 may be arranged, combined, and the like, in any of a variety of ways, without departing from the scope of the present invention. For example, category/activity store 256 may be arranged as separate components, such as an activity store and a category store, or the like. Moreover, view manager 254, category/activity store 256, and profile store 258 may reside in one or more separate computing devices, substantially similar to server 200. Server 200 may also include an SMTP handler application to interface with DEA manager 254 for transmitting and receiving email. Server 200 may also include an HTTP handler application for receiving and handing HTTP requests, and an HTTPS handler application for handling secure connections. The HTTPS handler application may initiate communication with an external application in a secure fashion. Server 200 also includes input/output interface 224 for communicating with external devices, such as a mouse, keyboard, scanner, or other input devices not shown in FIG. 2. Likewise, server 200 may further include additional mass storage facilities such as CD-ROM/DVD-ROM drive 226 and hard disk drive 228. Hard disk drive 228 is utilized by server 102 to store, among other things, application programs, databases, view manager 254, category/activity store 256, profile store 258, and the like. Generalized Operation The operation of certain aspects of the present invention will now be described with respect to FIGS. 3-4. Briefly, FIGS. 3A-3B illustrate a logical flow diagram generally showing one embodiment of a process for enabling social network users to customize a view of their profile information. Process 300, which spans FIGS. 3A-3B, may be implemented, for example, within SNS 106 of FIG. 1, and accessed employing a client device, such as client devices 102-104 of FIG. 1. Process 300 is typically entered when a social network user that is registered to employ the customization process indicates intent to manage a view of their profile. Thus, process 300 begins, after a start block, at decision block 302, where a determination is made whether the social network user wishes to manage their basic profile. Typically, if the social network user has not provided basic user profile information, such as when the user has just registered, or the like, then the answer to decision block 302 may be yes. In any event, if it is determined that the social network user is to manage their basic profile, processing branches to block 304; otherwise, processing continues to decision block 306. In one embodiment, the user profile may be created quickly by automatically importing predetermined user data from a variety of sources, including, but not limited, to the user's email address book, group associations, and the like. At block 304, the social network user may update their basic profile. Updates may include, modifying basic profile information about themselves, including age, gender, email address, interests, and the like. Basic profile information is not limited to these items, however, and others may be included, substituted, or the like, without departing from the scope of the invention. In any event, upon updating the basic profile information, process 300 continues to decision block 306. At decision block 306, a determination is made whether the social network user is to manage a category. As described above, a category includes a classification of social network users within an individual user's social network. Typically, the social network users are within the user's first degree of separation, such as friends, soccer teammates, co-workers, family, and the like. A degree of separation is one criterion that may be employed to represent a relationship between social network users. Degrees of separation for example, may indicate that the two social network users have a direct relationship, such as through direct email correspondences, inclusion of each other's email addresses within one's address book, or the like. Higher degrees of separation may indicate a further removed relationship, such as a friend of a friend, and the like. Thus, the present invention is not limited to first degrees of separation, and higher degrees may be employed without departing from the scope of the invention. Such categories are directed towards providing a convenient mechanism to organize one's connections, and control information that is revealed to others, to efficiently manage communications, such as enabling email to all social network members in one's soccer teammate's category, and the like. Moreover, categories may be employed to minimize the likelihood of receiving spam. For example, a category may be employed to minimize access to information. A category may also be employed in conjunction with a spam filter to determine whether a message is from a member of a category. However, use of a category is not limited to these spam examples, and others may be employed without departing from the scope of the invention. As such, managing a category includes the ability to create, edit, and delete a user specified category. In any event, if the determination is to manage a category, processing branches to decision block 308; otherwise, processing proceeds to decision block 316. At decision block 308, a determination is made whether the user indicates an intent to create a new category. If the user indicates intent to create a new category, processing proceeds to block 310, where the new category is created; otherwise, processing branches to block 312. Creation of a new category may include providing a name to the category, a description of the category, and the like. The category may also be created when another social network user includes the current user in their social network. Processing next proceeds to block 312. At block 312, criteria may be created, modified, and the like, that establishes the type of information a member of the category may view. For example, criteria may be established that enables one category to view any profile information associated with employment, but not religion, or the like. Criteria may be established that enables another category to view selected photographs, sets of photographs, and the like, while another category may be unable to view any photographs. Criteria may also be established that enables a category to view one's hobbies, information associated with selected hobbies, and the like, while another category may be unable to view other information associated with hobbies. For example, a category may have been created for one's fishing buddies and another category for one's religious membership. Criteria may then be established that enables the fishing buddy category to view any information associated with hobbies, sports, and the like, including recent purchases and recommendations associated with hobbies. However, hobby information might be screened from being viewable by members of one's religious category. The above are merely examples, as the possibilities are virtually endless as how one may wish to establish criteria for viewable information. Unlike traditional implementations, the present invention enables a social network user to establish criteria based on relationship criteria, such as degrees of separation, and the like that maps against various categories of information, such as hobby information, and the like. As such, by applying the criteria to viewable information by a category, one may minimize the likelihood of receiving spam. Processing continues next to block 314, where membership to the category is managed. Based, in part, on the criteria, membership may be added or deleted. For example, membership to a category may have been established based on a relationship, such as any person within two degrees of separation from this other person. However, membership is not constrained to this example, and virtually any criteria, and the like, may be employed to determine membership to a category. Additionally, membership may be obtained from virtually any source, including, but not limited to, one's email address book, another's address book, a buddy list, a database, an association, and the like. Membership may also be revised based on additional user input at this block, including revising selected member participation, further revising membership criteria, other connections between online portal subscribers, and the like. In any event, upon completion of block 314, processing proceeds to decision block 316. At decision block 316, a determination is made whether the user indicates an intent to manage membership within an activity. If the user indicates intent to manage membership within an activity, processing continues to decision block 318; otherwise, process 300 flows to decision block 328 of FIG. 3B. At decision block 318, a determination is made whether the user indicates intent to join an activity. Activities are typically predetermined so as to enable other social network users to perform searches, make inquiries, receive messages, and the like. As such, activities are typically, but not necessarily, accessible to virtually any social network user that wishes to join. Moreover, activities are typically, but not necessarily, managed by other than the single user. Thus, if the user indicates intent to join an existing activity, processing continues to block 320, where the user is presented with at least one predetermined activity for which the user may join. Otherwise, if the user does not intend to join an activity, processing continues to decision block 322. Such activities may include, but are not limited to, dating, careers, military, alumni, help, advice, expertise, and the like. Upon completion of block 320, processing continues to decision block 322. At decision block 322, a determination is made whether the user indicates an intent to be removed from an activity for which the user is already a member. If so, processing proceeds to block 326, where the user selects the activity from which the user indicates intent to be removed. Upon completion of block 326, or if the answer is not to drop an activity, processing flows to decision block 328 of FIG. 3B. At decision block 328 of FIG. 3B, a determination is made whether the user indicates an intent to manage a group affiliation. If so, processing proceeds to block 340; otherwise, processing branches to decision block 346. At block 340, a group affiliation is identified. The user may provide the group affiliation based on an online group, club, and the like, based on an offline group, club, association, and the like. For example, a group affiliation may be based on another's affiliation to an offline fly-fishing club, a chess club, an online fly-fishing club, a group such as a Yahoo! group, and the like. Virtually any affiliation may be employed to establish group affiliation criteria. Upon completion of block 340, processing continues to block 342. At block 342, group criteria may be created, modified, and the like, that establishes the type of information a group affiliation established in block 340 may view. For example, the group criteria may be established that enables a member of the predetermined group to view one's hobbies associated with the subject of that group. For example, where the group is associated with chess, the group criteria may enable viewing of books one purchased on the subject of chess. However, the invention is not so limited, and virtually any group criteria may be established based on a group affiliation to in turn establish group profile information. Upon establishing the group profile information at block 342, processing flows to decision block 346. At decision block 346, a determination is made whether a relationship strength is to be managed. If so, processing flows to block 348; otherwise, processing returns to a calling process to perform other actions. At block 348, a relationship strength is rated. Virtually any rating of a relationship may be employed. In one embodiment, however, a rating is based on inputting a criterion, for another social network user. For example, a rating may be applied that distinguishes a “close friend” from a “casual acquaintance,” and the like. Upon completion of block 348, process 300 flows to block 350, where a relationship strength criteria is managed that provides a view of one's profile information based on the relationship strength identified at block 348. For example, the criteria may enable the social network user that has a relationship strength of “close friend” to view more intimate profile information that another social network user. In any event, upon completion of block 350, processing returns to the calling process to perform other actions. FIG. 4 illustrates a logical flow diagram generally showing one embodiment of a process for managing a customized view of a social network user's profile information. Process 400 of FIG. 4 may be implemented, for example, on SNS 106 of FIG. 1. Process 400 is typically entered when a social network user provides a request to view another social network user's profile information. Thus, process 400 begins, after a start block, at decision block 402, where a determination is made whether the request is related to an activity. If the request is related to an identified activity processing proceeds to block 404 where the activity is determined; otherwise, processing flows to decision block 406. At block 404, determination of the identified activity may include, confirming that the profile requested is associated with a member of the identified activity. If it is, then the activity profile information associated with the identified activity is retrieved. Processing then continues to decision block 406. At decision block 406, a determination is made whether the request for the user profile information is from a member of a category established, in part, by the user. If the request is not from a member of an established category, processing proceeds to decision block 410; otherwise processing continues to block 408. At block 408, the category is determined, for which the requesting user is a member. Determination may include a determination of additional profile information based, in part, on established criteria, category identified profile information, and the like. The determined category profile information is then retrieved. Processing continues to decision block 410. At decision block 410, a determination is made whether the request is from a user affiliated with a predetermined group. If the request is from a user affiliated with a predetermined group, processing flows to block 412; otherwise, processing continues to decision block 414. At block 412, the group is determined, for which the requesting user is affiliated. Determination of such affiliation may include a determination of additional profile information based, in part, on established criteria for the group. For example, the group criteria may include whether selected profile information is provided based on affiliation to one group, to one group but not another group, affiliation with a predetermined set of groups, and the like. In any event, application of the group criteria enables retrieval of group profile information. Processing then flows to decision block 414. At decision block 414, a determination is made whether profile information may be made available based on a relationship strength. If it is, processing flows to block 416; otherwise, processing continues to block 418. At block 416, the predetermined relationship strength is employed as criteria to retrieve relationship strength profile information. Processing flows next to block 418. At block 418, the basic profile information is retrieved. Processing continues next to block 420 where the basic profile information and other retrieved profile information (if there was any) are formatted for presentation to the requesting user. Formatting of the profile information may include eliminating presentation of redundant information, organizing the information, and the like. Upon presentation of the profile information, process 400 returns to a calling process to perform other actions. It will be understood that each block of the flowchart illustrations discussed above, and combinations of blocks in the flowchart illustrations above, can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions, which execute on the processor, create means for implementing the actions specified in the flowchart block or blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer-implemented process such that the instructions, which execute on the processor, provide steps for implementing the actions specified in the flowchart block or blocks. Accordingly, blocks of the flowchart illustration support combinations of means for performing the specified actions, combinations of steps for performing the specified actions and program instruction means for performing the specified actions. It will also be understood that each block of the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified actions or steps, or combinations of special purpose hardware and computer instructions. The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | <SOH> BACKGROUND OF THE INVENTION <EOH>Social networking includes a concept that an individual's online personal network of friends, family colleagues, coworkers, and the subsequent connections within those networks, can be utilized to find more relevant connections for dating, job networking, service referrals, activity partners, and the like. Because individuals are more likely to trust and value the opinions from people they know than from complete strangers, social networking is typically directed towards mining these network relationships in a way that is often more difficult to do offline. Thus, there has been a flurry of companies launching services that help people to build and mine their personal networks. However, these efforts have been predominately directed towards dating and job opportunities. Many of these companies are struggling with developing additional services that will build customer loyalty. Without the ability to extend the value of the existing networks, social networking loses its appeal. Thus, there is a need in the industry for better mechanisms to manage, mine, and cultivate personal networks. Therefore, it is with respect to these considerations and others that the present invention has been made. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified. For a better understanding of the present invention, reference will be made to the following Detailed Description of the Invention, which is to be read in association with the accompanying drawings, wherein: FIG. 1 shows a functional block diagram illustrating one embodiment of an environment for practicing the invention; FIG. 2 shows one embodiment of a server device that may be included in a system implementing the invention; FIGS. 3A-3B illustrate a logical flow diagram generally showing one embodiment of a process for customizing a view of social network user information; and FIG. 4 illustrates a logical flow diagram generally showing one embodiment of a process for providing a customized view of social network user information, in accordance with the present invention. detailed-description description="Detailed Description" end="lead"? | 20040426 | 20070911 | 20050811 | 58937.0 | 1 | WONG, LESLIE | METHOD AND SYSTEM FOR CUSTOMIZING VIEWS OF INFORMATION ASSOCIATED WITH A SOCIAL NETWORK USER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,569 | ACCEPTED | Athletic protector convertible from hard-cup to soft-cup configuration | An athletic cup that is convertible from a hard cup configuration to a soft cup configuration. The hard cup configuration can be used for contact sports or ball sports where maximum protection is needed. The cup can be converted to the soft cup configuration for non-contact sports where a lesser degree of protection is adequate. The cup comprises a hard cup and a soft cup that are detachably connected to each other to form the hard cup configuration. To convert to the soft cup configuration, the hard cup is detached and the soft cup is worn by itself. | 1. An athletic protector for protecting the genitals, comprising: a relatively soft and resilient soft cup molded as a one-piece structure and having a domed central portion and a peripheral edge portion extending about a periphery of the domed central portion; and a relatively rigid hard cup having a domed shape complementary to that of the domed central portion of the soft cup; wherein the soft cup and hard cup respectively define interlocking male and female connecting members that are removably engageable with one another for affixing the hard cup to the soft cup in a releasable manner. 2. The athletic protector of claim 1, wherein the soft cup defines the female connecting members and the hard cup defines the male connecting members. 3. The athletic protector of claim 2, wherein the female connecting members comprise grooves formed proximate the peripheral edge region of the soft cup for receiving the male connecting members of the hard cup. 4. The athletic protector of claim 3, wherein the male connecting members comprise outer peripheral edge portions of the hard cup. 5. The athletic protector of claim 4, wherein the outer peripheral edge portions of the hard cup define beads and the grooves in the soft cup are complementary in shape to the beads. 6. The athletic protector of claim 4, wherein the hard cup has a top edge portion defining one of the male connecting members and a bottom edge defining another of the male connecting members. 7. The athletic protector of claim 6, wherein the hard cup has opposite side edges extending between the top and bottom edge portions, and wherein the soft cup defines a pair of engagement members respectively engaged by the opposite side edges of the hard cup such that impact forces on the hard cup are transmitted in part to the engagement members of the soft cup. 8. The athletic protector of claim 1, wherein the soft cup defines ventilation apertures, and the hard cup defines ventilation holes in alignment with the ventilation apertures of the soft cup. 9. The athletic protector of claim 8, wherein each ventilation hole in the hard cup is surrounded by a raised boss shaped to fit closely into a corresponding ventilation aperture in the soft cup. 10. The athletic protector of claim 1, wherein the soft cup comprises thermoplastic elastomer. 11. The athletic protector of claim 10, wherein the soft cup comprises polymer foam having a durometer hardness of about 70 to 90 Shore A. 12. The athletic protector of claim 1, wherein the hard cup comprises a material selected from the group consisting of polycarbonate, acrylonitrile-butadiene-styrene, polyethylene, polypropylene, and blends thereof. 13. The athletic protector of claim 12, wherein the hard cup comprises polypropylene copolymer. 14. The athletic protector of claim 1, wherein the hard cup has opposite side edges each of which defines a recessed portion for lessening interference with a wearer's thighs. 15. An athletic protector for protecting the genitals, comprising: a relatively soft and resilient soft cup molded as a one-piece structure and having a domed central portion and a peripheral edge portion extending about a periphery of the domed central portion, wherein the soft cup defines female connecting members comprising grooves formed proximate the peripheral edge region of the soft cup for receiving male connecting members of a hard cup usable with the soft cup. 16. The athletic protector of claim 15, wherein the soft cup comprises thermoplastic elastomer. 17. The athletic protector of claim 16, wherein the soft cup comprises polymer foam having a durometer hardness of about 70 to 90 Shore A. 18. The athletic protector of claim 15, in combination with a hard cup having outer peripheral edge portions structured and arranged to removably fit into the grooves in the soft cup to attach the hard cup and soft cup together. | BACKGROUND OF THE INVENTION The present invention relates to athletic protectors for protecting the genitals. Athletic protectors for protecting the genitals during sporting activities generally fall into either the “hard cup” or the “soft cup” type. Hard cups are typically worn for contact sports or those involving high-speed projectiles (e.g., baseball, hockey, lacrosse, etc.), where there is a significant likelihood of being struck in the groin with a hard blow. The traditional type of hard cup includes a rigid plastic shell bonded to a softer material that forms a margin or edge region of the cup for contacting the wearer's body during use. Such hard cups are not particularly comfortable to wear. Soft cups are much more pliable than hard cups, and are usually worn in non-contact sports or activities that do not involve a significant likelihood of receiving a hard, high-velocity blow to the groin. A soft cup offers more protection than a jock strap alone, but not nearly as much as a hard cup. The chief advantage of the soft cup is that it is much more comfortable to wear than a hard cup. A particular individual who is involved in both contact sports and non-contact sports generally would have to own at least one hard cup and at least one soft cup. BRIEF SUMMARY OF THE INVENTION The present invention provides an athletic cup that is convertible from a hard cup configuration to a soft cup configuration. The hard cup configuration can be used for contact sports or ball sports where maximum protection is needed. The cup can be converted to the soft cup configuration for non-contact sports where a lesser degree of protection is adequate. Toward these ends, the cup comprises a hard cup and a soft cup that are detachably connected to each other to form the hard cup configuration. To convert to the soft cup configuration, the hard cup is detached and the soft cup is worn by itself. The soft cup is a relatively soft and resilient, molded one-piece structure having a domed central portion and a peripheral edge portion extending about a periphery of the domed central portion. The hard cup is relatively rigid and has a domed shape complementary to that of the domed central portion of the soft cup. The soft cup and hard cup respectively define interlocking male and female connecting members that are removably engageable with one another for affixing the hard cup to the soft cup in a releasable manner. In one embodiment of the invention, the soft cup includes opposed grooves at opposed regions of the peripheral edge portion, at the convex (outer) side of the soft cup, with the opposed grooves having their open sides facing generally toward a center of the domed central portion of the soft cup. Opposite edges of the hard cup are engaged in the opposed grooves to secure the two cups together with the hard cup overlying the outer side of the domed central portion of the soft cup. The edges of the hard cup can define beads and the grooves in the soft cup can be complementary in shape to receive the beads in a snap-fit fashion. The soft cup can be flexed to disengage the hard cup edges from the grooves so as to detach the hard cup. The grooves in the soft cup thus comprise female connecting members and the edges of the hard cup comprise male connecting members. Other configurations of male and female connecting members could be used instead of the edges and grooves described above. In one embodiment of the invention, the hard cup has opposite side edges extending between the top and bottom edge portions, and the soft cup defines a pair of shoulders respectively abutted by the opposite side edges of the hard cup such that impact forces on the hard cup are transmitted in part to the shoulders of the soft cup. Advantageously, the side edges of the hard cup have portions that are recessed inwardly of the opposite side edges of the soft cup. The recessed portions help avoid interference with the wearer's thighs that might otherwise occur if the recessed portions were not provided. The soft cup can include ventilation apertures. The hard cup can include ventilation holes that are aligned with the ventilation apertures in the soft cup. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a sectioned side view of a brief having a pocket in which an athletic protector in accordance with one embodiment of the invention is held; FIG. 2 is a front elevation of the athletic protector; FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2; FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2; FIG. 5 is a perspective view of the athletic protector in the hard-cup configuration; FIG. 6 is an exploded perspective view of the athletic protector, generally from above, showing the hard cup detached from the soft cup to convert to the soft-cup configuration; and FIG. 7 is an exploded perspective view of the athletic protector generally from below. DETAILED DESCRIPTION OF THE INVENTION The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. FIG. 1 depicts an athletic protector 10 in accordance with one embodiment of the invention retained within a pocket P of a brief B, which functions to hold the protector in its proper position during activity. Alternatively, the protector could be used with a conventional jock strap or the like. FIGS. 2-7 depict the athletic protector 10 in further detail. The athletic protector 10 includes a soft cup 20 of relatively soft, resiliently flexible material, and a hard cup 40 of relatively hard, rigid material. The soft cup and hard cup are detachably connected. The soft cup has a generally cup-shaped or domed central portion 22 and a peripheral edge portion 24 extending along the outer periphery of the domed central portion. The soft cup 20 in plan view or front elevation (FIG. 2) has a rounded triangular shape, being wider at its upper end than at its lower end. In use, the lower end of the soft cup is proximate the perineal region of the body and the upper end of the soft cup is proximate the pubic arch. The peripheral edge portion 24 is relatively thick and wide where it lies against the body so that impact forces on the athletic protector are distributed over a relatively large area of the body. The soft cup includes ventilation apertures 26 in the domed central portion. The hard cup 40 has a domed shape complementary to that of the domed central portion 22 of the soft cup. The hard cup in plan view also has a generally triangular shape, being wider at its top end than at its bottom end. Along a top edge of the hard cup is a rim or bead 42 of greater thickness than the adjoining domed region of the hard cup. Similarly, along a bottom edge of the hard cup is a thickened rim or bead 44. The hard cup includes ventilation holes 46 positioned so they are aligned with the ventilation apertures 26 in the soft cup when the hard cup is connected to the soft cup. Each hole 46 can be surrounded by a raised boss 47 shaped to fit closely into a corresponding ventilation aperture 26 of the soft cup. The bosses 47 thus help to hold the hard cup in proper alignment with the soft cup and add lateral integrity to the assembly of the hard cup and soft cup. The connection of the hard cup 40 to the soft cup 20 will now be described. The soft cup 20 defines a groove 32 in its outward-facing surface (i.e., the surface that faces away from the wearer's body) at a location proximate the juncture between the domed central portion 22 and the peripheral edge portion 24 along the upper edge of the soft cup. The soft cup also defines a groove 34 in its outward-facing surface proximate the juncture between the domed central portion and the peripheral edge portion along the lower edge of the soft cup. The grooves 32, 34 have their open sides facing generally toward a center of the domed central portion of the soft cup. The grooves 32, 34 are shaped in cross-section in complementary fashion to the cross-sectional shapes of the beads 42, 44 along the top and bottom edges of the hard cup 40. In particular, the grooves have a keyhole type shape with a wide part and a narrow part. The wide parts of the grooves receive the relatively thicker beads on the hard cup, but the beads must first pass through the narrow parts of the grooves. In this manner, the beads 42, 44 on the hard cup fit into the grooves 32, 34 of the soft cup in a snap-fit fashion. The material of the soft cup is resiliently flexible to permit the beads to be inserted into the grooves. The beads fit into the grooves in a close-fitting manner so that they tend to resist being pulled back out of the grooves. However, when it is desired to detach the hard cup from the soft cup, the flexible material of the soft cup allows enough deformation to permit the beads to be pulled out of the grooves with a reasonable amount of force. The soft cup 20 can be molded of various polymer materials such as the class of materials referred to as thermoplastic elastomers. For instance, the soft cup can comprise polyethylene, polyurethane, polypropylene, or ethylene vinyl acetate. A suitable material, for example, is product number 5403-80A from Technical Polymers LLC of Lawrenceville, Ga. The polymer molding composition can include a chemical or physical foaming agent so that the composition foams to form a multitude of air cells in the finished product. Advantageously, the soft cup material has a durometer hardness of about 70-90, preferably about 80, on the Shore A scale. The hard cup 40 can be molded of various polymer materials that have substantial rigidity. Such materials include but are not limited to polycarbonate, acrylonitrile-butadiene-styrene (ABS), polyethylene, polypropylene, and blends thereof. A preferred material is polypropylene copolymer, such as product number TI-6120-NB available from Sunoco Chemicals, Polymers Division, of Philadelphia, Pa. To improve the comfort of wearing the athletic protector 10 in the hard cup configuration, the hard cup 40 advantageously has opposite side edges 48 that are recessed inwardly of the corresponding side edges of the soft cup. The recessed side edges 48 lessen the interference between the hard cup 40 and the wearer's thighs that can occur in certain body positions. Advantageously, the soft cup 20 includes shoulders or grooves, comprising engagement members 36, that are abutted or engaged by the recessed side edges 48 of the hard cup. The engagement members 36 help hold the hard cup and soft cup together and also absorb force from the hard cup when the athletic protector is struck, so that the impact force is transmitted to the soft cup along the entire periphery of the hard cup rather than only along the upper and lower edges of the hard cup. The athletic protector 10 is usable in either a hard cup configuration or a soft cup configuration. In the hard cup configuration, the hard cup 40 is attached to the soft cup 20 by snapping the beads 42 and 44 on the edges of the hard cup into the grooves 32 and 34 in the soft cup. The athletic protector can then be inserted into a jock strap, brief, or other supporting garment that aids in retaining the protector in proper position during wear. To use the protector 10 in the soft cup configuration, the hard cup 40 is detached from the soft cup 20, and only the soft cup is inserted into the supporting garment such as the brief B shown in FIG. 1. Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to athletic protectors for protecting the genitals. Athletic protectors for protecting the genitals during sporting activities generally fall into either the “hard cup” or the “soft cup” type. Hard cups are typically worn for contact sports or those involving high-speed projectiles (e.g., baseball, hockey, lacrosse, etc.), where there is a significant likelihood of being struck in the groin with a hard blow. The traditional type of hard cup includes a rigid plastic shell bonded to a softer material that forms a margin or edge region of the cup for contacting the wearer's body during use. Such hard cups are not particularly comfortable to wear. Soft cups are much more pliable than hard cups, and are usually worn in non-contact sports or activities that do not involve a significant likelihood of receiving a hard, high-velocity blow to the groin. A soft cup offers more protection than a jock strap alone, but not nearly as much as a hard cup. The chief advantage of the soft cup is that it is much more comfortable to wear than a hard cup. A particular individual who is involved in both contact sports and non-contact sports generally would have to own at least one hard cup and at least one soft cup. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides an athletic cup that is convertible from a hard cup configuration to a soft cup configuration. The hard cup configuration can be used for contact sports or ball sports where maximum protection is needed. The cup can be converted to the soft cup configuration for non-contact sports where a lesser degree of protection is adequate. Toward these ends, the cup comprises a hard cup and a soft cup that are detachably connected to each other to form the hard cup configuration. To convert to the soft cup configuration, the hard cup is detached and the soft cup is worn by itself. The soft cup is a relatively soft and resilient, molded one-piece structure having a domed central portion and a peripheral edge portion extending about a periphery of the domed central portion. The hard cup is relatively rigid and has a domed shape complementary to that of the domed central portion of the soft cup. The soft cup and hard cup respectively define interlocking male and female connecting members that are removably engageable with one another for affixing the hard cup to the soft cup in a releasable manner. In one embodiment of the invention, the soft cup includes opposed grooves at opposed regions of the peripheral edge portion, at the convex (outer) side of the soft cup, with the opposed grooves having their open sides facing generally toward a center of the domed central portion of the soft cup. Opposite edges of the hard cup are engaged in the opposed grooves to secure the two cups together with the hard cup overlying the outer side of the domed central portion of the soft cup. The edges of the hard cup can define beads and the grooves in the soft cup can be complementary in shape to receive the beads in a snap-fit fashion. The soft cup can be flexed to disengage the hard cup edges from the grooves so as to detach the hard cup. The grooves in the soft cup thus comprise female connecting members and the edges of the hard cup comprise male connecting members. Other configurations of male and female connecting members could be used instead of the edges and grooves described above. In one embodiment of the invention, the hard cup has opposite side edges extending between the top and bottom edge portions, and the soft cup defines a pair of shoulders respectively abutted by the opposite side edges of the hard cup such that impact forces on the hard cup are transmitted in part to the shoulders of the soft cup. Advantageously, the side edges of the hard cup have portions that are recessed inwardly of the opposite side edges of the soft cup. The recessed portions help avoid interference with the wearer's thighs that might otherwise occur if the recessed portions were not provided. The soft cup can include ventilation apertures. The hard cup can include ventilation holes that are aligned with the ventilation apertures in the soft cup. | 20040427 | 20071120 | 20051222 | 78662.0 | 0 | TOMPKINS, ALISSA JILL | ATHLETIC PROTECTOR CONVERTIBLE FROM HARD-CUP TO SOFT-CUP CONFIGURATION | SMALL | 0 | ACCEPTED | 2,004 |
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10,832,654 | ACCEPTED | Security barrier | An apparatus and method for installing and deploying a barrier utilizing one or more gas generators. The invention includes a barrier component installed beneath the ground surface or substantially parallel to the ground and raised by activation of the gas generator. The device can be trigger automatically without human intervention and thereby faster deployment of the barrier. The invention permits the passage of pedestrians, vehicles, etc. or activation into a barrier position. | 1. A ground level barrier system comprising: a. at least one first outer cylinder having a longitudinal axis of orientation and a first end and a second end wherein the first end is closed; b. at least one second inner cylinder located at least partially within the first cylinder and having the same longitudinal axis of orientation as the first cylinder and with a first end and a second end wherein one second end is closed; c. a gas generator to move the second cylinder along the longitudinal axis of orientation in a manner that the second cylinder extends from the second end of the first cylinder and above the plane of the ground level; d. at least one retaining mechanism to prevent the first end of the second cylinder from moving out past the second end of the first cylinder and to hold the second end of the second cylinder in an extended position out of the first cylinder; and e. a mechanism to activate the gas generator. 2. The system of claim 1 wherein the longitudinal orientation of the extended second cylinder is at least 45 degrees to the plane of the ground level. 3. The system of claim 1 wherein at least a portion of the barrier system is located below the ground surface level. 4. The system of claim 1 further comprising multiple telescoping second cylinders extended by the gas generator. 5. The system of claim 1 wherein the gas generator device is activated by movement of an object along the ground surface. 6. The system of claim 5 further comprising a plurality of first and second cylinders and gas generator devices. 7. A ground level protective barrier system comprising: a) a housing component that can be placed on a ground surface containing i) at least one first cylinder having a first end and a second end wherein the first end is closed; ii) a first connector holding the first end of the first cylinder to the housing; iii) at least one second cylinder located partially within the first cylinder and having a separate first end and a closed second end and having the same longitudinal axis of orientation of the first cylinder and moveable in relation to the first cylinder along the axis of orientation so that the second end of the second cylinder can be extended past the second end of the first cylinder; iv) a gas generator located within the first and second cylinders to move the second cylinder along the longitudinal axis of orientation in a manner that the second cylinder extends from the second end of the first cylinder; v) at least one retaining mechanism to prevent the first end of the second cylinder from moving out past the second end of the first cylinder and to hold the second end of the second cylinder in an extended position out of the first cylinder; vi) a barrier component having a first end and second end; vii) a first pivot component connecting the first end of the barrier component to the second end of the second piston; viii) a locking mechanism fixed to the housing to lock the first pivot component into a fixed position on the housing; ix) a structural support having a first end and a second end; x) a second pivot component connecting the second end of the barrier component to the first end of the structural support; xi) a third pivot component connecting the second end of the structural support to at least one element of a group consisting of the first piston, the first connector and the housing. b) a sensor component; c) a communication component to convey an activation signal from the sensor component the gas generator; and d) a power source. 8. The system of claim 7 further comprising a plurality of first cylinder, second cylinder and gas generator components. 9. The system of claim 7 wherein the barrier component has a longitudinal axis of orientation substantially parallel to the longitudinal axis of orientation of the first and second cylinders prior to an activation of the gas cylinder. 10. The system of claim 7 wherein the barrier component has a longitudinal axis of orientation substantially orthogonal to the plane of the ground surface after activation of the gas cylinder. 11. The system of claim 7 further comprising at least one compartment within the housing for holding variable quantities of additional weight. 12. The system of claim 11 wherein the compartment can be controllably filled and drained of fluid. 13. The system of claim 12 wherein the fluid is water. 14. The system of claim 7 wherein the sensor component detects movement of an object. 15. The system of claim 7 wherein the housing component contains the sensor mechanism. 16. The system of claim 7 wherein the housing component contains the power source. 17. The system of claim 7 wherein at least one of a group of components consisting of the housing component, first cylinder, second cylinder, locking mechanism, barrier component and structural support contain fiber reinforcing materials. 18. The system of claim 7 wherein the sensor mechanism detects compression. 19. The system of claim 7 wherein the sensor mechanism utilizes RF signals. 20. The system of claim 7 wherein the sensor mechanism utilizes acoustic signals. 21. The system of claim 7 wherein the sensor mechanism utilizes light signals. 22. The system of claim 7 wherein the mass of the object is used to secure the barrier system in a fixed location. 23. A method for deploying a ground level barrier comprising the following steps: a) placing barrier component proximate to the ground surface in a position that does not impede passage across the ground surface; b) placing a sensor mechanism that can detect objects moving across the ground proximate to the barrier component; c) providing a mechanism for communication between the sensor and a barrier triggering mechanism; d) connecting the barrier component to a gas generator device; and e) connecting the gas generator to the triggering mechanism to permit the deployment of the barrier into a position to impede object movement in response to sensor detecting the movement of objects. | BACKGROUND OF INVENTION 1. Field of Use The invention pertains to a high strength impact resistant and rapidly deployable security barrier for the protection of persons and property from objects such as trucks and cars traveling at ground surface level. 2. Prior Art Vehicle and traffic barricades are well known and are in wide use for building and personnel security applications. These systems can be permanent or temporary. The barricades can be stationary or mobile with relatively rapid deployment for raising/lowering. The barricades can be wall like sections providing a resistive mass of reinforced concrete or hollow resinous plastic structures filled with water. Other types of traffic or vehicle control barriers are bollards that are fixed in position or that can be raised and lowered from the ground surface level. Bollards have been shown to be capable of incapacitating or stopping vehicles up to 7.5 tons GVW moving at speeds of 50 mph. The current raisable bollard systems have deficiencies that have been demonstrated based on current world events and terrorism threats. These deficiencies are related to their dependency on human interaction to deploy the barrier of the bollard system, they are slow to activate, provide inadequate capabilities to prevent intrusion, and they are dependent on electric power or air systems which can be compromised by threats. The mechanism used to power the raising and lowering can be springs, hydraulics, motors or gas cylinders. However, existing bollards or barriers that are raised to selectively block or control vehicle movement require either human intervention that retards deployment time, thereby diminishing effectiveness, or do not have sufficient mass to effectively block a large or heavy vehicle. Other bollard/barrier devices require installation beneath the ground surface level and separately powered control and motor mechanisms to raise (deploy) the barrier. There is accordingly a need for a rapidly deployable barrier system having sufficient capability to provide an effective barrier to heavy motor vehicles. There is also a need for a non-obtrusive barrier protective system than can be easily and quickly installed and removed. SUMMARY OF INVENTION The invention pertains to a method and apparatus for erecting protective barriers/bollards utilizing a gas generation system (gas generator) to power the raising of the barrier structure to block the passage of a vehicle. The gas generator can be activated by a variety of means and independent of human intervention. The energy supplied by the gas generator allows deployment of the barrier from a stored to protective position at a speed significantly greater than achieved by existing methods. This allows the activation device to be placed close to the barrier, thereby permitting use of an automated barrier protective system in relatively confined spaces with minimized instances of unintended or unnecessary activation. The gas generator power source also permits a variety of mechanical mechanisms for raising the barrier from a stored to protective position. The barrier can be raised in a relatively straight direction substantially normal to the plane of the ground surface. The barrier can also be raised from a stored position relatively parallel to the plane of the ground surface level to a position normal to the plane. The activation of the barrier component of the barrier system can be achieved by a variety of means. One method would be activation occurring in response to the wheels of a motor vehicle passing over a pressure sensitive triggering mechanism. It will be readily appreciated that the pressure sensitivity can be adjusted to distinguish between a motor vehicle and a pedestrian. The activation of the barrier system may also be a motion detector, or a magnetic, strain, chemical, infra-red or radiation sensor. A remote sensor can signal activation by RF signal, requiring little power. The power source may be batteries or similar independent means, thereby minimizing deactivation of the protective system by power failure or sabotage. It is therefore an object of the invention to provide a rapidly deployable barrier. It is another object of the invention to provide a barrier system that has a minimal visual impact to the protected structure or for protective surveillance. It is a further object of the invention to provide a barrier that can be activated without human intervention. It is another object of the invention to provide a barrier that can be quickly installed and removed It is another object of the invention that the protective barrier can be portable and installed with minimal site preparation. It is another object of the invention is a protective barrier system without preparation or intrusion beneath the ground surface level. It is also an object of the invention to provide a protective system that is operational/activation energy self-contained. Other benefits of the invention will also become apparent to those skilled in the art and such advantages and benefits are included within the scope of this invention. SUMMARY OF DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention. These drawings, together with the general description of the invention given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. FIG. 1 is a schematic cross sectional view of one embodiment of the invention comprising an outer cylinder and an inner piston-like cylinder installed substantially below the ground surface. FIG. 1A is a schematic of the embodiment after deployment of the inner cylinder, comprising the barrier component, into a protective position above the ground surface level. FIGS. 2, 2A and 2B illustrate guides utilized in one embodiment of the invention. FIG. 3 illustrates a barrier system comprising telescoping cylinders. FIG. 3A illustrates a barrier system deployed after a triggering event. FIG. 3B illustrates an embodiment utilizing a plurality of telescoping barrier sections with a structural support. FIG. 4 depicts an additional embodiment of the invention wherein the gas generator a barrier are installed in a position parallel to the ground and normal to the deployed position. FIG. 4A is an illustration of a barrier base locking component mechanism. FIGS. 4C and 4D are schematic illustrations of the risible/deployed barrier component of the barrier system. FIG. 4E is a schematic illustration of the coupling mechanism of the barrier stability structure component and structural member component. FIG. 4F is a schematic side view depiction of one embodiment of the invention in a stored position. FIGS. 5A, 5B, 5C and 5D are illustrations of a wall-like barrier structure utilizing multiple gas generators. FIG. 6 is an illustration of the invention having a flexible sensor triggering device. FIGS. 8, 8A and 8B are illustrations of a portable and rapidly installed system. FIG. 9 illustrates an embodiment of the invention incorporating means to add mass to the system. FIGS. 10 and 10A illustrate the installation and deployment of one embodiment of the invention in relationship to an approaching vehicle. DETAILED DESCRIPTION OF INVENTION The above general description and the following detailed description are merely illustrative of the subject invention and additional modes, advantages and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention. The requirements for the barrier system will vary based on the intended application. These variations are related to the denial requirements, the type of installation (permanent or temporary), location of the system, and the type of asset to be protected. The invention proposed consists of an autonomous or automatic barrier or barrier restraint system, including automatic trigger sensors, communication devices to deploy the barrier component of the systems, automatic sensors to detect or activate the system, and an independent, self contained power supply to provide monitoring, activation, or alarm. Deployment of the barrier component, regardless of the specific configuration of the barrier system, e.g., bollard, gate or wall-like sectional barrier, will be carried out by a gas generator. The gas generator will be integral to the system and be capable of deploying a barrier which is capable of stopping a 15000 lb gross vehicle weight (GVW) vehicle and which deploys the barrier in 150 milli-seconds or less. This is nominally 10 times faster deployment than the fastest barrier currently available and the proposed system does not depend on any human interaction which requires significant additional time. What this means is that a vehicle moving at 50 mph will travel 110 ft in 1.5 seconds. The proposed invention will permit 11 feet or less of travel at 50 mph from the time the barrier is activated until the vehicle is stopped. Add to the conventional system the time required for personnel to activate it and this would require detection of the threat and activation of the restraint system nominally 100's of feet before the vehicle reaches the barrier. The gas generator will be integral to the restraint device. The gas generator will contain solid propellant that upon combustion creates heated gas to rapidly expand within a cylinder that raises the barrier component into its operating position. A mechanical mechanism will lock the restraint device into place. The propellant is ignited by a device termed a squib or igniter. The squib receives an electric signal from the integral power supply. This electrical signal may be activated manually or automatically depending on selection of how the restraint system is configured. The receipt of the signal to activate the squibs is received via radio frequency (RF) which can be encrypted as necessary for security reasons. The RF can also be sent by detectors that can detect motion, magnetic field, radiation, mass, chemicals or explosives. As an alternative to the gas generator, the restraint system could also be deployed through of a stored high-pressure gas or mechanical energy storage devices such as springs. Activation of the device would occur through an electromechanical switching device that will release the stored gas or the compressed springs. These devices will be slower to provide deployment than a gas generator and these types of devices will result in increase weight and maintenance requirements. The alternate systems do not utilize ordnance, however, the gas generator technology is very mature and they are commonly used in automobiles, aircraft evacuation slides and munitions dispensing. The drawings contained within this specification illustrate various embodiments of the invention. In addition to the traditional bollard (e.g. a typically round structure that protrudes above the ground level), this invention also includes a rapidly deployable barrier that is activated using both a gas generator and an automatic or manual deployment device as described previously. This system, called a “Toggle Retractable Barrier System” can be permanently installed on a roadway or other ground level surface or in a shallow recess. The “Toggle” system is held in a horizontal position until deployed. Referring to the models below, the structural member (or stability member) serves as a cover for the system and protects the deployment mechanism until activated. Upon activation, the pressure resulting from the gas generator drives a cylinder which raises the stability member (or barrier) into an upright position. The locking mechanism shown in the model locks the stability member into position. This design is very flexible in that it is portable and may be configured to accommodate multiple barriers in series or parallel. A benefit of this design is that the barrier takes advantage of the vehicle mass in anchoring the system to the ground. These system designs may be deployed individually in a pattern or all simultaneously depending on the instructions provided to its communication component. The system subject of this invention may also be constructed of various materials having high compression, shear and tensile strengths. Although these materials include metals, particularly ferrous metals, fiber reinforced composite materials may be used, particularly where light weight is desired. Such designs may be combined with components allowing weight to be added to the system after placement in the selected location. The end uses of this invention are to protect vital assets and personnel from terrorist acts. A barrier system is applicable to embassies, power plants fuel storage depots, military and industrial installations, traffic control, and critical industrial facilities. The subject invention will utilize the same technology in terms of stopping the vehicle but will perform this function with/without human intervention. In other words, the bollard system can be made autonomous with its own sensors and triggering system. Where human intervention activates the bollard or barrier system, the response is rapid (less than 150 milliseconds), thus allowing an operator a last second decision to stop a threat with as little time as 12 feet from the penetration point of the asset being protected. The invention consists of using a rapidly deployable barrier system activated by a gas generator deployed the barrier. The activation of the gas generator is not dependent on any external support such as electricity or air pressure and is activated by RF signal. The RF signal can be activated by numerous different sensors that detect movement, proximity, light curtains, acoustic, pressure plate, infrared, vision system, chemical detectors, explosive detectors, magnetic or radiation detectors. A key advantage of the RF command link is the ability to configure the system allowing the user to use or not use its variability to detect and activate. Various sensor systems allow the user to configure the activation of the barrier. For example, if the system is configured automatic, an underground magnetic detector could arm the system. A second sensor such as motion or speed detection could trigger the system when detecting the threat indicates it will not stop. The barrier system may contain its own power through rechargeable power that can incorporate solar cell technology supply. The proposed invention may also have the ability to monitor its status. Therefore, in the event of power failure, the barrier system continues to function and is not compromised. Other systems depend on electric, hydraulic or air to activate their systems. These are all dependent on electric power. FIG. 1 illustrates a cross sectional view of one embodiment of the invention 800 installed substantially below the ground surface level 105 and within the ground 100. The top covering 275 of the barrier is approximately level with the ground surface 105 so as not to impede the passage of vehicles or pedestrians. The system also does not impede vision or viewing of the object being protected nor does in impede the vision of approach area for surveillance. The barrier 800 is oriented along an axis 270 substantially normal to the ground surface plane 105. The components of the barrier include an outer cylinder 200 and inner cylinder 250. The outer cylinder is closed at the bottom 203. The inner cylinder is closed at the top 275. A gas generator 300 is located within the inner cylinder 250. Detection and activation mechanisms of the barrier are not shown. The inner and outer cylinders 250 200 have offsetting protruding sub-components 251 211 which prevent the bottom of the inner cylinder from moving past the top of the outer cylinder. There may also be seals or rings (not shown) installed between the first and second cylinder to contain the expansive gas, thereby directing the energy to the movement of the second cylinder. FIG. 1A illustrates the barrier system 800 after ignition of the gas generator 300. The ignition of the gas generator results in a very rapid expanding gas force within the inner cylinder 250. The gas expands in all directions as represented by the vector arrows 680. The expansive gas force is retained by the rigid top and side walls of the inner cylinder 250 but presses downward 615 on the bottom 203 of the outer cylinder 200, thereby causing the inner cylinder 250 to move upward 610 in a piston-like manner along the center axis 270 in relation to the outer cylinder. The inner cylinder thereby is explosively pushed above the plane of the ground surface 105, while the outer cylinder remains anchored in the ground 100. The movement of the inner cylinder is controlled by the complimentary protrusions 211 251 or retaining rings of the outer and inner cylinders. FIGS. 2, 2A and 2B illustrate an embodiment of the invention utilizing piston or cylinder guides 215 and 216 within the walls of the outer cylinder 200 and inner cylinder 250. Also illustrated in FIG. 2 are the retaining rings or ridges 211 251. For clarity of illustration, the inner and outer cylinders are shown independently, but it will be appreciated that they are installed together in relation to the center longitudinal axis 270. FIG. 2A illustrates a downward cross sectional view of the outer cylinder 200, showing the placement of grooves 215 longitudinally installed in the wall of the outer cylinder. Also illustrated is the cylinder bottom surface 203. FIG. 2B illustrates a downward cross sectional view of the inner cylinder 250, including the complimentary protrusions 216 on the outer wall of the inner cylinder. The relationship of the cylinder guides to the center axis 270 is also illustrated. It will be appreciated that the number of guides may be varied. The groove guides may be installed in the outer surface of the inner cylinder 250 with counter part and complimentary protrusions installed in the inner wall surface of the outer cylinder 200. The piston or cylinder guides minimize the possibility of the inner cylinder becoming cocked or jammed within the outer cylinder in a direction non-parallel to the center axis 270 when moving in response to the sudden and powerful force of the expanding gas. The jamming could prevent the inner cylinder extending to the full permissible direction above the ground surface (not shown). FIG. 4 illustrates another embodiment of the invention 800 wherein the gas generator (not shown) within a first cylinder 300 propels an inner second cylinder or piston 307 in a direction 670 substantially parallel to the ground surface 105. Movement in the opposing direction is prevented by the closed first end 301 secured by attachment mechanism 309 to a base component 810. In an alternate embodiment (not shown), the gas generator may be directly attached to the housing or attachment component (and without containment within a first and second cylinder configuration) and used alone to power the extension of a piston connected to the barrier component. The barrier component 290 is contained within the base component 810 placed on top of the ground 100. The piston is pivotably attached by means of a hinge or pivot device to the bottom segment 298 of the stability member 290. The movement of the piston in direction 670 causes the stability member to be pushed and locked 299 upright in direction 610, being substantially normal to the ground surface 105. It will be understood that prior to activation by the ignition of the gas generator 300, the stability member 290 is stored in a substantially horizontal position within the base 810. The upper portion 292 of the stability member is hingeably attached 510 to a reinforcing structural member 500. The structure member provides reinforcing strength against collapse by a moving object such as a heavy motor vehicle traveling in direction 675. The top covering 275 of the barrier is approximately level with the ground surface 105 so as not to impede the passage of vehicles or pedestrians. The system also does not impede vision or viewing of the object being protected nor does in impede the vision of approach area for surveillance. The barrier 800 is oriented along an axis 270 substantially normal to the ground surface plane 105. The components of the barrier include an outer cylinder 200 and inner cylinder 250. The outer cylinder is closed at the bottom 203. The inner cylinder is closed at the top 275. A gas generator 300 is located within the inner cylinder 250. Detection and activation mechanisms of the barrier are not shown. The inner and outer cylinders 250 200 have offsetting protruding sub-components 251 211 which prevent the bottom of the inner cylinder from moving past the top of the outer cylinder. FIG. 4A illustrates a component 299 of the invention utilized to lock the bottom portion (not shown but being item 298 in FIG. 4) of the barrier component into place within the barrier base structure (also not shown). The bottom portion of the barrier component attached proximate to the piston is moved in the direction 670 in response to the activation of the gas generator. The barrier component is pushed into a space 400 past the locking sub-component mechanisms 262 263. The locking sub-components are pivotably moveable (vector arrows 688 689 on axes 281 282) on pivot sub-components 272 273. As the barrier component is pushed past the locking sub-components, the sub-components are pushed into an annulus 266 265. A spring or similar mechanical device (not shown) can be used to push the locking sub-components into the original position, thereby holding the barrier component in the annulus. As the barrier component is moved in response to activation of the gas cylinder in the direction 670, the top portion of the barrier component 292 may also be deflected upward 610 by a component (not shown). FIG. 4C illustrates a side of the barrier component 290. The bottom portion 298 is attached to the piston (not shown) by pivotable means 215 and locked into the locking sub-component contained in the base (not shown). Also illustrated is the axis of rotation 274. FIG. 4D illustrates a frontal view of the stability structure 290 and also showing the axis of rotation 274 for the bottom segment and the axis of rotation 553 of the upper component 292 with the reinforcing structure (not shown). It will be appreciated that the longitudinal axis 272 is rotated from a substantially horizontal position relative to the base to a vertical position relative the ground surface (not shown). The locking component 299 can be in conjunction with a component (not shown) to divert the upper section 292 of the barrier component (stability member) 290 toward a vertical position. FIG. 4E illustrates the relationship of the stability structure 290 with the pivotably attached 510 structural member end 500. The other components illustrated in FIG. 4D are also illustrated in 4E. FIG. 4F is a schematic illustration of the structural member 500, barrier stability member 290, locking mechanism 299, gas generator 300 and piston 307 as they would exist in a stored position prior to activation and along an axis 270. It will be appreciated that the structural member 500 may fit over the other components within the base unit 290. Other components illustrated are the pivot end of the barrier 292 (understood to be actually connected to the structural member 500, the rotatable bottom sub-component 298 attached to the piston by means hingeable means 315 (vector arrow 687), and the gas generator attachment means 309. Also illustrated by vector arrow 670 is the direction of movement of the piston 307 powered by the gas generator 300. A vector arrow 610 illustrates the direction of movement of the barrier stability member end 292 raised from the base. A vector arrow 675 illustrates the direction of the object to be stopped by the invention. FIGS. 5A, 5B, 5C and 5D illustrate an embodiment wherein the barrier component 290 is propelled into a deployed position by multiple gas generators or gas generator/cylinder combinations 307. FIG. 5A illustrates a front perspective of 3 cylinders 300 oriented horizontally within the housing 810 and substantially normal to the broad, wall-like barrier 290. This horizontal orientation is also illustrated in FIG. 5B, being a side view schematic, including the barrier component 290, housing 810 and cylinder 300. FIG. 5B also illustrates the piston component 307 that, depending upon the configuration, may be the second inner cylinder. Also illustrated is the locking mechanism 299, the pivot mechanism 510, and the structural support mechanism 500. FIGS. 5C and 5D are more detailed side schematics of the housing 810, with the raisable barrier component 290, locking mechanism 299, gas generator/first cylinder 300 and piston/second cylinder 307. The direction of movement of the piston component 307 upon activation of the gas generator is shown by vector arrow 670. The change in orientation of the barrier component is illustrated by the arrow 29A 29B marking the side of the barrier component 290. This embodiment utilizing multiple gas generators allows a heavier or broader (wall like) barrier component to be deployed. FIG. 6 illustrates another embodiment of the barrier system 800 wherein the sensor mechanism 320 is a flexible pressure responsive device that can be placed on the ground surface at a varying distance and geometry relative to the housing 810 containing the barrier. The sensor is utilized to trigger activation of the gas generator within the housing, 810 for deployment of the barrier component (not shown). FIG. 3 illustrates another embodiment of the invention that permits a barrier to be deployed without installation of components below the ground surface. The barrier illustrated comprises three nested cylindrical components 200 251 252 having a common longitudinal axis of orientation 270. It will be understood that the axis of orientation 270 is substantially orthogonal to the plane of the ground surface (not shown). It will be appreciated that the number of nesting cylinder components can vary. The height of the system 660 is increased when the multiple nested cylinders are triggered and deployed upward by operation of the gas cylinder (not shown) in the direction indicated by vector arrow 610. FIG. 3A illustrates a similar embodiment having 4 nested cylindrical components 200 251 252 253 having a common longitudinal axis of orientation 270. This embodiment illustrates the cylinders deployed upward (vector arrow 610) in response to a triggering event. When deployed the height of the effective barrier increases from the height 660 of the single cylinder 200 to the combined deployed height 660+661+662+662 of the four cylinders 200 251 252 253. It will be appreciated that the effective height 661 662 663 contributed by the upper nesting cylinders will be less due to the requirement that there be a locking mechanism (not shown) securing each cylinder from vertical and lateral forces. The locking or security mechanisms prevent the cylinders of the barrier component from separating or collapsing after the gas cylinder discharges. These mechanisms may include, but are not limited to springs or cam activated pins or ratchets. FIG. 3B illustrates another embodiment incorporating the telescoping action of nested cylinders 200 251 252 combined with a structural support member 500 providing added lateral strength (vector arrow 675). Again, the telescoping cylinder components are deployed upward (vector arrow 610) along a shared common longitudinal axis 270 that is substantially orthogonal to the plane of the ground surface (not shown). The structural support member 500 is hingeably attached 510 to a component of the upper/inner nested cylinder 252 and hingeably attached to a connecting component 815. FIGS. 8, 8A and 8B further illustrate a portable, rapidly deployable embodiment of the invention that does not require installation below the ground surface. The barrier mechanism can be either the stability member and structural support powered by a gas cylinder, or the telescoping nested cylinders, also triggered by a gas cylinder. In the embodiment illustrated, the barrier structure is contained in one section 810 of a multi-section 810 811 system hingeably attached 410. The multiple sections can be deployed utilizing the hinge component 410. Also attached may be one or more ramp plates 820 hingeably 411 attached to a component section 810 811. FIG. 8A illustrates components 275 500 of the barrier system within one section 810. FIG. 8B illustrates the installed system on the ground surface (not shown), comprising the ramp plates, 820 attached to the sections 811 810, a pressure sensor 320 to trigger the barrier components 275 500 and the connecting hinges 410 411. Note that the pressure sensor is placed in a location to be triggered by a vehicle (not shown) passing over the sensor in the direction of vector arrow 675. (Reference is made to FIGS. 10 and 10A.) FIG. 9 illustrates an embodiment wherein the housing component 810 can contain holding compartments 850 for placement of additional mass such as sand or earth shoveled from the ground proximate to the area where the housing is placed, or water or other fluid. FIG. 9 illustrates openings 852 in each compartment and drain openings 855. It will be appreciated that other configurations are possible and that the drains will have control values or plugs and that the fill holes may have covers. Also illustrated is the approximate location of the barrier component 290 within the housing and the covering/support structure 500. This will allow the invention to be of minimized weight for transport and installation, yet readily supplemented with additional and removable mass to fix the barrier system at the selected location on the ground surface. As illustrated in FIG. 10 discussed below, the mass of the object to be stopped by the system may also be used for this purpose. FIG. 10 illustrates a vehicle 900 approaching an embodiment of the invention device 800 in the direction of shown by a vector arrow 675. The vehicle is travelling across the ground surface 105 and the invention is installed on the ground, in contrast to being buried in the ground 100. There is a mass-pressure sensitive triggering mechanism 820 in the in the front portion of the barrier housing FIG. 10A illustrates the barrier 800 activated by the vehicle striking the pressure sensor device 320. The weight of the vehicle 900 assists in anchoring the barrier in place and allowing the stability structure 290 to stop the vehicle. Also illustrated in the reinforcing structural support 500. This specification is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and describe are to be taken as the presently preferred embodiments. As already stated, various changes may be made in the shape, size and arrangement of components or adjustments made in the steps of the method without departing from the scope of this invention. For example, equivalent elements may be substituted for those illustrated and described herein and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this specification. What we claim is: | <SOH> BACKGROUND OF INVENTION <EOH>1. Field of Use The invention pertains to a high strength impact resistant and rapidly deployable security barrier for the protection of persons and property from objects such as trucks and cars traveling at ground surface level. 2. Prior Art Vehicle and traffic barricades are well known and are in wide use for building and personnel security applications. These systems can be permanent or temporary. The barricades can be stationary or mobile with relatively rapid deployment for raising/lowering. The barricades can be wall like sections providing a resistive mass of reinforced concrete or hollow resinous plastic structures filled with water. Other types of traffic or vehicle control barriers are bollards that are fixed in position or that can be raised and lowered from the ground surface level. Bollards have been shown to be capable of incapacitating or stopping vehicles up to 7.5 tons GVW moving at speeds of 50 mph. The current raisable bollard systems have deficiencies that have been demonstrated based on current world events and terrorism threats. These deficiencies are related to their dependency on human interaction to deploy the barrier of the bollard system, they are slow to activate, provide inadequate capabilities to prevent intrusion, and they are dependent on electric power or air systems which can be compromised by threats. The mechanism used to power the raising and lowering can be springs, hydraulics, motors or gas cylinders. However, existing bollards or barriers that are raised to selectively block or control vehicle movement require either human intervention that retards deployment time, thereby diminishing effectiveness, or do not have sufficient mass to effectively block a large or heavy vehicle. Other bollard/barrier devices require installation beneath the ground surface level and separately powered control and motor mechanisms to raise (deploy) the barrier. There is accordingly a need for a rapidly deployable barrier system having sufficient capability to provide an effective barrier to heavy motor vehicles. There is also a need for a non-obtrusive barrier protective system than can be easily and quickly installed and removed. | <SOH> SUMMARY OF INVENTION <EOH>The invention pertains to a method and apparatus for erecting protective barriers/bollards utilizing a gas generation system (gas generator) to power the raising of the barrier structure to block the passage of a vehicle. The gas generator can be activated by a variety of means and independent of human intervention. The energy supplied by the gas generator allows deployment of the barrier from a stored to protective position at a speed significantly greater than achieved by existing methods. This allows the activation device to be placed close to the barrier, thereby permitting use of an automated barrier protective system in relatively confined spaces with minimized instances of unintended or unnecessary activation. The gas generator power source also permits a variety of mechanical mechanisms for raising the barrier from a stored to protective position. The barrier can be raised in a relatively straight direction substantially normal to the plane of the ground surface. The barrier can also be raised from a stored position relatively parallel to the plane of the ground surface level to a position normal to the plane. The activation of the barrier component of the barrier system can be achieved by a variety of means. One method would be activation occurring in response to the wheels of a motor vehicle passing over a pressure sensitive triggering mechanism. It will be readily appreciated that the pressure sensitivity can be adjusted to distinguish between a motor vehicle and a pedestrian. The activation of the barrier system may also be a motion detector, or a magnetic, strain, chemical, infra-red or radiation sensor. A remote sensor can signal activation by RF signal, requiring little power. The power source may be batteries or similar independent means, thereby minimizing deactivation of the protective system by power failure or sabotage. It is therefore an object of the invention to provide a rapidly deployable barrier. It is another object of the invention to provide a barrier system that has a minimal visual impact to the protected structure or for protective surveillance. It is a further object of the invention to provide a barrier that can be activated without human intervention. It is another object of the invention to provide a barrier that can be quickly installed and removed It is another object of the invention that the protective barrier can be portable and installed with minimal site preparation. It is another object of the invention is a protective barrier system without preparation or intrusion beneath the ground surface level. It is also an object of the invention to provide a protective system that is operational/activation energy self-contained. Other benefits of the invention will also become apparent to those skilled in the art and such advantages and benefits are included within the scope of this invention. | 20040427 | 20060905 | 20051027 | 62797.0 | 1 | HARTMANN, GARY S | SECURITY BARRIER | SMALL | 0 | ACCEPTED | 2,004 |
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10,832,702 | ACCEPTED | System and a method for starch-based, slow-release oral dosage forms | A system for producing a slow release oral dosage of medication includes a starch based media, and an oral dosage formulation jetted onto the starch based media. | 1. A system for producing a slow release oral dosage of medication comprising: a starch based media; and an oral dosage formulation jetted onto said starch based media. 2. The system of claim 1, wherein said starch based media comprises one of a polymeric organic film former or a paper organic film former. 3. The system of claim 2, wherein said starch based media comprises one of a rice starch based paper; a potato starch based paper; a functional derivative of starch, or a modified polysaccharide film. 4. The system of claim 3, wherein said functional derivative of starch comprises one of a cross-linked starch, an oxidized starch, an acetylated starch, a hydroxypropylated starch, a carboxymethylated starch, or a partially hydrolyzed starch. 5. The system of claim 3, wherein said modified polysaccharide film comprises one of a cellulose derivate, a starch hydrolysate, a pullulan, an alginate, a carragenan, or a pectin. 6. The system of claim 1, wherein said starch based media further comprises a coating. 7. The system of claim 6, wherein said coating comprises an edible polymer. 8. The system of claim 7, wherein said edible polymer comprises one of a homopolymer of polyvinylphenol (PVP), a copolymer of PVP and polyvinylacetate, a crosslinked PVP particle, a copolymer of PVP and polyvinylacetate, a cationic PVP, a polyvinyl acetate (PVA) and PVA-polyethylene oxide (PEO) copolymer, a PVA-vinylacetal copolymer, a PVA-vinylacetal, a PVA-vinylamine copolymer, a poly vinyl methyl ether (PVME) homopolymer, a hydroxypropylmethylcellulose, a poly(2-ethyl oxazoline), a gelatin, or a methyl cellulose. 9. The system of claim 6, wherein said coating is configured to modify a release of said oral dosage. 10. The system of claim 1, wherein said oral dosage formulation comprises: an oral drug component; and a jettable vehicle component. 11. The system of claim 10, wherein said oral drug component comprises an insoluble drug. 12. The system of claim 10, wherein said oral drug component comprises one of an ace inhibitor, an antianxiety medication, a antihypertensive medication, a blood glucose regulator, an alzheimer-type dementia medication, an anorexiant, a central nervous system stimulant, an antidiuretic, a specific antidote, an antihistamine, an antipsychotic medication, an antimanic medication, a beta blocker, a calcium channel blocker, a contraceptive, a dermatologic, a diuretic, an estrogen, a progestin, an entrapyramidal movement disorder medication, a sedative, or a hypnotic medication. 13. The system of claim 12, wherein said oral drug component further comprises one of triazolam, felodipine, trandolapril, pergolide, rivastigmine tartrate, sibutramine hydrochloride, desmopressin acetate, flumazenil, desloratadine, risperidone, carvedilol, isradipine, norgestimate, methoxsalen, metolazone, estradiol, estrogens, conjugated estrogent, esterified cabergoline, zaleplon, or zolpidem tartrate. 14. The system of claim 10, wherein said oral drug component comprises one of Prednisolone, Glyburide, Lovastatin, Digoxin, or Nifedipine. 15. The system of claim 10, wherein said jettable vehicle further comprises: an edible solvent; a surfactant; and humectants. 16. The system of claim 15, wherein said edible solvent comprises one of water or an alcohol. 17. The system of claim 15, wherein said surfactant comprises one of lecithin, lecithin derivatives, glycerol esters, sorbitan derivatives, glycerol lactoesters of fatty acids, or ethoxylated fatty esters and oils. 18. The system of claim 15, wherein said humectant comprises one of glycerin, sorbitol, or mannitol. 19. The system of claim 15, wherein said jettable vehicle further comprises one of a colorant, a drier, a thinner, a wax, a lubricant, a reducing oil, a solvent, a body gum, a binding varnish, an antioxidant, an anti-skinning agent, a resin, or a binder. 20. The system of claim 1, wherein said oral dosage formulation is jetted onto said starch based media by an inkjet dispenser. 21. The system of claim 20, wherein said inkjet dispenser comprises one of a thermally actuated inkjet dispenser, a mechanically actuated inkjet dispenser, an electro-statically actuated inkjet dispenser, a magnetically actuated dispenser, a piezo-electrically actuated inkjet dispenser, or a continuous inkjet dispenser. 22. A system for forming a slow release oral dosage of medication comprising: a computing device; an inkjet material dispenser communicatively coupled to said computing device; a starch based media disposed adjacent to said inkjet material dispenser; and a material reservoir fluidly coupled to said inkjet material dispenser, said material reservoir being configured to supply an oral dosage formulation to said inkjet material dispenser. 23. The system of claim 22, wherein said computing device comprises one of a personal computer, a laptop computer, a personal digital assistant, or a cellular telephone. 24. The system of claim 22, wherein said inkjet material dispenser comprises one of a thermally actuated inkjet dispenser, a mechanically actuated inkjet dispenser, an electrostatically actuated inkjet dispenser, a magnetically actuated dispenser, a piezo-electrically actuated inkjet dispenser, or a continuous inkjet dispenser. 25. The system of claim 22, wherein said starch based media comprises one of a polymeric organic film former or a paper organic film former. 26. The system of claim 25, wherein said starch based media comprises one of a rice starch based paper; a potato starch based paper; a functional derivative of starch, or a modified polysaccharide film. 27. The system of claim 26, wherein said functional derivative of starch comprises one of a cross-linked starch, an oxidized starch, an acetylated starch, a hydroxypropylated starch, a carboxymethylated starch, or a partially hydrolyzed starch. 28. The system of claim 26, wherein said modified polysaccharide film comprises one of a cellulose derivate, a starch hydrolysate, a pullulan, an alginate, a carragenan, or a pectin. 29. The system of claim 22, wherein said starch based media further comprises a coating. 30. The system of claim 29, wherein said coating comprises an edible polymer. 31. The system of claim 30, wherein said edible polymer comprises one of a homopolymer of polyvinylphenol (PVP), a copolymer of PVP and polyvinylacetate, a crosslinked PVP particle, a copolymer of PVP and polyvinylacetate, a cationic PVP, a polyvinyl acetate (PVA) and PVA-polyethylene oxide (PEO) copolymer, a PVA-vinylacetal copolymer, a PVA-vinylacetal, a PVA-vinylamine copolymer, a poly vinyl methyl ether (PVME) homopolymer, a hydroxypropylmethylcellulose, a poly(2-ethyl oxazoline), a gelatin, or a methyl cellulose. 32. The system of claim 29, wherein said coating is configured to modify a release of said oral dosage. 33. The system of claim 22, wherein said oral dosage formulation comprises: an oral drug component; and a jettable vehicle component. 34. The system of claim 33, wherein said oral drug component comprises an insoluble drug. 35. The system of claim 33, wherein said oral drug component comprises one of an ace inhibitor, an antianxiety medication, a antihypertensive medication, a blood glucose regulator, an alzheimer-type dementia medication, an anorexiant, a central nervous system stimulant, an antidiuretic, a specific antidote, an antihistamine, an antipsychotic medication, an antimanic medication, a beta blocker, a calcium channel blocker, a contraceptive, a dermatologic, a diuretic, an estrogen, a progestin, an entrapyramidal movement disorder medication, a sedative, or a hypnotic medication. 36. The system of claim 35, wherein said oral drug component further comprises one of triazolam, felodipine, trandolapril, pergolide, rivastigmine tartrate, sibutramine hydrochloride, desmopressin acetate, flumazenil, desloratadine, risperidone, carvedilol, isradipine, norgestimate, methoxsalen, metolazone, estradiol, estrogens, conjugated estrogent, esterified cabergoline, zaleplon, or zolpidem tartrate. 37. The system of claim 33, wherein said oral drug component comprises one of Prednisolone, Glyburide, Lovastatin, Digoxin, or Nifedipine. 38. The system of claim 33, wherein said jettable vehicle further comprises: an edible solvent; a surfactant; and humectants. 39. The system of claim 22, further comprising a servo mechanism configured to controllably move said inkjet dispensing device, said servo mechanism being communicatively coupled to said computing device. 40. The system of claim 22, further comprising a substrate disposed adjacent to said inkjet material dispenser, said substrate being configured to transport said starch based media. 41. A system for producing a slow release oral dosage of medication comprising: a starch based media; and a thermal inkjet dispenser disposed adjacent to said starch based media; said thermal inkjet dispenser being configured to dispense an oral dosage formulation onto said starch based media. 42. The system of claim 41, wherein said starch based media comprises one of a polymeric organic film former or a paper organic film former. 43. The system of claim 42, wherein said starch based media comprises one of a rice starch based paper; a potato starch based paper; a functional derivative of starch, or a modified polysaccharide film. 44. The system of claim 43, wherein said functional derivative of starch comprises one of a cross-linked starch, an oxidized starch, an acetylated starch, a hydroxypropylated starch, a carboxymethylated starch, or a partially hydrolyzed starch. 45. The system of claim 43, wherein said modified polysaccharide film comprises one of a cellulose derivate, a starch hydrolysate, a pullulan, an alginate, a carragenan, or a pectin. 46. The system of claim 41, wherein said starch based media further comprises a coating configured to modify a release of said oral dosage. 47. The system of claim 46, wherein said coating comprises an edible polymer. 48. The system of claim 41, wherein said oral dosage formulation comprises: an oral drug component; and a jettable vehicle component. 49. The system of claim 48, wherein said oral drug component comprises an insoluble drug. 50. The system of claim 48, wherein said oral drug component comprises one of an ace inhibitor, an antianxiety medication, a antihypertensive medication, a blood glucose regulator, an alzheimer-type dementia medication, an anorexiant, a central nervous system stimulant, an antidiuretic, a specific antidote, an antihistamine, an antipsychotic medication, an antimanic medication, a beta blocker, a calcium channel blocker, a contraceptive, a dermatologic, a diuretic, an estrogen, a progestin, an entrapyramidal movement disorder medication, a sedative, or a hypnotic medication. 51. The system of claim 50, wherein said oral drug component further comprises one of triazolam, felodipine, trandolapril, pergolide, rivastigmine tartrate, sibutramine hydrochloride, desmopressin acetate, flumazenil, desloratadine, risperidone, carvedilol, isradipine, norgestimate, methoxsalen, metolazone, estradiol, estrogens, conjugated estrogent, esterified cabergoline, zaleplon, or zolpidem tartrate. 52. The system of claim 48, wherein said oral drug component comprises one of Prednisolone, Glyburide, Lovastatin, Digoxin, or Nifedipine. 53. The system of claim 48, wherein said jettable vehicle further comprises: an edible solvent; a surfactant; and humectants. 54. A method for forming a slow release dosage of oral medication comprising: disposing a starch based media adjacent to an inkjet dispenser; and jetting an oral dosage formulation onto said starch based media with said inkjet dispenser. 55. The method of claim 54, wherein said inkjet dispenser comprises one of a thermally actuated inkjet dispenser, a mechanically actuated inkjet dispenser, an electro-statically actuated inkjet dispenser, a magnetically actuated dispenser, a piezo-electrically actuated inkjet dispenser, or a continuous inkjet dispenser. 56. The method of claim 54, wherein said jetting an oral dosage formulation onto said starch based media further comprises: generating a desired oral dosage quantity on a computing device; translating said generated oral dosage quantity into servo commands; and transmitting said servo commands to a servo device coupled to said inkjet dispenser. 57. The method of claim 54, wherein said starch based media comprises one of a polymeric film former or a paper organic film formers 58. The method of claim 54, wherein said starch based media comprises one of a rice starch based paper; a potato starch based paper; a functional derivative of starch, or a modified polysaccharide film. 59. The method of claim 54, wherein said starch based media further comprises a coating configured to modify a release of said oral dosage. 60. The method of claim 59, wherein said coating comprises an edible polymer. 61. The method of claim 54, wherein said oral dosage formulation comprises: an oral drug component; and a jettable vehicle component. 62. The method of claim 61, wherein said oral drug component comprises an insoluble drug. 63. The method of claim 61, wherein said oral drug component comprises one of an ace inhibitor, an antianxiety medication, a antihypertensive medication, a blood glucose regulator, an alzheimer-type dementia medication, an anorexiant, a central nervous system stimulant, an antidiuretic, a specific antidote, an antihistamine, an antipsychotic medication, an antimanic medication, a beta blocker, a calcium channel blocker, a contraceptive, a dermatologic, a diuretic, an estrogen, a progestin, an entrapyramidal movement disorder medication, a sedative, or a hypnotic medication. 64. A system for forming a slow release oral dosage of medication comprising: a means for computing data; a means for jetting material communicatively coupled to said computing means; a starch based media disposed adjacent to said material jetting means; and a means for storing an oral dosage formulation, said formulation storage means being fluidly coupled to said material jetting means. 65. The system of claim 64, wherein said computing means comprises one of a personal computer, a laptop computer, a personal digital assistant, or a cellular telephone. 66. The system of claim 64, wherein said means for jetting material comprises an inkjet material dispenser. 67. The system of claim 64, wherein said starch based media comprises one of a polymeric or a paper organic film former. 68. The system of claim 64, wherein said starch based media comprises one of a rice starch based paper; a potato starch based paper; a functional derivative of starch, or a modified polysaccharide film. 69. The system of claim 64, wherein said starch based media further comprises a coating. 70. The system of claim 69, wherein said coating comprises an edible polymer. 71. The system of claim 70, wherein said edible polymer comprises one of a homopolymer of polyvinylphenol (PVP), a copolymer of PVP and polyvinylacetate, a crosslinked PVP particle, a copolymer of PVP and polyvinylacetate, a cationic PVP, a polyvinyl acetate (PVA) and PVA-polyethylene oxide (PEO) copolymer, a PVA-vinylacetal copolymer, a PVA-vinylacetal, a PVA-vinylamine copolymer, a poly vinyl methyl ether (PVME) homopolymer, a hydroxypropylmethylcellulose, a poly(2-ethyl oxazoline), a gelatin, or a methyl cellulose. 72. The system of claim 64, wherein said oral dosage formulation comprises: an oral drug component; and a jettable vehicle component. 73. The system of claim 72, wherein said jettable vehicle further comprises: an edible solvent; a surfactant; and humectants. 74. A jettable fluid for forming a slow release oral dosage of medication comprising: an oral drug component; and a jettable vehicle component. 75. The jettable fluid of claim 74, wherein said oral drug component comprises an insoluble drug. 76. The jettable fluid of claim 74, wherein said oral drug component comprises one of an ace inhibitor, an antianxiety medication, a antihypertensive medication, a blood glucose regulator, an alzheimer-type dementia medication, an anorexiant, a central nervous system stimulant, an antidiuretic, a specific antidote, an antihistamine, an antipsychotic medication, an antimanic medication, a beta blocker, a calcium channel blocker, a contraceptive, a dermatologic, a diuretic, an estrogen, a progestin, an entrapyramidal movement disorder medication, a sedative, or a hypnotic medication. 77. The jettable fluid of claim 76, wherein said oral drug component further comprises one of triazolam, felodipine, trandolapril, pergolide, rivastigmine tartrate, sibutramine hydrochloride, desmopressin acetate, flumazenil, desloratadine, risperidone, carvedilol, isradipine, norgestimate, methoxsalen, metolazone, estradiol, estrogens, conjugated estrogent, esterified cabergoline, zaleplon, or zolpidem tartrate. 78. The jettable fluid of claim 74, wherein said oral drug component comprises one of Prednisolone, Glyburide, Lovastatin, Digoxin, or Nifedipine. 79. The jettable fluid of claim 74, wherein said jettable vehicle further comprises: an edible solvent; a surfactant; and humectants. 80. The jettable fluid of claim 79, wherein said edible solvent comprises one of water or an alcohol. 81. The jettable fluid of claim 79, wherein said surfactant comprises one of lecithin, lecithin derivatives, glycerol esters, sorbitan derivatives, glycerol lactoesters of fatty acids, and ethoxylated fatty esters and oils. 82. The jettable fluid of claim 79, wherein said humectant comprises one of glycerin, sorbitol, or mannitol. 83. The jettable fluid of claim 79, wherein said jettable vehicle further comprises one of a colorant, a drier, a thinner, a wax, a lubricant, a reducing oil, a solvent, a body gum, a binding varnish, an antioxidant, an anti-skinning agent, a resin, or a binder. | BACKGROUND Traditional oral dosage drug formulations include both active pharmaceutical ingredients (API) and inactive ingredients. The inactive ingredients (also called excipients), are components of the final formulation of a drug that are not considered active pharmaceutical ingredients (API) in that they do not directly affect the consumer in the desired medicinal manner. Traditional oral dosage forms have several inactive ingredients. Among the traditional inactive ingredients included in oral dosage forms are binders that hold the tablet together, coatings configured to mask an unpleasant taste, disintegrants configured to make the tablet break apart when consumed, enteric coatings, fillers that assure sufficient material is available to properly fill a dosage form, enhancers configured to increase stability of the active ingredients, preservatives aimed at preventing microbial growth, and the like. The above-mentioned inactive ingredients have also been used to develop controlled release oral dosage solid formulations. These controlled release oral dosage solid formulations are designed to temporally control the release of the API from the oral dosage drug formulation. This temporal control allows for a time delayed release, or an extended release of a desired API formulation. The selection and optimization of the inactive ingredients to obtain an oral dosage solid form with the desired controlled release properties is both a complex and a lengthy process. In addition to the complexity and difficulty traditionally associated with selecting and optimizing inactive ingredients to obtain an oral dosage solid form with controlled release properties, there are a number of highly insoluble drugs that are not well suited to sustained or controlled delivery. The formulation of these highly insoluble APIs into controlled or modified-release dosage forms using traditional formulation methods is both expensive and challenging due to the APIs' insolubility. SUMMARY A system for producing a slow release oral dosage of medication includes a starch based media, and an oral dosage formulation jetted onto the starch based media. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate various embodiments of the present system and method and are a part of the specification. The illustrated embodiments are merely examples of the present system and method and do not limit the scope thereof. FIG. 1 is a perspective view of a traditional solid drug formulation, according to teachings of the prior art. FIG. 2 is a simple block diagram illustrating a system that may be used to deposit an oral drug formulation onto a starch based media, according to one exemplary embodiment. FIG. 3A is simple magnified view of a starch based media, according to one exemplary embodiment. FIG. 3B is a simple magnified view of a coated starch based media, according to one exemplary embodiment. FIG. 4 is a flow chart illustrating a method for selectively depositing a known quantity of an oral drug formulation onto a starch based media, according to one exemplary embodiment. FIG. 5 is a perspective view illustrating the dissolving of a starch based media incorporating the present system and method when ingested, according to one exemplary embodiment. FIG. 6 is a graph illustrating a dissolution rate of a starch based media containing an oral drug formulation according to one exemplary embodiment. Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. DETAILED DESCRIPTION A number of exemplary systems and methods for producing a slow-release oral dosage form are disclosed herein. More specifically, an oral drug formulation is jetted onto an edible starch based media to form an extended release dosage form. The edible starch-based media may also be coated with a polymer to further modify the release rate of an oral drug formulation jetted thereon. As used in the present specification and the appended claim, the term “edible” is meant to be understood broadly as any composition that is suitable for human consumption and is non-toxic. Similarly, the phrase “suitable for human consumption” is meant to be understood as any substance that complies with applicable standards such as food, drug, and cosmetic (FD&C) regulations in the United States and/or Eurocontrol experimental centre (E.E.C.) standards in the European Union. Additionally, the term “ink” is meant to be understood broadly as meaning any jettable fluid configured to be selectively emitted from an inkjet dispenser, regardless of whether it contains dye or any other colorant. The term “jettable” is meant to be understood both in the present specification and in the appended claims as any material that may be selectively deposited by any digitally addressable inkjet material dispenser. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present system and method for producing a slow-release oral dosage form. It will be apparent, however, to one skilled in the art, that the present method may be practiced without these specific details. Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. Exemplary Structure FIG. 1 illustrates a traditional solid oral drug formulation (100). As shown in FIG. 1, the traditional solid oral drug formulation (100) is a powder composition formed in the shape of a pill or a capsule. Often a name or other marking (110) is placed on the traditional solid drug formulation (100) to indicate source, identify chemical makeup, and/or to indicate a dosage. As noted above, the traditional solid oral drug formulations (100) have been formed with a number of inactive ingredients to produce controlled or modified-release dosage forms. However, as explained above, the selection and optimization of the inactive ingredients to obtain a solid oral dosage form with desired properties is a complex and lengthy process. According to the present exemplary system and method, two dimensional substrates in the form of paper-like media can replace the use of powders as inactive ingredients in the oral dosage solid form. Consequently, the paper-like media can be used in combination with inkjet technology to produce oral dosage solid forms of drugs without the complex and costly manufacturing process mentioned above. According to the present system and method, an edible starch based media (such as rice paper) in combination with an inkjet dispenser is used to produce an extended released oral drug formulation. FIG. 2 illustrates an exemplary system (200) that may be used to apply an oral drug formulation (260) to a starch based media (270) according to one exemplary embodiment. As shown in FIG. 2, the present system includes a computing device (210) controllably coupled through a servo mechanism (220) to a moveable carriage (240) having an inkjet dispenser (250) disposed thereon. A material reservoir (230) is also coupled to the moveable carriage (240), and consequently to the inkjet print head (250). A substrate (280) is located adjacent to the inkjet dispenser (250) having a starch based media (270) disposed thereon. The above-mentioned components of the present system will now be described in further detail below. The computing device (210) that is controllably coupled to the servo mechanism (220), as shown in FIG. 2, controls the selective deposition of an oral drug formulation (260) onto the starch based media (270). According to one exemplary embodiment, a representation of a desired quantity or dosage of the oral drug formulation (260) may be generated on an application hosted by the computing device (210). That representation may then be converted into servo instructions that are then housed in a processor readable media (not shown). When accessed by the computing device (210), the instructions housed in the processor readable media may be used to control the servo mechanisms (220) as well as the movable carriage (240) and inkjet dispenser (250), causing them to selectively deposit an oral drug onto the starch based media (270). The computing device (210) illustrated in FIG. 2 may be, but is in no way limited to, a workstation, a personal computer, a laptop, a personal digital assistant (PDA), or any other processor containing device. The moveable carriage (240) of the present printing system (200) illustrated in FIG. 2 is a moveable material dispenser that may include any number of inkjet material dispensers (250) configured to dispense the present oral drug formulation (260). The moveable carriage (240) may be controlled by a computing device (210) and may be controllably moved by, for example, a shaft system, a belt system, a chain system, etc. making up the servo mechanism (220). As the moveable carriage (240) operates, the computing device (210) may inform a user of operating conditions as well as provide the user with a user interface. As a desired quantity of the oral drug formulation (260) is printed on the starch based media (270), the computing device (210) may controllably position the moveable carriage (240) and direct one or more of the inkjet dispensers (250) to selectively dispense the oral drug formulation at predetermined locations on the starch based media as digitally addressed drops, thereby forming a desired dosage. The inkjet material dispensers (250) used by the present printing system (100) may be any type of inkjet dispenser configured to perform the present method including, but in no way limited to, thermally actuated inkjet dispensers, mechanically actuated inkjet dispensers, electro-statically actuated inkjet dispensers, magnetically actuated dispensers, piezo-electrically actuated inkjet dispensers, continuous inkjet dispensers, etc. Additionally, the ink-jet material dispenser can be heated to assist in dispensing the oral drug formulation. Moreover, the present oral drug formulation can be distributed using any number of printing processes including, but in no way limited to, inkjet printing, lithography, screen printing, gravure, and flexo printing. The material reservoir (230) that is fluidly coupled to the inkjet material dispenser (250) houses the present oral drug formulation (260) prior to printing. The material reservoir may be any sterilizeable container configured to hermetically seal the oral drug formulation (260) prior to printing and may be constructed of any number of materials including, but in no way limited to metals, plastics, composites, ceramics, or appropriate combinations thereof. FIG. 2 also illustrates the components of the present system that facilitate reception of the oral drug formulation (260) on the starch based media (270). As shown in FIG. 2, a substrate (280) may transport and/or positionally secure a starch based media (270) during a printing operation. The formation and composition of the oral drug formulation (260) and the starch based media (270) will now be described in detail below. Exemplary Composition According to one exemplary embodiment, the present system and method may be performed by selectively depositing the above-mentioned oral drug formulation (260) onto a starch based media (270). The starch based media (270) may include, but is in no way limited to, polymeric and/or paper organic film formers. Nonlimiting examples of such substrates include starch (natural and chemically modified), glycerin based sheets with or without a releasable backing, and the like; proteins such as gelatin, wheat gluten, and the like; cellulose derivatives such as hydroxypropylmethylcellulose, methocel, and the like; other polysaccharides such as pectin, xanthan gum, guar gum, algin, pullulan (an extracellular water-soluble microbial polysaccharide produced by different strains of Aureobasidium pullulans), and the like; sorbitol; seaweed; synthetic polymers such as polyvinyl alcohol, polymethylvinylether (PVME), poly-(2-ethyl 2-oxazoline), polyvinylpyrrolidone, and the like. Further examples of edible delivery substrates are those that are based on milk proteins, rice paper, potato wafer sheets, and films made from restructured fruits and vegetables. It should be understood that one or more of the above listed substrate materials, as well as additional materials included to modify the dissolution rates, may be used in combination in some embodiments. While the starch based media incorporated by the present system and method may take a number of different forms including, but in no way limited to, a paper made from a functional derivative of starch such as cross-linked, oxidized, acetylated, hydroxypropylated, carboxymethylated, and partially hydrolyzed starch; or a modified edible polysaccharide film made of cellulose derivates, starch hydrolysates, alginates, and/or carragenan; the present system and method will be described, for ease of explanation only, in the context of a rice based paper. Rice based paper is an edible starch based material which, according to one exemplary embodiment, includes potato starch fibers, water, and vegetable oil. FIG. 3A illustrates a magnified view of an uncoated starch based media (300) according to one exemplary embodiment. As illustrated in FIG. 3A, the uncoated starch based media (300) is made up of a number of interlocking starch based fibers (320). The starch based fibers (320) that make up the uncoated starch based media (300) is made essentially of soluble starch. The soluble starch is comprised of glucose units linked together by oxygen bridges called glycosides. The glucose molecules in the starch based fibers (320) are oriented in an alpha orientation rather than a beta orientation as in cellulose. As a consequence of the alpha orientation, the starch based fibers (320) are more readily soluble in water and more easily digested by bacteria and other living organisms than cellulose. Additionally, the starch based fibers (320) are configured to absorb an oral drug formulation (260; FIG. 2) or any other API disposed thereon. Once the starch based fibers (320) absorb an oral drug formulation (260; FIG. 2) or any other API disposed thereon, the oral drug formulation is retained therein until a dissolution of the starch based fibers (320) occurs causing a release of the drug formulation. According to another exemplary embodiment, illustrated in FIG. 3B, the starch based media (270; FIG. 2) used to receive the oral drug formulation (260; FIG. 2) is a coated starch based media (330). As shown in the magnified view of FIG. 3B, the coated starch based media (330) also includes a number of interlocked starch based fibers (320) as described above. However, according to the exemplary embodiment illustrated in FIG. 3B, there is also a coating (310) surrounding the interlocking starch based fibers (320). The coating (310) illustrated in FIG. 3B modifies the rate of water uptake and subsequent dissolution of the starch based fibers (320). Additionally, the coating (310) selected to cover the starch based fiber (320) may absorb a portion of the oral drug formulation (260; FIG. 2). Consequently, the rate of dissolution of the coating (310) when consumed, will affect the rate of release of an oral drug formulation (260; FIG. 2) as will be further detailed below with reference to FIG. 5. The coating (310) selected to coat the starch based fibers (320) may be any edible polymer including, but in no way limited to homopolymer of polyvinylphenol (PVP), copolymer of PVP and polyvinylacetate, crosslinked PVP particles, copolymer of PVP and polyvinylacetate, Cationic PVP, polyvinyl acetate (PVA) and PVA-polyethylene oxide (PEO) copolymer, PVA-vinylacetal copolymer, PVA-vinylacetal, PVA-vinylamine copolymer, poly vinyl methyl ether (PVME) homopolymer, hydroxypropylmethylcellulose, poly(2-ethyl oxazoline), gelatin, and methyl cellulose. According to one exemplary embodiment of the present system and method, the above-mentioned starch based media (270; FIG. 2) receives an oral drug formulation (260; FIG. 2) to form a solid drug dosage. The oral drug formulation (260) illustrated in FIG. 2 that is selectively deposited onto the starch based media (270; FIG. 2) includes both an oral drug component and a jettable vehicle component, as illustrated below. The oral drug component of the oral drug formulation (260) includes the desired API that forms a desired drug dosage. While the present system and method is exceptionally suited for traditionally insoluble oral drug components, any number of oral drug components may be incorporated by the present exemplary system and method including, but in no way limited to, Prednisolone, Glyburide, Lovastatin, Digoxin, and/or Nifedipine. Additionally, according to one exemplary embodiment, the oral drug component of the oral drug formulation (260) may include, but is in no way limited to, ace inhibitors, antianxiety medications, antihypertensive medications, blood glucose regulators, alzheimer-type dementia medications, anorexiants/central nervous system (CNS) stimulants, antidiuretics, specific antidotes, antihistamines, antipsychotics/antimanic medications, beta blockers, calcium channel blockers, contraceptives, dermatologics, diuretics, estrogens/progestins, entrapyramidal movement disorders (and hyperprolactinemia), and sedatives/hypnotics. Examples of the above mentioned oral drug components of the oral drug formulation (260) include, but are in no way limited to, triazolam, felodipine, trandolapril, pergolide, rivastigmine tartrate, sibutramine hydrochloride, desmopressin acetate, flumazenil, desloratadine, risperidone, carvedilol, isradipine, norgestimate, methoxsalen, metolazone, estradiol, estrogens, conjugated estrogent, esterified cabergoline, zaleplon, and zolpidem tartrate. In addition to the above-mentioned oral drug component, the present oral drug formulation (260; FIG. 2) includes a jettable vehicle component configured to provide properties to the oral drug formulation enabling the deposition of the oral drug formulation from an inkjet dispensing device. According to one exemplary embodiment, the jettable vehicle component of the oral drug formulation (260; FIG. 2) includes, but is in no way limited to, an edible solvent, surfactants, and/or humectants. Solvents and/or surfactants may be added to the oral drug formulation (260; FIG. 2) to enhance the jettable properties of the jettable oral drug formulation. Additional additives such as humectants can also be added to the jettable oral drug formulation to improve the reliability of an associated inkjet dispenser by reducing the likelihood of clogged nozzles. The edible solvent component of the jettable vehicle component is included in the present oral drug formulation (260) for dispersion and transport of the oral drug component as well as any other additives. The vehicle solvent imparts a jettable viscosity to the oral drug formulation (260) while also evaporating at a rate sufficient to make a desired dosage resistant to smudging soon after it is deposited on a starch based media (270). According to one exemplary embodiment, the solvent comprises water, thus creating a water-based vehicle. In addition to low cost, water is effective as a solvent for many additives, greatly reduces inkjet dispenser compatibility issues, effectively suspends oral drug formulations and colorants, and effectively controls drying rates of the oral drug formulation. More specifically, a water-based vehicle may comprise from 20% by volume water up to about 90% by volume water. In another exemplary embodiment, the solvent component of the ink vehicle includes a mixture of water and an alcohol, such as ethyl alcohol. The addition of an alcohol to a solvent affects the viscosity and drying rate of the oral drug formulation, as well as acting as a surfactant. Surfactants and emulsifiers may be added to the solvent component of the present oral drug formulation (260) in order to facilitate dispersion and/or dissolution of the oral drug component and any other additive in the solvent. Appropriate edible surfactant classes include, but are in no way limited to, lecithin, lecithin derivatives, glycerol esters, sorbitan derivatives, glycerol lactoesters of fatty acids, and ethoxylated fatty esters and oils. Examples of the above-mentioned classes include, but are in no way limited to, glycerol monolaurate, glycerol mono/dioleate, glycerol mono/diricinoleate, glycerol distearate, propylene glycerol dicaprylate/dicaprate, diethyleneglycol monolaurate, diethylene glycol monostearate, Decaglycerol mono/dioleate, triglycerol monoleate, hexaglycerol dioleate, hexaglycerol distearate, decaglycerol tetraoleate, decaglycerol decaoleate, Ethoxylated mono and diglycerides, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene (20) sorbitan tristearate, polyoxyethylene (20) sorbitan monooleate, Polyoxyethylene 20 sorbitan monolaurate, Polyoxyethylene 20 sorbitan monooleate, Polyoxyethylene 20 sorbitan monostearate, Polyoxyethylene 5 sorbitan monooleate, Polyoxyethylene sorbitan trioleate, Polyoxyethylene 20 sorbitan tristearate, acetylated monoglycerides, citric acid esters of monoglycerides, lactic acid esters of monoglycerides, polglycerol esters of fatty acids, propylene glycol esters of fatty acids, soorbitan esters of fatty acids, sodium stearoyl lacylates, mono and diglycerides with polysorbate 80, mono and diglycerides with polysorbate 65, citric ester of monoglycerides, citric and lactic mixed ester of monoglycerides, glycerol mono/diester of isostearic and succinic acid, glycerol mono/diester of palmitic/stearic acid and sodium stearate, diacetylated tartaric acid of ester of monglycerides, sorbitan monolaurate, PEG-10 sorbitan monolaurate, polysorbate 20, polysorbate 60, polysorbate 80, sorbitan monoleate, polysorbate 80, sorbitan monopalmitate, sorbitan sesquiolate, sorbitan triolate, sorbitan tristearate, POE-20 monolaurate, POE-20 sorbitan monostearate, POE-20 sorbitan tristearate, and POE-20 sorbitan monoleate. Exemplary trade names for the above-mentioned surfactants include, but are not limited to, Alcolec, Aldo Calgene Capmul Centrol, Centrolene, Centrolex, Centromix, Centromix, Drewpol, Durfax, Durtan, Durlac, Dur-Lo, Glycosperse, Grindsted, Ice, Imwitor, Liposorb, Mazol, Span, T-Maz, and Tween 20, 60, 65, or 80. According to one exemplary embodiment, a surfactant or emulsifier may be present in a concentration of up to about 20% by volume of the ink vehicle. In one particular embodiment, the surfactant or emulsifier comprises ethyl alcohol in a concentration of about 13% to about 20% by weight of the vehicle. A humectant may also be included in the present jettable vehicle component to control the moisture content and viscosity of the resulting oral drug formulation (260). The ink vehicle typically dries and is absorbed once it is disposed on the starch based media (270) or other substrate surface; however, drying prior to printing decreases viscosity and thus may inhibit the jettability of the oral drug formulation (260). Therefore, a humectant may be included in the vehicle to keep the oral drug formulation (260) from premature drying. The humectant may include, but is in no way limited to glycerin, sorbitol, mannitol, or any other edible humectant. According to one exemplary embodiment, the humectant is present in the vehicle as glycerin in a concentration of up to approximately 5% of the vehicle by volume. According to one exemplary embodiment, the vehicle component of the present oral drug formulation may also include other additives as desired including, but in no way limited to, driers, thinners, waxes, lubricants, reducing oils and solvents, body gum, binding varnish, antioxidants, anti-skinning agents, resins, and/or binders. Additionally, the present oral drug formulation (260) may also include an edible colorant component according to one exemplary embodiment. Suitable colorants include any edible compounds, or combinations thereof, including, but in no way limited to, FD&C approved colorants. The afore-mentioned colorants may also be water-soluble, further facilitating their incorporation into a water-based oral drug formulation. Exemplary Implementation and Operation Once the above-mentioned oral drug formulation (260; FIG. 2) is formed, it may be jetted onto a starch based media (270; FIG. 2) or other substrate to form a solid drug dosage. FIG. 4 illustrates an exemplary method for jetting an oral drug formulation onto a starch based media according to one exemplary embodiment. As shown in FIG. 4, the present method begins by positioning a starch based media under the present ink dispensing system (step 400). Once positioned, the ink dispensing system selectively deposits the oral drug formulation onto the starch based media (step 410) where it is subsequently absorbed (step 420). Upon deposition of the oral drug formulation onto the starch based media, a determination is made as to whether the present printing system (200; FIG. 2) has completed its drug formulation dispensing operation (step 430). If it is determined that the drug formulation dispensing operation is not complete (NO, step 430), the printing system again selectively jets an oral drug formulation onto the starch based media (step 410). If, however, the ink dispensing operation is complete (YES, step 430), the printed media is optionally examined for defects (step 440). If no defects are found (NO, step 450), the oral drug formulation dispensing process is complete. If, however, printing defects are found on the printed media (YES, step 450), the starch based media may be discarded (step 460) or otherwise re-processed. The above-mentioned steps will now be described in further detail below. As shown in FIG. 4, the present method for printing an oral drug formulation on a starch based media begins by positioning the starch based media under the dispensing system to facilitate reception of the oral drug formulation (step 400). As shown in FIG. 2, the starch based media (270) may be positioned under the dispensing system (200) by a moveable substrate (280). Alternatively, an operator or a number of mechanical transportation apparatuses may manually place the starch based media (270) adjacent to the dispensing system (200). Once the starch based media (270) is correctly positioned, the present dispensing system (200) may be directed by the computing device (210) to selectively deposit the oral drug formulation (260) onto the starch based media (step 410; FIG. 4). As was mentioned previously, the desired dosage of the oral drug formulation to be printed on the starch based media (270) may initially be determined on a program hosted by the computing device (210). The program created dosage may then be converted into a number of processor accessible commands, which when accessed, may control the servo mechanisms (220) and the movable carriage (240) causing them to selectively emit a specified quantity of oral drug formulation (260) onto the starch based media (270). Precision of the resulting oral drug deposition may be varied by adjusting a number of factors including, but in no way limited to, the type of inkjet material dispenser (250) used, the distance between the inkjet material dispenser (250) and the starch based media (270), and the dispensing rate. Once the oral drug formulation (260) has been selectively deposited onto the starch based media (270) according to the desired dosage, the deposited oral drug formulation may be absorbed by the starch based media (step 420; FIG. 4). When printed onto the starch based media (270) or other image receiving substrate, the various components of the oral drug formulation (260) enter the surface of the substrate or evaporate. Consequently, the oral drug formulation is affixed to the starch based media until consumption induces a selective release thereof. Upon deposition and subsequent absorption, it is determined whether or not the oral drug formulation dispensing operation has been completed on the starch based media (step 430). Completion of the oral drug formulation dispensing operation may be evaluated by a system operator or by the coupled computing device (210). According to one exemplary embodiment, the computing device (210) determines whether sufficient oral drug formulation (260) has been dispensed to produce the desired dosage on the starch based media (270). If sufficient oral drug formulation (260) has not been dispensed (NO, step 430; FIG. 4), the dispensing system (200) continues to selectively deposit jetted oral drug formulation onto the starch based media (step 410; FIG. 4). If, however, sufficient oral drug formulation (260) has been dispensed (YES, Step 430; FIG. 4), the dispensed quantity may optionally be checked for defects (step 440). Adequacy of the volume of oral drug formulation dispensed may be evaluated by a number of flow-rate sensors (not shown) disposed on the inkjet material dispenser (250). In order to check the printed media for defects (step 440), according to one exemplary embodiment, the starch based media (270) or other image receiving substrate may be analyzed according to weight, volume, or optical properties for obvious defects that may make the resulting substrate unacceptable. According to one exemplary embodiment, the starch based media (270) is subject to a series of optical scans configured to detect any alignment or deposition defects. According to one exemplary embodiment, if defects are discovered on the printed media (YES, step 450; FIG. 4), the starch based media may be discarded (step 460; FIG. 4) and the system adjusted. If, however, no image defects are discovered (NO, step 450; FIG. 4) the starch based media (270) may be packaged or otherwise distributed. According to one exemplary embodiment, the above mentioned process was used to produce a sample starch based media containing a desired dosage of oral drug formulation. According to the present exemplary embodiment, a solution of dimethylsulfoxide (DMSO): ethyl alcohol (EtOH): and glycerine in proportions of 80:17:3 (Volume/Volume) respectively was disposed by an inkjet dispenser onto the surface of a rice paper substrate manually placed adjacent to the inkjet material dispenser and on the surface of a coated rice paper substrate. According to this exemplary embodiment, the solution also included an API in the form of prednisolone in concentration of approximately 200 mg/mL. Five patterns of the solution measuring ⅛′ by 4″ were deposited with various inkjet dispensers. The samples were permitted to be absorbed and dry into the substrates for 2 hours at between 36-39 decrees Celsius. Once the samples were absorbed and dried, they were tested for dissolution rates using a dissolution apparatus at the following operating conditions: 50 RPM paddle speed from 0-60 minutes at a bath temperature of 37 degrees Celsius; and 250 RPM paddle speed from 61-120 minutes at a bath temperature 37 degrees Celsius. Samples of the dissolution rate were subsequently taken at the following time points: 5, 10, 20, 30, 45, 60, 65, and 120 minutes. Additionally, a second solution of the above-mentioned composition was disposed by an inkjet dispenser onto the surface of a rice paper substrate manually placed adjacent to the inkjet material dispenser and on the surface of a coated rice paper substrate. Again, five patterns of the solution measuring ⅛′ by 4″ were deposited with various inkjet dispensers. The samples were permitted to be absorbed and dry into the substrates for 2 hours at between 36-39 degrees Celsius. However, once the second set of samples were absorbed and dried, they were tested for dissolution rates using a dissolution apparatus at the following operating conditions: 50 RPM paddle speed from 0-54 hrs at a bath temperature of 37 degrees Celsius. Water was used as the dissolution media in the dissolution bath. Samples of the dissolution rate were subsequently taken at the following time points: 0, 6, 12, 18, 24, 36, 48, and 54 hours. FIG. 6 illustrates the results of the above-mentioned samples. As illustrated in FIG. 6, 100% of the above-mentioned API is released from the substrate after 24 hours under the above operating conditions. As a result of the above-mentioned processes, the effectiveness of the present system and method has been demonstrated. As illustrated in FIG. 5, when the starch based media containing an oral drug formulation (500) is consumed or otherwise placed in contact with a dissolution liquid, the starch fibers (320) and granules absorb water or other liquid forms of the dissolution liquid (510) due to formation of hydrogen bonds between the starch (a polysaccharide) and water. This water absorption causes a swelling of the fibers (320) creating an interlocking network, which restricts the release of any absorbed oral drug formulation molecules. Additionally, the restricted flow of water or other dissolution liquid (510) within the starch fibers (320) restricts the flow of the oral drug formulation out to solution until the molecules of the starch fibers are broken down through time, temperature, and mixing. A timed release of an oral drug formulation can be achieved using the present system and method by varying the rate of hydration of the starch fibers (320). According to one exemplary embodiment, uncoated rice paper releases between approximately 8 to 15% of the contained oral drug formulation per hour. However, the addition of a coating (310), as mentioned above, may be included to vary the release rate of the absorbed oral drug formulation. According to one exemplary embodiment, a higher release rate may be accomplished by including a coating (310). According to this exemplary embodiment, the main mechanism of dissolution for the first hour of a coated substrate is a dissolution of the coating (310) and any oral drug formulation that has been absorbed thereby. Once a substantial portion of the coating (310) has been dissolved by the dissolution liquid (510), the slower dissolution rate of the starch fibers (320) controls. The more easily the coating is dissolved and the lower the surface tension due to an increase of wetting of the fibers caused by the coating (310), the faster the starch based fibers are dissolved. Accordingly, the release rate of the oral drug formulation can be designed to have a varying release rate. In conclusion, the present system and method for producing a slow-release oral dosage form decreases the design constraints inherent in forming a slow-release oral dosage, thereby reducing the overall cost of such a system. By incorporating the inkjetting of a desired oral drug formulation onto a starch based media, the present system and method allow for precise dosage distribution while controlling the dissolution rate of the drug formulation. Additionally, by varying the coating of the starch based media, greater control of the dosage distribution may be obtained. The preceding description has been presented only to illustrate and describe exemplary embodiments of the present system and method. It is not intended to be exhaustive or to limit the system and method to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the system and method be defined by the following claims. | <SOH> BACKGROUND <EOH>Traditional oral dosage drug formulations include both active pharmaceutical ingredients (API) and inactive ingredients. The inactive ingredients (also called excipients), are components of the final formulation of a drug that are not considered active pharmaceutical ingredients (API) in that they do not directly affect the consumer in the desired medicinal manner. Traditional oral dosage forms have several inactive ingredients. Among the traditional inactive ingredients included in oral dosage forms are binders that hold the tablet together, coatings configured to mask an unpleasant taste, disintegrants configured to make the tablet break apart when consumed, enteric coatings, fillers that assure sufficient material is available to properly fill a dosage form, enhancers configured to increase stability of the active ingredients, preservatives aimed at preventing microbial growth, and the like. The above-mentioned inactive ingredients have also been used to develop controlled release oral dosage solid formulations. These controlled release oral dosage solid formulations are designed to temporally control the release of the API from the oral dosage drug formulation. This temporal control allows for a time delayed release, or an extended release of a desired API formulation. The selection and optimization of the inactive ingredients to obtain an oral dosage solid form with the desired controlled release properties is both a complex and a lengthy process. In addition to the complexity and difficulty traditionally associated with selecting and optimizing inactive ingredients to obtain an oral dosage solid form with controlled release properties, there are a number of highly insoluble drugs that are not well suited to sustained or controlled delivery. The formulation of these highly insoluble APIs into controlled or modified-release dosage forms using traditional formulation methods is both expensive and challenging due to the APIs' insolubility. | <SOH> SUMMARY <EOH>A system for producing a slow release oral dosage of medication includes a starch based media, and an oral dosage formulation jetted onto the starch based media. | 20040427 | 20110308 | 20051027 | 68020.0 | 0 | EDWARDS, LAURA ESTELLE | SYSTEM AND A METHOD FOR STARCH-BASED, SLOW-RELEASE ORAL DOSAGE FORMS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,796 | ACCEPTED | Programmable packet parsing processor | The present invention provides a packet processing device and method. A parsing processor provides instruction-driven content inspection of network packets at 10-Gbps and above with a parsing engine that executes parsing instructions. A flow state unit maintains statefulness of packet flows to allow content inspection across several related network packets. A state-graph unit traces state-graph nodes to keyword indications and/or parsing instructions. The parsing instructions can be derived from a high-level application to emulate user-friendly parsing logic. The parsing processor sends parsed packets to a network processor unit for further processing. | 1. A packet parsing processor, comprising: a parsing engine having an input to receive a signal that represents a network packet, the parsing engine to perform instruction-driven packet parsing on the packet responsive to parsing instructions; and a state-graph unit having an input/output coupled to a second input/output of the parsing engine, the state-graph unit to store the parsing instructions. 2. The packet processor of claim 1, wherein the parsing engine further comprises a hash unit store a portion of a parsing state, and wherein the parsing engine generates a key to look-up the portion of the parsing state. 3. The packet processor of claim 2, wherein the hash table comprises a TCP (Transmission Control Protocol) flow table and the key comprises a destination IP (Internet Protocol) address and destination port. 4. The packet processor of claim 1, wherein the parsing engine further comprises a plurality of scratchpads to store data while executing parsing instructions. 5. The packet processor of claim 1, wherein a parsing instruction is associated with a node in the state-graph, the parsing engine executing the parsing instruction responsive to a node match. 6. The packet processor of claim 1, wherein a portion of the parsing instructions emulate nodes from a software application for application recognition. 7. The packet processor of claim 1, wherein a parsing instruction comprises an encoded bitmap that represents whether characters have a transition. 8. The packet processor of claim 1, wherein the state-graph unit comprises an FCRAM (Fast Cycle Random Access Memory). 9. The packet processor of claim 1, wherein the parsing engine further comprises a plurality of processing cores to execute parsing instructions. 10. The packet processor of claim 1, further comprising a flow state unit having an input/output coupled to a first input/output of the parsing engine, the flow state unit to maintain a parse state across a packet flow. 11. The packet processor of claim 10, wherein the parsing engine stores the parser state in the flow state unit after parsing the network packet. 12. The packet processor of claim 1, wherein the packet processor is contained within a network device, coupled to a network operating at 10-Gbps or above, network device performing one from the group containing: data packet routing, data packet forwarding, data packet bridging. 13. A packet parsing processor of claim 1, wherein the packet parsing supports one from the group containing: intrusion detection, quality of service, application recognition, virus detection, and an application-level firewall. 14. A packet parsing processor, comprising: means for parsing a network packet responsive to parsing instructions; and means for graphing, coupled to the means for regular expression matching, the means for graphing identifying keyword matches between a state-graph and the network packet. 15. The packet processor of claim 14, wherein the means for parsing further comprises a means for hashing to store a parsing state, and the means for parsing generates a key to look-up a portion of the parsing state. 16. The packet processor of claim 15, wherein the means for hashing comprises a TCP (Transmission Control Protocol) hash table and the key comprises a destination IP (Internet Protocol) address and destination port. 17. The packet processor of claim 14, wherein the means for regular expression matching further comprises a plurality of means for storing data while executing parsing instructions. 18. The packet processor of claim 14, wherein a parsing instruction is associated with a node in the state-graph, the means for regular expression matching executing the parsing instruction responsive to a node match. 19. The packet processor of claim 1, wherein a portion of the parsing instructions emulate nodes from a software application for application recognition. 20. The packet processor of claim 14, wherein a parsing instruction comprises an encoded bitmap that represents whether characters have a transition. 21. The packet processor of claim 14, wherein the means for regular expression matching further comprises a plurality of means for executing parsing instructions. 22. The packet processor of claim 14, further comprising means for maintaining, coupled to the means for regular expression matching, the means for maintaining storing parse states for a plurality of packet flows 23. The packet processor of claim 14, wherein the means for regular expression matching stores the parser state in the means for maintaining after parsing the network packet. 24. A method of parsing packets in a processor, comprising: receiving a network packet, performing instruction-driven packet parsing on the network packet responsive to parsing instructions that traverse nodes of a state machine; and storing parsing instructions in memory addresses corresponding to the nodes. 25. The method of claim 24, wherein the performing instruction-driven packet parsing further storing a portion of a parsing state in a hash unit, and generating a key to look-up the portion of the parsing state. 26. The packet processor of claim 25, wherein the hash table comprises a TCP (Transmission Control Protocol) hash table and the key comprises a destination IP (Internet Protocol) address and destination port. 27. The method of claim 24, wherein the performing instruction-driven packet parsing further comprises executing parsing instructions in scratchpads. 28. The method of claim 24, further comprising: maintaining parse states for a plurality of packet flows. 29. The method of claim 24, wherein a parsing instruction is associated with a node in the state-graph, and identifying keyword matches further comprises identifying a parsing instruction at a node of the state graph, and executing the parsing instruction responsive to a node match. 30. The method of claim 24, wherein a portion of the parsing instructions emulate nodes from a software application for application recognition 31. The method of claim 24, wherein a parsing instruction comprises an encoded bitmap that represents whether characters have a transition. 32. The method of claim 24, wherein the identifying keyword matches comprises identifying keyword matches on a state-graph stored in an FCRAM (Fast Cycle Random Access Memory). 33. The method of claim 24, further comprising executing a parsing instruction. 34. The method of claim 24, the maintaining the flow states further comprises storing the parser state after parsing the network packet. 35. A computer program product, comprising a computer-readable medium having computer program instructions and data embodied thereon for parsing packets in a processor, comprising: receiving a network packet, performing instruction-driven packet parsing on the network packet responsive to parsing instructions that traverse nodes of a state machine; and storing parsing instructions in memory addresses corresponding to the nodes. 36. The computer program product of claim 35, wherein the performing instruction-driven packet parsing further storing a portion of a parsing state in a hash unit, and generating a key to look-up the portion of the parsing state. 37. The computer program product of claim 36, wherein the hash table comprises a TCP (Transmission Control Protocol) hash table and the key comprises a destination IP (Internet Protocol) address and destination port. 38. The computer program product of claim 35, wherein the performing instruction-driven packet parsing further comprises executing parsing instructions in scratchpads. 39. The computer program product of claim 35, further comprising: maintaining parse states for a plurality of packet flows. 40. The computer program product of claim 35, wherein a parsing instruction is associated with a node in the state-graph, and identifying keyword matches further comprises identifying a parsing instruction at a node of the state graph, and executing the parsing instruction responsive to a node match. 41. The computer program product of claim 35, wherein a portion of the parsing instructions emulate nodes from a software application for application recognition 42. The computer program product of claim 35, wherein a parsing instruction comprises an encoded bitmap that represents whether characters have a transition. 43. The computer program product of claim 35, wherein the identifying keyword matches comprises identifying keyword matches on a state-graph stored in an FCRAM (Fast Cycle Random Access Memory). 44. The computer program product of claim 35, further comprising executing a parsing instruction. 45. The computer program product of claim 35; the maintaining the flow states further comprises storing the parser state after parsing the network packet. | BACKGROUND OF THE INVENTION 1. Filed of the Invention This invention relates generally to a computer processor, and more specifically, to a packet parsing processor including a parsing engine to perform content inspection on network packets with an instruction set that provides programmable parsing operations. 2. Description of the Related Art Until recently, a lack of network bandwidth posed restraints on network performance. But emerging high bandwidth network technologies now operate at rates that expose limitations within conventional computer processors. Even high-end network devices using state of the art general purpose processors are unable to meet the demands of networks with data rates of 2.4-Gbps, 10-Gbps, 40-Gbps and higher. Network processors are a recent attempt to address the computational needs of network processing which, although limited to specialized functionalities, are also flexible enough to keep up with often changing network protocols and architecture. Compared to general processors performing a variety of tasks, network processors primarily perform packet processing tasks using a relatively small amount of software code. Examples of specialized packet processing include packet routing, switching, forwarding, and bridging. Some network processors even have arrays of processing units with multithreading capability to process more packets at the same time. As network processors have taken on additional functionalities, however, what was once a specialized device responsible for a few tasks has matured into a general processing device responsible for numerous network processing tasks. Consequentially, network processors are unable to perform application-level content inspection at high data rates. Application-level content inspection, or deep content inspection, involves regular expression matching of a byte stream in a data packet payload. An instruction set in a network processor is designed for general purpose network tasks, and not specifically for packet parsing. Thus, general purpose code used for parsing tasks is inefficient. Furthermore, content inspection is a computationally intensive task that dominates network processor bandwidth and other resources. In order to provide additional packet parsing functionality on the network processor, even more resources would need to be taken from other network processing tasks. Consequentially, current network processors are not suited for deep content inspection at high speeds. Moreover, current processors that are dedicated to parsing packets lack flexibility for adaptability to new signatures and protocols. These processors are instead hard-wired to handle state of the art signatures and protocols known at production time. Software used for packet processing can adapt to changes, but does not perform at a high enough data rate. Accordingly, there is a need for a robust packet processor that provides the flexibility and performance rate to perform content inspection concomitant with current and future networking demands. Furthermore, this solution should provide programmability to enhance traditional regular expression matching operations. SUMMARY OF THE INVENTION The present invention meets these needs by providing a dedicated parsing processor and method of parsing packets to meet the above needs. In one embodiment, the parsing processor provides instruction-driven content inspection of network packets with parsing instructions. The parsing processor can maintain statefulness of packet flows to perform content inspection across several related network packets as a single byte stream. The parsing processor traces state-graph nodes to determine which parsing instructions to fetch for execution. The parsing processor can exchange packets or other control information to a network processor for additional processing. In one embodiment, the parsing processor performs tasks such as intrusion detection and quality of service at a network speed of 10-Gbps. In another embodiment, the parsing instructions program a parsing engine to control tasks such as regular expression matching tasks and more. Another embodiment of the parsing instructions is derived from a high-level application recognition software program using graph-based recognition. As such, the parsing instructions comprise high-level software instructions compiled into machine code. In still another embodiment, the parsing processor comprises a flow state unit having an input/output coupled to a first input/output of the parsing engine. The flow state unit stores a parsing context including a parser state for packet flows. When a packet from a stateful flow is received by the parsing engine, the flow state unit sends the parsing context. Register banks include scratchpads for storing and parsing context and other data used during parsing computations. In yet another embodiment, the parsing processor comprises a state-graph unit having an input/output coupled to a second input/output of the parsing engine. The state-graph unit stores parsing instructions at state addresses representing nodes. As a result, the parsing engine is able to trace state nodes through character transitions of, for example, a state machine or Deterministic Finite Automata to a next state containing a next parsing instruction. Processor cores execute the parsing instruction against a byte stream of characters to, for example, identify a regular expression match. In one embodiment, the state-graph unit stores encoded instructions. States with more than five next states are encoded as a bitmap. A single bit in the bitmap can represent whether at least one of a set of characters contain a transition. Using the bitmap, 32-bits can represent 256 transitions rather than 2,048-bits. Another embodiment of the state-graph unit comprises ten FCRAMs (Fast Cycle Random Access Memories) providing approximately 10-Gbps throughput. In another embodiment, the parsing engine comprises a hash unit. The processor cores generate a key for hash unit look-ups by concatenating, for example, registers in the register bank. The hash unit outputs a next state corresponding to the key. Another embodiment of the hash table comprises a TCP flow table or a port table indexed by protocol type, destination IP address, destination port address, source IP address, and/or source port address. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a network device according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating the parsing processor according to one embodiment of the present invention. FIG. 3 is a sequence diagram illustrating an example of a state-graph according to one embodiment of the present invention. FIG. 4 is a sequence diagram illustrating parse state encoding according to one embodiment of the present invention. FIG. 5 is a flow chart illustrating the method of parsing network packets according to one embodiment of the present invention. FIG. 6 is a flow chart illustrating the method of determining parsing context according to one embodiment of the present invention. FIG. 7 is a flow chart illustrating the method of performing instruction-driven packet processing according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A system and method for parsing network packets are disclosed. Some embodiments of the system are set forth in FIGS. 1-2, and some embodiments of the method operating therein are set forth in FIGS. 3-7. The accompanying description is for the purpose of providing a thorough explanation with numerous specific details. Of course, the field of network processing is such that many different variations of the illustrated and described features of the invention are possible. Those skilled in the art will thus undoubtedly appreciate that the invention can be practiced without some specific details described below, and indeed will see that many other variations and embodiments of the invention can be practiced while still satisfying its teachings and spirit. Accordingly, the present invention should not be understood as being limited to the specific implementations described below, but only by the claims that follow. The processes, features, or functions of the present invention can be implemented by program instructions that execute in an appropriate computing device described below. The program instructions can be distributed on a computer readable medium, within a semiconductor device, or through a public network. Program instructions can be in any appropriate form, such as source code, object code, or scripts. FIG. 1 is a block diagram illustrating a network device 100 according to one embodiment of the present invention. The network device 100 operates to service high-speed networks with bandwidths of 2.4-Gbps, 10-Gbps, 40-Gbps, and above. The network device 100 can also provide services such as application recognition, quality of service guarantees, application-level firewalls, network-based intrusion detection, and the like. The network device 100 processes incoming packets 140 received from a network (not shown) to perform various tasks such as routing, switching, bridging, and packet forwarding using various network protocols such as TCP/IP (Transmission Control Protocol/Internet Protocol), ATM (Asynchronous Transfer Mode), IEEE802.3, IEEE 802.1 1, etc. The network device 100 sends processed outgoing packets 150 to the network. Although the network device 100 is shown to process one-way network traffic, another embodiment of the network device 100 processes two-way network traffic. The system 100 can comprise a specialized device such as a router, a switch, a bridge, a gateway, or a combination device such as the 12000-series systems manufactured and sold by Cisco Systems, Inc. of San Jose, Calif. More specifically, the network device 100 comprises a flow sequencer unit 110, a parsing processor 120, and a network processor unit 130 implemented as either hardware or software, alone or in combination. The components can also be implemented as a semiconductor, a field programmable device, a nanotechnology-based circuit, or any other type of circuit for implementing logic functionality at high data rates. The network device 100 components comprise, for example, separate integrated circuits attached to a common motherboard, several modules of a single integrated circuit, or even separate devices. In one embodiment, the network device 100 comprises additional components such as an operating system, co-processors, a CAM (Content Addressable Memory), a search engine, a packet buffer or other type of memory, and the like. In FIG. 1, a signal line 101 is coupled to an input of the flow sequencer unit 110, which forms an input of the network device 100, to carry optical, electrical, or other signals that represent incoming packets 140. Another signal line 102 couples a first output of the flow sequencer unit 110 to an input of the parsing processor 120. Still another signal line 103 couples a second output of the flow sequencer 103 to an input of the network processor 130. Yet another signal line 105 couples an input/output of the parsing processor 120 to an input/output of the network processor unit 130. Signal lines 104, 106 are coupled to outputs of the parsing processor 120 and the network processing unit 130, forming first and second outputs of the network device 100, to carry representations of outgoing packets 150. The signal lines 101-106 discussed here and signal lines discussed elsewhere comprise, for example, buses, dedicated paths, copper traces, and the like. Of course, the specific couplings signal lines 101-106 and other signal lines are example configurations and can vary without departing from the scope of the present invention. In operation, a data path flows from the flow sequencer unit 110 to the parsing processor 120 and, alternatively, to the network processor unit 130. By off-loading tasks from the network processor unit 130, the parsing processor 120 increases the network device 100 speed and efficiency, so that it can handle network speeds of 10-Gbps and more. The flow sequencer unit 110 tracks packet flows and identifies packets within a common flow, referred to as stateful packets. For example, individual packets for a video chat session or a secured transaction originate from the same source IP address and terminate at the same destination IP address and port. The flow sequencer unit 110 can use packet headers or explicit session indicators to correlate individual packets. In addition, the flow sequencer unit 110 can manipulate packet headers or otherwise indicate packet statefullness to the parsing processor 120. The parsing processor 120 parses packet content, using instruction-driven packet processing. This functionality can also be described as deep packet forwarding or deep packet parsing to indicate that packet inspection can include not only packet headers, but also data within packet payloads. The parsing processor 120 recognizes applications based on content contained within a packet payload such as URLs, application-layer software communication, etc. As a result, the parsing processor 120 can send messages to the network processor unit 130 such as a priority or quality of service indication, yielding better performance for the network application. In addition, the parsing processor 120 can recognize signatures for viruses or other malicious application-layer content before it reaches a targeted host. Such network based intrusion detection provides better network security. In one embodiment, the parsing processor 120 increases parsing efficiency by encoding character transitions. For example, rather than storing all possible 256 character transitions, the parsing processor 120 stores actual character transitions, or indications of which characters have transitions rather than the character transition itself. Because less data is needed in a state-graph constructed from character transitions, a memory can store more signatures and the parsing processor 120 can trace the memory at an increased rate. In another embodiment, the parsing processor 130 uses parsing instructions to perform regular expression matching and enhanced regular expression matching tasks. In still another embodiment, the parsing processor 130 emulates application recognition of high-level software which uses state-graph nodes. Accordingly, the parsing processor 120 executes parsing instructions based on complied high-level instructions or description language script. The parsing processor 120 is described in greater detail below with respect to FIG. 2. The network processor unit 130 executes general network processing operations on packets. The network processor unit 130 comprises, for example, an x86-type processor, a network processor, a multithreaded processor, a multiple instruction multiple data processor, a general processing unit, an application specific integrated circuit, or any processing device capable of processing instructions. FIG. 2 is a block diagram illustrating the parsing processor 120 according to one embodiment of the present invention. The parsing processor 120 comprises a parsing engine 210, a flow state unit 220, and a state-graph unit 230. The parsing engine 210 further comprises a parsing controller 218, processor cores 212, register banks 214, a hash unit 216, and a packet buffer 240. Signal lines 101, 201, 204, 205, 206, 202, 104 couple input/outputs of the parsing controller 218 to the flow sequencer 110, the flow state unit 220, the processor cores 212, the register banks 214, the hash units 216, the state-graph unit 230, and the network processor 130. Also, signal lines 207, 208, 241, 212, 213, 106, 104 connect input/outputs of the register banks 214 to the processor cores 212, the hash units 216, the packet buffer 240, the flow stat unit 220, the state-graph unit 230, the network processor 130, and the first network device 100 output. The parsing engine 210 controls content inspection of packets and other packet parsing functions. During processing, the parsing engine 210 maintains a parsing context for packets in the register banks 214 as shown below in the example of Table 1: TABLE 1 Parsing Context for Each Packet Size Field (bytes) Description Pak desc 4 Pointer to the current packet being parsed; packet header contains flow-id, packet length State 8 Current parse state Bit location 4 Current bit location being parsed Bit vector 8 Bit vector to reduce overhead of .*s Scratchpad 64 × 4 64 32-bit registers Classification register 4 32-bit register.containing classification Return address register 4 Saves return state address; used for function call at depth of one level NP transmit buffer 16 Buffer to hold variable sized fields from the byte stream to be send to the network processor unit 130 In one embodiment, the parsing engine 210 stores, in the flow state unit 220, parsing context for a packet that is part of a related packet flow. This allows the parsing engine 210 to parse related packets as a single byte stream. When a related packet is received, the parsing engine 210 retrieves parsing context as shown below in the example of Table 2: TABLE 2 Parsing Context Maintained in Flow State Unit 220 Size Field (bytes) Description State 8 Current parse state Bit vector 8 Bit vector to reduce overhead of .*s 4 registers 4 × 4 4 32-bit registers Classification register 4 32-bit register containing classification Return address register 4 Saves return state address; used for function call at depth of one level In another embodiment, the parsing engine 210 determines parsing context from the packet itself as shown in the example of Table 3: TABLE 4 Parsing Context from Packet Header Size Field (bytes) Description Pak desc 4 Packet identifier Parsing mode 3 Statefull (proxy mode) or stateless (per packet mode) Initial parse state 8 Starting state for per packet mode or first packet of proxy mode Flow_id 3 Flow_id used by flow state unit 220 for subsequent packets in flow Packet length 4 Length of packet Parsing offset 4 Offset from where to begin parsing In addition, the parsing engine 210 can retrieve parsing context from the hash unit 216. In one embodiment, the hash unit 216 stores a portion of the parsing context relative to the flow state unit 220. For example, the portion can include just a state address and classification value. In one embodiment, the parsing context contains a parse state that includes a current state and a next state. The state indicates the state-graph node from which characters will be traced. The next state is a result of the current character (or byte) and the state. An example parse state format that does not include parsing instructions is shown in Table 4: TABLE4 Parse State Format Without Instruction I- Reser- bit=0 ved State Char 0 Char 1 Char 2 Char 3 Char 4 1-bit 3-bits 20-bits 8-bits 8-bits 8-bits 8-bits 8-bits The parse state is encoded in a format depending on how many state transitions stem from the current state. In a first encoding for less than or equal to five next states, the transition characters themselves are stored in the Char fields. In a second encoding format for between 6 and 256 next states, a bitmap represents which characters have transitions. Parse state encoding is discussed below in more detail with respect to FIG. 4. Additionally, psuedocode for determining a next state from the State field is shown below in Table 6. In another embodiment, the parser state includes a parsing instruction. The parsing instruction specifies an action or task for the parsing processor 120. An example parse state format that includes an instruction is shown in Table 5: TABLE 5 Parse State Format with Instruction I-bit=1 Reserved State Instruction 1-bit 3-bits 20-bits 40-bits The parsing engine 210 also feeds state addresses of a node to the state-graph unit 230 and receives related parsing instructions. A “character” as used herein includes alphanumeric text and other symbols such as ASCII characters for any language or code that can be analyzed in whole, byte by byte, or bit by bit. As a result of executing instructions from the state-graph unit 230, the parsing engine 210 takes an action, such as jumping to an indicated state, skipping a certain number of bytes in the packet, performing a calculation using scratchpads, sending a message to the network processor 130, altering a header in the associated network packet by employing network processor 130, etc. The parsing engine 210 can also send state information of parsed packets to the flow state unit 220 for storage. The processor cores 212 execute instructions, preferably parsing instructions, related to parsing tasks of the parsing engine 210. The processor cores 212 also perform other data manipulation tasks such as fetching parsing instructions from the state-graph unit 230. The processor cores 212 comprise, for example, general processing cores, network processing cores, multiple instruction multiple data cores, parallel processing elements, controllers, multithreaded processing cores, or any other devices for processing instructions, such as an Xtensa core by Tensilica Inc. of Santa Clara, Calif., a MIPS core by MIPS Technologies, Inc. of Mountain View, Calif., or an ARM core by ARM Inc. of Los Gatos, Calif. In one embodiment, the processor cores 212 comprise 120 individual processor cores to concurrently process 120 packets in achieving 10-Gbps throughput. The register banks 214 provide temporary storage of packet fields, counters, parsing contexts, state information, regular expression matches, operands and/or other data being processed by the processor cores 212. The register banks 214 are preferably located near the processor cores 212 with a dedicated signal line 211 for low latency and high bandwidth data transfers. In one embodiment, a portion of the register banks 214 is set aside for each processor core 212. For example, 120 register banks can support 120 parsing contexts for 10-Gbps throughput. The register banks 214 comprise, for example, 32-bit scratchpads, 64-bit state information registers, 64-bit matched keyword registers, 64-bit vector register, etc. The hash unit 216 uses a hash table to index entries containing parser states or other parsing instructions, classifications and/or other information by keys. The hash unit 216 receives a key, generated by the processor cores 212, sent from a node in the state-graph machine 230, etc. For example, a processor core 212 obtains a 96-bit key by concatenating an immediate 32-bit (i.e., <immed>) operand from an instruction with 64-bits contained in two 32-bit registers. In one embodiment, the hash unit 216 stores a classification and a parser state for uniform treatment of similarly classified packets. The hash unit 216 can comprise a set of hash tables or a global hash table resulting from a combination of several hash tables including a TCP or other protocol hash table, a destination hash table, a port hash table, a source hash table, etc. When the global table comprises the set of hash tables, the key can be prepended with bits to distinguish between the individual tables without special hardware assist. In one embodiment, the TCP flow table stores information by key entries comprising, for example, a protocol type, destination IP address, a destination port, source IP address and/or source port. The TCP flow table provides immediate context information, classifications, classification-specific instructions, IP address and/or port specific instructions, and the like. In one embodiment, the hash unit 216 stores parsing instruction such as states in table entries. The processor cores 212 can implement parsing instructions, or preferably specific hash instructions, on the hash unit 216. Example parsing instructions for the hash unit 216 include instructions to look-up, insert, delete, or modify hash table entries responsive to parsing instructions with a key generated by concatenating an immediate operand with registers. The flow state unit 220 maintains flow states, or parsing states, for packets that are part of a packet flow for parsing across multiple packets. For example, the flow state unit 220 can store a state or next parsing instruction. The flow state unit 220 receives a flow identifier, which can be part of or related to the flow state information, from the parsing engine 210 to identify an entry. In one embodiment, the flow state information is set by the flow sequencer 110. In either case, the next state information is included in the parsing context sent to the parsing engine 210. The state-graph unit 230 stores parsing instructions in a data structure as state addresses. For example, the data structure, as executed by the processor cores 212, can be a Finite State Machine, a Deterministic Finite Automata, or any other data structure organized by state nodes and character transitions. Within the state-graph, signatures, URLs or other patterns for recognition are abstracted into common nodes and differentiated by transitions. As the parsing engine 210 fetches instructions, the state-graph unit 230 traces nodes until reaching, for example, a regular expression match, message, etc. embedded in a parsing instruction The state-graph unit 320 preferably comprises an FCRAM, but can comprise SDRAM, SRAM or other fast access memory. In one embodiment, each of ten state-graph units 230 provide 120 million 64-bit reads per second to support 10-Gbps throughput. The parsing instructions, either alone in combination, descriptions of various tasks for content instructions. Some parsing instructions merely embed data, while others marshal complex calculations. The parsing instructions can store a next state or node as an address. Example categories of the parsing instructions include: register instructions for storing and retrieving packet contents to/from a local scratchpad; ALU instructions for performing comparisons and arithmetic operations including bit vector operations; messaging instructions to programmatically produce messages on events during packet parsing for an external entity (e.g., network processing unit 130) to perform a task based on the event; function call instructions to support subroutines; hash look-up/update to operate on the hash unit 216 programmatically during packet parsing. Instructions can be described in a format of INSTR_NAME [<argument>]. Example bit vector instructions include: Bitvector_OR_hi<immed>; Bitvector_OR_lo<immed>—ORs immediate value to upper or lower bits of bit vector; Bitvector_AND_hi<immed>; Bitvector_AND lo<immed>—ANDs immediate value to upper or lower bits of bit vector; Bitvector_AND_SHIFT_OR_hi<immed>; Bitvector_AND_SHIFT_OR_lo<immed>—immediate operand is ANDed with the upper or lower bits of the bit vector; result is right-shifted by 1 and then ORed to the bit vector in place; and Bitvector_to_reg; Bitvector_from_reg; Bitvector_jump_conditional<bit-index>. Example register instructions include: Copy_to_scratchpad<address>—copies current byte from packet to specified address in register; Copy_immed_a<immed>—copies bit operand to a-register; Copy_scratchpad<from_address><to_address>—copies value from one scratchpad to another; a<−10a+char−‘0’—multiplies current value of a by 10 and adds current character to a number; used to convert string representations of a number to its register value; Skip_a —skips certain number of bytes in byte stream; Is_digit —checks to see if current character is a digit; and Br_a=immed<immed>; Br_a>immed<immed>; Br_a<immed<immed>—compares lower 16 bits of a-register with immediate 16 bit value. Example function call instructions include: Call<immed>—save state in return address register; jump to state address in <immed>; and Return—jump to state address in return address register. Example messaging instructions include: Send_msg<msg-id>; Halt<msg-id>—send message with message id set to <msg-id>; halts flow and sends message with message id set to <msg-id>; and Tx_buff<msg-id>; Send_tx_buff<msg-id>—transmits bytes from the byte stream; transmits contents of NP_transmit_buff. Example hash instructions include: Hash_look-up<immed>—if the key produces a hit in the hash unit 216, next state comprises the state indicated in the entry; if there is a miss, next state comprises the default state; Hash_insert<immed>—the hash unit 216 inserts (state+1) into an entry associated with the key; Hash_delete<immed>—the hash unit 216 deletes an entry associated with the key; and Hash_insert_classify <immed>—the hash unit 216 inserts (state+1, classification reg) into an entry associated with the key. In another embodiment, the state-graph unit 230 supports application discovery emulation of software. Such software can be programmed using a high-level language providing a user-friendly mechanism to specify parsing logic such as regular expression searches and other complex parsing actions. Next, a compiler translates the parsing logic specified in the high-level language into parsing or machine instructions. For regular expressions, the compiler can translate to a DFA. Similarly, other parsing logic needs to be compiled into a graph whose nodes consist of one or more parsing instructions. FIG. 3 is a sequence diagram illustrating an example of a state-graph 300 according to one embodiment of the present invention. The state-graph 300 combines the expressions “HTTP” and “HTML” into a state machine. Note that state-graphs 300 can combine thousands of expressions comprising hundreds of thousands of characters. The root node 302 as a starting state can have numerous transitions, but responsive the next character being “H”, the new state is node 304. Similarly, node 306 is the new state responsive to the character “T” subsequent to “H.” However, if a character other than “T” is received, then the new state returns to the root node 302. From node 306, there are two possible transitions, “T” which leads to node 308, and “M” which leads to node 312. If either a “P” follows “HTT” or an “L” follows “HTM”, then the new states are match node 310 and match node 314 respectively. A match node is a state representing a keyword match (i.e., “HTTP” or “HTML”). In one example, the parsing engine 210 writes an address following the keyword “PORT” as used in FTP to a TCP hash table. In another example, a parsing instruction directs the state-graph unit 230 to jump to a different root node to identify the URL following the “HTTP” characters. In yet another example, the parsing engine 210 sends a message to the network processor 230. FIG. 4 is a sequence diagram illustrating parse state encoding according to one embodiment of the present invention. Table 410 shows an unencoded parse state. Since the parse state can contain up to 256 transitions based on the 256 characters at 8-bits per character, the parse state consumes 2048 bits of memory. However, the parsing processor 120 encodes parse states for space efficiency. A first optimization is shown in table 420. In this case, when there are five or less actual transitions, those characters can be stored in 40 bits as shown above in Table 4. A second optimization is shown in tables 430 and 440. In this case, when there are more than five transitions, rather than storing characters, table 430 stores a bitmap of 128-bits. Each bit represents a character. In one example, a character bit is set to “1” if there is a transition for that character, and set to “0” if there is not. The second optimization further compresses data in table 440 where sets of 4 character bits in table 430 are represented by a single bit. Thus, if there is at least one transition with the set of 4 characters, the bit can be set to “1”, else it is set to “0”. Using this final optimization, the parse state is represented by 32-bits plus an additional bit to indicate whether the table encodes the upper 128 ASCII characters which are commonly used, or the lower 128 ASCII characters which are rarely used. Because encoding greatly reduces the number of bits needed to store next states, the parsing processor 120 can efficiently store a large number of transitions on-chip. In one embodiment, Char 0 indicates how to determine the next state from the encoded states. For example, if Char 0 is FF, the next state is the state field as shown above in Tale 4. If there are more than five transitions, Char 0 is FE or FD to indicate bit map encoding for the first 128 ASCII characters and the last 128 ASCII characters respectively. Otherwise, the parsing engine 210 assumes that there are greater than five transitions. Psuedocode for this example is shown in Table 6: TABLE 6 Psuedocode for Determining Parse State Case Psuedocode Char 0 is FF The next state is always State Char 0 is FE Bit map encoding for transitions on first 128 ASCII characters If char>+128 next state = State Bitmap =32 bit encoding in Char 1 to Char 4 If Bitmap[char/4]==0, next state = State Else Let count = Number of 1's in Bitmap strictly to the left of Bitmap [char/4] Next state = 4*count + char%4 + State + 1 Char 0 is FD Bit map encoding for transitions on last 128 ASCII characters If char<128 next state = State Else char = char − 128 Bitmap = 32 bit encoding in Char 1 to Char 4 If Bitmap [char/4]==0, next state = State Else Let count = Number of 1's in Bitmap strictly to the left of Bitmap [char/4] Next state = 4*count + char%4 + State + 1 Else Encoding for less than or equal to 5 outgoing transitions The next state for Char0 if not FF is (State + 1) The next state for Char1 if not FF is (State + 1) The next state for Char2 if not FF is (State + 1) The next state for Char3 if not FF is (State + 1) The next state for Char4 if not FF is (State + 1) For all other characters the next state is State FIG. 5 is a flow chart illustrating the method 500 of parsing network packets according to one embodiment of the present invention. The parsing engine 210 receives 510 a packet from the flow sequencer unit 110 into the packet buffer 240. Before parsing, the parsing engine 210 determines 520 a parsing context for the packet as described below with respect to FIG. 6. Generally, if the packet is part of a packet flow, or is stateful, at least part of the parsing context is already stored in the flow state unit 220 or hash unit 216. By maintaining statefullness of packets, content from the packet flow appears as a single bit stream to the state-graph unit 230. The parsing processor 120 performs 530 instruction-driven packet processing on the packet or packet flow as described below with reference to FIG. 7. Rather than merely identifying regular expression matches, the parsing instructions provide flexibility in parsing operations. For example, parsing instructions enable the packet processor unit 120 to extract the IP address from a packet and perform a look-up in the hash table 216. A parsing instruction in the hash look-up table 216 enables the packet processor 120 to skip the first 20 bytes of the packet and then extract the next four bytes. If the four extracted bytes match a fixed value, then additional actions can be taken. Also, the parsing instructions enable the parsing processor 120 to start pattern matching for predetermined patterns such as “.*abc”, “virus.dat”, “http”, etc. At the end of a packet, the parsing engine 210 stores 540 the parsing context for stateful packets in the flow state unit 220 and/or the hash unit 216. Also, the parsing engine 210 sends 550 the packet to the network processor unit 130 along with appropriate messages, or out of the network device 100. FIG. 6 is a flow chart illustrating the method 520 of determining parsing context according to one embodiment of the present invention. Note that FIG. 6 is merely an example which can be varied with different protocols, or by performing steps in a different order. The parsing engine 210 first determines whether packet context is contained in the headers 610 or other message from the flow sequencer 110. If so, the parsing engine 210 uses 615 the header information as parser context such as the next state. If not, the parsing engine 210 determines if a parser context is stored in the flow state unit 620. If so, the parsing engine 210 uses 625 saved parser context as identified, for example, by the flow_id. Otherwise, if the parsing engine 210 determines that a TCP table contains parser context 630, it uses 635 a parsing context, or at least a portion thereof, from the TCP flow table. The parsing engine 210 checks a TCP flow table using a key. The parsing engine 210 generates the key by, for example, concatenating the TCP information discussed above. If the parsing engine 210 determines that the TCP table does not contain parser index 630, it uses 645 a parsing context, or portion thereof, from the port table. FIG. 7 is a flow chart illustrating the method 530 of performing instruction-driven packet processing according to one embodiment of the present invention. In the parse state, the I-bit is set to “1” to indicate that it contains a parsing instruction as shown above in Table 5. Thus, once the parsing context is received, the parsing engine 210 gets 710 the next state from the parsing context. The parsing engine 210 fetches 720 a parsing instruction from the state-graph unit 230 using the state address. The processing cores 212 execute 730 the parsing instruction against the character to determine a next state. The parsing engine 210 advances 740 to the next character, and if it is an end byte stream character 750, ends the process. Otherwise, the process continues fetching 720 parsing instructions at the next state end of the byte stream. The above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. The scope of the invention is to instead be limited only by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Filed of the Invention This invention relates generally to a computer processor, and more specifically, to a packet parsing processor including a parsing engine to perform content inspection on network packets with an instruction set that provides programmable parsing operations. 2. Description of the Related Art Until recently, a lack of network bandwidth posed restraints on network performance. But emerging high bandwidth network technologies now operate at rates that expose limitations within conventional computer processors. Even high-end network devices using state of the art general purpose processors are unable to meet the demands of networks with data rates of 2.4-Gbps, 10-Gbps, 40-Gbps and higher. Network processors are a recent attempt to address the computational needs of network processing which, although limited to specialized functionalities, are also flexible enough to keep up with often changing network protocols and architecture. Compared to general processors performing a variety of tasks, network processors primarily perform packet processing tasks using a relatively small amount of software code. Examples of specialized packet processing include packet routing, switching, forwarding, and bridging. Some network processors even have arrays of processing units with multithreading capability to process more packets at the same time. As network processors have taken on additional functionalities, however, what was once a specialized device responsible for a few tasks has matured into a general processing device responsible for numerous network processing tasks. Consequentially, network processors are unable to perform application-level content inspection at high data rates. Application-level content inspection, or deep content inspection, involves regular expression matching of a byte stream in a data packet payload. An instruction set in a network processor is designed for general purpose network tasks, and not specifically for packet parsing. Thus, general purpose code used for parsing tasks is inefficient. Furthermore, content inspection is a computationally intensive task that dominates network processor bandwidth and other resources. In order to provide additional packet parsing functionality on the network processor, even more resources would need to be taken from other network processing tasks. Consequentially, current network processors are not suited for deep content inspection at high speeds. Moreover, current processors that are dedicated to parsing packets lack flexibility for adaptability to new signatures and protocols. These processors are instead hard-wired to handle state of the art signatures and protocols known at production time. Software used for packet processing can adapt to changes, but does not perform at a high enough data rate. Accordingly, there is a need for a robust packet processor that provides the flexibility and performance rate to perform content inspection concomitant with current and future networking demands. Furthermore, this solution should provide programmability to enhance traditional regular expression matching operations. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention meets these needs by providing a dedicated parsing processor and method of parsing packets to meet the above needs. In one embodiment, the parsing processor provides instruction-driven content inspection of network packets with parsing instructions. The parsing processor can maintain statefulness of packet flows to perform content inspection across several related network packets as a single byte stream. The parsing processor traces state-graph nodes to determine which parsing instructions to fetch for execution. The parsing processor can exchange packets or other control information to a network processor for additional processing. In one embodiment, the parsing processor performs tasks such as intrusion detection and quality of service at a network speed of 10-Gbps. In another embodiment, the parsing instructions program a parsing engine to control tasks such as regular expression matching tasks and more. Another embodiment of the parsing instructions is derived from a high-level application recognition software program using graph-based recognition. As such, the parsing instructions comprise high-level software instructions compiled into machine code. In still another embodiment, the parsing processor comprises a flow state unit having an input/output coupled to a first input/output of the parsing engine. The flow state unit stores a parsing context including a parser state for packet flows. When a packet from a stateful flow is received by the parsing engine, the flow state unit sends the parsing context. Register banks include scratchpads for storing and parsing context and other data used during parsing computations. In yet another embodiment, the parsing processor comprises a state-graph unit having an input/output coupled to a second input/output of the parsing engine. The state-graph unit stores parsing instructions at state addresses representing nodes. As a result, the parsing engine is able to trace state nodes through character transitions of, for example, a state machine or Deterministic Finite Automata to a next state containing a next parsing instruction. Processor cores execute the parsing instruction against a byte stream of characters to, for example, identify a regular expression match. In one embodiment, the state-graph unit stores encoded instructions. States with more than five next states are encoded as a bitmap. A single bit in the bitmap can represent whether at least one of a set of characters contain a transition. Using the bitmap, 32-bits can represent 256 transitions rather than 2,048-bits. Another embodiment of the state-graph unit comprises ten FCRAMs (Fast Cycle Random Access Memories) providing approximately 10-Gbps throughput. In another embodiment, the parsing engine comprises a hash unit. The processor cores generate a key for hash unit look-ups by concatenating, for example, registers in the register bank. The hash unit outputs a next state corresponding to the key. Another embodiment of the hash table comprises a TCP flow table or a port table indexed by protocol type, destination IP address, destination port address, source IP address, and/or source port address. | 20040426 | 20090908 | 20051027 | 95336.0 | 0 | PEZZLO, JOHN | PROGRAMMABLE PACKET PARSING PROCESSOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,912 | ACCEPTED | Two conductor thermally assisted magnetic memory | A method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell having a material wherein the coercivity is decreased upon an increase in temperature. In a particular embodiment, a first write magnetic field is established by a first write current flowing from a first voltage potential to a second voltage potential as applied to the first conductor. A second write magnetic field is established by a second write current flowing from a third voltage potential to a fourth voltage potential as applied to the second conductor. The voltage potential of the first conductor is greater than the voltage potential of the second conductor. As a result, a third current, flows from the first conductor through the SVM cell to the second conductor. The SVM cell has an internal resistance such that the flowing current generates heat within the SVM cell. As the SVM cell is self heated, the coercivity of the SVM cell falls below the combined write magnetic fields. | 1. A method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell providing an alterable orientation of magnetization in a material providing a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature, the method comprising: applying a first differential voltage across a first conductor generating a first write magnetic field; applying a second differential voltage across a second conductor generating a second write magnetic field, the second differential voltage applied contemporaneously with the first differential voltage; contemporaneously heating the SVM cell above a threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the SVM cell, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the orientation of the magnetization of the SVM cell may be changed to align with the applied first and second magnetic fields. 2. The method of claim 1, further including selecting a given SVM cell 3. The method of claim 1, wherein the SVM cell has a hard axis oriented transverse in relationship to an easy axis, the first conductor being parallel to the easy axis such that in operation the first write magnetic field is applied along the hard axis. 4. The method of claim 1, wherein the SVM cell has a hard axis oriented transverse in relationship to an easy axis, the second conductor being parallel to the hard axis such that in operation the second write magnetic field is applied along the easy axis. 5. A method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell having a data layer presenting an alterable orientation of magnetization in a material providing a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature, the method comprising: applying a first voltage potential to a first end of a first conductor; applying a second voltage potential to a second end of the first conductor; the second voltage potential being higher than the first voltage potential such that a first current flows in the first conductor providing a first write magnetic field; applying a third voltage potential to a first end of a second conductor, the third voltage potential being less than the first voltage potential; applying a fourth voltage potential to a second end of the second conductor, the fourth voltage potential being less than the first voltage potential and unequal to the third voltage potential such that a second current flows in the second conductor providing a second write magnetic field; heating the SVM cell above a threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell from the high potential of the first conductor to the lower potential of the second conductor, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the SVM cell, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the orientation of the magnetization of the data layer may be changed to align with the applied first and second magnetic fields. 6. The method of claim 5, further including selecting a given SVM cell 7. The method of claim 5, wherein the data layer has a hard axis oriented transverse in relationship to an easy axis, the first conductor being parallel to the easy axis such that in operation the first write magnetic field is applied along the hard axis. 8. The method of claim 5, wherein the data layer has a hard axis oriented transverse in relationship to an easy axis, the second conductor being parallel to the hard axis such that in operation the second write magnetic field is applied along the easy axis. 9. The method of claim 5, further comprising: maintaining the four voltage potentials simultaneously for a duration of time; removing the second voltage potential to remove the first current and the first write magnetic field; removing the first voltage potential to remove the third current flowing from the first conductor through the SVM cell to the second conductor; removing the third and fourth voltage potentials to remove the second current and the second write magnetic field. 10. The method of claim 5, wherein the third voltage potential is greater than the fourth voltage potential. 11. The method of claim 5, wherein the fourth voltage potential is greater than the third voltage potential. 12. The method of claim 5, wherein the at least three of the four applied voltage potentials are above a ground potential. 13. The method of claim 5, wherein the SVM cell has a high breakdown voltage. 14. The method of claim 5, wherein the SVM cell has a breakdown voltage greater than either the first or second heater potential. 15. The method of claim 5, wherein the first, second, third and fourth voltage potentials are applied contemporaneously. 16. The method of claim 5, wherein the heating of the SVM cell occurs contemporaneously with the application of the first and second write magnetic fields to the SVM cell. 17. The method of claim 5, wherein the SVM cell is coupled in series to a resistive heater device, the heating of the SVM cell including radiant heat provided by the resistive heater device in addition to the internal self heating. 18. A method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell presenting an alterable orientation of magnetization in a material providing a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature, the method comprising: applying a first write current through a first conductor to provide a first write magnetic field, the first write current established by providing a first voltage potential to a first end of the first conductor and a second voltage potential to a second end of the first conductor; applying a second write current through a second conductor to provide a second write magnetic field, the second write current established by providing a third voltage potential to a first end of the second conductor and a fourth voltage potential to a second end of the second conductor, the third and fourth voltage potentials being less than either of the first and second voltage potentials such that the first conductor has a higher voltage potential than the second conductor; heating the SVM cell above a threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell from the high potential of the first conductor to the lower potential of the second conductor, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the SVM cell, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the orientation of the magnetization of the SVM cell may be changed to align with the applied first and second magnetic fields. 19. The method of claim 18, further including selecting a given SVM cell 20. The method of claim 18, wherein the SVM cell has a hard axis oriented transverse in relationship to an easy axis, the first conductor being parallel to the easy axis such that in operation the first write magnetic field is applied along the hard axis. 21. The method of claim 18, wherein the SVM cell has a hard axis oriented transverse in relationship to an easy axis, the second conductor being parallel to the hard axis such that in operation the second write magnetic field is applied along the easy axis. 22. The method of claim 18, further comprising: maintaining the four voltage potentials simultaneously for a duration of time; removing the second voltage potential to remove the first current and the first write magnetic field; removing the first voltage potential to remove the third current flowing from the first conductor through the SVM cell to the second conductor; removing the third and fourth voltage potentials to remove the second current and the second write magnetic field. 23. The method of claim 18, wherein at least three of the applied voltage potentials are above a ground potential. 24. The method of claim 18, wherein the SVM cell has a high breakdown voltage. 25. The method of claim 18, wherein the SVM cell has a breakdown voltage greater than either the first or second heater potential. 26. The method of claim 18, wherein the first, second, third and fourth voltage potentials are applied contemporaneously. 27. The method of claim 18, wherein the heating of the SVM cell occurs contemporaneously with the application of the first and second write magnetic fields to the SVM cell. 28. The method of claim 18, wherein the SVM cell is coupled in series to a resistive heater device, the heating of the SVM cell including radiant heat provided by the resistive heater device in addition to the internal self heating. 29. A date storage device comprising: at least one spin valve memory (SVM) cell having a top and a bottom, the SVM cell providing an alterable orientation of magnetization in a material wherein the coercivity is decreased upon an increase in temperature, the orientation of magnetization having an easy axis and a hard axis; a first electrical conductor electrically coupled to the top of the SVM cell transverse to the easy axis of the SVM cell, the first electrical conductor having a first and a second end; a second electrical conductor electrically coupled to the bottom of the SVM cell opposite from the first electrical conductor; the second electrical conductor having a first and a second end; and a control logic write circuit switchably coupled to the first and second electrical conductors of a given SVM cell, the write circuit operable during a write operation such that: a first voltage potential is applied to the first end of the first conductor; a second voltage potential is applied to the second end of the first conductor; the second voltage potential being higher than the first voltage potential such that a first current flows in the first conductor providing a first write magnetic field; a third voltage potential is applied to the first end of the second conductor, the third voltage potential being less than the first voltage potential; a fourth voltage potential is applied to the second end of the second conductor, the fourth voltage potential being less than the first voltage potential and unequal to the third voltage potential such that a second current flows in the second conductor providing a second write magnetic field and such that the first conductor has a higher potential than the second conductor; the SVM cell is heated above a threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the data layer, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the magnetic orientation may be changed. 30. The data storage device of 29, wherein at least three of the applied voltage potentials are above a ground potential. 31. The data storage device of 29, wherein the SVM cell has a high breakdown voltage. 32. The data storage device of 29, wherein the SVM cell has a breakdown voltage greater than either the first or second heater potential. 33. The data storage device of 29, wherein the first, second, third and fourth voltage potentials are applied contemporaneously. 34. The data storage device of 29, wherein the heating of the SVM cell occurs contemporaneously with the application of the first and second write magnetic fields to the SVM cell. | FIELD OF THE INVENTION This invention relates generally to magnetic memory devices (commonly referred to as “MRAM”) in a two conductor architecture. BACKGROUND Increasingly sophisticated computer systems permit users to perform an expanding variety of computing tasks at faster and faster rates. The size of the memory and the memory access speed bear heavily upon the overall speed of the computer system. One principle underlying data storage in magnetic media (main or mass storage) is the ability to change and/or reverse the relative orientation of the magnetization of a storage data bit, (i.e. the logic state of a “0” or a “1”). The coercivity of a material is the level of demagnetizing force that must be applied to a magnetic particle to reduce and/or reverse the magnetization of the particle. Generally speaking, the smaller the magnetic particle, the higher its coercivity. Known magnetic memory cells may be tunneling magneto-resistance memory cells (TMR), giant magneto-resistance memory cells (GMR), or colossal magneto-resistance memory cells (CMR). These types of magnetic memory are commonly referred to as spin valve memory cells (SVM). FIGS. 1A and 1B provide a perspective view of a typical prior art magnetic memory cell having two conductors. As shown in prior art FIGS. 1A and 1B, a magnetic spin valve memory (SVM) cell 101 generally includes a data layer 103 which may alternatively be called a storage layer or bit layer, a reference layer 105 and an intermediate layer 107 between the data layer 103 and the reference layer 105. The data layer 103, the reference layer 105 and the intermediate layer 107 can be made from one or more layers of material. Where wiring layers are provided in a grid of rows and columns, electrical current and magnetic fields may be applied to the SVM cell 101 via electrically conductive row conductor 109 and electrically conductive column conductor 111. It is understood and appreciated that, as used herein, the terms row and column conductor have been selected for ease of discussion. Under appropriate circumstances, these labels may be reversed and/or otherwise substituted for such titles as word line and bit line. Using photolithographic techniques, the single SVM cell 101 shown in FIGS. 1A and 1B is typically combined with a plurality of other substantially identical SVM cells. In a typical MRAM device, the SVM cells are arranged in a cross-point array. Parallel conductive columns (column 1, 2, 3 . . . i not shown), also referred to as word lines, cross parallel conductive rows (row A, B, C . . . i not shown), also referred to as bit lines. The traditional principles of column and row arrays dictate that any given row will only cross any given column once. An SVM cell is placed at each intersecting cross-point between a row and a column. By selecting a particular row (B) and a particular column (3), any one memory cell positioned at their intersection (B, 3) can be isolated from any other memory cell in the array. Such individual indexing is not without complexities. The data layer 103 is usually a layer of magnetic material that stores a bit of data as an orientation of magnetization M1 that may be altered in response to the application of an external magnetic field or fields. More specifically, the orientation of magnetization M1 of the data layer 103 representing the logic state can be rotated (switched) from a first orientation 117, as in FIG. 1A, representing a logic state of “0”, to a second orientation 119, as in FIG. 1B representing a logic state of “1”, and/or vice versa. The reference layer 105 is usually a layer of magnetic material in which an orientation of magnetization M2 is “pinned”, as in fixed, in a predetermined direction or pinned orientation 121. The direction is predetermined and established by conventional microelectronic processing steps employed in the fabrication of the magnetic memory cell. The data layer 103 and reference layer 105 may be thought of as stacked bar magnets, each long on an X axis 113 and short on a Y axis 115. The magnetization of each layer has a strong preference to align along the easy axis, generally the long X axis 113. The short Y axis 115 is generally the hard axis. Alignment of the orientation of magnetization M1 of the data layer 103 in the first orientation 117 or second orientation 119 requires substantially the same amount of energy, and thus requires the same external magnetic field, to align the spins of the atomic particles in either direction. Typically, the logic state (a “0” or a “1”) of a magnetic memory cell depends on the relative orientations of magnetization M1 in the data layer 103 and M2 of the reference layer 105 (117 to 121 as shown in FIG. 1A or 119 to 121 as shown in FIG. 1B). For example, when an electrical potential bias is applied across the data layer 103 and the reference layer 105 in an SVM cell 101, electrons migrate between the data layer 103 and the reference layer 105 through the intermediate layer 107. The intermediate layer 107 is typically a thin dielectric layer, which is commonly referred to as a tunnel barrier layer. The phenomenon that causes the migration of electrons through the barrier layer may be referred to as quantum mechanical tunneling, or spin tunneling. The logic state may be determined by measuring the resistance of the SVM cell 101. For example, if the orientation 119 of the magnetization M1 in the data layer 103 is parallel to the pinned orientation 121 of magnetization in the reference layer 105, the SVM cell 101 will be in a state of low resistance, R (see FIG. 1B). If the first orientation 117 of the magnetization M1 in the data layer 103 is anti-parallel (opposite) to the pinned orientation 121 of magnetization in the reference layer 105, the SVM cell 101 will be in a state of high resistance, R+ΔR (see FIG. 1A). The orientation of M1, and therefore the logic state of the SVM cell 101, may be read by sensing the resistance of the SVM cell 101. Generally speaking, the smaller the magnetic particle, the higher its coercivity. A large coercivity is generally undesirable as it requires a greater magnetic field to facilitate switching, which in turn requires a greater power source and potentially larger conductors. Providing a large power source and large conductors is generally at odds with attempts to reduce the necessary size of components, and therefore permit larger memory stores in smaller and smaller spaces. In addition, the coercivity of a magnetic particle may be affected by temperature. Generally as temperature increases, coercivity decreases. With respect to MRAM and SVM cells, elevating the temperature of an SVM cell may indeed reduce the coercivity. The heating of an SVM cell 101 within an MRAM array may generally be accomplished through either of two forms. The first form is generalized heating where the desired SVM cell is heated collectively along with unselected/undesired SVM cells. In the most basic setting, the entire memory array is heated. Such generalized heating reduces the coercivity of unselected SVM cells along with the selected SVM cell and therefore may permit inadvertent and undesirable switching of unselected SVM cells, commonly referred to as half-select errors. The second form is selected heating where the desired SVM cell is heated independently of the unselected SVM cells within the memory. Such selected heating is traditionally accomplished with the use of movable heating probes or other external heaters which can provide a localized heat directly to a selected SVM cell, additional heating conductors and or elements placed proximately to the SVM cells of the memory, and/or the application of a heating pulse briefly passed through a selected SVM cell. The heating of a selected SVM cell 101 may therefore lower the coercivity of the cell and permit lower intensity magnetic fields to affect the magnetic orientation of the heated SVM cell 101 while not inadvertently affecting unselected and unheated SVM cells. Movable probes and external heaters are generally not practical for commercial memory applications requiring fast write response times, as there is an inherent latency due to the movement of the heating device. Additional heating conductors and/or heat elements disposed proximate to the SVM cells, though effective, require additional space within the memory device structure as well as requiring additional fabrication processes that likely increase costs. Heating pulses are typically brief to avoid over-load of the SVM cell and/or the electrical conductors coupled to the SVM cell. Brief heating pulses must additionally elevate the temperature of the SVM cell sufficiently to remain warm during the write operation when the heating pulse is not present. As time is a factor in a write operation, environmental factors may increase the cooling rate of the SVM cell and thus degrade the effectiveness of the heating pulse. Hence, there is a need for an ultra-high density magnetic memory which overcomes one or more of the drawbacks identified above. SUMMARY The present disclosure advances the art and overcomes problems articulated above by providing a two conductor thermally assisted magnetic memory device. In particular, and by way of example only, according to an embodiment of the present invention, this invention provides a method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell having a data layer characterized by an alterable orientation of magnetization, wherein the coercivity of the data layer is decreased during a write operation by heating the data layer as a result of current flowing through the selected two conductor SVM cell. The data layer in the SVM cell has a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature. The method including: applying a first differential voltage across a first conductor generating a first write magnetic field; applying a second differential voltage across a second conductor generating a second write magnetic field, the second differential voltage applied contemporaneously with the first differential voltage; heating the SVM cell to the threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the SVM cell, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the orientation of the magnetization of the SVM cell may be changed to align with the applied first and second magnetic fields. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A˜1B show perspective views of a prior art magnetic memory cell having two conductors; FIG. 2 provides a partial perspective view of a two-conductor spin valve memory (SVM) cell set for writing according to one embodiment; FIG. 3 provides a conceptual illustration of a cross-point array of two-conductor SVM cells shown in FIG. 2; FIG. 4 provides a flowchart depicting the steps of thermally assisting the write process for a two conductor SVM cell; FIG. 5 provides a partial perspective view of the SVM cell in FIG. 2 undergoing the write operations set forth in FIG. 4; FIGS. 6A and 6B provide charts depicting the relative voltage potentials applied during a write operation, according to one embodiment; and FIGS. 7A and 7B provide charts illustrating the application and removal of voltage potentials directed in the operations of FIG. 4. DETAILED DESCRIPTION Before proceeding with the detailed description, it is to be appreciated that the present teaching is by way of example, not limitation. The concepts herein are not limited to use or application with a specific type of magnetic memory. Thus, the instrumentalities described herein are for the convenience of explanation, shown and described with respect to exemplary embodiments. It will be appreciated that the principals herein may be equally applied in other types of magnetic memory. Referring now to the drawings, and more particularly to FIG. 2, there is shown a portion of a magnetic memory 200 having at least one spin valve magnetic memory (SVM) cell 202 having an electrically conductive first conductor 204 and an electrically conductive second conductor 206. The SVM cell 202 has a ferromagnetic data layer 208, an intermediate layer 210 and a reference layer 212. The data layer 208 permits the storing of a bit of data as an alterable orientation of magnetization M1. The intermediate layer 210 has opposing sides such that the data layer 208 in contact with one side is in direct alignment with, and substantially uniformly spaced from, the reference layer 212 in contact with the second side of the intermediate layer 210. The reference layer 212 provides a reference orientation of magnetization M2. In at least one embodiment, the reference layer 212 is a pinned reference layer, having a set orientation of magnetization M2. In an alternative embodiment the reference layer is a soft reference layer having a non-pinned orientation of magnetization M2. With respect to a traditional bar magnet, there are two equally stable easy spin directions (each rotated 180 degrees) along the easy axis, generally the longer axis of the magnet—the shorter axis being the hard axis. Alignment in either direction requires the same energy and requires the same external magnetic field to align the spins of the atomic particles in either direction. The data layer 208 is typically made of a ferromagnetic (FM) material. The data layer 208 comprises a material providing a stable orientation and a high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature. In addition the data layer 208 is characterized as having an easy axis 218 and a hard axis 220. In at least one embodiment, the easy axis 218 and hard axis 220 of the data layer 208 define the easy axis and hard axis of the overall SVM cell 202. The hysteresis loop of the data layer 208 is substantially symmetric, such that there are two substantially equivalent easy directions for magnetic alignment along the easy axis. The magnetic orientation M1 of the data layer 208 can be oriented in a chosen direction along generally the easy axis 218 when an appropriate magnetic field is applied, and remain in that orientation when the field is removed. More specifically, the orientation M1 is set by applying a magnetic field that overcomes the coercivity of the data layer 208, Hc(data). In short, the magnetic orientation M1 of the data layer 208 is alterable, but will be maintained in the last state of orientation. The first conductor 204 has a first end 222 and a second end 224. Similarly the second conductor 206 has a first end 226 and a second end 228. In at least one embodiment, the first conductor 204 is parallel to the easy axis 218 and the second conductor 206 is parallel to the hard axis 220. Moreover, the first conductor 204 is transverse to the second conductor 206, an arrangement more fully appreciated with respect to FIG. 3, described below. In addition, the SVM cell 202 may be described as having a top and a bottom. As shown in FIG. 2, the first conductor 204 is electrically coupled to the bottom of the SVM cell 202 and the second conductor 206 is electrically coupled to the top of the SVM cell 202. In an alternative embodiment, these connections may be flipped such that the first conductor 204 is attached to the top and the second conductor 206 to the bottom. A first voltage potential (V1) is switchably coupled to the first end 222 of the first conductor 204. A second voltage potential (V2) is switchably coupled to the second end 224 of the first conductor 204. A third voltage potential (V3) is switchably coupled to the first end 226 of the second conductor 206. A fourth voltage potential (V4) is switchably coupled to the second end 228 of the second conductor 206. An appropriate control logic 250, including a write circuit, is coupled to each voltage potential (V1, V2, V3, V4) source to control the application of a voltage potential to each end 222, 224 of the first conductor 204 and each end 226, 228 of the second conductor 206. As shown, control logic 250 is coupled to each voltage potential (V1, V2, V3, V4) source by control lines 252, 254, 256 and 258. Each control line is represented as a dotted line as each voltage potential (V1, V2, V3, V4) may be independently controlled by the control logic 250. FIG. 3 provides a conceptual illustration of a cross-point array 300 of magnetic memory 200 including spin valve memory (SVM) cells 202 as shown in FIG. 2. Each SVM cell 202 is represented as a resistor 302, 304, 306, . . . 318. The cross-point array 300 includes a plurality of parallel electrically conductive first conductors 204, 320 and 322 that may reside at a shared level or depth in the memory structure. A plurality of parallel electrically conductive second conductors 206, 324 and 326 in a second level or depth cross the first conductors 204, 320 and 322 thereby forming a cross-point array with a plurality of intersections. In at least one embodiment, the first conductors (204, 320, 322) are transverse to the second conductors (206, 324 326), and may be transversely normal or perpendicular in plan view. The first conductors (204, 320 322) may be described as conductive columns or conductive bit lines. The second conductors (206, 324 326) may be described as conductive rows or conductive word lines. Each SVM cell/resistor 302 through 318 is in electrical contact with, and located at, an intersection between a given first conductor 204, 320, and 322 and a given second conductor 206, 324, and 326. By way of example, one such intersection is shown at resistor 302 between first conductor 204 and second conductor 206. As such, electrical current and magnetic fields may be provided to a selected SVM cell represented by resistor 302 within the cross-point array 300 by first conductor 204 and second conductor 206. Although shown as a three by three cross-point array, it is understood and appreciated that the actual array may consist of substantially more first and second conductors. For example, cross-point array 300 may be a 16 KB, 32 KB, 64 KB, 128 KB, 256 KB or larger memory array. As indicated with the discussion of FIG. 2, each first conductor, for example first conductor 204, has a first end 222 and a second end 224. Likewise each second conductor, for example second conductor 206, has a first end 226 and a second end 228. The selection of first conductor 204 is facilitated, for example, by switching element 342 connecting to the first end 222 of first conductor 204 and switching element 344 connecting to the second end 224 of first conductor 204 (see also FIG. 2 for arrangement of conductors and first and second ends). Similarly, the selection of second conductor 206 is facilitated by switching element 346 connecting to the first end 226 of second conductor 206 and switching element 348 connecting to the second end 228 of second conductor 206. Control of each switching element (342, 344, 346, 348) is provided by the control logic 250 and control lines 252, 254, 256 and 258. For example, control line 252 is coupled to first voltage potential V1 to dynamically adjust V1 as it is applied through switch element 342 to the first end 222 of first conductor 204. Similarly control line 254 is coupled to second voltage potential V2 to dynamically adjust V2 as it is applied through switch element 344 to the second end 224 of first conductor 204. The dynamic adjustment of each voltage potential (V1, V2, V3, V4) by the control logic 250 is more fully described below. In at least one embodiment, an advantageous write process may be performed upon selected SVM cell 202 wherein the SVM cell 202 is heated contemporaneously with the application of magnetic fields. The method of selectively heating a specific cell and selectively applying magnetic fields may be more fully appreciated with respect to the flowchart provided in FIG. 4 in connection with FIG. 3 and FIG. 5. It will be appreciated that the described method need not be performed in the order in which it is herein described, but that this description is merely exemplary of at least one method of performing a thermally assisted write operation on a selected two conductor SVM cell 202 characterized by an alterable orientation of magnetization and comprising a material providing a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature. Under appropriate circumstances, such as where a sense operation has already been performed upon a selected SVM cell 202, and the requisite first conductor 204 and second conductor 206 intersecting the SVM cell 202 are known, the method may commence immediately. In other circumstances where a specific SVM cell 202 is known but unselected, the SVM cell must be selected as shown in block 400. In either case the selection is accomplished with appropriate control logic 250 directing switching elements 342, 344, 346 and 348 to switchably select specific first conductor 204 and specific second conductor 206. FIG. 5 conceptually illustrates the perspective view of a selected SVM cell 202 as described above and initially shown in FIG. 2. With an SVM cell 202 selected, the application of specific voltage potentials may commence substantially contemporaneously. More specifically, a first voltage potential V1 is applied to the first end 222 of first conductor 204, as shown in block 402. In at least one embodiment, V1 is a heating voltage potential (Vh). Second voltage potential V2 is applied to the second end 224 of the first conductor 204, as shown in block 404. As the first conductor 204 may be described as a column, in at least one embodiment, V2 is a write column potential and a heating potential (Vwc+Vh). V2 is higher in potential than V1 such that a current (I_col) flows in the first conductor 204, providing a first write magnetic field 500, represented as circling arrows in FIG. 5, as shown in block 406. I_col 360 is illustrated as a dotted line, shown in FIGS. 3 and 5. As I_col 360 is shown flowing from left to right in FIG. 5, the first write magnetic field 500 flows in a counterclockwise orientation about first conductor 204 in accordance with the right hand rule. The first write magnetic field 500 is applied along the hard axis 220 of SVM cell 202. The control logic 250 dynamically adjusts V1 and V2 to be unequal and thus provides for I_col. As described the relationship is V2>V1, however this may be reversed by the control logic 250. A third voltage potential V3 is applied to the first end 226 of the second conductor 206, as shown in block 408. As the second conductor 206 may be described as a row, in at least one embodiment, V3 is a write row potential (Vwr). In addition, the potential V3 is less than V1. A fourth voltage potential V4 (Vwr′) is applied to the second end 228 of the second conductor 206, as shown in block 410. The potential of V4 is less than the potential V1. In addition, so as to achieve the flow of current I_row 362, represented as a dotted line in FIG. 3 and FIG. 5, the potential of V4 and the potential of V3 are unequal. In one embodiment, the potential of V4 is greater than the potential of V3. In an alternative embodiment, the potential of V4 is less than the potential of V3. The relationship of the four voltage potentials operating during a write operation may be further summarized as follows (note V3≠V4): V1>V2>(V3 & V4) V2>V1>(V3 & V4) |V1−V2|=ΔV—col |V3−V4|=ΔV—row ΔV_col>ΔV_row ΔV—col−ΔV—row=ΔV—heat As V1 and V2 are both greater than V3 and V4, there exists a voltage potential drop across the SVM cell 202. As such, a third current, I_heat 264, will flow from the first conductor 204 through the SVM cell 202 to the second conductor 206. The heater component Vh of V1 and V2, providing I_heat to the given SVM cell 202, is not a leakage current. Vh is purposefully selected to generate a specific heat, raising the temperature of the specific SVM cell 202 to a specified threshold temperature for the SVM cell 202. As stated above, the SVM cell 202 has a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature. Though coercivity generally decreases as temperature increases, the threshold temperature for the SVM cell 202 is established to be high enough that inadvertent leakage currents and fluctuations in ambient temperature will not inadvertently raise the temperature of the SVM cell 202 to the threshold temperature. More specifically, in at least one embodiment, the Vh component may be close to the dielectric breakdown voltage of the SVM cell 202. Under appropriate circumstances, the appropriate level of Vh may be determined by a feedback system adjusting for the ambient temperature of the SVM cell 202. Moreover, summarizing the above, following the selection of a given SVM cell 202, in at least one embodiment, a first write current I_col 360 is applied through the first conductor 204 proximate to the SVM cell 202 to provide a first write magnetic field 500. The first write current I_col 360 is established by providing a first voltage potential V1 to the first end 222 of the first conductor 204 and a second voltage potential V2 to the second end 224 of the first conductor 204. A second write current I_row 362 is applied through the second conductor 206 proximate to the SVM cell 202 to provide a second write magnetic field 502. The second write current I_row 362 is established by providing a third voltage potential V3 to the first end 226 of the second conductor 206 and a fourth voltage potential V4 to the second end 228 of the second conductor 206. V3 and V4 are less than either V1 or V2 such that the first conductor 204 has a higher voltage potential than the second conductor 206. As shown in FIG. 5, the potential of V4 is less than the potential of V3 such that I_row 362 is flowing into the page, as indicated by the “+” sign. The flow of I_row 362 in the second conductor 206 provides a second write magnetic field 502, represented as circling arrows in FIG. 5, flowing clockwise in accordance with the right hand rule, shown in block 412. As shown in FIG. 5, the second write magnetic field 502 is applied along the easy axis 218 of SVM cell 202. The first write magnetic field 500 cooperatively interacts with the second write magnetic field 502, at the intersection of the first conductor 204 and the second conductor 206. As SVM cell 202 is located at this intersection, SVM cell 202 enjoys the cooperative field effect. It is understood that each SVM cell along the first conductor 204 will be subjected to the first write magnetic field 500. Likewise, each SVM cell along the second conductor 206 will be subjected to the second write magnetic field 502. To advantageously reduce inadvertent alteration of the magnetic orientation of unselected SVM cells (known as a half-select error), each write magnetic field 500 and 502 is separately insufficient to overcome the coercivity of an SVM cell's data layer. In addition, to further reduce the possibility of an inadvertent change in orientation in unselected SVM cells proximate to the selected SVM cell 202, the combined magnitude of the first write magnetic field 500 and the second write magnetic field 502 are insufficient to overcome the coercivity of an unheated unselected SVM cell. As stated above, the applied voltage potentials may be summarized as V2>V1>(V3 or V4). Moreover, at lest three of the four applied voltage potentials are above a ground potential. As V2 and V1 are greater than V3 and V4 the voltage potential of the first conductor 204 is greater than the voltage potential of the second conductor 206. As such a third current, I_heat 264, flows from the high potential of the first conductor 204, through the SVM cell 202, to the low potential of the second conductor 206. I_heat 364 is represented as a dotted line in FIG. 3 and FIG. 5. As SVM cell 202 has a resistive property, the passage of I_heat 364 through SVM cell 202 provides internal self heating, generating heat 366 (represented as radiant dash lines in FIG. 5) to the SVM cell 202, operation block 414. The behavior and properties of SVM memory cells are generally well understood. Three types of SVM cells in particular are known—a tunneling magneto-resistance memory cell (TMR), a giant magneto-resistance memory cell (GMR) and colossal magneto-resistance memory cell (CMR). GMR and CMR memory cells have similar magnetic behavior but their magneto-resistance arises from different physical effects, as the electrical conduction mechanisms are different. More specifically, in a TMR-based memory cell, the phenomenon is referred to as quantum-mechanical tunneling or spin-dependent tunneling. In a TMR memory cell, the intermediate layer 210 is a thin barrier of dielectric material through which electrons quantum mechanically tunnel between the data layer 208 and the reference layer 212. In a GMR memory cell, the intermediate layer 210 is a thin spacer layer of non-magnetic but conducting material. Here, the conduction is a spin-dependent scattering of electrons passing between the data layer 208 and the reference layer 212, though the intermediate layer 210. In either case, the resistance between the data layer 208 and the reference layer 212 will increase or decrease depending on the relative orientations of the magnetic fields M1 and M2. It is that difference in resistance that is sensed to determine if the data layer 208 is storing a logic state of “0” or a logic state of “1”. This same resistive property is advantageously utilized to generate internal self heating for SVM cell 202. To insure heating of the SVM cell 202 without destroying or damaging the SVM cell 202, in at least one embodiment the SVM cell 202 has a high breakdown voltage. More specifically, the atoms in insulating materials, such as the intermediate layer 210 in a TMR based memory cell, have tightly-bound electrons resisting the free flow of electrons. In at least one alternative embodyment, an additional resistive heater element (not shown) may coupled to the SVM cell 202. As I_heat 364 passing through the resistive heater device and the SVM cell 202, the resistive heater device provides additional radient heat to the SVM cell 202. This additional radient heat assists in elevating the SVM cell 202 above the threshold temperature. However, when enough voltage is applied, any insulating material will eventually succumb to what may be termed electrical “pressure”, and electron flow through the insulating material will occur. The breakdown voltage is therefore generally accepted to be the voltage at which the insulation between two conductors will fail, permitting electricity to conduct or arc through the insulator. In at least one embodiment, the SVM cell 202 has a breakdown voltage greater than either V1 or V2. In at least one embodiment, this increased breakdown voltage is achieved by providing a double SVM cell—specifically, two SVM cells directly in series between the first conductor 204 and second conductor 206. An elevated breakdown voltage advantageously permits the SVM cell 202 to obtain sufficient power dissipation in the form of heat 366 to assist the write operation. In at least one embodiment, the SVM cell 202 is a TMR cell wherein the intermediate layer 210 is a tunnel layer made from an electrically insulating material (a dielectric) that separates and electrically isolates the data layer 208 from the reference layer 212. Suitable dielectric materials for the dielectric intermediate layer 210 may include, but are not limited to: Silicon Oxide (SiO2), Magnesium Oxide (MgO), Silicon Nitride (SiNx), Aluminum Oxide (Al2O3), Aluminum Nitride (AlNx) and Tantalum Oxide (TaOx). In at least one embodiment, the intermediate layer 210 is Aluminum Oxide. In at least one other embodiment, the SVM cell 202 is a GMR or CMR cell wherein the intermediate layer 210 is made from a non-magnetic material such as a 3d, a 4d, or a 5d transition metal listed in the periodic table of the elements. Suitable non-magnetic materials for a non-magnetic intermediate layer 210 may include, but are not limited to: Copper (Cu), Gold (Au) and Silver (Ag). In at least one embodiment, the intermediate layer 210 is Copper. The ferromagnetic data layer 208 and the reference layer 212 may be made from a material that includes, but is not limited to: Nickel Iron (NiFe), Nickel Iron Cobalt (NiFeCo), Cobalt Iron (CoFe), and alloys of such metals. More specifically, in at least one embodiment the data layer 208 and the reference layer 212 are Nickel Iron (NiFe). In addition, the first conductor 204 and second conductor 206 may be made from materials that include, but are not limited to, Copper (Cu), Gold (Ag), Silver (Au). While the actual thickness of the intermediate layer 210 is dependent upon the materials selected to create the intermediate layer 210 and the type of tunnel memory cell desired, in general, the intermediate layer 210 has a thickness of about 0.5 nm to about 5.0 nm. However, under appropriate circumstances this thickness may be increased or decreased. The application of voltage potentials V1, V2, V3 and V4 occurs substantially contemporaneously. This is illustrated by operations 402 through 414 being placed between parallel lines 416 and 418 in FIG. 4. As a result the heating of the SVM cell 202 occurs substantially contemporaneously with the application of the first write magnetic field 500 and the application of the second write magnetic field 502. The combined first and second magnetic fields 500, 502 are greater than the coercivity of the heated SVM cell 202, such that the orientation of magnetization M1 of the data layer 208 may be to align with the first and second applied magnetic fields 500, 502, as shown in operation 420. In contrast, if the SVM cell 220 is not heated to the threshold temperature, the same voltages providing the same magnetic fields would be insufficient to change the orientation of magnetization M1. The application of heat 366 contemporaneous with the application of the combined magnetic fields (500, 502) is advantageous as the effects of environmental factors upon the SVM cell 202 are reduced. In addition, whereas pulse heating operates in a heat first, write second process, contemporaneous heating advantageously permits the proper elevated temperature to be maintained throughout the write operation. The improved write operation characteristics are advantageously achieved without increasing the relative size or complexity of the memory device, such as cross-point array 300. As such, low fabrication cost and high SVM cell density are maintained, if not improved. In at least one embodiment, the four voltage potentials (V1-V4) are maintained for a duration of time, specifically a duration of time sufficient for the combined first write magnetic field 500 and second write magnetic filed 502 to orient M1. The potential V2 is then removed from the second end 224 of the first conductor 204, operation 422. The removal of V2 removes the presence of the first write magnetic field 500. The potential V1 is then removed from the first end 222 of the first conductor 204, operation 424. The removal of V1 removes the presence of the heating potential and removes I_heat 364 from flowing through SVM cell 202. The internal heat 366 of SVM cell 202 may be sufficient that the coercivity of SVM cell 202 is susceptible to the remaining second write magnetic field 502. The potentials V3 and V4 are removed from the second conductor 206, operation 426. Although the heating current I_heat 364 is provided by the voltage potentials establishing the first and second write currents, I_col 360 and I_row 362, the heating current I_heat 364 operates independently. More specifically, I_heat 364 is not a required current component for either I_col 360 or I_row 362 to establish the first write magnetic field 500 or the second write magnetic field 502. The graphs provided in FIGS. 6A and 6B conceptually illustrate the relationships between the four voltage potentials V1-V4. FIG. 6A illustrates the current I_row 362 as it flows through the second conductor 206. As illustrated I_row 362 may flow in either direction depending upon which voltage potential is greater, V3 or V4. As shown, V3 or V4 may be substantially about a ground potential. The dotted lines of Vwc+Vh and Vh illustrate the relative potential differences between V3, V4 and V1, V2. FIG. 6B illustrates the current I_col 360 as it flows through the first conductor 204. In both charts, Vwc is effectively elevated above Vwr by Vh. Moreover, absent Vh, the relative potential in the first conductor 204 may be substantially equivalent to the potential in the second conductor 206. The charts provided in FIGS. 7A and 7B conceptually illustrate the temporal alignments of the application and removal of the four voltage potentials V1-V4. The vertical rise and fall in each line associated with V1 through V4 is intended to illustrate application or removal of the voltage potential. More specifically, FIG. 7A illustrates a case where the potential of V1 is greater than the potential of V2. As is shown, in at least one embodiment V1 is applied at time T1 and V2 is applied at time T2, followed by V3 at T3 and V4 at T4. In FIG. 7A it may be fully appreciated that all four voltages are contemporaneously applied between time T4 and time T5, indicating that both heat 366 and magnetic fields 500, 502 are applied to the selected SVM cell 202. The illustrated order of removal for the applied potentials aids in maintaining the oriented alignment of M1. FIG. 7B strongly parallels FIG. 7A with the noted exception that V3 is greater than V4. As such, V4 is applied at time T3 and V3 is applied at T4. The order of removal is reversed as well. Another embodiment may be appreciated to be a data storage device including at least one the thermally assisted two conductor SVM cell 202 and a control logic write circuit operable to apply four voltage potentials to the at least one SVM cell 202 in accordance with the above description. A computer with a main board, CPU and at least one memory store comprised of an embodiment of such a device raises the advantages of the improved thermally assisted two conductor write method to a system level. Changes may be made in the above methods, systems and structures without departing from the scope hereof. It should thus be noted that the matter contained in the above description and/or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method, system and structure, which, as a matter of language, might be said to fall therebetween. | <SOH> BACKGROUND <EOH>Increasingly sophisticated computer systems permit users to perform an expanding variety of computing tasks at faster and faster rates. The size of the memory and the memory access speed bear heavily upon the overall speed of the computer system. One principle underlying data storage in magnetic media (main or mass storage) is the ability to change and/or reverse the relative orientation of the magnetization of a storage data bit, (i.e. the logic state of a “0” or a “1”). The coercivity of a material is the level of demagnetizing force that must be applied to a magnetic particle to reduce and/or reverse the magnetization of the particle. Generally speaking, the smaller the magnetic particle, the higher its coercivity. Known magnetic memory cells may be tunneling magneto-resistance memory cells (TMR), giant magneto-resistance memory cells (GMR), or colossal magneto-resistance memory cells (CMR). These types of magnetic memory are commonly referred to as spin valve memory cells (SVM). FIGS. 1A and 1B provide a perspective view of a typical prior art magnetic memory cell having two conductors. As shown in prior art FIGS. 1A and 1B , a magnetic spin valve memory (SVM) cell 101 generally includes a data layer 103 which may alternatively be called a storage layer or bit layer, a reference layer 105 and an intermediate layer 107 between the data layer 103 and the reference layer 105 . The data layer 103 , the reference layer 105 and the intermediate layer 107 can be made from one or more layers of material. Where wiring layers are provided in a grid of rows and columns, electrical current and magnetic fields may be applied to the SVM cell 101 via electrically conductive row conductor 109 and electrically conductive column conductor 111 . It is understood and appreciated that, as used herein, the terms row and column conductor have been selected for ease of discussion. Under appropriate circumstances, these labels may be reversed and/or otherwise substituted for such titles as word line and bit line. Using photolithographic techniques, the single SVM cell 101 shown in FIGS. 1A and 1B is typically combined with a plurality of other substantially identical SVM cells. In a typical MRAM device, the SVM cells are arranged in a cross-point array. Parallel conductive columns (column 1 , 2 , 3 . . . i not shown), also referred to as word lines, cross parallel conductive rows (row A, B, C . . . i not shown), also referred to as bit lines. The traditional principles of column and row arrays dictate that any given row will only cross any given column once. An SVM cell is placed at each intersecting cross-point between a row and a column. By selecting a particular row (B) and a particular column ( 3 ), any one memory cell positioned at their intersection (B, 3 ) can be isolated from any other memory cell in the array. Such individual indexing is not without complexities. The data layer 103 is usually a layer of magnetic material that stores a bit of data as an orientation of magnetization M 1 that may be altered in response to the application of an external magnetic field or fields. More specifically, the orientation of magnetization M 1 of the data layer 103 representing the logic state can be rotated (switched) from a first orientation 117 , as in FIG. 1A , representing a logic state of “0”, to a second orientation 119 , as in FIG. 1B representing a logic state of “1”, and/or vice versa. The reference layer 105 is usually a layer of magnetic material in which an orientation of magnetization M 2 is “pinned”, as in fixed, in a predetermined direction or pinned orientation 121 . The direction is predetermined and established by conventional microelectronic processing steps employed in the fabrication of the magnetic memory cell. The data layer 103 and reference layer 105 may be thought of as stacked bar magnets, each long on an X axis 113 and short on a Y axis 115 . The magnetization of each layer has a strong preference to align along the easy axis, generally the long X axis 113 . The short Y axis 115 is generally the hard axis. Alignment of the orientation of magnetization M 1 of the data layer 103 in the first orientation 117 or second orientation 119 requires substantially the same amount of energy, and thus requires the same external magnetic field, to align the spins of the atomic particles in either direction. Typically, the logic state (a “0” or a “1”) of a magnetic memory cell depends on the relative orientations of magnetization M 1 in the data layer 103 and M 2 of the reference layer 105 ( 117 to 121 as shown in FIG. 1A or 119 to 121 as shown in FIG. 1B ). For example, when an electrical potential bias is applied across the data layer 103 and the reference layer 105 in an SVM cell 101 , electrons migrate between the data layer 103 and the reference layer 105 through the intermediate layer 107 . The intermediate layer 107 is typically a thin dielectric layer, which is commonly referred to as a tunnel barrier layer. The phenomenon that causes the migration of electrons through the barrier layer may be referred to as quantum mechanical tunneling, or spin tunneling. The logic state may be determined by measuring the resistance of the SVM cell 101 . For example, if the orientation 119 of the magnetization M 1 in the data layer 103 is parallel to the pinned orientation 121 of magnetization in the reference layer 105 , the SVM cell 101 will be in a state of low resistance, R (see FIG. 1B ). If the first orientation 117 of the magnetization M 1 in the data layer 103 is anti-parallel (opposite) to the pinned orientation 121 of magnetization in the reference layer 105 , the SVM cell 101 will be in a state of high resistance, R+ΔR (see FIG. 1A ). The orientation of M 1 , and therefore the logic state of the SVM cell 101 , may be read by sensing the resistance of the SVM cell 101 . Generally speaking, the smaller the magnetic particle, the higher its coercivity. A large coercivity is generally undesirable as it requires a greater magnetic field to facilitate switching, which in turn requires a greater power source and potentially larger conductors. Providing a large power source and large conductors is generally at odds with attempts to reduce the necessary size of components, and therefore permit larger memory stores in smaller and smaller spaces. In addition, the coercivity of a magnetic particle may be affected by temperature. Generally as temperature increases, coercivity decreases. With respect to MRAM and SVM cells, elevating the temperature of an SVM cell may indeed reduce the coercivity. The heating of an SVM cell 101 within an MRAM array may generally be accomplished through either of two forms. The first form is generalized heating where the desired SVM cell is heated collectively along with unselected/undesired SVM cells. In the most basic setting, the entire memory array is heated. Such generalized heating reduces the coercivity of unselected SVM cells along with the selected SVM cell and therefore may permit inadvertent and undesirable switching of unselected SVM cells, commonly referred to as half-select errors. The second form is selected heating where the desired SVM cell is heated independently of the unselected SVM cells within the memory. Such selected heating is traditionally accomplished with the use of movable heating probes or other external heaters which can provide a localized heat directly to a selected SVM cell, additional heating conductors and or elements placed proximately to the SVM cells of the memory, and/or the application of a heating pulse briefly passed through a selected SVM cell. The heating of a selected SVM cell 101 may therefore lower the coercivity of the cell and permit lower intensity magnetic fields to affect the magnetic orientation of the heated SVM cell 101 while not inadvertently affecting unselected and unheated SVM cells. Movable probes and external heaters are generally not practical for commercial memory applications requiring fast write response times, as there is an inherent latency due to the movement of the heating device. Additional heating conductors and/or heat elements disposed proximate to the SVM cells, though effective, require additional space within the memory device structure as well as requiring additional fabrication processes that likely increase costs. Heating pulses are typically brief to avoid over-load of the SVM cell and/or the electrical conductors coupled to the SVM cell. Brief heating pulses must additionally elevate the temperature of the SVM cell sufficiently to remain warm during the write operation when the heating pulse is not present. As time is a factor in a write operation, environmental factors may increase the cooling rate of the SVM cell and thus degrade the effectiveness of the heating pulse. Hence, there is a need for an ultra-high density magnetic memory which overcomes one or more of the drawbacks identified above. | <SOH> SUMMARY <EOH>The present disclosure advances the art and overcomes problems articulated above by providing a two conductor thermally assisted magnetic memory device. In particular, and by way of example only, according to an embodiment of the present invention, this invention provides a method of performing a thermally assisted write operation on a selected two conductor spin valve memory (SVM) cell having a data layer characterized by an alterable orientation of magnetization, wherein the coercivity of the data layer is decreased during a write operation by heating the data layer as a result of current flowing through the selected two conductor SVM cell. The data layer in the SVM cell has a stable orientation and high coercivity below a threshold temperature, and an alterable orientation and low coercivity above a threshold temperature. The method including: applying a first differential voltage across a first conductor generating a first write magnetic field; applying a second differential voltage across a second conductor generating a second write magnetic field, the second differential voltage applied contemporaneously with the first differential voltage; heating the SVM cell to the threshold temperature with a heating current flowing from the first conductor to the second conductor through the SVM cell, the SVM cell having a resistive property providing internal self heating to the SVM cell; and orienting the magnetization of the SVM cell, the combined first and second write fields being greater than the coercivity of the heated SVM cell such that the orientation of the magnetization of the SVM cell may be changed to align with the applied first and second magnetic fields. | 20040426 | 20060606 | 20051027 | 95786.0 | 0 | SOFOCLEOUS, ALEXANDER | TWO CONDUCTOR THERMALLY ASSISTED MAGNETIC MEMORY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,832,923 | ACCEPTED | System for transmitting current including magnetically decoupled superconducting conductors | A system for transmitting current is described. The system includes at least one generator, at least one cryostat, and at least one load. The system may further include one of terminations, a refrigeration system, and terminations and a refrigeration system. The cryostat has at least one electrical phase including at least one mandrel and magnetically decoupled superconducting conductors that may accomplished by, for example, braiding the superconductor. | 1. A system for transmitting current comprising: a. at least one generator having at least one phase; b. at least one superconducting cable having at least one cryostat containing at least one electrical phase including at least one mandrel and magnetically decoupled superconducting conductors; and c. at least one load. 2. The system for transmitting current according to claim 1 further including terminations. 3. The system for transmitting current according to claim 2 wherein the terminations include an electrical connector. 4. The system for transmitting current according to claim 2 wherein the terminations include a thermal connector. 5. The system for transmitting current according to claim 1 further including a refrigeration system. 6. The system for transmitting current according to claim 5 wherein the refrigeration system is a refrigerator. 7. The system for transmitting current according to claim 5 wherein the refrigeration system includes a mechanism for circulating cryogen through the cryostat. 8. A superconducting cable useable in a system for transmitting current including at least one generator having at least one phase and at least one load, the cable comprising at least one cryostat containing at least one electrical phase including: a. a mandrel; and b. braided magnetically decoupled superconducting conductors. 9. The cable according to claim 8 wherein the mandrel comprises a flexible material. 10. The cable according to claim 9 wherein the flexible material comprises one of an aluminum alloy and a copper alloy. 11. The cable according to claim 10 wherein the one of the aluminum alloy and a copper alloy comprises a single filament. 12. The cable according to claim 10 wherein the one of the aluminum alloy and a copper alloy comprises a plurality of filaments. 13. The cable according to claim 8 wherein the mandrel comprises a corrugated tube. 14. The cable according to claim 13 wherein the corrugated tube comprises a metallic material. 15. The cryostat according to claim 14 wherein the metallic material comprises a stainless steel. 16. The cable according to claim 13 wherein the corrugated tube comprises a non-metallic material. 17. The cryostat according to claim 16 wherein the non-metallic material comprises a polymer. 18. The cryostat according to claim 17 wherein the polymer is a reinforced polymer. 19. The cryostat according to claim 18 wherein the reinforced polymer is a fiberglass-reinforced polymer. 20. The cryostat according to claim 8 wherein the mandrel is cryogenically compatible. 21. The cable according to claim 8 wherein the braided magnetically decoupled superconducting conductors reduce AC losses. 22. The cable according to claim 8 wherein a first number of superconducting conductors in a first direction about the mandrel is substantially the same as a second number of superconducting conductors in a second direction about the mandrel. 23. The cable according to claim 8 wherein the braid comprises a weave pattern of over one, under one. 24. The cable according to claim 8 wherein the braid comprises a weave pattern of over two, under two. 25. The cable according to claim 8 wherein the braid comprises a biaxial braid (e.g., a braid angle, α, is an acute angle measured with respect to the axis of braiding (longitudinal axis). 26. The cable according to claim 8 wherein the superconductor conductor comprises a low temperature superconductor (LTS) conductor. 27. The cryostat according to claim 26 wherein the LTS conductor comprises a niobium-based alloy. 28. The cryostat according to claim 27 wherein the niobium-based alloy comprises an A15 superconducting phase. 29. The cryostat according to claim 27 wherein the niobium-based alloy includes one of titanium, tin, aluminum, and combinations thereof. 30. The cryostat according to claim 29 wherein the niobium-based alloy comprises a niobium-titanium-based alloy. 31. The cryostat according to claim 30 wherein the niobium-titanium-based alloy comprises between about 45 to about 50 weight percent titanium. 32. The cryostat according to claim 27 wherein the niobium-based alloy includes one of titanium, tin, aluminum, and combinations thereof, and one of tantalum, zirconium, tin, and combinations thereof. 33. The cryostat according to claim 29 wherein the niobium-based alloy comprises an A15 superconducting phase. 34. The cryostat according to claim 32 wherein the niobium-based alloy comprises an A15 superconducting phase. 35. The cryostat according to claim 34 wherein the niobium-based alloy comprises one of Nb3Sn and Nb3Al. 36. The cryostat according to claim 35 wherein the Nb3Sn comprises between about 18 to about 25 weight percent tin. 37. The cable according to claim 8 wherein the superconductor is a high temperature superconductor (HTS) conductor. 38. The cable according to claim 8 wherein the HTS conductor comprises a copper-based-HTS conductor. 39. The cable according to claim 8 wherein the copper-based-HTS conductor comprises one of La2-xMxCuO4, Ln2-xCexCuO4, ReBa2Cu3O7-d, Bi2Sr2CalCu2Ox, (Bi,Pb)2Sr2CalCu2Ox, Bi2Sr2CaCu3Ox, (Bi,Pb)2Sr2CaCu3Ox, and combinations thereof. 40. The cryostat according to claim 8 wherein the copper-based-HTS conductor comprises La2-xMxCuO4 and M comprises one of Ca, Sr, Ba, and combinations thereof. 41. The cryostat according to claim 8 wherein the copper-based-HTS conductor comprises Ln2-xCexCuO4, and Ln comprises one of Pr, Nd, Sm, Eu, Gd, and combinations thereof. 42. The cryostat according to claim 8 wherein the copper-based-HTS conductor comprises ReBa2Cu3O7-d, and Re comprises one of Y, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and combinations thereof. 43. The cable according to claim 39 wherein the copper-based-HTS conductor comprises YBa2Cu3O7-d (YBCO). 44. The cryostat according to claim 8 wherein the superconductor conductor comprises a metal substrate. 45. The cryostat according to claim 44 wherein the metal substrate has a thickness of between about 25 and about 127 micrometers. 46. The cryostat according to claim 45 wherein the superconductor conductor comprises YBCO having a thickness between about 1 to about 5 micrometers. 47. The cable according to claim 8 wherein the superconductor conductor comprises a magnesium boride. 48. The cryostat according to claim 47 wherein the magnesium boride comprises MgB2. 49. The cryostat according to claim 8 further including a thermal insulation. 50. The cryostat according to claim 49 wherein the thermal insulation comprises a vacuum-based insulation. 51. The cryostat according to claim 49 wherein the thermal insulation comprises a multiple-layer insulation. 52. The cryostat according to claim 51 wherein the multiple-layer insulation comprises superinsulation. 53. The cryostat according to claim 8 further including a protective jacket. 54. The cryostat according to claim 53 wherein the protective jacket comprises a polymer. 55. The cryostat according to claim 54 wherein the polymer comprises a polyvinyl chloride. 56. The cable according to claim 8 further including at least one electrically insulating material. 57. The cable according to claim 56 wherein at least one electrical insulating material comprises a plurality of the electrically insulating materials. 58. The cryostat according to claim 57 wherein the plurality of electrically insulating materials comprise at least about 4. 59. The cryostat according to claim 56 wherein the electrical insulating material comprises a cryogenically compatible material. 60. The cable according to claim 56 wherein at least one electrical insulating material comprises an extrusion. 61. The cable according to claim 8 further including at least one electrostatic shield. 62. The cable according to claim 61 wherein the at least one electrostatic shield comprise a conducting material. 63. The cable according to claim 61 wherein at least one electrostatic shield comprise a semiconducting material. 64. The cable according to claim 61 wherein at least one electrostatic shield is capable of shaping an electrical field. 65. The cable according to claim 61 wherein at least one electrostatic shield comprises a plurality of electrostatic shields. 66. The cable according to claim 65 wherein the plurality of electrostatic shields are on either side of an electrical insulation. 67. The cable according to claim 65 wherein the plurality of electrostatic shields comprises about two per each at least one electrically insulating material layer. 68. The cryostat according to claim 8 further including at least one spacer. 69. The cryostat according to claim 68 wherein the at least one spacer comprises a non-electrically conductive material. 70. The cryostat according to claim 68 wherein the at least one spacer comprises a cryogenically compatible material. 71. The cable according to claim 8 wherein at least one electrical phase comprise a plurality of electrical phases. 72. The cable according to claim 71 wherein at least two of the plurality of electrical phases include: a. a mandrel; and b. braided magnetically decoupled superconducting conductors. 73. The cable according to claim 71 wherein the plurality of electrical phases comprises at least about two electrical phases. 74. The cryostat according to claim 8 further including a cryogen path. 75. The cryostat according to claim 74 wherein the cryogen path is capable of directing a fluid. 76. The cryostat according to claim 75 wherein the fluid is a liquid. 77. The cryostat according to claim 76 wherein the liquid is liquid nitrogen. 78. The cryostat according to claim 78 wherein the fluid is a gas. 79. A system for transmitting current comprising: a. at least one generator having at least one phase; b. at least one superconducting cable having at least one cryostat containing at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors; c. terminations; and d. at least one load. 80. A system for transmitting current comprising: a. at least one generator having at least one phase; b. at least one superconducting cable having at least one cryostat containing at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors; c. at least one refrigeration system; and d. at least one load. 81. A method for manufacturing a system for transmitting current, said method comprising the steps of: a. providing at least one generator having at least one phase; b. at least one load; and c. providing at least one superconducting cable having at least one cryostat containing at least one electrical phase including at least one mandrel and magnetically decoupled superconducting conductors to transmit current over at least a portion of a distance between said at least one generator and said at least one load. 82. A method for manufacturing a cryostat useable in a system for transmitting current, said method comprising the steps of: a. providing a mandrel; and b. braiding a plurality of superconducting conductors on said mandrel so that the superconductor conductor are substantially magnetically decoupled. 83. A cable useable in useable in a system for transmitting current, said cable comprising: a. at least one mandrel; and b. a plurality of magnetically decoupled superconducting conductors deposed on said at least one mandrel. 84. A cable useable in useable in a system for transmitting current, said cable comprising: a. at least one mandrel; and b. a plurality of superconducting conductors braided on said at least one mandrel so as to magnetically decouple said superconducting conductors. | The present invention relates generally to a system for transmitting current and magnetically decoupled superconducting conductors for carrying at least one electrical phase of the system. BACKGROUND In the past three decades, electricity has risen from 25% to 40% of end-use energy consumption in the United States. With this rising demand for power comes an increasingly critical requirement for highly reliable, high quality power. As power demands continue to grow, older urban electric power systems in particular are being pushed to the limit of performance, requiring new solutions. Metal conductors, such as copper and aluminum, form a foundation of the world's electric power system, including generators, transmission and distribution systems, transformers, and motors. The discovery of high-temperature superconducting (HTS) compounds has led to an effort to develop conductors incorporating these compounds for the power industry to replace metal conductors. HTS conductors are one of the most fundamental advances in electric power system technology in more than a century. HTS conductors carry over one hundred times more current than do conventional metal conductors of the same physical dimension. The superior power density of HTS conductors will enable a new generation of power industry technologies. HTS conductors offer major size, weight, efficiency, and environmental benefits. HTS technologies will drive down costs and increase the capacity and reliability of electric power systems in a variety of ways. For example, an electrical cable consisting of HTS conductors is capable of transmitting two to five times more power through existing rights of way, thus improving the performance of power grids while reducing their environmental footprint. One way to characterize HTS conductors is by their cost per meter. An alternative way to characterize HTS conductors is by cost per kiloamp-meter. For example, by increasing the current carrying capacity for a given cost per meter of HTS conductor, the cost per kiloamp-meter is reduced. The maximum current carrying capacity is called the critical current. Among the several issues that need to be resolved for HTS conductors to be used effectively in power transmission is AC losses. The typical approaches to reducing the AC losses in a cable incorporating HTS conductors has relied on creating nearly monolithic annuli of HTS conductors. For example, the surface of a structure supporting the HTS conductors to create the annuli is nearly completely covered with HTS conductors. However, as the HTS conductors improve in current carrying capacity, there is often more conductor used to cover the surface than is necessary to carry the current. However, often in these types of designs, reducing the amount of HTS conductors only increases AC losses. Thus, there remains a need for a new and improved cable winding configuration that is capable of use in a system for transmitting current by taking advantage of improvements being made in superconductor conductors, while at the same time including acceptable and even improved properties with regard to AC losses. SUMMARY The present invention is directed to a system for transmitting current. The system includes a generator, a superconducting cable, and at least one load. Further, the system may include one of terminations, a refrigeration system, and terminations and a refrigeration system. The cable has at least one electrical phase including a mandrel and at least one band of magnetically decoupled superconducting conductors. The mandrel may be a flexible material. For example, single-filament or multiple-filament (e.g., plurality of filaments) alloys, such as one of an aluminum alloy and a copper alloy, may be used as a mandrel. No matter the construction or the material, it is advantageous that the mandrel be cryogenically compatible. A purpose of the magnetically decoupled superconducting conductors is to reduce AC losses. In addition to the at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors, the cable may also include one or more of thermal insulation, a protective jacket, electrically insulating material (dielectric), an electrostatic shield, a fault winding, and a cryogen path. Certainly, the cable includes at least one electrical phase and may include a plurality of electrical phases. The plurality may be three, and at least two of the plurality of electrical phases include a mandrel and braided magnetically decoupled superconducting conductors. Accordingly, one aspect of the present invention is to provide a system for transmitting current. The system includes at least one generator, at least one cryostat, and at least one load. The at least one generator generates at least one phase of electrical power. The at least one cryostat has at least one electrical phase including at least one mandrel and magnetically decoupled superconducting conductors. The generator and load can be assumed to represent equivalent simplifications of the electrical grid, and can be electrically interchanged. Another aspect of the present invention is to provide a superconducting cable useable in a system for transmitting current, such as the one mentioned above. The cable has at least one cryostat containing at least one electrical phase that includes a mandrel and braided magnetically decoupled superconducting conductors. Still another aspect of the present invention is to provide a system for transmitting current. The system includes at least one generator, at least one superconducting cable, at least one load, and one of terminations, at least one refrigeration system, and terminations and at least one refrigeration system. The at least one generator generates at least one phase of electrical power. The at least one cable has at least one cryostat containing at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors. These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic illustrating a system for transmitting current constructed according to the present invention; FIG. 2 is a schematic illustrating a superconducting cable useable in the system for transmitting current of FIG. 1; FIG. 3 is a schematic illustrating an electrical phase useable in the system for transmitting current of FIG. 1 and the cable of FIG. 2; and FIG. 4 is a cross-sectional schematic illustrating an alternative superconducting cable useable in the system for transmitting current of FIG. 1. DETAILED DESCRIPTION In the following description, like reference characters designate like or corresponding parts throughout the several views shown in the figures. It is also understood that terms such as “top,” “bottom,” “outward,” “inward,” and the like are words of convenience and are not to be construed as limiting terms. Referring to the drawings in general and to FIG. 1 in particular, it will be understood that the illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto. FIG. 1 shows a system 10 for transmitting current. The system 10 includes at least one of the following: generator 22, cable 8 containing at least one cryostat 12, load 24, terminations 26 and refrigeration system 28. The system 10 may include at least one splice 18. The at least one generator 22 may generate one, preferably three, phase electrical power. As may be seen in FIG. 2, the at least one cable 8 has at least one cryostat 12 containing at least one electrical phase 14. FIG. 3 shows the electrical phase 14 including at least one mandrel 16 and braided magnetically decoupled superconducting conductors 20. The generator 22 and the load 24 and the system 10 are any of those known in the art. The generator 22 and the load 24 may each also be seen as representing an entire grid of conductors, cables, busses, loads, transformers, generators, etc. as is known in the art. The refrigeration system 28 is sized so as to maintain any superconducting conductors within the cable 8 at a temperature below the critical temperature. The refrigeration system 28 also has to provide a method to transfer the heat from the cable 8 to the refrigeration system 28. The refrigeration system 28 may be a refrigerator and includes a mechanism for circulating cryogen through the cable 8. One example is to continuously circulate a cryogenic fluid through the cable 8 to collect the heat, and through the refrigeration system 28 to remove the heat. Examples of a refrigeration system 28 may be any such as is known in the art. Examples of terminations 26 may be any such as of those disclosed in any one of U.S. Pat. No. 6,525,265, “High Voltage Power Cable Termination,” issued Feb. 25, 2003, to Leijon et al.; PCT Pat. Appln. No. PCT/US02/31382, “Superconducting Cable Termination,” filed Oct. 2, 2002 for Southwire Company et al.; European Patent No. EP 1151442, “Electrical Power Transmission System Using Superconductors,” filed Dec. 22, 1999 for Pirelli Cavi E Sistemi S.P.A. et al.; World Patent No. W003103094, “Current Lead for Superconducting Apparatus,” filed May 31, 2002 for Pirelli & C.S.P.A. et al.; JP Patent No. 11073824, “Superconducting Cable Terminating Part,” published Mar. 16, 1999 for Tokyo Electric Power Co., Inc. et al.; U.S. Patent Publication No. U.S. 2003/0040439 A1, “Termination of the Conductor of a Superconducting Cable,” published on Feb. 27, 2003, for Castiglioni et al.; and U.S. Pat. No. 6,049,036, “Terminal For Connecting A Superconducting Multiphase Cable to a Room Temperature Electrical Equipment,” issued Apr. 11, 2000, to Metra, the entire disclosure of each being incorporated by reference herein. The splice 18 may be any of the type that permits the joining of superconducting conductors of varying lengths to create a greater length. A splice 18 may join shorter lengths of magnetically decoupled superconducting conductors 20 to create a greater length of magnetically decoupled superconducting conductors 20. Alternatively, a splice 18 may join a length of magnetically decoupled superconducting conductors 20 to a length of magnetically coupled superconducting conductors to create a greater length of superconducting conductors. In such case, a length of magnetically coupled superconducting conductors may be any of partially to substantially completely magnetically coupled. One example of a splice 18 is that disclosed in JP Publication No. 2000090998, “Superconducting Cable Joint,” published Mar. 31, 2000, to Sumitomo Electric Ind., Ltd., et al., the entire disclosure of each being incorporated by reference herein. The terminations 26 may be one of an electrical connector, a thermal connector, and combinations thereof. In the preferred embodiment, a plurality, typically three, of electrical phases 14 can be grouped together inside one cryostat 12 to form a cable 8, as shown in FIG. 2. In addition, the cable 8 may also include one or more of each of the following: thermal insulation 32, a protective jacket 34, and a cryogen path 46. Certainly the cable 8 includes at least one electrical phase 14 and may include a plurality of electrical phases 14. The plurality may be three, and at least two of the plurality of electrical phases include a mandrel 16 and braided magnetically decoupled superconducting conductors 20. For the purposes of this description, the phrase “electrical phase” is used to refer to a physical construction whose primary function is to carry electrical current at substantively one potential and substantively one frequency. The cryostat 12 serves to maintain the thermal region of the cable 8 separately from the surrounding environment. A cryostat 12 typically includes an inner surface 31, a thermal insulation 32, and an outer surface 33. The inner surface 31 is preferably in contact with a portion of cryogen path 46. The outer surface 33 of cryostat 12 is preferably in contact with the surrounding environment. The at least one electrical phase 14 is either introduced into a cryostat 12, or a cryostat 12 is constructed over the construction. A cryogen path 46 is capable of directing a fluid through the cryostat 12. The fluid may be a liquid, such as liquid nitrogen or liquid helium. Alternatively, the fluid may be a gas. The fluid thermally communicates between the refrigerator 28 and the cable 8, and may be any material or arrangement of materials that facilitates the operation of the cable 8 at a temperature at which the superconducting material exhibits its superconducting characteristics. The thermal insulation 32 may be any material or arrangement of materials that facilitates the operation of the cable 8 at a temperature at which the superconducting material exhibits its superconducting characteristics, such are known in the art. One example of a thermal insulation 32 is vacuum-based insulation. Such vacuum-based insulation may be a structure capable of maintaining sub-atmospheric pressure preferably of no greater that about 0.5 milliTorr. Alternatively, the thermal insulation 32 may be a multi-layer insulation in a comparable vacuum. The cryostat 12 has flexibility such that its electrical, physical, and mechanical properties do not substantially deteriorate upon bending upon a drum (to be stored and/or transported) or bending during the installation process. The cryostat 12 is preferably two concentric corrugated stainless steel tubes with a vacuum space between to form thermal insulation 32. However, the cryostat may be of any material or arrangement of materials that is compatible with the temperature at which the superconducting materials exhibits its superconducting characteristics, such are known in the art. Alternatively, the outer surface of cryostat 12 may be covered with a protective jacket 34. The protective jacket 34 is made using a material that provides the cryostat 12 with the capability to be maneuvered into pre-existing conduits, while at the same time protecting the cryostat 12 from damage that would inhibit or prevent its operation. The protective jacket 34 may be a polymer, such as a polyvinyl chloride. Referring to FIG. 3, the at least one electrical phase 14 consists of a mandrel 16 surrounded by at least one band of magnetically decoupled superconducting conductors 20, which may be covered with dielectric 36 (also sometimes called an electrically insulating material 36), which may be further covered with at least one additional band of magnetically decoupled superconducting conductors 20′. Preferably, a fault winding 38, 38′ either underlies or overlies the band of magnetically decoupled superconducting conductors 20′, and is connected electrically in parallel, at substantively the same electrical potential. In the preferred embodiment, the mandrel 16 acts as the fault winding 38 for the innermost band of magnetically decoupled superconducting conductors 20. Additionally, an electrostatic shield layer 40 may optionally underlie and/or overlie dielectric 36. The mandrel 16 may be a flexible material. Preferably, single filament and multiple filament (e.g., plurality of filaments) pure metals or alloys, such as one of an aluminum alloy and a copper alloy, may be used as a mandrel 16. Alternatively, the mandrel 16 may be a corrugated tube. Alternatively the mandrel 16 may be a pipe having a spiral groove (hereinafter referred to as a spiral tube). A bellows tube having a bellows may also be employed as a mandrel 16. Further, the mandrel 16 can also be prepared from a spirally wound material such as a spiral steel strip. Each of these shapes is adapted to provide the mandrel 16 with sufficient flexibility. The flexible mandrel 16 provides the inventive cable 8 with flexibility. Metallic materials, as well as non-metallic material, alone or in combination, may be used to construct the mandrel 16. Examples of metallic materials include stainless steel, copper, aluminum, and the like, while examples of non-metallic materials include polymers, ceramics, and combinations thereof. Reinforced polymer, such as a fiberglass-reinforced polymer, are contemplated. No matter the construction or the material, it is advantageous that the mandrel 16 be cryogenically compatible. It is also advantageous that the mandrel 16 have sufficient strength and flexibility at both operating and installation temperatures of the cable 8. Preferably, the mandrel 16 consists of a plurality of filaments of low resistance metals such as copper or copper alloys sized to handle any fault current that might be expected for the given electrical phase. In this embodiment, the mandrel acts as the fault winding 38 for the innermost band of magnetically decoupled superconducting conductors 20. All filaments within a discrete fault winding 38 are electrically connected in parallel. When a pipe, which optionally may have a spiral groove or a bellows tube, is employed as the mandrel 16, it may be drilled with holes of a size and pattern to allow the cryogen such as liquid helium (LHe) for low temperature superconducting (LTS) conductors or liquid nitrogen (LN2) for HTS conductors to flow into the butt gaps of the magnetically decoupled superconducting conductors 20 and flood the dielectric 36 (also sometimes called an electrically insulating material 36). In this embodiment, the mandrel 16 provides a central, tube-like cryogen path 46 for transporting cryogen from the refrigeration system 28. In one embodiment, mandrel 16 can further comprise a tape which is laid or wound on the mandrel 16. The tape can form a smooth surface for covering any grooves of the mandrel 16 so that the superconducting tapes do not buckle. It is possible to cover any grooves while maintaining flexibility of the mandrel 16 by laying the tape. The tape may consist of any material that is cryogenically compatible and that has sufficient strength and flexibility at both operating and installation temperatures of the cable 8. In another embodiment, the flexible mandrel 16 may be optionally covered with a wire braid or mesh. The mandrel 16 may have any one of a spiral groove surface, a web-shaped surface, a mat-shaped surface, and a braid-shaped surface on its exterior to form a surface for the construction of magnetically decoupled superconducting conductors 20. In the cryostat 12, the mandrel 16 is adapted to hold the tape-shaped superconducting conductors 20 at a bending strain of a prescribed range. This mandrel 16 has a length that is required for the cryostat 12 and is provided substantially at the center of the cryostat 12. The mandrel 16 is in a substantially cylindrical or spiral shape so that the superconducting conductors 20 are laid thereon and generally has a substantially constant diameter along its overall length. When practicing the present invention, it is possible to lay or wind several tape-shaped multi-filamentary superconducting conductors 20 on the mandrel 16. The superconducting conductors 20 may be braided in one or more layers while directing a surface thereof to the mandrel 16. Each layer may be formed by an arbitrary number of the superconducting conductors 20. When several superconducting conductors 20 are braided on the mandrel to create a layer of superconducting conductors 20, additional superconducting conductors 20 may be further braided thereon. When a sufficient number of superconducting conductors 20 are braided on the first layer of the superconducting conductors 20 as a second layer, a third layer of superconducting conductors 20 may then be braided thereon. No insulating layer is provided between each adjacent pair of layers. For the purposes of this description, the entirety of the adjacent pair of layers will be referred to as a band. All superconducting conductors within a discrete band are electrically connected in parallel. The band of magnetically decoupled superconducting conductors 20 consists of a plurality of superconducting conductors braided on the flexible mandrel 16. The superconducting conductor may consist of any construction of conductor that contains a portion including any superconducting material. Applicable form factors are substantively round (typically called wire), substantively flat (typically called tape), or any form between. The superconducting material can be deposed in one portion (typically called monofilament), two portions, or a plurality of portions (typically called multifilament). One type of superconducting material usable for making the superconductor conductor is a high temperature superconducting (HTS) material. One HTS material is a copper-based-HTS material. Examples of copper-based-HTS materials include La2-xMxCuO4, Ln2-xCexCuO4, ReBa2Cu3O7-d, bismuth-strontium-calcium-copper-oxide family of superconductors Such as, for example, Bi2Sr2CalCu2Ox, (Bi,Pb)2Sr2CalCu2Ox, and Bi2Sr2CaCu3Ox, (Bi,Pb)2Sr2CaCu3Ox (Bi2Sr2CalCu2Ox, (Bi,Pb)2Sr2CalCu2Ox, are often referred to as as BSCCO 2212 and Bi2Sr2CaCu3Ox, (Bi,Pb)2Sr2CaCu3Ox are often referred to as BSCCO 2223: all often referred to as BSCCO), and combinations thereof. In La2-xMxCuO4, M may be one of Ca, Sr, Ba, and combinations thereof. In Ln2-xCexCuO4, Ln may be one of Pr, Nd, Sm, Eu, Gd, and combinations thereof. In ReBa2Cu3O7-d, Re may be one of Y, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and combinations thereof. A specific ReBa2Cu3O7-d is YBa2Cu3O7-d that is often referred to YBCO. Examples of superconducting material usable may be any such as of those disclosed in any one of U.S. Pat. No. 6,601,289, “Manufacturing process of superconducting wire and retainer for heat treatment,” issued Aug. 5, 2003, to Kobayashi; U.S. Pat. No. 6,495,765, “Superconductors,” issued Dec. 17, 2002, to Riley, Jr.; U.S. Pat. No. 6,311,386, “Processing of (Bi,Pb) SCCO superconductor in wires and tapes,” issued Nov. 6, 2001, to Li, et al.; U.S. Pat. No. 6,295,716, “Production and processing of (Bi,Pb) SCCO superconductors,” issued Oct. 2, 2001, to Rupich, et al.; U.S. Pat. No. 5,942,466, “Processing of (Bi,Pb) SCCO superconductor in wires and tapes,” issued Aug. 24, 1999, to Li, et al.; U.S. Pat. No. 5,968,877, “High Tc YBCO superconductor deposited on biaxially textured Ni substrate,” issued Oct. 19, 1999, to Budai, et al.; U.S. Pat. No. 5,846,912, “Method for preparation of textured YBa2Cu3Ox superconductor,” issued Dec. 8, 1998, to Selvamanickam, et al.; U.S. Pat. No. 6,638,894, “Devices and systems based on novel superconducting material,” issued Oct. 28, 2003, to Batlogg, et al.; U.S. Pat. No. 6,251,530, “Thin-film of a high-temperature superconductor compound and method,” issued Jun. 26, 2001, to Bozovic, et al.; U.S. Pat. No. 4,994,433, “Preparation of thin film superconducting oxides,” issued Feb. 19, 1991, to Chiang; U.S. Pat. No. 6,194,352, “Multifilament composite BSCCO oxide superconductor,” issued Feb. 27, 2001, to Riley, Jr., et al.; U.S. Pat. No. 6,069,116, “Method of forming BSCCO superconducting composite articles,” issued May 30, 2000, to Li, et al.; U.S. Pat. No. 5,661,114, “Process of annealing BSCCO-2223 superconductors,” issued Aug. 26, 1997, to Otto, et al.; U.S. Pat. No. 5,661,114, “Process of annealing BSCCO-2223 superconductors,” issued Aug. 26, 1997, to Otto, et al.; and U.S. Pat. No. 5,635,456, “Processing for Bi/Sr/Ca/Cu/0-2223 superconductors,” issued U.S. Pat. No. 5,635,456, to Riley, Jr., et al.; the entire disclosure of each being incorporated by reference herein. One example of superconducting conductor is the type having an oxide superconductor and a stabilizing metal covering the same, also known as first generation superconducting conductor. Included in the first generation superconducting conductor is a tape-shaped multi-filamentary oxide superconducting wire having such a structure that is a number of filaments consisting essentially of an oxide superconductor contained in a stabilizing material of silver, silver alloys, nickel, and nickel alloys. The oxide superconductor may be prepared from an oxide superconductor such as bismuth, strontium, calcium, and copper oxide. Another example of superconducting conductor is the type having a coating of an oxide superconductor on a metallic tape substrate, the oxide superconductor in turn optionally coated by a stabilizing metal. This construction is also known as second generation superconducting conductor. Preferably, the stabilizing metal and the substrate used in the present invention are individually selected from the group consisting of silver, silver alloys, and nickel and nickel alloys, which may require a buffer layer. Another type of superconducting material usable for making the superconductor conductor is a low temperature superconducting (LTS) material. One LTS material is a niobium-based alloy. Examples of niobium-based alloys include those with one of titanium, tin, aluminum, and combinations thereof. These niobium-based alloys may further include one of tantalum, zirconium, tin, and combinations thereof. One group of LTS niobium-based alloys is a niobium-titanium-based alloy such as those including between about 45 to about 50 weight percent titanium. Another group of LTS niobium-based alloys includes an A15 superconducting phase. Such niobium-based alloys may includes one of tin, aluminum, and combinations thereof. Specific examples of LTS niobium-based alloys include Nb3Sn and Nb3Al. Yet another type of superconducting material usable for making the superconductor conductor is a magnesium boride such as, for example, MgB2. Examples of magnesium boride superconducting material usable may be any such as of those disclosed in any one of U.S. Pat. No. 6,511,943, “Synthesis of magnesium diboride by magnesium vapor infiltration process (MVIP),” issued Jan. 28, 2003, to Serquis, et al.; U.S. Patent Publication No. U.S. 2002/0127437 A1, “MgB2 superconductors,” published on Sep. 12, 2002, for Sang-Wook Cheong; et al.; U.S. Patent Publication No. U.S. 2002/0198111 A1, “Method for manufacturing MgB2 intermetallic superconductor wires,” published on Dec. 26, 2002, for Michael J. Tomsic; and U.S. Patent Publication No. U.S. 2004/0009879 A1, “Method for the production of superconductive wires based on hollow filaments made of MgB2,” published on Jan. 15, 2004, for Giovanni Giunchi, et al., the entire disclosure of each being incorporated by reference herein. The superconductor conductor useable in the present invention may include a substrate that facilitates the creation of a superconductor material having a length that makes practical its use, while at the same time facilitates a braiding of the superconductor about a mandrel 16. For example, the substrate may be a metal substrate, such as one having a thickness of between about 25 and about 127 micrometers. (25.4 micrometers is equal to 1 Mil.) If, for example, the superconductor material is YBCO, then its thickness may be between about 1 to about 5 micrometers. Since the YBCO on its alloy substrate is both stronger and thinner than the BSCCO, it allows for many new winding schemes. One such is braiding the conductors over the surface of the mandrel 16. Superconducting conductors 20, whether in the form of a wire (or individual tapes in the case of a power cable), are said to be decoupled when there is substantially no net magnetic field enclosed between any pair of superconducting conductors 20. This state can be achieved by transposing the superconducting conductors 20 as they are wound on a mandrel 16. Transposition may be achieved when every superconducting conductors 20 is at some proportion of the time in each of the possible magnetic fields. Wilson teaches in Superconducting magnets (published by Clarendon Press, Oxford, 1983) at page 197 that “a simple twisted cable in which the inner wires always remain inside and the outer wires remain outside would behave just like a large twisted composite and would suffer large self-field loss. Full transposition avoids this by ensuring that no net self-field flux is enclosed between the strands.” A purpose of the braided magnetically decoupled superconducting conductors 20 is to reduce AC losses. To that end, the braided magnetically decoupled superconducting conductors 20 include a first number of superconducting conductors in a first direction about the mandrel 16 and substantially the same number of superconducting conductors in a second direction about the mandrel 16. The braided magnetically decoupled superconducting conductors 20 may be formed in a weave pattern of over one, under one. Likewise, the braided magnetically decoupled superconducting conductors 20 may be formed in a weave pattern of over two, under two. That is, any weave pattern that creates a structure from the superconducting conductors 20 that produces a magnetically decoupled arrangement is an appropriate weave pattern. For example, weave pattern may be a biaxial braid forming a braid angle, α, with respect to the axis of braiding (α is an acute angle measured with respect to the longitudinal axis). In a best case, the AC loss can be reduced by a factor of the square root of the number of tapes. In one example, the individual tapes are insulated to prevent them from making incidental electrical contact with each other. Advantageously, the superconducting conductors 20 are braided on the mandrel 16 to create a magnetically decoupled arrangement. The superconducting conductors 20 are braided at a lay angle of up to about 90 degrees, advantageously from about 10 to about 60 degrees, and preferably from about 20 to about 40 degrees. Braids like this are typical on outside of cryogen transfer hoses, where they are wound from many parallel thin wires. Therefore, the technology to create such a braid already exists. Tension on the superconducting conductors during the braiding process, including the resting state of the final construction, are limited so as not to cause a decrease in critical current of the superconducting conductor of greater than 25%. This tension limit is dependant on the type, thickness, and construction of the particular superconducting conductor. According to the present invention, each superconducting conductor 20 is braided on a mandrel 16 having a prescribed diameter at a bending strain or a curvature of a prescribed range and a pitch of a prescribed range. A relatively loose bending is applied to the superconducting conductor 20 along its longitudinal direction. The superconducting conductor 20 that is braided on the mandrel 16 is bent at a bending strain limited so as not to cause a decrease in critical current of the superconducting conductor of greater than about 25%. This bending strain limit is dependant on the type, thickness, and construction of the particular superconducting conductor. YBCO has a much higher current density than BSCCO, which means that fewer tapes are needed to carry the operating current of the cable. Present cable designs rely on full coverage of the surface of the core to create a low loss cable winding. That can result in using extra YBCO tapes to cover the surface that are not necessary to carry the current. This will increase the cost of the cable. The braiding concept does not rely on full surface coverage and can use substantially less tapes in some instances, particularly in bands with greater winding diameters. Returning to FIG. 3, one embodiment of the present invention includes an electrical phase 14 having at least two distinct groups of superconducting conductors 20, 20′. Advantageously, a layer of dielectric 36 (also sometimes called an electrically insulating material 36) separates each of the at least two distinct groups of magnetically decoupled superconducting conductors 20, 20′. In one embodiment of the present invention, the at least two distinct groups of magnetically decoupled superconducting conductors 20, 20′ carry approximately equal amounts of the current flowing through the cable. Also advantageous is where the band of magnetically decoupled superconducting conductors 20 furthest from the mandrel 16 provides shielding of the current flowing through the other bands, creating a coaxial construction. This coaxial construction forces the magnetic field to stay substantially between the inner band of magnetically decoupled superconducting conductors 20 and the outer band of magnetically decoupled superconducting conductors 20′. There is substantially no magnetic field outside the magnetically decoupled superconducting conductors 20′, and therefore, there are no eddy current losses in the outer metallic enclosures or optional fault winding 38′. There is also substantially no magnetic field inside the magnetically decoupled superconducting conductors 20, 20′, and therefore, there are no eddy current losses in the mandrel or optional fault winding 38. Additionally, the coaxial construction forces the magnetic field to be substantially circumferential; thereby the local magnetic field is substantially parallel to the surface of the superconducting conductor 20. In some superconducting conductors, this parallel field orientation has better performance for a given magnitude of magnetic field. With this construction very large amounts of current can be carried depending upon the number and critical current of magnetically decoupled superconducting conductors 20. A fault winding 38 can lie between mandrel 16 and magnetically decoupled superconductors 20. Additionally, a fault winding 38′ can overlie magnetically decoupled superconductors 20′. The optional fault winding 38′ is at the same electrical potential as the magnetically decoupled superconducting conductors 20; and the optional fault winding 38′ is at the same electrical potential as the magnetically decoupled superconducting conductors 20′. The fault winding 38 include a plurality of filaments or tapes of low resistance metals such as copper or copper alloys sized to handle any fault current that might be expected for the given electrical phase. All filaments within a discrete fault winding 38 are electrically connected in parallel. Additionally, an electrostatic shield layer 40 may optionally underlie and overlie dielectric 36. Advantageously, the outermost band of magnetically decoupled superconductors 20 or fault winding 38 might be surrounded by a binder tape. The binder tape serves to hold the windings in a generally concentric position. Binder tape can be any material or combination of material that can meet the physical, mechanical, and thermal requirements. Preferably, it can be the same material as the dielectric 36. In some embodiments, the outermost band of magnetically decoupled superconducting conductors can be maintained at substantively ground potential to serve as an electrical as well as magnetic shield for the electrical phase 14. The present invention includes both shielded and unshielded electrical phases 14. In an embodiment, the dielectric 36 (also sometimes called an electrically insulating material 36) remains at the cryogenic temperature, and any material that can withstand the cryogenic temperature without any physical and mechanical degradation would be suitable. The polymeric dielectric material of one aspect of the present invention has good physical and mechanical properties at liquid nitrogen and lower temperatures. It has high dielectric strength and high breakdown voltage. Also, it is desirable that the electrical insulating material 36 be cryogenically compatible material. The at least one dielectric 36 (also sometimes called an electrically insulating material 36) may be capable of withstanding typical rated Basic Impulse Insulation Level (BIL) voltage levels for a given operating voltage, as are known in the art. The dielectric 36 (also sometimes called an electrically insulating material 36) may be any one of a polypropylene, Kraft paper, polypropylene laminated paper (typically called PPLP), polyimide, polyamide, polyethylene, cross-linked polyethylene (typically called XLPE) or EPR; or any material or combination of material that can meet the physical, mechanical, electrical and thermal requirements. The dielectric may be extruded or wound out of a plurality of tapes, extruded directly, or any method known in the art. Advantageously, an electrostatic shield layer 40 underlies and overlies the dielectric 36. The electrostatic shield layer serves to smooth out the electric field profile of the metallic elements of the cable (such as a layer of magnetically decoupled superconducting conductors 20). Concerning an appropriate material for at least one electrostatic shield layer 40, it is any that is capable of shaping an electrical field, whether used alone or in combination with other materials. To that end, the at least one electrostatic shield layer 40 may be any one of a conducting material, a semiconducting material, and combinations thereof. The plurality of electrostatic shields is a number that provides a structure appropriate for shaping an electrical field. Such number appears to be about two per layer of dielectric 36. The following is a comparison of the calculated losses for an about 34.5 kV cable in the configuration of the preferred embodiment, with about 4 mm-wide, about 2-micron thick YBCO on an about 2 mil substrate, with critical current density on the order of 1.5×1010 A/m2. Braiding reduces losses more dramatically for higher operating currents, as shown in Table 1. The comparison assumes a standard cable of a filamentary mandrel style design where the mandrel consists of copper to carry the fault current. Greater levels of the fault current correspond to larger mandrel diameters. The diameters shown are three-phase cable outer diameters, in inches. These numbers are given for approximate reference, since the real limitation on diameter is the voltage insulation, which is not covered here. The loss reduction is relatively constant for all typical fault current levels, and therefore for a large range of mandrel diameters. Losses in the superconductors in the braided construction are effectively constant for all voltages. TABLE 1 Ratio of standard losses to braided losses vs fault current kA Fault current Cable OD Operating current (Arms) (kA) in (cm) 500 800 1000 1250 1500 1750 2000 10 2.2 (5.6) 1.8 2.9 3.2 3.1 3.3 3.2 3.4 20 2.2 (5.6) 1.4 2.1 2.6 3.1 3.3 3.2 3.4 30 2.4 (6.1) 1.1 1.7 2.1 2.7 3.2 3.2 3.4 40 2.6 (6.6) 1.0 1.6 1.9 2.4 2.8 3.2 3.4 50 2.7 (6.8) 0.9 1.4 1.7 2.1 2.5 3.0 3.4 While typical embodiments have been set forth for the purpose of illustration, the foregoing description should not be deemed to be a limitation on the scope of the invention. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention. By way of example, A plurality of cryostats 12, each with preferably one electrical phase 14, can be grouped together to form a cable 8. The electrical phase 14 contains at least one band of braided magnetically decoupled superconductors 20. The dielectric 36 (also sometimes called an electrically insulating material 36) can be external to the cryostat 12 in this construction. Typically this construction does not have a band of superconductors 20′ acting as a shield. This embodiment may also contain one or more of the following: a fault winding 38, an electrostatic shield layer 40, thermal insulation 32, a protective jacket 34 and a cryogen path 46, and is typically called warm dielectric superconducting cable. Alternatively, FIG. 4 illustrates another embodiment of the present invention includes at least three, preferably four, distinct bands of braided magnetically decoupled superconducting conductors 20, 20′, 20″, 20′″ wound concentrically on one mandrel 16 (typically called a tri-axial construction). Advantageously, a layer of dielectric 36 (also sometimes called an electrically insulating material 36) separates each of the distinct bands of superconducting conductors 20. Each band of magnetically decoupled superconducting conductors 20 may be a separate electrical phase or shield. This embodiment may also contain one or more of the following: a fault winding 38, 38′, 38″, and 38′″, an electrostatic shield layer 40, a cryostat 12, thermal insulation 32, a protective jacket 34 and a cryogen path 46. Alternatively, a plurality of tri-axial constructions may be contained within one cryostat 12. This embodiment may also contain one or more of the following: a fault winding 38, an electrostatic shield layer 40, a cryostat 12, thermal insulation 32, a protective jacket 34 and a cryogen path 46. | <SOH> BACKGROUND <EOH>In the past three decades, electricity has risen from 25% to 40% of end-use energy consumption in the United States. With this rising demand for power comes an increasingly critical requirement for highly reliable, high quality power. As power demands continue to grow, older urban electric power systems in particular are being pushed to the limit of performance, requiring new solutions. Metal conductors, such as copper and aluminum, form a foundation of the world's electric power system, including generators, transmission and distribution systems, transformers, and motors. The discovery of high-temperature superconducting (HTS) compounds has led to an effort to develop conductors incorporating these compounds for the power industry to replace metal conductors. HTS conductors are one of the most fundamental advances in electric power system technology in more than a century. HTS conductors carry over one hundred times more current than do conventional metal conductors of the same physical dimension. The superior power density of HTS conductors will enable a new generation of power industry technologies. HTS conductors offer major size, weight, efficiency, and environmental benefits. HTS technologies will drive down costs and increase the capacity and reliability of electric power systems in a variety of ways. For example, an electrical cable consisting of HTS conductors is capable of transmitting two to five times more power through existing rights of way, thus improving the performance of power grids while reducing their environmental footprint. One way to characterize HTS conductors is by their cost per meter. An alternative way to characterize HTS conductors is by cost per kiloamp-meter. For example, by increasing the current carrying capacity for a given cost per meter of HTS conductor, the cost per kiloamp-meter is reduced. The maximum current carrying capacity is called the critical current. Among the several issues that need to be resolved for HTS conductors to be used effectively in power transmission is AC losses. The typical approaches to reducing the AC losses in a cable incorporating HTS conductors has relied on creating nearly monolithic annuli of HTS conductors. For example, the surface of a structure supporting the HTS conductors to create the annuli is nearly completely covered with HTS conductors. However, as the HTS conductors improve in current carrying capacity, there is often more conductor used to cover the surface than is necessary to carry the current. However, often in these types of designs, reducing the amount of HTS conductors only increases AC losses. Thus, there remains a need for a new and improved cable winding configuration that is capable of use in a system for transmitting current by taking advantage of improvements being made in superconductor conductors, while at the same time including acceptable and even improved properties with regard to AC losses. | <SOH> SUMMARY <EOH>The present invention is directed to a system for transmitting current. The system includes a generator, a superconducting cable, and at least one load. Further, the system may include one of terminations, a refrigeration system, and terminations and a refrigeration system. The cable has at least one electrical phase including a mandrel and at least one band of magnetically decoupled superconducting conductors. The mandrel may be a flexible material. For example, single-filament or multiple-filament (e.g., plurality of filaments) alloys, such as one of an aluminum alloy and a copper alloy, may be used as a mandrel. No matter the construction or the material, it is advantageous that the mandrel be cryogenically compatible. A purpose of the magnetically decoupled superconducting conductors is to reduce AC losses. In addition to the at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors, the cable may also include one or more of thermal insulation, a protective jacket, electrically insulating material (dielectric), an electrostatic shield, a fault winding, and a cryogen path. Certainly, the cable includes at least one electrical phase and may include a plurality of electrical phases. The plurality may be three, and at least two of the plurality of electrical phases include a mandrel and braided magnetically decoupled superconducting conductors. Accordingly, one aspect of the present invention is to provide a system for transmitting current. The system includes at least one generator, at least one cryostat, and at least one load. The at least one generator generates at least one phase of electrical power. The at least one cryostat has at least one electrical phase including at least one mandrel and magnetically decoupled superconducting conductors. The generator and load can be assumed to represent equivalent simplifications of the electrical grid, and can be electrically interchanged. Another aspect of the present invention is to provide a superconducting cable useable in a system for transmitting current, such as the one mentioned above. The cable has at least one cryostat containing at least one electrical phase that includes a mandrel and braided magnetically decoupled superconducting conductors. Still another aspect of the present invention is to provide a system for transmitting current. The system includes at least one generator, at least one superconducting cable, at least one load, and one of terminations, at least one refrigeration system, and terminations and at least one refrigeration system. The at least one generator generates at least one phase of electrical power. The at least one cable has at least one cryostat containing at least one electrical phase including at least one mandrel and braided magnetically decoupled superconducting conductors. These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings. | 20040427 | 20091027 | 20051027 | 57745.0 | 0 | NORRIS, JEREMY C | SYSTEM FOR TRANSMITTING CURRENT INCLUDING MAGNETICALLY DECOUPLED SUPERCONDUCTING CONDUCTORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,009 | ACCEPTED | Dispenser of icemaker in referigerator | Disclosed is a dispenser of an icemaker in a refrigerator for maximizing an inner space when a total size is the same, and for minimizing the total size when the inner space is the same. The dispenser of the icemaker in the refrigerator includes an ice chute being a passage through which the ice produced from the icemaker is discharged; and a container supporter provided at an outer case and disposed to be perpendicular to an outer surface of the outer case when the ice is discharged outside through the ice chute, the contain supporter allowing a container seated thereon to receive the ice discharged from the ice chute. The ice chute is closed and not exposed outside when the ice-discharging process is finished, and the container supporter is not exposed to the outer surface of the outer case. | 1. A dispenser of an icemaker in a refrigerator, comprising: an ice chute provided as a passage through which ice produced from a icemaker is discharged; and a container supporter provided at an outer case, and disposed to be perpendicular to an outer surface of the outer case when the ice is discharged outside through the ice chute, the container supporter allowing a container seated thereon to receive the ice discharged from the ice chute. 2. The dispenser of the icemaker in the refrigerator of claim 1, wherein the ice chute is closed not to be exposed outside when the ice is not discharged. 3. The dispenser of the icemaker in the refrigerator of claim 2, wherein the ice chute comprises: a first chute having an inlet provided on an inner wall of a front surface of the outer case and a passage extended downward in a wall direction of the outer case; and a sliding member having a second chute diagonally extended, the sliding member moving forward to be perpendicular to the front surface of the outer case for communicating the second chute with the first chute when the ice is discharged, and being inserted into the outer case when the ice is not discharged. 4. The dispenser of the icemaker in the refrigerator of claim 3, wherein the sliding member further comprises: a rack provided on a bottom surface thereof; and a pinion provided at a lower part of the rack and mated with the rack. 5. The dispenser of the icemaker in the refrigerator of claim 3, further comprising a cover having a first end coupled with a lower end of a front surface of the sliding member and a second end extended upward and fixed on the front surface of the outer case. 6. The dispenser of the icemaker in the refrigerator of claim 2, wherein the ice chute comprises: an ice-discharging pipe having an inlet provided on an inner surface of the outer case and an outlet provided on an outer surface of the outer case; and a cover provided at the outer case for opening and closing the outlet of the ice-discharging pipe. 7. The dispenser of the icemaker in the refrigerator of claim 6, wherein the cover is rotatably provided around a top end being coupled with the front surface of the outer case. 8. The dispenser of the icemaker in the refrigerator of claim 7, wherein the cover comprises a subsidiary pipe provided on a portion being in contact with the outlet portion of the ice-discharging pipe to be inserted into an inside of a passage on the outlet side of the ice discharging pipe. 9. The dispenser of the icemaker in the refrigerator of claim 8, wherein the subsidiary pipe comprises an ice passing hole at a lower part thereof for discharging the ice when the cover is rotated upward. 10. The dispenser of the icemaker in the refrigerator of claim 6, wherein the container supporter is provided under the cover and has an end being rotatably coupled with the front surface of the outer case. 11. The dispenser of the icemaker in the refrigerator of claim 10, wherein the container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. 12. The dispenser of the icemaker in the refrigerator of claim 10, wherein the container supporter rotates upward and covers the cover. 13. The dispenser of the icemaker in the refrigerator of claim 10, further comprising a link member for coupling the container supporter with the cover. 14. The dispenser of the icemaker in the refrigerator of claim 10, wherein an surface of the container supporter is adhered to be parallel to the outer surface of the outer case not to be projected from the outer surface of the outer case when the ice is not discharged. 15. The dispenser of the icemaker in the refrigerator of claim 1, wherein the container supporter is inserted into a wall of the outer case when the ice is not discharged through the ice chute. 16. The dispenser of the icemaker in the refrigerator of claim 15, wherein the container supporter comprises: a rack provided at a bottom surface thereof; and a pinion provided under the rack and mated with the rack. 17. The dispenser of the icemaker in the refrigerator of claim 1, wherein the container supporter is provided under the ice chute and has an end rotatably coupled with the front surface of the outer case. 18. The dispenser of the icemaker in the refrigerator of claim 17, wherein the container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. 19. The dispenser of the icemaker in the refrigerator of claim 18, wherein the container supporter closes the ice chute when the ice is not discharged. 20. The dispenser of the icemaker in the refrigerator of claim 17, wherein the container supporter comprises: a rotating axis horizontally provided at an end of the outer wall of the outer case; a driven gear provided at the rotating axis; and a driving gear mated with the driven gear. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Korean Application No. P2003-64503, filed on Sep. 17, 2003, which is hereby incorporated by reference as if fully set forth herein. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispenser of an icemaker in a refrigerator, and more particularly, to the dispenser of the ice-making apparatus with a structure for maximizing an inner space of the refrigerator. 2. Discussion of the Related Art In general, a refrigerator is divided into a cooling chamber and a freezer. The cooling chamber keeps a temperature at about 3° C.-4° C. for keeping food and vegetables fresh for a long time. The freezer keeps a temperature at a sub-zero temperature for keeping and storing meat and fish frozen for a long time and for making and storing ice. The recent refrigerator is developed for performing various additional functions besides a typical function thereof. The icemaker is one of the additional functions. FIG. 1 illustrates a schematic diagram showing a conventional refrigerator. FIG. 2 illustrates a schematic diagram showing an interior of the refrigerator including a conventional ice-making apparatus. FIG. 3 illustrates a schematic diagram showing an icemaker of a conventional ice-making apparatus. FIG. 4 illustrates a diagram showing a process of discharging the ice from an icemaker. FIG. 5 illustrates an ice bank of an ice-making apparatus in the conventional refrigerator. Referring to FIG. 1 to FIG. 5, an icemaker 10 is fixed at an upper part of the freezer in the refrigerator. The icemaker 10 is a device for freezing water and automatically discharging ice. A structure of a conventional icemaker 10 includes an ice-making chamber 11, a water supplier 12 provided at a side of the ice-making chamber 11 for supplying water to the ice-making chamber 11, a controller 13 provided on outside of the ice-making chamber 11 and having a motor (not shown), and an ejector for discharging the ice produced from the ice-making chamber 11. At a rear side of the ice-making chamber 10, a coupler 15 is provided for coupling the icemaker 10 with the freezer of the refrigerator. The ice-making chamber 11 is formed in a semi-cylindrical form and having a projection 11a therein for dividing the inner space such that the ice is produced in a predetermined size. The ejector 14 includes an axis formed to cross a center of the ice-making chamber 11 and a plurality of ejector fins 14a formed at a side of the axis of the ejector 14. The plurality of ejector fins 14a is a means of discharging the produced ice to the ice bank 20. A sliding bar 16 is provided at a side of the plurality of ejector fins 14a for sliding the produced ice down. In more detail, the ice moved by the plurality of ejector fins 14a are placed on the sliding bar 16, then slid down along the sliding bar 16, and moved into an inside of an ice bank 20 formed at a lower part of the icemaker. FIG. 4 illustrates a process of discharging ice from the icemaker 10 to the ice bank 20. A heater 17 is provided at a lower part of the ice-making chamber 11. The ice needs to be separated from a surface of the ice-making chamber for being moved. The heater 17 heats a lower surface of the ice-making chamber 11 and increases a temperature thereof for melting a surface of the ice so as to move the ice. At a door 1 of the cooling chamber of the refrigerator, the ice bank 20 and a dispenser 30 are provided except the icemaker 10. The ice bank 20 is an apparatus for storing the ice produced from the icemaker 10 and discharging the ice when a user wants the ice to use. Referring to FIG. 5, the ice bank 20 includes an ice remover 21, a motor 20 for rotating the ice remover, an ice crusher 23, and an ice discharger 24. The ice remover 21 formed in a spiral form removes the ice supplied from the icemaker 10 to the ice crusher 23 when the motor 22 rotates. The ice passed through the crusher 23 is discharged to the dispenser 30 through the ice discharger 24. The dispenser 30 includes a discharging passage 31 and a container supporter 35 provided at a lower part of the discharging passage. The discharging passage 31 includes an inlet provided on an inner wall of the door 1, an outlet provided on an outer wall of the door 1, and a pipe for communicating the inlet with the outlet. In this case, the inlet of the discharging passage is provided at a higher place than the outlet. The container supporter 35 is provided at a lower part of the discharging passage. In more detail, a vertical plane provided on the outer wall of the door at a lower part of the outlet of the discharging passage 31 includes a groove formed in a quadrilateral form. A process of discharging the ice from the ice-making apparatus structured as aforementioned will be described as follows. First, the icemaker being supplied with water through a water supply pipe produces the ice, and removes the ice to the ice bank provided at a lower part of the icemaker by using the ejector. The ice bank storing the ice discharges the ice outside through the ice-discharging passage when the user wants to use the ice. The ice discharged outside is entered into a container and provided to the user, the container securely provided on the container supporter including the groove formed on the outer wall of the door. However, the dispenser of the icemaker has following problems. First, the container supporter of the dispenser includes the groove with a predetermined depth on the outer wall of the door of the refrigerator. Accordingly, the door needs to be thicker than a predetermined thickness. The thick door takes up much of an inner space of the refrigerator. Therefore, a total size of the refrigerator is increased when the inner space of the refrigerator is made to be larger than a predetermined size. Second, an outlet side of the discharging passage of the dispenser is exposed outside and dirt is collected thereon resulting in a problem of polluting the ice discharged outside by the dirt. SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a dispenser of an icemaker in a refrigerator that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for maximizing an inner space of the apparatus. Another object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for minimizing a total size of the dispenser. A further object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for completely isolating an inside of an outer case from an outside thereof. Additional advantages, objects, and features of the invention will be set forth in part in the description Which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a dispenser of an icemaker of the present invention includes an ice chute provided as a passage through which the ice produced from the icemaker provided inside of an outer case is discharged, and a container supporter provided at the outer case and disposed to be perpendicular to an outer surface of the outer case when the ice is discharged outside through the ice chute, the container supporter allowing a container seated thereon to receive the ice discharged from the ice chute. The ice chute is closed and not exposed outside when the ice is not discharged. The ice chute includes a first chute having an inlet provided on an inner wall of a front surface of the outer case and a passage extended downward in a wall direction of the outer case, and a sliding member having a second chute diagonally extended, the sliding member moving forward to be perpendicular to the front surface of the outer case for communicating the second chute with the first chute when the ice is discharged, and being inserted into the outer case when the ice is not discharged. The sliding member further includes a rack provided at a bottom surface thereof; and a pinion provided at a bottom of the rack and mated with the rack. The dispenser of the icemaker further includes a cover having a first end coupled with a lower end of a front surface of the sliding member, and a second end extended upward and fixed on the front surface of the outer case. Meanwhile, the ice chute includes an ice-discharging pipe having an inlet provided on an inner surface of the outer case and an outlet provided on an outer surface of the outer case, and a cover provided at the outer case for opening and closing the outlet of the ice-discharging pipe. In this case, the cover is rotatably provided around a top end being coupled with the front surface of the outer case. The cover also includes a subsidiary pipe provided on a portion being in contact with the outlet portion of the ice-discharging pipe to be inserted into an inside of a passage on the outlet side of the ice discharging pipe. The subsidiary pipe comprises an ice-passing hole at a lower part thereof for discharging the ice when the cover is rotated upward. The container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. The container supporter rotates upward and covers the cover. The dispenser of the icemaker further includes a link member for coupling the container supporter with the cover. The container supporter is inserted into a wall of the outer case when the ice is not discharged through the ice chute. The container supporter includes a rack provided at a bottom surface thereof, and a pinion provided under the rack and mated with the rack. Contrary to the structure mentioned above, the container supporter may be provided under the ice chute and have an end being rotatably coupled with the front surface of the outer case. The container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. The container supporter closes the ice chute when the ice is not discharged. The container supporter includes a rotating axis horizontally provided at an end of the outer wall of the outer case, a driven gear provided at the rotating axis, and a driving gear mated with the driven gear. Owing to the dispenser of the icemaker with aforementioned structure, an inner space of the ice-discharging apparatus such as a refrigerator is maximized or a total size of the apparatus is minimized. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings; FIG. 1 illustrates a schematic diagram showing a conventional refrigerator. FIG. 2 illustrates a schematic diagram showing an interior of the refrigerator including a conventional ice-making apparatus. FIG. 3 illustrates a schematic diagram showing an icemaker of a conventional ice-making apparatus. FIG. 4 illustrates a diagram showing a process of discharging ice from an icemaker. FIG. 5 illustrates an ice bank of an ice-making apparatus in the conventional refrigerator. FIG. 6 illustrates a diagram showing a refrigerator with a dispenser of an ice-making apparatus in accordance with a first embodiment of the present invention. FIG. 7 illustrates a magnified view of a dispenser of an ice-making apparatus in accordance with a first embodiment of the present invention. FIG. 8 illustrates a diagram showing a dispenser of an ice-making apparatus in a state of discharging ice accordance with a first embodiment of the present invention. FIG. 9 illustrates a diagram showing a dispenser of an ice-making apparatus in accordance with a second embodiment of the present invention. FIG. 10 illustrates a diagram showing a dispenser of an ice-making apparatus in a state of discharging ice accordance with a second embodiment of the present invention. FIG. 11 illustrates a diagram showing a dispenser of an ice-making apparatus in a state of discharging ice accordance with a third embodiment of the present invention. FIG. 12 illustrates a diagram showing a dispenser of an ice-making apparatus in accordance with a fourth embodiment of the present invention. FIG. 13 illustrates a diagram showing a dispenser of an ice-making apparatus in a state of discharging ice accordance with a fourth embodiment of the present invention. FIGS. 14A and 14B illustrate a diagram showing a coupling material in accordance with a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In general, an icemaker is an apparatus for freezing supplied water in a predetermined size and discharging outside for supplying ice to a user when the user wants to use the ice. The icemaker provides crushed ice or uncrushed ice to the user in accordance with a choice of the user. In general, a refrigerator is provided with the icemaker, however, may be provided with a drinking apparatus such as a purifier. Hereinafter, a preferred embodiment of the dispenser discharging and supplying the ice to the user outside will be described referring to FIG. 6 and FIG. 15 in accordance with the icemaker with such function mentioned above. Referring to FIG. 6 to FIG. 7, a first embodiment of the dispenser of the icemaker in accordance with the present invention includes an ice chute 300 provided at a door and forming a front surface of an outer case of the refrigerator, and a container supporter 400 provided at a lower part of the ice chute 300. The ice chute 300 is a passage through which the ice produced from the icemaker is discharged. It is desirable that the passage is closed for preventing the ice from being exposed outside when the ice is not discharged. In other words, the ice chute 300 includes an inlet through which the ice is inserted from a side of the icemaker, and an outlet through which the ice is discharged. When the ice is not discharged, it is desirable that the outlet is closed for preventing dirt from being collected thereon. Ice chute 300 includes a first chute 310 having an inlet 311 provided on an inner wall of the door and a passage extended bottomward in a direction of an outer wall of the door, and a sliding member 320 with a second chute 321 communicating with the first chute 310 when the ice is discharged and having an outlet 321a exposed outside. In more detail, the sliding member 320 moves toward the front of the door and projects to be perpendicular to the front surface of the door. In this instance, the second chute 321 is communicated with the first chute 310. When the ice is not discharged from the ice chute, the sliding member 320 is inserted into a groove formed on the outer surface of the door 1. In this case, it is desirable that the sliding member 320 is not projected toward outside of the door surface and the sliding member includes a guide rail for a smooth movement. The sliding member 320 also includes a handle on a front surface thereof for being manually inserted or ejected. The dispenser also includes a spring or an oil pressure means (not illustrated) provided between a rear surface of the sliding member 320 and the groove for pressing a rear surface of the container supporter. The dispenser includes a binding for biding the sliding member. When the binding is released, the sliding member is ejected to a front of the door. If a front surface of the sliding member is pressed, the sliding member is inserted into the groove and locked by the biding. Contrary to the above statement, the sliding member 320 can be automatically inserted and ejected. For this, the sliding member includes a rack 322 provided at a lower surface thereof, and a pinion 323 provided at a lower part of the rack 322. A motor (not illustrated) driven by a controller rotates the pinion 323. In other words, when the user wants to use the ice and presses an ejection button provided at the controller (not illustrated), the motor rotates the pinion 323 and the rack 322 to, and projects the sliding member 320 by moving the sliding member 320 toward the front. The first chute 310 and the second chute 321 are communicated to discharge the ice. When the process for discharging the ice is finished, the motor is inversely rotated to insert the sliding member 320 into the groove so as to close the ice chute 300. The dispenser of icemaker with a structure mentioned above, further includes a cover 325 having a first end coupled with a front lower end of the sliding member and a second end fixed on the front surface of the door 1. The cover 325 covers an external appearance of the ice chute 300 as well as prevents dirt from being collected on a top surface of the sliding member. Is it desirable that a pipe for supplying drinking water is provided between the cover 325 and the door 1 so as to supply water in the container provided at the container supporter 400 when the user wants water or water with the ice. At the container supporter 400, a container for receiving the discharged ice is provided at a lower part of the ice chute. The container supporter 400 is provided at the door 1 forming the front surface of the outer case, projected vertically above the front surface of the door 1 when the ice is discharged to outside through the ice chute 300. Contrary to this, when the ice is not discharged, the container supporter is inserted into the groove 401 formed on the door. In this case, it is desirable that the container supporter is not projected to outside of the door and having a guide rail provided at the groove for smoothly moving. In this case, the container supporter 400 includes a handle (not illustrated) on the front surface thereof so as to be inserted and ejected manually. The dispenser also includes a spring or an oil pressure means (not illustrated) provided between a rear surface of the sliding member 320 and the groove for pressing the rear surface of the container supporter, and a binding for biding the sliding member. When the binding is released, the sliding member is ejected on the front of the door. If a front surface of the sliding member is pressed, the sliding member is inserted into the groove and locked by the biding. Contrary to this, the container supporter can be automatically inserted or ejected. For this, the container supporter, as the sliding member, includes the rack provided at the lower surface thereof, and the pinion provided at the lower part of the rack, the pinion rotatably provided For this, the sliding member includes a rack 322 provided on a lower surface thereof, and a pinion provided at a lower part of the rack and mated with the rack so as to rotate together by a motor (not illustrated) driven by a controller. In other words, when the user wants the ice and presses the ejection button, the motor rotates the pinion and the rack, and the container supporter is moved to the front and projected on the front of the door. When the ice discharging process is finished, the motor is inversely rotated to insert the sliding member 320 into the groove. In the dispenser of the icemaker with the structure mentioned above, it is desirable that the container supporter 410 is ejected earlier than the sliding member 320. In other words, it is desirable that the ice is discharged after the container supporter is ejected, the container is provided on top of the container supporter, and the sliding member is ejected. A second embodiment of the dispenser of the icemaker in accordance with the present invention will be described in reference to FIG. 9 to FIG. 10. Referring to FIG. 9, the dispenser of the icemaker includes an ice-discharging pipe, the pipe having an inlet 351 formed on an inner surface of the door 1 of the refrigerator and an outlet 352 formed on an outer surface of the door, a cover 360 provided on the outer surface of the door for opening and closing the outlet 352, and a container supporter 450 having the container securely provided thereon for receiving the ice discharged outside through the ice-discharging pipe. The inlet 351 is provided at an upper part of the outlet 352 for discharging the ice inserted from the icemaker by gravity. The cover 360 having a top end coupled with the door 1 of the refrigerator is rotatably provided around the top end 361. The cover 360 also includes a subsidiary pipe 362 provided on the inner surface of the cover in contact with the outlet of the ice-discharging pipe so as to insert the ice into the inside of passage on a side of the outlet 352 of the ice-discharging pipe. The subsidiary pipe 362 includes an ice-passing hole 363 provided at a lower part thereof in order to discharge the ice when the top cover is rotated upward. In other words, when the cover 360 is rotated, the ice-passing hole 363 of the subsidiary pipe 362 is exposed to the outside of the ice-discharging pipe 350 and the ice is discharged. In this instance, an end 364 of the subsidiary pipe is not exposed to the outside of the ice-discharging pipe. Although the user can manually opens and closes the cover 360, the outlet of the ice-discharging pipe is automatically opened and closed in accordance with the second embodiment. Meanwhile, the container supporter 450 is provided at the lower part of the cover and has an end rotatably coupled with the front surface of the refrigerator. When the ice is discharged, the container supporter 450 is rotated downward around the lower end 451 to be projected vertically on the front surface of the door 1. When the ice is not discharged, the container supporter is rotated upward around the lower end 451 to be in contact with the front surface of the door. Although not illustrated, in the present embodiment, the container supporter and the cover are formed in a semicircular form for an external appearance. It is desirable that grooves formed in same forms as the cover and the container supporter are provided on the outer wall of the door such that the container supporter and the cover are not projected on the front surface of the door when the ice is not discharged. In the mean time, when the ice is not discharged, it is not the cover but the container supporter directly opening and closing the ice chute. The container supporter 450 automatically rotates and includes a rotating axis provided horizontally at an end coupled with the outer wall of the outer case, a driven gear provided at the rotating axis, and a driving gear coupled with the driven gear. The structure will be described again in describing a fourth embodiment of the present invention. The motor operated by the controller (not illustrated) rotates the driving gear. The rotating method is applicable to a rotation of the cover 360. Contrary to the above statement, a portion 1a located at an inside of the cover on the outer wall of the door and the cover 360 are formed as a single body, and the top portion of the subsidiary pipe 362 includes the portion 1a on the outer wall of the door, the portion 1a integrated with the cover 360. The dispenser of the icemaker with the structure mentioned above is a third embodiment illustrated in FIG. 11. In accordance with the third embodiment of the present invention, the other components except the structure of the third embodiment is the same as the second embodiment and it will be omitted. Meanwhile, the container supporter 460 covers the cover 360 as illustrated in FIG. 12 to FIG. 14. The structure mentioned above is a fourth embodiment. In accordance with the present invention, all other compositions except the components explained below are the same as the second and the third embodiments. In accordance with the present invention, as illustrated in FIG. 14, the dispenser of the icemaker includes a link member 500 coupling the container supporter 460 and the cover 360. The link member 500 has a first end coupled with the lower side of the cover 360 and a second end coupled with a side of the container supporter 460. For this, the link member includes a top coupler 501 rotatably coupled with the lower side of the cover, and a bottom coupler 502 having a first end rotatably coupled with a second end of the top coupler and a second end rotatably coupled with the lower side of the container supporter. Contrary to the above statement, the link member 500 may include a soft string 503. The link member 500 becomes parallel to the cover for supporting weight of the container supporter having the container when the container supporter is rotated downward to be perpendicular to the outer wall of the outer case for discharging the ice. The container supporter 460 is automatically rotated. For this, the container supporter 460 includes a rotating axis 461 provided horizontally at an end coupled with the outer wall of the outer case, a driven gear 462 provided at the rotating axis, and a driving gear 463 mated with the driven gear for driving the driven gear. The dispenser of the icemaker with the structure mentioned above is operated as follows. First, when the user wants the ice and presses the ejection button of the controller, the container supporters (400, 450, 460) are provided to be perpendicular to the front surface of the door of the refrigerator. For this, the container supporter 400 in the first embodiment of the present invention is withdrawn to the front surface of the door by the rotation of the pinion and the container supporters 450 and 460 in the second and fourth embodiments are rotated downward by the driving gear to be perpendicular to the front surface of the door. Next, when the ice chute 300 and 350 are opened, the ice is discharged outside and received into the container provided on top of the container supporter. Then, the user takes the ice to put in a beverage or in food. The opening process of the ice chute is described above and a detailed description will be omitted. When the ice is discharged as much as the user needs, the container supporter is inserted into the inside of the groove provided at the door or is rotated upward by the driving gear, and adhered to the front surface of the door to be horizontal thereto in accordance with the present embodiment. Then, the container supporter or the cover closes the outlet of the ice chute. Effects of the present invention with above mentioned structure is summarized as follows. First, a space taken by the container supporter or the ice chute is minimized and an inner space of the refrigerator or an apparatus with an ice-discharging function is maximized in accordance with the present invention. Second, the space taken by the container supporter of the ice chute is minimized and the total size of the refrigerator or the apparatus with an ice-discharging function is minimized in accordance with the present invention. Third, the outlet of the ice chute provided on the ice discharging passage is completely closed when the ice is not discharged in order to prevent the dirt from being collected on the passage in accordance with the present invention. Fourth, the external appearance is improved because the ice chute and the container supporter are not projected outside or caved-in in accordance with the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a dispenser of an icemaker in a refrigerator, and more particularly, to the dispenser of the ice-making apparatus with a structure for maximizing an inner space of the refrigerator. 2. Discussion of the Related Art In general, a refrigerator is divided into a cooling chamber and a freezer. The cooling chamber keeps a temperature at about 3° C.-4° C. for keeping food and vegetables fresh for a long time. The freezer keeps a temperature at a sub-zero temperature for keeping and storing meat and fish frozen for a long time and for making and storing ice. The recent refrigerator is developed for performing various additional functions besides a typical function thereof. The icemaker is one of the additional functions. FIG. 1 illustrates a schematic diagram showing a conventional refrigerator. FIG. 2 illustrates a schematic diagram showing an interior of the refrigerator including a conventional ice-making apparatus. FIG. 3 illustrates a schematic diagram showing an icemaker of a conventional ice-making apparatus. FIG. 4 illustrates a diagram showing a process of discharging the ice from an icemaker. FIG. 5 illustrates an ice bank of an ice-making apparatus in the conventional refrigerator. Referring to FIG. 1 to FIG. 5 , an icemaker 10 is fixed at an upper part of the freezer in the refrigerator. The icemaker 10 is a device for freezing water and automatically discharging ice. A structure of a conventional icemaker 10 includes an ice-making chamber 11 , a water supplier 12 provided at a side of the ice-making chamber 11 for supplying water to the ice-making chamber 11 , a controller 13 provided on outside of the ice-making chamber 11 and having a motor (not shown), and an ejector for discharging the ice produced from the ice-making chamber 11 . At a rear side of the ice-making chamber 10 , a coupler 15 is provided for coupling the icemaker 10 with the freezer of the refrigerator. The ice-making chamber 11 is formed in a semi-cylindrical form and having a projection 11 a therein for dividing the inner space such that the ice is produced in a predetermined size. The ejector 14 includes an axis formed to cross a center of the ice-making chamber 11 and a plurality of ejector fins 14 a formed at a side of the axis of the ejector 14 . The plurality of ejector fins 14 a is a means of discharging the produced ice to the ice bank 20 . A sliding bar 16 is provided at a side of the plurality of ejector fins 14 a for sliding the produced ice down. In more detail, the ice moved by the plurality of ejector fins 14 a are placed on the sliding bar 16 , then slid down along the sliding bar 16 , and moved into an inside of an ice bank 20 formed at a lower part of the icemaker. FIG. 4 illustrates a process of discharging ice from the icemaker 10 to the ice bank 20 . A heater 17 is provided at a lower part of the ice-making chamber 11 . The ice needs to be separated from a surface of the ice-making chamber for being moved. The heater 17 heats a lower surface of the ice-making chamber 11 and increases a temperature thereof for melting a surface of the ice so as to move the ice. At a door 1 of the cooling chamber of the refrigerator, the ice bank 20 and a dispenser 30 are provided except the icemaker 10 . The ice bank 20 is an apparatus for storing the ice produced from the icemaker 10 and discharging the ice when a user wants the ice to use. Referring to FIG. 5 , the ice bank 20 includes an ice remover 21 , a motor 20 for rotating the ice remover, an ice crusher 23 , and an ice discharger 24 . The ice remover 21 formed in a spiral form removes the ice supplied from the icemaker 10 to the ice crusher 23 when the motor 22 rotates. The ice passed through the crusher 23 is discharged to the dispenser 30 through the ice discharger 24 . The dispenser 30 includes a discharging passage 31 and a container supporter 35 provided at a lower part of the discharging passage. The discharging passage 31 includes an inlet provided on an inner wall of the door 1 , an outlet provided on an outer wall of the door 1 , and a pipe for communicating the inlet with the outlet. In this case, the inlet of the discharging passage is provided at a higher place than the outlet. The container supporter 35 is provided at a lower part of the discharging passage. In more detail, a vertical plane provided on the outer wall of the door at a lower part of the outlet of the discharging passage 31 includes a groove formed in a quadrilateral form. A process of discharging the ice from the ice-making apparatus structured as aforementioned will be described as follows. First, the icemaker being supplied with water through a water supply pipe produces the ice, and removes the ice to the ice bank provided at a lower part of the icemaker by using the ejector. The ice bank storing the ice discharges the ice outside through the ice-discharging passage when the user wants to use the ice. The ice discharged outside is entered into a container and provided to the user, the container securely provided on the container supporter including the groove formed on the outer wall of the door. However, the dispenser of the icemaker has following problems. First, the container supporter of the dispenser includes the groove with a predetermined depth on the outer wall of the door of the refrigerator. Accordingly, the door needs to be thicker than a predetermined thickness. The thick door takes up much of an inner space of the refrigerator. Therefore, a total size of the refrigerator is increased when the inner space of the refrigerator is made to be larger than a predetermined size. Second, an outlet side of the discharging passage of the dispenser is exposed outside and dirt is collected thereon resulting in a problem of polluting the ice discharged outside by the dirt. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention is directed to a dispenser of an icemaker in a refrigerator that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for maximizing an inner space of the apparatus. Another object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for minimizing a total size of the dispenser. A further object of the present invention is to provide an apparatus having a function of discharging ice with a dispenser of an icemaker for completely isolating an inside of an outer case from an outside thereof. Additional advantages, objects, and features of the invention will be set forth in part in the description Which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a dispenser of an icemaker of the present invention includes an ice chute provided as a passage through which the ice produced from the icemaker provided inside of an outer case is discharged, and a container supporter provided at the outer case and disposed to be perpendicular to an outer surface of the outer case when the ice is discharged outside through the ice chute, the container supporter allowing a container seated thereon to receive the ice discharged from the ice chute. The ice chute is closed and not exposed outside when the ice is not discharged. The ice chute includes a first chute having an inlet provided on an inner wall of a front surface of the outer case and a passage extended downward in a wall direction of the outer case, and a sliding member having a second chute diagonally extended, the sliding member moving forward to be perpendicular to the front surface of the outer case for communicating the second chute with the first chute when the ice is discharged, and being inserted into the outer case when the ice is not discharged. The sliding member further includes a rack provided at a bottom surface thereof; and a pinion provided at a bottom of the rack and mated with the rack. The dispenser of the icemaker further includes a cover having a first end coupled with a lower end of a front surface of the sliding member, and a second end extended upward and fixed on the front surface of the outer case. Meanwhile, the ice chute includes an ice-discharging pipe having an inlet provided on an inner surface of the outer case and an outlet provided on an outer surface of the outer case, and a cover provided at the outer case for opening and closing the outlet of the ice-discharging pipe. In this case, the cover is rotatably provided around a top end being coupled with the front surface of the outer case. The cover also includes a subsidiary pipe provided on a portion being in contact with the outlet portion of the ice-discharging pipe to be inserted into an inside of a passage on the outlet side of the ice discharging pipe. The subsidiary pipe comprises an ice-passing hole at a lower part thereof for discharging the ice when the cover is rotated upward. The container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. The container supporter rotates upward and covers the cover. The dispenser of the icemaker further includes a link member for coupling the container supporter with the cover. The container supporter is inserted into a wall of the outer case when the ice is not discharged through the ice chute. The container supporter includes a rack provided at a bottom surface thereof, and a pinion provided under the rack and mated with the rack. Contrary to the structure mentioned above, the container supporter may be provided under the ice chute and have an end being rotatably coupled with the front surface of the outer case. The container supporter is rotated downward to be perpendicular to the front surface of the outer case when the ice is discharged. The container supporter closes the ice chute when the ice is not discharged. The container supporter includes a rotating axis horizontally provided at an end of the outer wall of the outer case, a driven gear provided at the rotating axis, and a driving gear mated with the driven gear. Owing to the dispenser of the icemaker with aforementioned structure, an inner space of the ice-discharging apparatus such as a refrigerator is maximized or a total size of the apparatus is minimized. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. | 20040428 | 20080108 | 20050317 | 58292.0 | 1 | TAPOLCAI, WILLIAM E | DISPENSER OF ICEMAKER IN REFRIGERATOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,040 | ACCEPTED | Actuating device for open/close member of vehicle | A connecting rod is provided with a bent portion in a substantially middle part thereof so that a lower section of the connecting rod below the substantially middle part in a vertical direction may be inclined, with respect to the longitudinal direction of a guide rail, toward a center of an opening, and at the same time, an upper section of the connecting rod above the substantially middle part may be substantially in parallel to the longitudinal direction of the guide rail and offset from a side face of the guide rail directed to the center of the opening toward the center of the opening, when the connecting rod is in a position corresponding to a closed position of an open/close member. | 1. An actuating device to open and close an open/close member of a vehicle which is pivotally mounted to an edge of an opening of said vehicle with a hinge shaft provided substantially horizontally, said actuating device comprising: a guide rail arranged on a body pillar located on a side edge of said opening and configured so that a longitudinal direction of the guide rail is inclined toward a center of the opening; a rack which is guided along the longitudinal direction of the guide rail; a motor unit for moving the rack along the longitudinal direction of the guide rail; and a connecting rod which is connected at an upper end thereof to said open/close member by one joint and connected at a lower end thereof to said rack by another joint; wherein said connecting rod is provided with a bent portion in a middle part thereof so that a lower section of said connecting rod below said middle part in a vertical direction is inclined with respect to the longitudinal direction of said guide rail, toward the center of said opening, and an upper section of said connecting rod above said middle part is substantially in parallel to the longitudinal direction of said guide rail and offset from a side face of said guide rail to the center of said opening, when said connecting rod is in a closed position of said open/close member. 2. The actuating device for the open/close member of the vehicle according to claim 1, wherein an upper end part of the guide rail is fixed to said body pillar, and a lower end part thereof is fixed to the motor unit which is fixed to said body pillar. | The present application is based on Japanese Patent Application No. 2003-153771, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a actuating device for an open/close member of a vehicle. 2. Related Art In a conventional actuating device for an open/close member of a vehicle, on each of vehicle pillars formed at both sides of an opening in a back part of a vehicle body which is adapted to be opened or closed by a rear gate which is pivotally mounted to a back end part of a vehicle roof by means of a substantially horizontal hinge shaft, there are provided a guide rail which is fixed to the vehicle body pillar in such a posture as inclined toward a center of the opening, a rack which is guided by the guide rail in a vertical direction, that is, in a longitudinal direction of the guide rail, a motor unit for moving the rack in the vertical direction, and a connecting rod extending in a vertical direction which is connected at its upper end to the rear gate by means of a universal joint, and connected at its lower end to the rack by means of a universal joint. The rack is moved in the vertical direction along the longitudinal direction of the guide rail thereby to displace the rear gate from a closed position to an open position or from the open position to the closed position (See Japanese Patent Application No. JP-A-2001-253241, for example). In the actuating device for the open/close member of the vehicle as described above, the opening formed in the back part of the vehicle is generally in a trapezoidal shape. For this reason, it has been necessary to arrange the guide rail for guiding the connecting rod at such a position that it may protrude from the vehicle pillar toward the opening to a large extent, so that a part of the connecting rod may not interfere with a side edge of the vehicle pillar which defines the opening, on occasion of moving the connecting rod for displacing the rear gate to the open position. In case where the guide rail has been arranged in this manner, the guide rail will protrude from the vehicle body pillar toward the opening to a large extent, when the rear gate is opened, which results in a problem that an appearance of the vehicle may be deteriorated and an opening width of the opening may be made narrow. SUMMARY OF THE INVENTION In view of the above described problem of the related art, an object of the invention is to provide an actuating device for an open/close member of a vehicle which will not make an opening width of an opening in the vehicle narrow, and will be excellent in quality. According to the invention, the above described problem will be solved in the following manner. (1) In an actuating device for an open/close member of a vehicle which is pivotally mounted to an end part of a vehicle roof by means of a substantially horizontal hinge shaft and adapted to open and close an opening of the aforesaid vehicle, by displacing the open/close member from a closed position to an open position or from the open position to the closed position, the aforesaid device being provided on a vehicle body pillar provided at each side edge of the aforesaid opening, and including a guide rail which is arranged in such a posture that a longitudinal direction of the guide rail is inclined toward a center of the opening, a rack which is guided along the longitudinal direction of the guide rail, a motor unit for moving the rack along the longitudinal direction of the guide rail, and a connecting rod which is connected at its upper end to the aforesaid open/close member by means of a universal joint and connected at its lower end to the aforesaid rack by means of a universal joint, the aforesaid connecting rod is provided with a bent portion in a substantially middle part thereof so that a lower section of the aforesaid connecting rod below the substantially middle part in a vertical direction may be inclined, with respect to the longitudinal direction of the aforesaid guide rail, toward the center of the aforesaid opening, and at the same time, an upper section of the aforesaid connecting rod above the substantially middle part may be substantially in parallel to the longitudinal direction of the aforesaid guide rail and offset from a side face of the aforesaid guide rail directed to the center of the aforesaid opening toward the center of the aforesaid opening, when the aforesaid connecting rod is in a position corresponding to the closed position of the aforesaid open/close member. (2) In the device as described in the above item (1), an upper end part of the guide rail is fixed to the vehicle body pillar, and a lower end part thereof is similarly fixed to the motor unit which is fixed to the aforesaid vehicle body pillar. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a back part of a vehicle showing a general structure of an embodiment of the invention; FIG. 2 is a back view showing a left half of the back part of the vehicle when an open/close member is in a closed state; FIG. 3 is a back view showing the left half of the back part of the vehicle when the open/close member is in an open state; FIG. 4 is a side view of the actuating device as seen from an inside of the vehicle; FIG. 5 is a cross sectional view taken along a line V-V in FIG. 4; FIG. 6 is a back view of the actuating device, when the connecting rod is in the lower position corresponding to the closed position of the open/close member; and FIG. 7 is a back view of the actuating device, when the connecting rod is in the upper position corresponding to the open position of the open/close member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, an embodiment of the invention will be described referring to the drawings. FIG. 1 is a side view of a back part of a vehicle showing a general structure of this embodiment, FIGS. 2 and 3 are back views showing a left half of the back part of the vehicle, FIG. 4 is a side view of an actuating device as seen from an inside of the vehicle, FIG. 5 is a cross sectional view taken along a line V-V in FIG. 4, and FIGS. 6 and 7 are back views of the actuating device. It is to be noted that a left side in FIG. 1, a depth direction in FIGS. 2 and 3, and a right side in FIG. 4 are regarded as “a forward direction” of the vehicle, while a right side in FIG. 1, a front side in FIGS. 2 and 3, and a left side in FIG. 4 are regarded as “a backward direction” of the vehicle. Moreover, a left to right direction in FIGS. 2 and 3 is regarded as “a lateral direction” of the vehicle. A vehicle 1 has a rear gate 4 which forms an open/close member pivotally mounted to a backward end part of a roof 3 by means of a substantially horizontal hinge shaft 2 extending in a lateral direction. An opening 6 in a substantially trapezoidal shape as seen from the back is defined by a backward edge of the roof 3, and right and left vehicle body pillars 5 which form the back part of the vehicle. The rear gate 4 can be displaced within a range between a closed position in which the opening 6 is closed as shown by a solid line in FIG. 1, and in FIG. 2, and an open position in which the opening 6 is opened by lifting a backward end of the rear gate 4 as shown by a phantom line in FIG. 1, and in FIG. 3. An actuating device 7 for displacing the rear gate 4 from the closed position to the open position, or from the open position to the closed position is provided on the vehicle body pillar at an inside of the vehicle body pillar 5, as shown mainly in FIGS. 2 and 3, near a connection part between a beam part 8 which is formed in a back and forth direction along a side face of the vehicle body and the vehicle body pillar 5, so that the device 7 may not protrude to a large extent from the vehicle body pillar 5 toward the opening 6. As shown in FIGS. 2 and 3, the actuating device 7 includes a guide rail 9 which is fixed to the vehicle body pillar 5 at the inside of the vehicle as will be described below, in such a posture that its longitudinal direction is inclined toward a center of the opening 6 (an upper end of the guide rail is positioned more close to the center of the opening 6 than its lower end, in other words, positioned rightward in FIGS. 2 and 3), a rack 10 which is guided in the longitudinal direction of the guide rail 9, a motor unit 11 for moving the rack 10 along the longitudinal direction of the guide rail 9, and a connecting rod 12 which is connected at its upper end to an upper part of the rear gate 4 by means of a universal joint 12a which is rotatable in a desired direction, and connected at its lower end to an upper end of the rack 10 by means of a universal joint which is rotatable in a desired direction and formed as will be described below. An engaging shaft 10a fixed to the upper end of the rack 10 and directed to the left to right direction is slidably engaged with a guide hole 9a which is provided in the guide rail 9, as shown in FIG. 4, thereby to guide the rack 10 in the longitudinal direction of the guide rail 9. Moreover, the universal joint for connecting the lower end of the connecting rod 12 to the upper end of the rack 10 in this embodiment is formed by idly engaging the engaging shaft 10a which is fixed to the upper end of the rack 10 and passed through the guide hole 9a of the guide rail 9 with a through hole 12e which is formed in the lower end part of the connecting rod 12, in such a manner that the lower end of the connecting rod 12 can be rotated and inclined to the left to right direction with respect to the engaging shaft 10a. Alternatively, a universal joint similar to the universal joint 12a may be also employed. The motor unit 11 has a motor 13 which is fixed to the vehicle body pillar 5 at the inside of the vehicle and adapted to be actuated by operating an operation switch provided near a driver's seat or another operating switch thereby to perform normal and reverse rotations, and a reduction system 14 which decelerates the rotation of the motor 13. The reduction system 14 has an output gear (not shown) which is meshed with a gear part 10b of the rack 10, and an electromagnetic clutch (not shown) for connecting and disconnecting a transmitting path between the motor 13 and the output gear. The guide rail 9 is fixed at its upper end to the vehicle body pillar 5 at the inside of the vehicle by means of a bolt (not shown), and at the same time, fixed at its lower end to the reduction system 14 of the motor unit 11 which is fixed to the vehicle body pillar 5. Accordingly, the guide rail 9 is fixed to the vehicle body pillar 5 at the inside of the vehicle in a manner of extending along an inclined edge 5a of the vehicle body pillar 5 which defines a side edge of the opening 6. In this manner, the lower end of the guide rail 9 can be reliably fixed to the motor unit 11, enabling the rack 10 which is guided by the guide rail 9 to be reliably meshed with the output gear of the motor unit 11, and hence, the rack 10 can be reliably moved in the longitudinal direction of the guide rail 9. In a substantially middle part of the connecting rod 12 in the longitudinal direction (in the vertical direction), there is formed a bent portion 12d which is bent in a substantially L shape. Due to this shape of the connecting rod 12, the connecting rod 12 can connect the rear gate 4 and the rack 10, as mainly shown in FIG. 2, in such a posture that in its lower position corresponding to the closed position of the rear gate 4 in which the connecting rod 12 is positioned in a lower part of the guide rail 9, a lower section 12c below the substantially middle part of the connecting rod 12 in the longitudinal direction may be inclined toward the center of the opening 6 with respect to the longitudinal direction of the guide rail 9, and at the same time, an upper section 12b above the middle part may be substantially in parallel to the longitudinal direction of the guide rail 9 and offset from a side face of the guide rail 9 directed to the center of the opening 6, by a determined amount, toward the center of the opening 6. According to the above described structure, even though the connecting rod 12 has moved to its upper position corresponding to the open position of the rear gate 4 in which the connecting rod 12 is positioned in an upper part of the guide rail 9 as mainly shown in FIG. 3, the connecting rod 12 will never interfere with the inclined edge 5a of the vehicle body pillar 5. Accordingly, it will be possible to provide the guide rail 9 in such a manner that the guide rail 9 may not protrude from the vehicle body pillar 5 toward the opening 6 to a large extent, and hence, the appearance of the vehicle can be enhanced and an opening width of the opening 6 will not be made narrow. In the closed position of the rear gate 4, when the operating switch is operated to open the rear gate 4, the motor 13 is controlled to perform the normal rotation, and the clutch of the reduction system 14 is magnetized thereby permitting the transmitting path between the motor 13 and the output gear to be connected. Then, the rack 10 is guided by the guide rail 9 and moved upward, following the rotation of the output gear of the motor unit 11. Along with the movement of the rack 10, the connecting rod 12 is moved from the lower position corresponding to the closed position of the rear gate 4 in which it is located in the lower part of the guide rail 9 as shown mainly in FIG. 2, to the upper position corresponding to the open position of the rear gate 4, as shown mainly in FIG. 3. Along with the movement of the connecting rod 12, the rear gate 4 will be displaced to the open position around the hinge shaft 2. Following the opening displacement of the rear gate 4, the upper end of the connecting rod 12 (the upper universal joint 12a) moves upward straightly, while drawing a locus around the hinge shaft 2. Accordingly, the lower section 12c of the connecting rod 12 will become close to the inclined edge 5a of the vehicle body pillar 5 while it moves upward, as shown in FIG. 3. However, because the connecting rod 12 has the bent portion 12d in the substantially middle part in the longitudinal direction, the connecting rod 12 will not interfere with the inclined edge 5a of the vehicle body pillar 5, even though the rear gate 4 has been displaced to the open position. On the other hand, in the open position of the rear gate 4, when the operating switch is operated to close the rear gate, the motor 13 is controlled to perform the reverse rotation, and the clutch is magnetized thereby permitting the rack 10 and the connecting rod 12 to move downward, and the rear gate 4 is rotated around the hinge shaft 2 to be displaced to the closed position. According to the invention, the following advantages can be attained. (a) It has become possible to arrange the guide rail on the vehicle body pillar without protruding toward the opening to a large extent, and therefore, the appearance can be enhanced and the opening width of the opening will not be made narrow. (b) In addition to the above advantage, the lower end of the guide rail can be reliably fixed to the motor unit. In this manner, the rack can be reliably moved along the longitudinal direction of the guide rail by means of the motor unit. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a actuating device for an open/close member of a vehicle. 2. Related Art In a conventional actuating device for an open/close member of a vehicle, on each of vehicle pillars formed at both sides of an opening in a back part of a vehicle body which is adapted to be opened or closed by a rear gate which is pivotally mounted to a back end part of a vehicle roof by means of a substantially horizontal hinge shaft, there are provided a guide rail which is fixed to the vehicle body pillar in such a posture as inclined toward a center of the opening, a rack which is guided by the guide rail in a vertical direction, that is, in a longitudinal direction of the guide rail, a motor unit for moving the rack in the vertical direction, and a connecting rod extending in a vertical direction which is connected at its upper end to the rear gate by means of a universal joint, and connected at its lower end to the rack by means of a universal joint. The rack is moved in the vertical direction along the longitudinal direction of the guide rail thereby to displace the rear gate from a closed position to an open position or from the open position to the closed position (See Japanese Patent Application No. JP-A-2001-253241, for example). In the actuating device for the open/close member of the vehicle as described above, the opening formed in the back part of the vehicle is generally in a trapezoidal shape. For this reason, it has been necessary to arrange the guide rail for guiding the connecting rod at such a position that it may protrude from the vehicle pillar toward the opening to a large extent, so that a part of the connecting rod may not interfere with a side edge of the vehicle pillar which defines the opening, on occasion of moving the connecting rod for displacing the rear gate to the open position. In case where the guide rail has been arranged in this manner, the guide rail will protrude from the vehicle body pillar toward the opening to a large extent, when the rear gate is opened, which results in a problem that an appearance of the vehicle may be deteriorated and an opening width of the opening may be made narrow. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the above described problem of the related art, an object of the invention is to provide an actuating device for an open/close member of a vehicle which will not make an opening width of an opening in the vehicle narrow, and will be excellent in quality. According to the invention, the above described problem will be solved in the following manner. (1) In an actuating device for an open/close member of a vehicle which is pivotally mounted to an end part of a vehicle roof by means of a substantially horizontal hinge shaft and adapted to open and close an opening of the aforesaid vehicle, by displacing the open/close member from a closed position to an open position or from the open position to the closed position, the aforesaid device being provided on a vehicle body pillar provided at each side edge of the aforesaid opening, and including a guide rail which is arranged in such a posture that a longitudinal direction of the guide rail is inclined toward a center of the opening, a rack which is guided along the longitudinal direction of the guide rail, a motor unit for moving the rack along the longitudinal direction of the guide rail, and a connecting rod which is connected at its upper end to the aforesaid open/close member by means of a universal joint and connected at its lower end to the aforesaid rack by means of a universal joint, the aforesaid connecting rod is provided with a bent portion in a substantially middle part thereof so that a lower section of the aforesaid connecting rod below the substantially middle part in a vertical direction may be inclined, with respect to the longitudinal direction of the aforesaid guide rail, toward the center of the aforesaid opening, and at the same time, an upper section of the aforesaid connecting rod above the substantially middle part may be substantially in parallel to the longitudinal direction of the aforesaid guide rail and offset from a side face of the aforesaid guide rail directed to the center of the aforesaid opening toward the center of the aforesaid opening, when the aforesaid connecting rod is in a position corresponding to the closed position of the aforesaid open/close member. (2) In the device as described in the above item (1), an upper end part of the guide rail is fixed to the vehicle body pillar, and a lower end part thereof is similarly fixed to the motor unit which is fixed to the aforesaid vehicle body pillar. | 20040428 | 20061017 | 20050106 | 92135.0 | 0 | THOMPSON, HUGH B | ACTUATING DEVICE FOR OPEN/CLOSE MEMBER OF VEHICLE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,085 | ACCEPTED | Display apparatus | A display apparatus including a display to display a picture; a signal processor to format a video signal to be output to the display; and a controller to output a control signal to the signal processor on the basis of a picture display state controlled through a control screen; wherein the picture display state is set by a user through the control screen, which is displayed concurrently with a plurality of reference screens displaying different values of the picture display state. | 1. A display apparatus comprising: a display to display a picture; a signal processor to format a video signal to be output to the display; and a controller to output a control signal to the signal processor on the basis of a picture display state controlled through a control screen; wherein the picture display state is set by a user through the control screen, which is displayed concurrently with a plurality of reference screens displaying different values of the picture display state. 2. The display apparatus according to claim 1, wherein the control screen comprises a drag bar having an adjuster, and the picture display state is controlled by dragging the adjuster on the drag bar. 3. The display apparatus according to claim 2, wherein the drag bar is controlled by existing direction keys on a remote control or the display. 4. The display apparatus according to claim 1, further comprising a user control with which the user controls the picture display state. 5. The display apparatus according to claim 4, wherein the user control comprises an OSD button or a remote controller. 6. The display apparatus according to claim 5, wherein the user control comprises a user interface having a function key to display a setup screen on the display. 7. The display apparatus according to claim 5, wherein the user control comprises function keys to stop displaying the picture on the display, and to display a previously stored setup screen. 8. The display apparatus according to claim 1, wherein the picture display state is a color temperature. 9. The display apparatus according to claim 8, further comprising a lookup table comprising at least one of control factors including an RGB gamma value, a color tone, a gain, a cut-off, and brightness, wherein the controller uses the lookup table to form the control signal. 10. The display apparatus according to claim 1, wherein the controller comprises a setup screen storage, and the control screen and the plurality of reference screens are previously stored in the setup screen storage. 11. The display apparatus according to claim 10, wherein the setup screen storage comprises an EEPROM or a flash memory. 12. The display apparatus according to claim 1, wherein the reference screens are invariable screens displaying different values of the pictures display state, and the control screen is a variable screen varying according to manipulation by the user. 13. The display apparatus according to claim 1, wherein the reference screens comprise pictures such that the user easily distinguishes the different values of the picture display state. 14. The display apparatus according to claim 1, wherein the reference screens are provided corresponding to each of the possible different values of the picture display state. 15. The display apparatus according to claim 1, wherein each of the reference screens displays different picture display state values of a same picture. 16. The display apparatus according to claim 1, wherein the picture display state is color, contrast, or brightness. 17. A display apparatus comprising: a display; and a controller to control a picture display state of a picture displayed on the display based on a user input; wherein a setup screen is displayed concurrently with a plurality of reference screens displaying different values of the picture display state, so that the user sees the different values of the picture display state that are available. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Korean Patent Application No. 2003-53252, filed Jul. 31, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display apparatus, and more, particularly, to a display apparatus in which a favorite picture display state is optionally and objectively controlled. 2. Description of the Related Art Generally, a display apparatus such as a TV, a monitor, etc., has to be controlled in a picture display state showing properties such as color, contrast, brightness, color temperature, etc., so as to substantially display the color temperature, the brightness, etc., of a screen as a user wants. However, because it takes a significant amount of time to control the color temperature of the display apparatus in detail, the conventional display apparatus typically has two to five settings of the color temperature stored in EEPROM (electrically erasable programmable read only memory) on a production line, so that a user can select one among the two to five settings of the color temperature stored in the EEPROM when there is a need to control the color of a screen. Therefore, the color temperature of the conventional display apparatus is simply selected among the plurality of settings of the color temperature set up on the production line, and cannot be voluntarily controlled as a user wants. Meanwhile, the color temperature of the display apparatus is typically controlled through control buttons provided on the display apparatus or a separate device. Generally, when a selection button among the control buttons is pressed, the color temperature corresponding to the selection button is directly applied to a current displayed screen. Then, when a setup button among the control buttons is pressed, the color temperature being applied to the current displayed screen is set up as the color temperature for the display device. When displaying the selected color temperature setting, the screen applied with the selected color temperature is displayed in a full screen, so that there is no reference screen allowing a user to objectively distinguish the currently viewed color temperature from the other possible color temperature settings. Therefore, a user cannot objectively control the color temperature as desired. SUMMARY OF THE INVENTION Accordingly, it is an aspect of the present invention to provide a display apparatus in which a favorite picture display state is optionally and objectively controlled referring to a reference screen. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. The foregoing and/or other aspects of the present invention are achieved by providing a display apparatus comprising a display to display a picture; a signal processor to format a video signal to be output to the display; and a controller to output a control signal to the signal processor on the basis of a picture display state controlled through a control screen; wherein the picture display state is set by a user through the control screen, which is displayed concurrently with a plurality of reference screens displaying different values of the picture display state. According to an aspect of the invention, the control screen may comprise a drag bar having an adjuster, and the picture display state is controlled by dragging the adjuster on the drag bar. According to an aspect of the invention, the display apparatus may further comprise a user control with which the user controls the picture display state. According to an aspect of the invention, the picture display state may be a color temperature. BRIEF DESCRIPTION OF THE DRAWINGS These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompany drawings of which: FIG. 1 is a control block diagram of a display apparatus according to the present invention; and FIG. 2 illustrates a reference screen and a control screen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. FIG. 1 is a control block diagram of a display apparatus according to an embodiment of the present invention. As shown therein, this display apparatus comprises a display 20 on which a picture is displayed; a signal processor 30 formatting a video signal to be displayed on the display 20; and a controller 40 offering a control screen allowing a user to set up a picture display state and a plurality of reference screens employed as a reference when the picture display state is controlled, and outputting a control signal to the signal processor 30 on the basis of the picture display state controlled through the control screen. Further, the display apparatus comprises a user control 60 allowing a user to control the picture display state. The signal processor 30 includes a video decoder to process an ordinary video signal, an ADC (analog to digital converter) to process a digital video signal, and a scaler to adapt the video signal processed by the video decoder and the ADC to the display 20. The video decoder receives a video signal such as NTSC (national television standard committee)—TV, VHS (video home system)—video, etc., and separates the video signal into a Y component, as a brightness signal, and R-Y and B-Y components as chrominance signals. Here, the R-Y and B-Y components are converted into RGB (red, green, blue) signals for color. Hereinafter, the brightness signal (Y) and the chrominance signals (R-Y and B-Y), output from the video decoder, will be represented as a YCbCr signal. The ADC is employed to process a video signal for a DVD (digital versatile disk) or an HDTV (high definition television), and outputs a video signal including the brightness signal (Y) and the chrominance signals (R-Y and B-Y). Hereinafter, the brightness signal (Y) and the chrominance signals (R-Y and B-Y), output from the ADC, will be represented as a YPbPr signal. The scaler adapts the YCbCr and YPbPr signals to a vertical frequency, resolution (the number of pixels), a screen ratio (16:9, 4:3), etc., of the display 20, and, at the same time, converts the YCbCr and YPbPr signals into a digital RGB signal by calculating the YCbCr and YPbPr signals through a computing mechanism according to the signal formats. The controller 40 offers a control screen allowing a user to set up the picture display state, and the plurality of reference screens employed as a reference when the picture display state is controlled. The control screen and the plurality of reference screens are previously stored in a setup screen storage 50 of the controller 40. Here, the setup screen storage 50 includes an EEPROM or a flash memory. As shown in FIG. 2, a setup screen 10 allowing a user to change a color temperature in a screen is displayed on the display 20, including the reference screens 10a through 10d and the control screen 11. Here, the reference screens 10a through 10d are invariable screens applied with predetermined color temperatures, and the control screen 11 is a variable screen varying in the color temperature corresponding to the selection of the user. It is preferable, though not necessary, that the reference screens 10a through 10d and the control screen 11 have pictures allowing the user to easily distinguish a difference in the color temperature. A landscape, a man, a building, gradation, and the like are a few suitable possibilities for the pictures of the reference screens 10a through 10d and the control screen 11. Further, the pictures are provided corresponding to each of the possible color temperature settings. In this embodiment, four invariable screens 10a, 10b, 10c, and 10d, with respective color temperatures of 6,500° K., 9,500° K., 13,000° K., and 25,000° K. are illustrated as the reference screens. This is merely an example of possible reference screens, and is not intended to limit this embodiment of the present invention to these values. Alternately, the number of the reference screens may be more or less than four. The plurality of reference screens allows a user to objectively distinguish a favorite color temperature from among the possible color temperature settings when a user wants to set up the color temperature. Here, the invariable screens preferably have all the same pictures to allow a user to distinguish the difference in the color temperature, but the invariable screens may have different pictures from each other. Also, it should be appreciated that the reference screens 10a through 10d may have a different picture than the control screen 11. The controller 40 (refer to FIG. 1) outputs the control signal to the signal processor 30 on the basis of the picture display state controlled through the control screen 11. The control screen 11 may include a drag bar 12 having an adjuster 12a capable of being dragged. Here, the drag bar 12 represents the whole color temperature that the display apparatus according to this embodiment of the present invention can display. In this embodiment, the color temperature ranges from 6,000K to 30,000° K. As the adjuster 12a of the drag bar 12 is dragged, the control screen 11 is changed to the color temperature corresponding to the position of the adjuster 12a on the drag bar 12. That is, when a user makes the setup screen 10 be displayed on the display 20 in order to control the color temperature, the controller 40 determines where the adjuster 12a is positioned on the drag bar 12. Subsequently, the controller 40 outputs the control signal to the signal processor 30 on the basis of the controlled color temperature corresponding to the position of the adjuster 12a, and then the signal processor 30 applies the controlled color temperature to only the control screen 11 of the display 20. Further, when a user sets up the controlled color temperature as the color temperature for the display device by using a predetermined setup button, the controller 40 receives a setup signal corresponding to the setup button. Subsequently, the controller 40 outputs the control signal corresponding to the controlled color temperature applied to only the control screen 11 to the signal processor 30. Then, the signal processor 30 applies the setup color temperature being applied to only the control screen 11 to the video signal for a full screen of the display 20. Here, the controlled color temperature being applied to only the control screen 11 may be temporarily stored in a memory (not shown) provided in the controller 40 while being controlled. The controlled color temperature stored in the memory can be read and outputted to the signal processor 30 while being set up. Further, to get more enhanced definition, the color temperature can be controlled through a lookup table having control factors such as an RGB gamma value, a color tone, a gain, a cut-off, brightness, etc., according to the color temperature. In this case, the signal processor 30 can make the setup color temperature be not applied to a video signal that is irrelevant to the color temperature, e.g., a video signal corresponding to a skin tone or RGB primary colors. The user control 60 may include a user interface having a function key to display the setup screen 10 on the display 20, and a drag key to drag the adjuster 12a on the control screen 11. Further, the user control 60 is preferably, though not necessarily, achieved by an OSD (on screen display) button provided on the display apparatus, or a remote control. The OSD button or the remote control has the function keys to stop displaying a picture based on a received video signal on the display 20 and to display the previously stored setup screen 10 so as to allow a user to set up the color temperature. Further, the drag key to control the color temperature can be implemented by existing direction keys. In this embodiment, the color temperature is exemplarily described as the picture display state, but the embodiment is not limited to color temperature. Alternatively, any controllable picture display state, such as color, contrast, brightness, etc., can be set up with reference to the reference screens according to the picture display states as described above. With this configuration, a user can optionally and objectively set up a favorite picture display with reference to the reference screens. As described above, the present invention provides a display apparatus in which a favorite screen display state is optionally and objectively controlled referring to a reference screen. Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a display apparatus, and more, particularly, to a display apparatus in which a favorite picture display state is optionally and objectively controlled. 2. Description of the Related Art Generally, a display apparatus such as a TV, a monitor, etc., has to be controlled in a picture display state showing properties such as color, contrast, brightness, color temperature, etc., so as to substantially display the color temperature, the brightness, etc., of a screen as a user wants. However, because it takes a significant amount of time to control the color temperature of the display apparatus in detail, the conventional display apparatus typically has two to five settings of the color temperature stored in EEPROM (electrically erasable programmable read only memory) on a production line, so that a user can select one among the two to five settings of the color temperature stored in the EEPROM when there is a need to control the color of a screen. Therefore, the color temperature of the conventional display apparatus is simply selected among the plurality of settings of the color temperature set up on the production line, and cannot be voluntarily controlled as a user wants. Meanwhile, the color temperature of the display apparatus is typically controlled through control buttons provided on the display apparatus or a separate device. Generally, when a selection button among the control buttons is pressed, the color temperature corresponding to the selection button is directly applied to a current displayed screen. Then, when a setup button among the control buttons is pressed, the color temperature being applied to the current displayed screen is set up as the color temperature for the display device. When displaying the selected color temperature setting, the screen applied with the selected color temperature is displayed in a full screen, so that there is no reference screen allowing a user to objectively distinguish the currently viewed color temperature from the other possible color temperature settings. Therefore, a user cannot objectively control the color temperature as desired. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an aspect of the present invention to provide a display apparatus in which a favorite picture display state is optionally and objectively controlled referring to a reference screen. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. The foregoing and/or other aspects of the present invention are achieved by providing a display apparatus comprising a display to display a picture; a signal processor to format a video signal to be output to the display; and a controller to output a control signal to the signal processor on the basis of a picture display state controlled through a control screen; wherein the picture display state is set by a user through the control screen, which is displayed concurrently with a plurality of reference screens displaying different values of the picture display state. According to an aspect of the invention, the control screen may comprise a drag bar having an adjuster, and the picture display state is controlled by dragging the adjuster on the drag bar. According to an aspect of the invention, the display apparatus may further comprise a user control with which the user controls the picture display state. According to an aspect of the invention, the picture display state may be a color temperature. | 20040428 | 20070911 | 20050203 | 75214.0 | 0 | NATNAEL, PAULOS M | DISPLAY APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,204 | ACCEPTED | Method, logic arrangement and program for assigning a primary trunk | Method, logic arrangement or program employ trunking identifiers to assign primary trunking connection between a switch pair. | 1. A method for assigning a primary trunking connection between a switch pair, comprising the steps of: exchanging, between said switch pair, first identity data for each of said switch pair and second identity data for ports owned by each of said switch pair; using said first identity data, by each of said switch pair independently, to determine which of said switch pair is master and which of said switch pair is subordinate; using said second identity data, by each of said switch pair independently, to determine which of said ports owned by said master has primacy over all other of said ports owned by said master; responsive to said determining, nominating, by each of said switch pair independently, a connection between said port having primacy at said master and any port owned by said subordinate, as primary trunking connection. 2. The method of claim 1, further comprising the step of nominating, by each of said switch pair independently, a connection between a port other than said port having primacy at said master and any port owned by said subordinate, as secondary trunking connection. 3. The method of claim 1, wherein said first identity data is numeric. 4. The method of claim 3, wherein said step of using said first identity data comprises comparing said first identity data from said master with said first identity data from said subordinate. 5. The method of claim 1, wherein said said second identity data is numeric. 6. The method of claim 5, wherein said step of using said first identity data comprises comparing said first identity data from said master with said first identity data from said subordinate. 7. The method of claim 1, wherein said switch pair lies in a topology comprising a host processor and a storage device. 8. The method of claim 7, wherein said storage device comprises a storage area network. 9. The method of claim 8, wherein said storage area network comprises a storage virtualization controller. 10. The method of claim 1, performed during switch initialization. 11. The method of claim 1, performed during switch recovery. 12. A logic arrangement for assigning a primary trunking connection between a switch pair, comprising: a data exchange component for exchanging, between said switch pair, first identity data for each of said switch pair and second identity data for ports owned by each of said switch pair; a first determining component for using said first identity data, by each of said switch pair independently, to determine which of said switch pair is master and which of said switch pair is subordinate; a second determining component for using said second identity data, by each of said switch pair independently, to determine which of said ports owned by said master has primacy over all other of said ports owned by said master; a nominating component, responsive to said first and said second determining components, for nominating, by each of said switch pair independently, a connection between said port having primacy at said master and any port owned by said subordinate, as primary trunking connection. 13. The logic arrangement of claim 12, further comprising a further nominating component for nominating, by each of said switch pair independently, a connection between a port other than said port having primacy at said master and any port owned by said subordinate, as secondary trunking connection. 14. The logic arrangement of claim 12, wherein said first identity data is numeric. 15. The logic arrangement of claim 14, wherein said first determining component comprises a comparator for comparing said first identity data from said master with said first identity data from said subordinate. 16. The logic arrangement of claim 12, wherein said said second identity data is numeric. 17. The logic arrangement of claim 16, wherein said second determining component comprises a comparator for comparing said first identity data from said master with said first identity data from said subordinate. 18. The logic arrangement of claim 12, wherein said switch pair lies in a topology comprising a host processor and a storage device. 19. The logic arrangement of claim 18, wherein said storage device comprises a storage area network. 20. The logic arrangement of claim 19, wherein said storage area network comprises a storage virtualization controller. 21. A computer program product comprising computer program code tangibly stored in a computer-readable medium, to, when loaded into a computer system and executed thereon, cause said computer system to assign a primary trunking connection between a switch pair by performing the steps of: exchanging, between said switch pair, first identity data for each of said switch pair and second identity data for ports owned by each of said switch pair; using said first identity data, by each of said switch pair independently, to determine which of said switch pair is master and which of said switch pair is subordinate; using said second identity data, by each of said switch pair independently, to determine which of said ports owned by said master has primacy over all other of said ports owned by said master; responsive to said determining, nominating, by each of said switch pair independently, a connection between said port having primacy at said master and any port owned by said subordinate, as primary trunking connection. 22. The computer program product of claim 21, further comprising computer program code tangibly stored in a computer-readable medium, to, when loaded into a computer system and executed thereon, cause said computer system to perform the step of nominating, by each of said switch pair independently, a connection between a port other than said port having primacy at said master and any port owned by said subordinate, as secondary trunking connection. 23. The computer program product of claim 21, wherein said first identity data is numeric. 24. The computer program product of claim 23, wherein said step of using said first identity data comprises comparing said first identity data from said master with said first identity data from said subordinate. 25. The computer program product of claim 21, wherein said said second identity data is numeric. 26. The computer program product of claim 25, wherein said step of using said first identity data comprises comparing said first identity data from said master with said first identity data from said subordinate. 27. The computer program product of claim 21, wherein said switch pair lies in a topology comprising a host processor and a storage device. | FIELD OF THE INVENTION The present invention relates to loop networks, and particularly to loop networks having attached switches with trunking communications capabilities. BACKGROUND OF THE INVENTION Loop network topologies such as Fibre Channel Arbitrated Loop (FC-AL) networks are currently starting to use switch technologies in order to improve bandwidth by taking advantage of the capabilities that spatial reuse can give. In order to do this, trunking is used, where trunking is an extra connection, that allows multiple Host Bus Adapters (HBAs) to use the same FC-AL for data transfer simultaneously; where the switch uses different trunks for different I/O paths, one for each HBA. This concept of inter-switch trunking is well-known in the art and need not be further described here. The current switch technology is not directly capable of appreciating (or assigning primary and secondary roles to) the trunks to be used dynamically, but rather needs the assignment to be appreciated for it. Herein lies a problem, where the switch technology needs to be informed of the nature of each trunk, such that it can perform this task. This can be achieved today by assigning certain characteristics to each possible connection. This, however, creates the problem that the nature of the connection is determined in advance rather than determined at the time of connection. Errors in the cabling can therefore cause the trunking to fail, which is very undesirable. Another alternative is to have a manual appreciation after the cables are assigned. This, however, relies on accurate understanding of the cabled system and as such is prone to operator error and also adds another step in the process where FC-AL does not normally need such a step. Techniques such as choosing the ‘first connection’ as the primary and the ‘second connection’ as the secondary are flawed, as the way in which this rule may cause the network to behave is dependent both upon time and switch behaviour, which may not be deterministic. SUMMARY OF THE INVENTION This invention thus preferably uses trunking identifiers to automatically assign the correct trunk type accordingly. It makes use of the details of the connection and a commonly-implemented method which is operable independently by each member of a switch pair; because both the data and the method are shared by both members, this provides a deterministic assigment method that is common to all components. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawing figures, in which: FIG. 1 shows a switch pair in which the present invention may be embodied; FIG. 2 illustrates the structure of the identity data at each of the switch pair according to a preferred embodiment of the present invention; and FIG. 3 illustrates the steps of one preferred method of operating a switch pair according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning to FIG. 1, there is shown a switch arrangement comprising a pair of switches S1, S2, each owning a set of ports: S1 owns P1, P2, P3; S2 owns P1′,P2′, P3′. Switch S1 is connected to host H1 and data storage D1, while switch S2 is connected to host H2 and data storage D2. The system has been cabled in the simplest possible way, giving a configuration that could be simply expressed as (S1,P1;S2,P1′) (S1,P2;S2,P2′) (S1,P3;S2,P3′). Turning to FIG. 2, switches S1 and S2 are shown, each with its respective ports P1, P2, P3; P1′, P2′, P3′. Also shown is a representation in each switch of the trunk connections between the ports. Thus, S1 is aware that it is connected to S2 via its own ports P1, P2, P3 (shown as the leftmost column in its ordered pair list). S1 can compare its serial number with that of S2. In this exemplary case it is lower, so S1 knows it is master, and thus selects the lowest numbered of its own ports (lowest serial number in the leftmost column): P1. Thus S1 nominates the trunk connection between P1 and P1′ as primary. S2, likewise, is aware that it is connected to S1 via its own ports P1′, P2′, P3′ (shown as the leftmost column in its ordered pair list). S2 can compare its serial number with that of S1. In this case it is higher, so S2 knows it is subordinate, and thus selects the lowest numbered of its master's ports (lowest serial number in the rightmost column): P1. Thus S2 also nominates the trunk connection between P1 and P1′ as primary. Should connection P1, P1′ become unavailable, each switch performs a similar nomination process by performing a like comparison using the remaining connected ports. Turning now to FIG. 3, there is illustrated a method for assigning a primary trunking connection between a switch pair (S1, S2), comprising the step of exchanging (302), between the switch pair (S1, S2), the identity data for each member of the switch pair. This may comprise a unique serial number, for example, a World Wide Number (WWN). At step 304, identity data for ports P1, P2, P3 . . . ) owned by each of said switch pair is exchanged. The exchange may be part of the initialization procedure, in which all components identify themselves to all other components in the network, or it may be performed as part of a recovery process, after an interruption of network or component service. At step 306 the identity data for each member of the switch pair is examined by each member of the switch pair independently, to determine at step 308 which of the switch pair is master and which of the switch pair is subordinate. This may be done by comparing the exemplary serial numbers and selecting, for example, the lowest as master. Each member of the switch pair performs the comparison independently of the other, and thus a deterministic outcome is achieved without the switch pair needing to communicate. This advantageously reduces the number of flows rquired, and thus improves the performance of the system. In a most preferred embodiment the first requirement of the method is that two types of identifiers are required. The first is a serial number that is unique for each switch device. The second is an identifier that is unique to each trunking port within any switch device. The method requires that on connection, this information is passed between trunking ports in the switch devices. In a firmware embodiment of the method of the present invention, the firmware associated with each switch now has the following information: its own switch serial number and its own trunking port assignment; the serial number of the connected switch and that switch's trunking port assigment. In one embodiment, for practical purposes, each port will be initially designated by default as a primary trunk, even if it is not connected. When a connection is made, the firmware logs the other switch serial number and port assigment against that port. The process then continues as described below. At step 310, the identity data for each port owned by each member of the switch pair is examined by each member of the switch pair independently, to determine which of the ports owned by the identified master switch has primacy over all the other ports owned by that master switch. At step 312, responsive to the determination described above, each of the switch pair independently nominates the connection between the port having primacy at the master and the port owned by the subordinate to which it is connected, as the primary trunking connection. Thus, as all the identity data for each switch and each owned port is shared and thus “known” to both members of the switch pair, each can independently nominate the correct connection as primary to preserve the determinism of the system in spite of any variations in the sequence of initialization or recovery. In a preferred firmware embodiment, the firmware in each switch can now build a table of assigments by port, that include the other switch's serial number and port assignment. If there is another port connected to that switch, as detected by finding a connection with a matching serial number, the firmware in each switch tests the serial number and uses a simple comparison to choose a switch to be master; for example, the switch with the lowest, or the highest, ranking serial number. Many alternative embodiments of this feature will be clear to one of ordinary skill in the art, and need not be enumerated here. If the firmware determines that it is directly associated with the master switch, it chooses the primary trunk as the one with, for example, the lowest port number, and the secondary with the second lowest, etc. The subordinate switch will know that it should not use its own port assigment and can therefore make the same analysis, but based on the master switch's ports. Removal of a connection causes each switch to reassign master and secondary roles accordingly. Each switch reexamines its switch and port identity data and determines which of the remaining trunking connections meets the shared criteria to become the new primary. The outcome is thus advantageously always a matched set of connections, primary to primary, secondary to secondary and so on regardless of the order in which the switch hardware informs the firmware of any particular connection. In the embodiment of the present invention hereinbefore described with reference to FIG. 3, all data associated with a complete set of connections between a switch pair is exchanged in one shot between the switches of the pair. However, it will be appreciated that, in other embodiments of the present invention, data associated with one or more ports in a switch pair may be exchanged independently of the other ports in the switch pair. It will also be appreciated that, in the event of one or more ports in a switch pair failing, data associated with such ports may be discarded from subsequent exchanges and the comparison reapplied from step 306 only for those ports remaining operational. | <SOH> BACKGROUND OF THE INVENTION <EOH>Loop network topologies such as Fibre Channel Arbitrated Loop (FC-AL) networks are currently starting to use switch technologies in order to improve bandwidth by taking advantage of the capabilities that spatial reuse can give. In order to do this, trunking is used, where trunking is an extra connection, that allows multiple Host Bus Adapters (HBAs) to use the same FC-AL for data transfer simultaneously; where the switch uses different trunks for different I/O paths, one for each HBA. This concept of inter-switch trunking is well-known in the art and need not be further described here. The current switch technology is not directly capable of appreciating (or assigning primary and secondary roles to) the trunks to be used dynamically, but rather needs the assignment to be appreciated for it. Herein lies a problem, where the switch technology needs to be informed of the nature of each trunk, such that it can perform this task. This can be achieved today by assigning certain characteristics to each possible connection. This, however, creates the problem that the nature of the connection is determined in advance rather than determined at the time of connection. Errors in the cabling can therefore cause the trunking to fail, which is very undesirable. Another alternative is to have a manual appreciation after the cables are assigned. This, however, relies on accurate understanding of the cabled system and as such is prone to operator error and also adds another step in the process where FC-AL does not normally need such a step. Techniques such as choosing the ‘first connection’ as the primary and the ‘second connection’ as the secondary are flawed, as the way in which this rule may cause the network to behave is dependent both upon time and switch behaviour, which may not be deterministic. | <SOH> SUMMARY OF THE INVENTION <EOH>This invention thus preferably uses trunking identifiers to automatically assign the correct trunk type accordingly. It makes use of the details of the connection and a commonly-implemented method which is operable independently by each member of a switch pair; because both the data and the method are shared by both members, this provides a deterministic assigment method that is common to all components. | 20040426 | 20090203 | 20051027 | 96768.0 | 0 | THOMPSON, JR, OTIS L | METHOD, LOGIC ARRANGEMENT AND PROGRAM FOR ASSIGNING A PRIMARY TRUNK | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,219 | ACCEPTED | 'Glow-in-the-dark' gazing globes and other ornaments, particularly for gardens | A method of fabricating glow-in-the-dark gazing globes or other objects, as well as the articles that result. The method comprises the steps of providing a hollow form having an inner wall made from a transparent or translucent material, the form including an aperture for gaining access to the interior thereof, and introducing one more photoluminescence or phosphorescent pigments into the form through the aperture so that they cling to the inner wall. In alternative embodiments, the pigments may be applied without an adhesive, as by naturally cling, vacuum evaporation, or other techniques. In a gazing globe embodiment, a stand may be included. In the preferred embodiment the method further includes the step of applying an adhesive to the inner wall of the form prior to the step of introducing one more photoluminescence of phosphorescent pigments. A plurality of different pigments may be introduced into the form to create a decorative or swirling effect. | 1. A method of fabricating a glow-in-the-dark gazing globe or other object, comprising the steps of: providing a hollow form having an inner wall made from a transparent or translucent material, the form including an aperture for gaining access to the interior thereof; and introducing one more photoluminescence or phosphorescent pigments into the form through the aperture so that they cling to the inner wall. 2. The method of claim 1, further including the step of applying an adhesive to the inner wall of the form prior to the step of introducing one more photoluminescence of phosphorescent pigments. 3. The method of claim 1, wherein a plurality of different pigments are introduced into the form. 4. The method of claim 1, wherein: the form is generally spherical; and including the step of positioning the form on a vertical stand. 5. The method of claim 2, wherein the pigments are introduced to produce a swirling pattern. 6. An object made in accordance with the method of claim 1. | REFERENCE TO RELATED APPLICATION This application claims priority from U.S. Provisional Patent Application Ser. No. 60/466,105, filed Apr. 28, 2003, the entire content of which is incorporated herein by reference. FIELD OF THE INVENTION This invention relates generally to outdoor ornaments and, in particular, to gazing globes and other statuary with ‘glow-in-the-dark’ features. BACKGROUND OF THE INVENTION Garden ornaments such as gazing globes have become very popular as decorative elements in gardens and other outdoor environments. Such items are generally provided as a piece of statuary, including a spherical globe with a highly-polished or reflective surface supported by a base. Existing products typically use glass globes internally mirrored surface tinted in a wide variety of colors. SUMMARY OF THE INVENTION This invention resides in a method of fabricating glow-in-the-dark gazing globes or other objects, as well as the articles that result. The method comprises the steps of providing a hollow form having an inner wall made from a transparent or translucent material, the form including an aperture for gaining access to the interior thereof, and introducing one more photoluminescence or phosphorescent pigments into the form through the aperture so that they cling to the inner wall. In alternative embodiments, the pigments may be applied without an adhesive, as by naturally cling, vacuum evaporation, or other techniques. In a gazing globe embodiment, a stand may be included. In the preferred embodiment the method further includes the step of applying an adhesive to the inner wall of the form prior to the step of introducing one more photoluminescence of phosphorescent pigments. A plurality of different pigments may be introduced into the form to create a decorative or swirling effect. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified drawing showing the way in which an adhesive may be applied to the inside of a gazing globe; FIG. 2 is a drawing which shows the way in which a glow-in-the-dark powder may be introduced into the globe of FIG. 1; FIG. 3 is a drawing which shows the way in which multiple nozzles may be used to introduce multiple particulates; and FIG. 4 is a drawing which shows a finished product on a stand. DETAILED DESCRIPTION OF THE INVENTION This invention extends the appeal and usefulness of garden ornaments, including gazing gloves, by providing a glow-in-the-dark product. In the preferred embodiment, one or more phosphorescent or photo luminescent pigments may be used to create a swirling affect or other interesting pattern. However, in an alternative environment, a single or solid coloration is used. FIG. 1 is a simplified drawing showing the way in which an adhesive may be applied to the inside of a gazing globe. FIG. 2 is a drawing which shows the way in which a glow-in-the-dark powder may be introduced into the globe of FIG. 1. FIG. 3 is a drawing which shows the way in which multiple nozzles may be used to introduce multiple particulates. FIG. 4 is a drawing which shows a finished product on a stand. In terms of manufacture, a clear or at least translucent glass or plastic globe 102 or other object having an opening 104 is first internally coated with an adhesive. The adhesive may be water-bourne or non-water-bourne, may be applied in a spray 110 or atomized form or by brushing, and preferably dries in a transparent form. While the adhesive coating is still wet or tacky, photo-luminescent or phosphorescent pigments are sprayed on with an atomizer 220 or otherwise introduced so that they become embedded in the adhesive and form an inner coating. Either a single spray head may be used, or multiple spray heads 330, 332 may be used simultaneously or at different times to produce a desired affect. It is also possible to apply the pigments without an adhesive, as by naturally cling, vacuum evaporation, or other techniques. In a gazing globe embodiment, a swirling effect may be created by introducing pigments on an angle or rotating the globe, and/or placed on a vertical stand, as shown in FIG. 4. Various pigments are applicable to the invention, and they may be combined with other pigments that are not photoactive to create a reflection as well as glow-in-the-dark features. Applicable pigments include alkaline earth metal aluminates such as strontium aluminate, silicate aluminate, or alkaline earth aluminate, with glow colors ranging from green-yellow to purple-blue. Depending upon the mixture, “earth metals” can include strontium, magnesium, calcium, and barium. Silicon and titanium may also be present. It is typically doped with europium. An opaque fluorescent pigment may be added to provide visibility in a brighter environment. As a side effect, the fluorescent pigments also tint the glow which can produce glow colors such as orange alkaline earth silicate may also be used, which produces a very pure sky blue glow color. Other candidates includes zinc sulfide (with green red, and orange formulations). ZnS:Cu, for example, may be obtained from Pete's Luminous Creations of Singapore. Although the embodiment described herein utilizes spherical objects, it will be apparent to one of skill in the art that any other shape may be used, so long as access is provided to an internal cavity for the application of adhesive and pigments. As additional examples of many, the invention may accordingly be used to provide glow-in-the-dark animal forms, faux rocks, statues, bird baths, planters and so forth. | <SOH> BACKGROUND OF THE INVENTION <EOH>Garden ornaments such as gazing globes have become very popular as decorative elements in gardens and other outdoor environments. Such items are generally provided as a piece of statuary, including a spherical globe with a highly-polished or reflective surface supported by a base. Existing products typically use glass globes internally mirrored surface tinted in a wide variety of colors. | <SOH> SUMMARY OF THE INVENTION <EOH>This invention resides in a method of fabricating glow-in-the-dark gazing globes or other objects, as well as the articles that result. The method comprises the steps of providing a hollow form having an inner wall made from a transparent or translucent material, the form including an aperture for gaining access to the interior thereof, and introducing one more photoluminescence or phosphorescent pigments into the form through the aperture so that they cling to the inner wall. In alternative embodiments, the pigments may be applied without an adhesive, as by naturally cling, vacuum evaporation, or other techniques. In a gazing globe embodiment, a stand may be included. In the preferred embodiment the method further includes the step of applying an adhesive to the inner wall of the form prior to the step of introducing one more photoluminescence of phosphorescent pigments. A plurality of different pigments may be introduced into the form to create a decorative or swirling effect. | 20040427 | 20070807 | 20050106 | 64853.0 | 5 | AFTERGUT, JEFFRY H | 'GLOW-IN-THE-DARK' GAZING GLOBES AND OTHER ORNAMENTS, PARTICULARLY FOR GARDENS | SMALL | 0 | ACCEPTED | 2,004 |
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10,833,292 | ACCEPTED | Directional broadcast feeder for fish and game | A broadcast feeder for projecting food aggregate or pellets directionally into an area up to, for example, sixty or more feet away from the feed container. The action is controlled to provide a predetermined quantity of aggregate at a predetermined time. The velocity of the feed as it exits the feeder is such that the area directly surrounding the feeder is free of feed particulate. A modular design affords the ability to operate as a self-contained unit with its own storage hopper or as a retrofit module added to existing conventional barrel type scatter type feeders. The projection of the feed is accomplished by propelling the feed pellets with a center intake centrifugal air blower assembly designed such that no special feed gates, baffles or chutes are required. | 1. A directional feeder system for propelling particulate matter, the system comprising: a funnel operable to receive the particulate matter in a top opening thereof and direct the particulate matter through a bottom opening more narrow than the top opening; an impeller top plate assembly comprising a particulate hole operable to receive the particulate matter from the bottom opening of said funnel and at least one air hole operable to allow air to flow through; an impeller assembly comprising at least one blade, wherein the particulate matter can flow through the particulate hole of said impeller top plate assembly and is contacted by the at least one blade; a housing for enclosing said impeller assembly, said housing comprising an exit hole for expelling the particulate matter as the at least one blade forces the particulate matter through the exit hole; and an electric motor connected to said impeller assembly operable to rotate the at least one blade of said impeller assembly. 2. A directional feeder system in accordance with claim 1, wherein said impeller top plate assembly, said impeller assembly and said housing are oriented at a nonzero angle with respect to a particulate flow direction through the bottom opening of said funnel. 3. A directional feeder system in accordance with claim 2, wherein the nonzero angle is approximately 30 degrees. 4. A directional feeder system as claimed in claim 1, further comprising a scatter plate disposed within said funnel between the top opening and the bottom opening, wherein said scatter plate is operable to scatter particulate matter within said funnel. 5. A directional feeder system as claimed in claim 4, further comprising a storage device operable to store particulate matter and direct the particulate matter onto said scatter plate. 6. A directional feeder system for propelling particulate matter, the system comprising: a scatter type feeder comprising a storage bin for storing the particulate matter and a scatter plate for scattering the particulate matter in 360 degree pattern; and a directional device comprising a funnel operable to collect the particulate matter as it is scattered by the scatter plate and channeling the collected particulate matter to an impeller device operable to propel the particulate matter in a predetermined single direction. 7. A directional feeder system as claimed in claim 6, wherein the particulate matter propelled in the predetermined direction creates a pattern which is less than 360 degrees. 8. A directional feeder system as claimed in claim 6, wherein said scatter plate is driven by a first drive motor and said impeller device is driven by a second drive device different than the first drive device. 9. A directional feeder system comprising: a particulate intake device operable to channel particulate matter to a center intake impeller device, wherein the center intake impeller device receives particulate matter through a center hole in a top plate and propels the particulate matter through a hole in a side casing surrounding the impeller device and wherein further, the center intake impeller device is at a nonzero angle with respect to a channeling direction of the particulate intake device. 10. A directional feeder system as claimed in claim 9, wherein the top plate of the center intake impeller device comprises air holes operable to permit air to flow through to an inside of the center intake impeller device. 11. A directional feeder system comprising: a centrifugal air blower operable to draw air in through a center of a top portion thereof, accelerate the air through a center portion thereof and expel high velocity air through a side portion located beneath the top portion; and a feeder operable to deliver feed particulate to the center portion of the centrifugal air blower, wherein the feed particulate is drawn down through the center portion of the centrifugal air blower and accelerated by the accelerated air, and the accelerated feed particulate is dispensed from the side portion of the centrifugal air blower. 12. A directional feeder system as claimed in claim 11, wherein said centrifugal air blower comprises an impeller comprising a plurality of blades fixed to an impeller plate, wherein the feed particulate is delivered to a center portion of the impeller plate from the center portion of the centrifugal air blower and as the impeller rotates the feed particulate travels with the air flow which is accelerated by the rotating blades, and the feed particulate is expelled from the side portion of the centrifugal air blower. 13. A directional feeder system as claimed in claim 12, wherein the centrifugal air blower further comprises a guide plate adjacent the impeller plate and operable to guide the accelerated air and feed particulate in a predetermined direction. 14. A directional feeder system as claimed in claim 12, wherein the air is accelerated in a spiraling fashion down through the center portion of the centrifugal air blower. 15. A directional feeder system as claimed in claim 14, wherein the feed particulate is assisted by the spiraling air flow as it travels down through the center portion of the centrifugal air blower and portions of the feed particulate have limited contact with the impeller blades as the air and feed particulate are expelled from the side portion of the centrifugal air blower. 16. A method of delivering feed matter in a predetermined direction from a feed container, the method comprising: creating a spiraling air flow pattern in an air blower, wherein air is taken in at the center of a low pressure side of an air blower and the air is accelerated through the air blower to the output side of the air blower; delivering the feed particulate into the spiraling air flow at the low pressure side of the air blower; guiding the feed particulate using the accelerated air through a center portion of the air blower; and expelling accelerated air and feed particulate in the predetermined direction. 17. The method as claimed in claim 16, wherein the feed particulate is assisted by the air flow and limited from contacting parts of the air blower. | TECHNICAL FIELD OF THE INVENTION Various types of active or powered game feeders are available which utilize a battery-powered timer and electric motor to provide energy to scatter or broadcast particulate feed over an area for animal, bird or fish consumption. The simplest of this type of feeder is the scatter plate type feeder, which utilizes a rotating disk of various forms to propel the feed outward in a circular arc around the periphery of the feed station. Directional feeders are also available. Directional feeders use a high speed rotating finned paddle wheel to accelerate and propel the feed unidirectionally from the dispensing apparatus. Functionally the paddles contact the feed and continually impart a force to the food pellets sufficient to ensure they are expelled at a rate that prevents them from accumulating about the food pellet dispensing apparatus. The present invention uses a center feed centrifugal air blower design to create a spiraling high velocity air flow to accelerate the food pellets along the compressor blades and impart a force sufficient to propel the feed particulate away from the feeder in a unidirectional manner. BACKGROUND OF THE INVENTION The majority of existing game feeders, which function to a predetermined feeding schedule, are scatter plate type feeders. This type of feeder generally consists of a barrel type bulk container with a funnel located at the base. Suspended below the funnel is a disk or scatter plate directly attached to a battery driven motor which is controlled by an electric timer. When the scatter plate is stationary the feed flows out of the funnel onto the stationary scatter plate and accumulates upwards in a conical shape until it restricts the opening and stops further flow. At preprogrammed feed intervals the timer applies power to the motor. Powered rotation of the scatter plate creates an inertial force on the feed particulate, slinging it out in a circular unidirectional sweep around the feeder. Fins and sidewalls are frequently added to the scatter plate to stabilize the feed cone or increase the feed throw distance. The first function of the scatter plate is to act as a valve to turn the feed flow on and off from the funnel. The secondary function is to broadcast the feed out in a circular pattern for consumption. Scatter plate type feeders are simple reliable and low cost for most general game feeding requirements. There are, however, numerous game feeding requirements where the conventional scatter type game feeders are severely limited. Typical of these applications is when the feed must be projected out away from the feeder in a single direction to a predefined feed area. For example, a typical requirement for a directional feeder arises when the bulk feeder is or must be protected behind a corral, structure or fence, and, thus, the feeder must project feed into an open or game accessible area. A further example is projecting feed into a fishpond or lake without the use of floats, docks, and cables or floating assemblies. Both, scatter-type feeders and directional feeders are useful for commercial or private game management. The purpose of the present invention is to simplify the application between the two types of feeders discussed, whereby a stand-alone, bulk directional feeder can be utilized or a conventional scatter feeder can be converted to a directional type by the addition of a directional feeder module. The directional feeder modules can be added to or removed from the conventional feeders as requirements dictate. SUMMARY OF THE INVENTION To address the issues discussed above in regard to conventional feeders, the present invention is directed to the design and application of a primary module, which is a center intake, centrifugal air blower assembly for a feeder. On a center intake compressor or blower, air is drawn through a opening at the center of a spiral case and rotating impeller. As the air is drawn in it is rapidly accelerated outward in a spiral motion and forced by this rotating centrifugal force to the larger opening or exhaust at the front of the spiral housing. A low-pressure area is created at the central intake point and as the impeller accelerates the air, the pressure and velocity increase rapidly to expel the air at the frontal exhaust opening. The application of a center intake centrifugal blower in this invention relies on the introduction of feed particulate or pellets into the low-pressure central intake area. In the air stream, the particulates are accelerated with the airflow along the impeller blades at a high velocity to rapidly exit from the exhaust opening at the front of the feeder. By creating and using a high velocity air stream or air flow to direct and accelerate the feed pellets a high efficiency is achieved with less friction on the impeller and case assembly. To simplify the means of injecting the feed pellets into the center intake opening, the blower assembly is tilted, e.g., thirty degrees, from vertical in reference to the hopper or bulk container. By tilting the blower a direct path is created from the hopper funnel to the blower intake, which eliminates the requirements for complicated chutes and elbows. By utilizing a conventional scatter plate at the primary storage hopper funnel as the on/off switch to control the feed flow, the requirement for an actuated gate is eliminated. Further, by eliminating a shut-off gate, the associated baffles, which are often required to lesson the feed weight on the gate, are not required. An application scenario is one where the centrifugal blower hopper and scatter plate assembly module mounted in a small housing unit can be attached to an existing barrel type scatter plate feeder to convert it to a directional feeder. The module can also be housed into a larger case with its own bulk storage and hopper for a stand-alone self-contained directional feeder. In operation, the feed particulate or pellets are stored in a primary bulk container or hopper with a funnel at the base. This primary assembly may be a component in the stand-alone directional feeder or a barrel type scatter feeder, which is to be converted to or utilized as a directional feeder. Either type of unit is controlled by a pre-programmed timer, which controls the sequence of operation. A feeding sequence begins by the timer turning on the centrifugal blower motor to bring it to operational speed. When the blower is at operational speed the timer will turn on the scatter plate drive motor thereby starting a metered flow of feed into the secondary hopper which will flow by gravity into the intake of the high speed centrifugal blower. As the feed is metered into the centrifugal blower's spiral air flow, it is accelerated along the compressor blades and propelled out of the frontal blower exhaust opening. The running cycle will continue until a pre-programmed time is reached at which point the timer will shut off the scatter plate drive motor which will stop the feed flow from the primary hopper. Power will continue to be delivered to the centrifugal blower for a short time sufficient for the blower to clear any feed residue in the assembly and then shut off. Through this sequence one full feed cycle has taken place. Multiple feed cycles and settings can be preprogrammed into the timer for around-the-clock unattended operation. A primary object of the invention is to provide a high efficiency directional feeder module, which does not require the use of special shut off gates, baffles or chutes. It is a further object of the invention to provide a means where the projection of the feed particulate is accomplished with a minimum of physical impact, friction or shredding of the feed. It is also an object of the invention to provide the means whereby the feed pellets will be smoothly accelerated to a high velocity capable of propelling the feed up to sixty feet from the feeder assembly in a single direction. Another object of the invention is to provide a modular component assembly being the air blower assembly, which contained in a small case, can be retrofitted to existing barrel type scatter feeders to convert them to directional feeders. It is a further object of the invention to provide a directional feeder module, which can be attached to a bulk container of any size, which contains a gravity feed funnel, and convert it to a directional feeder. It is also an object of the invention to provide self-contained directional feeders of different container capacities using common component modules. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing perspective of a self contained directional feeder in accordance with the present invention. FIG. 2 is a drawing perspective of a typical drum barrel type scatter feeder which has been converted to a directional feeder by the addition of a small case retrofit module in accordance with the invention. FIG. 3 is a perspective view of a self-contained feeder in accordance with the invention. FIG. 4 is a cut-away perspective view of a drum type scatter feeder, converted to a directional feederin accordance with the invention. FIG. 5 is an exploded view of the directional feeder blower module assembly, according to the present invention. DETAILED DESCRIPTION OF THE INVENTION The directional feeder assemblies shown in FIGS. 1 and 2 show two different embodiments of the present invention. Each embodiment utilizes the same primary centrifugal blower assembly, depicted in the exploded perspective detailed FIG. 5. The output or opening that discharges the feed pellets or aggregate is located at 31. Drawing FIG. 3 shows a sectioned view of the embodiment of FIG. 1 which is a self-contained directional feeder of approximately 125 lbs capacity in this case. The feeder consists of an outer case 18 with four attached legs 23 and a removable cover 19. An internal battery and timer 20 power and control the sequence of operation. A transparent sight glass to enable viewing of the hopper feed level is shown at 21. Hopper funnel 17 is attached to the outer case 18 at its top rim. Side support is provided by four ribs 22, which are attached to the outer case 18. These ribs 22 are used to attach the secondary collection funnel 11 and blower assembly shown in FIG. 5. The bottom of the container 24 is perforated (not shown) to allow free air exchange to all areas below the primary hopper funnel 17. FIG. 4 shows a sectional view of the embodiment of FIG. 2 consisting of a barrel type scatter feeder, which has been converted to a directional feeder according to the invention. The pre-existing components of the feeder consist of the drum 28 (for example, a typical 55 gallon drum can ge used) with three each legs attached 30. At the bottom of the drum 28 is the primary collection funnel 29. Attached to the bottom of the pre-existing barrel assembly is the primary blower assembly detailed in FIG. 5. The blower assembly is attached to the barrel by its outer case 25 which contains the secondary funnel 11 attached within its outer rim. The outer case 25 has a side cutout 26 with the timer and battery assembly 20 affixed to the door for easy access. The outer case 25 has a perforated bottom 27 to provide free air exchange to the blower assembly detailed in FIG. 5. FIG. 5 is an exploded view of the component parts that comprise the centrifugal blower assembly common to all feeders in accordance with the present invention. Electric motor 1 is attached to the blower base plate 3 through motor spacer plate 2. The base plate 3 is attached to a spiral shaped scroll housing 4 by means of a number of common spiral plate mounting brackets 5. Affixed to the motor output shaft is a centrifugal impeller assembly 6 that consists of seven shaped blades mounted on a rotation plate. The shaped blades are mounted around the periphery of the rotation plate and do not extend into the center of the assembly in order to provide an open central intake area for air and feed insertion. Atop the spiral impeller assembly is a top plate 7 which contains a large central opening for air intake and which is attached to the assembly by the spiral plate brackets 5. Attached to the top plate 7 by common screws is a sandwich structure composed of a screen plate 8 and a feed tube plate 9 with a duel intake plate 10 on the outside. The duel intake plate 10 directs the feed particulate into the center and allow air to pass through cutouts 15 around its periphery. Matching cutouts 15 also exist around the protruding feed tube protrusion on the feed tube plate 9 to pass air into the impeller 6 opening. The screen plate 8 is composed of a flat screen with a center opening for the feed tube. The screen plate 8 prevents any stray feed particulate from escaping the blower assembly. Seated above the duel intake plate 10 is the secondary hopper funnel 11. Attached across the hopper funnel 11 is a motor mount bracket 13 on which is mounted the scatter plate motor 12. The scatter plate 14 is fixed to the output shaft of motor 12. The scatter plate 14 is positioned to provide a feed particulate cone build up from the bulk container funnel 17 in FIG. 3 or bulk container funnel 29 in FIG. 4. This feed particulate cone build up occurs at location 16 and provides the function of releasing and metering the feed into the secondary funnel 11 when the scatter plate motor 12 is running, or prohibiting feed flow when the motor 12 is stationary. In operation the feed particulate or pellets are stored in a bulk primary container hopper 18 or 28 with a funnel 17 or 29 located at its base. The operation of the system is controlled by a pre-programmed timer 20, which controls the sequence of operation. The directional broadcasting sequence begins by the timer switching ON the centrifugal blower motor 1. After a time delay for the blower motor to reach operational speed, the timer 20 will switch ON the scatter plate motor 12. Rotation of scatter plate 14 will cast a metered flow of feed from the feed cone build-up at location 16 into the secondary hopper 11 which, guided by the duel intake plate 10, will flow by gravity through the feed tube on the feed tube plate 9. The feed tube plate 9 has a section cut out of the feed tube such that the feed will flow into the intake of the high-speed centrifugal blower. As the feed is metered into the centrifugal blower's spiral airflow, it is accelerated along the impeller blades 6 and propelled out of the frontal blower exhaust opening at 31. The running cycle will continue for a pre-programmed time, at which point the timer 20 will shut OFF the scatter plate drive motor 12, which will stop the feed flow from the primary hopper. The timer 20 will continue enabling power delivery to the centrifugal blower motor 1 for a short time, sufficient for the blower to clear any feed residue in the assembly, and then shut OFF. The above description of the preferred embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and its attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>The majority of existing game feeders, which function to a predetermined feeding schedule, are scatter plate type feeders. This type of feeder generally consists of a barrel type bulk container with a funnel located at the base. Suspended below the funnel is a disk or scatter plate directly attached to a battery driven motor which is controlled by an electric timer. When the scatter plate is stationary the feed flows out of the funnel onto the stationary scatter plate and accumulates upwards in a conical shape until it restricts the opening and stops further flow. At preprogrammed feed intervals the timer applies power to the motor. Powered rotation of the scatter plate creates an inertial force on the feed particulate, slinging it out in a circular unidirectional sweep around the feeder. Fins and sidewalls are frequently added to the scatter plate to stabilize the feed cone or increase the feed throw distance. The first function of the scatter plate is to act as a valve to turn the feed flow on and off from the funnel. The secondary function is to broadcast the feed out in a circular pattern for consumption. Scatter plate type feeders are simple reliable and low cost for most general game feeding requirements. There are, however, numerous game feeding requirements where the conventional scatter type game feeders are severely limited. Typical of these applications is when the feed must be projected out away from the feeder in a single direction to a predefined feed area. For example, a typical requirement for a directional feeder arises when the bulk feeder is or must be protected behind a corral, structure or fence, and, thus, the feeder must project feed into an open or game accessible area. A further example is projecting feed into a fishpond or lake without the use of floats, docks, and cables or floating assemblies. Both, scatter-type feeders and directional feeders are useful for commercial or private game management. The purpose of the present invention is to simplify the application between the two types of feeders discussed, whereby a stand-alone, bulk directional feeder can be utilized or a conventional scatter feeder can be converted to a directional type by the addition of a directional feeder module. The directional feeder modules can be added to or removed from the conventional feeders as requirements dictate. | <SOH> SUMMARY OF THE INVENTION <EOH>To address the issues discussed above in regard to conventional feeders, the present invention is directed to the design and application of a primary module, which is a center intake, centrifugal air blower assembly for a feeder. On a center intake compressor or blower, air is drawn through a opening at the center of a spiral case and rotating impeller. As the air is drawn in it is rapidly accelerated outward in a spiral motion and forced by this rotating centrifugal force to the larger opening or exhaust at the front of the spiral housing. A low-pressure area is created at the central intake point and as the impeller accelerates the air, the pressure and velocity increase rapidly to expel the air at the frontal exhaust opening. The application of a center intake centrifugal blower in this invention relies on the introduction of feed particulate or pellets into the low-pressure central intake area. In the air stream, the particulates are accelerated with the airflow along the impeller blades at a high velocity to rapidly exit from the exhaust opening at the front of the feeder. By creating and using a high velocity air stream or air flow to direct and accelerate the feed pellets a high efficiency is achieved with less friction on the impeller and case assembly. To simplify the means of injecting the feed pellets into the center intake opening, the blower assembly is tilted, e.g., thirty degrees, from vertical in reference to the hopper or bulk container. By tilting the blower a direct path is created from the hopper funnel to the blower intake, which eliminates the requirements for complicated chutes and elbows. By utilizing a conventional scatter plate at the primary storage hopper funnel as the on/off switch to control the feed flow, the requirement for an actuated gate is eliminated. Further, by eliminating a shut-off gate, the associated baffles, which are often required to lesson the feed weight on the gate, are not required. An application scenario is one where the centrifugal blower hopper and scatter plate assembly module mounted in a small housing unit can be attached to an existing barrel type scatter plate feeder to convert it to a directional feeder. The module can also be housed into a larger case with its own bulk storage and hopper for a stand-alone self-contained directional feeder. In operation, the feed particulate or pellets are stored in a primary bulk container or hopper with a funnel at the base. This primary assembly may be a component in the stand-alone directional feeder or a barrel type scatter feeder, which is to be converted to or utilized as a directional feeder. Either type of unit is controlled by a pre-programmed timer, which controls the sequence of operation. A feeding sequence begins by the timer turning on the centrifugal blower motor to bring it to operational speed. When the blower is at operational speed the timer will turn on the scatter plate drive motor thereby starting a metered flow of feed into the secondary hopper which will flow by gravity into the intake of the high speed centrifugal blower. As the feed is metered into the centrifugal blower's spiral air flow, it is accelerated along the compressor blades and propelled out of the frontal blower exhaust opening. The running cycle will continue until a pre-programmed time is reached at which point the timer will shut off the scatter plate drive motor which will stop the feed flow from the primary hopper. Power will continue to be delivered to the centrifugal blower for a short time sufficient for the blower to clear any feed residue in the assembly and then shut off. Through this sequence one full feed cycle has taken place. Multiple feed cycles and settings can be preprogrammed into the timer for around-the-clock unattended operation. A primary object of the invention is to provide a high efficiency directional feeder module, which does not require the use of special shut off gates, baffles or chutes. It is a further object of the invention to provide a means where the projection of the feed particulate is accomplished with a minimum of physical impact, friction or shredding of the feed. It is also an object of the invention to provide the means whereby the feed pellets will be smoothly accelerated to a high velocity capable of propelling the feed up to sixty feet from the feeder assembly in a single direction. Another object of the invention is to provide a modular component assembly being the air blower assembly, which contained in a small case, can be retrofitted to existing barrel type scatter feeders to convert them to directional feeders. It is a further object of the invention to provide a directional feeder module, which can be attached to a bulk container of any size, which contains a gravity feed funnel, and convert it to a directional feeder. It is also an object of the invention to provide self-contained directional feeders of different container capacities using common component modules. | 20040428 | 20070529 | 20051103 | 65224.0 | 1 | NGUYEN, TRINH T | DIRECTIONAL BROADCAST FEEDER FOR FISH AND GAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,833,356 | ACCEPTED | Radio frequency identification controlled heatable objects | A temperature controlled heatable object is provided in which a temperature sensor is connected to a Radio Frequency Identification (RFID) tag. The RFID tag is located within the handle of the object, and the temperature sensor is placed in contact with the object. In a first embodiment of the invention, the temperature sensor is partially imbedded within the object via a notch located in the side of the object. In a second embodiment of the invention, a temperature sensor is imbedded within a tunnel drilled within the base of the object. In a third embodiment, a temperature sensor is imbedded between the bottom of the object and a slab attached to the bottom of the object. The sensor can be located in a slot formed in either the slab or the bottom or the object. Handles and receivers for mounting the handles to the temperature controllable objects are also provided. | 1. A radio frequency identification controlled object comprising: a temperature sensor placed in contact with a heatable portion of the object; and a radio frequency identification tag associated with said temperature sensor and located outside of a heat-generation zone for the object, said tag being operable to communicate temperature information obtained by said temperature sensor with a heating device. 2. The radio frequency identification controlled object as claimed in claim 1 wherein said temperature sensor is placed in contact with a primary heat-distribution layer of said heatable portion of the object. 3. The radio frequency identification controlled object as claimed in claim 2 wherein said primary heat-distribution layer comprises an aluminum core for the object. 4. The radio frequency identification controlled object as claimed in claim 3 wherein said heatable portion of the object further comprises a ferromagnetic layer associated with said aluminum core. 5. The radio frequency identification controlled object as claimed in claim 1 wherein said temperature sensor is at least partially imbedded in said heatable portion of the object. 6. The radio frequency identification controlled object as claimed in claim 5 wherein said temperature sensor is placed in contact with a primary heat-distribution layer of said heatable portion. 7. The radio frequency identification controlled object as claimed in claim 5 wherein said temperature sensor is at least partially imbedded within a notch in said heatable portion of the object. 8. The radio frequency identification controlled object as claimed in claim 5 wherein said temperature sensor is imbedded within a tunnel in said heatable portion of the object. 9. The radio frequency identification controlled object as claimed in claim 5 wherein said heat generation portion of the object comprises a primary base portion and a slab attached to a surface of said primary base portion, and wherein said temperature sensor is located between said primary base portion and said slab. 10. The radio frequency identification controlled object as claimed in claim 9 wherein said temperature sensor is located within a slot formed in said base portion of the object. 11. The radio frequency identification controlled object as claimed in claim 9 wherein said temperature sensor is located within a slot formed in said slab. 12. The radio frequency identification controlled object as claimed in claim 1 wherein said heatable portion of the object is heated by magnetic induction. 13. The radio frequency identification controlled object as claimed in claim 1 wherein said radio frequency identification tag is located within a handle of the object. 14. The radio frequency identification controlled object as claimed in claim 1 wherein the object comprises a cookware object. 15. The radio frequency identification controlled object as claimed in claim 1 wherein the object comprises a servingware object. 16. A radio frequency identification controlled object comprising: a temperature sensor at least partially imbedded within a heatable portion of the object; and a radio frequency identification tag associated with said temperature sensor, said tag being operable to communicate temperature information obtained by said temperature sensor to a heating device. 17. The radio frequency identification controlled object as claimed in claim 16 wherein said radio frequency identification tag is located remote from said heatable portion of the object. 18. The radio frequency identification controlled object as claimed in claim 16 wherein said temperature sensor is at least partially imbedded within a notch in said heatable portion of the object. 19. The radio frequency identification controlled object as claimed in claim 16 wherein said temperature sensor is imbedded within a tunnel in said heatable portion of the object. 20. The radio frequency identification controlled object as claimed in claim 16 wherein said heat generation portion of the object comprises a primary base portion and a slab attached to a surface of said primary base portion, and wherein said temperature sensor is located between said primary base portion and said slab. 21. The radio frequency identification controlled object as claimed in claim 20 wherein said temperature sensor is located within a slot formed in said base portion of the object. 22. The radio frequency identification controlled object as claimed in claim 20 wherein said temperature sensor is located within a slot formed in said slab. 23. The radio frequency identification controlled object as claimed in claim 16 wherein said heatable portion of the object is heated by magnetic induction. 24. The radio frequency identification controlled object as claimed in claim 16 wherein said radio frequency identification tag is located within a handle of the object. 25. The radio frequency identification controlled object as claimed in claim 16 wherein the object comprises a cookware object. 26. The radio frequency identification controlled object as claimed in claim 16 wherein the object comprises a servingware object. 27. A heatable object comprising: a temperature sensor at least partially imbedded within a heatable portion of the object; and a transmitter associated with said temperature sensor, said transmitter being operable to communicate temperature information obtained by said temperature sensor to a heating device. 28. The object as claimed in claim 27 wherein said transmitter is located remote from said heatable portion of the object. 29. The object as claimed in claim 27 wherein said transmitter comprises a radio frequency identification tag. 30. The object as claimed in claim 29 further comprising: a handle including a cavity in which said radio frequency identification tag is located; and a receiver for connecting said handle to the object. 31. The object as claimed in claim 30 wherein said receiver includes support members for engaging said handle and a window between said support members. 32. The object as claimed in claim 30 wherein said handle cavity includes opposing channels for alignment of said radio frequency identification tag. 33. The object as claimed in claim 32 wherein each of said channels includes a graduated opening for guidance of said radio frequency identification card into said channels. 34. The object as claimed in claim 30 wherein said handle is removably connected to said receiver. 35. The object as claimed in claim 34 further comprising at least one spring clip positioned within a graduated groove in said handle for removably connecting said handle to said receiver. 36. The object as claimed in claim 27 wherein the object comprises a cookware object. 37. The object as claimed in claim 27 wherein the object comprises a servingware object. a notch in 38. The object as claimed in claim 27 wherein said temperature sensor is at least partially imbedded within a notch in said heatable portion of the object. 39. The object as claimed in claim 27 wherein said temperature sensor is at least partially imbedded within a tunnel in said heatable portion of the object. 40. The object as claimed in claim 39 further comprising a notch adjacent an outer end of said tunnel, and a receiver including a tab for engagement with said notch. 41. The object as claimed in claim 39 further comprising a receiver adapted to cover an outer opening of said tunnel, said receiver further comprising: an injection port associated with said tunnel; and a wire passage from said handle to said slot. 42. The object as claimed in claim 27 wherein said heatable portion of the object comprises a primary base portion and a slab attached to said primary base portion, and wherein said temperature sensor is at least partially imbedded between said primary base portion and said slab. 43. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed in said base portion of the object. 44. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed in said slab. 45. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed between said base portion and said slab, and further comprising a receiver including an insert for engagement with said slot. 46. The object as claimed in claim 42 wherein said receiver is adapted to cover an outer opening of a slot in the object, said receiver further comprising: an injection port associated with said slot; and a wire passage from said handle to said slot. 47. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed between said base portion and said slab, said slot further comprising a stamped tunnel including an outer edge portion protruding from said slot, and said receiver includes a cavity for engagement with said protruding outer edge portion of said stamped tunnel. 48. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed between said base portion and said slab, and said receiver comprises a rod connected to said temperature sensor and adapted for insertion into said slot. 49. The object as claimed in claim 48 wherein said slab includes an injection port extending into said slot at a location adjacent to said temperature sensor. 50. The object as claimed in claim 42 wherein said temperature sensor is located within a slot formed between said base portion and said slab, and said receiver comprises a tube for insertion of said temperature sensor into said slot. 51. The object as claimed in claim 50 wherein said slab includes an injection port extending into said slot at a location adjacent to said temperature sensor, and said receiver includes an injection port associated with said tube. 52. The object as claimed in claim 42 wherein the object comprises a cookware object. 53. The object as claimed in claim 42 wherein the object comprises a servingware object. 54. A heatable object comprising: a temperature sensor at least partially imbedded within a notch the object; and a transmitter associated with said temperature sensor, said transmitter being operable to communicate temperature information obtained by said temperature sensor to a heating device. 55. A heatable object comprising: a temperature sensor at least partially imbedded within a tunnel in the object; and a transmitter associated with said temperature sensor, said transmitter being operable to communicate temperature information obtained by said temperature sensor to a heating device. 56. A heatable object comprising: a primary base portion; a slab attached to a surface of said primary base portion; a temperature sensor located between said primary base portion and said slab; and a transmitter associated with said temperature sensor, said transmitter being operable to communicate temperature information obtained by said temperature sensor to a heating device. 57. A handle for a radio frequency identification controlled heatable object, said handle comprising: an internal cavity; and opposing channels for alignment of a radio frequency identification tag. 58. The handle as claimed in claim 54 wherein each of said channels includes a graduated opening for guidance of said radio frequency identification tag into said channels. 59. The handle as claimed in claim 54 further comprising a removable connection for connecting said handle to a receiver. 60. The handle as claimed in claim 59 further comprising at least one spring clip positioned within a graduated groove in said handle for removably connecting said handle to said receiver. 61. The handle as claimed in claim 54 further comprising a gripping end distal to said internal cavity, said gripping end protruding upward from said internal cavity. 62. The handle as claimed in claim 54 wherein the heatable object comprises a cookware object. 63. The handle as claimed in claim 54 wherein the heatable object comprises a servingware object. 64. A receiver for connecting a handle to a radio frequency identification controlled object, said receiver comprising: support members for engaging a handle; and a window between said support members. 65. The receiver as claimed in claim 64 further comprising a tab for engagement with a notch in the object. 66. The receiver as claimed in claim 64 further comprising an insert for engagement with a slot in the object. 67. The receiver as claimed in claim 64 adapted to cover an outer opening of a slot or tunnel in the object, said receiver further comprising: an injection port associated with the slot or tunnel; and a wire passage from the handle to the slot or tunnel. 68. The receiver as claimed in claim 64 further comprising a cavity for engagement with a protruding outer edge portion of the object. 69. The receiver as claimed in claim 64 further comprising a rod connected to a temperature sensor and adapted for insertion into a slot or tunnel within the object. 70. The receiver as claimed in claim 64 further comprising a tube for insertion of a temperature sensor into a slot or tunnel within the object. 71. The receiver as claimed in claim 70 further comprising an injection port associated with said tube. 72. The receiver as claimed in claim 64 wherein the radio frequency identification controlled object comprises a cookware object. 73. The receiver as claimed in claim 64 wherein the radio frequency identification controlled object comprises a servingware object. | FIELD OF THE INVENTION The present invention is broadly concerned with temperature regulated cookware and servingware items, such as pots, pans, buffet serving pans, serving dishes, platters, and the like. More particularly, the invention is concerned with cookware and servingware objects that are temperature regulated using Radio Frequency Identification (RFID) technology and temperature sensors associated with the objects. An RFID tag, which is associated with a temperature sensor, includes information regarding heating characteristics of the particular object. The RFID tag transmits the information regarding the heating characteristics of the object as well as temperature reading information to a reader located within a cookware appliance, which are used by the cookware appliance to regulate the temperature of the cooking process. BACKGROUND OF THE INVENTION Cooking is often referred to as an art, not only because of the combination of ingredients that go into a particular recipe, but also due to the skill necessary for proper application and infusion of varying levels of heat over a given period of time throughout the different phases of the food preparation process. Traditional cookware appliances, such as ovens (microwave ovens being an exception), grills, heat lamps and stoves, all utilize the thermodynamic process of conduction to transfer heat from the outer surface of the food item to its interior. This is generally true regardless of the type of heat source used to heat the surface of the food, be it a radiation heat source (i.e. a heat lamp), conduction heat source (i.e. a stovetop), or a convection heat source (i.e. a convection oven or a food dehydrator). The time and temperature necessary to cook fully and properly a specific food item through conduction is dependant upon the thermal conductivity of the item, the uncooked temperature of the item (i.e. frozen, room temperature, etc.), as well as the size and shape of the item. A food item having higher thermal conductivity will cook faster than a similarly sized and shaped food item having a lower thermal conductivity, as the heat will more quickly migrate from the outer surface to the interior. Likewise, a generally smaller or thinner food item will cook faster than a generally larger or thicker food item of the same thermal conductivity, as the heat must migrate a shorter distance through the thinner item. Frozen items require considerably more heat to cook than do non-frozen or thawed items. While increasing the cooking temperature for an item will increase the amount of heat that migrates from the surface to the interior of a food item, applying too much heat at one time will result in cooking the outer surface of the item faster than the heat can migrate to the interior, usually resulting in burning or scorching of the surface and undercooking of the interior. Therefore, obtaining real-time information regarding the temperature of the item being cooked, during the cooking process is often beneficial to ensure proper heating. The use of thermometers or other temperature sensors to monitor and control the cooking process is well known. A common thermometer used to monitor and control the cooking process is a probe-type or contact thermometer which is inserted directly into the food item to obtain a temperature of the interior of the food item. Such thermometers are undesirable for many cooking applications. For, example, when cooking in pots or pans using a lid, the use of a probe-type thermometer requires removal of the lid each time a temperature reading is taken. Continuous removal of the lid during cooking reduces the transfer of heat to the item being cooked, and often results it a detrimental loss of moisture. In addition, the use of contact thermometers usually require manual adjustment of the power of the cooking appliance to obtain and maintain a desired temperature. Not to mention the probe-type thermometer is yet another cooking instrument that must be located and properly used during the often complex cooking process. To overcome the disadvantages associated with contact thermometers, a number of cookware-associated non-contact thermometers have been developed that are attached to, or incorporated into, cookware objects such as pots and pans. Such non-contact thermometers are often in communication with the cooking appliance to control the power level based on the temperature reading. Nevertheless, as discussed below, none of these non-contact thermometers, which control the cooking process solely based upon the temperature of the cookware object, provide a means of obtaining consistent and accurate measurement and control of the temperature of the food item being cooked within the cookware object. U.S. Pat. No. 3,742,178 to Harnden, Jr. describes a non-contact thermometer placed in thermal contact with an inner wall surface of an inner cup of a cookware object, located between the inner cup and an outer cup in which the inner cup is nested. The inner cup is constructed of a ferromagnetic material that can be heated by an induction coil located in an induction cook-top appliance. Maintaining a stable connection between the temperature sensor and the inner wall of the inner cup is difficult due to thermal expansions and contractions during heating and cooling of the pot. In addition, a large temperature differential may often exist between the inner wall of the inner cup and the outer wall of the inner cup, particularly when extremely cold items are placed within the cookware object while the inner cup is being heated. This large temperature differential makes an accurate determination of the temperature of the food item within the pot difficult, if not impossible to obtain when the temperature reading is taken at the inner wall surface of the inner cup. In the cookware object taught by Harnden, Jr., the field produced by the induction coil for heating the object also powers the temperature sensor which transmits temperature information to the cook-top appliance via radio frequency to control heating of the cookware object. Although such an arrangement works with induction heating appliances, the temperature sensor of Harnden, Jr. is inoperable when used with a traditional gas or electric stove which heats the cookware object by conduction. Furthermore, the nested cup design of Harnden, Jr., which includes a gap between the inner wall surfaces of the inner and outer cups filled with either thermal insulation material, air or vacuum, is inefficient for conducting heat from the outer cup to the inner cup, making use of the cookware object of Harnden, Jr. with traditional appliances undesirable even if use of the temperature sensor is utilized. U.S. Pat. No. 5,951,900 to Smrke describes a non-contact temperature sensor that attempts to overcome many of the disadvantages of Harnden, Jr. by inclusion of a temperature sensor mounted to the exterior surface of a lid of cookware object. The temperature sensor of Smrke transmits, either via radio frequency or via wire, temperature information to a cookware appliance to control heating of the cookware object. Although Smrke asserts that a determination of the temperature on the lid of a cookware object is ideal for controlling cooking because such temperature is dependant upon heater power, pot type, food quantity, etc., Smrke does not provide an accurate means of determining temperature of the food item within the cookware object. Furthermore, as discussed above, maintaining a stable connection between the temperature sensor and a surface of the cookware object to which the sensor is attached is difficult due to thermal expansions and contractions during heating and cooling of the object. Both Harnden, Jr. and Smrke teach cookware objects that are temperature regulated solely by the temperature obtained by the temperature sensors. While temperature information from the object is important, it is often not sufficient to obtain a desired regulation temperature within a desired period of time. For example, it is well known that the power applied to an object placed upon an induction cook-top depends greatly upon the distance between the object's ferromagnetic material and the work coil of the cook-top. Should an object require a particular graduated power application to prevent overheating of some parts of the object while reaching the desired regulation temperature throughout the object, it is essential that the proper power be coupled to the object. Furthermore, most practical heating operations require that the prescribed regulation temperature be reached within a maximum prescribed time. This restraint makes it even more important that proper power be applied during each temperature gradation. A means to correct for inconsistent power coupling that is based upon comparisons between power measurements and stored power coupling data is essential to achieve consistent heating operations and accurate temperature regulation. U.S. Pat. No. 6,320,169 to Clothier, the disclosure of which is incorporated herein by reference, teaches the use of a Radio Frequency Identification (RFID) tag attached to an induction heatable object to transmit information (typically about a heating characteristic of the object) to a control system of an induction heating device. RFID is an automatic identification technology similar in application to bar code technology, but which uses radio frequency instead of optical signals. RFID systems can be either read-only or read/write. For a read-only system such as Motorola's OMR-705+ reader and IT-254E tag, an RFID system consists of two major components, a reader and a special “tag”. The reader performs several functions, one of which is to produce a low-level radio frequency magnetic field, typically either at 125 kHz or at 13.56 MHz. The RF magnetic field emanates from the reader by means of a transmitting antenna, typically in the form of a coil. A reader may be sold in two separate parts: an RFID coupler, including a radio processing unit and a digital processing unit, and a detachable antenna. An RFID tag also contains an antenna, also typically in the form of a coil, and an integrated circuit (IC). Read/write systems permit two-way communication between the tag and reader/writer, and both the tag and the reader/writer typically include electronic memory for the storing of received information. Although Clothier discloses that RFID controlled objects can be either cookware or servingware objects, all of the objects disclosed by Clothier are in the form of servingware objects, such as plates and cups. Such objects, which are designed to keep food that has already been cooked at an adequate serving temperature, are subjected to significantly lower temperatures and usually heated for shorter time intervals than are pots, pans and other cookware items, i.e. approximately 250 degrees Fahrenheit for servingware versus approximately 900 degrees Fahrenheit for cookware. Therefore, servingware objects have fewer design constraints than do cookware objects. For example, each of the servingware objects disclosed by Clothier include RFID tags located in the base of the objects, thermally insulated from the heating element or heatable portion of the object. The RFID tag is thermally insulated from the heatable portion of the object due to the limited operating temperatures for most RFID tags. The RFID tag is located in the base of the servingware objects disclosed by Clothier so as to be positioned parallel to and within a range of several inches from the RFID reader/writer located in the induction heating device to enable communication between the tag and the reader/writer during heating of the object. Nevertheless, locating an RFID tag in the base of a cookware object such as a pot or pan, makes adequate thermal insulation difficult to obtain. In addition, even if sufficient thermal insulation is provided, such insulation prevents the cookware object from being heated by traditional cook-top appliances, such as gas or electric stoves conduction stoves as the RFID tag is located directly in the heat-generation zone (i.e. the area directly above the heat source—such as the gas or electric burner for traditional heating appliances, or the induction coil for induction heating appliances—in which the energy used to heat the object is directed) for the object. The RFID servingware objects disclosed by Clothier are primarily temperature regulated using heating algorithms based upon the heating characteristics transmitted from the object to the induction heating device. Clothier further discloses the inclusion of temperature regulation switches in combination with the RFID tag to better regulate the temperature of the object during heating. The temperature switches disclosed by Clothier operate to prevent or alter the transmission of information from the RFID tag to the induction heating device controller when the thermal switch experiences a predetermined temperature condition. Thus the temperature switches disclosed by Clothier do not provide the ability to obtain a temperature reading other than providing confirmation that the predetermined temperature has been exceeded. This results in a finite number of temperatures, based upon the number of temperature switches, to which the object can be accurately regulated. While such a finite number of predetermined temperatures is acceptable for servingware objects that function to keep already cooked food warm, cookware items, such as pots and pans require a much broader range of regulation temperatures. In fact, cooking of a single item can often require heating in several phases at varying temperatures. The RFID controlled servingware object combined with temperature switches disclosed by Clothier is in the form of a sizzle plate typically used in restaurants. The temperature switches, which are connected to the RFID tag are placed in contact with the undersurface of the cast iron plate. While such an arrangement may be adequate for lower temperature servingware such as the sizzle plate, the problems associated with maintaining a stable connection to a surface of the heatable object discussed above still exist. SUMMARY OF THE INVENTION An object of the instant invention is to provide a temperature regulated object (or item). Another object of the instant invention is to provide a temperature regulated item that can be used for as servingware, cookware, and the like. Yet another object of the instant invention is to provide a temperature regulated item in which a temperature reading taken of the item is utilized in regulating the item's temperature. Another object of the instant invention is to provide a temperature regulated object in which the temperature reading provides an accurate indication of the temperature of the food being heated within the item without contacting the food. Still another object of the instant invention is to provide a temperature regulated item in which the temperature reading provides an accurate indication of the temperature of the food being heated within the item, and which can be used with traditional or induction heating devices. Another object of the invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item. Yet another object of the present invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item that is capable of regulating the item to an wide range of temperatures. Still another object of the instant invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item, wherein the item is suitable for high temperature applications such as cooking. Another object of the present invention is to provide a temperature regulated item including a temperature sensor contacting a heatable portion of the item, wherein the connection between the sensor and the heatable portion of the item is capable of withstanding thermal expansion and contraction during heating and cooling of the item. An other object of the instant invention is to provide a temperature regulated item that having a temperature sensor contacting a heatable portion of the item, wherein the connection between the sensor and the heatable portion of the item is capable of withstanding thermal expansion and contraction during heating and cooling of the item, and which is capable of utilizing heating characteristics other than a temperature reading to regulate cooking temperature for the item. The above described objects are achieved using a temperature regulated object including a heatable body, a temperature sensor and an RFID tag. The temperature sensor contacts the heatable body of the object, and is connected to the RFID tag by a pair of wires. The RFID tag acts as a transmitter (and sometimes as receiver) to communicate with a reader/writer located in a cook-top for heating the object, providing temperature information and other information regarding the object (such as heating characteristics) to the cook-top. The temperature information and the heating information is used by the cook-top to control the temperature of the object. An illustrative embodiment of the instant invention is described in which the heatable object is a cookware object such as a pan. In a first embodiment of the invention, the temperature sensor is partially imbedded within a notch located in the side and toward the bottom of the pan, placed in contact with a conductive core of the pan. Partially imbedding the sensor in the body of the pan provides an improved connection between the sensor and the heatable body of the pan that is more capable of withstanding thermal expansion and contraction caused by heating and cooling of the pan. In addition, the partially imbedded temperature sensor is located closer to the interior of the pan and the food item being cooked, providing a more accurate reading of the temperature of the food item than is possible by measuring the temperature of the bottom surface of the pan, which will be influenced by the heat source. Furthermore, by partially imbedding the sensor, it is possible to utilize pan walls that are thinner than the diameter of the sensor. In a second embodiment of the instant invention, the temperature sensor is imbedded within a tunnel that is formed in the bottom wall of the pan. In a preferred embodiment the pan in manufactured in a manner known in the art, and the tunnel is then drilled into the base of the pan. As with the side-notch embodiment, the bottom tunnel provides increased durability of the connection between the temperature sensor and the heatable portion of the pan, and places the temperature sensor closer to the interior of the pan. In addition, the bottom tunnel permits the temperature sensor to be located at the center of the pan where one of the hottest temperatures for the pan is obtained and is very robust against a dislocation of the pan from the center of the heating object, like a center of induction coil or center of halogen heater or center of electric heater and so on. In a third embodiment of the instant invention, the temperature sensor is imbedded between the bottom of the pan and a slab connected to the pan bottom. One variation of this slab-bottom includes a slot formed in the slab for placement of the temperature sensor and associated wires. This allows for placement of a temperature sensor at the center of the pan base, even when the pan walls are relatively thin (thinner than the diameter of the sensor). Another variation of the slab bottom includes a slot formed in the bottom of the pan itself. In this embodiment, the temperature sensor is positioned closer to the interior of the pan. The RFID tag is located within a cavity formed in the handle of the pan of the instant invention to position the tag outside of the heat-generation zone for the pan. This reduces the temperature to which the tag is subjected, maximizing the life of the tag. Ramped guide channels are located within the cavity to guide the RFID tag into a proper assembled location. The handle holds the RFID tag parallel to the cook-top surface for maximum signal strength during operation. The inventive handle includes a releasable spring-clip connection between the handle and a receiver for supporting the handle. The receiver of the instant invention supports the handle. A window between a pair of opposing supports maximizes the strength of the signal transmitted between the RFID tag and the reader/writer by minimizing obstruction of the RFID tag antenna. In a preferred embodiment of the invention, the receiver includes an injection port for injecting a potting material into a tunnel or slot in which the temperature sensor in located. In alternative preferred embodiments, a rigid rod or tube is connected to the receiver and the temperature sensor to aid in insertion of the sensor in the tunnel or slot during assembly. The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention and various features thereof. DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention, illustrative of the best modes in which the applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims. FIG. 1 is an exploded perspective view of a RFID controlled frying pan of the instant invention in which a temperature sensor is positioned in a notch in the side of the pan. FIG. 2 is a partial top plan view of the RFID controlled frying pan shown in FIG. 1. FIG. 3 is a partial section view taken along line A-A of FIG. 2 showing the notched side and corresponding temperature sensor in detail. FIG. 4 is a side elevation view of a receiver for connecting a handle to the frying pan shown in FIG. 1. FIG. 5 is a rear elevation view of the receiver of FIG. 4. FIG. 6 is a frontal perspective view of the receiver of FIG. 4. FIG. 7 is a perspective view of a handle for the frying pan shown in FIG. 1. FIG. 8 is an end view of the handle shown in FIG. 7. FIG. 9 is an exploded perspective view of a RFID controlled sauce pan of the instant invention in which a temperature sensor is positioned at the center of the base of the pan. FIG. 10 is an exploded perspective view of a RFID controlled frying pan of the instant invention in which a temperature sensor is positioned at the center of the base of the pan. FIG. 11 is an exploded perspective view of a RFID controlled pot of the instant invention in which a temperature sensor is positioned at the center of the base of the pot. FIG. 12 is an exploded perspective view of a RFID controlled frying pan of the instant invention in which a temperature sensor is positioned at the center of the base of the pan through the use of a tunnel extending into the base of the pan. FIG. 13 is a side elevation view of an embodiment of a receiver for connecting the RFID housing handle to any of the pans shown in FIG. 9 through 11. FIG. 14 is a rear elevation view of the receiver of FIG. 13. FIG. 15 is a detailed perspective view of the pan of FIG. 12 showing a notch for accepting a end tab of a receiver. FIG. 16 is a detailed perspective view of the pan of FIG. 15 showing a receiver assembled with the notch. FIG. 17 is a partial section view of the pan of FIG. 12 fully assembled showing the tunnel, receiver and corresponding temperature sensor in detail. FIG. 18 is an exploded perspective view of a first embodiment of a slab bottom pan having a slot in the base of the pan. FIG. 19 is a partial section view of second embodiment of a slab bottom pan having a slot in the slab, showing a first embodiment for a receiver. FIG. 20 is a partial section view of second embodiment of a slab bottom pan having a slot in the slab, showing an alternative embodiment for a receiver. FIG. 21 is a partial perspective view of the receiver presented in FIG. 20. FIG. 22 is a partial section view of second embodiment of a slab bottom pan having a slot in the slab, showing another alternative embodiment for a receiver. FIG. 23 is a partial perspective view of a second embodiment of a slab bottom pan having a slot in the slab, showing another alternative embodiment for a receiver and a stamped-tunnel slot. DESCRIPTION OF PREFERRED EMBODIMENTS As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the principles of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. The instant invention is concerned with temperature regulated objects in which a temperature reading from the object is transmitted to a controller for a heat source. The controller for the heat source utilizes the temperature reading to control the amount of heat applied from the heat source on the object to control a cooking process. In a preferred embodiment of the instant invention, other information about the object, such as identification information or heating characteristics for the object, are transmitted to the controller of the heat source. This other information, along with the temperature reading, is utilized by the controller of the heat source in regulating the temperature of the object during the cooking process. Preferred embodiments of the instant invention are described herein in the form of temperature regulated cookware objects, such as pots and pans; it will however be appreciated that the instant invention relates to all temperature regulated objects including cookware objects as well as servingware objects. In addition, the instant invention relates to component parts of temperature regulated objects. In a preferred embodiment, the temperature regulated objects of the instant invention are intended to be used in connection with a Radio Frequency Identification (RFID) controlled induction heating appliance, similar to that discussed in U.S. Pat. No. 6,320,169, the disclosure of which is incorporated herein by reference. Nevertheless, it will be appreciated that temperature regulated objects intended to be heated by RFID controlled traditional cookware appliances (i.e. gas and electric stoves) are included within the scope of the instant invention. Furthermore, the scope of the instant invention includes temperature regulated objects utilizing non-RFID alternative means of transmitting object heating characteristic information and temperature reading information to a cookware appliance which are now known or later discovered. Referring to FIGS. 1 through 3, a first embodiment of an RFID controlled cookware object, in the form of a frying pan is shown. FIG. 1 shows an exploded view of cookware object 10 including pan body 20, primary handle 40, and secondary (helper) handle 50. Primary handle 40 is connected to pan body 20 via bracket/receiver 30. Spring clips 80 releasably secure primary handle 40 to receiver 30 through the engagement of clip ends 82 with holes 32 in receiver 30. Helper handle 50 is connected to pan body 20 via bracket 55. An RFID tag, 60, is connected to temperature sensor 70 via a pair of wires, 72. RFID tag 60 is stored in a cavity located within handle 40. Wires 72 extend from the interior of the cavity through a portal 34 of receiver 30 to sensor 70 which is generally located between receiver 30 and the exterior of pan body 20 within notch 22 formed into the side of pan body 20. Pan body 20 is fabricated from materials and manufactured by means well known in the art. Types of materials commonly used for fabrication of pan body 20 include, but are not limited to, cast iron, stainless steel, aluminum, aluminum alloys, copper, copper-clad stainless steel, etc. In a preferred embodiment, pan body 20 is fabricated to be used for induction cooking. Although a number of materials can be utilized for fabrication of a pan body capable of induction heating, the construction of a multi-ply body comprising layers of several different materials is quite common. The specific material used for each ply or layer, the thickness of each layer, and the total number of layers will vary depending upon the size, shape, desired appearance and desired heating characteristics of the pan. In an exemplary embodiment, pan body 20 is a 5-ply construction, including a first layer of magnetic stainless steel forming the interior cooking surface of the pan, a second inner-layer of 3003 pure aluminum, a third inner-layer of 1145 aluminum alloy, a fourth inner-layer of 1145 aluminum, and a fifth layer of magnetic stainless steel forming the exterior surface of the pan. The two surface layers of magnetic stainless steel provide strength, durability, easy cleaning and a long-lasting, attractive appearance to the pan body. The exterior surface layer of magnetic stainless steel builds up heat generated from a stove cook-top (either by conduction in a traditional stove, or by induction utilizing the ferromagnetic properties of the steel in an induction stove)generally at the center of the base of the pan body. The three layers of aluminum and aluminum alloy, which form an aluminum core for the pan, absorb heat quickly from the exterior layer of steel, and smoothly and evenly distribute the heat through conduction across the bottom and sides of the pan body to the inner layer of steel. FIGS. 4 through 6 show detail views of receiver 30 for use with the RFID controlled cookware object shown in FIGS. 1 through 3. Receiver 30 includes support members 36 for engaging handle 40. Spring clips 80 frictionally engage with support member 36 to releasably secure handle 40 to receiver 30. Support members 36 of receiver 30 perform several functions, one is to support handle 40 in the manner described above, an other is to increase and/or concentrate the transmission signal strength between tag 60 and a reader/writer located below the surface of a cook-top. The transmission signal is increased and/or concentrated through the use of window 37 that is formed between the lower interior edges of opposing support members 36. Window 37 provides a generally unobstructed transmission zone between tag 60 and the reader/writer of the cook-top. The size and shape of window 37 is adjusted based upon the particular arrangement of the antenna of pan tag 60 to help tune the transmission signal by reducing obstruction between the antenna of pan tag 60 and the antenna of the reader/writer located in the cook-top. FIGS. 2 and 3 show detail views of receiver 30 in attached engagement with pan body 20, wherein handle 40 has been removed. Receiver 30 includes member 39 extending downward from support members 36 to the base of pan body 20. Channel 38 is formed in member 39 to permit wires 62 and sensor 70 to be located in the cavity created between member 39 of receiver 30 and pan body 20. Member 39 covers notch 22 and sensor 70 which is located in notch 22. Notch 22 is machined (EDM, CNC, etc.) into the side of pan body 20 exposing the aluminum core and permitting contact of the aluminum core by sensor 70. The lower-most portion of member 39 extends beyond the bottom of sensor 70 and inward to surround sensor 70 and provide a clean, generally flush base for the assembled combination of pan body 20 and receiver 30. Receiver 30 is manufactured of a metal such as steel, aluminum alloy, or any other material suitable for supporting handle 40 to pan body 20. In the preferred embodiment described herein, in which pan body 20 is heated by induction, receiver 30 is manufactured from a non-ferromagnetic material, such as non-magnetic stainless steel, to reduce the possibility that receiver 30 will be heated by the magnetic field of the cook-top. Receiver 30 includes recess 33 which corresponds to a locator (not shown) protruding from pan body 20. The combination of the locator and recess 33 ensures proper alignment of receiver 30 over notch 22 during assembly and throughout the life of cookware object 10. In a preferred embodiment, receiver 30 is welded or braised to pan body 20 for a long-lasting, durable connection, and channel 38 is filled with a potting material, such as a high temperature silicon like Loctite® 5406, to protect the exposed aluminum core of pan body 20 and to secure sensor 70 within notch 22. To aid in an automated braising process, receiver 30 includes a number of nubs (welding/braising lugs) 35 protruding from the back surface of the receiver, which contact the outer surface of pan body 20 when receiver is properly positioned over notch 22. Nubs 35 are formed of a material having a lower melting point than the material used to manufacture receiver 30, allowing nubs 35 to be melted for braising by applying heat to the surface of receiver 30 opposite nubs 35, without melting receiver 30. Tag 60 is located within end 42 of handle 40. To position tag 60 within operating range from the reader/writer located within the cook-top, receiver 30 locates handle end 42 relatively close to the base of pan body 20. On most cookware items, such a placement of handle end 42 is much lower than normally utilized. In many instances, low placement of the handle on a cookware object can make the object difficult to handle and even unsafe, especially when the cookware object is used on traditional stoves-tops in which the burner surface gets extremely hot. To provide safer and easier handling of pan 10, handle 40 curves upward from end 42 to end 44. This allows the cook to grasp handle 40 at end 44 without being too close to the surface of the cook-top. FIGS. 7 and 8 show handle 40 apart from pan 10. End 42 of handle 40 includes section 46 that is cut away in relief to permit handle end 42 to engage with receiver 30. In addition, the relief cutaway results in a flush outer-surface connection between handle end 42 and receiver 30, giving pan 10 a clean professional appearance. Cutaway section 46 further includes an additional relief-cut graduated ramp and groove on each side of handle 40 for receipt of spring clips 80. Grooves 48 are cut partially into the top of handle 40 and extend down each side to the bottom of handle 40. Ramps 49 are cut into each side of handle 40, originating from grooves 48 and sloping upward to the end of handle 40. Spring clips 80 are positioned into grooves 48 and ramps 49 on each side of handle 40 such that end 84 of each spring clip fits within groove 48, the main body of each spring clip extends generally along ramp 49, and opposing end 82 of each spring clip curves downward from handle 40 at the pan-side end of handle 40. As is discussed above, spring clips 80 releasably secure primary handle 40 to receiver 30 through the engagement of clip ends 82 with holes 32 in receiver 30. Ramps 49 provide room for lateral movement of ends 82 of spring clips 80 during assembly and disassembly of handle 40 to receiver 30. Handle 40 can be removed from receiver 30 by depressing ends 82 of spring clips 80 through holes 32 of receiver 30 and simultaneously pulling handle 40 away from receiver 30. End 42 of handle 40 includes internal cavity 41 for housing RFID tag 60. Each side of cavity 41 includes a graduated guide ramp, 43, which slopes downward from the pan-side end of handle 40 toward the interior of cavity 41. Ramp 43 leads to channel 45 which extends into cavity 41. During assembly, RFID tag 60 is inserted into cavity 41 of handle 40, ramps 43, located on each side of cavity 41, guide tag 60 into channels 45. When fully assembled, channels 45 hold RFID tag 60 generally parallel to the cook-top surface, providing optimum signal transmission between the antenna of RFID tag 60 and the antenna of the reader/writer. As any condensation or moisture within cavity 41 can harm tag 60, handle 40 includes notch 47 located at the pan-side end to permit drainage of any moisture that accumulates within cavity 41. Although handle 40 can be constructed from any suitable material, handle 40 is preferably molded of a phenolic resin commonly used for pot and pan handles of the prior art. Use of a phenolic resin to mold handle 40 provides for quick and easy production of a unitary handle including cutaway relief 46, grooves 48, ramps 49, cavity 41, notch 47 and all other components of handle 40. Use of alternate materials that are not suitable for molding or casting would require machining of handle 40 to provide such components as cutaway relief 46, grooves 48, ramps 49, cavity 41, and notch 47. In addition, a phenolic material provides minimal interference to the transmission between RFID tag 60 and the reader/writer in the stove-top. As is shown in FIG. 3, sensor 70 is partially imbedded within the wall of pan body 20. Notch 22 extends slightly more than half way into the thickness of the wall of pan body 20, permitting sufficient contact between sensor 70 and the aluminum core of pan body 20, while also maintaining the integrity of the pan structure, particularly the integrity of the interior cooking surface of pan body 20. Partially imbedding sensor 70 within pan body 20 basically provides three points of contact between sensor 70 and pan body 20, one at inner face 23 of notch 22, and one on each of sides 24 and 26 of notch 22. Such an arrangement maintains a more stable connection between sensor 70 and pan body 20 that is less impacted by thermal expansions and contractions during heating and cooling of the object, than is possible with surface connections used in prior art devices. In addition, partially imbedding temperature sensor 70 into pan body 20 locates sensor 70 closer to the food being cooked within object 10, providing a more accurate temperature for cooking purposes than the prior art surface-mounted sensors. In a preferred embodiment, temperature sensor 70 is a resistance temperature detector (RTD), which changes electrical resistance with the change of temperature. The electrical resistance of RTD sensor 70 is measured by RFID tag 60 which is connected to sensor 70 by wires 62. RFID tag 60 then transmits temperature information to the reader/writer located within the stove so that the power level provided by the stove can be adjusted accordingly by a controller within the stove to maintain the desired cooking temperature. The temperature information transmitted from tag 60 to the stove can be the resistance measurement, or alternatively, the actual temperature reading based upon the resistance measurement. In a preferred embodiment, tag 60 includes a microprocessor connected to sensor 70 via wires 62. The microprocessor stores specification information regarding sensor 70, such as a resistance measurement to temperature table, and using the resistance measurement obtained from sensor 70 along with the specification information, calculates the temperature. Tag 60 then transmits the temperature to the reader/writer in the stove-top to be used by control algorithms of the stove-top controller. In an alternative embodiment, tag 60 transmits the resistance measurement directly to the stove-top controller and the controller will calculate the temperature. In this embodiment, it will be necessary for the stove-top controller to obtain specification information regarding sensor 70 to calculate the temperature. Such information can be stored in tag 60 and transmitted to the controller along with the resistance measurement. The side-notch location of temperature sensor 70 described in connection with FIGS. 1 through 6, provides considerable versatility for materials in construction of cookware object 10. In particular, the total thickness of the walls of pan body 20 can vary in thickness regardless of the diameter of sensor 70. As is seen in FIG. 3, sensor 70 can have a diameter greater than the total thickness of the wall of pan body 20, and partly protrude from the exterior surface of pan body 20. Such an arrangement is beneficial it situations in which it is desirable to have relatively thin walls for the pan body. Nevertheless, the location of the temperature sensor at the side of pan body 20 does not provide the optimum temperature reading for temperature regulation of the cookware. The optimum temperature reading is generally found at the center of the base of the pan body, as this is where the food items are usually positioned, and also where the highest temperature reading will be found. When sensor 70 is positioned at the side-notch location, the temperature at the center of the base of pan body 20 can be estimated using the conductivity constants for the materials of pan body 20. If it is desirable to obtain the exact (rather than estimated) temperature of the center of the base of the pan body, it is necessary to position the temperature at the center of the pan body. FIGS. 9 through 23, discussed below, show several embodiments of heatable cookware objects, and related components, in which the temperature sensor is located at the center of the base of the object. In a first embodiment, the sensor is positioned within a tunnel that extends into the center of the base of the object from the side of the object. In a preferred embodiment, the tunnel is drilled or machined in the object after the object has been manufactured. In a second embodiment, the sensor is within a tunnel that is formed between the bottom of the object and a slab that is connected to the bottom of the object. FIGS. 9 through 11 show exploded views of three different types of pans, 110, 210, utilizing either a tunnel (110) or a slab bottom (210) to locate a temperature sensor at the center of the base of the pan. While both the tunnel, 110, and the slab bottom, 210, embodiments enable location of the temperature sensor at the center of the base of pan 110, 210, each embodiment provides several unique advantages. Tunnel pan 110 results in pan body 120 having a unitary construction, and generally positions the temperature sensor in relatively close proximity to the food item being cooked, as opposed to slab bottom pan 220. Nevertheless, the wall thicknesses of pan body 120 will usually be thicker than those of pan body 220 and also pan body 20 of the side notch embodiment, 10, (discussed above), so as to allow the temperature sensor to become fully imbedded in pan body 120. Other advantages of the various embodiments of the instant invention will become apparent through the following description. FIG. 9 shows an exploded view of cookware object 110, 210 including pan body 120, 220 in the form of a two quart saucepan or pot. Saucepan 110, 210 also includes handle 40, which is of identical construction as handle 40 discussed above. Handle 40 is connected to pan body 120, 220 via bracket/receiver 130, 230. Spring clips 80 (identical to those discussed above) releasably secure handle 40 to receiver 130, 230 through the engagement of clip ends 82 with holes 132, 232 in receiver 130, 230. An RFID tag, 60 (identical to that discussed above), is connected to temperature sensor 70 (identical to that discussed above) via a pair of wires, 72 (identical to those discussed above, but longer to extend to the center of the pan base). RFID tag 60 is stored in a cavity located within handle 40. Gasket 90, made of high temperature silicon, is located between receiver 130, 230 and handle 40 to thermally shield tag 60 from radiating heat of the pan sidewall, aiding in maintaining the temperature within the cavity of handle 40 below the desired maximum operating temperature of tag 60 (generally 100° C.). Wires 72 extend from the interior of the cavity through portal 94 of silicon gasket 90, through portal 134, 234 of receiver 130, 230, between receiver 130, 230 and the exterior of pan body 120, 220, and to sensor 70 which is generally located between at the center of the base of pan body 120, 220. FIG. 10 shows an exploded view of cookware object 110, 210 including pan body 120, 220 in the form of a frying pan similar to pan 10 discussed above. Pan 110, 210 includes primary handle 40, and secondary (helper) handle 50, both of which are of identical construction as primary handle 40 and helper handle 50 discussed above. Primary handle 40 is connected to pan body 120, 220 via bracket/receiver 130, 230. Lateral member 139, 239 of receiver 130, 230 shown in FIG. 10 is shorter in length to accommodate the shallower frying pan of FIG. 10 than is the same member for the deeper pans shown in FIGS. 9 and 11. Spring clips 80 (identical to those discussed above) releasably secure primary handle 40 to receiver 130, 230 through the engagement of clip ends 82 with holes 132, 232 in receiver 130, 230. Helper handle 50 is connected to pan body 120, 220 via bracket 55 and screw 57. An RFID tag, 60 (identical to that discussed above), is connected to temperature sensor 70 (identical to that discussed above) via a pair of wires, 72 (identical to those discussed above, but longer to extend to the center of the pan base). RFID tag 60 is stored in a cavity located within handle 40. Gasket 90, made of high temperature silicon, is located between receiver 130, 230 and handle 40 to thermally shield tag 60, aiding in maintaining the temperature within the cavity of handle 40 below the desired maximum operating temperature of tag 60 (generally 100° C.). Wires 72 extend from the interior of the cavity through portal 94 of silicon gasket 90, through portal 134, 234 of receiver 130, 230, between receiver 130, 230 and the exterior of pan body 120, 220, and to sensor 70 which is generally located between at the center of the base of pan body 120, 220. FIG. 11 shows an exploded view of cookware object 110, 210 including pan body 120, 220 in the form of a four quart sauce pan/pot. Pot 110, 210 includes primary handle 140, and secondary (helper) handle 150. Primary handle 140 is connected to pan body 120, 220 via bracket/receiver 130, 230. Spring clips 80 (identical to those discussed above) releasably secure primary handle 140 to receiver 130, 230 through the engagement of clip ends 82 with holes 132, 232 in receiver 130, 230. Helper handle 150 is connected to pan body 120, 220 via bracket 155 and spring clips 80. An RFID tag, 60 (identical to that discussed above), is connected to temperature sensor 70 (identical to that discussed above) via a pair of wires, 72 (identical to those discussed above, but longer to extend to the center of the pan base). RFID tag 60 is stored in a cavity located within handle 140. Gasket 90, made of high temperature silicon, is located between receiver 130, 230 and handle 140 to thermally shield tag 60, aiding in maintaining the temperature within the cavity of handle 140 below the desired maximum operating temperature of tag 60 (generally 100° C.). Another gasket, 90, can also be located between bracket 155 and secondary handle 150 to maintain a cooler operating temperature for handle 150. Wires 72 extend from the interior of the cavity in handle 140 through portal 94 of silicon gasket 90, through portal 134, 234 of receiver 130, 230, between receiver 130, 230 and the exterior of pan body 120, 220, and to sensor 70 which is generally located between at the center of the base of pan body 120, 220. Primary handle 140 shown in FIG. 11 is constructed in a similar manner to handle 40 discussed above, the primary difference being the arrangement of the grasping ends 44 and 144 of handles 40 and 144, respectively. Handle grasping end 144 extends generally upward from pot-side end 142 of handle 140 and then extends outward away from pot body 120, 220. Grasping end 144 of handle 140 is generally shorter and taller than grasping end 44 of handle 40 to accommodate the deeper pot on which handle 144 is utilized. Generally, shorter handles positioned toward the top of deeper pot bodies are customary in the art to provide better aesthetics and handling of the deeper bodies. Pot-side end 142 of handle 140 is constructed in a manner identical to pan-side end 42 of handle 40, including (but not limited to) the relief-cutaway section, the spring retaining grooves and ramps, internal cavity and the drain notch. Although helper handle 150 does not require an internal cavity for housing an RFID tag, for ease of manufacturing, helper handle 150 is identical to handle 140. In addition, bracket 155 can be identical to receiver 130, 230. In the preferred embodiment shown in FIG. 11, bracket 155 is identical to receiver 130, 230, except that the unnecessary lateral member, 139, 239, is removed. Referring to FIG. 12, an exploded, bottom perspective view of a pan, 110, similar to that presented in FIG. 9, is shown in which tunnel 122 extends to the center of the base of pan body 120. As discussed above with respect to FIG. 9, pan 110 includes handle 40 connected to pan body 120 via bracket/receiver 130. Spring clips 80 releasably secure handle 40 to receiver 130. RFID tag, 60, is connected to temperature sensor 70 via wires, 72, and RFID tag 60 is stored in a cavity located within handle 40. Gasket 90 is located between receiver 130 and handle 40. In a preferred embodiment, tunnel 122 is drilled into the base of pan body 120 after pan body 120 has been manufactured. In this manner, a wide variety of preexisting pan bodies can be utilized without the need of special manufacturing processes for those bodies. FIGS. 13 and 14 show detailed views of an embodiment of receiver 130, 230 that can be used with any of the tunnel (110) or slab-bottom (220) pans discussed herein. Receiver 130, 230 is manufactured, operates, and is assembled to pan body 120, 220 in the same or similar manner as that of receiver 30 discussed above. Receiver 130, 230 shall now be described wherein like numbers (i.e. 30, 130, 230) represent similar components to those of receiver 30. Receiver 130, 230 includes opposing support members 136, 236 for engaging the handle, and window 137, 237 located between opposing support members 136, 236. Receiver 130, 230 also includes lateral member 139, 239 extending downward from support members 136, 236 to the base of pan body 120, 220. Channel 138, 238 is formed in member 139, 239 to permit wires 62 to pass through the cavity created between member 139, 239 of receiver 130, 230 and pan body 120, 220. Lateral member 139, 239 includes an end tab, 133, 233, that engages with a notch in the pan body or the bottom slab to provide a clean, generally flush base for the assembled combination of pan body 120, 220 and receiver 130, 230. The inclusion of end tab 133, 233 for insertion into a notch located within the pan body, eliminates the need for locator recess 33 and the associated locator discussed above with respect to receiver 30, as the combination of end tab 133, 233 and the notch in the pan body will ensure proper assembly. As with receiver 30, receiver 130, 230 includes nubs 135, 235 for use in an automated welding/braising assembly process. Receiver 130, 230 further includes injection port 131, 231 near the bottom of lateral member 139, 239 for insertion of a needle or injector. Injection port 131, 231, which is not present in receiver 30, allows for the injection of a silicon potting material, such as Loctite® 5406, to be injected into the tunnel or between the pan body and attached slab, protecting the internal layers of the pan and/or slab and securing the temperature sensor in position. Although end tab 133, 233 shown in FIGS. 13 and 14 includes a generally central tab extending beyond the sides of end tab 133, 233 (as can be seen in FIG. 11), it will be appreciated that end tab 133, 233 can be of any number of shapes and sizes to mate with a corresponding notch in the pan body. For example, FIGS. 15 and 16 show an embodiment of receiver 130 for insertion into notch 124 of pan body 120 wherein end tab 133 of receiver 130 is generally flat. As is shown in FIG. 15, notch 124 is cut, machined or drilled into the perimeter surface of pan body 120 at the end of tunnel 122. Although tunnel 122 shown in FIG. 15 is generally cylindrical, it will be appreciated that the shape of the tunnel may vary depending upon the shape of the temperature sensor. End tab 133 of receiver 130 mates with notch 124 in pan body 120 to form a generally flush connection between pan body 120 and receiver 130. Injection port 131 in receiver 130 allows for insertion of a needle for injecting a potting material into tunnel 122 once receiver 130 has been assembled to pan body 120. FIG. 17 shows a partial section view of pan 110 presented in FIG. 12 fully assembled. As is shown in FIG. 17, the diameter of tunnel 122 is slightly larger than that of temperature sensor 70. In addition the total diameter of wires 62 is less than the diameter of temperature sensor 70. This provides enough space for insertion of a needle into tunnel 122 when receiver 130 is assembled to pan body 120 and temperature sensor 70 and associated wires 62 are located in tunnel 122. The needle is inserted into tunnel 122 through injection port 131 located at the base of lateral member 139 of receiver 130. As the potting material fills tunnel 122, and surrounds temperature sensor 70 and wire 62, the needle is removed and injection port 131 is closed using a Laser, tig, or similar welding process. Pan body 120 shown in FIG. 17 is constructed of a 5 ply material as discussed above. The layers of pan body 120 may however be thicker than those discussed above with respect to pan body 20, to allow temperature sensor 70 to be fully imbedded within pan body 120. Tunnel 122 is located within the aluminum core (the three internal layers of the pan body) so that temperature sensor 70 is in contact with the aluminum core. In addition, the stainless steel layers (the two surface layers) are laminated on both sides of each layer to provide better corrosion protection from possible exposure caused by tunnel 122 extending into pan body 120 from its exterior. Referring to FIG. 18, an exploded, bottom perspective view of a pan, 210, similar to that presented in FIG. 9, is shown in which slot 222 is milled between the center of the base of pan body 220 to the perimeter of the base of pan body 220. Pan 210 includes a thin slab, 226, made of stainless steel (although a combination of aluminum and stainless steel layers, or any other suitable material can be utilized in alternative embodiments), which is attached to the bottom of pan body 220. Slab 226 is braised to the bottom of pan body 220 using a suitable solder, such as an 1170 melt solder. Although not shown in FIG. 18, pan 210 includes handle 40 connected to pan body 220 via bracket/receiver 230. Spring clips 80 releasably secure handle 40 to receiver 230. RFID tag, 60, is connected to temperature sensor 70 via wires, 72, and RFID tag 60 is stored in a cavity located within handle 40. Gasket 90 is located between receiver 230 and handle 40. In a preferred embodiment, slot 222 is machined into the base of pan body 220 after pan body 220 has been manufactured. In this manner, a wide variety of preexisting pan bodies can be utilized without the need of special manufacturing processes for those bodies. In another preferred embodiment, pan body 220 is of 5 ply construction, as discussed above. In this embodiment, slot 222 is milled into pan body 220 so that sensor 70 is placed in contact with the aluminum core of pan body 220. FIGS. 19 through 23 show several variations of a second embodiment of pan 210 having a slab attached to the bottom of pan body 220, in which slot 222 is formed in slab 226 instead of being milled in pan body 220. Locating slot 222 within slab 226 allows for a thinner wall thickness for pan body 220, and eliminates the need to perform any machining operations on pan body 220 once the body is manufactured (other than braising slab 226 to pan body 220). In a preferred embodiment of the slab base pan having a slot formed within the slab, slab 226 is constructed of an aluminum layer (or aluminum alloy) and a steel layer (although any other suitable material can be utilized for slab 226 depending upon the conductive, inductive and various other properties desired). Slot 222 is formed in the aluminum layer to position temperature sensor 70 in contact with the heat conductive aluminum to provide a more accurate temperature reading. The steel layer is positioned opposite the side of slab 226 that contacts pan body 220 to provide a durable, attractive finish to pan 210. In addition, the steel layer can be heated by induction if pan 210 is used on an induction stove-top. FIG. 19 shows a partial section view of slab-bottom pan 210 fully assembled having a generally rectangular slot formed in the slab. As is shown in FIG. 19, the height and width of slot 222 milled into slab 226 is slightly larger than that of temperature sensor 70. In addition the total height and width of wires 62 is less than the height and width of temperature sensor 70. This provides enough space for insertion of needle 300 into slot 222 when receiver 230 is assembled to pan body 220 and temperature sensor 70 and associated wires 62 are located in slot 222. Needle 300 is inserted into slot 222 through injection port 231 located at the bottom of lateral member 239 of receiver 230. As the potting material fills slot 222, and surrounds temperature sensor 70 and wires 62, needle 300 is removed and injection port 231 is closed using a Laser, tig, or similar welding process. The bottom of lateral member 239 of receiver 230 includes tab 233 that fits within slot 222 of slab 226. As is shown in FIG. 19, the bottom of lateral member 239 extends below tab 233 slightly less than the thickness of slab 226 existing below tunnel 222 to provide a generally flush bottom connection between slab 226 and receiver 230. Gap 225 is positioned between the bottom of lateral member 239 of receiver 230 and slab 226 to allow for thermal expansion and contraction to slab 226 and receiver 230 during heating and cooling of pan 210. FIG. 20 shows a partial section view of slab-bottom pan 210 fully assembled including a generally rectangular slot formed in the slab and a temperature sensor rod attached to receiver 230. Rod 310 is a rigid member that connects sensor 70 to receiver 230 for easier insertion of sensor 70 into pan body 220 during assembly. As is shown in FIG. 20, the height and width of slot 222 milled into slab 226 is slightly larger than that of temperature sensor 70. In addition the total height and width of wires 62 and rod 310 is less than the height and width of slot 222, allowing wires 62, rod 310 and sensor 70 to all fit within slot 222. Micro hole 228 is included at the bottom of slab 226 extending into slot 222. Micro hole 228 allows for the injection of a potting material into slot 222 which surrounds temperature sensor 70 and wires 62. Once the potting material is injected into slot 222, micro hole 228 is closed using a Laser, tig, or similar welding process. FIG. 21 shows a bottom perspective view of receiver 230 presented in FIG. 20. The bottom of lateral member 239 of receiver 230 includes tab 233 that fits within slot 222 of slab 226. As is shown in FIG. 21 (and FIG. 20), the bottom of lateral member 239 extends below tab 233 slightly less than the thickness of slab 226 existing below tunnel 222 to provide a generally flush bottom connection between slab 226 and receiver 230. Gap 225 is positioned between the bottom of lateral member 239 of receiver 230 and slab 226 to allow for thermal expansion and contraction to slab 226 and receiver 230 during heating and cooling of pan 210. Rod 310 is positioned within hole 315 located within tab 233. Wire channels 238a and 238b are included in tab 233 for wires 62 to extend from wire channel 238 of receiver 230 into slot 222. FIG. 22 shows a partial section view of slab-bottom pan 210 fully assembled including a generally cylindrical slot formed in the slab and an insertable tube attached to receiver 230. Tube 320 is a rigid member connected to receiver 230 into which sensor 70 is inserted for easier insertion of sensor 70 into pan body 220 during assembly. Tube 320 surrounds sensor 70 and wires 62, with the end of sensor 70 extending beyond tube 320. As is shown in FIG. 22, the diameter of slot 222 formed into slab 226 is slightly larger than that of tube 320, allowing wires 62, and sensor 70, located within tube 320, to all fit within slot 222. Hole 228 is included at the bottom of slab 226 extending into slot 222 just in front of the end of tube 320. Hole 228 allows for the injection of a potting material into slot 222 which surrounds temperature sensor 70 and tube 320. Once the potting material is injected into slot 222, hole 228 is closed using a Laser, tig, or similar welding process. Receiver 230 also includes injection port 231 for injecting potting material into tube 320. The total diameter of wires 62 is less than the diameter of tube 230. This provides enough space for insertion of needle 300 into tube 320 when receiver 230 is assembled to pan body 220 and tube 320, temperature sensor 70 and associated wires 62 are located in slot 222. Needle 300 is inserted into tube 320 through injection port 231 located at the bottom of lateral member 239 of receiver 230. As the potting material fills tube 320, and surrounds wires 62, needle 300 is removed and injection port 231 is closed using a Laser, tig, or similar welding process. FIG. 23 shows an alternative embodiment of slab-bottom pan 210 including a tunnel formed in slab 226. A stamped stainless steel tunnel, 227, is positioned in slot 222 of slab 226. Tunnel 227 protrudes from the outer perimeter of slab 226 for engagement with wire channel 238 of receiver 230. Once the temperature controllable objects discussed above (either 10, 110, or 210) have been manufactured an assembled, the RFID tags are initialized and control algorithms and data are downloaded to the tags. The control algorithms and data can include such information as the class of the object, i.e. sauce pan, frying pan, serving tray, warming dish, etc. In addition, information regarding the location of the temperature sensor can be included (i.e. side notch, bottom center, etc.) for use in determining ideal cooking temperatures. Heating characteristics, such as conductivity of the materials of the object, thickness, number of layers, etc., can also be downloaded to the tag, or alternatively these characteristics can be used in determining the class of the object. It will be appreciated that components from any of the embodiments of heatable objects discussed above can be interchanged with similar components of any of the other embodiments of heatable objects discussed herein. For example, the insert rod or insertable tube receivers discussed in connection with pans 210 could be utilized in connection with pans 110. Likewise, handles 40, 140, 50, and 150, as well as silicon gasket 90, and handle mounting hardware, can be interchangeably utilized on any of pans 10, 110, and 210. In addition, the methods of manufacturing and locating the temperatures sensors (i.e. side-notch 10, tunnel-bottom 110, or bottom-slab 210) can be interchangeably utilized with any of the various pots and pans discussed an shown herein, as well as in any cookware, servingware or other heatable objects now known or later discovered. In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described. Although the foregoing detailed description of the present invention has been described by reference to exemplary embodiments, and the best mode contemplated for carrying out the present invention has been shown and described, it will be understood that certain changes, modification or variations may be made in embodying the above invention, and in the construction thereof, other than those specifically set forth herein, may be achieved by those skilled in the art without departing from the spirit and scope of the invention, and that such changes, modification or variations are to be considered as being within the overall scope of the present invention. Therefore, it is contemplated to cover the present invention and any and all changes, modifications, variations, or equivalents that fall with in the true spirit and scope of the underlying principles disclosed and claimed herein. Consequently, the scope of the present invention is intended to be limited only by the attached claims, all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Having now described the features, discoveries and principles of the invention, the manner in which the invention is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | <SOH> BACKGROUND OF THE INVENTION <EOH>Cooking is often referred to as an art, not only because of the combination of ingredients that go into a particular recipe, but also due to the skill necessary for proper application and infusion of varying levels of heat over a given period of time throughout the different phases of the food preparation process. Traditional cookware appliances, such as ovens (microwave ovens being an exception), grills, heat lamps and stoves, all utilize the thermodynamic process of conduction to transfer heat from the outer surface of the food item to its interior. This is generally true regardless of the type of heat source used to heat the surface of the food, be it a radiation heat source (i.e. a heat lamp), conduction heat source (i.e. a stovetop), or a convection heat source (i.e. a convection oven or a food dehydrator). The time and temperature necessary to cook fully and properly a specific food item through conduction is dependant upon the thermal conductivity of the item, the uncooked temperature of the item (i.e. frozen, room temperature, etc.), as well as the size and shape of the item. A food item having higher thermal conductivity will cook faster than a similarly sized and shaped food item having a lower thermal conductivity, as the heat will more quickly migrate from the outer surface to the interior. Likewise, a generally smaller or thinner food item will cook faster than a generally larger or thicker food item of the same thermal conductivity, as the heat must migrate a shorter distance through the thinner item. Frozen items require considerably more heat to cook than do non-frozen or thawed items. While increasing the cooking temperature for an item will increase the amount of heat that migrates from the surface to the interior of a food item, applying too much heat at one time will result in cooking the outer surface of the item faster than the heat can migrate to the interior, usually resulting in burning or scorching of the surface and undercooking of the interior. Therefore, obtaining real-time information regarding the temperature of the item being cooked, during the cooking process is often beneficial to ensure proper heating. The use of thermometers or other temperature sensors to monitor and control the cooking process is well known. A common thermometer used to monitor and control the cooking process is a probe-type or contact thermometer which is inserted directly into the food item to obtain a temperature of the interior of the food item. Such thermometers are undesirable for many cooking applications. For, example, when cooking in pots or pans using a lid, the use of a probe-type thermometer requires removal of the lid each time a temperature reading is taken. Continuous removal of the lid during cooking reduces the transfer of heat to the item being cooked, and often results it a detrimental loss of moisture. In addition, the use of contact thermometers usually require manual adjustment of the power of the cooking appliance to obtain and maintain a desired temperature. Not to mention the probe-type thermometer is yet another cooking instrument that must be located and properly used during the often complex cooking process. To overcome the disadvantages associated with contact thermometers, a number of cookware-associated non-contact thermometers have been developed that are attached to, or incorporated into, cookware objects such as pots and pans. Such non-contact thermometers are often in communication with the cooking appliance to control the power level based on the temperature reading. Nevertheless, as discussed below, none of these non-contact thermometers, which control the cooking process solely based upon the temperature of the cookware object, provide a means of obtaining consistent and accurate measurement and control of the temperature of the food item being cooked within the cookware object. U.S. Pat. No. 3,742,178 to Harnden, Jr. describes a non-contact thermometer placed in thermal contact with an inner wall surface of an inner cup of a cookware object, located between the inner cup and an outer cup in which the inner cup is nested. The inner cup is constructed of a ferromagnetic material that can be heated by an induction coil located in an induction cook-top appliance. Maintaining a stable connection between the temperature sensor and the inner wall of the inner cup is difficult due to thermal expansions and contractions during heating and cooling of the pot. In addition, a large temperature differential may often exist between the inner wall of the inner cup and the outer wall of the inner cup, particularly when extremely cold items are placed within the cookware object while the inner cup is being heated. This large temperature differential makes an accurate determination of the temperature of the food item within the pot difficult, if not impossible to obtain when the temperature reading is taken at the inner wall surface of the inner cup. In the cookware object taught by Harnden, Jr., the field produced by the induction coil for heating the object also powers the temperature sensor which transmits temperature information to the cook-top appliance via radio frequency to control heating of the cookware object. Although such an arrangement works with induction heating appliances, the temperature sensor of Harnden, Jr. is inoperable when used with a traditional gas or electric stove which heats the cookware object by conduction. Furthermore, the nested cup design of Harnden, Jr., which includes a gap between the inner wall surfaces of the inner and outer cups filled with either thermal insulation material, air or vacuum, is inefficient for conducting heat from the outer cup to the inner cup, making use of the cookware object of Harnden, Jr. with traditional appliances undesirable even if use of the temperature sensor is utilized. U.S. Pat. No. 5,951,900 to Smrke describes a non-contact temperature sensor that attempts to overcome many of the disadvantages of Harnden, Jr. by inclusion of a temperature sensor mounted to the exterior surface of a lid of cookware object. The temperature sensor of Smrke transmits, either via radio frequency or via wire, temperature information to a cookware appliance to control heating of the cookware object. Although Smrke asserts that a determination of the temperature on the lid of a cookware object is ideal for controlling cooking because such temperature is dependant upon heater power, pot type, food quantity, etc., Smrke does not provide an accurate means of determining temperature of the food item within the cookware object. Furthermore, as discussed above, maintaining a stable connection between the temperature sensor and a surface of the cookware object to which the sensor is attached is difficult due to thermal expansions and contractions during heating and cooling of the object. Both Harnden, Jr. and Smrke teach cookware objects that are temperature regulated solely by the temperature obtained by the temperature sensors. While temperature information from the object is important, it is often not sufficient to obtain a desired regulation temperature within a desired period of time. For example, it is well known that the power applied to an object placed upon an induction cook-top depends greatly upon the distance between the object's ferromagnetic material and the work coil of the cook-top. Should an object require a particular graduated power application to prevent overheating of some parts of the object while reaching the desired regulation temperature throughout the object, it is essential that the proper power be coupled to the object. Furthermore, most practical heating operations require that the prescribed regulation temperature be reached within a maximum prescribed time. This restraint makes it even more important that proper power be applied during each temperature gradation. A means to correct for inconsistent power coupling that is based upon comparisons between power measurements and stored power coupling data is essential to achieve consistent heating operations and accurate temperature regulation. U.S. Pat. No. 6,320,169 to Clothier, the disclosure of which is incorporated herein by reference, teaches the use of a Radio Frequency Identification (RFID) tag attached to an induction heatable object to transmit information (typically about a heating characteristic of the object) to a control system of an induction heating device. RFID is an automatic identification technology similar in application to bar code technology, but which uses radio frequency instead of optical signals. RFID systems can be either read-only or read/write. For a read-only system such as Motorola's OMR-705+ reader and IT-254E tag, an RFID system consists of two major components, a reader and a special “tag”. The reader performs several functions, one of which is to produce a low-level radio frequency magnetic field, typically either at 125 kHz or at 13.56 MHz. The RF magnetic field emanates from the reader by means of a transmitting antenna, typically in the form of a coil. A reader may be sold in two separate parts: an RFID coupler, including a radio processing unit and a digital processing unit, and a detachable antenna. An RFID tag also contains an antenna, also typically in the form of a coil, and an integrated circuit (IC). Read/write systems permit two-way communication between the tag and reader/writer, and both the tag and the reader/writer typically include electronic memory for the storing of received information. Although Clothier discloses that RFID controlled objects can be either cookware or servingware objects, all of the objects disclosed by Clothier are in the form of servingware objects, such as plates and cups. Such objects, which are designed to keep food that has already been cooked at an adequate serving temperature, are subjected to significantly lower temperatures and usually heated for shorter time intervals than are pots, pans and other cookware items, i.e. approximately 250 degrees Fahrenheit for servingware versus approximately 900 degrees Fahrenheit for cookware. Therefore, servingware objects have fewer design constraints than do cookware objects. For example, each of the servingware objects disclosed by Clothier include RFID tags located in the base of the objects, thermally insulated from the heating element or heatable portion of the object. The RFID tag is thermally insulated from the heatable portion of the object due to the limited operating temperatures for most RFID tags. The RFID tag is located in the base of the servingware objects disclosed by Clothier so as to be positioned parallel to and within a range of several inches from the RFID reader/writer located in the induction heating device to enable communication between the tag and the reader/writer during heating of the object. Nevertheless, locating an RFID tag in the base of a cookware object such as a pot or pan, makes adequate thermal insulation difficult to obtain. In addition, even if sufficient thermal insulation is provided, such insulation prevents the cookware object from being heated by traditional cook-top appliances, such as gas or electric stoves conduction stoves as the RFID tag is located directly in the heat-generation zone (i.e. the area directly above the heat source—such as the gas or electric burner for traditional heating appliances, or the induction coil for induction heating appliances—in which the energy used to heat the object is directed) for the object. The RFID servingware objects disclosed by Clothier are primarily temperature regulated using heating algorithms based upon the heating characteristics transmitted from the object to the induction heating device. Clothier further discloses the inclusion of temperature regulation switches in combination with the RFID tag to better regulate the temperature of the object during heating. The temperature switches disclosed by Clothier operate to prevent or alter the transmission of information from the RFID tag to the induction heating device controller when the thermal switch experiences a predetermined temperature condition. Thus the temperature switches disclosed by Clothier do not provide the ability to obtain a temperature reading other than providing confirmation that the predetermined temperature has been exceeded. This results in a finite number of temperatures, based upon the number of temperature switches, to which the object can be accurately regulated. While such a finite number of predetermined temperatures is acceptable for servingware objects that function to keep already cooked food warm, cookware items, such as pots and pans require a much broader range of regulation temperatures. In fact, cooking of a single item can often require heating in several phases at varying temperatures. The RFID controlled servingware object combined with temperature switches disclosed by Clothier is in the form of a sizzle plate typically used in restaurants. The temperature switches, which are connected to the RFID tag are placed in contact with the undersurface of the cast iron plate. While such an arrangement may be adequate for lower temperature servingware such as the sizzle plate, the problems associated with maintaining a stable connection to a surface of the heatable object discussed above still exist. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the instant invention is to provide a temperature regulated object (or item). Another object of the instant invention is to provide a temperature regulated item that can be used for as servingware, cookware, and the like. Yet another object of the instant invention is to provide a temperature regulated item in which a temperature reading taken of the item is utilized in regulating the item's temperature. Another object of the instant invention is to provide a temperature regulated object in which the temperature reading provides an accurate indication of the temperature of the food being heated within the item without contacting the food. Still another object of the instant invention is to provide a temperature regulated item in which the temperature reading provides an accurate indication of the temperature of the food being heated within the item, and which can be used with traditional or induction heating devices. Another object of the invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item. Yet another object of the present invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item that is capable of regulating the item to an wide range of temperatures. Still another object of the instant invention is to provide a temperature regulated item having a temperature sensor contacting a heatable portion of the item, wherein the item is suitable for high temperature applications such as cooking. Another object of the present invention is to provide a temperature regulated item including a temperature sensor contacting a heatable portion of the item, wherein the connection between the sensor and the heatable portion of the item is capable of withstanding thermal expansion and contraction during heating and cooling of the item. An other object of the instant invention is to provide a temperature regulated item that having a temperature sensor contacting a heatable portion of the item, wherein the connection between the sensor and the heatable portion of the item is capable of withstanding thermal expansion and contraction during heating and cooling of the item, and which is capable of utilizing heating characteristics other than a temperature reading to regulate cooking temperature for the item. The above described objects are achieved using a temperature regulated object including a heatable body, a temperature sensor and an RFID tag. The temperature sensor contacts the heatable body of the object, and is connected to the RFID tag by a pair of wires. The RFID tag acts as a transmitter (and sometimes as receiver) to communicate with a reader/writer located in a cook-top for heating the object, providing temperature information and other information regarding the object (such as heating characteristics) to the cook-top. The temperature information and the heating information is used by the cook-top to control the temperature of the object. An illustrative embodiment of the instant invention is described in which the heatable object is a cookware object such as a pan. In a first embodiment of the invention, the temperature sensor is partially imbedded within a notch located in the side and toward the bottom of the pan, placed in contact with a conductive core of the pan. Partially imbedding the sensor in the body of the pan provides an improved connection between the sensor and the heatable body of the pan that is more capable of withstanding thermal expansion and contraction caused by heating and cooling of the pan. In addition, the partially imbedded temperature sensor is located closer to the interior of the pan and the food item being cooked, providing a more accurate reading of the temperature of the food item than is possible by measuring the temperature of the bottom surface of the pan, which will be influenced by the heat source. Furthermore, by partially imbedding the sensor, it is possible to utilize pan walls that are thinner than the diameter of the sensor. In a second embodiment of the instant invention, the temperature sensor is imbedded within a tunnel that is formed in the bottom wall of the pan. In a preferred embodiment the pan in manufactured in a manner known in the art, and the tunnel is then drilled into the base of the pan. As with the side-notch embodiment, the bottom tunnel provides increased durability of the connection between the temperature sensor and the heatable portion of the pan, and places the temperature sensor closer to the interior of the pan. In addition, the bottom tunnel permits the temperature sensor to be located at the center of the pan where one of the hottest temperatures for the pan is obtained and is very robust against a dislocation of the pan from the center of the heating object, like a center of induction coil or center of halogen heater or center of electric heater and so on. In a third embodiment of the instant invention, the temperature sensor is imbedded between the bottom of the pan and a slab connected to the pan bottom. One variation of this slab-bottom includes a slot formed in the slab for placement of the temperature sensor and associated wires. This allows for placement of a temperature sensor at the center of the pan base, even when the pan walls are relatively thin (thinner than the diameter of the sensor). Another variation of the slab bottom includes a slot formed in the bottom of the pan itself. In this embodiment, the temperature sensor is positioned closer to the interior of the pan. The RFID tag is located within a cavity formed in the handle of the pan of the instant invention to position the tag outside of the heat-generation zone for the pan. This reduces the temperature to which the tag is subjected, maximizing the life of the tag. Ramped guide channels are located within the cavity to guide the RFID tag into a proper assembled location. The handle holds the RFID tag parallel to the cook-top surface for maximum signal strength during operation. The inventive handle includes a releasable spring-clip connection between the handle and a receiver for supporting the handle. The receiver of the instant invention supports the handle. A window between a pair of opposing supports maximizes the strength of the signal transmitted between the RFID tag and the reader/writer by minimizing obstruction of the RFID tag antenna. In a preferred embodiment of the invention, the receiver includes an injection port for injecting a potting material into a tunnel or slot in which the temperature sensor in located. In alternative preferred embodiments, a rigid rod or tube is connected to the receiver and the temperature sensor to aid in insertion of the sensor in the tunnel or slot during assembly. The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention and various features thereof. | 20040428 | 20070102 | 20051103 | 64956.0 | 2 | ROBINSON, DANIEL LEON | RADIO FREQUENCY IDENTIFICATION CONTROLLED HEATABLE OBJECTS | SMALL | 0 | ACCEPTED | 2,004 |
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10,833,494 | ACCEPTED | Catheter system for stenting bifurcated vessels | A catheter system and method are described for stenting a vessel at a bifurcation or sidebranch of the vessel. The catheter system includes a first balloon catheter, a second balloon catheter and a releasable linking device for holding the first and second balloon catheters arranged in a side-by-side configuration and aligned with one another along a longitudinal axis. The linking device allows the catheter system to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters, yet is releasable so that one or both of the balloon catheters can be released from the linking device and maneuvered separately from the rest of the catheter system when desired. The method utilizes the described catheter system for stenting bifurcated vessels using a modified “kissing balloons” technique. | 1. A catheter system comprising: a first catheter having a shaft with a proximal end and a distal end; a second catheter having a shaft with a proximal end and a distal end; and a linking device attachable near the proximal ends of the catheters for releasably linking the first catheter and the second catheter together in a side-by-side configuration and with the first catheter and the second catheter aligned with one another along a longitudinal axis. 2. The catheter system of claim 1, wherein the first catheter and the second catheter are balloon catheters. 3. The catheter system of claim 2, further comprising a stent mounted on at least one of the balloon catheters. 4. The catheter system of claim 2, wherein the first catheter and the second catheter are configured as rapid exchange balloon dilatation catheters. 5. The catheter system of claim 4, wherein a proximal section of each rapid exchange balloon dilatation catheter is constructed of hypodermic tubing joined to a flexible distal section. 6. The catheter system of claim 4, wherein at least one of the catheters comprises an elongated flexible extension tube extending distally from the dilatation balloon. 7. The catheter system of claim 1, wherein the linking device is configured to hold at least one guidewire stationary with respect to the catheter system. 8. The catheter system of claim 1, wherein the first catheter and the second catheter are configured as over-the-wire catheter balloon dilatation catheters. 9. The catheter system of claim 1, wherein the linking device comprises a body with a first channel and a second channel arranged in a side-by-side configuration, the first channel being configured to releasably hold the shaft of the first catheter and the second channel being configured to releasably hold the shaft of the second catheter. 10. The catheter system of claim 1, wherein the linking device comprises a body with a first channel and a second channel arranged in a side-by-side configuration, a first locking device associated with the first channel configured to releasably hold the shaft of the first catheter, and a second locking device associated with the second channel configured to releasably hold the shaft of the second catheter. 11. The catheter system of claim 1, wherein the linking device comprises a first linking member attached to the shaft of the first catheter and a second linking member attached to the shaft of the second catheter, the first linking member and the second linking member have interlocking features so that the first linking member and the second linking member can be releasably attached to one another. 12. The catheter system of claim 1, wherein the linking device comprises a peel-away sheath releasably attaching the shaft of the first catheter and the shaft of the second catheter together. 13. The catheter system of claim 1, wherein the linking device comprises a split-tube releasably attaching the shaft of the first catheter and the shaft of the second catheter together. 14. A catheter linking device comprising: a linking device body having a first channel and a second channel arranged in a side-by-side configuration within the linking device body, the first channel being configured to releasably hold a shaft of a first catheter and a second channel being configured to releasably hold a shaft of a second catheter. 15. The catheter linking device of claim 14, further comprising a first locking device associated with the first channel configured to releasably hold the shaft of the first catheter, and a second locking device associated with the second channel configured to releasably hold the shaft of the second catheter. 16. The catheter system of claims 14, wherein the linking device comprises a split-tube releasably attaching the shaft of the first catheter and the shaft of the second catheter together. 17. A method of catheterizing a patient, comprising: providing a catheter system including a first catheter having a shaft with a proximal end and a distal end, a second catheter having a shaft with a proximal end and a distal end, and a releasable linking device; linking the first catheter and the second catheter together in a side-by-side configuration near the proximal ends of the catheters with the releasable linking device; inserting the distal ends of the catheters into the patient and advancing the catheter system as a unit. 18. The method of claim 17, further comprising: mounting a stent on at least one of the catheters and deploying the stent within a vessel in the patient. 19. The method of claim 18, wherein the first catheter has an inflatable balloon mounted near the distal end of the first catheter and the second catheter has an inflatable balloon mounted near the distal end of the second catheter and wherein the linking device links the first catheter and the second catheter together with the inflatable balloons arranged in a side-by-side configuration. 20. The method of claim 18, wherein the first catheter has an inflatable balloon mounted near the distal end of the first catheter and the second catheter has an inflatable balloon mounted near the distal end of the second catheter and wherein the linking device links the first catheter and the second catheter together with the inflatable balloons arranged in a staggered or tandem configuration. | CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Ser. No. 60/512,259, filed Oct. 16, 2003, and U.S. Provisional Application Ser. No. 60/534,469, filed Jan. 5, 2004, the disclosures of which are incorporated by reference in their entirety. FIELD OF THE INVENTION The present invention relates generally to catheters and catheter systems for performing angioplasty and vascular stenting. More particularly it relates to a catheter system and method for stenting a vessel at a bifurcation or sidebranch of the vessel. BACKGROUND OF THE INVENTION The following patents and patent applications relate to catheters and catheter systems for performing angioplasty and stenting of bifurcated vessels. These and all patents and patent applications referred to herein are incorporated by reference in their entirety. U.S. Pat. No. 6,579,312 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,540,779 Bifurcated stent with improved side branch aperture and method of making same U.S. Pat. No. 6,520,988 Endolumenal prosthesis and method of use in bifurcation regions of body lumens U.S. Pat. No. 6,508,836 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,494,875 Bifurcated catheter assembly U.S. Pat. No. 6,475,208 Bifurcated catheter assembly U.S. Pat. No. 6,428,567 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,387,120 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,383,213 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,371,978 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,361,544 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,325,826 Extendible stent apparatus U.S. Pat. No. 6,264,682 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,258,073 Bifurcated catheter assembly U.S. Pat. No. 6,254,593 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,221,098 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,210,380 Bifurcated catheter assembly U.S. Pat. No. 6,165,195 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,142,973 Y-shaped catheter U.S. Pat. No. 6,117,117 Bifurcated catheter assembly U.S. Pat. No. 6,086,611 Bifurcated stent U.S. Pat. No. 5,720,735 Bifurcated endovascular catheter U.S. Pat. No. 5,669,924 Y-shuttle stent assembly for bifurcating vessels and method of using the same U.S. Pat. No. 5,613,980 Bifurcated catheter system and method U.S. Pat. No. 6,013,054 Multifurcated balloon catheter U.S. Pat. No. 4,896,670 Kissing balloon catheter U.S. Pat. No. 5,395,352 Y-adaptor manifold with pinch valve for an intravascular catheter U.S. Pat. No. 6,129,738 Method and apparatus for treating stenoses at bifurcated regions U.S. Pat. No. 6,544,219 Catheter for placement of therapeutic devices at the ostium of a bifurcation of a body lumen U.S. Pat. No. 6,494,905 Balloon catheter U.S. Pat. No. 5,749,825 Means method for treatment of stenosed arterial bifurcations U.S. Pat. No. 5,320,605 Multi-wire multi-balloon catheter U.S. Pat. No. 6,099,497 Dilatation and stent delivery system for bifurcation lesions U.S. Pat. No. 5,720,735 Bifurcated endovascular catheter U.S. Pat. No. 5,906,640 Bifurcated stent and method for the manufacture and delivery of same U.S. Pat. No. 5,893,887 Stent for positioning at junction of bifurcated blood vessel and method of making U.S. Pat. No. 5,755,771 Expandable stent and method of delivery of same US 20030097169A1 Bifurcated stent and delivery system US 20030028233A1 Catheter with attached flexible side sheath US 20020183763A1 Stent and catheter assembly and method for treating bifurcations US 20020156516A1 Method for employing an extendible stent apparatus US 20020116047A1 Extendible stent apparatus and method for deploying the same US 20020055732A1 Catheter assembly and method for positioning the same at a bifurcated vessel WO 9944539A2 Dilatation and stent delivery system for bifurcation lesions WO 03053507 Branched balloon catheter assembly WO 9924104 Balloon catheter for repairing bifurcated vessels WO 0027307 The sheet expandable trousers stent and device for its implantation FR 2733689 Endoprosthesis with installation device for treatment of blood-vessel bifurcation stenosis SUMMARY OF THE INVENTION The present invention relates generally to catheters and catheter systems for performing angioplasty and vascular stenting. More particularly it relates to a catheter system and method for stenting a vessel at a bifurcation or sidebranch of the vessel. In a first aspect, the invention comprises a catheter system for stenting bifurcated vessels. The catheter system includes a first balloon catheter, a second balloon catheter and a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. The catheter system may include one or more vascular stents of various configurations mounted on the first and/or second balloon catheters. The linking device allows the catheter system to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. Typically, the catheter system will also include a first and second steerable guidewire for guiding the first and second balloon catheters within the patient's blood vessels. Optionally, the linking device may also be configured to hold one or both of the guidewires stationary with respect to the catheter system. The catheter system may be arranged with the inflatable balloons in a side-by-side configuration for stenting the bifurcated vessels using a method similar to the “kissing balloons” technique. Alternatively, the catheter system may be arranged with the inflatable balloons in a low-profile staggered or tandem configuration for stenting the bifurcated vessels using a modified “kissing balloons” technique. When arranged in the staggered or tandem configuration, the second balloon catheter may optionally be constructed with a flexible tubular extension that extends the guidewire lumen distally from the inflatable balloon. In a second aspect, the invention comprises a linking device for holding the first and second balloon catheters of the system in a side-by-side configuration and aligned with one another along a longitudinal axis. The linking device allows the catheter system to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. Optionally, the linking device may also be configured to hold one or both of the guidewires stationary with respect to the catheter system. The linking device is preferably releasable so that one or both of the balloon catheters and/or the guidewires can be released from the linking device and maneuvered separately from the rest of the catheter system. In one embodiment the linking device is self-releasing in the sense that the linking device demounts itself from the first and second balloon catheters as the catheter system is advanced into the patient's body. In a third aspect, the invention comprises a method for stenting bifurcated vessels utilizing the described catheter system. In a first variation of the method, the inflatable balloons are arranged in a side-by-side configuration for stenting the bifurcated vessels in a method similar to the “kissing balloons” technique, but utilizing a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. In a second variation of the method, the inflatable balloons are arranged in a staggered or tandem configuration for stenting the bifurcated vessels using a modified “kissing balloons” technique that also utilizes a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. When desired, the linking device may be released so that one or both of the balloon catheters and/or the guidewires can be maneuvered separately from the rest of the catheter system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of a catheter system for stenting bifurcated vessels according to the present invention. FIG. 2 shows the catheter system of FIG. 1 in use for stenting a bifurcated vessel with a bifurcated stent. FIG. 3 shows a variation of the catheter system of FIG. 1 for stenting a bifurcated vessel. FIG. 4 shows the catheter system of FIG. 3 in use for stenting a bifurcated vessel. FIG. 5 shows a second embodiment of a catheter system for stenting bifurcated vessels. FIGS. 6A-9 show various embodiments of a linking device for use with the catheter system of the present invention. FIGS. 10-13 show the catheter system of FIG. 5 in use for stenting a bifurcated vessel using a main stent and a sidebranch stent. FIG. 14 shows a third embodiment of a catheter system for stenting bifurcated vessels. FIG. 15 shows a cross section of a split-tube linking device for the catheter system of FIG. 14. FIG. 16 shows an alternate cross section of a split-tube linking device for the catheter system of FIG. 14. FIG. 17 shows the catheter system of FIG. 14 in use. FIG. 18 shows a distal portion of a catheter system for stenting bifurcated vessels. FIG. 19 shows a bifurcated vessel after stenting with the catheter system of FIG. 18. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a first embodiment of the catheter system 100 of the present invention for stenting bifurcated vessels. The catheter system 100 includes a first balloon catheter 102 and a second balloon catheter 104. An inflatable balloon 130, 132 is mounted on each of the first and second balloon catheters 102, 104 near the distal end of the catheters. A balloon-expandable vascular stent 150 is mounted on the catheter system 100, typically by crimping or swaging the stent 150 over both of the inflatable balloons 130, 132. The stent structure is shown generically and is not intended to be limited to any particular strut geometry. Typically, the catheter system 100 will also include a first and second steerable guidewire 140, 142 for guiding the first and second balloon catheters 102, 104 within the patient's blood vessels. The first and second steerable guidewires 140, 142 will typically have a diameter of 0.010-0.018 inches (approximately 0.25-0.46 mm), preferably 0.014 inches (approximately 0.36 mm). A linking device 160 releasably joins the first balloon catheter 102 and the second balloon catheter 104 together near the proximal ends of the catheters. The linking device 160 holds the first and second balloon catheters 102, 104 in a side-by-side configuration and aligned with one another along a longitudinal axis. The linking device 160 allows the catheter system 100 to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent 150 from the catheters. Optionally, the linking device 160 may also be configured to hold one or both of the guidewires 140, 142 stationary with respect to the catheter system 100. The first and second balloon catheters 102, 104 may be of any known construction for balloon angioplasty or stent delivery catheters, including rapid exchange and over-the-wire catheter constructions. In a particularly preferred embodiment, the first and second balloon catheters are constructed as rapid exchange catheters, wherein a proximal section 106, 108 of each catheter is constructed of hypodermic tubing, which may be formed from stainless steel, a superelastic nickel-titanium or titanium-molybdenum alloy or the like. The exterior of the proximal section 106, 108 is preferably coated with PTFE or another highly lubricious coating. A proximal connector 122, 124, such as a luer lock connector or the like, is attached at the proximal end of the proximal section 106, 108 and communicates with a balloon inflation lumen that extends through the hypodermic tubing. Each catheter includes a flexible distal section 110, 112 joined to the proximal section 106, 108. Typically, the flexible distal section 110, 112 has two lumens that extend through most of its length, including a guidewire lumen that extends from a proximal guidewire port 114, 116 to a distal port 118, 120 at the distal end of the catheter, and a balloon inflation lumen that connects from the balloon inflation lumen of the proximal section 106, 108 to the interior of the inflatable balloon 130, 132, which is mounted near the distal end of the flexible distal section 110, 112. The first and second inflatable balloons 130, 132 may have the same length and diameter and pressure compliance or they may have different lengths, diameters and/or pressure compliances, depending on the geometry of the target vessel that the catheter system 100 is intended for. The inflatable balloons 130, 132 may be made from a variety of known angioplasty balloon materials, including, but not limited to, PVC, polyethylene, polyolefin, polyamide, polyester, PET, PBT, and blends, alloys, copolymers and composites thereof. The first and second inflatable balloons 130, 132 may be made from the same material or different materials. The flexible distal section 110, 112 is typically constructed of flexible polymer tubing and may have a coaxial or multilumen construction. Preferably, one, two or more radiopaque markers are mounted on the flexible distal section 110, 112 to indicate the location of the inflatable balloons 130, 132 under fluoroscopic imaging. A transition element may be included to create a gradual transition in stiffness between the proximal section 106, 108 and the flexible distal section 110, 112, and to avoid a stress concentration at the juncture between the two sections. The transition element may be constructed as a tapered or spiral wound element that is formed as an extension of the hypodermic tubing or from a separate piece of wire or tubing. In this illustrative example, the catheter system 100 is configured for delivering a Y-shaped bifurcated stent 150. The bifurcated stent 150 has a main trunk 152 connected to first and second sidebranches 154, 156 of the stent. The catheter system 100 is prepared for use by inserting the inflatable balloons 130, 132 in a deflated and folded state through the main trunk 152 of the bifurcated stent 150, with one balloon extending into each of the first and second sidebranches 154, 156. The bifurcated stent 150 is then crimped or swaged over the inflatable balloons 130, 132. A support wire may be inserted into each of the guidewire lumens to support them during the crimping or swaging step. The proximal sections 106, 108 of the catheters are inserted into the linking device 160 to hold the first and second balloon catheters 102, 104 in a side-by-side configuration and aligned with one another along a longitudinal axis. This preparation may be carried out at the manufacturing facility or it may be performed at the point of use by a medical practitioner. FIG. 2 shows the catheter system 100 of FIG. 1 in use for stenting a bifurcated vessel. The catheter system 100 is inserted into a body lumen that is desired to be stented and advanced to the point of the bifurcation. For stenting coronary arteries or carotid arteries, the catheter system 100 is typically inserted through a guiding catheter that has been previously positioned at the ostium of the target vessel. For stenting in peripheral arteries or other body lumens, the catheter system 100 may be inserted directly into the vessel, for example using the Seldinger technique or an arterial cutdown, or it may be inserted through an introducer sheath or guiding catheter placed into the vessel. The first and second balloon catheters 102, 104 are maneuvered with the help of the steerable guidewires 140, 142 so that the first and second inflatable balloons 130, 132, with the first and second sidebranches 154, 156 of the stent 150 mounted thereon, extend into the respective first and second sidebranches of the bifurcated vessel. The first and second inflatable balloons 130, 132 are inflated separately and/or together to expand the stent 150 and to seat it securely within the vessel, as shown in FIG. 2. This is similar to the “kissing balloons” technique that has been previously described in the literature. An advantage of the present invention over prior methods is that the linking device 160 allows the catheter system 100 to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent 150 from the catheters. Once the stent 150 has been deployed, both balloons 130, 132 are deflated and the catheter system 100 is withdrawn from the patient. Alternatively, one or both of the balloon catheters 102, 104 can be released from the linking device 160 and used separately for dilating and/or stenting other vessels upstream or downstream of the stent 150. FIG. 3 shows a variation of the catheter system 100 of the present invention for stenting a bifurcated vessel. The construction of the catheter system 100 is very similar to the catheter system described above in connection with FIG. 1 with the exception that the system utilizes a straight, i.e. non-bifurcated, stent 170. The stent structure is shown generically and is not intended to be limited to any particular strut geometry. In one particularly preferred embodiment, the stent 170 is in the form of an open-cell stent, having a cylindrical body 174 with one or more side openings 172 that are suitable for placement at a bifurcation or sidebranch of the vessel without hindering blood flow into the sidebranch. Because of their flexibility and open structure, open-cell stents are well suited for stenting bifurcated vessels. The side openings 172 can be expanded or remodeled with a dilatation balloon inserted through the side opening or with two dilatation balloons, using the “kissing balloons” technique. A closed-cell stent with large side openings and/or expandable side openings may also be utilized. Alternatively, the catheter system may utilize a side-hole stent intended for stenting bifurcations or for stenting a main vessel at the location of a sidebranch vessel. In this case, the stent has an approximately cylindrical body with a side hole intended to be positioned at the site of a sidebranch vessel. The side hole may be preformed in the stent or it may be a slit or a potential hole that can be expanded to form a side hole. The catheter system 100 is prepared for use by inserting the inflatable balloons 130, 132 in a deflated and folded state into the stent 170, with the first balloon 130 extending all the way through the cylindrical body 174 and the second balloon 132 exiting the cylindrical body 174 at the side opening 172 that is intended to be positioned at the bifurcation or sidebranch vessel. Alternatively, the second balloon 132 may be positioned proximal to the side opening 172 so that only the distal tip of the catheter 104 or only the guidewire 142 exits the cylindrical body 174 at the side opening 172 to decrease the distal crossing profile of the catheter system 100. The stent 170 is then crimped or swaged over the inflatable balloons 130, 132. A support wire may be inserted into each of the guidewire lumens to support them during the crimping or swaging step. The proximal sections 106, 108 of the catheters are inserted into the linking device 160 to hold the first and second balloon catheters 102, 104 in a side-by-side configuration and aligned with one another along a longitudinal axis. This preparation may be carried out at the manufacturing facility or it may be performed at the point of use by a medical practitioner. FIG. 4 shows the catheter system 100 of FIG. 3 in use for stenting a bifurcated vessel. The catheter system 100 is inserted into a body lumen that is desired to be stented and advanced to the point of the bifurcation. For stenting coronary arteries or carotid arteries, the catheter system 100 is typically inserted through a guiding catheter that has been previously positioned at the ostium of the target vessel. For stenting in peripheral arteries or other body lumens, the catheter system 100 may be inserted directly into the vessel, for example using the Seldinger technique or an arterial cutdown, or it may be inserted through an introducer sheath or guiding catheter placed into the vessel. The first and second balloon catheters 102, 104 are maneuvered with the help of the steerable guidewires 140, 142 so that the first and second inflatable balloons 130, 132, with the stent mounted thereon, extend into the respective first and second sidebranches of the bifurcated vessel. The first inflatable balloon 130 will typically be positioned in the larger of the two sidebranches or in the main lumen of the vessel at the location of a smaller sidebranch vessel. The first inflatable balloon 130 is inflated to expand the stent and to seat it securely within the vessel, as shown in FIG. 4. Then, the first inflatable balloon 130 is deflated and the second inflatable balloon 132 is inflated to expand the side opening 172 at the location of the second sidebranch vessel. Optionally, the first and second inflatable balloons 130, 132 may be inflated simultaneously using the “kissing balloons” technique. Once the stent 170 has been deployed, both balloons 130, 132 are deflated and the catheter system 100 is withdrawn from the patient. Alternatively, one or both of the balloon catheters 102, 104 can be released from the linking device 160 and used separately for dilating and/or stenting other vessels upstream or downstream of the stent 170. Optionally, a sidebranch stent may be placed in the second sidebranch vessel before or after deployment of the stent 170. FIG. 5 shows a second embodiment of the catheter system 100 for stenting bifurcated vessels. The construction of the catheter system 100 is very similar to the catheter system described above in connection with FIGS. 1 and 3, with the exception that the second balloon catheter 104 is constructed with a flexible tubular extension 134 connected to the distal end of the catheter. The guidewire lumen extends through the flexible tubular extension 134. The flexible tubular extension 134 allows the first and second inflatable balloons 130, 132 to be assembled together in a staggered or tandem initial position. This variation of the catheter system 100 utilizes a main stent 170, which is typically a straight, i.e. non-bifurcated, stent, as described above. In addition, the catheter system 100 may optionally utilize a sidebranch stent 178. The stent structures are shown generically and are not intended to be limited to any particular strut geometry. These distal features of the catheter system 100 can be seen in greater detail in the enlarged view of FIG. 10. The catheter system 100 is prepared for use by first inserting the second inflatable balloon 132 in a deflated and folded state through the optional sidebranch stent 178 and crimping or swaging the sidebranch stent 178 over the second inflatable balloon 132. Alternatively, the sidebranch stent 178 may be mounted on a separate balloon catheter for use with the catheter system 100. The first inflatable balloon 130 is then inserted in a deflated and folded state into the main stent 170, with the first balloon 130 extending all the way through the cylindrical body 174. The flexible tubular extension 134 of the second balloon catheter 104 is inserted into the main stent 170 alongside the first balloon 130 with the flexible tubular extension 134 exiting the cylindrical body 174 at the side opening 172 that is intended to be positioned at the bifurcation or sidebranch vessel. Preferably, the flexible tubular extension 134 terminates at the side opening 172 of the main stent 170 to reduce the crossing profile of the distal portion of the stent 170. Alternatively, the flexible tubular extension 134 may extend distally from the side opening 172 if desired. The main stent 170 is then crimped or swaged over the first inflatable balloon 130 and the flexible tubular extension 134. A support wire may be inserted into each of the guidewire lumens to support them during the crimping or swaging step. The proximal sections 106, 108 of the catheters are inserted into the linking device 160 to hold the first and second balloon catheters 102, 104 in a side-by-side configuration and in a desired alignment with one another along the longitudinal axis. This preparation may be carried out at the manufacturing facility or it may be performed at the point of use by a medical practitioner. In an alternate embodiment of the catheter system 100 of FIG. 5, the second balloon catheter 104 may be constructed without a flexible tubular extension 134. In this case, the distal tip of the second balloon catheter 104 would be positioned proximal to the main stent 170 and the second steerable guidewire 142 would be inserted into the main stent 170 alongside the first balloon 130 with the guidewire 142 exiting the cylindrical body 174 at the side opening 172. This would provide an even lower crossing profile for the catheter system 100. FIGS. 6A-9 show various embodiments of a linking device 160 for use with the catheter system 100 of the present invention. FIG. 6A shows an end view and 6B shows a front view of a first embodiment of a linking device 160. The linking device 160 has a body 162 with a first channel 164 and a second channel 166 extending along a surface of the body in a side-by-side configuration, preferably with the first and second channels 164, 166 approximately parallel to one another. The first and second channels 164, 166 are preferably undercut and sized to have a captive interference fit with the proximal sections 106, 108 of the first and second balloon catheters 102, 104. The linking device 160 is preferably molded of a flexible polymer or elastomer with a high coefficient of friction so that it effectively grips the proximal sections 106, 108 of the first and second balloon catheters 102, 104 when they are inserted into the first and second channels 164, 166. In use, the linking device 160 holds the first and second balloon catheters 102, 104 arranged in a side-by-side configuration and aligned with one another along a longitudinal axis. The linking device 160 allows the catheter system 100 to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. When it is desired, one or both of the balloon catheters 102, 104 can be released from the linking device 160 and maneuvered separately from the rest of the catheter system 100. Optionally, the linking device 160 of FIG. 6B may also be configured to hold one or both of the guidewires 140, 142 stationary with respect to the catheter system 100. In this case, the body 162 of the linking device 160 would include one or two slots 168, shown in dashed lines in FIG. 6B, that are sized and configured to create a captive interference fit with the proximal section of the guidewires 140, 142. FIG. 6C shows an end view of the linking device 160 with optional slots 168 for holding the guidewires 140, 142. When it is desired, the guidewires 140, 142 can be released from the linking device 160 and maneuvered separately from the rest of the catheter system 100. In an alternative embodiment, the linking device 160 of FIGS. 6A-6B may be permanently attached to one of the balloon catheters and releasably attached to the other. In another alternative embodiment, the linking device 160 may be configured to attach instead to the proximal connectors 122, 124 of the balloon catheters 102, 104 or it may be molded into the proximal connectors 122, 124. FIG. 7A shows an end view and 7B shows a front view of a second embodiment of the linking device 160. The linking device 160 has a body 162 with a first channel 164 and a second channel 166 extending along one surface of the body in a side-by-side configuration, preferably with the first and second channels 164, 166 approximately parallel to one another. The first and second channels 164, 166 are preferably undercut and sized to have a captive sliding fit with the proximal sections 106, 108 of the first and second balloon catheters 102, 104. A first locking device 180 is associated with the first channel 164, and a second locking device 182 is associated with the second channel 166. The first and second locking devices 180, 182 are configured to releasably lock the proximal sections 106, 108 of the first and second balloon catheters 102, 104 in a desired alignment with one another along the longitudinal axis. Each of the locking devices 180, 182 will typically include a spring or other biasing member to hold the locking device in a locked position and a push button or other actuating member to release the locking device. The linking device 160 allows the catheter system 100 to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. When it is desired, one or both of the locking devices 180, 182 can be released to allow one of the balloon catheters 102, 104 to be advanced or retracted with respect to the other to adjust their longitudinal alignment. In addition, one or both of the balloon catheters 102, 104 can be released completely from the linking device 160 and maneuvered separately from the rest of the catheter system 100. Optionally, the linking device 160 of FIGS. 7A-7B may also be configured to hold one or both of the guidewires 140, 142 stationary with respect to the catheter system 100. In this case, the body 162 of the linking device 160 would include one or two additional locking devices, or slots or other structures configured to grip the proximal section of the guidewires 140, 142. When it is desired, the guidewires 140, 142 can be released from the linking device 160 and maneuvered separately from the rest of the catheter system 100. In an alternative embodiment, the linking device 160 of FIGS. 7A-7B may be permanently attached to one of the balloon catheters and releasably attached to the other. FIG. 8A shows an end view and 8B shows a front view of a third embodiment of the linking device 160. The linking device 160 has a first linking member 184 attached to the proximal section 106 of the first balloon catheter 102 and a second linking member 186 attached to the proximal section 108 of the second balloon catheter 104. The first linking member 184 and the second linking member 186 have interlocking features so that the two catheters can be releasably attached to one another. In the example shown, the interlocking features are corresponding male 187 and female 185 elements that can be attached and detached to one another in the manner of a snap or zip-lock device. FIG. 8C shows an end view of the linking device 160 with the first linking member 184 and the second linking member 186 detached from one another. Optionally, the linking device 160 can be configured so that the balloon catheters 102, 104 can be attached to one another in different longitudinal alignments. In other embodiments, the linking device 160 of FIGS. 8A-8C may utilize alternative interlocking features such as clamps, snaps, hook-and-loop fasteners, a releasable adhesive, a repositionable adhesive, etc. Optionally, the linking device 160 of FIGS. 8A-8C may also be configured to hold one or both of the guidewires 140, 142 stationary with respect to the catheter system 100. In this case, one or both of the linking members 184, 186 would include a locking device, slot or other structure configured to hold the proximal section of one of the guidewires 140, 142. This configuration would allow each guidewire and balloon catheter pair to be moved as a unit separately from the rest of the catheter system 100 when the linking members 184, 186 are separated. When it is desired, one or both of the guidewires 140, 142 can be released from the linking members 184, 186 and maneuvered separately from the rest of the catheter system 100. FIG. 9 shows a fourth embodiment of the linking device 160 that utilizes a peel-away sheath 190 for attaching the proximal sections 106, 108 of the first and second balloon catheters 102, 104 together. The peel-away sheath 190 may be made from heat shrink polymer tubing that is heat shrunk onto the proximal sections 106, 108 of the first and second balloon catheters 102, 104 to lock them together in a desired alignment with one another along the longitudinal axis. The peel-away sheath 190 has tabs or handles 196 to facilitate peeling the peel-away sheath 190 apart to release the balloon catheters 102, 104 so that they can be maneuvered separately from one another. The peel-away sheath 190 may utilize features, such as polymer orientation, perforations and/or an incised groove, to assure that the peel-away sheath 190 will peel apart along a longitudinal dividing line. FIGS. 10-13 show the catheter system 100 of FIG. 5 in use for stenting a bifurcated vessel using a main stent 170 and a sidebranch stent 178. The catheter system 100 is inserted into a body lumen that is desired to be stented and advanced to the point of the bifurcation. For stenting coronary arteries or carotid arteries, the catheter system 100 is typically inserted through a guiding catheter that has been previously positioned at the ostium of the target vessel. For stenting in peripheral arteries or other body lumens, the catheter system 100 may be inserted directly into the vessel, for example using the Seldinger technique or an arterial cutdown, or it may be inserted through an introducer sheath or guiding catheter placed into the vessel. The staggered or tandem initial position of the first and second inflatable balloons 130, 132 provides a very low crossing profile. The low crossing profile allows the catheter system 100 with a 3.0 or 3.5 mm (expanded diameter) coronary stent 170 mounted on it to be delivered through a 6 French (approximately 2 mm external diameter) guiding catheter, which will typically have an internal diameter of 0.066-0.071 inches (approximately 1.68-1.80 mm internal diameter). The catheter system 100 is maneuvered with the help of the steerable guidewires 140, 142 so that the first inflatable balloon 130, with the main stent 170 mounted on it, extends into the first sidebranch of the bifurcated vessel and the second steerable guidewire 142 extends into the second sidebranch, as shown in FIG. 10. The first inflatable balloon 130 will typically be positioned in the larger of the two sidebranches or in the main lumen of the vessel at the location of a smaller sidebranch vessel. When advancing the catheter system 100, the second steerable guidewire 142 may be positioned with its distal tip withdrawn into the flexible tubular extension 134 of the second balloon catheter 104 until the catheter system 100 reaches the bifurcation so that it will not be inadvertently damaged or interfere with advancement of the catheter system 100. This can be facilitated by inserting the proximal section of the second guidewire 142 into the optional slot or locking device 168 on the linking device 160. When the distal tip of the second balloon catheter 104 is in the vicinity of the sidebranch vessel, the second steerable guidewire 142 can be released from the linking device 160 and advanced with its distal tip extending from the flexible tubular extension 134 to engage the sidebranch vessel. Once the main stent 170 is in the desired position, the first inflatable balloon 130 is inflated to expand the main stent 170 and to seat it securely within the vessel, as shown in FIG. 11. Then, the first inflatable balloon 130 is deflated and the linking device 160 is released so that the second balloon catheter 104 can be advanced into the second sidebranch. The second inflatable balloon 132 is inflated to expand the sidebranch stent 178 and to seat it securely within the second sidebranch vessel, while simultaneously opening the side opening 172 in the main stent 170, as shown in FIG. 12. Alternatively, if a sidebranch stent is not used or if it is to be delivered on a separate balloon catheter, the second inflatable balloon 132 is inflated to open the side opening 172 in the main stent 170 at the location of the second sidebranch vessel. Optionally, the first and second inflatable balloons 130, 132 may be inflated simultaneously using the “kissing balloons” technique. Once the stents 170, 180 have been deployed, both balloons 130, 132 are deflated and the catheter system 100 is withdrawn from the patient. Alternatively, one or both of the balloon catheters 102, 104 can be released from the linking device 160 and used separately for dilating and/or stenting other vessels upstream or downstream of the main stent 170. Optionally, a sidebranch stent 178 may be placed in the second sidebranch vessel using a separate balloon catheter before or after deployment of the main stent 170. FIG. 14 shows a third embodiment of a catheter system 100 for stenting bifurcated vessels utilizing a linking device 160 constructed of an elongated split-tube 200. The split-tube 200 of the linking device 160 is configured to hold the proximal sections 106, 108 of the first and second balloon catheters 102, 104 arranged in a side-by-side configuration and aligned with one another along a longitudinal axis. A longitudinal split 202 extends the length of the split-tube 200. The longitudinal split 202 allows the split-tube 200 to be placed over the proximal sections 106, 108 of the catheters 102, 104 during catheter preparation and to be removed from the catheters 102, 104 at the appropriate time during the stenting procedure. The length of the split-tube 200 can vary. Good results were obtained with a catheter system 100 having a split-tube 200 that extends along most of the proximal sections 106, 108 of the balloon catheters 102, 104 between the proximal hubs 122, 124 and the proximal guidewire ports 114, 116 of the rapid exchange catheters. Preferably, the split-tube 200 of the linking device 160 is configured with a distal pull-tab 210 or other feature to facilitate lifting the distal part of the split-tube 200 to remove the linking device 160 and release the balloon catheters 102, 104 so that they can be maneuvered separately from one another. The pull-tab 210 is preferably located on a side of the split-tube 200 opposite to the longitudinal split 202. The pull-tab 210 can be formed by skiving or cutting away part of the tube 200 as shown. FIG. 15 shows a cross section of one embodiment of the split-tube 200 of the linking device 160 for the catheter system 100 of FIG. 14. The split-tube 200 has an inner lumen 204 that is sized and configured to hold the proximal sections 106, 108 of the first and second balloon catheters 102, 104 together with sufficient friction that the catheter system 100 can be advanced as a unit without any relative movement of the two catheters. In one particularly preferred embodiment, the split-tube 200 is manufactured as an extruded profile with an approximately circular outer profile and an approximately oval inner lumen 204. The longitudinal split 202 connects the inner lumen 204 with the exterior of the split-tube 200 at a thin part of the wall that coincides with the major axis of the oval inner lumen 204. The longitudinal split 202 is preferably formed during the extrusion of the split-tube 200. Alternatively, the tube 200 can be extruded without the longitudinal split 202 and then slitted along the length to form the longitudinal split 202 in a secondary operation. Suitable materials for the split-tube 200 include polyamide copolymers (e.g. PEBAX 6333 or PA 8020 from ATOFINA), polypropylene, and any extrudable medical grade polymer with a suitable combination of strength, flexibility and friction characteristics. The split-tube 200 of the linking device 160 can be made with many other possible configurations, including single-lumen and multiple-lumen configurations, and may include one or more longitudinal splits 202. By way of example, FIG. 16 shows an alternate cross section of a split-tube 200 of the linking device 160 for the catheter system 100 of FIG. 14. In this embodiment, the split-tube 200 has a first inner lumen 206 that is sized and configured to hold the proximal section 106 of the first balloon catheter 102 and a second inner lumen 208 that is sized and configured to hold the proximal section 108 of the second balloon catheter 104. The inner lumens 206, 208 are sized and configured to hold the proximal sections 106, 108 of the first and second balloon catheters 102, 104 with sufficient friction that the catheter system 100 can be advanced as a unit without any relative movement of the two catheters. Two longitudinal splits 202 connect the inner lumens 206, 208 with the exterior of the split-tube 200. The two longitudinal splits 202 are preferably located on the same side of the split-tube 200 opposite to the distal pull-tab 210 to facilitate removal of the linking device 160 from both catheters 102, 104 simultaneously. The longitudinal splits 202 are preferably formed during the extrusion of the split-tube 200. Alternatively, the tube 200 can be extruded without the longitudinal splits 202 and then slitted along the length to form the longitudinal splits 202 in a secondary operation. Optionally, the linking device 160 in FIG. 15 or FIG. 16 can include additional lumens, slots or other structures to hold one or both of the guidewires 140, 142 stationary with respect to the catheter system 100. FIG. 17 shows the catheter system 100 of FIG. 14 in use. The linking device 160 with the split-tube 200 has the advantage that, once it is started, the split-tube 200 will demount itself as the catheter system 100 is advanced so that the physician does not need to unpeel, remove or displace a linking member that would otherwise require a “third hand”. The catheter system 100 is prepared for use by aligning the first and second balloon catheters 102, 104 in the desired longitudinal alignment and then pressing the longitudinal split 202 of the split-tube 200 against the proximal sections 106, 108 of the catheters until they are enclosed within the inner lumen 204 (or lumens 206, 208) of the split-tube 200, as shown in FIG. 14. A stent or stents may then be crimped or mounted on the balloons 130, 132 in the desired configuration. This preparation may be carried out at the manufacturing facility or it may be performed at the point of use by a medical practitioner. The distal ends of the catheters 102, 104 with the stent or stents mounted thereon are inserted into the patient in the usual manner through a guiding catheter with a Y-fitting 220 or other hemostasis adapter on the proximal end of the guiding catheter. The distal pull-tab 210 is pulled toward the side to start demounting the split-tube 200 from the balloon catheters 102, 104, and then the first and second balloon catheters 102, 104 are advanced as a unit. As shown in FIG. 17, when the split-tube 200 encounters the Y-fitting 220, the split-tube 200 will peel away or demount itself from the proximal sections 106, 108 of the balloon catheters 102, 104. The stent or stents can be deployed in the vessel bifurcation using the methods described herein. FIG. 18 shows a distal portion of a catheter system 100 for stenting bifurcated vessels. The catheter system 100 is similar to that shown in FIG. 5 with a first balloon catheter 102 having a first inflatable balloon 130 and a second balloon catheter 104 having a second inflatable balloon 132 and a flexible tubular extension 134 extending distally from the balloon 132. The first and second inflatable balloons 130, 132 are assembled together in a staggered or tandem initial position as shown to provide a low crossing profile. The catheter system 100 can use any of the linking devices 160 described herein to maintain the longitudinal alignment of the catheters 102, 104 during insertion. A distal stent 122 is mounted on a distal portion of the first inflatable balloon 130 and a proximal stent 124 is mounted on a proximal portion of the first inflatable balloon 130 and the flexible tubular extension 134 of the second balloon catheter 104. Preferably, only a small space is left between the distal and proximal stents 122, 124. The distal stent 122 is configured to fit the distal main branch diameter and proximal stent 124 is configured to fit the proximal main branch diameter and the bifurcation itself. Preferably, the proximal stent 124 is configured so that it can be overdilated if necessary to fit the vessel at the bifurcation. In addition, the catheter system 100 may optionally utilize a sidebranch stent 178 mounted on the second balloon 132, as illustrated in FIG. 5. The distal stent 122 and the proximal stent 124 are deployed using sequential and/or simultaneous inflation of the first and second inflatable balloons 130, 132 using the methods described herein. FIG. 19 shows a bifurcated vessel after stenting with the catheter system 100 of FIG. 18. Using separate distal and proximal stents 122, 124 allows the stents to be independently sized to fit the target vessel and it allows independent expansion of the two stents without any links between them that could cause distortion of one or both stents during deployment. While the present invention has been described herein with respect to the exemplary embodiments and the best mode for practicing the invention, it will be apparent to one of ordinary skill in the art that many modifications, improvements and subcombinations of the various embodiments, adaptations and variations can be made to the invention without departing from the spirit and scope thereof. Although the present invention has been primarily described in relation to angioplasty and stenting of bifurcated blood vessels, the apparatus and methods of the invention can also be used for other applications as well. For example, the catheter system can be used for stenting bifurcated lumens in other organ systems of the body. In addition, the linking devices described herein can be used in other applications where it is desired to hold two or more catheters or similar devices arranged in a side-by-side configuration and aligned with one another along a longitudinal axis. The principles of the invention can also be applied to catheters other than balloon catheters. | <SOH> BACKGROUND OF THE INVENTION <EOH>The following patents and patent applications relate to catheters and catheter systems for performing angioplasty and stenting of bifurcated vessels. These and all patents and patent applications referred to herein are incorporated by reference in their entirety. U.S. Pat. No. 6,579,312 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,540,779 Bifurcated stent with improved side branch aperture and method of making same U.S. Pat. No. 6,520,988 Endolumenal prosthesis and method of use in bifurcation regions of body lumens U.S. Pat. No. 6,508,836 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,494,875 Bifurcated catheter assembly U.S. Pat. No. 6,475,208 Bifurcated catheter assembly U.S. Pat. No. 6,428,567 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,387,120 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,383,213 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,371,978 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,361,544 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,325,826 Extendible stent apparatus U.S. Pat. No. 6,264,682 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,258,073 Bifurcated catheter assembly U.S. Pat. No. 6,254,593 Bifurcated stent delivery system having retractable sheath U.S. Pat. No. 6,221,098 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,210,380 Bifurcated catheter assembly U.S. Pat. No. 6,165,195 Stent and catheter assembly and method for treating bifurcations U.S. Pat. No. 6,142,973 Y-shaped catheter U.S. Pat. No. 6,117,117 Bifurcated catheter assembly U.S. Pat. No. 6,086,611 Bifurcated stent U.S. Pat. No. 5,720,735 Bifurcated endovascular catheter U.S. Pat. No. 5,669,924 Y-shuttle stent assembly for bifurcating vessels and method of using the same U.S. Pat. No. 5,613,980 Bifurcated catheter system and method U.S. Pat. No. 6,013,054 Multifurcated balloon catheter U.S. Pat. No. 4,896,670 Kissing balloon catheter U.S. Pat. No. 5,395,352 Y-adaptor manifold with pinch valve for an intravascular catheter U.S. Pat. No. 6,129,738 Method and apparatus for treating stenoses at bifurcated regions U.S. Pat. No. 6,544,219 Catheter for placement of therapeutic devices at the ostium of a bifurcation of a body lumen U.S. Pat. No. 6,494,905 Balloon catheter U.S. Pat. No. 5,749,825 Means method for treatment of stenosed arterial bifurcations U.S. Pat. No. 5,320,605 Multi-wire multi-balloon catheter U.S. Pat. No. 6,099,497 Dilatation and stent delivery system for bifurcation lesions U.S. Pat. No. 5,720,735 Bifurcated endovascular catheter U.S. Pat. No. 5,906,640 Bifurcated stent and method for the manufacture and delivery of same U.S. Pat. No. 5,893,887 Stent for positioning at junction of bifurcated blood vessel and method of making U.S. Pat. No. 5,755,771 Expandable stent and method of delivery of same US 20030097169A1 Bifurcated stent and delivery system US 20030028233A1 Catheter with attached flexible side sheath US 20020183763A1 Stent and catheter assembly and method for treating bifurcations US 20020156516A1 Method for employing an extendible stent apparatus US 20020116047A1 Extendible stent apparatus and method for deploying the same US 20020055732A1 Catheter assembly and method for positioning the same at a bifurcated vessel WO 9944539A2 Dilatation and stent delivery system for bifurcation lesions WO 03053507 Branched balloon catheter assembly WO 9924104 Balloon catheter for repairing bifurcated vessels WO 0027307 The sheet expandable trousers stent and device for its implantation FR 2733689 Endoprosthesis with installation device for treatment of blood-vessel bifurcation stenosis | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates generally to catheters and catheter systems for performing angioplasty and vascular stenting. More particularly it relates to a catheter system and method for stenting a vessel at a bifurcation or sidebranch of the vessel. In a first aspect, the invention comprises a catheter system for stenting bifurcated vessels. The catheter system includes a first balloon catheter, a second balloon catheter and a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. The catheter system may include one or more vascular stents of various configurations mounted on the first and/or second balloon catheters. The linking device allows the catheter system to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. Typically, the catheter system will also include a first and second steerable guidewire for guiding the first and second balloon catheters within the patient's blood vessels. Optionally, the linking device may also be configured to hold one or both of the guidewires stationary with respect to the catheter system. The catheter system may be arranged with the inflatable balloons in a side-by-side configuration for stenting the bifurcated vessels using a method similar to the “kissing balloons” technique. Alternatively, the catheter system may be arranged with the inflatable balloons in a low-profile staggered or tandem configuration for stenting the bifurcated vessels using a modified “kissing balloons” technique. When arranged in the staggered or tandem configuration, the second balloon catheter may optionally be constructed with a flexible tubular extension that extends the guidewire lumen distally from the inflatable balloon. In a second aspect, the invention comprises a linking device for holding the first and second balloon catheters of the system in a side-by-side configuration and aligned with one another along a longitudinal axis. The linking device allows the catheter system to be advanced as a unit and helps prevent premature or inadvertent dislodgement of the stent from the catheters. Optionally, the linking device may also be configured to hold one or both of the guidewires stationary with respect to the catheter system. The linking device is preferably releasable so that one or both of the balloon catheters and/or the guidewires can be released from the linking device and maneuvered separately from the rest of the catheter system. In one embodiment the linking device is self-releasing in the sense that the linking device demounts itself from the first and second balloon catheters as the catheter system is advanced into the patient's body. In a third aspect, the invention comprises a method for stenting bifurcated vessels utilizing the described catheter system. In a first variation of the method, the inflatable balloons are arranged in a side-by-side configuration for stenting the bifurcated vessels in a method similar to the “kissing balloons” technique, but utilizing a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. In a second variation of the method, the inflatable balloons are arranged in a staggered or tandem configuration for stenting the bifurcated vessels using a modified “kissing balloons” technique that also utilizes a linking device for holding the first and second balloon catheters in a side-by-side configuration and aligned with one another along a longitudinal axis. When desired, the linking device may be released so that one or both of the balloon catheters and/or the guidewires can be maneuvered separately from the rest of the catheter system. | 20040427 | 20100105 | 20050421 | 57646.0 | 0 | TRUONG, KEVIN THAO | CATHETER SYSTEM FOR STENTING BIFURCATED VESSELS | SMALL | 0 | ACCEPTED | 2,004 |
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10,833,565 | ACCEPTED | Effective method to improve sub-micron color filter sensitivity | An image sensor device and method for forming said device are described. The image sensor structure comprises a substrate with photodiodes, an interconnect structure formed on the substrate, a color filter layer above the interconnect structure, a first microlens array, an overcoat layer, and a second microlens array. A key feature is that a second microlens has a larger radius of curvature than a first microlens. Additionally, each first microlens and second microlens is a flat convex lens. Thus, a thicker second microlens with a short focal length is aligned above a thinner first microlens having a long focal length. A light column that includes a first microlens, a second microlens and a color filter region is formed above each photodiode. A second embodiment involves replacing a second microlens in each light column with a plurality of smaller second microlenses that focus light onto a first microlens. | 1. A microlens component of an image sensor formed above a color filter layer having of an array of color regions on a substrate, comprising: (a) a first microlens array formed above the color filter layer, said first microlens array having a plurality of first microlenses wherein each first microlens has a radius of curvature; (b) a planar transparent overcoat layer formed on said first microlens array; and (c) a second microlens array formed on said overcoat layer, said second microlens array has a plurality of second microlenses wherein each second microlens has a radius of curvature. 2. The image sensor of claim 1 wherein a first microlens is a flat convex lens. 3. The image sensor of claim 1 wherein a second microlens is a flat convex lens. 4. The image sensor of claim 1 wherein the radius of curvature of a second microlens is larger than the radius of curvature of a first microlens. 5. The image sensor of claim 1 wherein the overcoat layer is comprised of a negative tone photoresist that has >99% transparency to light used in the image sensor. 6. An image sensor, comprising: (a) a substrate having a plurality of photodiodes formed thereon; (b) a plurality of light columns aligned above said photodiodes wherein a light column is formed in a stack of transparent insulation layers above each photodiode; (c) a color filter layer comprised of an array of color filter regions formed above said stack of transparent insulation layers; (d) a first microlens array formed above the color filter layer, said first microlens array having a plurality of first microlenses wherein each first microlens has a radius of curvature; (e) a planar transparent overcoat layer formed on said first microlens array; and (f) a second microlens array formed on said overcoat layer, said second microlens array has a plurality of second microlenses wherein each second microlens has a radius of curvature and is aligned over a first microlens. 7. The image sensor of claim 6 wherein a light column is further comprised of a vertical arrangement of a second microlens, a first microlens, and a color filter region so that light impinging on the surface of a second microlens is focused with high efficiency through a first microlens and color filter region onto a photodiode. 8. The image sensor of claim 6 wherein a first microlens is a flat convex lens. 9. The image sensor of claim 8 wherein a first microlens has a radius of curvature between about 0.5 and 1.4 Angstroms. 10. The image sensor of claim 6 wherein a second microlens is a flat convex lens. 11. The image sensor of claim 9 wherein a second microlens has a radius of curvature between about 0.5 and 1.4 microns that is greater than the radius of curvature of a first microlens and wherein a second microlens has a width about equal to the width of a first microlens. 12. The image sensor of claim 6 wherein the radius of curvature of a second microlens is larger than the radius of curvature of a first microlens. 13. The image sensor of claim 6 wherein the second microlens array is comprised of a plurality of subunits each having a plurality of second microlenses that focus light onto a first microlens. 14. The image sensor of claim 13 wherein the second microlenses in a subunit have a collective width that is equal to the width of a first microlens. 15. The image sensor of claim 6 wherein the overcoat layer and insulation layer are comprised of a negative tone photoresist that has >99% transparency to light within the light column. 16. An image sensor device, comprising: (a) a substrate having a plurality of photodiodes formed thereon; (b) an interconnect structure comprised of a stack of metal layers and insulation layers formed on said substrate; (c) a plurality of light columns aligned above said photodiodes wherein a light column is formed in a stack of insulation layers above each photodiode and between said metal layers in the interconnect structure; (d) a color filter layer comprised of an array of color filter regions formed above said interconnect structure; (e) a first microlens array formed above the color filter layer, said first microlens array having a plurality of first microlenses wherein each first microlens has a radius of curvature; (f) a planar transparent overcoat layer formed on said first microlens array; and (g) a second microlens array formed on said overcoat layer, said second microlens array has a plurality of second microlenses wherein each second microlens has a radius of curvature and is aligned above a first microlens. 17. The image sensor device of claim 16 wherein a light column is further comprised of a vertical arrangement of a second microlens, a first microlens, and a color filter region so that light impinging on the surface of a second microlens is focused with high efficiency through a first microlens and color filter region onto a photodiode. 18. The image sensor device of claim 16 further comprised of a transparent spacer layer formed between the color filter layer and the first microlens array. 19. The image sensor device of claim 16 wherein the insulation layer, spacer layer, and overcoat layer are comprised of a negative tone photoresist that has >99% transparency to light within a light column. 20. The image sensor device of claim 16 wherein a first microlens is a flat convex lens. 21. The image sensor device of claim 21 wherein the first microlens has a radius of curvature between about 0.5 and 1.4 Angstroms. 22. The image sensor device of claim 16 wherein a second microlens is a flat convex lens. 23. The image sensor device of claim 21 wherein a second microlens has a radius of curvature between about 0.5 and 1.4 microns that is greater than the radius of curvature of a first microlens and wherein a second microlens has a width about equal to the width of a first microlens. 24. The image sensor device of claim 16 wherein the radius of curvature of a second microlens is larger than the radius of curvature of a first microlens. 25. The image sensor device of claim 16 wherein the second microlens array is comprised of a plurality of subunits each having a plurality of second microlenses that focus light onto a first microlens. 26. The image sensor device of claim 25 wherein the second microlenses in a subunit have a collective width that is equal to the width of a first microlens. 27. The image sensor device of claim 25 wherein a second microlens in a subunit has a flat convex shape with a radius of curvature in the range of about 0.5 to 1.2 microns. 28. A method of forming an image sensor on a substrate comprising: (a) providing a semiconductor substrate having a plurality of photodiodes formed therein; (b) forming a color filter layer comprised of an array of color filter regions on said substrate; (c) forming a first microlens array that includes a plurality of first microlenses having a radius of curvature above said color filter layer; (d) forming a planar transparent overcoat layer on said first microlens array; and (e) forming a second microlens array that includes a plurality of second microlenses having a radius of curvature on said overcoat layer. 29. The method of claim 28 wherein the color filter layer is comprised of a negative tone photoresist that is crosslinked and has a thickness of about 0.5 to 1.8 microns. 30. The method of claim 28 wherein a light column that includes a vertical arrangement of a second microlens, a first microlens, and a color filter region is aligned above a photodiode. 31. The method of claim 28 wherein the overcoat layer has a thickness between about 1.5 and 2.5 Angstroms. 32. The method of claim 28 wherein a first microlens is a flat convex lens. 33. The method of claim 28 wherein a second microlens is a flat convex lens. 34. The method of claim 28 wherein a first microlens has a radius of curvature in the range of about 0.5 to 1.4 microns. 35. The method of claim 28 wherein forming a first microlens comprises reflowing a positive tone photoresist pattern comprised of a Novolak resin and a DNQ photosensitive compound at about 160° C. for about 10 minutes. 36. The method of claim 35 wherein forming the transparent overcoat layer comprises a 220° C. bake that hardens the first microlens array. 37. The method of claim 28 wherein a second microlens has a radius of curvature between about 0.5 and 1.4 microns that is greater than the radius of curvature of a first microlens and wherein a second microlens has a width about equal to the width of a first microlens. 38. The method of claim 28 wherein forming a second microlens comprises reflowing a positive tone photoresist pattern comprised of a Novolak resin and a DNQ photosensitive compound at about 160° C. for about 10 minutes and then hardening at 220° C. 39. The method of claim 28 wherein the radius of curvature of a second microlens is larger than the radius of curvature of a first microlens. 40. The method of claim 28 wherein the second microlens array is comprised of a plurality of subunits each having a plurality of second microlenses that focus light onto a first microlens. 41. The method of claim 40 wherein the second microlenses in a subunit have a collective width that is equal to the width of a first microlens. 42. The method of claim 28 further comprised of forming a transparent spacer layer between the color filter layer and first microlens array. 43. The method of claim 28 wherein the substrate is further comprised of an interconnect structure that includes a stack of transparent insulation layers formed above the plurality of photodiodes, said color filter layer is formed above said interconnect structure. | FIELD OF THE INVENTION The invention relates to a solid state imaging device (hereafter referred to as a CMOS image sensor) and a method of manufacturing the same. More particularly, the image sensor has an improved microlens component that increases the sensitivity of the device. BACKGROUND OF THE INVENTION A complementary metal oxide semiconductor (CMOS) image sensor is a key component of many digital video cameras. The CMOS image sensor is typically comprised of an upper stack that includes one or more layers of color filters, a microlens array, and an overcoat for the microlens and a lower stack that includes interlevel dielectric (ILD) layers, interlevel metal (ILM) layers, and passivation layers which are fabricated on a substrate. High sensitivity is an important characteristic for a CMOS image sensor since the image quality may suffer if sensitivity is not high enough. The function of the microlens component is to focus light through a color filter layer and the lower stack onto the sensing area or photodiode. Other layers in the light path must have a high transparency to that a minimal amount of light intensity is lost. The elementary unit of the image sensor is a pixel which is an addressable area element with intensity and color attributes related in large part to the spectral signal contrast obtained from the photon collection efficiency of the microlens array, spectra transmission through the color filters, microlenses, and other layers in the imaging path, and the spectral response and efficiency of the photodiode. Constant advances in technology that have reduced the smallest dimension in the CMOS device to less than a micron have also forced the pixel size to shrink to less than 5 um. When a plurality of color regions are formed in a color filter layer, the width of a color region is called a pixel. Newer technologies require an increased number of ILM layers that lengthens the distance (focal length) between a microlens and a photodiode. The longer focal length is a big challenge to maintaining adequate sensor sensitivity. Although a thinner microlens is able to produce a longer focal length, the quantum efficiency of a thin microlens is lower than that of a thicker microlens because of less surface area. Therefore, an improved design is needed for the upper stack and especially for the microlens component in a CMOS image sensor that increases sensitivity and is compatible with a pixel size that is smaller than 5 um. A microlens is typically formed by patterning a photoresist that is preferably a positive tone type in which unexposed regions of the photoresist layer are chemically unaltered and remain on the substrate after an aqueous base developer is used to remove exposed regions. The resulting photoresist pattern is heated to a temperature that deforms a stripe or rectangular shape into a cylinder shape or a square shape into a hemisphere shape as shown in FIG. 1. The thermal treatment produces a microlens 1 with a flat bottom and top surface curvature such that the thickness T1 hereafter referred to as the radius of curvature in the center of the microlens 1 is greater than the thickness TX at other points (X) on the microlens surface. The thickness TX becomes progressively smaller as the distance D from the center increases until reaching a minimum at the edges 3. This design enables light 4 from above the microlens to be focused to a point 5 on a photodiode 6 below the microlens. The distance between the microlens 1 and the focal point 5 is the focal length FL. In this design, a spacer layer 7, color filter layer 8, planarization layer 9, ILD layer 10, and ILM layer 11, and protective layer 12 are also depicted. Although color filter layer 8 is shown as a single layer with regions 8a, 8b, 8c alternating between green 8a and red 8b or blue 8c, the color filters may also be stacked such that each color filter is contained in a separate layer. Futhermore, the color filter layer 8 may be located above the microlens 1 array rather than below it. The pixel width (PW) is shown as the width of one color filter region 8a, 8b, or 8c. U.S. Pat. No. 5,796,154 discloses a design including two layers of microlenses each having a thickness of about 2 microns that are separated by a transparent acrylate layer and preferably a color filter. The photorefractive index of the microlenses is higher than that of the acrylate and color filter. Since the lower microlens array does not reside on a planar surface, the size and oval shape of the microlens can be difficult to reproduce. In addition, the poly(vinylphenol)/diazonaphthoquinone diazide (DNQ) based photoresist that comprises the lower microlens has less suitable dissolution characteristics for patterning than a more common Novolak resin/DNQ photoresist. A key feature in related U.S. Pat. Nos. 6,171,885 and 6,274,917 is microlens formation prior to color filter fabrication in order to minimize rework and place the microlens array in closer proximity to the photodiodes. A planarization layer is used to separate the microlens array from overlying color filter layers. A high efficiency color filter process to improve color balance in an image sensor is described in U.S. Pat. No. 6,395,576. The color coating sequence involves coating a blue color filter layer first to form a color pixel structure with wider process window and improved adhesion to a substrate. The thickness of each color filter is adjusted in real time by a spectrophotometric algorithmic analyzer that drives a feedback servo control loop. SUMMARY OF THE INVENTION An objective of the present invention is to provide a microlens component in a CMOS image sensor that offers improved sensitivity in a device that has several metal (ILM) layers and requires a long focal length. A further objective of the present invention is to provide a microlens component in a CMOS image sensor that offers improved sensitivity in a sub-micron device that has a pixel size smaller than about 5 microns. A still further objective of the present invention is to provide a method of fabricating a CMOS image sensor having improved efficiency that is compatible with existing tools and materials and can be performed in a low cost manner. These objectives are achieved by providing a lower stack of layers for a CMOS image sensor device. In one embodiment, a dielectric layer such as SiO2 is formed on a substrate and a photodiode array is formed in the dielectric layer. Then a first metal layer (M1) is formed on the dielectric layer between photodiodes. A second ILD layer which is preferably an oxide is deposited on the M1 layer and substrate followed by a second metal layer (M2), a third ILD layer, a third metal layer (M3) and a fourth ILD layer. Next, a silicon oxynitride passivation layer is formed by conventional means on the uppermost ILD layer. The interconnect structure comprised of the ILD, ILM, and passivation stack also has contacts between the M1 layer and a conductive layer in the substrate, and has vias between M1 and M2 layers and between M2 and M3 layers. An insulation layer is deposited on the passivation layer and is preferably a photoresist layer that provides high transmittance to light that passes through overlying color filters. A color filter layer that includes a plurality of green, red, and blue color regions is then formed above the insulation layer. The color filter layer is comprised of a crosslinked negative photoresist that has been dyed in specific regions to selectively transmit wavelengths in a blue, red, or green spectral range and forms the uppermost layer in the lower stack of layers. Next, an upper stack of layers which is comprised of the microlens component of the CMOS image sensor is formed on the color filter layer. An optional spacer layer preferably comprised of the same material as in the insulation layer may be deposited on the color filter layer. A first microlens array with a plurality of first microlenses is then fabricated on the spacer layer by patterning a positive tone photoresist and heating to reflow and form flat convex shapes. There is one first microlens having a radius of curvature (H1) that is aligned above each color filter region and the width of a first microlens is less than or equal to a pixel width. A planar overcoat layer which is preferably comprised of the same transparent material as in the insulation layer is formed on the first microlens array. A post-exposure bake at 220° C. not only hardens the overcoat layer but also hardens the first microlens array. A second microlens array comprised of a plurality of second microlenses is fabricated on the overcoat layer by first patterning a positive tone photoresist, heating to reflow, and hardening with a 220° C. bake to form flat, convex shapes. A second microlens has a width that is essentially equal to the width of a first microlens. Moreover, there is a second microlens aligned over each first microlens. A second microlens preferably has a radius of curvature (H2) that is greater than H1. The larger radius of curvature provides for a shorter focal length and higher photon collection efficiency for a second microlens compared to a first microlens. Light that is efficiently collected by a second microlens is focused on a first microlens. The first microlens has a long focal length that is capable of focusing light through a light column within a thick lower stack of layers onto a photodiode. The invention is also a microlens component of a CMOS image sensor with improved sensitivity that is formed on a lower stack of layers that includes a photodiode array on a substrate and a color filter layer as the top layer in the lower stack. The lower stack typically includes a interconnect structure on the substrate and an insulation layer formed on the insulation layer. The microlens component is comprised of a first microlens array formed above the color filter layer, a planar transparent overcoat layer on the first microlens array, and a second microlens array formed on the overcoat layer. Each of the plurality of microlenses in the first microlens array and in the second microlens array has a flat convex shape. An important feature is that the radius of curvature of a second microlens is greater that the radius of curvature of a first microlens. A light column is formed which involves a vertical arrangement of a photodiode, a color filter region, a first microlens, and a second microlens. Other intermediate layers described previously have a high transmittance to minimize loss of light intensity as light passes through the light column. Photon collection efficiency (ψ) of a microlens is expressed by the equation ψ=4PI×R2 where PI is the photorefractive index of a microlens and R is the radius of curvature. In a second embodiment, the second microlens array of the microlens component in an image sensor is comprised of a plurality of subunits which are each comprised of a plurality of second microlenses. The collective width of the plurality of second microlenses in a subunit is equal to the width of a first microlens. A subunit of second microlens is aligned over a first microlens so that a vertical light column is formed that includes a photodiode, a color filter region, a first microlens, and a second microlens. The radius of curvature of a second microlens is preferably greater than the radius of curvature of a first microlens. It is important that there is no gap between adjacent second microlenses in a subunit. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a prior art example of an image sensor in which a microlens array is formed above a color filter layer that is aligned above a photodiode. FIGS. 2a-2c are cross-sectional views of a method of forming a microlens component of an image sensor in which a second microlens is aligned over a first microlens, a color filter region, and a photodiode according to the first embodiment of the present invention. FIG. 2d depicts a light column in an image sensor structure and FIG. 2e shows the light path through the light column according to the present invention. FIGS. 3a-3b are cross-sectional views that illustrate a method of forming a microlens component in an image sensor in which a second microlens array comprised of a plurality of subunits of second microlenses is aligned over a first microlens, a color filter region, and a photodiode according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION The present invention is a microlens component of a CMOS image sensor that provides improved sensitivity for sub-micron devices that have a pixel size of less than 5 microns. A process is also described for forming the improved CMOS image sensor. The drawings are provided by way of example and are not intended to limit the scope of the invention. Furthermore, the relative sizes of the various elements within the drawings are not necessarily drawn to size. Referring to FIG. 2a, a substrate 18 is provided that may contain active and passive devices that are not shown in order to simplify the drawing. A lower stack of layers for a CMOS image sensor will now be described. A first dielectric layer 20 such as SiO2 is deposited on the substrate 18 and a photodiode array comprised of photodiodes 21 is fabricated within the first dielectric layer by conventional means. An interconnect structure comprised of a first metal (ILM) layer 22 is formed on dielectric layer 20 but not over photodiodes 21. The interconnect structure may be further comprised of a second dielectric (ILD) layer 23, a second ILM layer 24, a third ILD layer 25, a third metal layer 26, and a fourth ILD layer 27 that are successively formed above the first ILM layer 22. Although 3 ILM and 4 dielectric layers are depicted, the invention is equally effective for a plurality of ILM and ILD layers. The ILD layers 23, 25, 27 are typically silicon oxide but may be a low k dielectric material such as fluorine doped SiO2 or carbon doped SiO2 and are otherwise known as insulation layers. ILM layers 22, 24, 26 are preferably copper, aluminum or an Al/Cu alloy. The ILD layers and ILM layers are formed by methods known to those skilled in the art and are not described herein. Note that the ILM layers 22, 24, 26 are aligned in vertical arrays. The ILM layers 23, 25, 27 are highly transparent to light used in the image sensor and form the bottom portion of a light column between adjacent vertical arrays of ILM layers. Typically, there are also vias (not shown) that connect one ILM layer with an overlying ILM layer and contacts (not shown) that connect a first ILM layer 22 with an active area in the substrate. The lower stack of layers generally includes one or more passivation layers. In one embodiment, a passivation layer 28 which is preferably silicon oxynitride is deposited by a chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD) method on the fourth ILD layer 27. A planarization layer 29 may be formed on the passivation layer 28 and is preferably a negative tone photoresist with high (>99%) transparency to light in the visible wavelength range of about 340 to 650 nm which is transmitted within a light column. The photoresist is coated, baked, and then exposed with one or more wavelengths in a range of about 240 to 450 nm. A post-expose bake may be employed to promote a crosslinking reaction initiated by the exposure. As a result, the crosslinked photoresist that is planarization layer 29 does not mix with an overlying layer which is formed in a subsequent step. The planarization layer 29 has a thickness between about 4000 and 18000 Angstroms. A color filter layer 30 is fabricated on planarization layer by a conventional method and is comprised of color filter regions 30a, 30b, 30c that are each dyed to provide a color filter that selectively transmits wavelengths in a certain spectral range. In the exemplary embodiment, region 30a is a green filter, region 30b is a red filter, and region 30c is a blue filter. The order of green, red, blue is not critical but it is important for each color of green, red, and blue to be represented in three adjacent color regions. The width of each color filter region is shown as a pixel width PW1. This invention is especially applicable for a PW1 that is less than about 5 microns. The color filter layer 30 is preferably a crosslinked negative tone photoresist that does not mix with overlying or underlying layers. The color filter layer 30 has a thickness in the range of about 0.5 to 1.8 microns and forms the uppermost layer in the lower stack of layers. A key feature of the present invention is the formation of an upper stack of layers that is comprised of the microlens component of the image sensor. In one embodiment, a transparent spacer layer 31 is formed on the color filter layer 30 by preferably employing the same process and photoresist composition that is used to form the planarization layer 29. The spacer layer 31 preferably has a planar surface and is from about 1.7 to 2 microns thick. A planar spacer layer 31 enables a wide process latitude in a subsequent photoresist patterning step. A first microlens array is fabricated by initially patterning a photoresist layer 32 on the spacer layer 31 by a conventional method. The photoresist layer 32 preferably has a positive tone composition that is comprised of a Novolak resin and a DNQ photosensitive compound. Exposed portions (not shown) are removed in an aqueous base developer while unexposed portions of the photoresist layer 32 remain on the spacer layer 31. Note that each unexposed portion of the photoresist layer 32 is aligned above a color filter region 30a, 30b, or 30c. Referring to FIG. 2b, the photoresist layer 32 is heated to approximately 160° C. for about 10 minutes which causes the photoresist layer to reflow. Surface tension produces a first microlens array comprised of a plurality of first microlenses 32a that have a flat convex shape after cooling. In other words, a first microlens has a flat bottom on the spacer layer 31 while the top and sides form a curved surface with a convex shape that has a radius of curvature H1. The width of a first microlens 32a is about the same as the width of the original unexposed portion of the photoresist layer 32. The radius of curvature H1 for a first microlenses 32a is from about 0.5 to 1.4 microns while the width of a first microlens is less than or equal to a pixel width. At this point, an overcoat layer 33 that is preferably comprised of the same highly transparent material as in the planarization layer 29 and spacer layer 31 is formed by coating and baking a photoresist in a range of about 90° C. to 150° C. The overcoat layer 33, spacer layer 31, and planarization layer 29 preferably have a photorefractive index (PI) in the range of about 1.4 to 1.7. The overcoat layer 33 which has a thickness from about 1.5 to 2.5 microns is exposed and then post-expose baked at about 220° C. for 1000 to 1200 seconds to crosslink the overcoat layer 33 and harden the first microlenses 32a. The post-expose bake also serves to form a more planar overcoat layer 33 which is necessary for a wide process window in a subsequent patterning step. A second microlens array is formed on the overcoat layer 33 by patterning a photoresist layer 34 that is preferably comprised of the same photoresist composition used in the photoresist layer 32. However, other photoresist compositions that include a Novolak resin and a DNQ sensitive compound are acceptable. Note that each unexposed portion of the photoresist layer 34 is aligned over a first microlens 32a and that the openings between the unexposed portions are above vertical arrays of the ILM layers 22, 24, 26. Moreover, the width of an unexposed portion of the photoresist layer 34 is essentially equal to the width of a first microlens 32a. Referring to FIG. 2c, the photoresist layer 34 is reflowed by heating the substrate 18 to approximately 160° C. for about 10 minutes and is then hardened by an additional bake at 220° C. to generate a second microlens array comprised of second microlenses 34a that have a flat convex shape. A second microlens 34a is formed with a flat bottom on the overcoat layer 33 while the top and sides form a curved surface with a convex shape and a radius of curvature H2 between about 0.5 an 1.4 microns. The width Y of a second microlens 34a is preferably the same as the width of a first microlens 32a. As a result, a light column is formed in the upper stack of layers and is comprised of a second microlens 34a, an underlying first microlens 32a, a portion of the overcoat layer 33 between a first microlens 32a and a second microlens 34a, and a portion of the spacer layer 31 between a first microlens and an underlying color filter region 30a, 30b, or 30c. It is understood that a light column in the upper stack of layers is aligned over a light column in the lower stack of layers to form a continuous vertical light column. A vertical light column is defined as a light column that is oriented in a direction which is perpendicular to the surface of the substrate 18 on which a photodiode 21 is formed. The inventors have found that a key requirement for the microlens component of the present invention is that H2 must be greater than H1. When H2>H1, a second microlens has a greater photon collection efficiency than a first microlens. Photon collection efficiency (ψ) of a microlens in the first or second microlens array is expressed by the equation ψ=4PI×R2 where PI is the photorefractive index of a microlens and R is the radius of curvature. Preferably, the PI is form about 1.4 to 1.7 for a first microlens 32a or second microlens 34a. More preferably, the PI of a first microlens 32a and a second microlens 34a is essentially the same as the PI of the planarization layer 29, spacer layer 31, and the overcoat layer 33 to minimize the amount of light that is scattered as light is transmitted through a light column. Those skilled in the art will appreciate that when H2>H1, a first microlens will have a longer focal length than a second microlens. This relationship provides an advantage for the microlens component of the image sensor in the present invention because light captured by the high ψ of a second microlens is efficiently focused onto a first microlens which in turn focuses the light through a thick lower stack of layers. In other words, a second microlens having a high ψ would not have a large enough focal length to be able to focus light efficiently through a thick lower stack of layers to a photodiode with a pixel size of less than about 5 microns. On the other hand, a first microlens with a long focal length does not have a high enough ψ by itself to provide a high sensitivity signal. Only a combination of a first microlens array and a second microlens array as described in the first embodiment provides a high sensitivity in addition to a long focal length for small pixel sizes of less than about 5 microns. This arrangement is more efficient than a dual microlens array described in prior art where a microlens in a first array has the same R as a microlens in a second array. The present invention is compatible with newer technologies that have a thick lower stack comprised of a plurality of ILM and ILD layers where a long focal length in the image sensor device is required. The method of the first embodiment is cost efficient since the planarization layer, spacer layer, and overcoat layer may have the same composition and are processed in existing tools. Additionally, the first microlens array and the second microlens array have the same positive tone photoresist composition which reduces the number of materials needed in a manufacturing line. Each layer in the microlens component is processed so that crosslinking or hardening by a heat treatment prevents intermixing with adjacent layers that could degrade device performance. The present invention is also a microlens component within an upper stack of layers in a CMOS image sensor as depicted in FIGS. 2c-2e. The upper stack is formed on a lower stack of layers on a substrate. In one embodiment, the lower stack is comprised of an interconnect structure that includes ILM layers 22, 24, 26 and ILD layers 23, 25, 27 formed above a plurality of photodiodes 21 in a photodiode array on a substrate 18. There is a passivation layer 28 on ILD layer 27 and a planarization layer 29 formed on passivation layer 28. The top layer in the lower stack is a color filter layer 30 which has a plurality of color filter regions including color filter regions 30a, 30b, 30c formed on the planarization layer 29. The upper stack is comprised of a spacer layer 31 formed on a color filter layer 30, a first microlens array having a plurality of first microlenses 32a on the spacer layer, an overcoat layer 33 on the first microlens array, and a second microlens array having a plurality of second microlenses 34a formed on the overcoat layer. Referring to FIG. 2d, an enlarged view of a middle vertical section of the image sensor in FIG. 2c is shown. In the exemplary embodiment, a light column that includes the color filter region 30b is depicted and has a lower portion 40a and an upper portion 40b formed above a photodiode 21. The lower portion 40a is formed in the lower stack of layers and is comprised of portions of the ILD layers 23. 25. 27 as well as portions of the planarization layer 29 and passivation layer 28. The upper portion 40b includes a first microlens 32a, a second microlens 34a, and portions of the overcoat layer 33 and spacer layer 31. The width Y of the upper portion 40b is larger than or equal to the width Z of the lower portion 40a. Referring to FIG. 2e, incident light 41 on a second microlens 34a is focused as a beam 42 onto an underlying first microlens 32a which in turn focuses a beam 43 through a spacer layer 31 and the lower stack of layers onto a photodiode 21. Returning to FIG. 2c, an important feature of the microlens component of the image sensor is that the radius of curvature H2 of a second microlens is greater than the radius of curvature H1 of a first microlens. This relationship enables a second microlens with a high ψ to focus light on an underlying first microlens that has a long focal length and is capable of focusing light through a thick lower stack of layers onto a photodiode. As mentioned previously, this microlens design is more efficient that other dual lens structures in prior art. In a second embodiment, the process of the first embodiment is followed through the formation of the overcoat layer 33. A second microlens array having a plurality of subunits which are each comprised of a plurality of second microlenses is then formed above the overcoat layer 33 as illustrated in FIGS. 3a-3b. Referring to FIG. 3a, a positive tone photoresist which preferably has the same composition as the photoresist used to form the first microlens array is patterned on the overcoat layer 33 to form a photoresist layer 35 that has openings which may not necessarily have vertical sidewalls. The width W1 of the openings in a portion of the photoresist layer 35 formed over a first microlens 32a is smaller than the openings W2 which corresponds to the distance between adjacent first microlenses 32a. A portion of the photoresist layer 35 between adjacent openings having a width W2 will subsequently become a subunit of second microlenses. In the exemplary embodiment, the number of second microlenses formed in each subunit is three. However, the invention is also effective with a plurality of “n” second microlenses in each subunit. Note that each subunit of second microlenses is aligned above a first microlens 32a. Referring to FIG. 3b, the structure in FIG. 3a is heated to approximately 160° C. for about 10 minutes to reflow photoresist layer 35 which is then hardened by another bake at 220° C. to form second microlenses 35a that have a width W3 and a radius of curvature between about 0.5 and 1.2 microns. A second microlens 35a has a flat convex shape with a flat bottom formed on the overcoat layer 33 and top and sides that form a curved surface with a convex shape. It is important that there is no space W1 remaining between second microlenses 35a. When there are “n” second microlenses 35a in a subunit, then the collective width of n×W3 is equivalent to the width of an underlying first microlens 32a. As a result, a light column is formed in the upper stack of layers and is comprised of a plurality of second microlenses 35a in a subunit in the second microlens array, an underlying first microlens 32a, a portion of the overcoat layer 33 between a first microlens 32a and a plurality of overlying second microlenses 35a, and a portion of the spacer layer between a first microlens and an underlying color filter region 30a, 30b, or 30c. It is understood that the light column in the upper stack of layers is aligned above a light column in a lower stack of layers as described previously. The ψ value of a subunit of second microlenses 35a is expressed by the equation ψ=4PI×N2×(R/N)2 where PI is the photorefractive index of a second microlens, R is the radius of curvature of a second microlens, and N is the number of second microlenses. Preferably, PI is from about 1.4 to 1.7 for a first microlens 32a and for a second microlens 35a. More preferably, the PI of a first microlens 32a and a second microlens 35a is essentially the same as the PI of the planarization layer 29, spacer layer 31, and overcoat layer 33 to minimize the amount of light that is scattered as light is transmitted through a light column. The ψ value of a subunit of second microlenses 35a may be equal to or slightly less than the ψ value of a second microlens 34a described in the first embodiment. However, the efficiency of the microlens component of the second embodiment is still higher than for a dual microlens structure described in prior art in which a first microlens and an overlying second microlens have the same radius of curvature. This result is achieved because the radius of curvature H3 of a second microlens 35a is greater than the radius of curvature H1 of a first microlens 32a. Therefore, a subunit of second microlenses 35a with a relatively short focal length is able to efficiently capture light which is then focused onto a first microlens 32a. The first microlens 32a has a long focal length that is capable for focusing light through a thick lower stack of layers onto a photodiode 21. The microlens design of the second embodiment is especially effective for an image sensor that has a pixel size of less than about 5 microns. The present invention is compatible with newer technologies that have a thick lower stack comprised of a plurality of ILM and ILD layers because of the long focal length of a first microlens. The method is cost effective since the planarization layer, spacer layer, and overcoat layer have the same composition and are processed in existing tools. Additionally, the first microlens array and the second microlens array may have the same positive tone photoresist composition which reduces the number of materials needed in a manufacturing line. Each layer in the microlens component of the image sensor is processed so that crosslinking or hardening by a heat treatment prevents intermixing with adjacent layers which could degrade the final device performance. The present invention is also a microlens component within an upper stack of layers in a CMOS image sensor as depicted in FIG. 3b. The upper stack is formed on a lower stack of layers on a substrate. In one embodiment, the lower stack is comprised of an interconnect structure that includes ILM layers 22, 24, 26 and ILD layers 23, 25, 27 formed above a plurality of photodiodes 21 in a photodiode array on a substrate 18. There is a passivation layer 28 on ILD layer 27 and a planarization layer 29 formed on passivation layer 28. The top layer in the lower stack is a color filter layer 30 which has a plurality of color filter regions including color filter regions 30a, 30b, 30c formed on the planarization layer 29. The upper stack is comprised of a spacer layer 31 formed on a color filter layer 30, a first microlens array having a plurality of first microlenses 32a on the spacer layer, an overcoat layer 33 on the first microlens array, and a second microlens array having a plurality of subunits each having a plurality of second microlenses 35a formed on the overcoat layer. In the exemplary embodiment in FIG. 3b, a second microlens array is comprised of a plurality of subunits each having a plurality of second microlenses. Each subunit is aligned over a first microlens. It is understood that a top portion of a light column formed by a subunit of second microlenses, an underlying first microlens, a portion of the overcoat layer between the subunit in the second microlens array and a first microlens, and a portion of the spacer layer between the overlying first microlens and underlying color filter region is aligned above a bottom portion of a light column in the lower stack. Furthermore, a first microlens 32a and a second microlens 35a have a flat convex shape. The collective width of “n” second microlenses 35a in a subunit is essentially equal to the width of a first microlens 32a. For example, in FIG. 3b, 3×W3 is equal to the width of a first microlens. An important feature of a second microlens 35a is that its radius of curvature H3 is larger than the radius of curvature H1 of a first microlens 32a. This relationship enables a subunit of second microlenses 35a to have a high photon collection efficiency similar to a second microlens 34a in the first embodiment. A subunit focuses light onto a first microlens 32a that has a long focal length and is able to focus light through a thick lower stack of layers. The microlens component design of the second embodiment is especially effective for image sensors having a pixel size of less than about 5 microns. The advantage of the second embodiment is that a microlens component comprised of a second microlens array with a subunit having a high ψ value and short focal length and a first microlens array having a first microlens with a long focal length provides a higher sensitivity in a image sensor device than previously achieved. While this invention has been particularly shown and described with reference to, the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>A complementary metal oxide semiconductor (CMOS) image sensor is a key component of many digital video cameras. The CMOS image sensor is typically comprised of an upper stack that includes one or more layers of color filters, a microlens array, and an overcoat for the microlens and a lower stack that includes interlevel dielectric (ILD) layers, interlevel metal (ILM) layers, and passivation layers which are fabricated on a substrate. High sensitivity is an important characteristic for a CMOS image sensor since the image quality may suffer if sensitivity is not high enough. The function of the microlens component is to focus light through a color filter layer and the lower stack onto the sensing area or photodiode. Other layers in the light path must have a high transparency to that a minimal amount of light intensity is lost. The elementary unit of the image sensor is a pixel which is an addressable area element with intensity and color attributes related in large part to the spectral signal contrast obtained from the photon collection efficiency of the microlens array, spectra transmission through the color filters, microlenses, and other layers in the imaging path, and the spectral response and efficiency of the photodiode. Constant advances in technology that have reduced the smallest dimension in the CMOS device to less than a micron have also forced the pixel size to shrink to less than 5 um. When a plurality of color regions are formed in a color filter layer, the width of a color region is called a pixel. Newer technologies require an increased number of ILM layers that lengthens the distance (focal length) between a microlens and a photodiode. The longer focal length is a big challenge to maintaining adequate sensor sensitivity. Although a thinner microlens is able to produce a longer focal length, the quantum efficiency of a thin microlens is lower than that of a thicker microlens because of less surface area. Therefore, an improved design is needed for the upper stack and especially for the microlens component in a CMOS image sensor that increases sensitivity and is compatible with a pixel size that is smaller than 5 um. A microlens is typically formed by patterning a photoresist that is preferably a positive tone type in which unexposed regions of the photoresist layer are chemically unaltered and remain on the substrate after an aqueous base developer is used to remove exposed regions. The resulting photoresist pattern is heated to a temperature that deforms a stripe or rectangular shape into a cylinder shape or a square shape into a hemisphere shape as shown in FIG. 1 . The thermal treatment produces a microlens 1 with a flat bottom and top surface curvature such that the thickness T 1 hereafter referred to as the radius of curvature in the center of the microlens 1 is greater than the thickness T X at other points (X) on the microlens surface. The thickness T X becomes progressively smaller as the distance D from the center increases until reaching a minimum at the edges 3 . This design enables light 4 from above the microlens to be focused to a point 5 on a photodiode 6 below the microlens. The distance between the microlens 1 and the focal point 5 is the focal length FL. In this design, a spacer layer 7 , color filter layer 8 , planarization layer 9 , ILD layer 10 , and ILM layer 11 , and protective layer 12 are also depicted. Although color filter layer 8 is shown as a single layer with regions 8 a , 8 b , 8 c alternating between green 8 a and red 8 b or blue 8 c , the color filters may also be stacked such that each color filter is contained in a separate layer. Futhermore, the color filter layer 8 may be located above the microlens 1 array rather than below it. The pixel width (PW) is shown as the width of one color filter region 8 a , 8 b , or 8 c. U.S. Pat. No. 5,796,154 discloses a design including two layers of microlenses each having a thickness of about 2 microns that are separated by a transparent acrylate layer and preferably a color filter. The photorefractive index of the microlenses is higher than that of the acrylate and color filter. Since the lower microlens array does not reside on a planar surface, the size and oval shape of the microlens can be difficult to reproduce. In addition, the poly(vinylphenol)/diazonaphthoquinone diazide (DNQ) based photoresist that comprises the lower microlens has less suitable dissolution characteristics for patterning than a more common Novolak resin/DNQ photoresist. A key feature in related U.S. Pat. Nos. 6,171,885 and 6,274,917 is microlens formation prior to color filter fabrication in order to minimize rework and place the microlens array in closer proximity to the photodiodes. A planarization layer is used to separate the microlens array from overlying color filter layers. A high efficiency color filter process to improve color balance in an image sensor is described in U.S. Pat. No. 6,395,576. The color coating sequence involves coating a blue color filter layer first to form a color pixel structure with wider process window and improved adhesion to a substrate. The thickness of each color filter is adjusted in real time by a spectrophotometric algorithmic analyzer that drives a feedback servo control loop. | <SOH> SUMMARY OF THE INVENTION <EOH>An objective of the present invention is to provide a microlens component in a CMOS image sensor that offers improved sensitivity in a device that has several metal (ILM) layers and requires a long focal length. A further objective of the present invention is to provide a microlens component in a CMOS image sensor that offers improved sensitivity in a sub-micron device that has a pixel size smaller than about 5 microns. A still further objective of the present invention is to provide a method of fabricating a CMOS image sensor having improved efficiency that is compatible with existing tools and materials and can be performed in a low cost manner. These objectives are achieved by providing a lower stack of layers for a CMOS image sensor device. In one embodiment, a dielectric layer such as SiO 2 is formed on a substrate and a photodiode array is formed in the dielectric layer. Then a first metal layer (M 1 ) is formed on the dielectric layer between photodiodes. A second ILD layer which is preferably an oxide is deposited on the M 1 layer and substrate followed by a second metal layer (M 2 ), a third ILD layer, a third metal layer (M 3 ) and a fourth ILD layer. Next, a silicon oxynitride passivation layer is formed by conventional means on the uppermost ILD layer. The interconnect structure comprised of the ILD, ILM, and passivation stack also has contacts between the M 1 layer and a conductive layer in the substrate, and has vias between M 1 and M 2 layers and between M 2 and M 3 layers. An insulation layer is deposited on the passivation layer and is preferably a photoresist layer that provides high transmittance to light that passes through overlying color filters. A color filter layer that includes a plurality of green, red, and blue color regions is then formed above the insulation layer. The color filter layer is comprised of a crosslinked negative photoresist that has been dyed in specific regions to selectively transmit wavelengths in a blue, red, or green spectral range and forms the uppermost layer in the lower stack of layers. Next, an upper stack of layers which is comprised of the microlens component of the CMOS image sensor is formed on the color filter layer. An optional spacer layer preferably comprised of the same material as in the insulation layer may be deposited on the color filter layer. A first microlens array with a plurality of first microlenses is then fabricated on the spacer layer by patterning a positive tone photoresist and heating to reflow and form flat convex shapes. There is one first microlens having a radius of curvature (H 1 ) that is aligned above each color filter region and the width of a first microlens is less than or equal to a pixel width. A planar overcoat layer which is preferably comprised of the same transparent material as in the insulation layer is formed on the first microlens array. A post-exposure bake at 220° C. not only hardens the overcoat layer but also hardens the first microlens array. A second microlens array comprised of a plurality of second microlenses is fabricated on the overcoat layer by first patterning a positive tone photoresist, heating to reflow, and hardening with a 220° C. bake to form flat, convex shapes. A second microlens has a width that is essentially equal to the width of a first microlens. Moreover, there is a second microlens aligned over each first microlens. A second microlens preferably has a radius of curvature (H 2 ) that is greater than H 1 . The larger radius of curvature provides for a shorter focal length and higher photon collection efficiency for a second microlens compared to a first microlens. Light that is efficiently collected by a second microlens is focused on a first microlens. The first microlens has a long focal length that is capable of focusing light through a light column within a thick lower stack of layers onto a photodiode. The invention is also a microlens component of a CMOS image sensor with improved sensitivity that is formed on a lower stack of layers that includes a photodiode array on a substrate and a color filter layer as the top layer in the lower stack. The lower stack typically includes a interconnect structure on the substrate and an insulation layer formed on the insulation layer. The microlens component is comprised of a first microlens array formed above the color filter layer, a planar transparent overcoat layer on the first microlens array, and a second microlens array formed on the overcoat layer. Each of the plurality of microlenses in the first microlens array and in the second microlens array has a flat convex shape. An important feature is that the radius of curvature of a second microlens is greater that the radius of curvature of a first microlens. A light column is formed which involves a vertical arrangement of a photodiode, a color filter region, a first microlens, and a second microlens. Other intermediate layers described previously have a high transmittance to minimize loss of light intensity as light passes through the light column. Photon collection efficiency (ψ) of a microlens is expressed by the equation ψ=4PI×R 2 where PI is the photorefractive index of a microlens and R is the radius of curvature. In a second embodiment, the second microlens array of the microlens component in an image sensor is comprised of a plurality of subunits which are each comprised of a plurality of second microlenses. The collective width of the plurality of second microlenses in a subunit is equal to the width of a first microlens. A subunit of second microlens is aligned over a first microlens so that a vertical light column is formed that includes a photodiode, a color filter region, a first microlens, and a second microlens. The radius of curvature of a second microlens is preferably greater than the radius of curvature of a first microlens. It is important that there is no gap between adjacent second microlenses in a subunit. | 20040428 | 20080513 | 20051103 | 71562.0 | 0 | HSU, AMY R | EFFECTIVE METHOD TO IMPROVE SUB-MICRON COLOR FILTER SENSITIVITY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,582 | ACCEPTED | System and method for interleaving memory | One system may comprise an interleave system that determines a desired interleave for at least a selected portion of a distributed memory system. A migration system is associated with the interleave system to migrate blocks of data to implement the desired interleave. | 1. A system comprising: an interleave system that determines a desired interleave for at least a selected portion of a distributed memory system; and a migration system associated with the interleave system to migrate blocks of data to implement the desired interleave. 2. The system of claim 1, further comprising a mapping system that provides memory location information in response to an input associated with data, the memory location information being updated to identify a distribution of memory in the memory system corresponding to the desired interleave. 3. The system of claim 2, wherein the mapping system further comprises a first map entry that includes a plurality of subentries associated with memory segments interleaved across a set of cells in the memory system, and at least a second cell map entry that includes a plurality of subentries associated with memory segments interleaved across the set of cells in the memory system. 4. The system of claim 3, wherein each subentry in the mapping system corresponds to a contiguous memory address region in a respective cell of the memory system. 5. The system of claim 2, wherein the mapping system further comprises a plurality of subentries, each corresponding to a configurable region of contiguous memory at a respective physical location in one of a plurality of cells of the memory system. 6. The system of claim 2, further comprising at least one memory controller associated with the memory system, the memory controller accessing the data from at least one memory location based the memory location information provided by the mapping system. 7. The system of claim 1, wherein the interleave system invokes the migration system in response to a predefined stimulus, such that the migration system transfers blocks of data from originally assigned respective memory locations of the memory system to second respective memory locations of the memory system according to the desired interleave determined by the interleave system. 8. The system of claim 7, wherein the predefined stimulus further comprises a run-time stimulus received by the interleave system subsequent to a system boot process. 9. The system of claim 8, wherein the predefined stimulus further comprises at least one of adding memory into the memory system, deleting memory from the memory system and reallocating memory among partitions in the memory system. 10. The system of claim 1, wherein access to the blocks of data is prevented temporarily during migration of each respective block of data. 11. A distributed memory multi-processor system comprising the system of claim 1, the distributed memory multi-processor system comprising: a plurality of cells communicatively coupled to each other, each of the plurality of cells including at least one processor, a main memory system, and a cell controller, at least one cell controller in a respective cell including the interleave system. 12. The distributed memory multi-processor system of claim 11, wherein the migration system is configured to selectively migrate the blocks of data across the main memory systems of the plurality of cells to implement the desired interleave. 13. A system comprising: an interleave system that dynamically re-interleaves at least a selected portion of a distributed memory system to implement a desired memory interleave in response to a stimulus; and a mapping system that provides memory location information in response to an input associated with data, the memory location information being updated based on the dynamically re-interleaving of the at least a selected portion of the distributed memory system. 14. The system of claim 13, wherein the stimulus further comprises at least one of adding memory into the memory system, deleting memory from the memory system and reallocating memory in the memory system. 15. The system of claim 13, wherein the interleave system provides interleave data that defines the desired memory interleave in response to the stimulus, the system further comprising a migration system that migrates data within the memory system based on the interleave data. 16. The system of claim 13, wherein the map component further comprises: a first cell map entry comprising a first plurality of memory subentries interleaved across a set of cells of the memory system; and at least a second cell map entry comprising a second plurality of memory subentries interleaved across the set of cells of the memory system. 17. The system of claim 13, wherein the map component further comprises a plurality of subentries, each corresponding to a configurable chunk of contiguous memory at a physical location in one of a plurality of cells of the memory system. 18. The system of claim 13, further comprising at least one memory controller communicatively associated with the memory system and the map component, the memory controller accessing at least one corresponding memory location of the memory system based on the memory location information provided in response to the input. 19. A distributed memory multi-processor system comprising the system of claim 13, the distributed memory multi-processor system comprising: a plurality of cells communicatively coupled to each other, each of the plurality of cells including at least one processor, a main memory system, and a cell controller, at least one of the plurality of cells comprising the interleave system. 20. The distributed memory multi-processor system of claim 19, further comprising a migration system associated with the interleave system, the migration system being configured to selectively migrate blocks of data from first memory locations to second memory locations, as defined by the desired interleave, to provide a desired distribution of memory interleave across the main memory systems of the plurality of cells. 21. A distributed memory, multi-processor system comprising: a plurality of cells communicatively coupled to each other; each of the plurality of cells comprising a cell controller and cell memory, the cell memory of the plurality of cells collectively defining a memory system; and the cell controller of at least one of the plurality of cells further comprising an interleave system configured to dynamically interleave selected memory regions of the main memory of at least some of the plurality of cells by modifying a first memory distribution of the memory system to provide a desired memory interleave for the memory system. 22. The system of claim 21, wherein the interleave system provides interleave data that defines the desired memory interleave, the system further comprising a migration system that migrates data within the memory system based on the interleave data. 23. The system of claim 22, wherein the interleave system employs the migration system to implement the desired interleave in response to a stimulus, the migration system transferring blocks of data from previously assigned respective memory locations of the memory system to second respective memory locations of the memory system according to the desired interleave. 24. The system of claim 23, wherein access to the blocks of data is prevented temporarily during migration of each respective block of data. 25. The system of claim 23, wherein the stimulus further comprises a run-time stimulus received by the interleave system. 26. The system of claim 23, wherein the stimulus further comprises at least one of adding memory to the memory system, deleting memory from the memory system and a request to reallocate memory in the memory system. 27. The system of claim 22, further comprising a mapping system that provides memory location information in response to an input associated with requested data, the memory location information being updated according to the desired interleave. 28. A system for interleaving data, comprising: means for determining a desired distribution of memory across a plurality of distributed memory regions of a memory system; and means for migrating data from first respective memory locations associated with to second respective memory locations based on the desired distribution of memory. 29. The system of claim 28, further comprising means for blocking access to the data during migration of the data to the second respective memory locations. 30. The system of claim 28, further comprising means for mapping physical memory locations in the memory system in response to a request for accessing a contiguous array of data, and for updating means for mapping to identify the memory locations for data corresponding to the desired distribution of memory. 31. A method comprising: ascertaining a desired memory interleave for at least a selected portion of a distributed memory system; and migrating blocks of data from first respective memory locations associated with the blocks of data to second respective memory locations based on the desired memory interleave. 32. The method of claim 30, further comprising updating entries in a cell map to identify the memory locations for data corresponding to the desired memory interleave. 33. The method of claim 32, further comprising: providing memory location information from the cell map; and accessing data from at least one physical memory location of the memory system by a memory controller based on the memory location information. 34. The method of claim 30, further comprising dynamically causing the desired interleave to be ascertained in response to a predefined stimulus. 35. The method of claim 34, wherein the predefined stimulus further comprises at least one of adding memory into the memory system, deleting memory from the memory system and reallocating memory in the memory system. 36. The method of claim 31, further comprising temporarily preventing access to the blocks of data during at least a substantial portion of the migrating thereof. 37. A distributed memory multi-processor system configured to dynamically interleave and re-interleave memory across a plurality of memory modules located in different cells of the distributed memory multi-processor system, the different cells being communicatively coupled to each other. | BACKGROUND In multi-processor systems, memory can be configured to improve performance. One approach is to spread memory across different memory controllers, which approach is referred to as interleaving. A desirable interleave distributes memory substantially evenly across available memory controllers. As memory is more evenly distributed, large contiguous arrays of data touch each of the memory controllers substantially the same amount. Therefore, by interleaving memory, the memory is more evenly distributed so as to mitigate hot spots. Hot spots can occur, for example, if a given memory controller is overloaded due to unevenly large distributions of contiguous data being locally associated with the given memory controller. SUMMARY One embodiment of the present invention may comprise a system that includes an interleave system that determines a desired interleave for at least a selected portion of a distributed memory system. A migration system is associated with the interleave system to migrate blocks of data to implement the desired interleave. Another embodiment of the present invention may comprise a system that includes an interleave system that dynamically re-interleaves at least a selected portion of a distributed memory system to implement a desired memory interleave in response to a stimulus. A mapping system provides memory location information in response to an input associated with data, the memory location information being updated based on the dynamically re-interleaving of the at least a selected portion of the distributed memory system. Another embodiment of the present invention may comprise a distributed memory, multi-processor system. The distributed memory, multi-processor system includes a plurality of cells communicatively coupled to each other, each of the plurality of cells comprising a cell controller and cell memory, the cell memory of the plurality of cells collectively defining a memory system. The cell controller of at least one of the plurality of cells further comprising an interleave system configured to dynamically interleave selected memory regions of the main memory of at least some of the plurality of cells by modifying a first memory distribution of the memory system to provide a desired memory interleave for the memory system. Another embodiment of the present invention may comprise a method that includes ascertaining a desired memory interleave for at least a selected portion of a distributed memory system, and migrating blocks of data from first respective memory locations associated with the blocks of data to second respective memory locations based on the desired memory interleave. Another embodiment of the present invention may comprise a distributed memory multi-processor system configured to dynamically interleave and re-interleave memory across a plurality of memory modules located in different cells of the distributed memory multi-processor system, the different cells being communicatively coupled to each other. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an embodiment of a system for interleaving memory. FIG. 2 depicts another embodiment of a system for interleaving memory. FIG. 3 depicts an example embodiment of a computer system that can implement memory interleaving. FIG. 4 depicts an example representation of a cell map for an interleaved two-cell memory system. FIG. 5 depicts the representation of the cell map of FIG. 4 after another cell has been added. FIG. 6 depicts the representation of the cell map of FIG. 5 after the additional memory cell has been interleaved into the memory system. FIG. 7 depicts another representation of the cell map of FIG. 5 after the additional memory cell has been interleaved into the memory system. FIG. 8 depicts an example of the cell map of FIG. 6 after memory has been removed from the memory system. FIG. 9 depicts an example of the cell map of FIG. 8 after the remaining memory cells have been re-interleaved. FIG. 10 depicts a flow diagram illustrating a method. FIG. 11 depicts a flow diagram illustrating another method for interleaving memory. DETAILED DESCRIPTION FIG. 1 depicts a schematic example of a system 10 for interleaving memory. The system 10 can be utilized to dynamically interleave various portions of a memory system 12. The system can be employed in the context of a distributed memory multi-processor system, in which the memory system includes a plurality of physical memory devices distributed in the multi-processor system. As an example, one type of multi-processor system is a Cache Coherency Non-Uniform Memory Access (ccNUMA) architecture, although other distributed-memory multi-processor architectures can also implement the system 10 described herein. A typical ccNUMA multi-processor system includes a plurality of memory structures that may define the memory system 12. The memory structures can include a plurality of memory modules (e.g., dual-inline memory modules (DIMM) or single in-line memory modules (SIMM)) distributed across a plurality of cells in the multi-processor system. For example, a cell can correspond to an aggregation of memory, such as implemented on a cell board that contains one or more memory modules. Additionally, the memory system 12 can include virtual memory implemented (e.g., by the operating system) in the multi-processor system. The system 10 includes a controller 14 that is operatively associated with the memory system 12. For example, the controller 14 may be communicatively coupled locally (e.g., via a local bus or interconnect) with a first subset of memory in the memory system 12 and communicatively coupled remotely (e.g., via a backplane or interconnect) to one or more other subsets of memory in the memory system 12. Each of the other subsets of the memory system 12 can include one or more memory modules or memory subsystems. Thus, each respective cell of the multi-processor system can include one or more memory subsystems that collectively form the memory system 12. In a multi-processor system that includes a plurality of cells, a controller (e.g., a cell controller) similar to the controller 14 can be employed for controlling each of the plurality of cells. The cell controllers can be communicatively connected to each other to provide shared access to the distributed memory of the memory system 12. For instance, cell controllers can be communicatively connected through one or more general interconnects or backplanes (e.g., implemented as crossbars). The controller 14 is associated with a map system or component 16, such as can be implemented as a cell map. The map component 16 provides memory location information in response to an input associated with data. The memory location provided corresponds to the distribution of memory within the memory system 12. That is, the map component includes a plurality of entries that logically map to physical memory locations (or memory chunks) in the memory system 12. The entries in the map component 16 can be utilized to define a distribution of memory segments across the memory system 12 (or at least a portion of the memory system). The map component 16 can be implemented as hardware, software or a combination of software and hardware. While the map component 16 is illustrated as being separate from the controller 14, the map component can be implemented as part of the controller (e.g., a memory controller on a cell board). The map component 16 can be implemented as a table having a plurality of rows and a plurality of columns, where each row corresponds to an interleaving entry, and each column within a row corresponds to an entry item that identifies one of the cells in the multi-processor system. For instance, each entry in the cell map can correspond to a contiguous chunk of memory in a respective cell, which can be a configurable block of memory. Different entries can be allocated to different physical regions of the memory system. The map component 16 provides memory location information for data in response to an input, such as a request for accessing data. The map component 16 can also identify the particular region of the identified cell associated with the input. The input can be any input that identifies a block of data, such as including a memory address or cache line address. The distribution of memory segments in the map component 16 can correspond to a memory interleave for at least a portion the memory system 12. The system 10 also includes an interleave block 18 communicatively coupled with the controller 14. The interleave block 18 is operative to interleave chunks of memory in the memory system 12. That is, the interleave block 18 dynamically re-interleaves at least a selected portion of the memory system 12 to achieve a desired memory interleave, such as by spreading or distributing memory across memory subsystems located at a plurality of different cells. The interleave block 18 can implement an interleaving (or re-interleaving) process in response to a predefined stimulus. The stimulus can be provided by the controller 14, the operating system or other hardware or software components operating in the distributed memory system. The predefined stimulus can be a run-time stimulus, such as may be provided during normal operation of the distributed memory system. For example, the interleave block 18 can re-interleave memory in the memory system 12 in response to adding memory to the memory system. Alternatively, or additionally, the interleave block 18 can re-interleave data if one or more memory segments are deleted from interleaved memory of the memory system 12. Memory can be deleted, for example, if a cell is removed from the multi-processor system or if one or more memory modules are removed from system operation. The addition or deletion of memory to the memory system 12 can occur in conjunction with the addition or deletion of a cell that includes the respective memory. Another possible stimulus for initiating re-interleave of memory corresponds to reallocating memory among two or more existing partitions of the memory system 12. For instance, a given partition of the memory system 12 may initially contain a certain percentage of local memory and another percentage of interleaved memory. The interleave block 18 can be instructed or otherwise determine that a different mix of local and interleaved memory is desired. Additionally or alternatively, the allocation of memory amongst different partitions can be modified by the interleave block 18. While the interleave block 18 is illustrated as being separate from the controller 14, the interleave block could also be implemented as part of the controller. Those skilled in the art will understand and appreciate that the interleave block 18 can be employed to interleave data in response to various other stimuli, such as in response to an appropriate system command from the operating system (e.g., a request to interleave memory with existing interleaved or non-interleave memory). Since the interleaving does not require system reboot or stalling of system operation, an interleave operation can be implemented whenever desired, such as to optimize performance (e.g., by providing a predefined stimulus to initiate the interleave). By way of example, the interleave block 18 implements the re-interleaving by first determining a desired interleave for the memory system 12. This example assumes that the memory system 12 forms a memory domain spread across plural cells, which may correspond to a portion of the memory that exists in a multi-processor system. The interleave block 18 can include software and/or hardware that determines the desired interleave. For example, the interleave block 18 examines the available memory in each cell, as the available memory can provide a potential destination for at least a portion of memory that is moved during the re-interleaving. The interleave block 18 then identifies the memory locations that are to be moved in connection with the interleaving. The interleave block 18, for example, provides an indication of the identified memory locations to a migration system (not shown) to migrate the data according to the desired interleave determined by the interleave block 18. By way of further example, the migration can be implemented by the controller 14 or other hardware taking ownership of blocks of data. For instance, the interleave block 18 can be configured to implement selected functions of the controller, in which case the interleave block may communicate with the memory system directly, as indicated by a dotted line. The blocks of data are then moved from selected locations associated with a first set of memory locations in the memory system 12 (e.g., corresponding to either a non-interleaved or original interleaved configuration) to selected destinations within a second set of memory locations of the memory system. The resulting memory locations for the data provide the desired interleave. In order to facilitate migrating the data during a re-interleaving process, the controller 14 can temporarily prevent access to the selected memory locations by other devices in the system 10 during their transfer. For example, the controller 14 or other systems implementing the migration can set an associated status bit of each memory block so that the memory block is placed “on hold” during migration. While “on hold,” a memory block is unable to respond to requests for data at such memory location during migration. Those skilled in the art will appreciate various approaches that can be employed to prevent access to a memory block during migration as well as to accommodate requests that consequently might fail during the migration phase of interleaving. After a block of data has been moved from the first memory location into the selected destination memory location, access to the data can be re-enabled. For example, the controller 14 can reset the associated status bit of the memory block. The interleave block 18 also updates the map component 16 based on the migration so that the map component properly identifies the location of individual memory segments in the domain of the memory system 12. Accordingly, the map component 16 provides correct location information (e.g., which cell and memory region of the cell) for data, such as in response to a request for the data (e.g., issued by a processor to the controller 14). The map component 16 thus provides information for routing a request for data to a correct cell, which may be local or remote relative to the controller 14, to enable efficient access to such data. For example, assume that a microprocessor (e.g., either a local processor associated with the controller 14 or a remote processor associated with a different cell controller) issues a request for data that results in a cache miss. The request is thus provided to the controller 14 for accessing main memory 12. The controller 14 can forward the request from the processor to an appropriate cell that owns the requested data based on the entries in the map component 16. The controller associated with the cell receiving the request can, in turn, implement the request by accessing the data resident at such cell. In contrast, if the input request is for data in the same cell in which the microprocessor is co-located, the controller 14 can access the data from corresponding local memory in the memory system 12. In view of the foregoing, those skilled in the art will understand and appreciate that re-interleaving can be implemented dynamically, without requiring reboot or stalling the system. As a result, re-interleaving can be implemented any time to improve performance, including before or after memory addition or deletion. Additionally, the system 10 enables deletion of memory on multi-processor systems that have interleaved memory. FIG. 2 depicts an example of a system 50 that can be utilized for interleaving locations of an associated memory system 52. The memory system 52 can include memory subsystems 54. The memory system 52 includes a plurality of memory subsystems 54 indicated as MEM 1 through MEM Q, where Q is a positive integer greater than or equal to one denoting the number of memory subsystems. The memory system 52 can include one or more memory subsystems 54 for each respective cell. The memory subsystems 54 can each include the same or a different amount of memory, which can be configurable. A cell map 56 includes a plurality of entries 58, indicated as ENTRY 1 through ENTRY M, where M is an integer greater than or equal to one denoting the number cell map entries. Each entry 58, for example, corresponds to a memory region or partition that includes one or more subentries 60. As an example, a given entry 60 can correspond to an operating instance (e.g., a server) running on an associated multi-processor system. Different entries 58 can also be employed to identify local memory locations (e.g., within the same cell) and remote memory locations (e.g., located in different cells). Each entry can include a configurable amount of memory, such as may be required for the operating instance. In ENTRY 1, the subentries 60 are indicated as S1-SN, and, for ENTRY M, corresponding subentries are indicated as S1-SP, where N and P are integers greater than or equal to one denoting the number of subentries. N and P typically are different values, although they could be the same. The subentries 60 in the respective cell map entries 58 each corresponds to a memory segment (a memory chunk) of the respective entry in the memory system 52. The memory chunks can be configurable memory segments. For example, each subentry 60 can correspond to a fixed number of bytes, such as 0.5 gigabytes. Alternatively, different subentries 60 in the cell map 56 can correspond to different sized memory locations. The subentries 60 and entries 58 in the cell map 56 thus identify corresponding logical units of memory and the interleaving associated with the memory subsystems 54. The cell map 56 can be implemented as a content addressable memory (CAM) or other structure that can be used to ascertain a location of data. In the context of a multi-processor system, the cell map 56 can provide location information as a function of a tag address for a given line of data, which tag address operates as a search field utilized by the camming function provided by the cell map. The tag address can be defined by the cache coherency protocol being implemented in the multi-processor system. The cell map 56 thus provides an indication of a given cell (e.g., a cell number) and/or other location information (e.g., region of a given cell) associated with the given line of data being requested. The tag address can be provided to the cell map 56 as part of a request for data (e.g., a read or write request from a processor or from an input/output device). The system 50 also includes an interleave system 62 that is operative to interleave memory locations of the memory system 52. The interleaving of memory in at least a portion of the memory system 52 is reflected in the various subentries 60 of the respective cell map 56. For example, in a cell map 56 having forty-nine entries 58, one entry (e.g., entry M) can include 64 subentries and the remaining 48 entries each can include 16 subentries. A contiguous array of data can be distributed across the subentries of different cells with each of the entries. It is to be understood that the cell map 56 can provide interleaving information for one or more memory domains that form the memory system 52. The interleave system 62 includes an interleave engine 64 that is programmed and/or configured to control memory interleave. In response to a stimulus to implement memory interleaving, the interleave engine 62 determines the amount of memory in a given memory domain that is available for interleaving. The domain of available memory corresponds to at least a portion of the memory system 52. The determination of available memory can be performed by the interleave engine 62 providing a system request to the memory system 52 to ascertain available (e.g., unused) memory in each of the memory subsystems 54 that can be utilized as part of an interleaving process. As described herein, the interleaving system 62 can operate to perform re-interleaving when memory is added or deleted, such as will occur in conjunction with adding or deleting a respective cell of a multi-processor system. Additionally, the interleave system 60 can perform interleaving at any time to improve performance, such as to reallocate memory amongst two or more partitions in the memory system 52. After determining the amount of available memory for interleaving, the interleave engine 64 can aggregate and assign a selected portion of the available memory to a cell map entry 58. For example, the interleave engine 64 can determine a largest power of two for available memory and assign such memory to one or more entries 58 having a plurality (e.g., 64) subentries 60 in the entry. The remaining available memory can then be assigned to subsequent other of the cell map entries 58, each of which may have a smaller number of subentries 60 (e.g., 16 subentries per cell map entry). In this way, the cell map 56 provides an address map for data in the memory system 52, which can include one large cell map entry 58 and a plurality of smaller entries 58 having fewer subentries relative to the large entry. The interleave engine 64 also employs a re-interleaving algorithm to examine the memory system 52 and to determine a desired interleave for the memory. The interleave engine 64 employs the interleave algorithm to generate interleave data 66 based on the memory available for interleaving and the desired interleave for such data. The interleave data 66 specifies how memory should be migrated in the memory system 52 to provide the desired interleave determined by the interleave engine 64. The interleave data 66 can identify the distribution of memory (e.g., how contiguous memory is spread across the memory subsystems 54) based on the stimulus that caused the interleave or re-interleave to occur. The interleave of the memory system 52 will vary depending on, for example, if one or more memory subsystems 54 are added to the memory system 52, as well as if memory subsystem 54 are deleted. Those skilled in the art will appreciate various algorithms that can be utilized to implement the desired interleave to improve performance, such as by mitigating hot spots. A migration system 70 is utilized to transfer data as part of the interleaving process based on the interleave data 66. The migration system 70 can be implemented as a migration hardware component, although the migration system can be implemented as software or a combination of software and hardware. The migration system 70 is operatively associated with an operating system 72 of the multi-processor system. The operating system 72 can control some or all of the interactions between the migration system 70 and the memory system 52, as well as interactions between other aspects of the system 50 and the memory system 52. The interleave system 62 invokes the migration system 70 (e.g., via a predefined migration instruction or request) to cause migration to occur in connection with implementing interleaving based on the interleave data 66. As described herein, this can occur in response to adding or removing memory as well as other stimuli, such as associated with performing memory optimization. As an example, it is assumed that new memory (e.g., one or more subsystems 54) has been added to the memory system 52, such as can occur in response to a new cell being added to a multi-processor system. The new cell is communicatively coupled to the existing cells via an interconnect or backplane system. The interleave system 62 enables the migration system 70 to take initial ownership of the new memory added to the memory system 52. The migration system 70 is operative to prevent access to respective memory blocks in the new memory of the memory system 52 until the migration and interleaving have been completed. The access can be prevented temporarily, for example, by stalling each memory block (e.g., a cache line) during migration of the block. The ownership of the new memory by the migration system 70 thus can be utilized to mitigate race conditions and preclude use of the new memory or selected portions thereof until it has been appropriately interleaved into the memory system 52. Those skilled in the art will understand and appreciate various mechanisms that can be utilized by the migration system 70 to prevent access to the memory blocks that are being interleaved, including mechanisms typically resident in the operating system 72. Additionally, cache coherency protocols implemented in the system can set the new memory to a busy (or otherwise inaccessible) condition so that requests for the data will be blocked until the migration and interleaving is completed. Another technique that can be utilized to block access to the memory that is being interleaved is to load requests for blocked memory into a queue structure, such as can be implemented separately from or part of the main memory system 52. After a memory block has been released by the migration system 70, indicating that migration of the block has been completed, associated queued requests can then be processed. The migration system 70 can also perform migration for selected memory blocks of the original interleaved memory. By way of continuing example, the migration system 70 can issue a request to old or existing memory locations in the memory system 52 for each block of such memory that is to be migrated in connection with interleaving the new memory. Each block of memory to be migrated can correspond to a cache line, a plurality of lines or any size block that may be appropriate for the system 50. As part of the migration process, the migration system 70 accesses the old (e.g., previously interleaved) memory to obtain a current version of the data from the selected portions of memory being migrated. Additionally, steps are taken to prevent access to the data that is being migrated from the existing memory locations. For example, if a memory block has been accessed by the migration system 70, then all subsequent requests to data in that memory block are prevented temporarily. Those skilled in the art will understand and appreciate that substantially the same mechanisms for blocking access to the new memory (as mentioned above) can be used for blocking access to the data in existing memory that is being migrated. The migration system 70 thus obtains ownership of the current version of the data from the existing memory block. The migration system 70, in turn, transfers the data to the corresponding location in the new memory as defined by the interleave data 66. A migration acknowledgement can be issued in response to receiving the data from the existing memory to indicate that data migration has occurred successfully. The memory controller associated with the old memory location can appropriately mark the data as “gone” in response to the migration acknowledgement. The “gone” marking can be employed by the operating system or other aspects of the cache coherency protocol to identify that a particular line of data is no longer at the old memory location. Additionally, the “gone” marking further can be utilized to provide a pointer to or otherwise identify the new memory location to which the data has been migrated as part of the memory interleave. The migration system 70 can also inform the interleave system 60 that migration has been completed for a given memory block to facilitate subsequent access to the data that has been re-interleaved. The entries 58 and subentries 60 in the cell map 56 are also modified to reflect the migrated block of data. For example, the interleave system 62 or the migration system 70 can provide the update information to the cell map 56. The interleave process, including migration, can be completed on a memory block-by-block basis until the newly added memory has been interleaved as specified by the interleave data 66. By implementing the migration on a block-by-block basis, those skilled in the art will understand and appreciate that sufficiently small blocks can be migrated to mitigate the impact on overall system operation. As a result of migrating sufficiently small memory blocks, the interleaving and migration can be implemented dynamically during normal operation without requiring a system reboot or significantly affecting run time operation. Alternatively or additionally, those skilled in the art will understand that the migration system 70 can be implemented using appropriate system supports of the operating system 72. For example, the migration system can employ virtual memory in the memory system 52 via the operating system 72 by temporarily migrating selected memory blocks to a hard disk drive or other types of storage medium. In this example, the migration system 70 can retrieve the data from virtual memory for transfer into the desired new memory location to which it is being migrated based on the interleave data 66. FIG. 3 depicts a block diagram illustrating an example of a distributed-memory multi-processor system 100. The system 100 includes a plurality of cells 102 indicated respectively at CELL 1, CELL 2 through CELL M, where M is an integer greater than or equal to one denoting the number of cells. Each of the cells 102, which can be implemented as a cell board, is communicatively coupled to other cells via an interconnect 104, such as a backplane or crossbar structure. An I/O (input/output) subsystem 104 is associated with each of the cells 102. The I/O subsystem 104 can provide an interface or pathway for accessing an associated bus structure (e.g., a PCI bus structure) or other devices, such as through corresponding adapter (not shown). Those skilled in the art will understand and appreciate various types of I/O devices that can be accessed or can access memory via the I/O subsystem 104. The I/O subsystem 104 can be implemented to include an application specific integrated circuit (ASIC) that provides an interface between each respective cell 102 and a corresponding bus structure having one or more input/output devices coupled to the corresponding bus structure. Additionally, another interconnect 108 can be coupled to the interconnect 104 for accessing another cell-based architecture that includes one or more other cells (not shown). The other cell-based architecture can be similarly configured to that shown and described in FIG. 3. The interconnect 108 and associated cells (not shown) can be utilized for implementing larger capacity systems. Those skilled in the art will understand and appreciate that the system 100, however, can be implemented with any number of cells, with the interleaving being implemented as a function of the number of cells and the memory in each respective cell. For purposes of brevity, the internal contents are shown only for CELL 1, although those skilled in the art will understand and appreciate that each of the other respective cells 102 can be implemented in a similar manner. Alternatively, different configurations could also be implemented relative to the different cells 102. Turning to the contents of CELL 1, CELL 1 includes a cell controller 110 coupled to a cell memory subsystem 112 through an associated buffer network 114. The buffer network 114 can include a queue (e.g., an input queue and an output queue) to provide intelligent buffering of requests and responses between the memory subsystem 112 and controller 110. One or more central processing units (CPUs) 116 are also connected to the controller 110 for accessing the memory subsystem 112. Each of the CPUs 116 can include an associated cache (not shown) for storing data for local access by the CPU without requiring access to the memory subsystem 112. The CPUs 116 can implement a directory-based or non-directory-based cache coherency protocol. In the arrangement shown in FIG. 3, the CPUs 116 and the I/O subsystem 106 each can be considered memory accessing devices operative to access data in the memory subsystem 112 via the controller 110. The controller 110 can include firmware, a configuration and status register (CSR) and an ordered access queue for accessing the data in the memory subsystem 112. The memory subsystem 112 can include any number of one or more memory modules, including one or more DIMM or SIMM memory devices. Memory modules can be installed into or removed from the memory system 112. The addition or removal of such memory modules can correspond to a stimulus that affects a characteristic of a memory domain in the system 100. As described herein, the controller 110 re-interleaves the aggregate memory in the system 100, as may be desired, in response to such a stimulus. The memory domain can include the memory in the memory subsystem 112, as well as corresponding memory subsystems in the other cells 102 (e.g., CELL 2 through CELL M) connected to CELL 1 through the interconnect 104, as well as other remote cells (not shown) having memory that may be coupled via the interconnect 108. The interleaving or re-interleaving of memory in the system 100 can be implemented similar to that described with respect to FIG. 2. Briefly stated, in response to a predefined stimulus, the cell controller 110 determines the amount of memory in a given memory domain that is available for interleaving. After determining the amount of available memory for interleaving, the controller 110 can aggregate and assign a selected portion of the available memory to a cell map entry. The cell map provides an address map for data in the domain that includes the memory subsystem 112. The domain, for example, can include plurality cell map entries, each having a number of subentries. As described herein, the subentries of a given cell map entry can be spread across a plurality of memory subsystems associated with different cells, the distribution being defined by a desired interleave. The controller 110 also examines the memory and determines the desired interleave for the aggregate memory domain. The desired interleave defines a desired distribution of memory (e.g., how contiguous memory should be spread across the memory subsystems) in the memory domain being interleaved or re-interleaved. The controller 110 or another hardware and/or software structure associated with the controller is employed to migrate data as part of the interleaving process based on the desired interleave that is determined. The manner in which migration is performed can vary, for example, based on whether memory has been added to a domain, deleted from a domain or whether an interleave has been initiated for another reason. The interleave process, including data migration, can be implemented on a memory block by memory block basis, until the memory has been interleaved as specified by the desired interleave. By implementing the migration on each selected memory block independently, those skilled in the art will understand and appreciate that sufficiently small blocks of memory can be selected to mitigate the impact on system operation. As a result, the interleaving and migration can be implemented dynamically during normal operation without requiring a system reboot. To further facilitate data migration during interleave, access to each memory block can be blocked until after the migration and interleaving have been completed. Those skilled in the art will understand and appreciate various mechanisms that can be utilized to prevent access to data in memory blocks that are being interleaved, such as including those access prevention mechanisms described herein. Additionally, after migration has been completed, a pointer or other identifier can be employed to identify new interleaved memory locations for data. The migration system 70 can also inform the interleave system 60 that migration has been completed for a given memory block to facilitate subsequent access to the data that has been re-interleaved. The entries and subentries in the cell map 56 are also updated to correspond to the memory interleave that is performed. In view of the foregoing structural and functional features, examples of re-interleaving will be better appreciated with respect to the representations of cell maps depicted in FIGS. 4-9. In particular, FIGS. 4-6 and 7 depict examples of re-interleaving memory associated with adding a cell having memory and FIGS. 6, 8 and 9 depict an example of re-interleaving associated with memory deletion. Referring to FIG. 4, a cell map 150 is depicted for two cells, CELL 0 and CELL 1. In this example, each cell includes four memory regions, indicated as REG 1, REG 2, REG 3, and REG 4. Those skilled in the art will understand and appreciate that a given cell can include any number of memory regions, each region being a configurable size chunk of memory. For instance, each given memory region can include 0.5 gigabytes chunk of memory, although other size memory regions can also be utilized. In the example of FIG. 4, the memory regions in CELL 0 and CELL 1 are interleaved. In particular, the original memory interleave in the cell map 150 assigns each chunk of each cell a number, indicated as 0-7, such as can correspond to a data array that is the aggregate of the chunks (e.g., a four gigabyte data array for a 0.5 gigabyte chunk size). Each memory region, for example, can correspond to a portion of a cache line, a complete cache line or to more than one cache line. Assuming that each memory chunk corresponds to a cache line, each cache line can be assigned to an alternating cell in the cell map 150 to provide a desired original interleave. For example, chunk 0 is assigned to REG 1 of CELL 0, chunk 1 is assigned to REG 1 of CELL 1, and then the array of data revisits cell 0 in which chunk 2 is assigned to REG 2 of CELL 0, and chunk 3 is assigned to REG 2 of CELL 1 and so on, as depicted in FIG. 4. Those skilled in the art will understand and appreciate that other interleave configurations can also be utilized. By way of further example, the following equations can be utilized by a cell map to identify the location of a given cache line for a desired memory interleave. The operands in the equations are self-descriptive. For instance, a cache_line_address can be represented as follows: cache—line—address=(global address) shift right by (log2(cache line size)) Eq. 1 Similarly, a chunk number can be expressed as follows: chunk number=cache—line—address MOD(ways of interleave), Eq. 2 where the term “ways of interleave” corresponds to a value identifying the number of ways to interleave (e.g., ways of interleave=8 in the example of FIG. 4). Each chunk of memory also can include a sub_chunk address for that can be expressed as follows in Eq. 3: sub—chunk—address=cache—line—address shift right by (log2(ways of interleave)). FIG. 5 depicts an example a cell map 152 in which a new cell (indicated as CELL 2) has been added to system represented by the cell map 150 of FIG. 4. CELL 2 includes memory chunks 0, 1, 2 and 3 assigned to the respective regions REG 1-REG 4 of CELL 2. Stippling is utilized in FIG. 5 to differentiate between the memory chunks associated with CELL 2 and the memory chunks of the original interleaved cells. In FIG. 5, the chunks of cell 2 are not interleaved with the other cells in the system. The interleave arrangement depicted in FIG. 5 corresponds to a sub-optimal interleave in which a contiguous memory region (e.g., 2 gigabytes of CELL 2) is essentially non-interleaved with the other cells in the system. The interleave of CELL 2 can be considered sub-optimal. For example, it is possible that a hot spot could develop associated with the memory region of cell 2 since the cell controller of CELL 2 might be activated continually when accessing data in the contiguous memory region (chunks 0, 1, 2 and 3 of CELL 2). FIG. 6 depicts an example of a cell map 154 for a desired interleave that can be provided by interleaving the newly added memory of CELL 2 with the originally interleaved cells, namely, with CELL 0 and CELL 1. In order to interleave CELL 2 with the other cells, a corresponding interleave system examines the memory associated with the cells being interleaved to determine what amount of memory is available for re-interleaving. The interleaved distribution can be stored as interleaved data in memory and utilized to control migration of data memory to implement the memory interleave. For example, to re-interleave, the memory regions can be swapped or old memory can be migrated before the new memory associated with CELL 2 is utilized. The resulting interleave depicted in FIG. 6 can be implemented in stages. For example, migration can first be implemented by moving memory chunks from one or both of the original interleaved cells CELL 0 and CELL 1. The re-interleave can also include migrating data between CELL 0 and CELL 1. In the example of FIG. 6, every other memory chunk is assigned to a different cell, thereby spreading the contiguous address space across the respective cells, namely CELL 0, CELL 1 and CELL 2. In REG 3, for instance, chunk 6 is assigned to CELL 0, chunk 7 is assigned to CELL 1 and chunk 0 of the newly added CELL 2, which was originally in REG 1 of CELL 2 (FIG. 5), has been assigned to REG 3 of CELL 2. The next chunk 1, which was originally in REG 2 of CELL 2 (FIG. 5), revisits CELL 0 such that chunk 1 of the newly added cell 2 is assigned to REG 4 of CELL 0. As a result, the interleave implemented to provide the cell map 154 in FIG. 6 has reassigned a contiguous array of memory as consecutive memory chunks to alternating ones of the respective cells. The actual migration of the respective chunks can be performed on respective configurable portions or memory blocks (e.g., subchunks) of each respective memory region being moved, such as described herein. FIG. 7 depicts an example of a cell map 156 for an alternative desired interleave from that shown in FIG. 6. The interleave represented in the cell map 156 can be provided by interleaving the newly added memory of CELL 2 (as depicted in FIG. 5) with the previously interleaved cells, namely, with CELL 0 and CELL 1 (as depicted in FIG. 4). The interleave depicted in FIG. 7 can achieve similar performance to the interleave arrangement of FIG. 6, but can be implemented with fewer migration steps than the example of FIG. 6. In order to implement the interleave of FIG. 7, the interleave system determines a desired interleave distribution of memory chunks in cells (e.g., CELL 0, CELL 1 and CELL 2). The distribution of memory chunks in the cell map 156 is substantially the same as the cell map 154 of FIG. 6. In order to implement the re-interleave to modify the interleave arrangement illustrated in FIG. 5 to provide the interleave arrangement of FIG. 7, chunks 6 and 7, which were originally in REG 4 of CELL 0 and CELL 1 are swapped with chunks 0 and 1 of the newly added CELL 2. As a result, chunks 0 and 1, which were originally in REG 1 and REG 2, respectively of CELL 2 (FIG. 5), are moved respectively to REG 4 of CELL 0 and to REG 4 of CELL 1. By providing a similar distribution of memory amongst the cells CELL 0, CELL 1 and CELL 2 of the cell map, this approach is able to achieve similar performance to the interleave of FIG. 6, although implemented with fewer migration steps. Those skilled in the art will appreciate various other approaches that can be employed to provide a desired interleave when memory is added. FIGS. 6, 8 and 9 depict an example of a re-interleave that can be implemented in response to deleting address space associated with a given cell, namely CELL 0. This example begins with the original interleave shown in the cell map 154 of FIG. 6, and assumes that CELL 0 is to be deleted. Since CELL 0 corresponds to a predetermined size address space (e.g., two gigabytes), the interleave system instructs the operating system to locate a corresponding memory region of substantially equal size in the cells that will remain after the deletion. This may include vacating some or all of the memory that will be required to implement the re-interleave. Since in this example each of the memory regions is assumed to be the same size, the interleave system can instruct the operating system to remove the portion of interleaved memory corresponding to the shaded region of FIG. 6, which corresponds to memory regions of original CELL 2 added in FIG. 5. FIG. 8 depicts an intermediate phase of the re-interleave in which the shaded region from FIG. 6 has been vacated from the respective cells in preparation for migration of data from CELL 0. Those skilled in the art will understand and appreciate that any available (e.g., unused) memory in the interleaved memory can be vacated to provide space for the data that is being vacated from the cell (or cells) being deleted. After the respective memory region has been vacated by the operating system, the corresponding chunks of memory from CELL 0 can now be migrated in to the vacated regions of CELL 1 and CELL 2, such as by sequentially moving desired size memory blocks of each memory chunk (e.g., cache line). As shown in FIG. 9, memory chunks 0, 3 and 6, which were in CELL 0 of the originally interleaved memory, have been migrated to CELL 1 and CELL 2. In particular, chunk 0 has been migrated to REG 3 of CELL 2, chunk 3 has been migrated to REG 4 of CELL 1, and chunk 6 has been migrated to REG 4 of CELL 2. This migration completes the memory re-interleave such that the remaining memory of CELL 1 and CELL 2 are substantially evenly distributed. Those skilled in the art will understand and appreciate that the interleave system described above enables re-interleave of systems before and after memory addition or deletion to improve performance. Additionally, the interleave system enables deletion of memory on already interleaved systems. The re-interleaving can be implemented without requiring system reboot or downtime since the migration occurs in configurable blocks of memory. In view of the foregoing structural and functional features described above, certain methods will be better appreciated with reference to FIGS. 10 and 11. It is to be understood and appreciated that the illustrated actions, in other embodiments, may occur in different orders and/or concurrently with other actions. Moreover, not all illustrated features may be required to implement a method. It is to be further understood that the following methodologies can be implemented in hardware (e.g., as one or more integrated circuits or circuit boards containing a plurality of microprocessors), software (e.g., as executable instructions running on one or more processors or controllers), or any combination thereof. FIG. 10 depicts a method 200 that includes ascertaining a desired memory interleave for at least a selected portion of a distributed memory system, as shown at 210. The method 200 also includes migrating blocks of data from first respective memory locations associated with the blocks of data to second respective memory locations based on the desired memory interleave, as shown at 220. FIG. 11 depicts a method 250 that can be employed to interleave memory, such as in a distributed memory multi-processor system. The method begins at 260 in which a cell map is provided for available memory in the system. The cell map, which can be implemented as hardware, software or a combination of hardware and software (e.g., CAM memory), is able to identify a cell and/or other memory location information in response to an address tag. The address tag, for example, can be provided in a request for data. The cell map can include an original interleave, which may have been implemented by the method 250 or by another approach, such as can occur at system boot. At 270, a determination is made as to whether a stimulus has been received that requires interleaving to be implemented. For example, the stimulus can correspond to a change in the memory structure of the system, such as in response to adding or removing memory (e.g., as may be contained on a cell board). Alternatively or additionally, the stimulus can correspond to an instruction or command to initiate interleave or re-interleave on a selected memory. When no such stimulus is received (NO), the method 250 can remain at 270. When a stimulus is received (YES), the method proceeds to 280. At 280, a desired interleave is determined. The desired interleave can include ascertaining available memory and employing an algorithm to determine a distribution of memory chunks to improve performance and mitigate hot spots, such as described herein. From 280, the method proceeds to 290. At 290, a memory block (BLOCKi) is migrated. The BLOCKi can be any configurable size (e.g., 64 bytes, 64 Kbytes, etc.). The migration of BLOCKi further can involve temporarily blocking access to data being migrated, which can be implemented as mentioned herein, for example. At 300, a determination is made as to whether migration is complete. This determination can be made based on whether any additional memory blocks are required to be moved to implement the desired interleave, as determined at 280. If the migration is not complete (NO), the method proceeds to 310 in which the next memory block is accessed for migration. From 310, the method returns to 290 for migrating the next memory block BLOCKi (e.g., i=i+1). Since sufficiently small blocks of memory can be migrated individually to implement the desired interleave, the impact on normal system operation can be mitigated. As a result, the method 250 can operate to interleave or re-interleave memory in the system without requiring system reboot or stalling system operations. After it has been determined at 300 that the migration has been completed (YES), the method proceeds to 320 in which the cell map is updated. As a result, a cell controller having access to the cell map can properly identify locations for data, thereby facilitating access to such data. For instance, the cell map can identify locations for data on the same cell as the cell controller resides or alternatively, the location can be remote requiring access through one or more interconnects. What have been described above are examples of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. | <SOH> BACKGROUND <EOH>In multi-processor systems, memory can be configured to improve performance. One approach is to spread memory across different memory controllers, which approach is referred to as interleaving. A desirable interleave distributes memory substantially evenly across available memory controllers. As memory is more evenly distributed, large contiguous arrays of data touch each of the memory controllers substantially the same amount. Therefore, by interleaving memory, the memory is more evenly distributed so as to mitigate hot spots. Hot spots can occur, for example, if a given memory controller is overloaded due to unevenly large distributions of contiguous data being locally associated with the given memory controller. | <SOH> SUMMARY <EOH>One embodiment of the present invention may comprise a system that includes an interleave system that determines a desired interleave for at least a selected portion of a distributed memory system. A migration system is associated with the interleave system to migrate blocks of data to implement the desired interleave. Another embodiment of the present invention may comprise a system that includes an interleave system that dynamically re-interleaves at least a selected portion of a distributed memory system to implement a desired memory interleave in response to a stimulus. A mapping system provides memory location information in response to an input associated with data, the memory location information being updated based on the dynamically re-interleaving of the at least a selected portion of the distributed memory system. Another embodiment of the present invention may comprise a distributed memory, multi-processor system. The distributed memory, multi-processor system includes a plurality of cells communicatively coupled to each other, each of the plurality of cells comprising a cell controller and cell memory, the cell memory of the plurality of cells collectively defining a memory system. The cell controller of at least one of the plurality of cells further comprising an interleave system configured to dynamically interleave selected memory regions of the main memory of at least some of the plurality of cells by modifying a first memory distribution of the memory system to provide a desired memory interleave for the memory system. Another embodiment of the present invention may comprise a method that includes ascertaining a desired memory interleave for at least a selected portion of a distributed memory system, and migrating blocks of data from first respective memory locations associated with the blocks of data to second respective memory locations based on the desired memory interleave. Another embodiment of the present invention may comprise a distributed memory multi-processor system configured to dynamically interleave and re-interleave memory across a plurality of memory modules located in different cells of the distributed memory multi-processor system, the different cells being communicatively coupled to each other. | 20040428 | 20140812 | 20051103 | 62732.0 | 0 | PATEL, KAUSHIKKUMAR M | SYSTEM AND METHOD FOR INTERLEAVING MEMORY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,747 | ACCEPTED | Bat having a flexible handle | A bat has an elongate tubular striking member of a first material, and an elongate handle member of a second material. The handle may be of composite material laid up in selected layers and orientation to produce selected weight distribution, strength, and stiffness and improved batting capabilities. The striking member and handle member may have juncture sections which are substantially rigidly interconnected through mating configurations. | 1. A bat having a longitudinal axis and capable of being tested with a three-point bend stiffness test device having first and second supports, the bat comprising: an elongate tubular striking member having a distal end, a proximal end, and a striking region intermediate the distal and proximal ends; and a separate handle member having a distal end and a proximal end, the handle member coupled to the striking member, the handle member having a resistance to bending along the longitudinal axis in the range of 10-1000 lbs/in a three-point bend stiffness test wherein the handle member is transversely supported in a first direction by the first and second supports spaced apart a selected distance, with the first support adjacent the distal end and the second support adjacent the proximal end, and the handle member is transversely loaded in a second direction, opposite the first direction, at a location on the handle member in a region between 30% and 40% of the selected distance from the distal end of the handle member. 2. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 800-900 lbs/in. 3. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 700-800 lbs/in. 4. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 600-700 lbs/in. 5. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 500-600 lbs/in. 6. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 400-500 lbs/in. 7. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 300-400 lbs/in. 8. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 200-300 lbs/in. 9. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 100-200 lbs/in. 10. The bat of claim 1, the handle member has a resistance to bending along the longitudinal axis in the range of 10-100 lbs/in. 11. The bat of claim 1, wherein the handle member is firmly joined adjacent its distal end to the proximal end of the striking member to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the handle member and the striking member. 12. The bat of claim 1, wherein the striking member is formed of a material having a first effective mass, and wherein the handle member is formed of a material having a second effective mass which is less than the first effective mass. 13. The bat of claim 1, wherein the bat has an overall first length, wherein the striking member has a second length, wherein the handle member has a third length, and wherein the second and third lengths are each shorter than the first length. 14. The bat of claim 1, wherein the striking member includes a first juncture section positioned adjacent the proximal end of the striking member, wherein the handle member includes a second juncture section positioned adjacent the distal end of the handle member, and wherein the first junction section is engaged with the second junction section. 15. The bat of claim 14, wherein the first juncture section is integrally formed to the striking member, and wherein the second juncture section is integrally formed to the handle member. 16. The bat of claim 14, wherein the bat has an overall first length, and wherein the first juncture section has a length no greater than 25% of the first length. 17. The bat of claim 14, wherein the bat has an overall first length, and wherein the second juncture section has a length no greater than 25% of the first length. 18. The bat of claim 14, wherein the first and second juncture sections of the striking member and handle member are substantially frusto-conical, each having a major diameter section and a minor diameter portion, with the major diameter portion of the juncture section of the handle member being greater than a minor diameter portion of the juncture section of the striking member. 19. The bat of claim 15, wherein the striking region of the striking member has a first diameter, wherein the handle member has a gripping portion positioned toward its proximal end, wherein the gripping portion having a second diameter which is less than the first diameter, and wherein the second juncture section is captured in first juncture section. 20. The bat of claim 14, which further comprises adhesive material interposed between the first and second juncture sections. 21. The bat of claim 1, wherein the striking member is formed from a material selected from the group consisting of a metal, wood, a fiber composite material, and a non-metallic material. 22. The bat of claim 1, wherein the striking member is formed of a material having a first specific gravity, wherein the handle member is formed of a material having a second specific gravity, and wherein the specific gravity of the handle member is less than the specific gravity of the striking member. 23. The bat of claim 1, wherein the handle member is formed from a material selected from the group consisting of a metal, wood, a fiber composite material, and a non-metallic material. 24. The bat of claim 1, which further comprises a second tubular member concentric with the striking region of the striking member. 25. The bat of claim 24, wherein the second tubular member is configured to move independently of the striking member upon impact with a ball. 26. The bat of claim 1, wherein the striking member is a one-piece integrally formed tubular member. 27. The bat of claim 26, wherein the handle member is a one-piece integrally formed tubular unit, and wherein the striking member is directly connected to the handle member. 28. The bat of claim 26, wherein the handle member is a one-piece integrally formed tubular unit, and wherein the striking member is coupled to the handle member by a non-metallic substance. 29. The bat of claim 28, wherein the non-metallic substance is selected from the group consisting of an adhesive, an epoxy, an elastomer, a chemical bonding agent and a combination thereof. 30. A bat having a longitudinal axis, the bat capable of being tested with a three-point bend stiffness test device having first and second supports, the bat comprising: a non-wooden, one-piece bat frame including a distal end, a proximal end, an elongate tubular striking portion, and a handle portion, one of the handle portion and the striking portion including a tapered region, the frame having a resistance to bending along the longitudinal axis in the range of 10-950 lbs/in a three-point bend stiffness test wherein the frame is transversely supported in a first direction by the first and second supports, wherein the first support is positioned at a first predetermined position, the first predetermined position being the location where the tapered region has a first predetermined outer diameter, the second support positioned a first predetermined distance from the first predetermined position, and wherein the frame is transversely loaded in a second direction, opposite the first direction, on the handle member at a second predetermined position that is located on the handle portion a second predetermined distance from the first predetermined position, the second predetermined distance being between 30% and 40% of the first predetermined distance. 31. The bat of claim 30, wherein the first predetermined outer diameter is within the range of 2.1 to 2.25 inches. 32. The bat of claim 31, wherein the first predetermined distance is approximately 19 inches from the first predetermined position. 33. The bat of claim 32, wherein the second predetermined distance is approximately 7 inches. 34. The bat of claim 30, the frame has a resistance to bending along the longitudinal axis in the range of 800-950 lbs/in. 35. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 700-800 lbs/in. 36. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 600-700 lbs/in. 37. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 500-600 lbs/in. 38. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 400-500 lbs/in. 39. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 300-400 lbs/in. 40. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 200-300 lbs/in. 41. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 100-200 lbs/in. 42. The bat of claim 30, the handle member has a resistance to bending along the longitudinal axis in the range of 10-100 lbs/in. 43. The bat of claim 30, wherein the frame is formed of a material selected from the group consisting of a metal, a metallic alloy, a composite material, and combinations thereof. 44. The bat of claim 30, further comprising a second tubular member concentric with the striking portion of the frame. 45. The bat of claim 44, wherein the second tubular member is configured to move independently of the striking portion upon impact with a ball. 46. A method of categorizing a plurality ball bats wherein each bat includes a frame having a striking portion and a handle portion, the method comprising the steps of: creating at least two distinct bat categories based upon at least one bat characteristic, wherein the at least one bat characteristic includes at least one of the resistance to bending of the frame of the bat and the resistance to bending of the handle portion of the frame of the bat; determining the resistance to bending of one of the frame and the handle portion for the plurality of bats; and assigning one of the at least two categories to each of the plurality of bats based, at least in part, upon one of the resistance to bending of the frame and the resistance to bending of the handle portion. 47. The method of claim 46, wherein the resistance to bending of the bat frame is determined using a three-point bend stiffness test. 48. The method of claim 47 wherein the three-point bend stiffness test includes a three-point bend stiffness device having first and second supports, wherein the frame is transversely supported in a first direction by the first and second supports, wherein the first support is positioned a first predetermined distance from a distal end of the frame and the second support positioned a second predetermined distance from a proximal end of the frame, and wherein the frame is transversely loaded in a second direction, opposite the first direction, at a location that is approximately equi-distant from the first and second supports. 49. The method of claim 46, wherein the resistance to bending of the handle portion of the frame of the bat is determined using a three-point bend stiffness test. 50. The method of claim 49, wherein the three-point bend stiffness test includes a three-point bend stiffness test device having first and second supports, wherein the handle portion includes a distal end and a proximal end, and wherein the handle portion is transversely supported in a first direction by the first and second supports spaced apart a selected distance, with the first support adjacent the distal end of the handle portion and the second support adjacent the proximal end of the handle portion, and the handle portion is transversely loaded in a second direction, opposite the first direction, at a location on the handle portion in a region between 30% and 40% of the selected distance from the distal end of the handle portion. 51. The method of claim 46, wherein the at least two distinct bat categories is at least three distinct bat categories. 52. The method of claim 46, wherein the at least two distinct bat categories is at least four distinct bat categories. 53. The method of claim 46, wherein the at least one bat characteristic includes is at least two bat characteristic, and wherein the second bat characteristic is selected from the group consisting of the weight of the bat, the length of the bat, the application the bat was configured for, the material of the handle portion of the bat, and the material of the frame of the bat. 54. The method of claim 53, wherein the at least two bat characteristics includes a characteristic related to the intended user of the bat, and wherein the characteristic related to the user of the bat is selected from the group consisting of the skill level of the user, the strength of the user, the size of the user, and the age of the user. 55. The method of claim 46, wherein the resistance to bending of the bat frame for one or more of the plurality of bats is determined from the design specifications of the bat frame. 56. The method of claim 46, wherein the resistance to bending of the handle portion of the frame of the bat for one or more of the plurality of bats is determined from the design specifications of the handle portion of the frame. | RELATED U.S. APPLICATION DATA The present invention is a continuation-in-part of U.S. patent applicatoin Ser. No. 10/115,593, entitled “Bat With Composite Handle,” filed on Apr. 2, 2002 by Eggiman et al. FIELD OF THE INVENTION This invention relates to a ball bat, and more particularly to a ball bat with a striking barrel member made to provide desired striking capabilities, and a handle member made to provide desired swinging capabilities, and a method for manufacturing such which produces a rigid interconnection between the barrel and handle members. BACKGROUND AND SUMMARY OF THE INVENTION Tubular metallic baseball bats are well known in the art. A familiar example is a tubular aluminum bat. Such bats have the advantage of a generally good impact response, meaning that the bat effectively transfers power to a batted ball. This effective power transfer results in ball players achieving good distances with batted balls. An additional advantage is improved durability over crack-prone wooden bats. Even though presently known bats perform well, there is a continuing quest for bats with better hitting capabilities. Accordingly, one important need is to optimize the impact response of a bat. Further, it is important to provide a bat with proper weighting so that its swing weight is apportioned to provide an appropriate center of gravity and good swing speed of impact components during use. Generally speaking, bat performance may be a function of the weight of the bat, distribution of the weight, the size of the hitting area, the effectiveness of force transfer between the handle and the striking barrel, and the impact response of the bat. The durability of a bat relates, at least in part, to its ability to resist denting or cracking and depends on the strength and stiffness of the striking portion of the bat. An attempt to increase the durability of the bat often produces an adverse effect on the bat's performance, as by possibly increasing its overall weight and stiffness, or having less than optimum weight distribution. It has been discovered that a hitter often can increase bat speed by using a lighter bat, thereby increasing the force transferred to the ball upon impact. Thus it would be advantageous to provide a bat having a striking portion which has sufficient durability to withstand repeated hitting, yet which has a reduced overall bat weight to permit increased bat speed through use of an overall lighter weight bat. It also has been discovered that greater hitting, or slugging, capability may be obtained by providing a bat with a handle made of a material different from the material of the striking portion or formed in such a manner as to have different capabilities. One manner for providing such is to produce a bat with a composite handle, wherein the composite material may be structured to provide selected degrees of flexibility, stiffness, and strength. For example, in one hitting situation it may be best to have a bat with a more flexible handle, whereas for other hitting situations it is advantageous to have a handle with greater stiffness. An example of a prior attempt to provide a bat with a handle connected to a barrel section is shown in U.S. Pat. No. 5,593,158 entitled “Shock Attenuating Ball Bat.” In this patent an attempt was made to produce a bat with handle and barrel member separated by an elastomeric isolation union for reducing shock (energy) transmission from the barrel to the handle, and, inherently from the handle to the barrel. Accordingly, such a design does not allow for maximum energy transfer from the handle to the barrel during hitting. As a result, the bat produces less energy transfer or impact energy to the ball due to the elastomeric interconnection between the handle and barrel. Therefore there is a continuing need for a bat that provides the flexibility of a separate handle member and striking member and maximizes the energy transfer between the two members. The present invention provides an improved bat with a striking portion with good durability and striking capabilities and a handle portion with desirable weight and stiffness characteristics to permit greater bat speed during hitting. One embodiment of the invention provides a bat having an elongate tubular striking member with a juncture section which converges inwardly toward the longitudinal axis of the bat on progressing toward an end of the striking member, and an elongate handle member having an end portion thereof which is firmly joined to the converging end portion of the striking member to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the handle member and the striking member. In another embodiment, the bat has an elongate tubular striking member having a juncture section adjacent its proximal end, the striking member being composed of metal having a first effective mass, and an elongate handle member composed of a material having a second effective mass which is less than the first effective mass of the striking member, the handle member having a juncture section adjacent its distal end, with the juncture sections of the striking member and handle member overlapping and being joined together to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the striking member and the handle member on hitting. Because the handle member is of a lower effective mass it will help to produce a lighter weight bat with the possibility of a greater swing speed. The present invention provides a novel bat and method for producing the same wherein the striking portion is comprised of the most appropriate, or optimum, structure for striking and the handle is comprised of the most appropriate, or optimum, structure for swinging, and the two are joined for optimum slugging capability. The present invention provides a bat, and method for making a bat, wherein selected materials are used in selected portions of the bat to achieve proper weight, or mass, distribution for optimum swing speed and to provide desired strength and stiffness of selected portions. According to a principal aspect of a preferred form of the invention, a bat has a longitudinal axis and an overall first length, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes an elongate tubular striking member and a separate handle member. The striking member has a distal end, a proximal end, and a striking region intermediate the distal and proximal ends. The handle member has a distal end and a proximal end, and is coupled to the striking member. The handle member has a resistance to bending along the longitudinal axis of the bat in the range of 10-1000 lbs/in a three-point bend stiffness test wherein the handle member is transversely supported in a first direction by the first and second supports spaced apart a selected distance, with the first support adjacent the distal end and the second support adjacent the proximal end, and the handle member is transversely loaded in a second direction, opposite the first direction, at a location on the handle member in a region between 30% and 40% of the selected distance from the distal end of the handle member. According to another principal aspect of the present invention, a bat has a longitudinal axis, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes a non-wooden, one-piece bat frame. The frame includes a distal end, a proximal end, an elongate tubular striking portion, and a handle portion. Either the handle portion or the striking portion includes a tapered region. The frame has a resistance to bending along the longitudinal axis in the range of 10-950 lbs/in a three-point bend stiffness test wherein the frame is transversely supported in a first direction by the first and second supports, wherein the first support is positioned at a first predetermined position, wherein the first predetermined position being the location where the tapered region has a first predetermined outer diameter, wherein the second support positioned a first predetermined distance from the first predetermined position, and wherein the frame is transversely loaded in a second direction, opposite the first direction, on the handle member at a second predetermined position that is located on the handle portion a second predetermined distance from the first predetermined position. The second predetermined distance is between 30% and 40% of the first predetermined distance. According to another principal aspect of the present invention, a method of categorizing a plurality ball bats includes the following steps. At least two distinct bat categories are created based upon at least one bat characteristic. The at least one bat characteristic includes either the resistance to bending of the frame of the bat or the resistance to bending of the handle portion of the frame of the bat. The method further includes determining the resistance to bending of one of the frame and the handle portion for the plurality of bats. The method also includes assigning one of the at least two categories to each of the plurality of bats based, at least in part, upon either the resistance to bending of the frame or the resistance to bending of the handle portion. The present invention contemplates producing a handle member with multiple composite layers which are appropriately oriented and joined to provide a handle which has selected strength and stiffness. By providing a bat with a handle member made of composite material which may be laid up in multiple layers with selected orientation and strength, the handle member may be structured to provide selected degrees of strength, flexibility, and vibration transfer in an assembled bat. The present invention also contemplates producing a handle member of a thermoplastic material. In one embodiment, one of the juncture sections of the striking member or the juncture section of the handle member has projections thereon which extend radially from remainder portions of the juncture section a distance substantially equal to the thickness of a desired layer of adhesive to join the striking member and handle member. Such projections firmly engage the facing surface of the other member and this, in conjunction with the adhesive applied between the two members, provides a firm interconnection therebetween. This invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings described herein below, and wherein like reference numerals refer to like parts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view through the longitudinal center of a bat in accordance with one embodiment of the invention. FIG. 2 is a magnified sectional view of a juncture section of the bat of FIG. 1. FIG. 3 is a cross sectional view taken generally along the line 3-3 in FIG. 2. FIG. 4 is a view taken generally along the line 4-4 in FIG. 2, with a portion of the striking member broken away. FIG. 5 is a view similar to FIG. 4, but with a different rib configuration. FIG. 6 is a magnified sectional view of a portion of the handle taken generally along the line 6-6 in FIG. 2. FIGS. 7-9 are perspective views of a flared end portion of the handle with forming members associated therewith during the production of the handle member to produce projecting ribs on the juncture section of the handle. FIG. 10 is an enlarged longitudinal cross section of a handle member as may be used in the bat of FIG. 1, with portions broken away to illustrate composite lay up of the handle member with multiple composite material layers disposed at various regions along the length of the handle and with some sections of the handle having more layers than others and being composed of different materials to obtain selected handle member mass, strength and stiffness characteristics. FIG. 11 is a side elevation view of a test fixture for testing the bending strength of a handle member with an exemplary handle member mounted therein for testing. FIG. 12 is a side elevation view of a test fixture for testing the bending strength of a full length assembled bat with an exemplary handle member mounted therein for testing. FIG. 13 is a side view of a bat having a one-piece integral frame. FIG. 14 is a side elevation view of a test fixture for testing the bending strength of a bat with an exemplary assembled bat, or a bat having a one-piece integral frame, mounted therein for testing. DETAILED DESCRIPTION Referring to FIG. 1, an elongate tubular ball bat 10 having a longitudinal axis, or centerline, 20 comprises an elongate tubular striking member 12. The striking member has a proximal, or inner, end 12a and a distal, or outer, end 12b. A striking region 14 is disposed intermediate ends 12a, 12b. A frusto-conical juncture section 16 of the striking member adjacent end 12a converges toward centerline 20 on progressing toward end 12a. In the embodiment illustrated in FIGS. 1 and 2 striking region 14 has a substantially cylindrical inner cavity, with an inner diameter D1. A cylindrical tubular insert 22 is received in the striking region cavity to form a multiple-wall bat. The insert has proximal, or inner, and distal, or outer, ends 22a, 22b, respectively. End 22a is disposed adjacent juncture section 16. The bat also could be made as a single-wall bat without insert 22. Juncture section 16 has a major diameter equal to D1 and a minor diameter noted D2 at its end 12a. An elongate tubular handle member 30 is secured to and projects longitudinally outwardly from end 12a and juncture section 16 of the striking member. The assembled bat 10 has an overall length L1. Striking member 12 has a length L2 and handle member 30 has a length L3. As seen lengths L2 and L3 are each substantially less than L1. The handle member 30 in the illustrated embodiment may be made of a composite material or other appropriate material as will be discussed in greater detail below. It has opposed distal, or outer, end 30a, and proximal, or inner, end 30b. The handle member has an elongate, hollow, tubular, substantially cylindrical gripping portion 32 of a diameter D3 throughout a major portion of its length, and a frusto-conical juncture section 34 adjacent end 30a. As best seen in FIGS. 1 and 2, juncture section 34 diverges outwardly from the longitudinal axis in a configuration complementary to the converging portion of juncture section 16 of the striking member. Juncture section 34 has a minor diameter D3 (less than D2), a major diameter D4 (greater than D2, but less than D1), and a length which is no greater than 25% of the overall length L1 of the assembled bat. End 12a of striking member 12 provides an opening with a diameter D2 greater than diameter D3 of gripping portion 32 of handle member 30. The diverging portion of juncture section 34 of the handle member is such that the outer surface of juncture section 34 is substantially complementary to the configuration of the inner surface of juncture section 16 of the striking member so that they may fit in close contact with each other when assembled as illustrated in FIGS. 1 and 2. Referring to FIGS. 3 and 4, it will be seen that juncture section 34 of the handle member in the illustrated embodiment has a plurality of elongate, radially extending ribs, or projections, 40 on its outer surface. These ribs extend substantially longitudinally of the handle member, and are spaced apart circumferentially substantially equally about juncture section 34, or at approximately 120° from each other as illustrated. Projections, or ribs, 40 extend outwardly from remainder portions of the juncture section of the handle member a distance substantially equal to the thickness of a layer of adhesive which it is desired to apply between juncture section 16 of the striking member and juncture section 34 of the handle member to secure these two members together to form the completed bat. It has been found desirable to apply a layer of adhesive between the juncture sections of the handle member and the striking member, which is in a range of 0.001 to 0.010 inch thick, and preferably within a range of 0.002 to 0.005 inch thick. Thus ribs 40 project outwardly from remainder portions of juncture section 34 a distance in a range of 0.001 to 0.010 inch and more preferably in a range of 0.002 to 0.005 inch. When assembled as illustrated in the drawings, the outer surfaces of projections 40 firmly engage the inner surface of juncture section 16 of the striking member, with a layer of adhesive filling the space between the circumferentially spaced ribs, or projections, to adhesively join the striking member to the handle member in this juncture section. A layer of such adhesive is indicated generally at 42. Although projections 40 are shown as formed on the handle, it should be recognized that projections formed on the inner surface of the juncture section of the striking member and extending radially inwardly from remainder portions of the striking member could be used also. FIG. 4 illustrates an embodiment of the invention in which the ribs 40 are substantially straight, and extend longitudinally of the handle member. FIG. 5 illustrates another embodiment in which the ribs 46 are curved, such that they extend somewhat helically about the outer surface of juncture section 34. They function similarly to ribs 40. Although the projections, which may be formed on the external surface of the juncture section of the handle or on the internal surface of the juncture section of the striking member, have been illustrated and described generally as elongate ribs, it should be recognized that the purpose of such projections is to provide a firm contacting engagement between the juncture section portions of the handle member and striking member to produce a substantially rigid interconnection therebetween. Thus, the projections do not necessarily have to be elongate ribs as illustrated. Instead, there could be a plurality of projections of substantially any shape extending outwardly from remainder portions of the juncture section of the handle member or projecting inwardly from the inner surface of the juncture section of the striking member, or any combination thereof, such that firm interengagement is provided between the striking member and the handle member. For example the projections may be a pebbled surface configuration, criss-crossed ribs, irregularly shaped ribs, or any other configuration that provides a plurality of raised surfaces for direct contact with the other member to provide a substantially rigid interconnection between the handle member and the striking member. The complementary converging and diverging configurations of the juncture sections of the striking member and handle member prevent the two parts from being pulled apart longitudinally in opposite directions, such as by pulling outwardly on opposite ends of the bat. The adhesive is provided to inhibit longitudinal movement of the handle member and striking member upon application of forces thereagainst such as might occur if forces were exerted at opposite ends of the bat in an attempt to compress them toward each other. Although adhesive has been noted as a means for securing the two members against relative longitudinal movement in the one direction, it should be recognized that other means could be used also. For example, mechanical locking means of various types could be employed. Although not shown herein, the striking member or handle member could be formed with a radially projecting lip which engages a portion on the other member when the parts are moved into the positions illustrated in FIGS. 1-4 to prevent longitudinal separation of the members. Further, although it has been mentioned that adhesive can fill the spaces between the projections, it is not necessary that the spaces between the projections always be filled, and a less than filling quantity of adhesive may be adequate. When assembled as illustrated in the drawings, juncture section 34 of the handle member fits tightly within juncture section 16 of the striking member and a layer of adhesive interposed therebetween rigidly interconnects the striking member and handle member. In a particularly preferred embodiment, the striking member 12 is a one-piece integrally formed generally tubular member, and the handle member 30 is a one-piece integrally formed tubular unit. The striking and handle members 12 and 30 are preferably connected to each other such that at least a portion of the striking member 12 directly contacts at least a portion of the handle member 30. A non-metallic substance (an adhesive) is also preferably disposed between the handle and striking members 12 and 30 to further secure the connection between the handle and striking members. In other alternative preferred embodiments, the handle and striking members can be coupled together in a manner that prevents direct contact between the handle and striking members. In such alternative preferred embodiments, a non-metallic substance can be used to couple the handle member to the striking member. The non-metallic substance can be an adhesive, an elastomer, an epoxy, a chemical bonding agent or combinations thereof. In other alternative preferred embodiments, other types of conventional fastening or coupling means, including metallic fasteners and rings, can be used. Further, because direct contact between the handle and striking members is not necessarily present in these alternative preferred embodiments, the juncture sections each of the handle and striking members can be formed with or without ribs or other projections. The fully assembled bat as shown in FIG. 1 includes a knob 48 secured to the proximal end 30b of the handle member and a plug 50 inserted in and closing the distal end 12b of the striking member. Referring to FIG. 1, a weighted member, or plug, 54 is inserted and secured in the proximal end portion of handle member 30. The structure and function of member 54 will be described in greater detail below. A generally cylindrical transition sleeve 52 having a somewhat wedge-shaped cross section as illustrated in FIG. 2 is secured to handle member 30 to abut end 12a of the striking member to produce a smooth transition between end 12a of the striking member and the outer surface of handle member 30. Rather than applying a transition sleeve 52, the proximal end 12a of juncture section 16 of the striking member may be swaged to a gradually thinner edge region with a rounded proximal edge. Describing a method by which the bat illustrated in the figures may be produced, striking member 14 is formed of a material and in a manner to provide desired impact, or striking capabilities. The striking member may be formed by swaging from aluminum tube (or other metal found appropriate for the striking region of a bat) to yield an integral weld-free member. While swaging is one means of producing such striking member, it should be understood that other methods of manufacturing might work equally as well. The striking member is formed with a circular cross section having a striking region which has a cylindrical interior surface defining an interior cavity of a first selected cross sectional dimension, or diameter, D1. This produces a striking member having a first effective mass. The effective mass may be a function of the specific gravity of the material, size, thickness, or other characteristics. The juncture section 16 converges inwardly toward longitudinal axis 20 to an opening at end 12a having an internal diameter indicated D2 which is less than D1. Insert 22 has an outer diameter corresponding generally to, but possibly slightly smaller than, D1 such that it may be inserted into the striking portion 14 of striking member 12. Its proximal, or inner, end 22a may engage the beginning of the inward converging portion of juncture section 16 which prevents the insert from shifting further toward end 12a of the striking member. End 12b of the striking member 12 is bent over to form a circular lip with a bore extending therethrough. An end plug 50 is placed in the end of the bat to engage end 22b of the insert to hold it in place. The striking member 12 may be formed of tubular metal material of a first specific gravity, which may be, but is not limited to, aluminum, steel, titanium, or other suitable metal material. The striking member also might be formed of composite or other suitable materials. Insert 22 also may be made of any such tubular metal or a composite. The insert serves a function as set out in prior U.S. Pat. Nos. 5,415,398 and 6,251,034. Since the striking member is formed separately from the handle member, the striking member may be formed in such a manner and from such materials as to produce the desired, or optimum, impact, or striking capabilities. Thus the requirements of the striking member and handle member are decoupled permitting each to be made of such materials and in such a manner as to provide optimum point location of mass in the bat and optimum strength and stiffness or flexibility where needed. The handle member may be formed from material, which produces a different, and generally a lower, effective mass than it would have if composed in a manner or of a material similar to that from which the striking member is formed. The different effective mass of the handle member may be a function of the specific gravity of the material forming the striking member, its size, thickness or other characteristics. For example the material of the handle member may have a different specific gravity than the material from which the striking member is formed. In one preferred embodiment, the handle member is formed of a thermoplastic material, a fiber reinforced thermoplastic and combinations thereof. Some examples of thermoplastic materials include nylon, urethane, ABS, polyvinylchloride and combinations thereof. The fiber reinforced thermoplastic material can include fibers formed of fiberglass, aramid, carbon, Kevlar®, high molecular weight polyethylene in strand form, or other conventional fiber materials. In some instances the handle member may be formed of a composite material, such as carbon fiber, having a second specific gravity less than the first specific gravity of the striking member. In other instances the handle member may be formed of materials or in such a manner as to provide one or more operational or functional characteristics which differ from those which the handle member would have if merely formed in the same manner of the same material as the striking member. For example the handle may be formed from other materials such as titanium, aluminum, plastic or other appropriate material. Referring to FIG. 6, in one embodiment the handle member includes multiple tubular composite layers as indicated generally at 60-66. The layers 60-66 are disposed adjacent each other and are arranged in a substantially concentric manner. The number of layers must be sufficient to withstand the swinging action of the bat, a gripping force applied thereto by a user, and the bending force imposed thereon when striking with the bat. However, preferably only the number of layers necessary to withstand such stresses would be provided, since more layers will add additional weight to the handle member. The number, position, and orientation of the multiple layers will vary depending upon the size and type of bat used. In one embodiment, the handle member may include the seven layers, 60-66, as shown. The number and thickness of layers and their position, and orientation may vary as needed to provide desired flexibility or stiffness and to withstand gripping forces and hitting stresses. Each composite layer in the embodiment illustrated includes structural material to provide structural stability and matrix material to support the structural material. The structural material may be a series of fibers supported within the matrix material. In one preferred embodiment, most of the layers include fibers that preferably extend substantially longitudinally of the handle member. When the bat strikes a ball, the greatest stress component on the handle member may be in bending, thus the majority of the fibers preferably are directed longitudinally to withstand these stresses. For example, the even numbered layers 60, 62, 64, 66 may be longitudinally extending layers, whereas odd numbered layers 61, 63, 65, which are fewer in number, may be circumferentially disposed layers. The longitudinally extending layers often are referred to as longitudinal, or 0° layers, since they have fibers that are directed substantially parallel to the longitudinal axis. The other layers may be what are termed 90° layers, or circumferential layers, since they have fibers, in which the majority thereof are directed at substantially 90° relative to the longitudinal axis. Specific layers may be constructed with fibers directed at substantially 90° relative to the longitudinal axis and other fibers directed at substantially 0° and woven together within each layer. Or the layers may be uni-directional layers wherein the fibers within the layers are parallel. In another preferred embodiment, one or more of the multiple tubular composite layers 60-66 can formed primarily of fibers extending in a non-longitudinal direction, with only a small percentage, or none, of the fibers extending in a longitudinal direction. In this preferred embodiment, the fibers can be laid substantially 90° from the longitudinal axis, in various angled positions between 1-89°, or in combinations thereof. By having a small percentage, or none, of the fibers extending at 0° (longitudinally), the stiffness of the handle can be reduced and optimized to fit a particular application. In another alternative preferred embodiment, one or more of the multiple composite layers can be formed of fibers, or fiber segments, in a random, or generally uniformly, configuration. In this embodiment, the layers include carbon fibers. However the fibers could be other type of known fiber material, such as, but not limited to, Kevlar®, boron, aramid, fiberglass, or high molecular weight polyethylene in strand form. A metallic mesh also might be used. The matrix in the layers preferably is sufficiently durable and has sufficiently high adhesion properties to continue supporting the structural material even after repeated use. In a preferred embodiment, the matrix material is a toughened epoxy. Alternatively, the matrix can be some other thermally setting resin such as a polyester or vinyl ester. A person skilled in the art will appreciate that a thermoplastic resin can be used, rather than a thermally setting resin. In particularly preferred embodiments, the handle member 30 has a weight of about 158 grams and is formed with the number of layers between 28 to 40, wherein the weight of each layer varies from 0.6 to 14.0 grams. At least one layer of such embodiments is a braided layer having a percentage of the fibers within the braided layer extending longitudinally and the remaining fibers of the braided layer extending substantially circumferentially. Also, from 1 to 4 layers are formed with non-woven or non-braided fibers extending in two separate directions, such as, for example, 0 degrees and 90 degrees. Additionally, in particularly preferred embodiments, the handle member 30 includes between 2 and 10 layers having longitudinally extending fibers. In particularly preferred embodiments, the handle member 30 includes a plurality of layers having helically extending fibers at various angles relative to the longitudinal axis, such as, for example, between 10 and 16 layers extend at plus or minus 30 degrees from the longitudinal axis, between 6 and 16 layers extend at plus or minus 45 degrees from the longitudinal axis, and 2 or less layers extend at plus or minus 60 degrees from the longitudinal axis. Also, in particularly preferred embodiments, between 3 and 24 layers are formed of carbon fibers and between 13 and 25 layers are formed of fiberglass fibers. The layers are formed in a variety of different lengths varying from 5 cm to 67 cm. The layers, which are less than 67 cm, are placed at varying positions along the full length of the handle member. The layers are also formed in a variety of different widths ranging between 3.3 and 17.5 cm. Other layers have widths that vary along their length from between 0 to 17.5 cm. The number of layers having widths that vary along their length range between 8 and 11 layers. The fibers within layers are formed with an area fiber density of between 0.0143 and 0.048 grams/cm2, and each layer can be formed with a weight in a range of 0.6 to 14 grams. In alternative preferred embodiments, one or more of the characteristics of the handle member can be altered, such as, for example: the weight, size, thickness and stiffness of the handle member; the number, size, composition and orientation of the layers; and the composition, density, and orientation of the fibers within a layer. The handle member preferably has a weight within a range of 3 to 8 ounces. The handle member 30 can be formed without a braided layer or with an alternate number of braided layers. The handle member 30 can be formed with five or more layers of fibers wherein the non-woven fibers extend in two directions or with no such layers. Two or more of the layers can include other combinations of longitudinally, circumferentially and helically extending fibers. The handle member can be formed of multiple layers having helically extending fibers wherein any one layer can have fibers extending between plus or minus 1 to 89 degrees from the longitudinal axis. The fibers within the layers can be formed of other materials, such as, for example, glass, boron, graphite or other metal. FIG. 10 is a simplified illustration of the manner in which multiple layers of fiber composite material may be assembled. As is shown some of the layers extend the full length of the handle (layers 90a, b, c, d), while others are shorter and reside in selected regions of the handle member (90e, f, g, h, i, j, k). Only a limited number of layers are shown in FIG. 10, for the sake of simplicity in the illustration. The handle member includes a proximal gripping portion and a distal tapered portion, wherein one of the proximal gripping portion and the distal tapered portion is formed with a larger number of layers than the remaining portion. The characteristics of the handle member therefore can vary over its length. The handle member 30, when formed of a composite material and produced in accordance with the present invention, can be produced with a stiffness, or resistance to bending along the longitudinal axis 20 of the bat 10, within the range of 10 to 1980 lbs/in. when measured using a test method described below. In one preferred embodiment, the handle member 30 is formed with a stiffness or resistance to bending within the range of 400-900 lbs/in. (The term “lbs/in.” refers to the amount of force in pounds applied perpendicular to the member to produce on inch of deflection in a test method described below.) In other alternative preferred embodiments, the handle member 30 is formed with a stiffness, or resistance to bending along the longitudinal axis 20 of the bat 10, at specific levels within the range of 10 to 1980 lbs/in. The inventors of the present invention have discovered that, contrary to conventional bat design and construction, when the handle member 30 of the bat 10 is configured with a low stiffness, or resistance to bending along a longitudinal axis of the bat, the feel and perceived performance of the bat 10 significantly improves without negatively affecting the reliability of the bat. The present invention contemplates multiple preferred embodiments of ball bats in which the stiffness, or a resistance to bending along the longitudinal axis of the bat, of the handle member 30 is significantly lower than conventional bats. While conventional bat design focuses on bats having a resistance to bending typically far above 1000 lbs/in. (often 2200-2500 lbs/in for conventional metallic bats), in order to prevent the bat from becoming “too whippy,” the present invention incorporates ball bats having handle members with significantly lower stiffness values (resistance to bending along the longitudinal axis of the bat), which are then tuned or optimized to maximize the feel and performance of the ball bat for a particular user. Conventional performance bat design seeks to obtain a stiff handle member or portion to be used in conjunction with a responsive striking member or portion. A responsive striking member or portion provides the desired trampoline effect upon impact with a ball, and a stiff handle member maximizes the mass and the force that can be applied or transferred to the ball upon impact with the striking member or portion. A stiffer handle member or portion is also desired under conventional bat design because it allows the batter to bring the head of the bat around for impact faster and in a more controlled manner. Contrary to conventional performance bat design, the inventors of the present invention have discovered that producing a handle member, or portion, of a bat with a significantly lower resistance to bending in a longitudinal direction along the bat, provides the bat with a significantly improved feel to the user, particularly during off-center hits. Existing metallic and composite ball bats often provide painful stinging or harsh vibrational feedback through the handle member or handle portion of the bat to the user when the bat contacts the ball away from the “sweet spot” of the striking member. This effect is often heightened at lower temperatures. A bat having a handle member, or portion, with a very low resistance to bending in the longitudinal direction of the bat, however, significantly improves the feel of the bat by altering or reducing the size or configuration of the impact energy extending along the bat. The handle member or handle portion having the low resistance to bending tends to isolate, alter and/or reduce the painful, harsh vibrational energy generated in a bat from an off-center impact with a game ball. Often, the harsh or painful sensation felt by a batter when impacting a ball can have a significant negative impact on the ball player, particularly younger or less skilled players who do not always contact the ball at the sweet spot of the striking member or portion. Many players consciously, or subconsciously, alter or reduce the speed, motion or fluidity of their swing in an effort to avoid experiencing the stinging or harsh vibrational energy that can be generated upon impact with a ball. The handle member or handle portion, having a significantly reduced resistance to bending, alters, dampens, separates, isolates and/or reduces this negative vibrational energy or sensation transmitted to the ball player, particularly during mis-hits. After repeated use of such bats having a handle member or portion with a significantly lower resistance to bending, the ball player experiences the improved feel provided by the bat, particularly during mis-hits. The player typically will become more aggressive at the plate, swinging freer, smoother and often faster, thereby often improving his or her performance, even when mis-hitting the ball. Further, more skilled batters may be able to adjust their swings to maximize the impact of the significantly more flexible handle members. More skilled players potentially can bring the barrel or striking portion of the bat around into the point of impact with a ball in a manner that takes advantage of the flexibility of the handle to produce potentially greater bat head or striking portion speed. By lowering the resistance to bending of the handle member 30 well beyond the level of conventional bats, the present invention creates a significantly broader range of bat configurations and provides the ability to properly match a bat to a ball player. Other factors such as the player's size, age, strength, skill level and swing speed, as well as the type of ball game being played can be used along with the resistance to bending of the handle member to select a ball bat that is best suited for an individual player. The present invention includes a large number of bat configurations having resistance to bending levels that are significantly lower than conventional bats. In one particularly preferred embodiment, the handle member has a resistance to bending along the longitudinal axis within the range of 900-1000 lbs/in. In another particularly preferred embodiment, the handle member has a resistance to bending along the longitudinal axis within the range of 800-900 lbs/in. In another particularly preferred embodiment, the handle member has a resistance to bending along the longitudinal axis within the range of 700-800 lbs/in. In other particularly preferred embodiments, the handle member can have a resistance to bending along the longitudinal axis within the ranges of 600-700 lbs/in., 500-600 lbs/in., 400-500 lbs/in., 300-400 lbs/in., 200-300 lbs/in., 100-200 lbs/in., 10-100 lbs/in., or combinations and variations of these ranges. Each one of these ranges, or variations of these ranges, can be used to provide a bat having a resistance to bending that is best suited for a particular ball player for a particular type of ball game. Each of these ranges or range variations can be used to produce an optimal bat for a particular type of ball player for a particular application. Referring to FIG. 11, the stiffness of the handle member 30 is determined through a three-point bend stiffness test wherein the handle member is placed upon first and second supports 90 and 92 of a universal test machine, or similar test machine, such as the universal test machine produced by Tinius Olsen Testing Machine Co., Inc. of Willow Grove, Pa. The first support 90 is a V-block support positioned at the distal end 30a of the handle member 30. The V-block support configuration of the first support 90 also serves to inhibit both longitudinal and transverse movement of the distal end 30a of the handle member 30. The second support 92 is a roller support including a roller 94 rotatable about a horizontal axis 96 spaced from V-block support 90 and positioned near the proximal end 30b of the handle member 30. For handle members 30 greater than or equal to 19 inches, the second support 92 is positioned a distance D6 of 19 inches from support 90. The second support 92 also supports the handle member 30 in a first direction, preferably by maintaining the proximal end such that the longitudinal axis 20 of the bat 10 is in a substantially horizontal position. The second support 92 enables the proximal end 30b to move longitudinally. The third point of the bend stiffness test is provided by a crosshead 100, preferably having a semi-circular or circular shape. Most preferably, the semicircular crosshead has a radius of 2.0 inches. The crosshead is configured to extend in a second direction opposite of the first direction. The crosshead may be moved downwardly onto the horizontally positioned handle member 30 with a force noted F1 imposed thereon. The crosshead is connected to a load cell (not shown) which includes a strain gauge for measuring the load applied to the crosshead during displacement of the crosshead. The crosshead 100 is positioned a distance D7 from the first support 90. Distance D7 is in a range of 30% to 40% of distance D6, and more preferably 7 inches, such that the semicircular crosshead contacts the handle member at a location approximately 7.0 inches from the distal end 30a of the handle member 30. During testing, the handle member is positioned as described above. The crosshead is driven in the second direction at a speed of 1.0 inches per minute. As the crosshead moves in the second direction (i.e., downwardly in FIG. 12) the testing machine with input from the load cell calculates the load (F1) per the lateral deflection, or displacement, of the handle member 30. Table 1 below illustrates the resistance to bending along the longitudinal axis of a bat of handle members of an existing bat formed with separate striking and handle members, as well as handle members of bats formed under the present invention. TABLE 1 RESISTANCE TO BENDING ALONG A LONGITUDINAL AXIS FOR HANDLE MEMBERS OF BATS HAVING SEPARATE HANDLE AND STRIKING MEMBERS Resistance to Bending Test (lbs/in) Sample # Sample Description Test a Test b Average ts04-050 Easton ® Connexion ™/ 1559.20 1553.48 1556.34 z-core titanium/−3 besr certified/34″/31 oz/mdl. bt7-z/ baseball/handle-barrel separated ts04-060-1 DeMarini ® Sample No. 1 18.79 18.21 18.50 ts04-060 DeMarini ® Sample No. 2 25.94 24.97 25.45 ts04-049 DeMarini ® Sample No. 3 30.71 31.51 31.11 ts04-049-1 DeMarini ® Sample No. 4 36.71 38.82 37.77 vxw DeMarini ® Sample No. 5 557.81 593.91 575.86 evo 1 DeMarini ® Sample No. 6 609.03 627.56 618.30 sf2 1 DeMarini ® Sample No. 7 797.58 720.04 758.81 handle-1 DeMarini ® Sample No. 8 1589.56 1530.03 1559.80 Easton ® is a registered trademark of Jas. D. Easton, Inc. Connexion ™ is a trademark of Easton Sports, Inc. The DeMarini® Samples 1-7 are examples of handle members of the present invention having resistance to bending values well below the handle members of existing bats, which are configured with separate striking and handle members. The handle members having the reduced resistance to bending values provide the ball player with a significantly improved feel and perceived performance. DeMarini Sample 1 has a resistance to bending value that is over 95% lower than the resistance to bending of the handle member of the existing Easton® Connexion™ bat model of Table 1. The bat 10 of the present invention can be formed with separate striking and handle members 12 and 30 (see FIGS. 1-5) or as a bat 110 having an integral one-piece frame 110 as shown in FIG. 13. The frame 110 includes a striking portion 112 integrally connected with the handle portion 114. The frame 110 is formed of a strong, flexible material, preferably a composite material. Alternatively, other materials can be used, such as, for example, a tubular metal material or a combination of composite and metal materials. Through the use of composite materials throughout the frame 110, the frame 110 can be designed with different characteristics in the striking portion 112 compared to the handle portion 114. Preferably, the handle portion 114 is configured to be significantly more flexible than the striking portion 112. Referring to FIG. 12, one method of performing the three-point bend stiffness test on an assembled bat is illustrated. When testing a bat the first support 92 is positioned such that a proximal side of the first support lies a distance D8, which may be approximately 6 inches, from the distal end 12b of the striking member 12, and the second support 92 is positioned a distance D9, which may be approximately 6 inches, from the proximal end 30b of the handle member 30. The distance between supports 90, 92 is noted at D10 and the cross head is positioned a distance D10 from support 92, which is approximately one half D10 so as to contact the bat at a point between and generally equi-distant from the first and second supports. During testing, the bat 10 is positioned as described above. The crosshead is driven in the second direction (downwardly in FIG. 12) at a speed of 0.5 inches per minute. As the crosshead moves in the second direction, the testing machine with input from the load cell calculates the load per displacement of the bat. Referring to FIG. 14, another method of performing the three-point bend stiffness test on an assembled bat is illustrated. The stiffness of the bat 10 (or 100) is determined through a three-point bend stiffness test wherein the handle member 30 (or handle portion 110) of the bat 10 (or bat 110) is placed upon the first and second supports 90 and 92 of the universal test machine, or similar test machine. The first support 90 is a V-block support positioned toward the distal end of the handle portion 30 of the bat 10 and at the tapered region of the bat 10 (the tapered region can be part of the handle portion, part of the striking portion or a combination of both portions). The tapered region of the bat 10 is measured to identify the location of a predetermined outside diameter of the bat 10. Preferably, an outside diameter of 2.1 inches is selected. Alternatively, an outside diameter within the range of 2.1 to 2.25 inches can be selected. The tapered region of the bat 10 is placed into the first support 90 at the location where the predetermined outside diameter (preferably 2.1 inches) occurs. The V-block support configuration of the first support 90 also serves to inhibit the transverse movement of the bat 10. The second support 92 is spaced from the V-block support 90 and is positioned near the proximal end 30b of the handle member 30. The handle member or portion is then placed over the second support 92. The second support 92 is preferably positioned a distance D6 of 19 inches from support 90. The second support 92 also supports the handle member 30 in a first direction, preferably by maintaining the proximal end such that the longitudinal axis 20 of the bat 10 is in a substantially horizontal position. The second support 92 enables the proximal end 30b to move longitudinally. If the bat 10 (or the bat 110) is configured such that the handle member 30 (or the handle portion 110) of the bat 10 (or the bat 110) does not extend to the second support 92, a different predetermined outside diameter value along the tapered region of the bat 10 can be selected. A diameter greater than 2.1 inches up to 2.25 inches can be used. The third point of the bend stiffness test is provided by the crosshead 100. The crosshead is configured to extend in the second direction opposite of the first direction. The crosshead may be moved downwardly onto the horizontally positioned handle portion or handle member 30 with a force noted F1 imposed thereon. The crosshead is connected to the load cell (not shown) which includes the strain gauge for measuring the load applied to the crosshead during displacement of the crosshead. The crosshead 100 is positioned a distance D7 from the first support 90. Distance D7 is in a range of 30% to 40% of distance D6, and more preferably 7 inches, such that the semicircular crosshead contacts the handle member at a location approximately 7.0 inches from the location of the predetermined diameter (preferably 2.1 inches along the tapered region of the bat 10). During testing, the handle member is positioned as described above. The crosshead is driven in the second direction at a speed of 1.0 inches per minute. As the crosshead moves in the second direction (i.e., downwardly in FIG. 13) the testing machine with input from the load cell calculates the load (F1) per the lateral deflection, or displacement, of the handle member 30. The bat of the present invention can be formed such that the stiffness of the bat 10 is within the range of 10 to 2500 lbs/in. In one particularly preferred embodiment, the bat 10 is formed with a stiffness, or resistance to bending, within the range of 500 to 1500 lbs/in, and more preferably in a range of 400-900 lbs/in. A conventional aluminum bat typically has a stiffness, or resistance to bending, of approximately 2200 to 2500 lbs/in. In one particularly preferred embodiment, the bat is formed with a resistance to bending along the longitudinal axis within the range of 800-950 lbs/in. In another particularly preferred embodiment, the bat has a resistance to bending along the longitudinal axis within the range of 700-800 lbs/in. In other particularly preferred embodiments, the bat can have a resistance to bending along the longitudinal axis within the ranges of 600-700 lbs/in., 500-600 lbs/in., 400-500 lbs/in., 300-400 lbs/in., 200-300 lbs/in., 100-200 lbs/in., 10-100 lbs/in., or combinations and variations thereof. Each one of these ranges, or variations of these ranges, can be used to provide a bat having a resistance to bending that is best suited for a particular ball player for a particular type of ball game. Table 2 provides a listing of the resistance to bending along the longitudinal axis 20 of a number of existing ball bats and a number of ball bats configured under the present invention, measured using the second full (assembled) bat test method described above. (The term “lbs/in.” refers to the amount of force in pounds applied perpendicular to the bat to produce on inch of deflection in a test method described below.) TABLE 2 RESISTANCE TO BENDING ALONG A LONGITUDINAL AXIS OF ASSEMBLED BATS Resistance to Bending Test (lbs/in) Sample # Sample Description Test a Test b Average ts04-032 Easton ® Connexion ™/−3/33″/30 oz/baseball 1413.79 1450.00 1431.90 ts04-033 Worth ® supercell est/cryogenic/34″/27 oz/softball 1683.40 1689.93 1686.67 ts04-034 Easton ® z-core/−3/titanium/graphite reinforced 2320.11 2173.16 2246.64 sc777/34″/31 oz/mdl.bz71-2/baseball ts04-035 Worth ® 3dx/−3/34″/31 oz/model 3dxab/baseball 2166.02 2087.44 2126.73 ts04-036 Easton ® Connexion ™ /−3/32″/29 oz/baseball 1518.40 1565.50 1541.95 ts04-037 Baum ® aaa-pro/33″/33 oz/baseball 1895.87 1991.07 1943.47 ts04-038 Louisville Slugger ® TPX ™/gen1x/−3/33″/30 oz/ 2313.61 2299.33 2306.47 model cb203/baseball ts04-039 Easton ® z2k/−3/graphite reinforced sc500 scandium/ 2707.45 2656.00 2681.72 mdl.bz2-kc/baseball ts04-040 Easton ® (all aluminum)/youth baseball bat/31″ 1328.10 1323.59 1325.84 ts04-041 Easton ® Connexion ™ z-core/34″/26 oz/mdl. st1-2/ 1111.51 1151.69 1131.60 softball ts04-042 Worth ® Wicked ™/34″/28 ox/model wwsc/softball 1330.71 1375.98 1353.34 ts04-043 Easton ® synergy/34″ 28 oz/mdl. Scx2/softball 1005.63 992.40 999.02 ts04-044 Louisville Slugger ® TPS/air attack 3/34″/28 oz/ 1990.48 1891.51 1940.99 model sb22/softball ts04-045 Louisville Slugger ® TPS/air c555/−10.5 oz/34″/ 1868.15 1835.37 1851.76 model fp25/fastpitch ts04-046 Mizuno ® techfire/victory stage/33″/model 2tp-50340/ 2727.27 2780.90 2754.09 softball ts04-047 Easton ® cxn Connexion ™/sc888/29″/18.5 oz/mdl. 1094.30 1183.22 1138.76 lt8-z/youth baseball ts04-048 Easton ® Connexion ™/youth baseball bat/31″ 1128.07 1120.31 1124.19 ts04-004 DeMarini ® Sample No. 9 306.44 306.40 306.42 ts03-191 DeMarini ® Sample No. 10 529.59 464.58 497.08 ts03-040 DeMarini ® Sample No. 11 668.60 674.12 671.36 wcb-32-1 DeMarini ® Sample No. 12 894.84 928.07 911.46 wcb-33-1 DeMarini ® Sample No. 13 906.95 944.00 925.48 ts03-151 DeMarini ® Sample No. 14 1176.81 1164.74 1170.78 ts03-107 DeMarini ® Sample No. 15 2347.97 2348.82 2348.40 Easton ® is a registered trademark of Jas. D. Easton, Inc. Connexion ™ is a trademark of Easton Sports, Inc. Worth ® is a registered trademark of Worth, Inc. Wicked ™ is a trademark of Worth, Inc. Baum ® is a registered # trademark of Baum Research & Development Company, Inc. Louisville Slugger ® is a registered trademark of Hillerich & Bradsby, Co. TPS ™ and TPX ™ are trademarks of Hillerich & Bradsby, Co. Mizuno ® is a registered trademark of Mizuno Corp. Table 2 illustrates bats having different stiffnesses, or different resistance to bending values, of a number of existing ball bats. Table 2 also illustrates the reduced resistance to bending of the bats of DeMarini Samples 9-13. The DeMarini Samples are configured in accordance with the present invention and provide for resistance to bending values that are significantly lower than those measured on existing ball bats. The DeMarini Samples 1-7 and 9-13 of Tables 1 and 2 illustrate only a few of the variations in handle stiffness or resistance to bending contemplated under the present invention. As stated above, the present invention enables the bat to be produced with significantly less stiffness, greater flexibility, and significantly better feel to the player, without negatively affecting the batting performance of the bat. The present invention enables one of ordinary skill in the art to vary the composition of the bat to produce a bat that is optimally configured, adjusted or tuned to meet the needs of a particular player. The present invention also enables one of ordinary skill in the art to produce a bat that optimizes flexibility and, through the direct connection between the handle member and the striking member, maximizes energy transfer between the handle and striking members, and the power output of the bat. It should be noted that examples set out herein are only exemplary in nature, and should not be considered limiting as to the structure and method of manufacture of bats according to the invention. For example, although the bat has been described with a metal striking member and a composite handle member, such a wide difference in materials for the two members may not be necessary. For example, the striking member and the handle member both may be made of composite material, but with constructions which provide varying operational or functional characteristics beneficial for the specific portion of the bat which they form. The present invention also includes a method of categorizing a plurality ball bats or bat models (two or more) based, at least in part, upon the stiffness, or the resistance to bending of the bat along its longitudinal axis. The method includes creating at least two distinct bat categories, or groupings of bats, based upon at least one bat characteristic. The at least two bat categories or groupings of bats can be two, three, four or more categories or groups. The at least one bat characteristic includes at least the resistance to bending of the frame of the bat along the longitudinal axis of the bat, or the resistance to bending of the handle portion of the frame of the bat along the longitudinal axis of the bat. Preferably, the at least one bat characteristic used to create the two or more categories or groupings of bats is two or more bat characteristics, wherein the second characteristic is the weight of the bat, the length of the bat, the application the bat was configured for, the material of the handle portion of the bat, and the material of the frame of the bat. Further characteristics of the ball player for which a particular bat is intended for also can be used. Such characteristics can include a batter's skill level, a batter's swing speed, a batter's experience level, a batter's strength, a batter's age, and a batter's size. Still further, the application for which the bat is intended for can also be used as one of the additional characteristics used to define the categories. The method also includes determining the resistance to bending of either the frame or the handle portion for the plurality of bats, or bat models. This resistance to bending along the longitudinal axis of the bat, or handle portion of the bat, can be accomplished through actual testing or through use of design specifications. The method further includes assigning one of the at least two categories to each of the plurality of bats based, at least in part, upon either the resistance to bending of the frame or the resistance to bending of the handle portion. The method of testing for the resistance to bending of the bat frame or the handle portion of the frame is preferably accomplished using one of the three, three-point bend stiffness test approaches described above. Accordingly, the above-described method facilitates provided the bat that best fits a particular player. In other words, the bat can be flex-tuned to a particular player. For example, youth baseball bats may be configured with handle portions having a lower resistance to bending along the longitudinal axis of the bat than adult baseball bats. In other example, the youth baseball bats may be categorized with different stiffness levels, or different levels of resistance to bending, in order to appropriately match a bat to a particular youth player. One youth model would be stiff, the second less stiff, and the third even less stiff, or more flexible. In constructing the bat of the illustrated embodiment the striking member 12 may be formed as set out above. End 12b initially remains cylindrical, without the bent over portion as illustrated in FIG. 1. The tubular handle member may be formed by wrapping sheets of preimpregnated composite material on a mandrel. A first layer is wrapped on the mandrel, followed by a second layer, etc., until the desired number of layers have been wrapped on the mandrel in the desired positions and orientations to form the tubular handle member. The mandrel has a configuration which produces both the elongate substantially cylindrical gripping portion 32 and the diverging frusto-conical juncture section 34. To form projecting ribs 40, and referring to FIGS. 7-9, after a sufficient number of layers of preimpregnated composite material have been wrapped onto the mandrel, a plurality of forming members indicated generally at 70, 72, 74 having a selected arcuate configuration are placed on the outside of the juncture section of the handle member while the composite material is still malleable. FIG. 7 shows members 70, 72, 74 prior to placement on the outside of the juncture section 34 and the placement of such is illustrated in dashed outline in FIG. 7. As is seen members 70, 72, 74 do not extend fully about the juncture section when placed thereon, but instead have gaps therebetween. Members 70, 72, 74 have a thickness substantially equal to the desired projection for ribs 40 and the space between adjacent edges of elements 70, 72, 74 is the desired width of ribs 40. As mentioned previously, the projections may be in forms other than elongate ribs and other molding or forming members may be provided to achieve the desired projection configurations. When the forming members are placed against the juncture section as noted, the tubular member then may be wrapped in shrink tape and placed in an oven between 250 and 300° F. for about 45 minutes to one hour. The shrink tape preferably is temperature resistant and has high shrinkage and compaction capability when heated. As the shrink tape contracts it presses the composite layers into a desired configuration about the forming mandrel and presses members 70, 72, 74 into the composite material as seen in FIG. 8 to form depressions between areas which become projecting ribs 40. The depressions are indicated generally at 76, 78, 80, respectively, having a depth equal to the thickness of members 70, 72, 74. FIG. 9 illustrates the configuration thus produced when members 70, 72, 74 are removed. Heating the handle member speeds the curing process, but it may be allowed to cure at a lower temperature for a longer period of time. For example, the handle member may be allowed to cure at room temperature for several days. The pressure applied by the shrink tape may range from 15 to 150 psi depending both on the type of the shrink tape used and the flow properties of the matrix material used. Alternately, some other known apparatus may be used to pressurize the handle member during curing, such as a bladder or a vacuum bag. The handle member (or striking member if chosen to do so) also may be formed of a chopped fiber slurry. The chopped fibers can be carbon, glass, fiberglass, boron, or various metals. Although not illustrated in the figures, it should be recognized that other methods may be used for forming the handle and providing a desired series of projections thereon. One method of doing so is to wrap sheets of pre-impregnated composite material onto a mandrel as previously described to form the general configuration for the handle with its cylindrical gripping portion and flared frusto-conical juncture section. The materials wrapped on the mandrel then may be placed in a clam shell style mold having the desired external configuration for the handle, including forms to produce a selected pattern of projections thereon. After the clam shell mold has been placed about the exterior of the handle, the forming mandrel is removed, a pressure bladder is inserted where the mandrel previously had been, and pressure is applied on the bladder to force the wrapped materials outwardly against the mold. The materials then are allowed to cure and are removed from the mold with the desired external configuration. Although the handle member has been described using a plurality of sheets of impregnated composite material, the layers may be formed by some other method, such as a filament winding process. With a filament winding process, a continuous fiber, rather than a preimpregnated sheet as described above, is wrapped around a mandrel. The filament winding process may use a preimpregnated fiber. Alternately, the continuous fiber may run through a resin bath before it is wrapped onto the mandrel. The filament winding process typically winds the fiber in a helical path along the mandrel, making it difficult to produce a layer having fibers that are exactly 90 degrees relative to the longitudinal axis of the layers. Thus the layers may include layers that are at an angle substantially 90 degrees, but not exactly at 90 degrees. The handle member, being produced of composite material, permits selective production to obtain a handle member of the desired weight while still obtaining the necessary strength and stiffness. In an alternative preferred embodiment, the handle member can be formed of a thermoplastic material, as described above. The handle member formed of a thermoplastic material is preferably produced through injection molding. The injection molding process includes the steps of obtaining a mold having a cavity configured for the desired structure, such as the handle member. The mold cavity is then filled with the thermoplastic material under heat and pressure. The thermoplastic material can include fiber reinforcement, and/or it can be formed of a combination of thermoplastic materials. The thermoplastic material is then allowed to cure. After curing, the structure (the handle member) is removed from the mold. If a fiber-reinforced thermoplastic material is used, the injection process can be configured to orientate a significant portion the fibers, or fiber segments, in a particular direction. As such, the handle member formed of a thermoplastic material can be generally anisotropic. Preferably, the handle member formed of a thermoplastic material is formed to be generally isotropic (wherein the fibers, or fiber segments, are randomly configured). After the handle member has been formed it is inserted through the open end 12b of striking member 12, such that gripping portion 32 extends longitudinally outwardly from end 12a of the striking member. Prior to inserting the handle member a layer of adhesive is applied either to the outer surface of juncture section 34 of the handle member or the inner surface of juncture section 14 of the striking member. The striking member 12 and handle 30 are urged in opposite directions along the longitudinal axis, such that the juncture section 34 of the handle member is forced into tight engagement with the interior surface of juncture section 16. As this occurs, the adhesive applied between the parts is pressed into recesses 76, 78, 80 and ribs 40, or other projections, firmly contact, or engage, the inner surface of juncture section 16. Excess adhesive will be allowed to flow outwardly from end 30a of the handle member, with only the selected thickness of adhesive remaining. It has been found that an adhesive such as Scotch-Weld™ DP-100 epoxy adhesive or PT 1000 urethane adhesive from Willamette Valley Co., of Eugene, Ore., works well in this application. Other appropriate adhesives also may be used. In a preferred embodiment, projections 40 extend outwardly from remainder portions of the outer surface of the juncture section of the handle member in a range of 0.001 to 0.010 inch, and more preferably in a range of 0.002 to 0.005 inch and have a width in a range of 0.125 to 0.75 inch and more preferably in a range of 0.2 to 0.3 inch. The layer of adhesive will have a thickness generally equal to height of the projections and is allowed to cure and form a substantially rigid, firm interconnection between the striking member and the handle member. The substantially rigid interconnection between the juncture sections of the striking member and handle member provided by the adhesive and direct engagement of the projections with the inner surface of the striking member permits substantially complete striking energy transfer between the handle member and the striking member. After the handle member has been secured to the striking member, insert 22 is inserted into the striking member, the outer end 12b is rolled over into the configuration illustrated in FIG. 1, and stop member 50 is inserted therein. Transition member 52 (when used) is attached to provide a smooth transition between the inner end 12a of the striking member and handle 30. Prior to, or following, assembly of the handle member and striking member, weighted member, or plug, 54 is inserted and secured in the proximal end portion of the handle member as shown in FIG. 1. Weighted plug 54 is a generally cylindrical member coupled to the proximal end 30b of the handle member 30. The weighted plug preferably is sized to fit snugly within the proximal end 30b of the handle member 30 and preferably is affixed to the proximal end 30b with a suitable adhesive. Alternative means for coupling the plug 54 to the proximal end 30b of the handle member 30 also are contemplated, such as, for example, press-fit connections, fasteners, and other mechanical latching mechanisms. The weighted plug 54 is formed of a relatively dense material, preferably a metal. Alternatively, the weighted plug 54 can be formed of other materials, such as, for example, sand, a fluid or a polymeric material. The plug 54 is formed with a weight in the range of 0.5 to 7.0 ounces, and preferably within a range of 2 to 5 ounces, and a length in the range of 1.0 to 4.0 inches. The weighted plug 54 places additional weight, or mass, generally directly beneath the player's grip during swinging, thereby facilitating the player's ability to swing the bat and to increase his or her bat speed. The weighted plug 54 provides the player with a pivot point, which facilitates rotation of the bat about the mass or grip location of the player. Additionally, the weighted plug 54 also serves to dampen, or substantially reduce, the shock, vibration and “sting” commonly felt by a player when hitting a ball, particularly when the ball is hit away from a desired hitting region of the striking member, or the “sweet spot.” The weighted plug 54 serves as a vibration sink that substantially lowers the amplitude of the vibrational energy generated upon impact of the bat 10 with a ball at the location of the plug 54 thereby reducing the vibration or shock felt by the player. In another alternative preferred embodiment, the plug 54 is integrally formed with the knob 48. The use of the weighted plug 54 is just one example of the advantages achieved in the present invention from redistributing the weight, or mass, within the bat 10 through decoupling of the handle member 30 and the striking member 12. When forming the handle member 30 of a composite material, the weight of the handle member 30 can be reduced from that of a conventional metal handle member. This weight can then be redistributed to other locations on the bat, such as at the proximal end of the handle member 30 to improve, or tune, the performance of the bat 10. In the present invention, the weighted plug 54 can be added to the bat 10 to enable the player to increase his or her bat speed, and to reduce the shock and vibration felt by the user, without excessively or unnecessarily increasing the weight of the bat 10. In another alternative preferred embodiment, weight can be redistributed to the striking member 12. The method described herein and the bat produced provide a bat which has improved striking capabilities. Such improved striking capabilities are provided by the structural characteristics of the bat. In one instance increased bat swing speed is allowed by producing a bat with a handle which is lighter than would be the case if it were made of the same material or in a manner similar to the striking portion of the bat. This reduction in weight of the handle in relation to the striking portion and providing a substantially rigid interconnection between the two permits increased bat speed and substantially complete striking energy transfer between the striking member and the handle member. Further it provides desirable weight distribution in the bat with the greatest effective mass in the striking region and lower effective mass in the handle. It also has been found that the slugging, or hitting, characteristics of the bat may be varied by mating various composite handle members with striking members of different materials or configurations, with a substantially rigid interconnection therebetween. Thus different models of bats may be produced, tuned to selected requirements. By providing a bat constructed with an independently produced striking member and handle member which are rigidly interconnected at a juncture region, bats may be made with numerous selected functional characteristics. The striking member may be made of materials which provide optimum ball striking effectiveness, while the handle member may be constructed in such a fashion that is allows the batter to impart the maximum possible force from the batter's hands to the bat and to produce the greatest swing speed. The handle member may be laid up from a variety of composite materials with selected thicknesses, orientations, and positions within the handle member to produce desired strength, weight, stiffness, etc., in the overall handle or even within selected regions of the handle. Explaining further, selected regions of the handle may have a greater or lesser number of layers of composite material than other regions, the thicknesses or structural materials within the layers may vary at different regions of the handle member, and other characteristics may be varied through selected lay up of materials in the handle member during production. As an example of desirable differences in handle members which may be formed, it has been found that certain bats, such as for softball use, will work better with a stiffer handle member, whereas for baseball a more flexible, or less stiff, handle member is preferable. With the structure and method for producing such set out herein, a bat may be optimized for the selected usage by selection of materials and lay up for the various components of the bat. While there have been illustrated and described preferred embodiments of the present invention, it should be appreciated that numerous changes and modifications may occur to those skilled in the art and it is intended in the appended claims to cover all of those changes and modifications which fall within the spirit and scope of the present invention. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>Tubular metallic baseball bats are well known in the art. A familiar example is a tubular aluminum bat. Such bats have the advantage of a generally good impact response, meaning that the bat effectively transfers power to a batted ball. This effective power transfer results in ball players achieving good distances with batted balls. An additional advantage is improved durability over crack-prone wooden bats. Even though presently known bats perform well, there is a continuing quest for bats with better hitting capabilities. Accordingly, one important need is to optimize the impact response of a bat. Further, it is important to provide a bat with proper weighting so that its swing weight is apportioned to provide an appropriate center of gravity and good swing speed of impact components during use. Generally speaking, bat performance may be a function of the weight of the bat, distribution of the weight, the size of the hitting area, the effectiveness of force transfer between the handle and the striking barrel, and the impact response of the bat. The durability of a bat relates, at least in part, to its ability to resist denting or cracking and depends on the strength and stiffness of the striking portion of the bat. An attempt to increase the durability of the bat often produces an adverse effect on the bat's performance, as by possibly increasing its overall weight and stiffness, or having less than optimum weight distribution. It has been discovered that a hitter often can increase bat speed by using a lighter bat, thereby increasing the force transferred to the ball upon impact. Thus it would be advantageous to provide a bat having a striking portion which has sufficient durability to withstand repeated hitting, yet which has a reduced overall bat weight to permit increased bat speed through use of an overall lighter weight bat. It also has been discovered that greater hitting, or slugging, capability may be obtained by providing a bat with a handle made of a material different from the material of the striking portion or formed in such a manner as to have different capabilities. One manner for providing such is to produce a bat with a composite handle, wherein the composite material may be structured to provide selected degrees of flexibility, stiffness, and strength. For example, in one hitting situation it may be best to have a bat with a more flexible handle, whereas for other hitting situations it is advantageous to have a handle with greater stiffness. An example of a prior attempt to provide a bat with a handle connected to a barrel section is shown in U.S. Pat. No. 5,593,158 entitled “Shock Attenuating Ball Bat.” In this patent an attempt was made to produce a bat with handle and barrel member separated by an elastomeric isolation union for reducing shock (energy) transmission from the barrel to the handle, and, inherently from the handle to the barrel. Accordingly, such a design does not allow for maximum energy transfer from the handle to the barrel during hitting. As a result, the bat produces less energy transfer or impact energy to the ball due to the elastomeric interconnection between the handle and barrel. Therefore there is a continuing need for a bat that provides the flexibility of a separate handle member and striking member and maximizes the energy transfer between the two members. The present invention provides an improved bat with a striking portion with good durability and striking capabilities and a handle portion with desirable weight and stiffness characteristics to permit greater bat speed during hitting. One embodiment of the invention provides a bat having an elongate tubular striking member with a juncture section which converges inwardly toward the longitudinal axis of the bat on progressing toward an end of the striking member, and an elongate handle member having an end portion thereof which is firmly joined to the converging end portion of the striking member to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the handle member and the striking member. In another embodiment, the bat has an elongate tubular striking member having a juncture section adjacent its proximal end, the striking member being composed of metal having a first effective mass, and an elongate handle member composed of a material having a second effective mass which is less than the first effective mass of the striking member, the handle member having a juncture section adjacent its distal end, with the juncture sections of the striking member and handle member overlapping and being joined together to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the striking member and the handle member on hitting. Because the handle member is of a lower effective mass it will help to produce a lighter weight bat with the possibility of a greater swing speed. The present invention provides a novel bat and method for producing the same wherein the striking portion is comprised of the most appropriate, or optimum, structure for striking and the handle is comprised of the most appropriate, or optimum, structure for swinging, and the two are joined for optimum slugging capability. The present invention provides a bat, and method for making a bat, wherein selected materials are used in selected portions of the bat to achieve proper weight, or mass, distribution for optimum swing speed and to provide desired strength and stiffness of selected portions. According to a principal aspect of a preferred form of the invention, a bat has a longitudinal axis and an overall first length, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes an elongate tubular striking member and a separate handle member. The striking member has a distal end, a proximal end, and a striking region intermediate the distal and proximal ends. The handle member has a distal end and a proximal end, and is coupled to the striking member. The handle member has a resistance to bending along the longitudinal axis of the bat in the range of 10-1000 lbs/in a three-point bend stiffness test wherein the handle member is transversely supported in a first direction by the first and second supports spaced apart a selected distance, with the first support adjacent the distal end and the second support adjacent the proximal end, and the handle member is transversely loaded in a second direction, opposite the first direction, at a location on the handle member in a region between 30% and 40% of the selected distance from the distal end of the handle member. According to another principal aspect of the present invention, a bat has a longitudinal axis, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes a non-wooden, one-piece bat frame. The frame includes a distal end, a proximal end, an elongate tubular striking portion, and a handle portion. Either the handle portion or the striking portion includes a tapered region. The frame has a resistance to bending along the longitudinal axis in the range of 10-950 lbs/in a three-point bend stiffness test wherein the frame is transversely supported in a first direction by the first and second supports, wherein the first support is positioned at a first predetermined position, wherein the first predetermined position being the location where the tapered region has a first predetermined outer diameter, wherein the second support positioned a first predetermined distance from the first predetermined position, and wherein the frame is transversely loaded in a second direction, opposite the first direction, on the handle member at a second predetermined position that is located on the handle portion a second predetermined distance from the first predetermined position. The second predetermined distance is between 30% and 40% of the first predetermined distance. According to another principal aspect of the present invention, a method of categorizing a plurality ball bats includes the following steps. At least two distinct bat categories are created based upon at least one bat characteristic. The at least one bat characteristic includes either the resistance to bending of the frame of the bat or the resistance to bending of the handle portion of the frame of the bat. The method further includes determining the resistance to bending of one of the frame and the handle portion for the plurality of bats. The method also includes assigning one of the at least two categories to each of the plurality of bats based, at least in part, upon either the resistance to bending of the frame or the resistance to bending of the handle portion. The present invention contemplates producing a handle member with multiple composite layers which are appropriately oriented and joined to provide a handle which has selected strength and stiffness. By providing a bat with a handle member made of composite material which may be laid up in multiple layers with selected orientation and strength, the handle member may be structured to provide selected degrees of strength, flexibility, and vibration transfer in an assembled bat. The present invention also contemplates producing a handle member of a thermoplastic material. In one embodiment, one of the juncture sections of the striking member or the juncture section of the handle member has projections thereon which extend radially from remainder portions of the juncture section a distance substantially equal to the thickness of a desired layer of adhesive to join the striking member and handle member. Such projections firmly engage the facing surface of the other member and this, in conjunction with the adhesive applied between the two members, provides a firm interconnection therebetween. This invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings described herein below, and wherein like reference numerals refer to like parts. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>Tubular metallic baseball bats are well known in the art. A familiar example is a tubular aluminum bat. Such bats have the advantage of a generally good impact response, meaning that the bat effectively transfers power to a batted ball. This effective power transfer results in ball players achieving good distances with batted balls. An additional advantage is improved durability over crack-prone wooden bats. Even though presently known bats perform well, there is a continuing quest for bats with better hitting capabilities. Accordingly, one important need is to optimize the impact response of a bat. Further, it is important to provide a bat with proper weighting so that its swing weight is apportioned to provide an appropriate center of gravity and good swing speed of impact components during use. Generally speaking, bat performance may be a function of the weight of the bat, distribution of the weight, the size of the hitting area, the effectiveness of force transfer between the handle and the striking barrel, and the impact response of the bat. The durability of a bat relates, at least in part, to its ability to resist denting or cracking and depends on the strength and stiffness of the striking portion of the bat. An attempt to increase the durability of the bat often produces an adverse effect on the bat's performance, as by possibly increasing its overall weight and stiffness, or having less than optimum weight distribution. It has been discovered that a hitter often can increase bat speed by using a lighter bat, thereby increasing the force transferred to the ball upon impact. Thus it would be advantageous to provide a bat having a striking portion which has sufficient durability to withstand repeated hitting, yet which has a reduced overall bat weight to permit increased bat speed through use of an overall lighter weight bat. It also has been discovered that greater hitting, or slugging, capability may be obtained by providing a bat with a handle made of a material different from the material of the striking portion or formed in such a manner as to have different capabilities. One manner for providing such is to produce a bat with a composite handle, wherein the composite material may be structured to provide selected degrees of flexibility, stiffness, and strength. For example, in one hitting situation it may be best to have a bat with a more flexible handle, whereas for other hitting situations it is advantageous to have a handle with greater stiffness. An example of a prior attempt to provide a bat with a handle connected to a barrel section is shown in U.S. Pat. No. 5,593,158 entitled “Shock Attenuating Ball Bat.” In this patent an attempt was made to produce a bat with handle and barrel member separated by an elastomeric isolation union for reducing shock (energy) transmission from the barrel to the handle, and, inherently from the handle to the barrel. Accordingly, such a design does not allow for maximum energy transfer from the handle to the barrel during hitting. As a result, the bat produces less energy transfer or impact energy to the ball due to the elastomeric interconnection between the handle and barrel. Therefore there is a continuing need for a bat that provides the flexibility of a separate handle member and striking member and maximizes the energy transfer between the two members. The present invention provides an improved bat with a striking portion with good durability and striking capabilities and a handle portion with desirable weight and stiffness characteristics to permit greater bat speed during hitting. One embodiment of the invention provides a bat having an elongate tubular striking member with a juncture section which converges inwardly toward the longitudinal axis of the bat on progressing toward an end of the striking member, and an elongate handle member having an end portion thereof which is firmly joined to the converging end portion of the striking member to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the handle member and the striking member. In another embodiment, the bat has an elongate tubular striking member having a juncture section adjacent its proximal end, the striking member being composed of metal having a first effective mass, and an elongate handle member composed of a material having a second effective mass which is less than the first effective mass of the striking member, the handle member having a juncture section adjacent its distal end, with the juncture sections of the striking member and handle member overlapping and being joined together to provide a rigid interconnection therebetween to permit substantially complete striking energy transfer between the striking member and the handle member on hitting. Because the handle member is of a lower effective mass it will help to produce a lighter weight bat with the possibility of a greater swing speed. The present invention provides a novel bat and method for producing the same wherein the striking portion is comprised of the most appropriate, or optimum, structure for striking and the handle is comprised of the most appropriate, or optimum, structure for swinging, and the two are joined for optimum slugging capability. The present invention provides a bat, and method for making a bat, wherein selected materials are used in selected portions of the bat to achieve proper weight, or mass, distribution for optimum swing speed and to provide desired strength and stiffness of selected portions. According to a principal aspect of a preferred form of the invention, a bat has a longitudinal axis and an overall first length, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes an elongate tubular striking member and a separate handle member. The striking member has a distal end, a proximal end, and a striking region intermediate the distal and proximal ends. The handle member has a distal end and a proximal end, and is coupled to the striking member. The handle member has a resistance to bending along the longitudinal axis of the bat in the range of 10-1000 lbs/in a three-point bend stiffness test wherein the handle member is transversely supported in a first direction by the first and second supports spaced apart a selected distance, with the first support adjacent the distal end and the second support adjacent the proximal end, and the handle member is transversely loaded in a second direction, opposite the first direction, at a location on the handle member in a region between 30% and 40% of the selected distance from the distal end of the handle member. According to another principal aspect of the present invention, a bat has a longitudinal axis, and is capable of being tested with a three-point bend stiffness test device having first and second supports. The bat includes a non-wooden, one-piece bat frame. The frame includes a distal end, a proximal end, an elongate tubular striking portion, and a handle portion. Either the handle portion or the striking portion includes a tapered region. The frame has a resistance to bending along the longitudinal axis in the range of 10-950 lbs/in a three-point bend stiffness test wherein the frame is transversely supported in a first direction by the first and second supports, wherein the first support is positioned at a first predetermined position, wherein the first predetermined position being the location where the tapered region has a first predetermined outer diameter, wherein the second support positioned a first predetermined distance from the first predetermined position, and wherein the frame is transversely loaded in a second direction, opposite the first direction, on the handle member at a second predetermined position that is located on the handle portion a second predetermined distance from the first predetermined position. The second predetermined distance is between 30% and 40% of the first predetermined distance. According to another principal aspect of the present invention, a method of categorizing a plurality ball bats includes the following steps. At least two distinct bat categories are created based upon at least one bat characteristic. The at least one bat characteristic includes either the resistance to bending of the frame of the bat or the resistance to bending of the handle portion of the frame of the bat. The method further includes determining the resistance to bending of one of the frame and the handle portion for the plurality of bats. The method also includes assigning one of the at least two categories to each of the plurality of bats based, at least in part, upon either the resistance to bending of the frame or the resistance to bending of the handle portion. The present invention contemplates producing a handle member with multiple composite layers which are appropriately oriented and joined to provide a handle which has selected strength and stiffness. By providing a bat with a handle member made of composite material which may be laid up in multiple layers with selected orientation and strength, the handle member may be structured to provide selected degrees of strength, flexibility, and vibration transfer in an assembled bat. The present invention also contemplates producing a handle member of a thermoplastic material. In one embodiment, one of the juncture sections of the striking member or the juncture section of the handle member has projections thereon which extend radially from remainder portions of the juncture section a distance substantially equal to the thickness of a desired layer of adhesive to join the striking member and handle member. Such projections firmly engage the facing surface of the other member and this, in conjunction with the adhesive applied between the two members, provides a firm interconnection therebetween. This invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings described herein below, and wherein like reference numerals refer to like parts. | 20040428 | 20060829 | 20050106 | 58690.0 | 2 | GRAHAM, MARK S | BAT HAVING A FLEXIBLE HANDLE | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,833,914 | ACCEPTED | VOLTAGE REGULATOR | A voltage regulator, regulating a supply voltage and outputting a regulated voltage. The voltage regulator comprises a two stage OP which outputs a first voltage and a second voltage according to a reference voltage and a feedback voltage. A NMOS transistor controlled by a voltage detection unit, to receive the second voltage when the detected supply voltage is in a high mode. A PMOS transistor controlled by the voltage detection unit, to receive the first voltage when the detected supply voltage is in a low mode. A feedback circuit for receiving the regulated voltage and outputting the feedback voltage to the two stage OP. | 1. A voltage regulator, to regulate a supply voltage and output a regulated voltage, the voltage regulator comprises: a two stage OP, wherein a first voltage and a second voltage are output according to a reference voltage and a feedback voltage, when the feedback voltage is raised, the first voltage is raised, and the second voltage is decreased; a voltage detection unit for detecting the supply voltage; a first regulating unit controlled by the voltage detection unit, receiving the second voltage and operated for outputting the regulated voltage when the detected supply voltage is in a high mode, when the second voltage is lowered, the regulated voltage is also lowered; and a second regulating unit controlled by the voltage detection unit, receiving the first voltage and outputting the regulated voltage when the detected supply voltage is in a low mode, the first voltage is raised, the regulated voltage is lowered; and a feedback circuit, receiving the regulated voltage for outputting the feedback voltage. 2. The voltage regulator of claim 1, wherein the two stage OP comprises: a first stage amplifier, having a non-inverting terminal to receive the reference voltage, an inverting terminal to receive the feedback voltage, and an output terminal to output the first voltage; a second stage amplifier, coupled to the output terminal of the first stage amplifier, to output the second voltage which has a inverse polarity to the first voltage. 3. The voltage regulator of claim 2, wherein the first regulating unit comprises: a first switch; a second switch; an NMOS transistor comprising; a drain terminal coupled to the supply voltage; a gate terminal coupled to an output terminal of the second stage amplifier through the first switch and to a ground through the second switch; a source terminal coupled to an output of the voltage regulator; and the first switch is turned on and the second switch is turned off by the voltage detecting unit when the detected supply voltage is in the high mode, the first switch is turned off and the second switch is turned on by the voltage detecting unit when the detected supply voltage is in the low mode. 4. The voltage regulator of claim 2, wherein the second regulating unit comprises: a third switch; a fourth switch; a PMOS transistor comprising: a source terminal coupled to the supply voltage; a gate terminal coupled to the output of the first stage amplifier through a third switch and the source terminal through a fourth switch; and a drain terminal coupled to the output of the voltage regulator; and the third switch is turned on and the fourth switch is turned off by the voltage detection unit when the detected supply voltage is in the low mode, the third switch is turned off and the fourth switch is turned on by the voltage detection unit when the detected supply voltage is in the high mode. 5. The voltage regulator of claim 1, wherein the feedback circuit comprises: a first resistor, having a first terminal to receive the regulated voltage, a second terminal for outputting the feedback voltage; and a second resistor, having a first terminal coupled to the second terminal of the first resister, a second terminal coupled to a ground. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage regulator, and ore particularly, to a dual mode voltage regulator. 2. Description of the Related Art Generally, for stabilizing the voltage output to an internal circuit supplied by a supply voltage, a voltage regulator is set between a supply voltage and a load. FIG. 1 is a schematic circuit diagram showing a related circuit structure of a voltage regulator 1. The voltage regulator 1 has an OP 10 and a NMOS transistor 11. The disadvantage of the voltage regulator 1 with NMOS transistor 11 is that it requires a high supply voltage VDD. Another configuration of a voltage regulator 1′ is shown in FIG. 2. The voltage regulator 1′ has an OP 10 and a PMOS transistor 11′. Though it can be operated in low supply voltage VDD, the voltage regulator 1′ has stability problems and worse transient response. A large external compensation capacitor must be disposed at the output to determine start up delay time. When the regulator in Multi-Media Card applications, the regulator must be operated under dual voltage (e.g. 3.3 V and 1.8 V). Thus, it is more difficult to stabilize the supply voltage without use of an external capacitor. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a voltage regulator, cable of providing stable voltage in various supply voltages. In order to achieve the above object, the invention provides an voltage regulator, to regulate a supply voltage and output a regulated voltage. The voltage regulator comprises a two stage OP, a voltage detection unit, a first regulating unit, a second regulating unit, and a feedback circuit. Wherein a reference voltage and a feedback voltage are applied to the two stage OP to output a first voltage and a second voltage. When the feedback voltage is raised, the first voltage is raised, and the second voltage is lowered. The voltage detecting unit directs the first regulating unit to receive the second voltage and output the regulated voltage when the detected supply voltage is in a high mode. When the second voltage is lowered, the regulated voltage is also lowered. The voltage detecting unit directs the second regulating unit to receive the first voltage and output the regulated voltage when the detected supply voltage is in a low mode. When the first voltage is raised, the regulated voltage is lowered. The feedback circuit is coupled to the output of the regulated circuit to receive the regulated voltage and output the feedback voltage. A detailed description is given in the following with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: FIG. 1 is a schematic circuit diagram showing a conventional regulator; FIG. 2 is a schematic diagram showing another conventional regulator; FIG. 3 is a schematic circuit in accordance with the present invention; FIG. 4 is a schematic circuit of the regulated circuit operating in a high mode. FIG. 5 is a schematic circuit of the regulated circuit operating in a low mode. DETAILED DESCRIPTION OF THE INVENTION FIG. 3 is a schematic circuit diagram according to an embodiment of the invention. The voltage regulator 2 receives a supply voltage Vcc and outputs a regulated voltage VREG, the voltage regulator 2 includes a two stage OP 20, a first regulating unit 3, a second regulating unit 4, a feedback circuit 21 and a voltage detection unit 22. The two stage amplifier 20 has a first stage amplifier 200 with a gain=−A1 and a second stage amplifier 201 with a gain=−A2, wherein the first stage amplifier 200 has a non-inverting terminal to receive a reference voltage VBG, an inverting terminal to receive a feedback voltage, and an output terminal to output the first voltage. The second stage amplifier 201 is coupled to the output terminal of the first stage amplifier 200, to output a second voltage which has an inverse polarity to the first voltage. The first regulating unit 3 includes a NMOS transistor N1, a first switch S1 and a second switch S2. The NMOS transistor N1 comprises a drain terminal coupled to the supply voltage Vcc, a gate terminal coupled to the output of the second stage amplifier 201 through the first switch S1 and to a ground GND through the second switch S2. A source terminal of the NMOS transistor N1 is coupled to an output of the voltage regulator 2. The second regulating unit 4 includes a PMOS transistor P1, a third switch S3 and a fourth switch S4. The PMOS transistor P1 comprises a source terminal coupled to the supply voltage Vcc, a gate terminal coupled to the output of the first stage amplifier 200 through the third switch S3 and the source terminal through the fourth switch S4. A drain terminal of the PMOS P1 is coupled to the output of the voltage regulator. The feedback circuit 21 has a first resistor R1 and a second resistor R2. The first resistor R1 comprises a first terminal for receiving the regulated voltage VREG, a second terminal for outputting the feedback voltage. The second resistor R2 has a first terminal coupling to the second terminal of the first resistor R1, and a second terminal coupling to a ground GND. The voltage detection unit 22 is a multi-value voltage power on reset (POR) or a voltage detector (VDT). The voltage detecting unit 22 is coupled to the supply voltage Vcc to detect the supply voltage Vcc, and control the on/off of the four switches S1˜S4. Referring again to FIG. 3, When the voltage detection unit 22 detects the supply voltage Vcc in a high mode (ex:3.3V), the switches S1 and S4 are turned on by the voltage detection unit 22. NMOS N1 is turned on and the PMOS P1 is turned off. The voltage regulator 2 is operated in NMOS output stage as shown in FIG. 4. During operation, for example, if the regulator voltage VREG is pulled low in a short time, the feedback voltage is lowered, the first voltage is lowered and the second voltage applied to the gate terminal of NMOS N1 is raised. As is known in the art, an NMOS transistor acts as a source follower if its gate acts as input and its source acts as output. Furthermore, the voltage at the output of a source follower will “follow” the voltage at the input of the source follower. Hence, the source terminal of NMOS transistor N1 is raised and the regulated voltage VREG at the output of the regulator 2 is also raised (pulled high) until the regulated voltage VREG is approximately equal to the reference voltage VBG. Referring again to FIG. 3, When the voltage detection unit 22 detects the supply voltage Vcc in a low mode (ex:1.8 V ), the switches S2 and S3 are turned on by the voltage detection unit 22. NMOS N1 is turned off and the PMOS P1 is turned on. The voltage regulator 2 is operated in PMOS P1 output stage as illustrated in FIG. 5. During operation, for example, if the regulator voltage VREG is pulled low in a short time, the feedback voltage is lowered; and the first voltage applied to the gate terminal of PMOS P1 is also lowered. Current passing through source-drain terminal of PMOS transistor P1 is increased and the regulated voltage VREG at the output of the regulator 2 is also raised (pulled high) until the regulated voltage VREG is approximately equal to the reference voltage VBG. The present invention offers enhanced output performance in comparison with the related art. The voltage regulator is directed to operate in an NMOS mode or in a PMOS mode by the voltage detection unit detecting the voltage type. The regulator with PMOS output stage is bettered suited than a regulator with NMOS output stage in low mode power supply voltage. Regulators with NMOS output stage, however, provide higher driving speed than a regulator that with PMOS output stage in high mode power supply voltage. The proposed dual mode regulator can provide a nearly stable output voltage in power supplies with various voltages. While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments and the protection component is mot limited to the NMOS transistor. On the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation to encompass all such modifications and similar arrangements. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a voltage regulator, and ore particularly, to a dual mode voltage regulator. 2. Description of the Related Art Generally, for stabilizing the voltage output to an internal circuit supplied by a supply voltage, a voltage regulator is set between a supply voltage and a load. FIG. 1 is a schematic circuit diagram showing a related circuit structure of a voltage regulator 1 . The voltage regulator 1 has an OP 10 and a NMOS transistor 11 . The disadvantage of the voltage regulator 1 with NMOS transistor 11 is that it requires a high supply voltage V DD . Another configuration of a voltage regulator 1 ′ is shown in FIG. 2 . The voltage regulator 1 ′ has an OP 10 and a PMOS transistor 11 ′. Though it can be operated in low supply voltage V DD , the voltage regulator 1 ′ has stability problems and worse transient response. A large external compensation capacitor must be disposed at the output to determine start up delay time. When the regulator in Multi-Media Card applications, the regulator must be operated under dual voltage (e.g. 3.3 V and 1.8 V). Thus, it is more difficult to stabilize the supply voltage without use of an external capacitor. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, an object of the present invention is to provide a voltage regulator, cable of providing stable voltage in various supply voltages. In order to achieve the above object, the invention provides an voltage regulator, to regulate a supply voltage and output a regulated voltage. The voltage regulator comprises a two stage OP, a voltage detection unit, a first regulating unit, a second regulating unit, and a feedback circuit. Wherein a reference voltage and a feedback voltage are applied to the two stage OP to output a first voltage and a second voltage. When the feedback voltage is raised, the first voltage is raised, and the second voltage is lowered. The voltage detecting unit directs the first regulating unit to receive the second voltage and output the regulated voltage when the detected supply voltage is in a high mode. When the second voltage is lowered, the regulated voltage is also lowered. The voltage detecting unit directs the second regulating unit to receive the first voltage and output the regulated voltage when the detected supply voltage is in a low mode. When the first voltage is raised, the regulated voltage is lowered. The feedback circuit is coupled to the output of the regulated circuit to receive the regulated voltage and output the feedback voltage. A detailed description is given in the following with reference to the accompanying drawings. | 20040428 | 20051227 | 20051103 | 63905.0 | 0 | LAXTON, GARY L | VOLTAGE REGULATOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,833,991 | ACCEPTED | Implementation of protection layer for bond pad protection | A method of protecting a bond pad during die-sawing comprising the following steps. A substrate having a bond pad formed thereover is provided. A bond pad protection layer is formed over the bond pad. The substrate is die-sawed and the bond pad protection layer is removed by heating. | 1. A method of protecting a bond pad during die-sawing, comprising the steps of: providing a substrate having a bond pad formed thereover; forming a bond pad protection layer over the bond pad; die-sawing the substrate; and removing the bond pad protection layer by heating. 2. The method of claim 1, wherein the substrate is a wafer. 3. The method of claim 1, wherein the substrate is comprised of silicon or germanium. 4. The method of claim 1, wherein the bond pad is comprised of copper or aluminum. 5. The method of claim 1, wherein the bond pad is comprised of aluminum. 6. The method of claim 1, wherein the bond pad protection layer is comprised of an organic material. 7. The method of claim 1, wherein the bond pad protection layer is comprised of benzitriazoles or benzimidazoles. 8. The method of claim 1, wherein the bond pad protection layer is comprised of benzimidazoles. 9. The method of claim 1, wherein the bond pad protection layer is formed by a curtain-print method, a spread method or spin-coat method. 10. The method of claim 1, wherein the bond pad protection layer is formed by a spin coat method. 11. The method of claim 1, wherein the bond pad protection layer has a thickness of from about 1000 to 50,000 Å. 12. The method of claim 1, wherein the bond pad protection layer has a thickness of from about 10,000 to 20,000 Å. 13. The method of claim 1, wherein the bond pad protection layer is volatile at a temperature about 175° C. 14. The method of claim 1, including the subsequent step of die mounting the substrate wherein the bond pad protection layer is vaporized during the die mounting. 15. The method of claim 1, including the step of forming a patterned passivation layer over the substrate and the bond pad before formation of the bond pad protection layer; the patterned passivation layer including an opening exposing a portion of the bond pad. 16. A method of protecting a bond pad during die-sawing, comprising the steps of: providing a substrate having a bond pad formed thereover; the bond pad having a probe mark; forming a bond pad protection layer over the bond pad and the probe mark; and die-sawing the substrate, whereby the bond pad protection layer retards enlargement of the probe mark during the die-sawing. 17. The method of claim 16, wherein the substrate is a wafer. 18. The method of claim 16, wherein the substrate is comprised of silicon or germanium. 19. The method of claim 16, wherein the bond pad is comprised of copper or aluminum. 20. The method of claim 16, wherein the bond pad is comprised of aluminum. 21. The method of claim 16, wherein the bond pad protection layer is comprised of an organic material. 22. The method of claim 16, wherein the bond pad protection layer is comprised of benzitriazoles or benzimidazoles. 23. The method of claim 16, wherein the bond pad protection layer is comprised of benzimidazoles. 24. The method of claim 16, wherein the bond pad protection layer is formed by a curtain-print method, a spread method or spin-coat method. 25. The method of claim 16, wherein the bond pad protection layer is formed by a spin coat method. 26. The method of claim 16, wherein the bond pad protection layer has a thickness of from about 1000 to 50,000 Å. 27. The method of claim 16, wherein the bond pad protection layer has a thickness of from about 10,000 to 20,000 Å. 28. The method of claim 16, wherein the bond pad protection layer is volatile at a temperature about 175° C. 29. The method of claim 16, including the subsequent step of die mounting the substrate wherein the bond pad protection layer is vaporized during the die mounting. 30. The method of claim 16, including the step of forming a patterned passivation layer over the substrate and the bond pad before formation of the bond pad protection layer; the patterned passivation layer including an opening exposing a portion of the bond pad. 31. The method of claim 16, wherein the probe mark is formed by attaching a probe to the bond pad. 32. The method of claim 16, whereby the bond pad protection layer prevents any enlargement of the probe mark during the die-sawing. 33. The method of claim 16, including the subsequent step of removing the bond pad protection layer by heating. 34. A bond pad structure, comprising: a substrate having a bond pad formed thereover; and an organic bond pad protection layer over the bond pad. 35. The structure of claim 34, wherein the substrate is a wafer. 36. The structure of claim 34, wherein the substrate is comprised of silicon or germanium. 37. The structure of claim 34, wherein the bond pad is comprised of copper or aluminum. 38. The structure of claim 34, wherein the bond pad is comprised of aluminum. 39. The structure of claim 34, wherein the bond pad protection layer is comprised of benzitriazoles or benzimidazoles. 40. The structure of claim 34, wherein the bond pad protection layer is comprised of benzimidazoles. 41. The structure of claim 34, wherein the bond pad protection layer is formed by a curtain-print method, a spread method or spin-coat method. 42. The method of claim 34, wherein the bond pad protection layer is formed by a spin coat method. 43. The structure of claim 34, wherein the bond pad protection layer has a thickness of from about 1000 to 50,000 Å. 44. The structure of claim 34, wherein the bond pad protection layer has a thickness of from about 10,000 to 20,000 Å. 45. The structure of claim 34, wherein the bond pad protection layer is volatile at a temperature about 175° C. 46. The structure of claim 34, including a patterned passivation layer between the bond pad; and the bond pad protection layer; the patterned passivation layer including an opening exposing a portion of the bond pad. | BACKGROUND OF THE INVENTION A probe mark is left on bond pads after chip probe (CP) sorting. This probe mark will be enlarged during the integrated circuit (IC) assembly wafer die-sawing due to a so-called “Galvanic effect,” i.e. an electrochemical reaction on the bond pad during the die-sawing. This may: expose the bond pad under-layer which has a great impact on the subsequent wire bonding process; degrade the wire bond integrity; and lead to assembly yield loss. This probe mark enlargement is especially so and more serious for the larger 12-inch wafers since longer die-sawing is required for the larger area of the 12 inch-wafer. To minimize this exacerbated problem for the larger 12-inch wafers conventionally, attempts are made to shorten the 12-inch wafer die-saw process time although sometimes this is not possible. U.S. Pat. No. 6,335,224 B1 to Peterson et al. discloses protection of microelectronic devices during packaging. U.S. Pat. No. 6,297,561 B1 to Liu et al. discloses a semiconductor chip. U.S. Pat. No. 6,251,694 B1 to Liu et al. discloses a method of testing and packaging a semiconductor chip. SUMMARY OF THE INVENTION Accordingly, it is an object of one or more embodiments of the present invention to provide a method of protecting bond pads during die-sawing. Other objects will appear hereinafter. It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, substrate having a bond pad formed thereover is provided. A bond pad protection layer is formed over the bond pad. The substrate is die-sawed and the bond pad protection layer is removed by heating. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate similar or corresponding elements, regions and portions and in which: FIGS. 1 to 5 schematically illustrate a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Information Known to the Inventors—Not to be Considered Prior Art The following is information known to the inventors and is not to necessarily be considered prior art for the purposes of the present invention. Re the Galvanic effect, in the presence of a suitable electrolyte (moisture), corrosion will occur (Al2Cu as the cathode, Al an the anode). The corrosion of aluminum proceeds around the Al2Cu particles leading to the formation of pits until the Al2Cu particles become electrically isolated from the surrounding metal: 2Al+3Cu2+→2Al3++3Cu As the wafer is continually dipped in deionized water (DI), this galvanic cell reaction would continue to proceed. Eventually dredging the base of copper (Cu) nucleus and leave a hole in the pads. Initial Structure—FIG. 1 As shown in FIG. 1, a structure 10 has an uppermost conductive portion 12 formed thereover that is electrically connected to a bond pad 18 by conductive via structures 14 within a dielectric layer 16. A patterned passivation layer 20 is formed over the dielectric layer 16 and over the bond pad 18. Patterned passivation layer 20 includes an opening 21, exposing a portion of bond pad 18. Structure 10 is preferably a silicon or germanium substrate and is understood to possibly include a semiconductor wafer or substrate, active and passive devices formed within the wafer, conductive layers and dielectric layers (e.g., inter-poly oxide (IPO), intermetal dielectric (IMD), etc.) formed over the wafer surface. The term “semiconductor structure” is meant to include devices formed within a semiconductor wafer and the layers overlying the wafer. Uppermost conductive portion 12 is preferably comprised of copper, aluminum, or an aluminum-copper alloy and is more preferably aluminum. Conductive via structures 14 are preferably comprised of copper or tungsten (W) and is more preferably tungsten. Bond pad 18 is preferably comprised of copper or aluminum and is more preferably aluminum and has a thickness of preferably from about 0.5 to 2.0 μm. Dielectric layer 16 is preferably comprised of silicon oxide. Passivation layer 20 is preferably comprised of silicon oxide or silicon nitride and is more preferably silicon nitride. Passivation layer opening 21 has a base width of preferably from about 40 to 100 μm and more preferably from about 40 to 60 μm. Probe 22 Positioning for Chip Probe Sorting—FIG. 2 As shown in FIG. 2, a probe 22 is positioned onto a portion of the bond pad 18 for chip probe sorting. After chip probe sorting, the bond pad 18 has a probe mark 24 formed on the upper portion of the bond pad 18 that is generally caused by the probe tip scratching the pad surface. Probe Mark 24—FIG. 3 As shown in FIG. 3, probe 22 is removed after chip probe sorting leaving probe mark 24 which removes a portion of the bond pad 18 but does not expose the underlying conductive via structures 14 or the uppermost conductive portion 12. Formation of Bond Pad Protection Layer 26—FIG. 4 As shown in FIG. 4, the inventors have discovered that by forming an bond pad protection layer 26 over the probe marked bond pad 18′ and the passivation layer 20, the probe mark 24 will not be enlarged due to the subsequent IC assembly die-sawing by the “Galvanic effect” (see above). The bond pad protection layer 26 is preferably comprised of an organic material (as will be used for illustrative purposes hereafter) and insulates the surface of the probe marked bond pad 18′ and thus prevents the otherwise “Galvanic effect” enlargement of the probe mark 24. The bond protection layer 26 is preferably organic so that it vaporizes upon heating (see below). Organic bond pad protection layer 26 is preferably applied by a curtain-print, spread or spin-coat method and more preferably by a spin coat method. Organic bond pad protection layer 26 is formed to a thickness of preferably from about 1000 to 50,000 Å and more preferably from about 10,000 to 20,000 Å and is preferably comprised of benzitriazoles or benzimidazoles and is more preferably benzimidazoles. Post IC Assembly Wafer Die-Sawing—FIG. 5 FIG. 5 illustrates the structure of FIG. 4 after IC assembly wafer die-sawing and demonstrates that the probe mark 24 is not enlarged in the probe marked bond pad 18′. The organic bond pad protection layer 26 will be vaporized during the subsequent die mount and epoxy cure process (high temperature, i.e. a temperature greater than about 175° C.) so that the wire bond process and wire bond integrity will not be impacted. Moreover, the assembly yield loss due to the probe mark 24 can be resolved and minimized. While particular embodiments of the present invention have been illustrated and described, it is not intended to limit the invention, except as defined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>A probe mark is left on bond pads after chip probe (CP) sorting. This probe mark will be enlarged during the integrated circuit (IC) assembly wafer die-sawing due to a so-called “Galvanic effect,” i.e. an electrochemical reaction on the bond pad during the die-sawing. This may: expose the bond pad under-layer which has a great impact on the subsequent wire bonding process; degrade the wire bond integrity; and lead to assembly yield loss. This probe mark enlargement is especially so and more serious for the larger 12-inch wafers since longer die-sawing is required for the larger area of the 12 inch-wafer. To minimize this exacerbated problem for the larger 12-inch wafers conventionally, attempts are made to shorten the 12-inch wafer die-saw process time although sometimes this is not possible. U.S. Pat. No. 6,335,224 B1 to Peterson et al. discloses protection of microelectronic devices during packaging. U.S. Pat. No. 6,297,561 B1 to Liu et al. discloses a semiconductor chip. U.S. Pat. No. 6,251,694 B1 to Liu et al. discloses a method of testing and packaging a semiconductor chip. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of one or more embodiments of the present invention to provide a method of protecting bond pads during die-sawing. Other objects will appear hereinafter. It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, substrate having a bond pad formed thereover is provided. A bond pad protection layer is formed over the bond pad. The substrate is die-sawed and the bond pad protection layer is removed by heating. | 20040428 | 20060912 | 20051103 | 60221.0 | 0 | THAI, LUAN C | IMPLEMENTATION OF PROTECTION LAYER FOR BOND PAD PROTECTION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,834,220 | ACCEPTED | Manhole cover | The present invention a manhole cover includes a cylindrical manhole including manhole lugs, wherein the manhole lugs extend around the upper outer periphery of the manhole; the cover includes cover lugs, the cover lugs extend around the outer periphery of the cover. The cover co-operatively mates with and closes off the manhole. A strap also extends around the cover and manhole lugs such that applying tension to the strap assembly forceably urges together the cover and manhole lugs wherein said strap for clamping together the manhole lugs to the cover lugs thereby placing cover into a sealed position. | 1. A manhole cover comprising: (a) a cylindrical manhole including manhole lugs, wherein said manhole lugs extending around the upper outer periphery of said manhole; (b) a cover including cover lugs, said cover lugs extending around the outer periphery of said cover, said cover for co-operatively mating with and closing off said manhole; (c) a means for clamping together said manhole lugs to said cover lugs thereby placing cover into a sealed position. 2. The manhole cover claimed in claim 1, wherein said clamping means including a strap which extends around said cover and manhole lugs such that applying tension to said strap forceably urges together said cover and manhole lugs thereby placing cover into a sealed position. 3. The manhole cover claimed in claim 1, wherein said clamping means including a strap assembly having a left and right strap, each strap pivotally connected at one end to a hinge means for pivotally connecting said left and right strap, and each strap connected at the other end to a tightening means for applying tension to said straps for forceably urging together said cover and manhole lugs thereby placing cover into a sealed position and straps in a locked position, and by releasing said tightening means for releasing tension on said straps such that they can pivot freely away from each other into an unlocked position. 4. The manhole cover claimed in claim 3, wherein said hinge means including a strap hinge pin operatively connected to each strap for pivotally connecting said straps. 5. The manhole cover claimed in claim 3, wherein said hinge means includes a strap hinge assembly including a left hinge bracket attached to one end of said left strap, and a right hinge bracket attached to one end of said right strap, and further including a strap hinge pin pivotally connecting said hinge brackets. 6. The manhole cover claimed in claim 3, wherein said tightening means including a bolt and nut operatively connected to said straps for applying tension to said straps when said nut is tightened onto said bolt. 7. The manhole cover claimed in claim 3, wherein said tightening means including a bolt bracket assembly including a bolt left bracket attached to said left strap and a bolt right bracket attached to said right strap and a bolt and nut for applying tension to said straps when said nut is tightened onto said bolt. 8. The manhole cover claimed in claim 7, wherein said bolt left bracket including a T bolt saddle for receiving a T bolt therein. 9. The manhole cover claimed in claim 3 wherein said cover lugs and manhole lug each including a chamfered surface corresponding to a V shaped strap chamfered portion such that applying tension to said straps imparts compressive forces urging together said cover and manhole lugs. 10. The manhole cover claimed in claim 1, further including a pivoting means for pivoting of said cover between a sealed position and an open position. 11. The manhole cover claimed in claim 10, wherein said pivoting means including a cover hinge pin operably pivotally connecting said cover to said manhole. 12. The manhole cover claimed in claim 10, wherein said pivoting means including a cover hinge flange connected t6 said cover and at least one cover hinge bracket connected to said manhole, and a cover hinge pin operably pivotally connecting said cover hinge flange to said hinge brackets. 13. The manhole cover claimed in claim 4, further including a means for longitudinally sliding said clamping means away from said manhole when said straps in said unlocked position. 14. The manhole cover claimed in claim 13, wherein said sliding means including a slot defined in a spacer plate which is attached to said manhole such that said hinge pin is slidably received within said longitudinally oriented slot thereby allowing said clamping means to be moved longitudinally to a cleared position. 15. The manhole cover claimed in claim 14, wherein said slot oriented such that when said clamping means urged longitudinally backwards along said slot said straps clear said manhole and cover lugs to a cleared position, permitting said cover to be pivoted to an open position. | FIELD OF THE INVENTION The present invention relates to manhole covers for pressure vessels and in particular relates to a manhole cover for a railway car pressure vessel. BACKGROUND OF THE INVENTION Currently manhole covers on railway pressure vessels are large, heavy steel plate circular covers which are bolted down with six to eight large eye bolts. The eye bolts that are used are a source of maintenance in that the bolts often break, the threads wearing, the nuts seize. In addition the installation and removal of the cover with the eye bolts is labour intensive, requiring a substantial amount of time in order to open and close the existing manhole covers. Furthermore, the eye bolts securing the man whole cover are normally standing straight up with the threads exposed to the impact from tools, loading equipment and possible contact with the ground and other obstacles in the event of derailment of the rail car should the vessel overturn. Leaking of the pressure vessel can occur when an eye bolt is damaged or missing or the cover is incorrectly tightened or when the cover is permanently deformed from over tightening. All of the above deficiencies in the existing manhole cover designs are the leading cause of commodity leaks in the north American rail car fleet. Therefore, there is a need for a new and improved manhole cover locking system which overcomes the deficiencies of the current manhole cover designs and in particularly eliminates the need for six to eight large eye bolts which are positioned vertically upward from the cover. SUMMARY OF THE INVENTION A manhole cover comprising: (a) a manhole including manhole lugs; (b) a cover including cover lugs, said cover co-operatively mating with said manhole; (c) a strap means for clamping together said manhole lugs and cover lugs, by applying tension to said strap means. Preferably wherein said clamping means including a strap which extends around said cover and manhole lugs such that applying tension to said strap forceably urges together said cover and manhole lugs thereby placing cover into a sealed position. Preferably wherein said clamping means including a strap assembly having a left and right strap, each strap pivotally connected at one end to a hinge means for pivotally connecting said left and right strap, and each strap connected at the other end to a tightening means for applying tension to said straps for forceably urging together said cover and manhole lugs thereby placing cover into a sealed position and straps in a locked position, and by releasing said tightening means for releasing tension on said straps such that they can pivot freely away from each other into an unlocked position. Preferably wherein said hinge means including a strap hinge pin operatively connected to each strap for pivotally connecting said straps. Preferably wherein said hinge means includes a strap hinge assembly including a left hinge bracket attached to one end of said left strap, and a right hinge bracket attached to one end of said right strap, and further including a strap hinge pin pivotally connecting said hinge brackets. Preferably wherein said tightening means including a bolt and nut operatively connected to said straps for applying tension to said straps when said nut is tightened onto said bolt. Preferably wherein said tightening means including a bolt bracket assembly including a bolt left bracket attached to said left strap and a bolt right bracket attached to said right strap and a bolt and nut for applying tension to said straps when said nut is tightened onto said bolt. Preferably, wherein said bolt left bracket including a T bolt saddle for receiving a T bolt therein. Preferably wherein said cover lugs and manhole lug each including a chamfered surface corresponding to a V shaped strap chamfered portion such that applying tension to said straps imparts compressive forces urging together said cover and manhole lugs. Preferably further including a pivoting means for pivoting of said cover between a sealed position and an open position. Preferably wherein said pivoting means including a cover hinge pin operably pivotally connecting said cover to said manhole. Preferably wherein said pivoting means including a cover hinge flange connected to said cover and at least one cover hinge bracket connected to said manhole, and a cover hinge pin operably pivotally connecting said cover hinge flange to said hinge brackets. Preferably further including a means for longitudinally sliding said clamping means away from said manhole when said straps in said unlocked position. Preferably wherein said sliding means including a slot defined in a spacer plate which is attached to said manhole such that said hinge pin is slidably received within said longitudinally oriented slot thereby allowing said clamping means to be moved longitudinally to a cleared position. Preferably wherein said slot oriented such that when said clamping means urged longitudinally backwards along said slot said straps clear said manhole and cover lugs to a cleared position, permitting said cover to be pivoted to an open position. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only with reference to the following drawings in which: FIG. 1 is a left side, side elevational view of the manhole cover shown in FIG. 2. FIG. 2 is a top plan view of the manhole cover. FIG. 3 is a right side, side elevational view of the manhole covers shown in FIG. 2. FIG. 4 is a front side, side elevational view of the manhole cover shown in FIG. 2. FIG. 5 is a cross sectional schematic view of the manhole cover fastened down to a manhole. FIG. 6 is a top plan schematic view of the locking strap together with the hinge assembly as well as the bolt bracket assembly wherein the strap is shown in an open position in dashed lines and in the closed position in solid lines. FIG. 7 is a side elevational view of the locking strap shown in FIG. 6. FIG. 8 is a cross sectional view of the locking strap taken along the lines 8-8 of FIG. 6. FIG. 9 is a top schematic perspective view of the locking strap together with the strap hinge assembly and the bolt bracket assembly. FIG. 10 is an exploded schematic assembly view of the manhole together with portions of the cover hinge assembly, the cover plate handle and handle flange. FIG. 11 is a top schematic perspective view of the manhole cover in its assembled condition showing the strap in the locked position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention, a manhole cover shown generally as 20 includes the following major components namely, cover plate 22, strap assembly 24, cover hinge assembly 26 bolt bracket assembly 46 and manhole walls 28. Manhole walls 28 includes manhole lugs 30 extending around the upper outer periphery 53 of manhole 93, and having a manhole chamfered surface 32 for engaging with strap assembly 24. Cover plate 22 includes cover lug 34 extending around an outer periphery 53 of cover plate 22, having a cover chamfered surface 36 for engaging with strap assembly 24. Referring now particularly to FIG. 9 showing strap assembly 24, includes a right strap 40, a left strap 42, a strap hinge assembly 44 and a bolt bracket assembly 46. Right strap 40 and left strap 42 are hingeably connected at one end with strap hinge assembly 44 which includes a right hinge bracket 48, a left hinge bracket 50 and a strap hinge pin 52. Right strap 40 and left strap 42 are rigidly connected to right hinge bracket 48 and left hinge bracket 50 respectively in any manner known in the art including welding, rivetting, bolting etc. Strap assemble 24 can be tightened together with bolt bracket assembly 46 which includes bolt left bracket 54, bolt right bracket 56, T-bolt 60, bolt nut 58, and sleeve 62. Referring to FIGS. 6, 7 and 8, right strap 40 and left strap 42 include a vertical strap portion 64 and an upper and lower chamfered portion 66 creating V shaped chamfered. surfaces. Referring now to FIG. 10 which shows the details of cover hinge assembly 26. Cover hinge assembly 26 includes two cover hinge brackets 70, separated by spacer plate 71, a cover hinge 72 and a cover hinge flange 74 which is rigidly connected at one end to cover plate 22. The other end of cover plate 22 includes a handle flange 80 having a handle 82 mounted rigidly thereon. Spacer plate 71 also includes a slot 84 for receiving strap hinge pin 52 there through, such that strap hinge pin 52 can slideably move along slot 84 when opening and closing strap assembly 24, thereby allowing the opening and closure of cover plate 22 of manhole cover 20. Further referring now to FIG. 5, manhole cover 20 includes a cover gasket 90 which fits in between manhole walls 28 and cover plate 22, therefore providing an air and liquid tight seal once cover plate 22 is securely fastened down onto manhole walls 28. Gasket 90 seals onto sealing surface 51 of manhole walls 28. In Use Manhole cover 20 is used as follows: Manhole cover 20 is shown in FIGS. 1 through 5 and also in FIG. 11 is shown in the closed position or sealed position 57. In FIG. 5 for example, cover plate 22 is shown seated against manhole walls 28 and sealed with a cover gasket 90. Sealing between cover plate 22 and manhole wall 28 is accomplished with either a hard gasket and/or an elastomeric gasket which fits in gasket groove 91 defined in cover plate 22. Other sealing means can be used as known in the art. Closing Manhole Cover In order to close manhole cover 20, onto manhole 93, cover plate 22 is rotated about cover hinge pin 72 until it makes contact with the top of manhole walls 28. Lying between cover plate 22 and manhole walls 28 is a cover gasket 90 fitted within a gasket groove 91 and is adapted to be retained within gasket groove 91 upon opening of cover plate 22. Cover plate 22 has a cover hinge flange 74, rigidly connected to cover plate 22 at one end and is hinged onto cover hinge brackets 70, via cover hinge pin 72. On the other end of cover plate 22 is a handle flange 80 which is rigidly connected to cover plate 22, having a handle 82 mounted thereon. Urging handle 82 upwardly, one can open cover plate 22 removing it from manhole wall 28 and by pivoting cover plate 22 about cover hinge pin 72. One can lower cover plate 22 onto manhole wall 28, thereby creating a seal with cover gasket 90 between cover plate 22 and manhole 93. Once cover plate 22 is in the closed or sealed position 57 as shown in FIG. 5, a strap assembly 24 is mounted in position around manhole lugs 30 as well as cover lugs 34. Strap assembly 24 is best shown in FIG. 9, and includes a right strap 40 and left strap 42 which are hingeably connected at strap hinge assembly 44 which includes a left hinge bracket 50 and right hinge bracket 48, such that the left and right straps 42 and 40 respectively pivot about strap hinge pin 52. Referring now specifically to FIGS. 6, 7 and 8, one will see that right strap 40 and left strap 42 have a vertical strap portion 64 and two chamfered strap portions 66. The chamfered portions 66 register and co-operatively make contact with chamfered surface 32 and cover camfered surface 36. This modified V configuration allows one to forceably compress cover plate 22 onto manhole walls 28 by constricting right strap 40 and left strap 42 around the outer circumference of cover lugs 34 and manhole lugs 30. On the end distal from strap hinge assembly 44 is a bolt bracket assembly 46 which includes a bolt right bracket 56 for right strap 40 and bolt left bracket 54 for left strap 42. Bolt left bracket 54 also defines a T bolt saddle 97 which receives T bolt 60 and bolt right bracket 56 receives bolt nut 58 and a sleeve 62 wherein sleeve 62 covers over any exposed threads of T bolt 60. T bolt 60 preferably has acme threads defined thereon which cooperatively engage with bolt nut 58. Any excessive length of T bolt 60 is covered with a sleeve 62, thereby protecting any exposed threads from damage. Tightening bolt nut 58, forceably urges bolt left bracket 54 together with bolt right bracket 56, thereby imparting constrictive forces on right strap 40 and left strap 42, thereby forceably urging cover plate 22 onto cover gasket 90 which applies increasing pressure onto manhole walls 28, thereby providing a fluid proof seal. In this manner by simply tightening one bolt, namely bolt nut 58, the entire closing and sealing mechanism is accomplished. Opening Cover Plate 22 In order to open cover plate 22, from the locked position 81 shown in dark lines in FIG. 6 the reverse procedure of the above described is carried out. Firstly, bolt nut 58 is loosened off, thereby loosening the tension in right strap 40 and left strap 42. Right strap 40 and left strap 42 pivot away from each other about strap hinge pin 52. When bolt nut 58 is eased off far enough, it is possible to dislodge T bolt 60 from T bolt saddle 97 which is defined in bolt left bracket 54. As shown in FIG. 6, T bolt 60 is dislodged from T bolt saddle 97 allowing further pivoting of right strap 40 from left strap 42 to the position as shown in dotted lines in FIG. 6 which is the unlocked position 83. Further to ensure that right strap 40 and left strap 42 completely clear manhole lugs 30 and cover lugs 34, one can then forceably urge the entire strap assembly 24 rearwardly towards cover hinge assembly 26 by slideably urging strap hinge pin 52 longitudinally backwards along slot 84 along longitudinal direction 77 to a cleared position not shown. Once right strap 40 and left strap 42 have cleared manhole lugs 30 and cover lugs 34 completely, it is possible to hingeable lift cover plate 22 about cover hinge pin 72, thereby pivoting manhole cover 20 from the sealed position 57 to an open position not shown. It should be apparent to persons skilled in the arts that various modifications and adaptation ofthis structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim. | <SOH> BACKGROUND OF THE INVENTION <EOH>Currently manhole covers on railway pressure vessels are large, heavy steel plate circular covers which are bolted down with six to eight large eye bolts. The eye bolts that are used are a source of maintenance in that the bolts often break, the threads wearing, the nuts seize. In addition the installation and removal of the cover with the eye bolts is labour intensive, requiring a substantial amount of time in order to open and close the existing manhole covers. Furthermore, the eye bolts securing the man whole cover are normally standing straight up with the threads exposed to the impact from tools, loading equipment and possible contact with the ground and other obstacles in the event of derailment of the rail car should the vessel overturn. Leaking of the pressure vessel can occur when an eye bolt is damaged or missing or the cover is incorrectly tightened or when the cover is permanently deformed from over tightening. All of the above deficiencies in the existing manhole cover designs are the leading cause of commodity leaks in the north American rail car fleet. Therefore, there is a need for a new and improved manhole cover locking system which overcomes the deficiencies of the current manhole cover designs and in particularly eliminates the need for six to eight large eye bolts which are positioned vertically upward from the cover. | <SOH> SUMMARY OF THE INVENTION <EOH>A manhole cover comprising: (a) a manhole including manhole lugs; (b) a cover including cover lugs, said cover co-operatively mating with said manhole; (c) a strap means for clamping together said manhole lugs and cover lugs, by applying tension to said strap means. Preferably wherein said clamping means including a strap which extends around said cover and manhole lugs such that applying tension to said strap forceably urges together said cover and manhole lugs thereby placing cover into a sealed position. Preferably wherein said clamping means including a strap assembly having a left and right strap, each strap pivotally connected at one end to a hinge means for pivotally connecting said left and right strap, and each strap connected at the other end to a tightening means for applying tension to said straps for forceably urging together said cover and manhole lugs thereby placing cover into a sealed position and straps in a locked position, and by releasing said tightening means for releasing tension on said straps such that they can pivot freely away from each other into an unlocked position. Preferably wherein said hinge means including a strap hinge pin operatively connected to each strap for pivotally connecting said straps. Preferably wherein said hinge means includes a strap hinge assembly including a left hinge bracket attached to one end of said left strap, and a right hinge bracket attached to one end of said right strap, and further including a strap hinge pin pivotally connecting said hinge brackets. Preferably wherein said tightening means including a bolt and nut operatively connected to said straps for applying tension to said straps when said nut is tightened onto said bolt. Preferably wherein said tightening means including a bolt bracket assembly including a bolt left bracket attached to said left strap and a bolt right bracket attached to said right strap and a bolt and nut for applying tension to said straps when said nut is tightened onto said bolt. Preferably, wherein said bolt left bracket including a T bolt saddle for receiving a T bolt therein. Preferably wherein said cover lugs and manhole lug each including a chamfered surface corresponding to a V shaped strap chamfered portion such that applying tension to said straps imparts compressive forces urging together said cover and manhole lugs. Preferably further including a pivoting means for pivoting of said cover between a sealed position and an open position. Preferably wherein said pivoting means including a cover hinge pin operably pivotally connecting said cover to said manhole. Preferably wherein said pivoting means including a cover hinge flange connected to said cover and at least one cover hinge bracket connected to said manhole, and a cover hinge pin operably pivotally connecting said cover hinge flange to said hinge brackets. Preferably further including a means for longitudinally sliding said clamping means away from said manhole when said straps in said unlocked position. Preferably wherein said sliding means including a slot defined in a spacer plate which is attached to said manhole such that said hinge pin is slidably received within said longitudinally oriented slot thereby allowing said clamping means to be moved longitudinally to a cleared position. Preferably wherein said slot oriented such that when said clamping means urged longitudinally backwards along said slot said straps clear said manhole and cover lugs to a cleared position, permitting said cover to be pivoted to an open position. | 20040429 | 20060912 | 20051103 | 98298.0 | 0 | ADDIE, RAYMOND W | MANHOLE COVER | SMALL | 0 | ACCEPTED | 2,004 |
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10,834,270 | ACCEPTED | Dye composition comprising 2-chloro-6-methyl-3-aminophenol, at least two oxidation bases chosen from para-phenylenediamine derivatives and at least one associative thickening polymer | The present disclosure relates to a composition for oxidation dyeing keratin fibers, for instance, human keratin fibers such as the hair, comprising 2-chloro-6-methyl-3-aminophenol as a coupler, para-phenylenediamine or para-tolylenediamine as at least one first oxidation base, N,N-bis(β-hydroxyethyl)-para-phenylenediamine or 2-(β-hydroxyethyl)-para-phenylenediamine as at least one second oxidation base, and at least one associative thickening polymer. The present disclosure also relates to a multi-compartment device or kit for the oxidation dyeing of keratin fibers comprising the compositions disclosed herein, and to the dyeing process using these compositions. | 1. A composition for oxidation dyeing of keratin fibers, comprising, in a medium that is suitable for dyeing: at least one coupler chosen from 2-chloro-6-methyl-3-aminophenol and the addition salts thereof; at least one first oxidation base chosen from para-phenylenediamine, para-tolylenediamine, and the addition salts thereof; at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof; and at least one associative thickening polymer. 2. The composition according to claim 1, wherein the at least one associative thickening polymer comprises hydrophilic regions and hydrophobic regions that comprise at least one C8-C30 fatty chain. 3. The composition according to claim 1, wherein the at least one associative polymer is obtained by grafting a compound comprising at least one C8-C30 fatty chain onto a polymer, by free-radical polymerization starting with at least one monomer, at least one of which comprises a C8-C30 fatty chain, or by polycondensation starting with at least one monomer, at least one of which comprises a C8-C30 fatty chain. 4. The composition according to claim 1, wherein the at least one associative thickening polymer is chosen from anionic, cationic, amphoteric, and nonionic associative thickening polymers. 5. The composition according to claim 4, wherein at least one of the associative thickening polymers is anionic. 6. The composition according to claim 5, wherein the at least one anionic associative polymer comprises at least one hydrophilic unit chosen from olefinic unsaturated carboxylic acids, and at least one hydrophobic unit chosen from (C10-C30)alkyl esters of unsaturated carboxylic acids. 7. The composition according to claim 5, wherein the at least one anionic associative polymer comprises acrylic acid, an acrylic or methacrylic acid (C12-C22)alkyl ester, and a crosslinking agent. 8. The composition according to claim 7, wherein the at least one anionic associative polymer comprises from 60% to 95% by weight of acrylic acid, from 4% to 40% by weight of a C10-C30 alkyl acrylate, and from 0% to 6% by weight of a copolymerizable polyethylenic unsaturated monomer, relative to the total weight of the anionic associative polymer. 9. The composition according to claim 7, wherein the at least one anionic associative polymer comprises from 96% to 98% by weight of acrylic acid, from 1% to 4% by weight of a C10-C30 alkyl acrylate and from 0.1% to 0.6% by weight of crosslinking polymerizable monomer, relative to the total weight of the anionic associative polymer. 10. The composition according to claim 5, wherein the at least one anionic associative polymer is chosen from polyurethanes. 11. The composition according to claim 4, wherein at least one of the associative polymers is cationic. 12. The composition according to claim 11, wherein the at least one cationic associative polymer is chosen from quaternized cellulose derivatives. 13. The composition according to claim 12, wherein the quaternized cellulose derivatives are chosen from quaternized hydroxyethylcelluloses modified with groups comprising at least one fatty chain. 14. The composition according to claim 13, wherein the at least one fatty chain of the hydroxyethylcelluloses is chosen from alkyl radicals comprising from 8 to 30 carbon atoms. 15. The composition according to claim 11, wherein the at least one cationic associative polymer is chosen from polyurethanes. 16. The composition according to claim 4, wherein at least one of the associative polymers is nonionic and chosen from polyurethane polyethers. 17. The composition according to claim 16, wherein the polyurethane polyethers are polycondensates of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of stearyl alcohol and of at least one diisocyanate. 18. The composition according to claim 17, wherein the polyurethane polyethers are polycondensates of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of stearyl alcohol and of methylenebis(4-cyclohexyl isocyanate) (SMDI), at a concentration of 15% by weight in a matrix of 4% maltodextrin and 81% water. 19. The composition according to claim 16, wherein the polyurethane polyethers are polycondensates of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of decyl alcohol and of at least one diisocyanate. 20. The composition according to claim 19, wherein the polyurethane polyethers are polycondensates of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of decyl alcohol and of methylenebis(4-cyclohexyl isocyanate) (SMDI), at a concentration of 35% by weight in a mixture of 39% propylene glycol and 26% water. 21. The composition according to claim 1, further comprising at least one additional oxidation base chosen from para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases, and the addition salts thereof. 22. The composition according to claim 1, comprising as the sole oxidation bases: at least one first oxidation base chosen from para-phenylenediamine and para-tolylenediamine, and the addition salts thereof; and at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine and 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof. 23. The composition according to claim 1, further comprising at least one additional coupler chosen from meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene-based couplers, heterocyclic couplers, and the addition salts thereof. 24. The composition according to claim 1, comprising as the sole coupler 2-chloro-6-methyl-3-aminophenol and the addition salts thereof. 25. The composition according to claim 1, wherein each oxidation base is present in an amount ranging from 0.001% to 10% by weight, relative to the total weight of the dye composition. 26. The composition according to claim 1, wherein each coupler is present in an amount ranging from 0.001% to 10% by weight, relative to the total weight of the dye composition. 27. The composition according to claim 1, further comprising at least one oxidizing agent. 28. The composition according to claim 27, wherein the at least one oxidizing agent is chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, peracids and oxidase enzymes. 29. A process for the oxidation dyeing of keratin fibers, comprising applying to keratin fibers a dye composition comprising, in a medium that is suitable for dyeing: at least one coupler chosen from 2-chloro-6-methyl-3-aminophenol and the addition salts thereof; at least one first oxidation base chosen from para-phenylenediamine, para-tolylenediamine, and the addition salts thereof; at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof; and at least one associative thickening polymer; wherein a color is developed with at least one oxidizing agent. 30. The process according to claim 29, wherein said at least one oxidizing agent is mixed with the dye composition at the time of application, or is applied simultaneously with, or sequentially to, the dye composition. 31. The process according to claim 29, wherein the at least one oxidizing agent is chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, peracids and oxidase enzymes. 32. The process according to claim 30, wherein the at least one oxidizing agent is mixed at the time of application with the dye composition. 33. The process according to claim 29, wherein the at least one oxidizing agent is present in an oxidizing composition. 34. The process according to claim 33, wherein the oxidizing composition is applied to the keratin fibers simultaneously with, or sequentially to, the dye composition. 35. A multi-compartment device, wherein at least one first compartment comprises a dye composition comprising, in a medium that is suitable for dyeing: at least one coupler chosen from 2-chloro-6-methyl-3-aminophenol and the addition salts thereof; at least one first oxidation base chosen from para-phenylenediamine, para-tolylenediamine, and the addition salts thereof; at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof; and at least one associative thickening polymer; and at least one second compartment comprises a composition comprising at least one oxidizing agent. | This application claims benefit of U.S. Provisional Application No. 60/507,121, filed Oct. 1, 2003. The present disclosure relates to a composition for the oxidation dyeing of keratin fibers, for instance human keratin fibers such as the hair, comprising 2-chloro-6-methyl-3-aminophenol as at least one coupler, at least one first oxidation base chosen from para-phenylenediamine and para-tolylenediamine, at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine and 2-(β-hydroxyethyl)-para-phenylenediamine, and at least one associative thickening polymer. It is known practice to dye keratin fibers, for instance human keratin fibers such as the hair, with dye compositions comprising oxidation dye precursors, which are also known as oxidation bases, such as ortho- or para-phenylenediamines, ortho- or para-aminophenols and heterocyclic compounds. These oxidation bases are colorless or weakly colored compounds that, when combined with oxidizing products, can give rise to colored compounds by a process of oxidative condensation. It is also known that the shades obtained with these oxidation bases may be varied by combining them with couplers or coloration modifiers. For example, the coloration modifiers may be chosen from aromatic meta-diamines, meta-aminophenols, meta-diphenols and certain heterocyclic compounds such as indole compounds. The variety of molecules used as oxidation bases and couplers allows a wide range of colors to be obtained. The “permanent” coloration obtained with these oxidation dyes should, moreover, satisfy a certain number of criteria. For example, it should not have any toxicological drawbacks, it should allow shades to be obtained in the desired intensity, and it should show good resistance to external agents such as light, bad weather, washing, permanent-waving, perspiration and rubbing. The dyes should also allow white hairs to be covered and, they should be as unselective as possible, i.e., they should produce the smallest possible color differences along the same length of keratin fiber, that may in fact be differently sensitized, or damaged, from its end to its root. Compositions for the oxidation dyeing of keratin fibers, comprising 2-chloro-6-methyl-3-aminophenol or 2-methyl-6-chloro-3-aminophenol as coupler, in combination with at least one oxidation base chosen from oxidation bases conventionally used for oxidation dyeing, for instance certain para-phenylenediamines, para-aminophenol or heterocyclic oxidation bases, have already been proposed, for instance in German Patent Application DE 30 16,008. Patent application WO 96/15765 describes compositions for the oxidation dyeing of keratin fibers, comprising 2-chloro-6-methyl-3-aminophenol as coupler and 2-(β-hydroxyethyl)-para-phenylenediamine as oxidation base. Patent Application EP 0 966,251 describes compositions for the oxidation dyeing of keratin fibers, containing 2-chloro-6-methyl-3-aminophenol as a coupler, combined with at least two oxidation bases of different nature chosen from para-phenylenediamines, double bases, para-aminophenols, ortho-aminophenols and heterocyclic oxidation bases. However, such compositions are not entirely satisfactory, for instance with respect to the staying power of the colorations obtained with respect to the various attacking factors to which the hair may be subjected, such as shampoo, light, sweat and permanent-reshaping operations, and with respect to the strength of the colorations obtained. Thus it would be useful to provide novel compositions for the oxidation dyeing of keratin fibers that may not have the drawbacks of those of the prior art. For example, it would be useful to provide novel compositions that can produce strong, chromatic, aesthetic colorations in varied shades, which can show little selectivity and good resistance to the various attacking factors to which the hair may be subjected, such as shampoo, light, sweat and permanent-reshaping operations. Accordingly, disclosed herein is a composition for the oxidation dyeing of keratin fibers, comprising, in a suitable dyeing medium: at least one coupler chosen from 2-chloro-6-methyl-3-aminophenol and the addition salts thereof; at least one first oxidation base chosen from para-phenylehediamine, para-tolylenediamine, and the addition salts thereof; at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof; and at least one associative thickening polymer. The composition of the present disclosure, for example, can allow a chromatic, very strong, sparingly selective and fast coloration of keratin fibers to be obtained. Another embodiment of the present disclosure is a process for the oxidation dyeing of keratin fibers, for instance human keratin fibers such as the hair, using the composition as disclosed herein. The associative polymers that may be used according to the present disclosure may be chosen from water-soluble and water-dispersible polymers capable, in an aqueous medium, of reversibly associating together or with other molecules, and their chemical structure comprises hydrophilic regions and hydrophobic regions comprising at least one C8-C30 fatty chain, such as a C10-C30 fatty chain. These polymers may be obtained from free-radical polymerization and polycondensation, each starting with at least one monomer, at least one of which comprises a C8-C30 fatty chain, such as a C10-C30 fatty chain; alternatively, they can be obtained from the grafting onto a polymer, such as a polyhydroxylated polymer, a compound comprising at least one C8-C30 fatty chain, such as a C10-C30 fatty chain. As used herein, the term “thickening polymer” means a polymer that has, for example, as a solution or a dispersion at 5% by weight of active material in water, a viscosity measured using a Rheomat RM 180 rheometer, at 25° C., at least equal to 500 cP, at a shear rate of 100 s−1. The associative polymers according to the present disclosure may be chosen from anionic, cationic, amphoteric and non-ionic associative polymers. For. instance, the at least one associative polymer may be chosen from anionic, cationic and nonionic polymers. Among the associative polymers of anionic type that may be used, non-limiting mention may be made of: (I) anionic associative polymers comprising at least one hydrophilic unit and at least one fatty-chain allyl ether unit, for instance, those whose hydrophilic unit comprises an ethylenic unsaturated anionic monomer, for example vinylcarboxylic acid, acrylic acid, methacrylic acid, and mixtures thereof, and wherein the fatty-chain allyl ether unit is chosen from monomers of formula (V): CH2═CR′CH2OBnR (V) wherein: R′ is chosen from hydrogen atoms and CH3 radicals; B is an ethyleneoxy radical; n is an integer ranging from 0 to 100; R is a hydrocarbon-based radical chosen from alkyl, arylalkyl, aryl, alkylaryl and cycloalkyl radicals, comprising from 8 to 30 carbon atoms, for instance from 10 to 24 carbon atoms, such as from 12 to 18 carbon atoms. For example, a unit of formula (V) may be a unit wherein R′ is hydrogen, n is equal to 10, and R is a stearyl (C18) radical. Anionic associative polymers of this type are described and prepared, according to an emulsion polymerization process, in European Patent No. EP-0 216,479. Among the anionic associative polymers described above, according to the present disclosure, non-limiting mention may be made of the polymers formed from 20% to 60% by weight of acrylic acid and/or of methacrylic acid, from 5% to 60% by weight of lower alkyl(meth)acrylates, from 2% to 50% by weight of fatty-chain allyl ether of formula (V), and from 0% to 1% by weight of at least one crosslinking agent which is a known copolymerizable unsaturated polyethylenic monomer, for instance diallyl phthalate, allyl(meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate and methylenebisacrylamide. Among the crosslinking agents, non-limiting mention may be made of crosslinked terpolymers of methacrylic acid, of ethyl acrylate and of polyethylene glycol (10 EO) stearyl ether (Steareth-10), for example, those sold by the company Allied Colloids under the names Salcare SC 80® and Salcare SC 90®, which are aqueous 30% emulsions of a crosslinked terpolymer of methacrylic acid, of ethyl acrylate and of steareth-10 allyl ether (40/50/10). (II) anionic associative polymers comprising at least one hydrophilic unit of unsaturated olefinic carboxylic acid type, and at least one hydrophobic unit of (C10-C30)alkyl ester of unsaturated carboxylic acid type. For example, these polymers may be chosen from those wherein the hydrophilic unit of unsaturated olefinic carboxylic acid type corresponds to the monomer of formula (VI): wherein R1 is chosen from hydrogen atoms, and CH3 and C2H5 radicals, i.e., acrylic acid, methacrylic acid and ethacrylic acid units; and wherein the hydrophobic unit of (C10-C30)alkyl ester of unsaturated carboxylic acid type corresponds to the monomer of formula (VII): wherein: R2 is chosen from hydrogen atoms, and CH3 and C2H5 radicals, that is, acrylate, methacrylate and ethacrylate units, for example H leads to acrylate units and CH3 leads to methacrylate units; R3 is chosen from C10-C30 alkyl radicals, such as C12-C22 alkyl radicals. (C10-C30) alkyl esters of unsaturated carboxylic acids according to the present disclosure include, for example, lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate and dodecyl acrylate, and the corresponding methacrylates, lauryl methacrylate, stearyl methacrylate, decyl methacrylate, isodecyl methacrylate and dodecyl methacrylate. Anionic polymers of this type are described and prepared, for example, in U.S. Pat. Nos. 3,915.921 and 4,509,949. Among the anionic associative polymers of this type that may be used, non-limiting mention may be made of polymers formed from a monomer mixture comprising: (i) essentially acrylic acid; (ii) an ester of formula (VII) described above wherein R2 is chosen from hydrogen atoms and CH3 radicals, and R3 is chosen from alkyl radicals cmprising from 12 to 22 carbon atoms; (iii) and a crosslinking agent, which is chosen from known copolymerizable polyethylenic unsaturated monomers, for instance diallyl phthalate, allyl(meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate and methylenebisacrylamide. Among anionic associative polymers of this type that may be used, non-limiting mention may be made of those comprising from 60% to 95% by weight of acrylic acid as the hydrophilic. unit, from 4% to 40% by weight of C10-C30 alkyl acrylate as the hydrophobic unit and from 0% to 6% by weight of at least one crosslinking polymerizable monomer; or alternatively those comprising from 96% to 98% by weight of acrylic acid as the hydrophilic unit, from 1% to 4% by weight of C10-C30 alkyl acrylate as the hydrophobic unit and from 0.1% to 0.6% by weight of at least one crosslinking polymerizable monomer such as those described above. Among the polymers described above, which may be used according to the present disclosure, non-limiting mention may be made of the products sold by the compariy Goodrich under the trade names Pemulen TR1®, Pemulen TR2® and Carbopol 1382®, such as Pemulen TR1®, and the product sold by the company SEPPIC under the name Coatex SX®. (III) maleic anhydride/C30-C38 α-olefin/alkyl maleate terpolymers, such as the product (maleic anhydride/C30-C38 α-olefin/isopropyl maleate copolymer) sold under the name Performa V 1608® by the company Newphase Technologies. (IV) acrylic terpolymers comprising: 20% to 70% by weight of a carboxylic acid containing α,β-monoethylenic unsaturation; 20% to 80% by weight of a non-surfactant monomer containing α,β-monoethylenic unsaturation other than a carboxylic acid containing α,β-monoethylenic unsaturation; 0.5% to 60% by weight of a nonionic monourethane, which is the product of reaction of a monohydric surfactant with a monoisocyanate containing monoethylenic unsaturation; such as those described in the patent application EP-A-0 173,109, for instance, the terpolymer described in Example 3, which is a methacrylic acid/methyl acrylate/behenyl dimethyl-meta-isopropenylbenzylisocyanate ethoxylated (40 EO) terpolymer, as an aqueous 25% dispersion. (V) copolymers comprising among their monomers a carboxylic acid containing α,β-monoethylenic unsaturation, and an ester of a carboxylic acid containing α,β-monoethylenic unsaturation and of an oxyalkylenated fatty alcohol. For example, these compounds may also comprise as monomers: esters of a carboxylic acid containing α,β-monoethylenic unsaturation and of a C1-C4 alcohol. A non-limiting example of a compound of this type that may be mentioned is Aculyn 22® sold by the company Rohm & Haas, which is a methacrylic acid/ethyl acrylate/stearyl methacrylate oxyalkylenated terpolymer. (VI) and associative polyurethanes of anionic nature, such as Viscophobe DB 1000 from the company Union Carbide. Among the associative polymers of cationic type, non-limiting mention may be made of: (I) the cationic associative polyurethanes whose family has been described by the French Patent Application 0 009,609 assigned to L'Oreal, may be chosen from those of general formula (VIII): R—X—(P)n-[L-(Y)m]r-L′-(P′)p—X′—R′ (VIII) wherein: R and R′, which may be identical or different, are chosen from hydrophobic groups and hydrogen atoms; X and X′, which may be identical or different, are chosen from groups comprising an amine functional group optionally bearing a hydrophobic group, and L″ groups; L, L′ and L″, which may be identical or different, are chosen from groups derived from diisocyanate; P and P′, which may be identical or different, are chosen from groups comprising an amine functional group optionally bearing a hydrophobic group; Y ris chosen from hydrophilic groups; r is an integer ranging from 1 to 100, for instance, from 1 to 50, such as from 1 to 25; n, m and p each range, independently of each other, from 0 to 1000; and wherein the molecule comprises at least one entity chosen from protonated and quaternized amine functional groups, and at least one hydrophobic group. For example, according to one aspect of the polyurethanes, the only hydrophobic groups are the groups R and R′ at the chain ends. Other non-limiting examples of cationic associative polyurethanes that may be used include those of formula (VIII) described above wherein: R and R′ are each independently chosen from hydrophobic groups; X and X′ are each an L″ group; n and p range from 1 to 1000; and L, L′, L″, P, P′, Y and m have the meaning given above. Still other non-limiting examples of cationic associative polyurethanes that may be used include those of formula (VIII) above wherein: R and R′ are each independently chosen from hydrophobic groups; X and X′are each an L″ group; n and p are each equal to zero; and L, L′, L″, Y and m have the meaning given above. When n and p are equal to zero, the polymers do not comprise units derived from a monomer comprising an amine functional group incorporated into the polymer during the polycondensation. The protonated amine functions of these polyurethanes result from the hydrolysis of excess isocyanate functional groups, at the chain end, followed by alkylation of the primary amine functions formed with alkylating agents comprising a hydrophobic group, i.e., compounds of the type RQ or R′Q, wherein R and R′ are as defined above and Q comprises a leaving group such as a halide, a sulphate, etc. Yet another example of cationic associative polyurethanes that may be used include those of formula (VIII) above wherein: R and R′ are each independently chosen from hydrophobic groups; X and X′ are each independently chosen from groups comprising a quaternary amine; n and p are each equal to zero; and L, L′, Y and m have the meaning given above. The number-average molecular mass of the cationic associative polyurethanes may range, for example, from 400 to 500,000, for instance, from 1000 to 400,000, such as from 1,000 to 300,000. As used herein, the expression “hydrophobic group” means a radical or polymer comprising a saturated or unsaturated, linear or branched hydrocarbon-based chain, which may comprise at least one hetero atom, such as phosphorus, oxygen, nitrogen and sulfur, or a radical comprising a perfluoro or silicone chain. When the hydrophobic group comprises a hydrocarbon-based radical, it comprises at least 10 carbon atoms, for instance from 10 to 30 carbon atoms, such as from 12 to 30 carbon atoms, and from 18 to 30 carbon atoms. For example, the hydrocarbon-based group may be derived from a monofunctional compound. By way of non-limiting example, the hydrophobic group may be derived from a fatty alcohol such as stearyl alcohol, dodecyl alcohol or decyl alcohol. It may also comprise hydrocarbon-based polymers such as, for example, polybutadiene. When X and/or X′ are chosen from groups comprising a tertiary or quaternary amine, X and/or X′ are chosen from at least one of the following formulae: wherein: R2 is chosen from linear and branched alkylene radicals comprising from 1 to 20 carbon atoms optionally comprising an entity chosen from saturated and unsaturated rings, and arylene radicals, wherein at least one of the carbon atoms may possibly be replaced with a hetero atom chosen from nitrogen, sulfur, oxygen, and phosphorus; R1 and R3, which may be identical or different, are chosen from linear and branched C1-C30 alkyl and alkenyl radicals, and aryl radicals, wherein at least one of the carbon atoms may possibly be replaced with a hetero atom chosen from nitrogen, sulfur, oxygen, and phosphorus; A− is chosen from physiologically acceptable counter-ions. The groups L, L′ and L″, derived from groups derived from a diisocyanate, are chosen from groups of formula: wherein: Z is chosen from -oxygen and sulfur atoms, and —NH— radicals; and R4 is chosen from linear and branched alkylene radicals comprising from 1 to 20 carbon atoms, optionally comprising an entity chosen from saturated and unsaturated rings, and arylene radicals, wherein at least one of the carbon atoms may possibly be replaced with a hetero atom chosen from nitrogen, sulfur, oxygen and phosphorus. The groups P and P′ comprising an amine functional group are be chosen from at least one of the following formulae: wherein: R5 and R7, which may be identical or different, are chosen from linear and branched alkylene radicals comprising from 1 to 20 carbon atoms optionally comprising an entity chosen from saturated and unsaturated rings, and arylene radicals, wherein at least one of the carbon atoms may possibly be replaced with a hetero atom chosen from nitrogen, sulphur, oxygen, and phosphorus; R6, R8 and R9, which may be identical or different, are chosen from linear and branched C1-C30 alkyl and alkenyl radicals, and aryl radicals, wherein at least one of the carbon atoms may possibly be replaced with a hetero atom chosen from nitrogen, sulfur, oxygen, and phosphorus; R10 is chosen from linear and branched, optionally unsaturated alkylene groups that may comprise at least one hetero atom chosen from nitrogen, oxygen, sulfur and phosphorus; and A− is chosen from physiologically acceptable counter-ions. As used herein, the term “hydrophilic group” means a polymeric or non-polymeric water-soluble group. By way of example, when the hydrophilic group is not a polymer, non-limiting mention may be made of ethylene glycol, diethylene glycol and propylene glycol. When the hydrophilic group is a hydrophilic polymer, in accordance with one aspect of the present disclosure, non-limiting mention may be made, for example, of polyethers, sulphonated polyesters, sulphonated polyamides and mixtures thereof. The hydrophilic compound may be, for example, a polyether such as a poly(ethylene oxide) or poly(propylene oxide). The cationic associative polyurethanes of formula (VIII) according to the present disclosure may be formed from diisocyanates and from various compounds with functional groups comprising labile hydrogen. The functional groups comprising labile hydrogen may be chosen from alcohol, primary and secondary amines and thiol functional groups giving, after reaction with the diisocyanate functional groups, polyurethanes, polyureas and polythioureas, respectively. The term “polyurethanes” in the present disclosure encompasses these three types of polymer, namely polyurethanes per se, polyureas and polythioureas, and also copolymers thereof. A first type of compound involved in the preparation of the polyurethanes of formula (VIII) is a compound comprising at least one unit comprising an amine functional group. This compound may be multifunctional, or for instance, difunctional. According to one aspect of the present disclosure, this compound may comprise two labile hydrogen atoms borne, for example, by a hydroxyl, primary amine, secondary amine or thiol functional group. A mixture of multifunctional and-difunctional compounds in which the percentage of multifunctional compounds is low may also be used. As mentioned above, this compound may comprise more than one unit comprising an amine functional group. If this is the case, it is a polymer bearing a repetition of the unit comprising an amine functional group. Compounds of this type may be chosen from those of the following formulae: HZ-(P)n-ZH and HZ-(P′)p-ZH wherein Z, P, P′, n and p are as defined above. Non-limiting examples of compounds comprising an amine functional group that may be mentioned include N-methyldiethanolamine, N-tert-butyldiethanolamine and N-sulphoethyldiethanolamine. The second compound involved in the preparation of the polyurethanes of formula (VIII) is a diisocyanate chosen from those of formula: O═C═N—R4—N═C═O wherein R4 is as defined above. By way of example, non-limiting mention may be made of methylenediphenyl diisocyanate, methylenecyclohexane diisocyanate, isophorone diisocyanate, toluene diisocyanate, naphthalene diisocyanate, butane diisocyanate and hexane diisocyanate. A third compound involved in the preparation of the polyurethanes of formula (VIII) is a hydrophobic compound intended to form the terminal hydrophobic groups of the polymer of formula. (VIII). This compound comprises a hydrophobic group and a functional group comprising a labile hydrogen, for example a hydroxyl, primary or secondary amines, or thiol functional groups. By way of non-limiting example, this compound may be a fatty alcohol such as, for instance, stearyl alcohol, dodecyl alcohol or decyl alcohol. When this compound comprises a polymeric chain, it may be, for example, α-hydroxylated hydrogenated polybutadiene. The hydrophobic group of the polyurethanes of formula (VIII) may also result from the quaternization reaction of a tertiary amine of a compound comprising at least one tertiary amine unit. Thus, the hydrophobic group may be introduced via a quaternizing agent. This quaternizing agent may be a compound chosen from RQ and R′Q, as defined above. The cationic associative polyurethane may also comprise a hydrophilic block. This block is provided by a fourth type of compound involved in the preparation of the polymer. This compound may be multifunctional, for instance, difunctional. It is also possible to have a mixture of multifunctional and difunctional polymers wherein the percentage of multifunctional compound is low. The functional groups comprising a labile hydrogen may be chosen from alcohol, primary and secondary amine, and thiol functional groups. This compound may be a polymer terminated at the chain ends with one of these functional groups comprising a labile hydrogen. By way of non-limiting example, when the hydrophilic block is not a polymer, mention may be made of ethylene glycol, diethylene glycol and propylene glycol. When the hydrophilic block is a hydrophilic polymer, non-limiting mention may be made, for example, of polyethers, sulphonated polyesters and sulphonated polyamides, and mixtures thereof. The hydrophilic compound may be chosen from, for example, a polyether and, for instance poly(ethylene oxide) or poly(propylene oxide). The hydrophilic group termed Y in formula (VIII) is optional. For example, the units comprising a quaternary amine or a protonated functional group may suffice to provide the solubility or water-dispersibility required for this type of polymer in an aqueous solution. Although the presence of a hydrophilic group Y is optional, cationic associative polyurethanes comprising such a group are used in one aspect of the present disclosure. (II) quaternized cellulose derivatives and polyacrylates comprising non-cyclic amine side groups. Non-limiting examples of quaternized cellulose derivatives that may be used include: quaternized celluloses modified with groups comprising at least one fatty chain, such as alkyl, arylalkyl or alkylaryl groups comprising at least 8 carbon atoms, and mixtures thereof; quaternized hydroxyethylcelluloses modified with groups comprising at least one fatty chain, such as alkyl, arylalkyl or alkylaryl groups comprising at least 8 carbon atoms, and mixtures thereof. The alkyl radicals borne by the above quaternized celluloses or hydroxyethylcelluloses may comprise, for example, from 8 to 30 carbon atoms. The aryl radicals may be chosen from, for instance, phenyl, benzyl, naphthyl and anthryl groups. Non-limiting examples of quaternized alkylhydroxyethylcelluloses comprising C8-C30 fatty chains that may be mentioned include the products Quatrisoft LM 200®, Quatrisoft LM-X 529-18-A®, Quatrisoft LM-X 529-18B® (C12 alkyl) and Quatrisoft LM-X 529-8® (C18 alkyl) sold by the company Amerchol and the products Crodacel QM®, Crodacel QL® (C12 alkyl) and Crodacel QS® (C18 alkyl) sold by the company Croda. (III) cationic polyvinyllactams, the family of which was in the French Patent Application FR 0 101,106. Such polymers comprise: (a) at least one monomer chosen from vinyllactam and alkylvinyllactam type; (b) at least one monomer chosen from those of formulae (IX) and (X): wherein: X is chosen form oxygen atoms and NR6 radicals; R1 and R6, which may be identical or different, are chosen from hydrogen atoms and linear and branched C1-C5 alkyl radicals; R2 is chosen from linear and branched C1-C4 alkyl radicals; R3, R4 and R5, which may be identical or different, are chosen from hydrogen atoms, linear and branched C1-C30 alkyl radicals and radicals of formula (XI): —(Y2)r—(CH2—CH(R7)—O)x—R8 (XI) wherein: Y, Y1 and Y2, which may be identical or different, are chosen from linear and branched C2-C16 alkylene radicals; R7 is chosen from hydrogen atoms and linear and branched C1-C4 alkyl radicals, and linear and branched C1-C4 hydroxyalkyl radicals; R8 is chosen from hydrogen atoms and linear and branched C1-C30 alkyl radicals; p, q and r, which may be identical or different, are integers equal either to the value 0 or the value 1; m and n, which may be identical or different, are integers ranging from 0 to 100; x is an integer ranging from 1 to 100; Z− is chosen from organic and mineral acid anions, with the proviso that: at least one of the substituents R3, R4, R5 or R8 is chosen from linear and branched C9-C30 alkyl radicals; if m or n does not equal zero, then q is equal to 1; if m or n is equal to zero, then p or q is equal to 0. The cationic poly(vinyllactam) polymers according to the present disclosure may be crosslinked or non-crosslinked and may also be block polymers. For example, the counter-ion Z− of the monomers of formula (IX) is chosen from halide ions, phosphate ions, the methosulphate ion and the tosylate ion. For example, R3, R4 and R5, which may be identical or different, may be chosen from hydrogen atoms and linear and branched C1-C30 alkyl radicals. The monomer (b), for instance, may be a monomer of formula (IX) wherein, for example, m and n may be equal to zero. The vinyllactam or alkylvinyllactam monomer may be chosen from compounds of formula (XII): wherein: s is an integer ranging from 3 to 6; R9 is chosen from hydrogen atoms and C1-C5 alkyl radicals; R10 is chosen from hydrogen atoms and C1-C5 alkyl radicals; and with the proviso that at least one of the radicals R9 and R10 is a hydrogen atom. For example, the monomer (XII) may be vinylpyrrolidone. The cationic poly(vinyllactam) polymers according to the present disclosure may also comprise at least one additional monomer, such as cationic or nonionic monomers. Among compounds that may be used according to the present disclosure, non-limiting mention may be made of the following terpolymers comprising: (a) at least one monomer of formula (XII); (b) at least one monomer of formula (IX) wherein p=1, q=0, R3 and R4, which may be identical or different, are chosen from hydrogen atoms and C1-C5 alkyl radicals, and R5 is chosen from C9-C24 alkyl radicals; and (c) at least one monomer of formula (X) wherein R3 and R4, which may be identical or different, are chosen from hydrogen atoms and C1-C5 alkyl radicals. For instance, terpolymers comprising, by weight, 40% to 95% of monomer (a), 0.1% to 55% of monomer (c) and 0.25% to 50% of monomer (b) may be used. Such polymers are described in the patent application WO 00/68282, the content of which is incorporated herein by reference. Among cationic poly(vinyllactam) polymers that may be used according to the present disclosure, non-limiting mention may be made of: vinylpyrrolidone/dimethylaminopropylmethacrylamide/dodecyidimethylmethacrylamidopropylammonium tosylate terpolymers, vinylpyrrolidone/d imethylaminopropylmethacrylamide/cocoyldimethylmethacrylamidopropylammonium tosylate terpolymers, and vinylpyrrolidone/dimethylaminopropylmethacrylamide/lauryidimethylmethacrylamidopropylammonium tosylate or chloride terpolymers. The weight-average molecular mass of the cationic poly(vinyllactam) polymers according to the present disclosure may range, for instance, from 500 to 20,000,000, for example, ranging from 200,000 to 2,000,000, such as from 400,000 to 800,000. The amphoteric associative polymers that may be used according to the present disclosure, may be chosen from polymers comprising at least one non-cyclic cationic unit. For instance, the polymers prepared from or comprising 1 to 20 mol % of a monomer comprising a fatty chain, such as 1.5 to 15 mol %, for example, 1.5 to 6 mol %, relative to the total number of moles of monomers, may also be used. Further non-limiting examples of the amphoteric associative polymers that may be used according to the present disclosure include those that comprise, or are prepared by copolymerizing: (1) at least one monomer of formula (XIII) or (XIV): wherein: R1 and R2, which may be identical or different, are chosen from hydrogen atoms and methyl radicals; R3, R4 and R5, which may be identical or different, are chosen from linear and branched alkyl radicals comprising from 1 to 30 carbon atoms; Z is chosen from NH groups and oxygen atoms; n is an integer ranging from 2 to 5; A− is an anion derived from organic or mineral acids, such as a methosulphate anion or a halide such as chloride or bromide; (2) at least one monomer of formula (XV) R6—CH═CR7—COOH (XV) wherein: R6 and R7, which may be identical or different, are chosen from hydrogen atoms and methyl radicals; and (3) at least one monomer of formula (XVI): R6—CH═CR7—COXR8 (XVI) wherein: R6 and R7, which may be identical or different, are chosen from hydrogen atoms and methyl radicals; X is chosen from oxygen and nitrogen atoms; and R8 is chosen from linear and branched alkyl radicals comprising from 1 to 30 carbon atoms; wherein at least one of the monomers of formula (XIII), (XIV) or (XV) comprises at least one fatty chain. The monomers of formulae (XIII) and (XIV) of the present disclosure may be chosen from, for example: dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate; diethylaminoethyl methacrylate, diethylaminoethyl acrylate; dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate; dimethylaminopropylmethacrylamide, dimethylaminopropylacrylamide; wherein these monomers may optionally be quaternized, for example with a C1-C4 alkyl halide or a C1-C4 dialkyl sulphate. For further instance, the monomer of formula (XIII) may be chosen from acrylamidopropyltrimethylammonium chloride and methacrylamidopropyltrimethylammonium chloride. The monomers of formula (XIV) of the present disclosure may be chosen from acrylic acid, methacrylic acid, crotonic acid and 2-methylcrotonic acid. For instance, the monomer of formula (XIV) may be acrylic acid. The monomers of formula (XIV) of the present disclosure may also be chosen from C12-C22, such asC16-C18 alkyl acrylates and methacrylates. The monomers comprising the fatty-chain amphoteric polymers as disclosed herein may be already neutralized and/or quaternized. The ratio of the number of cationic charges/anionic charges may be, for instance, equal to about 1. The amphoteric associative polymers according to the present disclosure may comprise, for example, from 1 to 10 mol %, such as from 1.5 to 6 mol % of the at least one monomer of formula (XIII), (XIV) or (XV) comprising a fatty chain. The weight-average molecular weights of the amphoteric associative polymers as disclosed herein may range from 500 to 50,000,000, such as from 10,000 to 5,000,000. The amphoteric associative polymers according to the present disclosure may also comprise other monomers such as nonionic monomers, for instance, such as C1-C4 alkyl acrylates or methacrylates. Amphoteric associative polymers according to the present disclosure are described and prepared, for example, in patent application WO 98/44012. Among the amphoteric associative polymers as disclosed herein, non-limiting mention may be made of acrylic acid/(meth)acrylamidopropyltrimethylammonium chloride/stearyl methacrylate terpolymers. According to the present disclosure, the nonionic associative polymers may be chosen from: (1) celluloses modified with groups comprising at least one fatty chain; non-limiting examples that may be mentioned include: hydroxyethylcelluloses modified with groups comprising at least one fatty chain, such as alkyl, arylalkyl or alkylaryl groups, or mixtures thereof, and in which the alkyl groups are preferably C8-C22, for instance the product Natrosol Plus Grade 330 CS® (C16 alkyls) sold by the company Aqualon, or the product Bermocoll EHM 100® sold by the company Berol Nobel, those modified with alkylphenyl polyalkylene glycol ether groups, such as the product Amercell Polymer HM-1500® (nonylphenyl polyethylene glycol (15) ether) sold by the company Amerchol; (2) hydroxypropyl guars modified with groups comprising at least one fatty chain, such as the product Esaflor HM 22® (C22 alkyl chain) sold by the company Lamberti, and the products RE210-18® (C14 alkyl chain) and RE205-1® (C20 alkyl chain) sold by the company Rhône-Poulenc; (3) copolymers of vinylpyrrolidone and of fatty-chain hydrophobic monomers; non-limiting examples that may be mentioned include: the products Antaron V216® or Ganex V216® (vinylpyrrolidone/hexadecene copolymer) sold by the company I.S.P., the products Antaron V220® or Ganex V220® (vinylpyrrolidone/eicosene copolymer) sold by the company I.S.P.; (4) copolymers of C1-C6 alkyl methacrylates or acrylates and of amphiphilic monomers comprising at least one fatty chain, such as, for example, the oxyethylenated methyl acrylate/stearyl acrylate copolymer sold by the company Goldschmidt under the name Antil 208®; (5) copolymers of hydrophilic methacrylates or acrylates and of hydrophobic monomers comprising at least one fatty chain, such as, for example, the polyethylene glycol methacrylate/lauryl methacrylate copolymer; (6) polyurethane polyethers comprising in their chain both hydrophilic blocks usually of polyoxyethylenated nature and hydrophobic blocks which may be aliphatic sequences alone and/or cycloaliphatic and/or aromatic sequences; (7) polymers with an aminoplast ether skeleton comprising at least one fatty chain, such as the Pure Thix® compounds sold by the company Sud-Chemie. For example, the polyurethane polyethers may comprise at least two hydrocarbon-based lipophilic chains comprising from 6 to 30 carbon atoms separated by a hydrophilic block, the hydrocarbon-based chains possibly being pendent chains, or chains at the end of the hydrophilic block. For instance, it is possible for at least one pendent chain to be included. In addition, the polymer may comprise a hydrocarbon-based chain at one end or at both ends of a hydrophilic block. The polyurethane polyethers may be multiblock, for instance, in triblock form. Hydrophobic blocks may be at each end of the chain, for example: triblock copolymer with a hydrophilic central block, or distributed both at the ends and in the chain, for example, a multiblock copolymer. These same polymers may also be graft polymers or starburst polymers. The nonionic fatty-chain polyurethane polyethers may be triblock copolymers wherein the hydrophilic block is a polyoxyethylenated chain comprising from 50 to 1000 oxyethylene groups. The nonionic polyurethane polyethers comprise a urethane linkage between the hydrophilic blocks, whence arises the name. By extension, also included among the nonionic fatty-chain polyurethane polyethers are those in which the hydrophilic blocks are linked to the lipophilic blocks via other chemical bonds. As examples of nonionic fatty-chain polyurethane polyethers that may be used as disclosed herein, non-limiting mention may also be made of Rheolate 205® containing a urea function, sold by the company Rheox, or the Rheolates® 208, 204 or 212, and also Acrysol RM 184®. Further non-limiting mention may also be made of the product Elfacos T210® containing a C12-14 alkyl chain, and the product Elfacos T212® containing a C18 alkyl chain, from Akzo. The product DW 1206B® from Rohm & Haas containing a C20 alkyl chain and a urethane linkage, sold at a solids content of 20% in water, may also be used. It is also possible to use solutions or dispersions of these polymers, such as, in water or in aqueous-alcoholic medium. Non-limiting examples of such polymers that may be mentioned include Rheolate® 255, Rheolate® 278 and Rheolate® 244 sold by the company Rheox. The products DW 1206F and DW 1206J sold by the company Rohm & Haas may also be used. The polyurethane polyethers that may be used according to the present disclosure, for instance, include those described in the article by G. Fonnum, J. Bakke and Fk. Hansen—Colloid Polym. Sci 271, 380-389 (1993). For further example, according to the present disclosure, it is possible to use a polyurethane polyether that may be obtained by polycondensation of at least three compounds comprising (i) at least one polyethylene glycol comprising from 150 to 180 mol of ethylene oxide, (ii) stearyl alcohol or decyl alcohol, and (iii) at least one diisocyanate. Such polyurethane polyethers are sold, for instance, by the company Rohm & Haas under the names Aculyn 46® and Aculyn 44®. Aculyn 46® is a polycondensate of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of stearyl alcohol and of methylenebis(4-cyclohexyl isocyanate) (SMDI), at 15% by weight in a matrix of maltodextrin (4%) and water (81%); Aculyn 44® is a polycondensate of polyethylene glycol containing 150 to 180 mol of ethylene oxide, of decyl alcohol and of methylenebis(4-cyclohexylisocyanate) (SMDI), at 35% by weight in a mixture of propylene glycol (39%) and water (26%). In one embodiment according to the present disclosure, for example, the associative polymers may be chosen from nonionic and cationic associative polymers, such as polyether polyurethanes comprising hydrophilic and hydrophobic blocks, polymers comprising an aminoplast ether skeleton comprising at least one fatty chain, cationic associative polyurethanes, quaternized cellulose derivatives comprising at least one fatty chain, and cationic polyvinyllactams. In another embodiment of the present disclosure, the associative polymer may be chosen from quaternized (C8-C30)alkylhydroxyethylcelluloses, such as laurylhydroxyethylcellulose. The nonionic, anionic, cationic or amphoteric associative polymers may be used, for example, in an amount ranging from 0.01% to 10% by weight, relative to the total weight of the dye composition. For instance, this amount may range from0.1%to 5% by weight, such as from 0.5% to 3% by weight. The composition as disclosed herein may additionally comprise at least one additional oxidation base chosen from oxidation bases conventionally used in oxidation dyeing other than para-phenylenediamine, para-tolylenediamine, N,N-bis(β-hydroxyethyl)-para-phenylenediamine and 2-(β-hydroxyethyl)-para-phenylenediamine. By way of non-limiting example, these additional oxidation bases may be chosen from para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases, and the addition salts thereof. Among the para-phenylenediamines that may be used, non-limiting mention may be made, for example, of 2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine, N,N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylenediamine, 4-amino-N,N-diethyl-3-methylaniline, 4-amino-N,N-bis(β-hydroxyethyl)-2-methylaniline, 4-amino-N,N-bis(β-hydroxyethyl)-2-chloroaniline, 2-fluoro-para-phenylene-diamine, 2-isopropyl-para-phenylenediamine, N-(β-hydroxypropyl)-para-phenylenediamine, 2-hydroxymethyl-para-phenylenediamine, N,N-dimethyl-3-methyl-para-phenylenediamine, N-ethyl-N-(β-hydroxyethyl)-para-phenylenediamine, N-(β,γ-dihydroxypropyl)-para-phenylenediamine, N-(4′-aminophenyl)-para-phenylenediamine, N-phenyl-para-phenylenediamine, 2-(β-hydroxyethyloxy)-para-phenylenediamine, 2-(β-acetylaminoethyloxy)-para-phenylenediamine, N-(β-methoxyethyl)-para-phenylenediamine, 2-thienyl-para-phenylenediamine, 2-(β-hydroxyethyl)amino-5-aminotoluene, and the addition salts thereof. Further among the para-phenylenediamines listed above, non-limiting mention may be made of 2-isopropyl-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2-chloro-para-phenylenediamine, 2-(β-acetylaminoethyloxy)-para-phenylenediamine, and the addition salts thereof. Among the bisphenylalkylenediamines that may be used, non-limiting mention may be made, for example, of N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol, N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine, N,N′-bis(4′-aminophenyl)tetramethylenediamine, N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)tetramethylenediamine, N,N′-bis(4′-methylaminophenyl)-tetramethylenediamine, N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methylphenyl)ethylenediamine, 1,8-bis(2,5-diaminophenoxy)-3,6-dioxaoctane, and the addition salts thereof. Among the para-aminophenols that may be used, non-limiting mention may be made, for example, of para-aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluorophenol, 4-amino-3-hydroxymethylphenol, 4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol, 4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol, 4-amino-2-(β-hydroxyethylaminomethyl)phenol, 4-amino-2-fluorophenol, 4-amino-2-chlorophenol 4-amino-6-[(5′-amino-2′-hydroxy-3′-methylphenyl)methyl]-2-methylphenol, bis(5-amino-2-hydroxyphenyl)methane, 4-amino-2,6-dichlorophenol, and the addition salts thereof. Among the ortho-aminophenols that may be mentioned used, for example, non-limiting mention may be made of 2-aminophenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol, 5-acetamido-2-aminophenol, and the addition salts thereof. Among the heterocyclic bases that may be used, non-limiting mention may be made, for example, of pyridine derivatives, pyrimidine derivatives and pyrazole derivatives. Among the pyridine derivatives that may be used, non-limiting mention may be made of the compounds described, for example, in the patents GB 1,026,978 and GB 1,153,196, as well as 2,5-diaminopyridine, 2-(4-methoxyphenyl)amino-3-aminopyridine, 2,3-diamino-6-methoxypyridine, 2-(β-methoxyethyl)amino-3-amino-6-methoxypyridine, 3,4-diaminopyridine, and the addition salts thereof. Other pyridine oxidation bases that may be useful in the present disclosure include the 3-aminopyrazolo[1,5-a]pyridine oxidation bases or the addition salts thereof described, for example, in patent application FR 2,801,308. By way of example, non-limiting mention may be made of pyrazolo[1,5-a]pyrid-3-ylamine; 2-acetylaminopyrazolo[1,5-a]pyrid-3-ylamine; 2-morpholin-4-ylpyrazolo[1,5-a]pyrid-3-ylamine; 3-aminopyrazolo[1,5-a]pyridine-2-carboxylic acid; 2-methoxypyrazolo[1,5-a]pyrid-3-ylamino; (3-aminopyrazolo[1,5-a]pyrid-7-yl)methanol; 2-(3-aminopyrazolo[1,5-a]pyrid-5-yl)ethanol; 2-(3-aminopyrazolo[1,5-a]pyrid-7-yl)ethanol; (3-aminopyrazolo[1,5-a]pyrid-2-yl)-methanol; 3,6-diaminopyrazolo[1,5-a]pyridine; 3,4-diaminopyrazolo[1,5-a]pyridine; pyrazolo[1,5-a]pyridine-3,7-diamine; 7-morpholin-4-ylpyrazolo[1,5-a]pyrid-3-ylamine; pyrazolo[1,5-a]pyridine-3,5-diamine; 5-morpholin-4-ylpyrazolo[1,5-a]pyrid-3-ylamine; 2-[(3-aminopyrazolo[1,5-a]pyrid-5-yl)(2-hydroxyethyl)amino]ethanol; 2-[(3-aminopyrazolo[1,5-a]pyrid-7-yl)(2-hydroxyethyl)amino]ethanol; 3-aminopyrazolo-[1,5-a]pyrid-5-ol; 3-aminopyrazolo[1,5-a]pyrid-4-ol; 3-aminopyrazolo[1,5-a]pyrid-6-3-aminopyrazolo[1,5-a]pyrid-7-ol, and also the addition salts thereof. Among the pyrimidine derivatives that may be used, non-limiting mention. may be made of the compounds described, for example, in the German Patent DE 23 59,399, or Japanese Patent Nos. JP 88-169571 and JP 05-63124; European Patent No. EP 0 770 375 or patent application WO 96/15765; such as 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine and 2,5,6-triaminopyrimidine, the addition salts thereof and the tautomeric forms thereof, when a tautomeric equilibrium exists. Among the pyrazole derivatives that may be used, non-limiting mention may be made of the compounds described in German Patent Nos. DE 38 43,892 and DE 41 33,957 and patent applications WO 94/08969, WO 94/08970, FR-A-2,733,749 and DE 195 43,988, such as 4,5-diamino-1-methylpyrazole, 4,5-diamino-1-(β-hydroxyethyl)pyrazole, 3,4-diaminopyrazole, 4,5-diamino-1-(4′-chlorobenzyl)pyrazole, 4,5-diamino-1,3-dimethylpyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole, 4,5-diamino-1-methyl-3-phenylpyrazole, 4-amino-1,3-dimethyl-5-hydrazinopyrazole, 1-benzyl-4,5-diamino-3-methylpyrazole, 4,5-diamino-3-tert-butyl-1-methylpyrazole, 4,5-diamino-1-tert-butyl-3-methylpyrazole, 4,5-diamino-1-ethyl-3-methylpyrazole, 4,5-diamino-1-ethyl-3-(4′-methoxyphenyl)pyrazole, 4,5-diamino-1-ethyl-3-hydroxymethylpyrazole, 4,5-diamino-3-hydroxymethyl-1-methylpyrazole, 4,5-diamino-3-hydroxymethyl-1-isopropylpyrazole, 4,5-diamino-3-methyl-1-isopropylpyrazole, 4-amino-5-(2′-aminoethyl)amino-1,3-dimethylpyrazole, 3,4,5-triaminopyrazole, 1-methyl-3,4,5-triaminopyrazole, 3,5-diamino-1-methyl-4-methylaminopyrazole, 3,5-diamino-4-(β-hydroxyethyl)amino-1-methylpyrazole, and the addition salts thereof. For example, the composition according to the present disclosure may comprise as the only oxidation bases: at least one first oxidation base chosen from para-phenylenediamine, para-tolylenediamine, and the addition salts thereof; and at least one second oxidation base chosen from N,N-bis(β-hydroxyethyl)-para-phenylenediamine, 2-(β-hydroxyethyl)-para-phenylenediamine, and the addition salts thereof. Each oxidation base present in the composition as disclosed herein may be present in an amount ranging from 0.001% to 10%, such as from 0.005% to 6% by weight, relative to the total weight of the dye composition. The composition according to the present disclosure may comprise, in addition to the 2-chloro-6-methyl-3-aminophenol, at least one additional coupler chosen from couplers conventionally used in the oxidation dyeing of keratin fibers. Among the couplers that may be used, for example, non-limiting mention may be made of meta-phenylenediamines, meta-aminophenols other than 2-chloro-6-methyl-3-aminophenol, meta-diphenols, naphthalene-based couplers, heterocyclic couplers, and the addition salts thereof. Further non-limiting examples that may be mentioned include 2-methyl-5-aminophenol, 5-N-(β-hydroxyethyl)amino-2-methylphenol, 3-aminophenol, 1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene, 4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1-(β-hydroxyethyloxy)benzene, 2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene, 1,3-bis(2,4-diaminophenoxy)propane, 3-ureidoaniline, 3-ureido-1-dimethylaminobenzene, sesamol, 1-β-hydroxyethylamino-3,4-methylenedioxybenzene, α-naphthol, 2-methyl-1-naphthol, 6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole, 2-amino-3-hydroxypyridine, 6-hydroxybenzomorpholine, 3,5-diamino-2,6-dimethoxypyridine, 1-N-(β-hydroxyethyl)-amino-3,4-methylenedioxybenzene, 2,6-bis(β-hydroxyethylamino)toluene, and the addition salts thereof. For example, the composition of the present disclosure may comprise, as the sole coupler, at least one coupler chosen from 2-chloro-6-methyl-3-aminophenol and the addition salts thereof. In the composition as disclosed herein, each coupler may be present in an amount ranging from 0.001% to 10% by weight, such as from 0.005% to 6% by weight, relative to the total weight of the dye composition. In general, the addition salts of the oxidation bases and of the couplers that may be used in the context of the present disclosure may be for example, chosen from acid addition salts, such as hydrochlorides, hydrobromides, sulphates, citrates, succinates, tartrates, lactates, tosylates, benzenesulphonates, phosphates and acetates, and base addition salts, such as sodium hydroxide, potassium hydroxide, aqueous ammonia, amines or alkanolamines. The dye composition in accordance with the present disclosure may also comprise at least one direct dye that may be chosen from, for instance, nitrobenzene dyes, azo direct dyes and methine direct dyes. These direct dyes may be of nonionic, anionic or cationic nature. The medium that is suitable for dyeing, also known as a dye support, generally comprises water or a mixture of water and at least one organic solvent to dissolve the compounds that would not be sufficiently soluble in the water. Non-limiting examples of organic solvents that may be mentioned include C1-C4 lower alkanols, such as ethanol and isopropanol; polyols and polyol ethers, for instance 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, and also aromatic alcohols, for instance benzyl alcohol or phenoxyethanol, and mixtures thereof. The solvents may be present in an amount ranging from 1% and 40% by weight, such as from 5% to 30% by weight, relative to the total weight of the dye composition. The dye composition as disclosed herein-may also comprise various adjuvants conventionally used in hair dye compositions, such as anionic, cationic, nonionic, amphoteric and zwitterionic surfactants and mixtures thereof; anionic, cationic, nonionic, amphoteric and zwitterionic polymers and mixtures thereof; mineral and organic thickeners;and, for instance, anionic, cationic, nonionic and amphoteric associative thickening polymers; antioxidants; penetrating agents; sequestering agents; fragrances; buffers; dispersants; conditioners, for instance volatile or non-volatile, modified or unmodified silicones; film-forming agents; ceramides; preserving agents and opacifiers. Each of the above adjuvants may be present in an amount ranging from 0.001% to 20% by weight, relative to the weight of the composition. Needless to say, a person skilled in the art will take care to select any of these additional optional compounds such that the advantageous properties intrinsically associated with the oxidation dye composition in accordance with the present disclosure are not, or are not substantially, adversely affected by the envisaged addition(s). The pH of the dye composition in accordance with the present disclosure may range from 3 to 12 such as from 5 to 11. It may be adjusted to the desired value by means of acidifying or basifying agents usually used in dyeing keratin fibers, or alternatively using standard buffer systems. Among the acidifying agents that may be used, non-limiting mention may be made, for example, of mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid, sulphuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid and lactic acid, and sulphonic acids. Among the basifying agents that may be used, non-limting mention may be made, for example, of aqueous ammonia, alkaline carbonates, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine and derivatives thereof, sodium hydroxide, potassium hydroxide and the compounds of formula (I): wherein W is a propylene residue optionally substituted with an entity chosen from hydroxyl groups and C1-C4 alkyl radicals; Ra, Rb, Rc and Rd, which may be identical or different, are chosen from hydrogen atoms, and C1-C4 alkyl and C1-C4 hydroxyalkyl radicals. The dye composition as disclosed herein may be in various forms, such as in the form of liquids, creams or gels, or in any other form that is suitable for dyeing keratin fibers, such as human hair. A process of the present disclosure is a process wherein the composition as defined above is applied to the keratin fibers, and the color is developed with at least one oxidizing agent. The color may be revealed at acidic, neutral or alkaline pH and the oxidizing agent may be added to the composition of the invention just at the time of use, or it may be introduced using an oxidizing composition comprising it, applied simultaneously with or sequentially to the composition of the present disclosure. For example, according to one embodiment of the present disclosure, the composition as disclosed herein is mixed, for instance at the time of use, with a composition comprising, in a medium that is suitable for dyeing, at least one oxidizing agent, this oxidizing agent being present in an amount that is sufficient to develop a coloration. The mixture obtained is then applied to the keratin fibers. After a leave-in time ranging from 3 to 50 minutes, such as from 5 to 30 minutes, the keratin fibers are rinsed, washed with shampoo, rinsed again and then dried. The oxidizing agents conventionally used for the oxidation dyeing of keratin fibers include, for example, hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulphates, peracids, and oxidase enzymes, among which non-limiting mention may be made of peroxidases, 2-electron oxidoreductases such as uricases, and 4-electron oxygenases, for instance laccases. In one embodiment of the present disclosure, hydrogen peroxide is used. The oxidizing composition may also comprise various adjuvants conventionally used in hair dye compositions and as defined above. The pH of the oxidizing composition comprising the at least one oxidizing agent is such that, after mixing with the dye composition, the pH of the resulting composition applied to the keratin fibers ranges for example, from 3 to 12, such as from 5 to 11. It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibers and as defined above. The ready-to-use composition that is finally applied to the keratin fibers may be in various forms, such as in the form of liquids, creams or gels, or in any other form that is suitable for dyeing keratin fibers, such as human hair. Another embodiment of the present disclosure is a multi-compartment device or “kit” for dyeing, wherein at least one first compartment comprises a dye composition as disclosed herein, and at least one second compartment comprises an oxidizing composition. This device may be equipped with a means for applying the desired mixture to the hair, such as the devices described in French Patent FR 2,586,913 in the name of L'Oreal. Using this device, it is possible to dye keratin fibers with a process that involves mixing a dye composition of the present disclosure with at least one oxidizing agent as defined above, and applying the mixture obtained to the keratin fibers for a time that is sufficient to develop the desired coloration. Other than in the operating example, or where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. The following examples are intended to illustrate the invention without limiting the scope as a result. The percentages are given on a weight basis. The following example is intended to illustrate the invention without limiting the scope as a result. EXAMPLES Dye compositions were prepared as indicated below: Example 1 2 2-Chloro-6-methyl-3-aminophenol 1.37 g 1.37 g para-Phenylenediamine 0.71 g para-Tolylenediamine 0.53 g N,N-Bis(β-hydroxyethyl)-para-phenylenediamine 0.68 g sulphate monohydrate 2-(β-Hydroxyethyl)-para-phenylenediamine 1.05 g dihydrochloride Dye support (*) (*) Demineralized water qs 100 g 100 g (*): Common dye support Decyl alcohol containing 3 moles of ethylene oxide 17.5 g Decyl alcohol containing 5 moles of ethylene oxide 4.5 g Lauryl alcohol containing 12 moles of ethylene oxide 6.0 g Oleocetyl alcohol containing 30 moles of ethylene oxide 4.5 g Oleic acid 2.0 g Oleyl alcohol 1.8 g Alkyl(C13/C15)ether carboxylic acid monoethanolamide 4.0 g containing 2 moles of ethylene oxide Glycerol 3.0 g Tetramethylhexamethylene diamine/dichloro 1,3 propylene 2.0 g polycondensate as an aqueous solution containing 60% of A.S. (active substances) Merquat 280 2.0 g Sequestering agent qs Reducing agent qs Aqueous ammonia (20% NH3) 8.0 g Aculyn 44 0.4 g Each composition was mixed, at the time of use, in a plastic bowl for two minutes, with an oxidizing composition given below, at a rate of 1 part of dye composition per 1.5 parts of oxidizing composition. Cetylstearyl alcohol 2.3 g Cetylstearyl alcohol containing 30 moles of ethylene oxide 0.6 g Alkyl(C13/C15 70/30, 50% linear)ether carboxylic acid 0.9 g monoethanolamide containing 2 moles of ethylene oxide Glycerol 0.5 g Hydrogen peroxide 7.5 g Stabilizers qs Sequestering agents qs Fragrance qs Demineralized water, qs 100 g Each of the two mixtures obtained was applied to locks of natural hair containing 90% white hairs, and was left on for 30 minutes. The locks were rinsed with water, washed with a standard shampoo, rinsed again and then dried. The hair coloration was evaluated visually. The shades obtained are given in the table below. Example 1 2 Tone height chestnut light chestnut Glint purplish purplish | 20040429 | 20071127 | 20050106 | 68296.0 | 0 | ELHILO, EISA B | DYE COMPOSITION COMPRISING 2-CHLORO-6-METHYL-3-AMINOPHENOL, AT LEAST TWO OXIDATION BASES CHOSEN FROM PARA-PHENYLENEDIAMINE DERIVATIVES AND AT LEAST ONE ASSOCIATIVE THICKENING POLYMER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,834,451 | ACCEPTED | Methods and apparatus for improving data integrity for small computer system interface (SCSI) devices | A SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device. | 1. A method for improving data integrity for small computer system interface (SCSI) devices, comprising: identifying, on a SCSI bus at a SCSI device, a SCSI ID of a SCSI initiator device that has won an arbitration; storing the SCSI ID in a register at the SCSI device; identifying, on the SCSI bus at the SCSI device, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device; comparing the SCSI ID of the selected SCSI target device and a SCSI ID of the SCSI device; if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are the same: comparing the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register; processing a SCSI command from the SCSI initiator device if the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are different; and refraining from processing the SCSI command from the SCSI initiator device if the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are the same. 2. The method of claim 1, wherein the SCSI device comprises a disk drive. 3. The method of claim 1, wherein the SCSI device comprises a hard disk drive and the method is employed in a hard disk controller (HDC) of the hard disk drive. 4. The method of claim 1, wherein the SCSI initiator device comprises a server. 5. The method of claim 1, further comprising: repeating the act of identifying and storing the SCSI ID of a SCSI initiator device for each phase of a plurality of arbitration phases. 6. The method of claim 1, wherein the SCSI command comprises a WRITE command. 7. The method of claim 1, wherein the SCSI command comprises a READ command. 8. The method of claim 1, further comprising: refraining from processing the SCSI command from the SCSI initiator device if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are different. 9. The method of claim 1, further comprising: wherein the SCSI initiator device wins an arbitration during an arbitration phase; and wherein the SCSI device receives the SCSI ID of the selected SCSI target device during a selection phase. 10. A method for improving data integrity for small computer system interface (SCSI) devices, comprising: identifying, on a SCSI bus at a SCSI device, a SCSI ID of a selected SCSI target device; comparing the SCSI ID of the selected SCSI target device and a SCSI ID corresponding to a SCSI initiator device that has won an arbitration; and refraining from processing a SCSI command from the SCSI initiator device based on determining that the SCSI ID of the selected target SCSI device and the SCSI ID corresponding to the SCSI initiator device are the same. 11. The method of claim 10, further comprising: identifying, on the SCSI bus at the SCSI device, the SCSI ID of the SCSI initiator device that has won the arbitration; and storing the SCSI ID in a register at the SCSI device. 12. The method of claim 10, further comprising: refraining from performing the comparing if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are different. 13. The method of claim 10, further comprising: if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are the same: processing the SCSI command from the SCSI initiator device based on determining that the SCSI ID of the selected target SCSI device and the SCSI ID corresponding to the SCSI initiator device are different. 14. The method of claim 10, wherein the SCSI device comprises a disk drive. 15. A disk drive, comprising: one or more disks; a controller; a small computer system interface (SCSI) interface for coupling to a SCSI bus; the controller being adapted to compare a SCSI ID of the selected SCSI target device on the SCSI bus and a SCSI ID of the SCSI device and, if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are determined to be the same: compare the SCSI ID of a selected SCSI target device on the SCSI bus and a SCSI ID corresponding to a SCSI initiator device stored in a register accessible to the controller; process a SCSI command from the SCSI initiator device if no match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register; and refrain from processing the SCSI command from the SCSI initiator device if a match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register. 16. The disk drive of claim 15, wherein the SCSI command comprises a WRITE command. 17. The disk drive of claim 15, wherein the SCSI command comprises a READ command. 18. The disk drive of claim 15, wherein the SCSI initiator device comprises a computer or server. 19. A system which utilizes small computer system interface (SCSI) communications, comprising: a SCSI initiator device; a plurality of SCSI target devices; a SCSI bus for coupling the SCSI initiator device and the plurality of SCSI target devices through SCSI interfaces; the SCSI initiator device being adapted to assert its SCSI ID on the SCSI bus after winning an arbitration for control over the SCSI bus; at least one of the SCSI target devices being adapted to: store the SCSI ID of the SCSI initiator device in a register; identify, on the SCSI bus, a SCSI ID of a selected SCSI target device selected by the SCSI initiator device; compare the SCSI ID of the selected SCSI target device and a SCSI ID of the SCSI target device; if a match exists between the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI target device: compare the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register; process a SCSI command from the SCSI initiator device if the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are different; and refrain from processing the SCSI command from the SCSI initiator device if a match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register. 20. The system of claim 19, wherein the SCSI target device comprises a disk drive. 21. The system of claim 19, wherein the SCSI target device comprises a hard disk drive and the method is employed in a hard disk controller (HDC) of the hard disk drive. 22. The system of claim 19, wherein the SCSI initiator device comprises a server. 23. The system of claim 19, further comprising: wherein the SCSI target device is further adapted to repeat the storing of the SCSI ID of a SCSI initiator device for each of a plurality of arbitration phases. 24. The system of claim 19, wherein the SCSI command comprises a WRITE command. 25. The system of claim 19, wherein the SCSI command comprises a READ command. 26. The system of claim 19, wherein the SCSI target device is further adapted to refrain from processing the SCSI command from the SCSI initiator device if no match exists between the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to methods and apparatus for improving data integrity for small computer system interface (SCSI) devices. 2. Description of the Related Art A small computer system interface (SCSI) is a well known and widely used type of interface for computer and data storage devices. A SCSI is generally used to couple a computer system to a device or to couple devices together for communications. Communications are provided between the computer system and the device or between devices through a SCSI interface using a SCSI protocol. SCSI communication generally works very well and is commercially popular. However, a particular data integrity problem with the SCSI protocol has been found when a SCSI “initiator” device is assigned with the same SCSI ID as an SCSI “target” device. This problem will be described in detail with respect to FIGS. 1 and 2. FIG. 1 is an illustrative representation of a SCSI initiator device 102 and a plurality of SCSI target devices 104. SCSI initiator device 102 and the plurality of SCSI target devices 104 are coupled together for communication via a SCSI bus 112. SCSI initiator device 102 may be a computer or server and SCSI target devices 104 may be hard disk drives, for example. In this example, there are three (3) SCSI target devices 104 which include SCSI target devices 106, 108, and 110. Each SCSI device 102, 106, 108, and 110 is assigned a SCSI ID. In this example, SCSI initiator device 102 is assigned SCSI ID=3, SCSI target device 106 is assigned SCSI ID=1, SCSI target device 108 is assigned SCSI ID=2, and SCSI target device 110 is assigned SCSI ID=3. Note that SCSI initiator device 102 is assigned with the same SCSI ID as SCSI target device 110 (i.e. SCSI ID=3). If SCSI initiator device 102 selects SCSI target device 108, for example, SCSI target device 110 will undesirably respond to the selection intended for SCSI target device 108. When this occurs, there is no conventional mechanism which prevents the wrong target (e.g. SCSI target device 110) from taking control of SCSI bus 112 and completing the SCSI protocol which includes Command, Data, and Status phases. If the SCSI command intended for SCSI target device 108 is a WRITE command (e.g. SCSI opcodes 0x0A, 0x2A, 0x2E, 0x3F, 0x41), data on the media of SCSI target device 110 is corrupted with data intended to be written at SCSI target device 108. If the SCSI command intended for SCSI target device 108 is a READ command (SCSI opcodes 0x08, 0x28, 0x3E), data from SCSI target device 110 would be returned to SCSI initiator device 102. In both cases, data integrity has been compromised. Even other SCSI commands will compromise data integrity with this scenario. FIG. 2 is a flowchart which describes the data integrity problem in further detail. FIGS. 1 and 2 will be referred to in combination in the following description. Beginning at a start block 202 of FIG. 2, SCSI initiator device 102 having SCSI ID=3 selects SCSI target device 108 having SCSI=2 on SCSI bus 112 (step 204 of FIG. 2). In response, SCSI target device 110 having SCSI=3 detects its own SCSI ID on SCSI bus 112 and responds to the selection (step 206 of FIG. 2). In effect, SCSI target device 110 “thinks” it has been selected by SCSI initiator device 102. SCSI target device 110 therefore takes control over SCSI bus 112 and proceeds to the next bus phase(s) (step 208 of FIG. 2). Next, SCSI initiator device 102 transmits a WRITE command on SCSI bus 112 (step 210). In response, SCSI target device 110 completes “Message Out” and “Command” phases for the write and disconnects from SCSI bus 112 (step 214 of FIG. 2). SCSI target device 110 then prepares its buffers, reconnects to SCSI bus 112, and selects SCSI target device 108 having SCSI ID=2 (step 216 of FIG. 2). In response, SCSI initiator device 110 having SCSI ID=3 detects its own SCSI ID on SCSI bus 112, thinking that SCSI target device 110 has reselected it, and responds to the reselection (step 218 of FIG. 2). SCSI target device 110 is now connected to SCSI initiator device 102. SCSI target device 110 then requests “Data-Out” for the WRITE command (step 220 of FIG. 2). In response, SCSI initiator device 102 writes data to the media (e.g. a disk) at SCSI target device 110 (step 222 of FIG. 2). After completion, SCSI target device 110 responds with a “Good Status” indication to SCSI initiator device 110 (step 226 of FIG. 2) and Command Complete (step 228 of FIG. 2). As apparent, SCSI target device 110 has been undesirably corrupted with data not intended to be written to it. Accordingly, there is an existing need to overcome these and other deficiencies of the prior art. SUMMARY Methods and apparatus for improved data integrity for small computer system interface (SCSI) devices are described herein. In one illustrative example of the present invention, a SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device. BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and advantages of the present invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings: FIG. 1 is an illustrative representation of a SCSI initiator device coupled to a plurality of SCSI target devices via a SCSI bus, for illustrating a problem of SCSI data integrity; FIG. 2 is a flowchart which describes the problem of SCSI data integrity in more detail; FIG. 3 is an illustrative representation of a SCSI initiator device coupled to a plurality of SCSI target devices via a SCSI bus, the environment within which the present invention may be embodied; FIG. 4 is a first portion of a flowchart of FIGS. 4-5 which describes a method of improving data integrity for SCSI devices; and FIG. 5 is a second portion of the flowchart of FIGS. 4-5 which describes a method of improving data integrity for SCSI devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Methods and apparatus for improved data integrity for small computer system interface (SCSI) devices are described herein. In one illustrative example of the present invention, a SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device. The following description represents several embodiments presently contemplated for carrying out the present invention. This description is made for the purpose of illustrating the general principles of the present invention and is not meant to limit the inventive concepts claimed herein. FIG. 3 is an illustrative representation of a system 302 having improved data integrity for small computer system interface (SCSI) devices. System 302 includes a SCSI initiator device 304 and a plurality of SCSI target devices 306. SCSI initiator device 304 and the plurality of SCSI target devices 306 are coupled together for communication via a SCSI bus 314. In this example, there are three (3) SCSI target devices 306 which include SCSI target devices 308, 310, and 312. Each SCSI device 304, 308, 310, and 312 is assigned a SCSI ID. Note that SCSI initiator device 304 may be assigned with the same SCSI ID as one of the SCSI target devices 306. SCSI initiator device 304 may be a computer or server and SCSI target devices 306 may be a SCSI data storage device, such as but not limited to a hard disk drive as depicted in FIG. 3. Each hard disk drive includes one or more hard disks, a hard disk controller (HDC), and an SCSI interface. For example, SCSI device 308 which is a hard disk drive includes one or more hard disks 320, a HDC 322, and an SCSI interface 324. System 302 is also illustrated with more generality in FIG. 3 in a system 350 depicted below it, which includes a plurality of SCSI devices 356 coupled via a service delivery subsystem 364 (e.g. a SCSI bus). Each SCSI device 356 includes at least a controller (such as a hard disk controller or HDC) and a SCSI interface. The primary approach taken by the present invention involves storing the SCSI ID of the SCSI device that has won arbitration into a register of each SCSI device. The stored SCSI ID is used by each SCSI device in the configuration to ensure that it does not conflict with the SCSI ID of a selected SCSI device. If the SCSI IDs are in conflict (i.e. if they are equal), the selection phase is aborted by that particular (re)selected SCSI device; otherwise the selection phase is continued for that (re)selected SCSI device. More particularly, an arbitration state machine of each SCSI device in the configuration identifies the SCSI ID of the winner of an arbitration phase on the SCSI bus and stores it in a register. This special register may be referred to as an ARBWIN register (ARBWIN being short for “arbitration winner”). During a subsequent (re)selection phase, a (re)selection state machine of each SCSI device in the configuration identifies whether its SCSI ID is on the SCSI bus to determine if it has been (re)selected. If the SCSI device detects that it has been (re)selected, it compares its SCSI ID against the SCSI ID stored in the ARBWIN register. If the SCSI IDs are equal, an invalid condition has been detected (i.e. the initiator and the target have the same SCSI ID) and the selection state machine is aborted until the next (re)selection occurs. Particularly, the SCSI device causes a (re)selection timeout to occur in response to the invalid condition, to thereby prevent it from being improperly (re)selected and continuing with the protocol. If the SCSI IDs are different, the selection state machine is continued and the SCSI protocol is followed as is conventional. Advantageously, the wrong SCSI device does not respond to SCSI commands (e.g. WRITE or READ commands) intended for a different SCSI device. Note that by using the language “(re)selection”, reference is being made to either case of selection (initiator to target) or reselection (target to initiator); however, the specification and claims may recite the language “selection” to embrace either case. With reference now to FIG. 3, assume that SCSI initiator device 304 won an arbitration during an arbitration phase. Each SCSI target device 306 stores the SCSI ID of SCSI initiator device 304 from SCSI bus 314 in its associated ARBWIN register. This register is accessible by and preferably contained in the controller (e.g. the HDC) of each SCSI device. Subsequently, a SCSI ID of a selected SCSI target device is identified on SCSI bus 314 by all SCSI target devices 306. If the SCSI ID of the selected SCSI target device on SCSI bus 314 and the SCSI ID of the SCSI device are the same, the SCSI ID of the selected SCSI target device and the SCSI ID stored in the ARBWIN register are compared. A SCSI command issued by SCSI initiator device 304 is processed by the selected SCSI device based on its determining that the SCSI ID of the selected target SCSI device and the SCSI ID stored in its ARBWIN register are different. On the other hand, the SCSI command issued by SCSI initiator device 304 is not processed based on determining that the SCSI ID of the selected target SCSI device and the SCSI ID stored in its ARBWIN register are the same. FIG. 4 is a first portion of a flowchart which describes a method of improving data integrity for SCSI devices in further detail. This first portion of the flowchart corresponds to a SCSI “arbitration phase” of the method. Beginning at a start block. 402, a bus free phase is validated by an SCSI device for the arbitration phase (step 404). After waiting a delay period for bus settling (step 406), the SCSI device asserts a BSY signal (i.e. “Busy” signal for bus being in-use) and its own SCSI ID on the SCSI bus (step 408). After waiting a delay period for bus settling (step 410), the SCSI device identifies whether it has won arbitration (step 412). If the SCSI device did not win the arbitration at step 412 (“No”), the SCSI device clears all of its signals on the SCSI bus (step 414) and the flowchart repeats back at step 404 for subsequent arbitrations. If the SCSI device won the arbitration at step 412 (“Yes”), the SCSI device asserts a SEL signal (i.e. “Selection” signal for particular SCSI device) and asserts its own SCSI ID on the SCSI bus (step 416). In response, each SCSI device in the configuration stores the SCSI ID of the arbitration winner in its associated ARBWIN register (step 418). The flowchart then proceeds to a (re)selection phase (step 420). Note that the method of FIG. 4 occurs for each arbitration performed in the configuration, where each SCSI device writes over the SCSI ID of the previous arbitration in the ARBWIN register. FIG. 5 is a second portion of the flowchart of FIG. 4 which describes a method of improving data integrity for SCSI devices in further detail. This second portion of the flowchart corresponds to a SCSI “selection phase” which immediately follows the arbitration phase. Beginning at a start block 502, a selection phase is validated by an SCSI device for the selection phase (step 504). A SCSI initiator device that has won the previous arbitration (e.g. see FIG. 4) selects one of the SCSI target devices by outputting the target SCSI ID on the SCSI bus. Each SCSI device in the configuration monitors the SCSI bus to determine whether it has been selected, that is, whether the SCSI ID on the SCSI bus matches its own SCSI ID (step 506). If the SCSI device has not been selected at step 506 (i.e. its SCSI ID is not on the SCSI bus), then the flowchart repeats beginning again at step 504 for subsequent selections. If the SCSI device, has been selected at step 506 (i.e. if its SCSI ID is on the SCSI bus), then the SCSI device compares its SCSI ID with the SCSI ID stored in its ARBWIN register (step 508). If the SCSI IDs are the same at step 508, then the SCSI device aborts the selection phase and the flowchart repeats beginning again at step 504 for subsequent selections. Specifically, the SCSI target device causes a selection timeout to occur in response to the invalid condition, to prevent it from being improperly selected and continuing with the protocol. Any subsequent SCSI command (e.g. WRITE or READ command) from the SCSI initiator device will be ignored by the SCSI device. If the SCSI IDs are different at step 508, however, then the SCSI continues with the selection phase as is conventional though steps 512, 514, 516, and 518. In particular, the SCSI device identifies whether the SCSI initiator device has negated the SEL signal on the SCSI bus (step 512) and, when it has, it continues to step 514. In step 514, the SCSI device identifies whether the SCSI initiator device has asserted an ATN signal (i.e. “Attention” signal for message ready) on the SCSI bus. If the ATN signal is asserted at step 514, then the SCSI device proceeds to the “Message Out” phase in step 516. If the ATN signal is not asserted at step 514, then the SCSI device proceeds to the “Command Phase” or “Data Phase” in step 518. Such subsequent conventional steps may include the processing of a WRITE command or a READ command, for example. Methods and apparatus for improved data integrity for small computer system interface (SCSI) devices have been described. In one illustrative example of the present invention, a SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device. Thus, a method of the present invention may include the acts of identifying, on a SCSI bus at a SCSI device, a SCSI ID of a selected SCSI target device; and if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are the same: comparing the SCSI ID of the selected SCSI target device and a SCSI ID corresponding to a SCSI initiator device stored in a register at the SCSI device; processing a SCSI command from the SCSI initiator device based on determining that the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are different; and refraining from processing the SCSI command from the SCSI initiator device based on determining that the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are the same. A system of the present invention which utilizes SCSI communication includes a SCSI initiator device; a plurality of SCSI target devices; and a SCSI bus for coupling the SCSI initiator device and the plurality of SCSI target devices through SCSI interfaces of the devices. The SCSI initiator device is adapted to assert its SCSI ID on the SCSI bus after winning an arbitration for control over the SCSI bus. At least one of the SCSI target devices is adapted to store the SCSI ID of the SCSI initiator device in a register; identify, on the SCSI bus, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device; compare the SCSI ID of the selected SCSI target device and a SCSI ID of the SCSI target device; and if a match exists between the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI target device: compare the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register; process a SCSI command from the SCSI initiator device if the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register are different; and refrain from processing the SCSI command from the SCSI initiator device if a match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register. A disk drive of the present invention includes one or more disks; a controller; and a SCSI interface for coupling to the controller and to a SCSI bus. The controller is adapted to compare a SCSI ID of the selected SCSI target device on the SCSI bus and a SCSI ID of the SCSI device and, if the SCSI ID of the selected SCSI target device and the SCSI ID of the SCSI device are determined to be the same: compare the SCSI ID of a selected SCSI target device on the SCSI bus and a SCSI ID corresponding to a SCSI initiator device stored in a register which is accessible by the controller; process a SCSI command from the SCSI initiator device if no match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register; and refrain from processing the SCSI command from the SCSI initiator device if a match exists between the SCSI ID of the selected target SCSI device and the SCSI ID stored in the register. It is to be understood that the above is merely a description of preferred embodiments of the invention and that various changes, alterations, and variations may be made without departing from the true spirit and scope of the invention as set for in the appended claims. Note that by using the language “(re)selection”, reference is being made to either case of selection (initiator to target) or reselection (target to initiator); however, the specification and claims may recite the language “selection” to embrace either case. Few if any of the terms or phrases in the specification and claims have been given any special meaning different from their plain language meaning, and therefore the specification is not to be used to define terms in an unduly narrow sense. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to methods and apparatus for improving data integrity for small computer system interface (SCSI) devices. 2. Description of the Related Art A small computer system interface (SCSI) is a well known and widely used type of interface for computer and data storage devices. A SCSI is generally used to couple a computer system to a device or to couple devices together for communications. Communications are provided between the computer system and the device or between devices through a SCSI interface using a SCSI protocol. SCSI communication generally works very well and is commercially popular. However, a particular data integrity problem with the SCSI protocol has been found when a SCSI “initiator” device is assigned with the same SCSI ID as an SCSI “target” device. This problem will be described in detail with respect to FIGS. 1 and 2 . FIG. 1 is an illustrative representation of a SCSI initiator device 102 and a plurality of SCSI target devices 104 . SCSI initiator device 102 and the plurality of SCSI target devices 104 are coupled together for communication via a SCSI bus 112 . SCSI initiator device 102 may be a computer or server and SCSI target devices 104 may be hard disk drives, for example. In this example, there are three (3) SCSI target devices 104 which include SCSI target devices 106 , 108 , and 110 . Each SCSI device 102 , 106 , 108 , and 110 is assigned a SCSI ID. In this example, SCSI initiator device 102 is assigned SCSI ID=3, SCSI target device 106 is assigned SCSI ID=1, SCSI target device 108 is assigned SCSI ID=2, and SCSI target device 110 is assigned SCSI ID=3. Note that SCSI initiator device 102 is assigned with the same SCSI ID as SCSI target device 110 (i.e. SCSI ID=3). If SCSI initiator device 102 selects SCSI target device 108 , for example, SCSI target device 110 will undesirably respond to the selection intended for SCSI target device 108 . When this occurs, there is no conventional mechanism which prevents the wrong target (e.g. SCSI target device 110 ) from taking control of SCSI bus 112 and completing the SCSI protocol which includes Command, Data, and Status phases. If the SCSI command intended for SCSI target device 108 is a WRITE command (e.g. SCSI opcodes 0x0A, 0x2A, 0x2E, 0x3F, 0x41), data on the media of SCSI target device 110 is corrupted with data intended to be written at SCSI target device 108 . If the SCSI command intended for SCSI target device 108 is a READ command (SCSI opcodes 0x08, 0x28, 0x3E), data from SCSI target device 110 would be returned to SCSI initiator device 102 . In both cases, data integrity has been compromised. Even other SCSI commands will compromise data integrity with this scenario. FIG. 2 is a flowchart which describes the data integrity problem in further detail. FIGS. 1 and 2 will be referred to in combination in the following description. Beginning at a start block 202 of FIG. 2 , SCSI initiator device 102 having SCSI ID=3 selects SCSI target device 108 having SCSI=2 on SCSI bus 112 (step 204 of FIG. 2 ). In response, SCSI target device 110 having SCSI=3 detects its own SCSI ID on SCSI bus 112 and responds to the selection (step 206 of FIG. 2 ). In effect, SCSI target device 110 “thinks” it has been selected by SCSI initiator device 102 . SCSI target device 110 therefore takes control over SCSI bus 112 and proceeds to the next bus phase(s) (step 208 of FIG. 2 ). Next, SCSI initiator device 102 transmits a WRITE command on SCSI bus 112 (step 210 ). In response, SCSI target device 110 completes “Message Out” and “Command” phases for the write and disconnects from SCSI bus 112 (step 214 of FIG. 2 ). SCSI target device 110 then prepares its buffers, reconnects to SCSI bus 112 , and selects SCSI target device 108 having SCSI ID=2 (step 216 of FIG. 2 ). In response, SCSI initiator device 110 having SCSI ID=3 detects its own SCSI ID on SCSI bus 112 , thinking that SCSI target device 110 has reselected it, and responds to the reselection (step 218 of FIG. 2 ). SCSI target device 110 is now connected to SCSI initiator device 102 . SCSI target device 110 then requests “Data-Out” for the WRITE command (step 220 of FIG. 2 ). In response, SCSI initiator device 102 writes data to the media (e.g. a disk) at SCSI target device 110 (step 222 of FIG. 2 ). After completion, SCSI target device 110 responds with a “Good Status” indication to SCSI initiator device 110 (step 226 of FIG. 2 ) and Command Complete (step 228 of FIG. 2 ). As apparent, SCSI target device 110 has been undesirably corrupted with data not intended to be written to it. Accordingly, there is an existing need to overcome these and other deficiencies of the prior art. | <SOH> SUMMARY <EOH>Methods and apparatus for improved data integrity for small computer system interface (SCSI) devices are described herein. In one illustrative example of the present invention, a SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device. | 20040429 | 20080311 | 20051103 | 65186.0 | 0 | PHAN, DEAN | METHODS AND APPARATUS FOR IMPROVING DATA INTEGRITY FOR SMALL COMPUTER SYSTEM INTERFACE (SCSI) DEVICES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,834,463 | ACCEPTED | Systems and methods for monitoring network exchanges between a client and a server | Systems and methods for monitoring exchanges between a client and a server across a network. Implementation of the present invention takes place in association with a client and server that use standard Internet protocol to exchange requests and responses over a network. An extendable network monitor is employed to obtain a network monitor trace. Entire requests and responses are rebuilt. Chunked information is coalesced. Interleaved packets are collected. Bodies of data written in extensible markup language are reformatted by including white space and highlighting important data. Bodies of data written in hyper-text markup language are optionally removed from the requests and responses. As such, and in accordance with the present invention, the requests and responses exchanged by a client and a server across a network are made easily readable to a user, thereby allowing the user to read, interpret, and analyze the exchanges to ensure that the exchanges occurred correctly and as expected. | 1. In a networked computer system that includes a plurality of interleaved packets transmitted across a network and a plurality of buffers, one or more of the plurality of packets representing a first exchange and one or more of the plurality of packets representing a second exchange, a method for sorting the packets comprising the steps for: identifying for each transmitted packet a source port and a destination port for the packet; storing each packet in one of the plurality of buffers, wherein each buffer represents a unique combination of source port and destination port, and wherein a buffer stores all packets representing an exchange that corresponds to the unique combination; determining whether all transmitted packets representing a first exchange have been stored in a first buffer; flushing the first buffer upon determining that all transmitted packets representing the first exchange have been stored in the first buffer; and resetting the first buffer. 2. A method as recited in claim 1, wherein a code is used to represent the unique combination. 3. A method as recited in claim 1, wherein the step for determining is performed by comparing a number of bytes in the first buffer with a number of bytes provided in a packet header. | This application is a divisional of U.S. application Ser. No. 09/579,946, filed May 26, 2000, entitled “Systems and Methods for Monitoring Network Exchanges Between a Client and a Server.” For purposes of disclosure, the foregoing application is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. The Field of the Invention The present invention relates to systems and methods for monitoring exchanges between a client and a server across a network. More specifically, the present invention relates to systems and methods that read a network monitor trace and rebuild the requests and responses to make the exchanges easily readable to a user by rebuilding entire requests and responses, coalescing chunked information, collecting interleaved packets, reformatting extensible markup language (“XML”) bodies, if present, and optionally removing any hyper-text markup language (“HTML”) bodies from the requests and responses. 2. The Relevant Technology The Internet protocol known as hyper-text transfer protocol—distributed authoring and versioning (“HTTP/Dav”) is becoming the foundation for application development on exchange server technology, which employs a client/server relationship. The HTTP/Dav protocol uses XML to execute requests and corresponding responses between a client and a server across a network. The requests and responses pass through a protocol stack in order to be transmitted across the network. To provide a more efficient transmission across the network, it is customary for a protocol stack to dissect the request or response that passes through the stack into fragments. The fragments are then incorporated into blocks of data, known as “packets,” which are in the form of long buffers of bytes. The packets are then individually sent across the network connection. As such, and by way of example, a given request sent by a client to a server across a network can comprise many packets. While standard Internet protocol ensures that the packets of a specific request or response will be properly ordered once received, all of the packets that correspond to a given request or response are not necessarily transmitted together. Instead, the packets corresponding to a request or response are interleaved with packets that correspond to other requests and/or responses in order to optimize the transmission of data across the network. To further optimize the transmission of data across the network, the data in the body of the packet is frequently “chunked.” This means that rather than placing the data into a single buffer, the data is strung together. Therefore, by way of example, if a client communicates a 32-kilobyte request to a server, this request may be chunked into one or more segments that are strung together, each segment being transmitted individually to the server. The requests and responses exchanged between a client and a server are visible to a network monitor. The network monitor, also referred to as a “packet sniffer,” sees the packets that are transmitted across the network, arranges the packets in the order that they were sent, and creates a trace. While a network monitor trace is valuable for recording the HTTP/Dav activity, it is a very poor tool for analyzing the activity because it understands neither HTTP/Dav protocol nor XML. The trace displays the network packets as a very unfriendly jumble of bytes in what is known as the frame viewer window, which may provide, by way of example, six columns of text (generally in hex) that is six bytes wide and twenty pages deep. The reading of the trace is further complicated when the data is chunked because the data is all strung together. Furthermore, the reading of the trace becomes even more complicated because of the interleaving of the transmitted packets. As such, upon desiring to read the portion of the trace specific to a given request and/or response, a reader easily confuses data that he/she believes corresponds to the given request and/or response with data that corresponds to other requests and/or responses. BRIEF SUMMARY OF THE INVENTION The present invention relates to systems and methods for monitoring exchanges between a client and a server across a network. More specifically, the present invention relates to systems and methods that read a network monitor trace and rebuild the requests and responses to make the exchanges easily readable to a user by rebuilding entire requests and responses, coalescing chunked information, collecting interleaved packets, reformatting XML bodies if present, and optionally removing any HTML bodies from the requests and responses. Embodiments of the present invention may be practiced in network computing environments with many types of computer system configurations and provide a mechanism that allows for the viewing, interpretation and analysis of, by way of example, a network exchange between a client and a server. Embodiments of the present invention employ an extendable network monitor, such as by way of example, Full Netmon, to record the exchanges transmitted across a network. The network monitor obtains a copy of the exchange in a network monitor trace that is displayed in a very unfriendly jumble of bytes. The systems and methods of the present invention can call on, by way of example, an executable program module to allow the exchanges to be made easily readable so that the exchanges can be interpreted and analyzed to verify that the requests and/or responses occurred correctly and as expected. The information when exchanged is sent across a network in packets. The packets are gathered and the source and destination of each packet is identified. The packets are distributed to variable locations referred to as “buckets” for storage. Once in a bucket, the packet information is stored in a buffer until all of the packets corresponding to a particular exchange between a client and a server have been received. Once received, the packet information is processed so that the exchange can be read, interpreted and analyzed. The packet information is then flushed and the bucket is reset and made ready to be reused. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above-recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawing depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 illustrates an exemplary system that provides a suitable operating environment for the present invention; FIG. 2 is a block diagram that illustrates an exemplary configuration for practicing the present invention, where an exchange between a client and a server across a network is monitored to verify that the exchange occurred correctly and as expected; FIG. 3 is a flow chart that details an exemplary embodiment for gathering and distributing the packet information in accordance with the present invention; and FIG. 4 is a flow chart that details an exemplary embodiment for processing and formatting the packet information so that the exchange represented by the packets can be read, interpreted and analyzed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention extends to both systems and methods for monitoring exchanges between a client and a server across a network. More specifically, the present invention relates to systems and methods that read a network monitor trace and rebuild the requests and/or responses in such a way as to make the exchanges easily readable to a user by rebuilding entire requests and responses, coalescing chunked information, collecting interleaved packets, reformatting XML bodies if present, and optionally removing any HTML bodies from the requests and responses. Embodiments of the present invention may comprise a special purpose or general-purpose computer including various computer hardware, as discussed in greater detail below. Embodiments within the scope of the present invention also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store is desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such a connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of computer-readable media. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. FIG. 1 and the following discussion are intended to provide a brief, general description of a suitable computing environment in which the invention may be implemented. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by computers in network environments. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program code means for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps. Those skilled in the art will appreciate that the invention may be practiced in network computing environments with many types of computer system configurations, including personal computers, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination of hardwired or wireless links) through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. With reference to FIG. 1, an exemplary system for implementing the invention includes a general purpose computing device in the form of a conventional computer 20, including a processing unit 21, a system memory 22, and a system bus 23 that couples various system components including the system memory 22 to the processing unit 21. The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) 24 and random access memory (RAM) 25. A basic input/output system (BIOS) 26, containing the basic routines that help transfer information between elements within the computer 20, such as during start-up, may be stored in ROM 24. The computer 20 may also include a magnetic hard disk drive 27 for reading from and writing to a magnetic hard disk 39, a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29, and an optical disk drive 30 for reading from or writing to removable optical disk 31 such as a CD-ROM or other optical media. The magnetic hard disk drive 27, magnetic disk drive 28, and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32, a magnetic disk drive-interface 33, and an optical drive interface 34, respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer-executable instructions, data structures, program modules and other data for the computer 20. Although the exemplary environment described herein employs a magnetic hard disk 39, a removable magnetic disk 29 and a removable optical disk 31, other types of computer readable media for storing data can be used, including magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, RAMs, ROMs, and the like. Program code means comprising one or more program modules may be stored on the hard disk 39, magnetic disk 29, optical disk 31, ROM 24 or RAM 25, including an operating system 35, one or more application programs 36, other program modules 37, and program data 38. A user may enter commands and information into the computer 20 through keyboard 40, pointing device 42, or other input devices (not shown), such as a microphone, joy stick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 coupled to system bus 23. Alternatively, the input devices may be connected by other interfaces, such as a parallel port, a game port or a universal serial bus (USB). A monitor 47 or another display device is also connected to system bus 23 via an interface, such as video adapter 48. In addition to the monitor, personal computers typically include other peripheral output devices (not shown), such as speakers and printers. The computer 20 may operate in a networked environment using logical connections to one or more remote computers, such as remote computers 49a and 49b. Remote computers 49a and 49b may each be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 20, although only memory storage devices 50a and 50b and their associated application programs 36a and 36b have been illustrated in FIG. 1. The logical connections depicted in FIG. 1 include a local area network (LAN) 51 and a wide area network (WAN) 52 that are presented here by way of example and not limitation. Such networking environments are commonplace in office-wide or enterprise-wide computer networks, intranets and the Internet. When used in a LAN networking environment, the computer 20 is connected to the local area network 51 through a network interface or adapter 53. When used in a WAN networking environment, the computer 20 may include a modem 54, a wireless link, or other means for establishing communications over the wide area network 52, such as the Internet. The modem 54, which may be internal or external, is connected to the system bus 23 via the serial port interface 46. In a networked environment, program modules depicted relative to the computer 20, or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing communications over wide area network 52 may be used. While those skilled in the art will appreciate that the present invention may be practiced in network computing environments with many types of computer system configurations, FIG. 2 illustrates an exemplary configuration for an exchange to occur between a client and a server across a network such that the exchange can be viewed, interpreted and analyzed to ensure that the exchange occurred correctly and as expected. In FIG. 2, client 60 is a client that communicates with a server 70 across a network 66. Both client 60 and server 70 include a network interface to enable the communication between client 60 and server 70 across network 66. The network interfaces are respectively illustrated as network interface 62 and network interface 72. Each network interface includes a pathway for data to enter into and exit out of the network interface. The pathway is referred to as a “port.” FIG. 2 illustrates the embodiment where network 66 is the Internet and Internet protocol, such as, by way of example, HTTP/Dav is employed in a client/server configuration. In the configuration, a request for processing is made across the network and is followed by a response that is received in reply to the initial request. By way of example, in the embodiment illustrated in FIG. 2, a request for processing is sent from client 60 and is received by server 70. Since the request originated at client 60 and was sent to server 70, the port included in network interface 62 is illustrated as a source port 64 and likewise the port included in network interface 72 is illustrated as a destination port 74. In reply to the request, server 70 sends back a response to client 60. It is desirable to be able to view, interpret and analyze the requests and responses exchanged between a source port and a destination port in order to verify that the requests and/or responses occurred correctly and as expected between the client and the server. An extendable network monitor, such as, by way of example, Full Netmon, can be employed to record the exchanges transmitted across a network and can call on, by way of example, an executable program module to allow the exchanges to be easily readable, as will be further discussed below in accordance with FIGS. 3 and 4. When information is transmitted across a network, the information is individually sent in blocks of data to efficiently transmit the information. These blocks of data are commonly referred to as packets, frames, or datagrams, and each block of data is in the form of a long buffer of bytes. The data blocks or packets are visible to the network monitor, which obtains a copy of the packets, arranges the packets in the order that they were sent, and creates a trace. While a network monitor creates a trace of the information sent across a network, the packets are displayed in a very unfriendly jumble of bytes within the trace. By way of example, the trace may provide six columns of text (generally in hex) that may be six bytes wide and twenty pages deep. Furthermore, the packets of one request or response are generally interleaved with packets of other requests and/or responses in the trace since that is the way the packets were sent in order to make the data transmission more efficient across the network. In accordance with the systems and methods of the present invention, the requests and responses can be made to be easily readable and thus the requests and corresponding responses that are exchanged between a client and a server can be interpreted and analyzed to verify that the requests and/or responses occurred correctly and as expected. Referring now to FIG. 3, a flow diagram is illustrated that details an exemplary embodiment for gathering packets into a network monitor trace, identifying the source and destination of each packet, and distributing the packets to variable locations referred to as “buckets” for storage. Each variable location or bucket uniquely stores packets that have a specific combination of source port and destination port. As explained above, packets transmitted across a network are visible to a network monitor and in step 80 of FIG. 3 the network monitor collects a packet. The collected packet is an identical copy of the original packet transmitted across the network. In accordance with the present invention, once a packet is collected, execution proceeds to step 82, which identifies the source port and destination port that correspond to the collected packet. By way of example, the collected packet may correspond to a request sent from client 60 of FIG. 2 to server 70 across network 66. In the example, the source and destination ports corresponding to the collected packet would therefore be source port 64 and destination port 74. Every source port and destination port is unique and identifiable and, therefore, each combination of source port and destination port that corresponds to a collected packet is also unique and identifiable. A numeric code, referred to as a “key,” is used to represent the combination of source port and destination port that corresponds to a collected packet. The key can be, by way of example, a 32-bit number that is a unique identifier for an exchange or communication between a given source port and destination port. After the source port and destination port that correspond to the collected packet are identified in step 82, execution proceeds to decision block 84 to determine whether or not a key exists for the combination of source port and destination port that corresponds to the collected packet. The keys are stored in a listing such as, by way of example, a table, a list, a tree, or the like. In the embodiment illustrated in FIG. 3, the listing is a table and if decision block 84 determines that a key exists for the combination of source port and destination port that corresponds to the collected packet, execution proceeds to step 86 to locate the key in the table. Alternatively, if decision block 84 determines that a key does not exist for the combination of source port and destination port that corresponds to the collected packet, a key is created in step 86 and is included in the table. Upon creating the key in step 86, execution proceeds to step 88 to locate the key in the table. Once the key is located in the table, decision block 90 determines whether or not a bucket exists for the key. A bucket is a variable location that stores packets having the identical key. The table can, by way of example, correlate existing keys with existing buckets. If a bucket corresponding to the key of the collected packet exists, the collected packet is pushed to the bucket in step 94 for storing the collected packet in the bucket. Alternatively, if decision block 90 determines that a bucket corresponding to the key of the collected packet does not exist, execution proceeds to step 92, where a bucket is created for the key and the collected packet is then pushed to the bucket in step 94 to store the collected packet in the created bucket. Upon pushing the packet to the corresponding bucket, execution returns back to step 80 for the collection of another packet. In an embodiment of the present invention, the process detailed in FIG. 3 continues and allows a copy of each packet transmitted across a network to be stored in a bucket that corresponds to the key for that collected packet. As such, a bucket collects a variety of packets, each representing part of an exchange made between a client and a server across a network. Referring now to FIG. 4, a flow chart is illustrated that details an exemplary embodiment for processing and formatting the packet information stored within an individual bucket to ensure that all of the packets corresponding to a particular exchange between a client and a server have been received, and to cause the packet information to be humanly readable in order for the exchange to be interpreted and analyzed. Once a packet is pushed to a bucket, as illustrated in step 94 of FIG. 3, decision block 100 of FIG. 4 determines whether or not all of the headers have been received. In the embodiment illustrated in FIG. 4, the standard Internet protocol referred to as HTTP is employed for transmitting information over a network. In accordance with HTTP, the headers are separated from the body by an empty line, such as, by way of example, a line with nothing preceding a carriage return line feed (“CRLF”). The reception of an empty line indicates that all of the headers have been received and thus the entire packet has been collected for a particular request-response exchange. If decision block 100 determines that all of the headers have not yet been received, such as, by not having received an empty line, the collected packet is placed into a buffer within the bucket in step 102 and execution proceeds to step 104 where the network monitor collects a packet. (Step 104 of FIG. 4 is identical to step 80 of FIG. 3.) Alternatively, if decision block 100 determines that all of the headers have been received, indicating that the entire packet has been collected, execution proceeds to decision block 106 for a determination of whether or not the body is chunked. In accordance with standard Internet protocol, chunked encoding is a way of stringing data together without placing the data in a single buffer. By employing the process of chunked encoding, the transmission of information across a network can be optimized. Therefore, it is common for the body of an HTTP-Dav request or response to be chunked. Decision block 106 separates packets that have undergone a process of chunked encoding from packets that have undergone another encoding process, such as, by way of example, the process of content encoding. If it is determined at decision block 106 that the collected packet has not undergone a process of chunked encoding, execution proceeds to decision block 108 for a determination of whether the bucket is complete. By way of example, when content encoding is employed, a header called “content length” is used. In accordance with standard Internet protocol, content length provides the number of bytes that are located in the body of an exchange. Therefore, if the number of bytes located in the buffer of the bucket equals the number of bytes provided by content length then decision block 108 determines that all of the packets for a given exchange have been collected. The bucket is therefore complete and execution proceeds to decision block 110. Alternatively, if the number of bytes located in the buffer of the bucket does not equal the number of bytes provided by “content length,” then decision block 108 determines that all of the packets for a given exchange have not been collected. Therefore, the bucket is not complete and execution proceeds to step 102. As provided above, in step 102 the collected packet is placed into a buffer within the uncompleted bucket and execution proceeds to step 104 where the network monitor collects a packet. (Step 104 of FIG. 4 is identical to step 80 of FIG. 3.) Returning to decision block 106, if it is determined that the body of the HTTP-Dav request or response is chunked, execution proceeds to step 112 where a flag is set. The flag notifies that the body has undergone a process of chunked encoding and thus the content length is unknown. Embodiments in accordance with the present invention account for the situation where the body is chunked and the chunk is split into one or more packets. No relationship exists between the chunked encoding and the separation of the data into packets since the processes occur at different locations of the protocol stack. At decision block 114, a determination is made as to whether all of the chunks have been received. By way of example, when a body is chunked, each chunk is preceded by a value that indicates the total size of the chunk. Therefore, a determination can be made that an entire chunk has been received when the amount of collected bytes equals or is greater than the value that preceded the chunk. Moreover, a determination is made that all of the chunks have been received when a chunk size of zero is received. If decision block 114 determines that all of the chunks have been received, execution proceeds to decision block 110. Alternatively, if decision block 114 determines that all of the chunks have not been received, execution proceeds to step 116 where the collected packet is placed into a buffer within the corresponding bucket and execution proceeds to step 118 where the network monitor collects a packet. (Step 118 of FIG. 4 is identical to step 80 of FIG. 3.) At decision block 110 a determination is made as to whether XML is employed. In accordance with standard Internet protocol, a header referred to as “content type” defines the language used, such as, by way of example, XML. If decision block 110 determines that XML is not employed then execution proceeds to step 122. Alternatively, if the content type is XML and therefore XML is employed then the packets in the bucket are pushed through an XML pretty printer in step 120. The XML pretty printer adds white space to the body and highlights important data. Execution then proceeds to step 122. In step 122 the packet information in the bucket is flushed, meaning the contents of the buffer are emptied onto a disk by printing them to a file, adding them to a database, etc. As such, the requests and/or responses exchanged across a network can be viewed, interpreted and analyzed to ensure that the exchange occurred correctly and as expected. Upon flushing the bucket, execution proceeds to step 124 where the bucket is reset, which includes zeroing out the buffer, so that it can be reused to analyze other network exchanges. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. The Field of the Invention The present invention relates to systems and methods for monitoring exchanges between a client and a server across a network. More specifically, the present invention relates to systems and methods that read a network monitor trace and rebuild the requests and responses to make the exchanges easily readable to a user by rebuilding entire requests and responses, coalescing chunked information, collecting interleaved packets, reformatting extensible markup language (“XML”) bodies, if present, and optionally removing any hyper-text markup language (“HTML”) bodies from the requests and responses. 2. The Relevant Technology The Internet protocol known as hyper-text transfer protocol—distributed authoring and versioning (“HTTP/Dav”) is becoming the foundation for application development on exchange server technology, which employs a client/server relationship. The HTTP/Dav protocol uses XML to execute requests and corresponding responses between a client and a server across a network. The requests and responses pass through a protocol stack in order to be transmitted across the network. To provide a more efficient transmission across the network, it is customary for a protocol stack to dissect the request or response that passes through the stack into fragments. The fragments are then incorporated into blocks of data, known as “packets,” which are in the form of long buffers of bytes. The packets are then individually sent across the network connection. As such, and by way of example, a given request sent by a client to a server across a network can comprise many packets. While standard Internet protocol ensures that the packets of a specific request or response will be properly ordered once received, all of the packets that correspond to a given request or response are not necessarily transmitted together. Instead, the packets corresponding to a request or response are interleaved with packets that correspond to other requests and/or responses in order to optimize the transmission of data across the network. To further optimize the transmission of data across the network, the data in the body of the packet is frequently “chunked.” This means that rather than placing the data into a single buffer, the data is strung together. Therefore, by way of example, if a client communicates a 32-kilobyte request to a server, this request may be chunked into one or more segments that are strung together, each segment being transmitted individually to the server. The requests and responses exchanged between a client and a server are visible to a network monitor. The network monitor, also referred to as a “packet sniffer,” sees the packets that are transmitted across the network, arranges the packets in the order that they were sent, and creates a trace. While a network monitor trace is valuable for recording the HTTP/Dav activity, it is a very poor tool for analyzing the activity because it understands neither HTTP/Dav protocol nor XML. The trace displays the network packets as a very unfriendly jumble of bytes in what is known as the frame viewer window, which may provide, by way of example, six columns of text (generally in hex) that is six bytes wide and twenty pages deep. The reading of the trace is further complicated when the data is chunked because the data is all strung together. Furthermore, the reading of the trace becomes even more complicated because of the interleaving of the transmitted packets. As such, upon desiring to read the portion of the trace specific to a given request and/or response, a reader easily confuses data that he/she believes corresponds to the given request and/or response with data that corresponds to other requests and/or responses. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention relates to systems and methods for monitoring exchanges between a client and a server across a network. More specifically, the present invention relates to systems and methods that read a network monitor trace and rebuild the requests and responses to make the exchanges easily readable to a user by rebuilding entire requests and responses, coalescing chunked information, collecting interleaved packets, reformatting XML bodies if present, and optionally removing any HTML bodies from the requests and responses. Embodiments of the present invention may be practiced in network computing environments with many types of computer system configurations and provide a mechanism that allows for the viewing, interpretation and analysis of, by way of example, a network exchange between a client and a server. Embodiments of the present invention employ an extendable network monitor, such as by way of example, Full Netmon, to record the exchanges transmitted across a network. The network monitor obtains a copy of the exchange in a network monitor trace that is displayed in a very unfriendly jumble of bytes. The systems and methods of the present invention can call on, by way of example, an executable program module to allow the exchanges to be made easily readable so that the exchanges can be interpreted and analyzed to verify that the requests and/or responses occurred correctly and as expected. The information when exchanged is sent across a network in packets. The packets are gathered and the source and destination of each packet is identified. The packets are distributed to variable locations referred to as “buckets” for storage. Once in a bucket, the packet information is stored in a buffer until all of the packets corresponding to a particular exchange between a client and a server have been received. Once received, the packet information is processed so that the exchange can be read, interpreted and analyzed. The packet information is then flushed and the bucket is reset and made ready to be reused. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. | 20040429 | 20080408 | 20050127 | 87554.0 | 0 | HARRELL, ROBERT B | SYSTEMS AND METHODS FOR MONITORING NETWORK EXCHANGES BETWEEN A CLIENT AND A SERVER | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,834,504 | ACCEPTED | POLYMERIC STRUCTURES AND METHOD FOR MAKING SAME | Polymeric structures, methods for making same, fibrous structures comprising same and product incorporating same are provided. | 1-7. (canceled) 8. A fibrous structure comprising a fiber comprising a non-PVOH hydroxyl polymer starch wherein the fibrous structure exhibits a wet lint score of less than about 25. 9. (canceled) 10. The fibrous structure according to claim 8 wherein the fibrous structure comprises two or more regions that exhibit different values of a common intensive property relative to each other. 11. The fibrous structure according to claim 10 wherein the common intensive property is selected from the group consisting of: density, basis weight, caliper, substrate thickness, elevation, opacity, crepe frequency and mixtures thereof. 12. A fibrous product comprising one or more fibrous structures according to claim 8. 13. (canceled) 14. The fibrous structure according to claim 8 wherein the fibrous structure exhibits a dry lint score of less than about 50. 15-41. (canceled) 42. The fibrous structure according to claim 8 wherein the fibrous structure exhibits a wet pill area of less than about 4%. 43. The fibrous structure according to claim 8 wherein the fibrous structure exhibits a dry pill area of less than about 5%. 44. The fibrous structure according to claim 8 wherein the fibrous structure exhibits a stretch at peak load of at least about 5%. 45. The fibrous structure according to claim 8 wherein the fibrous structure exhibits a stretch at failure load of at least about 10%. 46. The fibrous structure according to claim 8 wherein the fiber further comprises a crosslinking system comprising a crosslinking agent, wherein the non-PVOH hydroxyl polymer starch is crosslinked by the crosslinking agent such that the fiber as a whole does not exhibit a melting point. 47. The fibrous structure according to claim 8 wherein the fiber exhibits a fiber diameter of less than about 50 μm. 48. A fibrous structure comprising a fiber comprising a non-PVOH hydroxyl polymer starch wherein the fibrous structure exhibits a wet pill area of less than about 4%. 49. The fibrous structure according to claim 48 wherein the fibrous structure comprises two or more regions that exhibit different values of a common intensive property relative to each other. 50. The fibrous structure according to claim 49 wherein the common intensive property is selected from the group consisting of: density, basis weight, caliper, substrate thickness, elevation, opacity, crepe frequency and mixtures thereof. 51. The fibrous structure according to claim 48 wherein the fiber exhibits a fiber diameter of less than about 50 μm. 52. A fibrous product comprising one or more fibrous structures according to claim 48. | FIELD OF THE INVENTION The present invention relates to polymeric structures comprising a non-PVOH processed hydroxyl polymer composition comprising a hydroxyl polymer, fibrous structures comprising such polymeric structures and methods for making same. BACKGROUND OF THE INVENTION In recent years, formulators of fibrous structures have attempted to move away from wood-based cellulosic fibers to polymeric fibers. Polymeric fiber-containing fibrous structures are known in the art. See for example, EP 1 217 106 A1. However, such prior art attempts to make polymeric fiber-containing fibrous structures have failed to achieve the intensive properties of their wood-based cellulosic fiber-containing fibrous structure cousins. Accordingly, there is a need for a polymeric structure and/or a fibrous structure comprising a polymeric structure in fiber form that exhibits intensive properties substantially similar to or better than wood-based cellulosic fiber-containing fibrous structures. SUMMARY OF THE INVENTION The present invention fulfills the need described above by providing a polymeric structure and/or a fibrous structure comprising a polymeric structure in fiber form that exhibits substantially similar or better intensive properties as compared to wood-based cellulosic fiber-containing fibrous structures. In one aspect of the present invention, a polymeric structure comprising a non-PVOH processed hydroxyl polymer composition comprising a hydroxyl polymer, wherein the polymeric structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In another aspect of the present invention, a fibrous structure comprising a polymeric structure in the form of a fiber in accordance with the present invention, wherein the fibrous structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In even another aspect of the present invention, a fibrous product comprising one or more fibrous structures in accordance with the present invention is provided. In still another aspect of the present invention, a method for making a polymeric structure, the method comprising the steps of: a. providing a non-PVOH polymer melt composition comprising a hydroxyl polymer; and b. polymer processing the non-PVOH polymer melt composition to form a polymeric structure; wherein the polymeric structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In yet another aspect of the present invention, a polymeric structure in fiber form produced in accordance with a method of the present invention, is provided. In even still another aspect of the present invention, a method for making a fibrous structure, the method comprising the steps of: a. providing a non-PVOH polymer melt composition comprising a hydroxyl polymer; b. polymer processing the non-PVOH polymer melt composition to form a polymeric structure in fiber form; and c. incorporating the polymeric structure in fiber form into a fibrous structure; wherein the fibrous structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In even yet another aspect of the present invention, a fibrous structure comprising two or more fibers at least one of which comprises a polymeric structure in fiber form, wherein the fibrous structure comprises a first region comprising associated fibers and a second region comprising non-associated fibers, is provided. In still yet another aspect of the present invention, a fibrous product comprising one or more fibrous structures comprising a first region comprising associated fibers and a second region comprising non-associated fibers, is provided. In even still yet another aspect of the present invention, a method for making a fibrous structure, the method comprising the steps of: a. providing a fibrous structure comprising two or more fibers at least one of which comprises a polymeric structure in fiber form; and b. associating the two or more fibers with each other such that a fibrous structure comprising a first region comprising associated fibers and a second region comprising non-associated fibers is formed, is provided. Accordingly, the present invention provides a polymeric structure, a fibrous structure comprising such a polymeric structure in fiber form, a fibrous product comprising one or more such fibrous structures, method for making such a polymeric structure, method for making such a fibrous structure comprising a polymeric structure in fiber form and a polymeric structure in fiber form produced by such a method. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic illustration of a method for making a polymeric structure in accordance with the present invention. FIG. 2 is a schematic illustration of a camera set-up suitable for use in the Lint/Pilling Test Method described herein. DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS “Polymeric structure” as used herein means any physical structure produced by polymer processing the non-PVOH polymer melt composition of the present invention. Nonlimiting examples of such polymeric structures include fibers, films and foams. Such polymeric structures, especially when in fiber form, may be used, optionally along with other physical structures such as cellulosic fibers and thermoplastic water-insoluble polymer fibers, to form fibrous structures. Preferably the polymeric structure of the present invention as a whole has no melting point or in other words the polymeric structure is a non-thermoplastic polymeric structure. It is also desirable that the polymeric structure of the present invention be substantially homogeneous. “Non-PVOH” as used herein means that little, such as less than 5% and/or less than 3% and/or less than 1% and/or less than 0.5% by weight of polyvinyl alcohol is present in a composition and/or polymeric structure. In a preferred embodiment, 0% of polyvinyl alcohol is present in a composition and/or polymeric structure. “Fail Stretch” as used herein is defined by the following formula: Length of Polymeric StructureFL−Length of Polymeric StructureI×100%/Length of Polymeric StructureI wherein: Length of Polymeric StructureFL is the length of the polymeric structure at failure load; Length of Polymeric Structure, is the initial length of the polymeric structure prior to stretching. “Peak Stretch” as used herein is defined by the following formula: Length of Polymeric StructurePL−Length of Polymeric StructureI×100%/Length of Polymeric StructureI wherein: Length of Polymeric StructurePL is the length of the polymeric structure at peak load; Length of Polymeric StructureI is the initial length of the polymeric structure prior to stretching. The Strength of the Polymeric Structure is determined by measuring a polymeric structure's Total Dry Tensile Strength. (both MD and CD) or “TDT”. TDT or Stretch is measured by providing one (1) inch by five (5) inch (2.5 cm×12.7 cm) strips of polymeric structure and/or fibrous product comprising such polymeric structure in need of testing. Each strip is placed on an electronic tensile tester Model 1122 commercially available from Instron Corp., Canton, Mass. The crosshead speed of the tensile tester is 2.0 inches per minute (about 5.1 cm/minute) and the gauge length is 1.0 inch (about 2.54 cm). The tensile tester calculates the stretch at Peak Load and the stretch at Failure Load. Basically, the tensile tester calculates the stretches via the formulae described above. The Stretch at Peak Load, as used herein, is the average of the Stretch at Peak Load for MD and CD. The Stretch at Failure Load, as used herein, is the average of the Stretch at Failure Load for MD and CD. “Machine direction” (or MD) is the direction parallel to the flow of the polymeric structure being made through the manufacturing equipment. “Cross machine direction” (or CD) is the direction perpendicular to the machine direction and parallel to the general plane of the polymeric structure. “Fiber” as used herein means a slender, thin, and highly flexible object having a major axis which is very long, compared to the fiber's two mutually-orthogonal axes that are perpendicular to the major axis. Preferably, an aspect ratio of the major's axis length to an equivalent diameter of the fiber's cross-section perpendicular to the major axis is greater than 100/1, more specifically greater than 500/1, and still more specifically greater than 1000/1, and even more specifically, greater than 5000/1. The fibers of the present invention may be continuous or substantially continuous. A fiber is continuous if it extends 100% of the MD length of the fibrous structure and/or fibrous product made therefrom. In one embodiment, a fiber is substantially continuous if it extends greater than about 30% and/or greater than about 50% and/or greater than about 70% of the MD length of the fibrous structure and/or fibrous product made therefrom. The fiber can have a fiber diameter as determined by the Fiber Diameter Test Method described herein of less than about 50 microns and/or less than about 20 microns and/or less than about 10 microns and/or less than about 8 microns and/or less than about 6 microns. The polymeric structures of the present invention, especially fibers of the present invention, may be produced by crosslinking hydroxyl polymers together. In one embodiment, the polymeric structure, especially in fiber form, formed as a result of the crosslinking, as a whole, exhibits no melting point. In other words, it degrades before melting. Nonlimiting examples of a suitable crosslinking system for achieving crosslinking comprises a crosslinking agent and optionally a crosslinking facilitator, wherein the hydroxyl polymer is crosslinked by the crosslinking agent. The fibers comprising a hydroxyl polymer may include melt spun fibers, dry spun fibers and/or spunbond fibers, staple fibers, hollow fibers, shaped fibers, such as multi-lobal fibers and multicomponent fibers, especially bicomponent fibers. The multicomponent fibers, especially bicomponent fibers, may be in a side-by-side, sheath-core, segmented pie, ribbon, islands-in-the-sea configuration, or any combination thereof. The sheath may be continuous or non-continuous around the core. The ratio of the weight of the sheath to the core can be from about 5:95 to about 95:5. The fibers of the present invention may have different geometries that include round, elliptical, star shaped, rectangular, and other various eccentricities. In another embodiment, the fibers comprising a hydroxyl polymer may include a multiconstituent fiber, such as a multicomponent fiber, comprising a hydroxyl polymer of the present invention along with a thermoplastic, water-insoluble polymer. A multicomponent fiber, as used herein, means a fiber having more than one separate part in spatial relationship to one another. Multicomponent fibers include bicomponent fibers, which are defined as fibers having two separate parts in a spatial relationship to one another. The different components of multicomponent fibers can be arranged in substantially distinct regions across the cross-section of the fiber and extend continuously along the length of the fiber. A nonlimiting example of such a multicomponent fiber, specifically a bicomponent fiber, is a bicomponent fiber in which the hydroxyl polymer represents the core of the fiber and the thermoplastic, water-insoluble polymer represents the sheath, which surrounds or substantially surrounds the core of the fiber. The polymer melt composition from which such a fiber is derived preferably includes the hydroxyl polymer and the thermoplastic, water-insoluble polymer. In another multicomponent, especially bicomponent, fiber embodiment, the sheath may comprise a hydroxyl polymer and a crosslinking system having a crosslinking agent, and the core may comprise a hydroxyl polymer and a crosslinking system having a crosslinking agent. With respect to the sheath and core, the hydroxyl polymer may be the same or different and the crosslinking agent may be the same or different. Further, the level of hydroxyl polymer may be the same or different and the level of crosslinking agent may be the same or different. One or more substantially continuous or continuous fibers of the present invention may be incorporated into a fibrous structure, such as a web. Such a fibrous structure may ultimately be incorporated into a commercial product, such as a single- or multi-ply fibrous product, such as facial tissue, bath tissue, paper towels and/or wipes, feminine care products, diapers, writing papers, cores, such as tissue cores, and other types of paper products. “Ply” or “Plies” as used herein means a single fibrous structure optionally to be disposed in a substantially contiguous, face-to-face relationship with other plies, forming a multi-ply fibrous product. It is also contemplated that a single fibrous structure can effectively form two “plies” or multiple “plies”, for example, by being folded on itself. Ply or plies can also exist as films or other polymeric structures. “Basis Weight” as used herein is the weight per unit area of a sample reported in lbs/3000 ft2 or g/m2. Basis weight is measured by preparing one or more samples of a certain area (m2) and weighing the sample(s) of a fibrous structure and/or film according to the present invention on a top loading balance with a minimum resolution of 0.01 g. The balance is protected from air drafts and other disturbances using a draft shield. Weights are recorded when the readings on the balance become constant. The average weight (g) is calculated and the average area of the samples (m2). The basis weight (g/m2) is calculated by dividing the average weight (g) by the average area of the samples (m2). “Caliper” as used herein means the macroscopic thickness of a fibrous structure, fibrous product or film. Caliper of a fibrous structure, fibrous product or film according to the present invention is determined by cutting a sample of the fibrous structure, fibrous product or film such that it is larger in size than a load foot loading surface where the load foot loading surface has a circular surface area of about 3.14 in2. The sample is confined between a horizontal flat surface and the load foot loading surface. The load foot loading surface applies a confining pressure to the sample of 15.5 g/cm2 (about 0.21 psi). The caliper is the resulting gap between the flat surface and the load foot loading surface. Such measurements can be obtained on a VIR Electronic Thickness Tester Model II available from Thwing-Albert Instrument Company, Philadelphia, Pa. The caliper measurement is repeated and recorded at least five (5) times so that an average caliper can be calculated. The result is reported in millimeters. In one embodiment of the present invention, the fibrous structure exhibits an average caliper that is less than its bulk caliper “Apparent Density” or “Density” as used herein means the basis weight of a sample divided by the caliper with appropriate conversions incorporated therein. Apparent density used herein has the units g/cm3. “Weight average molecular weight” as used herein means the weight average molecular weight as determined using gel permeation chromatography according to the protocol found in Colloids and Surfaces A. Physico Chemical & Engineering Aspects, Vol. 162, 2000, pg. 107-121. “Plasticity” as used herein means at least that a polymeric structure and/or fibrous structure exhibits a capability of being shaped, molded and/or formed. “Fibrous product” as used includes but is not limited to a wiping implement for post-urinary and post-bowel movement cleaning (toilet tissue), for otorhinolaryngological discharges (facial tissue), and multi-functional absorbent and cleaning uses (absorbent towels). “Lint” and/or “Pills” as used herein means discrete pieces of a polymeric structure, especially a fibrous structure and/or fibrous product that become separated from the original polymeric structure and/or fibrous structure and/or fibrous product typically during use. Traditional toilet tissue and toweling are comprised essentially of short cellulose fibers. During the wiping process—both wet and dry, these short fibers can detach from the structure and become evident as lint or pills. The present invention employs essentially continuous fibers vs. traditional discrete, short cellulose fibers. Generally speaking, fibrous structures of the present invention resist linting vs. their cellulose cousins due to the continuous nature of the fibers. Furthermore, fibrous structures of the present invention will resist pilling vs. their cellulose cousins provided the bonding and fiber strength and stretch are sufficient enough to prevent free fiber breakage and entanglement with adjacent fibers during the wiping process. “Intensive Properties” and/or “Values of Common Intensive Properties” as used herein means density, basis weight, caliper, substrate thickness, elevation, opacity, crepe frequency, and any combination thereof. The fibrous structures of the present invention may comprise two or more regions that exhibit different values of common intensive properties relative to each other. In other words, a fibrous structure of the present invention may comprise one region having a first opacity value and a second region having a second opacity value different from the first opacity value. Such regions may be continuous, substantially continuous and/or discontinuous. “Dry spinning” and/or “Solvent spinning” as used herein means that polymeric structures are not spun into a coagulating bath, unlike wet spinning. “Associated” as used herein with respect to fibers means that two or more discrete fibers are in close proximity to one another at one or more positions along the fiber lengths, but less than their entire lengths such that one fiber influences the actions of the other fiber. Nonlimiting examples of means for associating fibers include bonding together (adhesively and/or chemically and/or electrostatically) and/or fusing together such that at the point of association one fiber unit is formed. “Non-associated” as used herein with respect to fibers means that the fibers are not associated as defined herein. METHODS OF THE PRESENT INVENTION The methods of the present invention relate to producing polymeric structures such as fibers, films or foam from a non-PVOH polymer melt composition comprising a hydroxyl polymer and/or to producing fibrous structures comprising a polymeric structure in fiber form. In one nonlimiting embodiment of a method in accordance with the present invention, as described below, a non-PVOH polymer melt composition is polymer processed to form a fiber. The fiber can then be incorporated into a fibrous structure. Any suitable process known to those skilled in the art can be used to produce the polymer melt composition and/or polymer process the polymer melt composition and/or the polymeric structure of the present invention. Nonlimiting examples of such processes are described in published applications: EP 1 035 239, EP 1 132 427, EP 1 217 106, EP 1 217 107 and WO 03/066942. A. Non-PVOH Polymer Melt Composition “Non-PVOH polymer melt composition” as used herein means a composition that comprises a melt processed hydroxyl polymer. “Melt processed hydroxyl polymer” as used herein means any polymer, except polyvinyl alcohol, that contains greater than 10% and/or greater than 20% and/or greater than 25% by weight hydroxyl groups and that has been melt processed, with or without the aid of an external plasticizer and/or with or without the presence of a pH adjusting agent. More generally, melt processed hydroxyl polymers include polymers, which by the influence of elevated temperatures, pressure and/or external plasticizers may be softened to such a degree that they can be brought into a flowable state (all melt processing operations/processes), and in this condition may be shaped as desired. The non-PVOH polymer melt composition may be a composite containing a blend of different polymers, wherein at least one is a melt processed hydroxyl polymer according to the present invention, and/or fillers both inorganic and organic, and/or fibers and/or foaming agents. In one embodiment, the non-PVOH polymer melt composition comprises two or more different melt processed hydroxyl polymers according to the present invention. As used herein, “different melt processed hydroxyl polymers” includes without limitation, melt processed hydroxyl polymers that contain at least one different moiety relative to another melt processed hydroxyl polymer and/or melt processed hydroxyl polymers that are members of different chemical classes (e.g., starch versus chitosan). The non-PVOH polymer melt composition may already be formed or a melt processing step may need to be performed to convert a raw material hydroxyl polymer into a melt processed hydroxyl polymer, thus producing the non-PVOH polymer melt composition. Any suitable melt processing step known in the art may be used to convert the raw material hydroxyl polymer into the melt processed hydroxyl polymer. The non-PVOH polymer melt composition may comprise a) from about 30% and/or 40% and/or 45% and/or 50% to about 75% and/or 80% and/or 85% and/or 90% and/or 99.5% by weight of the non-PVOH polymer melt composition of a hydroxyl polymer; b) a crosslinking system comprising from about 0.1% to about 10% by weight of the non-PVOH polymer melt composition of a crosslinking agent; and c) from about 0% and/or 10% and/or 15% and/or 20% to about 50% and/or 55% and/or 60% and/or 70% by weight of the non-PVOH polymer melt composition of an external plasticizer (e.g., water). B. Polymer Processing “Polymer processing” as used herein means any operation and/or process by which a polymeric structure comprising a processed hydroxyl polymer is formed from a non-PVOH polymer melt composition. Nonlimiting examples of polymer processing operations include extrusion, molding and/or fiber spinning. Extrusion and molding (either casting or blown), typically produce films, sheets and various profile extrusions. Molding may include injection molding, blown molding and/or compression molding. Fiber spinning may include spun bonding, melt blowing, continuous fiber producing and/or tow fiber producing. A “processed hydroxyl polymer” as used herein means any hydroxyl polymer that has undergone a melt processing operation and a subsequent polymer processing operation. C. Polymeric Structure The non-PVOH polymer melt composition can be subjected to one or more polymer processing operations such that the non-PVOH polymer melt composition is processed into a polymeric structure such as a fiber, film or foam comprising the hydroxyl polymer and a crosslinking system according to the present invention. Post Treatment of Polymeric Structures Once the non-PVOH polymer melt composition has been processed into a polymeric structure, such as a fiber, a film, a foam, or a plurality of fibers that together form a fibrous structure, the structure may be subjected to post-treatment curing and/or differential densification. Curing of the structure may occur before and/or after densifying a region of the structure. Preferably curing occurs before densifying a region of the structure. In one embodiment, the structure produced via a polymer processing operation may be cured at a curing temperature of from about 110° C. to about 200° C. and/or from about 120° C. to about 195° C. and/or from about 130° C. to about 185° C. for a time period of from about 0.01 and/or 1 and/or 5 and/or 15 seconds to about 60 minutes and/or from about 20 seconds to about 45 minutes and/or from about 30 seconds to about 30 minutes prior to densifying a region of the structure. Alternative curing methods may include radiation methods such as UV, e-beam, IR and other temperature-raising methods. Further, the structure may also be cured at room temperature for days, either after curing at above room temperature or instead of curing at above room temperature. The structure prior to being densified may comprise non-associated substantially continuous or continuous fibers comprising a hydroxyl polymer. Further, the substantially continuous or continuous fibers may comprise crosslinked hydroxyl polymers. Even further yet, the structure may comprise from about 10% and/or from about 15% and/or from about 20% to about 60% and/or to about 50% and/or to about 40% by weight of the structure of moisture. Before differential densification, the structure may be in the form of a non-associated structure, especially if the structure comprises one or more fibers. The structure in such non-differential densified form is inferior in intensive properties, especially tensile (stretch), than its wood-based cellulosic fibrous structure cousins. Accordingly, the structure of the present invention may be subjected to differential densification via a differentially densifying operation. Such differential densification can occur on-line in a continuous process that includes forming the structure and then differentially densifying the structure. Alternatively, the differential densification can occur off-line in a non-continuous process. Any differentially densifying process known to those of ordinary skill in the art may be used to differentially densify the structures of the present invention. As a result of differential densification, the structure comprises two or more regions that exhibit different densities as compared to the other. In one embodiment, the differentially densifying process comprises the step of imparting plasticity into a structure in need of differential densification such that regions of different density can be created in the structure. In other words, the differentially densifying process comprises the step of imparting plasticity into a structure in need of differential densification such that a pattern can be created in the structure. The pattern is designed to impart regions of different densities in the structure. Exposing the structure in need of differential densification to a humid environment, such as from about 20% to about 95% and/or from about 40% to about 90% and/or from about 50% to about 85% and/or from about 65% to about 80% relative humidity for a sufficient time, such as at least 1 second and/or at least 3 seconds and/or at least 5 seconds, can impart sufficient plasticity to the structure to permit differential densification to be created in the structure. In one embodiment, the differentially densifying process comprises subjecting the structure to a patterned roller such that the pattern on the roller is imparted to the structure, thus causing the structure to become differentially densified. In another embodiment, the differentially densifying process comprises contacting the structure, which is in contact with a patterned belt/fabric with pressure from a smooth roller thus imparting the pattern of the belt/fabric to the structure causing the structure to become differentially densified. The differentially densifying of a structure in accordance with the present invention preferably occurs after the structure has been formed, not concurrent with the formation of the structure. The structure of the present invention may be differentially densified more than once. For example, a structure may be differentially densified, then cured, and then differentially densified again according to the present invention. In another embodiment, the structure may comprise two or more “plies” of structure which can then be differentially densified as a multi-ply structure. The structure may be differentially densified, then differential densified again and then cured. Alternatively, the structure of the present invention may be cured, then differentially densified according to the present invention Curing of the structure, in accordance with the present invention, may occur at any point in time relative to any differentially densifying process. It may occur before (preferably immediately before), after (preferably immediately after), before and after (preferably immediately before and immediately after), or not at all. The differentially densifying process may occur once or a plurality of times. Ultrasonics may also be used to aid in differential densification of the structure, especially in conjunction with a patterned roller. The ultrasonics may be generated by any suitable ultrasonic device. For example, a horn or ultrasonic wave generator that is capable of imparting energy to the structure such that the structure deforms according to the pattern on the patterned roller can be used. In still another embodiment, the step of differentially densifying comprises contacting the fibrous structure with a structure-imparting element comprising a pattern in the presence of humidity and applying a force to the fibrous structure and/or structure-imparting element such that the fibrous structure takes the shape of the pattern on the structure-imparting element to form a differential densified polymeric structure. In yet still another embodiment, step of differentially densifying the fibrous structure comprises sandwiching the fibrous structure between two belts in the presence of humidity, wherein at least one of the belts is a structured belt comprising a pattern and applying a force to at least one of the belts such that the fibrous structure takes the shape of the pattern on the structured belt to form a differential densified polymeric structure. A nonlimiting example of a differential densification process for differentially densifying a structure in accordance with the present invention is provided below. DIFFERENTIAL DENSIFICATION EXAMPLE A non-PVOH polymer melt composition containing approximately 40% water is extruded from a twin screw extruder. Crosslinker and other additives are introduced into the melt and mixed via in-line static mixers. The non-PVOH polymer melt composition with additives is then pumped to a meltblown style spinnerette where fibers are extruded and attenuated into fine fibers. One suitable hydroxyl polymer is starch under the tradename Penfilm 162, available from Penford Products Inc. Crosslinkers and additives used are urea glyoxal adduct (“UGA”), ammonium sulfate, and acrylic latex. Total additives are typically 10% or less on a wt % basis of dry hydroxyl polymer. The attenuated fibers are dried with entrained hot air and deposited on a collector belt. The collector belt is typically set at 22-25″ from the end of the spinnerette and the structure, a fibrous structure, formed on the collector belts is a non-associated fibrous structure. FIG. 1 schematically illustrates one embodiment of a differential densification operation 10. After forming, the non-associated fibrous structure 12 is subjected to an environmentally controlled humid environment, such as in a humidity chamber 14. Typical relative humidity range is 70-78%. As the fibrous structure 12 is conveyed through the chamber 14, the fine starch fibers are plasticized, allowing differential densification to be possible. Upon exiting the chamber 14, the plasticized fibrous structure 12′ is passed through a patterned nip 16 to associate regions of the fibrous structure, thus producing an associated fibrous structure 12″. The associated fibrous structure regions 18 correspond to the pattern utilized on either the carrier belt (not shown) or the roller itself 20. One patterned belt employed has been a square weave open mesh belt, available from Albany International Inc and known as style “Filtratech 10”. Nip pressure varies depending on the pattern employed, but is typically in the 200-300 pli range. The fibers present in the fibrous structure are now associated and the fibrous structure exhibits excellent handling properties. After a curing period for the crosslinking system and additives to react, the associated fibrous structure exhibits dry and wet properties acceptable for disposable fibrous products and can be used as a variety of disposable implements, especially toilet tissue or toweling. The table below summarizes key physical properties of one embodiment of a fibrous structure in accordance with the present invention at different conditions; namely, pre-differential densification, post-differential densification, and post-differential densification cured as compared to a typical commercial tissue such as Charmin® 1-ply. Typical Post Tissue Pre- Post densification (Charmin ® densification densification Cured 1-ply) Dry MD + CD 142 293 441 400 Tensile g/in Dry Fail 29 16 18 25 Stretch % Dry Burst g 80 92 261 150 Dry Burst 0.5 0.47 1.5 1.7 Energy g/cm Basis Weight 36 36 36 36 g/m2 Hydroxyl Polymers Hydroxyl polymers in accordance with the present invention include any hydroxyl-containing polymer, with the exception of polyvinyl alcohol, that can be incorporated into a polymeric structure of the present invention, preferably in the form of a fiber. In one embodiment, the hydroxyl polymer of the present invention includes greater than 10% and/or greater than 20% and/or greater than 25% by weight hydroxyl moieties. Nonlimiting examples of hydroxyl polymers in accordance with the present invention include polyols, such as starch, starch derivatives, chitosan, chitosan derivatives, cellulose derivatives such as cellulose ether and ester derivatives, gums, arabinans, galactans, proteins and various other polysaccharides and mixtures thereof. The hydroxyl polymer preferably has a weight average molecular weight of from about 10,000 to about 40,000,000 g/mol. Higher and lower molecular weight hydroxyl polymers may be used in combination with hydroxyl polymers having the preferred weight average molecular weight. Well known modifications of natural starches include chemical modifications and/or enzymatic modifications. For example, the natural starch can be acid-thinned, hydroxy-ethylated or hydroxy-propylated or oxidized. “Polysaccharides” herein means natural polysaccharides and polysaccharide derivatives or modified polysaccharides. Suitable polysaccharides include, but are not limited to, gums, arabinans, galactans and mixtures thereof. Crosslinking System The crosslinking system of the present invention may further comprise, in addition to the crosslinking agent, a crosslinking facilitator. “Crosslinking facilitator” as used herein means any material that is capable of activating a crosslinking agent thereby transforming the crosslinking agent from its unactivated state to its activated state. In other words, when a crosslinking agent is in its unactivated state, the hydroxyl polymer present in the non-PVOH polymer melt composition does not undergo premature crosslinking (“unacceptable” crosslinking) as determined according to the Shear Viscosity Change Test Method described herein. When a crosslinking agent in accordance with the present invention is in its activated state, the hydroxyl polymer present in the polymeric structure may, and preferably does, undergo acceptable crosslinking via the crosslinking agent as determined according to the Initial Total Wet Tensile Test Method described herein. The crosslinking facilitator may include derivatives of the material that may exist after the transformation/activation of the crosslinking agent. For example, a crosslinking facilitator salt being chemically changed to its acid form and vice versa. A crosslinking system may be present in the non-PVOH polymer melt composition and/or may be added to the non-PVOH polymer melt composition before polymer processing of the non-PVOH polymer melt composition. Nonlimiting examples of suitable crosslinking facilitators include acids having a pKa of between about 0 and about 6 and/or between about 1.5 and about 6 and/or between about 2 and about 6 or salts thereof. The crosslinking facilitators may be Bronsted Acids and/or salts thereof, preferably ammonium salts thereof. In addition, metal salts, such as magnesium and zinc salts, can be used alone or in combination with Bronsted Acids and/or salts thereof, as crosslinking facilitators. Nonlimiting examples of suitable crosslinking facilitators include acetic acid, benzoic acid, citric acid, formic acid, glycolic acid, lactic acid, maleic acid, phthalic acid, phosphoric acid, sulfuric acid, succinic acid and mixtures thereof and/or their salts, preferably their ammonium salts, such as ammonium glycolate, ammonium citrate and ammonium sulfate. Nonlimiting examples of suitable crosslinking agents include polycarboxylic acids, imidazolidinones and other compounds resulting from alkyl substituted or unsubstituted cyclic adducts of glyoxal with ureas, thioureas, guanidines, methylene diamides, and methylene dicarbamates and derivatives thereof, and mixtures thereof. Test Methods All tests described herein including those described under the Definitions section and the following test methods are conducted on samples that have been conditioned in a conditioned room at a temperature of 73° F.±4° F. (about 23° C.±2.2° C.) and a relative humidity of 50%±10% for 24 hours prior to the test. Further, all tests are conducted in such conditioned room. Tested samples and felts should be subjected to 73° F.±4° F. (about 23° C.±2.2° C.) and a relative humidity of 50%±10% for 24 hours prior to capturing images. A. Lint/Pilling Test Method i. Sample Preparation Prior to the testing, fibrous product samples, 4.5″×16″ strips of fibrous product, are conditioned according to Tappi Method #T402OM-88. Each fibrous product sample (6 samples if testing both sides, 3 samples if testing a single side) is first prepared by removing and discarding any pieces of the sample which might have been abraded in handling. For fibrous products formed from multiple plies of fibrous structure, this test can be used to make a lint measurement on the multi-ply fibrous product, or, if the plies can be separated without damaging the fibrous product, a measurement can be taken on the individual plies making up the fibrous product. If a given sample differs from surface to surface, it is necessary to test both surfaces and average the scores in order to arrive at a composite lint score. In some cases, fibrous products are made from multiple-plies of fibrous structures such that the facing-out surfaces are identical, in which case it is only necessary to test one surface. Each sample is folded upon itself to make a 4.5″ CD×4″ MD sample. For two-surface testing, make up 3 (4.5″ CD×4″ MD) samples with a first surface “out” and 3 (4.5″ CD×4″ MD) samples with the second surface “out”. Keep track of which samples are first surface “out” and which are second surface “out”. Obtain a 30″×40″ piece of Crescent #300 cardboard from Cordage Inc. (800 E. Ross Road, Cincinnati, Ohio, 45217). Using a paper cutter, cut out six pieces of cardboard of dimensions of 2.5″×6″. Puncture two holes into each of the six pieces of cardboard by forcing the cardboard onto the hold down pins of the Sutherland Rub tester. Center and carefully place each of the cardboard pieces on top of the six (two surface testing) or three (single surface testing) previously folded samples. Make sure the 6″ dimension of the cardboard is running parallel to the machine direction (MD) of each of the samples. Fold one edge of the exposed portion of the sample onto the back of the cardboard. Secure this edge to the cardboard with adhesive tape obtained from 3M Inc. (¾″ wide Scotch Brand, St. Paul, Minn.). Carefully grasp the other over-hanging tissue edge and snugly fold it over onto the back of the cardboard. While maintaining a snug fit of the sample onto the cardboard, tape this second edge to the back of the cardboard. Repeat this procedure for each sample. Turn over each sample and tape the cross direction edges of the sample to the cardboard for the dry lint/pilling test. One half of the adhesive tape should contact the sample while the other half is adhering to the cardboard. Repeat this procedure for each of the samples. If the sample breaks, tears, or becomes frayed at any time during the course of this sample preparation procedure, discard and make up a new sample with a sample strip. For the wet lint/pilling test, tape the leading cross direction edge of the sample to the cardboard and a table top upon which the sample is placed. Position the sample on the cardboard such that the trailing edge of the sample is approximately ¼″ from the cardboard edge. The leading edge of the sample is taped to the cardboard and table top such that the opposite (trailing) edge of the cardboard is positioned at the edge of the table top. There will now be 3 first surface “out” samples on cardboard and (optionally) 3 second surface “out” samples on cardboard. ii. Felt Preparation Obtain a 30″×40″ piece of Crescent #300 cardboard from Cordage Inc. (800 E. Ross Road, Cincinnati, Ohio, 45217). Using a paper cutter, cut out six pieces of cardboard of dimensions of 2.25″×7.25″. Draw two lines parallel to the short dimension and down 1.125″ from the top and bottom most edges on the white side of the cardboard. Carefully score the length of the line with a razor blade using a straight edge as a guide. Score it to a depth about half way through the thickness of the sheet. This scoring allows the felt/cardboard combination to fit tightly around the weight of the Sutherland Rub tester. Draw an arrow running parallel to the long dimension of the cardboard on this scored side of the cardboard. Cut six pieces of a black felt (F-55 or equivalent from New England Gasket, 550 Broad Street, Bristol, Conn. 06010) to the dimensions of 2.25″×8.5″×0.0625″. Place the felt on top of the unscored, green side of the cardboard such that the long edges of both the felt and cardboard are parallel and in alignment. Also allow about 0.5” of the black felt to overhang the top and bottom most edges of the cardboard. Snugly fold over both overhanging felt edges onto the backside of the cardboard with Scotch brand tape, alternatively, the felt can be snugly fit to the cardboard when attaching the felt/cardboard combination to the weight, discussed below. Prepare a total of six of these felt/cardboard combinations. For the wet lint/pilling test, the felt/cardboard combination includes a 9″ strip of Scotch brand tape (0.75″ wide) that is placed along each edge of the felt (parallel to the long side of the felt) on the felt side that will be contacting the sample. The untapped felt between the two tape strips has a width between 18-21 mm. Three marks are placed on one of the strips of tape at 0, 4 and 8 centimeters from the trailing back edge of the felt. All samples must be run with the same lot of felt. iii. Felt/Cardboard/Weight Component The felt/cardboard combination is associated with a weight. The weight may include a clamping device to attach the felt/cardboard combination to the weight. The weight and any clamping device totals five (5) pounds. The weight is available from Danilee Company, San Antonio, Tex. The weight has an effective contact area of 25.81 cm2 (4 in2) and provides a contact pressure of about 1.25 psi. iv. Conducting Dry Lint/Pills Test The amount of dry lint and/or dry pills generated from a fibrous product according to the present invention is determined with a Sutherland Rub Tester (available from Danilee Company, San Antonio, Tex.). This tester uses a motor to rub a felt/cardboard/weight component 5 times (back and forth) over the fibrous product, while the fibrous product is restrained in a stationary position. The gray value of the felt is measured before and after the rub test. The difference between these two gray values is then used to calculate a dry lint score and/or a dry pill score. The Sutherland Rub Tester must first be calibrated prior to use. First, turn on the Sutherland Rub Tester pressing the “reset” button. Set the tester to run 5 strokes at the lower of the two speeds. One stroke is a single and complete forward and reverse motion of the weight. The end of the rubbing block should be in the position closest to the operator at the beginning and at the end of each test. Prepare a calibration sample on cardboard as described above. In addition, prepare a calibration felt on cardboard as described above. Both of these calibration articles will be used for calibration of the instrument and will not be used in the acquisition of data for the actual samples. Place the calibration sample/cardboard combination on the base plate of the tester by slipping the holes in the board over the hold-down pins. The hold-down pins prevent the sample from moving during the test. Clip the calibration felt/cardboard combination onto the weight component described above with the cardboard side contacting the pads of the weight. Make sure the calibration felt/cardboard combination is resting flat against the weight. Hook this weight onto the tester arm of the Sutherland Rub Tester gently placing it on top of the calibration sample/cardboard combination. The calibration felt must rest level on the calibration sample and must be in 100% contact with the calibration sample surface. Activate the Sutherland Rub Tester by pressing the “start” button. Keep a count of the number of strokes and observe and make a mental note of the starting and stopping position of the calibration felt covered weight in relationship to the calibration sample. If the total number of strokes is five and if the position of the calibration felt covered weight is the same at the end as it was in the beginning of the test, the tester is calibrated and ready to use. If the total number of strokes is not five or if the start and end positions of the calibration felt covered weight are different, then instrument may require servicing and/or recalibration. During the actual testing of samples, monitor and observe the stroke count and the starting and ending points of the felt covered weight. v. Conducting Wet Lint/Pills Test Wet lint/pills are determined by pulling, during one pass, a wetted felt/cardboard/weight component over a sample. To wet the felt, pipet 0.6 ml of deionized water onto the felt, distributing the water as evenly as possible between the 4 and 8 cm marks as represented on the tape attached to the felt. Wait 10 seconds and then place the felt/cardboard/weight component on the center of the sample. After 1 second, pull the felt/cardboard/weight component by the leading edge horizontally until the felt/cardboard/weight component is completely off the table. Pull the weight in a manner to avoid placing any additional force on the felt/cardboard/weight component other than the horizontal pull force. The process of pulling the felt/cardboard/weight component takes about 0.5 to 1.5 seconds. The pulling process should occur as a substantially continuous or continuous motion. Carefully remove the felt/cardboard combination from the felt/cardboard/weight component and allow to dry before capturing the image. Then complete image analysis operations and calculations on the felt and/or sample as described below. vi. Image Capture The images of the felt (untested), sample (untested) and felt (tested) are captured using a Nikon Digital Camera (DIX) with a Nikon Nikkor 24-85 mm f2.8-f4 D 1F AF lens (set to 85 mm maximum zoom) and Nikon Capture software installed on an appropriate computer. As schematically illustrated in FIG. 2, the camera 22 attached to a Kodak camera stand/lighting set-up (not shown) having four incandescent lamps 24 (Polaroid MP4 Land Camera model 44-22, 120 volt 150 watts each) that are directed at the felt 26 positioned 31 cm (12.2 inches) under the lens of the mounted camera. The individual incandescent lamps 24 are positioned 27.94 cm (11 inches) apart. Each pair of incandescent lamps 24 are positioned 88.9 cm (35 inches) apart. The incandescent lamps 24 are positioned 56.83 cm (22⅜ inches) above the felt 26. The camera is connected via an appropriate cable to the computer. The camera should be turned on in PC mode. Turn the button to macro on the camera lens and flip the switch to the orange mark on the lens base. Adjust zoom to its maximum level of 85 mm. Turn the auto focus feature off. The Nikon Capture software needs to be in operating order to capture images. The settings for the Nikon Capture software are as follows: Exposure 1—manual exposure mode, 1/30 second shutter speed, f/6.3 aperture and 0 EV exposure compensation; Exposure 2—center weighted meter mode, ISO 125 sensitivity and incandescent white balance; Storage Settings—raw (12 bit) data format, no compression, color image type and large (3008×1960) image size; Mechanical—single shooting mode, single area AF area mode, manual focus mode. A calibration felt/cardboard combination is placed under the camera such that the felt is centered under the lens of the camera. Manually focus the camera on the felt. Take an image. The exposure difference needs to be in the range of +2.5 to ±2.75. Save the image as a TIFF file (RGB) 8-bit. This image is used to perform the lint and pilling calculations in the Image Analysis Software (Optimas 6.5). Additional images of the sample/cardboard combination (untested) and the felt/cardboard combination (tested) need to be captured in the same manner. Also, an image of a known length standard (e.g., a ruler) is taken (exposure difference does not matter for this image). vii. Image Analysis The images captured are analyzed using Optimas 6.5 Image Analysis software commercially available from Media Cybernetics, L.P. Imaging set-up parameters, as listed herein, must be strictly adhered to in order to have meaningfully comparative lint score and pill score results. First, an image with a known length standard (e.g., a ruler) is brought up in Optimas, and used to calibrate length units (millimeters in this case). For dry testing, the tested felt image has a region of interest (ROI area) of approximately 4510 mm2 (82 mm by 55 mm). The exact ROI area is measured and recorded (variable name: ROI area). For wet lint/pills testing, the tested felt image has 2 regions of interest (ROI areas): 1) the “wetted” region (between the 4-8 cm marks on the tape) and 2) the “dragged” region (between the 0-4 cm marks on the tape). Each ROI area is approximately 608 mm2 (38 mm×16 mm). The exact ROI area is measured and recorded (variable name: ROI area). An image of an untested black felt is opened, and the average gray value (using the same ROI of the untested felt as the tested felt) is measured and recorded (variable name: untested felt Gray Value avg). The tested sample luminance is saturated white (gray value=255) and constant for samples of interest. If believed to be different, measure the tested sample in a similar fashion as was done for the untested felt, and record (variable name: untested sample Gray Value avg). The luminance threshold is calculated as the numerical average of the untested felt Gray Value avg and untested sample Gray Value avg. The tested felt image is opened, and the ROI is created and properly positioned such that the ROI surrounds the region of the tested felt image to be analyzed. The average luminance for the ROI is recorded (variable name: ROI Gray Value avg). Pills are determined as follows: Optimas creates boundary lines in the image where pixel luminance values cross through the threshold value (e.g., if the threshold a Gray Value of 155, boundary lines are created where pixels of higher and lower value exist on either side. The criteria for determining a pill is that it must have an average luminance greater than the threshold value, and have a perimeter length greater than 2 mm for dry pills, and 0.5 mm for wet pills. The pill areas present in the ROI are summed (variable name: Total Pilled Area). viii. Calculations The data obtained from the image analysis is used in the following calculations: Pilled Area % =Total Pilled Area / ROI area Avg. Pill Size (Area Weighted Avg., mm2)=Σ(Pilled Areas)2/Total Pilled Area Lint Score=unpilled felt Gray Value avg−untested felt Gray Value avg where: unpilled felt Gray Value avg=[(ROI Gray Value avg * ROI area)−(pilled Gray Value avg * pilled area)]/Total Unpilled Area Total Area Lint & Pill Score=ROIGray Value avg−untested felt Gray Value avg By taking the average of the lint score on the first-side surface and the second-side surface, the lint is obtained which is applicable to that particular web or product. In other words, to calculate lint score, the following formula is used: Dry Lint Score = Dry Lint Score , 1 st side + Dry Lint Score , 2 nd side 2 Dry Pill Area % = Dry Pill Area % , 1 st side + Dry Pill Area % , 2 nd side 2 Wet Lint Score = [ ( Wetted Area Lint Score + Dragged Area Lint Score ) 1 st side + ( Wetted Area Lint Score + Dragged Area Lint Score ) 2 nd side ] 2 Wet Pill Area % = [ ( Wetted Area Pill Area % + Dragged Area Pill Area % ) 1 st side + ( Wetted Area Pill Area % + Dragged Area Pill Area % ) 2 nd side ] 2 B. Shear Viscosity of a Polymer Melt Composition Measurement Test Method The shear viscosity of a polymer melt composition of the present invention is measured using a capillary rheometer, Goettfert Rheograph 6000, manufactured by Goettfert USA of Rock Hill S.C., USA. The measurements are conducted using a capillary die having a diameter D of 1.0 mm and a length L of 30 mm (i.e., L/D=30). The die is attached to the lower end of the rheometer's 20 mm barrel, which is held at a die test temperature of 75° C.. A preheated to die test temperature, 60 g sample of the polymer melt composition is loaded into the barrel section of the rheometer. Rid the sample of any entrapped air. Push the sample from the barrel through the capillary die at a set of chosen rates 1,000-10,000 seconds−1. An apparent shear viscosity can be calculated with the rheometer's software from the pressure drop the sample experiences as it goes from the barrel through the capillary die and the flow rate of the sample through the capillary die. The log (apparent shear viscosity) can be plotted against log (shear rate) and the plot can be fitted by the power law, according to the formula η=Kγn-1, wherein K is the material's viscosity constant, n is the material's thinning index and γ is the shear rate. The reported apparent shear viscosity of the composition herein is calculated from an interpolation to a shear rate of 3,000 sec−1 using the power law relation. C. Shear Viscosity Change Test Method Viscosities of three samples of a single polymer melt composition of the present invention comprising a crosslinking system to be tested are measured by filling three separate 60 cc syringes; the shear viscosity of one sample is measured immediately (initial shear viscosity) (it takes about 10 minutes from the time the sample is placed in the rheometer to get the first reading) according to the Shear Viscosity of a Polymer Melt Composition Measurement Test Method. If the initial shear viscosity of the first sample is not within the range of 5-8 Pascal·Seconds as measured at a shear rate of 3,000 sec−1, then the single polymer melt composition has to be adjusted such that the single polymer melt composition's initial shear viscosity is within the range of 5-8 Pascal·Seconds as measured at a shear rate of 3,000 sec−1 and this Shear Viscosity Change Test Method is then repeated. Once the initial shear viscosity of the polymer melt composition is within the range of 5-8 Pascal·Seconds as measured at a shear rate of 3,000 sec-1, then the other two samples are measured by the same test method after being stored in a convection oven at 80° C. for 70 and 130 minutes, respectively. The shear viscosity at 3000 sec−1 for the 70 and 130 minute samples is divided by the initial shear viscosity to obtain a normalized shear viscosity change for the 70 and 130 minute samples. If the normalized shear viscosity change is 1.3 times or greater after 70 minutes and/or is 2 times or greater after 130 minutes, then the crosslinking system within the polymer melt composition is unacceptable, and thus is not within the scope of the present invention. However, if the normalized shear viscosity change is less than 1.3 times after 70 minutes and/or (preferably and) is less than 2 times after 130 minutes, then the crosslinking system is not unacceptable, and thus it is within the scope of the present invention with respect to polymer melt compositions comprising the crosslinking system. Preferably, the crosslinking system is acceptable with respect to polymeric structures derived from polymer melt compositions comprising the crosslinking system as determined by the Initial Total Wet Tensile Test Method. Preferably, the normalized shear viscosity changes will be less than 1.2 times after 70 minutes and/or less than 1.7 times after 130 minutes; more preferably less than 1.1 times after 70 minutes and/or less than 1.4 times after 130 minutes. D. Initial Total Wet Tensile Test Method An electronic tensile tester (Thwing-Albert EJA Materials Tester, Thwing-Albert Instrument Co., 10960 Dutton Rd., Philadelphia, Pa., 19154) is used and operated at a crosshead speed of 4.0 inch (about 10.16 cm) per minute and a gauge length of 1.0 inch (about 2.54 cm), using a strip of a polymeric structure of 1 inch wide and a length greater than 3 inches long. The two ends of the strip are placed in the upper jaws of the machine, and the center of the strip is placed around a stainless steel peg (0.5 cm in diameter). After verifying that the strip is bent evenly around the steel peg, the strip is soaked in distilled water at about 20° C. for a soak time of 5 seconds before initiating cross-head movement. The initial result of the test is an array of data in the form load (grams force) versus crosshead displacement (centimeters from starting point). The sample is tested in two orientations, referred to here as MD (machine direction, i.e., in the same direction as the continuously wound reel and forming fabric) and CD (cross-machine direction, i.e., 90° from MD). The MD and CD wet tensile strengths are determined using the above equipment and calculations in the following manner: Initial Total Wet Tensile=ITWT(gf/inch)=Peak LoadMD(gf)/2 (inchwidth)+Peak LoadCD(gf)/2 (inchwidth) The Initial Total Wet Tensile value is then normalized for the basis weight of the strip from which it was tested. The normalized basis weight used is 36 g/m2, and is calculated as follows: Normalized{ITWT}={ITWT}*36 (g/m2)/Basis Weight of Strip (g/m2) If the initial total wet tensile of a polymeric structure, especially a fibrous structure and/or fibrous product comprising a polymeric structure comprising a crosslinking system of the present invention is at least 3 g/2.54 cm (3 g/in) and/or at least 4 g/2.54 cm (4 g/in) and/or at least 5 g/2.54 cm (5 g/in), then the crosslinking system is acceptable and is, along with its corresponding polymeric structure and/or fibrous structure and/or fibrous product, within the scope of the present invention. E. Fiber Diameter Test Method A polymeric structure comprising fibers of appropriate basis weight (approximately 5 to 20 grams/square meter) is cut into a rectangular shape, approximately 20 mm by 35 mm. The sample is then coated using a SEM sputter coater (EMS Inc, PA, USA) with gold so as to make the fibers relatively opaque. Typical coating thickness is between 50 and 250 nm. The sample is then mounted between two standard microscope slides and compressed together using small binder clips. The sample is imaged using a 10× objective on an Olympus BHS microscope with the microscope light-collimating lens moved as far from the objective lens as possible. Images are captured using a Nikon D1 digital camera. A Glass microscope micrometer is used to calibrate the spatial distances of the images. The approximate resolution of the images is 1 μm/pixel. Images will typically show a distinct bimodal distribution in the intensity histogram corresponding to the fibers and the background. Camera adjustments or different basis weights are used to achieve an acceptable bimodal distribution. Typically 10 images per sample are taken and the image analysis results averaged. The images are analyzed in a similar manner to that described by B. Pourdeyhimi, R. and R. Dent in “Measuring fiber diameter distribution in nonwovens” (Textile Res. J. 69(4) 233-236, 1999). Digital images are analyzed by computer using the MATLAB (Version. 6.3) and the MATLAB Image Processing Tool Box (Version 3.)The image is first converted into a grayscale. The image is then binarized into black and white pixels using a threshold value that minimizes the intraclass variance of the thresholded black and white pixels. Once the image has been binarized, the image is skeltonized to locate the center of each fiber in the image. The distance transform of the binarized image is also computed. The scalar product of the skeltonized image and the distance map provides an image whose pixel intensity is either zero or the radius of the fiber at that location. Pixels within one radius of the junction between two overlapping fibers are not counted if the distance they represent is smaller than the radius of the junction. The remaining pixels are then used to compute a length-weighted histogram of fiber diameters contained in the image. All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be considered as an admission that it is prior art with respect to the present invention. While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>In recent years, formulators of fibrous structures have attempted to move away from wood-based cellulosic fibers to polymeric fibers. Polymeric fiber-containing fibrous structures are known in the art. See for example, EP 1 217 106 A1. However, such prior art attempts to make polymeric fiber-containing fibrous structures have failed to achieve the intensive properties of their wood-based cellulosic fiber-containing fibrous structure cousins. Accordingly, there is a need for a polymeric structure and/or a fibrous structure comprising a polymeric structure in fiber form that exhibits intensive properties substantially similar to or better than wood-based cellulosic fiber-containing fibrous structures. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention fulfills the need described above by providing a polymeric structure and/or a fibrous structure comprising a polymeric structure in fiber form that exhibits substantially similar or better intensive properties as compared to wood-based cellulosic fiber-containing fibrous structures. In one aspect of the present invention, a polymeric structure comprising a non-PVOH processed hydroxyl polymer composition comprising a hydroxyl polymer, wherein the polymeric structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In another aspect of the present invention, a fibrous structure comprising a polymeric structure in the form of a fiber in accordance with the present invention, wherein the fibrous structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In even another aspect of the present invention, a fibrous product comprising one or more fibrous structures in accordance with the present invention is provided. In still another aspect of the present invention, a method for making a polymeric structure, the method comprising the steps of: a. providing a non-PVOH polymer melt composition comprising a hydroxyl polymer; and b. polymer processing the non-PVOH polymer melt composition to form a polymeric structure; wherein the polymeric structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In yet another aspect of the present invention, a polymeric structure in fiber form produced in accordance with a method of the present invention, is provided. In even still another aspect of the present invention, a method for making a fibrous structure, the method comprising the steps of: a. providing a non-PVOH polymer melt composition comprising a hydroxyl polymer; b. polymer processing the non-PVOH polymer melt composition to form a polymeric structure in fiber form; and c. incorporating the polymeric structure in fiber form into a fibrous structure; wherein the fibrous structure exhibits a stretch at peak load of at least about 5% and/or at least about 8% and/or at least about 10% and/or a stretch at failure load of at least about 10% and/or at least about 13% and/or at least about 20%, is provided. In even yet another aspect of the present invention, a fibrous structure comprising two or more fibers at least one of which comprises a polymeric structure in fiber form, wherein the fibrous structure comprises a first region comprising associated fibers and a second region comprising non-associated fibers, is provided. In still yet another aspect of the present invention, a fibrous product comprising one or more fibrous structures comprising a first region comprising associated fibers and a second region comprising non-associated fibers, is provided. In even still yet another aspect of the present invention, a method for making a fibrous structure, the method comprising the steps of: a. providing a fibrous structure comprising two or more fibers at least one of which comprises a polymeric structure in fiber form; and b. associating the two or more fibers with each other such that a fibrous structure comprising a first region comprising associated fibers and a second region comprising non-associated fibers is formed, is provided. Accordingly, the present invention provides a polymeric structure, a fibrous structure comprising such a polymeric structure in fiber form, a fibrous product comprising one or more such fibrous structures, method for making such a polymeric structure, method for making such a fibrous structure comprising a polymeric structure in fiber form and a polymeric structure in fiber form produced by such a method. | 20040429 | 20051018 | 20051103 | 59036.0 | 0 | EDWARDS, NEWTON O | POLYMERIC STRUCTURES AND METHOD FOR MAKING SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,834,585 | ACCEPTED | Roller grill having rollers with a roughened surface | A roller grill assembly includes a roller grill housing and a plurality of rollers that are rotatably mounted in the housing, each roller having an external surface. The assembly also includes one or more heating elements provided in each roller for heating the external surfaces of the rollers and a roughened coating overlying at least a portion of the external surfaces of the rollers, the roughened coating generating friction between the rollers and food items placed on the rollers for effectively rotating the food items. The roughened coating is food-safe and includes roughening particles having a size of between 5-300 microns. | 1. A roller grill assembly comprising: a plurality of rotatable rollers disposed in an array, each said roller having an external surface; a roughened coating covering at least a portion of the external surface of each said roller, wherein said roughened coating generates friction between said rollers and food items placed on said rollers for effectively rotating said food items. 2. The assembly as claimed in claim 1, wherein said roughened coating substantially covers the external surface of each said roller. 3. The assembly as claimed in claim 1, further comprising one or more heating elements thermally coupled with the external surfaces of said rollers. 4. The assembly as claimed in claim 1, wherein said roughened coating includes roughening particles mixed therein, said roughening particles having a size of between 5-400 microns. 5. The assembly as claimed in claim 4, wherein said roughening particles have a size of between 5-300 microns. 6. The assembly as claimed in claim 4, wherein said roughening particles are selected from the group consisting of ceramic, aluminum oxide, silicon carbide and garnet. 7. The assembly as claimed in claim 1, wherein said roughened coating includes a non-stick substance and roughening particles disposed in said non-stick substance. 8. The assembly as claimed in claim 1, wherein each said roller is a cylindrical tube. 9. The assembly as claimed in claim 1, wherein each said roller is made of metal. 10. The assembly as claimed in claim 9, wherein said metal is selected from the group consisting of stainless steel and cold rolled steel. 11. The assembly as claimed in claim 1, wherein said roughened coating includes a non-stick material. 12. The grill assembly as claimed in claim 1, wherein said rollers have first and second ends, and wherein said assembly further comprises supports in contact with the first and second ends of said rollers for rotatably supporting said rollers. 13. The assembly as claimed in claim 12, further comprising a roller grill housing, wherein said supports are secured to said housing for rotatably supporting said rollers. 14. A roller grill assembly comprising: a roller grill housing; a plurality of rollers rotatably mounted in said housing, each said roller having an external surface; one or more heating elements provided in each said roller for heating the external surfaces of said rollers; a roughened coating covering at least a portion of the external surfaces of said rollers, wherein said roughened coating generates friction between said rollers and food items placed on said rollers for effectively rotating said food items. 15. The assembly as claimed in claim 14, wherein said roughened coating includes roughening particles disposed therein having a size of between 5-300 microns. 16. The assembly as claimed in claim 15, wherein said roughening particles are food safe. 17. The assembly as claimed in claim 15, wherein said roughened coating further comprises binder particles for binding said coating to the external surfaces of said rollers. 18. The assembly as claimed in claim 14, wherein said roughened coating substantially covers the external surfaces of said rollers. 19. A roller tube for a roller grill assembly comprising: a substantially cylindrical tube having first and second ends and an external surface extending between said first and second ends; a roughened coating covering at least a portion of the external surface of said cylindrical tube. 20. The roller tube as claimed in claim 19, wherein said roughened coating includes roughening particles having a size of about 5-300 microns. 21. The assembly as claimed in claim 19, wherein said roughened coating substantially covers the external surface of said cylindrical tube. 22. The roller tube as claimed in claim 20, wherein said roughening particles are selected from the group of particles consisting of ceramic, aluminum oxide, silicon carbide and garnet. 23. The assembly as claimed in claim 19, wherein said roughened coating comprises non-contiguous areas of roughened coating material covering the external surface of said roller and regions of the external surface exposed between said roughened coating. 24. The assembly as claimed in claim 19, wherein said roughened coating comprises a contiguous area of roughened coating material completely covering the external surface of said roller. | BACKGROUND OF THE INVENTION The present invention generally relates to cooking equipment and more particularly relates to roller grills for cooking and heating food items. Roller grill assemblies typically use an array of heatable tubes that are rotatably mounted within a grill housing. In operation, food items are placed upon the roller tubes and the roller tubes are rotated as heat is transferred to the food items. Unfortunately, conventional roller grills are frequently unable to effectively rotate food items having uneven or rough outer surfaces such as items having a bread-like outer layer or crust surrounding a filling, e.g. an egg roll or corn dog. There have been some minor advances in roller grill assembly technology directed to effectively rotating food items. For example, referring to FIG. 2 of U.S. Pat. No. 6,349,634, a roller grill includes a roller 20 having a grid of wires 30 affixed to the roller. The grid is preferably disposed in contact with the surface of the roller 20 to facilitate heat transfer from the roller to food articles in contact with the roller. The grid attachment enhances the ability of the roller to both rotate and uniformly heat articles of food. The grid attachment, however, is difficult to clean, which may discourage proper cleaning of the system. This may result is unsanitary conditions. In spite of the above advances, there remains a need for a roller grill having rollers that effectively rotate food items, particularly food items having an uneven or rough outer surface. There also remains a need for roller grills that are easy to clean. SUMMARY OF THE INVENTION In certain preferred embodiments of the present invention, a roller grill assembly includes a plurality of rotatable rollers disposed in an array, whereby each roller has an external surface, and a roughened coating covering at least a portion of the external surface of each roller. The roughened coating desirably generates friction between the rollers and food items placed on the rollers for effectively rotating the food items. In certain preferred embodiments, the roughened coating substantially covers the entire external surface of each roller. In other preferred embodiments, the roughened coating may only cover a portion of the external surface of each roller. The roughened coating may include a series of intermittent stripes over the external surface of the roller. In still other preferred embodiments, the roughened coating may cover about one-quarter or one-half of the roller with the remaining portion of the roller having a smooth external surface. The roughened coating may include a curable material such as a curable polymer with particles mixed therein. The particles may include binder particles having a size of about 2-15 microns and more preferably about 2-7 microns. The mixed-in particles may also include roughening particles for providing surface roughness having a size of between 5-300 microns. In certain preferred embodiments, the roughening particles over 50 microns provide the surface roughness that is discernable to human senses. In certain preferred embodiments, the binder particles effectively bind the roughening particles to the coating and to the external surface of the roller. The roughening particles are preferably food-safe particles. In highly preferred embodiments, the roughening particles may be ceramic, aluminum oxide, silicon carbide or garnet. In certain preferred embodiments, the roller grill assembly may include a drive element coupled with the rollers for selectively rotating the rollers. The drive element may include a drive chain. Each of the rollers is preferably a cylindrical tube having a first opening at a first end, a second opening at a second end, and a hollow interior defined by an internal surface and an external surface. Each roller tube is desirably made of a thermally conductive material such as metal. In certain preferred embodiments, the metal is selected from the group consisting of stainless steel and cold rolled steel. The assembly may also include supports in contact with the first and second ends of the rollers for rotatably supporting the rollers. The assembly may also include a roller grill housing whereby the supports are secured within the housing for rotatably supporting the rollers. In highly preferred embodiments, the roughened coating includes a non-stick material such as Teflon®, with the roughening particles disposed in the non-stick material. In other preferred embodiments of the present invention, a roller grill assembly includes a roller grill housing, a plurality of rollers being rotatably mounted in the housing, whereby each roller has an external surface, and one or more heating elements provided for heating the external surfaces of the rollers. The assembly also desirably includes a roughened coating overlying at least a portion of the external surface of the roller, wherein the roughened coating generates friction between the rollers and food items placed on the rollers for effectively rotating the food items. In still other preferred embodiments of the present invention, a roller tube for a roller grill assembly includes a substantially cylindrical tube having first and second ends, an external surface extending between the first and second ends, and a roughened coating covering at least a portion of the external surface of the cylindrical tube. In certain preferred embodiments, the roughened coating substantially covers the external surface of the cylindrical tube. The roughened coating may include granular or roughening particles such as ceramic, aluminum oxide, silicon carbide or garnet. The roughened coating may comprise distinct areas of roughened coating material covering the external surface of the roller, with smooth areas of the external surface of the roller disposed between the roughened coating areas. The roughened coating may also comprise a contiguous area of roughened coating material completely covering the external surface of the roller. These and other preferred embodiments of the present invention will be described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view of a roller grill having rollers with a roughened coating, in accordance with certain preferred embodiments of the present invention. FIGS. 2A and 2B show a method of making a roller having a roughened coating, in accordance with certain preferred embodiments of the present invention. FIG. 3 shows a front elevational view of a roller for a roller grill having a roughened coating, in accordance with certain preferred embodiments of the present invention. FIG. 4 shows a roller for a roller grill assembly having a roughened coating at least partially covering the external surface of the roller, in accordance with certain preferred embodiments of the present invention. FIG. 5 shows a roller having a roughened coating over at least a portion of the external surface thereof, in accordance with still other preferred embodiments of the present invention. FIG. 6 shows a roller having a roughened coating, in accordance with another preferred embodiment of the present invention. FIG. 7 shows a food item being rotated by rollers having a roughened coating, in accordance with certain preferred embodiments of the present invention. DETAILED DESCRIPTION FIG. 1 shows a roller grill assembly 20 including a housing 22 having a front control panel 24, a left support 26 and an opposing right support 28. The roller grill assembly 20 includes an array of heatable rollers 30 rotatably mounted in the left and right supports 26, 28. The heatable rollers 30 are preferably rotatable in the same direction. In operation, the heatable rollers 30 rotate and transmit heat to food items placed atop the rollers. Each heatable roller has a roughened coating 32 overlying at least a portion of an external surface of the roller. In certain preferred embodiments, the roller grill may incorporate one or more features disclosed in commonly assigned U.S. patent application Ser. No. 10/423,401, filed Apr. 25, 2003, the disclosure of which is hereby incorporated by reference herein. FIGS. 2A and 2B show a method of forming a roughened coating over an external surface of a roller. Referring to FIG. 2A, roller tube 30 has a first end 34 defining a first opening 36. The roller tube 30 also includes an interior surface 40 and an exterior surface 42 opposite the interior surface. The external surface of the roller is preferably cleaned before the roughened coating is applied. Referring to FIG. 2A, a roughened coating 32 is applied over the external surface 42 of tube 30. In certain preferred embodiments, prior to application, the roughened coating is prepared by providing a food-safe, curable material such as a curable polymer and mixing roughening particles in the curable material. A binder material such as binder particles may also be mixed into the curable material for effectively binding the roughening particles to the coating and/or to the external surface of the roller. The roughened coating including the roughening particles is then applied to the external surface of the rollers. In highly preferred embodiments, the coating is sprayed onto the external surface of the rollers. The coating material is then cured to bind the coating and the roughening particles to the external surface of the roller. The roughened coating may be cured using heat or air. In certain preferred embodiments, the coating is flash cured at 200-400 F for about one-three minutes. In other preferred embodiments, the coating may be cured at 700-800 F for about three-seven minutes or at 680 F for about 12-18 minutes. In certain preferred embodiments, the roughened coating includes a food-safe material. The roughened coating preferably includes a curable material such as a curable polymer, a curable non-stick material, or a curable liquid. The roughening particles are preferably mixed with the curable material. The roughening particles may be ceramic, aluminum oxide, silicon carbide or garnet. In other preferred embodiments, the roughened coating may be formed by pitting the external surface of the roller and then applying a curable material over the pitted external surface, whereby the coating conforms to the shape of the external surface. The coating may have the above-described roughening particles and/or binder particles mixed therein. FIG. 3 shows roller tube 30 having a roughened coating 32 overlying an external surface of the roller tube. The roughed coating is preferably bound to the external surface of the rollers during the above-described curing process. The roughened coating has peaks and valleys that are adapted to engage the outer surfaces of food items for effectively rotating the food items, particularly those food items having a non-smooth outer surface, e.g. a corn dog or egg roll. Referring to FIG. 4, in another preferred embodiment, roller tube 130 has an external surface 142 with a roughened coating 132 covering a portion of the external surface 142. The roughened coating comprises a series of stripes that extend in a direction generally perpendicular to a longitudinal axis of the roller. Referring to FIG. 5, in another preferred embodiment of the present invention, roller 230 includes an external surface 242 having a roughened coating 232 at least partially covering a portion of the external surface 242. The roughened coating 232 comprises a series of stripes extending in a direction generally parallel to a longitudinal axis of roller 230. Referring to FIG. 6, in another preferred embodiment of the present invention, roller 330 has an external surface 342 and a roughened coating 332 covering a portion of the external surface. In the particular preferred embodiment shown in FIG. 6, the roughened coating 333 cover approximately one-half of the external surface 342 of the roller 330, with a second half 335 of the roller being smooth or being covered by a smooth, non-stick coating over the external surface. Referring to FIG. 7, a food item 50 having a non-smooth, uneven or rough outer surface 52 is positioned between adjacent rollers 30a and 30b. When the food item 50 is placed atop rollers 30a and 30b, the peaks and valleys of the roughened coating 32 of each roller generates friction between the rollers and the outer surface of the food item 50 for effectively rotating the food item. The roughened coating provides a significant improvement over roller grills having smooth outer surfaces, particularly when attempting to rotate food items having uneven or rough outer surfaces such as egg rolls and corn dogs having a flour-based coating. Such prior art devices do not effectively rotate food items having non-smooth outer surfaces. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention generally relates to cooking equipment and more particularly relates to roller grills for cooking and heating food items. Roller grill assemblies typically use an array of heatable tubes that are rotatably mounted within a grill housing. In operation, food items are placed upon the roller tubes and the roller tubes are rotated as heat is transferred to the food items. Unfortunately, conventional roller grills are frequently unable to effectively rotate food items having uneven or rough outer surfaces such as items having a bread-like outer layer or crust surrounding a filling, e.g. an egg roll or corn dog. There have been some minor advances in roller grill assembly technology directed to effectively rotating food items. For example, referring to FIG. 2 of U.S. Pat. No. 6,349,634, a roller grill includes a roller 20 having a grid of wires 30 affixed to the roller. The grid is preferably disposed in contact with the surface of the roller 20 to facilitate heat transfer from the roller to food articles in contact with the roller. The grid attachment enhances the ability of the roller to both rotate and uniformly heat articles of food. The grid attachment, however, is difficult to clean, which may discourage proper cleaning of the system. This may result is unsanitary conditions. In spite of the above advances, there remains a need for a roller grill having rollers that effectively rotate food items, particularly food items having an uneven or rough outer surface. There also remains a need for roller grills that are easy to clean. | <SOH> SUMMARY OF THE INVENTION <EOH>In certain preferred embodiments of the present invention, a roller grill assembly includes a plurality of rotatable rollers disposed in an array, whereby each roller has an external surface, and a roughened coating covering at least a portion of the external surface of each roller. The roughened coating desirably generates friction between the rollers and food items placed on the rollers for effectively rotating the food items. In certain preferred embodiments, the roughened coating substantially covers the entire external surface of each roller. In other preferred embodiments, the roughened coating may only cover a portion of the external surface of each roller. The roughened coating may include a series of intermittent stripes over the external surface of the roller. In still other preferred embodiments, the roughened coating may cover about one-quarter or one-half of the roller with the remaining portion of the roller having a smooth external surface. The roughened coating may include a curable material such as a curable polymer with particles mixed therein. The particles may include binder particles having a size of about 2-15 microns and more preferably about 2-7 microns. The mixed-in particles may also include roughening particles for providing surface roughness having a size of between 5-300 microns. In certain preferred embodiments, the roughening particles over 50 microns provide the surface roughness that is discernable to human senses. In certain preferred embodiments, the binder particles effectively bind the roughening particles to the coating and to the external surface of the roller. The roughening particles are preferably food-safe particles. In highly preferred embodiments, the roughening particles may be ceramic, aluminum oxide, silicon carbide or garnet. In certain preferred embodiments, the roller grill assembly may include a drive element coupled with the rollers for selectively rotating the rollers. The drive element may include a drive chain. Each of the rollers is preferably a cylindrical tube having a first opening at a first end, a second opening at a second end, and a hollow interior defined by an internal surface and an external surface. Each roller tube is desirably made of a thermally conductive material such as metal. In certain preferred embodiments, the metal is selected from the group consisting of stainless steel and cold rolled steel. The assembly may also include supports in contact with the first and second ends of the rollers for rotatably supporting the rollers. The assembly may also include a roller grill housing whereby the supports are secured within the housing for rotatably supporting the rollers. In highly preferred embodiments, the roughened coating includes a non-stick material such as Teflon®, with the roughening particles disposed in the non-stick material. In other preferred embodiments of the present invention, a roller grill assembly includes a roller grill housing, a plurality of rollers being rotatably mounted in the housing, whereby each roller has an external surface, and one or more heating elements provided for heating the external surfaces of the rollers. The assembly also desirably includes a roughened coating overlying at least a portion of the external surface of the roller, wherein the roughened coating generates friction between the rollers and food items placed on the rollers for effectively rotating the food items. In still other preferred embodiments of the present invention, a roller tube for a roller grill assembly includes a substantially cylindrical tube having first and second ends, an external surface extending between the first and second ends, and a roughened coating covering at least a portion of the external surface of the cylindrical tube. In certain preferred embodiments, the roughened coating substantially covers the external surface of the cylindrical tube. The roughened coating may include granular or roughening particles such as ceramic, aluminum oxide, silicon carbide or garnet. The roughened coating may comprise distinct areas of roughened coating material covering the external surface of the roller, with smooth areas of the external surface of the roller disposed between the roughened coating areas. The roughened coating may also comprise a contiguous area of roughened coating material completely covering the external surface of the roller. These and other preferred embodiments of the present invention will be described in more detail below. | 20040429 | 20061205 | 20051103 | 94388.0 | 1 | ALEXANDER, REGINALD | ROLLER GRILL HAVING ROLLERS WITH A ROUGHENED SURFACE | SMALL | 0 | ACCEPTED | 2,004 |
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10,834,678 | ACCEPTED | Bounding box signal detector | A description of signal behavior in the vicinity of a time and voltage of interest is produced by defining a region in the (time, voltage) plane that is a closed straight sided figure whose vertices are identified by threshold crossings offset for the voltage of interest and clocked by time delays offset from a clock time of interest. A first set of latches clocked by the time delays accumulates the state of signal behavior relative to the threshold voltages as it occurs, and their contents are subsequently transferred to a second set of latches at the start of a new clock cycle, allowing a new accumulation to begin and also allowing a detection logic circuit to operate on a unified and completed collection of indicators of what the just concluded description amounts to. The detection logic circuit responds to the combinations of latched indications to produce a signal corresponding to that description. The closed figure need not be a rectangle, and it may also serve as an indication that a signal went into a region that it should not have, e.g., an eye violation detector. | 1. A method of characterizing a work signal's behavior during a time interval, the method comprising the steps of: (a) defining a time interval by START and END timing signal transitions; (b) comparing the work signal to a first threshold voltage to produce a logical first comparison value; (c) comparing the work signal to a second threshold voltage to produce a logical second comparison value; (d) capturing as a first term the logical first comparison value upon an occurrence of the START transition; (e) capturing as a second term the logical second comparison value upon an occurrence of the START transition; (f) capturing as a third term the logical first comparison value upon an occurrence of the END transition; (g) capturing as a fourth term the logical second comparison value upon an occurrence of the END transition; and (h) producing at least one characterization signal indicative of the occurrence in the first through fourth terms of a selected combination thereof. 2. A method as in claim 1 wherein the START and END transitions are transitions in separate signals produced by delaying the active edge of a clock signal, and further comprising the step of capturing the first through fourth terms as buffered first through fourth terms upon the occurrence of the START transition, and further wherein step (h) operates upon the buffered first through fourth terms. 3. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was rising at about the time of the START transition. 4. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was rising at a time between the START and END transitions. 5. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was rising at about the time of the END transition. 6. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was falling at about the time of the START transition. 7. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was falling at a time between the START transition and END transitions. 8. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was falling at about the time of the END transition. 9. A method as in claim 2 wherein a characterization signal produced by step (h) represents that the work signal was essentially quiet between the START and END transitions. 10. A method as in claim 2 wherein the START and END transitions and the first and second threshold voltages have been selected to represent a desired eye opening and a characterization signal produced by step (f) represents that the work signal entered that desired eye opening. 11. A method as in claim 1 wherein the comparisons in steps (b) and (c) are each delayed after the START transition by selected amounts. 12. A method as in claim 1 further comprising the steps of: (i) producing a MIDDLE timing signal transition between the occurrence of the START and END transitions; (j) comparing the work signal to a third threshold voltage that is between the first and second threshold voltages to produce a logical third comparison value; (k) capturing as a fifth term the logical third comparison value upon an occurrence of the MIDDLE transition; and (l) wherein step (h) is further responsive to the fifth term. | BACKGROUND OF THE INVENTION There are many types of electronic test equipment whose operation includes the digital acquisition of a series of analog voltage values. In some cases, such as in real time digital oscillography, an acquisition record is required for a large number of consecutive samples taken in rapid succession. These types of applications generally require a high speed ADC (Analog to Digital Converter), and are typically very expensive to implement. There are other kinds of related applications where a significantly lower cost is desired, which can be achieved if certain performance requirements can be relaxed. These other applications often take advantage of an expected periodicity wherein the signal's previous behavior is repeated, and given enough time a complete description of the signal can be created by sampling different locations within that behavior during successive instances of the behavior. This can remove the need for sustained high speed operation from the ADC. Some digital oscilloscopes operate in this mode. There is yet another variation on this latter mode, where the signal behavior is not required or expected to repeat its exact waveform during the successive instances of sampling at different locations. For example, an EDA (Eye Diagram Analyzer) is more interested in the locations of edges, their rise and fall times and their exerted voltage levels between transitions, rather than in the particular waveform as a voltage history versus time. EDAs often acquire data for large number of signals at the same time (e.g., for all the signals in a wide bus). It is economically impractical to use an expensive data acquisition technique that might be justifiable for two or four channels in a digital oscilloscope for all sixty-four or one hundred twenty-eight channels of an EDA. Accordingly, there have been developed for such applications various ways to lower the cost of the per-channel data acquisition hardware. These techniques often rely on combinations of delay elements and threshold comparators to produce indications that a certain combination of signal parameters was observed. The occurrence (or lack thereof) is noted, the parameters changed, and the process continued. For example, U.S. patent application Ser. No. 10/629,269 entitled IMPROVED EYE DIAGRAM ANALYZER CORRECTLY SAMPLES LOW dv/dt VOLTAGES filed 29 Jul. 2003 by David D. Eskeldson and Richard A. Nygaard JR. describes various arrangements of adjustable delay elements and adjustable threshold detectors that indicate, relative to a reference point in time (such as the edge of a clock signal), if a signal of interest within an SUT (System Under Test) exhibited different relationships to the thresholds at closely spaced points in time that are ΔT apart. If it did not, then that negative piece of information (in isolation, anyway) does not tell us much about where the signal was, but if there WERE different relationships exhibited, then we know within certain time and voltage resolutions that the signal was within or passed through a region described by the thresholds and the delays involved. Such detection is termed a “HIT.” It is customary for an ordinate or vertical dimension to represent voltage, while an abscissa or horizontal dimension represents time. In the case of an EDA built around these types of detectors, the region is left to dwell for a certain length of time, the number of HITs recorded in a data structure whose locations correspond to values along the time and voltage axes, and then the region is moved to an adjacent or other selected location in the (time, voltage) plane. The moving of the region can be accomplished through either sweeping the data channel delay or sweeping the clock channel delay. In due course there is enough information amassed to construct an eye diagram from the numbers of HITs recorded in the various locations of the data structure. The eye diagram is depicted as a graph drawn in the (time, voltage) plane. The prior art (time, voltage) detection mechanisms described in IMPROVED EYE DIAGRAM ANALYZER CORRECTLY SAMPLES LOW dv/dt VOLTAGES are of interest as a point of departure. We now indulge in an extremely abbreviated discussion of those techniques. Refer now to FIG. 1, wherein is shown a simplified block diagram 11 for a swept data channel delay (time, voltage) detection technique usable in an EDA. FIG. 2 is a simplified block diagram 12 of a similar swept clock channel delay technique. It will be noted that they both use the same mechanism to sample data channel voltage. Wit reference to diagram 47, we could say that the signal of interest must have crossed a horizontal line segment (A to B) at the voltage of the threshold and whose length is the time difference ΔT (we also keep track of where ΔT starts). In particular, note that in FIG. 1 a variable SWEPT DATA SIGNAL DELAY 10 produces a voltage-compared data channel signal 2 that has been delayed by a variable amount according to what amount of delay in a cycle of swept amounts of delay is currently in effect. The signal 2 is applied to a D input of a latch 3 (A) that is clocked by a clock signal 1, that while it has been delayed by a CONFIGURABLE CLOCK TRIM DELAY mechanism 9, may be thought of as being “the SUT clock”. The voltage-compared data channel signal 2 is also applied to the D input of another latch 4 (B) that is clocked by a slightly delayed (by dt DELAY) version of the clock signal 1. The idea is that if the SUT data signal for that channel passed through the comparison threshold at a time corresponding to the current SWEPT DATA SIGNAL DELAY, then the two latches 3 and 4 will capture different values, which condition is detected by XOR gate 6 and used to increment a # OF HITS COUNTER 7. We call this mechanism a TRANSITION DETECTOR (8), and say that a HIT occurs when the SUT data signal crosses the voltage described by the horizontal line segment A to B (during ΔT). In FIG. 2 there is a block diagram 12 of the swept clock channel delay technique, which, it will be appreciated from the figure, has the same TRANSITION DETECTOR (8). In fact, the block diagrams 11 and 12 are seemingly identical, although they operate in different manners. What used to be a CLOCK TRIM DELAY 9 in FIG. 1 is now operated as SWEPT CLOCK DELAY 13 in FIG. 2, and what used to be SWEPT DATA SIGNAL DELAY 10 in FIG. 1 is now operated as DATA SIGNAL DE_SKEW DELAY 14. With both of the techniques of FIGS. 1 and 2 the reliance on detecting a transition through a certain threshold to decide upon a signal value at the time of sampling remains open to failure to detect a HIT when the signal voltage does not aggressively transition at the time of the sample. The basic voltage sampling mechanism relies somewhat on noise in the signal and uncertainty in the comparator to cause HITs along the top (exerted/not exerted) and baseline (not exerted/exerted) signal values. A perfectly clean noise-free signal having no dv/dt between its rise and fall, combined with an ideal comparator, would produce no HITs except during the rise and fall. So we have a situation where, if the SUT's signals are really quite good and the measurement hardware is also really quite good, then the eye diagram goes away except at the transitions; it would seem that better is worse! So far, nobody's equipment is quite that good, but the notion of “better is worse” is a disgusting situation that motivates the improvements described in connection with FIGS. 3 and 4. Refer now to FIG. 3, wherein is shown a simplified block diagram 16 of an improvement to the above-described TRANSITION DETECTOR 8 that tolerates low dv/dt. It involves the use of a second threshold comparison, and produces a result that could be described as the OR of crossing the above-described horizontal line segment (A to B) with the condition that the signal fell within or crossed a vertical line segment (A to C) located a one end of the horizontal line segment. These line segments are depicted in the diagram 48. In FIG. 3 the architecture shown is for swept data channel delay. A conditioned SUT data channel signal 17 is applied to a COMPARATOR 19 that also receives a DATA THRESHOLD voltage 20. The logical output signal from the COMPARATOR 19 is applied through an adjustable DELAY 23 (the SWEPT part of this architecture arises from varying the adjustable delay) to the D inputs of LATCHES 27 (A) and 35 (B). (It will be appreciated that the various adjustable delay elements shown can be tapped sequences of buffers in series.) A conditioned SUT CLOCK IN signal 29 is applied to another COMPARATOR 30 that receives a CLOCK THRESHOLD voltage 31. The logical output of the COMPARATOR 30 is applied through a CLOCK TRIM DELAY 32 (that is typically set and then left alone) as a clocking signal 33 to the LATCH 27, and via an additional DELAY 34 to LATCH 35. DELAY 34 corresponds to the dt DELAY 5 of FIGS. 1 and 2, and the two LATCHES 27 and 35 of FIG. 3 to LATCHES 3 and 4, respectively (for either of FIGS. 1 and 2). XOR gate 38 of FIG. 3 serves the same purpose as XOR gate 6 of FIGS. 1 and 2, and to this point we have described much of the same basic structure as the TRANSITION DETECTOR 8 of FIGS. 1 and 2. That is, if the DATA IN signal 17 experiences a transition through the threshold 20 during a period of time occupied by DELAY 34, as located by DELAY 23, then the two latches 27 and 35 will have different values, and the exerted output from XOR gate 38 will pass through OR gate 39 to set LATCH 40 and produce a signal HIT 41 that is then used in various ways by the balance of the EDA, and that do not concern us here. Now note that the DATA IN signal 17 is also applied to a second COMPARATOR 18 whose threshold 22 is different from the DATA THRESHOLD 20 by an amount set by an OFFSET VOLTAGE 21. The logical output from COMPARATOR 18 is applied through DELAY 24 (which preferably tracks DELAY 23, save that it may be offset to compensate channel-to-channel skew) as signal 26 to the D input of LATCH 28 (C) that is clocked by signal 33. A moment's consideration will confirm that if the DATA IN signal 17 is, at the time located by the DELAY 32 (i.e., clocked by signal 33), of a value that is within the (signed) OFFSET VOLTAGE 21 from the DATA THRESHOLD 20, then the two LATCHES 28 and 27 will have different values after being clocked by signal 33. As a particular example when the OFFSET value 21 is positive, LATCH 27 will be set, and LATCH 28 will not be set. The underlying implication that may be drawn is that the level (voltage value at the time of sampling) of the SUT data signal of interest is close (within the OFFSET value 21) to the value of the DATA THRESHOLD 20. On the other hand, if the SUT data signal level is safely on one side of the DATA THRESHOLD 20 by an amount exceeding the OFFSET 21, then both LATCHES 27 and 28 will be set, while in the other case (voltage level on the “other side”) neither LATCH will be set. In either case, they (27, 28) are both the same after being clocked by signal 33. However, as noted, in the case of interest (which is a HIT), the LATCHES will be different, and XOR gate 37 will detect such and OR gate 39 will merge this HIT indication with the output of XOR gate 38. The merged result is applied to LATCH 40, from whence things proceed as usual, save that we are now able to detect HITs that may have eluded the TRANSITION DETECTOR 8 of FIGS. 1 and 2. We call this improved mechanism a TRANSITION/RANGE DETECTOR, and say that it detects a HIT when either the SUT data signal crosses the voltage described by the horizontal line segment A to B (during ΔT), or when the SUT signal lies within the voltage range A to C at the start of ΔT, or perhaps (and which is equivalent, but requires slightly different circuitry) lies within the voltage range B to C at the end of ΔT. Lastly, note optional DELAY 36. If there were no such DELAY 36 then the LATCH 40 captures the results for a cycle of CLOCK IN 31 that is one cycle advanced ahead of the present cycle. In a pipelined system this is not a major shortcoming, as things are later aligned by pipeline delays, anyway. If the delay is present, and chosen to be more than DELAY 34 and less than a clock cycle, then “newest” results are clocked into LATCH 41. A brief reference to FIG. 4 will reveal a simplified block diagram 45 that is as similar to the block diagram 16 of FIG. 3 as FIG. 2 is similar to FIG. 1. The operation of the circuit is essentially the same as described for FIG. 3, save that the DELAYs 43 and 44 produce a TRIM DELAY that de-skews the data channels, and DELAY 42 operates as a SWEPT CLOCK DELAY. It is not so much that the above-described systems do not work—they do. But we can imagine other circumstances where we would like more than a simple “it was present” or “it was absent” type of indication for our efforts. For example: “Did it pass all the way through the region, and if so, in which direction?” We might even prefer that the region involved be something other than a line segment or two line segments. But on the other hand, we are mindful that however we choose to augment the acquisition circuitry, we are bound to do it for all sixty-four or one hundred twenty-eight channels, which is a powerful incentive in favor of techniques that return significant amounts of information for relatively little additional hardware. What to do? SUMMARY OF THE INVENTION A more informative description of a signal's behavior in the vicinity of a time relative to a transition in a clock and at a voltage of interest can be produced by defining a region in the (time, voltage) plane that is a closed straight sided figure whose vertices are identified by threshold crossings offset for the voltage of interest and clocked by time delays offset from the clock time of interest. A first set of latches clocked by the time delays accumulates the state of the signal's behavior relative to the threshold voltages as it occurs, and their contents are subsequently transferred to a second set of latches at the start of a new clock cycle, allowing a new accumulation to begin and also allowing a detection logic circuit to operate on a unified and completed collection of indicators of what the just concluded description amounts to. The detection logic circuit, which may be combinatorial logic or a look-up table, responds to the combinations of latched indications to produce a signal corresponding to that description. The closed figure need not be a rectangle, and its use need not be limited to finding the particular manner in which a signal traversed its interior, but may also serve as an indication that a signal went into a region that it should not have, e.g., as an eye violation detector. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified block diagram of a prior art TRANSITION DETECTOR for an eye diagram analyzer that uses swept data channel delay; FIG. 2 is a simplified block diagram of a prior art TRANSITION DETECTOR for an eye diagram analyzer that uses swept clock channel delay; FIG. 3 is a simplified block diagram of a prior art TRANSITION/RANGE DETECTOR for an eye diagram analyzer using swept data channel delay; FIG. 4 is a simplified block diagram of a prior art TRANSITION/RANGE DETECTOR for an eye diagram analyzer using swept clock delay. FIG. 5 is a simplified block diagram of a four point BOUNDING BOX DETECTOR constructed in accordance with the principles of the invention; FIG. 6 is a chart illustrating an aspect of the operation of the block diagram of FIG. 4; and FIG. 7 is a simplified block diagram illustrating elements to be added to the block diagram of FIG. 5 to produce a six point BOUNDING BOX DETECTOR. DESCRIPTION OF A PREFERRED EMBODIMENT We turn now to FIG. 5, wherein is depicted a simplified block diagram 46 of what we shall term a four point BOUNDING BOX DETECTOR. Diagram 49 in the upper left-hand corner of the figure illustrates, in general, one kind of four point BOUNDING BOX, which in this case is defined by the four vertices labeled A, B, C and D. Each vertex represents a particular combination of a threshold being met at a certain time. So, A and B have the same threshold voltage (which will be VOFF in this case), but are ΔT apart in time. A signal X1 (72) is produced by a VARIABLE DELAY 71 applied to SUT_CLK 70, and is delayed from SUT_CLK by a ranging time offset we term TOFF. X1 is the start of a time interval we call ΔT and that is delimited by another signal X2 (74). X2 is produced from X1 by another VARIABLE DELAY 73. It will be appreciated that the VARIABLE DELAY circuits can be, for example, a tapped series of buffers. We can see how this works by noticing that the input signal 50, which in this case is illustrated as being a differential pair D_IN(+) and D_IN(−), is applied to a COMPARATOR 53 whose output 55 we shall call Y1. The comparison also involves a ranging offset voltage VOFF in series with D_IN(−). By varying VOFF we can make Y1 be a function of any desired voltage level. Relative to a clock signal from the system under test (SUT_CLK 70) a VARIABLE DELAY circuit 71 produces a signal X1. Ignoring the optional ADVANCING DELAYS 57 and 58, a LATCH A 59 clocked by X1 and capturing Y1 records if the input signal 50 exceeds VOFF at X1. VOFF is one end of a voltage range called ΔV, whose other end is obtained by a voltage source 52 referenced to the (−) input of COMPARATOR 53. The combined offset of VOFF and ΔV is applied to the (−) input of COMPARATOR 54, whose output 56 we term Y2. Ignoring the OPTIONAL ADVANCING delays 57 and 58, a LATCH C 60 clocked by X1 and capturing Y2 records if the input signal 50 exceeds VOFF+ΔV at X1. After a moment's reflection, the reader will appreciate that after X1, certain combinations of A and C have useful meanings. For example, A AND NOT C can be interpreted as the voltage value of D_IN lying between the two thresholds represented by Y1 and Y2 at time X1, which is to say, along the line AC in diagram 49. In like fashion the circuit captures with LATCHES B 61 and D 62 the values of Y1 and Y2 at time X2 (74). Upon the next instance of X1 the four values for A, B, C and D are clocked into a second set of LATCHES A′ (63), B′ (64), C′ (65) and D′ (66). Now these values are one clock signal behind reality, but we have all four at the same time and one whole clock cycle to decide what their combination means. This partial cycle latency may be too slow for certain applications, but it is by no means too slow for all, and is certainly fast enough for, say, use in an EDA. Accordingly, the values of the four LATCHES A′ (63), B′ (64), C′ (65) and D′ (66) are applied to a DETECTION LOGIC circuit 67, which produces outputs indicative of useful combinations of those LATCHES. Those indicated combinations are latched upon the next X1 into corresponding LATCHES 68 and 69, whereupon they are noticed and operated upon by some system (not shown, but which might be part of an EDA) that is interested in that sort of thing. It will also be appreciated that line BD is similar to line AC, except that it is for the end of ΔT, where AC is for the start of ΔT. Furthermore, just as we enquired about combinations of A and C, we can do the same for B and D, and also for the entire collection of A and B and C and D. For example, if we observe A AND NOT B then we have good reason to believe that D_IN was falling and crossed the line AB during ΔT. However, since we have in this case four particular terms to consider, a little thought will confirm that not all combinations are possible for these particular terms. For example, it is not logical that the input voltage can be both above and below the same threshold voltage at the same time. Hence, any combination including C AND NOT A is suspect. FIG. 6 contains a chart 75 that indicates the circumstances for each of the sixteen possibilities for the four terms A, B, C and D of FIG. 5. The DETECTION LOGIC that implements the chart 75 (or a different one for a different application) can be a collection of gates performing combinatorial logic, or, when the number of inputs is high, perhaps a look-up table implemented by a small ROM. It will be appreciated that A and B (or A′ and B′) represent the same voltage VOFF at time ΔT apart, starting at TOFF, that C and D (or C′ and D′) represent the same voltage VOFF+ΔV at time ΔT apart, starting at TOFF, and that these conditions are represented in the diagram 49 by the line segments AB and CD, respectively. In similar fashion the line segment AC represents a range of voltages ΔV apart at time X1, while the line segment BD represents the same voltage range at time X2. The four vertices A, B, C and D form a closed figure, and within certain limits we are entitled to attribute to it certain properties, as is done by the chart in FIG. 6. There ARE limits, however, such as signals whose time variant traces have points of inflection that lie within the figure formed by the vertices. So, for example, a signal that crosses CD from outside the box ABCD, changes direction and goes back out again by re-crossing CD from inside, will not detected as having encountered the box. There are a number of such circumstances, and they amount to the well known situation where high speed phenomena are often inaccurately described by slow speed sampling. To continue in this vein, we note that “crossing” a vertical line segment (such as AC), where “crossing” means there was an occurrence of ANY voltage on the line segment at the time of interest, CAN INDEED be detected as a combination of terms. However, the particular hardware we have shown does not actually do the exact corresponding thing for horizontal lines: “Was the signal EVER at this voltage during this time interval?” Hardware to do that can be contemplated, and amounts to appreciating: (1) That “at this voltage” means “equals”; (2) That there is an attending practical issue of tolerance that the pure mathematical conception of equality does not require, with the implication that for a given resolution it is a range of voltages that is actually being detected, and not an EXACT voltage; and (3) That the amount of time spent at the voltage of interest might correspond to a point an not an interval. Now, if there WERE an “equals comparator” that possessed exactitude and tolerated zero duration to boot, we would simply arrange for its output (if there were one) to “latch-up” during the time interval of interest. But there are no comparators, and probably never will be, that REALLY do the “equals” comparison. Without such a comparator we are unable to accomplish the stated task. Instead, actual comparators for analog quantities respond to a range if they are “equality detectors,” or else have ≦ or ≧ as their function (threshold comparison). One solution is to combine two threshold comparators to identify a small range taken to be the practical equivalent of a point. There remains the speed of operation issue concerning how fast things can be recognized and recorded. There is a similar set of philosophical observations concerning speed of operation, which we can omit as being familiar, and for which the usual solution is to restrict the dv/dt of the input signal to some limit that can be dealt with. Accordingly, we will henceforth assume that the input signal has been bandwidth limited to what can be dealt with by the available comparators and latches. To return to the correct interpretation of the horizontal line segments, it is now fair to ask if they represent the revised question: “Was the signal EVER sufficiently close to a particular value during the time interval?” That is the most stringent question that we can expect our hardware to answer. Putting all these ideas together, we arrive at a more informed position where we now ask only: “Was the input signal within a range of voltages during a certain interval of time?” The question is to be a practical one, and not an ideal one. Upon reflection, it will be appreciated that, for example, the BOUNDING BOX ABCD is a practical representation of such a range of voltage during an interval of time, and that while there are indeed limitations on what it means to “cross” AB, AB taken with CD is definitive, provided we accept the limitations of resolution. As physical beings in a physical universe we appear to have no physical access to the ideal of exact equality or to instantaneous behavior, and settle for close approximations. That is what we get if we make the BOUNDING BOX ABCD small enough, and then treat the BOUNDING BOX as a unit. Hence, we treat the entire combination of the latched states A′, B′, C′ and D′ as a unit outcome, and get on with the rest of our affairs. In other words, we can take a small enough BOUNDING BOX as a correct substitute for not being able to tell if a signal's value “really” crossed a horizontal line during an interval: we let the BOUNDING BOX act in place of the line and rely on there being two parallel horizontal lines in the BOUNDING BOX whose presence gets us off the exactitude hook, as it were. Bandwidth limiting of the input signal and fast sampling take care of the speed issue. So, one way to use the circuitry of FIG. 5 is to make the BOUNDING BOX ABCD a small rectangle, and then vary VOFF and TOFF to move it around through a (time, voltage ) plane or space as desired. For example, in an EDA application, the size of the BOUNDING BOX would be selected according to the user's resolution requirements, and it would be left to dwell at various locations (values for VOFF and TOFF) for appropriate amounts of time, and the number of HITs recorded, etc. If we are prepared to add more comparators and/or clock signals, we can add more vertices to a BOUNDING BOX to provide more terms that can be applied to the DETECTION LOGIC. For example, the side of a BOUNDING BOX could have a staircase shape. It is clear from the philosophical discussion above that vertices whose interconnecting lines are other than vertical or horizontal produce results that must be more loosely interpreted. For example, a line sloping up and to the right may mean only that the input was above one threshold at the start of a time interval and below a higher threshold at the end of that time interval. If there is to be continuity of the input signal (a reasonable belief), there will be a combination of terms that implies that the sloping line was crossed, but we have no idea of when within the interval, or at what voltage within the difference of the two thresholds. Another way to use the BOUNDING BOX is to make it large, say, so that it just fits inside what is expected to be a proper eye description. Now it can function as an eye violation detector that also indicates, in general, how any violations occurred. In conclusion, we consider some extensions to the ideas set out above. First, return to FIG. 5 and notice the optional ADVANCING DELAYs 57 and 58. If they are present, they allow the BOUNDING BOX DETECTORto be “anchored” with respect to X1. So, if the ADVANCING DELAY is set to avalue δ (and we assume here that δ is small; a fraction of a clock cycle), then the inputs to LATCHs A and C will represent locations in time earlier than X1, while LATCHs B and D continue to be clocked ΔT after X1. Thus, δ could be set to a minimum set-up value, while ΔT is set to a minimum hold value. In this way, with correct values for the RANGING OFFSETs and the appropriate logic function in the DETECTION LOGIC, we obtain a signal representing a Setup/Hold & Noise Margin Trigger, which we could also call a Clock-Centered Eye Violation Trigger. FIG. 7 illustrates an extension 76 to the block diagram 46 of FIG. 5. It adds the additional terms E, F and G, as indicated by the diagram 77. To this end, LATCHs E, F and G are clocked by an signal X1.5 (90) that is obtained by a DELAY circuit 88 driven by X1. The signal X1.5 occurs between instances of X1 and X2. The signal X2 continues to be where it was, but is now produced by another (shorter) DELAY circuit 89. X1 is used to clock LATCHs E, F and G into LATCHs E′, F′ and G′. LATCHs E and F are responsive to voltage comparisons Y1 and Y2, just as are LATCHs A and C, respectively. LATCH G is responsive to a new term Y3 representing a threshold that is, for example, one half of VDIFF or ΔV/2. The DETECTION LOGIC (formerly 67, now 87) is, of course, augmented to deal with the additional terms E′, F′ and G′. It will be noted that G′ can be taken as the logical value of the signal D_IN that existed at the time corresponding to each of the other terms A′-F′. Also, it is clear that the six-point BOUNDING BOX (76 with 46) with terms A′ through G′ can be understood as a unit on its own, or as two individual four-point BOUNDING BOXs AECF and EBFD that share EGF as a common side. | <SOH> BACKGROUND OF THE INVENTION <EOH>There are many types of electronic test equipment whose operation includes the digital acquisition of a series of analog voltage values. In some cases, such as in real time digital oscillography, an acquisition record is required for a large number of consecutive samples taken in rapid succession. These types of applications generally require a high speed ADC (Analog to Digital Converter), and are typically very expensive to implement. There are other kinds of related applications where a significantly lower cost is desired, which can be achieved if certain performance requirements can be relaxed. These other applications often take advantage of an expected periodicity wherein the signal's previous behavior is repeated, and given enough time a complete description of the signal can be created by sampling different locations within that behavior during successive instances of the behavior. This can remove the need for sustained high speed operation from the ADC. Some digital oscilloscopes operate in this mode. There is yet another variation on this latter mode, where the signal behavior is not required or expected to repeat its exact waveform during the successive instances of sampling at different locations. For example, an EDA (Eye Diagram Analyzer) is more interested in the locations of edges, their rise and fall times and their exerted voltage levels between transitions, rather than in the particular waveform as a voltage history versus time. EDAs often acquire data for large number of signals at the same time (e.g., for all the signals in a wide bus). It is economically impractical to use an expensive data acquisition technique that might be justifiable for two or four channels in a digital oscilloscope for all sixty-four or one hundred twenty-eight channels of an EDA. Accordingly, there have been developed for such applications various ways to lower the cost of the per-channel data acquisition hardware. These techniques often rely on combinations of delay elements and threshold comparators to produce indications that a certain combination of signal parameters was observed. The occurrence (or lack thereof) is noted, the parameters changed, and the process continued. For example, U.S. patent application Ser. No. 10/629,269 entitled IMPROVED EYE DIAGRAM ANALYZER CORRECTLY SAMPLES LOW dv/dt VOLTAGES filed 29 Jul. 2003 by David D. Eskeldson and Richard A. Nygaard JR. describes various arrangements of adjustable delay elements and adjustable threshold detectors that indicate, relative to a reference point in time (such as the edge of a clock signal), if a signal of interest within an SUT (System Under Test) exhibited different relationships to the thresholds at closely spaced points in time that are ΔT apart. If it did not, then that negative piece of information (in isolation, anyway) does not tell us much about where the signal was, but if there WERE different relationships exhibited, then we know within certain time and voltage resolutions that the signal was within or passed through a region described by the thresholds and the delays involved. Such detection is termed a “HIT.” It is customary for an ordinate or vertical dimension to represent voltage, while an abscissa or horizontal dimension represents time. In the case of an EDA built around these types of detectors, the region is left to dwell for a certain length of time, the number of HITs recorded in a data structure whose locations correspond to values along the time and voltage axes, and then the region is moved to an adjacent or other selected location in the (time, voltage) plane. The moving of the region can be accomplished through either sweeping the data channel delay or sweeping the clock channel delay. In due course there is enough information amassed to construct an eye diagram from the numbers of HITs recorded in the various locations of the data structure. The eye diagram is depicted as a graph drawn in the (time, voltage) plane. The prior art (time, voltage) detection mechanisms described in IMPROVED EYE DIAGRAM ANALYZER CORRECTLY SAMPLES LOW dv/dt VOLTAGES are of interest as a point of departure. We now indulge in an extremely abbreviated discussion of those techniques. Refer now to FIG. 1 , wherein is shown a simplified block diagram 11 for a swept data channel delay (time, voltage) detection technique usable in an EDA. FIG. 2 is a simplified block diagram 12 of a similar swept clock channel delay technique. It will be noted that they both use the same mechanism to sample data channel voltage. Wit reference to diagram 47 , we could say that the signal of interest must have crossed a horizontal line segment (A to B) at the voltage of the threshold and whose length is the time difference ΔT (we also keep track of where ΔT starts). In particular, note that in FIG. 1 a variable SWEPT DATA SIGNAL DELAY 10 produces a voltage-compared data channel signal 2 that has been delayed by a variable amount according to what amount of delay in a cycle of swept amounts of delay is currently in effect. The signal 2 is applied to a D input of a latch 3 (A) that is clocked by a clock signal 1 , that while it has been delayed by a CONFIGURABLE CLOCK TRIM DELAY mechanism 9 , may be thought of as being “the SUT clock”. The voltage-compared data channel signal 2 is also applied to the D input of another latch 4 (B) that is clocked by a slightly delayed (by dt DELAY) version of the clock signal 1 . The idea is that if the SUT data signal for that channel passed through the comparison threshold at a time corresponding to the current SWEPT DATA SIGNAL DELAY, then the two latches 3 and 4 will capture different values, which condition is detected by XOR gate 6 and used to increment a # OF HITS COUNTER 7 . We call this mechanism a TRANSITION DETECTOR ( 8 ), and say that a HIT occurs when the SUT data signal crosses the voltage described by the horizontal line segment A to B (during ΔT). In FIG. 2 there is a block diagram 12 of the swept clock channel delay technique, which, it will be appreciated from the figure, has the same TRANSITION DETECTOR ( 8 ). In fact, the block diagrams 11 and 12 are seemingly identical, although they operate in different manners. What used to be a CLOCK TRIM DELAY 9 in FIG. 1 is now operated as SWEPT CLOCK DELAY 13 in FIG. 2 , and what used to be SWEPT DATA SIGNAL DELAY 10 in FIG. 1 is now operated as DATA SIGNAL DE_SKEW DELAY 14 . With both of the techniques of FIGS. 1 and 2 the reliance on detecting a transition through a certain threshold to decide upon a signal value at the time of sampling remains open to failure to detect a HIT when the signal voltage does not aggressively transition at the time of the sample. The basic voltage sampling mechanism relies somewhat on noise in the signal and uncertainty in the comparator to cause HITs along the top (exerted/not exerted) and baseline (not exerted/exerted) signal values. A perfectly clean noise-free signal having no dv/dt between its rise and fall, combined with an ideal comparator, would produce no HITs except during the rise and fall. So we have a situation where, if the SUT's signals are really quite good and the measurement hardware is also really quite good, then the eye diagram goes away except at the transitions; it would seem that better is worse! So far, nobody's equipment is quite that good, but the notion of “better is worse” is a disgusting situation that motivates the improvements described in connection with FIGS. 3 and 4 . Refer now to FIG. 3 , wherein is shown a simplified block diagram 16 of an improvement to the above-described TRANSITION DETECTOR 8 that tolerates low dv/dt. It involves the use of a second threshold comparison, and produces a result that could be described as the OR of crossing the above-described horizontal line segment (A to B) with the condition that the signal fell within or crossed a vertical line segment (A to C) located a one end of the horizontal line segment. These line segments are depicted in the diagram 48 . In FIG. 3 the architecture shown is for swept data channel delay. A conditioned SUT data channel signal 17 is applied to a COMPARATOR 19 that also receives a DATA THRESHOLD voltage 20 . The logical output signal from the COMPARATOR 19 is applied through an adjustable DELAY 23 (the SWEPT part of this architecture arises from varying the adjustable delay) to the D inputs of LATCHES 27 (A) and 35 (B). (It will be appreciated that the various adjustable delay elements shown can be tapped sequences of buffers in series.) A conditioned SUT CLOCK IN signal 29 is applied to another COMPARATOR 30 that receives a CLOCK THRESHOLD voltage 31 . The logical output of the COMPARATOR 30 is applied through a CLOCK TRIM DELAY 32 (that is typically set and then left alone) as a clocking signal 33 to the LATCH 27 , and via an additional DELAY 34 to LATCH 35 . DELAY 34 corresponds to the dt DELAY 5 of FIGS. 1 and 2 , and the two LATCHES 27 and 35 of FIG. 3 to LATCHES 3 and 4 , respectively (for either of FIGS. 1 and 2 ). XOR gate 38 of FIG. 3 serves the same purpose as XOR gate 6 of FIGS. 1 and 2 , and to this point we have described much of the same basic structure as the TRANSITION DETECTOR 8 of FIGS. 1 and 2 . That is, if the DATA IN signal 17 experiences a transition through the threshold 20 during a period of time occupied by DELAY 34 , as located by DELAY 23 , then the two latches 27 and 35 will have different values, and the exerted output from XOR gate 38 will pass through OR gate 39 to set LATCH 40 and produce a signal HIT 41 that is then used in various ways by the balance of the EDA, and that do not concern us here. Now note that the DATA IN signal 17 is also applied to a second COMPARATOR 18 whose threshold 22 is different from the DATA THRESHOLD 20 by an amount set by an OFFSET VOLTAGE 21 . The logical output from COMPARATOR 18 is applied through DELAY 24 (which preferably tracks DELAY 23 , save that it may be offset to compensate channel-to-channel skew) as signal 26 to the D input of LATCH 28 (C) that is clocked by signal 33 . A moment's consideration will confirm that if the DATA IN signal 17 is, at the time located by the DELAY 32 (i.e., clocked by signal 33 ), of a value that is within the (signed) OFFSET VOLTAGE 21 from the DATA THRESHOLD 20 , then the two LATCHES 28 and 27 will have different values after being clocked by signal 33 . As a particular example when the OFFSET value 21 is positive, LATCH 27 will be set, and LATCH 28 will not be set. The underlying implication that may be drawn is that the level (voltage value at the time of sampling) of the SUT data signal of interest is close (within the OFFSET value 21 ) to the value of the DATA THRESHOLD 20 . On the other hand, if the SUT data signal level is safely on one side of the DATA THRESHOLD 20 by an amount exceeding the OFFSET 21 , then both LATCHES 27 and 28 will be set, while in the other case (voltage level on the “other side”) neither LATCH will be set. In either case, they ( 27 , 28 ) are both the same after being clocked by signal 33 . However, as noted, in the case of interest (which is a HIT), the LATCHES will be different, and XOR gate 37 will detect such and OR gate 39 will merge this HIT indication with the output of XOR gate 38 . The merged result is applied to LATCH 40 , from whence things proceed as usual, save that we are now able to detect HITs that may have eluded the TRANSITION DETECTOR 8 of FIGS. 1 and 2 . We call this improved mechanism a TRANSITION/RANGE DETECTOR, and say that it detects a HIT when either the SUT data signal crosses the voltage described by the horizontal line segment A to B (during ΔT), or when the SUT signal lies within the voltage range A to C at the start of ΔT, or perhaps (and which is equivalent, but requires slightly different circuitry) lies within the voltage range B to C at the end of ΔT. Lastly, note optional DELAY 36 . If there were no such DELAY 36 then the LATCH 40 captures the results for a cycle of CLOCK IN 31 that is one cycle advanced ahead of the present cycle. In a pipelined system this is not a major shortcoming, as things are later aligned by pipeline delays, anyway. If the delay is present, and chosen to be more than DELAY 34 and less than a clock cycle, then “newest” results are clocked into LATCH 41 . A brief reference to FIG. 4 will reveal a simplified block diagram 45 that is as similar to the block diagram 16 of FIG. 3 as FIG. 2 is similar to FIG. 1 . The operation of the circuit is essentially the same as described for FIG. 3 , save that the DELAYs 43 and 44 produce a TRIM DELAY that de-skews the data channels, and DELAY 42 operates as a SWEPT CLOCK DELAY. It is not so much that the above-described systems do not work—they do. But we can imagine other circumstances where we would like more than a simple “it was present” or “it was absent” type of indication for our efforts. For example: “Did it pass all the way through the region, and if so, in which direction?” We might even prefer that the region involved be something other than a line segment or two line segments. But on the other hand, we are mindful that however we choose to augment the acquisition circuitry, we are bound to do it for all sixty-four or one hundred twenty-eight channels, which is a powerful incentive in favor of techniques that return significant amounts of information for relatively little additional hardware. What to do? | <SOH> SUMMARY OF THE INVENTION <EOH>A more informative description of a signal's behavior in the vicinity of a time relative to a transition in a clock and at a voltage of interest can be produced by defining a region in the (time, voltage) plane that is a closed straight sided figure whose vertices are identified by threshold crossings offset for the voltage of interest and clocked by time delays offset from the clock time of interest. A first set of latches clocked by the time delays accumulates the state of the signal's behavior relative to the threshold voltages as it occurs, and their contents are subsequently transferred to a second set of latches at the start of a new clock cycle, allowing a new accumulation to begin and also allowing a detection logic circuit to operate on a unified and completed collection of indicators of what the just concluded description amounts to. The detection logic circuit, which may be combinatorial logic or a look-up table, responds to the combinations of latched indications to produce a signal corresponding to that description. The closed figure need not be a rectangle, and its use need not be limited to finding the particular manner in which a signal traversed its interior, but may also serve as an indication that a signal went into a region that it should not have, e.g., as an eye violation detector. | 20040428 | 20070814 | 20051103 | 68047.0 | 0 | KIM, KEVIN | BOUNDING BOX SIGNAL DETECTOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,834,959 | ACCEPTED | Signal isolators using micro-transformer | A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals. | 1. A logic signal isolator comprising: a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals. 2. The isolator of claim 1, wherein the receiver includes circuitry for distinguishing between the received signals corresponding to the transmitted signals of the first type and second type and using the distinguished received signals to reconstitute the received logic signal. 3. The isolator of claim 1 or claim 2, wherein the signals of the first type comprise multiple pulses in a predetermined pattern and the signals of the second type comprise one or more pulses in a different pattern. 4. The isolator of claim 1 or claim 2, wherein the signals of the first type comprise pulses of a first duration and the signals of the second type comprise pulses of a second, distinguishable duration. 5. The isolator of claim 1 or claim 2, wherein at least one of the signals of the first or the second type comprise at least one burst. 6. The isolator of claim 1 or claim 2, wherein the transmitter circuit is on a first substrate and the receiver is on a second substrate electrically isolated from the first substrate. 7. The isolator of claim 6, wherein the primary winding and the secondary winding are substantially planar windings arrange in a stacked arrangement with at least one of the windings substantially in or on one of the substrates. 8. The isolator of claim 7, wherein the primary winding is a bottom winding and the secondary winding is a top winding. 9. The isolator of claim 8 further including a compensation network connected to the top winding. 10. The isolator of claim 7 wherein the primary winding is a top winding and the secondary winding is a bottom winding. 11. A digital logic isolator, comprising: a. a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground; b. means for providing to the primary winding signals of a first type in response to transitions of a first type in an input logic signal; c. means for providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal; and d. means for receiving from the secondary winding signals corresponding to the signals of the first and second types and for reconstituting the input logic signal from them. 12. A method of providing an isolated logic signal output in response to a logic signal input, comprising: a. providing a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground; b. providing to the primary winding signals of a first type in response to transitions of a first type in the input logic signal; c. providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal; and d. receiving from the secondary winding signals corresponding to the signals of the first and second types and reconstituting the input logic signal from them. 13. The method of claim 12 wherein the signals of a first type comprise multiple pulses, the signals of the second type comprise a single pulse and reconstituting the input logic signal comprises distinguishing between the signals corresponding to said multiple pulses and the signals corresponding to said single pulses so as to provide an output signal reconstituting the transitions in the input logic signal. 14. The method of claim 12 wherein the signals of a first type or the signals of a second type comprise a burst. 15. The method of claim 14 wherein both signals of a first type and the signals of a second type comprise bursts distinguishable from each other by frequency, duration or other characteristic. 16. The method of claim 12 wherein a signal of the first type comprises a pulse of a first duration and a signal of the second type comprises a pulse of a second duration different from the first duration and distinguishable therefrom and reconstituting the input logic signal comprises distinguishing between received signals corresponding to the pulses of a first duration and the pulses of a second duration so as to provide an output signal reconstituting the transitions in the input logic signal. 17. A logic isolator comprising: a. a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; b. a damping network connected across the top winding; c. a transmitter circuit receiving a logic input signal and driving a signal to said bottom winding; and d. a receiving circuit connected to receive from the top winding a signal corresponding to the signal driving the bottom winding and generating an output comprising a reconstituted logic input signal. 18. A logic isolator comprising: a. a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; b. a damping network connected across the top winding; c. a transmitter circuit receiving a logic input signal and providing a transformer driving signal; d. a receiving circuit connected to receive from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and e. means for programming the isolator by coupling the driving signal to a selected one of the windings and coupling the receiving circuit to the other one of the windings. 19. The isolator of claim 18 wherein the means for programming comprises a fusible connection programmed by blowing open a conductive path. 20. The isolator of claim 18 wherein the means for programming comprises bond wires provided between the transformer windings on the one hand and the transmitter and receiving circuits, on the other hand. 21. The isolator of claim 18 wherein the means for programming comprises programmable circuitry configurable to connect the transmitter circuit to either the top winding or the bottom winding and to connect the receiving circuit to the other winding. 22. The isolator of claim 21 wherein the programmable circuitry includes programmable switching circuits and a memory containing programming to control the switching circuits. 23. The isolator of claim 22 wherein the memory is read-only memory. 24. A dual-channel, bi-directional isolator comprising: a. first and second micro-transformers arranged on a first substrate, each transformer having a top winding and a bottom winding; b. a first transmitter circuit connected to drive the bottom winding of the first transformer; c. a second transmitter circuit connected to drive the top winding of the second transformer; d. a first receiver circuit connected to receive signals from the bottom winding of the second transformer; e. a second receiver circuit connected to receive signals from the top winding of the first transformer. 25. The isolator of claim 24 wherein the first transmitter circuit and first receiver circuit are on the first substrate, and the second transmitter circuit and second receiver circuit are on a second substrate which is electrically isolated from the first substrate. 26. A single channel bi-directional isolator comprising: a. a micro-transformer arranged on a first substrate, the transformer having a top winding and a bottom winding; b. a first transmitter circuit connected to drive the bottom winding; c. a second transmitter circuit and connected to drive the top winding; d. a first receiver circuit connected to receive signals from the top winding; e. a second receiver circuit connected to receive signals from the bottom winding; and f. the first and second transmitter circuits transmitting so as to avoid interfering with each other. 27. The isolator of claim 26 wherein the first transmitter circuit and the second receiver circuit are on the first substrate and the second transmitter circuit and the first receiver circuit are on a second substrate which is electrically isolated from the first substrate. 28. A delay element for use in a pulse generator to supply a supply-voltage-independent delay interval, comprising first and second current sources which supply currents I1 and I2, respectively, and a switching element; the sum of currents I1 and I2 being directly proportional to the supply voltage, and a threshold of the switching element being a predetermined portion of the supply voltage. 29. The delay element of claim 28 wherein said first current source comprises a single transistor and a resistor, the resistor, of resistance value R, having one end connected to the supply voltage and the other end connected to said transistor. 30. The delay element of claim 29 further including a capacitor of capacitance C connected to an input of the switching element and charged by the current sources such that I1=(VDD−VT)/R, where the transistor is a MOS transistor, VT is the threshold voltage of the MOS transistor, VDD is the supply voltage, I2=VT/R, I1+I2=VDD/R and the delay interval is approximately 0.5RC if the switching threshold if the switching element is set to be VDD/2. 31. A logic isolator comprising: a. a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; b. a damping network connected across the top winding; c. a first module coupled to the top winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; d. a second module coupled to the bottom winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; e. means for programming the isolator such that the first module operates in the transformer drive mode while the second circuit operates in the receive mode or that the first module operates in the receive mode while the second module operates in the transformer drive mode. 32. The isolator of claim 31 wherein the means for programming comprises at least one fusible connection programmed by blowing open at least one conductive path. 33. The isolator of claim 31 wherein the means for programming comprises one or more bond wires provided between the transformer windings on the one hand and the first and second modules, on the other hand. 34. The isolator of claim 31 wherein the means for programming comprises programmable circuitry configurable to connect the first module to either the top winding or the bottom winding and to connect the second module to the other winding. 35. The isolator of claim 21 wherein the programmable circuitry includes programmable switching circuits and a memory containing programming to control the switching circuits. 36. The isolator of claim 22 wherein the memory is read-only memory. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 60/466,602 entitled “BI-DIRECTIONAL SIGNAL ISOLATORS USING MICRO-TRANSFORMERS,” filed on Apr. 30, 2003, which is herein incorporated by reference in its entirety. FIELD OF THE INVENTION This invention relates to signal isolators, more particularly digital signal isolators, and even more particularly to digital signal isolators employing transformers to establish an isolation barrier. BACKGROUND OF THE INVENTION In a variety of environments, signals must be transmitted between diverse sources and circuitry using those signals, while maintaining electrical (i.e., galvanic) isolation between the sources and the using circuitry. Isolation may be needed, for example, between microcontrollers, on the one hand, and devices or transducers which use microcontroller output signals, on the other hand. Electrical isolation is intended, inter alia, to prevent extraneous transient signals, including common-mode transients, from inadvertently being processed as status or control information, or to protect the equipment from shock hazards or to permit the equipment on each side of an isolation barrier to be operated at a different supply voltage, among other known objectives and uses. A variety of isolation techniques are known, including the use of optical isolators that convert input electrical signals to light levels or pulses generated by light emitting diodes, and then to receive and convert the light signals back into electrical signals. Isolators also exist which are based upon the use of Hall effect devices, magneto-resistive sensors, capacitive isolators and coil- or transformer-based isolators. Optical isolators, which are probably the most prevalent, present certain well-known limitations Among other limitations, they require significant space on a card or circuit board, they draw a large current, they do not operate well at high frequencies, and they are very inefficient. They also provide somewhat limited levels of isolation. To achieve greater isolation, optical-electronic isolators have been made with some attempts at providing an electrostatic shield between the optical transmitter and the optical receiver. However, a conductive shield which provides a significant degree of isolation is not sufficiently transparent for use in this application. In the area of non-optical isolation amplifiers for use in digital signaling environments, U.S. Pat. No. 4,748,419 to Somerville, shows the differentiation of an input data signal to create a pair of differential signals that are each transmitted across high-voltage capacitors to create differentiated spike signals for the differential input pair. Circuitry on the other side of the capacitor barrier has a differential amplifier, a pair of converters for comparing the amplified signal against high and low thresholds, and a set/reset flip-flop to restore the spikes created by the capacitors into a logic signal. In such a capacitively-coupled device, however, during a common mode transient event, the capacitors couple high, common-mode energy into the receiving circuit. As the rate of voltage change increases in that common-mode event, the current injected into the receiver increases. This current potentially can damage the receiving circuit and can trigger a faulty detection. Such capacitively coupled circuitry thus couples signals that should be rejected. The patent also mentions, without elaboration, that a transformer with a short R/L time constant can provide an isolation barrier, but such a differential approach is nonetheless undesirable because any mismatch in the non-magnetic (i.e., capacitive) coupling of the windings would cause a common-mode signal to appear as a difference signal. Transformer cost and size may also be a negative factor, and transformers having cores of magnetic materials such as ferrites become inefficient at high frequencies and are not useful for coupling high-speed digital signals. Commonly-owned U.S. Pat. No. 5,952,849 shows another logic isolator which avoids use of optical coupling. This logic isolator exhibits high transient immunity for isolating digital logic signals. A need exists, however, for a less expensive, higher performance digital signal isolator with good dynamic characteristics at high frequencies or speeds. Moreover, needs exist for logic isolators which provide improved low-cost bidirectional signal transmission capabilities and which can be configured for a variety of signal transmission configurations. A need further exists for improved signaling schemes for use in isolators, to permit a logic isolator to be based on a single micro-transformer. SUMMARY OF THE INVENTION These needs are addressed with a logic signal isolator comprising, in a first aspect, a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically (i.e., electrically) isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals. The isolator's receiver may include circuitry for distinguishing between the received signals corresponding to the transmitted signals of the first type and second type and using the distinguished received signals to reconstitute the received logic signal. The signals of the first type may, for example, comprise multiple pulses in a predetermined pattern and the signals of the second type comprise one or more pulses in a different pattern. The signals of the first type also may comprise pulses of a first duration and the signals of the second type may comprise pulses of a second, distinguishable duration. At least one of the signals of the first or the second type also may comprise at least one burst. If both comprise bursts, they may be at different frequencies or be for different durations. The transmitter circuit may be on a first substrate and the receiver may be on a second substrate electrically isolated from the first substrate. The primary winding and the secondary winding desirably may be substantially planar windings arrange in a stacked arrangement with at least one of the windings substantially in or on one of the substrates. The primary winding then may be a bottom winding (closer to the substrate) and the secondary winding may be a top winding (further from the substrate). When the primary winding is a bottom winding, the isolator may further include a compensation network connected to the top winding for damping its response. Alternatively, the primary winding may be a top winding and the secondary winding may be a bottom winding. According to another aspect of the invention, a bi-directional isolator is provided by including a second transmitter connected to drive said secondary winding in response to a second received logic signal, such that in response to a first type of edge in the second received logic signal, a signal of a third predetermined type is supplied to the secondary winding and in response to a second type of edge in the second received logic signal, a signal of a fourth predetermined type is supplied to said secondary winding, the secondary winding and the second transmitter being referenced to the second ground; and the primary winding being referenced to the first ground and said primary winding supplying to a second receiver circuit signals received in correspondence to the signals provided to the secondary winding, the second receiver reconstructing the second received logic signal. The isolator's second receiver may include circuitry for distinguishing between the signals received from the primary winding and using the distinguished received signals to reconstitute the second received logic signal. The signals from the first transmitter and the second transmitter may be similar or different. According to another aspect, a digital logic isolator comprises a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground, means for providing to the primary winding signals of a first type in response to transitions of a first type in an input logic signal, means for providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal, and means for receiving from the secondary winding signals corresponding to the signals of the first and second types and for reconstituting the input logic signal from them. According to still anther aspect of the invention, a method of providing an isolated logic signal output in response to a logic signal input comprises providing a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground, providing to the primary winding signals of a first type in response to transitions of a first type in the input logic signal, providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal, and receiving from the secondary winding signals corresponding to the signals of the first and second types and reconstituting the input logic signal from them. The signals of a first type may comprise multiple pulses, the signals of the second type may comprise a single pulse and reconstituting the input logic signal may comprise distinguishing between the signals corresponding to said multiple pulses and the signals corresponding to said single pulses so as to provide an output signal reconstituting the transitions in the input logic signal. The signals of a first type or the signals of a second type comprise a burst. If both the signals of a first type and the signals of a second type comprise bursts, they may be distinguishable from each other by frequency, duration or other characteristic. A signal of the first type alternatively may comprise a pulse of a first duration and a signal of the second type may comprise a pulse of a second duration different from the first duration and distinguishable therefrom; and reconstituting the input logic signal may comprise distinguishing between received signals corresponding to the pulses of a first duration and the pulses of a second duration so as to provide an output signal reconstituting the transitions in the input logic signal. According to another aspect of the invention, a logic isolator comprises a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding, with a damping network connected across the top winding. A transmitter circuit receives a logic input signal and drives a signal to said bottom winding; and a receiving circuit is connected to receive from the top winding a signal corresponding to the signal driving the bottom winding and generates an output comprising a reconstituted logic input signal. According to still another aspect, a logic isolator comprises a micro-transformer having, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a transmitter circuit receiving a logic input signal and providing a transformer driving signal; a receiving circuit connected to receive from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator by coupling the driving signal to a selected one of the windings and coupling the receiving circuit to the other one of the windings. In such an isolator, the means for programming may comprise a fusible connection(s) programmed by blowing open a conductive path(s). The means for programming alternatively may comprise bond wires provided between the transformer windings on the one hand and the transmitter and receiving circuits, on the other hand. As a further alternative, the means for programming comprises programmable circuitry configurable to connect the transmitter circuit to either the top winding or the bottom winding and to connect the receiving circuit to the other winding. The programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may be read-only memory. According to yet another aspect, a logic isolator comprises a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a first module coupled to the top winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; a second module coupled to the bottom winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator such that the first module operates in the transformer drive mode while the second circuit operates in the receive mode or that the first module operates in the receive mode while the second module operates in the transformer drive mode. Various alternatives may be used as the means for programming. Such means may comprise, for example, at least one fusible connection programmed by blowing open at least one conductive path. As another example, the means for programming may comprise one or more bond wires provided between the transformer windings on the one hand and the first and second modules, on the other hand. The means for programming also may comprise programmable circuitry configurable to connect the first module to either the top winding or the bottom winding and to connect the second module to the other winding. Such programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may include a read-only memory. According to still another aspect, a dual-channel, bi-directional isolator comprises first and second micro-transformers arranged on a first substrate, each transformer having a top winding and a bottom winding. A first transmitter circuit is connected to drive the bottom winding of the first transformer; a second transmitter circuit is connected to drive the top winding of the second transformer. A first receiver circuit is connected to receive signals from the bottom winding of the second transformer. A second receiver circuit is connected to receive signals from the top winding of the first transformer. Preferably, but not necessarily, the first transmitter circuit and first receiver circuit are on the first substrate, and the second transmitter circuit and second receiver circuit are on a second substrate which is electrically isolated from the first substrate. Yet another aspect of the invention is a single channel bi-directional isolator comprising a micro-transformer arranged on a first substrate, the transformer having a top winding and a bottom winding; a first transmitter circuit connected to drive the bottom winding; a second transmitter circuit connected to drive the top winding; a first receiver circuit connected to receive signals from the top winding; a second receiver circuit connected to receive signals from the bottom winding; and the first and second transmitter circuits transmitting so as to avoid interfering with each other. Preferably, but not necessarily, the first transmitter circuit and the second receiver circuit are on the first substrate and the second transmitter circuit and the first receiver circuit are on a second substrate which is electrically isolated from the first substrate. According to still another aspect, there is provided a delay element for use in pulse generating circuits for generating pulses usable, for example, to drive a transformer as above-described. The delay element is useful for generating a delay interval, and therefore a pulse duration, of a length that is substantially independent of the supply voltage—i.e., is insensitive to variations in supply voltage. The delay element comprises first and second current sources which supply currents I1 and I2, respectively, in parallel, and a switching element. The sum of currents I1 and I2 is directly proportional to the supply voltage, and a threshold of the switching element is a predetermined portion of the supply voltage. The delay element may further include a capacitor of capacitance C, connected to a node in common with the input of the switching element and the current sources, chargeable by the current sources. Preferably, the first current source comprises a single transistor and a resistor, the resistor, of resistance value R, having one end connected to the supply voltage and the other end connected to said transistor. Current I1=(VDD−VT)/R, where the transistor is a MOS transistor, VT is the threshold voltage of the MOS transistor, VDD is the supply voltage, I2=VT/R, I1+I2=VDD/R. The delay interval is then approximately 0.5RC if the switching threshold of the switching element is set to be VDD/2, and is relatively insensitive to changes in VDD. Such a delay element may be used in conventional pulse generating circuits that rely upon use of a delay element. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: FIG. 1 is a simplified schematic circuit diagram of a transformer-based isolator according to the prior art; FIG. 2 is a simplified schematic circuit diagram of a glitch filter for use in an isolator according to the invention; FIG. 3 is a set of waveforms for the circuit of FIG. 2; FIG. 4 is a simplified schematic circuit diagram of a first embodiment of a transformer-based isolator embodying aspects taught herein; FIG. 5 is a set of waveforms for the circuit of FIG. 4; FIG. 6 is a simplified schematic circuit diagram of a second embodiment of a transformer-based isolator embodying aspects taught herein. FIG. 7 is a waveform depicting two distinguishable pulses of different pulse width, such as may be used in an alternative embodiment of an isolator as taught herein; FIG. 8 is a diagrammatic illustration of an isolator according to some aspects of the invention, wherein the primary winding is a top winding; FIG. 9 is an illustration of input and output waveforms when driving a micro-transformer of the type preferably employed in implementing embodiments of the isolators taught herein, particularly illustrating the difference between driving top and bottom transformer windings; FIG. 10 is a diagrammatic illustration of an isolator according to some aspects of the invention, wherein the primary winding is a bottom winding; FIG. 11 is a diagrammatic illustration of a bidirectional dual channel isolator such as may be implemented using the teachings herein; FIG. 12 is a simplified schematic circuit diagram for a supply-independent delay element for use in a pulse generator (transmitter) in isolators such as are taught herein; and FIGS. 13 and 14 are simplified schematic circuit diagrams for current sources for use in the delay element of FIG. 12. DETAILED DESCRIPTION This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “icomprising,” or “having,” “containing”, “involving”, and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Micro-transformer based digital isolators have been developed in recent years by applicants and their colleagues. This genus of digital isolators shows dramatic improvements over traditional opto-isolators in terms of speed, power, edge symmetry and cost. The transmission methods employed in these micro-transformer based digital isolators fall into two main categories. The first category is based on edge detection; the second, on level detection. Those designs that are based on edge detection have the advantage of lower power, lower pulse width distortion and higher common mode transient immunity over those based on level detection. Typically, implementations based on edge detection require two transmitters, two receivers and two transformers to make a single channel isolator. A need exists for a less expensive design. As shown herein, a digital isolator may be formed, which is based on a micro-transformer-created isolation barrier, using only a single transmitter, a single receiver and a single transmitter. This approach dramatically reduces the die cost while still preserving the merits of edge detection. Further, in a vertically stacked arrangement of micro-transformer windings, the present invention enables bi-directional signal transfer. That is, the signal can be transferred from the top coil to the bottom coil or from the bottom coil to the top coil. This capability can be leveraged to make bi-directional, multi-channel signal isolators or to program the channel direction of a single data channel. This invention preserves the main advantages of high speed, low power, high common-mode immunity and adds to them a reduction in size and enhanced ease of integration. By the term “micro-transformer,” there is meant transformer formed in, partially in, or on, a semiconductor substrate of flat, parallel conductive windings and having no magnetic core. These transformers are also referred to as “air-core” transformers though there actually will be more than air between the windings, typically one or more layers of dielectric materials. A block diagram of a typical prior art example of a transformer-based isolator for digital signals is shown in FIG. 1. There, the isolator 100 comprises (after an optional, though preferable, glitch filter 101), a pair of edge detectors 102 and 104, edge detector 104 being driven by the logical complement to the signal driving edge detector 102, by means of inverter 106. The output of edge detector 102 provides a pulse, the SET_HI signal to the primary winding of transformer 108 responsive to detection of a low-to-high transition (i.e., a leading edge) in the output of the glitch filter 101. The secondary winding of transformer 108 is connected to the set input of a flip-flop 110. The output of edge detector 104 is a pulse named the SET_LO signal which is supplied to the primary winding 120A of transformer 120 responsive to detection of a high-to-low transition (i.e., a falling edge) in the output of the glitch filter 101. The secondary winding of transformer 120 is supplied to the reset input of flip-flop 110. Typically, though not shown for the sake of avoiding obfuscation, the connection from each transformer secondary winding to the flip-flop 110 is not direct, but is made through a Schmitt trigger or other waveform-shaping circuitry intended to provide clean, fast transitions to the flip-flop. Note that the primary windings 108A and 120A of transformers 108 and 120, respectively, as well as the glitch filter and the two edge detectors, are connected (referenced) to a first electrical ground, GNDA, while the secondary windings 108A and 120B, together with the flip-flop 110, are referenced to a second electrical ground, GNDB, which is isolated from the first ground. The outputs of the edge detectors 102 and 104 comprise encoded leading edge and falling edge indicators. These indicators may be in the form of pulses, short bursts, or any periodic signal. So, the edge detectors may be monostable multivibrators, differentiators or other suitable circuits. In the illustration, a single pulse of about ins duration is shown as an edge indicator signal. Glitch filter 101 may be of any suitable design. A brick wall filter is typical. Typically, it should have a bandwidth larger than that to which the edge detectors respond. FIG. 2 provides a schematic circuit diagram for a usable filter, corresponding timing diagrams showing the waveforms at the input, nodes A-D and the filter output being provided in FIG. 3. The filtered pulse width is given approximately by CVthreshold/i, where Vthreshold is the threshold voltage of the Schmitt triggers 22 and 24 and i is the current from current sources 26,28. Turning now to FIG. 4, a basic embodiment for practicing the present invention is shown. FIG. 4 illustrates a logic signal isolator 200 in which encoded leading and falling edge indicators from a pair of edge detectors 202 and 204 (corresponding to edge detectors 102 and 104 of FIG. 1) are sent to a single transformer 210. Unlike the above-discussed design, however, the leading edge and falling edge indicators are encoded as different, distinguishable signals. That is, the SET_HI signal output from leading edge detector 202 is distinct from the SET_LO signal output from falling edge detector 204. The receiving side circuitry connected to the secondary winding 210B of transformer 210 (again, typically via a Schmitt trigger or other suitable wave-shaping circuit, not show) then reconstructs the logic edges based on distinguishing between those two signals. An example is illustrated wherein edge detector 202 produces two consecutive short pulses 232 and 234 as a leading edge indicator and edge detector 204 produces only a single pulse 236 as a falling edge indicator. The pulses 232 and 234 preferably have a known, fixed spacing between them. If transformer 210 is a high bandwidth micro-transformer, the pulse widths may be as narrow as 1 ns or even less. The outputs of edge detectors 202 and 204 are combined by and OR gate 240, to drive the primary winding 210A of the transformer. The pulses cannot be so short or weak in amplitude that the OR gate will not respond properly. Of course, the concept is to use two different, distinguishable signals. They need not be a single pulse and a double pulse. For example, a narrow pulse (e.g., 1 ns) could be used as one edge indicator and a wider pulse (e.g., 2 ns) could be used as the other edge indicator. It is only necessary that the receiver be able to distinguish the two signals. The concept lends itself to the use of other distinguishable signals but at the same time, one would not wish to use an unnecessarily complicated arrangement or one which would add any significant delay in signal processing. For signals other than those illustrated, it might be necessary to replace OR gate 240 with other elements that would effectively combine the outputs of the edge detectors into a single signal for driving the transformer. The two pulses in the SET_HI signal have a known, fixed spacing between them. The total duration of the two pulses and the intervening gap between them in the SET-HI signal, if sufficiently short with respect to the shortest interval between two leading edges in the input signal, will permit resolution between the SET-HI and SET_LO pulses. A receiver circuit 250, connected to secondary winding 210B, recovers the output of transformer 210, distinguishes between the SET_HI and SET_LO pulses, and reconstructs the input logic signal as a data out signal. More specifically, the received pulses at node 252 clock a D-type flip-flop 254 and also act as the input to a non-retriggerable edge-triggered mono-stable multivibrator 256. The multivibrator 256 puts out a pulse on line 258 that is of duration at least as long as the combination of pulse 232 and the interval between pulse 232 and pulse 234 in the SET_HI signal. If the two pulses 232 and 234 are each approximately 1 ns in duration and the interval between them is of like duration, then the pulse on line 258 should be at least about 2 ns long; 3 ns is used in this example to allow some “hold” time to facilitate clocking of flip-flop 254. Line 258 connects to the D input of flip-flop 254, to the reset input of that flip-flop and to the input of inverter 262. The output of inverter 262 is connected to the input of an edge detector 264 and the QB output (the complementary output) of flip-flop 254 is connected to the input of another edge detector 266. The output of edge detector 264 is connected to one input of each of AND gates 272 and 274. The output of edge detector 266 is connected to the second input of AND gate 272 and through inverter 276 to the second input of AND gate 274. In turn, the output of AND gate 272 is connected to the set input of set/reset flip-flop 278 and the output of AND gate 274 is connected to the reset input of flip-flop 278. The DATA OUT signal, corresponding to an isolated and slightly delayed version of the DATA IN signal received by the glitch filter, appears at the Q output of flip-flop 278. The operation of this circuit will now be explained with reference to the waveforms of FIG. 5. Assume that the DATA IN input has the waveform 302. At node 252, the COIL signal is received. Pulses 232 and 234 have been generated by edge detector (i.e., transmitter) 202 in response to the leading, positive-going edge of the input signal and pulse 236 has been generated by edge detector 204 in response to the negative-going, trailing edge of the input signal. The edge-triggered mono-stable (ETMS) multivibrator 256 generates an output waveform on line 258 as shown at ETMS. In the ETMS signal, the leading edge of pulse 232 causes the pulse 304 to be generated. The multivibrator 256 does not do anything in response to the falling edge of pulse 232 or to either edge of the second pulse 234. Only after pulse 304 has been output is the multivibrator 256 able to respond to a new input, which it does when it receives the leading edge of pulse 236. Detection of the leading edge of pulse 236 causes the outputting of pulse 306. The second of the two initial pulses, pulse 234, is detected and the output signal is formed as follows. When the first pulse 232 clocks the flip-flop 254, the D input of the flip-flop still sees a low output from the edge-triggered mono-stable multivibrator on line 258. That means the QB output of the flip-flop 254 is set to a high value and the Q output is set to a low value. When the second pulse 234 is received and clocks flip-flop 254, the output of the edge-triggered mono-stable is now high and the QB output of flip-flop 254 transitions to a low value, meaning that the Q output of flip-flop 254 goes high as at the leading edge of the pulse 308 in the “2 Pulse Detect” signal on FIG. 5. This H-L edge is sensed by edge detector 266, which produces a pulse 310 to the second (bottom) input of AND gate 272. The output of the edge-triggered mono-stable is also supplied to the input of inverter 262. So, after the propagation delay through inverter 262, edge detector 264 sees a high-to-low transition (edge) at the output of inverter 262 and responsively generates a positive-going pulse 312 to the first (top) input of AND gate 272 and to a first (top) input of AND gate 274. Inverter 262 is designed to have a propagation delay that is substantially equal to that from the D input to the QB output of flip-flop 254. Hence, edge detectors 264 and 266 produce substantially concurrent output pulses 310 and 312 to AND gate 272. As a result, the output 314 of AND gate 272 goes from low to high at the same time and sets the set (S) input of the SR flip-flop 278; and the Q output thereof, being the DATA OUT signal, goes high. As the second (bottom) input of AND gate 274 is responsive to the output of edge detector 266 through inverter 276, the first and second pulses have no impact on the output of AND gate 274 and do not affect the output of flip-flop 278. However, when third pulse 236 triggers edge-triggered mono-stable 256, to produce its second output pulse 306, this results as stated above, in the generation of a pulse at the output of edge detector 264 upon the falling edge of the mono-stable output pulse. The second input of AND gate 274 from inverter 276 will be high at this time because the only time it is low is when the output of edge detector 266 generates the second pulse detection signal 308. Therefore, the reset (R) input of flip-flop 278 sees the output pulse 316 from AND gate 274 upon the falling edge of the output pulse from edge detector 264 (plus propagation delay), and flip-flop 278 is reset and the DATA OUT signal goes low. An alternative embodiment 200′ for the pulse receiver circuitry is shown in FIG. 6. Edge detectors 264, 266 and gates 272, 274 and 276 have been eliminated and the output flip-flop 278′ is changed from a set-reset flip-flop to a D-type flip-flop. Again, the first pulse 232 clocks flip-flop 254 before the edge-triggered mono-stable 256 has generated an output pulse on the D input of flip-flop 278′. Therefore, the Q output of flip-flop 254 assumes a low state. When the second pulse 234 clocks flip-flop 254, the D input thereof now sees the output pulse 304 from the edge-triggered mono-stable and the Q output of flip-flop 254 transitions to a high value. The falling edge of the mono-stable pulse 304 is coupled to the clock input of flip-flop 278′ through inverter 262, and clocks flip-flop 278′; as a result, the high value from the Q output of flip-flop 254 supplies a high value on the Q output of flip-flop 278′, and the DATA OUT signal. The falling edge of the mono-stable output pulses also reset flip-flop 254 via its RB (i.e., R complement) input. The output flip-flop278′ is next clocked, again, by the falling edge of the output pulse from the mono-stable, being edge 306B, of pulse 306 generated in response to the third pulse, 236, on the transformer. At the time of edge 306B, flip-flop 254 has been reset to have a low output and the output of flip-flop 278′ accordingly goes low. To assure proper operating states, a reset signal termed PWReset-B is supplied to the reset (complement) input of flip-flop 278′ and causes flip-flop 278′ to be reset whenever device power is reset. An alternative signaling arrangement, mentioned above, is shown in FIG. 7. There, instead of using two pulses to indicate a rising edge and one pulse to indicate a falling edge in the input signal, a double-width pulse 350 is used to indicate a rising edge and a single-width pulse 360 is used to indicate a falling edge. Those skilled in the art of electrical engineering will readily be able to device logic circuitry to discriminate between a pulse of single width duration Δ and a pulse of double width duration 2Δ. An exemplary physical implementation for an isolator according to the present invention, capable of being packaged in an integrated circuit form, is shown in FIG. 8. There, a transmitter (or driver) circuit 802 is formed on a first substrate 804. A transformer comprising a first winding 806A and a second winding 806B is formed on a second substrate 808, along with a receiver circuit 810. Wire leads 812A, 812B from bond pads 814A and 814B on substrate 804 connect the driver output to the primary winding 806A of the transformer. As shown there, obviously, the primary (driving) coil winding is the top coil 806A and the secondary (receiving) coil winding is the bottom coil 806B. It is important to note that the two coils, even if made in the same dimensions and geometry, will exhibit different quality factor Q, because the bottom coil has higher capacitance to substrate 808. Referring to FIG. 9A, when an idealized square voltage pulse 902 drives the top winding 904 of such a transformer, the voltage received at the bottom winding 906 will exhibit a waveform something like 908. By contrast, if the bottom coil 906 is driven by the idealized pulse 912 as shown in FIG. 9B, then the received voltage waveform at the top coil 904 will typically be as shown at 914, exhibiting ringing due to the fact that the top coil has a higher Q than the bottom coil. This undesired ringing makes it difficult to use the transformer for bi-directional signal transfer. However, bidirectional signal transfer is desired in at least some embodiments of the present invention and it is possible to establish a greater degree of symmetry as shown in FIG. 9C, by adding a damping network 916 on the receiving top coil. The damping network consists of a resistor 922 and a capacitor 924 in series. Damping with a resistor only would dramatically reduce the received signal and typically would not be acceptable. The capacitor 924 has very low impedance at high frequencies and blocks DC current through the damping resistor, providing the desired response characteristics. Note that with the damping network, the received waveform 926 from the top coil is substantially the same as the received waveform from the bottom coil as shown at 908 in FIG. 9A. Through use of such a damping network, the edge-detection based isolator above described can be implemented as pictured in FIG. 10. There, it can be seen that the primary coil is the bottom coil 906 instead of the top coil 904. A bi-directional dual isolator arrangement as shown in FIG. 11 is thus enabled. This bi-directional isolator has a pair of stacked transformers arranged side by side. A first transformer is formed by the windings 1102A and 1102B, while a second transformer is formed by the windings 1104A and 1104B. Only one substrate 1106 carries the transformer structure because the primary winding now can be the top coil or bottom coil of a transformer. Absent this possibility, each of the two substrates 1106 and 1108 would need to have an isolated transformer structure thereon and the product would be considerably more expensive to make. Alternatively, it is possible to make a single channel bi-directional isolator having only one vertically stacked transformer, with one transmitter driving the transformer while the other transmitter is idled. Synchronization of the transmissions in two directions can be programmed externally or through proper command encoding/decoding. For some applications, where bandwidth and data rate are not paramount considerations, instead of using pulses to drive the transformer primaries, other signals such as analog bursts at predetermined frequencies and of predetermined durations may be employed. In such situations, signals can be transmitted bi-directionally concurrently through a single transformer. Advantageously, single- and multiple-channel isolators can be manufactured so that the selection of configuration (i.e., which channels transmit in which directions) can be made in final assembly and test steps of production. That lowers product cost by allowing one product core to be made and sold for multiple configurations. The designs shown above lend themselves to this approach in one of two ways. In a first approach, a logic isolator comprises a micro-transformer having, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a transmitter circuit receiving a logic input signal and providing a transformer driving signal; a receiving circuit connected to receive from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator by coupling the driving signal to a selected one of the windings and coupling the receiving circuit to the other one of the windings. In general, the programming would have to be effected before final testing of the isolator in order to maintain isolation between input and output. In such an isolator, the means for programming may, for example, comprise a fusible connection(s) programmed by blowing open a conductive path(s). The means for programming alternatively may comprise bond wires provided between the transformer windings on the one hand and the transmitter and receiving circuits, on the other hand. In either instance, the isolator cannot be tested until isolation-destroying paths are blown open or isolation-destroying bond wires are removed (if there had been any); of course, bond wires could selectively be installed as the last step in manufacture, before testing. As a further alternative, the means for programming may comprise programmable circuitry configurable to connect the transmitter circuit to either the top winding or the bottom winding and to connect the receiving circuit to the other winding. Again, however, only one set of valid connections can be established if input-output isolation is to be maintained. The programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may be read-only memory. A second approach may be based on providing modules, each having both a transformer-driving circuit (i.e., transmitter) and a receiver circuit, such that the module is configured to operate only as a driving circuit or only as a receiving circuit, configuring done at final assembly or by the user. In this approach, a logic isolator comprises a micro-transformer having, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a first module coupled to the top winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; a second module coupled to the bottom winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator such that the first module operates in the transformer drive mode while the second circuit operates in the receive mode or that the first module operates in the receive mode while the second module operates in the transformer drive mode. Various alternatives may be used as the means for programming. Such means may comprise, for example, at least one fusible connection programmed by blowing open at least one conductive path. As another example, the means for programming may comprise one or more bond wires provided between the transformer windings on the one hand and the first and second modules, on the other hand. The means for programming also may comprise programmable circuitry configurable to connect the first module to either the top winding or the bottom winding and to connect the second module to the other winding. Such programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may include a read-only memory. Utilizing these approaches, a dual-channel, bi-directional isolator comprises first and second micro-transformers arranged on a first substrate, each transformer having a top winding and a bottom winding. A first transmitter circuit is connected to drive the bottom winding of the first transformer; a second transmitter circuit is connected to drive the top winding of the second transformer. A first receiver circuit is connected to receive signals from the bottom winding of the second transformer. A second receiver circuit is connected to receive signals from the top winding of the first transformer. Preferably, but not necessarily, the first transmitter circuit and first receiver circuit are on the first substrate, and the second transmitter circuit and second receiver circuit are on a second substrate which is electrically isolated from the first substrate. Similarly, a single channel bi-directional isolator comprising a micro-transformer arranged on a first substrate, the transformer having a top winding and a bottom winding; a first transmitter circuit connected to drive the bottom winding; a second transmitter circuit connected to drive the top winding; a first receiver circuit connected to receive signals from the top winding; a second receiver circuit connected to receive signals from the bottom winding; and the first and second transmitter circuits transmitting so as to avoid interfering with each other. Preferably, but not necessarily, the first transmitter circuit and the second receiver circuit are on the first substrate and the second transmitter circuit and the first receiver circuit are on a second substrate which is electrically isolated from the first substrate. Such isolators typically have to work with a wide range of supply voltage. If such a characteristic is desired, and the driving signals are to be pulses, then it is also necessary that the transmitters (i.e., edge detectors or pulse generators of whatever nature) be able to generate pulses of precise, voltage-independent pulse width. Methods to generate such voltage-independent pulse widths will now be discussed. A delay element typically is required in such pulse generators. And as illustrated schematically in FIG. 12, a delay element 1200 comprises two current sources 1202 and 1204 which supply currents I1 and I2, respectively, one capacitor, C, and one switching element such as an inverter or a Schmitt trigger 1206. The sum of currents I1 and I2 is such that it is directly proportional to the supply voltage, and the switching threshold is half or some other constant portion of the supply voltage. A simplified example of a current source 1202 for generating current I1 is shown in FIG. 13. There, current source 1202 comprises a single transistor 1212 and a resistor R. The resistor R has one end connected to the supply voltage VDD and the other end connected to the drain of transistor 1212. Current I1=(VDD−VT)/R, where VT is the threshold voltage of the MOS transistor 1212. Current I2=VT/R, I1+I2=VDD/R. Consequently, the delay time will be 0.5RC if the switching threshold is set to be VDD/2. Current source 1204 for generating current I2 can be easily implemented. For example, a simplified schematic circuit diagram for such a current source is shown in FIG. 14. Transistor 1214 imposes the voltage VT across resistor R, inducing current I2 and that current is mirrored in the drain path of transistor 1214. The delay element 1200 can be easily used to generate pulses whose width is independent of the supply voltage. Of course, the illustrated design need not be used to form the required current source. Any design can be used that will produce a supply-independent pulse width. In the examples shown, this is achieved by adding a first current that is proportional to the supply voltage to a second current that is inversely proportional to the supply voltage. Other approaches are not ruled out. Having discussed the principles involved and having illustrated multiple embodiments, it will be further apparent that various alterations thereto and additional embodiments will occur to those skilled in the art. Any such alterations, amendments, improvements and additional embodiments are intended to be within the spirit and scope of the invention, which is not limited by the foregoing examples but only as required by the appended claims and equivalence thereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>In a variety of environments, signals must be transmitted between diverse sources and circuitry using those signals, while maintaining electrical (i.e., galvanic) isolation between the sources and the using circuitry. Isolation may be needed, for example, between microcontrollers, on the one hand, and devices or transducers which use microcontroller output signals, on the other hand. Electrical isolation is intended, inter alia, to prevent extraneous transient signals, including common-mode transients, from inadvertently being processed as status or control information, or to protect the equipment from shock hazards or to permit the equipment on each side of an isolation barrier to be operated at a different supply voltage, among other known objectives and uses. A variety of isolation techniques are known, including the use of optical isolators that convert input electrical signals to light levels or pulses generated by light emitting diodes, and then to receive and convert the light signals back into electrical signals. Isolators also exist which are based upon the use of Hall effect devices, magneto-resistive sensors, capacitive isolators and coil- or transformer-based isolators. Optical isolators, which are probably the most prevalent, present certain well-known limitations Among other limitations, they require significant space on a card or circuit board, they draw a large current, they do not operate well at high frequencies, and they are very inefficient. They also provide somewhat limited levels of isolation. To achieve greater isolation, optical-electronic isolators have been made with some attempts at providing an electrostatic shield between the optical transmitter and the optical receiver. However, a conductive shield which provides a significant degree of isolation is not sufficiently transparent for use in this application. In the area of non-optical isolation amplifiers for use in digital signaling environments, U.S. Pat. No. 4,748,419 to Somerville, shows the differentiation of an input data signal to create a pair of differential signals that are each transmitted across high-voltage capacitors to create differentiated spike signals for the differential input pair. Circuitry on the other side of the capacitor barrier has a differential amplifier, a pair of converters for comparing the amplified signal against high and low thresholds, and a set/reset flip-flop to restore the spikes created by the capacitors into a logic signal. In such a capacitively-coupled device, however, during a common mode transient event, the capacitors couple high, common-mode energy into the receiving circuit. As the rate of voltage change increases in that common-mode event, the current injected into the receiver increases. This current potentially can damage the receiving circuit and can trigger a faulty detection. Such capacitively coupled circuitry thus couples signals that should be rejected. The patent also mentions, without elaboration, that a transformer with a short R/L time constant can provide an isolation barrier, but such a differential approach is nonetheless undesirable because any mismatch in the non-magnetic (i.e., capacitive) coupling of the windings would cause a common-mode signal to appear as a difference signal. Transformer cost and size may also be a negative factor, and transformers having cores of magnetic materials such as ferrites become inefficient at high frequencies and are not useful for coupling high-speed digital signals. Commonly-owned U.S. Pat. No. 5,952,849 shows another logic isolator which avoids use of optical coupling. This logic isolator exhibits high transient immunity for isolating digital logic signals. A need exists, however, for a less expensive, higher performance digital signal isolator with good dynamic characteristics at high frequencies or speeds. Moreover, needs exist for logic isolators which provide improved low-cost bidirectional signal transmission capabilities and which can be configured for a variety of signal transmission configurations. A need further exists for improved signaling schemes for use in isolators, to permit a logic isolator to be based on a single micro-transformer. | <SOH> SUMMARY OF THE INVENTION <EOH>These needs are addressed with a logic signal isolator comprising, in a first aspect, a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically (i.e., electrically) isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals. The isolator's receiver may include circuitry for distinguishing between the received signals corresponding to the transmitted signals of the first type and second type and using the distinguished received signals to reconstitute the received logic signal. The signals of the first type may, for example, comprise multiple pulses in a predetermined pattern and the signals of the second type comprise one or more pulses in a different pattern. The signals of the first type also may comprise pulses of a first duration and the signals of the second type may comprise pulses of a second, distinguishable duration. At least one of the signals of the first or the second type also may comprise at least one burst. If both comprise bursts, they may be at different frequencies or be for different durations. The transmitter circuit may be on a first substrate and the receiver may be on a second substrate electrically isolated from the first substrate. The primary winding and the secondary winding desirably may be substantially planar windings arrange in a stacked arrangement with at least one of the windings substantially in or on one of the substrates. The primary winding then may be a bottom winding (closer to the substrate) and the secondary winding may be a top winding (further from the substrate). When the primary winding is a bottom winding, the isolator may further include a compensation network connected to the top winding for damping its response. Alternatively, the primary winding may be a top winding and the secondary winding may be a bottom winding. According to another aspect of the invention, a bi-directional isolator is provided by including a second transmitter connected to drive said secondary winding in response to a second received logic signal, such that in response to a first type of edge in the second received logic signal, a signal of a third predetermined type is supplied to the secondary winding and in response to a second type of edge in the second received logic signal, a signal of a fourth predetermined type is supplied to said secondary winding, the secondary winding and the second transmitter being referenced to the second ground; and the primary winding being referenced to the first ground and said primary winding supplying to a second receiver circuit signals received in correspondence to the signals provided to the secondary winding, the second receiver reconstructing the second received logic signal. The isolator's second receiver may include circuitry for distinguishing between the signals received from the primary winding and using the distinguished received signals to reconstitute the second received logic signal. The signals from the first transmitter and the second transmitter may be similar or different. According to another aspect, a digital logic isolator comprises a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground, means for providing to the primary winding signals of a first type in response to transitions of a first type in an input logic signal, means for providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal, and means for receiving from the secondary winding signals corresponding to the signals of the first and second types and for reconstituting the input logic signal from them. According to still anther aspect of the invention, a method of providing an isolated logic signal output in response to a logic signal input comprises providing a transformer having a primary winding referenced to a first ground and a secondary winding referenced to a second ground isolated from the first ground, providing to the primary winding signals of a first type in response to transitions of a first type in the input logic signal, providing to the primary winding signals of a second type different from the signals of the first type in response to transitions of a second type in the input logic signal, and receiving from the secondary winding signals corresponding to the signals of the first and second types and reconstituting the input logic signal from them. The signals of a first type may comprise multiple pulses, the signals of the second type may comprise a single pulse and reconstituting the input logic signal may comprise distinguishing between the signals corresponding to said multiple pulses and the signals corresponding to said single pulses so as to provide an output signal reconstituting the transitions in the input logic signal. The signals of a first type or the signals of a second type comprise a burst. If both the signals of a first type and the signals of a second type comprise bursts, they may be distinguishable from each other by frequency, duration or other characteristic. A signal of the first type alternatively may comprise a pulse of a first duration and a signal of the second type may comprise a pulse of a second duration different from the first duration and distinguishable therefrom; and reconstituting the input logic signal may comprise distinguishing between received signals corresponding to the pulses of a first duration and the pulses of a second duration so as to provide an output signal reconstituting the transitions in the input logic signal. According to another aspect of the invention, a logic isolator comprises a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding, with a damping network connected across the top winding. A transmitter circuit receives a logic input signal and drives a signal to said bottom winding; and a receiving circuit is connected to receive from the top winding a signal corresponding to the signal driving the bottom winding and generates an output comprising a reconstituted logic input signal. According to still another aspect, a logic isolator comprises a micro-transformer having, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a transmitter circuit receiving a logic input signal and providing a transformer driving signal; a receiving circuit connected to receive from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator by coupling the driving signal to a selected one of the windings and coupling the receiving circuit to the other one of the windings. In such an isolator, the means for programming may comprise a fusible connection(s) programmed by blowing open a conductive path(s). The means for programming alternatively may comprise bond wires provided between the transformer windings on the one hand and the transmitter and receiving circuits, on the other hand. As a further alternative, the means for programming comprises programmable circuitry configurable to connect the transmitter circuit to either the top winding or the bottom winding and to connect the receiving circuit to the other winding. The programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may be read-only memory. According to yet another aspect, a logic isolator comprises a micro-transformer comprising, on a substrate, vertically stacked, a bottom winding and a top winding disposed over and insulated from the bottom winding; a damping network connected across the top winding; a first module coupled to the top winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; a second module coupled to the bottom winding capable of either receiving a logic input signal and providing a transformer driving signal or receiving from the transformer a signal corresponding to the driving signal and generating an output comprising a reconstituted logic input signal; and means for programming the isolator such that the first module operates in the transformer drive mode while the second circuit operates in the receive mode or that the first module operates in the receive mode while the second module operates in the transformer drive mode. Various alternatives may be used as the means for programming. Such means may comprise, for example, at least one fusible connection programmed by blowing open at least one conductive path. As another example, the means for programming may comprise one or more bond wires provided between the transformer windings on the one hand and the first and second modules, on the other hand. The means for programming also may comprise programmable circuitry configurable to connect the first module to either the top winding or the bottom winding and to connect the second module to the other winding. Such programmable circuitry may include programmable switching circuits and a memory containing programming to control the switching circuits. The memory may include a read-only memory. According to still another aspect, a dual-channel, bi-directional isolator comprises first and second micro-transformers arranged on a first substrate, each transformer having a top winding and a bottom winding. A first transmitter circuit is connected to drive the bottom winding of the first transformer; a second transmitter circuit is connected to drive the top winding of the second transformer. A first receiver circuit is connected to receive signals from the bottom winding of the second transformer. A second receiver circuit is connected to receive signals from the top winding of the first transformer. Preferably, but not necessarily, the first transmitter circuit and first receiver circuit are on the first substrate, and the second transmitter circuit and second receiver circuit are on a second substrate which is electrically isolated from the first substrate. Yet another aspect of the invention is a single channel bi-directional isolator comprising a micro-transformer arranged on a first substrate, the transformer having a top winding and a bottom winding; a first transmitter circuit connected to drive the bottom winding; a second transmitter circuit connected to drive the top winding; a first receiver circuit connected to receive signals from the top winding; a second receiver circuit connected to receive signals from the bottom winding; and the first and second transmitter circuits transmitting so as to avoid interfering with each other. Preferably, but not necessarily, the first transmitter circuit and the second receiver circuit are on the first substrate and the second transmitter circuit and the first receiver circuit are on a second substrate which is electrically isolated from the first substrate. According to still another aspect, there is provided a delay element for use in pulse generating circuits for generating pulses usable, for example, to drive a transformer as above-described. The delay element is useful for generating a delay interval, and therefore a pulse duration, of a length that is substantially independent of the supply voltage—i.e., is insensitive to variations in supply voltage. The delay element comprises first and second current sources which supply currents I 1 and I 2 , respectively, in parallel, and a switching element. The sum of currents I 1 and I 2 is directly proportional to the supply voltage, and a threshold of the switching element is a predetermined portion of the supply voltage. The delay element may further include a capacitor of capacitance C, connected to a node in common with the input of the switching element and the current sources, chargeable by the current sources. Preferably, the first current source comprises a single transistor and a resistor, the resistor, of resistance value R, having one end connected to the supply voltage and the other end connected to said transistor. Current I 1 =(VDD−VT)/R, where the transistor is a MOS transistor, VT is the threshold voltage of the MOS transistor, VDD is the supply voltage, I 2 =VT/R, I 1 +I 2 =VDD/R. The delay interval is then approximately 0.5RC if the switching threshold of the switching element is set to be VDD/2, and is relatively insensitive to changes in VDD. Such a delay element may be used in conventional pulse generating circuits that rely upon use of a delay element. | 20040429 | 20060711 | 20050317 | 98200.0 | 1 | TAN, VIBOL | SIGNAL ISOLATORS USING MICRO-TRANSFORMERS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,117 | ACCEPTED | Cross racing bike front brake lever | A cross-racing bike brake lever has on its contact surface external to the grip of the brake lever provided with multiple recesses for the fingers of the rider to hold against while executing a hand brake on the inner side of the grip so that the rider comfortably moves his or her fingers to rest flushed on the recesses and holds against the inner side of the grip with fingers at where close to their joint of the fingertips to execute an easy, sure and comfortable hand brake for improved safety. | 1. An improved structure of a cross-racing bike brake lever to provide an easy, safe and comfortable execution of a hand brake; having its outer side of a grip of the brake lever provided with multiple recesses and its inner side of the grip defined as an operation surface; the length of the cross section of the contact surface being greater than that of the operation surface; fingers of the rider having an easy and flushed contact of the grip and secured execution of the hand brake by holding against the operation surface with distal phalanxes. | BACKGROUND OF THE INVENTION (a) Technical Field of the Invention The present invention is related to a cross racing bike front brake lever and more particularly, to one provides a safe and convenient brake lever suited to a cross racing bike. (b) Description of the Prior Art As its designation suggests, a cross-racing bike is for speedy riding, and is characterized by that the handle is provided low and curved backward for the rider to keep low profile to minimize drag while riding. Accordingly, it is essential to have the optimal design and structure for the brake lever adapted to the bike. The brake lever generally found with a cross-racing bike has a curved style with smooth surface and is erected outside the lower curved portion of the handle. However, for the rider seeking to challenge the extreme of speed, he or she has much more demand for a brake lever that has a streamlined style and smooth surface, but also allows easy, safe and comfortable grip. SUMMARY OF THE INVENTION The primary purpose of the present invention is to provide a cross-racing bike brake lever that permits an easy and secured hand brake for improved safety. To achieve the purpose, the contact surface of fingers on the outer side of the grip of the brake lever is provided with multiple recesses for the fingers to touch so that the rider is able to have fingers comfortably slide flushed into those recesses while holding against the inner surface with the joints of fingertips to execute the hand brake. Another purpose of the present invention is to provide a cross-racing bike brake lever that has the length of the cross section of the contact surface greater than that for the fingers to hold against the brake lever so to facilitate the execution of a hand brake for the fingers to hold against the brake lever. The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the present invention. FIG. 2 is a right side view of the present invention. FIG. 3 is a front view of the present invention. FIG. 4 is a left side view of the present invention. FIG. 5 is a schematic view showing the present invention in use. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. Referring to FIGS. 1 through 5, an improved structure of a cross-racing bike brake lever of the present invention has multiple recesses 112 for fingers of the rider to rest on provided on a contact surface 111 of the outer side of a grip 11 of a brake lever 1 while the inner side of the grip 11 defines an operation surface 113 for the distal phalanxes to execute a hand brake by holding against the operation surface. Accordingly, the rider while executing a hand brake has fingers to forthwith slide onto those recesses 112 on the contact surface 111 and holds against the operation surface 113 with distal phalanxes to achieve an easy, secured and comfortable hand brake for improved safety. Furthermore, the length L1 of the cross section of the contact surface 111 is longer than that L2 of the operation surface 113 to facilitate the flushed rest of the fingers thereon to grip the brake lever. The present invention by providing multiple recesses to compromise the grip by fingers of the rider and an operation surface on the inner side of the brake lever to facilitate the execution of the hand brake with distal phalanxes to achieve easy, safe and comfortable hand brake is complying with ergonomics and meets the requirements of a utility patent. Therefore, this application is duly filed accordingly. It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>(a) Technical Field of the Invention The present invention is related to a cross racing bike front brake lever and more particularly, to one provides a safe and convenient brake lever suited to a cross racing bike. (b) Description of the Prior Art As its designation suggests, a cross-racing bike is for speedy riding, and is characterized by that the handle is provided low and curved backward for the rider to keep low profile to minimize drag while riding. Accordingly, it is essential to have the optimal design and structure for the brake lever adapted to the bike. The brake lever generally found with a cross-racing bike has a curved style with smooth surface and is erected outside the lower curved portion of the handle. However, for the rider seeking to challenge the extreme of speed, he or she has much more demand for a brake lever that has a streamlined style and smooth surface, but also allows easy, safe and comfortable grip. | <SOH> SUMMARY OF THE INVENTION <EOH>The primary purpose of the present invention is to provide a cross-racing bike brake lever that permits an easy and secured hand brake for improved safety. To achieve the purpose, the contact surface of fingers on the outer side of the grip of the brake lever is provided with multiple recesses for the fingers to touch so that the rider is able to have fingers comfortably slide flushed into those recesses while holding against the inner surface with the joints of fingertips to execute the hand brake. Another purpose of the present invention is to provide a cross-racing bike brake lever that has the length of the cross section of the contact surface greater than that for the fingers to hold against the brake lever so to facilitate the execution of a hand brake for the fingers to hold against the brake lever. The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. | 20040430 | 20070213 | 20051103 | 77657.0 | 0 | YOUNG, EDWIN | CROSS RACING BIKE FRONT BRAKE LEVER | SMALL | 0 | ACCEPTED | 2,004 |
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10,835,197 | ACCEPTED | Maritime emissions control system | An Advanced Maritime Emissions Control System (AMECS) comprises several Exhaust Intake Bonnets (EIBs) of different size and/or shape, an Emissions Capture System (ECS), and an Advanced Maritime Emissions Control Unit (AMECU) mounted on an Unpowered Seagoing Barge (USB). The EIB comprises a cage formed by downward curved ribs, a shroud which is lowerable to cover the ribs, a belt near a lower edge of the EIB for retaining and sealing the EIB to a stack, and a mechanism for tightening the lower edge of the EIB (and thus the belt) around the stack. The ECS lifts one of the several EIBs onto the stack of an Ocean Going Vessel (OGV). Exhaust from the stack is drawn through a large diameter duct to the AMECU. The AMECU processes the exhaust through multiple treatment stages. The stages include pre conditioning the exhaust, oxidizing, reducing, polishing, and precipitating. | 1. An advanced maritime emissions control system comprising: a bonnet for capturing the exhaust from a ship stack; an emissions control unit for processing the exhaust from the stack; and a duct for carrying the exhaust from the bonnet to the emissions control unit. 2. The emissions control system of claim 1, further including: a tower; and an articulating arm extending from the tower, wherein the bonnet is positioned on the stack by the articulating arm. 3. The emissions control system of claim 1, further including: a tower; and an articulating arm extending from the tower, wherein the duct is supported by the articulating arm. 4. The emissions control system of claim 3, wherein the articulating arm includes segments. 5. The emissions control system of claim 4, wherein the articulating arm includes pivoting joints between the segments. 6. The emissions control system of claim 4, wherein the segments include an end segment connectable to the bonnet for placing the bonnet on the stack, and wherein the end segment is disconnectable from the bonnet. 7. The emissions control system of claim 1, wherein the bonnet is selectable from a multiplicity of shaped bonnets. 8. The emissions control system of claim 1, wherein the bonnet comprises a top, a cage extending from the top, and a shroud lowerable over the cage. 9. The emissions control system of claim 8, wherein the cage comprises downwardly reaching curved ribs. 10. The emissions control system of claim 9, wherein the ribs comprise between eight and twenty four ribs. 11. The emissions control system of claim 10, wherein the tubes comprise about sixteen ribs. 12. The emissions control system of claim 9, wherein shroud cords attach to a lower edge of the shroud and wherein pulling on the shroud cords lowers the shroud over the tubes. 13. The emissions control system of claim 9, wherein the ribs comprise tubes, and wherein the tubes include pulleys near a lower end of each tube, and wherein the shroud cords loop around the pulleys, wherein the shroud cords are pulled upward through the tubes to lower the shroud. 14. The emissions control system of claim 1, wherein the emissions control unit includes a Pre Conditioning Chamber (PCC) quench vessel. 15. The emissions control system of claim 1, wherein the emissions control unit includes an oxidation column. 16. The emissions control system of claim 1, wherein the emissions control unit includes a reduction column. 17. The emissions control system of claim 1, wherein the emissions control unit includes a caustic column. 18. The emissions control system of claim 1, wherein the emissions control unit includes a wet electrostatic precipitation system. 19. A method for emissions control, the method comprising: securing a bonnet over a stack of an Ocean Going Vessel (OGV) to capture exhaust; drawing the exhaust captured by the bonnet through a duct to an emissions control unit; and processing the exhaust by the emissions control unit. 20. The method of claim 19, wherein the bonnet includes a cage and a shroud, and wherein securing the bonnet over the stack comprises: positioning the cage over a stack; tightening the cage around the stack; and lowering the shroud over the cage. 21. The method of claim 19, wherein processing the exhaust by the emissions control system comprises: processing the exhaust using a Pre Conditioning Chamber (PCC) quench vessel; processing the exhaust using an oxidation column; processing the exhaust using a reduction column; processing the exhaust using a caustic (or polishing) column; and processing the exhaust using a wet electrostatic precipitation system. 22. A bonnet for capturing exhaust from a stack, the bonnet comprising: a frame having an upward end, outward side, an inward side, and a downward end; a shroud on the outward side for enclosing the frame; a belt attached to the inward side near the downward end; and means for tightening the downward end around the stack. 23. The bonnet of claim 22, wherein the bonnet is one of several bonnets of different sizes and shapes suitable to cooperating with Ocean Going Vessel (OGV) stacks of different sizes and shapes. 24. The bonnet of claim 23, wherein the several bonnets comprise four bonnets of different sizes and shapes. 25. The bonnet of claim 22, wherein the frame comprises springy downwardly extending ribs. 26. The bonnet of claim 22, wherein the belt is made from a foam material to provide an air seal between the shroud and the stack, and to retain the bonnet in place on the stack. 27. The bonnet of claim 22, wherein the belt is between six inches and fourteen inches thick and between ten inches to fourteen inches high. 28. The bonnet of claim 27, wherein the belt is approximately ten inches thick and approximately twelve inches high. 29. The bonnet of claim 22, further including a capture ring assembly at the frame upward end, the capture ring including an upward facing opening with a self-aligning locking mechanism for cooperation with an articulating arm. 30. The bonnet of claim 22, further including a camera and laser guided positioning system, wherein video from the camera is provided to an operator to use in positioning the bonnet over the stack, and wherein when the bonnet is in position over the stack, the laser guided positioning system automatically guides the bonnet into position around the stack. 30. The bonnet of claim 22, wherein the means for tightening the downward end around the stack comprises a cord running around the outside of the frame near the downward end of the frame, and wherein drawing the cord tightens the downward end of the frame around the stack. 31. The bonnet of claim 30, further including a constant-torque motor which when activated, tightens the cord thereby tightening the belt and providing consent pressure between the belt and the stack. 32. The bonnet of claim 22, wherein the shroud is lowerable over the frame, and raisable to a position at the upward end of the frame. 33. The bonnet of claim 32, wherein the shroud is lowerable and raisable using shroud cords attached to a lower edge of the shroud, wherein the shroud cords loop down outside the frame from the upward end of the frame, around pulleys near the downward end of the frame, and back to the upward end of the frame. 34. The bonnet of claim 22, wherein the bonnet includes at least one pressure sensor which provides a pressure measurements to regulate the speed of a blower assembly to maintain a constant negative pressure within the intake duct. 35. The bonnet of claim 22, wherein the bonnet includes an interface for a flexible duct, and wherein the flexible duct allows relative motion between the bonnet and an emissions control unit, wherein the exhaust from the stack is drawn through the flexible duct. | BACKGROUND OF THE INVENTION The present invention relates to the reduction of emissions from Ocean Going Vessels (OGVs), and more particularly to a system for capturing and processing emissions from OGVs in the vicinity of a port. A substantial quantity of pollutants are produced by burning fuel in OGVs. The pollutants produced when an engine burns bunker an/or diesel fuel is a complex mixture of thousands of gases and fine particles, commonly known as soot, which contains more than forty toxic air contaminates. These contaminates include arsenic, benzene, and formaldehyde along with other ozone-forming pollutants that are components of smog and acid rain, such as carbon dioxide (CO2), sulphur dioxide (SO2), and nitrogen oxides (NOx). An OGV may create and exhaust as much NOx as 12,500 automobiles or as an oil refinery, and thus is a substantial health risk to port workers and residents of surrounding communities, and may physically damage structures and equipment. BRIEF SUMMARY OF THE INVENTION The present invention addresses the above and other needs by providing an Advanced Maritime Emissions Control System (AMECS) comprising a multiplicity Exhaust Intake Bonnets (EIBs), an Emissions Capture System (ECS) comprising a tower and actuating arm, an Advanced Maritime Emissions Control Unit (AMECU), and a duct connecting the EIB to the AMECU. The AMECS is preferably mounted on an Unpowered Seagoing Barge (USB). The AMECS is deployed when an Ocean Going Vessel (OGV) is at sea, for example, when the OGV is approaching the three miles limit. The USB carrying the AMECS, is assisted by a tug to meet the OGV at a point off the coast. As the USB approaches the OGV, the tug positions the USB along the OGV side opposite to the side from which the OGV will be unloaded. Once alongside the OGV, the USB is secured to the OGV, and preferably, a stabilization arm is extended between the tower and the OGV, to absorb shock and provide stability for the ECS. The ECS is then activated, hosting an EIB selected from a multiplicity of EIBs shaped to accommodate the particular ship's stack configuration, onto the stack. An EIB attachment mechanism (preferably including a soft belt which may be tightened around the stack by drawing a cord) is then actuated to create a soft attachment between the EIB and the ship's stack. Once the USB is secured to the OGV, and EIB is properly attached to the stack, the AMECU is started thereby forming a pressure drop in the duct. This begins the process of directing the stack exhaust into the AMECU residing on the USB. A shroud is then lowered from a upward end of the EIB over the EIB, thereby forming a seal around the stack. An end segment of the articulating arm is then retracted, leaving a flexible end section of the duct connected to the EIB. Thus attached, the assembly is able to sustain movement between of the USB relative to the OGV of approximately five vertical feet and approximately five horizontal feet, without adversely affecting the attachment of the EIB or placing too great a stress on the stack. The OGV and attached USB are then guided into port and docked. The AMECS system may remain alongside the OGV, ensuring that the exhausted emissions are reduced as much as existing technology can provide. Alternatively, a shore based AMECS may be connected to the stack while the OGV is docked. When the OGV is ready for departure, it is guided out of the harbor and out to sea a distance of, for example, approximately three miles, where the EIB is detached and the OGV is released allowing it to proceed to its next destination. To release the EIB, the blowers are shut down, the shroud retracted, the articulating arm reattached, and the tension to the cord removed allowing the belt to relax, thereby permitting the EIB to be removed. The AMECS is then returned to its serving dock where any stored solid contaminates are removed and the system readied for the next OGV to arrive. In accordance with one aspect of the invention, there is provided an Advanced Maritime Emissions Control System (AMECS) for Ocean Going Vessels (OGVs) comprising a barge, a tower mounted to the barge, an articulating arm mounted to the tower, an Exhaust Intake Bonnet (EIB) attached to a last segment of the articulating arm, an Advanced Maritime Emissions Control Unit (AMECU), and a duct for carrying the exhaust from the EIB to the AMECU. The EIB captures the exhaust from an OGV stack, and the AMECU processes the exhaust. The EIB is selected from a set of several EIBs of different sizes and/or shapes. An exemplar AMECU 22 includes two primary treatment systems. The first system accomplishes reduction of nitrogen oxides (NOx) as its primary purpose, and the second system focuses on the reduction of Particulate Matter (PM). Each system may have as a secondary benefit, the reduction of other atmospheric contaminants. An exemplar first system is a four-stage particulate/NOx/SO2 scrubber system. The first system includes a Pre Conditioning Chamber (PCC) quench vessel first stage, an oxidation column second stage, a reduction column third stage, and a caustic (or polishing) column fourth stage. An exemplar second system is a wet electrostatic precipitation system to further reduce the concentration of PM. Various numbers of stages, functions of the stages, orders of the stages, or contaminant reduction processes in any or all of the stages may be utilized to construct an AMECU. Alternative exemplar first systems may include, but are not limited to, Selective Catalytic Reactors (SCR) and various emerging technologies such as thermal or plasma enhanced catalytic or non-catalytic NOx removal or NOx conversion systems, and other technologies to reduce NOx or convert NOx into more benign compounds. Alternative exemplar second systems may include, but are not limited to, washers, ionizing wet scrubbers, wet scrubbers, packed column scrubbers, cyclone scrubbers, impingement scrubbers, eductor scrubbers, vortex scrubbers, venturi scrubbers, and others, as well as filters of various types, both passive and dynamic. Some of these devices may also be used as the first stage in a multistage system. An AMECS including any combination of these, or similar devices, is intended to come within the scope of the present invention. In accordance with another aspect of the invention, there is provided a method for emissions control, the method comprising securing a bonnet over a stack of an Ocean Going Vessel (OGV), drawing exhaust from the stack through a duct to an emissions control system, and processing the exhaust by the emissions control system. Securing the bonnet over the stack comprises positioning a cage over a stack, tightening the cage around the stack, and lowering a shroud over the cage. Processing the exhaust by the emissions control system preferably comprises two primary treatment systems. The first system accomplishes reduction of nitrogen oxides (NOx) as its primary purpose, and the second system focuses on the reduction of Particulate Matter (PM). BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: FIG. 1 is an Advanced Maritime Emissions Control System (AMECS) according to the present invention. FIG. 2A depicts an AMECS deploying a bonnet over a stack of an Ocean Going Vessel (OGV). FIG. 2B shows the bonnet over the stack with an end segment of an articulating arm retracted from the bonnet. FIG. 3A shows the bonnet positioned above the stack. FIG. 3B shows a cage of the bonnet positioned on the stack. FIG. 3C shows a lower edge of the cage drawn around the stack. FIG. 3D shows a shroud partially lowered over the cage. FIG. 3E shows the shroud fully lowered over the cage. FIG. 3F shows the bonnet after the articulating arm is detached. FIG. 4 shows a detailed view of the bonnet over the stack. FIG. 4A shows a more detailed view of a lower end of a rib of the cage. FIG. 5A is a side view of an Advanced Maritime Emissions Control Unit (AMECU) and associated equipment. FIG. 5B is a top view of the AMECU and associated equipment. FIG. 6 describes a method for emissions control using the AMECS according to the present invention. FIG. 6A described the steps for processing emissions. Corresponding reference characters indicate corresponding components throughout the several views of the drawings. DETAILED DESCRIPTION OF THE INVENTION The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. An Advanced Maritime Emissions Control System (AMECS) 10 according to the present invention is shown generally in FIG. 1. The AMECS 10 comprises at least one Exhaust Intake Bonnet (EIB) 14, an Emissions Capture System (ECS), and an Advanced Maritime Emissions Control Unit (AMECU) 22. The AMECS 10 is preferably mounted on an Unpowered Seagoing Barge (USB) 12. The ECS comprises a tower 16, and an articulating arm. The articulating arm comprising four segments 18a, 18b, 18c, and 18d connected by joints 17. The EIB 14 is preferably one of a multiplicity of shaped EIBs, and more preferably one of a set of four shaped EIBs, each shaped EIB is formed to cooperate with a different size and/or shape stack. The articulating arm segments 18a-18d are connected by joints 17, and the end segment 18d is detachably attachable to the EIB 14 using a payload grip 27. A first camera is attached to the articulating arm, preferably on or near the payload grip 27, to aid in guiding the payload grip 27 during attachment to the EIB 14. The EIB 14 is in fluid communication with the AMECU 22 through a duct 19. An end section of the duct 19 proximal to the EIB 14 is a flexible duct section 19a. The duct 19 is connected to the AMECU 22 which processes a flow indicated by arrows 15 to reduce undesirable emissions. When in use, the flow travels from the EIB 14 to the AMECU 22. When not in use, the EIB 14 may be detached from the articulating arm, and rest on an EIB stand 14a. The articulating arm 18a-18d is preferably between fifty feet and one hundred and twenty feet long, and is more preferably approximately one hundred feet long. The duct 19 is preferably between twelve inches and thirty six inches in diameter, and more preferably approximately eighteen inches in diameter, and is preferably made from stainless steel. The EIBs 14 are preferably between fifteen feet and forty feet across, and are suitable for cooperation with stacks of various shape and up to twenty five feet or more across. The tower 16 is preferably between fifty feet and one hundred and twenty feet high, and is more preferably approximately one hundred feet high. The actuating arm of the present invention is similar to known four section booms used on concrete pump trucks, for example the KVM 32 built by Schwing America Inc. in Saint Paul, Minn. The boom of the KVM 32 is capable of reaching as far as 106 feet vertically, or 93 feet laterally. Booms like the boom of the KVM 32 are described in U.S. Pat. No. 5,460,301 for “Concrete Pump Vehicle” and duct joint geometries for use with booms are described in detail in U.S. Pat. No. 6,463,958 for “Distributing Device for Thick Substance, Especially Concrete.” The '301 and '958 patent are herein incorporated by reference. The AMECS 10 is shown with the EIB 14 residing over a stack 26 of an Ocean Going Vessel 24 in FIG. 2A. The end segment 18d of the actuating arm remains attached to the EIB 14. Following attachment of the EIB 14 to the stack 26 (described in FIGS. 3A-3F), the end segment 18d is detached from the EIB 14 and pivoted to a stored position as shown in FIG. 2B leaving the flexible portion 19a of the duct, and a wire harness 70 attached to the EIB 14. The duct 19 is supported by a duct support 25 attached to the articulating arm, providing sufficient freedom of movement to allow for some relative motion between the USB 12 and the OGV 24. Preferably, approximately five feet of lateral and vertical movement is provided. The position of the USB 12 relative to the OGV 24 is stabilized by a stabilization arm 11 connected between the tower 16 and the OGV 24. The arm 11 is preferably connected to the tower 16 a little below a midpoint of the tower 16, and the arm 11 extends approximately horizontally to the OGV 24. The arm 11 includes a shock absorber to minimize the load on the hull of the OGV 24 and to stabilize the ECS. The tower 16 and articulating arm 18a-18d preferably provide sufficient height to place the EIB 14 over the stacks of common OGVs 24, and more preferably allow sufficient height to place the EIB 14 over the stack of the largest OGVs 24. An example of a set of steps of attachment of the EIB 14 to the stack 26 are shown in FIGS. 3A through 3F. The EIB 14 including ribs 28 forming a cage-like structure (or frame), a top portion 33 above a shroud 30, and a belt 32 near the bottom of the ribs 28, is shown above the stack 26 in FIG. 3A. The EIB 14 is shown lowered over the stack 26 in FIG. 3B. The downward end of the EIB 14 is drawn to close around the stack 26 in FIG. 3C. The shroud 30 is partially lowered over the ribs 28 in FIG. 3D. The shroud 30 is fully lowered over the ribs 28 in FIG. 3E. The articulating arm is detached in FIG. 3F, and the attachment of the EIB 14 to the stack 26 in compete. The steps described above are not exclusive and, for example, the articulating arm may be detached before lowing the shroud 30 over the ribs 28. The EIB 14 preferably includes eight to twenty four ribs 28, and more preferably sixteen ribs 28. A detailed view of the EIB 14 is shown in FIG. 4. A top portion 33 resides above the shroud 30, and preferably comprises a capture ring assembly 34 at the top of the EIB 14, which capture ring assembly 34 is used to attach to the EIB 14 to the payload grip 27 (see FIG. 1). The capture ring assembly 34 is designed to be easily attached and detached from the payload grip 27 (see FIG. 1). An upper opening of the capture ring assembly 34 has a large aperture, with a self-aligning locking mechanism for engaging the payload grip 27. Preferably, the payload grip 27 includes a spring latching mechanism which will release locking members into the capture ring assembly 34 when the payload grip 27 is in the proper position. At least one motor 36 is connected to a hub 40, the motor 36 and hub 40 preferably residing inside the top portion 33 and are indicted by dashed lines in FIG. 4. The motor 36 is preferably a constant-torque motor that when activated, tightens a cord 42 thereby compressing the ribs 28 and providing consent pressure for a friction-seal. Cord ends 42a and 42b of the cord 42 wind around the hub 40. The cord 42 runs down to belt pulleys 45, and then around the outside of the ribs 28 through guides 43 to draw the EIB 14 around the stack 26. The EIB 14 may thus be closed (or compressed) around the stack 26 by winding ends the cord ends 42a, 42b onto the hub 40. The motor 36 controls the tension on the cord 42, to provide an air seal between the EIB 14 and the stack 26, to firmly hold the EIB 14 on the stack 26, and to prevent damage to the EIB 14 or the stack 26 during operation of the AMECS 10. Shroud cords 44 loop vertically around the outside of the EIB 14 between an upward end and a downward end of the frame, and are attached to the shroud 30 near a lower edge 52 of the shroud 30, to raise and lower the shroud 30 over the ribs 28. A shroud notch 41 in the guide 43 provides a seat for the shroud 30 when fully lowered. A second camera and a laser guided positioning system are preferably attached to the EIB 14 to aid in guiding the EIB 14 over the stack 26. For example, a camera may be mounted in the top portion 33 and pointed down. Video from the camera is used to assist the operator in positioning the EIB 14 over the ships stack 26. Once the EIB 14 is over the stack 26, the laser positioning system guides the EIB 14 into its final position around the stack 26. Alternatively, a system for controlling a boom such as described in U.S. Pat. No. 5,823,218 for “Large Manipulator, Especially for Self-Propelled Concrete Pumps, and Method for Operating it,” may be used to automatically position the EIB 14. The system described in the '218 patent may also be utilized to maintain the position of the articulating arm relative to the stack 26 during operation of the AMECS 10, and for re-attaching the articulating arm to the EIB 14 when the EIB 14 is to be removed from the stack 26. The '218 patent is herein incorporated by reference. The EIB 14 further preferably includes a pressure sensor, and more preferably includes two pressure sensors (a primary sensor and a backup sensor) to provide feedback to a System Operational Control Unit (SOCU), which in turn regulates the speed of a tower blower assembly maintaining a constant negative pressure within the duct 19, wherein the blower is preferably a centrifugal blower. Maintaining constant pressure assures that nearly all of the exhaust gases are captured and funneled into the AMECU 22 for processing, without adversely affecting engine performance and while compensating for main and auxiliary engine turn-on and startup, and for back pressure in the AMECU 22. A more detailed view of a lower portion of a rib 28 is shown in FIG. 4A. The rib 28 is preferably a springy (i.e., returns to an original shape when released) curved tube, is preferably made from stainless steel or fiberglass, and has a lower end 54. The rib 28 is required to retain sufficient memory to “spring” back to the open position when the cord 42 is released. A shroud pulley 46 resides on an axle 48 held by a bracket 50 near the lower end 54. The shroud cord 44 runs around the shroud pulley 46 and through the rib 28. The shroud cord 44 is preferably drawn by a motor residing above the ribs 28. In another embodiment, a motor with a hub resides near the lower end 54 of each rib 28, and the shroud cord 44 is wound around the hub. The belt 32 is shown in cross-sectional view, and the cord 42 is shown running through a guide 43. While the bracket 50 and guide 43 are shown as two distinct parts in FIG. 4A, they may be a single bracket/guide. The shroud 30 is preferably made from a heat and emission resistant material for long life, for example, kevlar® fiber or kapton® polyimide film, and the shroud 30 preferably resists damage from chemicals found in OGV 24 exhaust, and temperatures up to 350 degrees Celsius. The belt 32 is preferably between six inches and fourteen inches thick and ten inches to fourteen inches high, and more preferably approximately ten inches thick and approximately twelve inches high. The belt 32 is preferably made from a soft or sponge-like (i.e., foam) material which provides a degree of air seal between the EIB 14 and the stack 26, and also retains the EIB 14 onto the stack 26 through surface friction and will not damage the stack. For example, the belt may be made from neoprene or the like material. Alternatively, the belt may be an inflatable belt. The cords 42, 44 are preferably made from non UV sensitive material, and more preferably from nylon. A detailed view of an exemplar AMECU 22 layout and associated equipment is shown in FIG. 5A in side view, and in FIG. 5B in top view. The exemplar AMECU 22 comprises two primary treatment systems. The first system, accomplishes reduction of nitrogen oxides (NOx) as its primary purpose, and the second system focuses on the reduction of particulate matter (PM). Each system has as a secondary benefit, the reduction of other atmospheric contaminants. The first system comprises four stages. The first stage comprises a Pre Conditioning Chamber (PCC) quench vessel 22a. The second stage comprises oxidation column 22b. The third stage comprises reduction column 22c. The fourth stage comprises a caustic (or polishing) column 22d. The second system comprises a single stage which is a wet electrostatic precipitation system 22e which further reduces the concentration of PM. While a five stage AMECU 22 is described herein, AMECS 10 may include an emissions control unit with a different number of stages, different order of stages, different allocation, and/or, different processing to reduce other emissions, and any AMECS including any of these variations of emissions control units for processing OGV exhaust is intended to come within the scope of the present invention. Arrows 15 indicate the direction of exhaust flow through the AMECU 22. Continuing with FIGS. 5A, 5B, The AMECU 22 resides proximal to waste tanks 60, storage tanks 61, a power source 64 and the cabin 13 which serves as a control room. A method for using the AMECS 10 for emissions control is described in FIG. 6. The method includes positioning the EIB 14 over a stack 26 of an OGV 24 at step 100. Tightening a cage around the stack at step 102. Lowering a shroud over the cage at step 104. Retracting the end segment 22d at step 106. Drawing the exhaust through the duct 19 to the AMECU 22 at step 108. Processing the exhaust at step 110. Releasing the processed exhaust at step 112. Processing the exhaust at step 110 preferably comprises the steps of pre conditioning the exhaust at step 114, oxidizing at step 116, reducing at step 118, polishing at step 120, and precipitating at step 122. The invention further contemplates a land based structure in place of the USB 12 for use when the OGV 24 is moored to a dock, or for control of emissions from land based equipment. The land based structure would support the same elements as the USB 12 based AMECS 10 with the exception that the tower 16, AMECU 22, and associated equipment would be supports on the land instead of on the USB 12. The system may, for example, be mounted to a truck, a trailer, or a rail road car. While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to the reduction of emissions from Ocean Going Vessels (OGVs), and more particularly to a system for capturing and processing emissions from OGVs in the vicinity of a port. A substantial quantity of pollutants are produced by burning fuel in OGVs. The pollutants produced when an engine burns bunker an/or diesel fuel is a complex mixture of thousands of gases and fine particles, commonly known as soot, which contains more than forty toxic air contaminates. These contaminates include arsenic, benzene, and formaldehyde along with other ozone-forming pollutants that are components of smog and acid rain, such as carbon dioxide (CO 2 ), sulphur dioxide (SO 2 ), and nitrogen oxides (NO x ). An OGV may create and exhaust as much NO x as 12,500 automobiles or as an oil refinery, and thus is a substantial health risk to port workers and residents of surrounding communities, and may physically damage structures and equipment. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention addresses the above and other needs by providing an Advanced Maritime Emissions Control System (AMECS) comprising a multiplicity Exhaust Intake Bonnets (EIBs), an Emissions Capture System (ECS) comprising a tower and actuating arm, an Advanced Maritime Emissions Control Unit (AMECU), and a duct connecting the EIB to the AMECU. The AMECS is preferably mounted on an Unpowered Seagoing Barge (USB). The AMECS is deployed when an Ocean Going Vessel (OGV) is at sea, for example, when the OGV is approaching the three miles limit. The USB carrying the AMECS, is assisted by a tug to meet the OGV at a point off the coast. As the USB approaches the OGV, the tug positions the USB along the OGV side opposite to the side from which the OGV will be unloaded. Once alongside the OGV, the USB is secured to the OGV, and preferably, a stabilization arm is extended between the tower and the OGV, to absorb shock and provide stability for the ECS. The ECS is then activated, hosting an EIB selected from a multiplicity of EIBs shaped to accommodate the particular ship's stack configuration, onto the stack. An EIB attachment mechanism (preferably including a soft belt which may be tightened around the stack by drawing a cord) is then actuated to create a soft attachment between the EIB and the ship's stack. Once the USB is secured to the OGV, and EIB is properly attached to the stack, the AMECU is started thereby forming a pressure drop in the duct. This begins the process of directing the stack exhaust into the AMECU residing on the USB. A shroud is then lowered from a upward end of the EIB over the EIB, thereby forming a seal around the stack. An end segment of the articulating arm is then retracted, leaving a flexible end section of the duct connected to the EIB. Thus attached, the assembly is able to sustain movement between of the USB relative to the OGV of approximately five vertical feet and approximately five horizontal feet, without adversely affecting the attachment of the EIB or placing too great a stress on the stack. The OGV and attached USB are then guided into port and docked. The AMECS system may remain alongside the OGV, ensuring that the exhausted emissions are reduced as much as existing technology can provide. Alternatively, a shore based AMECS may be connected to the stack while the OGV is docked. When the OGV is ready for departure, it is guided out of the harbor and out to sea a distance of, for example, approximately three miles, where the EIB is detached and the OGV is released allowing it to proceed to its next destination. To release the EIB, the blowers are shut down, the shroud retracted, the articulating arm reattached, and the tension to the cord removed allowing the belt to relax, thereby permitting the EIB to be removed. The AMECS is then returned to its serving dock where any stored solid contaminates are removed and the system readied for the next OGV to arrive. In accordance with one aspect of the invention, there is provided an Advanced Maritime Emissions Control System (AMECS) for Ocean Going Vessels (OGVs) comprising a barge, a tower mounted to the barge, an articulating arm mounted to the tower, an Exhaust Intake Bonnet (EIB) attached to a last segment of the articulating arm, an Advanced Maritime Emissions Control Unit (AMECU), and a duct for carrying the exhaust from the EIB to the AMECU. The EIB captures the exhaust from an OGV stack, and the AMECU processes the exhaust. The EIB is selected from a set of several EIBs of different sizes and/or shapes. An exemplar AMECU 22 includes two primary treatment systems. The first system accomplishes reduction of nitrogen oxides (NOx) as its primary purpose, and the second system focuses on the reduction of Particulate Matter (PM). Each system may have as a secondary benefit, the reduction of other atmospheric contaminants. An exemplar first system is a four-stage particulate/NOx/SO 2 scrubber system. The first system includes a Pre Conditioning Chamber (PCC) quench vessel first stage, an oxidation column second stage, a reduction column third stage, and a caustic (or polishing) column fourth stage. An exemplar second system is a wet electrostatic precipitation system to further reduce the concentration of PM. Various numbers of stages, functions of the stages, orders of the stages, or contaminant reduction processes in any or all of the stages may be utilized to construct an AMECU. Alternative exemplar first systems may include, but are not limited to, Selective Catalytic Reactors (SCR) and various emerging technologies such as thermal or plasma enhanced catalytic or non-catalytic NOx removal or NOx conversion systems, and other technologies to reduce NOx or convert NOx into more benign compounds. Alternative exemplar second systems may include, but are not limited to, washers, ionizing wet scrubbers, wet scrubbers, packed column scrubbers, cyclone scrubbers, impingement scrubbers, eductor scrubbers, vortex scrubbers, venturi scrubbers, and others, as well as filters of various types, both passive and dynamic. Some of these devices may also be used as the first stage in a multistage system. An AMECS including any combination of these, or similar devices, is intended to come within the scope of the present invention. In accordance with another aspect of the invention, there is provided a method for emissions control, the method comprising securing a bonnet over a stack of an Ocean Going Vessel (OGV), drawing exhaust from the stack through a duct to an emissions control system, and processing the exhaust by the emissions control system. Securing the bonnet over the stack comprises positioning a cage over a stack, tightening the cage around the stack, and lowering a shroud over the cage. Processing the exhaust by the emissions control system preferably comprises two primary treatment systems. The first system accomplishes reduction of nitrogen oxides (NOx) as its primary purpose, and the second system focuses on the reduction of Particulate Matter (PM). | 20040429 | 20070821 | 20051103 | 68076.0 | 1 | PHAM, MINH CHAU THI | MARITIME EMISSIONS CONTROL SYSTEM | SMALL | 0 | ACCEPTED | 2,004 |
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10,835,228 | ACCEPTED | Hydroxy-biphenyl-carbaldehyde oxime derivatives and their use as estrogenic agents | This invention provides estrogen receptor modulators having the structure: wherein R1 to R6 and R8 are as defined in the specification; or a pharmaceutically acceptable salt thereof. | 1. A compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 2. The compound of claim 1 wherein R8 is H. 3. The compound of claim 2 wherein: R1 and R2 are each, independently, H, halogen, CN, phenyl, or lower alkyl, said phenyl and lower alkyl being unsubstituted; and R3, R4, R5, and R6, are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy. 4. The compound of claim 2 wherein the compound is of the formula: 5. The compound of claim 4 wherein R3, R5, and R6 are each independently H, Cl, F, methyl, or methoxy and R2 is H, Cl, F, or methyl. 6. The compound of claim 2 wherein the compound is of the formula: 7. The compound of claim 6 wherein R3, R5, and R6 are each independently H, Cl, F, methyl, or methoxy and R2 is H, Cl, F, or methyl. 8. The compound of claim 2 that is: (a) 4′-Hydroxy-3-methyl[1,1′-biphenyl]-4-carbaldehyde oxime; (b) 4′-Hydroxy[1,1′-biphenyl]-4-carbaldehyde oxime; (c) 3-Chloro-4′-hydroxy[1,1′-biphenyl]-4-carbaldehyde oxime; (d) 2-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (e) 3-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (f) 2-Chloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (g) 3-Chloro-4′-hydroxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde oxime; (h) 4′-Hydroxy-2-methyl-1,1′-biphenyl-4-carbaldehyde oxime; (i) 3-Chloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (j) 3-Chloro-3′,5′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (k) 3,5-Dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (l) 3,5-Dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; (m) 2,3-Dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime; or (n) 2,3-Dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime. 9. A pharmaceutical composition comprising: a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof; and a pharmaceutical carrier. 10. A compound of the formula wherein: R1 is OH or lower alkoxy; and R5, R6, and R7 are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, lower alkoxy, said phenyl, lower alkyl, and lower alkoxy being optionally substituted; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 11. The compound of claim 10 wherein R5, R6, and R7 are each, independently, H, Me, Cl, F, or methoxy. 12. The compound of claim 10 where the compound is 4′-Hydroxy-3-methoxy-1,1′-biphenyl-4-carbaldehyde oxime. 13. A pharmaceutical composition comprising: wherein: R1 is OH or lower alkoxy; and R5, R6, and R7 are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, lower alkoxy, said phenyl, lower alkyl, and lower alkoxy being optionally substituted; or a pharmaceutically acceptable salt thereof or a prodrug thereof; and a pharmaceutical carrier. 14. A method of inhibiting osteoporosis in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: where R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 15. A method of inhibiting osteoarthritis, hypocalcemia, hypercalcemia, Paget's disease, osteomalacia, osteohalisteresis, multiple myeloma or other forms of cancer having deleterious effects on bone tissues in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 16. A method of inhibiting benign or malignant abnormal tissue growth in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 17. The method of claim 16 wherein the abnormal tissue growth is prostatic hypertrophy, uterine leiomyomas, breast cancer, endometriosis, endometrial cancer, polycystic ovary syndrome, endometrial polyps, benign breast disease, adenomyosis, ovarian cancer, melanoma, prostrate cancer, cancers of the colon, or CNS cancers. 18. A method of lowering cholesterol, triglycerides, Lp(a), or LDL levels; or inhibiting hypercholesteremia; hyperlipidemia; cardiovascular disease; atherosclerosis; peripheral vascular disease; restenosis, or vasospasm; or inhibiting vascular wall damage from cellular events leading toward immune mediated vascular damage in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 19. A method of inhibiting free radical induced disease states in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 20. A method of providing cognition enhancement or neuroprotection; or treating or inhibiting senile dementias, Alzheimer's disease, congnitive decline, or neurodegenerative disorders in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 21. A method of inhibiting inflammatory bowel disease, ulcerative proctitis, Crohn's disease, colitis, hot flashes, vaginal or vulvar atrophy, atrophic vaginitis, vaginal dryness, pruritus, dyspareunia, dysuria, frequent urination, urinary incontinence, urinary tract infections, vasomotor symptoms; male pattern baldness; skin atrophy; acne; type II diabetes; dysfunctional uterine bleeding; or infertility in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. 22. A method of inhibiting leukemia, endometrial ablations, chronic renal or hepatic disease or coagulation diseases or disorders in a mammal in need thereof, comprising providing to said mammal an effective amount of a compound of the formula: wherein R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. | CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims benefit to U.S. Provisional Application Ser. No. 60/467,394, filed May 2, 2003, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION This invention relates to novel 4′-hydroxy-biphenyl-carbaldehyde oxime derivatives, their uses as estrogenic agents, and methods of their preparation. BACKGROUND OF THE INVENTION The pleiotropic effects of estrogens in mammalian tissues have been well documented, and it is now appreciated that estrogens affect many organ systems [Mendelsohn and Karas, New England Journal of Medicine 340: 1801-1811 (1999), Epperson, et al., Psychosomatic Medicine 61: 676-697 (1999), Crandall, Journal of Womens Health & Gender Based Medicine 8: 1155-1166 (1999), Monk and Brodaty, Dementia & Geriatric Cognitive Disorders 11: 1-10 (2000), Hum and Macrae, Journal of Cerebral Blood Flow & Metabolism 20: 631-652 (2000), Calvin, Maturitas 34: 195-210 (2000), Finking, et al., Zeitschrift fur Kardiologie 89: 442-453 (2000), Brincat, Maturitas 35: 107-117 (2000), Al-Azzawi, Postgraduate Medical Journal 77: 292-304 (2001)]. Estrogens can exert effects on tissues in several ways. Probably, the most well characterized mechanism of action is their interaction with estrogen receptors leading to alterations in gene transcription. Estrogen receptors are ligand-activated transcription factors and belong to the nuclear hormone receptor superfamily. Other members of this family include the progesterone, androgen, glucocorticoid and mineralocorticoid receptors. Upon binding ligand, these receptors dimerize and can activate gene transcription either by directly binding to specific sequences on DNA (known as response elements) or by interacting with other transcription factors (such as AP1), which in turn bind directly to specific DNA sequences [Moggs and Orphanides, EMBO Reports 2: 775-781 (2001), Hall, et al., Journal of Biological Chemistry 276: 36869-36872 (2001), McDonnell, Principles Of Molecular Regulation. p351-361(2000)]. A class of “coregulatory” proteins can also interact with the ligand-bound receptor and further modulate its transcriptional activity [McKenna, et al., Endocrine Reviews 20: 321-344 (1999)]. It has also been shown that estrogen receptors can suppress NFκB-mediated transcription in both a ligand-dependent and independent manner [Quaedackers, et al., Endocrinology 142: 1156-1166 (2001), Bhat, et al., Journal of Steroid Biochemistry & Molecular Biology 67: 233-240 (1998), Pelzer, et al., Biochemical & Biophysical Research Communications 286: 1153-7 (2001)]. Estrogen receptors can also be activated by phosphorylation. This phosphorylation is mediated by growth factors such as EGF and causes changes in gene transcription in the absence of ligand [Moggs and Orphanides, EMBO Reports 2: 775-781 (2001), Hall, et al., Journal of Biological Chemistry 276: 36869-36872 (2001)]. A less well-characterized means by which estrogens can affect cells is through a so-called membrane receptor. The existence of such a receptor is controversial, but it has been well documented that estrogens can elicit very rapid non-genomic responses from cells. The molecular entity responsible for transducing these effects has not been definitively isolated, but there is evidence to suggest it is at least related to the nuclear forms of the estrogen receptors [Levin, Journal of Applied Physiology 91: 1860-1867 (2001), Levin, Trends in Endocrinology & Metabolism 10: 374-377 (1999)]. Two estrogen receptors have been discovered to date. The first estrogen receptor was cloned about 15 years ago and is now referred to as ERβ [Green, et al., Nature 320: 134-9 (1986)]. The second was found comparatively recently and is called ERβ [Kuiper, et al., Proceedings of the National Academy of Sciences of the United States of America 93: 5925-5930 (1996)]. Early work on ERβ focused on defining its affinity for a variety of ligands and, indeed, some differences with ERα were seen. The tissue distribution of ERα has been well mapped in the rodent and it is not coincident with ERα. Tissues such as the mouse and rat uterus express predominantly ERα, whereas the mouse and rat lung express predominantly ERβ [Couse, et al., Endocrinology 138: 4613-4621 (1997), Kuiper, et al., Endocrinology 138: 863-870 (1997)]. Even within the same organ, the distribution of ERα and ERβ can be compartmentalized. For example, in the mouse ovary, ERβ is highly expressed in the granulosa cells and ERα is restricted to the thecal and stromal cells [Sar and Welsch, Endocrinology 140: 963-971 (1999), Fitzpatrick, et al., Endocrinology 140: 2581-2591 (1999)]. However, there are examples where the receptors are coexpressed and there is evidence from in vitro studies that ERα and ERβ can form heterodimers [Cowley, et al., Journal of Biological Chemistry 272: 19858-19862 (1997)]. The most potent endogenous estrogen is 17β-estradiol. A large number of compounds have been described that either mimic or block the activity of 17β-estradiol. Compounds having roughly the same biological effects as 17β-estradiol are referred to as “estrogen receptor agonists”. Those which block the effects of 17β-estradiol, when given in combination with it, are called “estrogen receptor antagonists”. In reality, there is a continuum between estrogen receptor agonist and estrogen receptor antagonist activity and some compounds behave as estrogen receptor agonists in some tissues but estrogen receptor antagonists in others. These compounds with mixed activity are called selective estrogen receptor modulators (SERMS) and are therapeutically useful agents (e.g. EVISTA) [McDonnell, Journal of the Society for Gynecologic Investigation 7: S10-S15 (2000), Goldstein, et al., Human Reproduction Update 6: 212-224 (2000)]. The precise reason why the same compound can have cell-specific effects has not been elucidated, but the differences in receptor conformation and/or in the milieu of coregulatory proteins have been suggested. It has been known for some time that estrogen receptors adopt different conformations when binding ligands. However, the consequence and subtlety of these changes only recently has been revealed. The three dimensional structures of ERα and ERβ have been solved by co-crystallization with various ligands and clearly show the repositioning of helix 12 in the presence of an estrogen receptor antagonist, which sterically hinders the protein sequences required for receptor-coregulatory protein interaction [Pike, et al., Embo 18: 4608-4618 (1999), Shiau, et al., Cell 95: 927-937 (1998)]. In addition, the technique of phage display has been used to identify peptides that interact with estrogen receptors in the presence of different ligands [Paige, et al., Proceedings of the National Academy of Sciences of the United States of America 96: 3999-4004 (1999)]. For example, a peptide was identified that distinguished between ERα bound to the full estrogen receptor agonists 17β-estradiol and diethylstilbesterol. A different peptide was shown to distinguish between clomiphene bound to ERα and ERβ. These data indicate that each ligand potentially places the receptor in a unique and unpredictable conformation that is likely to have distinct biological activities. As mentioned above, estrogens affect a panoply of biological processes. In addition, where gender differences have been described (e.g. disease frequencies, responses to challenge, etc), it is possible that the explanation involves the difference in estrogen levels between males and females. SUMMARY OF THE INVENTION The present invention relates to a compound of the formula: where R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In one preferred embodiment, R8 is H. In another aspect, the invention relates to a compound of the formula: In yet another aspect, the invention is directed to a compound of the formula: In a further aspect, the invention is drawn to a compound of the formula where R1 is OH or lower alkoxy; and R5, R6, and R7 are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, lower alkoxy, said phenyl, lower alkyl, and lower alkoxy being optionally substituted; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In another aspect, the invention is drawn to a pharmaceutical composition that comprises one or more of compound of the invention and a pharmaceutically acceptable carrier. In yet other aspects, the invention is directed to use of the compounds of the invention in the treatment or prevention of diseases such as inflammatory bowel diseases. DETAILED DESCRIPTION OF THE INVENTION This invention provides novel 4′-hydroxy-biphenyl-carbaldehyde oxime derivatives. These compounds, which preferably act as estrogenic agents, are useful for the treatment and prevention of diseases such as inflammatory bowel diseases (including Crohn's disease and colitis). In one aspect, the invention is directed to compounds of the formula: where R1 and R2, are each, independently, H, halogen, CN, phenyl, or lower alkyl; R3, R4, R5 and R6, are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R8 are each, independently, H, —C(O)R9, or lower alkyl; and R9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In one preferred embodiment, R8 is H. Compounds according to the invention can be: In certain aspects, R3, R5, and R6 are each independently H, Cl, F, methyl, or methoxy and R2 is H, Cl, F, or methyl. In another aspect, the invention is directed to compounds of the formula: In certain aspects, R3, R5, and R6 are each independently H, Cl, F, methyl, or methoxy and R2 is H, Cl, F, or methyl. In yet another aspect, the invention is drawn to compounds of the formula where R1 is OH or lower alkoxy; and R5, R6, and R7 are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, lower alkoxy; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In certain embodiments, R5, R6, and R7 are each, independently, H, Me, Cl, F, or methoxy. Pharmaceutically acceptable salts can be formed from organic and inorganic acids, for example, acetic, propionic, lactic, citric, tartaric, succinic, fumaric, maleic, malonic, mandelic, malic, phthalic, hydrochloric, hydrobromic, phosphoric, nitric, sulfuric, methanesulfonic, napthalenesulfonic, benzenesulfonic, toluenesulfonic, camphorsulfonic, and similarly known acceptable aids when a compound of this invention contains a basic moiety. Salts may also be formed from organic and inorganic bases, such as alkali metal salts (for example, sodium, lithium, or potassium) alkaline earth metal salts, ammonium salts, alkylammonium salts containing 1-6 carbon atoms or dialkylammonium salts containing 1-6 carbon atoms in each alkyl group, and trialkylammonium salts containing 1-6 carbon atoms in each alkyl group, when a compound of this invention contains an acidic moiety. The term “alkyl”, as used herein, whether used alone or as part of another group, refers to a substituted or unsubstituted aliphatic hydrocarbon chain and includes, but is not limited to, straight and branched chains containing from 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, unless explicitly specified otherwise. For example, methyl, ethyl, propyl, isopropyl, butyl, i-butyl and t-butyl are encompassed by the term “alkyl.” Specifically included within the definition of “alkyl” are those aliphatic hydrocarbon chains that are optionally substituted. The carbon number as used in the definitions herein refers to carbon backbone and carbon branching, but does not include carbon atoms of the substituents, such as alkoxy substitutions and the like. The term “alkenyl”, as used herein, whether used alone or as part of another group, refers to a substituted or unsubstituted aliphatic hydrocarbon chain and includes, but is not limited to, straight and branched chains having 2 to 8 carbon atoms and containing at least one double bond. Preferably, the alkenyl moiety has 1 or 2 double bonds. Such alkenyl moieties may exist in the E or Z conformations and the compounds of this invention include both conformations. Specifically included within the definition of “alkenyl” are those aliphatic hydrocarbon chains that are optionally substituted. Heteroatoms, such as O, S or N—R1, attached to an alkenyl should not be attached to a carbon atom that is bonded to a double bond. The term “phenyl”, as used herein, whether used alone or as part of another group, referes to a substituted or unsubstituted phenyl group. An optionally substituted alkyl, alkenyl, and phenyl may be substituted with one or more substituents. Suitable optionally substituents may be selected independently from nitro, cyano, —N(R11)(R12), halo, hydroxy, carboxy, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, heteroaryloxy, alkylalkoxy, alkoxycarbonyl, alkoxyalkoxy, perfluoroalkyl, perfluoroalkoxy, arylalkyl, alkylaryl, hydroxyalkyl, alkoxyalkyl, alkylthio, —S(O)2—N(R11)(R12), —C(═O)—N(R11)(R12), (R11)(R12)N-alkyl, (R11)(R12)N-alkoxyalkyl, (R11)(R12)N-alkylaryloxyalkyl, —S(O)s-aryl (where s=0-2) or —S(O)s-heteroaryl (where s=0-2). In certain embodiments of the invention, preferred substitutents for alkyl, alkenyl, alkynyl and cycloalkyl include nitro, cyano, —N(R11)(R12), halo, hydroxyl, aryl, heteroaryl, alkoxy, alkoxyalkyl, and alkoxycarbonyl. In certain embodiments of the invention, preferred substituents for aryl and heteroaryl include —N(R11)(R12), alkyl, halo, perfluoroalkyl, perfluoroalkoxy, arylalkyl and alkylaryl. When alkyl or alkenyl moieties are substituted, for example, they may typically be mono-, di-, tri- or persubstituted. Examples for a halogen substituent include 1-bromo vinyl, 1-fluoro vinyl, 1,2-difluoro vinyl, 2,2-difluorovinyl, 1,2,2-trifluorovinyl, 1,2-dibromo ethane, 1,2-difluoro ethane, 1-fluoro-2-bromo ethane, CF2CF3, CF2CF2CF3, and the like. The term halogen includes bromine, chlorine, fluorine, and iodine. The term “lower alkyl” refers to an alkyl group having 1 to 6 carbon atoms, in some embodiments 1 to 3 carbon atoms are preferred. The term “lower alkoxy,” as used herein, refers to the group R—O— where R is an alkyl group of 1 to 6 carbon atoms, in some embodiments 1 to 3 carbon atoms are preferred. As used in accordance with this invention, the term “providing,” with respect to providing a compound or substance covered by this invention, means either directly administering such a compound or substance, or administering a prodrug, derivative, or analog which will form the equivalent amount of the compound or substance within the body. The compounds of this invention can be used as estrogen receptor modulators useful in the treatment or inhibition of conditions, disorders, or disease states that are at least partially mediated by an estrogen deficiency or excess, or which may be treated or inhibited through the use of an estrogenic agent. The compounds of this invention are particularly useful in treating a peri-menopausal, menopausal, or postmenopausal patient in which the levels of endogenous estrogens produced are greatly diminished. Menopause is generally defined as the last natural menstrual period and is characterized by the cessation of ovarian function, leading to the substantial diminution of circulating estrogen in the bloodstream. As used herein, menopause also includes conditions of decreased estrogen production that may be surgically, chemically, or be caused by a disease state which leads to premature diminution or cessation of ovarian function. Accordingly, the compounds of this invention are useful in treating or inhbiting osteoporosis and in the inhibition of bone demineralization, which may result from an imbalance in a individual's formation of new bone tissues and the resorption of older tissues, leading to a net loss of bone. Such bone depletion results in a range of individuals, particularly in post-menopausal women, women who have undergone bilateral oophorectomy, those receiving or who have received extended corticosteroid therapies, those experiencing gonadal dysgenesis, and those suffering from Cushing's syndrome. Special needs for bone, including teeth and oral bone, replacement can also be addressed using these compounds in individuals with bone fractures, defective bone structures, and those receiving bone-related surgeries and/or the implantation of prosthesis. In addition to those problems described above, these compounds can be used in treatment or inhibition for osteoarthritis, hypocalcemia, hypercalcemia, Paget's disease, osteomalacia, osteohalisteresis, multiple myeloma and other forms of cancer having deleterious effects on bone tissues. The compounds of this invention are also useful in treating or inhibiting benign or malignant abnormal tissue growth, including prostatic hypertrophy, uterine leiomyomas, breast cancer, endometriosis, endometrial cancer, polycystic ovary syndrome, endometrial polyps, benign breast disease, adenomyosis, ovarian cancer, melanoma, prostrate cancer, cancers of the colon, CNS cancers, such as glioma or astioblastomia. The compounds of this invention are cardioprotective and they are useful in in lowering cholesterol, triglycerides, Lp(a), and LDL levels; inhibiting or treating hypercholesteremia; hyperlipidemia; cardiovascular disease; atherosclerosis; peripheral vascular disease; restenosis, and vasospasm; and inhibiting vascular wall damage from cellular events leading toward immune mediated vascular damage. These cardiovascular protective properties are of great importance when treating postmenopausal patients with estrogens to inhibit osteoporosis and in the male when estrogen therapy is indicated. The compounds of this invention are also antioxidants, and are therefore useful in treating or inhibiting free radical induced disease states. Specific situations in which antioxidant therapy is indicated to be warranted are with cancers, central nervous system disorders, Alzheimer's disease, bone disease, aging, inflammatory disorders, peripheral vascular disease, rheumatoid arthritis, autoimmune diseases, respiratory distress, emphysema, prevention of reperfusion injury, viral hepatitis, chronic active hepatitis, tuberculosis, psoriasis, systemic lupus erythematosus, adult respiratory distress syndrome, central nervous system trauma and stroke. The compounds of this invention are also useful in providing cognition enhancement, and in treating or inhibiting senile dementias, Alzheimer's disease, cognitive decline, neurodegenerative disorders, providing neuroprotection or cognition enhancement. The compounds of this invention are also useful in treating or inhibiting inflammatory bowel disease, ulcerative proctitis, Crohn's disease, and colitis; menopausal related conditions, such as vasomotor symptoms including hot flushes, vaginal or vulvar atrophy, atrophic vaginitis, vaginal dryness, pruritus, dyspareunia, dysuria, frequent urination, urinary incontinence, urinary tract infections, vasomotor symptoms, including hot flushes, myalgia, arthralgia, insomnia, irritability, and the like; male pattern baldness; skin atrophy; acne; type II diabetes; dysfunctional uterine bleeding; and infertility. The compounds of this invention are useful in disease states where amenorrhea is advantageous, such as leukemia, endometrial ablations, chronic renal or hepatic disease or coagulation diseases or disorders. The compounds of this invention can be used as a contraceptive agent, particularly when combined with a progestin. When administered for the treatment or inhibition of a particular disease state or disorder, it is understood that the effective dosage may vary depending upon the particular compound utilized, the mode of administration, the condition, and severity thereof, of the condition being treated, as well as the various physical factors related to the individual being treated. Effective administration of the compounds of this invention may be given at an oral dose of from about 0.1 mg/day to about 1,000 mg/day. Preferably, administration will be from about 10 mg/day to about 600 mg/day, more preferably from about 50 mg/day to about 600 mg/day, in a single dose or in two or more divided doses. The projected daily dosages are expected to vary with route of administration. Such doses may be administered in any manner useful in directing the active compounds herein to the recipient's bloodstream, including orally, via implants, parenterally (including intravenous, intraperitoneal and subcutaneous injections), rectally, intranasally, vaginally, and transdermally. Oral formulations containing the active compounds of this invention may comprise any conventionally used oral forms, including tablets, capsules, buccal forms, troches, lozenges and oral liquids, suspensions or solutions. Capsules may contain mixtures of the active compound(s) with inert fillers and/or diluents such as the pharmaceutically acceptable starches (e.g. corn, potato or tapioca starch), sugars, artificial sweetening agents, powdered celluloses, such as crystalline and microcrystalline celluloses, flours, gelatins, gums, etc. Useful tablet formulations may be made by conventional compression, wet granulation or dry granulation methods and utilize pharmaceutically acceptable diluents, binding agents, lubricants, disintegrants, surface modifying agents (including surfactants), suspending or stabilizing agents, including, but not limited to, magnesium stearate, stearic acid, talc, sodium lauryl sulfate, microcrystalline cellulose, carboxymethylcellulose calcium, polyvinylpyrrolidone, gelatin, alginic acid, acacia gum, xanthan gum, sodium citrate, complex silicates, calcium carbonate, glycine, dextrin, sucrose, sorbitol, dicalcium phosphate, calcium sulfate, lactose, kaolin, mannitol, sodium chloride, talc, dry starches and powdered sugar. Preferred surface modifying agents include nonionic and anionic surface modifying agents. Representative examples of surface modifying agents include, but are not limited to, poloxamer 188, benzalkonium chloride, calcium stearate, cetostearl alcohol, cetomacrogol emulsifying wax, sorbitan esters, colloidol silicon dioxide, phosphates, sodium dodecylsulfate, magnesium aluminum silicate, and triethanolamine. Oral formulations herein may utilize standard delay or time release formulations to alter the absorption of the active compound(s). The oral formulation may also consist of administering the active ingredient in water or a fruit juice, containing appropriate solubilizers or emulsifiers as needed. In some cases it may be desirable to administer the compounds directly to the airways in the form of an aerosol. The compounds of this invention may also be administered parenterally or intraperitoneally. Solutions or suspensions of these active compounds as a free base or pharmacologically acceptable salt can be prepared in water suitably mixed with a surfactant such as hydroxy-propylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols and mixtures thereof in oils. Under ordinary conditions of storage and use, these preparation contain a preservative to prevent the growth of microorganisms. The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils. For the purposes of this disclosure, transdermal administrations are understood to include all administrations across the surface of the body and the inner linings of bodily passages including epithelial and mucosal tissues. Such administrations may be carried out using the present compounds, or pharmaceutically acceptable salts thereof, in lotions, creams, foams, patches, suspensions, solutions, and suppositories (rectal and vaginal). Transdermal administration may be accomplished through the use of a transdermal patch containing the active compound and a carrier that is inert to the active compound, is non toxic to the skin, and allows delivery of the agent for systemic absorption into the blood stream via the skin. The carrier may take any number of forms such as creams and ointments, pastes, gels, and occlusive devices. The creams and ointments may be viscous liquid or semisolid emulsions of either the oil-in-water or water-in-oil type. Pastes comprised of absorptive powders dispersed in petroleum or hydrophilic petroleum containing the active ingredient may also be suitable. A variety of occlusive devices may be used to release the active ingredient into the blood stream such as a semi-permeable membrane covering a reservoir containing the active ingredient with or without a carrier, or a matrix containing the active ingredient. Other occlusive devices are known in the literature. Suppository formulations may be made from traditional materials, including cocoa butter, with or without the addition of waxes to alter the suppository's melting point, and glycerin. Water soluble suppository bases, such as polyethylene glycols of various molecular weights, may also be used. The reagents used in the preparation of the compounds of this invention can be either commercially obtained or can be prepared by standard procedures described in the literature. The preparation of several representative examples of this invention are described in the following Schemes 1-11. EXAMPLE 1 4-tert-Butyl-dimethylsilyoxyphenylboronic acid Method A. To a solution of (4-bromo-phenoxy)-tert-butyl-dimethylsilane (20 mL, 23.48g, 0.082 moles) in tetrahydrofuran (200 mL) at −78° C. was slowly added n-butyl lithium (39.2 mL of 2.5 M solution in hexane, 0.098 moles) under N2 with stirring over a few minutes. The solution was stirred for 1 hour and triisopropyl borate (66.2 mL, 54.0g, 0.29 moles) was added by syringe at −78° C. The solution was stirred for 1 hr at −78° C. and then allowed to warm to room temperature overnight. The reaction was cooled to 0° C. and water (20 mL) and 2 N HCl (20 mL) were added into the reaction mixture. Then the whole mixture was stirred with of 2 N HCl (360 mL) for 10 minutes. The mixture was extracted with ethyl acetate (3×250 mL). The combined organic layers were concentrated to a volume of about 50 mL. Crystallization was induced with cold hexane, and the solid product was collected by filtration and dried under vacuum to yield 14.5g (70%) of the title compound as a white solid: 1H NMR (DMSO-d6): δ 0.19 (6H, s), 0.94 (9H, s), 6.80 (2H, d, J=8.4 Hz), 7.69 (2H, d, J=8.36 Hz), 7.87 (2H, s). EXAMPLE 2 4′-Hydroxy-3-methyl[1,1′-biphenyl]-4-carbonitrile Method B. A mixture of 4-bromo-2-methylbenzonitrile (1.8g, 9.18 mmol), 4-tert-butyl-dimethylsilyoxyphenylboronic acid (3.0g, 11.9 mmol), sodium carbonate (13.8 mL of 2 M aqueous solution, 27.5 mmol), tetrakis(triphenylphosphine)palladium (0.53g, 0.46 mmol), and ethylene glycol dimethyl ether (70 mL) were heated to reflux overnight. The mixture was cooled to room temperature and poured into water, then extracted with ethyl acetate (3×), washed with brine, dried over sodium sulfate, filtered, and the solvent evaporated. Purification by silica chromatography (15%-25% ethyl acetate-hexane) to yield 1.81g (94%) of the title compound as a yellowish solid: mp 177-178° C.; 1H NMR (DMSO-d6): δ 2.52 (3H, s), 6.88 (2H, d, J=8.50 Hz), 7.6 (3H, d, J=8.49 Hz), 7.71 (1H, s), 7.77 (2H, d, J=8.12 Hz), 9.79 (1H, s); IR 2220 cm−1; MS (ESI) m/z 208 (M−H)−. Anal. for C14H11NO: Calc'd: C: 80.36, H: 5.30, N: 6.69 Found: C: 79.91, H: 5.27, N: 6.57. EXAMPLE 3 4′-Hydroxy-3-methyl[1,1′-biphenyl]-4-carbaldehyde A solution of 4′-hydroxy-3-methyl[1,1′-biphenyl]-4-carbonitrile (500 mg, 2.39 mmol) in dry toluene was cooled to −78° C. and diisobutylaluminum hydride (4.0 mL of 1.5 M solution in toluene, 5.98 mmol) was added all at once. The reaction mixture was allowed to warm to room temperature over a period of 3.5 h. Methanol (1.2 mL) was added followed by water (1.2 mL) at 0° C. and the mixture was stirred at room temperature for 20 min. 1 N HCl solution was added with stirring until pH<7. The mixture was extracted with ethyl acetate (3×), washed with brine, dried over sodium sulfate, filtered, and the solvent evaporated. Purification by silica chromatography (15%-25% ethyl acetate-hexane) to yield 459 mg (91%) of the title compound as a white solid: mp 161-162° C.; 1H NMR (DMSO-d6): δ 2.67 (3H, s), 6.88 (2H, d, J=8.41 Hz), 7.59-7.65 (4H, m), 7.85 (1H,d, J=8.03 Hz), 9.78 (1H, s), 10.22 (1H, s); IR 1680 cm−1; MS (ESI) m/z 211 (M−H)−. Anal. for C14H12O2: Calc'd: C: 79.23, H: 5.70 Found: C: 78.79, H: 5.90. EXAMPLE 4 4′-{[tert-Butyl(dimethyl)silyl]oxy}-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting 4-bromobenzaldehyde (730 mg, 3.97 mmol) with 4-tert-butyl-dimethylsilyoxyphenylboronic acid (1.3g, 5.16 mmol) according to Method B to yield 600 mg (48%) of white crystal: 1H NMR (DMSO-d6): δ 0.24 (6H, s), 1.01 (9H, s), 6.94 (2H, d, J=8.54 Hz), 7.53 (2H, d, J=8.56 Hz), 7.72 (2H, d, J=8.19 Hz), 7.93 (2H, d, 8.20 Hz), 10.04 (1H, s). EXAMPLE 5 4′-Hydroxy[1,1′-biphenyl]-4-carbaldehyde A mixture of 4′-{[tert-butyl(dimethyl)silyl]oxy}-1,1′-biphenyl-4-carbaldehyde (320 mg, 1.03 mmol), anhydrous KF (120 mg, 2.06 mmol) and 48% aqueous HBr (35 ul, 0.31 mmol) in 6 mL dry DMF was stirred at room temperature under N2 for 1 h. TLC indicated starting material present and therefore more 48% aqueous HBr (35 uL, 0.31 mmol) was added into the reaction and the mixture was continued to stir for 1.5 h. The mixture was then poured, with cooling, into 1 N aqueous HCl (30 mL). The aqueous mixture was extracted with EtOAc (3×). The combined extracts were washed with saturated NaCl solution, and dried over Na2SO4. The solvent was evaporated under reduced pressure and the product (100%) which was used directly in the next step. 1H NMR (DMSO-d6): δ 6.89 (2H, d, J=8.43 Hz), 7.63 (2H, d, J=8.46 Hz), 7.83 (2H, d, J=8.16 Hz), 7.94 (2H, d, J=8.02 Hz), 9.79 (1H, s), 10.01 (1H, s). EXAMPLE 6 Trifluoro-methanesulfonic acid 3-chloro-4-formyl-phenyl ester Method D. To a solution of 2-chloro-4-hydroxy benzaldehyde (1.31g, 8.4 mmol) and pyridine (1.1 mL, 13.4 mmol) in 80 mL of dichloromethane at 0° C. was added trifluoromethanesulfonic anhydride (1.84 mL, 3.08g, 10.9 mmol). The solution was allowed to slowly warm to room temperature and stirred for 2.5 h. The solution was cooled to 0° C. and stirred with ice water to decompose any excess anhydride. The mixture was made slightly basic by the addition of saturated sodium bicarbonate solution. The resulting layers were separated and the aqueous layer was extracted with dichloromethane (3×100 mL). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and the solvent removed under vacuum to afford a orange oil which was purified by silica chromatography (5% ethyl acetate-hexanes) to yield 1.83g (76%) of the title compound as a clear, colorless oil: 1H NMR (DMSO-d6) δ 7.73 (1H, dd, J=2.35 Hz, J=8.64 Hz), 8.04-8.07 (2H, m), 10.30 (1H,s). EXAMPLE 7 Trifluoro-methanesulfonic acid 2-fluoro-4-formyl-phenyl ester The title compound was prepared by reacting 3-fluoro-4-hydroxybenzaldehyde (1.2g, 8.56 mmol) with trifluoromethanesulfonic anhydride (1.87 mL, 3.14g, 11.1 mmol) according to Method D to yield a yellow oil which was used directly in the next step without purification: 1H NMR (CDCl3): δ 7.53-7.58 (1H, m), 7.77-7.85 (2H, m), 10.01 (1H, d, J=1.45 Hz). EXAMPLE 8 4′-{[Tert-butyl(dimethyl)silyl]oxy}-3-chloro-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 3-chloro-4-formyl-phenyl ester (1.78g, 6.18 mmol) with 4-tert-butyl-dimethylsilyoxyphenylboronic acid (2.03g, 8.03 mmol) according to Method B to yield 0.92g (43%) of white solid: mp 38-39° C.; 1H NMR (DMDO-d6); δ 0.23 (6H, s), 0.97 (9H, s), 6.98 (2H, d, J=8.79 Hz), 7.74 (2H, d, J=8.79 Hz), 7.81 (1H, d, J=7.81 Hz), 7.89 (1H, d, J=1.95 Hz), 7.91 (1H, d, J=7.81 Hz), 10.34 (1H, s); MS (ESI) m/z 231/233 (M−H)−(deprotected product ion). Anal. for C19H23ClO2Si: Calc'd: C: 65.78, H: 6.68 Found: C: 65.59, H: 6.60. EXAMPLES 9 and 10 Trifluoro-methanesulfonic acid 2-fluoro-4-formyl-phenyl ester (2.1g, 7.72 mmol) were reacted with 4-tert-butyl-dimethylsilyoxyphenylboronic acid (2.14g, 8.49 mmol) according to Method B to produce the following two compounds: 4′-{[tert-butyl(dimethyl)silyl]oxy}-2-fluoro-1,1′-biphenyl-4-carbaldehyde 1.62g (63%) of waxy yellowish solid: 1H NMR (Acetone-d6): δ 0.28 (6H, s), 1.02 (9H, s), 7.02-7.06 (2H, m), 7.57-7.60 (2H, m), 7.71-7.78 (2H, m), 7.85 (1H, dd, J=7.91 Hz, J=1.51 Hz), 10.07 (1H, d, J=1.73 Hz); 13C NMR (Acetone-d6): δ−4.29, 18.80, 26.00, 116.82 (d, J=23.90 Hz), 121.15, 126.69 (d, J=3.25 Hz), 128.42 (d, 1.21 Hz), 131.30 (d, J=3.48 Hz), 132.20 (d, J=3.44 Hz), 135.27 (d, J=13.61), 138.09 (d, J=6.64 Hz), 157.23, 160.68 (d, J=248.56 Hz), 191.51; IR 1692 cm−; MS (ESI) m/z 331 (M+H)+, 372 (M+H+ACN)+. Anal. for C19H23FO2Si: Calc'd: C: 69.06 H: 7.02 Found: C: 69.71 H: 7.34. 2-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde 0.32g (19%) of yellowish solid: mp 149-150° C.; 1H NMR (Acetone-d6):. δ 7.08-7.13 (2H, m), 7.62-7.67 (2H, m), 7.80-7.91 (2H, m), 7.94 (1H, dd, J=1.58 Hz), 8.93 (1H, s), 10.16 (1H, d, J=1.73 Hz); IR 1669 cm−; MS (ESI) m/z 215 (M−H)−1. Anal. for C13H9FO2: Calc'd: C: 72.22, H: 4.20 Found: C: 71.38, H: 4.12. EXAMPLE 11 4′-{[tert-Butyl(dimethyl)silyl]oxy}-3-chloro[1,1, ′-biphenyl]-4-carbaldehyde oxime The title compound was prepared by reacting 4′-{[tert-butyl(dimethyl)silyl]oxy}-3-chloro-1,1′-biphenyl-4-carbaldehyde (405 mg, 1.17 mmol) with hydroxylamine hydrochloride (154 mg, 2.22 mmol) according to Method C to yield a yellowish oil which was used in the next step without purification: MS (ESI) m/z 362/364 (M+H)+. EXAMPLE 12 4′-{[Tert-butyl(dimethyl)silyl]oxy}-2-fluoro-[1,1′-biphenyl]-4-carbaldehyde oxime The title compound was prepared by reacting 4′-{[tert-butyl(dimethyl)silyl]oxy}-2-fluoro-1,1′-biphenyl-4-carbaldehyde (450 mg, 1.36 mmol) with hydroxylamine hydrochloride (190 mg, 2.73 mmol) according to Method C to yield a white solid which was used in the next step without purification: MS (ESI) m/z 344 (M−H)−, 346 (M+H)+. EXAMPLE 13 3-Fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting 4-bromo-2-fluoro-benzaldehyde (3g, 14.8 mmol) with 4-methoxyphenylboronic acid (2.70g, 17.8 mmol) according to Method B to yield 3.2g (94%) of white solid: mp 85-86° C.; 1H NMR (DMSO-d6): δ 3.83 (3H, s). 7.06-7.09 (2H, m), 7.70-7.75 (2H, m), 7.79-7.82 (2H, m), 7.88 (1H, t, J=7.96 Hz), 10.22 (1H, s); IR 1681 cm−1; MS (ESI) m/z 231 (M+H)+. Anal. for C14H11FO2: Calc'd: C: 73.03, H: 4.82 Found: C: 72.99, H: 4.73 EXAMPLE 14 3-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde Method F. To a mixture of 3-fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde (0.986g, 4.29 mmol) in methylene chloride (35 mL) at 0° C. was slowly added boron tribromide (10.7 mL of 1 N solution in methylene chloride, 10.7 mmol). The mixture was allowed to warm slowly to room temperature and was stirred overnight. Water (4 mL) was injected into the mixture with stirring in an ice-water bath. The resulting mixture was poured into water and extracted with ethyl acetate (3×). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, evaporation of the solvent and purification by silica column chromatography (15%-30% ethyl acetate-hexane) to yield 150 mg (16%) of the title compound as white solid. An analytical sample was afforded by reverse-phase preparative HPLC: mp 164-166° C.; 1H NMR (Acetone-d6): δ 76.98-7.01 (2H, m), 7.56 (1H, dd, J=12.49 Hz, J=1.64 Hz), 7.63-7.66 (1H, m), 7.67-7.70 (2H, m), 7.89 (1H, t, J=7.85 Hz), 8.88 (1H, (1H, s); MS (ESI) m/z 215 (M−H)−. Anal. for C13H9FO2: Calc'd: C: 72.22, H: 4.20 Found: C: 71.83, H: 4.04 EXAMPLE 15 Trifluoro-methanesulfonic acid 2-chloro-4-formyl-phenyl ester The title compound was prepared by reacting 3-chloro-4-hydroxybenzaldehyde (5g, 31.9 mmol) with trifluoromethanesulfonic anhydride (7.0 mL, 11.7g, 41.5 mmol) according to Method D to yield 9.15g (100%) of a yellow oil which was used directly in the next step without purification: 1H NMR: δ 7.92 (1H, d, J=8.48 Hz), 8.07 (1H, dd, J=8.51 Hz, J=1.93 Hz), 8.30 (1H, d, J=1.92 Hz), 10.04 (1H, s). EXAMPLE 16 2-Chloro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 2-chloro-4-formyl-phenyl ester (5g, 17.4 mmol) with 4-methoxyphenylboronic acid (3.44 g, 22.6 mmol) according to Method B to yield 3.83g (89%) of white solid: mp 85-87° C.; 1H NMR (DMSO-d6): δ 3.82 (3H, s), 7.07 (2H, d, J=8.83 Hz), 7.46 (2H, d, J=8.45 Hz), 7.63 (1H, d, J=7.87 Hz), 7.92 (1H, dd, J=7.87 Hz, J=1.56 Hz), 8.07 d, J=1.49 Hz); 13C NMR (DMSO-d6): δ 55.14, 113.72, 127.80, 129.72, 130.42, 130.82, 132.15, 132.21, 136.11, 144.90, 159.33, 191.73; IR 1692 cm−1; MS (EI) m/z 246/248 M+. Anal. for C14H11ClO2: Calc'd: C: 68.16 H: 4.49 Found: C: 67.76 H: 4.36 EXAMPLE 17 2′-Chloro-4′-(dibromomethyl)-1,1′-biphenyl-4-ol The title compound was prepared by reacting 2-chloro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde (800 mg, 3.25 mmol) with boron tribromide (8.1 mL of 1 N solution in methylene chloride, 8.13 mmol) according to Method F to yield 600 mg (50%) of yellowish solid: mp 107-108° C.; 1H NMR (DMSO-d6): δ 6.86 (2H, d, J=8.52 Hz), 7.29 (2H, d, J=8.50 Hz), 7.43 (1H, s), 7.45 (1H, d, J=8.12 Hz), 7.64 (1H, dd, J=8.07 Hz, J=1.83 Hz), 7.74 (1H, d, J=1.79 Hz), 9.71 (1H, bs); 13C NMR (DMSO-d6): δ 40.66, 114.94, 125.66, 127.34, 128.14, 130.39, 130.87, 131.80, 140.95, 142.14, 157.36; MS (ESI) m/z 373/375/377/379 (M−H)−. Anal. for C13H9Br2ClO: Calc'd: C: 41.48, H: 2.41 Found: C: 41.64, H: 2.14 EXAMPLE 18 Trifluoro-methanesulfonic acid 4-formyl-3-methoxy-phenyl ester The title compound was prepared by reacting 4-hydroxy-2-methoxybenzaldehyde (3g, 19.7 mmol) with trifluoromethanesulfonic anhydride (4.3 mL, 7.2g, 25.6 mmol) according to Method D to yield a brown syrup which was used in the next step without purification: 1H NMR: δ 3.97 (3H, s), 7.21 (1H, dd, J=8.64 Hz, J=2.17 Hz), 7.47 (1H, d, J=2.24 Hz), 7.87 (1H, d, J=8.64 Hz), 10.31 (1H, s). EXAMPLE 19 Trifluoro-methanesulfonic acid 4-formyl-2-methyl-phenyl ester The title compound was prepared by reacting 4-hydroxy-3-methylbenzaldehyde (2.5g, 18.4 mmol) with trifluoromethanesulfonic anhydride (4.0 mL, 6.75g, 23.9 mmol) according to Method D to yield a brown oil which was used directly in the next step without purification. EXAMPLE 20 4′-Hydroxy-3-methoxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 4-formyl-3-methoxy-phenyl ester (11.0 mmol) with 4-tert-butyl-dimethylsilyoxyphenyl-boronic acid (3.50g, 13.86 mmol) according to Method B to yield 880 mg (35%, over two steps) of yellowish solid: mp 159-161° C.; 1H NMR (DMDO-d6): δ 4.01 (3H, s), 6.89 (2H, d, J=8.62 Hz), 7.31 (1H, d, J=8.16 Hz), 7.36 (1H, d, J=1.15 Hz), 7.66 (2H, d, J=8.63 Hz), 7.72 (1H, d, J=8.09 Hz), 9.80 (1H, s), 10.34 (1H, s); mp 159-161° C.; IR 1660 cm−; MS (ESI) m/z 227 (M−H)−, 229 (M+H)+. Anal. for C14H12O3: Calc'd: C: 73.67, H: 5.30 Found: C: 73.44, H: 4.99. EXAMPLE 21 4′-Hydroxy-2-methyl-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 4-formyl-2-methyl-phenyl ester (9.3 mmol) with 4-tert-butyl-dimethylsilyoxyphenylboronic acid (2.35g, 9.3 mmol) according to Method B to yield 1.12 mg (57%, over two steps) of yellowish solid: mp 94-96° C.; 1H NMR (DMSO-d6): ): δ 2.33 (3H, s), 6.86 (2H, d, J=8.55 Hz), 7.22 (2H, d, J=8.51 Hz), 7.39 (1H, d, J=7.81 Hz), 7.61 (1H, d, J=7.82 Hz), 7.81 (1H, s), 9.65 (1H, s), 10.00 (1H, s); IR 1670 cm−1; MS (ESI) m/z 211 (M−H)−, 213 (M+H)+. Anal. for C14H12O2: Calc'd: C: 79.23 H: 5.70 Found: C: 77.49 H: 5.67 EXAMPLE 22 3-Fluoro-4-methoxyphenylboronic acid The title compound was prepared by reacting 4-bromo-2-fluoroanisole (10g, 0.049 moles) with n-butyl lithium (23.4 mL of 2.5 M solution in hexane, 0.059 moles) followed by triisopropyl borate (45.2 mL, 36.9g, 0.196 moles) according to Method A to yield 7.1g (85.2%) of a white solid: MS (ESI) m/z 169 (M−H)−. EXAMPLE 23 3-Chloro-3′-fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 3-chloro-4-formyl-phenyl ester (2.8g, 9.62 mmol) with 3-fluoro-4-methoxyphenylboronic acid (1.8g, 10.6 mmol) according to Method B to yield 1.87g (74%, over two steps) of white solid: mp 116-118° C.; 1H NMR (DMSO-d6): δ 3.91 (3H, s), 7.30 (1H, t, J=8.79 Hz), 7.66-7.68 (1H, m), 7.79 (1H, dd, J=12.91 Hz, J=2.47 Hz), 7.85-7.87 (1H, m), 7.91 (1H, d, J=8.24 Hz), 7.96 (1H, d, J=1.65 Hz), 10.34 (1H, s); IR 1688 cm−1; MS (ESI) m/z 265/267 (M+H)+. Anal. for C14H10ClFO2: Calc'd: C: 63.53, H: 3.81 Found: C: 63.29, H: 3.63. EXAMPLE 24 3-Chloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting 3-chloro-3′-fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde (990 mg, 3.75 mmol) with boron tribromide (11.25 mL of 1 N solution in methylene chloride, 11.25 mmol) according to Method F to yield 940 mg (100%) of yellowish solid. The compound was used in the next step without purification. The analytical sample was obtained by HPLC purification: mp 206-208° C.; 1H NMR (DMSO-d6): δ 7.06 (1H, t, J=8.79 Hz), 7.51-7.53 (1H, m), 7.71 (1H, d, J=2.47 Hz, J=12.63 Hz), 7.81-7.83 (1H, m), 7.89 (1H, d, J=7.96 Hz), 7.91 (1H, d, J=1.66 Hz), 10.329(1H, s), 10.330 (1H, s); IR 1667 cm−1; MS (ESI) m/z 249/251 (M−H)−. Anal. for C13H8CIFO2: Calc'd: C: 62.29, H: 3.22 Found: C: 61.97, H: 3.21. EXAMPLE 25 3-Chloro-3′,5′-difluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde The title compound was prepared by reacting trifluoro-methanesulfonic acid 3-chloro-4-formyl-phenyl ester (1g, 3.5 mmol) with 3,5-difluoro-4-tert-butyldimethylsilyoxy-boronic acid (1.1g, 3.8 mmol) according to Method B to yield 0.56g (60%) of yellow solid: mp 233-235° C.; 1H NMR (DMSO-d,): δ 7.64 (2H, d, J=7.85 Hz), 7.85-7.91 (2H, m), 7.98 (1H, s), 10.33 (1H, s), 10.70 (1H, bs); IR 1665 cm−1; MS (ESI) m/z (267/269) (M−H)−. Anal. for C13H7CIF2O2: Calc'd: C: 58.12, H: 2.63 Found: C: 57.79, H: 2.72. EXAMPLES 26 and 27 Trifluoro-methanesulfonic acid 3-chloro-4-formyl-phenyl ester (3.78g, 13.12 mmol) was reacted with with 4-methoxy-2-methylphenylboronic acid (2.61g, 15.7 mmol) according to Method B to produce two compounds: 3-Chloro-4′-methoxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde 2.18g (64%) white solid :mp 77-79° C.; 1H NMR (DMSO-d6): δ 2.26 (3H, s), 3.79 (3H, s), 6.88 (1H, dd, J=8.41 Hz, J=2.66 Hz), 6.93 (1H, d, J=2.50 Hz), 7.23 (1H, J=8.40 Hz), 7.50 (1H, dd, J=7.93 Hz, J=1.32 Hz), 7.58 (1H, d, J=1.53 Hz), 7.91 (1H, d, J=7.57 Hz), 10.36 (1H, s); IR 1682 cm−1; MS (ESI) m/z 261/263 (M+H) +. Anal. for C15H13ClO2: Calc'd: C: 69.10, H: 5.03 Found: C: 69.13, H: 4.73. 4,4″-Dimethoxy-2,2″-dimethyl-1,1′:3′,1″-terphenyl-4′-carbaldehyde 0.56g (12%) colorless; 1H NMR (DMSO-d6): δ 2.10 (3H, s), 2.29 (3H, s), 3.78 (3H, s), 3.80 (3H, s), 6.85-6.88 (2H, m), 6.91 (1H, d, J=2.38 Hz), 6.95 (1H, d, J=2.38 Hz), 7.18 (1H, d, J=8.32 Hz), 7.24-7.25 (2H, m), 7.52 (1H, dd, J=7.74 Hz, J=1.78 Hz), 7.95 (1H, d, J=8.33 Hz), 9.68 (1H, s); IR 1679 cm−; MS (ESI) m/z 347 (M+H)+. Anal. for C23H22O3: Calc'd: C: 79.74, H: 6.40 Found: C: 79.25, H: 6.05. EXAMPLE 28 3-Chloro-4′-hydroxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde 3-Chloro-4′-methoxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde (1.0g, 3.84 mmol) and pyridinium HCl (6g) in a sealed tube was heated at 195° C. with stirring for 1 hr. The reaction mixture was cooled to room temperature and stirred with 2 N HCl solution and ethyl acetate. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (×2). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and evaporation of the solvent provided (1g) dark green solid. The product was used without any further purification. An analytical sample was obtained by HPLC purification giving a white solid; mp 125-127° C.; 1H NMR (DMSO-d6): δ 2.21 (3H, s), 6.68-6.72 (2H, m), 7.11 (1H, d, J=8.15 Hz), 7.47 (1H, d, J=7.89 Hz), 7.55 (1H, d, J=1.48 Hz), 7.89 (1H, d, J=7.98 Hz), 9.62 (1H, s), 10.2=35 (1H, s); MS (ESI) m/z 245/247 (M−H)−, 247/249 (M+H)+. Anal. for C14H11ClO2: Calc'd: C: 68.16, H: 4.49 Found: C: 67.63, H: 4.43. EXAMPLE 29 4′-Hydroxy-3-methyl[1,1′-biphenyl]-4-carbaldehyde oxime A mixture of 4′-hydroxy-3-methyl[1,1′-biphenyl]-4-carbaldehyde (310 mg, 1.46 mmol), hydroxylamine hydrochloride (203 mg, 2.92 mmol) and pyridine (236 ul, 2.92 mmol) in 15 mL absolute methanol was refluxed for 2.5 h. The solvent was removed under reduced pressure and the mixture was dissolved in ethyl acetate and water, extracted with ethyl acetate (×3), washed with brine, dried over sodium sulfate, and filtered. Evaporation of the solvent and purification by recrystallization (ethyl acetate, acetone and hexane) gave 177 mg (53%) of the title compound as a yellowish solid: mp 195-197° C.; 1H NMR (DMSO-d6): δ 2.43 (3H, s), 6.84 (2H, d, J=8.48 Hz), 7.42-7.45 (2H, m), 7.5 (2H, d, J=8.51 Hz), 7.66 (1H, d, J=8.00 Hz), 8.32 (1H, s), 9.60 (1H, s), 11.25 (1H, s); 13C NMR (DMSO-d6): δ 19.62, 115.60, 123.40, 126.60, 127.56, 127.99, 129.05, 130.03, 136.34, 140.43, 146.80, 157.24; MS (ESI) n/z 226 (M−H)−, 228 (M+H)+. Anal. for C14H13NO2: Calc'd: C: 73.99, H: 5.77, N: 6.16 Found: C: 73.81, H: 5.75, N: 6.04. EXAMPLE 30 4′-Hydroxy[1,1′-biphenyl]-4-carbaldehyde oxime The title compound was prepared by reacting 4′-hydroxy[1,1′-biphenyl]-4-carbaldehyde (1.03 mmol) with hydroxylamine hydrochloride (140 mg, 2 mmol) according to Method C to yield 193 mg (79%, over two steps) of yellowish solid: mp 207-210° C.; 1H NMR (DMSO-d6): δ 6.85 (2H, d, J=8.37 Hz), 7.53 (2H, d, J=8.39 Hz), 7.62 (4H, s), 8.15 (1H, s), 9.62 (1H, s), 11.21 (1H, s); MS (ESI) m/z 212 (M−H)−. Anal. for C13H11NO2: Calc'd: C: 73.23, H: 5.20, N: 6.57 Found: C: 72.78, H: 5.41, N: 6.38. EXAMPLE 31 3-Chloro-4′-hydroxy[1,1′-biphenyl]-4-carbaldehyde oxime Method E. Tetrabutylammonium fluoride (1.29 mL of 1.0 M solution in tetrahydrofuran, 1.29 mmol) was added into a solution of 4′-{[tert-butyl(dimethyl)silyl]oxy}-3-chloro[1,1′-biphenyl]-4-carbaldehyde oxime (1.17 mmol) in 10 mL tetrahydrofuran. The mixture was stirred at room temperature for 10 min then poured into ethyl acetate and water. The resulting layers were separated and the aqueous layer was extracted with ethyl acetate (3×). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and and the solvent removed under vacuum. Purified by silica chromatography (20%-30% ethyl acetate-hexane) provided 0.186 mg (64%) of the title compound as yellowish solid: mp 187-189° C.; 1H NMR (DMSO-d6): δ 6.86(2H, d, J=8.55 Hz), 7.56-7.63 (3H, m), 7.71 (1H, d, J=1.60 7.84 (1H, d, J=8.26 Hz), 8.36 (1H, s), 9.75 (1H, s), 11.66 (1H, s); MS (ESI) m/z (M−H)−, 248 (M+H)+. Anal. for C13H10ClNO2: Calc'd: C: 63.04, H: 4.07, N: 5.66 Found: C: 62.96, H: 4.10, N: 5.42. EXAMPLE 32 2-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 4′-{[tert-butyl(dimethyl)silyl]oxy}-2-fluoro-[1,1′-biphenyl]-4-carbaldehyde oxime (1.02 mmol) with tetrabutylammonium fluoride (1.12 mL of 1.0 M solution in tetrahydrofuran, 1.12 mmol) according to Method E to yield 198 mg (84%) of a white solid: mp 178-180° C.; 1H NMR (DMSO-d6): δ 6.84-6.89 (2H, m), 7.39-5.54 (5H, m), 8.17 (1H, s), 9.71 (1H, s), 11.43 (1H, s); MS (ESI) m/z 230 (M−H)−, 232 (M+H)+. Anal. for C13H10FNO2: Calc'd: C: 67.53, H: 4.36, N: 6.06 Found: C: 67.13, H: 4.11, N: 6.00. EXAMPLE 33 3-Fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (154 mg, 0.713 mmol) with hydroxylamine hydrochloride (99 mg, 1.43 mmol) according to Method C to yield 156 mg (95%) of yellowish solid: mp 181-183° C.; 1H NMR (DMSO-d6): δ 6.84-6.87 (2H, m), 7.48-7.53 (2H, m), 7.57-7.60 (2H, m), 7.76 (1H, t, J=8.14 Hz), 8.22 (1H, s), 9.74 (1H, s), 11.56 (1H, s); MS (ESI) m/z 230 (M−H)−, 232 (M+H)+. Anal. for C13H10FNO2: Calc'd: C: 67.53, H: 4.36, N: 6.06 Found: C: 68.10, H: 4.28, N: 6.01. EXAMPLE 34 2-Chloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 2′-chloro-4′-(dibromomethyl)-1,1′-biphenyl-4-ol (270 mg, 0.722 mmol) with hydroxylamine hydrochloride (185 mg, 2.66 mmol) according to Method C to yield 160 mg (90%) of white solid: mp 178-179° C.; 1H NMR (DMSO-d6): δ 6.85 (2H, d, J=8.54 Hz), 7.28 (2H, d, J=8.51 Hz), 7.39 (1H, d, J=7.98 Hz), 7.60 (1H, dd, J=7.65 Hz, J=1.42 Hz), 7.72 (1H, d, J=1.34 Hz), 8.18 (1H, s), 9.67 (1H, s), 11.45 (1H, s); MS (ESI) m/z 246/248 (M−H)−. Anal. for C13H10ClNO2: Calc'd: C: 63.04, H: 4.07, N: 5.66 Found: C: 63.07, H: 3.99, N: 5.67. EXAMPLE 35 4′-Hydroxy-3-methoxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 4′-hydroxy-3-methoxy-1,1′-biphenyl-4-carbaldehyde (225 mg, 0.986 mmol) with hydroxylamine hydrochloride (137 mg, 1.97 mmol) according to Method C to yield 210 mg (88%) of yellowish solid: mp 228-230° C.; 1H NMR (DMSO-d6): δ 3.91 (3H, s), 6.85 (2H, d, J=8.29 Hz), 7.18 (1H, d, J=8.08 Hz), 7.21 (1H, s), 7.56 (2H, d, J=8.59 Hz), 7.68 (1H, d, J=7.98 Hz), 8.28 (1H, s), 9.63 (1H, s), 11.19 (1H, s); MS (ESI) m/z 242 (M−H)−, 244 (M+H)+. Anal. for C14H13NO3: Calc'd: C: 69.12, H: 5.39, N: 5.76 Found: C: 68.87, H: 5.29, N: 5.64. EXAMPLE 36 4′-Hydroxy-2-methyl-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 4′-hydroxy-2-methyl-1,1′-biphenyl-4-carbaldehyde (350 mg, 1.65 mmol) with hydroxylamine hydrochloride (230 mg, 3.30 mmol) according to Method C to yield 360 mg (96%) of white solid: mp 169-171° C.; 1H NMR (DMSO-d6): δ 2.25 (3H, s), 6.82 (2H, d, J=8.52 Hz), 7.16 (2H, d, J=8.45 Hz), 7.18 (1H, d, J=7.84 Hz), 7.44 (1H, d, J=7.93 Hz), 7.47 (1H, s), 8.11 (1H, s), 9.52 (1H, s), 11.19 (1H, s); MS (ESI) m/z 226 (M−H)−, 228 (M+H)+. Anal. for C14H13NO2: Calc'd: C: 73.99, H: 5.77, N: 6.16 Found: C: 73.72, H: 5.63, N: 6.37. EXAMPLE 37 3-Chloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3-chloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (1.52 mmol) with hydroxylamine hydrochloride (233 mg, 3.34 mmol) according to Method C to yield 260 mg (66%) of yellowish solid: mp 198-200° C.; 1H NMR (DMSO-d6): δ 7.03 (1H, t, J=8.79 Hz), 7.41-7.43 (1H, m), 7.60 (1H, dd, J=12.91 Hz, J=2.20 Hz), 7.64-7.66 (1H, m), 7.77 (1H, d, J=1.92 Hz), 7.84 (1H, d, J=8.24 Hz), 8.36 (1H, s),10.16 (1H, bs), 11.68 (1H, bs); MS (ESI) m/z 264/266 (M−H)−, 266/268 (M+H)+. Anal. for C13H9ClFNO2: Calc'd: C: 58.77, H: 3.41, N: 5.27 Found: C: 58.67, H: 3.65, N: 4.99. EXAMPLE 38 3-Chloro-3′, 5′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3-chloro-3′,5′-difluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (200 mg, 0.746 mmol) with hydroxylamine hydrochloride (156 mg, 2.24 mmol) according to Method C to yield 100 mg (47%) of white solid: mp 216-219° C.; 1H NMR (DMSO-d6): δ 7.54 (2H, d, J=8.51 Hz), 7.70 (1H, d, J=7.97 Hz), 7.84-7.86 (2H, m), 8.37 (1H, s), 10.52 (1H, s), 11.74 (1H,s); MS (ESI) m/z 282/284 (M−H)−, 284/286 (M+H)+. Anal. for C13H8CIF2NO2: Calc'd: C: 55.05, H: 2.84, N: 4.94 Found: C: 54.96, H: 3.02, N: 4.75. EXAMPLE 39 3-Chloro-4′-hydroxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3-chloro-4′-hydroxy-2′-methyl-1,1′-biphenyl-4-carbaldehyde (500 mg, 2.03 mmol) with hydroxylamine hydrochloride (425 mg, 6.10 mmol) in anhydrous tetrahydrofuran (50 mL) and methanol (20 mL) according to Method C to yield 350 mg (57% over two steps) of white solid: mp 169-171° C.; 1H NMR (DMSO-d6): δ 2.19 (3H, s), 6.65-6.70 (2H, m), 7.06 (1H, d, J=8.14 Hz), 7.31 (1H, d, J=8.05 Hz), 7.41 (1H, d, J=1.40 Hz), 7.83 (1H, d, J=8.08 Hz), 8.38 (1H, s), 9.51 (1H, s), 11.69 (1H, s); MS (ESI) m/z 260/262 (M−H)−, 262/264 (M+H)+. Anal. calc'd for C14H12ClNO2: Calc'd: C: 64.25; H: 4.62; N: 5.35 Found: C: 63.87; H: 4.43; N: 5.31 EXAMPLE 40 (2,6-Dichloro-4-methoxy-phenyl)-methanol A mixture of 3,5 dichloroanisole (16.;39g, 92.59 mmol), HCl (250 mL of concentrated solution), and sulfuric acid (2.5 mL of concentrated solution) was stirred at 60° C. overnight. The mixture was cooled to room temperature and the organic layer was removed. The aqueous layer was extracted with dichloromethane (2×100 mL). The combined organic layers were washed with water and the solvent was removed by evaporation. To the remaining oil was added NaOH (180 mL of 1N solution) and dioxane (85 mL). The mixture was stirred at reflux for 3 hours and cooled to room temperature. The organic layer was removed and the aqueous layer was extracted with dichloromethane (3×100 mL). The combined organic layers were washed with water, washed with brine, dried over sodium sulfate, and filtered. The residue was purified on silica (90% hexanes-10% ethyl acetate) to yield 5.82g (30%) of the title compound as a white solid: mp 71-72° C.; 1H NMR (CDCl3): δ 1.88 (1H, s), 3.73 (3H, s), 4.81 (2H, s), 6.81 (2H, s); MS (EI) m/z 206/208/210 (M+−). Anal. for C8H8Cl2O2: Calc'd: C: 46.41 H:3.89 Found: C:46.38 H:3.69. EXAMPLE 41 2,6-Dichloro-4-methoxy-benzaldehyde A suspension of (2,6-dichloro-4-methoxy-phenyl)-methanol (5.69g, 27.49 mmol) and MnO2 (15g) in benzene (100 mL) was stirred at reflux, utilizing a Dean-Stark trap, overnight. The suspension was cooled to room temperature, filtered through Celite, and the solvent was removed by evaporation to yield 4.69g (83%) of crude white solid. An analytical sample was obtained by recrystallization from methanol to yield white needle crystals: mp 104-106° C.; 1H NMR (DMSO-d6): δ 3.90 (3H, s), 7.21 (2H, s), 10.29 (1H, s); MS (EI) m/z 204/206/218 (M+−). Anal. for C8H6Cl2O2: Calc'd: C:46.86 H:2. Found: C:46.67 H:2.89. EXAMPLE 42 2,6-Dichloro-4-hydroxy-benzaldehyde To a solution of 2,6-dichloro-4-methoxy-benzaldehyde (3.44g, 16.8 mmol) in dichloromethane (120 mL) at 0° C. was slowly added boron tribromide (42 mL of 1N in dichloromethane, 42 mmol). The solution was allowed to warm to room temperature while stirring overnight and was quenched with saturated sodium bicarbonate solution (250 mL). The resulting mixture was extracted with ethyl acetate (3×200 mL). The combined organic layers were washed with water, washed with brine, dried over sodium sulfate, and filtered. The solvent was removed by evaporation and the residue was purified on silica (70% hexanes-30% ethyl acetate) to yield 2.19g (68%) of a pink solid. Trituration with ethyl acetate-hexanes yielded an analytical sample of the title compound as a white solid: mp: 214-217° C.; 1H NMR (DMSO-d6): δ 6.95 (2H, s), 10.26 (1H, s), 11.44 (1H, s); MS (EI) m/z 189.8/191.8/193.8 (M+−). Anal. for C7H4Cl2O2: Calc'd: C:44.02 H:2.11 Found: C:44.08 H:2.07. EXAMPLE 43 3,5-Dichloro-4-formyl-phenyl trifluoromethanesulfonate The title compound was prepared by reacting 2,6-dichloro-4-hydroxy-benzaldehyde (2.35g, 12.3 mmol) with trifluoromethanesulfonic anhydride (4.51g, 16.0 mmol) according to method E to yield a 3.45g (87%) of a clear yellow oil. TLC analysis of this oil indicated that it appeared to decompose into the starting phenol upon standing. 1H NMR (DMSO-d6): δ 8.03 (2H, s), 10.31 (1H, s). EXAMPLE 44 3,5-Dichloro-4′hydroxy-biphenyl-4-carbaldehyde The title compound was prepared by reacting 3,5-dichloro-4-formyl-phenyl trifluoromethanesulfonate (0.73g, 2.26 mmol) with 4-tert-butyldimethylsilyloxyphenyl boronic acid (0.80g, 3.2 mmol) according to method C to yield 0.30g (50%) of a yellow solid: mp:178-180° C.; 1H NMR (DMSO-d6): δ 6.88 (2H, d, J=8.84 Hz), 7.72 (2H, d, J=8.71 Hz), 7.84 (2H, s), 9.95 (1H, s), 10.38 (1H, s); MS (EI) m/z 266.0/268.0/270.0 (M+). Anal. for C13H8Cl2O2.0.5 H2O: Calc'd: C:56.55 H:3.29 Found: C:56.36 H:2.90. EXAMPLE 45 2,3-Dichloro-4-methoxybenzaldehyde To a solution of 2,3-dichloroanisole (10.00g, 56.6 mmol) in anhydrous dichloromethane (45 ml) was added TiCl4 (10.5 ml, 96.1 mmol) quickly. α, α′-dichloromethyl methyl ether (5.1 ml, 56.6 mmol) was then added slowly and the inner temperature was maintained between 15° C. to 20° C. The mixture was stirred room temperature for 5 h, poured into crushed ice slowly, extracted with dichloromethane (3×), washed with saturated sodium bicarbonate until pH=7, then washed with brine. The organic layer was dried over anhydrous sodium sulfate, concentrated to give 11.34g (98%) of white solid. An analytical sample was afforded by reverse-phase preparative HPLC: mp 112-113° C.; 1H NMR (CDCl3): δ 4.01 (3H, s), 6.97 (1H, d, J=8.77 Hz), 7.90 (1H, d, J=8.82 Hz), 10.36 (1H, s); MS (ESI) m/z 205/207/209 (M+H)+. Anal. for C8H6Cl2O2: Calc'd: C:46.86 H:2.95; Found: C:46.92 H:2.70. EXAMPLE 46 2,3-Dichloro-4-hydroxybenzaldehyde The title compound was prepared by reacting 2,3-dichloro-4-methoxybenzaldehyde (10g, 49 mmol) with boron tribromide (147 ml of 1N solution in CH2Cl2, 147 mmol) according to method D to yield 11.3g dark grey solid which is mainly the designed product indicated by 1H-NMR. It was triturated with 30% CHCl3 in hexane to give 3.6g of grey solid as pure product. An analytical sample was afforded as white solid by reverse-phase preparative HPLC: mp 176-178° C.; 1H NMR (DMSO-d6): δ 7.10 (1H, d, J=8.68 Hz), 7.74 (1H, d, J=8.67 Hz), 10.16 (1H, s), 11.95 (1H, s); MS (ESI) m/z 189/191/193 (M−H)−, 193/191/195 (M+H)+. Anal. for C7H4Cl2O2 Calc'd: C: 44.02 H: 2.11 Found: C: 43.87 H: 1.67. EXAMPLE 47 Trifluoro-methanesulfonic acid 2,3-dichloro-4-formyl-phenyl ester The title compound was prepared by reacting 2,3-dichloro-4-hydroxybenzaldehyde (2.50g, 13.2 mmol) with trifluoromethanesulfonic anhydride (2.88 ml, 4.80g, 17.1 mmol) according to example 43 to yield 3.69g (82%) of a brown crystal which was used directly in the next step without purification. An analytical sample was afforded as white solid by silica chromatography (5% ethyl acetate-hexane): mp 44-45° C.; 1H NMR (DMSO-d6): δ 7.88 (1H, d, J=8.74 Hz), 8.02 (1H, d, J=8.81 Hz), 10.28 (1H, s); MS (EI) m/z 322/324/326 (M)+. Anal. for C8H3Cl2F3O4S: Calc'd: C: 29.74 H:0.94; Found: C: 30.19H:0.86. EXAMPLES 48-50 Trifluoro-methanesulfonic acid 2,3-dichloro-4-formyl-phenyl ester (1.39g, 4.33 mmol) was reacted with boronic acid 21 (1.20g, 4.76 mmol) according to method B to produce the following three compounds: 2,3-Dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (48). 310 mg (27%) of white solid: mp 172-174° C.; 1H NMR (DMSO-d6): δ 6.86-6.91 (2H, m), 7.32-7.35 (2H, m), 7.53 (1H, dd, J=7.94 Hz, J=0.45 Hz), 7.85 (1H, d, J=8.01 Hz), 9.85 (1H, s), 10.35 (1H, s); MS (ESI) m/z 265/267/269 (M−H)−. Anal. for C13H8C2O2: Calc'd: C:58.46 H:3.02; Found: C:57.75 H:2.82. 2-Chloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (49) 90 mg (9%) of off white solid: mp 114-116° C.; 1H NMR (DMSO-d6): δ 6.85-6.90 (2H, m), 7.32-7.36 (2H, m), 7.61(1H, d, J=7.87 Hz), 7.89 (1H, dd, J=1.55 Hz), 8.05 (1H, d, J=1.52 Hz), 9.79 (1H, s), 10.02 (1H, s); MS (ESI) m/z 231/233 (M−H)−, 233/235 (M+H)+. Anal. for C13H9Cl2O2: Calc'd: C:67.11 H:3.90 Found: C:67.44 H:3.87 2′-Dichloro-4,4″-dihydroxy-1,1′:3′,1″-terphenyl-4′-carbaldehyde (50) 130 mg (9%) of off white solid: mp 222-223° C.; 1H NMR (DMSO-d6): δ 6.85-6.88 (2H, m), 6.88-6.91 (2H, m), 7.17-7.20 (2H, m), 7.31-7.35 (2H, m), 7.52 (1H, dd, J=7.96 Hz, J=0.89 Hz), 7.84 (1H, d, J=8.07 Hz), 9.55 (1H, d, J=0.77 Hz), 9.73 (1H, s), 9.74 (1H, s); MS (ESI) m/z 323/325 (M−H)−, 325/327 (M+H)+. Anal. for C19H13ClO3: Calc'd: C:70.27 H:4.03 Found: C:69.80 H:3.88 EXAMPLE 51 2,3-Dichloro-3′-fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting trifluoro-methanesulfonic acid 2,3-dichloro-4-formyl-phenyl ester (1.90g, 5.90 mmol) with 21 (1.30g, 7.67 mmol) according to method B to yield 0.84g (47%) of white solid: mp 160-164° C.; 1H NMR (DMDO-d6): δ 3.90 (3H, m), 7.28-7.30 (2H, m), 7.41-7.43 (1H, m), 7.57 (1H, d, J=8.30 Hz), 7.87 (1H, d, J=7.81 Hz), 10.35 (1H, s); MS (EI) m/z 298/300/302 (M)+. Anal. for C14H9Cl2O2: Calc'd: C:56.21 H:3.03 Found: C:57.55 H:2.97. EXAMPLES 52 and 53 2,3-Dichloro-3′-fluoro-4′-methoxy-1,1′-biphenyl-4-carbaldehyde (0.72g, 2.42 mmol) was reacted with boron tribromide (7.25 ml of 1N solution in CH2Cl2, 7.25 mmol) according to method E to produce the following two compounds: 2′,3′-Dichloro-4′-(dibromomethyl)-3-fluoro-1,1′-biphenyl-4-ol (52) 130 mg (13%) of grey thick syrup: 1H NMR (DMSO-d6): δ 7.04 (1H, t, J=8.54 Hz), 7.11 (1H, dd, J=8.41 Hz, J=1.97 Hz), 7.32 (1H, dd, J=12.18 Hz , J=1.94 Hz), 7.51 (1H, d, J=8.27 Hz), 7.54 (1H, s), 7.95 (1H, d, J=8.23 Hz), 10.23 (1H, s); MS (ESI) m/z 425/427/429 (M−H)−. Anal. for C13H7Br2Cl2FO2: Calc'd: C:36.40 H: 1.65 Found: C:37.60 H: 1.69. 2,3-Dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (53) 140 mg (20%) of white solid: mp 170-171° C.; 1H NMR (DMSO-d6): δ 7.07 (1H, t, J=8.60 Hz), 7.15 (1H, dd, J=8.40 Hz, J=1.79 Hz), 7.35 (1H, dd, J=12.15 Hz, J=1.87 Hz), 7.56 (1H, d, J=7.97 Hz), 7.86 (1H, d, J=8.09 Hz ), 10.31 (1H, s), 10.35 (1H, s); MS (ESI) m/z 283/285/287 (M−H)−. Anal. for C13H7Cl2FO2: Calc'd:C:54.77 H:2.47 Found: C:54.93 H:2.18. EXAMPLE 54 3,5-Dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3,5-dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (170 mg, 0.637 mmol) with hydroxylamine hydrochloride (89 mg, 1.27 mmol) according to Method F to yield 160 mg (89%) of a white solid: mp 183-186° C.; 1H NMR (DMSO-d6): δ 6.86 (2H, d, J=8.79 Hz), 7.63 (2H, d, J=8.79 Hz), 7.76 (2H, s), 8.25 (1H, s), 9.81 (1H, s), 11.78 (1H, s); MS (ESI) m/z 280/282/284 (M−H)−, 282/284/286 (M+H)+. EXAMPLE 55 3,5-Dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 3,5-dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde (290 mg, mmol) with hydroxylamine hydrochloride (140 mg, 1.27 mmol) according to Method F to yield 260 mg (85%) of a white solid: mp 185-190° C.; 1H NMR (DMSO-d6): δ 7.03 (1H, t, J=8.86 Hz), 7.46-7.49 (1H, m), 7.68 (1H, dd, J=12.74 Hz, J=2.26 Hz), 7.82 (2H, s), 8.25 (1H, s), 10.24 (1H, s), 11.80 (1H, s); MS (ESI) m/z 298/300/302 (M−H)−, 300/302/304 (M+H)+. Anal. for C13H8Cl2FNO2.0.2 H2O: Calc'd: C:51.41 H:2.79 N:4.61 Found: C:51.70 H:2.75 N:4.21. EXAMPLE 56 2,3-Dichloro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime The title compound was prepared by reacting 48 (140 mg, 0.526 mmol) with hydroxylamine hydrochloride (110 mg, 1.58 mmol) according to method F to yield 148 mg (100%) of off white solid: mp 208-210° C.; 1H NMR (DMSO-d6): δ 6.84-6.87 (2H, m), 7.26-7.29 (2H, m), 7.36 (1H, d, J=7.94 Hz). 7.80 (1H, d, J=8.20 Hz), 8.41 (1H, s), 9.72 (1H, s), 11.83 (1H, s); MS (ESI) m/z 280/282/284 (M−H)−, 282/284/286 (M+H)+. Anal. for C13H9Cl2NO2: Calc'd: C:55.35 H:3.22 N:4.96 Found: C:55.78 H:3.59 N:4.44. EXAMPLE 57 52 (85 mg, 0.20 mmol) was reacted with hydroxylamine hydrochloride (376 mg, 5.39 mmol) and pyridine (0.43 ml, 5.34 mmol) for 8 days according to method C to produce the following two compounds: 2,3-Dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carbaldehyde oxime (57) 17.6 mg (30%) of white solid: mp 225-227° C.; 1H NMR (DMSO-d6): δ 7.04 (1H, t, J=8.54 Hz ), 7.10 (1H, dd, J=8.35 Hz , J=1.88 Hz ), 7.28 (1H, dd, J=Hz , J=2.01 Hz), 7.39 (1H, d, J=8.14 Hz), 7.81 (1H, d, J=8.15 Hz), 8.41 (1H, s), 10.18 (1H, s), 11.87 (1H, s); MS (ESI) m/z 298/300/302 (M−H)−, 300/302/304 (M+H)+. Anal. for C13H8Cl2FNO2.0.09 TFA: Calc'd: C:51.00 H:2.63 N:4.51 Found: C:50.97 H:2.37 N:4.33. Methyl 2,3-dichloro-3′-fluoro-4′-hydroxy-1,1′-biphenyl-4-carboxylate 16.9 mg (27%) of white solid: mp 152-154° C.; 1H NMR (DMSO-d6): δ 3.90 (3H, s), 7.05 (1H, t, J=8.54 Hz), 7.11 (1H, dd, J=8.41 H, J=1.55 Hz), 7.31 (1H, dd, J=12.16 Hz, J=1.68 Hz), 7.47 (1H, d, J=8.02 Hz), 7.76 (1H, d, J=8.64 Hz); MS (ESI) m/z 313/315/317 (M+H)+. Anal. for C14H9Cl2FO3: Calc'd: C:53.36 H:2.88 Found: C:51.94 H:2.54. EXAMPLE 58 Table 1. 4′-Hydroxy-Biphenyl-carbaldehyde Oxime Derivatives Ex. R1 R2 R3 R5 R6 R7 ERβ(nM) ERα(nM) 29 H Me H H H H 163 3193 30 H H H H H H 3840 >5000 31 H Cl H H H H 85 1540 32 H H F H H H 421 3450 33 H F H H H H 161 1720 34 H H Cl H H H 98 398 35 H OMe H H H H 1058 7990 36 H H Me H H H 585 2821 37 H Cl H H F H 54 1910 38 H Cl H H F F 268 >7000 39 H Cl H Me H H 27 174 54 Cl Cl H H H H 8 64 55 Cl Cl H H F H 9 270 56 H Cl Cl H H H 49 851 57 H Cl Cl H F H 81 1957 The results obtained in the standard pharmacologic test procedure demonstrate that the compounds of this invention are estrogenic compounds, some with strong preferential affinity for the ERβ receptor. The compounds of this invention range from having high preferential affinity for ERβ over ERα to almost equal affinity for both receptors. Thus, compounds of this invention will span a range of activity based, at least partially, on their receptor affinity selectivity profiles. Additionally, because each novel receptor ligand complex is unique and thus its interaction with various coregulatory proteins is unique, compounds of this invention will display different modulatory behavior depending on the cellular context they are in. For example, in some cell-types, it is possible for a compound to behave as an estrogen agonist while in other tissues, an antagonist. Compounds with such activity have sometimes been referred to as SERMs (Selective Estrogen Receptor Modulators). Unlike many estrogens, however, many of the SERMs do not cause increases in uterine wet weight. These compounds are antiestrogenic in the uterus and can completely antagonize the trophic effects of estrogen agonists in uterine tissue. These compounds, however, act as estrogen agonists in the bone, cardiovascular, and central nervous systems. Due to this tissue selective nature of these compounds, they are useful in treating or preventing in a mammal disease states or syndromes which are caused or associated with an estrogen deficiency (in certain tissues such as bone or cardiovascular) or an excess of estrogen (in the uterus or mammary glands). Even beyond such cell-specific modulation, compounds of this invention also have the potential to behave as agonists on one receptor type while behaving as antagonists on the other. For example, it has been demonstrated that compounds can be an antagonist on ERβ while being an agonist on ERα (Meyers, Marvin J.; Sun, Jun; Carlson, Kathryn E.; Katzenellenbogen, Benita S.; Katzenellenbogen, John A. J. Med. Chem. (1999), 42(13), 2456-2468). Such ERSAA (Estrogen Receptor Selective Agonist Antagonist) activity provides for pharmacologically distinct estrogenic activity within this series of compounds. Standard pharmacological test procedures are readily available to determine the activity profile of a given test compound. The following examples briefly summarize several representative test procedures. Standard pharmacological test procedures for SERMs are also provided in U.S. Pat. Nos. 4,418,068 and 5,998,402. EXAMPLE 59 Rat Uterotrophic/Antiuterotrophic Test Procedure The estrogenic and antiestrogenic properties of the compounds can be determined in an immature rat uterotrophic assay (4 day) that (as described previously by L. J. Black and R. L. Goode, Life Sciences, 26, 1453 (1980). Immature Sprague-Dawley rats (female, 18 days old) were tested in groups of six. The animals are treated by daily ip injection with 10 uG compound, 100 uG compound, (100 uG compound+1 uG 17β-estradiol) to check antiestrogenicity, and 1 uG 17β-estradiol, with 50% DMSO/50% saline as the injection vehicle. On day 4 the animals are sacrificed by CO2 asphyxiation and their uteri removed and stripped of excess lipid, any fluid removed and the wet weight determined. A small section of one horn is submitted for histology and the remainder used to isolate total RNA in order to evaluate complement component 3 gene expression. EXAMPLE 60 6-Week Ovariectomized Rat Test Procedure—Bone and Cardioprotection Female Sprague Dawley CD rats, ovx or sham ovx, are obtained 1 day after surgery from Taconic Farm (weight range 240-275g). They are housed 3 or 4 rats/cage in a room on a 12/12 (light/dark) schedule and provided with food (Purina 5K96C rat chow) and water ad libitum. Treatment for all studies begin 1 day after the animals arrival and dosed 7 days per week as indicated for 6 weeks. A group of age matched sham operated rats not receiving any treatment serve as an intact, estrogen replete control group for each study. All treatments are prepared in 1% tween 80 in normal saline at defined concentrations so that the treatment volume is 0.1 mL/100g body weight. 17β-estradiol is dissolved in corn oil (20 μg/mL) and delivered subcutaneously, 0.1 mL/rat. All dosages are adjusted at three week intervals according to group mean body weight measurements. Five weeks after the initiation of treatment and one week prior to the termination of the study, each rat is evaluated for bone mineral density (BMD). The total and trabecular density of the proximal tibia are evaluated in anesthetized rats using an XCT-960M (pQCT; Stratec Medizintechnik, Pforzheim, Germany). The measurements are performed as follows: Fifteen minutes prior to scanning, each rat is anesthetized with an intraperitoneal injection of 45 mg/kg ketamine, 8.5 mg/kg xylazine, and 1.5 mg/kg acepromazine. The right hind limb is passed through a polycarbonate tube with a diameter of 25 mm and taped to an acrylic frame with the ankle joint at a 900 angle and the knee joint at 180°. The polycarbonate tube is affixed to a sliding platform that maintains it perpendicular to the aperture of the pQCT. The platform is adjusted so that the distal end of the femur and the proximal end of the tibia would be in the scanning field. A two dimensional scout view is run for a length of 10 mm and a line resolution of 0.2 mm. After the scout view is displayed on the monitor, the proximal end of the tibia is located. The pQCT scan is initiated 3.4 mm distal from this point. The pQCT scan is 1 mm thick, has a voxel (three dimensional pixel) size of 0.140 mm, and consists of 145 projections through the slice. After the pQCT scan is completed, the image is displayed on the monitor. A region of interest including the tibia but excluding the fibula is outlined. The soft tissue is automatically removed using an iterative algorithm. The density of the remaining bone (total density) is reported in mg/cm3. The outer 55% of the bone is peeled away in a concentric spiral. The density of the remaining bone (Trabecular density) is reported in mg/cm3. One week after BMD evaluation the rats are euthanized by carbon dioxide suffocation and blood collected for cholesterol determination. The uteri are removed and the weights taken. Total cholesterol is determined using a Boehringer-Mannheim Hitachi 911 clinical analyzer using the Cholesterol/HP kit. Statitstics were compared using one-way analysis of variance with Dunnet's test. EXAMPLE 61 MCF-7/ERE Antiproliferative Test Procedure Stock solutions of test compounds (usually 0.1 M) are prepared in DMSO and then diluted 10 to 100-fold with DMSO to make working solutions of 1 or 10 mM. The DMSO stocks are stored at either 4° C. (0.1 M) or −20° C. (<0.1M). MCF-7 cells are passaged twice a week with growth medium [D-MEM/F-12 medium containing 10% (v/v) heat-inactivated fetal bovine serum, 1% (v/v) Penicillin-Streptomycin, and 2 mM glutaMax-1]. The cells are maintained in vented flasks at 37° C. inside a 5% CO2/95% humidified air incubator. One day prior to treatment, the cells are plated with growth medium at 25,000/well into 96 well plates and incubated at 37° C. overnight. The cells are infected for 2 hr at 37° C. with 50 μl/well of a 1:10 dilution of adenovirus 5-ERE-tk-luciferase in experimental medium [phenol red-free D-MEM/F-12 medium containing 10% (v/v) heat-inactived charcoal-stripped fetal bovine serum, 1% (v/v) Penicillin-Streptomycin, 2 mM glutaMax-1, 1 mM sodium pyruvate]. The wells are then washed once with 150 μλ of experimental medium. Finally, the cells are treated for 24 hr at 37° C. in replicates of 8 wells/treatment with 150 μλ/well of vehicle (<0.1% v/v DMSO) or compound that is diluted >1000-fold into experimental medium. Initial screening of test compounds is done at a single dose of 1 μM that is tested alone (agonist mode) or in combination with 0.1 nM 17β-estradiol (EC80; antagonist mode). Each 96 well plate also includes a vehicle control group (0.1% v/v DMSO) and an agonist control group (either 0.1 or 1 nM 17β-estradiol). Dose-response experiments are performed in either the agonist and/or antagonist modes on active compounds in log increases from 10−14 to 10−5 M. From these dose-response curves, EC50 and IC50 values, respectively, are generated. The final well in each treatment group contains 5 μl of 3×10−5 M ICI-182,780 (10−6 M final concentration) as an ER antagonist control. After treatment, the cells are lysed on a shaker for 15 min with 25 μl/well of 1× cell culture lysis reagent (Promega Corporation). The cell lysates (20 μl) are transferred to a 96 well luminometer plate, and luciferase activity is measured in a MicroLumat LB 96 P luminometer (EG & G Berthold) using 100 μl/well of luciferase substrate (Promega Corporation). Prior to the injection of substrate, a 1 second background measurement is made for each well. Following the injection of substrate, luciferase activity is measured for 10 seconds after a 1 second delay. The data are transferred from the luminometer to a Macintosh personal computer and analyzed using the JMP software (SAS Institute); this program subtracts the background reading from the luciferase measurement for each well and then determines the mean and standard deviation of each treatment. The luciferase data are transformed by logarithms, and the Huber M-estimator is used to down-weight the outlying transformed observations. The JMP software is used to analyze the transformed and weighted data for one-way ANOVA (Dunnett's test). The compound treatments are compared to the vehicle control results in the agonist mode, or the positive agonist control results (0.1 nM 15β-estradiol) in the antagonist mode. For the initial single dose experiment, if the compound treatment results are significantly different from the appropriate control (p<0.05), then the results are reported as the percent relative to the 15β-estradiol control [i.e., ((compound-vehicle control)/(17β-estradiol control-vehicle control))×100]. The JMP software is also used to determine the EC50 and/or IC50 values from the non-linear dose-response curves. EXAMPLE 62 Inhibition of LDL Oxidation—Antioxidant Activity Porcine aortas are obtained from an abattoir, washed, transported in chilled PBS, and aortic endothelial cells are harvested. To harvest the cells, the intercostal vessels of the aorta are tied off and one end of the aorta clamped. Fresh, sterile filtered, 0.2% collagenase (Sigma Type I) is placed in the vessel and the other end of the vessel then clamped to form a closed system. The aorta is incubated at 37° C. for 15-20 minutes, after which the collagenase solution is collected and centrifuged for 5 minutes at 2000×g. Each pellet is suspended in 7 mL of endothelial cell culture medium consisting of phenol red free DMEM/Ham's F12 media supplemented with charcoal stripped FBS (5%), NuSerum (5%), L-glutamine (4 mM), penicillin-streptomycin (1000 U/ml, 100 μg/ml) and gentimicin (75 μg/ml), seeded in 100 mm petri dish and incubated at 37° C. in 5%CO2. After 20 minutes, the cells are rinsed with PBS and fresh medium added, this was repeated again at 24 hours. The cells are confluent after approximately 1 week. The endothelial cells are routinely fed twice a week and, when confluent, trypsinized and seeded at a 1:7 ratio. Cell mediated oxidation of 12.5 μg/mL LDL is allowed to proceed in the presence of the compound to be evaluated (5 μM) for 4 hours at 37° C. Results are expressed as the percent inhibition of the oxidative process as measured by the TBARS (thiobarbituric acid reactive substances) method for analysis of free aldehydes (Yagi K., Biochem Med 15:212-216 (1976)). EXAMPLE 63 D12 Hypothalmic Cell Test Procedure D12 rat hypothalamic cells are subcloned from the RCF17 parental cell line and stored frozen. They are routinely grown in DMEM:F12 (1:1), glutaMAX-1 (2 mM), penicillin (100 U/ml)-streptomycin (100 mg/ml), plus 10% fetal bovine serum (FBS). The cells are plated in phenol red-free medium (DMEM:F12, glutaMAX, penicillin-streptomycin) containing 2-10% charcoal stripped FBS at a subconfluent density (1-4×10 6 cells/150 mm dish). The cells are refed 24 h later with medium containing 2% stripped serum. To test for agonist activity, cells are treated with 10 nM 17β-estradiol or various doses of test compound (1 mM or a range from 1 pM to 1 mM). To test for antagonist activity the cells are treated with 0.1 nM 17β-estradiol in the absence or presence of varying doses (100 pM to 1 mM) of test compound. Control dishes are also treated with DMSO as a negative control. Forty-eight hours after hormone addition, the cells are lysed and binding test procedure performed. For each binding test procedure 100-150 mg protein is incubated with 10 nM 3H-R5020+100-fold excess R5020 in a 150 ml volume. Triplicate reactions (three with R5020, three without R5020) are prepared in a 96 well plate. The protein extract is added first followed by 3H-R5020 or 3H-R5020+100× unlabeled R5020. The reaction is performed for 1-2 hr at room temperature . The reaction is stopped by the addition of 100 ml cold 5% charcoal (Norit SX-4), 0.5% dextran 69K (Pharmacia) in TE pH 7.4. After 5 min at room temperature, the bound and unbound ligand are separated by centrifugation (5 min, 1000 RCF, 4° C.). The supernatant solution (˜150 ml) is removed and transferred to a scintillation vial. Following the addition of scintillation fluid (Beckman Ready Protein+), the samples are counted for 1 min in a scintillation counter. EXAMPLE 64 Progesterone Receptor in the CNS Preoptic Area Sixty (60) day old female Sprague-Dawley rats are ovariectomized. The animals are housed in an animal care facility with a 12-h light, 12-h dark photoperiod and free access to tap water and rodent chow. Ovariectomized animals are randomly divided into groups that are injected with vehicle (50% DMSO, 40% PBS, 10% ethanol vehicle), 15β-estradiol (200 ng/kg) or the compound to be tested. Additional animals are injected with the test compound 1 hr prior to injection of 15β-estradiol to evaluate the antagonistic properties of this compound. Six hrs after s.c. injection, animals are euthanized with a lethal dose of CO2 and their brains collected and frozen. Tissue collected from animals is cut on a cryostat at −16° C. and collected on Silane-coated microscope slides. The section-mounted slides are then dried on a slide warmer maintained at 42° C. and stored in desiccated slide boxes at −80° C. Prior to processing, the desiccated slide boxes are slowly warmed to room temperature (−20° C. for 12-16 hrs; 4° C. for 2 hrs; room temperature for 1 hr) to eliminate condensation formation on slides and thus minimize tissue and RNA degradation. The dry slides are loaded into metal racks, postfixed in 4% paraformaldehyde (pH 9.0) for 5 min and processed as previously described. A plasmid containing a 815 bp fragment of the rat PR cDNA 9 (ligand binding domain) is linearized and used to generate a S35-UTP labeled probe that is complimentary to a portion of the rat PR mRNA. Processed section-mounted slides are hybridized with 20 μml of hybridization mix containing the riboprobe (4-6×10 6 DPM/slide) and 50% formamide and incubated overnight in a 55° C. humidified chamber. In the morning, the slides are placed in metal racks that are immersed in 2×SSC (0.15M NaCl, 0.015M sodium citrate; pH 7.0)/10 mM DTT. The racks are all transferred to a large container and washed in 2×SSC/10 mM DTT for 15 min at RT with gentle agitation. Slides are then washed in RNase buffer at 37° C. for 30 min, treated with RNase A (2 mg/ml) for 30 min at 37° C., and washed for 15 min in room temperature 1× SSC. Subsequently, the slides are washed (2×30 min) in 65° C. in 0.1×SSC to remove nonspecific label, rinsed in room temperature 0.1×SSC for 15 min and dehydrated with a graded series of alcohol: ammonium acetate (70%, 95%, and 100%). Air dried slides are opposed to x-ray film for 3 days and then photographically processed. The slides from all animals are hybridized, washed, exposed and photographically processed together to eliminate differences due to interassay variation in conditions. EXAMPLE 65 Rat Hot Flush—CNS Effects Ovariectomized-female, 60 day-old Sprague-Dawley rats are obtained following surgery. The surgeries are done a minimum of 8 days prior to the first treatment. The animals are housed individually under 12 h light/dark cycle and given standard rat chow and water ad libitum. Two control groups are included in every study. Doses are prepared based on mg/kg mean group body weight in either 10% DMSO in sesame oil (sc studies) or in 1.0% tween 80 in saline (po studies). Animals are administered test compounds at doses ranging from 0.01 to 10 mg/kg mean group body weight. Vehicle and ethinyl estradiol (EE) controls (0.1 mg/kg, sc or 0.3 mg/kg, po) control groups are included in each test. When the compounds are tested for their antagonist activity, EE is coadministered at 0.1 or 0.3 mg/kg for sc or po studies, respectively. The test compounds are administered up to the day tail skin temperature is measured. After the acclimation period of four days, the animals are treated once daily with the compound(s) of interest. There are 10 animals/treatment group. Administration of the compound is either by sc injection of 0.1 ml in the nape of the neck or po in a volume of 0.5 ml. On the 3rd day of treatment, a morphine pellet (75 mg morphine sulfate) is implanted subcutaneously. On the 5th day of treatment, one or two additional morphine pellets are implanted. On the eighth day, approximately half of the animals are injected with Ketamine (80 mg/kg, intramuscularly) and a thermocouple, connected with to a MacLab Data Acquisition System (API Insturments, Milford, Mass.) is taped on the tail approximately one inch from the root of the tail. This system allowed the continuous measurement of tail skin temperature. Baseline temperature is measured for 15 min, then naloxone (1.0 mg/kg) is given sc (0.2 ml) to block the effect of morphine and tail skin temperature is measured for one hour thereafter. On the ninth day, the remaining of the animals are set up and analyzed similarly. EXAMPLE 66 Vasomotor Function in Isolated Rat Aortic Rings Sprage-Dawley rats (240-260grams) are divided into 4groups: 1. Normal non-ovariectomized (intact) 2. Ovariectomized (ovex) vehicle treated 3. Ovariectomized 17β-estradiol treated (1 mg/kg/day) 4. Ovariectomized animals treated with test compound (i.e., 1 mg/kg/day) Animals are ovariectomized approximately 3 weeks prior to treatment. Each animal receives 1 mg/kg/day of either 17β-estradiol sulfate or test compound suspended in distilled, deionized water with 1% tween-80 by gastric gavage. Vehicle treated animals received an appropriate volume of the vehicle used in the drug treated groups. Animals are euthanized by CO2 inhalation and exsanguination. Their thoracic aortas are rapidly removed and placed in 37° C. physiological solution with the following composition (mM): NaCl (54.7), KCl (5.0), NaHCO3 (25.0), MgCl22H2O (2.5), D-glucose (11.8) and CaCl2 (0.2) gassed with CO2—O2, 95%/5% for a final pH of 7.4. The advantitia is removed from the outer surface and the vessel is cut into 2-3 mm wide rings. Rings are suspended in at 10 mL tissue bath with one end attached to the bottom of the bath and the other to a force transducer. A resting tension of 1gram is placed on the rings. Rings are equilibrated for 1 hour, signals are acquired and analyzed. After equilibration, the rings are exposed to increasing concentrations of phenylephrine (10−8 to 10−4 M) and the tension recorded. Baths are then rinsed 3 times with fresh buffer. After washout, 200 mM L-NAME is added to the tissue bath and equilibrated for 30 minutes. The phenylephrine concentration response curve is then repeated. EXAMPLE 67 Eight Arm Radial Arm Maze—Cognition Enhancement Male Sprague-Dawley, CD rats (Charles River, Kingston, N.Y.) weighing 200-250g on arrival are used. For one week, the rats are housed, six per cage, with standard laboratory chow and water available ad libitum. Housing is in a colony room maintained at 22° C. and had a 12 hour light/dark cycle with lights on at 6:00 AM. Following habituation to the facility, animals are individually housed and maintained at 85% of free-feeding weight. Once stable weights are attained, the rats are acclimated to the 8-arm radial maze. The structure of the maze is an adaptation from that of Peele and Baron (Pharmacology, Biochemistry, and Behavior, 29:143-150, 1988). The maze is elevated to a height of 75.5 cm and composed of a circular area surrounded by 8 arms radiating away from the center, equidistant from one another. Each arm is 58 cm long×13 cm high. A clear plexiglass cylinder is loared to enclose the animal in the center portion of the maze prior to the start of each session. Each arm of the maze is equipped with 3 sets of photocells interfaced to a data acquisition unit, which in turn is interfaced to a computer. The photocells are used to track the movement of the rat in the maze. Pellet feeders located above food cups at the end of each arm, dispensed two 45 mg chocolate pellets when the outer photocell of the arm is activated for the first time in a given session. The maze is located in a testing room with black and white geometric posters on each wall to serve as visual cues. During all training and testing procedures, white noise is audible (˜70 db). The training procedure consists of five phases, each with daily sessions lasting 5 or 10 minutes. A 10 second delay is imposed between the time the rat is placed in the center portion of the maze and when the cylinder is raised to begin the session. During Phase 1, food-restricted pairs of rats are placed on the maze for 10 minutes with 45 mg chocolate food pellets scattered throughout the 8 arms of the maze. During Phase II, each rat is placed individually on the maze for a 10 minute period, with pellets scattered from the middle photocell to the food cup of each arm. During Phase III, each rat is placed on the maze for a 10 minute period, with food pellets located only in and around the food cups in each arm. In Phase IV, each rat is allowed 10 minutes to collect two pellets from each arm. Re-entry into an arm is considered an error. Rats are trained daily in this manner until they achieved criterion performance with less than or equal to 2 total errors on three consecutive days of training. Total habituation and training time is approximately 3 weeks. Test compound is prepared in phosphate buffered saline and administered in a volume of 1 ml/kg. Scopolamine HBr (0.3 mg/kg s.c.) served as the impairing agent, producing an increase in error rate (loss of memory). Test compound is given intraperitoneally simultaneously with scopolamine, 30 minutes prior to the first maze exposure on any given test day. To assess the test compound, an 8×8 balanced latin square for repeated measures is designed, in order to achieve a high experimental efficiency with the least amount of animals. Eight experimental sessions, two per week, are conducted with the 8 treatments (vehicle, scopolamine, 3 doses of test compound in combination with scopolamine) randomized within each session. Each treatment followed every other treatment the same number of times. Therefore, the residual effect of every treatment could be estimated and removed from the direct treatment effect. Following ANOVA, multiple comparisons are performed using Dunnett's two-sided test on adjusted means. Animals that did not make 4 correct choices within 5 minutes during the first exposure, or that had not made a total of 8 choices by the end of the 2nd exposure, are considered to have “timed-out” for that session. Any animal that “timed-out” following administration of more than one dose of the test compound is excluded from the analysis. EXAMPLE 68 Neuroprotection Inhibition of Time-Dependent Death of Cells in Primary Cortical Neuron Cultures Primary cortical neurons were produced from rat brains that were 0-1 day old using a variation of methods described by Monyer et al. 1989, Brain Research 483:347-354. Dispersed brain tissue was grown in DMEM/10% PDHS (pregnant donor horse serum) for three days and then treated with cytosine arabinoside (ARC) for two days to remove contaminating glial cells. On day 5, the ARC media was removed and replaced with DMEM/10% PDHS. The neuronal cells were cultured for a further 4-7 days before use. Control primary neuronal cultures show progressive cell death between days 12 and 18 in culture. Twelve cultures were evaluated on days 12 and 16 for levels of the enzyme lactate dehydrogenase (LD) after adding test compound to 6 cultures maintained in DMEM and 10% PDHS on day 9 and maintaining the remaining cultures as controls. LD was assayed using a variation of the method by Wroblewski et al. 1955, Proc. Soc. Exp. Biol. Med. 90:210-213. LD is a cytosolic enzyme which is commonly used in both clinical and basic research to determine tissue viability. An increase in media LD is directly related to cell death. Neuroprotection Against Cytotoxicity Induced by Hypoglycemia C6glioma cells obtained from ATCC were plated in RPMI media with FBS at a concentration of 1×10<6>cells/ml in FALCON 25 cm2 tissue culture flasks. Four hours prior to the onset of hypoglycemia, the maintenance media was discarded, monolayers were washed twice in the appropriate media and then incubated for four hours at 37° C. in either serum free or serum free plus test compound. Kreb's Ringer Phosphate buffer was used to wash the monolayers twice before the addition of appropriate glucose treatment. RPMI medium contains 2 mg glucose/ml; flasks were divided into groups of 6 each receiving 100% glucose (2 mg/ml), 80% glucose (1.6 mg/ml), 60% glucose (1.2 mg/ml) or 0% glucose (buffer) or supplemented with test compound. All flasks were incubated for 20 hours and then evaluated for total, live, and dead cell number utilizing trypan blue. Neuroprotection Against Excitotoxic Amino Acids Five culture dishes containing SK-N-SH neuroblastoma cells were treated with test compound and 5 culture dishes were treated with RPMI media. Four hours later, all cell were treated with NMDA (500 mu M) for 5 minutes. Total live cells and dead cells were then determined. Neuroprotection Against Oxygen-Glucose Deprivation Analysis of pyknotic nuclei to measure apoptosis: Cortical neurons are prepared from E18 rat fetus and plated in 8-well chamber slides precoated with poly-D-lysine (10 ng/ml) and serum at a density of 100,000 cells/well. Cells are plated in high glucose DMEM containing 10% FCS and kept in the incubator at 37° C. with 10% CO2/90% air. On the next day, serum is removed by replacing culture media with high glucose DMEM containing B27 supplement and cells are kept in the incubator without further media change until the day of experiment. On day 6, slides are divided into two groups; control group and OGD group. Cells in control group receive DMEM with glucose and custom B27 (without antioxidants). Cells in OGD group receive no-glucose DMEM with custom B27, which has been degassed under vacuum for 15 min. Cells are flushed with 90% N2/10% CO2 for 10 min in an airtight chamber and incubated at 37° C. for 6 hrs. After 6 hrs, both control and OGD cells are subject to replacement of media containing either vehicle (DMSO) or test compound in glucose-containing DMEM with custom B27. Cells are returned to normoxic incubator at 37° C. After 24 hrs, cells are fixed in 4% PFA for 10 min at 4° C. and stained with Topro (Fluorescent nuclear binding dye). Apoptosis is assessed using Laser Scanning Cytometer by measuring pyknotic nuclei. Measurement of LDH release as an indication of cell death: Cortical neurons are prepared from E18 rat fetus and plated in 48-well culture plates precoated with poly-D-lysine (10 ng/ml) and serum at a density of 150,000 cells/well. Cells are plated in high glucose DMEM containing 10% FCS and kept in the incubator at 37° C. with 10% CO2/90% air. On the next day, serum is removed by replacing culture media with high glucose DDMM containing B27 supplement. On day 6, cells are divided into two groups; control group and OGD group. Cells in control group receive DMEM with glucose and custom B27 (without antioxidants). Cells in OGD group receive no-glucose DMEM with custom B27, which has been degassed under vacuum for 15 min. Cells are flushed with 90% N2/10% CO2 for 10 min in an airtight chamber and incubated at 37° C. for 6 hrs. After 6 hrs, both control and OGD cells are subject to replacement of media containing either vehicle (DMSO) or test compound in glucose-containing DMEM with custom B27. Cells are returned to normoxic incubator at 37° C. After 24 hrs, cell death is assessed by measuring cellular release of LDH (lactate dehydrogenase) into the culture medium. For LDH assay, an aliquot of 50 μl culture medium is transferred into the 96 well plate. After the addition of 140 μl 0.1M potassium phosphate buffer (pH 7.5) and 100 μl 0.2 mg/ml NADH, the plate is let sit in the dark at room temperature for 20 min. The reaction is initiated by the addition of 10 μl of sodium pyruvate. The plate is read immediately at 340 nM in a Thermomax plate reader (Molecular Devices). The absorbance, an index of NADH concentration, is recorded every 6 seconds for 5 minutes and the slope indicating the rate of NADH disappearance is used to calculate LDH activity. LDH Activity(U/ml)=(ΔA/min) (TCF)(20) (0.0833)/(0.78) where: 0.0833=proportionality constant 0.78=instrument light path length (cm) Example 69 HLA Rat Test Procedure—Crohn's Disease and Inflammatory Bowel Disorders Male HLA-B27 rats are obtained from Taconic and provided unrestricted access to a food (PMI Lab diet 5001) and water. At the start of the study, rats are 22-26 weeks old. Rats are dosed subcutaneously once per day for seven days with one of the formulations listed below. There are five rats in each group and the last dose is administered two hours before euthanasia. vehicle (50% DMSO/50% Dulbecco's PBS) 17α-ethinyl-17β-estradiol (10 μg/kg) test compound Stool quality is observed daily and graded according to the following scale: Diarrhea=3; soft stool=2; normal stool=1. At the end of the test procedure, serum is collected and stored at −70° C. A section of colon is prepared for histological analysis and an additional segment is analyzed for myeloperoxidase activity. The following method is used to measure myeloperoxidase activity. Colon tissue is harvested and flash frozen in liquid nitrogen. A representative sample of the entire colon is used to ensure consistency between samples. The tissue is stored at −80° C. until use. Next, the tissue is weighed (approximately 500 mg) and homogenized in 1:15 w/v of 5 mM H2KPO4 (pH6) washing buffer. The tissue is spun down at 20,000×g in a Sorvall RC 5B centrifuge for 45 minutes at 2-8° C. Supernatant is then discarded. Tissue is resuspended and homogenized in 2.5 ml (1:5 w/v) of 50 mM H2KPO4 with 10 mM EDTA and 0.5% Hex Ammonium Bromide to help solubilize the intracellular MPO. Tissue is frozen in liquid Nitrogen, thawed in a 37° C.-water bath and sonicated for 15 seconds to ensure membrane lysis. This procedure is repeated 3 times. Samples are then kept on ice for 20 minutes and centrifuged at 12,000×g for 15 minutes at 2-8° C. The supernatant is analyzed following these steps. The test mixture is prepared by adding 2.9 ml of 50 mM H2KPO4 with 0.167 O-Dianisidine/ml with 0.0005% H2O2 into a reaction tube. When hydrogen peroxide is degraded, O-Dianisidine is oxidized and absorbs at 460 nm in a concentration dependent manner. The mixture is heated to 25° C. One hundred (100) μL of the tissue supernatant is added to the reaction tube, incubated for one minute at 25° C., then 1 ml is transferred to a disposable plastic cuvette. OD is measured every 2 minutes reaction time at 460 nm against a blank containing 2.9 ml of the reaction mixture and 100 μl of the 0.5% ammonium bromide solution. Enzyme activity units are quantified by comparison of absorbence @ 460 to a standard curve prepared with purified human MPO 31.1 Units/Vial. The MPO is reconstituted and serially diluted using 50 mM H2KPO4 with 10 mM EDTA and 0.5% Hex Ammonium Bromide to four known concentrations. Sample absorbencies are compared against this curve to determine activity. Histological analysis is performed as follows. Colonic tissue is immersed in 10% neutral buffered formalin. Each specimen of colon is separated into four samples for evaluation. The formalin-fixed tissues are processed in a vacuum infiltration processor for paraffin embedding. The samples are sectioned at 5 μm and then stained with hematoxylin and eosin (H&E) for blinded histologic evaluations using a scale modified after Boughton-Smith. After the scores are completed the samples are unblinded, and data are tabulated and analyzed by ANOVA linear modeling with multiple mean comparisons. All patents, publications, and other documents cited herein are hereby incorporated by reference in their entirety. | <SOH> BACKGROUND OF THE INVENTION <EOH>The pleiotropic effects of estrogens in mammalian tissues have been well documented, and it is now appreciated that estrogens affect many organ systems [Mendelsohn and Karas, New England Journal of Medicine 340: 1801-1811 (1999), Epperson, et al., Psychosomatic Medicine 61: 676-697 (1999), Crandall, Journal of Womens Health & Gender Based Medicine 8: 1155-1166 (1999), Monk and Brodaty, Dementia & Geriatric Cognitive Disorders 11: 1-10 (2000), Hum and Macrae, Journal of Cerebral Blood Flow & Metabolism 20: 631-652 (2000), Calvin, Maturitas 34: 195-210 (2000), Finking, et al., Zeitschrift fur Kardiologie 89: 442-453 (2000), Brincat, Maturitas 35: 107-117 (2000), Al-Azzawi, Postgraduate Medical Journal 77: 292-304 (2001)]. Estrogens can exert effects on tissues in several ways. Probably, the most well characterized mechanism of action is their interaction with estrogen receptors leading to alterations in gene transcription. Estrogen receptors are ligand-activated transcription factors and belong to the nuclear hormone receptor superfamily. Other members of this family include the progesterone, androgen, glucocorticoid and mineralocorticoid receptors. Upon binding ligand, these receptors dimerize and can activate gene transcription either by directly binding to specific sequences on DNA (known as response elements) or by interacting with other transcription factors (such as AP1), which in turn bind directly to specific DNA sequences [Moggs and Orphanides, EMBO Reports 2: 775-781 (2001), Hall, et al., Journal of Biological Chemistry 276: 36869-36872 (2001), McDonnell, Principles Of Molecular Regulation. p351-361(2000)]. A class of “coregulatory” proteins can also interact with the ligand-bound receptor and further modulate its transcriptional activity [McKenna, et al., Endocrine Reviews 20: 321-344 (1999)]. It has also been shown that estrogen receptors can suppress NFκB-mediated transcription in both a ligand-dependent and independent manner [Quaedackers, et al., Endocrinology 142: 1156-1166 (2001), Bhat, et al., Journal of Steroid Biochemistry & Molecular Biology 67: 233-240 (1998), Pelzer, et al., Biochemical & Biophysical Research Communications 286: 1153-7 (2001)]. Estrogen receptors can also be activated by phosphorylation. This phosphorylation is mediated by growth factors such as EGF and causes changes in gene transcription in the absence of ligand [Moggs and Orphanides, EMBO Reports 2: 775-781 (2001), Hall, et al., Journal of Biological Chemistry 276: 36869-36872 (2001)]. A less well-characterized means by which estrogens can affect cells is through a so-called membrane receptor. The existence of such a receptor is controversial, but it has been well documented that estrogens can elicit very rapid non-genomic responses from cells. The molecular entity responsible for transducing these effects has not been definitively isolated, but there is evidence to suggest it is at least related to the nuclear forms of the estrogen receptors [Levin, Journal of Applied Physiology 91: 1860-1867 (2001), Levin, Trends in Endocrinology & Metabolism 10: 374-377 (1999)]. Two estrogen receptors have been discovered to date. The first estrogen receptor was cloned about 15 years ago and is now referred to as ERβ [Green, et al., Nature 320: 134-9 (1986)]. The second was found comparatively recently and is called ERβ [Kuiper, et al., Proceedings of the National Academy of Sciences of the United States of America 93: 5925-5930 (1996)]. Early work on ERβ focused on defining its affinity for a variety of ligands and, indeed, some differences with ERα were seen. The tissue distribution of ERα has been well mapped in the rodent and it is not coincident with ERα. Tissues such as the mouse and rat uterus express predominantly ERα, whereas the mouse and rat lung express predominantly ERβ [Couse, et al., Endocrinology 138: 4613-4621 (1997), Kuiper, et al., Endocrinology 138: 863-870 (1997)]. Even within the same organ, the distribution of ERα and ERβ can be compartmentalized. For example, in the mouse ovary, ERβ is highly expressed in the granulosa cells and ERα is restricted to the thecal and stromal cells [Sar and Welsch, Endocrinology 140: 963-971 (1999), Fitzpatrick, et al., Endocrinology 140: 2581-2591 (1999)]. However, there are examples where the receptors are coexpressed and there is evidence from in vitro studies that ERα and ERβ can form heterodimers [Cowley, et al., Journal of Biological Chemistry 272: 19858-19862 (1997)]. The most potent endogenous estrogen is 17β-estradiol. A large number of compounds have been described that either mimic or block the activity of 17β-estradiol. Compounds having roughly the same biological effects as 17β-estradiol are referred to as “estrogen receptor agonists”. Those which block the effects of 17β-estradiol, when given in combination with it, are called “estrogen receptor antagonists”. In reality, there is a continuum between estrogen receptor agonist and estrogen receptor antagonist activity and some compounds behave as estrogen receptor agonists in some tissues but estrogen receptor antagonists in others. These compounds with mixed activity are called selective estrogen receptor modulators (SERMS) and are therapeutically useful agents (e.g. EVISTA) [McDonnell, Journal of the Society for Gynecologic Investigation 7: S10-S15 (2000), Goldstein, et al., Human Reproduction Update 6: 212-224 (2000)]. The precise reason why the same compound can have cell-specific effects has not been elucidated, but the differences in receptor conformation and/or in the milieu of coregulatory proteins have been suggested. It has been known for some time that estrogen receptors adopt different conformations when binding ligands. However, the consequence and subtlety of these changes only recently has been revealed. The three dimensional structures of ERα and ERβ have been solved by co-crystallization with various ligands and clearly show the repositioning of helix 12 in the presence of an estrogen receptor antagonist, which sterically hinders the protein sequences required for receptor-coregulatory protein interaction [Pike, et al., Embo 18: 4608-4618 (1999), Shiau, et al., Cell 95: 927-937 (1998)]. In addition, the technique of phage display has been used to identify peptides that interact with estrogen receptors in the presence of different ligands [Paige, et al., Proceedings of the National Academy of Sciences of the United States of America 96: 3999-4004 (1999)]. For example, a peptide was identified that distinguished between ERα bound to the full estrogen receptor agonists 17β-estradiol and diethylstilbesterol. A different peptide was shown to distinguish between clomiphene bound to ERα and ERβ. These data indicate that each ligand potentially places the receptor in a unique and unpredictable conformation that is likely to have distinct biological activities. As mentioned above, estrogens affect a panoply of biological processes. In addition, where gender differences have been described (e.g. disease frequencies, responses to challenge, etc), it is possible that the explanation involves the difference in estrogen levels between males and females. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to a compound of the formula: where R 1 and R 2 , are each, independently, H, halogen, CN, phenyl, or lower alkyl; R 3 , R 4 , R 5 and R 6 , are each independently, H, OH, halogen, CN, phenyl, lower alkyl, or lower alkoxy; R 8 are each, independently, H, —C(O)R 9 , or lower alkyl; and R 9 is lower alkyl; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In one preferred embodiment, R 8 is H. In another aspect, the invention relates to a compound of the formula: In yet another aspect, the invention is directed to a compound of the formula: In a further aspect, the invention is drawn to a compound of the formula where R 1 is OH or lower alkoxy; and R 5 , R 6 , and R 7 are each, independently, H, OH, halogen, CN, phenyl, lower alkyl, lower alkoxy, said phenyl, lower alkyl, and lower alkoxy being optionally substituted; or a pharmaceutically acceptable salt thereof or a prodrug thereof. In another aspect, the invention is drawn to a pharmaceutical composition that comprises one or more of compound of the invention and a pharmaceutically acceptable carrier. In yet other aspects, the invention is directed to use of the compounds of the invention in the treatment or prevention of diseases such as inflammatory bowel diseases. detailed-description description="Detailed Description" end="lead"? | 20040429 | 20071009 | 20050127 | 94546.0 | 0 | VALENROD, YEVGENY | HYDROXY-BIPHENYL-CARBALDEHYDE OXIME DERIVATIVES AND THEIR USE AS ESTROGENIC AGENTS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,255 | ACCEPTED | Weight generation method for multi-antenna communication systems utilizing RF-based and baseband signal weighting and combining | A signal weighting and combining method implemented within a receiver having a plurality of receive antennas is disclosed herein. Each receive antenna is disposed to produce a received RF signal in response to a transmitted RF signal received through a channel. The method includes weighting the plurality of received RF signals produced by the antennas in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel, thereby forming a plurality of weighted RF signals. The method further includes combining ones of the plurality of weighted RF signals in order to form one or more combined RF signals. A similar splitting and weighting method capable of being implemented within a transmitter having a plurality of transmit antennas is also disclosed. | 1. In a receiver having a plurality of receive antennas disposed to produce a corresponding plurality of received RF signals, each of said plurality of received RF signals being generated in response to a transmitted RF signal received through a channel, a signal weighting and combining method comprising: weighting said plurality of received RF signals in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of said receiver averaged over said channel, thereby forming a plurality of weighted RF signals; and combining ones of said plurality of weighted RF signals in order to form one or more combined RF signals. 2. The method of claim 1 wherein said output signal-to-noise ratio is averaged in the time domain over a time response of said channel. 3. The method of claim 1 wherein said output signal-to-noise ratio is averaged in the frequency domain over a channel bandwidth of said channel. 4. The method of claim 3 wherein said channel bandwidth is equivalent to a bandwidth of said transmitted RF signal. 5. The method of claim 1 further including calculating said plurality of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 6. The method of claim 5 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 7. The method of claim 5 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 8. In a multi-antenna transmitter disposed to transmit an RF input signal through a plurality of transmit antennas so as to produce a corresponding plurality of RF output signals, each of said RF output signals being received by a receiver after propagating through a channel, an RF splitting and weighting method comprising: dividing said RF input signal in order to form a plurality of divided RF signals; and weighting said plurality of divided RF signals in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of said receiver averaged over said channel, thereby forming said plurality of RF output signals. 9. The method of claim 8 wherein said output signal-to-noise ratio is averaged in the time domain over a time response of said channel. 10. The method of claim 8 wherein said output signal-to-noise ratio is averaged in the frequency domain over a channel bandwidth of said channel. 11. The method of claim 10 wherein said channel bandwidth is equivalent to a bandwidth of said RF output signals. 12. The method of claim 8 further including calculating said plurality of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 13. The method of claim 12 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 14. The method of claim 12 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 15. The method of claim 1 wherein said transmitted RF signal includes one of: a code division multiple access signal, a single carrier signal, an orthogonal frequency division multiplexed signal and a UWB signal. 16. The method of claim 8 wherein said set of RF output signals include one of: a code division multiple access signal, a single carrier signal, an orthogonal frequency division multiplexed signal and a UWB signal. 17. In a communication system including a transmitter having a set of transmit antennas disposed to transmit a set of spatially-multiplexed RF output signals through a channel, and a receiver having a plurality of receive antennas disposed to generate a corresponding first plurality of spatially-multiplexed received RF signals in response to receipt of said spatially-multiplexed RF output signals, an RF processing method comprising: generating said set of spatially-multiplexed RF output signals by performing a splitting and weighting operation upon plural RF input signals, said splitting and weighting operation utilizing a first set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of said receiver averaged over said channel; and forming a second plurality of spatially-multiplexed received RF signals by performing a weighting and combining operation upon said first plurality of spatially-multiplexed received RF signals, said weighting and combining operation utilizing a second set of RF weighting values selected in accordance with said one or more output signal-to-noise ratios. 18. The method of claim 17 wherein said one or more output signal-to-noise ratios are averaged in the time domain over a time response of said channel. 19. The method of claim 17 wherein said one or more output signal-to-noise ratios are averaged in the frequency domain over a channel bandwidth of said channel. 20. The method of claim 17 further including calculating said first set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 21. The method of claim 17 further including calculating said second set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 22. The method of claim 20 or claim 21 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 23. The method of claim 20 or claim 21 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 24. The method of claim 17 further including performing a splitting and weighting operation upon plural baseband input signals utilizing a first set of baseband weighting values in order to form a first set of baseband signals wherein said plural RF input signals are generated based upon one or more of said first set of baseband signals. 25. The method of claim 17 further including: downconverting said second plurality of spatially-multiplexed received RF signals in order to form a first set of baseband signals, and performing a baseband weighting and combining operation upon said first set of baseband signals utilizing a first set of baseband weighting values. 26. The method of claim 1 further including: downconverting said one or more combined RF signals in order to form one or more baseband signals, and performing a baseband weighting and combining operation upon said one or more baseband signals utilizing a set of baseband weighting values. 27. The method of claim 8 further including performing a splitting and weighting operation upon an input baseband signal utilizing a set of baseband weighting values in order to form a first plurality of baseband signals wherein said RF input signal is generated based upon one or more of said first plurality of baseband signals. 28. The method of claim 26 or 27 where said set of baseband weighting values is computed jointly with said plurality of RF weighting values. 29. In a receiver having a plurality of receive antennas disposed to produce a corresponding plurality of spatially-multiplexed received RF signals in response to receipt through a channel of spatially-multiplexed transmitted RF signal energy, a signal weighting and combining method comprising: weighting each of said plurality of spatially-multiplexed received RF signals utilizing a corresponding set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of said receiver averaged over said channel, thereby forming plural spatially-multiplexed weighted RF signals; and combining ones of said plural spatially-multiplexed weighted RF signals in order to form one or more spatially-multiplexed combined RF signals. 30. The method of claim 29 wherein said one or more output signal-to-noise ratios are averaged in the time domain over a time response of said channel. 31. The method of claim 29 wherein said one or more output signal-to-noise ratios are averaged in the frequency domain over a channel bandwidth of said channel. 32. The method of claim 31 wherein said channel bandwidth is equivalent to a bandwidth of said spatially-multiplexed transmitted RF signal energy. 33. The method of claim 29 further including calculating said RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 34. The method of claim 33 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 35. The method of claim 33 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 36. In a multi-antenna transmitter disposed to transmit a spatially-multiplexed RF input signal through a plurality of transmit antennas so as to produce a corresponding plurality of spatially-multiplexed RF output signals, each of said spatially-multiplexed RF output signals being received by a receiver after propagating through a channel, an RF splitting and weighting method comprising: dividing said spatially-multiplexed RF input signal in order to form a plurality of spatially-multiplexed divided RF signals; weighting said plurality of spatially-multiplexed divided RF signals utilizing a set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of said receiver averaged over said channel in order to form plural spatially-multiplexed weighted. RF signals; and, combining ones of said plural spatially-multiplexed weighted RF signals, thereby forming said plurality of spatially-multiplexed RF output signals. 37. The method of claim 36 wherein said one or more output signal-to-noise ratios are averaged in the time domain over a time response of said channel. 38. The method of claim 36 wherein said one or more output signal-to-noise ratios are averaged in the frequency domain over a channel bandwidth of said channel. 39. The method of claim 38 wherein said channel bandwidth is equivalent to a bandwidth of said spatially-multiplexed RF output signals. 40. The method of claim 36 further including calculating said set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 41. The method of claim 40 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 42. The method of claim 40 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 43. In a communication system including a transmitter having a set of transmit antennas disposed to transmit a set of RF output signals through a channel, and a receiver having a plurality of receive antennas disposed to generate a corresponding plurality of received RF signals in response to receipt of said RF output signals, an RF processing method comprising: generating said set of RF output signals by performing a splitting and weighting operation upon an RF input signal, said splitting and weighting operation utilizing a first set of RF weighting values selected to maximize an output signal-to-noise ratio of said receiver averaged over said channel; and generating one or more received combined RF signals by performing a weighting and combining operation upon said plurality of received RF signals using a second set of RF weighting values, said second set of RF weighting values being selected to maximize said output signal-to-noise ratio. 44. The method of claim 43 wherein said output signal-to-noise ratio is averaged in the time domain over a time response of said channel. 45. The method of claim 43 wherein said output signal-to-noise ratio is averaged in the frequency domain over a channel bandwidth of said channel. 46. The method of claim 43 further including calculating said first set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 47. The method of claim 43 further including calculating said second set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 48. The method of claim 46 or claim 47 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 49. The method of claim 46 or claim 47 wherein said channel cross-conrelation matrix is averaged over a channel delay profile of said channel. 50. The method of claim 43 further including performing a splitting and weighting operation upon an input baseband signal utilizing a first set of baseband weighting values in order to form a first set of baseband signals wherein said RF input signal is generated based upon one or more of said first set of baseband signals. 51. The method of claim 43 further including: downconverting said one or more received combined RF signals in order to form a first set of baseband signals, and performing a baseband weighting and combining operation upon said first set of baseband signals utilizing a first set of baseband weighting values. 52. The method of claim 17 or 43 wherein said first set of RF weighting values and said second set of RF weighting values are computed jointly. 53. The method of claim 25 or 51 wherein said first and second set of RF weighting values and said first set of baseband weighting values are computed jointly. 54. The method of claim 24 or 50 wherein said first and second set of RF weighting values and said first set of baseband weighting values are computed jointly. 55. In a receiver having at least first and second receive antennas disposed to produce at least first and second received RF signals in response to a transmitted RF signal received through a channel, a signal weighting and combining method comprising: weighting said at least first and second received RF signals respectively in accordance with first and second RF weighting values selected to maximize an output signal-to-noise ratio of said receiver averaged over said channel, thereby forming first and second paired single-weight RF signals; and combining said first and second paired single-weight RF signals in order to form one or more combined RF signals. 56. The method of claim 55 wherein one of said first and second RF weighting values is normalized to unity. 57. The method of claim 55 further including calculating said first and second RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 58. The method of claim 57 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 59. The method of claim 57 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 60. In a multi-antenna transmitter disposed to transmit an RF input signal through first and second transmit antennas so as to produce first and second RF output signals, said first and second RF output signals being received by a receiver after propagating through a channel, an RF splitting and weighting method comprising: dividing said RF input signal in order to form first and second divided RF signals; and weighting said first and second divided RF signals respectively in accordance with first and second RF weighting values selected to maximize an output signal-to-noise ratio of said receiver averaged over said channel, thereby forming said first and second RF output signals. 61. The method of claim 60 wherein one of said first and second RF weighting values is normalized to unity. 62. The method of claim 60 further including calculating said first and second RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 63. The method of claim 62 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 64. The method of claim 62 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 65. In a receiver having a plurality of receive antennas disposed to produce a corresponding plurality of spatially-multiplexed received RF signals in response to receipt through a channel of spatially-multiplexed transmitted RF signal energy, a signal weighting and combining method comprising: weighting first and second of said plurality of spatially-multiplexed received RF signals respectively in accordance with first and second RF weighting values selected in accordance with one or more output signal-to-noise ratios of said receiver averaged over said channel, thereby forming first and second paired single-weight RF signals; weighting third and fourth of said plurality of spatially-multiplexed received RF signals respectively in accordance with third and fourth RF weighting values selected in accordance with said one or more output signal-to-noise ratios of said receiver averaged over said channel, thereby forming third and fourth paired single-weight RF signals; combining said first and second paired single-weight RF signals in order to form a first combined signal and combining said third and fourth paired single-weight RF signals in order to form a second combined signal; and processing said first combined signal using a first RF chain and processing said second combined signal using a second RF chain. 66. The method of claim 65 wherein one of said first and second RF weighting values is normalized to unity. 67. The method of claim 66 wherein one of said third and fourth RF weighting values is normalized to unity. 68. The method of claim 65 further including calculating said RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 69. The method of claim 66 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 70. The method of claim 66 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. 71. In a multi-antenna transmitter disposed to transmit a spatially-multiplexed RF input signal through a plurality of transmit antennas so as to produce a corresponding plurality of spatially-multiplexed RF output signals, each of said spatially-multiplexed RF output signals being received by a receiver after propagating through a channel, an RF splitting and weighting method comprising: dividing said spatially-multiplexed RF input signal in order to form a plurality of spatially-multiplexed divided RF signals; weighting first and second of said plurality of spatially-multiplexed divided RF signals using respective first and second RF weighting values in order to form first and second paired single-weight RF signals in communication with first and second of said plurality of transmit antennas, said first and second RF weighting values being selected in accordance with one or more output signal-to-noise ratios of said receiver averaged over said channel; and weighting third and fourth of said plurality of spatially-multiplexed divided RF signals using respective third and fourth RF weighting values in order to form third and fourth paired single-weight RF signals in communication with third and fourth of said plurality of transmit antennas, said third and fourth RF weighting values being selected in accordance with said one or more output signal-to-noise ratios of said receiver. 72. The method of claim 71 wherein one of said first and second RF weighting values is normalized to unity. 73. The method of claim 72 wherein one of said third and fourth RF weighting values is normalized to unity. 74. The method of claim 71 further including calculating said set of RF weighting values using the eigenvector corresponding to the largest eigenvalue of a channel cross-correlation matrix averaged over said channel. 75. The method of claim 74 wherein said channel cross-correlation matrix is averaged over said channel in the frequency domain. 76. The method of claim 74 wherein said channel cross-correlation matrix is averaged over a channel delay profile of said channel. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. §119(e) to U.S. provisional application Ser. No. 60/467,295, entitled WEIGHT GENERATION METHOD FOR RF SIGNAL COMBINING IN MULTI-ANTENNA COMMUNICATION SYSTEMS, filed May 1, 2003, which is herein incorporated by reference in its entirety. This application is also related to copending U.S. non-provisional application Ser. No. 10/801,930, entitled MULTI-ANTENNA COMMUNICATION SYSTEMS UTILIZING RF-BASED AND BASEBAND SIGNAL WEIGHTING AND COMBINING, filed Mar. 16, 2004. FIELD OF THE INVENTION The present invention relates to communication systems utilizing transmitters and receivers having multiple antenna elements. More particularly, the present invention relates to a weight generation method for facilitating RF-based signal weighting and combining, either exclusively or in combination with baseband signal weighting and combining, in connection with transmission and reception of signals using multi-antenna transmitters and receivers. BACKGROUND OF THE INVENTION Most current wireless communication systems are composed of nodes configured with a single transmit and receive antenna. However, for a wide range of wireless communication systems, it has been predicted that the performance, including capacity, may be substantially improved through the use of multiple transmit and/or multiple receive antennas. Such configurations form the basis of many so-called “smart” antenna techniques. Such techniques, coupled with space-time signal processing, can be utilized both to combat the deleterious effects of multipath fading of a desired incoming signal and to suppress interfering signals. In this way both the performance and capacity of digital wireless systems in existence or being deployed (e.g., CDMA-based systems, TDMA-based systems, WLAN systems, and OFDM-based systems such as IEEE 802.11a/g) may be improved. The impairments to the performance of wireless systems of the type described above may be at least partially ameliorated by using multi-element antenna systems designed to introduce a diversity gain and suppress interference within the signal reception process. This has been described, for example, in “The Impact of Antenna Diversity On the Capacity of Wireless Communication Systems”, by J. H. Winters et al, IEEE Transactions on Communications, vol. 42, No. 2/3/4, pages 1740-1751, February 1994. Such diversity gains improve system performance by mitigating multipath for more uniform coverage, increasing received signal-to-noise ratio (SNR) for greater range or reduced required transmit power, and providing more robustness against interference or permitting greater frequency reuse for higher capacity. Within communication systems incorporating multi-antenna receivers, it is known that a set of M receive antennas are capable of nulling up to M-1 interferers. Accordingly, N signals may be simultaneously transmitted in the same bandwidth using N transmit antennas, with the transmitted signal then being separated into N respective signals by way of a set of N antennas deployed at the receiver. Systems of this type are generally referred to as multiple-input-multiple-output (MIMO) systems, and have been studied extensively. See, for example, “Optimum combining for indoor radio systems with multiple users,” by J. H. Winters, IEEE Transactions on Communications, Vol. COM-35, No. 11, November 1987; “Capacity of Multi-Antenna Array Systems In Indoor Wireless Environment” by C. Chuah et al, Proceedings of Globecom '98 Sydney, Australia, IEEE 1998, pages 1894-1899 November 1998; and “Fading Correlation and Its Effect on the Capacity of Multi-Element Antenna Systems” by D. Shiu et al, IEEE Transactions on Communications vol. 48, No. 3, pages 502-513 March 2000. One aspect of the attractiveness of multi-element antenna arrangements, particularly MIMOs, resides in the significant system capacity enhancements that can be achieved using these configurations. Under the assumption of perfect estimates of the applicable channel at the receiver, in a MIMO system with N transmit and N receive antenna elements, the received signal decomposes to N “spatially-multiplexed” independent channels. This results in an N-fold capacity increase relative to single-antenna systems. For a fixed overall transmitted power, the capacity offered by MIMOs scales linearly with the number of antenna elements. Specifically, it has been shown that with N transmit and N receive antennas an N-fold increase in the data rate over a single antenna system can be achieved without any increase in the total bandwidth or total transmit power. See, e.g., “On Limits of Wireless Communications in a Fading Environment When Using Multiple Antennas”, by G. J. Foschini et al, Wireless Personal Communications, Kluwer Academic Publishers, vol. 6, No. 3, pages 311-335, March 1998. In experimental MIMO systems predicated upon N-fold spatial multiplexing, more than N antennas are often deployed at a given transmitter or receiver. This is because each additional antenna adds to the diversity gain and antenna gain and interference suppression applicable to all N spatially-multiplexed signals. See, e.g., “Simplified processing for high spectral efficiency wireless communication employing multi-element arrays”, by G. J. Foschini, et al, IEEE Journal on Selected Areas in Communications, Volume: 17 Issue: 11, November 1999, pages 1841-1852. Although increasing the number of transmit and/or receive antennas enhances various aspects of the performance of MIMO systems, the necessity of providing a separate RF chain for each transmit and receive antenna increases costs. Each RF chain is generally comprised a low noise amplifier, filter, downconverter, and analog to digital to converter (A/D), with the latter three devices typically being responsible for most of the cost of the RF chain. In certain existing single-antenna wireless receivers, the single required RF chain may account for in excess of 30% of the receiver's total cost. It is thus apparent that as the number of transmit and receive antennas increases, overall system cost and power consumption may unfortunately dramatically increase. It would therefore be desirable to provide a technique for utilizing relatively larger numbers of transmit/receive antennas without proportionately increasing system costs and power consumption. The above-referenced copending non-provisional application provides such a technique by describing a wireless communication system in which it is possible to use a smaller number of RF chains within a transmitter and/or receiver than the number of transmit/receiver antennas utilized. In the case of an exemplary receiver implementation, the signal provided by each of M (M>N) antennas is passed through a low noise amplifier and then split, weighted and combined in the RF domain with the signals from the other antennas of the receiver. This forms N RF output signals, which are then passed through N RF chains. The output signals produced by an A/D converter of each RF chain are then digitally processed to generate the N spatially-multiplexed output signals. By performing the requisite weighting and combining at RF using relatively inexpensive components, an N-fold spatially-multiplexed system having more than N receive antennas, but only N RF chains, can be realized at a cost similar to that of a system having N receive antennas. That is, receiver performance may be improved through use of additional antennas at relatively low cost. A similar technique can be used within exemplary transmitter implementations incorporating N RF chains and more than N transmit antennas. SUMMARY OF THE INVENTION The present invention is directed to a system and method for generating weight values for weighting elements included within the signal weighting and combining arrangements used in various multi-antenna transmitter and receiver structures. Specifically, the present invention may be applied to RF-based weighting and combining arrangements within such multi-antenna transmitter and receiver structures. The present invention may also find application when both RF-based and baseband weighting and combining arrangements are incorporated within the same multi-antenna transmitter or receiver structure. In one aspect the present invention relates to a signal weighting and combining method implemented within a receiver having a plurality of receive antennas. Each receive antenna is disposed to produce a received RF signal in response to a transmitted RF signal received through a channel. The method includes weighting the plurality of received RF signals produced by the antennas in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel, thereby forming a plurality of weighted RF signals. The method further includes combining ones of the plurality of weighted RF signals in order to form one or more combined RF signals. The present invention also pertains to an RF splitting and weighting method implemented within a multi-antenna transmitter disposed to transmit an RF input signal through a plurality of transmit antennas so as to produce a corresponding plurality of RF output signals. Each of the RF output signals are received by a receiver after propagating through a channel. The method includes dividing the RF input signal in order to form a plurality of divided RF signals. The plurality of divided RF signals are then weighted in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel, thereby forming the plurality of RF output signals. In another aspect the present invention relates to an RF processing method implemented within a communication system including a transmitter and a receiver. The transmitter is configured with a set of transmit antennas disposed to transmit a set of spatially-multiplexed RF output signals through a channel. The receiver includes a plurality of receive antennas disposed to generate a corresponding first plurality of spatially-multiplexed received RF signals in response to receipt of the spatially-multiplexed RF output signals. The RF processing method includes generating the set of spatially-multiplexed RF output signals by performing a splitting and weighting operation upon plural RF input signals. This splitting and weighting operation utilizes a first set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel. The method further includes forming a second plurality of spatially-multiplexed received RF signals by performing a weighting and combining operation upon the first plurality of spatially-multiplexed received RF signals. This weighting and combining operation utilizes a second set of RF weighting values selected in accordance with the one or more output signal-to-noise ratios. The present invention also relates to a signal weighting and combining method implemented within a receiver having a plurality of receive antennas disposed to produce a corresponding plurality of spatially-multiplexed received RF signals in response to spatially-multiplexed transmitted RF signal energy received over a channel. The method includes weighting each of the plurality of spatially-multiplexed received RF signals utilizing a corresponding set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel, thereby forming plural spatially-multiplexed weighted RF signals. Ones of the plural spatially-multiplexed weighted RF signals are then combined in order to form one or more spatially-multiplexed combined RF signals. In yet another aspect the present invention pertains to an RF splitting and weighting method implemented within a multi-antenna transmitter configured with a plurality of transmit antennas disposed to transmit a spatially-multiplexed RF input signal. The corresponding plurality of spatially-multiplexed RF output signals produced by the plurality of transmit antennas are received by a receiver after propagating through a channel. The method includes dividing the spatially-multiplexed RF input signal in order to form a plurality of spatially-multiplexed divided RF signals. The plurality of spatially-multiplexed divided RF signals are then weighted utilizing a set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel, in order to form plural spatially-multiplexed weighted RF signals. Ones of the plural spatially-multiplexed weighted RF signals are then combined so as to form the plurality of spatially-multiplexed RF output signals. The present invention further relates to an RF processing method capable of being implemented within a communication system including a transmitter and a receiver. The transmitter is configured with a set of transmit antennas disposed to transmit a set of RF output signals through a channel. The receiver includes a plurality of receive antennas disposed to generate a corresponding plurality of received RF signals in response to receipt of the RF output signals. The method includes generating the set of RF output signals by performing a splitting and weighting operation upon an RF input signal utilizing a first set of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel. The method further includes generating one or more received combined RF signals by performing a weighting and combining operation upon the plurality of received RF signals using a second set of RF weighting values selected to maximize the output signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature of the features of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 illustratively represents a conventional MIMO communication system. FIG. 2 shows a block diagram of a MIMO communication system having a transmitter and a receiver configured to effect RF-based weighting and combining. FIG. 3 depicts a receiver structure in a single-channel (SC) single-input-multiple-output (SIMO)-OFDM system in the case in which a baseband combining arrangement is used. FIG. 4 depicts the receiver structure in a SC-SIMO-OFDM system in the case in which an RF-based weighting and combining network is employed. FIG. 5 depicts the transmitter and receiver structure of a SC-MIMO-OFDM system in the case in which a baseband combining arrangement is employed. FIG. 6 illustratively represents the transmitter and receiver structure of a SC-MIMO-OFDM system utilizing an RF weighting and combining arrangement. FIG. 7 depicts the transmitter and receiver structure of a spatially-multiplexed (SM)-MIMO-OFDM system incorporating baseband combining arrangements. FIG. 8 illustratively represents a transmitter and a receiver structure of a SM-MIMO-OFDM system which each include both RF-based and baseband weighting and combining arrangements. FIG. 9 depicts a space-time direct sequence spread spectrum (DSSS) Rake receiver structure configured with multiple receive antennas and incorporating a baseband weighting and combining arrangement. FIG. 10 depicts a space-time direct sequence spread spectrum (DSSS) receiver structure configured with multiple receive antennas and containing an RF weighting and combining arrangement. FIG. 11 illustratively represents a transmitter and a receiver structure of a SM-MIMO-OFDM system which each include both a paired single-weight RF-based weighting and combining arrangement and a baseband weighting and combining arrangement. DETAILED DESCRIPTION OF THE INVENTION INTRODUCTION As is discussed below, the present invention is directed to a method of weighting and combining for use in multi-antenna systems, including N-fold spatially-multiplexed multi-antenna systems. In a particular embodiment of the invention, the weighting values for a given signal combining arrangement are set so as to maximize the output signal-to-noise ratio of the applicable multi-antenna system. The inventive weight generation method may be employed within several different types of multi-antenna communication systems including, for example, those described within the above-referenced copending non-provisional application. In particular embodiments the inventive technique may be applied to a multi-antenna receiver within a “single channel” system (i.e., a system lacking spatial multiplexing), to a multi-antenna transmitter in a single channel system, or to the transmitter or receiver of a MIMO system employing spatial multiplexing. The present invention contemplates that the weighting values or “weights” may generally be calculated from the eigenvector corresponding to the largest eigenvalue of the average channel cross-correlation matrix. The average is taken over a given channel domain, including the frequency bandwidth, the tap delay profile, the time impulse response, or the Rake fingers profile. When the teachings of the invention are applied to a multi-antenna receiver structure incorporating an RF-based weighting and combining arrangement, a single frequency-independent weight is typically defined such that the constituent set of weight coefficients are constant over a given channel domain. That is, the weight coefficients will generally be invariant over the frequency bandwidth, tap delay profile, time impulse response, and the Rake fingers profile of the channel. In this case the weights are chosen so as to maximize the output signal-to-noise ratio of the receiver as averaged over the applicable channel, which results in generation of a one-dimensional weight vector w that is common to the entire channel frequency band. A substantially similar approach may be used to generate the values for the weighting elements of RF-based weighting and combining arrangements configured for inclusion within multi-antenna transmitter structures. When a multi-antenna receiver structure is configured to include both RF-based and baseband weighting and combining arrangements, the weighting values for the baseband arrangement are typically computed in a manner consistent with the invention over both space and frequency. Each such computation is performed so as to maximize the output signal-to-noise ratio with respect to a given signal component (e.g., a signal tone or tap delay) with knowledge of the channel frequency response associated with such signal component. Once the baseband weights have been computed an M-dimensional weight vector Wk is formed, where M denotes the number of antenna elements of the multi-antenna receiver structure. During operation, signals incident upon the M antenna elements of the receiver structure are collected into an M-dimensional received signal vector. Each signal component inherent within each of the M received signals represented by the M-dimensional received signal vector is then multiplied by the M-dimensional weight vector wk. A substantially similar approach may be used to generate the values for the weighting elements of baseband weighting and combining arrangements incorporated within multi-antenna transmitter arrangements. The method of the present invention may also be used to facilitate weight generation in a multiple-input-multiple-output (MIMO) communication system having a transmitter operative to broadcast a number (N) of spatially-multiplexed signals (using at least N transmit antennas). In this case the receiver includes a number (M) of receive antennas that is greater than the number N of spatially-multiplexed signals. In order to effect RF-based weighting, the received signals are split, weighted and combined at RF using frequency-independent weights to form a set of N output signals, each of which is fed to a corresponding RF chain for processing at baseband. The inventive method thus permits the output signal-to-noise ratio to be maximized in multi-antenna systems with temporal/frequency domain processing using low cost RF weighting. In order to facilitate appreciation of the principles of the invention, an overview is provided of exemplary architectures for implementing weighting and combining within such multi-antenna systems. This overview is followed by a detailed description of the inventive method of weight generation, which may be applied within the context of such weighting and combining schemes. Overview of System Architecture The above-referenced non-provisional copending patent application discloses a method and apparatus for use in a wireless communication system which permits a smaller number of RF chains to be used within a transmitter and/or receiver than the number of transmit/receiver antennas utilized. In an exemplary implementation of the disclosed system within a spatially-multiplexed MIMO communication arrangement, a number (N) of RF chains are used in support of N-fold spatial multiplexing. In the disclosed system, the signal provided by each of M (M>N) antennas of a receiver is passed through a low noise amplifier and then split, weighted and combined in the RF domain with the signals from the other antennas of the receiver. This forms N RF output signals, which are then passed through N RF chains. In this exemplary implementation each RF chain includes a filter, downconverter, and A/D converter. The output signals produced by the A/D converter of each RF chain are then digitally processed to generate the N spatially-multiplexed output signals. By performing the requisite weighting and combining at RF using relatively inexpensive components, an N-fold spatially-multiplexed system having more than N receive antennas, but only N RF chains, can be realized at a cost similar to that of a system having N receive antennas. That is, receiver performance may be improved through use of additional antennas at relatively low cost. A similar technique can be used at a transmitter incorporating N RF chains and more than N transmit antennas. Specifically, in the exemplary embodiment the N RF chains are followed by RF splitters, weighting elements and combiners collectively operative to generate signals for each of the more than N transmit antennas. As at the receiver, by performing such weighting and combining in the RF domain using relatively inexpensive components, an N-fold spatially-multiplexed system having more than N transmit antennas, but only N RF chains, can be realized at a cost similar to that of a system having N transmit antennas. That is, transmitter performance may be improved through use of additional antennas at relatively low cost. The reduced-complexity antenna arrangement and receiver disclosed in the above-referenced non-provisional copending patent application is premised on performing, within the RF domain, some or all of the weighting and combining operations necessary for spatially-multiplexed communication. These operations may be performed using a plurality of RF chains within each transmitter/receiver that are fewer in number than the number of transmit/receive antennas deployed. Spatial Multiplexing As is known, spatial multiplexing (SM) provides a mode of signal transmission predicated upon the use of multiple antennas at both a transmitter and a receiver in such a way that the bit rate of a wireless radio link may be increased without correspondingly increasing power or bandwidth consumption. In the case in which N antennas are used at both a transmitter and a receiver, an input stream of information symbols provided to the transmitter is divided into N independent substreams. Spatial multiplexing contemplates that each of these substreams will occupy the same “channel” (e.g., time slot, frequency, or code/key sequence) of the applicable multiple-access protocol. Within the transmitter, each substream is separately applied to the N transmit antennas and propagated over an intervening multipath communication channel to a receiver. The composite multipath signals are then received by a receive array of N receive antennas deployed at the receiver. At the receiver, a “spatial signature” defined by the N phases and N amplitudes arising at the receive antenna array for a given substream is then estimated. Signal processing techniques are then applied in order to separate the received signals, which permits the original substreams to be recovered and synthesized into the original input symbol stream. The principles of spatially-multiplexed communication and exemplary system implementations are further described in, for example, “Optimum combining for indoor radio systems with multiple users”, by J. H. Winters, IEEE Transactions on Communications, Vol. COM-35, No. 11, November 1987, which is hereby incorporated by reference in its entirety. Conventional MIMO System The utility of the weight generation technique of the present invention may be more fully appreciated by first considering a conventional MIMO communication system, which is illustratively represented by FIG. 1. As shown, the MIMO system 100 of FIG. 1 includes a transmitter 110 depicted in FIG. 1A and a receiver 130 depicted in FIG. 1B. The transmitter 110 and receiver 130 include a set of T transmit RF chains and a set of R receive RF chains, respectively, which are configured to transmit and receive a group of N spatially-multiplexed signals. Within the system 100 it is assumed that either (i) T is greater than N and R is equal to N, (ii) T is equal to N and R is greater than N, or (iii) both T and R are greater than N. Referring to FIG. 1A, an input signal S to be transmitted, which typically consists of a stream of digital symbols, is demultiplexed by demultiplexer 102 into N independent substreams S1, 2 . . . , N. The substreams S1, 2 . . . , N are then sent to digital signal processor (DSP) 105, which generates a set of T output signals T1, 2 . . . , T. The T output signals T1, 2 . . . , T are typically generated from the N substreams S1, 2 . . . , N by weighting, i.e., multiplying by a complex number, each of the N substreams S1, 2 . . . , N by T different weighting coefficients to form NT substreams. These NT substreams are then combined in order to form the T output signals T1, 2 . . . , T. The T output signals T1, 2 . . . , T are then converted to T analog signals A1, 2 . . . , T using a set of T digital-to-analog (D/A) converters 108. Each of the T analog signals A1, 2 . . . , T is then upconverted to the applicable transmit carrier RF frequency within a mixer 112 by mixing with a signal provided by a local oscillator 114. The resulting set of T RF signals (i.e., RF1 , 2 . . . , T) are then amplified by respective amplifiers 116 and transmitted by respective antennas 118. Referring now to FIG. 1B, the RF signals transmitted by the transmitter 110 are received by a set of R receive antennas 131 deployed at the receiver 130. Each of the R signals received by an antenna 131 is amplified by a respective low noise amplifier 133 and passed through a filter 135. The resultant filtered signals are then each down-converted from RF to baseband using mixers 137, each of which is provided with a signal from local oscillator 138. Although the receiver of FIG. 1B is configured as a homodyne receiver, a heterodyne receiver characterized by an intermediate IF frequency could also be used. The respective R baseband signals produced by the mixers 137 are then converted to digital signals using a corresponding set of R analog-to-digital (AID) converters 140. The resulting R digital signals D1, 2 . . . , R are then weighted and combined using digital signal processor 142 to form N spatially-multiplexed output signals S′1, 2 . . . , N, which comprise estimates of the transmitted signals S1, 2 . . . , N. The N output signals S′1, 2 . . . , N are then multiplexed using a multiplexer 155 in order to generate an estimate 160 (S′) of the original input signal S. RF Weighting and Combining in Spatially-Multiplexed Communication Systems Turning now to FIG. 2, there is shown a block diagram of a MIMO communication system 200 having a transmitter 210 and receiver 250 configured in accordance with the principles of the above-referenced non-provisional patent application. In the implementation of FIG. 2 the transmitter 210 and receiver 250 effect N-fold spatial multiplexing using only N transmit/receive RF chains, even though more than N transmit/receive antennas are respectively deployed at the transmitter 210 and receiver 250. Specifically, the transmitter 210 includes a set of MT transmit antennas 240 and the receiver includes a set of MR receive antennas 260, it being assumed that either (i) MT is greater than N and MR is equal to N, (ii) MT is equal to N and MR is greater than N, or (iii) both MT and MR are greater than N. As shown in FIG. 2A, an input signal S to be transmitted is demultiplexed by demultiplexer 202 into N independent substreams SS1, 2 . . . , N. The substreams SS1, 2 . . . , N are then converted to N analog substreams AS1, 2 . . . , N using a corresponding set of D/A converters 206. Next, the N analog substreams AS1, 2 . . . , N are upconverted to the applicable transmit carrier RF frequency using a set of mixers 212 provided with the signal produced by a local oscillator 214. The resultant N RF signals (i.e., RF1, 2 . . . , N) are then each split MT ways by dividers 218 in order to form N·(MT) RF signals. These N·(MT) RF signals are each weighted using complex multipliers 226x,y, where x identifies a signal origination point at one of the N dividers 218 and y identifies a corresponding signal termination point at one of a set of MT combiners 230. The weighted RF signals are combined using the combiners 230, thereby yielding a set of MT output signals. A corresponding set of MT amplifiers 234 then amplify these MT output signals, with the amplified output signals then being transmitted using the MT antennas 240. The weighting values of the complex multipliers 226x,y may be generated so as to maximize the SNR of the output signal at the receiver. Referring to FIG. 2B, the MT RF signals transmitted by the transmitter 210 are received by the set of MR receive antennas 260 deployed at the receiver 250. Each of the MR received signals is amplified by a respective low noise amplifier 264 and then split N ways by one of a set of MR dividers 268. The resulting MR·(N) split signals are then each weighted by respective weighting circuits 272x,y, where x identifies a signal origination point at one of the MR dividers 268 and y identifies a corresponding signal termination point at one of a set of N combiners 276. These weighted signals are then combined using the N combiners 276 in order to form a set of N signals, which are passed through a corresponding set of N filters 280. The resulting N filtered signals are then down-converted to baseband using a set of N mixers 282, each of which is provided with a carrier signal produced by a local oscillator 284. Although the receiver 250 is realized as a homodyne receiver in the embodiment of FIG. 2B, it could also be implemented as a heterodyne receiver characterized by an intermediate IF frequency. The N baseband signals produced by the mixers 282 are then converted to digital signals via a corresponding set of N A/D converters 286. The N digital signals are then further processed using digital signal processor 288 to form the N spatially-multiplexed output signals SS′1, 2 . . . , N, which are the estimates of the N independent substreams SS1, 2 . . . , N. The N output signals SS′1, 2 . . . , N are then multiplexed via a multiplexer 292 in order to generate the output signal S′, which is an estimate of the input signal S. It is observed that the transmitter 210 and receiver 250 are capable of implementing, within the RF domain, the same spatial weighting or linear combining schemes as are conventionally implemented at baseband via the system 100 of FIG. 1. However, the DSP 288 within the inventive receiver 250 may still perform many other baseband signal processing operations potentially effected within the system 100, such as, for example, successive interference cancellation (see, e.g., “V-BLAST: An architecture for realizing very high data rates over the rich-scattering wireless channel”, Proceedings of URSI ISSSE, September 1998, pp. 295-300). Again, it is a feature of the disclosed system that only N transmit/receive RF chains need be employed, even when substantially more than N transmit/receive antennas are deployed. The inventive weight generation technique has applicability to, for example, (i) receivers using multiple antennas in what are referred to herein as single channel systems (i.e., system lacking spatial multiplexing), (ii) transmitters using multiple antennas in single channel systems, and (iii) systems in which a smaller number of RF chains are used at the transmitter and/or receiver than the number of transmit/receiver antennas in a MIMO system with spatial multiplexing. Although the weight generation techniques described herein may be utilized in the development of RF-based weighting and combining schemes implemented using low-cost RF components, the teachings of the present invention are equally applicable to implementations containing both RF-based and baseband weighting and combining arrangements. Accordingly, both RF-based and baseband weighting and combining schemes are described hereinafter. In this regard various implementations using the weighting techniques of the invention may include only RF weighting and combining schemes while others contemplate use of both RF and baseband weighting and combining schemes. In general, it is expected that weighting and combining consistent with the description herein may be more economically performed in the RF domain than at baseband, but that implementations including both RF-based and baseband combining arrangements may in certain cases offer superior performance results. Weight Generation Method for RF Weighting and Combining Based on Maximum Output Signal-To-Noise Ratio In accordance with one aspect of the present invention, the weighting values or “weights” used during the RF-based weighting and combining process described herein are selected so as to maximize the output signal-to-noise ratio of the applicable multi-antenna system. In general, the embodiments described below are configured such that the signals received by multiple antennas are weighted and combined at RF using a single frequency-independent weight for each antenna. In an exemplary embodiment a single frequency-independent weight is defined such that the weight coefficients are constant over a given channel domain, including the frequency bandwidth, the tap delay profile, the time impulse response, and the Rake fingers profile. The weight generation method of the invention enables calculation of the weights that maximize the output signal-to-noise ratio, as averaged over the channel. Furthermore, the method of the invention can also be used for weight generation at the transmitter when multiple antennas are used for transmission, with the transmitted signal split and weighted at RF using a single frequency-independent weight for each transmit antenna. As is described in further detail below, in one embodiment of the invention it is contemplated that weights be selected on the basis of the eigenvector corresponding to the largest eigenvalue of the average channel cross-correlation matrix. Again, the average is taken over a given channel domain, including the frequency bandwidth, the tap delay profile, the time impulse response, or the Rake fingers profile. In the case of a multi-antenna receiver in a single channel system where the OFDM modulation is employed, the weights are given by the eigenvector corresponding to the largest eigenvalue of the channel cross-correlation matrix averaged over the bandwidth of the signal. For the multi-antenna transmitter in a single channel system, the weights are given by the eigenvector corresponding to the largest eigenvalue of the cross-correlation matrix of the transpose conjugate of the channel averaged over the bandwidth of the signal. A slightly different approach is taken in cases involving a multi-antenna transmitter and a multi-antenna receiver in a single channel system. Specifically, in this case the weights for the transmitter are given by the eigenvector corresponding to the largest eigenvalue of the cross-correlation matrix of the product of (i) the transpose conjugate of the channel, and (ii) the receiver weights, where the product is averaged over the bandwidth of the signal. The weights for the receiver are given by the eigenvector corresponding to the largest eigenvalue of the cross-correlation matrix of the product of (i) the channel, and (ii) the transmitter weights, where the product is averaged over the bandwidth of the signal. This approach is also used to determine the weights for each signal at a transmitter and a receiver disposed within a MIMO system utilizing spatial multiplexing. In this case each such weight is a function of the channel propagation matrix and channel cross-correlation matrix corresponding to the signal of interest. In the case of a multi-antenna receiver in a single channel system utilizing direct sequence spread spectrum modulation, the weights are given by the eigenvector corresponding to the largest eigenvalue of the channel cross-correlation matrix averaged over the multiple tap delays or the Rake finger profile of the signal. Exemplary Scenarios The weight generation techniques of the present invention will be described hereinafter with reference to the exemplary scenarios illustratively represented by FIGS. 3-10. Specifically, the weight generation methods will be explained within the context of the following four scenarios: 1) a receiver using multiple antennas in a single channel SIMO system without spatial multiplexing, 2) a transmitter using multiple antennas in a single channel multiple-input single output (MISO) system without spatial multiplexing, 3) a transmitter using multiple antennas and a receiver using multiple antennas in a single channel MIMO system without spatial multiplexing, and 4) a system whereby a smaller number of RF chains are used at the transmitter and/or receiver than the number of transmitter/receiver antennas in a MIMO system with spatial multiplexing. Again, implementations involving exclusively RF-based weighting and combining arrangements, as well as with both RF-based and baseband arrangements, are described for each of the preceding cases. For illustrative purposes, many of the following examples are described with reference to systems utilizing OFDM modulation; however, the application of the invention to an exemplary system based upon a direct sequence spread spectrum (DS-SS) has also been described. The DS-SS receiver can be extended to include the spatial domain in the form of a space-time Rake receiver, which is operative to combine the multi-path taps in the temporal and spatial domains. This extension illustrates that the techniques described herein may be generalized to virtually any system employing temporal/frequency domain processing in a frequency-selective fading environment. FIG. 3 depicts a receiver structure 300 in a SC-SIMO system in the case in which a baseband combining arrangement 310 is used. Such a baseband combining arrangement may be incorporated within a SC-SIMO receiver structure which also contains an RF-based weighting and combining arrangement (see, e.g., FIG. 4 and the accompanying discussion). In this way a portion of the requisite weighting and combining is performed within the RF domain and the balance at baseband. The values of the baseband weighting elements 314 utilized within the receiver structure 300 are computed over both space and frequency in accordance with the invention. Exemplary implementations of the receiver structure of FIG. 3 adhere to the requirements of the 802.11a standard. That is, the transmitter (not shown) in communication with the receiver structure 300 uses OFDM modulation, where a stream of N consecutive quadrature amplitude modulation (QAM)-modulated data symbols, denoted by {so,s1, . . . , sNt−1} is modulated onto a set of Nt orthogonal subcarriers, see, e.g., J. Heiskala and J. Terry, OFDM Wireless LANs: A Theoretical and Practical Guide, Sams Publishing, December 2001. At the receiver 300, the signal received at each antenna element 320 is demodulated and down-converted from RF to baseband within RF chain 330. Then the cyclic prefix (CP), which was added at the transmitter to mitigate inter-symbol interference (ISI), is removed 340. The symbols, via a serial-to-parallel conversion 350, are then mapped to the subcarriers of a 64-point fast Fourier transform (FFT) 360. In a noise-limited scenario, the reconstructed data signal at the output of the FFT 360 of the ith receive antenna element 320 for the k-th tone is given by r i , k = H i ( ⅇ j 2 π N t k ) · s k + n i , k ( 1. ) where H is the channel frequency response of the L-tap channel impulse response denoted by {ho, h1, . . . , hL−1} and n is complex-valued additive white Gaussian noise (AWGN) with zero-mean and variance σ2. The relationship between frequency-domain H and time-domain h is: H ( ⅇ j 2 π N t k ) = ∑ l = 0 L - 1 h l ⅇ - j 2 π N t lk ( 2. ) The received signals from each antenna element 320 are collected in an M-dimensional vector, where M is the number of receive antenna elements. The received vector at tone k becomes: r _ k = H _ k · s k + n _ k where r _ k = [ r 1 , k , r 2 , k , … r M , k ] T , H k = [ H 1 ( ⅇ j 2 π N t k ) , H 2 ( ⅇ j 2 π N t k ) , … , H M ( ⅇ j 2 π N t k ) ] T , and n _ k = [ n 1 , k , n 2 , k , … n M , k ] T are all M - dimensional vectors . ( 3. ) The received vector is multiplied at each tone by an M-dimensional weight vector wk. The resulting output signal at tone k is given by yk=wkH·rk=wkHHk·sk+wkHnk (4.) The corresponding output signal-to-noise ratio (SNR) at tone k is SNR k = σ s 2 σ 2 w _ k H H _ k H _ k H w _ k w _ k H w _ k ( 5. ) where σs2=E[sksk*] and σ2=E[nknk*] are considered constant over the frequency domain. In a noise-limited scenario, the weight maximizing the output SNR at tone k is: wk=Hk/∥Hk∥2 (6.) The corresponding output signal yk becomes y k = s ^ k = s k + H _ k H H _ k 2 n _ k where yk corresponds to the estimate of the data symbol transmitted on tone k. The corresponding maximum output SNR is then SNR max , k = σ s 2 σ 2 H _ k 2 = σ s 2 σ 2 ∑ i = 1 M H i ( ⅇ j 2 π N t k ) 2 ( 7. ) This corresponds to the Maximum Ratio Combining (MRC) solution, where the output SNR at tone k is the sum of the individual SNR received at each antenna element at tone k. It is observed that the use of linear combining weights can lead to channel noise enhancement. Whenever a convolutional encoder is used at the transmitter, the information about the output noise on each individual sub-carrier should be incorporated into the Viterbi algorithm used at the receiver to provide significant performance improvement in fading channels, as shown in J. Heiskala and J. Terry, OFDM Wireless LANs: A Theoretical and Practical Guide, Sams Publishing, December 2001. Specifically, each “soft” bit entering the Viterbi decoder is weighted by a factor that is inversely proportional to the “enhanced” noise, such noise being a function of the sub-carrier channel on which the soft bit was transmitted. This adjustment allows the convolutional decoder to apply different weights to the information it receives from different tones. In this way the contribution of the information from tones experiencing poor channel conditions may be diminished by the weighting, while the contribution of information from tones experiencing favorable channel conditions may be augmented. Such variable weighting is expected to result in improved performance under frequency-varying conditions. The computation of the metric weighting used in Viterbi decoding proceeds as follows: The error signal at tone k is expressed as: e(k)=sk−wkH·rk=sk(1−wkH·Hk)−wkH·nk (8.) The mean squared error (MSE)—or post-combining noise variance—is thus ΣH=E|e(k)|=2=E|sk|2(1−wkH·Hk)(1−HkH·wk)+σ2wkHwk (9.) ΣH=σs2(1−HkH·wk−wkH·Hk+wkH·HkHkH·wk)+σ2wkHwk (10.) With wk=Hk/∥Hk∥2 from (6), then ΣH=σ2/∥Hk∥2. Since σ2 assumed to be constant over the frequency bandwidth, it can be ignored without affecting the performance of the Viterbi decoder. The metrics weighting (MW), denoted by MW(k), are then Σ′H=1/∥Hk∥2; MW(k)=1/Σ′H=∥Hk∥2 (11.) Each bit composing the symbol sk is weighted by MW(k). In summary, the present case contemplates that a different weight be computed at each tone based on the knowledge of the channel frequency response at the tone so as to maximize the output SNR at the tone. Unfortunately, straightforward implementation of this approach results in incurring the expense of dedicating one RF chain to each receive antenna. The next case considered is one in which the spatial received signals are combined in the RF domain such that only a single RF chain need be used. This approach advantageously minimizes costs within the applicable user equipment. As is discussed below, the weighting element values are derived consistent with the present invention using this approach by maximizing the average output signal-to-noise ratio over the signal bandwidth of interest. FIG. 4 depicts a receiver structure 400 in a SC-SIMO system in the case in which an RF-based weighting and combining network 410 is employed. In this case the weights 420 may be defined by a one-dimensional vector that is common to all tones. The computation of the weights 420 may be carried out in baseband, in which case the values of the weights 420 are fed back to the RF domain via an internal bus. As mentioned previously, in alternate implementations the RF-based weighting and combining arrangement within the receiver structure 400 may be complemented by a baseband weighting and combining arrangement. This results in a portion of the requisite weighting and combining being performed in the RF domain and the balance being effected at baseband. In configuration depicted in FIG. 4, the output of the FFT 460 at tone k is given by yk=wH·rk=wHHk·sk+wHnk (12.) where w is an M-dimensional vector which no longer depends on the subscript k. Based on (12), the output SNR at tone k is SNR k = σ s 2 σ 2 w _ H H _ k H _ k H w _ w _ H w _ ( 13. ) The sum of the individual SNRs across all tones is then SNR _ = ∑ k = 0 N t - 1 SNR k = σ s 2 σ 2 w _ H ∑ k = 0 N t - 1 H _ k H _ k H w _ w _ H w _ = σ s 2 σ 2 w _ H HH H w _ w _ H w _ ( 14. ) where H=[H0, . . . ,HNt−1]. In accordance with the invention, it is desired to find the weight vector w that maximizes the average output SNR (where the average is taken over the frequency tones). The problem reduces to arg max w _ w _ H HH H w _ w _ H w _ = λ max ( 15. ) Equation (15) is an eigenvalue problem (see S. Haykin, Adaptive Filter Theory, 3rd Ed., Prentice Hall, 1996), and w is the eigenvector corresponding to the largest eigenvalue λmax Of HHH. The solution is formulated as: w=eig(λmax,HHH) (16.) As a last step, the output signal yk is multiplied by a scalar such that the FFT output signal is expressed as a function of sk plus a noise residual component. Recall that the output of the FFT 460 at tone k is given by yk=wH·rk=wHHk·sk+wHnk (17.) Assume that wHHk=αk (18.) Then, the output signal yk is multiplied by a scalar uk such that uk*wHHk=1. In this case, uk is given by u k = α k α k 2 = w H H k w _ H H _ k H _ k H w _ ( 19. ) The scaled FFT output, denoted by zk, becomes zk=ŝk=uk*yk=sk+uk*wHnk (20.) Of course, the multiplication of yk by uk* does not affect the output SNR at tone k (since it multiplies both signal and noise components). The output SNR at tone k is given by (13). The computation of the metric weighting used in Viterbi decoding proceeds as follows: The error signal at tone k is expressed as: e(k)=sk−uk*wHrk=sk(1−uk*wHHk)−uk*wHnk (21.) The MSE—or post-combining noise variance—is thus ΣH=E|e(k)|2=σ2|uk|2wHw (22.) By using the expression of uk in (19), ΣH becomes Σ H = σ 2 w _ H w _ w _ H H _ k H _ k H w _ Since σ2 is assumed to be constant over the frequency bandwidth, and w is also constant over frequency, the product σ2wHw can be ignored without affecting the performance of the Viterbi decoder. The metrics weighting (MW) denoted by MW(k) are then Σ H ′ = 1 w _ H H _ k H _ k H w _ ; MW ( k ) = 1 / Σ H ′ = w _ H H _ k H _ k H w _ ( 23. ) A derivation similar to that described above with reference to the case of a single-antenna transmitter and a multi-antenna receiver may be used to obtain the weights applicable to the case of a multi-antenna transmitter and a single-antenna receiver. The weight solutions are set forth below. Weight Solution for Baseband Combining Arrangement Consistent with one embodiment of the invention, the weight solution at each tone is the eigenvector of the matrix HkHHk corresponding to the largest eigenvalue. wk=eig(λmax,HkHHk) (24.) where Hk is a row vector of size 1×nT (with nT as the number of transmit antenna elements) which represents the channel frequency response at tone k. Note that in order to keep the total transmit power P constant regardless of the number of transmit antennas, the norm of wk is constrained such that: wkHwk=|wk∥2=P/σs2 (25.) Weight Solution for RF Combining Arrangement The single frequency-independent weight solution that maximizes the output SNR in a SC-MISO system is given by the eigenvector of the matrix HHH corresponding to the largest eigenvalue. w=eig(λmax,HHH) (26.) where HH=[H0H, . . . ,HNt−1H] is a nT×Nt matrix. In order to keep the total transmit power P constant regardless of the number of transmit antennas, the norm of w is constrained such that: wHw=∥w∥2=P/σs2 (27.) An RF-based weighting and combining arrangement may be implemented exclusively in the RF domain in accordance with the frequency-independent weight solution of (26) and (27), or may be supplemented by a baseband weighting and combining arrangement defined by (24) and (25). Turning now to FIG. 5, there is shown a transmitter 510 and a receiver 520 of a single channel (SC) MIMO-OFDM system 500 in the case in which a baseband combining arrangement is employed. Specifically, the transmitter 510 includes a Tx baseband combining arrangement 512 and the receiver 520 includes an Rx baseband combining arrangement 522. Such a baseband combining arrangement may be incorporated within SC MIMO-OFDM transmitter and receiver structures which also contain RF-based weighting and combining arrangements (see, e.g., FIG. 6 and the accompanying discussion). In this way a portion of the requisite weighting and combining is performed within the RF domain and the balance at baseband. The transmitter 510 in FIG. 5 is composed of nT transmitting antenna elements 524, each of which conveys a weighted version of the same data sub-stream and uses the OFDM modulation. In other words, the stream of Nt consecutive QAM-modulated data symbols denoted by {s1,0,s1,1, . . . ,s1,Nt−1} is weighted at each transmit antenna element 524 and modulated onto a set of Nt orthogonal subcarriers. The transmit signal at tone k out of antenna j is txsj,k=vj,k·s1,k (28.) The transmit vector at tone k is txsk=vk·s1,k (29.) Therefore the transmit weights 528 can be viewed as a nT×Nt matrix, which preferably is a function of the propagation channel 530. This, however, requires the transmitter 510 to be aware of the characteristics of the channel 530. In order to keep the total transmit power P constant regardless of the number of transmit antenna elements 524, we assume that each of the digital symbols transmitted out of each transmitter antenna element 524 has a power P/nT, i.e., E[s1,ks1,k*]=P/nT=σs2 (30.) The total transmit power based on (29) is TXPW=E[s1,k*vkHvks1,k]=vkHvkE[s1,ks1,k*]=vkHvkP/nT (31.) Since we want to constrain the total transmit power to P such that TXPW=P (32.) then the constraint on the transmit weight is expressed as trace(vkvkH)=vkHvk=∥vk∥2=nT (33.) At the receiver 520, the signal received at each antenna element 540 is demodulated and down-converted from RF to baseband within RF chain 542. Then the cyclic prefix (CP), which was added 544 at the transmitter 510 to mitigate ISI, is removed 546. The symbols, via a serial-to-parallel conversion 550, are then mapped to the subcarriers of a 64-point FFT 554. In a noise-limited scenario, the reconstructed data signal at the output of the FFT 554 of the ith receive antenna element 540 for the kth tone is given by r i , k = s 1 , k ∑ j = 1 nT H i , j ( ⅇ j 2 π N t k ) · v j , k + n i , k ( 34. ) where Hi,j is the channel frequency response of the L-tap channel impulse response denoted by {hi,j,0,hi,j,1, . . . ,hi,j,L−1} corresponding to transmit and receive antenna elements j and i, respectively, and where n is complex-valued additive white Gaussian noise (AWGN) with zero-mean and variance σ2. The received signals are collected from each antenna element in an M-dimensional vector. The received vector at tone k becomes: rk=Hk·vk·s1,k+nk (35.) where H k = [ H 1 , 1 ( ⅇ j 2 π N t k ) , … , H 1 , n T ( ⅇ j 2 π N t k ) ⋮ H M , 1 ( ⅇ j 2 π N t k ) , … , H M , n T ( ⅇ j 2 π N t k ) ] is a M×nT matrix. The received vector is multiplied at each tone by the complex conjugate of a M×1 vector denoted by uk. The resulting output at tone k is given by yk=ŝ1,k=ukH·rk=ukHHk·vk·s1,k+ukHnk (36.) where yk is the estimate of s1,k. The singular value decomposition (SVD) is an attractive technique for solving the joint optimization of the transmit and receive weights 528, 560, as shown in J. B. Andersen, “Antenna arrays in mobile communications: gain, diversity, and channel capacity,” IEEE Ant. prop. Mag., 12-16, April 2000. An SVD expansion is a description of Hk, as given by Hk=UkSkVkH (37.) where Sk is a diagonal matrix of real, non-negative singular values, which are the square roots of the eigenvalues of Gk=HkHHk. Thus, ukHHk·vk={square root}{square root over (λmax,k)} (38.) The solution for the transmitter and receiver weights 528, 560 are given directly from the right and left singular vectors of Hk corresponding to the largest singular value. Note again that the transmit weights 528 are normalized according to (33) such that: ukHHk·vk={square root}{square root over (λmax,k)}·{square root}{square root over (nT)} (39.) The corresponding maximum output SNR is then SNR max , k = ( u _ k H H k · v _ k ) 2 E [ s 1 , k s 1 , k * ] σ 2 u _ k 2 = λ max , k n T P / n T σ 2 ( 40. ) SNR max , k = P λ max , k σ 2 ( 41. ) The computation of the metric weighting used in Viterbi decoding proceeds as follows: The error signal at tone k is expressed as: e(k)=s1,k−yk (42.) Assuming that uk may be normalized by {square root}{square root over (λmax,k)}·{square root}{square root over (nT)}, we rewrite (36) as y k = s 1 , k + u _ k H n T λ max , k n _ k ( 43. ) The MSE—or post-combining noise variance—is thus Σ H , k = E e ( k ) 2 = ( s 1 , k - y k ) · ( s 1 , k * - y k * ) ( 44. ) Σ H , k = σ 2 u _ k H u _ k n T λ max , k = σ 2 n T λ max , k ( 45. ) where the fact that singular vectors have norm unity has been used. Since σ2/nT is constant over the frequency bandwidth, it does not need to be taken into account in the metric. The metrics weighting (MW) are thus equal to MW(k)=λmax,k (46.) Each bit comprising the symbol yk is weighted by MW(k). In summary, the implementation of the case of FIG. 5 involves computation, based on the knowledge of the channel frequency response at each tone, of a different transmit and receive weight at each tone such that the output SNR is maximized at the tone. Next, a case is described with reference to FIG. 6 in which the spatial transmitted and received signals are combined in the RF domain. This permits use of an architecture containing only a single RF chain, which facilitates economical implementation of user equipment. FIG. 6 illustratively represents a transmitter 610 and a receiver 620 of a SC-MIMO-OFDM system 600 utilizing RF weighting and combining arrangements 612 and 614, respectively. The transmitter 610 of the system 600 is composed of nT transmit antenna elements 622, each of which conveys a weighted version of the same data sub-stream and uses OFDM modulation. However, in contrast to the case of FIG. 5, the combining weights 630 in the present exemplary case are implemented using RF-based elements capable of being defined by a single vector. This advantageously permits the number of RF transmit chains to be reduced to one. At the receiver 620, the combining weights 634 are also implemented at RF as a single vector, and the combined received signal is then passed through a single RF chain for demodulation. In alternate implementations the RF-based weighting and combining arrangements 612, 614 within the transmitter 610 and receiver 620 of FIG. 6 may be complemented by baseband weighting and combining arrangements. This results in a portion of the requisite weighting and combining being performed in the RF domain and the balance being effected at baseband. In the configuration of FIG. 6, the transmit signal at tone k out of antenna j is txsj,k=vj·s1,k (47.) The transmit vector at tone k is txsk=v·s1,k (48.) The transmit weights can thus be viewed as an nT×1 vector, which preferably is a function of the propagation channel 650. However, it is no longer a function of the channel frequency selectivity, as it is common to all tones. As the total transmit power is kept equal to P, it follows that: E[s1,ks1,k*]=P/nT=σs2 (49.) Then the constraint on the transmit weight 630 is expressed as trace(vvH)=vHv=∥v∥2=nT (50.) The signal propagates through the channel 650, and the received signals from each antenna element 660 of the receiver 620 are collected in an M-dimensional vector. The received vector at tone k becomes: rk=Hk·v·s1,k+nk (51.) The received vector is multiplied at RF by an M×1 receive weight vector denoted by u and physically realized by weighting elements 634. It is then passed through an RF chain 670 for demodulation and downconversion. The combined received signal at the output of the FFT 674 can thus be written as: yk=ŝ1,k=uHrk=uHHk·v·s1,k+uHnk (52.) where yk is the estimate of s1,k. The corresponding output SNR at tone k is: SNR k = ( u _ H H k · v _ ) 2 E [ s 1 , k s 1 , k * ] σ 2 u _ 2 = ( u _ H H k · v _ ) 2 P / n T σ 2 u _ 2 ( 53. ) The mean SNR over frequency is expressed as SNR _ = 1 N t ∑ k = 0 N t - 1 SNR k = P / n T N t σ 2 u _ 2 ∑ k = 0 N t - 1 ( u _ H H k · v _ ) 2 ( 54. ) or equivalently SNR _ = P / n T N t σ 2 u _ 2 ∑ k = 0 N t - 1 u _ H H k v _ v _ H H k H u _ ( 55. ) For a given vector v, u is designed such that the following sum is maximized: u _ H ( ∑ k = 0 N t - 1 H k v _ v _ H H k H ) u _ u _ H u _ ( 56. ) The solution for u that maximizes the quantity in (56) is the eigenvector of the matrix ( ∑ k = 0 N t - 1 H k v _ v _ H H k H ) corresponding to the largest eigenvalue. The solution is formulated as: u _ = eig ( λ max , ∑ k = 0 N - 1 H k v _ v _ H H k H ) ( 57. ) For a given vector u, v is designed such that the following sum is maximized: v _ H ( ∑ k = 0 N t - 1 H k H u _ u _ H H k ) v _ v _ H v _ ( 58. ) The solution for v that maximizes the quantity in (58) is the eigenvector of the matrix ( ∑ k = 0 N t - 1 H k H u _ u _ H H k ) corresponding to the largest eigenvalue. The solution may be formulated as: v _ = eig ( λ max , ∑ k = 0 N t - 1 H k H u _ u _ H H k ) ( 59. ) The solution for v depends on u and vice-versa, and thus becomes a joint problem capable of being solved by, for example, a numerical search. The computation of the metric weighting utilized in Viterbi decoding proceeds as follows: The error signal at tone k is expressed as: e(k)=s1,k−yk (60.) Assuming that u may be normalized at each tone by (uHHk·v)*, equation (52) is rewritten as y k = s 1 , k + u _ H u _ H H k · v _ n _ k ( 61. ) The MSE—or post-combining noise variance—is thus ∑ H , k = E e ( k ) 2 = ( s 1 , k - y k ) · ( s 1 , k * - y k * ) ( 62. ) ∑ H , k = σ 2 u _ H u _ ( u _ H H k · v _ ) 2 ( 63. ) Since σ2uHu is constant over the frequency bandwidth, it does not need to be taken into account in the metric. The metrics weighting (MW) are thus equal to MW(k)=(uHHk·v)2 (64.) Each bit comprising the symbol yk is weighted by MW(k). FIG. 7 depicts the transmitter 710 and receiver 720 of a spatially-multiplexed MIMO-OFDM system 700. As shown, the transmitter 710 and receiver respectively incorporate Tx and Rx baseband weighting and combining arrangements 712, 722. Consistent with the invention, these baseband weighting and combining arrangements may be incorporated within spatially-multiplexed MIMO-OFDM transmitter and receiver structures together with RF-based weighting and combining arrangements (see, e.g., FIG. 8 and the accompanying discussion). In this way a portion of the requisite weighting and combining is performed within the RF domain and the balance at baseband. The transmitter 710 is composed of nT transmitting antenna elements 714, each of which conveys a weighted combination of N distinct sub-streams (i.e. spatially-multiplexed signals) and uses OFDM modulation, where a stream of Nt consecutive QAM-modulated data symbols, denoted by {si,o,si,1, . . . , si,Nt−1}, i=1, . . . , N is modulated onto a set of Nt orthogonal subcarriers. In the system 700, the transmit signal at tone k out of the jth antenna element is txs j , k = ∑ i = 1 N v j , i , k · s i , k ( 65. ) The transmit vector at tone k is txs _ k = v k · s k = ∑ i = 1 N v _ i , k · s i , k ( 66. ) where Vk is the transmit weight matrix at tone k of size nT×N. The total transmit power based on (66) is TXPW = ∑ i = 1 N E [ s i , k * v _ i , k H v _ i , k s i , k ] = ∑ i = 1 N v _ i , k H v _ i , k E [ s i , k s i , k * ] = P / n T ∑ i = 1 N v _ i , k H v _ i , k ( 67. ) where E[si,ksi,k*]=P/nT=σs2, i=1, . . . , N (68.) Since it is desired to constrain the total transmit power to P such that TXPW=P (69.) then the constraint on the transmit weight 730 is expressed as trace ( V k H V k ) = ∑ i = 1 N v _ i , k H v _ i , k = n T ( 70. ) In order to simplify the example, a case is presented in which the number (nT) of transmit antenna elements 714 is equal to the number of spatially-multiplexed signals N. To simplify further, the weight matrix Vk at each tone is made equal to the identity matrix. Under these conditions the transmit vector at tone k simplifies to: txsk=sk (71.) It is to be understood that in other embodiments, nT can be made larger than N and/or the weight matrix Vk can be a matrix other than the identity matrix. For example, when Vk is dependent upon the channel, various “precoding” methods can assist in the computation of Vk given a specific criterion to optimize. At the receiver 720, the signal received at each antenna element 740 is demodulated and down-converted from RF to baseband within an RF chain 744. Then the cyclic prefix (CP), which was added (746) at the transmitter 710 to mitigate ISI, is removed (748). The symbols, via a serial-to-parallel conversion 754, are then mapped to the subcarriers of a 64-point FFT 758. In a noise-limited scenario with N=nT=2, the reconstructed data signal at the output of the FFT 758 of the ith receive antenna element 740 for the kth tone is given by r i , k = H i , 1 ( ⅇ j 2 π N t k ) · s 1 , k + H i , 2 ( ⅇ j 2 π N t k ) · s 2 , k + n i , k ( 72. ) The received signals from each antenna element 740 are collected in an M-dimensional vector. The received vector at tone k becomes: rk=Hk·sk+nk (73.) In this case the received vector is multiplied at each tone by the complex conjugate of an M×N matrix denoted by Wk. The resulting output at tone k is given by yk=WkH·rk=WkHHk·sk+WkHnk (74.) where yk=[y1,k, . . . , yN,k]T and sk=[s1,k, . . . , sN,k]T are an N-dimensional vectors. The matrix Wk can be expressed as Wk=[wk,1, . . . , wk,N]. The solution for Wk is given by the well-known minimum mean squared error (MMSE) solution (i.e. Wiener-Hopf solution), see, e.g., S. Haykin, Adaptive Filter Theory, 3rd Ed., Prentice Hall, 1996. The general solution is given by: Wk=(HkRs,kHkH+Rn,k−1HkRs,k (75.) where Rs,k=E[skskH] and Rn,k=E[nknkH]. Assuming that Rs=σs2/N and Rn=σ2/M, the solution simplifies to: W k = ( H k H k H + σ 2 σ s 2 I M ) - 1 H k or equivalently , ( 76. ) W k H = ( H k H H k + σ 2 σ s 2 I N ) - 1 H k H ( 77. ) The computation of the metric weighting used in Viterbi decoding proceeds as follows: The error signal j at tone k is expressed as: ej(k)=sj,k−wk,jH·rk (78.) The MSE—or post-combining noise variance—is thus ΣH,j,k=E|ej(k)|2=(sj,k−wk,jH·rk)·(sj,k*−rkHwk,j) (79.) ΣH,j,k=σs2(1−Hk,jH·wk,j−wk,jH·Hk,j+wk,jH·HkHkH·wk,j)+σ2wk,jHwk,j (80.) where H _ k , j = [ H 1 , j ( ⅇ j 2 π N t k ) ⋮ H M , j ( ⅇ j 2 π N t k ) ] The metrics weighting (MW) for signal j denoted by MWj(k) are equal to the inverse of ΣH,j,k. MWj(k)=1/ΣH,j,k (81.) Each bit comprising the symbol sj,k is weighted by MWj(k). In summary, in the case of FIG. 7 a different weight is computed at each tone based on knowledge of the channel frequency response at each tone, thereby maximizing the output SNR at each tone. FIG. 8 illustratively represents a communication system 800 including a transmitter 810 and a receiver 820, each of which includes both RF-based and baseband weighting and combining arrangements. Specifically, the transmitter 810 includes an RF weighting and combining arrangement 812 and a baseband weighting and combining arrangement 814, and the receiver 820 includes an RF weighting and combining arrangement 822 and a baseband weighting and combining arrangement 824. As shown, the transmitter 810 is composed of nT transmit antenna elements 830, each of which conveys a weighted combination of N distinct sub-streams (i.e. spatially-multiplexed signals) and uses OFDM modulation. Since at least a portion of the combining weights are realized as RF elements 832 within the transmitter 810, the number of transmit RF chains 840 is advantageously reduced to the number of spatially-multiplexed signals. This type of an arrangement is believed to permit cost-effective implementation. In the configuration of FIG. 8, the transmit signal at tone k from the jth antenna 830 is: txs j , k = ∑ i = 1 N v j , i · s i , k ′ where ( 82. ) s i , k ′ = ∑ l = 1 N v i , l , k ′ · s l , k ( 83. ) and where the terms v and v′ represent the RF and baseband weights, respectively. The transmit vector at tone k is txsk=V·Vk′·sk (84.) where V is the transmit RF weight matrix of size nT×N and is independent of the index k (as it is constant over the frequency tones), and where Vk′ is the transmit baseband weight matrix of size N×N and is dependent upon on the index k (as it is a function of frequency). In order to simplify the above example, we consider that Vk′ is equal to the identity matrix at each tone. It is to be understood that in other embodiments, Vk′ can be a matrix other than the identity matrix. For example, when Vk′ is dependent upon the channel, various “preceding” methods and the like can assist in the computation of Vk′ given a specific criterion to optimize. In this case, the transmit vector at tone k becomes txs _ k = V · s _ k = ∑ i = 1 N v _ i · s i , k To preserve the total transmit power, the constraint on the matrix V is written as: trace(VHV)=nT (85.) assuming that σs2=E[si,ksi,k*]=P/nT, i=1, . . . , N As mentioned above, the receiver 820 of FIG. 8 also utilizes distinct RF and baseband weighting and combining arrangements. Specifically, a first set of weights 850 for the RF-based arrangement 822 are implemented at RF and are common to all tones, while a second set of weights 854 are utilized within the baseband arrangement 824. Note that the step of computing the RF weights 850 may also be carried out in baseband, in which case the values of the weights 850 are fed back to the RF domain via an internal bus, creating a feedback delay. In this configuration, the output at the FFT 858 at tone k for the ith receive chain is given by r i , k = u _ i H H k · V · s _ k + u _ i H n _ k ( 86. ) r i , k = u _ i H H k · v _ i · s i , k + u _ i H ( ∑ j ≠ i N H k · v _ j · s j , k + n _ k ) ( 87. ) where ui=[u1,i, . . . ,uM,i]T. The received signals are collected from each receive chain in a N-dimensional vector. At tone k, this received signal vector rk becomes of dimension N×1 and may be expressed as: rk=UH(Hk·V·sk+nk)=UHHk·V·sk+UHnk (88.) where U=[u1, . . . , uN] is an M×N matrix containing the set of weights implemented at RF. Expression (88) can also be written as: rk=Hkn·sk+ηk (89.) where Hkn=UHHk·V and ηk=UHnk. The received signal model defined by equation (87) is composed of N signal, components and a noise component. Since the transmitter 810 broadcasts N spatially-multiplexed signals in parallel and each of these signals have to be detected individually by the receiver 820, each receiver chain considers one spatially-multiplexed signal as the desired signal component while the remaining N−1 spatially-multiplexed signals are considered as interferers. Stating that the ith receive chain considers the ith spatially-multiplexed signal as the desired signal component, equation (87) is rewritten as ri,k=uiHHk·vi·si,k+uiHμi,k (90.) where μ is considered as the noise plus interference signal. In this embodiment, the RF weight vectors ui and vi are designed to maximize the SNR (while the baseband weights 854 cancel the interference created by the multiple spatially-multiplexed signals). The SNR associated with the kth tone of the ith receive chain is expressed as SNR i , k = σ s 2 u _ i H H k · v _ i · v _ i H H k H u _ i σ 2 u _ i H u _ i ( 91. ) The aggregate SNR across all k tones of the ith receive chain is then SNR _ i = ∑ k = 0 N t - 1 SNR i , k = σ s 2 u _ i H ( ∑ k = 0 N t - 1 H k · v _ i · v _ i H H k H ) u _ i σ 2 u _ i H u _ i ( 92. ) which can be alternatively written as: SNR _ i = σ s 2 v _ i H ( ∑ k = 0 N t - 1 H k H · u _ i · u _ i H H k ) v _ i σ 2 u _ i H u _ i ( 93. ) Solving equations (92) and (93) for ui and vi for i=1, . . . , N, is a joint problem, which is capable of being solved by, for example, using a numerical search. The solution for ui which maximizes {overscore (SNR)}i for a given vi is given by the eigenvector of the matrix ( ∑ k = 0 N t - 1 H k · v _ i · v _ i H H k H ) corresponding to the largest eigenvalue. The solution may be formulated as: u _ i = eig ( λ max , ∑ k = 0 N t - 1 H k · v _ i · v _ i H H k H ) , i = 1 , … , N ( 94. ) Meanwhile, the solution for vi which maximizes {overscore (SNR)}i for a given ui is given by the eigenvector of the matrix ( ∑ k = 0 N t - 1 H k H · u _ i · u _ i H H k ) corresponding to the largest eigenvalue. This solution is expressed as: v _ i = eig ( λ max , ∑ k = 0 N t - 1 H k H · u _ i · u _ i H H k ) , i = 1 , … , N ( 95. ) The received vector is then multiplied at each tone by the complex conjugate of an N×N matrix denoted by Wk so as to enable detection of the transmitted signals. The resulting output signal at tone k is given by yk=WkH·rk=WkHHkn ·sk+WkHηk=WkHUH(Hk·V·sk+nk) (96.) It is observed that while the weights Wk are a function of the applicable frequency tone, the RF weights U and V are common to all tones (and therefore have no dependency on subscript k). Equation (96) may be solved for Wk using, for example, the well-known minimum mean squared error (MMSE) solution (i.e., the Wiener-Hopf solution). See, e.g., S. Haykin, Adaptive Filter Theory, 3rd Ed., Prentice Hall, 1996. The general solution is given by W k = ( H k ″ R s , k H k ″ H + R η , k ) - 1 H k ″ R s , k We have R s , k = σ s 2 I N and R η , k = E [ η _ k η _ k H ] = σ 2 U H U , thus ( 97. ) W k = ( H k ″ H k ″ H + σ 2 σ s 2 U H U ) - 1 H k ″ ( 98. ) Wk is derived directly from the knowledge of matrices Hk, U and V, where U and V are given by equations (94) and (95). The computation of the metric weighting for use in Viterbi decoding proceeds as follows: The error signal j at tone k is expressed as: ej(k)=sj,k−wk,jH·rk (99.) The MSE—or post-combining noise variance—is thus ΣH,j,k=E|ej(k)|2=(sj,k−wk,jH·rk)·(sj,k*−rkHwk,j) (100.) The metrics weighting (MW) for signal j denoted by MWj(k) are equal to the inverse of ΣH,j,k. MWj(k)=1/ΣH,j,k (101.) Each bit comprising the symbol sj,k is weighted by MWj(k). The above results were illustrated for the case of an OFDM modulation scheme, where frequency-selective fading is expressed in discrete form on each tone. However, for single carrier systems, the propagation channel can be expressed as a continuous function of frequency. In this case the above results can be generalized to an integral over the bandwidth of the signal, rather than the sum of the Nt discrete components over the bandwidth of the channel. Next, a case for a system based on direct sequence spread spectrum processing in the spatial and temporal domains is presented with reference to FIG. 9. This may be considered to extend the space-frequency domain cases described above to the context of space-temporal domain processing. Turning now to FIG. 9, there is depicted a Rake receiver structure 900 configured with receive antennas 910 and incorporating a baseband weighting and combining arrangement 930. Signals received by the antennas 910 are demodulated and down-converted within RF chains 920. Such a baseband weighting and combining arrangement 930 may be incorporated within Rake receiver structures which also contain RF-based weighting and combining arrangements (see, e.g., FIG. 10 and the accompanying discussion). In this way a portion of the requisite weighting and combining is performed within the RF domain and the balance at baseband. In the exemplary case of FIG. 9, the values of the baseband weighting elements 934 are computed over the dimensions of both space and time. At the receiver 900, multipath signals received by a set of N receive antennas 910 (i=1 to N) from over a set of M different delay paths (j=1 to M), may be represented as rij=Aijejφij·x·p+nij=Aijejφij·s+nij (102.) where Aij are the fading signal envelopes, φij are the corresponding phases, x is the transmitted signal (data symbols), p is the spreading sequence, and each nij is an additive white Gaussian noise (AWGN) component. A corresponding representation in the form of a space-time matrix is given below: R=H·s+N (103.) where H represents the N×M channel gain matrix H = [ h 11 h 12 ⋯ h 1 M h 21 h 22 ⋯ h 2 M ⋮ ⋮ ⋯ ⋮ h N 1 h N 1 ⋯ h NM ] = [ h _ 1 h _ 2 ⋯ h _ M ] ( 104. ) At each delay j the signal vector is rj=hj·s+nj (105.) In the case of baseband combining, vector rj is multiplied by the complex weight vector wjH yj=wjHrj=wjHhj·s+wjHnj (106.) The corresponding output SNR, assuming the Gaussian approximation for simplification (i.e., the interference and noise component is uncorrelated and of equal power across receive antennas) is SNR j = σ s 2 σ 2 w _ j H h _ j h _ j H w _ j w _ j H w _ j ( 107. ) where σs2=E[ss*] and σ2=E[nijnij*]. In a noise-limited scenario, the weight maximizing the output SNR in this case is wj=hj (108.) The corresponding SNR (before de-spreading) is SNR j = σ s 2 σ 2 h _ j H h _ j h _ j H h _ j h _ j H h _ j = σ s 2 σ 2 h _ j H h _ j = σ s 2 σ 2 ∑ i = 1 N h ij 2 ( 109. ) This corresponds to the Maximum Ratio Combining (MRC) solution, where the output SNR is the sum of individual SNRs at a particular delay over multiple antenna elements. Furthermore, each of the M fingers 950 of the Rake receiver separates and de-spreads the signals at a given delay as follows: uj=yj·p=hjHhj·s·p+hjHnj·p=G·hjHhj·x+hjHnj (110.) The corresponding SNR (after de-spreading) is SNR j = G σ x 2 σ 2 h _ j H h _ j = G σ x 2 σ 2 ∑ i = 1 N h ij 2 ( 111. ) where G is the processing gain and σx2=E[xx*]. Finally, the Rake combiner 960 optimally combines the output from fingers at different delays in accordance with the MRC metric: SNR z = ∑ j = 1 M SNR j = G σ x 2 σ 2 ∑ i = 1 N ∑ j = 1 M h ij 2 ( 112. ) FIG. 10 depicts a space-time direct sequence spread spectrum (DSSS) receiver 1000 which contains an RF weighting and combining arrangement 1010. As shown, the RF weighting and combining arrangement 1010 feeds an RF chain 1018, which effects demodulation and down-conversion to baseband. In the exemplary implementation the weighting values 1014 for the combining arrangement 1010 may be expressed as a one-dimensional vector that is applicable to all fingers 1020 of the Rake receiver 1000. The computation step may be carried out in baseband, in which case the values of the weights 1014 are fed back to the RF weighting and combining arrangement 1010 via an internal bus (not shown). In alternate implementations the RF-based weighting and combining arrangement 1010 within the receiver structure of FIG. 10 may be complemented by a baseband weighting and combining arrangement. This results in a portion of the requisite weighting and combining being performed in the RF domain and the balance being effected at baseband. As in the baseband-combining case of FIG. 9, at each delay j the signal vector can be represented as rj=hj·s+nj (113.) With smart-antenna combining, vector rj is multiplied by a complex weight vector vH so as to obtain yj=vHrj=vHhjs+vHnj (114.) The corresponding SNR at each delay j is SNR j = σ s 2 σ 2 v _ H h _ j h _ j H v _ v _ H v _ ( 115. ) where σs2=E[ss*] and σ2=E[nijnij*]. Next the sum of SNRs (where the sum is taken across all RAKE fingers) is maximized: SNR = ∑ j = 1 M SNR j = σ s 2 σ 2 v _ H HH H v _ v _ H v _ ( 116. ) Equation (116) is recognized as a standard eigenvalue decomposition problem; that is, v _ H HH H v _ v _ H v _ = λ max and ( 117. ) HH H v _ = λ max v _ ( 118. ) Accordingly, the SNR maximizing weight vector v is the eigenvector corresponding to the strongest eigenvalue of HHH. It is next demonstrated that the solution for v given in Equation (118) effectively maximizes the SNR at the output of the Rake combiner 1040. After de-spreading, the Rake combiner combines the signals at delays captured by Rake fingers 1020, using MRC metrics. Equation (114) may be rewritten to reflect the case of a single delay j yj=vHrj=vHhj·s+vHnj (119.) We substitute kj=vHhj and ηj=vHnj and obtain y j = κ j · s + η j and ( 120. ) SNR j = κ j s · s * κ j H η j η j H = σ s 2 σ η j 2 κ j 2 ( 121. ) Vectors y, κ and η are defined at multiple delays j=1 to M: y _ = [ y 1 y 2 ⋮ y M ] ; κ _ = [ κ 1 κ 2 ⋮ κ M ] ; η _ = [ η 1 η 2 ⋮ η M ] ( 122. ) The Rake receiver 1000 coherently combines elements of y in order to obtain z=ξHy=ξHκ·s+ξHη (123.) The weights are ξ=κ, so that z = κ _ H κ _ · s + κ _ H η _ = ∑ j = 1 M κ j 2 · s + κ _ H η _ ( 124. ) The corresponding SNR of output z is SNR z = ∑ j = 1 M κ j 2 · s ( ∑ j = 1 M κ j 2 · s ) H κ _ H η _ η _ H κ _ = σ s 2 σ η 2 ( ∑ j = 1 M κ j 2 ) 2 ∑ j = 1 M κ j 2 = σ s 2 σ η 2 ∑ j = 1 M κ j 2 ( 125. ) assuming σηj=σηfor all j. By comparing Equation (121) to Equation (125), it is concluded that: SNR z = ∑ j = 1 M SNR j ( 126. ) and therefore from Equations (115)-(118) we obtain: SNR z = ∑ j = 1 M SNR j = σ s 2` σ 2 ∑ j = 1 M v _ H h _ j h _ j H v _ v _ H v _ = σ s 2 σ 2 λ max ( 271. ) After de-spreading, the final result may be expressed as: SNR z = G σ x 2 σ 2 λ max ( 128. ) The vector weight v has thus been designed such that the quantity ∑ j = 1 M SNR j is maximized. In view of Equation (126), it has also been shown that these weights maximize the SNR at the output of the Rake combiner 1040 (given the constraint that the vector weight v is constant across all fingers). FIG. 11 illustratively represents a communication system 1100 effectively comprising a simplified version of the communication system 800 represented in FIG. 8. The system 1100 includes a transmitter 1110 and a receiver 1120, each of which includes both RF-based and baseband weighting and combining arrangements. Specifically, the transmitter 1110 includes an RF weighting and combining arrangement 1112 and a baseband weighting and combining arrangement 1114, and the receiver 1120 includes an RF weighting and combining arrangement 1122 and a baseband weighting and combining arrangement 1124. As shown, the transmitter 1110 is composed of nT=4 transmit antenna elements 1130, each of which conveys a weighted combination of N=2 distinct sub-streams (i.e. spatially-multiplexed signals) and uses OFDM modulation. The system 1100 may be characterized as a paired single-weight (“paired SW”) system, since a pair of antenna elements 1130 in the transmitter 1110 and a pair of antenna elements 1134 in the receiver 1120 are each effectively connected to a single RF chain 1140, 1142. This approach affords the system 1100 the performance advantages associated with multi-antenna implementations while even further reducing cost and implementation complexity relative to the system represented in FIG. 8. Indeed, for the exemplary case in which four antenna elements 1130 are deployed at the transmitter 1110 and four antenna elements 1134 are likewise deployed at the receiver 1120 so as to support communication of two spatially-multiplexed signals, only two RF weight coefficients 1132 are required at the transmitter 1110 and only two RF weight coefficients 1150 are required at the receiver 1120 (i.e., a total of four weighting coefficients are utilized within the system 1100). In contrast, a similar four-antenna implementation in the system of FIG. 8 requires a total of six RF weight coefficients at each of the transmitter and receiver; (that is, in this case the system of FIG. 8 would utilize a total of twelve RF weight coefficients). It is noted that the foregoing assumes that at least one weight coefficient has been normalized to unity in each of the transmitters and receivers of the systems of FIGS. 8 and 11. The reduced number of RF weights required by the system 1100 directly translates into a less costly and simplified implementation. In the configuration of FIG. 11, the transmit signal at tone k from the jth antenna 1130 is: txs j , k = ∑ i = 1 N v j , i · s i , k ′ where ( 129. ) s i , k ′ = ∑ l = 1 N v i , l , k ′ · s l , k ( 130. ) and where the terms v and v′ represent the RF and baseband weights, respectively. The transmit vector at tone k is txsk=V·Vk′·sk (131.) where V is the transmit RF weight matrix of size nT×N and is independent of the index k (as it is constant over the frequency tones), and where Vk′ is the transmit baseband weight matrix of size N×N and is dependent upon on the index k (as it is a function of frequency). As a consequence of the dedication of a pair of antennas to a single RF chain within the paired SW system 1100, the structure of V is given as: V = [ v a 0 v b 0 0 v c 0 v d ] ( 132. ) such that the pair of antennas indexed by i sends a signal containing contributions only of si,k′. If the columns in V are normalized by their first coefficient, the structure of V becomes: V = [ 1 0 v 1 0 0 1 0 v 2 ] ( 133. ) In order to simplify the above example, it is considered that Vk′ is equal to the identity matrix at each tone. It is to be understood that in other embodiments, Vk′ can be a matrix other than the identity matrix. For example, when Vk′ is dependent upon the channel, various “precoding” methods and the like can assist in the computation of Vk′ given a specific criterion to optimize. To simplify further, consider that V is equal to: V = [ 1 0 0 0 0 1 0 0 ] ( 134. ) In other words, the transmitter 1110 has been simplified such that only two of four antennas 1130 are used and each such antenna 1130 transmits its own spatially-multiplexed signal, i.e., the transmit vector at tone k becomes txsk=sk (135.) where txsk is a N×1 vector. It is to be understood that in other embodiments, V can be given by the general expression (133). As mentioned above, the receiver 1120 of FIG. 11 also utilizes distinct RF and baseband weighting and combining arrangements. Specifically, a first set of weights 1150 for the RF-based arrangement 1122 are implemented at RF and are common to all tones, while a second set of weights 1154 are utilized within the baseband arrangement 1124. Note that the step of computing the RF weights 1150 may also be carried out in baseband, in which case the values of the weights 1150 are fed back to the RF domain via an internal bus, creating a feedback delay. In this configuration, the output at the FFT 1158 at tone k for the ith receive chain is given by ri,k=uiHHk·sk+uiHnk (136.) where ui is the RF weight vector associated with the ith pair of receive antennas 1134. The received signals are collected from each receive chain in an N-dimensional vector. At tone k, this received signal vector rk becomes of dimension N×1 and may be expressed as: rk=UH(Hk·sk+nk)=UHHk·sk+UHnk (137.) where U=[u1, . . . , uN] is an M×N matrix containing the set of weights implemented at RF with the specific structure: U = [ u a 0 u b 0 0 u c 0 u d ] ( 138. ) After normalization, U becomes: u = [ 1 0 u 1 0 0 1 0 u 2 ] ( 139. ) Expression (137) can also be written as: rk=Hkn ·sk+ηk (140.) where Hkn =UHHk and ηk=UHnk. The received signal ri,k can be rewritten as r i , k = u _ i H H _ i , k · s i , k + u _ i H ( ∑ j ≠ i N H _ j , k · s j , k + n _ k ) ( 141. ) where ui is the ith column of the matrix U given by (139), and Hi,k is the ith column of the matrix Hk. The received signal model defined by equation (141) is composed of N signal components and a noise component. Since the transmitter 1110 broadcasts N spatially-multiplexed signals in parallel and each of these signals have to be detected individually by the receiver 1120, each receiver chain considers one spatially-multiplexed signal as the desired signal component while the remaining N−1 spatially-multiplexed signals are considered as interferers. Considering that the ith receive chain considers the ith spatially-multiplexed signal as the desired signal component, equation (141) is rewritten as: ri,k=uiHHi,k·si,k+uiHμi,k (142.) where μ is considered as the noise plus interference signal. In this embodiment, the RF weight vectors ui are designed to maximize the SNR (while the baseband weights 1154 cancel the interference created by the multiple spatially-multiplexed signals). The SNR associated with the kth tone of the ith receive chain is expressed as SNR i , k = σ s 2 u _ i H H _ i , k H _ i , k H u _ i σ 2 u _ i H u _ i ( 143. ) The aggregate SNR across all k tones of the ith receive chain is then SNR _ i = ∑ k = 0 N t - 1 SNR i , k = σ s 2 u _ i H ( ∑ k = 0 N t - 1 H _ i , k H _ i , k H ) u _ i σ 2 u _ i H u _ i . ( 144 ) The solution for ui which maximizes {overscore (SNR)}i is given by the eigenvector of the matrix ( ∑ k = 0 N t - 1 H _ i , k H _ i , k H ) corresponding to the largest eigenvalue, and may be formulated as: u _ i = eig ( λ max , ∑ k = 0 N t - 1 H _ i , k H _ i , k H ) , i = 1 , … , N . ( 145 ) The received vector is then multiplied at each tone k by the complex conjugate of an N×N matrix denoted by Wk so as to enable detection of the transmitted signals. The resulting output signal at tone k is given by: yk=WkH·rk=WkHHkn ·sk+WkHηk=WkHUH(Hk·sk+nk) (146.)) It is observed that while the weights Wk are a function of the applicable frequency tone k, the RF weights U are common to all tones. Equation (146) may be solved for Wk using, for example, the well-known minimum mean squared error (MMSE) solution (i.e., the Wiener-Hopf solution). See, e.g., S. Haykin, Adaptive Filter Theory, 3rd Ed., Prentice Hall, 1996. The general solution is given by W k = ( H k ″ R s , k H k ″ H + R η , k ) - 1 H k ″ R s , k . ( 147 ) We have R s , k = σ s 2 I N and R η , k = E [ η _ k η _ k H ] = σ 2 U H U , thus W k = ( H k ″ H k ″ H + σ 2 σ s 2 U H U ) - 1 H k ″ . ( 148 ) Wk is derived directly from the knowledge of matrices Hk and U, where U is given by equations (145). It should be apparent from the above description that the paired SW system of FIG. 11 comprises a special case of the communication system described with reference to FIG. 8. In particular, the weight coefficients for the paired SW system may be computed in accordance with the same principles used to derive the coefficient values utilized within the system of FIG. 8, subject to the constraint that certain of the RF weight coefficients are set to zero. Although implementations of the paired SW concept have been presented for the specific case of four antennas and two spatially-multiplexed signals, the inventive concept is equally applicable to systems of larger size which are capable of processing greater numbers of spatially-multiplexed signals. Moreover, the inventive paired SW concept is similarly applicable to single-channel systems. The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. In other instances, well-known circuits and devices are shown in block diagram form in order to avoid unnecessary distraction from the underlying invention. Thus, the foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Most current wireless communication systems are composed of nodes configured with a single transmit and receive antenna. However, for a wide range of wireless communication systems, it has been predicted that the performance, including capacity, may be substantially improved through the use of multiple transmit and/or multiple receive antennas. Such configurations form the basis of many so-called “smart” antenna techniques. Such techniques, coupled with space-time signal processing, can be utilized both to combat the deleterious effects of multipath fading of a desired incoming signal and to suppress interfering signals. In this way both the performance and capacity of digital wireless systems in existence or being deployed (e.g., CDMA-based systems, TDMA-based systems, WLAN systems, and OFDM-based systems such as IEEE 802.11a/g) may be improved. The impairments to the performance of wireless systems of the type described above may be at least partially ameliorated by using multi-element antenna systems designed to introduce a diversity gain and suppress interference within the signal reception process. This has been described, for example, in “The Impact of Antenna Diversity On the Capacity of Wireless Communication Systems”, by J. H. Winters et al, IEEE Transactions on Communications, vol. 42, No. 2/3/4, pages 1740-1751, February 1994. Such diversity gains improve system performance by mitigating multipath for more uniform coverage, increasing received signal-to-noise ratio (SNR) for greater range or reduced required transmit power, and providing more robustness against interference or permitting greater frequency reuse for higher capacity. Within communication systems incorporating multi-antenna receivers, it is known that a set of M receive antennas are capable of nulling up to M-1 interferers. Accordingly, N signals may be simultaneously transmitted in the same bandwidth using N transmit antennas, with the transmitted signal then being separated into N respective signals by way of a set of N antennas deployed at the receiver. Systems of this type are generally referred to as multiple-input-multiple-output (MIMO) systems, and have been studied extensively. See, for example, “Optimum combining for indoor radio systems with multiple users,” by J. H. Winters, IEEE Transactions on Communications, Vol. COM-35, No. 11, November 1987; “Capacity of Multi-Antenna Array Systems In Indoor Wireless Environment” by C. Chuah et al, Proceedings of Globecom '98 Sydney, Australia, IEEE 1998, pages 1894-1899 November 1998; and “Fading Correlation and Its Effect on the Capacity of Multi-Element Antenna Systems” by D. Shiu et al, IEEE Transactions on Communications vol. 48, No. 3, pages 502-513 March 2000. One aspect of the attractiveness of multi-element antenna arrangements, particularly MIMOs, resides in the significant system capacity enhancements that can be achieved using these configurations. Under the assumption of perfect estimates of the applicable channel at the receiver, in a MIMO system with N transmit and N receive antenna elements, the received signal decomposes to N “spatially-multiplexed” independent channels. This results in an N-fold capacity increase relative to single-antenna systems. For a fixed overall transmitted power, the capacity offered by MIMOs scales linearly with the number of antenna elements. Specifically, it has been shown that with N transmit and N receive antennas an N-fold increase in the data rate over a single antenna system can be achieved without any increase in the total bandwidth or total transmit power. See, e.g., “On Limits of Wireless Communications in a Fading Environment When Using Multiple Antennas”, by G. J. Foschini et al, Wireless Personal Communications, Kluwer Academic Publishers, vol. 6, No. 3, pages 311-335, March 1998. In experimental MIMO systems predicated upon N-fold spatial multiplexing, more than N antennas are often deployed at a given transmitter or receiver. This is because each additional antenna adds to the diversity gain and antenna gain and interference suppression applicable to all N spatially-multiplexed signals. See, e.g., “Simplified processing for high spectral efficiency wireless communication employing multi-element arrays”, by G. J. Foschini, et al, IEEE Journal on Selected Areas in Communications, Volume: 17 Issue: 11, November 1999, pages 1841-1852. Although increasing the number of transmit and/or receive antennas enhances various aspects of the performance of MIMO systems, the necessity of providing a separate RF chain for each transmit and receive antenna increases costs. Each RF chain is generally comprised a low noise amplifier, filter, downconverter, and analog to digital to converter (A/D), with the latter three devices typically being responsible for most of the cost of the RF chain. In certain existing single-antenna wireless receivers, the single required RF chain may account for in excess of 30% of the receiver's total cost. It is thus apparent that as the number of transmit and receive antennas increases, overall system cost and power consumption may unfortunately dramatically increase. It would therefore be desirable to provide a technique for utilizing relatively larger numbers of transmit/receive antennas without proportionately increasing system costs and power consumption. The above-referenced copending non-provisional application provides such a technique by describing a wireless communication system in which it is possible to use a smaller number of RF chains within a transmitter and/or receiver than the number of transmit/receiver antennas utilized. In the case of an exemplary receiver implementation, the signal provided by each of M (M>N) antennas is passed through a low noise amplifier and then split, weighted and combined in the RF domain with the signals from the other antennas of the receiver. This forms N RF output signals, which are then passed through N RF chains. The output signals produced by an A/D converter of each RF chain are then digitally processed to generate the N spatially-multiplexed output signals. By performing the requisite weighting and combining at RF using relatively inexpensive components, an N-fold spatially-multiplexed system having more than N receive antennas, but only N RF chains, can be realized at a cost similar to that of a system having N receive antennas. That is, receiver performance may be improved through use of additional antennas at relatively low cost. A similar technique can be used within exemplary transmitter implementations incorporating N RF chains and more than N transmit antennas. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to a system and method for generating weight values for weighting elements included within the signal weighting and combining arrangements used in various multi-antenna transmitter and receiver structures. Specifically, the present invention may be applied to RF-based weighting and combining arrangements within such multi-antenna transmitter and receiver structures. The present invention may also find application when both RF-based and baseband weighting and combining arrangements are incorporated within the same multi-antenna transmitter or receiver structure. In one aspect the present invention relates to a signal weighting and combining method implemented within a receiver having a plurality of receive antennas. Each receive antenna is disposed to produce a received RF signal in response to a transmitted RF signal received through a channel. The method includes weighting the plurality of received RF signals produced by the antennas in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel, thereby forming a plurality of weighted RF signals. The method further includes combining ones of the plurality of weighted RF signals in order to form one or more combined RF signals. The present invention also pertains to an RF splitting and weighting method implemented within a multi-antenna transmitter disposed to transmit an RF input signal through a plurality of transmit antennas so as to produce a corresponding plurality of RF output signals. Each of the RF output signals are received by a receiver after propagating through a channel. The method includes dividing the RF input signal in order to form a plurality of divided RF signals. The plurality of divided RF signals are then weighted in accordance with a corresponding plurality of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel, thereby forming the plurality of RF output signals. In another aspect the present invention relates to an RF processing method implemented within a communication system including a transmitter and a receiver. The transmitter is configured with a set of transmit antennas disposed to transmit a set of spatially-multiplexed RF output signals through a channel. The receiver includes a plurality of receive antennas disposed to generate a corresponding first plurality of spatially-multiplexed received RF signals in response to receipt of the spatially-multiplexed RF output signals. The RF processing method includes generating the set of spatially-multiplexed RF output signals by performing a splitting and weighting operation upon plural RF input signals. This splitting and weighting operation utilizes a first set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel. The method further includes forming a second plurality of spatially-multiplexed received RF signals by performing a weighting and combining operation upon the first plurality of spatially-multiplexed received RF signals. This weighting and combining operation utilizes a second set of RF weighting values selected in accordance with the one or more output signal-to-noise ratios. The present invention also relates to a signal weighting and combining method implemented within a receiver having a plurality of receive antennas disposed to produce a corresponding plurality of spatially-multiplexed received RF signals in response to spatially-multiplexed transmitted RF signal energy received over a channel. The method includes weighting each of the plurality of spatially-multiplexed received RF signals utilizing a corresponding set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel, thereby forming plural spatially-multiplexed weighted RF signals. Ones of the plural spatially-multiplexed weighted RF signals are then combined in order to form one or more spatially-multiplexed combined RF signals. In yet another aspect the present invention pertains to an RF splitting and weighting method implemented within a multi-antenna transmitter configured with a plurality of transmit antennas disposed to transmit a spatially-multiplexed RF input signal. The corresponding plurality of spatially-multiplexed RF output signals produced by the plurality of transmit antennas are received by a receiver after propagating through a channel. The method includes dividing the spatially-multiplexed RF input signal in order to form a plurality of spatially-multiplexed divided RF signals. The plurality of spatially-multiplexed divided RF signals are then weighted utilizing a set of RF weighting values selected in accordance with one or more output signal-to-noise ratios of the receiver averaged over the channel, in order to form plural spatially-multiplexed weighted RF signals. Ones of the plural spatially-multiplexed weighted RF signals are then combined so as to form the plurality of spatially-multiplexed RF output signals. The present invention further relates to an RF processing method capable of being implemented within a communication system including a transmitter and a receiver. The transmitter is configured with a set of transmit antennas disposed to transmit a set of RF output signals through a channel. The receiver includes a plurality of receive antennas disposed to generate a corresponding plurality of received RF signals in response to receipt of the RF output signals. The method includes generating the set of RF output signals by performing a splitting and weighting operation upon an RF input signal utilizing a first set of RF weighting values selected to maximize an output signal-to-noise ratio of the receiver averaged over the channel. The method further includes generating one or more received combined RF signals by performing a weighting and combining operation upon the plurality of received RF signals using a second set of RF weighting values selected to maximize the output signal-to-noise ratio. | 20040429 | 20090526 | 20050407 | 89766.0 | 0 | BAYARD, EMMANUEL | WEIGHT GENERATION METHOD FOR MULTI-ANTENNA COMMUNICATION SYSTEMS UTILIZING RF-BASED AND BASEBAND SIGNAL WEIGHTING AND COMBINING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,420 | ACCEPTED | Liquid-repellent film-coated member, constitutive member of liquid-jet device, nozzle plate of liquid-jet head, liquid-jet head, and liquid-jet device | The present invention provides a member comprising a substrate, an undercoat film formed on a surface of the substrate, and a liquid-repellent film of metal alkoxide formed on a surface of the undercoat film. Also disclosed are nozzle head, liquid-jet head and liquid-jet device employing the above-described member. | 1. A member comprising a substrate, an undercoat film formed on a surface of the substrate, and a liquid-repellent film of metal alkoxide formed on a surface of the undercoat film. 2. The member according to claim 1, wherein the liquid-repellent film is a molecular film of a polymer of metal alkoxide. 3. The member according to claim 1, wherein the metal alkoxide has a fluorine-containing long-chain polymer group. 4. The member according to claim 1, wherein the metal alkoxide is a metal acid salt having a liquid-repellent group. 5. The member of according to claim 1, wherein the metal alkoxide is a silane coupling agent. 6. The member according to claim 1, wherein the undercoat film comprises a plasma polymerization film of a silicone material, or contains SiO2, ZnO, NiO, SnO2, Al2O3, ZrO2, copper oxide, silver oxide, chromium oxide or iron oxide. 7. The member according to claim 1 or 2, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through oxidation and hydrogenation; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. 8. The member according to claim 1 or 2, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through irradiation with plasma or UV rays; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. 9. The member according to claim 1, wherein the substrate comprises a metal material or a composite material. 10. The member according to claim 1, wherein the substrate comprises a resinous material. 11. The member according to claim 9, wherein the metal material is stainless steel. 12. The member according to claim 9, wherein the composite material contains silicon, sapphire or carbon. 13. The member according to claim 10, wherein the resinous material comprises at least one compound selected from the group consisting of polytetrafluoroethylene, polyethylene, polyimide, polyamidimide, polyphenylene sulfide, polyether-ether ketone, polyoxymethylene, polystyrene, acrylonitrile-butadiene-styrene, polybutylene terephthalate, polyphenylene ether, potassium titanate fiber-composite resin, polypropylene, ethylene-propylene-diene tercopolymer, olefin elastomer, urethane elastomer, chloroprene rubber, silicone rubber and butyl rubber. 14. The member according to claim 1, wherein the substrate is resistant to heat at least at 400° C., and the liquid-repellent film is formed on the undercoat film by a process comprising: heating the undercoat film; and dipping the undercoat film in a metal alkoxide solution while heated. 15. The member according to claim 14, wherein the heating temperature of the undercoat film falls between 200 and 400° C. 16. A nozzle plate for a liquid-jet head, which comprises the member according to any of claims 1 to 14. 17. A liquid-jet head comprising the nozzle plate according to claim 16. 18. A liquid-jet device equipped with the liquid-jet head according to claim 17. 19. The member according to any of claims 1 to 8, 10 and 13, which is a head cap, a head cleaning wiper, a head cleaning wiper-holding lever, a gear, a platen, or a carriage. 20. A liquid-jet device equipped with the member according to claim 19. | FIELD OF THE INVENTION The present invention relates to a liquid-repellent film-coated member, a constitutive member of liquid-jet devices, a nozzle plate of liquid-jet heads, a liquid-jet head, and a liquid-jet device. In particular, the invention relates to a liquid-jet device that has an undercoat film and a liquid-repellent film of a metal alkoxide molecular film formed not only on the surface of the nozzle plate substrate of the liquid-jet head thereof, but also on the surfaces of other constitutive members thereof (including members other than metal members, such as resinous members and composite material members). BACKGROUND OF THE INVENTION An inkjet printer head, one embodiment of liquid-jet head through which liquid droplets are jetted out toward media via the nozzle orifices thereof, has a nozzle plate, and a plurality of fine inkjet orifices through which ink is jetted out are formed in the nozzle plate at fine intervals. If ink adheres to the surface of the nozzle plate, then other ink that is jetted out later may be influenced by the surface tension and the viscosity of the previously-adhering ink to have a curved jetting trajectory. This arises a problem that the ink could not be applied to a predetermined site. Accordingly, the nozzle plate surface has to be subjected to liquid-repelling treatment for protecting it from ink adhesion. Some methods mentioned below are known as the technique of liquid-repelling treatment. One of the methods is as follows: A nozzle plate at room temperature is dipped in a solution of a liquid-repellent silane coupling agent such as an alkoxysilane solution for tens seconds. In this stage, the temperature of the alkoxysilane is at around room temperature. Next, the dipped nozzle plate is pulled up out of the solution at a rate of about few mm/sec, thus forming a monomolecular film of an alkoxysilane polymer on its surface. The nozzle plate is then dried for one full day at room temperature to vaporize the solvent, thereby obtaining a water-repellent monomolecular film on the metal surface of the nozzle plate through dehydrating polycondensation. As another example of the methods, a method described in Patent Document 1 can be cited. This method comprises dipping an absorbent in a mixture of a fluorine-containing polymer compound and a compound having a fluorine-substituted hydrocarbon group and a silazane, alkoxysilane or halogenosilane group, then pulling it up out of the solution, and moving the absorbent while pressed against a nozzle plate to effect coating on the nozzle plate. After thus coated, the nozzle plate is thermally dried and cured at 150° C. for 1 hour to thereby form a liquid-repellent film thereon. As a still other example of the methods, a method described in Patent Document 2 can be cited. This method comprises masking a nozzle plate, at a part thereof not requiring liquid-repellency, with an aluminium mask, and dipping it in a solution mixed with a substance having a plurality of trichlorosilyl groups, for about 30 minutes to thereby form a chlorosilane monomolecular film thereon. Then, the chlorosilane monomolecular film is washed with chloroform and then with water so that it is reacted to form a siloxane monomolecular film. The siloxane monomolecular film is dipped in a solution of a substance having a fluorocarbon group and a chlorosilane group for about 1 hour, whereby a fluorine-containing monomolecular film is formed on the surface of the nozzle head and the thin aluminium film thereon. Next, the thin aluminium film is etched away, and thus a liquid-repellent monomolecular film is formed on the surface of the nozzle head. Patent Document 1: JP-A 5-116309 Patent Document 2: JP-A 5-116324 The alkoxysilane molecular film reacts with the OH group that terminates the nozzle plate surface and bonds to the nozzle plate. Accordingly, if a large number of OH groups exist on the nozzle plate surface, then alkoxysilane molecules corresponding to the existing OH groups bond to the nozzle plate. In other words, if a larger number of OH groups exist thereon, then the resulting molecular film has a higher density and, as a result, the liquid-repellency of the resulting nozzle plate is higher. However, since the number of OH groups existing on the surface of metal such as stainless steel is smaller than that on the surface of glass or the like, the obtained molecular film formed through polymerization of a silane coupling material on the surface of metal merely had a low density and poor adhesion. Accordingly, there was a problem that the water-repellency of the molecular film is low and that the film could not ensure its water-repellency for a long period of time. Ink heretofore used in the background art was generally dye-based ink, and its solvent was water. Therefore, a water-repellent molecular film could repel such dye-based ink so long as it has water repellency. Recently, however, pigment-based ink has become used to cope with high-quality prints from digital still cameras, etc. For the solvent for such pigment-based ink, a resin-based dispersant is used. Therefore, molecular films for printer members for such pigment-based ink are required to have both water repellency and oil repellency (hereinafter collectively referred to as “liquid repellency”). However, the molecular films disclosed in Patent Documents 1 and 2 do not have both water repellency and oil repellency, and hence involve a problem that the molecular films are wetted. Heretofore, the members of liquid-jet devices other than nozzle plates were not treated for ink repellency. The absence of ink-repellency treatment arises the following problem. Ink adheres to no small extent to the members such as cap and wiper that directly contact with ink, and if the members are formed of wettable material, then the ink having adhered thereto may stay thereon as such. When the adhered ink is left as it is, it may thicken to cause staining and operation failure of the members. Especially with respect to wiper members, ink is led through or to various members, such as from wiper body (rubber, elastomer, urethane) to wiper-holding lever (polyoxymethylene (POM)), then to system body (acrylonitrile-butadiene-styrene (ABS)) and to waste absorbent, and is absorbed by these members. Therefore, there is a probability that ink may be hardly led through or to these members. In addition, thickened ink may adhere to a lower part of a carriage on which a head is to be mounted, and it may be transferred onto the head upon operation of the wiper. SUMMARY OF THE INVENTION The present invention has been made for solving the above-mentioned problems. Accordingly, an object of the invention is to provide a member having a liquid-repellent film of a metal alkoxide in which the adhesion of the metal alkoxide liquid-repellent film to the surface of the substrate such as nozzle plate is high and the density of the liquid-repellent film is high. Another object of the invention is to provide a constitutive member comprising the above-mentioned member. A still other object of the invention is to provide a nozzle plate comprising the member, and to provide a liquid-jet head and a liquid-jet device that comprise the nozzle plate. Other objects and effects of the invention will become apparent from the following description. To attain the above-mentioned objects, the invention is to use liquid-repellent film-coated members not only for nozzle plate (formed of metal) of liquid-jet head in liquid-jet devices but also for any other system-constituting members (formed of resin material, composite material) of liquid-jet devices. In the invention, the liquid-repellent film-coated member is constructed by treating the surface of the undercoat film formed on the surface of a substrate for OH formation, and then forming thereon a liquid-repellent film of a metal alkoxide molecular film, preferably, employing a metal alkoxide having a fluorine-containing long-chain polymer group as the metal alkoxide. Thereby, the invention has made it possible to prevent staining of system members and to prevent operation failure thereof, and has succeeded in solving the above-mentioned problems. Specifically, the above-mentioned objects of the invention have been achieved by providing the following members, nozzle plate, liquid-jet head, and liquid-jet devices. (1) A member comprising a substrate, an undercoat film formed on a surface of the substrate, and a liquid-repellent film of metal alkoxide formed on a surface of the undercoat film. (2) The member according to item (1) above, wherein the liquid-repellent film is a molecular film of a polymer of metal alkoxide. (3) The member according to item (1) above, wherein the metal alkoxide has a fluorine-containing long-chain polymer group. (4) The member according to item (1) above, wherein the metal alkoxide is a metal acid salt having a liquid-repellent group. (5) The member of according to item (1) above, wherein the metal alkoxide is a silane coupling agent. (6) The member according to item (1) above, wherein the undercoat film comprises a plasma polymerization film of a silicone material, or contains SiO2, ZnO, NiO, SnO2, Al2O3, ZrO2, copper oxide, silver oxide, chromium oxide or iron oxide. (7) The member according to item (1) or (2) above, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through oxidation and hydrogenation; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. (8) The member according to item (1) or (2) above, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through irradiation with plasma or UV rays; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. (9) The member according to item (1) above, wherein the substrate comprises a metal material or a composite material. (10) The member according to item (1) above, wherein the substrate comprises a resinous material. (11) The member according to item (9) above, wherein the metal material is stainless steel. (12) The member according to item (9) above, wherein the composite material contains silicon, sapphire or carbon. (13) The member according to item (10) above, wherein the resinous material comprises at least one compound selected from the group consisting of polytetrafluoroethylene, polyethylene, polyimide, polyamidimide, polyphenylene sulfide, polyether-ether ketone, polyoxymethylene, polystyrene, acrylonitrile-butadiene-styrene, polybutylene terephthalate, polyphenylene ether, potassium titanate fiber-composite resin, polypropylene, ethylene-propylene-diene tercopolymer, olefin elastomer, urethane elastomer, chloroprene rubber, silicone rubber and butyl rubber. (14) The member according to item (1) above, wherein the substrate is resistant to heat at least at 400° C., and the liquid-repellent film is formed on the undercoat film by a process comprising: heating the undercoat film; and dipping the undercoat film in a metal alkoxide solution while heated. (15) The member according to item (14) above, wherein the heating temperature of the undercoat film falls between 200 and 400° C. (16) A nozzle plate for a liquid-jet head, which comprises the member according to any of items (1) to (14) above. (17) A liquid-jet head comprising the nozzle plate according to item (16) above. (18) A liquid-jet device equipped with the liquid-jet head according to item (17) above. (19) The member according to any of items (1) to (8), (10) and (13) above, which is a head cap, a head cleaning wiper, a head cleaning wiper-holding lever, a gear, a platen, or a carriage. (20) A liquid-jet device equipped with the member according to item (19) above. As so described hereinabove, the invention is to use liquid-repellent film-coated members not only for nozzle plate (mainly formed of metal) of liquid-jet head in liquid-jet devices but also for any other system-constituting members (including those formed of resin material or composite material) such as head cap, head cleaning wiper, head cleaning wiper-holding lever, gear, platen or carriage of liquid-jet devices. Applying the ink-repellent treatment to parts of system units solves the following troubles (i) to (iii) with liquid-jet devices. (i) When the parts that frequently contact with ink, such as head cap, head cleaning wiper, head cleaning wiper-holding lever, etc. are processed for ink repellency, then the parts themselves can be protected from ink adhesion thereto. Specifically, it is as follows: Head cap receives few cap marks (adhesion of thickened ink) from the face of nozzle plate (NP). Wiping performance of the head cleaning wiper lasts long as ink adhesion thereto reduces. Head cleaning wiper-holding lever readily lead waste ink from wiper to waste absorbent. Gear operation failure caused by ink wrapping around thereof is reduced. Thickened ink transfer to head caused by thickened ink adhesion to carriage is prevented. (ii) The parts themselves (especially those for driving operation, such as gear) are protected from ink adhesion thereto, and are therefore prevented from operation failure owing to thickened ink adhesion thereto. (iii) The system-constituting members may be processed for ink repellency irrespective of the contact angle of their materials (mainly engineering plastic resins such as polyphenylene sulfide (PPS), polyoxymethylene (POM), acrylonitrile-butadiene-styrene (ABS), elastomer, rubber), and therefore recovery of waste ink is easy. In other words, ink having adhered to head cap and wiper can be readily led to waste absorbent. In the liquid-repellent film-coated member of the invention, an undercoat film is formed on the surface of the substrate as described above. The material for the substrate is not specifically limited, and may be any of metal material, composite material and resinous material. More effectively, the surface roughness (Ra) of the substrate is 65 nm or less, preferably 35 nm or less. The undercoat film may be suitably selected and used depending on the substrate. For example, it may comprise a plasma polymerization film of a silicone material, or may contain SiO2, ZnO, NiO, SnO2, Al2O3, ZrO2, copper oxide, silver oxide, chromium oxide or iron oxide. The surface of the undercoat film is oxidized and hydrogenated, specifically, it is irradiated with plasma or UV rays and then exposed to air whereby the surface may be terminated with OH group (i.e., the surface is hydroxylated). Then, when a liquid-repellent film of metal alkoxide is formed on the thus-processed undercoat film, the OH groups on the undercoat film bond to the liquid-repellent film of metal alkoxide. As a result, a liquid-repellent film of metal alkoxide having high density and high adhesion can be formed. In the case where the substrate is resistant to heat at least at 400° C., the undercoat film may be dipped in a metal alkoxide solution while heated, so as to form a liquid-repellent film of metal alkoxide on the undercoat film. In this embodiment, a molecular film of alkoxysilane polymer having a uniform thickness may be formed on the surface of the undercoat film. In the molecular film thus formed, the metal atom derived from the metal alkoxide bonds to the undercoat film via the oxygen atom. When the metal alkoxide used in the invention has a fluorine-containing long-chain polymer group, then the fluorine-containing long-chain polymer group that bonds to the metal atom derived from the metal alkoxide exists on the surface side of the film. Referring to the condition of the molecular film in this stage, the metal atoms bond three-dimensionally and the fluorine-containing long-chain polymer groups are complicatedly entangled with each other. Accordingly, the molecular film is in a dense condition, and ink hardly penetrates thereinto. As a result, the liquid-repellent film-coated member of the invention ensures excellent liquid repellency and keep it for a long period of time. In addition, because of its high density, the liquid-repellent film has excellent abrasion resistance. A summary of a process for producing the liquid-repellent film-coated member of the invention is described below. The liquid-repellent film-coated member of the invention is produced according to a process comprising at least (1) substrate washing, (2) undercoat film formation, (3) surface activation of undercoat film, (4) liquid-repellent metal alkoxide film formation, (5) wetting and drying treatment, and (6) annealing. The step (1) “substrate washing” is for removing unnecessary matters that are inconvenient for undercoat film formation, from the substrate. Details of the washing condition shall be suitably determined depending on the material, form and size of the substrate. Details of the film-forming condition in the step (2) “undercoat film formation” shall be suitably determined depending on the material, form and size of the substrate and on the type and thickness of the undercoat film to be formed. The step (3) “surface activation of undercoat film” is for imparting OH groups to the surface of the undercoat film in order that the liquid-repellent film of metal alkoxide to be formed thereon is more firmly bonded thereto. Specifically, examples of this step include irradiation of the undercoat film surface with plasma or UV rays. Details of the treatment condition shall be suitably determined depending on the type and thickness of the undercoat film and on the type of the metal alkoxide for the liquid-repellent film to be formed. Details of the film-forming condition in the step (4) “liquid-repellent metal alkoxide film formation” shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. In the step (5) “wetting and drying treatment”, the coated substrate is put in a high-temperature high-humidity atmosphere for polymerization of the metal alkoxide to give a molecular film thereof. Details of the treatment condition shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. In the step (6) “annealing”, the coated substrate is treated at a temperature higher than the temperature in the previous step (5) “wetting and drying treatment”, and this is for terminating the polymerization reaction of the metal alkoxide. Details of the treatment condition shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. The liquid-jet head of the invention has a feature that it comprises the nozzle plate mentioned above. The liquid-jet device of the invention has a feature that it comprises the above-mentioned liquid-jet head, or comprises a head cap, a head cleaning wiper, a head cleaning wiper-holding lever, a gear, a platen and/or a carriage, each of which has the liquid-repellent film-coated member of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a cross section of an inkjet printer according to one embodiment of the invention. FIG. 2 is an explanatory view of a film-forming device for plasma polymerization film according to one embodiment of the invention. FIG. 3 is a schematic view showing the bonding in a molecular film according to one embodiment of the invention. FIG. 4 is a schematic view showing the condition of a molecular film according to one embodiment of the invention. FIG. 5 is a perspective view of an inkjet printer according to one embodiment of the invention. The reference numerals used in the drawings denote the followings, respectively. 10: Inkjet printer head 12: Ink guide 14: Ink reservoir 16: Pressure room 18: Nozzle plate 20: Inkjet orifice 22: Plasma polymerization film 24: Molecular film 24a: Silicon atom 24b: Fluorine-containing long-chain polymer group 26: Ink 30: Film-forming device 32: Chamber 34: Pump 36: Electrode 38: High-frequency power source 40: Stage 42: Gas-feed line 44: Material-feed line 46: Argon gas source 50: Material container 52: Heater 54: Liquid material DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The liquid-repellent film-coated member, the constitutive member of liquid-jet devices, the nozzle plate of liquid-jet heads, the liquid-jet head and the liquid-jet device of the invention are described in more detail below with reference to preferred embodiments of the present invention. The method of undercoat film formation and metal alkoxide film formation described below is one embodiment of the invention, in which a nozzle plate of a liquid-jet head, serving as a substrate and being formed of stainless steel, is to be coated with a liquid-repellent film. However, the invention is not limited thereto. FIG. 1 shows a cross-sectional view of an ink-jet printer head 10 using ink droplets as the liquid droplets to be jetted out through the nozzle orifices, which is one example of the liquid-jet head (one member of a liquid-jet device). The inkjet printer head 10 has an ink guide 12 via which ink is led inside the head. The ink guide 12 is connected to an ink reservoir 14, and is so designed that ink may be stored in the ink reservoir 14. The ink reservoir 14 communicates with a pressure room 16, and on the inkjet side thereof, the pressure room 16 is connected to an inkjet orifice 20 formed in the nozzle plate 18. The pressure room 16 is so designed that pressure may be applied to a part of its wall. This structure is arranged, for example, by forming a part of the wall of the pressure room 16 with a diaphragm, and providing an exciting electrode 17 (piezoelectric element) on its outside surface. When a voltage is applied to the exciting electrode 17, then the diaphragm is vibrated owing to the resulting electrostatic force and the inner pressure in the pressure room is thereby changed. By the inner pressure, ink is jetted out through the inkjet orifice 20. As the nozzle plate 18, one formed of stainless steel (in this embodiment, SUS316) is used. The surface of the nozzle plate 18 and the inner surface of the ink-jet orifice 20 are coated with a plasma polymerization film 22 that is formed through plasma polymerization of a silicone material. The surface of the plasma polymerization film 22 is coated with a liquid-repellent molecular film 24 of metal alkoxide. The metal alkoxide molecular film 24 may be any so long as it is repellent to water and oil, but is preferably a monomolecular film of a metal alkoxide having a fluorine-containing long-chain polymer group (hereinafter referred to as “long-chain RF group”) or a monomolecular film of a metal acid salt having a liquid-repellent group. The metal alkoxide include those containing, for example, any of Ti, Li, Si, Na, K, Mg, Ca, St, Ba, Al, In, Ge, Bi, Fe, Cu, Y, Zr or Ta, but those containing silicon, titanium, aluminium or zirconium are generally used. In this embodiment, the metal alkoxide containing silicon is used. Preferably, it is a fluorine-containing long-chain RF group-having alkoxysilane, or a liquid-repellent group-having metal acid salt. The long-chain RF group has a molecular weight of at least 1000, and examples thereof include, for example, a perfluoroalkyl chain and a perfluoro-polyether chain. One example of the long-chain RF group-having alkoxysilane is a long-chain RF group-having silane coupling agent. Suitable examples of the long-chain RF group-having silane coupling agent for the liquid-repellent film in the invention include, for example, heptatriacontafluoroeicosyltrimethoxysilane. Its commercial products include, for example, Optool DSX (trade name by Daikin Kogyo) and KY-130 (trade name by Shin-etsu Kagaku Kogyo). The surface free energy of fluorocarbon group (RF group) is smaller than that of alkyl group. Therefore, when metal alkoxide has RF group, then the resulting liquid-repellent film have improved liquid repellency and, in addition, other properties such as chemical resistance, weather resistance and abrasion resistance are also improved. As the long-chain structure of the RF group is longer, the liquid repellency of the film can be maintained for a longer period of time. The liquid-repellent group-having metal acid salt includes, for example, aluminates and titanates. Using the thus-designed inkjet printer head 10, an inkjet printer is constructed as shown in FIG. 5. Next described is a device for forming the plasma polymerization film 22 of a silicone material on the surface of nozzle plate 18 serving as the substrate. FIG. 2 shows an explanatory view of a device for forming the plasma polymerization film 22. The film-forming device 30 has a chamber 32, and a pump 34 is connected to the chamber 32. An electrode 36 is disposed on the top wall of the chamber 32, and a high-frequency power source 38 is connected to the electrode 36. The high-frequency power source 38 generates an electric power of, for example, about 300 W. A temperature-controllable stage 40, on which the nozzle plate 18 is mounted, is disposed on the bottom wall of the chamber 32 to be opposite to the electrode 36. A gas-feed line 42 and a material-feed line 44 are connected to the chamber 32. An argon gas source 46 is connected to the gas-feed line 42 via a flow control valve (not shown). The flow control valve controls the flow rate of the gas to be fed into the chamber 32. A material container 50 that contains a material for the plasma polymerization film 22 is connected to the material-feed line 44. A heater 52 is disposed below the material container 50, so that the liquid material 54 can be vaporized. The material for the plasma polymerization film 22 includes silicone oil and alkoxysilane, and more specifically includes dimethylpolysiloxane. Its commercial products include, for example, TSF451 (by GE Toshiba Silicone) and SH200 (by Toray Dow-Corning Silicone). Sucked by the negative pressure of the chamber 32, the vaporized material is fed into the chamber 32 via the material-feed line 44. Next described are a method of forming the plasma polymerization film 22 of a silicone material on the surface of the nozzle plate 18, and a method for forming the metal alkoxide molecular film 24 on the surface of the plasma polymerization film 22. In this embodiment, silicone (dimethylpolysiloxane) is used as the material for the plasma polymerization film 22; and fluorine-containing long-chain polymer group-having alkoxysilane (heptatriacontafluoroeicosyltrimethoxysilane) is used as the metal alkoxide. First, silicone is polymerized to form the plasma polymerization film 22 on the surface of the nozzle plate 18. The plasma polymerization film 22 is formed by the use of the film-forming device 30. First, the nozzle plate 18 is disposed on the stage 40 in the chamber 32. Next, the chamber 32 is degassed to a predetermined level via the pump 34. In this step, the temperature of the stage 40 is so controlled that the polymerization of the material on the nozzle plate 18 is promoted at the controlled temperature. For example, the stage 40 is kept at 25° C. or higher (in this embodiment, 40° C.). After the chamber 32 has been degassed to a predetermined level, argon gas is fed therein and the pressure in the chamber 0.32 is kept at a predetermined level, for example, at about 7 Pa. An electric power of, for example, about 100 W is applied thereto from the high-frequency power source 38 connected to the electrode 36, and argon plasma is thereby generated in the chamber 32. Heated by the heater 52, the silicone in the material container 50 vaporizes and, as mentioned above, this is sucked by the negative pressure in the chamber 32 and is fed into the chamber 32 via the material-feed line 44. Then, the weakly bonding part of the vaporized silicone is cut by the argon plasma and the silicone is polymerized to form the plasma polymerization film 22 on the surface of the nozzle plate 18. The nozzle plate 18 has the inkjet orifice 20. The plasma polymerization film 22 is also formed on the inner surface of the inkjet orifice 20. The surface of the plasma polymerization film 22 is terminated by the methyl group that constitutes the silicone, and the methyl group bonds to the silicon atom of the silicone. The plasma polymerization film 22 thus formed on the surface of the nozzle plate 18 is then annealed. For example, it is annealed in a nitrogen atmosphere at a temperature falling between 150° C. and 450° C. (in this embodiment, at 200° C.), whereby crosslinking of the plasma polymerization film 22 on the surface of the nozzle plate 18 is promoted. As a result, the hardness of the plasma polymerization film 22 increases, and the adhesion thereof to the nozzle plate also enhanced. Next, the surface of the plasma polymerization film 22 is etched with plasma. Etching is carried out for oxidizing the surface. That is, the bonding between the methyl group that terminates the surface of the plasma polymerization film 22, and the silicon atom is cut, and an oxygen atom is bonded to the silicon atom. The plasma treatment is effected by exposing the surface of the plasma polymerization film 22 to plasma of argon, nitrogen or oxygen. In place of exposure to such plasma, the plasma polymerization film 22 may be irradiated with UV rays from excimer laser or deuterium lamp. For example, when argon plasma is used for the oxidation treatment, the surface of the plasma polymerization film 22 is exposed to argon plasma for about 1 minute. The oxidation treatment is followed by a subsequent treatment of bonding a hydrogen atom to the oxygen atom. Specifically, the plasma polymerization film 22 is exposed to air whereby a hydrogen atom is bonded to the oxygen atom that terminates the surface of the plasma polymerization film 22 (i.e., the oxygen atom is hydroxylated). After the treatment, the number of the OH groups on the surface of the plasma polymerization film 22 is much larger than that on the surface of the non-coated nozzle plate 18. On the surface of the plasma polymerization film 22 thus formed on the nozzle plate 18, a water-repellent and oil-repellent metal alkoxide molecular film 24 is formed. The metal alkoxide used in this embodiment is a long-chain RF group-having alkoxysilane. For the alkoxysilane, used herein is the above-mentioned heptatriacontafluoroeicosyltrimethoxysilane. First, the alkoxysilane is mixed with a solvent such as thinner (in this embodiment, HFE-7200, trade name by Sumitomo 3M) to prepare a solution thereof having a concentration of, for example, 0.1% by weight. Next, the nozzle plate 18 coated with the plasma polymerization film 22 is heated at 200 to 400° C., and then dipped in the above-mentioned solution. A molecular film of a polymer of the metal alkoxide can be readily formed on the metal surface within a short time after the metal is dipped in the metal alkoxide solution. Therefore, the time for forming the molecular film on the metal may be shortened. In addition, a thick and high-density molecular film can be formed. Accordingly, a molecular film having excellent abrasion resistance can be obtained. For example, when the nozzle plate 18 is dipped at a temperature lower than 200° C., it is dipped therein for 0.5 seconds, and after having been thus dipped, the nozzle plate 18 is pulled up out of the solution at a rate of, for example, 2 mm/sec. FIG. 3 and FIG. 4 are schematic views of the molecular film 24 formed through polymerization of alkoxysilane on the surface of the plasma polymerization film 22 formed on the nozzle plate 18. FIG. 3 is a schematic view showing the bonding of the molecular film 24 to the plasma polymerization film 22. FIG. 4 is a schematic view showing the condition of the molecular film 24. When the nozzle plate 18 is dipped in the alkoxysilane solution, the molecular film 24 of a polymer of the alkoxysilane is formed on the surface of the plasma polymerization film 22 on the nozzle plate 18. The silicon atoms 24a of the molecular film 24 bond to the plasma polymerization film 22 via oxygen atom, and the fluorine-containing long-chain polymer groups 24b (hereinafter referred to as long-chain RF groups) bonding to the silicon atoms 24a are on the surface side of the film. In the molecular film 24 in this condition, the silicon atoms 24a bond three-dimensionally and the long-chain RF groups 24b are complicatedly entangled with each other. Accordingly, the molecular film 24 is in a dense condition, and ink 26 hardly penetrates into the molecular film 24. The molecular film 24 thus formed according to the above-mentioned method was tested for its surface abrasion resistance. In the abrasion resistance test, the surface of the molecular film 24 was rubbed with an absorbent that had been dipped in ink, by 1000-times rubbing operations. As a result, the surface of the molecular film 24 was not peeled, and even after repeatedly rubbed, the ink on the film surface was repelled within 5 seconds, showing no deterioration of the ink repellency of the film. According to this embodiment as described above, the plasma polymerization film 22 of the silicone material can be formed, through plasma polymerization of the material, on the surface of the nozzle plate 18 and on the inner surface of the inkjet orifice 20. The number of the methyl groups that terminate the surface of the plasma polymerization film is much larger than that of the OH groups on the surface of the nozzle plate 18. The surface of the plasma polymerization film 22 is irradiated with UV rays to cut the bonding between the silicon atom and the methyl group therein, and oxygen atom is bonded to the silicon atom. Then, the plasma polymerization film 22 is exposed to air to hydroxylate its surface. Accordingly, the number of the OH groups on the surface of the plasma polymerization film 22 is much larger than that on the surface of the nozzle plate 18. In the case where the nozzle plate 18 coated with the plasma polymerization film 22 is dipped in the alkoxysilane solution while heated, the liquid-repellent molecular film 24 is formed on the surface of the plasma polymerization film 22. Accordingly, when the nozzle plate 18 is pulled up out of the solution, the formed liquid-repellent molecular film 24 repels the alkoxysilane solution. This means that the process does not require a step of drying the processed nozzle plate 18. The molecular film 24 thus formed on the surface of the plasma polymerization film 22 by dipping the nozzle plate 18 in the alkoxysilane solution has a uniform thickness. Since the silane coupling agent such as the long-chain RF group-having alkoxysilane is used, the film formation does not require many chemical reactions. In the case where the nozzle plate 18 is dipped in the alkoxysilane solution under heat, the time for polymerizing the alkoxysilane on the surface of the plasma polymerization film 22 can be shortened. This means that the process of the present invention does not require a long polymerization time as required in the background art. The concentration of the alkoxysilane solution is 0.1% by weight. With the concentration, the solution can form the high-density molecular film 24. In contrast, the concentration of the solution that is used in the background art is about 0.3% by weight, and the molecular film formed from the solution has a smaller thickness and a lower density than that formed in this embodiment of the invention. This means that the method for forming the metal alkoxide film of this embodiment is cost-effective. Since the molecular film 24 reacts with and bonds to the OH groups that terminate the surface of the plasma polymerization film 22, its density is high. As opposed to this, in the background art, the molecular film is formed on the nozzle plate where the number of OH groups that terminate the surface thereof is not large, and therefore the density of the film is low. In addition, in the molecular film 24 that is formed through polymerization in this embodiment, the silicon atoms 24a bond three-dimensionally and the long-chain RF groups 24b are complicatedly entangled with each other. Accordingly, the film is thick and has a high density. As opposed to this, in the background art, the silicon atoms in the film bond two-dimensionally to the nozzle plate. Therefore, the film is thin. In addition, since the density of the film is low, the entangled structure of the long-chain RF groups in the film is disentangled when the film is dipped in a liquid. As a result, the liquid repellency of the film does not last long. However, in the embodiment of the present invention, since the density of the film is high and the long-chain RF groups are complicatedly entangled with each other. Accordingly, even when the film is dipped in a liquid, the long-chain RF groups are not disentangled. As a result, the component of ink 26 could hardly penetrate into the molecular film 24, and the film may sustain its liquid repellency for a long period of time. Even when pigment-based ink lands thereon, the film repels it immediately. The embodiment of the invention makes it unnecessary a special technique for removing adhered ink, in wiping performed at the start of printing with an ink-jet printer. Thus, wiping can be easily performed. FIG. 5 shows one example of an inkjet printer equipped with the inkjet printer head 10. The durability of the nozzle plate 18 processed for liquid repellency according to the invention is excellent, and those coated with an ink-repellent film of excellent organic solvent resistance are applicable to industrial use. In this embodiment illustrated herein, the nozzle plate 18 formed of stainless steel is dipped in a solution of the silane coupling agent. As other embodiments, any other metal than stainless steel, such as nickel or iron, may also be used for the material for the nozzle plate 18, and all metal may apply to the nozzle plate 18. In addition, any other substance than metal may also be used for the material for the nozzle plate 18. For example, glass or other silicon material may be used. For the parts of inkjet printer of which the substrate is formed of a composite material or a resinous material as described above but not stainless steel, for example, for head cap, head cleaning wiper, head cleaning wiper-holding lever, gear, platen or carriage thereof, an undercoat film that contains SiO2, ZnO, NiO, SnO2, Al2O3, ZrO2, copper oxide, silver oxide, chromium oxide or iron oxide may also be used as well as the plasma polymerization film of silicone material mentioned hereinabove. The undercoat film that contains SiO2, ZnO, NiO, SnO2, Al2O3, ZrO2, copper oxide, silver oxide, chromium oxide or iron oxide may be formed in any mode of liquid film formation (e.g., coating, spraying, dipping), vapor deposition or sputtering, as well as plasma polymerization. In the embodiment illustrated hereinabove, an piezoelectric element is used as an ink droplet-jetting element, serving to jet out the ink having been stored in the pressure room through the inkjet orifice. However, the invention includes another embodiment of disposing a heating element inside the pressure room and thereby jetting out ink droplets. The liquid-jet head of the embodiment illustrated above is an inkjet recording head, and this is for inkjet recording devices. Not limited thereto, the invention widely covers all types of liquid-jet heads and all types of liquid-jet devices. The liquid-jet heads that the invention covers include, for example, recording heads in image-recording devices such as printers; colorant-jet heads used in producing color filters for liquid-crystal displays, etc.; electrode material-jet heads used in forming electrodes in organic EL displays, FED (face-emitting displays), etc.; and biomaterial-jet heads used in producing biochips. While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. The present application is based on Japanese patent application Nos. 2003-129263 (filed May 7, 2003), 2003-129261 (filed May 7, 2003) and 2004-102925 (filed March 31, 2004), the contents thereof being herein incorporated by reference. | <SOH> BACKGROUND OF THE INVENTION <EOH>An inkjet printer head, one embodiment of liquid-jet head through which liquid droplets are jetted out toward media via the nozzle orifices thereof, has a nozzle plate, and a plurality of fine inkjet orifices through which ink is jetted out are formed in the nozzle plate at fine intervals. If ink adheres to the surface of the nozzle plate, then other ink that is jetted out later may be influenced by the surface tension and the viscosity of the previously-adhering ink to have a curved jetting trajectory. This arises a problem that the ink could not be applied to a predetermined site. Accordingly, the nozzle plate surface has to be subjected to liquid-repelling treatment for protecting it from ink adhesion. Some methods mentioned below are known as the technique of liquid-repelling treatment. One of the methods is as follows: A nozzle plate at room temperature is dipped in a solution of a liquid-repellent silane coupling agent such as an alkoxysilane solution for tens seconds. In this stage, the temperature of the alkoxysilane is at around room temperature. Next, the dipped nozzle plate is pulled up out of the solution at a rate of about few mm/sec, thus forming a monomolecular film of an alkoxysilane polymer on its surface. The nozzle plate is then dried for one full day at room temperature to vaporize the solvent, thereby obtaining a water-repellent monomolecular film on the metal surface of the nozzle plate through dehydrating polycondensation. As another example of the methods, a method described in Patent Document 1 can be cited. This method comprises dipping an absorbent in a mixture of a fluorine-containing polymer compound and a compound having a fluorine-substituted hydrocarbon group and a silazane, alkoxysilane or halogenosilane group, then pulling it up out of the solution, and moving the absorbent while pressed against a nozzle plate to effect coating on the nozzle plate. After thus coated, the nozzle plate is thermally dried and cured at 150° C. for 1 hour to thereby form a liquid-repellent film thereon. As a still other example of the methods, a method described in Patent Document 2 can be cited. This method comprises masking a nozzle plate, at a part thereof not requiring liquid-repellency, with an aluminium mask, and dipping it in a solution mixed with a substance having a plurality of trichlorosilyl groups, for about 30 minutes to thereby form a chlorosilane monomolecular film thereon. Then, the chlorosilane monomolecular film is washed with chloroform and then with water so that it is reacted to form a siloxane monomolecular film. The siloxane monomolecular film is dipped in a solution of a substance having a fluorocarbon group and a chlorosilane group for about 1 hour, whereby a fluorine-containing monomolecular film is formed on the surface of the nozzle head and the thin aluminium film thereon. Next, the thin aluminium film is etched away, and thus a liquid-repellent monomolecular film is formed on the surface of the nozzle head. Patent Document 1: JP-A 5-116309 Patent Document 2: JP-A 5-116324 The alkoxysilane molecular film reacts with the OH group that terminates the nozzle plate surface and bonds to the nozzle plate. Accordingly, if a large number of OH groups exist on the nozzle plate surface, then alkoxysilane molecules corresponding to the existing OH groups bond to the nozzle plate. In other words, if a larger number of OH groups exist thereon, then the resulting molecular film has a higher density and, as a result, the liquid-repellency of the resulting nozzle plate is higher. However, since the number of OH groups existing on the surface of metal such as stainless steel is smaller than that on the surface of glass or the like, the obtained molecular film formed through polymerization of a silane coupling material on the surface of metal merely had a low density and poor adhesion. Accordingly, there was a problem that the water-repellency of the molecular film is low and that the film could not ensure its water-repellency for a long period of time. Ink heretofore used in the background art was generally dye-based ink, and its solvent was water. Therefore, a water-repellent molecular film could repel such dye-based ink so long as it has water repellency. Recently, however, pigment-based ink has become used to cope with high-quality prints from digital still cameras, etc. For the solvent for such pigment-based ink, a resin-based dispersant is used. Therefore, molecular films for printer members for such pigment-based ink are required to have both water repellency and oil repellency (hereinafter collectively referred to as “liquid repellency”). However, the molecular films disclosed in Patent Documents 1 and 2 do not have both water repellency and oil repellency, and hence involve a problem that the molecular films are wetted. Heretofore, the members of liquid-jet devices other than nozzle plates were not treated for ink repellency. The absence of ink-repellency treatment arises the following problem. Ink adheres to no small extent to the members such as cap and wiper that directly contact with ink, and if the members are formed of wettable material, then the ink having adhered thereto may stay thereon as such. When the adhered ink is left as it is, it may thicken to cause staining and operation failure of the members. Especially with respect to wiper members, ink is led through or to various members, such as from wiper body (rubber, elastomer, urethane) to wiper-holding lever (polyoxymethylene (POM)), then to system body (acrylonitrile-butadiene-styrene (ABS)) and to waste absorbent, and is absorbed by these members. Therefore, there is a probability that ink may be hardly led through or to these members. In addition, thickened ink may adhere to a lower part of a carriage on which a head is to be mounted, and it may be transferred onto the head upon operation of the wiper. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made for solving the above-mentioned problems. Accordingly, an object of the invention is to provide a member having a liquid-repellent film of a metal alkoxide in which the adhesion of the metal alkoxide liquid-repellent film to the surface of the substrate such as nozzle plate is high and the density of the liquid-repellent film is high. Another object of the invention is to provide a constitutive member comprising the above-mentioned member. A still other object of the invention is to provide a nozzle plate comprising the member, and to provide a liquid-jet head and a liquid-jet device that comprise the nozzle plate. Other objects and effects of the invention will become apparent from the following description. To attain the above-mentioned objects, the invention is to use liquid-repellent film-coated members not only for nozzle plate (formed of metal) of liquid-jet head in liquid-jet devices but also for any other system-constituting members (formed of resin material, composite material) of liquid-jet devices. In the invention, the liquid-repellent film-coated member is constructed by treating the surface of the undercoat film formed on the surface of a substrate for OH formation, and then forming thereon a liquid-repellent film of a metal alkoxide molecular film, preferably, employing a metal alkoxide having a fluorine-containing long-chain polymer group as the metal alkoxide. Thereby, the invention has made it possible to prevent staining of system members and to prevent operation failure thereof, and has succeeded in solving the above-mentioned problems. Specifically, the above-mentioned objects of the invention have been achieved by providing the following members, nozzle plate, liquid-jet head, and liquid-jet devices. (1) A member comprising a substrate, an undercoat film formed on a surface of the substrate, and a liquid-repellent film of metal alkoxide formed on a surface of the undercoat film. (2) The member according to item (1) above, wherein the liquid-repellent film is a molecular film of a polymer of metal alkoxide. (3) The member according to item (1) above, wherein the metal alkoxide has a fluorine-containing long-chain polymer group. (4) The member according to item (1) above, wherein the metal alkoxide is a metal acid salt having a liquid-repellent group. (5) The member of according to item (1) above, wherein the metal alkoxide is a silane coupling agent. (6) The member according to item (1) above, wherein the undercoat film comprises a plasma polymerization film of a silicone material, or contains SiO 2 , ZnO, NiO, SnO 2 , Al 2 O 3 , ZrO 2 , copper oxide, silver oxide, chromium oxide or iron oxide. (7) The member according to item (1) or (2) above, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through oxidation and hydrogenation; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. (8) The member according to item (1) or (2) above, wherein the liquid-repellent film is formed by a process comprising: terminating the surface of the undercoat film with OH group through irradiation with plasma or UV rays; and reacting a metal alkoxide with the OH group at the surface of the undercoat film. (9) The member according to item (1) above, wherein the substrate comprises a metal material or a composite material. (10) The member according to item (1) above, wherein the substrate comprises a resinous material. (11) The member according to item (9) above, wherein the metal material is stainless steel. (12) The member according to item (9) above, wherein the composite material contains silicon, sapphire or carbon. (13) The member according to item (10) above, wherein the resinous material comprises at least one compound selected from the group consisting of polytetrafluoroethylene, polyethylene, polyimide, polyamidimide, polyphenylene sulfide, polyether-ether ketone, polyoxymethylene, polystyrene, acrylonitrile-butadiene-styrene, polybutylene terephthalate, polyphenylene ether, potassium titanate fiber-composite resin, polypropylene, ethylene-propylene-diene tercopolymer, olefin elastomer, urethane elastomer, chloroprene rubber, silicone rubber and butyl rubber. (14) The member according to item (1) above, wherein the substrate is resistant to heat at least at 400° C., and the liquid-repellent film is formed on the undercoat film by a process comprising: heating the undercoat film; and dipping the undercoat film in a metal alkoxide solution while heated. (15) The member according to item (14) above, wherein the heating temperature of the undercoat film falls between 200 and 400° C. (16) A nozzle plate for a liquid-jet head, which comprises the member according to any of items (1) to (14) above. (17) A liquid-jet head comprising the nozzle plate according to item (16) above. (18) A liquid-jet device equipped with the liquid-jet head according to item (17) above. (19) The member according to any of items (1) to (8), (10) and (13) above, which is a head cap, a head cleaning wiper, a head cleaning wiper-holding lever, a gear, a platen, or a carriage. (20) A liquid-jet device equipped with the member according to item (19) above. As so described hereinabove, the invention is to use liquid-repellent film-coated members not only for nozzle plate (mainly formed of metal) of liquid-jet head in liquid-jet devices but also for any other system-constituting members (including those formed of resin material or composite material) such as head cap, head cleaning wiper, head cleaning wiper-holding lever, gear, platen or carriage of liquid-jet devices. Applying the ink-repellent treatment to parts of system units solves the following troubles (i) to (iii) with liquid-jet devices. (i) When the parts that frequently contact with ink, such as head cap, head cleaning wiper, head cleaning wiper-holding lever, etc. are processed for ink repellency, then the parts themselves can be protected from ink adhesion thereto. Specifically, it is as follows: Head cap receives few cap marks (adhesion of thickened ink) from the face of nozzle plate (NP). Wiping performance of the head cleaning wiper lasts long as ink adhesion thereto reduces. Head cleaning wiper-holding lever readily lead waste ink from wiper to waste absorbent. Gear operation failure caused by ink wrapping around thereof is reduced. Thickened ink transfer to head caused by thickened ink adhesion to carriage is prevented. (ii) The parts themselves (especially those for driving operation, such as gear) are protected from ink adhesion thereto, and are therefore prevented from operation failure owing to thickened ink adhesion thereto. (iii) The system-constituting members may be processed for ink repellency irrespective of the contact angle of their materials (mainly engineering plastic resins such as polyphenylene sulfide (PPS), polyoxymethylene (POM), acrylonitrile-butadiene-styrene (ABS), elastomer, rubber), and therefore recovery of waste ink is easy. In other words, ink having adhered to head cap and wiper can be readily led to waste absorbent. In the liquid-repellent film-coated member of the invention, an undercoat film is formed on the surface of the substrate as described above. The material for the substrate is not specifically limited, and may be any of metal material, composite material and resinous material. More effectively, the surface roughness (Ra) of the substrate is 65 nm or less, preferably 35 nm or less. The undercoat film may be suitably selected and used depending on the substrate. For example, it may comprise a plasma polymerization film of a silicone material, or may contain SiO 2 , ZnO, NiO, SnO 2 , Al 2 O 3 , ZrO 2 , copper oxide, silver oxide, chromium oxide or iron oxide. The surface of the undercoat film is oxidized and hydrogenated, specifically, it is irradiated with plasma or UV rays and then exposed to air whereby the surface may be terminated with OH group (i.e., the surface is hydroxylated). Then, when a liquid-repellent film of metal alkoxide is formed on the thus-processed undercoat film, the OH groups on the undercoat film bond to the liquid-repellent film of metal alkoxide. As a result, a liquid-repellent film of metal alkoxide having high density and high adhesion can be formed. In the case where the substrate is resistant to heat at least at 400° C., the undercoat film may be dipped in a metal alkoxide solution while heated, so as to form a liquid-repellent film of metal alkoxide on the undercoat film. In this embodiment, a molecular film of alkoxysilane polymer having a uniform thickness may be formed on the surface of the undercoat film. In the molecular film thus formed, the metal atom derived from the metal alkoxide bonds to the undercoat film via the oxygen atom. When the metal alkoxide used in the invention has a fluorine-containing long-chain polymer group, then the fluorine-containing long-chain polymer group that bonds to the metal atom derived from the metal alkoxide exists on the surface side of the film. Referring to the condition of the molecular film in this stage, the metal atoms bond three-dimensionally and the fluorine-containing long-chain polymer groups are complicatedly entangled with each other. Accordingly, the molecular film is in a dense condition, and ink hardly penetrates thereinto. As a result, the liquid-repellent film-coated member of the invention ensures excellent liquid repellency and keep it for a long period of time. In addition, because of its high density, the liquid-repellent film has excellent abrasion resistance. A summary of a process for producing the liquid-repellent film-coated member of the invention is described below. The liquid-repellent film-coated member of the invention is produced according to a process comprising at least (1) substrate washing, (2) undercoat film formation, (3) surface activation of undercoat film, (4) liquid-repellent metal alkoxide film formation, (5) wetting and drying treatment, and (6) annealing. The step (1) “substrate washing” is for removing unnecessary matters that are inconvenient for undercoat film formation, from the substrate. Details of the washing condition shall be suitably determined depending on the material, form and size of the substrate. Details of the film-forming condition in the step (2) “undercoat film formation” shall be suitably determined depending on the material, form and size of the substrate and on the type and thickness of the undercoat film to be formed. The step (3) “surface activation of undercoat film” is for imparting OH groups to the surface of the undercoat film in order that the liquid-repellent film of metal alkoxide to be formed thereon is more firmly bonded thereto. Specifically, examples of this step include irradiation of the undercoat film surface with plasma or UV rays. Details of the treatment condition shall be suitably determined depending on the type and thickness of the undercoat film and on the type of the metal alkoxide for the liquid-repellent film to be formed. Details of the film-forming condition in the step (4) “liquid-repellent metal alkoxide film formation” shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. In the step (5) “wetting and drying treatment”, the coated substrate is put in a high-temperature high-humidity atmosphere for polymerization of the metal alkoxide to give a molecular film thereof. Details of the treatment condition shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. In the step (6) “annealing”, the coated substrate is treated at a temperature higher than the temperature in the previous step (5) “wetting and drying treatment”, and this is for terminating the polymerization reaction of the metal alkoxide. Details of the treatment condition shall be suitably determined depending on the type of the metal alkoxide and on the intended liquid repellency of the film. The liquid-jet head of the invention has a feature that it comprises the nozzle plate mentioned above. The liquid-jet device of the invention has a feature that it comprises the above-mentioned liquid-jet head, or comprises a head cap, a head cleaning wiper, a head cleaning wiper-holding lever, a gear, a platen and/or a carriage, each of which has the liquid-repellent film-coated member of the invention. | 20040430 | 20070911 | 20050106 | 66777.0 | 0 | SOLOMON, LISA | LIQUID-REPELLENT FILM-COATED MEMBER, CONSTITUTIVE MEMBER OF LIQUID-JET DEVICE, NOZZLE PLATE OF LIQUID-JET HEAD, LIQUID-JET HEAD, AND LIQUID-JET DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,510 | ACCEPTED | Closing in an electronic market | A method for trading a security in an electronic market includes receiving closing orders and orders for the security traded in the electronic market, disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determining a closing price for the security based on the closing orders and orders, and executing at least some of the closing orders at the determined closing price. | 1. A method for trading a security in an electronic market, comprising: receiving closing orders and orders for the security traded in the electronic market; disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading; determining a closing price for the security based on the closing orders and orders; and executing at least some of the closing orders at the determined closing price. 2. The method of claim 1, wherein the closing orders comprise imbalance only orders. 3. The method of claim 2, further comprising: modifying a limit price associated with one of the imbalance only orders based on a comparison between the limit price and an inside price. 4. The method of claim 1, wherein the closing orders comprise limit-on-close orders. 5. The method of claim 1 wherein the closing orders comprise market-on-close orders. 6. The method of claim 1, further comprising periodically producing the order imbalance indicator over a series of time periods. 7. The method of claim 6, wherein the order imbalance indicator at a first of the series of time periods comprises at least one of: an inside match price; a number of shares paired at an inside match price; an on-close order imbalance; a buy/sell direction of the on-close order imbalance; an indicative clearing price range associated with the first of the series of times; or a percentage by which an indicative price varies from an inside price. 8. The method of claim 1, wherein determining the closing price comprises: determining a preliminary closing price; comparing the preliminary closing price to a benchmark value representing market conditions prior to the close of trading; and determining the closing price based on the comparison. 9. An electronic market for trading of securities, comprising: a client station for entering a closing order for a security traded in the electronic market; a server system comprising: a queue storing the closing order along with other orders; a process to disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading; and a process to determine a closing price for the security based on the stored orders and execute at least some of the orders at the determined closing price. 10. The method of claim 9, wherein the closing orders comprise imbalance only orders. 11. The method of claim 10, further comprising: modifying a limit price associated with one of the imbalance only orders based on a comparison between the limit price and an inside price. 12. A computer program product residing on a computer-readable medium for use in an electronic market for trading of securities comprises instructions for causing a system to: receive closing orders and orders for the security traded in the electronic market; disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading; determine a closing price for the security based on the closing orders and orders; and execute at least some of the closing orders at the determined closing price. 13. The method of claim 12, wherein the closing orders comprise imbalance only orders. 14. The method of claim 13, further comprising: modifying a limit price associated with one of the imbalance only orders based on a comparison between the limit price and an inside price. 15. A method for trading a security in an electronic market, comprising: receiving closing orders and orders for the security traded in the electronic market; determining a closing price for the security based on the closing orders and orders, the closing price being within a predetermined range of a benchmark value representing market conditions prior to the close of trading; and executing at least some of the closing orders at the determined closing price. 16. The method of claim 15, wherein the benchmark value comprises a volume weighted average of orders executed during a predetermined time period before the close of trading. 17. A system comprising: a server system configured to send an information data stream to a trading system, the data stream comprising at least one of: an inside match price; or a near indicative clearing price. 18. The system of claim 17, wherein the inside match price is selected from an inside bid price, an inside offer price, an inside bid-offer midpoint price, or zero, based on an imbalance of closing orders. 19. The system of claim 17, wherein the near indicative clearing price comprises a price at which closing orders and continuous orders would execute if paired with each other. 20. The system of claim 17, wherein the server system resides in a venue for trading securities electronically. 21. The system of claim 20, wherein the venue is an electronic commerce network, an auction, an exchange, or an electronic exchange. 22. A system comprising: a client station coupled to a server system that is part of an electronic venue for trading financial products, and configured to send an order for a security to the server system, the order comprising data fields including: a price value; a number of shares value; and an indicator value that indicates the order as an imbalance only order. 23. The system of claim 22, wherein the imbalance only order executes in response to an imbalance in liquidity associated with the electronic venue. | BACKGROUND The invention relates to trading systems, particularly financial trading systems. Electronic equity markets, such as The Nasdaq Stock Market® collect, aggregate and display trade information to market participants. Market participants initiate trades of securities by sending trade information to the electronic market on which the securities are traded. The trade information includes continuous orders for execution during a market trading session. After the close of a market trading session, a closing price is determined for each security. SUMMARY Certain investors, including mutual funds and derivative traders, need to execute transactions in a security at the closing price using “on-close” orders. Some electronic markets perform a closing process that takes the final trade of a security executed during the trading session as the closing price for that security. Since this closing process is performed without special treatment for on-close orders, an electronic market center does not guarantee that a particular on-close order will trade at the closing price. Without a guarantee from an electronic market center that a particular order will trade at the closing price, investors turn to manual markets or broker-dealers to guarantee them the closing price for their transactions. In general, in one aspect, the invention features a method for trading a security in an electronic market. The method includes receiving closing orders and orders for the security traded in the electronic market, disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determining a closing price for the security based on the closing orders and orders, and executing at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features an electronic market for trading of securities. The electronic market includes a client station for entering a closing order for a security traded in the electronic market, and a server system. The server system includes a queue storing the closing order along with other orders, a process to disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, and a process to determine a closing price for the security based on the stored orders and execute at least some of the orders at the determined closing price. In general, in another aspect, the invention features a computer program product residing on a computer-readable medium for use in an electronic market for trading of securities comprises instructions for causing a system to receive closing orders and orders for the security traded in the electronic market, disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determine a closing price for the security based on the closing orders and orders, and execute at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features a method for trading a security in an electronic market. The method includes receiving closing orders and orders for the security traded in the electronic market, determining a closing price for the security based on the closing orders and orders, the closing price being within a predetermined range of a benchmark value representing market conditions prior to the close of trading, and executing at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features a system including a server system configured to send an information data stream to a trading system. The data stream includes at least one of an inside match price or a near indicative clearing price. In general, in another aspect, the invention features a system including a client station coupled to a server system that is part of an electronic venue for trading financial products, and configured to send an order for a security to the server system. The order includes data fields including: a price value, a number of shares value, and an indicator value that indicates the order as an imbalance only order. Embodiments of the invention may include one or more of the following features. The closing orders include imbalance only orders. The method includes modifying a limit price associated with one of the imbalance only orders based on a comparison between the limit price and an inside price. The closing orders may include limit-on-close orders and/or market-on-close orders. The method also includes periodically producing the order imbalance indicator over a series of time periods. The order imbalance indicator at a first of the series of time periods includes at least one of: an inside match price, a number of shares paired at an inside match price, an on-close order imbalance, a buy/sell direction of the on-close order imbalance, an indicative clearing price range associated with the first of the series of times, or a percentage by which an indicative price varies from an inside price. Determining the closing price includes determining a preliminary closing price, comparing the preliminary closing price to a benchmark value representing market conditions prior to the close of trading, and determining the closing price based on the comparison. The benchmark value includes a volume weighted average of orders executed during a predetermined time period before the close of trading. The inside match price is selected from an inside bid price, an inside offer price, an inside bid-offer midpoint price, or zero, based on an imbalance of closing orders. The near indicative clearing price includes a price at which closing orders and continuous orders would execute if paired with each other. The server system resides in a venue for trading securities electronically. The venue is an electronic commerce network, an auction, an exchange, or an electronic exchange. The imbalance only order executes in response to an imbalance in liquidity associated with the electronic venue. Embodiments of the invention may include one or more of the following advantages. Closing orders are executed in a single transaction. The information included in the imbalance indicator improves transparency and price discovery. Disseminating the imbalance indicator gives market participants an opportunity to adjust their trading based on the imbalance indicator by adjusting the price and/or size of existing imbalance only orders, or by submitting additional imbalance only orders. The closing process improves liquidity, reduces risk and reduces costs for investors seeking to trade at the closing price. Other features and advantages of the invention will become apparent from the following description, and from the claims. DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of an electronic market for trading securities. FIG. 2 shows exemplary order formats. FIG. 3 is a flow chart showing a process for determining a closing price. DESCRIPTION Referring to FIG. 1, an electronic market 10 is shown. The electronic market 10 includes client stations 12 in communication with a server system 20 over a distributed computing network 14 (e.g., the Internet, an intranet, a local area network, or other similar form of network). A client station 12 includes a process to send trade information (e.g., continuous orders, closing orders, etc.) entered by a user (e.g., a market participant, a market maker, etc.) to the server system 20. The server system 20 collects trade information from the client stations 12 and enters valid orders into a storage module 21. An order identifies a security and a number of shares of the security to be traded. A priced buy order includes a bid price at which to buy the shares. A priced sell order includes an offer price at which to sell the shares. The storage module 21 includes a queue 22 for each security traded in the market 10 that stores orders for that security. The server system 20 includes a trading module 24 that executes trades of securities electronically based on the entered orders. After an order is executed or canceled, the order is removed from the storage module 21. The trading module 24 also includes a closing process 26 that runs after the end of a trading session to determine a closing price for each security and execute at least some of the entered orders for a security at the determined closing price. The server system 20 disseminates information about the market on a data feed 16 (over the network 14 or, alternatively, over a separate communication line) to the client stations 12. In the electronic market 10, a user electronically trades with other users (as opposed to trading on a trading floor). Trading can occur over extended periods of time. An example of an electronic market, the Nasdaq Stock Market®, allows trading during a trading session (i.e., 9:30 a.m. to 4:00 p.m. ET). Orders placed and executed during the trading session are “continuous orders.” The server system 20 maintains an “inside bid” price corresponding to the price of the best (i.e., highest) continuous buy order, and an “inside offer” price corresponding to the price of the best (i.e., lowest) continuous sell order, based on the most recently received continuous orders. Orders placed during the trading session to be executed after the trading session at the closing price are “closing orders.” Two types of closing orders are “On-Close” orders and “Imbalance Only” (IO) orders. On-Close orders can be un-priced and entered as “market-on-close” (MOC) orders, or priced and entered as “limit-on-close” (LOC) orders. A LOC buy order includes a buy limit price and a LOC sell order includes a sell limit price. On-Close orders, both MOC and LOC orders, execute at the price determined by the closing process. Thus, LOC buy orders are subject to price improvement (i.e., reduction) if the buy limit price is greater than the determined closing price, and LOC sell orders are subject to price improvement (i.e., increase) if the sell limit price is less than the determined closing price. In one embodiment, On-Close orders can be entered, cancelled, and/or corrected between 9:30:01 a.m. EST and 3:50:00 p.m., e.g., just after market open and just prior to market close, but are not displayed or disseminated by the server system 20. IO orders execute only against any imbalance in liquidity, supplementing the liquidity provided by On-Close orders. IO order types are priced limit orders. The server system 20 enforces rules for entering or modifying submitted IO orders. For example, the server system 20 rejects IO orders that are submitted without a price. In one embodiment, IO orders are entered up until 3:59:59, e.g., just prior to market close, but they cannot be cancelled or modified after, e.g., 3:50:00 except to increase the number of shares or to increase the buy limit price or decrease the sell limit price. IO sell orders execute at or above the 4:00:00 inside offer, and IO buy orders execute at or below the 4:00:00 inside bid. Thus, IO buy orders are subject to price improvement (i.e., reduction) if the buy limit price is greater than the 4:00:00 inside bid, and LOC sell orders are subject to price improvement (i.e., increase) if the sell limit price is less than the 4:00:00 inside offer. As with On-Close orders, IO are not displayed or disseminated by the server system 20. Referring to FIG. 2, a first exemplary format 30 for orders includes a field 31 for entering a name or symbol representing a security, a b/s field 32 that represents whether the order is a buy (b) or sell (s) order, a price field 34, and a size field 36 that represents the number of shares in the order. The format 30 also includes a type field 37. The type field 37 can have various values representing different types of orders. If the value of the type field 37 is “MOC”, “LOC” or “IO”, then the order is a closing order. The value of the price field 34 is interpreted as a limit price for LOC and IO orders. The value of the size field 36 indicates a number of shares to be traded upon execution of the order. Alternatively, instead of including an explicit type field 37, the value of the type field 37 can be implicitly derived from evaluation of other fields. A second exemplary format 38 for orders includes an optional relative price field 40 for specifying a relative limit price for IO orders. An IO order that uses this relative price field 40 does not include a value in the price field 34, but instead specifies a limit price as a percentage deviation from a predetermined benchmark price. Orders may include other fields. Imbalance Indicator The information disseminated over the data feed 16 includes an “order imbalance indicator.” The order imbalance indicator includes information about closing orders, as described in more detail below, and the price at which those closing orders would execute at the time the order imbalance indicator is disseminated. For example, the order imbalance indicator is disseminated at predetermined time intervals before the close of the market. The information included in the order imbalance indicator at a given time, for a given security is based on an “order imbalance” in that exists in the market at that time. The trading module 24 identifies an order imbalance based on orders in a queue 22 for a security at a particular time by identifying a number of On-Close buy shares “MB” that are “marketable” at or above the inside offer (i.e., are MOC or LOC priced at or above the inside offer), and a number of On-Close sell shares “MS” that are “marketable” at or below the inside bid (i.e., are MOC or LOC priced at or below the inside bid). The trading module 24 identifies a number of shares of sell closing orders “PS” (On-close and IO orders) that can be paired (or “crossed”) with the marketable On-Close buy shares, and a number of shares of buy closing orders “PB” (On-close and IO orders) that can be paired with the marketable On-Close sell shares. The order imbalance corresponds to the number of shares of On-Close orders that are not executed when the maximum number of shares of closing orders are paired at the inside “inside match price.” When MIN(MB,PS)>MIN(MS,PB) the inside match price is the inside offer and there is a “buy side” order imbalance of MB-PS shares. When MIN(MB,PS)<MIN(MS,PB) the inside match price is the inside bid and there is a “sell side” order imbalance of MS-PB shares. The order imbalance can also be calculated as MAX(MB-PS,MS-PB). When the order imbalance is zero (i.e., MB-PS<0 and MS-PB<0) the inside match price is the “inside bid-offer midpoint” (i.e., the average of the inside bid and the inside offer). If there are no On-Close orders, then the inside match price is zero. The following information, described in (1)-(5) below, can be included in the order imbalance indicator at a given time, for a given security. The order imbalance indicator can be disseminated as a data stream and have a format that includes at least one of the information fields: PSH, MP, IMB, ISH, IPR, or PVI described below. (1) Paired Shares (PSH) and Inside Match Price (MP) The imbalance indicator includes the number of shares (PSH) corresponding to MOC, LOC and IO orders that are eligible to be paired at the current inside match price (MP), and the current inside match price (i.e., the match price at the given time). (2) Imbalance (IMB) and Imbalance Shares (ISH) The imbalance indicator includes the number of shares (ISH) corresponding to MOC and LOC orders that are not eligible to be paired at the current inside match price (i.e., the On-Close order imbalance), and a label (IMB) indicating “Buy” for a buy side imbalance, “Sell” for a sell side imbalance, “Zero Imbalance” for a zero order imbalance (i.e., all On-Close orders are paired), or “No Imbalance” when there are no On-Close orders. Alternatively, the label IMB can be indicated by numerical values. For example Buy or Sell can be indicated by positive or negative values, and a Zero Imbalance and/or No Imbalance can be indicated by a value of 0. (3) Indicative Price Range (IPR) The imbalance indicator includes an indicative price range for the closing price if the closing were to occur at the given time. The indicative closing price range is bounded on the far side (i.e., the top of the range) by the “far indicative closing price” at which the MOC, LOC, and IO orders would execute if paired with each other (with no unpaired On-Close orders). The indicative closing price range is bounded on the near side (i.e., the bottom of the range) by the “near indicative closing price” at which the MOC, LOC, IO and continuous orders (excluding volume that is available only by order delivery) would execute if paired with each other (with no unpaired On-Close orders). For either the near or far indicative closing price calculations, if the On-Close orders cannot be fully paired against offsetting orders, then no indicative closing price exists and the server system 20 disseminates a “no indicative price” indicator including the phrase “market buy” for a buy side imbalance or “market sell” for a sell side imbalance, and one or both of the near and far indicative closing prices are listed as zero. If there are no On-Close orders, the near and far indicative closing prices are listed as zero and the “no indicative price” indicator is blank. (4) Price Variance Indicator (PVI) The imbalance indicator includes a price variance indicator based on the percent by which the near indicative price varies from the inside bid, if the near indicative price is less than the inside bid, or from the inside offer, if the near indicative price is larger than the inside offer. If the near indicative price is between the inside bid and the inside offer (i.e., within the “inside spread”), then the price variance indicator is zero. The value of the price variance indicator is disseminated in coded form according to the codes listed in Table 1. TABLE 1 Code Value L <1% 1 1% 2 2% 3 3% 4 4% 5 5% 6 6% 7 7% 8 8% 9 9% A 10% to 19.99% B 20% to 29.99% C 30% or greater <space> Not Calculated (5) Timestamp (TS) The imbalance indicator includes the time (HH:MM:SS) when the Imbalance was calculated. The time corresponds to one of a series of times for dissemination of the imbalance indicator. At 3:50:00, the trading module 24 begins transmitting the order imbalance indicator over the data feed 16 (e.g., a Nasdaq TotalView® data feed, or an Application Programming Interface (API) data feed). The imbalance indicator is disseminated beginning at 3:50:00 and thereafter at more frequent intervals as the time to market close decreases: every 30 seconds beginning at 3:50, every 15 seconds beginning at 3:55, every 5 seconds beginning at 3:58, and every second from 3:59 until market close. Imbalance Indicator Example For example, at 3:59:00 p.m. the queue 22 for a security has the following continuous orders: TABLE 2 Buy Orders Size Price 4000 19.99 3000 19.98 2000 19.97 10000 19.96 TABLE 3 Sell Orders Size Price 500 20.00 35000 20.01 3000 20.02 10000 20.04 The inside bid is indicated as $19.99 and the inside offer is indicated as $20.00. The size of each order in number of shares is included in the queue 22 and listed in Table 2 and Table 3 above and Table 4 and Table 5 below. At 3:59:00 p.m., the queue 22 has the following closing orders: TABLE 4 Buy Orders Size Price Type 8000 Market MOC 3000 20.02 LOC 1000 19.99 LOC 4000 19.97 LOC 500 19.97 IO TABLE 5 Sell Orders Size Price Type 5000 Market MOC 3000 19.98 LOC 1000 19.98 IO 1000 20.00 IO 1000 20.02 LOC Based on these orders listed in Tables 2-5, the server system 20 would disseminate the following information in the order imbalance indicator: (1) 10,000 shares (PSH) paired at a $20.00 inside match price(MP); (2) 1,000 share (ISH) “Buy” imbalance (IMB); (3) indicative price range of $20.01-$20.02 (IPR); (4) variance indicator of “L” (PVI); (5) (TS) timestamp of “03:59:00.” Before determining the Paired Shares (PSH), the server system 20 temporarily re-prices (i.e., the queue 22 for the security stores the original price and a new price is stored in a temporary storage location in the storage module 21) IO buy or sell orders that are priced more aggressively than the inside bid or offer, respectively (as described above). In this example, the IO sell order of 1000 shares at $19.98, priced more aggressively than the inside offer of $20.00, is temporarily re-priced to $20.00. The IO orders are potentially re-priced again at the next dissemination of the order imbalance indicator based on the inside bid and offer at the time. The number of shares of On-Close buy orders MB that are marketable at or above the inside bid are 8,000 (at Market) and 3,000 (at $20.02) totaling 11,000 shares. The number of shares of sell closing orders PS that can be paired with those shares are 5,000 (at Market), 3,000 (at $19.98), and 2,000 (at $20.00; 1,000 of which correspond to the re-priced IO orders) totaling 10,000 shares. So the server system 20 is able to pair 10,000 shares (PSH) at the $20.00 inside offer, leaving a “Buy” (IMB) imbalance of 1,000 shares (ISH). The server system 20 determines the far indicative closing price as the price at which the greatest number of shares of MOC, LOC, and IO orders can be paired with each other. In this example, 11,000 shares can be executed at a price of $20.02. So the far indicative closing price is $20.02 The server system 20 determines the near indicative closing price as the price at which the greatest number of MOC, LOC, IO and continuous orders can be paired with each other. In this example, for the near indicative closing price, 11,000 shares can be executed at a price of $20.01 or $20.02. The server system 20 selects the price that leaves the smallest number of unpaired shares, which in this case is $20.01, leaving 4,500 unpaired shares on the sell side. (A price of $20.02 would leave 8,500 unpaired shares on the sell side.) So the near indicative closing price is $20.01. Closing Process At or shortly after market close (e.g., at 4:00:00 p.m.) the trading module 24 performs a closing process 26. The closing process 26 determines 40 a closing price for each security based on the closing orders and continuous orders in the storage module 21 at the close. After determining the final closing price, the closing process 26 executes 42 some or all of those orders at the determined final closing price. After the closing process 26 concludes (e.g., at approximately 4:00:05 p.m.) the server system 20 reports the closing orders executed (e.g., in a report to the consolidated tape for Nasdaq securities including the aggregate of shares executed at the closing price) and after hours trading may commence. The closing process 26 attempts to accomplish three goals, for each security, in decreasing priority: (1) maximize the number of shares executed at the closing price; (2) minimize On-Close order imbalance; and (3) minimize the distance of the closing price from the 4:00:00 inside bid-offer midpoint. Referring to FIG. 3, the closing process 26 determines 40 a final closing price for each security. The closing process 26 selects 50 a preliminary closing price that maximizes that number of shares executed. If more than one such price exists, the closing process 26 selects 52 a price that minimizes the On-Close order imbalance. If more than one such price exists, the closing process 26 selects 54 a price that is closest to the inside bid-offer midpoint at closing. After selecting a preliminary closing price, the closing process 26 performs a benchmark threshold test to protect against unusual occurrences (e.g., the closing price discovery mechanism described herein did not function as expected). The closing process 26 compares 56 the preliminary closing price of each security to one or more benchmark values representing market conditions approximately five seconds prior to the close. For example, one benchmark value that can be used is the volume weighted average of the orders executed by the trading module 24 over the period from 3:59:55 to 4:00:00 (Volume Weighted Average Price (VWAP)). Optionally, the volume weighted average of the inside bid-offer midpoint over the period from 3:59:54 to 3:59:57 (Volume Weighted Average Inside (VWAI)) can be used as a second benchmark value. If the preliminary closing price for a security is within a predetermined percentage (the “Threshold Percentage”) of the benchmark value (or of any of multiple benchmark values), the closing process 24 selects 58 the preliminary closing price as the final closing price for that security. The Threshold Percentage is selected, for example, based on market conditions and past results of the closing process 24. The server system 20 publicly publishes the Threshold Percentage (e.g., via the NasdaqTrader® website). Otherwise, if the preliminary closing price for a security is not within the Threshold Percentage of either the VWAI or the VWAP, the closing process 24 selects a final closing price for that security that is constrained to be within the Threshold Percentage of either benchmark according to the same three goals: (1) maximize the number of shares executed at the closing price; (2) minimize On-Close order imbalance; and (3) minimize the distance of the closing price from the 4:00:00 inside bid-offer midpoint. The closing process 24 selects 60 a closing price within the Threshold Percentage of either benchmark that maximizes that number of shares executed. If more than one such price exists, the closing process 26 selects 62 a price that minimizes the On-Close order imbalance. If more than one such price exists, the closing process 26 selects 64 a price that is closest to the inside bid-offer midpoint at closing. The closing process 26 executes 42 some or all of the orders for each security at the determined final closing price for that security. Order Execution Priority If, for a security, the closing process 26 executes fewer than all of the closing orders and all of the continuous orders that are available for automatic execution, then the closing process 26 executes orders in the following priority: (1) MOC orders, with time as the secondary priority (older orders before newer orders); (2) LOC orders, limit orders, IO orders, displayed quotes and reserve interest that are priced more aggressively than the final closing price, with time as the secondary priority; (3) LOC orders, IO orders, displayed interest of limit orders, and displayed interest of quotes at the final closing price, with time as the secondary priority; (4) Reserve interest at the Nasdaq Closing Cross price, with time as the secondary priority. The remaining unexecuted closing orders for that security are canceled. Closing Process Example For example, the continuous and closing orders for a security include following orders at closing (i.e., 4:00:00 p.m.): TABLE 6 Buy Orders Entry Time Side-type Size Price 3:00 Buy-OC 8000 Market 2:30 Buy-OC 3000 20.02 3:31 Buy-cont 4000 19.99 3:35 Buy-OC 1000 19.99 3:59 Buy-cont 3000 19.98 3:59 Buy-cont 2000 19.97 3:40 Buy-OC 4000 19.97 3:52 Buy-IO 500 19.97 3:30 Buy-cont 10000 19.96 TABLE 7 Sell Orders Entry Time Side-type Size Price 2:45 Sell-OC 5000 Market 3:00 Sell-OC 3000 19.98 3:55 Sell-IO 1000 19.98 3:59 Sell-cont 500 20.00 3:35 Sell-IO 1000 20.00 3:48 Sell-cont 5000 20.01 3:31 Sell-cont 3000 20.02 3:40 Sell-OC 1000 20.02 3:30 Sell-cont 10000 20.04 The closing process re-prices the 3:55 IO sell order priced at $19.98 to the inside offer price of $20.00 (based on the 3:59 continuous sell order priced at $20.00). The closing process 26 determines a final closing price of $20.01. Although 11,000 shares can be executed at both $20.01 and $20.02, and the On-Close order imbalance is 0 shares at both $20.01 and $20.02, the $20.01 price is closer to the 4:00:00 inside offer of $20.00. The closing process 26 executes 11,000 shares at the final closing price of $20.01 as follows: TABLE 8 Buy Orders Entry Time Side-type Size Shares Executed 3:00 Buy-OC 8000 ALL 2:30 Buy-OC 3000 ALL 3:31 Buy-cont 4000 0 3:35 Buy-OC 1000 0 3:59 Buy-cont 3000 0 3:59 Buy-cont 2000 0 3:40 Buy-OC 4000 0 3:52 Buy-IO 500 0 3:30 Buy-cont 10000 0 TABLE 9 Sell Orders Entry Time Side-type Size Shares Executed 2:45 Sell-OC 5000 ALL 3:00 Sell-OC 3000 ALL 3:55 Sell-IO 1000 ALL 3:59 Sell-cont 500 ALL 3:35 Sell-IO 1000 ALL 3:48 Sell-cont 5000 500 3:31 Sell-cont 3000 0 3:40 Sell-OC 1000 0 3:30 Sell-cont 10000 0 All shares of the eligible On-Close orders are executed. The 3:48 continuous sell order priced at $20.01 has 500 of its 5000 offered shares executed. The executed orders may be reported using an anonymous trading mechanism (e.g., reporting executed anonymous orders to the consolidated tape with SIZE as the contra party). The determined final closing price and the associated paired volume are disseminated via the data feed 16 as the “official closing price.” The closing process 26 (shown in FIG. 3) described herein is not limited to the embodiment described above; it may find applicability in any computing or processing environment. The closing process may be implemented in hardware, software, or a combination of the two. For example, the closing process may be implemented using circuitry, such as one or more of programmable logic (e.g., an ASIC), logic gates, a processor, and a memory. The closing process may be implemented in computer programs executing on programmable computers that each includes a processor and a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements). Each such program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language. The language may be a compiled or an interpreted language. Each computer program may be stored on an article of manufacture, such as a storage medium (e.g., CD-ROM, hard disk, or magnetic diskette) or device (e.g., computer peripheral), that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the functions of the closing process. The closing process may also be implemented as a machine-readable storage medium, configured with a computer program, where, upon execution, instructions in the computer program cause a machine to operate to perform the functions of the closing process described above. Embodiments of the closing process may be used in a variety of applications. Although the closing process is not limited in this respect, the closing process may be implemented with memory devices in microcontrollers, general purpose microprocessors, digital signal processors (DSPs), reduced instruction-set computing (RISC), and complex instruction-set computing (CISC), among other electronic components. Embodiments of the closing process may also be implemented using integrated circuit blocks referred to as core memory, cache memory, or other types of memory that store electronic instructions to be executed by a microprocessor or store data that may be used in arithmetic operations. Embodiments can be applied to a variety trading systems including a venue for trading securities electronically, such as an electronic commerce network, an electronic auction, an exchange, or an electronic exchange. The electronic market can use an opening process including any or all of the features described herein for the closing process (e.g., for determining an opening price before the opening of trading). A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. | <SOH> BACKGROUND <EOH>The invention relates to trading systems, particularly financial trading systems. Electronic equity markets, such as The Nasdaq Stock Market® collect, aggregate and display trade information to market participants. Market participants initiate trades of securities by sending trade information to the electronic market on which the securities are traded. The trade information includes continuous orders for execution during a market trading session. After the close of a market trading session, a closing price is determined for each security. | <SOH> SUMMARY <EOH>Certain investors, including mutual funds and derivative traders, need to execute transactions in a security at the closing price using “on-close” orders. Some electronic markets perform a closing process that takes the final trade of a security executed during the trading session as the closing price for that security. Since this closing process is performed without special treatment for on-close orders, an electronic market center does not guarantee that a particular on-close order will trade at the closing price. Without a guarantee from an electronic market center that a particular order will trade at the closing price, investors turn to manual markets or broker-dealers to guarantee them the closing price for their transactions. In general, in one aspect, the invention features a method for trading a security in an electronic market. The method includes receiving closing orders and orders for the security traded in the electronic market, disseminating an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determining a closing price for the security based on the closing orders and orders, and executing at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features an electronic market for trading of securities. The electronic market includes a client station for entering a closing order for a security traded in the electronic market, and a server system. The server system includes a queue storing the closing order along with other orders, a process to disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, and a process to determine a closing price for the security based on the stored orders and execute at least some of the orders at the determined closing price. In general, in another aspect, the invention features a computer program product residing on a computer-readable medium for use in an electronic market for trading of securities comprises instructions for causing a system to receive closing orders and orders for the security traded in the electronic market, disseminate an order imbalance indicator indicative of predicted trading characteristics of the security at the close of trading, determine a closing price for the security based on the closing orders and orders, and execute at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features a method for trading a security in an electronic market. The method includes receiving closing orders and orders for the security traded in the electronic market, determining a closing price for the security based on the closing orders and orders, the closing price being within a predetermined range of a benchmark value representing market conditions prior to the close of trading, and executing at least some of the closing orders at the determined closing price. In general, in another aspect, the invention features a system including a server system configured to send an information data stream to a trading system. The data stream includes at least one of an inside match price or a near indicative clearing price. In general, in another aspect, the invention features a system including a client station coupled to a server system that is part of an electronic venue for trading financial products, and configured to send an order for a security to the server system. The order includes data fields including: a price value, a number of shares value, and an indicator value that indicates the order as an imbalance only order. Embodiments of the invention may include one or more of the following features. The closing orders include imbalance only orders. The method includes modifying a limit price associated with one of the imbalance only orders based on a comparison between the limit price and an inside price. The closing orders may include limit-on-close orders and/or market-on-close orders. The method also includes periodically producing the order imbalance indicator over a series of time periods. The order imbalance indicator at a first of the series of time periods includes at least one of: an inside match price, a number of shares paired at an inside match price, an on-close order imbalance, a buy/sell direction of the on-close order imbalance, an indicative clearing price range associated with the first of the series of times, or a percentage by which an indicative price varies from an inside price. Determining the closing price includes determining a preliminary closing price, comparing the preliminary closing price to a benchmark value representing market conditions prior to the close of trading, and determining the closing price based on the comparison. The benchmark value includes a volume weighted average of orders executed during a predetermined time period before the close of trading. The inside match price is selected from an inside bid price, an inside offer price, an inside bid-offer midpoint price, or zero, based on an imbalance of closing orders. The near indicative clearing price includes a price at which closing orders and continuous orders would execute if paired with each other. The server system resides in a venue for trading securities electronically. The venue is an electronic commerce network, an auction, an exchange, or an electronic exchange. The imbalance only order executes in response to an imbalance in liquidity associated with the electronic venue. Embodiments of the invention may include one or more of the following advantages. Closing orders are executed in a single transaction. The information included in the imbalance indicator improves transparency and price discovery. Disseminating the imbalance indicator gives market participants an opportunity to adjust their trading based on the imbalance indicator by adjusting the price and/or size of existing imbalance only orders, or by submitting additional imbalance only orders. The closing process improves liquidity, reduces risk and reduces costs for investors seeking to trade at the closing price. Other features and advantages of the invention will become apparent from the following description, and from the claims. | 20040428 | 20100112 | 20051222 | 97458.0 | 1 | APPLE, KIRSTEN SACHWITZ | CLOSING IN AN ELECTRONIC MARKET | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,574 | ACCEPTED | Apparatus for radar | A radar is arranged to transmit electromagnetic energy in pulse repetition intervals and to receive reflections or echoes from objects in range gates intended for the purpose, which range gates are provided with Doppler filters. The radar is arranged to approve ambiguous echoes that are desirable and to suppress ambiguous echoes that are of no interest or that interfere with the display function of the radar. The radar works with a frequency that varies according to a staggered or wobbling pattern. The respective ambiguous echoes produce only one pulse in the respective range gates concerned, within a predetermined number of periods. The respective Doppler filter concerned is arranged to work with an impulse function response that only consists of a small number of samples. The Doppler filter is also arranged, during the predetermined number of periods, to give rise to a number of independent samples from reflectors within the radar's unambiguous range. When the sad independent samples exceed the small number of samples, the radar approves the ambiguous echo. Otherwise, it is suppressed. In this way, ambiguous echoes are prevented from interfering with the reception or display of the echoes on the display screen. The suppression of asynchronous interferences, for example pulses from other radar stations, can also be made easier in a simple way. | 1. An apparatus for radar that transmits electromagnetic impulses in pulse repetition intervals and receives energy pulses reflected by reflector(s) in range gates intended for the purpose, which range gates are provided with Doppler filters, and that is arranged to approve ambiguous echoes that are desirable and to suppress ambiguous echoes that are of no interest or that interfere with the display function of the radar, characterized in that the radar works with a varying pulse repetition interval according to a staggered or wobbling pattern; in that the respective Doppler filter concerned is arranged to work with an impulse function response with a length that is significantly shorter than a predetermined number of periods, for example eight periods, and thereby to produce for the respective received impulse a number of outgoing impulses, for example three; in that, upon the appearance in the radar of a representative single impulse for a second-time-around echo, a third-time-around echo, a fourth-time-around echo, etc., the Doppler filter concerned is arranged to emit an output impulse/output signal which, in its duration or length, is significantly shorter than the corresponding duration or length of the output impulse/output signal caused by the measured first-time-around echo; and in that the radar also comprises one or more threshold functions that, irrespective of the amplitudes of the said representative single impulses, generate significantly fewer incidences of threshold exceeding than a corresponding first-time-around impulse, thus producing output impulses/output signals for a plurality of pulse intervals, with the radar being arranged to ascertain the differences between the said incidences of threshold exceeding and to use these as the basis for the approval or the suppression. 2. The apparatus according to claim 1, wherein the said pattern of the varying pulse repetition interval is such a shape that, during one pass in the radar, only one response comes in from a second-, third-, fourth-, etc, time-around echo in each range gate concerned, while the normal first-time-around echo gives an impulse/signal for each measurement pulse. 3. The apparatus according to claim 2, wherein the respective ambiguous echo is arranged to produce only one impulse in the respective range gate within the predetermined number of periods. 4. The apparatus according to claim 1, wherein the radar is arranged to work with a requirement that at least a predetermined number of samples/pulses, for example six out of eight samples/pulses, must exceed a predetermined (primary) threshold to obtain the said approval. 5. The apparatus according to claim 1, wherein the Doppler filter comprises a second order delay line. 6. The apparatus according to claim 1, wherein the radar consists of a coherent-on-receive radar, where there is no coherence between successively transmitted adjacent pulses. 7. The apparatus according to claim 1, wherein the radar consists of a coherent-on-transmit radar arranged to utilize varying pulse repetition intervals during a pass and thereby make possible detection of target at all occurring speeds and thereby a better reconnaissance rate in combination with the ability to suppress second-time-around echoes, from both moving and fixed targets. 8. The apparatus according to claim 7, wherein the radar is arranged to suppress ambiguous echoes, even with amplitudes lower than corresponding amplitudes from actual clutter background. 9. The apparatus according to claim 1, wherein it works with an alternating sequence related to the pulse repetition interval, which sequence spreads multiple-time-around echoes maximally over a given measuring period. 10. The apparatus according to claim 1, wherein it works with an MTI filter that provides several independent samples or co-ordinations during each measuring period. 11. The apparatus according to claim 1, wherein it comprises an M/N integrator adjusted to the correlation characteristics of the output signal. 12. The apparatus according to claim 1, wherein, in connection with MTI radar, the frequency of a radially moving target is variable by a modulation index that is radial to the radial target or reflector speed. 13. The apparatus according to claim 1, wherein, in connection with coherent radar, this is arranged to reduce the risk of the incorrect display of ambiguous echoes in spite of PRI variation. 14. The apparatus according to claim 1, wherein, in connection with MTI radar, the PRI variation assists in filtering out fixed or moving ambiguous echoes that have a lower amplitude than reflected impulses/signals from occurring interference reflections caused by, for example, ground clutter, rain clutter, etc. 15. The apparatus according to claim 1, wherein the PRI variation is arranged to make possible suppression in the display of asynchronous interference, originating, for example, from other radar stations. 16. The apparatus according to claim 1, wherein it comprises an M/N detector, a so-called non-parametric detector, which is arranged to work or to make possible the reception of echoes that arise during a number of measurements in order to give rise to a detection irrespective of the amplitude of the incoming signals. | The present invention relates to an apparatus for radar that is arranged to transmit electromagnetic energy in the form of pulses with given or predetermined intervals and to receive reflections or echoes from objects that reflect the electromagnetic energy. The radar works with time intervals with a fixed delay relative to the transmitted pulse and range gates in which the echoes are received. The time delay between successive received pulses will vary from pulse to pulse with a radially moving target which can be transferred, using known Doppler radar technology, to a varying phase position relative to a stable reference oscillator. By passing the signals through a high pass filter, non-moving echoes can be suppressed, so-called MTI technology. In addition, the radar is to approve ambiguous echoes that are desirable and to suppress ambiguous echoes that are of no interest or that interfere with the display function of the radar. The target echoes that, due to the delay in the propagation path, incide on the radar after a new radar pulse has been transmitted, will be allocated a range gate corresponding to the actual propagation time minus the previously utilized pulse repetition interval. The measurement of range hereby becomes ambiguous, which is normally not desirable of the radar. If the phase position of the transmitted radar pulse relative to the reference oscillator is constant from pulse to pulse, so-called coherent-on-transmit radar, non-moving second-time-around echoes will, however, also be suppressed by the radar's MTI filter, assuming the radar utilizes a constant pulse repetition frequency. For radars that utilize transmitters with a relative phase position that varies between successive pulses, for example magnetron radars, Doppler filtering can only be achieved by measuring the actual phase position of the most recently transmitted pulse and thereafter, by various known methods, subtracting this phase position from phase positions measured in the various range gates. Such radars are called coherent-on-receive radars. By means of such methods, suppression of slowly moving targets can also be achieved with a magnetron radar, but normally only for echoes within the radar's unambiguous range, due to the fact that first-time-around echoes and second-time-around echoes cannot be distinguished. In accordance with the present invention, so-called PRI variation is to be used (PRI=Pulse Repetition Interval). The use of PRI variation leads to ambiguous echoes, where such occur, appearing at different ranges from pulse to pulse. High pass filtering of such signals in range gates results in each individual incoming echo being given a length that is determined by the impulse function response of the filter. This means that the number of independent measurements during a radar pass is limited and thereby the opportunities to utilize the duration of an indication rather than amplitude as a measurement of occurrence are reduced. By selecting a high pass filter with short impulse function response in relation to the measuring period, several independent measurements can be obtained during this measuring period and the previous method with M/N filter is utilized (M=primary detections; N=number of range gates). The M/N detector can also be called a non-parametric detector and is characterized in that an echo must appear during a number of measurements in order to be able to give rise to a detection, irrespective of the amplitude of the incoming impulse or signal. For coherent-on-receive radar stations, second-time-around echoes will not have any phase relation from pulse to pulse. Both fixed and moving echoes will therefore be able to pass through the high pass filtering of an MTI irrespective of whether fixed or variable PRI is used. For a coherent-on-transmit radar with fixed PRI, non-moving second-time-around echoes will in principle be suppressed, but not, however, moving second-time-around echoes. For a coherent-on-transmit radar with variable PRI, successive second-time-around echoes will fall in different range gates and will be perceived by the radar as impulses, that is impossible to suppress by normal high pass filtering. Radar that uses constant PRI will suppress both targets that have a phase variation that is low and those that have corresponding variation with a frequency that conforms to the selected pulse repetition frequency. These are called blind speeds. In order to eliminate such blind speeds, coherent-on-transmit radar stations often utilize PRI that alternates between different rotations of the radar, which gives an even lower data rate. By utilizing PRI alternating from pulse to pulse, a small reduction of the suppression capability of slow clutter is certainly achieved, but the gains with a higher data rate can in many cases outweigh this. In environments where second-time-around echoes occur, the degradation in performance of the radar as a result of this can, however, often be too large, unless the present invention is utilized. M/N detectors are also used to suppress non-correlated interference, for example from other radar stations. By the selection of short impulse function response of the radar in combination with M/N detector, such interference can also be eliminated. Radars of different types are already known and reference can be made, for instance, to U.S. Pat. No. 4,973,968, in which it is proposed to use a number of fixed pulse repetition intervals (PRI) and to use separate target detection for each such pulse repetition interval. A combination logic is used in connection with this. This is a method that is difficult to use for transmitter elements that have frequency change characteristics that depend greatly upon the current power factor of the transmitter. For such stations, a pulse length change can, it is true, be introduced at the same time as PRI variation in order to retain the power factor, but such a method can seldom be justified economically for, for example, a magnetron radar. Refer also to GB 2 335 103 that proposes the use of short pulse repetition intervals together with long pulse repetition intervals, in order by this means to be able to note the position of second-time-around echoes. The measured target amplitude of these echoes is thereafter subtracted from the positions in which they are expected to appear from the short pulse repetition intervals. This method suffers from the same problem with varying power factor as the previous method. In addition, the sensitivity of the detection of second-time-around echoes for the “normal” pulse rates by integration can be made greater than the sensitivity for the individual measurement pulses, which makes the method unreliable. In PCT document WO 99/47944, the use is already known of a method for resolving measurements with a radar that is ambiguous in range. Detections are noted in the different range gates and attempt is made to associate them with a range. The method proposed here is often utilized in radar stations with such a high pulse repetition frequency that unambiguity cannot be achieved within the required range area. The method works well for one target, but association difficulties arise even for only two or more. The present invention relates among other things to an apparatus for suppressing the display of echoes at ranges larger than the unambiguous range. The range to an object is estimated normally within the delay that the incoming echo has with reference to the most recently transmitted pulse. If the delay is so large that a new pulse has been able to be transmitted before the signal returns, the echo range will be estimated in relation to the most recently transmitted pulse and too short a range will be given. Such echoes, so-called ambiguous echoes, can be perceived as being close by and hence in many cases prioritized targets, and both block the detection of targets at unambiguous range and normally interfere with the display. This problem can be eliminated by changing the radar frequency between each pulse. Such a method requires, however, a transmitter that can generate such pulses and, in addition, in certain cases this method is not compatible with tactical operating requirements. Nor is a frequency hop from pulse to pulse compatible with filtering in order to suppress non-moving echoes, which requires fixed frequency. The indicated range of the ambiguous echoes is determined by the relevant pulse repetition interval. By changing this, the ambiguous echoes will be able to appear at several indicated ranges in the form of individual pulses or impulses. If the radar utilizes Doppler filtration by letting the echoes in each range gate pass through a filter with suitable frequency characteristics, this filter's impulse function response will disperse the energy from each pulse in the relevant gate. After such a filter, the occurrence of the original impulse can therefore not be detected simply and nor can it be eliminated simply. The apparatus according to said document U.S. Pat. No. 4,973,968 works with a requirement of the start of several pulse repetition intervals which could cause problems with first-time-around targets that are in the vicinity of the system's blind speeds. The other patent documents mentioned above deal, in principle, with other problems to those stated above. The present invention is intended to solve all or parts of the problems described above. The principal characteristics of an apparatus that solves the problems described above are, among other things, that the radar works with a varying frequency according to a staggered or wobbling pattern and that the respective Doppler filter concerned is arranged to work with an impulse function response with a length that is significantly shorter than a predetermined number of periods, for example eight periods. Further characteristics are that, upon the appearance in the radar of a representative single impulse for a second-time-around echo, a third-time-around echo, a fourth-time-around echo, etc., the Doppler filter concerned is arranged to emit an output impulse/output signal which, in its duration or length, is significantly shorter than the corresponding duration or length of the output impulse/output signal caused by the measured first-time-around echo, and that the radar also comprises one or more threshold functions which, irrespective of the amplitudes of the said representative single impulses, generate significantly fewer incidences of threshold exceeding than corresponding first-time-around impulses, thus producing output impulses/output signals for a plurality of pulse intervals. In this way, the radar is arranged to ascertain the differences between the said incidences of threshold exceeding and to use these as the basis for the approval or the suppression. In a preferred embodiment, the PRI pattern used by the radar is such a shape that, during one pass period, only one response comes in from a second- (third-, fourth-, etc.) time-around echo in each range gate concerned, while the normal first-time-around echo gives a signal for each measurement pulse. In further developments of the concept of the invention, the respective ambiguous echo for each completed PRI pattern only produces one impulse within the predetermined number of periods. In addition, the radar is arranged to work with the requirement that at least a predetermined number of samples/pulses, for example six out of eight samples/pulses, must exceed a predetermined or primary threshold to obtain the said approval. In addition, the Doppler filter can comprise a second order delay line. The invention is thus based on the idea of using a number of different pulse intervals, which for an MTI radar means that the frequency of radially moving targets will vary with a modulation index that is proportional to the radial target speed. This technique also makes possible coverage of radial speeds that give rise to frequencies that coincide with the average pulse repetition frequency, so-called blind speeds, which is known technology. For second-time-around echoes that do not incide into the same range gate at the different pulse repetition intervals, such echoes will give rise to individual impulses in the range gates concerned, which means that slow-moving echoes can also not be suppressed by being passed through a high pass filter, even for radar stations with known transmitter pulse phase. By means of the invention, suppression of blind speeds can make possible a higher measurement rate than alternative methods with frequency changing between successive passes, which means that PRF variation is also of interest for coherent radar stations and the present proposal to reduce the risk of penetration of ambiguous echoes eliminates a known disadvantage associated with the utilization of PRF variation. By combining the utilization of PRI variation, the MTI technology can also be used for discovering and thereby also filtering out fixed or moving ambiguous echoes that have a lower amplitude than reflected signals from occurring interference reflections of the ground clutter or rain clutter type. Reference is also made to the subsequent dependent claims. By means of what is proposed above, the problem mentioned by way of introduction can be given a relatively simple solution from a technical point of view. So-called non-parametric detection can be utilized. The combination with coherent clutter suppression is new and the use in combination with fully coherent radar has exceptional advantages. The invention can also eliminate disadvantages that can arise in the event of non PRI synchronous interference. Such interference can, for example, arise with the use of M/N filters that are used to suppress pulses that can arrive stochastically to the radar from other radar stations. The use of an MTI filter means that interfering pulses are prolonged, which previously made it more difficult to use M/N filters for suppression. A currently proposed embodiment of an apparatus that has the significant characteristics of the invention will be described below with reference to the attached drawings in which FIG. 1 shows schematically in outline form a radar that transmits pulses and receives echoes from detected objects, and FIG. 2 shows in outline the display apparatus of the radars. FIG. 1 shows a radar illustrated symbolically by 1. The radar is arranged to transmit electromagnetic energy or pulses 2 in pulse repetition intervals PRI and to receive reflections or echoes 3, 4 from objects 5, 6 that reflect the electromagnetic energy. The radar is arranged with range gates that are indicated in outline by 7, 7′, 7″. The respective range gates are provided with or interact with a Doppler filter or high pass filter 8. The radar works with a frequency that varies in accordance with a staggered or wobbling pattern. The functions achieved by the radar 1 are symbolized in outline by 9. The radar comprises an antenna 1a that is arranged to be able to rotate, with a rotating table 1b. A changeover device 1c connects the rotation table/antenna in turn to a transmitter 1d and a receiver 1e. The receiver 1e is connected to an analog-digital converter 1f. A clock is indicated by 1g and controls the transmitter and receiver circuits with a frequency related to the transmitted pulse length. The clock is connected to the transmitter 1d and the converter 1f. A transmitter pulse trigger 1h is also connected to the transmitter by means of which the staggering or wobbling function can be generated. After each transmitted pulse, the analog-digital converter 1f can be connected in turn to range gates 7a, 7b, 7c, 7d via a switch 1i. By means of the apparatus, impulses with varying pulse repetition intervals can be transmitted and received via the antenna 1a. The range gates, for example 7′, can be connected to a subsequent high pass filter/Doppler filter 8, which is provided with a threshold device 11 indicated symbolically, via which the range gates can be connected to a unit 12 with synthetic video indicated symbolically. The range gates 7′ are connected one by one to the unit 12 via a switch 13. The reflections 14, 15, 16 caused by the incoming echoes appear in the unit 12 in different numbers depending upon the position of the reflection-transmitting or echo-transmitting target or surroundings in relation to the unambiguous range of the previous pulse. The range gates 7″ are intended to illustrate the amplitudes of impulses as a function of time, with the range gate 7e showing the case with a moving echo, the range gate 7f showing the case with a fixed echo and the range gate 7g showing the case with varying PRI impulse repetition interval. In the case 7e, the amplitude 7e′ varies with the time, in the case 7f, the amplitude 7f′ is constant, and in the case 7g, there is the appearance of impulses 7g′ with different intervals. In accordance with the PRI variation or the PRI pattern, only one response should come in from each respective second-time-around echo, third-time-around echo and/or fourth-time-around echo, etc., in each range gate concerned. On the other hand, the first-time-around echo is to give a signal/impulse for each measurement pulse. Depending upon the signal or impulse processing in the range gates 7′, the high pass filter 8 and the threshold device 11, different numbers n, n′ of independent outgoing pulses are obtained in the unit in accordance with the above. The radar or the apparatus associated with this suppresses or permits, by means of a unit or circuit 17, the display on the radar's display unit of the echo in question. In the event of the number n, which here represents a large number, display is permitted, while the number n′ here represents individual or a few incidences of threshold exceeding that are suppressed in the display. The echoes or the reflections 3, 4 can be divided up into echoes 3 that provide impulses that reach the radar before the next pulse has been transmitted and echoes 4 that arise from objects 6 at a range that is so large that the echo reaches the receiver after the next impulse has been transmitted. Echoes that arise after a new pulse has been transmitted are called here ambiguous echoes. The radar's unambiguous range is often taken to be the range that corresponds to the shortest utilized PRI interval. The ambiguous echo can, in principle, consist of an echo that is to be able to be recorded by the radar or an echo that is to be suppressed as it can impair or interfere with the rest of the display. The indication range of the pulses varies in accordance with a staggered or wobbling pattern in a known way. The respective range gates receive only one pulse within a number of periods, for example eight periods. The respective Doppler filter 8 concerned is arranged to work with an impulse function response that affects only a few samples/pulses, for example, three samples or pulses. The Doppler filter is also arranged to cause statistically a number of independent samples/pulses during the said predetermined number of periods. In the case when the independent samples or pulses exceed the said small number of samples or pulses, this is detected by the unit 17 which causes the radar to enter the echo in question on its display unit. In the case when the number of measurements above a level, determined by the radar's noise or interference background, is less than a given value, for example a value 5 for measurements over eight samples, the signal is not displayed, while the signal is displayed if the number exceeds this value. In an embodiment, the apparatus or the radar can work with a requirement that is based on a predetermined number of samples or pulses having to exceed a predetermined amplitude threshold in order to obtain the said approval. Thus, for example, six out of eight samples or pulses must exceed the threshold in order to obtain approval. The Doppler filter can consist of a second order delay line 17 that brings about the short impulse function response from the filter. The radar can consist of a non-coherent MTI radar where there is no coherence between transmitted signals 2. Alternatively, the radar consist of a coherent-on-transmit radar or a coherent-on-receive radar. An M/N detector function that is not specially illustrated is included in the receiving apparatus and arranged in a known way, which M/N detector function enables the same echo to appear during a number of measurements in order to be able to give rise to a detection irrespective of the amplitude of the incoming pulse or signal. In FIG. 2, the radar's display unit is shown in outline, consisting of a plan position indicator upon which approved signals are displayed with the range that is proportional to the echo's measured delay relative to the most recent pulse and an angular position that depicts the direction of the antenna at the time of the measurement. At a radius R1 there is an echo 18 from a target 5 within the unambiguous range (cf. FIG. 1). An echo 19 at an ambiguous range R2+R comes from a target that gives ambiguous echoes. The rotation function of the display unit is indicated by 21. The display unit as such is symbolized by 22. The components listed above can consist of known types and will therefore not be described in greater detail. The invention is not limited to the embodiment described above by way of example, but can be modified within the framework of the following patent claims and concept of the invention. | 20040430 | 20060620 | 20050217 | 62509.0 | 0 | GREGORY, BERNARR E | APPARATUS FOR RADAR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,646 | ACCEPTED | Synchronous and resonant drives for producing multiple scan line pattern for electro-optically reading indicia | A raster pattern for reading bar code symbols is created by successively reflecting a light beam off scan mirrors oscillated respectively by a resonant motor drive and by another motor drive driven synchronously with the resonant drive. | 1. An arrangement for scanning a target, comprising: a) a light source for emitting a light beam; b) a first resonant drive operative in a self-resonating mode for oscillating a first scan mirror to reflect the light beam from the light source along a first direction across the target at a resonant frequency; c) a second drive operative in a driven mode for oscillating a second scan mirror to reflect the light beam from the first scan mirror along a second direction perpendicular to the first direction at a driven frequency; and d) a controller operatively connected to the drives, for driving the second drive in synchronism with the first drive to produce a scan pattern of multiple scan lines across the target with a given frequency relationship between the driven frequency and the resonant frequency. 2. The arrangement of claim 1, wherein one of the drives includes a stator having a pair of stator portions symmetrically positioned relative to an axis of symmetry, a rotor having a pair of rotor portions symmetrically positioned relative to the axis of symmetry, a pair of springs extending in parallelism between the stator portions and the rotor portions, and a central portion integral with the rotor and extending between the springs. 3. The arrangement of claim 2, wherein the stator portions, the rotor portions and the springs lie in a common plane, and wherein one of the scan mirrors is mounted on the central portion at one side of the common plane at an angle of inclination relative to the common plane. 4. The arrangement of claim 3, wherein said one drive includes a permanent magnet mounted on the central portion at an opposite side of the common plane, and an electromagnetic coil having a winding for generating a periodic magnetic field which magnetically interacts with a permanent magnetic field of the permanent magnet. 5. The arrangement of claim 1, wherein each drive includes a stator having a pair of stator portions symmetrically positioned relative to an axis of symmetry, a rotor having a pair of rotor portions symmetrically positioned relative to the axis of symmetry, a pair of springs extending in parallelism between the stator portions and the rotor portions, and a central portion integral with the rotor and extending between the springs. 6. The arrangement of claim 1, and a printed circuit board on which the light source, the drives and the controller are commonly mounted. 7. The arrangement of claim 6, and a handheld housing having a handle bounding an interior in which the printed circuit board is received. 8. The arrangement of claim 1, wherein the controller measures the resonant frequency of the first resonant drive and drives the first resonant drive at the resonant frequency, and wherein the controller detects reversals in direction of the first scan mirror during oscillation thereof and synchronously drives the second drive in response to said direction reversals to maintain said frequency relationship. 9. The arrangement of claim 8, wherein the first resonant drive has a feedback winding for generating a start-of-scan signal at the resonant frequency, the start-of-scan signal having transitions for said direction reversals; and wherein the controller includes a microprocessor for receiving and processing the start-of-scan signal to produce an output drive signal to drive the second drive as a function of said transitions. 10. The arrangement of claim 9, wherein the second drive is driven at each transition to produce a respective one of the scan lines. 11. The arrangement of claim 1, wherein the resonant frequency is greater than the driven frequency, and wherein the frequency relationship is a ratio of the resonant frequency to the driven frequency, and wherein the ratio is maintained constant by the controller during scanning of the target. 12. The arrangement of claim 2, and a temperature transducer connected to the controller, for measuring changes in temperature to adjust for stiffness variations in the springs. 13. A method of scanning a target, comprising the steps of: a) emitting a light beam; b) operating a first resonant drive in a self-resonant mode to oscillate a first scan mirror to reflect the light beam along a first direction across the indicia to be read at a resonant frequency; c) operating a second drive in a driven mode to oscillate a second scan mirror to reflect the light beam from the first scan mirror along a second direction perpendicular to the first direction at a driven frequency; and d) controlling the second drive to be driven in synchronism with the first drive to produce a scan pattern of multiple scan lines across the target with a given frequency relationship between the driven frequency and the resonant frequency. 14. The method of claim 13, wherein the controlling step includes measuring the resonant frequency of the first resonant drive and driving the first resonant drive at the resonant frequency, and further includes detecting reversals in direction of the first scan mirror during oscillation thereof and synchronously driving the second drive in response to said direction reversals to maintain said frequency relationship. 15. The method of claim 14, and the step of generating a start-of-scan signal at the resonant frequency, the start-of-scan signal having transitions for said direction reversals; and the step of receiving and processing the start-of-scan signal to produce an output drive signal to drive the second drive as a function of said transitions. 16. The method of claim 15, and the step of driving the second drive at each transition to produce a respective one of the scan lines. 17. The method of claim 13, wherein the resonant frequency is greater than the driven frequency, and wherein the frequency relationship is a ratio of the resonant frequency to the driven frequency, and wherein the ratio is maintained constant during scanning of the target. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an arrangement for, and a method of, reading indicia such as bar code symbols and, more particularly, to the use of synchronous and resonant drives for producing a multiple scan line raster pattern to read the symbols. 2. Description of the Related Art Various electro-optical systems or readers have been developed for reading indicia such as bar code symbols appearing on a label or on a surface of an article. The bar code symbol itself is a coded pattern of graphic indicia comprised of a series of bars of various widths spaced apart from one another to bound spaces of various widths, the bars and spaces having different light reflecting characteristics. The readers function by electro-optically transforming the pattern of the graphic indicia into a time-varying electrical signal, which is digitized and decoded into data relating to the symbol being read. Typically, a laser beam from a laser is directed along a light path toward a target that includes the bar code symbol on a target surface. A moving-beam scanner operates by repetitively sweeping the laser beam in a scan line or a series of scan lines across the symbol by means of motion of a scanning component, such as the laser itself or a scan mirror disposed in the path of the laser beam. Optics focus the laser beam into a beam spot on the target surface, and the motion of the scanning component sweeps the beam spot across the symbol to trace a scan line across the symbol. Motion of the scanning component is typically effected by an electrical drive motor. The readers also include a sensor or photodetector which detects light along the scan line that is reflected or scattered from the symbol. The photodetector or sensor is positioned such that it has a field of view which ensures the capture of the reflected or scattered light, and converts the latter into an electrical analog signal. In retroreflective light collection, a single optical component, e.g., a reciprocally oscillatory mirror, such as described in U.S. Pat. No. 4,816,661 or U.S. Pat. No. 4,409,470, both herein incorporated by reference, sweeps the beam across the target surface and directs the collected light to the sensor. In non-retroreflective light collection, the reflected laser light is not collected by the same optical component used for scanning. Instead, the sensor is independent of the scanning beam, and has a large field of view so that the reflected laser light traces across the sensor. Electronic control circuitry and software decode the electrical analog signal from the sensor into a digital representation of the data represented by the symbol that has been scanned. For example, the analog electrical signal generated by the photodetector may be converted by a digitizer into a pulse width modulated digitized signal, with the widths corresponding to the physical widths of the bars and spaces. Alternatively, the analog electrical signal may be processed directly by a software decoder. See, for example, U.S. Pat. No. 5,504,318. The decoding process usually works by applying the digitized signal to a microprocessor running a software algorithm, which attempts to decode the signal. If a symbol is decoded successfully and completely, the decoding terminates, and an indicator of a successful read (such as a green light and/or audible beep) is provided to a user. Otherwise, the microprocessor receives the next scan, and performs another decoding into a binary representation of the data encoded in the symbol, and to the alphanumeric characters so represented. Once a successful read is obtained, the binary data is communicated to a host computer for further processing, for example, information retrieval from a look-up table. The bar code symbols are formed from bars or elements typically rectangular in shape with a variety of possible widths. The specific arrangement of elements defines the character represented according to a set of rules and definitions specified by the code or “symbology” used. The relative size of the bars and spaces is determined by the type of coding used as is the actual size of the bars and spaces. The number of characters (represented by the bar code symbol) per unit length is referred to as the density of the symbol. To encode the desired sequence of the characters, a collection of element arrangements is concatenated together to form the complete bar code symbol, with each character of the message being represented by its own corresponding group of elements. In some symbologies, a unique “start” and “stop” character is used to indicate when the bar code begins and ends. A number of different bar code symbologies is in widespread use including UPC/EAN, Code 39, Code 128, Codeabar, and Interleaved 2 of 5. In order to increase the amount of data that can be represented or stored on a given amount of target surface area, several more compact bar code symbologies have been developed. One of these code standards, Code 49, exemplifies a “two-dimensional” symbol by reducing the vertical height of a one-dimensional symbol, and then stacking distinct rows of such one-dimensional symbols, so that information is encoded both vertically as well as horizontally. That is, in Code 49, there are several rows of bar and space patterns, instead of only one row as in a “one-dimensional” symbol. The structure of Code 49 is described in U.S. Pat. No. 4,794,239. Another two-dimensional symbology, known as “PDF417”, is described in U.S. Pat. No. 5,304,786. Still other symbologies have been developed in which the symbol is comprised not of stacked rows, but of a matrix array made up of hexagonal, square, polygonal and/or other geometric shapes, lines, or dots. Such symbols are described in, for example, U.S. Pat. No. 5,276,315 and U.S. Pat. No. 4,794,239. Such matrix code symbologies may include Vericode, Datacode, and MAXICODE. It is also known to scan two-dimensional symbols by successively reflecting the laser beam off two scan mirrors, each driven by a separate drive motor. The beam is deflected by one scan mirror in the horizontal (X) direction along one direction of the symbol, and is deflected by the other scan mirror in the vertical (Y) direction along another direction perpendicular to the one direction, thereby creating a multiple scan line pattern, also known as a raster pattern, across the entire width and entire height of the symbol. The drive motors of the prior art are identical, even though the raster pattern places different requirements on the motors. The drive circuitry for these identical motors is expensive and complex because it requires a separate drive microprocessor, a pair of digital to analog converters, a pair of high current drive amplifiers, and a pair of optical feedback circuits in order to create a raster pattern that is stable and repeatable from one reader to the next. The drive circuitry is required to drive the identical motors over a broad range of frequencies and amplitudes, while making them efficient enough to respond to different drive frequencies without using too much electrical current to minimize power consumption. SUMMARY OF THE INVENTION Objects of the Invention Accordingly, it is a general object of this invention to avoid the above drawbacks of the prior art. It is a general object of the present invention to provide an improved drive circuit for generating a stable and repeatable raster pattern for reading indicia. It is another object of the invention to reduce the complexity, cost and power consumption of such drive circuits. It is a further object of the present invention to optimize the different operations of different motor drives. FEATURES OF THE INVENTION In keeping with the above objects and others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in an arrangement for, and a method of, electro-optically reading indicia, such as two-dimensional bar code symbols, by emitting a light beam from a light source, and by successively reflecting the light beam from a first scan mirror and a second scan mirror along first and second directions respectively across the symbol to be read. The first and second scan mirrors are respectively oscillated by first and second drives which, in contrast to the prior art, are not identically operated. In accordance with this invention, the first drive is operative in a self-resonating mode to oscillate the first scan mirror at a resonant frequency, and the second drive is operative in a driven mode to oscillate the second scan mirror at a driven frequency. A controller is operatively connected to the drives, for driving the second drive in synchronism with the first drive to produce a scan pattern of multiple scan lines across the indicia with a given frequency relationship between the driven frequency and the resonant frequency. Driving the first drive at its resonant frequency greatly reduces its power consumption. Driving the second drive synchronously with the first drive insures that the scan pattern will be stable and repeatable from one reader to the next. The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken-away, perspective view of a triggered bar code reader with a handheld housing for use with the present invention; FIG. 2 is a broken-away, perspective view of parts of the reader of FIG. 1 with the housing and other parts removed for clarity; FIG. 3 is a broken-away, enlarged, perspective view of FIG. 2 as seen from its rear; FIG. 4 is a broken-away, enlarged, perspective view of FIG. 3 with parts removed for clarity; FIGS. 5, 6 and 7 are perspective views of a scan motor in successive stages of fabrication for use in the reader of FIG. 1; and FIG. 8 is a schematic view of drive circuitry for driving the scan motors for use in the reader of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As used in this specification and in the appended claims, the term “indicia” broadly encompasses not only symbol patterns composed of alternating bars and spaces of various widths commonly referred to as bar code symbols, but also other one- or two- dimensional graphic patterns, as well as alphanumeric characters. In general, the term in “indicia” may apply to a type of pattern or information which may be recognized or identified by scanning a light beam and by detecting reflected or scattered light as a representation of variations in light reflectivity at various points of the pattern or information. A bar code symbol is one example of an “indicia” which the present invention can scan. As a preferred embodiment, the implementation of the present invention in a handheld reader 10, as illustrated in FIG. 1, is described. The reader 10 includes a housing 12 having a handle 14 on which a trigger switch 16 is mounted. The housing includes a canopy above the handle, but removed for clarity from FIG. 1. A window module 18 is situated adjacent a front end of the housing. An optical module 20 is situated behind the window module 18. A printed circuit board (PCB) 22, whose front side is shown more clearly in FIG. 2, and whose rear side is shown more clearly in FIGS. 3-4, is situated behind the optical module 20 at a rear end of the housing. The PCB slides into the handle 14 at an obtuse angle relative to a horizontal plane to accommodate the slanted-back slope of the handle. As shown in FIG. 2, a sensor 24 is mounted on the front side of the PCB. Light returning from a symbol being read passes through the window module 18 through a collection lens and filter 26 in the lower part of the optical module 20 to the sensor 24 for detection. As described below, light from a light source passes through an aperture 28 in the PCB through another aperture 30 in the upper part of the optical module 20 and, in turn, through the window module 18 en route to the symbol for reflection therefrom. FIGS. 3-4 are similar, except that various supporting structures shown in FIG. 3 have been removed to better see the components supported thereby. Thus, as best seen in FIG. 4, a light source, such as a semiconductor laser 32 is mounted at the rear side of the PCB 22 and is operative for emitting a laser beam 34 horizontally through a focusing lens assembly 33 to a first scan mirror 36 for reflection upwardly to a second scan mirror for reflection forwardly through the aperture 28. The first scan mirror 36 is, as described more fully below, mounted for reciprocal oscillation by a first motor drive 40 operating in a self-resonant mode, while the second scan mirror is also mounted for reciprocal oscillation by a second motor drive 42 operating in a driven mode synchronous with the first motor drive 40. FIG. 4 also depicts a first electromagnetic coil 44 for the first drive 40 and a second electromagnetic coil 46 for the second drive 42. The coils 44, 46 are mounted at the rear side of the PCB, and each has a drive winding (94, 98 as seen in FIG. 8) operative for generating an electromagnetic field in response to energization by a periodic drive signal. Coil 44 also has a feedback winding 96 whose operation is described below. FIG. 3 shows a support chassis 48 operative for supporting the laser 32, the focusing lens assembly 33, the first drive 40, the second drive 42, and the coils 44, 46. The chassis 48 also provides shock protection and is fastened to the rear of the PCB. As shown in the successive views of FIGS. 5-7, either or both drives 40, 42 can be fabricated as follows: A stator 50 has a pair of stator portions 52, 54 spaced apart and symmetrically positioned relative to an axis of symmetry. The stator portions have through holes 56, 58. The stator includes a support bracket 60 having a pair of arms 62, 64 having stub shafts 66, 68. A rotor 70 has a pair of rotor portions 72, 74 spaced apart and symmetrically positioned relative to the axis of symmetry. The rotor portions have through holes 76, 78. The rotor also has an elongated central support portion 80 integral at one end therewith and extending along the axis of symmetry. The support portion 80 has an inclined mounting portion 82 at one side, and a cut-out section 84 at an opposite end thereof to reduce the mass of the support portion 80. The rotor and the stator are separate molded resilient parts of synthetic plastic material. These parts are placed in a liquid silicon injection mold, and a pair of generally planar, elongated, leaf springs 86, 88 of silicon is overmolded onto the stator and rotor portions. Specifically, spring 86 is molded onto stator portion 52 and rotor portion 72 and enters the holes 56, 76 for a secure anchorage. Spring 88 is molded onto stator portion 54 and rotor portion 74 and enters the holes 58, 78 for a secure anchorage. The springs are thicker at their ends overlying the holes, and thinner therebetween to enable their ready flexing about an axis perpendicular to the axis of symmetry. As shown in FIG. 7, the first scan mirror 36, or the second scan mirror, is adhered to the mounting portion 82 at an angle of 45° relative to a common plane in which the stator portions, the rotor portions and the springs lie. At the opposite side of the support portion 80, a permanent magnet 90 is likewise adhered. Returning to FIG. 4, the scan mirror 36 of the first drive 40 is facing upwardly, while its permanent magnet is facing the first coil 44. Also, the scan mirror of the second drive 42 is facing forwardly, while its permanent magnet 90 is facing the second coil 46. The drives 40, 42 are mounted at right angles to each other, thereby enabling the drives 40, 42 to sweep the beam in mutually orthogonal directions. The first and second drives are each operated differently to best suit the requirements of the raster pattern. The first drive 40 is required to oscillate its scan mirror at a large scan angle, e.g., 45°, and at a high speed, e.g., 50-60 Hz, lengthwise across the symbol along the X-direction. The second drive 42 is required to oscillate its scan mirror at a small scan angle, e.g., 4°, and at a lower speed, e.g., 10 Hz, along the height of the symbol along the Y-direction. The second scan mirror needs to be larger than the first scan mirror to accommodate the moving beam. The larger inertia for the second mirror is not a problem due to its lower speed. In accordance with this invention, the first drive 40 is operated in a self-resonating mode. As shown in FIG. 8, a bidirectional drive circuit 92 measures the natural resonant frequency of the first drive 40 and drives a drive winding 94 of the latter at or near that frequency. Driving the first drive near its natural frequency reduces the amount of power needed to drive the first drive. A suitable bidirectional drive circuit is described in U.S. Pat. No. 5,280,163, the entire contents of which are incorporated herein by reference thereto. In addition to the drive winding 94, the coil 44 includes a feedback winding 96 operative for generating a feedback signal by the movement of the permanent magnet of the first drive 40. The drive circuit 92 uses the feedback signal to determine which direction the rotor is moving, how fast it is moving, and when it changes direction. The drive circuit 92 processes the feedback signal into a start-of-scan (SOS) signal having a square waveform which is high when the rotor is moving in one direction, low when the rotor is moving in the opposite direction, and transitions when the rotor changes direction at the end of each scan. The frequency of the SOS signal is the same as the resonant frequency of the first drive because it is generated from the feedback signal which is created by the motion of the rotor. The multiple line raster pattern generated by the two drives 40, 42 is determined by the relative speeds and amplitudes of the motions of their rotors. It is the ratio of the frequencies of the rotors that determines the appearance of the raster pattern, not the absolute frequencies. As mentioned, the first drive 40 operates in the self-resonating mode. However, the resonant frequency of one rotor will vary from one reader to the next due to unavoidable differences in the mass of the scan mirror 36, the magnet 90 and plastic parts, and due to differences in the stiffness of the springs 86, 88 caused, for example, by ambient temperature. It therefore becomes necessary to drive the second drive 42 in one reader at a different speed than in another reader because their first drives will not be running at exactly the same speed. It is always possible to operate the second drive in a driven mode so that is has a desired frequency relationship with that of the first drive despite the differences mentioned above by insuring that the frequency of the second drive is derived from the frequency of the first drive. This can be done by locking the frequency of the second drive into a predetermined relationship with the frequency of the SOS signal which, as previously discussed, exactly represents the actual operating frequency of the first drive. A microprocessor 100, preferably but not necessarily, the same one used to decode the digitized signal, has an input for receiving the SOS signal and is operative to detect when the first drive has changed direction and is starting a new scan. The microprocessor preferably has built-in digital-to-analog converters and changes the voltage at its output by a predetermined amount each time the SOS signal transitions from low to high, or from high to low. The analog output voltage can be amplified and applied through a drive circuitry 102 to a drive winding 98 of the second drive 42, thereby moving the rotor of the second drive a predetermined amount each time the SOS signal indicates that the first drive is starting a new scan. Various kinds of raster patterns can be produced. For example, the second drive can have its rotor turned upwards by one degree for each of a first three SOS transitions, and then downwards by one degree for each of the next three SOS transitions, brining the rotor back to its original position. During the next three SOS transitions, the rotor can be turned downwards by one degree for each transition, and then upwards in one degree increments over the following three transitions. This creates a raster pattern of seven individual scan lines, which is stable and repeatable even if the first drive changes frequency because the motion of the rotor of the second drive is always synchronized with the SOS signal and the first drive. Other kinds of raster patterns can be made by varying the amount that the output voltages changes at each transition. For example, the rotor of the second drive can move upwards by one degree as described above, but then move downwards half way between the scan lines on the way up. The raster pattern can be changed at will, or stopped altogether under predefined conditions. The small motion of the second drive compared to that of the first drive requires a correspondingly small electrical current, thereby minimizing power consumption, even when the second drive is operated far from its resonant frequency. If the microprocessor 100 is the same as the one responsible for decoding, then it is desirable to move the second drive only upon an SOS transition when the first drive has reached the end of its scan, and no new symbol data is being swept. The microprocessor is available for decoding the rest of the time that the laser beam is being swept across the symbol. It may be desirable to start the second drive moving slightly before an SOS transition, because it will not move instantaneously when the drive voltage changes. The microprocessor can measure the time between scans and predict when the SOS signal is about to transition and thus change the drive voltage slightly before the SOS transition. The second drive is driven open loop, without any feedback to assure that it is accurately tracking the drive voltage. Yet, the motor of FIGS. 5-7 has proven to be reliable and consistent, except for ambient temperature variations that can change the stiffness of the springs 86, 88. A temperature transducer 104 is connected to the microprocessor to correct the drive voltage applied to the drive winding 98 to compensate for temperature variations. If the microprocessor does not have a built-in analog-to-digital converter, then the transducer 104 can be made to produce a frequency signal that varies with temperature. The microprocessor can measure the frequency to obtain temperature information and adjust the drive voltage accordingly. The microprocessor can also correct the drive voltage applied to the drive winding 94 of the first drive to compensate for temperature variations. It will be understood that each of the elements described above, or two or more together, also may find a useful application in other types of constructions differing from the types described above. While the invention has been illustrated and described as embodied in synchronous and resonant drives for producing multiple scan line pattern for electro-optically reading indicia, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to an arrangement for, and a method of, reading indicia such as bar code symbols and, more particularly, to the use of synchronous and resonant drives for producing a multiple scan line raster pattern to read the symbols. 2. Description of the Related Art Various electro-optical systems or readers have been developed for reading indicia such as bar code symbols appearing on a label or on a surface of an article. The bar code symbol itself is a coded pattern of graphic indicia comprised of a series of bars of various widths spaced apart from one another to bound spaces of various widths, the bars and spaces having different light reflecting characteristics. The readers function by electro-optically transforming the pattern of the graphic indicia into a time-varying electrical signal, which is digitized and decoded into data relating to the symbol being read. Typically, a laser beam from a laser is directed along a light path toward a target that includes the bar code symbol on a target surface. A moving-beam scanner operates by repetitively sweeping the laser beam in a scan line or a series of scan lines across the symbol by means of motion of a scanning component, such as the laser itself or a scan mirror disposed in the path of the laser beam. Optics focus the laser beam into a beam spot on the target surface, and the motion of the scanning component sweeps the beam spot across the symbol to trace a scan line across the symbol. Motion of the scanning component is typically effected by an electrical drive motor. The readers also include a sensor or photodetector which detects light along the scan line that is reflected or scattered from the symbol. The photodetector or sensor is positioned such that it has a field of view which ensures the capture of the reflected or scattered light, and converts the latter into an electrical analog signal. In retroreflective light collection, a single optical component, e.g., a reciprocally oscillatory mirror, such as described in U.S. Pat. No. 4,816,661 or U.S. Pat. No. 4,409,470, both herein incorporated by reference, sweeps the beam across the target surface and directs the collected light to the sensor. In non-retroreflective light collection, the reflected laser light is not collected by the same optical component used for scanning. Instead, the sensor is independent of the scanning beam, and has a large field of view so that the reflected laser light traces across the sensor. Electronic control circuitry and software decode the electrical analog signal from the sensor into a digital representation of the data represented by the symbol that has been scanned. For example, the analog electrical signal generated by the photodetector may be converted by a digitizer into a pulse width modulated digitized signal, with the widths corresponding to the physical widths of the bars and spaces. Alternatively, the analog electrical signal may be processed directly by a software decoder. See, for example, U.S. Pat. No. 5,504,318. The decoding process usually works by applying the digitized signal to a microprocessor running a software algorithm, which attempts to decode the signal. If a symbol is decoded successfully and completely, the decoding terminates, and an indicator of a successful read (such as a green light and/or audible beep) is provided to a user. Otherwise, the microprocessor receives the next scan, and performs another decoding into a binary representation of the data encoded in the symbol, and to the alphanumeric characters so represented. Once a successful read is obtained, the binary data is communicated to a host computer for further processing, for example, information retrieval from a look-up table. The bar code symbols are formed from bars or elements typically rectangular in shape with a variety of possible widths. The specific arrangement of elements defines the character represented according to a set of rules and definitions specified by the code or “symbology” used. The relative size of the bars and spaces is determined by the type of coding used as is the actual size of the bars and spaces. The number of characters (represented by the bar code symbol) per unit length is referred to as the density of the symbol. To encode the desired sequence of the characters, a collection of element arrangements is concatenated together to form the complete bar code symbol, with each character of the message being represented by its own corresponding group of elements. In some symbologies, a unique “start” and “stop” character is used to indicate when the bar code begins and ends. A number of different bar code symbologies is in widespread use including UPC/EAN, Code 39, Code 128, Codeabar, and Interleaved 2 of 5. In order to increase the amount of data that can be represented or stored on a given amount of target surface area, several more compact bar code symbologies have been developed. One of these code standards, Code 49, exemplifies a “two-dimensional” symbol by reducing the vertical height of a one-dimensional symbol, and then stacking distinct rows of such one-dimensional symbols, so that information is encoded both vertically as well as horizontally. That is, in Code 49, there are several rows of bar and space patterns, instead of only one row as in a “one-dimensional” symbol. The structure of Code 49 is described in U.S. Pat. No. 4,794,239. Another two-dimensional symbology, known as “PDF417”, is described in U.S. Pat. No. 5,304,786. Still other symbologies have been developed in which the symbol is comprised not of stacked rows, but of a matrix array made up of hexagonal, square, polygonal and/or other geometric shapes, lines, or dots. Such symbols are described in, for example, U.S. Pat. No. 5,276,315 and U.S. Pat. No. 4,794,239. Such matrix code symbologies may include Vericode, Datacode, and MAXICODE. It is also known to scan two-dimensional symbols by successively reflecting the laser beam off two scan mirrors, each driven by a separate drive motor. The beam is deflected by one scan mirror in the horizontal (X) direction along one direction of the symbol, and is deflected by the other scan mirror in the vertical (Y) direction along another direction perpendicular to the one direction, thereby creating a multiple scan line pattern, also known as a raster pattern, across the entire width and entire height of the symbol. The drive motors of the prior art are identical, even though the raster pattern places different requirements on the motors. The drive circuitry for these identical motors is expensive and complex because it requires a separate drive microprocessor, a pair of digital to analog converters, a pair of high current drive amplifiers, and a pair of optical feedback circuits in order to create a raster pattern that is stable and repeatable from one reader to the next. The drive circuitry is required to drive the identical motors over a broad range of frequencies and amplitudes, while making them efficient enough to respond to different drive frequencies without using too much electrical current to minimize power consumption. | <SOH> SUMMARY OF THE INVENTION <EOH> | 20040430 | 20060613 | 20051103 | 61839.0 | 0 | CAPUTO, LISA M | SYNCHRONOUS AND RESONANT DRIVES FOR PRODUCING MULTIPLE SCAN LINE PATTERN FOR ELECTRO-OPTICALLY READING INDICIA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,835,649 | ACCEPTED | Occlusal splint | The present invention is directed to an improved form of a splint having a contact portion for maintaining the vertical separation of rearwardly opposed teeth in the oral cavity of a patient wearing the splint. The splint is provided with a contact portion for contacting opposed forward teeth to the forward teeth to which the splint is attached such that movement of the opposed forward teeth with respect to the contact portion maintains the spacing of the rearward teeth. The contact portion is provided with a central or intermediate section to which a forward portion is angularly inclined. The splint is optionally provided with a third portion angularly inclined to the central or intermediate portion for stabilising the position of the jaw or teeth to prevent permanent or long term change in the jaw position (strictly). | 1. An occlusal splint for suppression of the intensity of forces of bruxism resulting from grinding and/or clenching of teeth of a person subjected to bruxism, said device comprising a body portion having a retaining means for securing the splint to at least some of the forward teeth of one arch of teeth of a person suffering from bruxism in order to locate the splint in a predetermined position in the mouth of the person, the body portion being provided with a contact portion arranged to face in a direction towards at least one of the front teeth of the other arch of teeth of the person, said front teeth of the first arch being opposed to the front teeth of the second arch wherein the contact portion includes at least a first portion or section for receiving the opposed forward teeth of the second arch when the teeth are in the normal habitual teeth together position during use of the splint and a second section which is located adjacent the first section for guiding movement of the opposed front teeth of the second arch when the jaw is clenched so that when the teeth are in the normal habitual teeth together position at least one of the opposed forward teeth of the second arch contacts the contact portion so as to at least maintain spacing of at least some of the rearwardly located teeth of one arch in spaced relationship from at least one of the rearwardly located teeth of the second arch and when the jaw is clenched at least one of the opposed forward teeth of the second arch is guided from the normal habitual teeth together position by movement along or with respect to a second section of the contact portion so as to at least maintain spacing of the rear opposed teeth of the first and second arch thereby preventing the opposed rear teeth from touching each other so as to suppress the intensity of forces of bruxism. 2. A device according to claim 1 in which the retaining means is a cavity, chamber, pocket, groove, slot indentation, opening or the like located at or towards one side or end of the device for receiving at least some of the front teeth to maintain the device in place in the mouth. 3. A device according to claim 2 in which the retaining means is at least two preferably at least four and more preferably at least six or more indentations moulded to the shape of the teeth to be received in the indentations. 4. A device according to claim 1 in which the contact portion allows for the spacing between the opposed rearward teeth being at least substantially maintained or preferably becoming substantially greater as one of the opposed forward teeth move forward with respect to the other opposed forward teeth. 5. A splint according to claim 1 in which the first set of teeth is the upper arch or teeth. 6. A splint according to claim 5 in which the teeth of the upper arch are the at least two upper central front teeth, preferably the central upper four teeth and more preferably the central upper six teeth. 7. A splint according to claim 1 in which the contact portion comprises at least the first and the second portion in which the first portion is a central or intermediate portion and the second portion is located adjacent or contiguous to the central portion, preferably located more forwardly of the central or intermediate portion 8. A device according to claim 1 in which the first and/or second contact portion is flat, curved or a combination of different shapes. 9. A splint according to claim 1 in which the second contact surface is angularly inclined to the central or intermediate portion. 10. A splint according to claim 1 in which the angle of inclination between the first contact portion and the second contact portion is from greater than about 90° to less than about 180°, preferably from about 110° to about 160° and more preferably from about 115° to 145°. 11. A splint according to claim 1 in which at least one or both of the contact surfaces forming the contact portion is curved, parabolic, circular or other curved geometric shape and the contact portion further includes a third section surface or portion in which the third portion is located at or towards the other side or end of the first section than the side or end having the second section. 12. A splint according to claim 1 in which the third section is located more rearwardly of the first and second portions in which the first portion is the central or intermediate portion and the second portion is the forward portion so that the third portion is the rearward or posterior portion. 13. A splint according to claim 1 in which the third portion is a lip, shelf, ledge or similar which is angularly inclined to the central or intermediate portion. 14. A splint according to claim 1 in which the second or forward portion is a forwardly inclined portion for increasing the clearance of the rearwardly located teeth whereas the rear or third portion prevents substantial rearward movement of the jaw to adopt a substantially permanent position. 15. A splint according to claim 1 in which the third section stabilises or tends to stabilise the position of the jaw to or towards the ususal habitual closing position. 16. A splint according to claim 1 in which the third or rearward portion prevents or minimises posterior shift and assists in moving the jaw into the normal position and remaining in this position when the device is not in use. 17. A method of treating a person suffering from a disorder associated with the oral cavity including forming a splint adapted to closely conform to at least some of the forwardly located teeth in the oral cavity of the patient, locating the splint in the oral cavity such that the splint is provided with a contact portion in which contact of opposed forward teeth maintains spacing of opposed rearward teeth so as to ameliorate the effects of bruxism. 18. A method according to claim 17 using a splint according to claim 1. | The present invention relates generally to intra-oral devices, and in particular to improvements in or to new forms of intra-oral devices. In particular, some embodiments of the present invention relate to intra-oral devices of the type that are worn by patients suffering from certain conditions which occur during sleep, such as for example, conditions associated with sleep disorders, bruxism or the like, in which the devices are provided with a contact portion for contact by opposing teeth in order to prevent a patient's rearwardly located teeth from contacting each other. Even more particularly, some embodiments of the present invention relate to an occlusal device having a modified contact portion and to methods of using such device, for inhibiting the forces of bruxism, and hence reducing or eliminating potential damage to teeth, including restored or repaired teeth or similar, caused as a result of voluntary or involuntary jaw clenching and grinding which usually occurs whilst the person is asleep. However, such conditions can occur during the day also. The present invention finds particular application as an occlusal splint having a modified contact portion and a method of using such an occlusal splint, in which the modified contact portion facilitates improved contact between the splint, particularly the contact portion of the splint, and the opposed forwardly located teeth (anterior teeth) in order to prevent opposed more rearwardly located teeth (posterior teeth) from contacting each other during use, particularly from contacting each other in a grinding movement. A particularly preferred form of the occlusal device of the present invention has an improved or modified contact portion which comprises two or more clearly defined contact surfaces, areas or portions which are substantially angularly inclined to each other so as to control movement of the teeth when the jaw moves in order to maintain the rearwardly opposed teeth in spaced apart relationship to each other during use, and in some instances to increase the distance that the teeth are in spaced apart relationship to each other, particularly the vertical spacing of the teeth. Thus, the splint is designed to stay in place on the front teeth to prevent the rear teeth from touching each other. Although the present invention will be described with particular reference to one form of an occlusal device having a compound contact portion in the form of a ramp or similar comprising at least two angularly inclined parts or surfaces for keeping opposed rearwardly located teeth in spaced apart relationship from each other during use, it is to be noted that the scope of the present invention is not restricted to the described embodiment, but rather the scope of the present invention is more extensive so as to include other forms and arrangements of the intra-oral device, other forms and arrangements of the contact portion, including different arrangements and orientations of the respective parts or portions of the contact surface, and the use of the various different forms of the device in a wide variety of situations for treating numerous conditions and disorders amongst a wide range of patients having different mouth types, mouth anatomy or the like. The habit of clenching the jaw and jaw muscles to bring the upper and lower teeth together and moving the teeth against each other particularly moving the teeth laterally against one other, is a problem or condition suffered by a significant number of the population. The general description of such movements of the jaw is bruxism. Normally, bruxism has two components which are (i) clenching of the jaw to force the teeth together against each other whilst maintaining the teeth static and (ii) grinding of the teeth which involves moving the teeth laterally against each other. Bruxism encompasses either one or both of these movements so that patients can suffer from a variety of forms of bruxism. Bruxism which includes any combination of clenching and/or grinding of the teeth can present serious dental health problems as well as produce general health problems. The term “bruxism” is more accurately defined as “the parafunctional clenching and grinding of teeth”. If left untreated, bruxism can lead to attrition and damage of tooth surfaces, loss of vertical dimension of occlusion, increased muscle tone, or tension or strains, fracture of teeth, chipping of teeth and pathological changes in the temporo mandibular joints (TMJs). It can also lead to muscle or muscular disease or dysfunction within muscles, such as for example, pathological changes within the muscles, typically in the masticatory muscles. The damage to masticatory muscles or structures is related to the duration and magnitude of force applied during the parafunctional activity. The greater the force, the greater the damage. Such grinding and clenching of the teeth is often associated with stress, and although bruxism can occur during the day or at night whilst the patient is asleep the forces of bruxism are greater at night and accordingly, more damage occurs at night. Often the patient is unaware of this condition and of the harm that is being caused until the damage is manifest and/or observable. It is often only when the harm or damage becomes apparent that the condition is diagnosed which is often too late to effect a complete cure or rehabilitation since amelioration of the condition often requires expensive and extensive treatment. Grinding of the teeth results from a patient tightly clenching his or her jaw muscles, thereby forcing together the occlusal surfaces of the opposed upper and lower teeth, sometimes with considerable force. As well as the actual clenching action itself, in which the opposed teeth are brought into contact with each other, the jaw muscles cause the upper and lower teeth to move laterally with respect to each other simultaneously while being forced into contact with each other, hence producing a grinding action in the teeth. Such grinding can, if unchecked, result in serious damage to the teeth of the patient, as well as compounding the harm caused by the clenching action. The damage also includes damage to teeth that have previously being restored and/or repaired, such as for example, fillings, crowns or the like. As an example, in the short term, constant grinding can wear enamel from tooth surfaces, particularly the crown or cusp of the tooth. In the long term, grinding can eventually wear through the enamel of the tooth and into the tooth pulp itself and/or through any previous repairs or restorations to or of the teeth, leading to irrepairable damage and harm to the tooth and nerves, such as for example, causing fractures of teeth or the like, as well as requiring further expensive restorations. Furthermore, the dysfunction of the clenching muscles, when chronic, can lead to the development of conditions such as temporo mandibular disorders, tension-type headaches, migraine and the like, resulting in permanent and/or temporary harm and/or injury to the patient. Although there have been a number of different appliances or devices for treating bruxism in the past, including devices known as occlusal devices, splints or the like all of the previously available devices have suffered from one or other defect or shortcoming when used to ameliorate the effects of bruxism. One form of the splints currently available termed “flat plane full mouth splints” are relatively large in size and accordingly, are uncomfortable to wear, particularly for lengthy periods of time, such as for example during sleep. Usually, such splints are so uncomfortable that many patients do not persist with their use and end up not wearing them thereby negating any benefit that may be derived from their use. Other types of splints which contact the front two incisor teeth only are smaller in size and hence more comfortable to wear but have a tendency to be dislodged easily from the teeth since they are held in contact with two teeth only, usually the upper pair of central incisors. Owing to their small size there is insufficient area of contact between the splint and the teeth to securely hold the splint in place during use. Also again owing to their small size, when the device dislodges from contact with the teeth there is a risk that such devices may be swallowed or inhaled, particularly when the fit between the device and the teeth becomes loose after prolonged use and wear. Other devices are provided with a contact portion to assist in maintaining the posterior teeth in spaced apart relationship to each other in which the contact position is in the form of a dome or ramp or similar protrusion or projection which usually extends beyond the front surface or face of the splint. However, in some embodiments of splints having a contact portion the size or area of the contact projection is insufficient to maintain the posterior teeth in spaced apart relationship as there is a tendency for the opposed front teeth to slide off the contact portion allowing the rear teeth to contact one another as the contact portion keeping the teeth apart is no longer positioned in the correct place to achieve this. Additionally, the shape of the contact surface being planar allows relative movement of the upper and lower arches containing the upper and lower teeth, respectively, with respect to one another so that it is still possible for the rear teeth to grind against one another even if the front teeth are in contact with the splint. Whilst such prior art splints are effective to an extent, there is the real possibility that the rear teeth could come into contact with each other even when the device is being worn owing to the size and shape of the contact portion. Whilst such devices go some way towards alleviating the effects of bruxism, they still suffered from a number of problems or disadvantages. One problem of existing contact portions is that in order for the contact portion to work successfully to take advantage of the jaw opening reflex, which is a reflex action activated by the incisor teeth being clenched, the contact portion needed to be so large or to intrude into the mouth to such an extent to ensure that the incisor teeth contacted the contact portion before the rear teeth came into contact with each other, that the splint was uncomfortable to wear. If the contact portion was made small there was provided only minimal separation of the opposed rear teeth. As a consequence, there is a need for an occlusal splint which is comfortable to wear, yet provides sufficient spacing between the opposed rear teeth to inhibit bruxism so as to eliminate or reduce the adverse effects caused by bruxism, and which controls or guides movement of the jaw, particularly the lower jaw or mandible to a greater extent in order to prevent or reduce the amount of contact between the rearwardly located teeth. Therefore, it is an aim of at least some embodiments of the present invention to provide an occlusal splint which is comfortable to wear by being small in size, typically smaller in size than the flat plane full mouth splints. It is another aim of at least some other embodiments of the present invention to provide an occlusal splint that suppresses the intensity of the forces of bruxism. It is a further aim of at least some other embodiments to provide an occlusal splint that reduces the vertical dimensions of separation between opposed teeth whilst still maintaining the teeth in spaced apart relationship to each other. It is a further aim to provide an occlusal splint that produces less strain on the Temporo-mandibular joint (TMJ). It is a further aim of the present invention to provide a splint which provides sufficient separation for the opposed rear teeth from one another, and which controls the movement of the opposed front teeth so as to maintain the gap between the opposed rear teeth. It is a further aim to provide a splint with a compound contact portion that has at least two contact surfaces located in two different planes. According to one aspect of the present invention there is provided an occlusal splint for suppression of the intensity of forces of bruxism resulting from grinding and/or clenching of teeth of a person suffering from bruxism, said device comprising a body portion having a retaining means for securing the splint to at least some of the forward teeth of one arch of teeth of a person suffering from bruxism in order to locate the splint in a predetermined position in the mouth of the person, the body portion being provided with a contact portion arranged to face in a direction towards at least one of the front teeth of the other arch of teeth of the person, said front teeth of the first arch being opposed to the front teeth of the second arch when the splint is located in place in the mouth, wherein the contact portion includes at least a first portion or section for receiving the opposed forward teeth of the second arch when the teeth are in the normal habitual teeth together position during the use of the splint and a second section which is located adjacent the first section for guiding movement of the opposed front teeth of the second arch when the jaw is clenched so that when the teeth are in the normal habitual teeth together position at least one of the opposed forward teeth of the second arch contacts the contact portion so as to at least maintain spacing of at least some the rearwardly located teeth of one arch in spaced relationship from at least one of the rearwardly located teeth of the second arch and when the jaw is clenched at least one of the opposed forward teeth of the second arch is guided from the normal habitual teeth together position by movement along or with respect to the second section so as to at least maintain spacing of the rear opposed teeth of the first and second arch thereby preventing the opposed rear teeth from touching each other so as to suppress the intensity of forces of bruxism. Typically, the retaining means is a cavity, chamber, pocket, groove, slot, opening or similar located at or towards one end of the occlusal splint. More typically the retaining means is located along the upper surface in use of the splint. Even more typically the retaining means is shaped so as to receive one or more of the front teeth. Even more typically the retaining means is shaped so as to receive the front teeth of the upper arch of teeth of the person wearing the splint. Even more typically, the retaining means receives at least two upper front teeth, preferably two or more upper front teeth, more preferably 4 to 6 upper front teeth, and most preferably six upper front teeth. Even more typically, the retaining means of the splint is molded to be received by and held in place by the six central or anterior or front upper teeth. Typically, the splint of the present invention maintains the minimal separation of the opposed rearwardly located teeth from one another. More typically, the separation between the opposed rearward teeth becomes greater as the opposed forward teeth move forward with respect to each other. Typically, bruxism may occur during the day or at night, and the effects of reduced bruxism using the splint of the present invention occur whilst the device is being worn, typically at night. More typically, there is research to suggest that when the device is worn there is up to about 70% reduction in the intensity of force of bruxism. Typically, the normal habitual teeth together position includes a teeth contact position that corresponds to the centric occlusion position when the mouth is empty of devices. Typically, movement of the forwardly located teeth with respect to the splint, preferably with respect to the contact portion of the splint, is in a generally forward direction and optionally in a sideways direction or in both directions. Typically, the splint cooperatively engages with at least four or more front teeth, more typically, with at least five or more front teeth, and preferably at least six front teeth. However, the splint can be fitted to 8 10 or even 12 upper teeth. Typically, the splint is retained on the central upper teeth, such as the incisior teeth. Typically, the front teeth are anterior teeth. More typically, the anterior teeth are the two pairs of incisor teeth and the first pair of canine teeth located on either side of the incisor teeth. Although the splint can be fitted to the upper or lower teeth, it is preferred that the splint is fitted to the upper teeth so that the lower teeth are the opposed teeth. When fitted to the upper teeth, the contact surfaces face the lower front teeth and assist in controlling movement of the lower front teeth and/or lower jaw (mandible) to some extent so as to maintain spacing of the upper and lower rear teeth from each other. Typically, the rearward teeth are posterior teeth, such as molars, including the first, second and third molars, and/or premolars, such as the first and second premolars and the like. Typically, the contact portion has at least two contact parts, sections, portions, surfaces or the like. More typically, each of the contact surfaces is flat, linear, planar, smooth, continuous, tapered or the like. Alternatively, the contact surface or surfaces is or are curved, including surfaces that are concave, convex or the like. Even more typically, at least one of the contact surfaces is an oblique plane, an inclined plane, a tapered plane. Even more typically, one of the two contact surfaces is flat or the like. Even more typically, the two contact surfaces of the splint are located in different planes to each other, more typically the two planes are inclined to each other, and even more typically the planes are substantially angularly inclined with respect to each other. Typically, the angle of inclination is from about greater than 90° to from about less than about 180°, preferably from about 110° to about 160°, and more preferably from about 115° to 145°. Even more typically, the angle of inclination varies over the length of the contact portion so that the contact portion is substantially curved. Thus, the inclined portion can be flat or can be curved. Typically, the curved portion can be convex or it can be concave, preferably concave to assist in maintaining the rearward teeth in spaced apart relationship. Typically, the curved portion is slightly curved. More typically, the curve can be parabolic, circular, or other curved geometric shape or similar. Furthermore the curved portion can be of any diameter, curvature, size or the like. Typically, the second portion of the contact portion is located forwardly of the first portion. Alternatively, the second portion is located rearwardly of the first portion. Preferably, the contact portion includes a third section, surface or portion. Typically the third portion is located at the other side or end of the first section than the end having the second section. More typically the third portion is located more rearwardly of the other two portions. More typically, the first section is a central or intermediate portion and the second section is located more forwardly of the central section, and the third section is located more rearwardly or linearly or posteriorly so as to extend rearwardly of the device. Typically, the third portion is a lip, shelf, ledge or similar. More typically, the lip is angularly inclined to the first or intermediate portion. Even more typically, the third section is tapered, preferably tapered in the opposite direction to the taper of the second section. The forward portion is a forwardly inclined portion for increasing the clearance of the rearwardly located teeth, whereas the lip portion prevents substantial rearward movement of the lower jaw. Thus, the combination of the two sections controls movement of the teeth so as to maintain the spacing of the rearwardly located teeth. Typically, the third section stabilises or tends to stabilise the position of the teeth to or towards the usual habitual closing position. Typically, the third or rearward portion is adapted to assist to at least maintain the spacing of the jaw and preferably, to increase the spacing of the jaw. Even more typically the rearward portion counters the tendency of the jaw to undergo a posterior shift forming a maloclusion. Even more typically, the third portion prevents posterior shift and assists in moving the jaw back into the normal position, particularly the normal habitual teeth together position. Even more typically, the device promotes centric occlusion whereby the top of the most rearward lower teeth and jaw are permitted to undergo substantially forward movement, preferably to the centre of the splint. The present invention will now be described by way of non-limiting example, with reference to the accompanying drawings, in which: FIG. 1 is a front isometric view of the device preparatory to being placed against the forward teeth of the upper arch of the mouth; FIG. 2 is a front isometric view of the device in use in which the device is in contact with the upper front teeth of the mouth; FIG. 3 is a front perspective view of the device in use when the person wearing the device is asleep with the mouth in the normal habitual mouth together position; FIG. 4 is a front top isometric view of one form of the dental device of the present invention shown in isolation; FIG. 5 is a front underneath view of the form of the device in FIG. 4 showing the angularly inclined surfaces forming the contact surface portion; FIG. 6 is a top plan view of the form of the device in FIG. 4; FIG. 7 is an underneath view of the embodiment shown in FIG. 4 showing the contact surfaces of the contact portion; FIG. 8 is a one side elevation view of the embodiment of FIG. 4; FIG. 9 is a cross-section of the device as shown in FIG. 8; FIG. 10 is a side elevation view of the device in use in the usual habitual teeth together closing position when a person is asleep; FIG. 11 is a sectional view along the line 11-11 of FIG. 10; FIG. 12 is a side elevation view of the device in use when the lower jaw is in a more relatively forward position as a person moves their jaw, showing an increased spacing between the rear teeth; and FIG. 13 is a cross-section view taken along the line 13-13 of FIG. 12. With particular reference to FIGS. 4-9, there is shown one form of the occlusal splint of the present invention. This form of the occlusal splint, generally denoted as 2, is made from a plastics material and is moulded to the shape of the forward teeth of a patient so as to be adapted to receive the six centrally located forward teeth 40 of the upper arch of the mouth of a patient, such as for example, the two pairs of upper incisor teeth and the upper pair of canine teeth: The splint is formed with an upper part, generally denoted as 4, which has a plurality of, typically six pockets, indentations, recesses or the like 6 for receiving therein the centrally located forward upper teeth 40. Each pocket is for receiving one tooth so that the six teeth are collectively received in the six pockets. Pockets 6 or the like are one form of the retaining means of the present invention for retaining the splint in place in the mouth and accurately locate the splint in the mouth whilst also securing the splint to the teeth to retain the splint in the mouth. In use, each of the six upper forward teeth 40 referred to previously are received snugly in a respective one of moulded pockets 6. This ensures a good stable fit of the splint on the teeth so as to maintain the splint in the correct position on the teeth thereby preventing inadverent dislodgement into the oral cavity during use, such as when the patient is asleep thereby preventing the splint from being swallowed or inhaled. The splint can be formed in a conventional manner, and is formed from conventional materials from which splints are made, such as suitable plastics materials or combinations of suitable plastics materials. In one embodiment, there is a relatively harder outer shell in the form of a tray or similar within which is located a layer of heat softenable material that is generally more readily shaped or moulded or the like than is the relatively harder outer material. To form the splint, and in some circumstances when adjustments to the splint are required the shell and inner layer are placed in hot water to soften the inner layer so as to make it mouldable, so that when the splint is placed in contact with the centrally located six upper teeth 40, the inner layer of the splint conforms exactly to the shape and profile of the six centrally located upper teeth 40 thereby forming the indentations 6. When the splint cools, the soft inner layer now moulded to the shape of the six upper central teeth hardens to retain this shape and the exact shape of the indentations of the teeth 6. In this manner, the splint 2 is held in place securely against the upper front teeth so that there is little or no tendency for the splint to be dislodged from the teeth, such as during use of the splint when the patent is asleep or similar and also to stabilise the splint against unwanted movement. The indentations for the teeth form the upper part 4 of the splint. In another embodiment, the splint is made from a single material with the upper portion 4 adapted to be molded to the exact shape of the teeth 40. The underside of the splint, which is the part of the splint providing control for movement of the lower teeth or jaw, is provided with a cavity, groove, rebate, hollowed portion, or similar depression or the like. The cavity forms at least part of a contact portion, generally denoted as 8. The contact portion 8, in one embodiment, comprises three sections or portions 10,20,30, all of which are located in different planes from one another. One of the sections, which is referred to as the first section 10, is a flat or substantially flat section centrally located between the sides or ends 12 of the splint. Section 10 is a generally flat planar contact surface for contacting the lower front teeth 42 of the patient in use in the centric occlusion position or the normal habitual teeth together portion when they the teeth brux or clench. When the lower teeth 42 rest against this generally flat surface 10, the splint is generally comfortable to wear and yet maintains sufficient spacing “s” between the rearwardly located teeth 44, as shown more particularly in FIGS. 10 and 11, which illustrates the splint being worn in the normal habitual teeth together position which is comfortable as the spacing “s” is less than the spacing of previously available other splints when being worn by patients in an attempt to counter the effects of bruxism. The second section 20 of the contact portion 8 is located forwardly of central section 10 and takes the form of a generally forwardly inclined, tapered or sloping skirt 22 defining a generally tapered or inclined inner surface which is the contact surface for the upper edges of the centrally located lower teeth 42. The contact surface 20 extends in a plane that is substantially angularly inclined to the plane containing the flat central or intermediate surface 10. The tapering of the front or forward contact portion 20 is adapted so that when the lower jaw moves forwardly, the upper edges of the lower front teeth 42 contact the contact portion 20 so that the lower front teeth move along the inclined plane of this tapered forward to directed surface 20 to increase the spacing of the more rearwardly located teeth 44 to a spacing “t”, which is greater than spacing “S” as shown particularly in FIGS. 12 and 13. Thus, any forward movement of the lower jaw either involuntarily or voluntarily results in the spacing of the rear teeth being least maintained substantially at a spacing “s” or more usually being increased substantially to a spacing “t” thereby overcoming the possibility of bruxism. The more rearwardly located contact surface 30 is also an inclined, tapered or oblique contact surface in the form of a lip, ledge or similar. It is to be noted that the angle of inclination of the rear contact surface 30 is greater than that of contact section 20 but the length of contact section 30 is shorter than the length of section 20. Thus, the rear contact section 30 is steeper than contact portion 20. The lip 30 is angularly inclined to the centrally located flat contact surface 10, and is tapered in a direction opposite to the taper of the front contact portion 20. The intent or purpose of the lip is to prevent a permanent rearward movement or shift of the jaw which would have resulted in changes in the occlusion, or in other words, to maintain permanent stability of the jaw position. It is to be noted that the extent of the general contact portion 8 is generally defined within the limits of the splint so that the front skirt 22, and more particularly front contact surface 20 does not extend beyond the front face of the splint and the rear contact surface 30 does not extend beyond the rear face of the splint. By the entire contact surface 8 being wholly contained with the boundary of the splint and not extending outwardly from the splint, the splint can be made more compact and is more comfortable to wear, particularly during sleep. Further, the splint 2 is made to extend generally arcuately about the mouth so as to be contoured to the curvature of the upper or lower arch within the mouth of the patient, preferably the upper arch. This promotes ease of use and comfort when in use as well as assisting in retaining the splint in place during use, such as when the patient is asleep. Further, the sides 12 of the splint 2 are tapered to prevent unwanted sideways movement of the jaw when clenching. In operation of the device 2 of the present invention, the splint allows the rearwardly located opposed teeth 44 to be more closely spaced towards each other, such as when in their centric occlusion habitual biting position, at a spacing “s”, which is more comfortable for the wearer to use, particularly during long periods of sleep. However, any forward, or sideward movement of the jaw (immediate disclusion) is generally limited and contained by the sloping surfaces 20, 30 and sides 12 as well as by the contour and/or shape of the cavity. Additionally, the splint prevents rearward movement of the lower jaw. Thus, there is a tendency for the jaw and the occlusion to be stablised in the optimum position. In the event that there is forward or rearward movement of the jaw, the lower teeth move along the tapered contact surface of the front contact portion 20 or the rear contact portion 30 respectively, which increases the spacing between the rearward teeth, such as for example from a spacing “s” to a spacing “t” thereby preventing the rearward teeth from contacting each other as the spacing between the rear teeth is increased, preventing the teeth from grinding contact with each other as well as maintaining occulsal stability of the teeth and jaw in the long term. Advantages of the present invention include that the occlusal splint is more comfortable to wear and owing to the angular inclination of the respective contact surfaces, the jaws tend to be maintained in this comfortable position. Any movement of the jaw, particularly the lower jaw, in any direction, increases the spacing of the rear teeth and there is a tendency for the jaw to return to the normal position and for the occlusion to remain stable in the long term even when the splint is not being worn. The device of the present invention allows a clear gap “S” between opposed upper and lower rear teeth 44 initially. There is decreased vertical dimension and minimal vertical opening of the mouth which is more comfortable for the patient, and is less damaging to the muscles and TMJ. There is reduced strain on the jaw, muscles and the like and the reduced potential for joint muscular problems. The device allows lip seal during sleep which is desirable as it prevents inflamation of the gums, gum disease, peridontal disease from dry mouth conditions and other conditions caused by this, as well as preventing dry and/or cracked lips, mouth or the like which are usually present when similar devices are worn as such devices are large, which prevents the lips from closing and sealing. The contact portion does not extend extensively or excessively from the front of the device. More particularly, the device reduces, inhibits, prevents or the like permanent or long term posterior shift of the mandible and a change in the occlusion as a result of muscle deprogramming. The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed. Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope. | 20040430 | 20070626 | 20050203 | 95950.0 | 0 | NGUYEN, CAMTU TRAN | OCCLUSAL SPLINT | SMALL | 0 | ACCEPTED | 2,004 |
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10,835,654 | ACCEPTED | SENSOR AUTO-RECALIBRATION | A sensor and method that detects a mis-calibration and automatically recalibrates itself without operator intervention. If the sensor determines that it was calibrated over an object such as a stud, the sensor may automatically update the calibration value with a new lower value without operator intervention. This process may repeat until the calibration value is set to a value that represents the wall covering alone without hidden objects behind it. | 1. A method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; the stud sensing device determining if it was calibrated over or near a stud; and the stud sensing device recalibrating itself if it determined that the stud sensing device was calibrated over or near the stud. 2. The method of claim 1, wherein the act of determining if the stud sensing device was calibrated over or near the stud includes: comparing the calibration value to the second density value; and determining that the stud sensing device was calibrated over or near the stud if the second density value is more than a threshold amount less than the calibration value. 3. The method of claim 1, wherein the act of determining if the stud sensing device was calibrated over or near the stud includes: comparing the calibration value to the second density value; and determining that the stud sensing device was calibrated over or near the stud if the second density value is between a first threshold amount under the calibration value and a second threshold amount less than the calibration value. 4. The method of claim 3, wherein the second threshold amount is an offset value from the calibration value. 5. The method of claim 3, wherein the second threshold amount is a constant value. 6. The method of claim 1, wherein the act of recalibrating the stud sensing device includes the stud sensing device resetting the calibration value based on the second density value. 7. The method of claim 6, wherein the act of resetting the calibration value based on the second density value includes the stud sensing device setting the calibration value equal to the second density value. 8. The method of claim 6, wherein the act of resetting the calibration value based on the second density value includes the stud sensing device decreasing the calibration value by a fraction of a difference between the calibration value and the second density value. 9. The method of claim 1, further comprising the acts of: moving the stud sensing device to a new location on the surface; sensing a new density at the new location; resetting the second density value based on the new sensed density; the stud sensing device determining if it was recalibrated over or near the stud; and the stud sensing device recalibrating itself if it determined that the stud sensing device was calibrated over or near the stud. 10. The method of claim 1, further comprising the act of indicating to a user when the stud sensing device is recalibrated. 11. The method of claim 10, wherein the act of indicating includes providing both an audible and visible indication to the user. 12. A stud sensing device capable of automatically recalibrating if it has erroneously been calibrated at a location over or near a stud, the stud sensing device comprising: a first memory adapted to hold a calibration value; a second memory adapted to hold a sensed value; a sensor adapted to be applied to a surface, thereby determining a density behind the surface and providing the sensed value, wherein the sensor is operationally coupled to the second memory; a comparator adapted to compare the first memory location to the second memory location, thereby determining if the calibration value represents a value sensed over or near the stud, wherein the comparator is operationally coupled to the first and second memories; and an updater adapted to update the first memory with an updated calibration value, wherein the updater is operationally coupled to an output of the comparator. 13. The sensor of claim 12, further comprising a controller adapted to coordinate operation of the sensor, the comparator and the updater. 14. The sensor of claim 12, further comprising an indicator adapted to indicate to a user when the first memory changes, wherein the indicator is operationally coupled to the output of the comparator. 15. The sensor of claim 12, wherein the stud sensing device updates the calibration value without operator intervention. 16. The method of claim 1, wherein the device recalibrates itself by updating a calibration value without user intervention. 17. A method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over or near a stud; recalibrating the stud sensing device if the stud sensing device was calibrated over or near the stud; wherein the act of determining whether the stud sensory device was calibrated over or near a stud includes: comparing the calibration value to the second density value; and determining that the stud sensing device was calibrated over or near the stud if the second density value is more than a threshold amount less than the calibration value. 18. A method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over or near a stud; recalibrating the stud sensing device if the stud sensing device was calibrated over or near the stud; wherein the act of determining whether the stud sensory device was calibrated over or near a stud includes: comparing the calibration value to the second density value; and determining that the stud sensing device was calibrated over or near the stud if the second density value is between a first threshold amount under the calibration value and a second threshold amount less than the calibration value. 19. A method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over or near a stud; recalibrating the stud sensing device if the stud sensing device was calibrated over or near the stud; wherein the act of recalibrating the stud sensing device includes resetting the calibration value based on the second density value; and wherein the act of resetting the calibration value based on the second density value includes setting the calibration value equal to the second density value. 20. A method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over or near a stud; recalibrating the stud sensing device if the stud sensing device was calibrated over or near the stud; wherein the act of recalibrating the stud sensing device includes resetting the calibration value based on the second density value; and wherein the act of resetting the calibration value based on the second density value includes decreasing the calibration value by a fraction of a difference between the calibration value and the second density value. | BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to sensors that detect objects, such as studs, behind a wall covering, such as sheetrock, and more particularly to sensors that detect and correct a miscalibration. 2. Description of Related Art U.S. Pat. No. 4,464,622 entitled “Electronic wall stud sensor,” issued Aug. 7, 1984, and incorporated in its entirety by reference herein, discloses an electronic wall stud sensor particularly suitable for locating a stud positioned behind a wall surface. (A “stud” is a structural member of a building to which an interior wall surface such as wall board or paneling is affixed.) Typically in the U.S., “2-by-4” wooden studs are used in construction. Nominally, a 2-by-4 stud is 51 mm (2 inches) wide and 102 mm (4 inches) deep and of any suitable length. The actual dimensions of a 2-by-4 are more typically 38 mm (1½ inches) wide and 89 mm (3½ inches) deep. Use of English units (inches) and U.S. stud sizes here is in conformance with U.S. construction practice and is not intended to be limiting, but is only illustrative. Finding studs is a typical problem for building repairs, picture hanging, etc. The sensor detects the stud by measuring a change in capacitance due to a change in the dielectric constant along the wall. Due to the placement of the studs, a wall surface exhibits changing dielectric constants while the sensor is moved along the wall's surface. The sensor includes a plurality of capacitor plates, a circuit for detecting changes in the capacitance, and an indicator. The plurality of capacitor plates is mounted in the sensor such that they can be positioned close to a wall's surface. In operation, an operator places a sensor over a covering surface (such as a wall, floor or ceiling). When the capacitor plates are drawn along the surface, the circuit detects a change in the capacitance of the plates due to a change in the average dielectric constant of the surface. A combination of a wall or other surface covering and an underlying stud or other member has a larger capacitance than a wall covering alone without a stud. The capacitor plates are used to measure the effective capacitance or change in capacitance of a wall. After the sensor is placed against the wall and before detection begins, the sensor first performs a calibration to null out the effect of a wall in the absence of a stud. The sensor initially calibrates itself by determining a calibration value that may be used as a reference value. If an operator placed the sensor over an object (such as a stud or joist) hidden behind the covering surface during calibration, the sensor may detect a capacitance greater than a capacitance representing just the wall covering. As a result, the sensor may store an erroneous calibration value. A sensor may detect the erroneous calibration value, alert the operator to begin the calibration process again, and halt the capacitance measurement process. Thus, the operator is forced to recognized the alert and know to reinitialize the calibrate process by restarting the sensor over a new area of the wall covering. It may be desirable to automatically recalibrate a sensor that was erroneously calibrated over a hidden object. SUMMARY Some embodiments provide a method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over a stud; and recalibrating the stud sensing device if the stud sensing device was calibrated over the stud. Some embodiments provide a stud sensing device capable of automatically recalibrating if it has erroneously been calibrated at a location over a stud, the stud sensing device comprising: a first memory adapted to hold a calibration value; a second memory adapted to hold a sensed value; a sensor adapted to be applied to a surface, thereby determining a density behind the surface and providing the sensed value, wherein the sensor is operationally coupled to the second memory; a comparator adapted to compare the first memory location to the second memory location, thereby determining if the calibration value represents a value sensed over the stud, wherein the comparator is operationally coupled to the first and second memories; and an updater adapted to update the first memory with an updated calibration value, wherein the updater is operationally coupled to an output of the comparator. Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1C illustrate a plan view of a prior art single plate capacitive sensor positioned against a wall at a lateral distance away from a hidden stud and the capacitance produced by the sensor and the wall. FIG. 2 shows a flow chart of an auto-recalibration process, in accordance with the present invention. FIGS. 3-6 each illustrate a capacitance curve and an overlying calibration capacitance of an auto-recalibration system, in accordance with the present invention. FIGS. 7-8 both show a system block diagram of an auto-recalibration system, in accordance with the present invention. DETAILED DESCRIPTION In the following description, reference is made to the accompanying drawings, which illustrate several embodiments of the present invention. It is understood that other embodiments may be realized and mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description is not to be taken in a limiting sense, and the scope of the embodiments of the present invention is defined only by the claims of the issued patent. Some portions of the detailed description which follows are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. A procedure, computer executed step, logic block, process, etc., are here conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those utilizing physical manipulations of physical quantities. These quantities can take the form of electrical, magnetic, or radio signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. These signals may be referred to at times as bits, values, elements, symbols, characters, terms, numbers, or the like. Each step may be performed by hardware, software, firmware, or combinations thereof. In operation, an operator places a sensor over a covering surface (such as a wall, floor, or ceiling). The sensor initially calibrates itself by determining a calibration value that may be used as a reference value. The operator may have unknowingly placed the sensor over an object (such as a stud or joist) hidden behind the covering surface. If the operator placed the sensor over an object hidden behind the covering surface, the sensor may measure a capacitance greater than a capacitance representing just the wall covering. As a result, the sensor may store an erroneous calibration value. With time, the sensor takes additional capacitance measurements. As the operator slides the sensor across the surface, resulting capacitance measurements may be larger or smaller than the stored calibration value. If the calibration value is too high in comparison to the additional capacitance measurements, the sensor may not detect a stud or may identify the stud as narrower than its actual width. In accordance with the present invention, if the sensor determines that it was calibrated over or near a hidden object, the sensor may automatically update the calibration value with a new lower value without operator intervention. This process may repeat until the calibration value is set to a value that represents the wall covering alone without hidden objects behind it. In addition, embodiments of this invention may be used with single plate sensor, sensors having side plates, sensors having two or more plates of similar area, or ratiometric sensors. FIG. 1A illustrates a plan view of a known capacitive sensor 120 having a single plate 122 positioned against a wall structure 99 at a lateral distance D away from a hidden stud 100. Each stud 100 has two edges 102 and defines a centerline 101 relative to its positioning to the wall 99. FIGS. 1B and 1C illustrate graphically a capacitance produced between the plate 122 and the wall 99. A capacitance curve 130 shows peaks at the centerline 101 of each stud 100 and a valley between a neighboring pair of studs 100. The capacitance curve 130 shows a minimum capacitance value when the sensor 120 is directly between the pair of studs 100. To mark an edge 102 of a stud 100, a sensor 120 uses a transition capacitance as a reference. To mark a centerline 101 of a stud 100, a sensor 120 must detect the peak of the capacitance curve 130. As capacitance curve 130 passes through a transition capacitance value, the centerline 124 of the sensor 120 may be approximately over an edge 102 of the stud 100. While the capacitance is above this value, the sensor 120 may indicate it is over the stud 100. The transition capacitance value may be set at the factor and may be less useful in locating edges and centers of studs located behind wall structures having unknown thicknesses and studs having non-standard widths. Alternatively, the transition capacitance may be set to an offset value above the calibration value. During calibration, a sensor may set an initial calibration value. If an operator placed the sensor between two studs, at a point where the measured capacitance is a minimum, the sensor may set the calibration value to a value that represents a calibration capacitance 140. If the operator placed the sensor over or near a stud, the measured capacitance may be a non-minimum value. As a result, the sensor may set the calibration value to a value that is too large, such as a value that represents an erroneous calibration capacitance 150. FIG. 2 shows a flow chart of an auto-recalibration process, in accordance with the present invention. At step 201, a sensor begins calibration by taking a first capacitance measurement of the wall covering. At step 202, the sensor uses the measured capacitance of the wall covering as a reference for future measurements. The sensor may store the reference as a calibration value in a first associated memory. At step 203, the sensor begins normal operation. A new capacitance measurement is taken by the sensor. The sensor may store the new capacitance measurement as a current measurement value in a second associated memory. At step 204, the current capacitance measurement is used to determine if the calibration value is a proper calibration value. A proper calibration value may be a value that represents a capacitance of just a wall covering without substantial influence from studs and other objects. An improper calibration value may have been taken over or near a stud or metal wiring. An improper calibration value may make a sensor ineffective or less effective at detecting an edge of a stud. Step 204, checking whether a correction is needed to the calibration value, may be executed with each new capacitance measurement. Alternatively, the calibration value may be checked at various times with one or more methods. For example, the calibration value may be checked with every Nth new capacitance measurement or may be checked periodically. The calibration value may be checked intermittently. The calibration value may be checked during a first few seconds after initialization. The calibration value may be checked after a time-out period has elapsed in which a stud has not been detected. For example, a calibration value may be checked every 1/10th of a second for the first 5 seconds then not checked again unless 15 seconds has passed without detection of a stud. Alternatively, a calibration value may be checked every ⅕th of a second while the sensor is operating. Alternatively, a calibration value may be checked with every new capacitance measurement taken. A calibration value may be deemed improper if a new capacitance measurement is less than the calibration value. Alternatively, a calibration value may be deemed improper if a new capacitance measurement is within an offset value from the calibration value. For example, if the calibration value is 115 and the offset value is 10, a new capacitance measurement may be deemed improper if the new capacitance measurement was 105 or less. Additionally, a calibration value may be deemed improper if an average or a running average of a series of new capacitance measurements is within an offset value from the calibration value. A running average may be computed by an arithmetic mean. A running average may be to a median value. A running average may be a computation of new capacitance measurements after excluding extreme or abnormal values. If the calibration value is proper, processing continues at step 206. The new capacitance measurement along with the calibration value may be used to detect edges and/or a center-line of an object. If the calibration value is improper, the calibration value may be updated at step 207. If the calibration value is updated, it may be replaced with a new value. The calibration value may be updated by one of a variety of methods. For example, the calibration value may be updated with a copy of the new capacitance measurement. Alternatively, the calibration value may be decremented by a fraction of the difference between the prior calibration value and new capacitance measurement. Alternatively, the calibration value may be decremented by a fraction of the difference between the prior calibration value and another value such as a running average of new capacitance measurements. Additionally, the calibration value may be updated with each determination that the calibration value was deemed improper or after a series of improper determinations. Alternatively, the calibration value may be updated periodically, intermittently, and/or during a defined period, such as the beginning of use or after a duration of no stud detection. FIGS. 3-6 each illustrate a capacitance curve and an overlying calibration capacitance of an auto-recalibration system, in accordance with the present invention. FIG. 3 shows a series of sensor measurements represented as sensor capacitance curve 130. In the scenario shown, a sensor initially sets a calibration value that represents an initial calibration capacitance at time T0. Between time T0 and time T1, the sensor measures new capacitance measurements (represented by curve 130) that are greater than the initial calibration value. The calibration value is left unchanged. At time T1, subsequent new capacitance measurements fall below the initial calibration capacitance. The calibration value may be deemed improper if a new capacitance measurement value is less than the current calibration value. The calibration value may then take the value of the lower new capacitance measurement, as shown in calibration capacitance curve 300. After a series of updates to the calibration value, an edge of a stud may be properly detected with a transition capacitance value based on the updated calibration value. FIG. 4 shows a series of sensor measurements represented as sensor capacitance curve 131. In the scenario shown, a sensor initially may set and update a calibration value between time T0 and time T2 as described above with reference to FIG. 3. Between time T2 and time T3, the sensor may be removed from a wall or rocked away from the wall. During this time new capacitance measurements may be extremely low as shown in sensor capacitance curve 131. It may be undesirable to update the calibration value to a value substantially lower than a value that represents the capacitance of a wall. A procedure to determine whether a calibration value is improper may compare the calibration value to a new capacitance measurement. If the difference is above a threshold value, the new capacitance measurement may be considered invalid and may be ignored. In such cases, a calibration value may be left unchanged as shown in the calibration capacitance curve 400. Alternatively, calibration value may be slowly adjusted towards the lower value. For example, during each iteration an calibration value may be updated with a value equal to the calibration value decremented one percent of a difference between the calibration value and the new capacitance measurement. Under circumstances that an operator initiates initialization while the sensor is off the wall or not at an angle flush with the wall, the sensor may erroneously set the calibration value to a value that represents a capacitance taken off of the wall. If during initialization the sensor determines that it is in a position away from the wall, the sensor may leave a calibration value at a default value or a null value. For example, a sensor may have a default initial value that represents a typical capacitance experienced by a sensor against multiple layers of sheetrock and multiple studs. Alternatively, a sensor may have a default initial value that indicates no value has been set. Alternatively, a sensor may have a default value representing a maximum possible value. Alternatively, a sensor may have a default value representing a minimum possible value. FIG. 5 shows a series of sensor measurements represented as sensor capacitance curve 130. In the scenario shown, a sensor may periodically update a calibration value. For example, at time T0, the sensor sets the calibration value to a value that represents an initial capacitance detected. Then the sensor periodically compares a new capacitance measurement to the calibration value. If the calibration value and a new capacitance measurement differ by more than a threshold amount, the sensor updates the calibration value. The threshold amount may be zero or a non-zero value. For example, at time T4 the sensor determines that the new capacitance measurement is more than a threshold amount below the calibration value. The sensor may then update the calibration value with a new value. For example, the sensor may update the calibration value with a value equal to the new capacitance measurement, as shown in the calibration capacitance curve 500 at time T4. The process repeats at the next period shown at time T5. Subsequent new capacitance measurement are within the threshold amount from the calibration value, therefore, the calibration value is not updated, as shown in the calibration capacitance curve 500 after time T5. FIG. 6 shows a series of sensor measurements represented as sensor capacitance curve 130. In the scenario shown, a sensor may periodically update a calibration value as described above with reference to FIG. 5. However, instead of updating a calibration value to a value equal to a new capacitance measurement, the calibration value is decremented by a fraction of a value that represents a difference between the calibration value and the new capacitance measurement. For example, at times T6, T7, T8 and T9, the calibration value may be updated by a value that equals the calibration value less one-half of the difference between the calibration value and the new capacitance measurement, as shown in calibration capacitance curve 600. A different fraction of the difference may be used, for example, one-fourth or three-fourths. The process may continue until the calibration value approximately equals the new capacitance measurement. Alternatively, the process may continue until a difference between the calibration value and a new capacitance measurement is less than a threshold value, as shown in calibration capacitance curve 600 after time T9. FIGS. 7-8 both show a system block diagram of an auto-recalibration system, in accordance with the present invention. FIG. 7 represents a data flow block diagram of a sensor system after initialization. Sensor circuitry (which is conventional) 701 measures and provides a capacitance measurement. The capacitance measurement may be recorded in a first associated memory 702. A comparator 703 uses the capacitance measurement from first memory 702 and a second memory 704. Second memory 704 may be initialized with a calibration value. By comparing values in first memory 702 and second memory 704, comparator 703 determines whether the calibration value is proper or improper. If the calibration value is improper, an updater 705 may compute or determine an updated calibration value and record it in second memory 704. When updater 705 modifies second memory 704, an indicator 706 may be activated. Indictor 706 may be used to alert an operator (e.g., via sound or a display) that a mis-calibration previously occurred and the sensor is attempting to automatically recalibrate itself to correct the error. FIG. 8 illustrates that the sensor system of FIG. 7 may be implemented using a microprocessor. For example, sensor circuitry 801 may measure and provide a capacitance measurement to a microprocessor 802 coding the software, etc. is well within the abilities of one of ordinary skill in the art in light of this disclosure, and may be accomplished using any suitable programming language. Software, firmware, assembly code, machine code or the like may be used to instruct and control microprocessor 802. Microprocessor (or microcontroller) 802 may include memory for storing a calibration value and one or more capacitance measurements and performs the functions of elements 702-705 of FIG. 7. Instructions may be used to compare or compute whether a new capacitance measurement may show that a calibration value is invalid or improper. If so, microprocessor 802 may include additional instructions to update or compute and store an updated calibration value. Furthermore, microprocessor 802 may be coupled to an indicator 803 to provide an alert, such as an audible and/or visual alert, to an operator. While the invention has been described in terms of particular embodiments and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the embodiments or figures described. Moreover, the figures provided are merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. The figures are intended to illustrate various implementations of the invention that can be understood and appropriately carried out by those of ordinary skill in the art. Therefore, it should be understood that the invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration and that the invention be limited only by the claims and the equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The present invention relates to sensors that detect objects, such as studs, behind a wall covering, such as sheetrock, and more particularly to sensors that detect and correct a miscalibration. 2. Description of Related Art U.S. Pat. No. 4,464,622 entitled “Electronic wall stud sensor,” issued Aug. 7, 1984, and incorporated in its entirety by reference herein, discloses an electronic wall stud sensor particularly suitable for locating a stud positioned behind a wall surface. (A “stud” is a structural member of a building to which an interior wall surface such as wall board or paneling is affixed.) Typically in the U.S., “2-by-4” wooden studs are used in construction. Nominally, a 2-by-4 stud is 51 mm (2 inches) wide and 102 mm (4 inches) deep and of any suitable length. The actual dimensions of a 2-by-4 are more typically 38 mm (1½ inches) wide and 89 mm (3½ inches) deep. Use of English units (inches) and U.S. stud sizes here is in conformance with U.S. construction practice and is not intended to be limiting, but is only illustrative. Finding studs is a typical problem for building repairs, picture hanging, etc. The sensor detects the stud by measuring a change in capacitance due to a change in the dielectric constant along the wall. Due to the placement of the studs, a wall surface exhibits changing dielectric constants while the sensor is moved along the wall's surface. The sensor includes a plurality of capacitor plates, a circuit for detecting changes in the capacitance, and an indicator. The plurality of capacitor plates is mounted in the sensor such that they can be positioned close to a wall's surface. In operation, an operator places a sensor over a covering surface (such as a wall, floor or ceiling). When the capacitor plates are drawn along the surface, the circuit detects a change in the capacitance of the plates due to a change in the average dielectric constant of the surface. A combination of a wall or other surface covering and an underlying stud or other member has a larger capacitance than a wall covering alone without a stud. The capacitor plates are used to measure the effective capacitance or change in capacitance of a wall. After the sensor is placed against the wall and before detection begins, the sensor first performs a calibration to null out the effect of a wall in the absence of a stud. The sensor initially calibrates itself by determining a calibration value that may be used as a reference value. If an operator placed the sensor over an object (such as a stud or joist) hidden behind the covering surface during calibration, the sensor may detect a capacitance greater than a capacitance representing just the wall covering. As a result, the sensor may store an erroneous calibration value. A sensor may detect the erroneous calibration value, alert the operator to begin the calibration process again, and halt the capacitance measurement process. Thus, the operator is forced to recognized the alert and know to reinitialize the calibrate process by restarting the sensor over a new area of the wall covering. It may be desirable to automatically recalibrate a sensor that was erroneously calibrated over a hidden object. | <SOH> SUMMARY <EOH>Some embodiments provide a method of recalibrating a stud sensing device for finding a location of a stud positioned behind a surface, the method comprising the acts of: holding the stud sensing device at a first location on the surface; placing the stud sensing device in an calibration mode; sensing a first density at the first location in the calibration mode; setting a calibration value based on the first sensed density; placing the stud sensing device in an operating mode; moving the stud sensing device to a second location on the surface; sensing a second density at the second location; setting a second density value based on the second sensed density; determining whether the stud sensing device was calibrated over a stud; and recalibrating the stud sensing device if the stud sensing device was calibrated over the stud. Some embodiments provide a stud sensing device capable of automatically recalibrating if it has erroneously been calibrated at a location over a stud, the stud sensing device comprising: a first memory adapted to hold a calibration value; a second memory adapted to hold a sensed value; a sensor adapted to be applied to a surface, thereby determining a density behind the surface and providing the sensed value, wherein the sensor is operationally coupled to the second memory; a comparator adapted to compare the first memory location to the second memory location, thereby determining if the calibration value represents a value sensed over the stud, wherein the comparator is operationally coupled to the first and second memories; and an updater adapted to update the first memory with an updated calibration value, wherein the updater is operationally coupled to an output of the comparator. Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto. | 20040429 | 20060124 | 20051103 | 95912.0 | 1 | LEDYNH, BOT L | SENSOR AUTO-RECALIBRATION | SMALL | 0 | ACCEPTED | 2,004 |
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10,835,758 | ACCEPTED | Foldable and self-opening garment hanger | A foldable and self-opening hanger has two arms that fold down to a closed position away from the hanger's hook member with adjacent bottom arm edges proximal to each other. The arms are closed manually in opposition to a restoring force provided by an internal resilient member that tends to move the arms away from each other toward an open position suitable for hanging light garments such as shirts and blouses that exert opposing forces on the arms less than restoring force provided by the internal resilient member. For heavier garments, a lock-release mechanism is provided that holds the arms in a fully open-locked position that supports coats, heavy sweaters and the like. A pair of release buttons on opposite sides of the hanger release the lock-release mechanism allowing arms to be folded manually to the fully closed position so the hanger may be inserted into the neck of a garment without opening buttons or zippers. The arms then can be released from the closed position by merely letting go of them and allowing the resilient member to spread the arms open to support the garment to be hung. | 1. A collapsible clothes hanger comprising: a) a hook member; b) an anchor body supported by said hook member, said anchor body including a pivot member mounted therein, said pivot member having opposite pivot ends disposed proximal to opposite sides of said body, defining a pivot axis extending there through; c) a pair of hanger arms comprising: d) respective proximal and distal ends and respective spaced apart, opposite lateral sides with respective top and bottom edges; e) said arms disposed with each of said proximal ends disposed adjacent to said opposite sides of said anchor body and with said distal ends extending away from said anchor body; f) said proximal ends further comprising respective rotatable supports to said opposite pivot ends of said pivot member so that said distal ends are rotatable over about ¼ of a full rotation about said pivot axis from a fully closed position with said respective bottom edges disposed proximal to each other, to a fully open position in which said distal arm ends project away from said anchor body and essentially opposite to each other; g) a first stop member defined on one of said proximal arm ends and a second stop member defined on the other of said proximal arm ends, said 1st and said 2nd stop members arranged to contact each other and prevent said arms from rotating beyond said fully open position; h) a latch mechanism operable to automatically latch each one of said arms to said anchor body in a full open and latched mode when said each arm is moved into said full open position from a less than full open position; i) a release mechanism operable to release said latch mechanism on each one of said arms, so that said each one of said arms can be rotated from said full open and latched mode toward a less than full open position; j) a resilient urging member continuously acting to force said pair of arms to rotate away from each other about said pivot member from said fully closed position, through said less than fully open position toward said fully open position. 2. The collapsible clothes hanger as set forth in claim 1, in which said latch mechanism comprises: a) a blocking stud projecting inward, parallel to said pivot axis, from an inside surface of an adjacent proximal arm end; b) wherein said anchor body comprises: i) a sidewall having an upper portion and a lower portion defining a blocking cantilever; (1) wherein said cantilever has a cross section defined by an inside cantilever face and an opposite outside cantilever face between an entry edge and an opposite blocking edge so that said cantilever is laterally rigid and axially flexible with respect to said pivot axis; (2) wherein said cantilever extends from a proximal fixed end at said side wall upper portion to a distal free end; (3) wherein said stud is located on said arm so that it is adjacent to said blocking edge when said arm is in the fully open position; (4) wherein said blocking stud and said blocking wedge cross section are proportioned so that contact of said blocking stud with said blocking edge prevents further rotation of said blocking stud and said arm when said arm is rotated from said fully open position toward said closed position. 3. The collapsible clothes hanger as set forth in claim 2, wherein said entry edge has a thickness narrower than said blocking edge. 4. The collapsible clothes hanger as set forth in claim 3, wherein said entry edge thickness is less than the difference between the blocking edge thickness and the projection depth of the blocking stud, whereby frictional wear between the entry edge and the stud are reduced. 5. The collapsible clothes hanger as set forth in claim 1, in which said release mechanism comprises a) A longitudinal cantilever release tongue formed in a proximal portion of a side panel of one of said arms by a U-shaped slot extending through said side panel and defining a proximal fixed edge and a distal free end; b) a release button disposed at said distal free end projects outward form said side panel, parallel to said pivot axis and disposed adjacent to an outer edge perimeter of said side panel portion; c) said cantilever release tongue and a blocking cantilever disposed on the same one of said opposite anchor body sides, cooperate to release said arm from said locked position when said release button is pressed inward toward said anchor body and an inside surface of said tongue bears against a facing outside surface of said blocking cantilever, with sufficient force to move said locking cantilever inward, toward said anchor body a sufficient distance so that an adjacent blocking stud disposed on said same one of said anchor body sides is not impeded from further rotation past said blocking cantilever when rotating from said fully open, latched position. 6. The collapsible clothes hanger as set forth in claim 1, further comprising: a) A shoulder recess disposed on a proximal top surface of said hanger arms having a set back from said hook member sufficient to prevent fingers or skin of one operating said hanger from being pinched between said proximal arm end and said hanger when opening said hanger arms toward or into said fully open and latched position. 7. The collapsible clothes hanger as set forth in claim 1, in which said resilient member comprises: a) Two channel sidewalls spaced apart to receive a spring coil disposed around a cylindrical mounting tube fixed to said anchor body coaxial with said pivot axis, said spring coil having a pair of lateral spring arms extending in opposite directions in said channel parallel to said sidewalls and below said hanger support; b) Said spring coil having a winding diameter larger than the OD of said cylindrical mounting tube; c) Said coil spring and oppositely directed spring arms proportioned so that said spring arms proportioned so that the contact the respective opposite underside of the hanger arms 104. The spring arms 322, 324 thus provide restoring force 129 to each hanger arm tending to cause them to move toward the fully open-locked position of FIG. 1 when the restoring force 129 exceeds the load force 126 exerted by clothes hung on hanger 100. | BACKGROUND INFORMATION BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to hangers used in clothing stores, dry cleaning establishments, and more particularly household use. Garment hangers are commonly used in clothing stores, garment factories, garment-cleaning companies, and in common households. Conventional fixed hangers are normally used to hang many different types of garments: suits, sweaters, T-shirts, dress shirts, dresses, blouses, and turtle neck sweaters, among them. It is particularly difficult to use conventional hangers on some types of garments, e.g. T-shirts and pull-over sweaters, due to the stresses exerted on the neck-opening for example, when attempting to insert a fixed arm hanger through the neck-opening. Some garments can be damaged when arranging on a fixed arm hanger. For example, the looped weave of a knitted sweater will easily tangle in the hook possibly causing threads to break or be pulled out of the weave. There are many varieties of foldable hangers that have not found acceptance in the market. The hangers shown in existing patents are either not cost-effective, are not reliable in performance, or have no redeeming return on investment to the garment industry, consumer, or otherwise. Some types of collapsible hangers require excessive garment manipulation to place on such hangers. Hangers with shortened arms are also unsatisfactory as other garments with large or scooped neck-openings can easily fall off. Accordingly, it is desirable to have an economic, foldable and self-opening hanger. BRIEF SUMMARY OF THE INVENTION The present invention is a foldable and self-opening hanger that uses a few simple parts. The number of garments that can utilize this feature is very large, for example, some types are suits, sweaters (standard and turtleneck), blouses, dress shirts, T-shirts, and lingerie. The foldable and self-opening hanger prevents stretching of the collar. The foldable and self-opening hanger is economical to manufacture and very convenient for the industry and consumer to use. Advantageously, the present invention is very easy to use by folding down the two arms (right and left), holding them together while insert the hanger into a collar or neck of a garment, once the two arms are placed inside the garment collar, or neck, and merely released, the arms will automatically open by spring action of a resilient member inside. Another advantage of the present foldable hanger invention is that it provides opening resilience sufficient to support light garments such as shirts and blouses without further attention. Yet another advantage is the lock-release mechanism which is engaged by spreading the hanger arms to a fully open-locked position that cause one or more inward projecting inner studs inside the arms to bear against one fixed face of an internal anchor member, preventing the arm from rotating toward the closed position with both arms together. The blocking stud and blocking face provided by the present invention are constructed to minimize wear and extend the life of the present foldable hanger invention. Other advantages of the present invention will becomes apparent from the detailed BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 front and back elevation views of an embodiment of the present hanger invention in the open-lock position. FIG. 2 front and back elevation views of an embodiment of the present hanger invention in the fully closed opening-tension mode. FIG. 3 front and back elevation perspective views of the hanger in FIG. 1. FIG. 4 illustrates a bottom perspective view of one arm and the anchor body of the hanger in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION In FIG. 1, FIG. 2, FIG. 3, and FIG. 4 there are shown views of a preferred embodiment 100 of the present collapsible hangar invention. FIG. 1 shows front and back views of the hangar 100 in a fully open locked mode in accordance with the present invention. FIG. 2 shows front and back views of the hangar 100 in the fully closed mode ready for insertion into or removal the neck of a garment. With regard to FIG. 1 there is shown a front (F) and back (B) view of one embodiment 100 of the present collapsible hangar invention in a fully open and locked position (the open-lock mode) ready to accept and support clothes as an ordinary hangar would. FIG. 1 shows the front (F) and back (B) elevation views of the hanger 100 with a hook member 102 and two opposed arms, 104 right and 104 left, extending right to left in the front view and left to right in the back view. The orientation of the hanger 100 is that of normal use, that is with a hook member 102 centered between, and vertically above the adjacent, proximal ends of two depending hanger arms 104R and 104L. The arms 104 right and 104 left have spaced apart upper and lower edges 106 right, 108 right, 106 left, 108 left. The upper and lower edges are not parallel but are disposed at a slight acute angle 107 from respective distal ends 118. Each arm is notched at its proximal upper edge to form a top shoulder 109 set back from the hook member 102 and recessed below the top of the arms. The proximal end of the outer wall of each arm has flange portion 112 whose perimeter extends around about ¾ of a circle The bottom surface of shoulder 109 extends to a proximal 2nd shoulder 111 forming a load-bearing face below the bottom of 109 to perpendicular to the base edges 108 arms and coplanar with the plane bisecting the hanger. On the opposite arm 104 and on the same (front or back) side, a proximal load-bearing finger 113 projects from the opposite top shoulder 109 as an extension of the opposing arm's outer wall on the same side of the hanger. The bearing face of 2nd shoulder 111 and the complementary bearing finger 113 distribute loads caused by an attempt to force the arms to rotate toward the hook member beyond the natural lock position. They are proportioned so that a reasonable load induced by such an attempt will be supported by the strength of the material chosen for the hanger. The proximal end of the outer wall of each arm 104 has a flange sector 112 whose perimeter has a circular extent from the bottom of the load bearing face 111, about 3/2 pi-radians around to the base edge 108 of its own arm. The circular flange sector 112 on the front and the back has its center coaxial with a pivot axis 116 perpendicular to the plane of the arms 104. A pair of opposing rivets, 120 are centered on the flanges 112, and fixed to the interior of the hanger. The rivets 120 are sized to fit closely, but freely through the center of a respective flange in order to give the flanges 112 and thus the two arms 104, the capability to rotate with respect to the hanger hook, if not otherwise locked together. For reference purposes, a baseline 122 is shown that intercepts the pivot axis 116 and is co-linear with the base edges 108 when the hanger is locked, as in FIG. 1. The pivot axis 116 is the center about which the base edges 108 move toward each other and the arms 104 rotate away from the lock position of FIG. 1 under the influence of forces from above (indicated by arrows 126 on the top edges 106), when they are released as is described below. A longitudinal release lever 127 in the form of cantilever tongue is defined in the plane of the flange by a U-shaped slot extending through the flange plane. The tongue has a release button 128 projecting outward from the outer surface of the flange at its distal end. The longitudinal aspect of the tongue is centered on the pivot axis, spaced away from the flange's center, in line with the pivot axis 116 but on the side opposite to the hook stem, and extends distal from the axis 116 to reach adjacent to, but short of the flange perimeter 124. Part of the slot defining the tongue 127 is partially covered in FIG. 1 and FIG. 2 by the head of rivet 120. Thus, the release tongue 127, flange 112 and arm 104 are unitary and move together in rotation, about the central axis 116. With regard to FIG. 2 there are shown front and back views of the hangar 100 in which the arms 104 are rotated down to a fully closed position with the base edge 108 of each arm in facing contact with its opposite base edge 108. The base edges 108 are aligned with the hook stem 130 since the rotation axis 116 is centered on the hanger hook stem, in this embodiment. Keeping the hanger in this closed position requires the arms to be held together against the urging of an internal spring member, described below, by exerting equal and opposing forces indicated by arrows 202 against the two top arm edges 106. Typically the arms would be held in the closed position shown in FIG. 2 by a person's hand (not shown) wrapped around the arms near their distal ends, in order to pass the distal end of the hangar arms into or out of the neck of a garment. The flanges 112 and their extending arms 104 are arranged to pivot around a pivot axis 116, toward or away from the hook member 102. The arms tend to rotate toward each other in the direction of the closed position of FIG. 2 under influence of forces exerted from above toward the top edges 106 of the hangar arms as indicated by arrows 126, when front and back release buttons 128 on opposite sides of the hanger are depressed toward the interior of the hangar sufficient to release the arms from the lock position shown in FIG. 1. Release buttons 128 are part of a releasable lock mechanism for hangar 100 and is described further below with reference to FIG. 3. A resilient member in the hanger 100 (described below) exerts restoring forces 129 coupled between the pivot axis and the opposite arms, where the restoring force tends to rotate the arms toward the lock position of FIG. 1 when the forces 126 are overcome by the restoring force of the resilient member. The hook member 102 may be formed from a round rod of semi rigid material such as metal or plastic. The rod 102 has an intermediate length longitudinal segment 130 extending distal from between the two hangar arms, and is centered on the pivot axis 116 and is perpendicular to the baseline 122. Between a distal end 132 of the intermediate length segment 130 and a free end 134, the rod 102 forms a curved segment 136 that is doubly curved, first toward one of the arms of the hangar and then reversing curvature to extend back toward the other, opposite arm, extending thereby over about three-quarters of the perimeter of a circle centered on the central pivot axis. The free end 134 and the distal end of the segment 130 are spaced apart so that the hook 102 can be placed over a clothes rod found in a typical closet. The hook portion is formed so it will partially encircle a common clothes rod or clothes peg in a closet while leaving enough separation between the free end of the hook and the upper end of the shaft to remove the hook from the rod or peg. The hook shape may be other than circular as long as the free end of the hook curves sufficiently around its most distal extent from the body piece, to keep the hanger and the clothes it is supporting, safely suspended on the clothes rod whenever it is disturbed slightly, from the vertical (in the plane defined by the curved hook portion). Referring to FIG. 2, the hanger 100 is shown in the closed position with both arms having bottom edges contacting the other. The release buttons 128 on the front and back of hanger 100 are unitary with the flange and the arm on that side and therefore rotates together with them around the pivot axis from the fully open and locked position of FIG. 1 to the fully closed position of FIG. 2. FIG. 3 is an exploded front and back perspective of the hangar 100 shown in FIG. 1 in which the same elements have the same reference labels. An inner anchor body member 302 is disposed between the two flanges. Anchor 302 defines an open end, upside down lateral channel 304 below a top cross piece 305 as the channel base between two spaced apart, front and back sidewalls 306f. The cross piece 305 is located above the pivot axis 116. The sidewalls 306 extend parallel and distal from the cross piece 305 on opposite sides of the stem 130 axis perpendicular to the pivot axis 116. The channel sidewalls 306 have an upper portion 314 and a lower portion 315. The lower portions 315 extend away from the pivot axis 116 to respective rounded free ends 308 distal to the pivot axis. The upper portion 314 of each sidewall is a planar, parallel pivot mount member, each defining a cylindrical borehole 310 coaxial with pivot axis 116, the borehole of each sidewall being the same diameter. A flat lower face 312 is perpendicular to the upper portion of each sidewall and located parallel to and below the pivot axis. The lower face 312 defines the interface between upper 314 and lower 315 portions of each anchor sidewall 306. The lower portion of each sidewall is a rectangular, blocking cantilever 315 projecting from its fixed end at face 312 to its distal free end 308. Each cantilever 315 is formed to be laterally rigid but axially flexible with respect to the pivot axis. The cantilever 315 is preferably formed with a wedge-shaped cross-section as described further below. Lateral channel 304 is perpendicular to the pivot axis with its open-end facing down. Top crosspiece 305 of the channel provides a base to which the stem 130 is fixed at its lower end. A cylindrical tube 318 with flat, opposite end faces is mounted inside the bore holes 310, with its end faces coplanar to the outside surfaces of the sidewalls 314. The two channel sidewalls 306 are spaced apart to receive a spring coil 320 disposed around the mounting tube. The spring coil has a pair of lateral spring arms 322, 324 extending in opposite directions in the channel 304 parallel to the sidewalls 306 and below the top cross piece 305. The spring coil has a winding diameter larger than the OD of the cylindrical mounting tube 318. The two opposing rivets, 120, are located at the front and back of the hanger 100 and centered on the pivot axis 116. The rivets 120 have flat, smooth faces 340 that fit slidably proximal to the outer surface of the flanges and have short posts 342 that extend to fit rotatably, through rivet apertures 344 formed in the center of the flanges. The rivet posts are sized to be pressed into and permanently fixed into the ID of tubular core member 318. The posts can be fixed by glue, soldering or press-fit by conventional means. The rivets are fixed into the mounting tube ID so that respective rivet faces 340 are spaced away from the corresponding opposite anchor body sides and the end faces of the tubular core member 318 are sufficient to allow the flanges 112 to slidably rotate. It is sufficient to allow spacing equal to the thickness of the flange plus an allowance tolerance about 0.01 inches. Referring now to FIG. 2, FIG. 3, and FIG. 4, a blocking stud 350 is mounted on the inside of each of the flange's inner surfaces and projects inward there from to a depth that is a significant fraction of the thickness of the adjacent anchor body sidewall 306. For one preferred embodiment of the present invention the blocking stud projection depth is about (Daniel, what is the dimension of the stud projection?) and the wall thickness is about (Daniel, what is the preferred wall thickness?) Each stud 350 is located on the inside of its flange adjacent to, but not touching, the locking cantilever 306 disposed on the same side of the anchor body as the stud's flange, when the arm and supporting flange are in the open-locked position with respect to the anchor body . . . The stud is proportioned so that it provides an immovable impediment to rotational, closing movement of the arm on which it is mounted when the flange 112 on which the stud 350 is mounted rotates the arm toward the closed position of FIG. 2 from the open-locked position of FIG. 1 and the blocking edge of the adjacent wedge cantilever 315, contacts it's the adjacent blocking stud 350. The coil spring 320 and the spring arms 322, 324 are proportioned so that the oppositely directed spring arms 322, 324 contact the respective opposite underside of the hanger arms 104. The spring arms 322, 324 thus provide restoring force 129 to each hanger arm tending to cause them to move toward the fully open-locked position of FIG. 1 when the restoring force 129 exceeds the load force 126 exerted by clothes hung on hanger 100. The release cantilever tongue and the locking cantilever cooperate to release a hanger arm from the locked position of FIG. 1, when the release button 128 of one tongue 127 is pressed inward toward the anchor body and the inside of that tongue bears against the facing outside surface of blocking wedge 314 disposed on the same side of the anchor body, with sufficient force to move that locking cantilever wedge inward, toward the anchor body a sufficient distance so that the adjacent blocking stud 350 on that side of the anchor body can rotate past the wedge when rotating from the lock open position of FIG. 1 toward the closed position of FIG. 2. This provides an easy means to close the hanger arms by merely pressing inward on the two release buttons while applying closing forces 126 sufficient to overcome the restoring forces 129 provided by the spring arms acting on the underside of the hanger arms on either side of the anchor body. The closing forces can be provided manually with one or both hands of a person. With regard to FIG. 4, in addition to the same elements of previous figures having the same reference numbers, there is shown an underside perspective view of the hanger 100 with the back arm 104 of FIG. 1 removed. This view shows more clearly the lower portion of the sidewalls 306 with the rectangular cantilever wedges 315 and one of the two locking studs 350. The discussion here of one side wall 306 and its cantilever wedge 315 applies equally for the ones on the opposite arm 104 since the arms are mirror images of each other; thus the description of one arm and its interaction with cooperating elements is sufficient for both arms. Each cantilever wedge 315 on the front or back of hanger 100, and the associated locking stud 350, the cantilever lever 127 and the release button 128 on the same front or back side form parts of the lock-release mechanism of the anchor body 302 referred to above with reference to FIG. 1. In accordance with the present invention, each wedge 315 has opposite wedge faces: an inside face 402 and an outside face 404. Inside face 402 is a coplanar extension of the inside surface of the upper portion of sidewall 306. The wedge faces 402, 404 extend distal from the chord face 312 to the free end 308 between two opposite edge faces: an entry face 406, and a blocking face 408, defining a blocking cantilever cross section. The two cantilever edges 406, 408 are spaced apart by a width, Wb, Wb and the location and size of the stud 350 are selected so that blocking edge 408 faces one proximal side of the edge perimeter of the blocking stud 350 when the arm is in the fully open, latched mode, and the entry edge 406 faces an opposite proximal side of the blocking stud edge perimeter when the arm and stud are in the fully closed position. Blocking edge face 408 preferably has the same thickness as the upper sidewall portion. The different thickness of the entry face and the blocking face give the lower sidewall portion 315 its wedge-shaped cross section. The blocking stud 350 on the adjacent flange extends inward from the inside surface of that flange to a stud depth that is a significant proportion of the sidewall thickness. The stud 350 is located adjacent to the blocking edge 408 when the flange is in the open-locked position. The blocking edge 408 is proportioned so that it provides an immovable impediment to the stud 350 to move over, or though, it when the flange 112 rotates the stud 350 from the open-locked position toward the closed position to contact the blocking edge 408. Entry edge face 406 is preferably a narrow edge, thinner than the thickness of the upper sidewall portion and is disposed distal to and facing away from blocking stud 350 on the inside surface of the adjacent flange 112 when the arm is in the open, locked position of FIG. 1. The projection of the stud inward from the inner surface of its flange and the respective thickness of the entry edge 406 and blocking edge 408 and the width of the blocking cantilever arm 315 between the entry edge 406 and blocking edge 408 are proportioned so that the entry edge 406 will clear the stud 350, when the stud is rotated toward the open-locked position of FIG. 1 from the closed position of FIG. 2 or a less than fully open, intermediate closed position. The thickness of entry edge 406 is less than the difference between the thickness of the blocking edge and the projecting depth of the stud 350. Continued rotation of the stud over the entry edge 406 and the slanted, outside wedge face 404 will cause the stud 350 to begin to come into contact with the outside wedge face 404 and then will cause the wedge 315 to deflect inward as the wedge face rides along the rotating stud. The wedge 315 continues to deflect inward with further rotation of the arm and stud 350 until the stud passes beyond the blocking edge 408, where it resiliently returns to its original, undeflected state, positioning the blocking edge 408 facing the proximal edge of stud 350 in the latched, fully open mode as an immovable impediment to closing rotation of the stud 350. The slanted outside wedge face and the narrower entry edge reduce frictional wear on both the entry edge 406 and stud 350 thereby potentially extending the useful life of the present hanger invention. These proportions therefore make it easy to put the hanger arms in the open-locked position from a fully-closed or intermediate closed position merely by rotating the arms into the open-locked position, taking advantage of the automatic deflection of the blocking wedge provided by the angled wedge face established by the different edge thickness 406, 408. Only when it is desired to close the hanger arms is it necessary to operate the release buttons 128. FIG. 4 shows more clearly the restoring force 129 supplied by one end (spring end 322) of the resilient coil spring 320 of this embodiment being applied to a lower bearing edge 420 of a supporting rib 422 molded integrally with the two side panels of 104. Besides providing the lower bearing surface 420 the rib 422 provides additional stability and strength for the arm 104 against twisting and bending forces tending to deform the arm 104. Returning again to FIG. 1, another of the advantages of the present invention is shown in regard to the shoulder 109 and the hanger stem 130. The shoulder 109 is set back from the stem 130 sufficiently so that the fingers or skin of one operating the hanger 100 will be much less likely to be pinched between the recessed shoulder 109 at the proximal ends of the hanger arms and the hanger stem 130 when opening the arms toward the fully open and latched position shown in FIG. 1. | <SOH> BACKGROUND INFORMATION <EOH> | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention is a foldable and self-opening hanger that uses a few simple parts. The number of garments that can utilize this feature is very large, for example, some types are suits, sweaters (standard and turtleneck), blouses, dress shirts, T-shirts, and lingerie. The foldable and self-opening hanger prevents stretching of the collar. The foldable and self-opening hanger is economical to manufacture and very convenient for the industry and consumer to use. Advantageously, the present invention is very easy to use by folding down the two arms (right and left), holding them together while insert the hanger into a collar or neck of a garment, once the two arms are placed inside the garment collar, or neck, and merely released, the arms will automatically open by spring action of a resilient member inside. Another advantage of the present foldable hanger invention is that it provides opening resilience sufficient to support light garments such as shirts and blouses without further attention. Yet another advantage is the lock-release mechanism which is engaged by spreading the hanger arms to a fully open-locked position that cause one or more inward projecting inner studs inside the arms to bear against one fixed face of an internal anchor member, preventing the arm from rotating toward the closed position with both arms together. The blocking stud and blocking face provided by the present invention are constructed to minimize wear and extend the life of the present foldable hanger invention. Other advantages of the present invention will becomes apparent from the detailed | 20040429 | 20060502 | 20051103 | 72572.0 | 0 | WORRELL JR, LARRY D | FOLDABLE AND SELF-OPENING GARMENT HANGER | SMALL | 0 | ACCEPTED | 2,004 |
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10,835,990 | ACCEPTED | Highly selective nitride etching employing surface mediated uniform reactive layer films | Disclosed is a method of selectively etching nitride in a chemical downstream etching process. The invention begins by placing a wafer having oxide regions and nitride regions in a chamber. Then, the invention performs a chemical downstream etching process using CH2F2 to etch and convert the nitride regions into surface mediated uniform reactive film (SMURF) regions comprising (NH4)2SiF6. This process then rinses the surface of the wafer with water to remove the surface mediated uniform reactive film regions from the wafer, leaving the oxide regions substantially unaffected. The chemical downstream etching process is considered selective because it etches the nitride regions at a higher rate than the oxide regions. | 1. A method of selectively etching nitride, said method comprising: placing a wafer having oxide regions and nitride regions in a chamber; performing a etching process using CH2F2 to convert said nitride regions into surface mediated uniform reactive film regions; and rinsing said surface mediated uniform reactive film regions from said wafer. 2. The method in claim 1, wherein said surface mediated uniform reactive film regions comprise (NH4)2SiF6. 3. The method in claim 1, wherein said rinsing process comprises rinsing said wafer with water. 4. The method in claim 1, wherein said etching process is performed at temperatures below 50° C. 5. The method in claim 1, further comprising introducing one of O2, Ar, and N2 into said chamber during said etching process to modulate the etch rate. 6. The method in claim 1, further comprising additional processing including at least one of: increasing concentrations of said CH2F2 in said chamber; and introducing N2 into said chamber. 7. The method in claim 1, wherein said etching process etches said nitride regions at a higher rate than said oxide regions. 8. A method of selectively etching nitride in a chemical downstream etching process, said method comprising: placing a wafer having oxide regions and nitride regions in a chamber; performing a chemical downstream etching process using CH2F2 convert said nitride regions into surface mediated uniform reactive film regions comprising (NH4)2SiF6; and rinsing said surface mediated uniform reactive film regions from said wafer. 9. The method in claim 8, wherein said surface mediated uniform reactive film regions are formed to a minimum thickness of approximately 100 angstroms prior to said rinsing process. 10. The method in claim 8, wherein said rinsing process comprises rinsing said wafer with water. 11. The method in claim 8, wherein said chemical downstream etching process is performed at temperatures below 50° C. 12. The method in claim 8, further comprising introducing one of O2, Ar, and N2 into said chamber during said chemical downstream etching process to modulate the etch rate. 13. The method in claim 8, further comprising additional processing including at least one of: increasing concentrations of said CH2F2 in said chamber; and introducing N2 into said chamber. 14. The method in claim 8, wherein said chemical downstream etching process etches said nitride regions at a higher rate than said oxide regions. 15. A method of selectively etching nitride in a chemical downstream etching process, said method comprising: placing a wafer having oxide regions and nitride regions in a chamber; performing a chemical downstream etching process using CH2F2, O2, CF4, and N2 to convert said nitride regions into surface mediated uniform reactive film regions comprising (NH4)2SiF6; and rinsing said surface modulated regions from said wafer. 16. The method in claim 15, wherein said surface mediated uniform reactive film regions are formed to a minimum thickness of approximately 100 angstroms prior to said rinsing process. 17. The method in claim 15, wherein said rinsing process comprises rinsing said wafer with water. 18. The method in claim 15, wherein said chemical downstream etching process is performed at temperatures below 50° C. 19. The method in claim 15, further comprising introducing one of O2, Ar into said chamber during said chemical downstream etching process to modulate the etch rate. 20. The method in claim 15, wherein said chemical downstream etching process etches said nitride regions at a higher rate than said oxide regions. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to selectively etching nitride in a chemical downstream etching process, and more particularly to an etching process that uses CH2F2 to etch and convert the nitride regions into surface mediated uniform reactive film (SMURF) regions comprising (NH4)2SiF6. 2. Description of the Related Art The standard process for highly selective isotropic nitride etching is a wet process, e.g., a hot phosphoric acid bath. This process suffers from the following drawbacks. It is difficult to control the etch rate and etch selectively over the life of the bath. This wet etching also has poor cross wafer uniformity (>20% 3σ). Also, the requirement for timed overetching approaches 50% with this process. Further, this etching chemistry is not compatible with resist or polysilicon and there are severe environmental handling and disposal issues with phosphoric acid. The phosphoric acid additionally has contamination issues with Cu, which can have undesired effects on devices. Alternate dry etch process have been offered which have a severe tradeoff between an acceptable nitride etch rate (>2000 A/min) and nitride/oxide etch selectivity (>50:1). Additionally, the reaction mechanisms are not understood conventionally and general prescriptions of process control have not been offered. The invention described below addresses these concerns. SUMMARY OF THE INVENTION Disclosed is a method of selectively etching nitride in a chemical downstream etching process. The invention begins by placing a wafer having oxide regions and nitride regions in a chamber. Then, the invention performs a chemical downstream etching process using CH2F2 to etch and convert the nitride, (starting from the top of the nitride regions) into surface mediated uniform reactive film (SMURF) regions comprising (NH4)2SiF6. As the etching progresses, the remaining nitride film is converted into a surface mediated uniform reactive film (SMURF). This process then rinses the surface of the wafer with water to remove the surface mediated uniform reactive film regions from the wafer, leaving the oxide regions substantially unaffected. The chemical downstream etching process is considered selective because it etches the nitride regions at a substantially higher rate than the oxide regions. The surface mediated uniform reactive film regions are formed to a minimum thickness of approximately 100 angstroms prior to the rinsing process (which is performed in a separate water rinsing tool) and the chemical downstream etching process is performed at temperatures below 50° C. to maintain at least this minimum thickness. The invention can also add O2, Ar, and/or N2 into the chamber during the chemical downstream etching process to modulate the etch rate. Similarly, the invention increases the concentrations of the CH2F2 in the chamber and/or introduces N2 into the chamber, during the etching process to increase the etching selectivity of the nitride regions with respect to the oxide regions. This high selective nitride etching is achieved when the SMURF is formed and present during the CH2F2 downstream process. High selective nitride etching cannot be achieved when the SMURF is not formed, even if etching is occurring with a CH2F2 downstream process. When the SMURF forms on the surface of the nitride film, enhanced nitride etching, and therefore ultra etch selectivity to oxide, is enabled. The present invention enables an effective dry etch alternative that meets and exceeds the following etch selective properties of hot phosphoric acid; oxide etch selectivity 0.70:1, linearly tunable high etch rates >2000 A/min, good cross wafer uniformity <6% (3 s), optical endpoint control, and etch computability and etch compatability to both resist and polysilicon. These, and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood from the following detailed description with reference to the drawings, in which: FIG. 1 is a flow diagram illustrating a preferred method of the invention; FIG. 2 is a schematic diagram of a chemical downstream etching apparatus according to the invention; FIGS. 3A and 3B are graphs illustrating the improved etch selectivity and etch rate achieved with the invention; FIG. 4 is a graph illustrating the effects of temperature on film thickness and etch rate; FIG. 5 is a diagram illustrating a pad nitride stripping and etchback process; FIG. 6 is a diagram illustrating a pad nitride stripping and etchback process; FIG. 7 is a diagram illustrating a pad nitride stripping and etchback process; FIG. 8 is a diagram illustrating a nitride spacer removal process; FIG. 9 is a diagram illustrating a nitride spacer removal process; FIG. 10 is a diagram illustrating a nitride liner removal process; FIG. 11 is a diagram illustrating a nitride liner removal process; FIG. 12 is a diagram illustrating a different nitride liner removal process; and FIG. 13 is a diagram illustrating a different nitride liner removal process. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the present invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the invention. Accordingly, the examples should not be construed as limiting the scope of the invention. The invention selectively etches nitride (such as a pad nitride, nitride spacer, nitride liner, etc.) in a chemical downstream etching process. As shown in the flowchart in FIG. 1, the invention begins by placing a wafer having oxide regions and nitride regions in a chamber 110. Then, the invention performs a chemical downstream etching process using CH2F2 112 to etch nitride. When the nitride regions are converted into surface mediated uniform reactive film (SMURF) regions comprising (NH4)2SiF6, nitride etching occurs. The invention then rinses the surface of the wafer with water 114 to remove the surface mediated uniform reactive film regions from the wafer (in a separate chamber), leaving the oxide regions substantially unaffected. The chemical downstream etching process is considered to be selective because it etches the nitride regions at a substantially higher rate than the oxide regions. The present invention enables an effective dry etch alternative that meets and exceeds the following etch selective properties of hot phosphoric acid; oxide etch selectivity 70:1, linearly tunable high etch rates >2000 A/min, good cross wafer uniformity <6% (3 s), optical endpoint control, and etch compatability and etch selectivity to both resist and polysilicon. In the present invention, the surface mediated uniform reactive film regions are formed on the etching substrate (i.e., Nitride) and not the exposed selective substrate (i.e., Oxide). The invention is useful with a nitride strip where the underlying oxide beneath the etched/stripped nitride layer does not etch. The formation of a SMURF layer is unlike standard reactive ion etching where etching of the substrate occurs while simultaneously selectively depositing a polymer layer on the selective substrate to protect the selective substrate and enable enhanced etch selectivity. With the present invention, no protective mask is formed over the oxide. The surface mediated uniform reactive film regions are formed to a minimum thickness of approximately 100 angstroms prior to the rinsing process (which is performed in a separate water rinsing tool) and the chemical downstream etching process is performed at temperatures below 50° C. to maintain at least this minimum thickness. The invention can also add O2, Ar, and/or N2 into the chamber during the chemical downstream etching process to modulate the etch rate. Similarly, the invention increases the concentrations of the CH2F2 in the chamber and/or introduces N2 into the chamber, during the etching process to increase the etching selectivity of the nitride regions with respect to the oxide regions. FIG. 2 is a schematic diagram of a chemical downstream etching apparatus in which the CH2F2 is applied along with one or more other chemicals including CF4, N2, O2, and other similar processing chemicals to the applicator tube 202. A microwave generator 204 ionizes the material to create a plasma 206. The action of a pump 218 draws the ionized plasma free radicals along a transport tube 208 down to a nozzle 210. Long-lived neutral free-radicals are then available to etch and chemically react with the wafer substrate 212 that is within the etching chamber 214. More specifically, the wafer 212 is held by an electrostatic chuck 216. As mentioned above, this etches the nitride films when the nitride regions are converted into surface mediated uniform reactive film (SMURF) regions comprising (NH4)2SiF6. The chemical downstream etching process is considered selective because it etches the nitride regions at a higher rate than the oxide regions. FIGS. 3A and 3B illustrate the increase in both etch selectivity and etch rate that is achieved by forming surface mediated uniform reactive film with the introduction of CH2F2 under certain process conditions into the chemical downstream etching process. For example, the first two etching processes shown to the left in FIG. 3A do not utilize CH2F2; however, the last three utilize CH2F2 and produce substantially improved etch selectivity. Similarly, the first two etching processes shown to the left in FIG. 3B also do not utilize CH2F2; however, the last three utilize CH2F2 which dramatically increases the etch rate. Therefore, the inventive use of CH2F2 in the chemical downstream etching process produces substantial improvements in both etch selectivity and in etch rate. Some general prescriptions relating to the requirements for the formation of the surface mediated uniform reactive film and hence the enhancement of the nitride etching selectivity have been observed by the inventors. For example, the higher the NxHy, and F content of a gas supplied to the applicator tube 202 correlates to a higher silicon nitride etch rate and improved etch selectivity. Similarly, a lower gas phase SixOy content results in higher etch selectivity. To the contrary, a higher SiF concentration correlates to a lower silicon nitride etch rate and thus a lower etch selectivity. Increased concentrations of buffer gases such as_O2 decreases both silicon nitride and silicon oxide etch rates thereby lowering the overall etch rate without affecting the etch selectivity. Also, N2 is strongly associated with the formation of the (NH4)2SiF6 regions and with a larger etch rate. Further, there is a strongly non-Arrehenius temperature behavior for the formation of the (NH4)2SiF6. More specifically, the thickness of the (NH4)2SiF6 layer directly correlates with temperature and the nitride etching rate and requires a temperature below 50° C. to form on the wafer surface. Below this temperature threshold, the formation of the SMURF layer, the nitride etching rate and the oxide etching selectivity directly increases with lower temperatures. This is shown, for example, in FIG. 4 where the (NH4)2SiF6 thickness drops to zero at approximately 50° C. and the etch selectivity decreases dramatically between approximately 30° C. and 50° C. FIGS. 5-13 illustrate various applications of the invention. More specifically, FIGS. 5-7 illustrate a pad nitride stripping and etchback process. In FIG. 5, item 500 represents an oxide, item 502 illustrates a nitride layer that has been converted into a SMURF, and item 504 illustrates a photoresist. The SMURF 502 is rinsed, to produce the structure shown in FIG. 6. Next, an additional SiN layer 506 is formed on the oxide 500 in an etchback process. FIGS. 8 and 9 illustrate a nitride spacer removal process. More specifically, FIG. 8 illustrates a polysilicon structure 806 formed on an oxide layer 800 and surrounded by an oxide layer 802. A nitride spacer 804 that is converted into a SMURF surrounds the oxide 802. The nitride spacer SMURF 804 is removed by rinsing as shown in FIG. 9. FIGS. 10 and 11 illustrate a nitride liner removal performed with the invention. In FIG. 10, a polysilicon structure 106 is formed on an oxide 104 and is also surrounded with an oxide 100. Between the polysilicon structures a nitride liner that is converted into a SMURF 102 is present. As shown in FIG. 11, the nitride liner SMURF 102 is removed by rinsing. FIGS. 12 and 13 illustrate a different nitride liner removal process. FIG. 12 illustrates polysilicon structures 124 and 126 formed on the oxide layer 122. The polysilicon structure 126 is surrounded by an oxide 120, while the polysilicon structure 124 has an oxide 121 formed on only two sides. A nitride liner that is converted into a SMURF is shown as item 128. As shown in FIG. 13, the nitride liner 128 is rinsed, and an additional oxide layer 123 is formed on the open side of the polysilicon structure 124. Therefore, as shown above, the invention provides a substantially improved chemical downstream etching process by introducing CH2F2 and controlling the temperature below approximately 50° C. This provides substantial increases in etch selectivity between nitrides and oxides, increases overall etch rate, and produces a crystalline residue film (NH4)2SiF6 in place of the nitrides which has been described herein as surface mediated uniform reactive film (SMURF) regions, and which is easily removed after the etching process by rinsing with water. In the examples above, highly oxide selective nitride etching can be demonstrated when processing conditions are consistent with the formation of the SMURF layer. Some advantages of this type of nitride etching within the chemical downstream etching chamber are that a) there is no potential damage of the selective oxide film due to plasma ions b) there is no low level metal impurities, which are commonly found in nitride etching with hot phosphoric acid (H3PO4), and which can degrade device performance. In contrast to previous examples of highly selective nitride etching, the etching rate for the processes described here can exceed a very competitive 2000 A/min. While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to selectively etching nitride in a chemical downstream etching process, and more particularly to an etching process that uses CH 2 F 2 to etch and convert the nitride regions into surface mediated uniform reactive film (SMURF) regions comprising (NH 4 ) 2 SiF 6 . 2. Description of the Related Art The standard process for highly selective isotropic nitride etching is a wet process, e.g., a hot phosphoric acid bath. This process suffers from the following drawbacks. It is difficult to control the etch rate and etch selectively over the life of the bath. This wet etching also has poor cross wafer uniformity (>20% 3σ). Also, the requirement for timed overetching approaches 50% with this process. Further, this etching chemistry is not compatible with resist or polysilicon and there are severe environmental handling and disposal issues with phosphoric acid. The phosphoric acid additionally has contamination issues with Cu, which can have undesired effects on devices. Alternate dry etch process have been offered which have a severe tradeoff between an acceptable nitride etch rate (>2000 A/min) and nitride/oxide etch selectivity (>50:1). Additionally, the reaction mechanisms are not understood conventionally and general prescriptions of process control have not been offered. The invention described below addresses these concerns. | <SOH> SUMMARY OF THE INVENTION <EOH>Disclosed is a method of selectively etching nitride in a chemical downstream etching process. The invention begins by placing a wafer having oxide regions and nitride regions in a chamber. Then, the invention performs a chemical downstream etching process using CH 2 F 2 to etch and convert the nitride, (starting from the top of the nitride regions) into surface mediated uniform reactive film (SMURF) regions comprising (NH 4 ) 2 SiF 6 . As the etching progresses, the remaining nitride film is converted into a surface mediated uniform reactive film (SMURF). This process then rinses the surface of the wafer with water to remove the surface mediated uniform reactive film regions from the wafer, leaving the oxide regions substantially unaffected. The chemical downstream etching process is considered selective because it etches the nitride regions at a substantially higher rate than the oxide regions. The surface mediated uniform reactive film regions are formed to a minimum thickness of approximately 100 angstroms prior to the rinsing process (which is performed in a separate water rinsing tool) and the chemical downstream etching process is performed at temperatures below 50° C. to maintain at least this minimum thickness. The invention can also add O 2 , Ar, and/or N 2 into the chamber during the chemical downstream etching process to modulate the etch rate. Similarly, the invention increases the concentrations of the CH 2 F 2 in the chamber and/or introduces N 2 into the chamber, during the etching process to increase the etching selectivity of the nitride regions with respect to the oxide regions. This high selective nitride etching is achieved when the SMURF is formed and present during the CH 2 F 2 downstream process. High selective nitride etching cannot be achieved when the SMURF is not formed, even if etching is occurring with a CH 2 F 2 downstream process. When the SMURF forms on the surface of the nitride film, enhanced nitride etching, and therefore ultra etch selectivity to oxide, is enabled. The present invention enables an effective dry etch alternative that meets and exceeds the following etch selective properties of hot phosphoric acid; oxide etch selectivity 0.70:1, linearly tunable high etch rates >2000 A/min, good cross wafer uniformity <6% (3 s), optical endpoint control, and etch computability and etch compatability to both resist and polysilicon. These, and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. | 20040430 | 20070911 | 20051103 | 62893.0 | 0 | GEORGE, PATRICIA ANN | HIGHLY SELECTIVE NITRIDE ETCHING EMPLOYING SURFACE MEDIATED UNIFORM REACTIVE LAYER FILMS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,133 | ACCEPTED | Storage switch traffic bandwidth control | A switch including a processor and method for monitoring bandwidth in the storage switch. The switch includes at least one physical port coupling at least one target and at least one initiator via the physical port. The monitoring method may include the steps of determining whether congestion occurs on the physical port and assigning a weight to bandwidth usage between the initiator and the target based on a minimum and maximum bandwidth settings for each target. The switch may further include a step of controlling bandwidth usage by each of said at least two targets based on minimum and maximum bandwidth settings for each of the targets. | 1. A method for use in a system for storing and accessing data, the system including at least one initiator, at least two targets, and at least one switch having a port, the method comprising: determining whether congestion occurs at the physical port; and controlling bandwidth usage by each of at least two targets based on minimum and maximum bandwidth settings for each of the targets. 2. The method of claim 1 wherein the step of controlling comprises rejecting additional commands from the initiator to at least one of the two targets. 3. The method of claim 1 wherein the step of controlling comprises monitoring traffic passing from each of the two targets to the port, and recording a data amount when either of the two targets exceeds a maximum bandwidth. 4. The method of claim 3 wherein the step of monitoring comprises incrementing the data amount by an amount of data read during an excess bandwidth period. 5. The method of claim 3 wherein the step of monitoring comprises decrementing the data amount when a command received for a target with a recorded excess data amount is rejected. 6. The method of claim 1 wherein the step of determining comprises monitoring the physical port for congestion and implementing said controlling step when the physical port is congested. 7. The method of claim 1 wherein said step of controlling comprises monitoring bandwidth from each of said two targets to determine whether the bandwidth exceeds an allowable maximum bandwidth for the target. 8. The method of claim 1 wherein said step of controlling comprises assigning a weight to each target when traffic from the target to the port exceeds an allowable maximum bandwidth for the target and rejecting commands to one of said two targets. 9. The method of claim 8 wherein the step of assigning a weight includes recording a bandwidth overage amount in a record associated with the target. 10. The method of claim 9 wherein the step of recording a bandwidth overage includes recording a number of bytes. 11. The method of claim 9 wherein the step of rejecting additional commands includes the step of determining a requested number of bytes from the command, and reducing the recorded bandwidth overage by the requested number of bytes. 12. The method of claim 9 wherein the step of assigning a weight includes marking traffic from the target to the port based on a two rate marker. 13. The method of claim 12 wherein the step of assigning a weight include marking the traffic using a two rate, three color marking system. 14. The method of claim 13 wherein the step of weighting includes recording all red marked traffic as a bandwidth overage. 15. The method of claim 9 wherein the step of weighting includes recording all yellow traffic as a bandwidth overage if a comparison of a normalized value of the maximum bandwidth exceeds a random number. 16. The method of claim 15 wherein the overage recorded is a frame size of the yellow traffic frame. 17. The method of claim 15 wherein commands directed to one of said at least two targets with a greater bandwidth overage are rejected until its overage is less than an overage of the other of said at least two targets. 18. A method for use in a system for storing and accessing data, the system including at least one initiator, at least two targets, and at least one switch having a port, the method comprising: monitoring traffic bandwidth from each of said at least two targets to the port; determining which target should have access to port resources based on a minimum and maximum bandwidth setting for each target; and controlling access to said targets by rejecting additional commands to the target based on the step of determining. 19. The method of claim 18 wherein said step of determining comprises assigning a priority to each target based on a weighting of traffic for each of said at least two targets. 20. The method of claim 19 wherein the step of assigning a weight includes marking the traffic using a two rate, three color marker. 21. The method of claim 20 wherein the step of assigning a weight includes recording all red marked traffic as a bandwidth overage. 22. The method of claim 20 wherein the step of assigning a weight includes recording all yellow traffic as a bandwidth overage if a comparison of a normalized value of the maximum bandwidth exceeds a random number. 23. The method of claim 20 wherein the overage recorded is a frame size. 24. The method of claim 20 wherein commands directed to one of said at least two targets with a greater bandwidth overage are rejected until its overage is less than an overage of the other of said at least two targets. 25. The method of claim 18 wherein each target includes at least one virtual target communicating with at least one respective physical logical unit. 26. The method of claim 25 wherein the step of monitoring includes monitoring traffic from each of said physical logical units through a respective virtual logical unit. 27. The method of claim 26 wherein the step of controlling comprises rejecting commands from the initiator to the virtual target. 28. A method for use in a system for storing and accessing data, the system including at least one initiator, at least two virtual logical units, at least two physical logical units, and at least one switch having a port, the port accessing each physical logical unit through the switch, the method comprising: monitoring the bandwidth consumed by each of said at least two virtual targets as a result of traffic from the associated physical logical unit; determining which target should have access to port resources based on a weighting of traffic returning from a virtual target; and restricting access to said virtual targets by rejecting additional commands to the target based on the weighting of the target. 29. The method of claim 28 wherein the step of determining comprises recording contention counts for each virtual target. 30. The method of claim 29 wherein the step of generating contention counts include marking traffic from the physical target to the virtual target using a two rate, three color marker. 31. The method of claim 30 wherein the step of generating contention counts includes setting one of said two rates to a maximum bandwidth for the virtual target and one of said two rates to a minimum bandwidth for the virtual target. 32. The method of claim 30 wherein a traffic marked yellow is recorded as a contention count if a normalized value of a maximum bandwidth for the virtual target is greater than a random number generated for comparison with the normalized value. 33. The method of claim 32 wherein the number of contention counts recorded is a frame size. 34. The method of claim 30 wherein traffic marked green is recorded as a reduction in contention counts 35. The method of claim 30 wherein said step of rejecting additional commands to the target is based on a comparison of recorded contention counts for each of the virtual targets. 36. The method of claim 30 wherein commands for the virtual target having an excess amount of contention counts is rejected. 37. The method of claim 36 wherein the excess amount of contention counts is the smallest number of contention counts of all virtual targets accessing the port. 38. The method of claim 37 wherein the excess amount is reduced by the requested number of bytes in a command rejected for the virtual target. 39. A storage switch having at least one physical port providing access to at least two targets, comprising: load balancing circuitry affiliated with the port including a memory storing a record of each target, the record including a minimum and maximum bandwidth allocation for the target; and processing circuitry affiliated with the port including a bandwidth monitor for each of said at least two targets, the processing circuitry maintaining a weighted record of bandwidth used by each target and rejecting additional commands to at least one target based on the record if the physical port is congested. 40. The switch of claim 39 wherein the processing circuitry includes a contention count generator and a two rate, three color meter and marker. 41. The switch of claim 40 wherein the contention count generator increments a contention count record for one of the two targets responsive to the traffic color marked by two rate three color marker. 42. The switch of claim 40 wherein the contention count is incremented if the color marked is yellow and a normalized value for the maximum bandwidth allocation is greater than a random number with which it is compared. 43. The switch of claim 40 wherein the contention count is decremented if the color marked is yellow and a normalized value for the maximum bandwidth allocation is less than a random number with which it is compared. 44. The switch of claim 40 wherein the contention count is decremented if the color marked is green. 45. The switch of claim 40 wherein the contention count is incremented if the color marked is red. 46. The switch of claim 39 wherein each target includes at least one virtual target communicating with at least one respective physical logical unit. 47. The switch of claim 46 wherein the processing circuitry includes a command rejecter for commands from the initiator to the virtual target responsive to the weighted record. 48. A storage network including: an initiator; at least two targets; a switch including at least one port coupled to the initiator, the switch providing access to the targets, the switch including at least one processor associated with the port having a record including bandwidth allocations for each of said at least two targets, and code operable to instruct the processor to: monitor bandwidth consumed by each of said at least two targets, determine which target should have access to port resources based on a weighting of traffic returning from a target to the port, and control access to said targets by rejecting additional commands to the target based on the weighting of the target. 49. The network of claim 48 wherein said code instructing the processor to monitor of monitoring the bandwidth comprises includes code assigning a weight to each target when traffic from the target to the port exceeds an allowable maximum bandwidth for the target. 50. The network of claim 49 wherein said code instructing the processor to assign a weight a includes code marking traffic from the target to the port based on a two rate marker. 51. The network of claim 50 wherein said code instructing the processor to assign a weight includes code for instructing the processor to mark the traffic using a two rate, three color marking system. 52. The network of claim 50 wherein said code instructing the processor to assign a weight includes code for instructing the processor to record all red marked traffic as a bandwidth overage. 53. The network of claim 50 wherein said code instructing the processor to assign a weight includes code for instructing the processor to mark all yellow traffic as a bandwidth overage if a comparison of a normalized value of the maximum bandwidth exceeds a random number. 54. The network of claim 50 wherein said code instructing the processor to assign a weight includes code for instructing the processor to record the overage recorded as a frame size. 55. The network of claim 50 wherein said code instructing the processor to control access includes code for instructing the processor to reject commands directed to one of said at least two targets with a greater bandwidth overage are rejected until its overage is less than an overage of the other of said at least two targets. 56. A method for monitoring bandwidth in a storage switch, the switching including at least one physical port coupling at least one target and at least one initiator via the physical port, comprising: determining whether congestion occurs on the physical port; assigning a weight to bandwidth usage between the initiator and the target based on a minimum and maximum bandwidth settings for each target. 57. The method of claim 56 wherein the step of assigning a weight includes the steps of monitoring bandwidth from the target using a two rate, three color marker. 58. The method of claim 57 wherein the step of assigning a weight includes recording all red marked traffic as a bandwidth overage. 59. The method of claim 57 wherein the step of assigning a weight includes recording all yellow traffic as a bandwidth overage if a comparison of a normalized value of the maximum bandwidth exceeds a random number. 60. The method of claim 59 wherein the overage recorded is a frame size. 61. The method of claim 59 wherein commands directed to one of said at least two targets with a greater bandwidth overage are rejected until its overage is less than an overage of the other of said at least two targets. 62. The method of claim 56 wherein the step of assigning a weight includes determining a smallest overage amount of all targets and adding the smallest overage amount as an excess amount. 63. The method of claim 56 wherein the bandwidth usage is the result of a read command. 64. The method of claim 56 wherein the bandwidth usage is the result of a write command. | CROSS-REFERENCE TO RELATED APPLICATIONS The following applications are cross-referenced and incorporated by reference herein in their entirety: U.S. patent application Ser. No. 10/051,321, entitled STORAGE SWITCH FOR STORAGE AREA NETWORK, filed Jan. 18, 2002; U.S. patent application Ser. No. 10/051,339, entitled ENFORCING QUALITY OF SERVICE IN A STORAGE NETWORK, filed Jan. 18, 2002; and U.S. patent application Ser. No. 10/051,053, entitled LOAD BALANCING IN A STORAGE NETWORK, filed Jan. 18, 2002. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to bandwidth control in a storage switch. 2. Description of the Related Art Storage Area Networks (SAN) have gained popularity in recent years. A SAN is defined by the Storage Networking Industry Association (SNIA) as a network whose primary purpose is the transfer of data between computer systems and storage elements and among storage elements. A storage area network (SAN) is a high-speed special-purpose network (or subnetwork) that interconnects different kinds of data storage devices with associated data servers on behalf of a larger network of users. Unlike connecting a storage device directly to a server, e.g., with a SCSI connection, and unlike adding a storage device to a LAN with a traditional interface such as Ethernet (e.g., a NAS system), the SAN forms essentially an independent network that does not tend to have the same bandwidth limitations as its direct-connect SCSI and NAS counterparts and also provides increased configurability and scalability. In a SAN environment, storage devices (e.g., tape drives and RAID arrays) and servers are generally interconnected via various switches and appliances. The connections to the switches and appliances are usually Fibre Channel. This structure generally allows for any server on the SAN to communicate with any storage device and vice versa. It also provides alternative paths from server to storage device. In other words, if a particular server is slow or completely unavailable, another server on the SAN can provide access to the storage device. A SAN also makes it possible to mirror data, making multiple copies available and thus creating more reliability in the availability of data. When more storage is needed, additional storage devices can be added to the SAN without the need to be connected to a specific server; rather, the new devices can simply be added to the storage network and can be accessed from any point. While typical SAN appliances do perform some switching, because there may be a large number of servers (many more than three), and because each appliance has few ports (usually only two or four), separate switches are needed to connect the many servers to the few appliances. Nevertheless, typical switches have little built-in intelligence and merely forward data to a selected appliance. Co-pending patent application 10/051,321 discloses a device which solves many of the issues attending the use of SANs through the introduction of a storage switch. The switch is capable of routing data between initiators and targets without buffering the data as required by earlier appliances used in SAN's. For example, some storage switches can route data packets without introducing more latency to the packets than would be introduced by a typical network switch. Such unbuffered data transfer between initiators and targets must be handled reliably and efficiently by the switch performing the interconnection. An example of a storage switch can be found in co-pending U.S. patent application Ser. No. 10/051,396, entitled VIRTUALIZATION IN A STORAGE SYSTEM, filed Jan. 18, 2002. Initiators typically couple to the switch and access one or more virtual and physical targets through the switch. One issue which may arise from coupling through the switch is a bandwidth overload on the port. Since data losses in a SAN are not acceptable, bandwidth management on the part relative to the virtual targets must be provided. SUMMARY OF THE INVENTION The present invention, roughly described, pertains to a method for use in a system for storing and accessing data. The system includes at least one initiator, at least one target, and at least one switch having a port. The method may comprise the steps of determining whether congestion occurs at the physical port; and controlling bandwidth usage by each of said at least two targets based on minimum and maximum bandwidth settings for each of the targets. In a further aspect, the step of controlling comprises rejecting additional commands from the initiator to at least one of the two targets. In another embodiment, the invention is a method for use in a system for storing and accessing data. The system includes at least one initiator, at least two targets, and at least one switch having a port. In this embodiment, the method comprises monitoring traffic bandwidth from each of said at least two targets to the port; determining which target should have access to port resources based on a minimum and maximum bandwidth setting for each target; and controlling access to said targets by rejecting additional commands to the target based on the step of determining. In a further aspect, the step of determining comprises assigning a priority to each target based on a weighting of traffic form each of said at least two targets. Still further, the step of assigning a weight includes marking the traffic using a two rate, three color marker. In yet another embodiment, the invention is method for use in a system for storing and accessing data. The system includes at least one initiator, at least one target, at least one virtual logical unit, at least one physical logical units, and at least one switch having a port, the port accessing each physical logical unit through the switch. In this embodiment, the method comprises monitoring the bandwidth consumed by each of said at least two virtual targets as a result of traffic from the associated physical logical unit; determining which target should have access to port resources based on a weighting of traffic returning from a virtual target; and restricting access to said virtual targets by rejecting additional commands to the target based on the weighting of the target. In a further aspect, the step of determining comprises recording contention counts for each virtual target. In yet another embodiment, the invention is a storage switch having at least one physical port providing access to at least one target. The switch includes load balancing circuitry affiliated with the port including a memory storing a record of each target, the record including a minimum and maximum bandwidth allocation for the virtual logical unit; and processing circuitry affiliated with the port including a bandwidth monitor for each of said at least two targets, the processing circuitry maintaining a weighted record of bandwidth used by each target and rejecting additional commands to at least one target based on the record if the physical port is congested. In a still further embodiment, the invention is a storage network. The storage network may include an initiator, at least one target and a switch. The switch may include at least one port coupled to the initiator, the switch providing access to the targets, the switch including at least one processor associated with the port having a record including bandwidth allocations for each of said at least two targets. The processor includes code operable to instruct the processor to: monitor bandwidth consumed by each of said at least two targets, determine which target should have access to port resources based on a weighting of traffic returning from a target to the port, and control access to said targets by rejecting additional commands to the target based on the weighting of the target. In another aspect, the invention is a method for monitoring bandwidth in a storage switch, the switching including at least one physical port coupling at least one target and at least one initiator via the physical port. The method may include the steps of determining whether congestion occurs on the physical port; assigning a weight to bandwidth usage between the initiator and the target based on a minimum and maximum bandwidth settings for each target. The present invention can be accomplished using hardware, software, or a combination of both hardware and software. The software used for the present invention is stored on one or more processor readable storage media including hard disk drives, CD-ROMs, DVDs, optical disks, floppy disks, tape drives, RAM, ROM or other suitable storage devices. In alternative embodiments, some or all of the software can be replaced by dedicated hardware including custom integrated circuits, gate arrays, FPGAs, PLDs, and special purpose computers. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a generalized functional block diagram of a storage switch in accordance with one embodiment; FIGS. 2a-2c are generalized functional block diagrams of a storage area network illustrating an exemplary provisioning of virtual targets; FIG. 3 is a generalized functional block diagram of a storage switch in accordance with one embodiment; FIG. 4 is a generalized functional block diagram of a linecard used in a storage switch in accordance with one embodiment; FIG. 5 is a flow diagram illustrating steps in accordance with an embodiment of the invention; FIG. 6A is a block diagram illustrating a storage area network with multiple virtual logical units communicating with an initiator via a single physical port on the storage switch; FIG. 6b is a functional block diagram similar to FIG. 6A illustrating the metering system of the present invention; FIG. 7a is a flow chart illustrating a general embodiment of the present invention; FIG. 7b is a flow chart illustrating the a first method of the present invention for controlling bandwidth within a switch; FIG. 8 is a flow chart illustrating a second embodiment including a specific method for determining throttle control in the system of the present invention. DETAILED DESCRIPTION An exemplary system 100 including a storage switch in accordance with one embodiment is illustrated in FIG. 1. System 100 can include a plurality of initiating devices such as servers 102. It will be appreciated that more or fewer servers can be used and that embodiments can include any suitable physical initiator in addition to or in place of servers 102. Although not shown, the servers could also be coupled to a LAN. As shown, each server 102 is connected to a storage switch 104. In other embodiments, however, each server 102 may be connected to fewer than all of the storage switches 104 present. The connections formed between the servers and switches can utilize any protocol, although in one embodiment the connections are Fibre Channel or Gigabit Ethernet (carrying packets in accordance with the iSCSI protocol). Other embodiments may use the Infiniband protocol, defined by Intel Inc., or other protocols or connections. In some embodiments, one or more switches 104 are each coupled to a Metropolitan Area Network (MAN) or Wide Area Network (WAN) 108, such as the Internet. The connection formed between a storage switch 104 and a WAN 108 will generally use the Internet Protocol (IP) in most embodiments. Although shown as directly connected to MAN/WAN 108, other embodiments may utilize a router (not shown) as an intermediary between switch 104 and MAN/WAN 108. In addition, respective management stations 110 are connected to each storage switch 104, to each server 102, and to each storage device 106. Although management stations are illustrated as distinct computers, it is to be understood that the software to manage each type of device could collectively be on a single computer. Such a storage switch 104, in addition to its switching function, can provide virtualization and storage services (e.g., mirroring). Such services can include those that would typically be provided by appliances in conventional architectures. In addition, the intelligence of a storage switch in accordance with an embodiment of the invention is distributed to every switch port. This distributed intelligence allows for system scalability and availability. The distributed intelligence allows a switch in accordance with an embodiment to process data at “wire speed,” meaning that a storage switch 104 introduces no more latency to a data packet than would be introduced by a typical network switch. Thus, “wire speed” for the switch is measured by the connection to the particular port. Accordingly, in one embodiment having OC-48 connections, the storage switch can keep up with an OC-48 speed (2.5 bits per ns). A two Kilobyte packet (with 10 bits per byte) moving at OC-48 speed can take as little as eight microseconds coming into the switch. A one Kilobyte packet can take as little as four microseconds. A minimum packet of 100 bytes can only elapse a mere 400 ns. More information on various storage area networks, including a network as illustrated in FIG. 1 can be found in U.S. patent application Ser. No. 10/051,396, entitled VIRTUALIZATION IN A STORAGE SYSTEM, filed Jan. 18, 2002 and U.S. patent application Ser. No. 10/051,321, entitled STORAGE SWITCH FOR STORAGE AREA NETWORK, filed Jan. 18, 2002. “Virtualization” generally refers to the mapping of a virtual target space subscribed to by a user to a space on one or more physical storage target devices. The terms “virtual” and “virtual target” come from the fact that storage space allocated per subscription can be anywhere on one or more physical storage target devices connecting to a storage switch 104. The physical space can be provisioned as a “virtual target” which may include one or more “logical units” (LUs), also referred to herein as “Virtual Logical Units (VLUs). Each virtual target consists of one or more LUs identified with one or more LU numbers (LUNs), which are frequently used in the iSCSI and FC protocols. Each logical unit is generally comprised of one or more extents—a contiguous slice of storage space on a physical device. Thus, a virtual target may occupy a whole storage device (one extent), a part of a single storage device (one or more extents), or parts of multiple storage devices (multiple extents). The physical devices, the LUs, the number of extents, and their exact locations are immaterial and invisible to a subscriber user. Storage space may come from a number of different physical devices, with each virtual target belonging to one or more “pools” in various embodiments, sometimes referred to herein as “domains.” Only users of the same domain are allowed to share the virtual targets in their domain in one embodiment. Domain-sets can also be formed that include several domains as members. Use of domain-sets can ease the management of users of multiple domains, e.g., if one company has five domains but elects to discontinue service, only one action need be taken to disable the domain-set as a whole. The members of a domain-set can be members of other domains as well. FIGS. 2a-2c illustrates one example of provisioning virtual targets in a storage area network. The system of FIG. 2 includes three physical devices 1061, 1062, and 1063, having a total of 6 LUs—LU1, LU2, LU3, LU4, LU5, LU6. In FIG. 2a, each physical device is coupled to a switch and placed in a pool accessible to two initiators X and Y, the “X-Y User Pool.” If initiator X and initiator Y each require one virtual target, then in one embodiment, the LUs are provisioned to form virtual targets VT1 and VT2, where VT1 includes as extents LUs 1-3 and VT2 includes as extents LUs 4-6 as depicted in FIG. 2b. VT1 is placed in the server X user domain and VT2 is placed in the server Y user domain. Initiator X will have access to VT1 but no VT2, while initiator Y will have access to VT2 but not VT1. If instead, for example, initiator Y requires a mirrored virtual target M with a total of 6 LUs, VT1 and VT2 can be created as members of the virtual target M. VT1 and VT2 can be placed in the switch's No Domain (a domain where the physical targets are not directly accessible to users) while M is made accessible to Y, as shown in FIG. 2c. As members of M, VT1 and VT2 will not be independently accessible. VT1 is comprised of a LUs 1-3 (physical device 1061), while VT2 is comprised of LUs 4-6 (physical devices 1062 and 1063). When a request is received to write data to the virtual target M, switch 104 will route the incoming data to both VT1 (physical device 1061) and VT2 (physical device 1062 and/or1063), thus storing the data in at least two physical locations. FIG. 3 illustrates a functional block diagram of a storage switch 104 in accordance with an embodiment of the invention. More information regarding the details of a storage switch such as storage switch 104 and its operation can be found in U.S. patent application Ser. No. 10/051,321, entitled STORAGE SWITCH FOR STORAGE AREA NETWORK, filed Jan. 18, 2002. In one embodiment, the storage switch 104 includes a plurality of linecards 302, 304, and 306, a plurality of fabric cards 308, and two system control cards 310, each of which will be described in further detail below. Although an exemplary storage switch is illustrated, it will be appreciated that numerous other implementations and configurations can be used in accordance with various embodiments. System Control Cards. Each of the two System Control Cards (SCCs) 310 connects to every line card 302, 304, 306. In one embodiment, such connections are formed by I2C signals, which are well known in the art, and through an Ethernet connection with the SCC. The SCC controls power up and monitors individual linecards, as well as the fabric cards, with the I2C connections. Using inter-card communication over the ethernet connections, the SCC also initiates various storage services, e.g., snapshot and replicate. In addition, the SCC maintains a database 312 that tracks configuration information for the storage switch as well as all virtual targets and physical devices attached to the switch, e.g., servers and storage devices. In addition, the database keeps information regarding usage, error and access data, as well as information regarding different domains and domain sets of virtual targets and users. The records of the database may be referred to herein as “objects.” Each initiator (e.g., a server) and target (e.g., a storage device) has a World Wide Unique Identifier (WWUI), which are known in the art. The database is maintained in a memory device within the SCC, which in one embodiment is formed from flash memory, although other memory devices can be used in various embodiments. The storage switch 104 can be reached by a management station 110 through the SCC 310 using an ethernet connection. Accordingly, the SCC also includes an additional Ethernet port for connection to a management station. An administrator at the management station can discover the addition or removal of storage devices or virtual targets, as well as query and update virtually any object stored in the SCC database 312. Fabric Cards. In one embodiment of switch 104, there are three fabric cards 308, although other embodiments could have more or fewer fabric cards. Each fabric card 308 is coupled to each of the linecards 302, 304, 306 in one embodiment and serves to connect all of the linecards together. In one embodiment, the fabric cards 308 can each handle maximum traffic when all linecards are populated. Such traffic loads handled by each linecard are up to 160 Gbps in one embodiment although other embodiments could handle higher or lower maximum traffic volumes. If one fabric card 308 fails, the two surviving cards still have enough bandwidth for the maximum possible switch traffic: in one embodiment, each linecard generates 20 Gbps of traffic, 10 Gbps ingress and 10 Gbps egress. However, under normal circumstances, all three fabric cards are active at the same time. From each linecard, the data traffic is sent to any one of the three fabric cards that can accommodate the data. Linecards. The linecards form connections to servers and to storage devices. In one embodiment, storage switch 104 supports up to sixteen linecards although other embodiments could support a different number. Further, in one embodiment, three different types of linecards are utilized: Gigabit Ethernet (GigE) cards 302, Fibre Channel (FC) cards 304, and WAN cards 306. Other embodiments may include more or fewer types of linecards. The GigE cards 302 are for Ethernet connections, connecting in one embodiment to either iSCSI servers or iSCSI storage devices (or other Ethernet based devices). The FC cards 304 are for Fibre Channel connections, connecting to either Fibre Channel Protocol (FCP) servers or FCP storage devices. The WAN cards 306 are for connecting to a MAN or WAN. FIG. 4 illustrates a functional block diagram of a generic line card 400 used in a storage switch 104 in accordance with one embodiment. Line card 400 is presented for exemplary purposes only. Other line cards and designs can be used in accordance with embodiments. The illustration shows those components that are common among all types of linecards, e.g., GigE 302, FC 304, or WAN 306. In other embodiments other types of linecards can be utilized to connect to devices using other protocols, such as Infiniband. Ports. Each line card 400 includes a plurality of ports 402. The ports form the linecard's connections to either servers or storage devices. Eight ports are shown in the embodiment illustrated, but more or fewer could be used in other embodiments. For example, in one embodiment each GigE card can support up to eight 1 Gb Ethernet ports, each FC card can support up to either eight 1 Gb FC ports or four 2 Gb FC ports, and each WAN card can support up to four OC-48 ports or two OC-192 ports. Thus, in one embodiment, the maximum possible connections are 128 ports per switch 104. The ports of each linecard are full duplex in one embodiment, and connect to either a server or other client, and/or to a storage device or subsystem. In addition, each port 402 has an associated memory 403. Although only one memory device is shown connected to one port, it is to be understood that each port may have its own memory device or the ports may all be coupled to a single memory device. Only one memory device is shown here coupled to one port for clarity of illustration. Storage Processor Unit. In one embodiment, each port is associated with a Storage Processor Unit (SPU) 401. In one embodiment the SPU rapidly processes the data traffic allowing for wire-speed operations. In one embodiment, each SPU includes several elements: a Packet Aggregation and Classification Engine (PACE) 404, a Packet Processing Unit (PPU) 406, an SRAM 405, and a CAM 407. Still other embodiments may use more or fewer elements or could combine elements to obtain the same functionality. For instance, some embodiments may include a PACE and a PPU in the SPU, but the SPU may share memory elements with other SPUs. PACE. Each port is coupled to a Packet Aggregation and Classification Engine (PACE) 404. As illustrated, the PACE 404 aggregates two ports into a single data channel having twice the bandwidth. For instance, the PACE 404 aggregates two 1 Gb ports into a single 2 Gb data channel. The PACE can classify each received packet into a control packet or a data packet. Control packets are sent to the CPU 414 for processing, via bridge 416. Data packets are sent to a Packet Processing Unit (PPU) 406, discussed below, with a local header added. In one embodiment the local header is sixteen bytes resulting in a data “cell” of 64 bytes (16 bytes of header and 48 bytes of payload). The local header is used to carry information and used internally by switch 104. The local header is removed before the packet leaves the switch. Accordingly, a “cell” can be a transport unit used locally in the switch that includes a local header and the original packet (in some embodiments, the original TCP/IP headers are also stripped from the original packet). Nonetheless, not all embodiments of the invention will create a local header or have “internal packets” (cells) that differ from external packets. Accordingly, the term “packet” as used herein can refer to either “internal” or “external” packets. The classification function helps to enable a switch to perform storage virtualization and protocol translation functions at wire speed without using a store-and-forward model of conventional systems. Each PACE has a dedicated path to a PPU, e.g. PPU 4061, while all four PACEs in the illustrated embodiment share a path to the CPU 414, which in one embodiment is a 104 MHz/32 (3.2 Gbps) bit data path. Packet Processing Unit (PPU). Each PPU such as PPU 4061 performs virtualization and protocol translation on-the-fly, meaning that cells are not buffered for such processing. It also implements other switch-based storage service functions, described later. The PPU is capable, in one embodiment, of moving cells at OC-48 speed or 2.5 Gbps for both the ingress and egress directions, while in other embodiments it can move cells at OC-192 speeds or 10 Gbps. The PPU in one embodiment includes an ingress PPU 4061i and an egress PPU 4061e, which both run concurrently. The ingress PPU 4061i receives incoming data from PACE 4041 and sends data to the Traffic Manager 408i while the egress PPU 4061e receives data from Traffic Manager 408e and sends data to a PACE 4041. Although only one PPU 4061 is shown in FIG. 4 as having an ingress PPU 4061i and an egress PPU 4061e, it is to be understood that in one embodiment all PPUs 406 will include both an ingress and an egress PPU and that only one PPU is shown in FIG. 4 with both ingress and egress PPUs for clarity of illustration. A large number of storage connections (e.g., server to virtual target) can be established concurrently at each port. Nonetheless, each connection is unique to a virtual target and can be uniquely identified by a TCP Control Block Index (in the case of iSCSI connections) and a port number. When a connection is established, the CPU 414 of the linecard 400 informs a PPU 406 of an active virtual target by sending it a Virtual Target Descriptor (VTD) for the connection. The VTD includes all relevant information regarding the connection and virtual target that the PPU will need to properly operate on the data, e.g., perform virtualization, translation, and various storage services. The VTD is derived from an object in the SCC database and usually contains a subset of information that is stored in the associated object in the SCC database. Similarly, Physical Target Descriptors (PTDs) are utilized in an embodiment of the invention. PTDs describe the actual physical devices, their individual LUs, or their individual extents (a contiguous part of or whole LU) and will include information similar to that for the VTD. Also, like the VTD, the PTD is derived from an object in the SCC database. To store the VTDs and PTDs and have quick access to them, in one embodiment the PPUs such as PPU 4061 are connected to an SRAM 4051 and CAM 4071. SRAM 4051 can store a VTD and PTD database. A listing of VTD Identifiers (VTD IDs), or addresses, as well as PTD Identifiers (PTD IDs), is also maintained in the PPU CAM 4071 for quick accessing of the VTDs. The VTD IDs are indexed (mapped) using a TCP Control Block Index and a LUN. The PTD IDs are indexed using a VTD ID. In addition, for IP routing services, the CAM 4071 contains a route table, which is updated by the CPU when routes are added or removed. In various embodiments, each PPU will be connected with its own CAM and SRAM device as illustrated, or the PPUs will all be connected to a single CAM and/or SRAM (not illustrated). For each outstanding request to the PPU (e.g., reads or writes), a task control block is established in the PPU SRAM 407 to track the status of the request. There are ingress task control blocks (ITCBs) tracking the status of requests received by the storage switch on the ingress PPU and egress task control blocks (ETCBs) tracking the status of requests sent out by the storage switch on the egress PPU. For each virtual target connection, there can be a large number of concurrent requests, and thus many task control blocks. Task control blocks are allocated as a request begins and freed as the request completes. Traffic Manager. There are two traffic managers (TMs) 408 on each linecard 400: one TM 408i for ingress traffic and one TM 408e for egress traffic. The ingress TM receives cells from all four SPUs, in the form of 64-byte data cells, in one embodiment. In such an embodiment, each data cell has 16 bytes of local header and 48 bytes of payload. The header contains a FlowID that tells the TM the destination port of the cell. In some embodiments, the SPU may also attach a TM header to the cell prior to forwarding the cell to the TM. Either the TM or the SPU can also subdivide the cell into smaller cells for transmission through the fabric cards in some embodiments. The ingress TM sends data cells to the fabric cards via a 128-bit 104 Mhz interface 410 in one embodiment. Other embodiments may operate at 125 Mhz or other speeds. The egress TM receives the data cells from the fabric cards and delivers them to the four SPUs. Both ingress and egress TMs have a large buffer 412 to queue cells for delivery. Both buffers 412 for the ingress and egress TMs are 64 MB, which can queue a large number of packets for internal flow control within the switch. The cells are not buffered as in cached or buffered switch implementations. There is no transport level acknowledgement as in these systems. The cells are only temporarily buffered to maintain flow control within the switch. The cells maintain their original order and there is no level high level processing of the cells at the TM. The SPUs can normally send cells to the ingress TM quickly as the outgoing flow of the fabric cards is as fast as the incoming flow. Hence, the cells are moving to the egress TM quickly. On the other hand, an egress TM may be backed up because the outgoing port is jammed or being fed by multiple ingress linecards. In such a case, a flag is set in the header of the outgoing cells to inform the egress SPU to take actions quickly. The egress TM also sends a request to the ingress SPU to activate a flow control function used in providing Quality of Service for Storage access. It is worth noting that, unlike communications traffic over the Internet, for storage traffic dropping a packet or cell is unacceptable. Therefore, as soon as the amount of cells in the buffer exceeds a specified threshold, the SPU can activate its flow control function to slow down the incoming traffic to avoid buffer overflow. Fabric Connection. The fabric connection 410 converts the 256-bit parallel signals of the TM (128 bits ingress and 128 bits egress, respectively), into a 16-bit serial interface (8-bit ingress and 8-bit egress) to the backplane at 160 Gbps. Thus the backplane is running at one sixteenth of the pins but sixteen times faster in speed. This conversion enables the construction of a high availability backplane at a reasonable cost without thousands of connecting pins and wires. Further, because there are three fabric cards in one embodiment, there are three high-speed connectors on each linecard in one embodiment, wherein the connectors each respectively connect the 8-bit signals to a respective one of the three fabric cards. Of course, other embodiments may not require three fabric connections 410. CPU. On every linecard there is a processor (CPU) 614, which in one embodiment is a PowerPC 750 Cxe. In one embodiment, CPU 414 connects to each PACE with a 3.2 Gb bus, via a bus controller 415 and a bridge 416. In addition, CPU 414 also connects to each PPU, CAM and TM, however, in some embodiments this connection is slower at 40 Mbps. Both the 3.2 Gb and 40 Mb paths allow the CPU to communicate with most devices in the linecard as well as to read and write the internal registers of every device on the linecard, download microcode, and send and receive control packets. The CPU on each linecard is responsible to initialize every chip at power up and to download microcode to the SPUs and each port wherever the microcode is needed. Once the linecard is in running state, the CPU processes the control traffic. For information needed to establish a virtual target connection, the CPU requests the information from the SCC, which in turn gets the information from an appropriate object in the SCC database. Distinction in Linecards—Ports. The ports in each type of linecard, e.g., GigE, FC, or WAN are distinct as each linecard supports one type of port in one embodiment. In other embodiments, other linecard ports could be designed to support other protocols, such as Infiniband. GigE Port. A gigabit Ethernet port connects to iSCSI servers and storage devices. While the GigE port carries all kinds of Ethernet traffic, the only network traffic generally to be processed by a storage switch 104 at wire speed in accordance with one embodiment of the invention is an iSCSI Packet Data Unit (PDU) inside a TCP/IP packet. Nonetheless, in other embodiments packets in accordance with other protocols (like Network File System (NFS)) carried over Ethernet connections may be received at the GigE Port and processed by the SPU and/or CPU. The GigE port receives and transmits TCP/IP segments for virtual targets or iSCSI devices. To establish a TCP connection for a virtual target, both the linecard CPU 414 and the SCC 310 are involved. When a TCP packet is received, and after initial handshaking is performed, a TCP control block is created and stored in the GigE port memory 403. A VTD is also retrieved from an object of the SCC database and stored in the CPU SDRAM 405 for the purpose of authenticating the connection and understanding the configuration of the virtual target. The TCP Control Block identifies a particular TCP session or iSCSI connection to which the packet belongs, and contains in one embodiment, TCP segment numbers, states, window size, and potentially other information about the connection. In addition, the TCP Control Block is identified by an index, referred to herein as the “TCP Control Block Index.” A VTD for the connection can be created and stored in the SPU SRAM 405. The CPU creates the VTD by retrieving the VTD information stored in its SDRAM and originally obtained from the SCC database. A VTD ID is established in a list of VTD IDs in the SPU CAM 407 for quick reference to the VTD. The VTD ID is affiliated with and indexed by the TCP Control Block Index. When the port receives iSCSI PDUs, it serves essentially as a termination point for the connection, but then the switch initiates a new connection with the target. After receiving a packet on the ingress side, the port delivers the iSCSI PDU to the PACE with a TCP Control Block Index, identifying a specific TCP connection. For a non-TCP packet or a TCP packet not containing an iSCSI PDU, the port receives and transmits the packet without acting as a termination point for the connection. Typically, the port 402 communicates with the PACE 404 that an iSCSI packet is received or sent by using a TCP Control Block Index. When the TCP Control Block Index of a packet is −1, it identifies a non-iSCSI packet. FC Port. An FC port connects to servers and FC storage devices. The FC port appears as a fibre channel storage subsystem (i.e., a target) to the connecting servers, meaning, it presents a large pool of virtual target devices that allow the initiators (e.g., servers) to perform a Process Login (PLOGI or PRLI), as are understood in the art, to establish a connection. The FC port accepts the GID extended link services (ELSs) and returns a list of target devices available for access by that initiator (e.g., server). When connecting to fibre channel storage devices, the port appears as a fibre channel F-port, meaning, it accepts a Fabric Login, as is known in the art, from the storage devices and provides name service functions by accepting, and processing the GID requests—in other words, the port will appear as an initiator to storage devices. In addition, an FC port can connect to another existing SAN network, appearing in such instances as a target with many LUs to the other network. At the port initialization, the linecard CPU can go through both sending Fabric Logins, Process Logins, and GIDs as well as receive the same. The SCC supports an application to convert FC ELS's to iSNS requests and responses. As a result, the same database in the SCC keeps track of both the FC initiators (e.g., servers) and targets (e.g., storage devices) as if they were iSCSI initiators and targets. When establishing an FC connection, unlike for a GigE port, an FC port does not need to create TCP control blocks or their equivalent; all the necessary information is available from the FC header. But, a VTD (indexed by a D_ID which identifies the destination of a frame) will still need to be established in a manner similar to that described for the GigE port. An FC port can be configured for 1 Gb or 2 Gb. As a 1 Gb port, two ports are connected to a single PACE as illustrated in FIG. 4; but in an embodiment where it is configured as a 2 Gb port, port traffic and traffic that can be accommodated by the SPU should match to avoid congestion at the SPU. The port connects to the PACE with a POS/PHY interface in one embodiment. Each port can be configured d separately, i.e. one PACE may have two 1 Gb ports and another PACE has a single 2 Gb port. WAN Ports. In embodiments that include a WAN linecard, the WAN linecard supports OC-48 and OC-192 connections in one embodiment. Accordingly, there are two types of WAN ports: OC-48 and OC-192. For OC-48, there is one port for each SPU. There is no aggregation function in the PACE, although there still is the classification function. A WAN port connects to SONET and works like a GigE port as it transmits and receives network packets such as ICMP, RIP, BPG, IP and TCP. A WAN port in one embodiment supports network security with VPN and IPSec that requires additional hardware components. Since OC-192 results in a faster wire speed, a faster SPU will be required in embodiments that support OC-192. Switch-Based Storage Operations One of ordinary skill in the art will have a general knowledge of the iSCSI and FC protocols. However, for more information on iSCSI refer to “draft-ieff-ips-iSCSI-09.txt,” an Internet Draft and work in progress by the Internet Engineering Task Force (IETF), Nov. 19, 2001, incorporated by reference herein. For more information about Fibre Channel (FC) refer to “Information Systems—dpANS Fibre Channel Protocol for SCSI,” Rev. 012, Dec. 4, 1995 (draft proposed American National Standard), incorporated by reference herein. In addition, both are further described in U.S. patent application Ser. No. 10/051,321, entitled STORAGE SWITCH FOR STORAGE AREA NETWORK, filed Jan. 18, 2002. Virtualization Exemplary ingress and egress processes for various packet types are described in co-pending application Ser. Nos. 10/051,321, 10/051,339 and 10/051,053. It will be understood that numerous processes for various packet types can be used in accordance with various embodiments. In one embodiment, after an incoming packet is classified as data or control traffic by the PPU, the PPU can perform virtualization for data packets without data buffering. For each packet received, the PPU determines the type of packet (e.g., command, R2T/XFER_RDY, Write Data, Read Data, Response, Task Management/Abort) and then performs either an ingress (where the packet enters the switch) or an egress (where the packet leaves the switch) algorithm to translate the virtual target to a physical target or vice versa. Thus, the virtualization function is distributed amongst ingress and egress ports. To further enable wire-speed processing, virtual descriptors are used in conjunction with a CAM, to map the request location to the access location. In addition, for each packet there may be special considerations. For instance, the virtual target to which the packet is destined may be spaced over several noncontiguous extents, may be mirrored, or both. Command Packet—Ingress To initiate a transfer task to or from the virtual target, a SCSI command is sent by an iSCSI or FC initiator in an iSCSI PDU or FCP IU, respectively. When such a packet is received at the PPU (after classification), the PPU CAM is next checked to determine if a valid VTD ID exists, using the TCP Control Block Index and the logical unit number (LUN), in the case of an iSCSI initiator, or the S_ID (an identification of the source of the frame) and the LUN, in the case of an FC initiator. The LUNs in each case are found in the respective iSCSI PDU or FCP IU. If no valid VTD ID is found, then a response packet is sent back to the initiator. If a valid VTD is found, then a check is made for invalid parameters, step 508. If invalid parameters exists, a response packet is sent back to the iSCSI or FC initiator. A Task Index is allocated along with an Ingress Task Control Block (ITCB). The Task Index points to or identifies the ITCB. The ITCB stores the FlowID (obtained from the VTD), the VTD ID, command sequence number or CmdSN (from the iSCSI packet itself), as well as an initiator (originator) identification (e.g., the initiator_task_tag sent in the iSCSI PDU or the OX_ID in the FCP frame header). The OX_ID is the originator (initiator) identification of the exchange. The ITCB is stored in the PPU SRAM. Of course there may be many commands in progress at any given time, so the PPU may store a number of ITCBs at any particular time. Each ITCB will be referenced by its respective Task Index. The VTD tracks the number of outstanding commands to a particular virtual target, so when a new ITCB is established, it increments the number of outstanding commands. In some embodiments, VTDs establish a maximum number of commands that may be outstanding to any one particular virtual target. The FlowID, the VTD ID, and the Task Index are all copied into the local header. The FlowID tells the traffic manager the destination linecards and ports. Later, the Task Index will be returned by the egress port to identify a particular task of a packet. Finally, the packet is sent to the traffic manager and then the routing fabric, so that it ultimately reaches an egress PPU. Command Packet—Egress After a command PDU or IU has passed through the switch fabric, it will arrive at a PPU, destined for an egress port. The PPU attempts to identify the physical device(s) that the packet is destined for. To do so, the VTD ID from the local header is used to search the PPU CAM for a PTD ID (Physical Target Descriptor Identifier). The VTD ID is affiliated with and indexes a particular PTD ID associated with the particular egress PPU. PTDs are stored in the PPU SRAM, like VTDs, and also contain information similar to that found in a VTD. If the search is unsuccessful, it is assumed that this is a command packet sent directly by the CPU and no additional processing is required by the PPU, causing the PPU to pass the packet to the proper egress port based on the FlowID in the local header. If the search is successful, the PTD ID will identify the physical target (including extent) to which the virtual target is mapped and which is in communication with the particular egress linecard currently processing the packet. The PPU next allocates a Task Index together with an egress task control block (ETCB). In an embodiment, the Task Index used for egress is the same as that used for ingress. The Task Index also identifies the ETCB. In addition, the ETCB also stores any other control information necessary for the command, including CmdSN of an iSCSI PDU or an exchange sequence for an FCP IU. Using the contents of the PTD, the PPU converts the SCSI block address from a virtual target to the block address of a physical device. Adding the block address of the virtual target to the beginning block offset of the extent can provide this conversion. Next the PPU generates proper iSCSI CmdSN or FCP sequence ID, and places them in the iSCSI PDU or FCP frame header. The PPU also constructs the FCP frame header if necessary (in some embodiments, after the ingress PPU reads the necessary information from the FCP header, it will remove it, although other embodiments will leave it intact and merely update or change the necessary fields at this step) or for a packet being sent to an iSCSI target, the TCP Control Block Index is copied into the local header from the PTD. In addition, the PPU provides any flags or other variables needed for the iSCSI or FCP headers. The completed iSCSI PDU or FCP frame are then sent to the PACE, which in turn strips the local header, and passes the packet to appropriate port. R2T or XFER RDY—Ingress After a command has been sent to a target storage device as described above, and the command is a write command, an R2T PDU or an XFER_RDY IU will be received from a storage device when it is ready to accept write data. The PPU identifies the corresponding ETCB, by using the initiator_task_tag or OX_ID inside the packet. If the PPU cannot identify a valid ETCB because of an invalid initiator_task_tag or OX_ID, the packet is discarded. Otherwise, once the ETCB is identified, the PPU retrieves the Ingress Task Index (if different from the Egress Task Index) and the VTD ID from the ETCB. The PPU also retrieves the FlowID from the PTD, which is also identified in the ETCB by the PTD ID. The FlowID indicates to the traffic manager the linecard of the original initiator (ingress) port. The FlowID, the VTD ID, and the Task Index are copied into the local header of the packet. Finally the packet is sent to the traffic manager and the switch fabric. R2T or XFER RDY—Egress After the R2T or XFER_RDY packet emerges from the switch fabric, it is received by a PPU, on its way to be passed back to the initiator (the device that initiated the original command for the particular task). The Task Index identifies the ITCB to the PPU, from which ITCB the original initiator_task_tag and the VTD ID can be obtained. The R2T/XFER_RDY Desired Data Transfer Length or BURST_LEN field is stored in the ITCB. The local header is updated with the FCP D_ID or the TCP Control Block Index for the TCP connection. Note that the stored S_ID from the original packet, which is stored in the ITCB, becomes the D_ID. If necessary, an FCP frame header is constructed or its fields are updated. The destination port number is specified in the local header in place of the FlowID, and placed along with the initiator_task_tag in the SCSI PDU or, for an FC connection, the RX_ID and OX_ID are placed in the FCP frame. The RX_ID field is the responder (target) identification of the exchange. The PPU also places any other flags or variables that need to be placed in the PDU or FCP headers. The packet is forwarded to the PACE, which identifies the outgoing port from the local header. The local header is then stripped, and forwarded to the proper port for transmission. In the event that the command is split over two or more extents, e.g., the command starts in one extent and ends in another, then the PPU must hold the R2T or XFER_RDY of the second extent until the data transfer is complete to the first extent, thus ensuring a sequential data transfer from the initiator. In addition, the data offset of the R2T or XFER_RDY of the second extent will need to be modified by adding the amount of data transferred to the first extent. Write Data Packet—Ingress After an initiator receives an R2T or XFER_RDY packet it returns a write-data packet. When a write-data iSCSI PDU or FC IU is received from an initiator, the ITCB to which the packet belongs must be identified. Usually, the ITCB can be identified using the RX_ID or the target_task_tag, which is the same as the Task Index in some embodiments. The SPU further identifies that received packets are in order. In some circumstances, however, the initiator will transfer unsolicited data: data that is sent prior to receiving an R2T or XFER_RDY. In such a case, the PPU must find the ITCB by a search through the outstanding tasks of a particular virtual target. But if the ITCB is not found, then the packet is discarded. If the ITCB is found, the total amount of data to be transferred is updated in the ITCB. The FlowID and Task Index are added to the local header of the packet. The packet is then forwarded to the traffic manager and ultimately to the switch fabric Write Data Packet—Egress When a write-data packet is received from the switch fabric (via the traffic manager), the ETCB for the packet needs to be identified. Typically, the ETCB can be identified using the Task Index in the local header. Once the ETCB is found, using the information inside the ETCB, the PPU generates proper iSCSI DataSN or FCP sequence ID, along with any other flags and variables, e.g, data offset, for the PDU or FCP frame header. The local header is updated with the TCP Control Block Index or the FCP D_ID from the PTD. The port number is also added to the local header. The finished iSCSI PDU or FCP frame is sent to the PACE, which removes the local header, and forwards the packet to the appropriate port. Read Data Packet—Ingress After receiving a read command, the target device will respond with a read-data packet, which will be received at the PPU (after undergoing classification in the PACE). The ETCB for the packet is then identified, using the OX_ID or initiator_task_tag. The PPU further verifies if the packet was received in order using sequence numbers or verifying that data offsets are in ascending order. If the packet was not in order, the read command is terminated in error. If the packet is in proper order, however, the VTD ID, Task Index, and FlowID are retrieved from the ETCB and VTD and copied into the local header. The packet is sent to the traffic manager and ultimately the switch fabric. In the event that a read-data packet crosses an extent boundary, the data offset of the packet from the second extent must be modified. This offset is usually performed on the egress side, described below, as the FlowID will identify the packet from the second extent. In addition, in order to ensure sequentially returned data, the read command to the second extent will not be sent until completion of the read from the first extent. Read Data Packet—Egress When a read-data packet is received by an PPU from the switch fabric, the ITCB for the packet is identified, usually using the Task Index in the local header. From the ITCB, the PPU retrieves the initiator_task_tag or OX_ID. Using the saved data in the ITCB, the PPU generates proper iSCSI DataSN or FCP sequence IDs as well as other flags or variables of the PDU or FCP frame header. The local header is updated with the TCP Control Block Index or FCP S_ID from the VTD. Note, however, that for a packet going back to the initiator, the S_ID from the original packet will be used as the D_ID. The outgoing port number is also added to the local header. The packet is then sent to the PACE, which removes the local heade, and forwards the packet to the appropriate port. Response Packet—Ingress A response packet will be received from a target device. The ETCB for the packet is then identified, using the initiator_task_tag or OX_ID of the packet. In some embodiments the initiator_task_tag or OX_ID will be the same as the Task Index. If the ETCB is not found, the packet is discarded. However, if the ETCB is found, then the Task Index is copied into the local header of the packet along with the VTD ID and the FlowID. The packet is sent to the traffic manager and ultimately to the switch fabric. Finally, because the response packet signals the completion of a task, the ETCB for the task is released. Response Packet—Egress After a response packet has been through the switch fabric, it will be received by an egress PPU. The ITCB for the packet is identified, using the Task Index from the local header. If the ITCB is not found, the packet is discarded. If the ITCB is found, the outstanding command count for the virtual target is decremented in the VTD. The PPU generates the LUN, iSCSI ExpStatSN or FCP sequence ID from information in the ITCB and, if necessary, constructs or updates the proper FCP header. The PPU also constructs other flags and variables for the PDU or FC frame header. The PPU updates the local header with the TCP Control Block Index or FCP S_ID (which becomes the D ID) retrieved from the VTD. The packet is forwarded to the PACE, step 2312, which removes the local header, and forwards the packet to the appropriate port, step 2316. The PPU frees the ITCB,. Storage Pools As shown in FIG. 2, in its physical configuration, a system in accordance with an embodiment of the invention includes a switch 204 coupled to one or more servers 202 and to one or more physical devices 206, i.e., storage devices or subsystems. Each physical target is comprised of one or more logical units (LUs) 207. It is from these LUs that virtual targets will ultimately be formed. However, before a virtual target can be created, or “provisioned,” the switch needs to be “aware” of the physical storage devices attached and/or available for access by it as well as the characteristics of those physical storage devices. Accordingly, in one embodiment of the invention, when a storage device or an initiator device is connected to or registered with the switch, the switch must learn about the performance characteristics of the new device. In one embodiment, the switch includes a utility program, which can measure storage access time, data transfer rate, cache support, number of alternate paths to the device, RAID support, and allowable maximum commands for the LUs of the physical device. In some embodiments, once a device is connected to the switch, the utility program will automatically discover the device and automatically gather the required information without any user or other intervention. In some such embodiments, the switch will “discover” the addition/removal of a device when there is a disturbance or reset on the signal lines to the port. Once the device is “discovered,” various inquiries are sent to the device to gather information regarding performance characteristics. For instance, read/write commands can be sent to measure transfer rate or to check access time. Alternatively, in some embodiments, the obtaining of performance characteristics can be done by having an administrator enter the performance characteristics at a management station 210, wherein the characteristics can then be provided to a switch 204. The switch provides users with the ability to define multiple components of a Quality of Service (QoS) policy. Through a QoS policy, a user can select the conditions of storing and retrieving data for initiators and targets. In one embodiment, a QoS policy is defined by three elements: provisioning a virtual target, provisioning an initiator connection, and defining a user domain. Nonetheless, some embodiments may not require all three elements to define a QoS policy. For instance, some embodiments may only require provisioning a virtual target and provisioning an initiator connection, but not the user domain. Other embodiments may use different elements altogether to define a QoS policy. Provisioning a Virtual Target Once the LUs for physical devices are in an accessible pool (i.e., not the “No Pool”), then a virtual target can be created from those LUs. To provision a virtual target, a user will select several characteristics for the virtual target in one embodiment of the invention including: the size (e.g., in Gigabytes); a storage pool, although in one embodiment the user may select only from the storage pools which the user is permitted to access; desired availability, e.g., always available (data is critical and must not ever go down), usually available, etc.; the WWUI of the virtual target; a backup pool; user authentication data; number of mirrored members; locations of mirrored numbers (e.g., local or remote). Still in other embodiments of the invention, different, additional, or fewer characteristics can also be selected. The switch then analyzes the available resources from the selected pool to determine if the virtual target can be formed, and in particular the switch determines if a number of LUs (or parts of LUs) to meet the size requirement for the virtual target are available. If so, the virtual target is created with one or more extents and a virtual target object is formed in the SCC database identifying the virtual target, its extents, and its characteristics. Examples of user-selected characteristics for four virtual targets are shown in Table 1 below: TABLE 1 Virtual Target Virtual Target A B C D size 1 TB 500 GB 100 GB 2 TB storage pool platinum gold bronze bronze availability always always high high WWUI drive A drive B drive C drive D backup pool tape 1 tape 2 tape 3 tape 4 authentication data connection connection pass- pass- ID and ID and word word password password # of mirrored members 3 2 2 1 locations of replicated sites local local remote none Switching priority (One of 4) 1 2 3 4 (if all else is equal, which target has priority) Read Load Balance-on or On Off Off Off off-when mirroring chosen Type of Media for backup Fastest Fast Medium Slow- (backup pool) est Mirroring-on or off On On Off Off How many paths to storage 2 2 1 1 from server (used for load balancing) Path to storage via how 2 2 1 1 many switches Auto Migration to another Off Off On Off target on excessive errors-on or off Physical storage- Exclusive Exclusive Exclu- Shared exclusive or shared sive Virtual target-exclusive or Exclusive Exclusive Shared Shared shared VPN on WAN connections Yes Yes No No IP Precedence (DiffServ, Yes Yes No No RFC 2474) MTBF 15 yrs. 10 yrs. 5 yrs. 5 yrs. In addition to provisioning a new virtual target, a switch in accordance with an embodiment of the invention can also modify existing virtual targets with new or different information or delete virtual targets when they are no longer needed. In one embodiment, the QoS policy is generally defined by virtual target (as provisioned), the initiator connection (as provisioned), and the User Domain. Accordingly, referring again to Table 1, above, the first three entries in the table—“ID of Initiator,” “ID of Virtual Target” and “ID of User Domain”—will inherently describe the QoS policy since the attributes of the initiator connection and virtual target were defined when these items were provisioned. For example, the minimum and maximum bandwidth for the initiator connection has already been identified (see Tables 2 and 3). The User Domain assists in defining the policy by determining, for example, if the initiator connection or virtual target connection is slower and forcing the QoS to the slower of the two. Of course, as mentioned above, the User Domain may not be necessary in all embodiments. As well, other embodiments may define an SLA using more, fewer, or different parameters than those shown in Table 4 above. FIG. 5 summarizes the steps to provision the virtual targets and connections in order to be able to provide QoS in one embodiment. As shown, a switch in accordance with an embodiment of the invention discovers and determines the characteristics of physical devices in communication with the switch, step 502. The switch then classifies those devices, step 504, and associates those devices with a particular storage pool, step 504. The switch will receive information for an initiator connection, step 508, and will then provision the connection, step 510, creating an object in the SCC database. The switch will also receive parameters for a virtual target, step 512, and will provision the virtual target in accordance with those parameters, step 514, if the resources are available, creating an object in the SCC database. Note that steps 508-514 can be performed in any order, the order shown in FIG. 5 being exemplary only. After the virtual target is provisioned, a user domain is created and the virtual target placed in the user domain or the virtual target is placed in a pre-existing user domain, step 516. A user could also attempt to access a previously provisioned virtual target (hence, step 514 may not be necessary for every connection). Finally, a switch in accordance with an embodiment of the invention receives SLA/QoS parameters, step 518. Enforcing Bandwidth Allocation in the Switch In one embodiment, it is possible to provision each virtual target with a number of virtual logical units, and specify minimum and maximum bandwidth allocations for each logical unit accessed through a single physical port. Where a single initiator writes or reads data to or from two or more virtual logical units through a single physical port on a switch, two or more physical logical units can reply and congest the physical port. FIG. 6a shows an exemplary situation where a single initiator accesses two virtual logical units (VLUs) via a single physical port 250 on switch 204 Each VLU in turn couples to one or more physical logical units (PLUs). While only two VLUs are shown, each communicating with one PLU, it should be understood that the number of VLUs and PLUs may communicate through physical port 250. Initiator 102 may include two applications, application 1 and application 2, each accessing a respective one of the virtual logical units. Application 1 accesses physical logical unit 206a through virtualized logical unit VLU1, while application 2 accesses physical logical unit 206b through virtualized logical unit VLU2. Each VLU is configured with a minimum and maximum bandwidth by the user as described above. Again, this bandwidth can be configured as a percentage of the available physical port capacity. In accordance with the invention, the user may assign bandwidth parameters of bandwidth management to each logical unit. For example, suppose VLU1 provides access to data which requires a high bandwidth access, while VLU2 provides access to non-critical data and does not require high bandwidth. In this situation, the switch may be configured to guarantee that the low latency data has greater access to the resources of physical port 250 than the non-critical data. In order to implement this bandwidth control, the system of the present invention monitors the bandwidth used by each VLU and throttles access to each VLU to control the overall bandwidth on the physical port 250. In one embodiment, the system uses a traffic marker to mark the traffic passing from the PLUs through the VLUs through the physical port 250 shown in FIG. 6a. In general, when traffic from physical logical unit (for example PLU2) arrives in a virtual logical unit (in this case VLU2), if the bandwidth is over the maximum allowed bandwidth for the given virtual logical unit, the excess amount of bytes is recorded in the virtual logical unit. Such traffic is allowed to pass to the application, but the overage information is used to throttle the connection to the VLU until the bandwidth drops to set levels. When the initiator issues a new command to VLU2, such as a read command to the physical logic unit, the transfer length in the command will be used to offset (reduce) the previously recorded overage amount. This new command and possibly subsequent commands are rejected until the entire excess amount that the VLU exceeded its share of bandwidth has been offset. In the case of FCP SCSI, for example, commands are rejected with a TASK_SET_FULL status FCP response until the entire excess amount has been offset. If the bandwidth of traffic from the physical logical unit to the virtual logical unit is less than the minimum allowed bandwidth, no excess amount is recorded on the virtual logical unit (in this example, VLU2). This generalized explanation of the bandwidth balancing algorithm of the present invention will be described in further detail below. The ability to configure the bandwidth for each VLU gives rise to two bandwidth management configuration scenarios, generally referred to herein as a static scenario and a dynamic scenario. If a user sets the bandwidth of the VLUs so that one VLU is limited to, for example, a very low percentage of the total physical port bandwidth, traffic from the other logical unit will be guaranteed a large percentage of the port bandwidth. In this static scenario, the full resources of the port are not utilized. For example, if the maximum bandwidth of VLU2 is limited to 20% of the port capacity, VLU2 will never exceed 20% of the port capacity even if no traffic is moving through VLU1. Hence, port resources are wasted. A dynamic scenario exists when each VLU is configured with a minimum and maximum bandwidth and the aggregate of all maximum bandwidths of all VLUSs accessed by the port exceeds 100% of the physical port capacity. In this dynamic scenario, if both VLUs could receive traffic at their maximum allowable bandwidths, the port capacity at port 250 will be exceeded, and the system must throttle the traffic from the respective PLUs. Suppose that VLU1 has a minimum bandwidth of 70% and a maximum bandwidth of 100%, and VLU2 has a minimum bandwidth of 10% and maximum bandwidth of a 100%. Because VLU1 has a minimum bandwidth of 70%, it is desirable that any balancing favor VLU1. In accordance with the invention, traffic at each VLU is monitored and marked, and traffic through the VLUs throttled by rejecting commands from the initiator to the VLU at port 250 until bandwidth though one of the VLUs drops below set levels. The general method of the present invention is illustrated in FIG. 7a. As shown therein, at step 702, traffic at the physical port is monitored to determine whether the port is congested. At step 704, if traffic is congested, traffic is throttled at step 706 by rejecting commands to respective VLUs communicating through port 250 to prevent congestion and prioritize access through the port based on the bandwidth configuration. This continues until traffic congestion on the port is not detected. FIG. 7b shows one implementation of the throttling step 706. As shown therein, the bandwidth (usually expressed in bits per second (bps) or bytes per second) of traffic returning from each PLU to the storage switch is monitored at step 710 as it arrives at the VLU. Next, a series of throttle control determination steps 705 is performed to determine whether the bandwidth on each VLU arriving from the PLU exceeds an allowable maximum. If so, this fact is used to throttle down traffic from the PLU or PLUs communicating with the VLU. If the bandwidth of traffic arriving at the VLU is less than allowed, the data is simply transmitted to the initiator. If the bandwidth exceeds the maximum bandwidth for the VLU, at step 720, any excess amount is recorded at step 730 in the VLU by the PPU. The traffic is allowed to pass to the initiator at step 730 and the command is forwarded to the PLU at step 765. At step 750, upon receiving the next command for the offending VLU, the system will determine at step 760 that the VLU has exceeded its bandwidth and the port will reject the command at step 770 and reduce the bandwidth by the amount of data requested in the command. For example, if VLU1 is allocated a bandwidth of 300 Mbytes/s and traffic at step 710 is determined to be 330 Mbytes/s, then at step 730, the excess amount of bytes (30 Mbytes/s multiplied by time) which are read during the offending period recorded at step 730. When a subsequent read command for VLU1 is received at step 750, the command will be rejected, (step 760 will be true) but the amount of bytes requested in the read will be deducted from the excess at step 770. This rejection and decrementing will occur until VLU1 no longer owes bandwidth at step 760, when the next command will be forwarded to the PLU at step 765. As explained in further detail below, in order to allow for any configuration of minimum and maximum bandwidth settings, a weighting scheme is utilized to determine which VLU to throttle at a given time. In addition, because a minimum and maximum bandwidth must be factored into the weighting process, a two rate, three color marker (trTCM) system is used to meter the traffic through each VLU. FIG. 6b illustrates the concept of a two rate three color marking system using two buckets per VLU to meter and mark traffic at each VLU. FIG. 8 illustrates the weighting system of the present invention using this trTCM marking. The weighting system uses the concept of contention counts to balance both the minimum and maximum bandwidth settings for the VLU. In general, instead of collecting and measuring actual bytes of traffic, contention counts are generated based on traffic color and a comparison of the maximum bandwidth allowed at the VLU to a random number. The smallest contention counts of all the VLUs on the same switch port 250 are used to determine the VLU's excess amount. Then this VLU's contention count is decreased by the excess amount. To determine contention counts, the trTCM marker meters a packet stream and marks frames either green, yellow or red. The packet is marked red if it exceeds a peak information rate, in this case, a maximum bandwidth. Otherwise it is marked either yellow or green depending on whether it exceeds or does not exceed a committed information rate, in this case, the minimum bandwidth. The meter meters each packet and passes the packet and the metering result to the marker. In the SSC, the PPU performs the metering and marking function, as well as the throttling of commands at port 250. Contention counts are maintained in the VTD for each VLU. In general, trTCM is configured by setting values to four traffic parameters, in this case, the maximum bandwidth MaxBW and its associated peak burst size, and the minimum bandwidth MinBW and its associated peak burst size. The burst sizes are measured in bytes. As illustrated in FIG. 6b, the meter is specified in terms of two token buckets 220, 222, 224, and 226 per stream. One bucket (such as buckets 220, 224) is configured for the minimum bandwidth and one bucket (such as buckets 222, 226) is configured for the maximum bandwidth. In one implementation of trTCM, the maximum size of the token bucket MaxBW is the maximum burst size and the maximum size of the token bucket for the MinBW is its burst size. The token buckets are initially set full and the token count equal to the respective burst sizes. Thereafter, the token count is incremented by one maximum bandwidth rate per second up to the maximum burst size and the token count for the minimum bandwidth bucket is incremented by the minimum bandwidth times per second up to the minimum burst size. In this configuration, the low-rate token bucket is configured for the minimum bandwidth and the high-rate token bucket is configured for the maximum bandwidth. The traffic that flows through both token buckets is marked green and is, therefore, protected. The traffic that flows through the high-rate token bucket, but not the low-rate token bucket, is marked yellow and is used to determine contention counts. Hence, traffic that does not flow through either token bucket is marked red. This amount is recorded and used to generate contention counts which are used to throttle subsequent traffic. More specifically, when the packet of size B bytes arrives at time T, if the token count in the maximum bandwidth bucket minus the size of the packet, is less than zero, the packet is marked red. If the token count in the minimum bandwidth bucket less the size of the packet is less than zero, the packet is marked yellow and the maximum bandwidth bucket is decremented by B bytes, otherwise the packet is green and both the minimum bandwidth and maximum bandwidth bucket are decremented by B bytes. It should be recognized that alternative configurations of this marking scheme may be utilized and this description is exemplary of only one embodiment. In addition, other marking schemes monitoring two rates relative to a maximum information rate may be utilized. FIG. 8 details the one embodiment for implementing the throttle control and bandwidth measurement steps 705 of FIG. 7. At step 820, after traffic arrives in the VLU from PLU1 at step 710, the traffic burst size read, and the traffic metered and marked in accordance with trTCM. In the example where both bandwidths are set to 100%, there will be no red traffic. If, for example, one of the two VLUs has a maximum bandwidth less than 100%, some of the traffic will be marked red For the VLU with a higher minimum bandwidth, fewer packets will be marked yellow. Hence, in the example above where VLU1 provides access to low latency data, and is set with a MinBW of 70% and a MaxBW of 100% of the capacity of the physical port, and VLU2 with MaxBW=100% and MinBW=10%, VLU2 will give rise to a larger number of yellow marked frames. As noted below, only yellow packets affect the contention counts and hence the priority weight assigned to a particular port. Next, at step 830, a determination is made as to whether the traffic is red, green or yellow. If the traffic is green at step 830, no action on the packet is taken. If the traffic is marked yellow at step 830, then at step 850, a classification of whether or not the traffic is a contention count is made. At step 850, the maximum bandwidth sending value for the VLU is normalized to an 8-bit value. Next, a random 8-bit value is generated for each frame in the stream. This random 8-bit value is compared to the normalized maximum bandwidth value. If the random number is more than the normalized maximum bandwidth value, the yellow frame is considered a contention frame. At step 870, the system adds contentions counts to the VLUs record. Specifically, the contention counts for the VLU are incremented by the size of the frame in step 870. This way, the higher the maximum bandwidth setting is, the less contention counts are added at step 870. Likewise, the higher the minimum bandwidth is, the fewer yellow frames will occur, and hence the fewer contention counts. This provides the VLU with the higher minimum and maximum bandwidth settings less occurrences of being throttled. If the traffic is red at step 830, it is automatically added to the excess amount for the VLU at step 840. An additional measurement bucket is provided at the physical port 250 in FIG. 6B. This token bucket measures the aggregate traffic of all VLUs accessing the physical port. A single rate token bucket is utilized to measure bandwidth control. When the aggregate traffic exceeds the physical port capacity, the VLU with the largest number of contention counts is selected for throttling. Tables 2-6 explain one implementation of implementing steps 760 and 770 to determine which VLU has an excess amount of contention counts, and hence, which VLU to throttle in step 770. Table 2 shows an exemplary number of contention counts for initiators VLU1 and VLU2: TABLE 2 Contention Excess Initiator Counts Amount VLU1 60 0 VLU2 300 0 In Table 2, VLU2 has a higher number of contention counts than VLU1. Hence, VLU2 will be throttled by the size of the request data until its contention counts drop below VLU1. The smallest contention counts of all VLUs on the same port are used to add to the VLU's excess amount. Then this VLU's contention count is decreased by this excess amount. For example, suppose the aggregate bandwidth is over the port capacity and, as in Table 2, VLU1 has 60 contention counts and the traffic on VLU2 has 300 contention counts. When the single rate bucket determines that the port is congested, the excess amount will be the smallest contention count of all VLUs on the same port, which in table 2 is 60. Hence, the count state will be as shown in Table 3: TABLE 3 Contention Excess Initiator Counts Amount VLU1 60 0 VLU2 240 60 When a next command is received at step 750, VLU2's command will be rejected, and the excess amount reduced by the size of the request in the command. Suppose, for example, the command is a read command and the read command was for 40 bytes, the resulting excess amount for VLU2 would be reduced by 40, as shown in Table 4: TABLE 4 Contention Excess Initiator Counts Amount A 25 0 B 240 20 The excess amount will continue to be offset by subsequent commands until it becomes zero or negative, as shown in Table 5: TABLE 5 Contention Excess Initiator Counts Amount A 25 0 B 240 0 or less If, after the traffic is throttled, the aggregate bandwidth is less than the port capacity, then the contention count conversion to excess amount need not be performed. However, contention counts can age over time. Over time, the contention counts gradually decrease to zero if there is no congestion, in accordance with the principles of the trTCM algorithm. Table 6 shows the state in the non-congesting period: TABLE 6 Contention Excess Initiator Counts Amount A 0 0 B 0 0 or less As long as congestion remains on the port 250, as detailed at steps 760, and 770, the current contention counts are used in the algorithm. It should be understood that the aforementioned numbers of “counts” and bandwidth are exemplary only. If congestion occurs again, the cycle in tables 2-6 is repeated. The foregoing detailed description of the invention has been presented for purposes of illustration and description. The invention is not limited to the example case. It applies to not only FCP and iSCSI read but also FCP and iSCSI writes. The congested port can be either a port connected to an initiator or a port connector to a target. Traffic could be from the initiator to the target or from the target to the initiator, since traffic can be monitored at the ingress port or the egress port. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention is directed to bandwidth control in a storage switch. 2. Description of the Related Art Storage Area Networks (SAN) have gained popularity in recent years. A SAN is defined by the Storage Networking Industry Association (SNIA) as a network whose primary purpose is the transfer of data between computer systems and storage elements and among storage elements. A storage area network (SAN) is a high-speed special-purpose network (or subnetwork) that interconnects different kinds of data storage devices with associated data servers on behalf of a larger network of users. Unlike connecting a storage device directly to a server, e.g., with a SCSI connection, and unlike adding a storage device to a LAN with a traditional interface such as Ethernet (e.g., a NAS system), the SAN forms essentially an independent network that does not tend to have the same bandwidth limitations as its direct-connect SCSI and NAS counterparts and also provides increased configurability and scalability. In a SAN environment, storage devices (e.g., tape drives and RAID arrays) and servers are generally interconnected via various switches and appliances. The connections to the switches and appliances are usually Fibre Channel. This structure generally allows for any server on the SAN to communicate with any storage device and vice versa. It also provides alternative paths from server to storage device. In other words, if a particular server is slow or completely unavailable, another server on the SAN can provide access to the storage device. A SAN also makes it possible to mirror data, making multiple copies available and thus creating more reliability in the availability of data. When more storage is needed, additional storage devices can be added to the SAN without the need to be connected to a specific server; rather, the new devices can simply be added to the storage network and can be accessed from any point. While typical SAN appliances do perform some switching, because there may be a large number of servers (many more than three), and because each appliance has few ports (usually only two or four), separate switches are needed to connect the many servers to the few appliances. Nevertheless, typical switches have little built-in intelligence and merely forward data to a selected appliance. Co-pending patent application 10/051,321 discloses a device which solves many of the issues attending the use of SANs through the introduction of a storage switch. The switch is capable of routing data between initiators and targets without buffering the data as required by earlier appliances used in SAN's. For example, some storage switches can route data packets without introducing more latency to the packets than would be introduced by a typical network switch. Such unbuffered data transfer between initiators and targets must be handled reliably and efficiently by the switch performing the interconnection. An example of a storage switch can be found in co-pending U.S. patent application Ser. No. 10/051,396, entitled VIRTUALIZATION IN A STORAGE SYSTEM, filed Jan. 18, 2002. Initiators typically couple to the switch and access one or more virtual and physical targets through the switch. One issue which may arise from coupling through the switch is a bandwidth overload on the port. Since data losses in a SAN are not acceptable, bandwidth management on the part relative to the virtual targets must be provided. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention, roughly described, pertains to a method for use in a system for storing and accessing data. The system includes at least one initiator, at least one target, and at least one switch having a port. The method may comprise the steps of determining whether congestion occurs at the physical port; and controlling bandwidth usage by each of said at least two targets based on minimum and maximum bandwidth settings for each of the targets. In a further aspect, the step of controlling comprises rejecting additional commands from the initiator to at least one of the two targets. In another embodiment, the invention is a method for use in a system for storing and accessing data. The system includes at least one initiator, at least two targets, and at least one switch having a port. In this embodiment, the method comprises monitoring traffic bandwidth from each of said at least two targets to the port; determining which target should have access to port resources based on a minimum and maximum bandwidth setting for each target; and controlling access to said targets by rejecting additional commands to the target based on the step of determining. In a further aspect, the step of determining comprises assigning a priority to each target based on a weighting of traffic form each of said at least two targets. Still further, the step of assigning a weight includes marking the traffic using a two rate, three color marker. In yet another embodiment, the invention is method for use in a system for storing and accessing data. The system includes at least one initiator, at least one target, at least one virtual logical unit, at least one physical logical units, and at least one switch having a port, the port accessing each physical logical unit through the switch. In this embodiment, the method comprises monitoring the bandwidth consumed by each of said at least two virtual targets as a result of traffic from the associated physical logical unit; determining which target should have access to port resources based on a weighting of traffic returning from a virtual target; and restricting access to said virtual targets by rejecting additional commands to the target based on the weighting of the target. In a further aspect, the step of determining comprises recording contention counts for each virtual target. In yet another embodiment, the invention is a storage switch having at least one physical port providing access to at least one target. The switch includes load balancing circuitry affiliated with the port including a memory storing a record of each target, the record including a minimum and maximum bandwidth allocation for the virtual logical unit; and processing circuitry affiliated with the port including a bandwidth monitor for each of said at least two targets, the processing circuitry maintaining a weighted record of bandwidth used by each target and rejecting additional commands to at least one target based on the record if the physical port is congested. In a still further embodiment, the invention is a storage network. The storage network may include an initiator, at least one target and a switch. The switch may include at least one port coupled to the initiator, the switch providing access to the targets, the switch including at least one processor associated with the port having a record including bandwidth allocations for each of said at least two targets. The processor includes code operable to instruct the processor to: monitor bandwidth consumed by each of said at least two targets, determine which target should have access to port resources based on a weighting of traffic returning from a target to the port, and control access to said targets by rejecting additional commands to the target based on the weighting of the target. In another aspect, the invention is a method for monitoring bandwidth in a storage switch, the switching including at least one physical port coupling at least one target and at least one initiator via the physical port. The method may include the steps of determining whether congestion occurs on the physical port; assigning a weight to bandwidth usage between the initiator and the target based on a minimum and maximum bandwidth settings for each target. The present invention can be accomplished using hardware, software, or a combination of both hardware and software. The software used for the present invention is stored on one or more processor readable storage media including hard disk drives, CD-ROMs, DVDs, optical disks, floppy disks, tape drives, RAM, ROM or other suitable storage devices. In alternative embodiments, some or all of the software can be replaced by dedicated hardware including custom integrated circuits, gate arrays, FPGAs, PLDs, and special purpose computers. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. | 20040430 | 20100810 | 20060511 | 64580.0 | H04L1226 | 0 | TRAN, PHUC H | STORAGE SWITCH TRAFFIC BANDWIDTH CONTROL | UNDISCOUNTED | 0 | ACCEPTED | H04L | 2,004 |
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10,836,208 | ACCEPTED | Electronic apparatus having a plurality of circuit substrates | An image forming apparatus including a first circuit substrate, a second circuit substrate, a first supporting member for supporting the first circuit substrate, a second supporting member for supporting the second circuit substrate, a holding member for holding the first supporting member and the second supporting member, and a connector for cablelessly connecting the first circuit substrate and the second circuit substrate together, wherein at least one of the first supporting member and the second supporting member is movable in a direction in which the connection by the connector is released, and the first supporting member and the second supporting member are mountable to and dismountable from the holding member independently of each other. | 1. An electronic apparatus comprising: a first circuit substrate; a second circuit substrate; a first supporting member for supporting said first circuit substrate; a second supporting member for supporting said second circuit substrate; a holding member for holding said first supporting member and said second supporting member; and a connector for cablelessly connecting said first circuit substrate and said second circuit substrate together, wherein at least one of said first supporting member and said second supporting member are movable in a direction in which the connection by said connector is released, and said first supporting member and said second supporting member are mountable to and dismountable from said holding member independently of each other. 2. An electronic apparatus according to claim 1, wherein a space is provided in a direction of movement of at least one of said first supporting member and said second supporting member so that said at least one supporting member can be moved in the direction in which the connection by said connector is released. 3. An electronic apparatus according to claim 1, wherein the connection by said connector is released, whereby the mounting and dismounting of said first supporting member and said second supporting member becomes possible. 4. An electronic apparatus comprising: a first plate; a second plate; a connecting portion for connecting said first plate and said second plate together; a first cable; and a second cable, wherein said connecting portion is a grounded electrically conductive member, and said first cable and said second cable are spaced apart from each other by said connecting portion. 5. An electronic apparatus according to claim 4, wherein said connecting portion is a portion in which a bent end portion of said first plate and a bent end portion of said second plate overlap each other. 6. An electronic apparatus according to claim 4, wherein said first cable and said second cable include an AC component cable and a DC component cable. 7. An electronic apparatus according to claim 4, wherein said first cable is an AC component cable, and said second cable is a DC component cable. 8. An electronic apparatus comprising: a first plate; a second plate; a fixing member fixed astride said first plate and said second plate; a first cable; and a second cable, wherein said fixing member is a grounded electrically conductive member, and said first cable and said second cable are spaced apart from each other with said fixing member interposed therebetween. 9. An electronic apparatus according to claim 8, wherein said fixing member is provided at a location whereat said first cable and said second cable intersect with each other. 10. An electronic apparatus according to claim 8, wherein said fixing member is provided so as to surround said first cable. 11. An electronic apparatus according to claim 8, wherein said first cable and said second cable include an AC component cable and a DC component cable. 12. An electronic apparatus according to claim 8, wherein said first cable is an AC component cable, and said second cable is a DC component cable. 13. An electronic apparatus according to claim 1, comprising an image forming portion for forming an image on a recording medium, wherein said first circuit substrate and said second circuit substrate are circuit substrates for controlling an operation of said image forming portion. 14. An electronic apparatus according to claim 4, comprising: an image forming portion for forming an image on a recording medium; and at least one circuit substrate for controlling an operation of said image forming portion, wherein said first cable and said second cable are cables for connecting said image forming portion and said circuit substrate together. 15. An electronic apparatus according to claim 14, wherein said circuit substrate is mounted on said first plate through a supporting member. 16. An electronic apparatus according to claim 8, comprising: an image forming portion for forming an image on a recording medium; and at least one circuit substrate for controlling an operation of said image forming portion, wherein said first cable and said second cable are cables for connecting said image forming portion and said circuit substrate together. 17. An electronic apparatus according to claim 16, wherein said circuit substrate is mounted on said first plate through a supporting member. | BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the layout design and mounting and dismounting of a circuit substrate in an electronic apparatus such as, for example, a printer or a copying machine. 2. Description of the Related Art In recent years, there have been popularized image forming apparatuses such as printers and copying machines using an electrophotographic process which can output a full-color image. Description will hereinafter be made with reference to the accompanying drawings. FIG. 5 shows an example of the construction of the essential portions of a conventional full-color printer. A photosensitive drum (hereinafter simply referred to as the photosensitive member) 1 as an image bearing member is provided so as to be rotatable in the direction indicated by the arrow A by a motor (not shown). Around the photosensitive member 1, there are disposed a primary charging device 7a, an exposing apparatus 8, a developing unit 13, a transfer roller 10 and a cleaner apparatus 12. The developing unit 13 has four developing apparatuses 13Y, 13M, 13C and 13K for full-color developing. The developing apparatuses 13Y, 13M, 13C and 13K develop a latent image on the photosensitive member 1 with yellow (Y), magenta (M), cyan (C) and black (K) toners. When the latent image is to be developed with the toner of each color, the developing unit 13 is rotated in the direction indicated by the arrow R by a motor (not shown), and the developing apparatus of that color is positioned so as to come into contact with the photosensitive member 1. The toner images of the respective colors developed on the photosensitive member 1 are successively transferred to a belt 2 as an intermediate transfer member by the transfer roller 10, and the toner images of the four colors are superimposed one upon another. The belt 2 is stretched over rollers 17, 18, 19 and 20. Of these, the roller 17 functions as a drive roller coupled to a drive source (not shown) and driving the belt 2, and drives the belt 2 in the direction indicated by the arrow B. The roller 19 functions as a tension roller for adjusting the tension of the belt 2, and the roller 20 functions as a backup roller for a transfer roller 21. A belt cleaner 22 is provided at a location opposed to the roller 17 with the belt 2 interposed therebetween, and any residual toners on the belt 2 are scraped off by a blade. A recording sheet drawn out of a recording sheet cassette 23 or 24 to a conveying path by a pickup roller 25a or 26a and a pair of separating rollers 25b or 26b is directed to a pair of registration rollers 29 by a pair of rollers 27 or 28. The recording sheet once stopped at the nip portion of the pair of registration rollers 29 is fed to a secondary transfer nip portion, i.e., the portion of contact between a secondary transfer roller 21 and the belt 2, in timed relationship with the toner images on the belt 2. The toner images formed on the belt 2 are transferred onto the recording sheet at this nip portion, and are heat-fixed by a fixing apparatus 5, and the recording sheet is discharged to a tray 30. In the color printer of the above-described construction, an image is formed in the following manner. First, a voltage is applied to the charging device 7a to thereby minus-charge the surface of the photosensitive member 1 uniformly at predetermined charging portion potential. Subsequently, the exposing apparatus 8 including a laser scanner or the like scans the photosensitive member 1 by a laser beam modulated in accordance with an image signal, whereby a latent image corresponding to an image is formed. A developing bias preset for each color is applied to the developing roller of the developing apparatus 13Y or the like, and the latent image formed on the photosensitive member 1 is developed with a toner when it passes the position of the developing roller, and is visualized as a toner image. The toner image is transferred to the belt 2 by the transfer roller 10, and a toner image of a first color is formed on the belt 2. This operation is repeated four times (correspondingly to the four colors), whereby toner images of the four colors are formed on the belt 2. At that time, the transfer roller 21 as a secondary transfer apparatus is spaced apart from the belt 2 by a mechanism (not shown) for moving it toward and away from the belt. The belt cleaner 22 is also spaced apart from the belt 2 by a mechanism (not shown) for moving it toward and away from the belt. After the toner images of the four colors have been transferred and immediately before the leading edge of the toner images comes to the position of the roller 20, the secondary transfer roller 21 is brought into contact with the belt 2 by the mechanism for moving it toward and away from the belt, and the toner images are transferred to the recording sheet at the nip portion thereof. The recording sheet to which the toner images have been transferred is fed to the fixing apparatus 5, whereby the toner images are fixed as a full-color image. Any toners residual on the photosensitive member 1 are removed and collected by the cleaner apparatus 12 and lastly, the photosensitive member 1 is charge-eliminated uniformly to the vicinity of 0 volt by a charge eliminating apparatus 7b, and becomes ready for the next image forming cycle. In such an image forming apparatus, there are carried a plurality of electric cables for effecting the exchange of electric power and data among various electric circuit substrates for controlling various operations. These electric circuit substrates include an AC power source circuit substrate for introducing electric power from a commercially available AC power source, a high voltage source circuit substrate for generating a high voltage for forming a toner image on the image bearing member, a DC power source circuit substrate for driving a motor or the like, and a control circuit substrate for controlling the driving of these circuits. Also, the above-described plurality of circuit substrates are connected together by cables for electrical energization. The installation places of the electric circuit substrates exist at all locations in the image forming apparatus from the use and the positional relation or the like with other parts, and along therewith, the cables connecting the substrates together are also installed at all locations in the image forming apparatus. In such an electrical arrangement using a plurality of cables, the distance between the AC component cable and the DC component cables is short and therefore, noise may shift from the AC component cable to the DC component cable to thereby give rise to the problem of adversely affecting the formed image or spoiling the stable operation of the apparatus. Also, in the DC component cable, a great deal of noise occurs from the circuit substrate transmitting and receiving data of a high clock. At present, as a countermeasure for this, there is used a countermeasure adopting a cableless connecting method of providing a covering material for electrically shielding the surfaces of the cables, or extending the cables at such an arrangement that the distance between the AC cable and the DC cable becomes long, or directly connecting respective connectors installed on the circuit substrates. As an example, the invention described in Japanese Patent Application Laid-Open No. 2001-238045 achieves a reduction in noise by covering a harness (flat cable) which is a noise causing source with a shield member exclusively therefor. Also, in the conventional image forming apparatus, in order to accurately hold a unit concerned in image forming, including these electric members, two pairs of large metal plates are used to form a frame (side plates). However, the method of providing a covering material for electrically shielding the surfaces of the cables as in the above-described example of the conventional art leads to a great increase in cost, and the method of extending the cables so that the distance between the AC cable and the DC cable may become long results in the greater lengths of the AC cable and the DC cable or the complication of wiring, thus reducing the maintenance property of other parts. Also, the method of directly connecting the respective connectors installed on the circuit substrates has resulted in the aggravation of the working property during assembly because the circuit substrates are connected together, and thereafter are assembled to an apparatus main body. Also, as regards supporting plates, metal plates of substantially the same size as that of the image forming apparatus have been used and this has caused the bulkiness (increased cost) of a molding machine and an increase in conveying cost. SUMMARY OF THE INVENTION The present invention has been made in view of such problems and an object thereof is to provide an electronic apparatus provided with electric circuit substrates having a cableless connecting method, which is enhanced in working property and maintenance property, and is low in cost and yet realizes lower noise. In order to achieve the above object, as an embodiment of the present invention, there is provided an electronic apparatus having a first circuit substrate, a second circuit substrate, a first supporting member for supporting the first circuit substrate, a second supporting member for supporting the second circuit substrate, a holding member for holding the first supporting member and the second supporting member, and a connector for cablelessly connecting the first circuit substrate and the second circuit substrate together, wherein at least one of the first supporting member and the second supporting member is movable in a direction in which the connection by the connector is released, and the first supporting member and the second supporting member are detachable from the holding member independently of each other. Also, as another embodiment of the present invention, there is provided an electronic apparatus having a first plate, a second plate, a connecting portion for connecting the first plate and the second plate together, a first cable and a second cable, wherein the connecting portion is a grounded electrically conductive member, and the first cable and the second cable are spaced apart from each other by the connecting portion. Also, as another embodiment of the present invention, there is provided an electronic apparatus having a first plate, a second plate, a fixing member fixed astride the first plate and the second plate, a first cable and a second cable, wherein the fixing member is a grounded electrically conductive member, and the first cable and the second cable are spaced apart from each other with the fixing member interposed therebetween. Other objects and features of the present invention will become apparent from the following description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the construction of an image forming apparatus as it is seen from the rear thereof. FIG. 2 shows the construction of the image forming apparatus as it is seen from above it. FIG. 3 shows the construction of the image forming apparatus as it is seen from a side thereof. FIG. 4 is a detailed view of a hitching portion and an opening aperture for hitching. FIG. 5 shows the construction of a conventional image forming apparatus. DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will hereinafter be described with reference to the accompanying drawings. An embodiment of the present invention will first be described with reference to the accompanying drawings. The functionally same portions as those in the example of the conventional art are given the same reference numerals and need not be described. FIGS. 1, 2 and 3 are schematic views illustrating the present invention. FIG. 1 shows the construction of an image forming apparatus to which the present invention is applied as it is seen from the rear thereof, FIG. 2 shows the construction of the image forming apparatus as it is seen from above it, and FIG. 3 is a cross-sectional view of the image forming apparatus as it is seen from a side thereof. A first supporting member 73 (hereinafter referred to as the controller box) is a member provided on the rear portion of an apparatus main body for supporting a control circuit substrate (controller substrate) 71 for controlling the operation of each circuit, a recording medium (hard disk) 74 in which data necessary when an image is processed is contained, a circuit substrate 75 for effecting the exchange of data with an apparatus outside the image forming apparatus, etc. A second supporting member 72 (hereinafter referred to as the drive control box) is a member provided on the rear portion for supporting a circuit substrate 70 for effecting the control of motor drive. The respective circuit substrates are fixed to the supporting members by screws. The controller box 73 and the drive control box 72 are arranged side by side and are secured to the apparatus main body by screws. The controller substrate 71 and the circuit substrate 70 are connected together by connectors 82 and 83 disposed on the respective substrates. Consequently, a code for electrical energization for connecting the circuit substrates can be abolished and it becomes possible to curtail the cost heretofore required for noise countermeasure. The drive control box 72, the controller box 73 and each circuit substrate are arranged side by side on the rear surface of the apparatus so as to readily permit access thereto during maintenance. A first drive source 76, a second drive source 77, etc. for driving the apparatus main body are disposed on the back sides of the first control box 72 and the controller box 73. The controller box 73 is slidable in a direction in which the connectors 82 and 83 are mounted and dismounted (a direction parallel to the surfaces of the circuit substrates), and the controller substrate can be mounted and dismounted with respect to the apparatus main body even if the drive control box 72 is not mounted and dismounted. Also, a space is provided at the end portion of the controller box 73 in the slide direction thereof so that the controller box 73 can slide. The drive control box 72 is slidable in the direction in which the connectors 82 and 83 are mounted and dismounted, and the circuit substrate 70 for effecting the control of drive can be mounted and dismounted with respect to the apparatus main body even if the controller box 73 is not mounted and dismounted. Also, a space is provided at the end portion of the drive control box 72 in the slide direction thereof so that the drive control box 72 can slide. When the controller box 73 and the drive control box 72 are to be slidden, they are slidden after screws used to mount them on the apparatus main body are removed in advance. The controller box 73 and the drive control box 72 are designed so as to be capable of being independently mounted and dismounted (so that one box can be detached without the other box being detached) and therefore, when such maintenance as the interchange or cleaning of a motor disposed in the more inside portion of the main body than the above-described substrates is to be effected, it becomes possible to have access to driving members 76 and 77 installed in the more inside portion of the main body than the circuit substrates without removing all of the circuit substrates connected together by a cableless type connector. FIG. 4 shows a detailed view of an opening aperture 81 for hitching provided in the drive control box 72 and a hitching portion 80 provided on the apparatus main body side. The controller box 73 and the drive control box 72 are mounted in such a manner that the opening apertures 81 for hitching are hitched on the hitching portions 80 provided on the apparatus main body side. That is, the hitching portions 80 are provided as holding members for holding the controller box 73 and the drive control box 72 on the apparatus main body. The opening aperture 81 for hitching in the drive control box 72, as shown in FIG. 4, is of a hook shape (a shape in which a corner of a rectangle is cut out in a rectangular shape), the width (a vertical direction as viewed in FIG. 4) of the left portion of the opening aperture is narrower than the width of the right portion. In a state in which the connectors 82 and 83 are connected, the hitching portion 80 is fitted in the narrow portion of the opening aperture 81 for hitching and therefore, the movement of the drive control box 72 is limited to thereby prevent a load from being applied to the connectors from any other direction than the direction in which the connectors are mounted and dismounted. Also, in a state in which the connection of the connectors 82 and 83 has been released, the hitching portion 80 is fitted in the wide portion of the opening aperture 81 for hitching and therefore, it becomes possible to dismount the drive control box 72 from the hitching portion 80. By constructing so, it becomes possible to dismount the drive control box 72 from the apparatus main body. The opening aperture for hitching provided on the controller box side is of a substantially line-symmetrical shape with respect to the opening aperture provided on the drive control box side. Therefore, only in a state in which the connectors 82 and 83 on the circuit substrate are separate from each other, it is possible to hitch the opening apertures 81 for hitching in the controller box 73 and the drive control box 72 on the hitching portions 80. Consequently, it becomes possible to avoid the problem that a load is applied from any other direction than the mounting and dismounting direction to the connectors connecting the substrates together to thereby damage the connectors, the circuit substrates, etc. That is, the controller box 73 and the drive control box 72 are of such a construction that they can be dismounted from the apparatus main body only after moved to a position in which the connection of the connectors 82 and 83 is released. As shown in FIG. 3, the plates 30 and 31 of the image forming apparatus are designed to vertically divide the apparatus into two, and a connecting portion 40 is designed such that the portions of a metal plate bent at a right angle overlap each other. This connecting portion 40 is constituted by a grounded electrically conductive member. An AC component cable 91 and a DC component cable 90 are installed so as to sandwich the connecting portion 40 of the plates 30 and 31 therebetween. Here, what is above the connecting portion 40 is the DC component cable 90 and what is below the connecting portion 40 is the AC component cable 91, but a converse arrangement may be adopted. Consequently, the AC component cable 91 and the DC component cable 90 are spaced apart from each other by the connecting portion 40 which is a grounded electrically conductive member and therefore, a reduction in noise becomes possible at a low cost without adopting the countermeasure of providing a covering material for electrically shielding the surfaces of the cables. A fixing member 35 is fixed to the plates 30 and 31 so as to cover the connecting portion 40 of the plates 30 and 31, and also has the role of a guide for the DC component cable 90 extending from the plate 31 to the plate 30 to clear the connecting portion 40. The fixing member 35 is located between the AC component cable 91 and the DC component cable 90 so as to space the AC component cable 91 and the DC component cable 90 apart from each other. The fixing member 35 is constituted by a grounded electrically conductive member. By adopting such a construction, it becomes possible to avoid the problem that noise shifts from the AC component cable 91 onto the DC component cable 90. Also, it becomes possible to protect the cables from the edge of the connecting portion 40 of the plates 30 and 31 and therefore, a wire saddle and an edge saddle or the like can be omitted, and it becomes possible to curtail the cost. While the present invention has been shown with respect to an example in which it is applied to an image forming apparatus, it is applicable to various electronic apparatuses having a plurality of circuit substrates. Also, the present invention is not restricted to the above-described embodiment, but various modifications thereof are possible. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to the layout design and mounting and dismounting of a circuit substrate in an electronic apparatus such as, for example, a printer or a copying machine. 2. Description of the Related Art In recent years, there have been popularized image forming apparatuses such as printers and copying machines using an electrophotographic process which can output a full-color image. Description will hereinafter be made with reference to the accompanying drawings. FIG. 5 shows an example of the construction of the essential portions of a conventional full-color printer. A photosensitive drum (hereinafter simply referred to as the photosensitive member) 1 as an image bearing member is provided so as to be rotatable in the direction indicated by the arrow A by a motor (not shown). Around the photosensitive member 1 , there are disposed a primary charging device 7 a , an exposing apparatus 8 , a developing unit 13 , a transfer roller 10 and a cleaner apparatus 12 . The developing unit 13 has four developing apparatuses 13 Y, 13 M, 13 C and 13 K for full-color developing. The developing apparatuses 13 Y, 13 M, 13 C and 13 K develop a latent image on the photosensitive member 1 with yellow (Y), magenta (M), cyan (C) and black (K) toners. When the latent image is to be developed with the toner of each color, the developing unit 13 is rotated in the direction indicated by the arrow R by a motor (not shown), and the developing apparatus of that color is positioned so as to come into contact with the photosensitive member 1 . The toner images of the respective colors developed on the photosensitive member 1 are successively transferred to a belt 2 as an intermediate transfer member by the transfer roller 10 , and the toner images of the four colors are superimposed one upon another. The belt 2 is stretched over rollers 17 , 18 , 19 and 20 . Of these, the roller 17 functions as a drive roller coupled to a drive source (not shown) and driving the belt 2 , and drives the belt 2 in the direction indicated by the arrow B. The roller 19 functions as a tension roller for adjusting the tension of the belt 2 , and the roller 20 functions as a backup roller for a transfer roller 21 . A belt cleaner 22 is provided at a location opposed to the roller 17 with the belt 2 interposed therebetween, and any residual toners on the belt 2 are scraped off by a blade. A recording sheet drawn out of a recording sheet cassette 23 or 24 to a conveying path by a pickup roller 25 a or 26 a and a pair of separating rollers 25 b or 26 b is directed to a pair of registration rollers 29 by a pair of rollers 27 or 28 . The recording sheet once stopped at the nip portion of the pair of registration rollers 29 is fed to a secondary transfer nip portion, i.e., the portion of contact between a secondary transfer roller 21 and the belt 2 , in timed relationship with the toner images on the belt 2 . The toner images formed on the belt 2 are transferred onto the recording sheet at this nip portion, and are heat-fixed by a fixing apparatus 5 , and the recording sheet is discharged to a tray 30 . In the color printer of the above-described construction, an image is formed in the following manner. First, a voltage is applied to the charging device 7 a to thereby minus-charge the surface of the photosensitive member 1 uniformly at predetermined charging portion potential. Subsequently, the exposing apparatus 8 including a laser scanner or the like scans the photosensitive member 1 by a laser beam modulated in accordance with an image signal, whereby a latent image corresponding to an image is formed. A developing bias preset for each color is applied to the developing roller of the developing apparatus 13 Y or the like, and the latent image formed on the photosensitive member 1 is developed with a toner when it passes the position of the developing roller, and is visualized as a toner image. The toner image is transferred to the belt 2 by the transfer roller 10 , and a toner image of a first color is formed on the belt 2 . This operation is repeated four times (correspondingly to the four colors), whereby toner images of the four colors are formed on the belt 2 . At that time, the transfer roller 21 as a secondary transfer apparatus is spaced apart from the belt 2 by a mechanism (not shown) for moving it toward and away from the belt. The belt cleaner 22 is also spaced apart from the belt 2 by a mechanism (not shown) for moving it toward and away from the belt. After the toner images of the four colors have been transferred and immediately before the leading edge of the toner images comes to the position of the roller 20 , the secondary transfer roller 21 is brought into contact with the belt 2 by the mechanism for moving it toward and away from the belt, and the toner images are transferred to the recording sheet at the nip portion thereof. The recording sheet to which the toner images have been transferred is fed to the fixing apparatus 5 , whereby the toner images are fixed as a full-color image. Any toners residual on the photosensitive member 1 are removed and collected by the cleaner apparatus 12 and lastly, the photosensitive member 1 is charge-eliminated uniformly to the vicinity of 0 volt by a charge eliminating apparatus 7 b , and becomes ready for the next image forming cycle. In such an image forming apparatus, there are carried a plurality of electric cables for effecting the exchange of electric power and data among various electric circuit substrates for controlling various operations. These electric circuit substrates include an AC power source circuit substrate for introducing electric power from a commercially available AC power source, a high voltage source circuit substrate for generating a high voltage for forming a toner image on the image bearing member, a DC power source circuit substrate for driving a motor or the like, and a control circuit substrate for controlling the driving of these circuits. Also, the above-described plurality of circuit substrates are connected together by cables for electrical energization. The installation places of the electric circuit substrates exist at all locations in the image forming apparatus from the use and the positional relation or the like with other parts, and along therewith, the cables connecting the substrates together are also installed at all locations in the image forming apparatus. In such an electrical arrangement using a plurality of cables, the distance between the AC component cable and the DC component cables is short and therefore, noise may shift from the AC component cable to the DC component cable to thereby give rise to the problem of adversely affecting the formed image or spoiling the stable operation of the apparatus. Also, in the DC component cable, a great deal of noise occurs from the circuit substrate transmitting and receiving data of a high clock. At present, as a countermeasure for this, there is used a countermeasure adopting a cableless connecting method of providing a covering material for electrically shielding the surfaces of the cables, or extending the cables at such an arrangement that the distance between the AC cable and the DC cable becomes long, or directly connecting respective connectors installed on the circuit substrates. As an example, the invention described in Japanese Patent Application Laid-Open No. 2001-238045 achieves a reduction in noise by covering a harness (flat cable) which is a noise causing source with a shield member exclusively therefor. Also, in the conventional image forming apparatus, in order to accurately hold a unit concerned in image forming, including these electric members, two pairs of large metal plates are used to form a frame (side plates). However, the method of providing a covering material for electrically shielding the surfaces of the cables as in the above-described example of the conventional art leads to a great increase in cost, and the method of extending the cables so that the distance between the AC cable and the DC cable may become long results in the greater lengths of the AC cable and the DC cable or the complication of wiring, thus reducing the maintenance property of other parts. Also, the method of directly connecting the respective connectors installed on the circuit substrates has resulted in the aggravation of the working property during assembly because the circuit substrates are connected together, and thereafter are assembled to an apparatus main body. Also, as regards supporting plates, metal plates of substantially the same size as that of the image forming apparatus have been used and this has caused the bulkiness (increased cost) of a molding machine and an increase in conveying cost. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made in view of such problems and an object thereof is to provide an electronic apparatus provided with electric circuit substrates having a cableless connecting method, which is enhanced in working property and maintenance property, and is low in cost and yet realizes lower noise. In order to achieve the above object, as an embodiment of the present invention, there is provided an electronic apparatus having a first circuit substrate, a second circuit substrate, a first supporting member for supporting the first circuit substrate, a second supporting member for supporting the second circuit substrate, a holding member for holding the first supporting member and the second supporting member, and a connector for cablelessly connecting the first circuit substrate and the second circuit substrate together, wherein at least one of the first supporting member and the second supporting member is movable in a direction in which the connection by the connector is released, and the first supporting member and the second supporting member are detachable from the holding member independently of each other. Also, as another embodiment of the present invention, there is provided an electronic apparatus having a first plate, a second plate, a connecting portion for connecting the first plate and the second plate together, a first cable and a second cable, wherein the connecting portion is a grounded electrically conductive member, and the first cable and the second cable are spaced apart from each other by the connecting portion. Also, as another embodiment of the present invention, there is provided an electronic apparatus having a first plate, a second plate, a fixing member fixed astride the first plate and the second plate, a first cable and a second cable, wherein the fixing member is a grounded electrically conductive member, and the first cable and the second cable are spaced apart from each other with the fixing member interposed therebetween. Other objects and features of the present invention will become apparent from the following description and the accompanying drawings. | 20040503 | 20080311 | 20050303 | 59597.0 | 0 | READY, BRYAN | ELECTRONIC APPARATUS HAVING A PLURALITY OF CIRCUIT SUBSTRATES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,396 | ACCEPTED | Location determination and location tracking in wireless networks | The present invention is directed to systems and methods which monitor a network environment, collect client information available online, and refine location determinations of individual clients based on observed information as well as online information. More particularly, the present invention is directed to systems and methods which monitor the wireless network, collect online receive signal strength indicator (RSSI) information observations from client users, without requiring knowledge of those clients' locations. The present invention is additionally directed to systems and methods to enhance the accuracy of the location determinations in a network, based on observed client information such as, for example, signal strength references. | 1. A system comprising: one or more wireless network access nodes, said one or more wireless network access nodes providing a plurality of antenna patterns; calculation logic for determining receive signal strength differences with respect to a signal as received by said one or more wireless access nodes using said plurality of antenna patterns, said signal being transmitted from a location unknown to said system; a radio map providing location estimates associated with use of said plurality of antenna patterns; and calculation logic for improving said location estimates of said radio map using said receive signal strength differences determined by said calculation logic for determining receive signal strength differences. 2. The system of claim 1, wherein said calculation logic for improving said location estimates iteratively improves said location estimates using a series of receive signal strength differences determined by said calculation logic for determining receive signal strength differences. 3. The system of claim 1, wherein said calculation logic for improving said location estimates includes a location-conditional probability density function for use in improving said location estimates using said receive signal strength differences. 4. The system of claim 3, wherein said location-conditional probability density function includes a probability for each location estimate of said radio map. 5. The system of claim 3, wherein said location-conditional probability density function is determined using a user density profile. 6. The system of claim 3, wherein said location-conditional probability density function is determined using weighting coefficients. 7. The system of claim 1, wherein said calculation logic for improving said location estimates includes weighting coefficients for weighting said receive signal strength differences in a location estimate calculation. 8. The system of claim 7, wherein said weighting coefficients include a weighting coefficient for each receive signal strength observation made with respect to a particular location estimate of said radio map. 9. The system of claim 1, wherein said radio map is formed by sampling a set of multiple grid points. 10. The system of claim 1, further comprising: a database containing antenna gain profile information for said plurality of antenna patterns of said wireless access nodes. 11. The system of claim 10, wherein said radio map is formed by establishing a set of location candidates and calculating a receive signal strength reference for an imaginary remote station transmitting from each location candidate. 12. The system of claim 11, wherein said receive signal strength references are calculated using a geometrical distance between each of location candidates and each of said wireless network access nodes and an angle between each of said location candidates and each of said wireless network access nodes. 13. The system of claim 10, wherein said database contains antenna gain differences associated with each antenna pattern of said plurality of antenna patterns. 14. The system of claim 1, wherein said radio map is populated with receive signal strength reference information for each of said plurality of antenna patterns. 15. The system of claim 1, wherein said plurality of antenna patterns comprise multiple narrow antenna patterns and a wide antenna pattern associated with a same wireless network access node. 16. The system of claim 1, wherein said calculation logic for determining receive signal strength differences, said calculation logic for iteratively improving said location estimates, and said radio map are disposed at a centralized system in communication with said one or more wireless network access nodes. 17. The system of claim 1, wherein said calculation logic for determining receive signal strength differences, said calculation logic for iteratively improving said location estimates, and said radio map are disposed in a distributed configuration. 18. The system of claim 1, wherein said calculation logic for determining receive signal strength differences, said calculation logic for iteratively improving said location estimates, and said database are disposed within one or more of said wireless network access nodes. 19. A method comprising: providing a plurality of antenna patterns in a service area; providing a radio map of location estimates associated with use of said plurality of antenna patterns; determining receive signal strength information with respect to a signal as received using said plurality of antenna patterns, said signal being transmitted from a location unknown to said system; and revising said location estimates of said radio map using said determined receive signal strength information. 20. The method of claim 19, wherein said revising said location estimates comprises: using a series of receive signal strength information determinations to iteratively revise said location estimates. 21. The method of claim 19, further comprising: determining a location-conditional probability density function, said location-conditional probability density function being used with said determined receive signal strength in said revising said location estimates. 22. The method of claim 21, wherein said determining said location-conditional density function comprises: determining a probability of a receive signal strength information profile for each location estimate of said radio map. 23. The method of claim 21, wherein said determining said location-conditional density function comprises: using a user density profile. 24. The method of claim 21, wherein said determining said location-conditional density function comprises: using weighting coefficients. 25. The method of claim 19, wherein said revising said location estimates comprises: applying weighting coefficients to said receive signal strength information. 26. The method of claim 25, wherein said weighting coefficients include a weighting coefficient for each receive signal strength observation made with respect to a particular location estimate of said radio map. 27. The method of claim 19, wherein said providing said radio map comprises: forming said radio map by sampling a set of multiple grid points. 28. The method of claim 19, wherein said providing said radio map comprises: forming said radio map by establishing a set of location candidates and calculating a receive signal strength reference for an imaginary remote station transmitting from each location candidate. 29. The method of claim 28, wherein said forming said radio map comprises: using antenna gain profile information for said plurality of antenna patterns for each location candidate. 30. The method of claim 28, wherein said receive signal strength references are calculated using a geometrical distance between each of location candidates and a wireless network access node and an angle between each of said location candidates and said wireless network access node. 31. The method of claim 28, wherein said providing said radio map comprises: populating said radio map with receive signal strength reference information for each of said plurality of antenna patterns. 32. The method of claim 19, further comprising: providing a database of antenna gain differences associated with each antenna pattern of said plurality of antenna patterns for use in said revising said location estimates. 33. The method of claim 19, wherein said plurality of antenna patterns comprise multiple narrow antenna patterns and a wide antenna pattern associated with a same wireless network access node. 34. The method of claim 19, further comprising: determining a location of a remote station using said revised location estimates of said radio map. 35. The method of claim 34, wherein said determining said location comprises: using said determined receive signal strength information. 36. The method of claim 34, wherein said determining said location comprises: using historical information to model a likelihood of the remote station transitioning in successive instants in time. 37. A system comprising: a map of points in a wireless network environment; a set of online observations from one or more network client users; computation logic for computing a weighting coefficient associated with observations of said set of online observations; calculation logic for calculating an update point for a point of said map, wherein said calculation logic uses observations of said set of online observations and their associated weighting coefficients in calculating said update point; and refining logic for updating said point of said map with said update point. 38. The system of claim 37, further comprising: determination logic for determining probability of a received signal strength, said determined probability being utilized by said calculation logic in calculating said update point. 39. The system of claim 37, further comprising: comparison logic for determining the difference between a plurality of points of said map and said update point for selecting said point of said map for updating with said update point. 40. The system of claim 37, wherein said map includes received signal strength information with respect to said points of said map. 41. The system of claim 40, wherein said received signal strength information is observed. 42. The system of claim 40, wherein said received signal strength information is predicted. 43. The system of claim 42, wherein said map of received signal strength information is predicted using a generic propagation model. 44. The system of claim 37, wherein refining logic updates said map without requiring manual measurements in said wireless network environment. 45. The system of claim 37, wherein said set of online observations contains a greater number of observations than the number of said observed points in said map. 46. The system of claim 37, wherein said computation logic, said calculation logic, and said refining logic are disposed at a centralized system in communication with a plurality of wireless network access nodes. 47. The system of claim 37, wherein said computation logic, said calculation logic, and said refining logic are disposed in a distributed configuration. 48. A method for refinement of a map of a wireless network environment using unsupervised learning, said method comprising: providing an initial received signal strength reference for a location on a map of a wireless network environment; providing one or more online observations from client users of said wireless network environment; assigning a probability density function to a receive signal strength reference for said location on said map; calculating a weighting coefficient for said location on said map; calculating an update received signal strength reference for said location on said map; and replacing said initial receive signal strength reference for said location on a map with said update received signal strength reference. 49. The method of claim 48, wherein a probability of said probability density function is location-conditional. 50. The method of claim 48, wherein said calculating an update received signal strength reference for said location on said map comprises: calculating said update received signal strength reference with said one or more online observations and said weighting coefficient. 51. The method of claim 48, further comprising: iteratively calculating a weighting coefficient for each of the one or more locations on said grid map of a wireless network environment; iteratively calculating an update received signal strength reference for each of the one or more locations on said grid map of a wireless network environment with said probability and said weighting coefficient; and iteratively replacing said initial receive signal strength reference for each of the one or more locations on a grid map of a wireless network environment with each of the said update received signal strength reference. 52. A method for online location determination of a stationary target, said method comprising: selecting a target client; selecting one or more wireless network access nodes; providing a radio map associated with said one or more wireless network access nodes and providing location candidates for a service area of said one or more wireless network access nodes; computing a distance in signal space between said target client and said location candidates to identify one or more location candidates; calculating a mean position of said one or more location candidates; and estimating a location of said target client using said mean position. 53. The method of claim 52, wherein estimating said location of said target client comprises: using a plurality of antenna beams associated with one or more of nearest wireless access nodes neighboring said target client. 54. The method of claim 53, wherein estimating said location of said target client comprises: estimating location of said target client using a weighted mean position. 55. The method of claim 52, further comprising: providing network access as a function of said location. 56. The method of claim 52, further comprising: providing data content as a function of said location. 57. The method of claim 52, further comprising: providing management of network resources as a function of said location. 58. A method for determining a location of a remote station in a wireless network, said method comprising: providing a radio map providing location estimates for a plurality of points in a service area of said wireless network; observing received signal strength information associated with a plurality of antenna patterns for a plurality of remote stations; and applying said observed receive signal strength information to said radio map to iteratively revise location estimates of said radio map. 59. The method of claim 58, wherein said providing said radio map comprises: calculating a radio map using a propigation model with respect to a grid of points in said service area. 60. The method of claim 58, wherein said applying said observed receive signal strength information to said radio map comprises: applying weighting coefficients to said observed receive signal strength information. 61. The method of claim 60, wherein said weighting coefficients include a weighting coefficient for each receive signal strength observation made with respect to a particular location estimate of said radio map. 62. The method of claim 58, wherein said applying said observed receive signal strength information to said radio map comprises: using a location-conditional probability density function. 63. The method of claim 62, further comprising: determining said location-conditional density function using weighting coefficients. 64. The method of claim 63, wherein said determining said location-conditional density function comprises: determining a probability of a receive signal strength information profile for each location estimate of said radio map. 65. The method of claim 63, wherein said determining said location-conditional density function comprises: using a user density profile. | CROSS-REFERENCE TO RELATED APPLICATIONS The present invention is related to co-pending and commonly assigned U.S. patent application Ser. No. 10/635,367 entitled “Location Positioning in Wireless Networks,” filed Aug. 6, 2003, the disclosure of which is hereby incorporated herein by reference. TECHNICAL FIELD The present invention is directed toward wireless communications and, more particularly, to refining location positioning determinations for wireless devices. BACKGROUND OF THE INVENTION It is sometimes desirable to locate the position of a station operable within a wireless, e.g., radio frequency (RF), network. For example, the United States Federal Communications Commission (FCC) has decreed that cellular telephone systems must implement systems to provide mobile telephone position information for use in emergency response, e.g., enhanced 911 (E911) emergency response. Additionally, the position of a station may be important for providing particular services, such as, for example, identifying subscribers and non-subscribers, resource allocation, network security, and location-sensitive content delivery, among other services. In order to estimate a station's location, a system typically measures a metric that is a function of distance. A typical measured metric is signal strength, which decays logarithmically with distance in free space. Time information, such as time of arrival of a signal or time difference of arrival of a signal at diverse antennas, may be utilized as a measured metric from which distance information may be determined. Typically, several reference points are used with distance information derived from the measured metric in estimating location. The use of global positioning system (GPS) receivers, which operate in conjunction with a network of middle earth orbit satellites orbiting the Earth to determine the receiver's position, has almost become ubiquitous in navigational applications. In such a GPS network, the aforementioned reference points are the satellites and the measured metric is the time of arrival of the satellite signal to the GPS receiver. The time of arrival of the satellite signal is typically directly proportional to the distance between the satellite and the GPS receiver due to a clear line of sight between the GPS receiver and satellite. By measuring the time of arrival associated with three satellites, a GPS receiver can calculate the longitude and latitude of the GPS receiver. By using time of arrival information with respect to a fourth satellite, a GPS receiver can also determine altitude. In the aforementioned cellular networks, techniques including signal strength measurements and/or time difference of arrival have been implemented for location determination. For example, U.S. Pat. No. 6,195,556, the disclosure of which is incorporated herein by reference, teaches the use of signal strength measurements in combination with the time difference of arrival of a station's signal in determining the location of the station. Additionally, U.S. Pat. No. 6,195,556 teaches the use of mapping of received signal characteristics associated with particular positions (e.g., receive “signature” associated with each of a plurality of remote station locations) for use in determining a station's location. In the case of the aforementioned cellular network, the base transceiver stations (BTSs) are generally relied upon as the reference points from which distance determinations are made. Wireless local area network (WLAN) location determination systems have been implemented in two phases: the offline phase and the online phase. In the offline phase, prediction or measurement of the fingerprint (e.g., signal strength, multipath characteristics, etcetera) of wireless access points at particular locations within the service area may be carried out. Location fingerprints may be predicted or measured off-line, such as when a network is being deployed, and are stored in a database resulting in a so-called radio map to relate the wireless signal information and coordinates of the known locations. In the online phase, the fingerprint associated with a remote station at an unknown location is measured during later operation of the network, and compared to the entries in the database. A location estimation algorithm is then applied to infer the location estimate for the unknown location. Location estimation algorithms include, for example but not limited to, triangulation, nearest neighborhood, K-nearest neighbor averaging, and history-based shortest path. Previously, developing an accurate radio map for location determination required manual calibration throughout the network environment, meaning that before a location determination could be made, an engineer would actually have to physically go out and make calibration measurements at some specified points over the area covered by the network. Based on the manual measurements, the system would construct the radio map, and then make a location determination. This is known as supervised calibration or supervised training. Making manual calibration measurements is expensive and consumes significant manpower. Furthermore, because the wireless environment is constantly changing, the measured parameters are also changing, and repeating calibration to update the measurements is impractical and inefficient. Supervised training, requiring manual calibration, provides relatively accurate resolution, but over time, the accuracy fails as the networks parameters change. It is, therefore, desirable to eliminate the need for making costly and time consuming manual measurements. BRIEF SUMMARY OF THE INVENTION The present invention is directed to systems and methods which monitor a network environment, collect client information available online, and refine location determinations of individual clients based on observed information as well as online information. More particularly, embodiments of the present invention comprise to systems and methods which monitor the wireless network, such as by collecting online receive signal strength indicator (RSSI) information observations from client users, to provide location determinations without requiring knowledge of those clients' precise locations. Embodiments of the present invention are additionally directed to systems and methods to enhance the accuracy of the location determinations in a network, based on observed client information such as, for example, signal strength references. In one embodiment of the present invention, the method employs online received signal strength observations from multiple clients, with known or unknown locations, together with the original observed or estimated signal strength database to refine a radio map of the network environment. Online RSSI observations from client users may be compared with the original observed or estimated signal strength database and the radio map may be refined based on unsupervised training capabilities. Unsupervised system training according to embodiments of the present invention reduces or eliminates the need for live calibration of the network, and instead, existing measurements online can be used to calibrate and fine tune the radio map of the network environment. Additionally, according to embodiments of the present invention, collected RSSI information may be obtained from the normal network transmissions and therefore, does not require any extra overhead to obtain and use the information in location determination. It is an object of embodiments of the present invention to create an original radio map of mobile station location without requiring manual calibration, by comparing online observations with a generic model estimation and following iterations through until the radio map is within a certain degree of accuracy. It is a further object of embodiments of the present invention to update an existing radio map of mobile station location created by supervised training, without manually re-measuring network parameters to update calibrations. It is a yet another object of embodiments of the present invention to use unsupervised training to update an existing radio map of mobile station location that was created by supervised training without expending additional money and manpower. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized that such equivalent constructions do not depart from the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which FIG. 1A shows a wireless network system into which embodiments of the present invention may be deployed; FIG. 1B shows antenna patterns of FIG. 1A having gain components in a wide azimuthal range as may be present in an actual deployment; FIGS. 2A and 2B show various multiple antenna pattern configurations as may be utilized according to embodiments of the present invention; FIG. 3 shows a flow diagram setting forth steps of a preferred embodiment algorithm for construction of a radio map; FIG. 4 shows a flow diagram setting forth steps of a preferred embodiment algorithm for iteratively refining a radio map for location determination; FIG. 5 shows a flow diagram setting forth steps of a preferred embodiment algorithm for online location determination; and FIG. 6 shows a flow diagram setting forth steps of a preferred embodiment algorithm for online location tracking. DETAILED DESCRIPTION OF THE INVENTION One embodiment of the present invention involves constantly monitoring a network environment, such as, for example, a wireless network, by collecting the information for client users, such as RSSI information, and making the information available online. Using this information made available online, the unsupervised learning theory may be used to refine a radio map of the network environment and result in more accurate location determinations. The theory of unsupervised learning in pattern classification is generally summarized here. For example, D={x1, x2, . . . , xn} denotes the set of n unlabeled feature observations drawn independently from a known number c of clusters w={w1, w2, . . . , wc}, according to the mixture density according to the mixture density p ( x ❘ θ ) = ∑ j = 1 c p ( x ❘ w j , θ j ) P ( w j ) , ( 1 ) where the forms for the cluster-conditional probability of the feature p(x|wj, θj) may be known (e.g. multi-variant Gaussian distribution), but the values for the c parameters θ={θ1, θ1, . . . , θc} may be unknown. The prior probabilities P(wj) may also be included among the unknown parameters. The objective is to estimate the parameters θ and P(wj) with j=1, 2, . . . c using the unlabeled observation set D. The maximum-likelihood estimations of θ and P(w) are the values that maximizes the joint density p(D|θ), represented by the equation: ( θ ^ , P ^ ( w ) ) = arg max θ , P ( w ) p ( D ❘ θ ) = arg max θ , P ( w ) ∏ k = 1 n p ( x k ❘ θ ) , ( 2 ) subject to the constraints that P(wj)≧0, and ∑ j = 1 c P ( w j ) = 1. In a multi-variant Gaussian distribution case, each parameter θj consists of the components of mean vector μj and covariance matrix Σj, and p(x|wj, θj) is given by p ( x ❘ w j , θ j ) = 1 ( 2 π ) d / 2 Σ j 1 / 2 exp [ - 1 2 ( x - μ j ) T Σ j - 1 ( x - μ j ) ] , ( 3 ) where d is the dimension of the feature vector, |Σj| and Σj−1 are the determinate and inverse, respectively, of Σj, and (x-μ)T is the transpose of x-μ. If the unknown quantities are μj and P(wj), the solution to equation (2) is governed by the following equations: μ ^ j = ∑ k = 1 n P ^ ( w j ❘ x k , μ ^ ) x k ∑ k = 1 n P ^ ( w j ❘ x k , μ ^ ) , j = 1 , … , c ( 4 ) P ^ ( w j ) = 1 n ∑ k = 1 n P ^ ( w j ❘ x k , μ ^ ) where ( 5 ) P ^ ( w j ❘ x k , μ ^ ) = p ( x k ❘ w j , μ j ^ ) P ^ ( w j ) ∑ i = 1 c p ( x k ❘ w i , μ ^ i ) P ^ ( w i ) . ( 6 ) While these equations appear to be rather formidable, the interpretation is actually quite simple and shows that the maximum-likelihood estimate for μj is merely a weighted average of the samples; the weight for the k-th sample is an estimate of how likely it is that xk belongs to the j-th cluster. In the extreme case where {circumflex over (P)}(wj|xk, {circumflex over (μ)}) is 1.0 when xk is from cluster wj and 0.0 otherwise, {circumflex over (P)}(wj) is the fraction of samples from wj, and {circumflex over (μ)}j is the mean of those samples. If fairly accurate initial estimations {circumflex over (μ)}j(0) and {circumflex over (P)}0(wj) are available, equations (4-6) indicate an iterative scheme for improving the estimations, according to the equations: P ^ i ( w j ❘ x k , μ ^ ) = p ( x k ❘ w j , μ j ^ ) P ^ i ( w j ) ∑ i = 1 c p ( x k ❘ w i , μ ^ i ) P ^ i ( w i ) ( 7 ) μ ^ j ( i + 1 ) = ∑ k = 1 n P ^ i ( w j ❘ x k , μ ( i ) ^ ) x k ∑ k = 1 n P ^ i ( w j ❘ x k , μ ^ ( i ) ) . ( 8 ) P ^ i + 1 ( w j ) = 1 n ∑ k = 1 n P ^ i ( w j ❘ x k , μ ^ ( i ) ) ( 9 ) This is, generally, a gradual procedure for maximizing the likelihood function. If the overlap between cluster-conditional densities is small, then the coupling between clusters will be small and converge will be fast. Application of this theory of unsupervised learning allows one to correct, refine or update the accuracy of a radio map through iteration, rather than re-measurement of the network environment and manual re-calibration. Embodiments of the present invention employ unsupervised learning theory applied directly in location determination technology to create the received signal strength references. Accordingly, location determination is regarded as a pattern classification problem. In specific, the clusters are the particular points in the service area of a network, and the feature space is the RSSI information of a wireless station as experienced by wireless access nodes in the network. Assuming that the received signal strength in a wireless environment follows a log-normal shadowing model, RSSI samples in dB scale from each location candidate are modeled as a multi-variant Gaussian distribution. Further assuming that the standard deviation of the shadowing effects is fixed and known, equations (7-9) can be used in a straight manner to iteratively update the signal strength references μ={μ1, μ1, . . . , μc} at candidate points w={w1, w2, . . . , wc}. Embodiments of the invention utilize an initial estimation of the signal strength references. For example, signal strength references obtained according to the method disclosed in United Stated patent application Ser. No. 10/635,367 entitled “Location Positioning in Wireless Networks,” may serve to provide an initial estimation on μ according to one embodiment of the present invention. An initial estimation on μ may alternatively be generated according to one embodiment of the present invention, as will be discussed. With sufficient RSSI observation samples, the signal strength reference at each grid point converges to a more accurate value. Directing attention to FIG. 1A, an exemplary wireless network system is shown as network 100. It should be appreciated that network 100 may comprise a portion of a WLAN, WMAN, cellular network, satellite network, and/or the like. However, to better aid the reader in understanding the concepts of the present invention, reference herein shall be made to an embodiment wherein network 100 comprises a portion of a WLAN or WMAN and, therefore, terminology consistent with such a wireless network is used. It will readily be understood by one of skill in the art that the relevant wireless network aspects discussed herein have corresponding structure in other wireless network configurations and, therefore, implementation of the present invention with respect to such other wireless network configurations will readily be understood from the disclosure herein. For example, wireless access nodes are present in each of the foregoing wireless networks, although perhaps referenced using a different lexicon (e.g., access point (WLAN and WMAN), base transceiver station (cellular network), and transceiver (satellite network)). In the embodiment illustrated in FIG. 1A, network backbone 151, such as may comprise wireline links, optic links, and/or wireless links, couples nodes of network 100. Specifically, processor-based system 150, such as may comprise a network server, a network workstation, a location positioning system, or even another network, e.g., the Internet, is shown coupled to access points (“APs”) 101-103 via network backbone 151. According to a preferred embodiment, network backbone 151 provides data communication according to a standard protocol, such as Ethernet, SONET, or the like, although proprietary protocols may be utilized if desired. APs 101-103 of the illustrated embodiment provide RF illumination of a service area using multiple antenna patterns. For example, APs 101-103 may implement smart antenna configurations employing phased arrays and/or antenna beam switching to provide multiple antenna patterns. Commercially available APs adapted to provide multiple antenna patterns include, for example, the 2.4 GHz Wi-Fi switches available from Vivato, Inc., San Francisco, Calif. The illustrated embodiment shows a configuration in which each AP has 10 approximately 36° directional antenna patterns and one omni-directional (approximately 360°) antenna pattern associated therewith. Specifically, AP 101 has directional antenna patterns 110-119 and omni-directional antenna pattern 11 associated therewith. Similarly, AP 102 has directional antenna patterns 120-129 and omni-directional antenna pattern 12 associated therewith and AP 103 has directional antenna patterns 130-139 and omni-directional antenna pattern 13 associated therewith. It should be appreciated that the directional antenna patterns of the illustrated embodiment are disposed to provide wave fronts along different azimuthal angles, thereby providing directional coverage throughout a portion of the service area around each corresponding AP. However, it should also be appreciated that operation of the present invention is not limited to the particular antenna pattern configuration represented in FIG. 1A. For example, an AP may be configured to provide coverage in less than a 360° radius about the AP. As shown in FIG. 2A, an AP might be configured to provide a relatively wide antenna pattern covering a desired area, or portion thereof, and multiple more narrow antenna patterns within that area. In the example of FIG. 2A, AP 201 is configured to provide wide antenna pattern 21, such as may comprise an approximately 120° beam, and narrow antenna patterns 210-213, such as may comprise approximately 30° beams. AP 201 is not limited to providing illumination of the area shown and may, for example, implement 2 additional such multiple antenna pattern configurations centered at different azimuthal angles, to thereby provide 360° illumination. As shown in FIG. 2B, an AP might be configured to provide multiple overlapping directional antenna patterns centered at a same azimuthal angle. Specifically, relatively wide antenna pattern 210, such as may comprise an approximately 60° beam, more narrow antenna pattern 211, such as may comprise an approximately 36° beam, and narrow antenna pattern 212, such as may comprise an approximately 5°, are each centered at a same azimuthal angle with respect to AP 202. As with AP 201 discussed above, AP 202 may implement additional such multiple antenna pattern configurations centered at different azimuthal angles, to thereby provide desired illumination. Irrespective of the particular antenna patterns implemented, the APs provide information communication links with respect to remote stations disposed within the service area of the wireless network. Referring again to FIG. 1A, remote station 10 is shown disposed in antenna patterns 11 and 111 of AP 101, antenna patterns 12 and 124 of AP 102, and antenna patterns 13 and 138 of AP 103. Any of APs 101-103 may be invoked to provide a wireless link with remote station 10, thereby facilitating network communication via network backbone 151 with respect to remote station 10. It should be appreciated that the antenna patterns illustrated in FIG. 1A are highly simplified in order to more clearly convey the concepts of the present invention. For example, rather than providing the highly directional, clearly defined beams of FIG. 1A, APs may provide patterns which have gain components throughout a relatively wide azimuthal range. Directing attention to FIG. 1B, radiation patterns 111-113 of AP 101 having a relatively wide azimuthal range of antenna gain components are shown, as might be experienced in an actual deployment. Accordingly, one of skill in the art will readily appreciate that a remote station may be disposed in areas outside of where the radiation patterns of various APs are illustrated to be overlapping and yet still be in wireless communication therewith. Such gain components associated with a number of antenna patterns in a direction of a particular remote station enhances the ability to accurately determine and refine accuracy of positions according to embodiments of the present invention. As previously mentioned, an initial estimation on signal strength references may be obtained according to the method disclosed in United Stated patent application Ser. No. 10/635,367 entitled “Location Positioning in Wireless Networks.” Additionally or alternatively, a database providing an initial estimation on signal strength references may be constructed as follows. For example, an indoor wireless channel propagation model may be used to obtain received signal strength references for construction of a radio map according to the following generic log path loss model: P ( d ) = P ( d 0 ) - 10 β lg ⅆ ⅆ 0 ( 10 ) where P(d0) represents the power (in dB scale) received at a reference distance d0 from a radiating transmit antenna and β is the path loss exponent. The values of the parameters P(d0) and β depend on the practical environment and radiation power. Directing attention to FIG. 3, a flow diagram setting forth steps of a preferred embodiment algorithm for construction of a radio map is shown. Step 301 of the embodiment illustrated in FIG. 3 sets up AP information. The variable K denotes the total number of APs in the environment to be mapped. Each AP, denoted as APk with 1≦k≦K, is equipped with a “smart antenna” panel that contains multiple radiation patterns. Each radiation pattern may have different gain profile. These gains are known or may be obtained from the antenna and/or beam forming characteristics of the system. For example, a particular antenna pattern may have a gain table associated therewith which may be provided by the manufacturer or relatively easily determined using well-known formulae in the RF engineering field. The variable Pk denotes the number of radiation patterns associated with the k-th AP. Then, the gain of the p-th (1≦p≦Pk) pattern at angle θ (0°≦0<360°) can be denoted by the variable Gaink[p,θ]. Different APs may be equipped with the same or different antenna panels. AP information also includes the physical location of each AP in the area of interest which may be represented by the x-y coordinate, and the smart antenna panel direction. Step 302 of the embodiment illustrated in FIG. 3 sets up a set of location candidates in the environment of interest. For example, an imaginary grid may be established to demarcate a number of positions within the environment, or a portion thereof, which provide a desired level of resolution with respect to location estimation. Each position demarcated by the grid may be regarded as a location candidate. The set {wj,j=1, 2, . . . , c} denotes a collection of candidate points in the environment of interest. The physical location of each element wj may be represented by x-y coordinate. Step 303 of the embodiment illustrated in FIG. 3 calculates the received signal strength reference. Assuming that there is an imaginary remote station transmitting from each location candidate wj, the received signal strength reference experienced by each antenna pattern of the multiple antenna patterns of an AP may be predicted according to the channel propagation model previously discussed. Specifically, the variable μj[k,p] denotes the signal strength reference at the p-th antenna pattern of the k-th AP from the j-th location candidate. The variable μj[k,p] can be calculated according to the following equation: μ j [ k , p ] = P ( d 0 ) - β lg ⅆ ( w i , AP k ) ⅆ 0 + Gain k [ p , θ ( w i , AP k ) ] , ( 11 ) where d(wi, APk) denotes the geometrical distance between the j-th point, wi, and the k-th AP, APk, and θ (wi, APk) is the angle between wi and APk with respect to the antenna panel direction of APk. Typically, in an embodiment of the present invention, P(d0) can be calculated, given the transmission power, using the Friis free space equation. In some environments, however, P(d0) may also be obtained empirically. For example, P(d0=1.7 m)=−36 dBm in a semi-open environment using a Lucent Orinoco WLAN Card. The path loss exponent β=3 in an office environment with typical cubicles. Equation (11) may be repeated until μi[k,p] has been computed for all k, p and j, thereby constructing a radio map using a generic propagation model together with multiple antenna radiation patterns. Steps of the embodiment illustrated in FIG. 3 are preferably performed when a network is initially deployed and/or when its configuration is changed. For example, the AP information may be modified when APs are added or removed from the network, when the location of an AP is changed, when the antenna pattern configuration of an AP is changed, and the like. A refining process implemented according to an embodiment of the present invention may be used to increase the accuracy of the radio map constructed as discussed in reference to the embodiment of the present invention illustrated in FIG. 4. Directing attention to FIG. 4, a flow diagram setting forth steps of a preferred embodiment algorithm for iteratively refining a radio map for location determination is shown. The system contains input data including an original radio map (database of received signal strength references), a set of prior probabilities of location candidates, and a set of online RSSI observations from multiple client users with known or unknown locations. The original radio map may be generated by manual measurements to be improved by unsupervised learning or by predictions to be refined to more accurate values by unsupervised learning. Step 401 of the embodiment illustrated in FIG. 4 sets up the location-conditional probability density function of a received signal strength. The variable x denotes a random vector of received signal strength observed from all the APs in the network with each AP containing multiple antenna patterns. The variable x[k,p] denotes the random variable of signal strength (in dB scale) from the k-th AP (1≦k≦K) at the p-th pattern (1≦p≦Pk). Each x[k,p] is assumed to be independent and have a Gaussian distribution with the same standard deviation a. The value of the parameter a depends on the standard deviation of the log normal shadowing in the environment of interest, and could be obtained empirically. For example, it may be assumed that σ=approximately 3˜5 dBm. Thus, the conditional probability of x given location candidate wi, 1≦j≦c, can be expressed according to the following equation: p ( x ❘ w j , θ j ) = c · exp { - 1 2 σ 2 ∑ k = 1 K ∑ p = 1 P k ( x [ k , p ] - μ j [ k , p ] ) 2 } , ( 12 ) where c is a constant for normalization, and μj is averaged signal strength, i.e. received signal strength reference. Step 402 of the embodiment illustrated in FIG. 4 iteratively updates the received signal strength reference. {μ1, μ2, . . . , μc}. The initial {circumflex over (μ)}j(0) may be predicted according to equation (11), measured through offline calibration, or obtained by other means. The initial prior probability {circumflex over (P)}0(wj) of each location candidate may be obtained assuming a uniform distribution, i.e. {circumflex over (P)}0(wj)=1/c for all j=1, 2, . . . c, or may be extracted from a given user density profile in the environment of interest. The variable D={x1, x2, . . . , Xn} denotes the set of RSSI observations available online, and n denotes the total number of observations. The initial weighting coefficient P(wj|xk, μ) for the k-th observation xk at location candidate wj is computed using equation (7). Accordingly, μj is re-computed using the n weighting coefficients according to equation (8) and P(wj) is updated according to equation (9). The iterative process of computing n weighting coefficients and computing μj and P(wj) may be repeated until there is no more change or very little change, for example, a change=0.1%, on the μj and P(wj) for all j. It should be appreciated that the algorithm described in Step 402 of the embodiment illustrated in FIG. 4 may vary significantly according to embodiments of the invention. For example, if the set of RSSI observations are known to be evenly distributed from location candidates, the update on the prior probabilities P(wj) in each iteration may alternatively be eliminated. In addition, the coverage area of APs in the network may not completely overlap. Therefore, RSSI vectors from particular locations may include null coordinates, that is, there is no observation on these coordinates which correspond to some APs or some antenna patterns of one AP. In such a case, the null coordinates of these incomplete RSSI vectors may be manually set to have a value smaller than the lowest RSSI level that a wireless LAN card can detect. For example, the null coordinates may have −100 dBm associated therewith. This approach eventually converges to set the values on the corresponding coordinates of the received signal strength reference vectors at the particular location candidates to be small so as to be undetectable by a wireless LAN card. Alternatively, when the received signal strength reference μj at location wj is being re-computed during each iteration, the null coordinates of incomplete online RSSI observation vectors may be set to contain the same values as those in the same coordinates of the vector μj during the previous iteration. This approach converges to allow the values on the corresponding coordinates of the received signal strength reference vectors at the particular location candidates to be unchanged and the same as the original. The original value may be null if obtained through offline calibration, or may be a very small value if predicted based on an accurate propagation model. Step 403 of the embodiment illustrated in FIG. 4 refines the radio map. The updated values of μj for j=1, . . . , c are returned as the new, updated signal strength references in the radio map. The enhanced algorithm of the present invention is most effective when the total number of RSSI observations is much larger then number of the candidate points in the environment, i.e. where n>>c. Steps of the embodiment illustrated in FIG. 4 are preferably performed when a sufficient number of online RSSI observations have been collected after a network is deployed, its configuration is modified, or the environment is changed. The online RSSI data may be observed through normal traffic. For example, new mobile clients may join the network from time to time at a random location within the service area of the network, and existing mobile clients may move from one location to another in the service area of the network. Without introducing any overhead in the network, sufficient RSSI data from mobile clients may be automatically collected on each AP using multiple antenna patterns through the normal traffic. The radio-map refining algorithm in FIG. 4 may be implemented by a processor-based system operable under the control of a set of instructions defining operations as described herein. For example, a computer system having a central processing unit, such as a processor from the Intel PENTIUM family of processors, memory, such as RAM, ROM, and/or disk storage, and suitable input/output capabilities may be utilized in implementing the steps shown in FIG. 4. Such a processor-based system may be comprised of one or more of APs 101-103 and/or processor-based system 150 shown in FIG. 1. The updated radio map may be stored in the memory of the processor-based system as a database. An online location determination phase may run concurrently with the previously discussed iterative process, above, although location estimates will be more accurate after many iterations of the previously discussed process. In determining the location of a remote station within the service area of the network, one or more APs will use multiple antenna patterns to collect information with respect to the received signal strength of the target remote station. This information is preferably sent to a processor-based system and compared to the received signal strength reference stored in the database on various techniques. For example, the distance approach disclosed in U.S. patent application Ser. No. 10/635,367 entitled “Location Positioning in Wireless Networks,” may be employed. In one embodiment of the present invention, k-nearest neighbor weighted averaging and history-based shortest path approaches may be selected for determining the location of a stationary user and a moving user, respectively. Directing attention to FIG. 5, a flow diagram setting forth steps of a preferred embodiment algorithm for k-nearest neighbor weighted averaging to determine the location of a stationary user is shown. The embodiment of the algorithm illustrated in FIG. 5 may run concurrently with the iterative process previously discussed or separately. According to FIG. 5, the system contains input data including the measured RSSI information with respect to the target client on the audible APs with all possible antenna patterns or a plurality of antenna patterns. Embodiments of the present invention may operate to estimate a remote station's position using a single AP due to the use of multiple antenna patterns. Additionally, multiple APs may be utilized to confirm the location estimate and/or to increase the reliability and/or accuracy of such an estimate. As shown in step 501 of the embodiment illustrated in FIG. 5, the difference between the observed RSSI data and the stored signal strength references from the same APs using the same antenna pattern in the radio map may be computed. In one embodiment of the present invention, the difference metric is defined as the Euclidean distance in the signal strength space with dB scale. The variable dj, with j=1, 2, . . . , c, denotes the distance associated with the j-th location candidate Wj. The smaller the distance in the signal space is, the nearer the location candidate would be to the target client in the physical space. As shown in step 502 of the embodiment shown in FIG. 5, k nearest neighboring points are selected and the weighting coefficient of each is computed. Within the location candidate set, k indices {i′, i=1, 2, . . . , k} whose signal strength references are nearest according to distances computed in the previous step to the given RSSI observations are selected. The value of k may be determined by the resolution of location candidates. For example, select k=15 when the spacing between two neighboring points demarcated by an imaginary grid is equal to one meter. The weighting coefficient is defined as the inverse of the distance, i.e. 1/di′. As shown in step 503 of the embodiment shown in FIG. 5, the location of the target client may be estimated as the weighted mean position of the k neighbors. Specifically, the location may be estimated according to the equation (13) w ^ = ∑ i ′ = 1 k 1 d i ′ + d 0 w i ′ ∑ i ′ = 1 k 1 d i ′ + d 0 ( 13 ) where d0 is a small real value used to avoid division by zero. While the algorithm in FIG. 5 contains a weighted average, a technique without using distance-metric-dependent weights may also be employed. In one embodiment of the online location tracking phase for moving clients of the present invention, only one pattern for each antenna panel is used to collect RSSI information due to real-time constraints. As many as 3 APs may be needed, however, based on the well-known triangulation method to estimate a location. By switching the antenna patterns more rapidly, more precise results may be achieved by using multiple patterns as used in the location determination phase. When tracking a target client, embodiments of the present invention employ the current and past RSSI observations from the client to the audible APs. The user's location at any given instant in time is likely to be near the location for the previous instant. By tracking the user continuously, signal strength information is complemented with the physical contiguity constant to continually improve the accuracy of location estimation. Directing attention to FIG. 6, a flow diagram setting forth steps of a preferred embodiment algorithm for determining the location of a mobile user is shown. According to the embodiment shown in FIG. 6, the system contains input data including the current and past RSSI samples from the target client to the audible APs at the default antenna pattern. A history of depth h of RSSI observations from the mobile target is maintained for each location estimation. As shown in step 601 of the embodiment shown in FIG. 6, the static case location determination is employed to determine the individual positioning for each instant of time as discussed previously, except that the distance metric, in the dynamic case, is computed over the selected default antenna pattern. As shown in the embodiment of the algorithm shown in FIG. 6, the dynamic case location determination uses the history data to provide a more accurate location tracking path. For example, by making use of previous location estimates and the station's moving speed, the current location may be predicted and any current erratic estimate based on the current signal power may be cancelled. In the dynamic case with a moving target, it is possible to take the same approach as in the static case and estimate each position independently. Since the target is moving, however, a more accurate location estimation can be achieved, particularly given that the static-case estimate may contain noise, by taking into account the “velocity” or “speed” of the moving target. As shown in step 602 of the embodiment shown in FIG. 6, in the dynamic case, eliminating any estimate exceeding a certain deviation removes noise. This prevents an erratic “jump” over a large distance, due to the generalization that the station's location at any given instant is likely to be near the location at the previous instant in time. As shown in step 603 of the embodiment shown in FIG. 6, in the dynamic case, a shortest path may be estimated using a Viterbi-like algorithm. For example, the 8 nearest neighboring points (in either signal space or physical space) of each estimated individual location for each instant in time, i.e., the 9 best guesses of the station's location for each time instance, may be chosen. Therefore, a history of depth h of such 9 neighbors, according to the earlier example, may be generated. The collected data of the exemplary 9 by h matrix can be viewed as a trellis tree. There are transitions only between columns containing consecutive sets (one set has 9 neighbors, for example). Each transition may be assigned a weight to model the likelihood of the user transitioning in successive instants in time between the locations represented by the two endpoints of the transition path. The larger the weight, the less likely the transition. The Euclidean distance between the two physical locations, calculated according to a simple metric, determines a weight. Each time the trellis tree (the matrix) is updated with the most 9 recent neighbors (and the deletion of the oldest set of neighbors), the shortest path between stages in the oldest and newest sets may be computed. According to embodiments of the present invention, the shortest path represents the most probabilistic movement of the station. Once the shortest path is determined, the station's location may be estimated as the point at the start of the path, as shown in Step 605 of the embodiment shown in FIG. 6. Application of this methodology indicates consideration of the physical contiguity constraint, and also implies a time delay of h signal strength samples. In this example, set h=3. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | <SOH> BACKGROUND OF THE INVENTION <EOH>It is sometimes desirable to locate the position of a station operable within a wireless, e.g., radio frequency (RF), network. For example, the United States Federal Communications Commission (FCC) has decreed that cellular telephone systems must implement systems to provide mobile telephone position information for use in emergency response, e.g., enhanced 911 (E911) emergency response. Additionally, the position of a station may be important for providing particular services, such as, for example, identifying subscribers and non-subscribers, resource allocation, network security, and location-sensitive content delivery, among other services. In order to estimate a station's location, a system typically measures a metric that is a function of distance. A typical measured metric is signal strength, which decays logarithmically with distance in free space. Time information, such as time of arrival of a signal or time difference of arrival of a signal at diverse antennas, may be utilized as a measured metric from which distance information may be determined. Typically, several reference points are used with distance information derived from the measured metric in estimating location. The use of global positioning system (GPS) receivers, which operate in conjunction with a network of middle earth orbit satellites orbiting the Earth to determine the receiver's position, has almost become ubiquitous in navigational applications. In such a GPS network, the aforementioned reference points are the satellites and the measured metric is the time of arrival of the satellite signal to the GPS receiver. The time of arrival of the satellite signal is typically directly proportional to the distance between the satellite and the GPS receiver due to a clear line of sight between the GPS receiver and satellite. By measuring the time of arrival associated with three satellites, a GPS receiver can calculate the longitude and latitude of the GPS receiver. By using time of arrival information with respect to a fourth satellite, a GPS receiver can also determine altitude. In the aforementioned cellular networks, techniques including signal strength measurements and/or time difference of arrival have been implemented for location determination. For example, U.S. Pat. No. 6,195,556, the disclosure of which is incorporated herein by reference, teaches the use of signal strength measurements in combination with the time difference of arrival of a station's signal in determining the location of the station. Additionally, U.S. Pat. No. 6,195,556 teaches the use of mapping of received signal characteristics associated with particular positions (e.g., receive “signature” associated with each of a plurality of remote station locations) for use in determining a station's location. In the case of the aforementioned cellular network, the base transceiver stations (BTSs) are generally relied upon as the reference points from which distance determinations are made. Wireless local area network (WLAN) location determination systems have been implemented in two phases: the offline phase and the online phase. In the offline phase, prediction or measurement of the fingerprint (e.g., signal strength, multipath characteristics, etcetera) of wireless access points at particular locations within the service area may be carried out. Location fingerprints may be predicted or measured off-line, such as when a network is being deployed, and are stored in a database resulting in a so-called radio map to relate the wireless signal information and coordinates of the known locations. In the online phase, the fingerprint associated with a remote station at an unknown location is measured during later operation of the network, and compared to the entries in the database. A location estimation algorithm is then applied to infer the location estimate for the unknown location. Location estimation algorithms include, for example but not limited to, triangulation, nearest neighborhood, K-nearest neighbor averaging, and history-based shortest path. Previously, developing an accurate radio map for location determination required manual calibration throughout the network environment, meaning that before a location determination could be made, an engineer would actually have to physically go out and make calibration measurements at some specified points over the area covered by the network. Based on the manual measurements, the system would construct the radio map, and then make a location determination. This is known as supervised calibration or supervised training. Making manual calibration measurements is expensive and consumes significant manpower. Furthermore, because the wireless environment is constantly changing, the measured parameters are also changing, and repeating calibration to update the measurements is impractical and inefficient. Supervised training, requiring manual calibration, provides relatively accurate resolution, but over time, the accuracy fails as the networks parameters change. It is, therefore, desirable to eliminate the need for making costly and time consuming manual measurements. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention is directed to systems and methods which monitor a network environment, collect client information available online, and refine location determinations of individual clients based on observed information as well as online information. More particularly, embodiments of the present invention comprise to systems and methods which monitor the wireless network, such as by collecting online receive signal strength indicator (RSSI) information observations from client users, to provide location determinations without requiring knowledge of those clients' precise locations. Embodiments of the present invention are additionally directed to systems and methods to enhance the accuracy of the location determinations in a network, based on observed client information such as, for example, signal strength references. In one embodiment of the present invention, the method employs online received signal strength observations from multiple clients, with known or unknown locations, together with the original observed or estimated signal strength database to refine a radio map of the network environment. Online RSSI observations from client users may be compared with the original observed or estimated signal strength database and the radio map may be refined based on unsupervised training capabilities. Unsupervised system training according to embodiments of the present invention reduces or eliminates the need for live calibration of the network, and instead, existing measurements online can be used to calibrate and fine tune the radio map of the network environment. Additionally, according to embodiments of the present invention, collected RSSI information may be obtained from the normal network transmissions and therefore, does not require any extra overhead to obtain and use the information in location determination. It is an object of embodiments of the present invention to create an original radio map of mobile station location without requiring manual calibration, by comparing online observations with a generic model estimation and following iterations through until the radio map is within a certain degree of accuracy. It is a further object of embodiments of the present invention to update an existing radio map of mobile station location created by supervised training, without manually re-measuring network parameters to update calibrations. It is a yet another object of embodiments of the present invention to use unsupervised training to update an existing radio map of mobile station location that was created by supervised training without expending additional money and manpower. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized that such equivalent constructions do not depart from the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. | 20040430 | 20080415 | 20051103 | 58694.0 | 2 | EWART, JAMES D | LOCATION DETERMINATION AND LOCATION TRACKING IN WIRELESS NETWORKS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,463 | ACCEPTED | Displaying least significant color image bit-planes in less than all image sub-frame locations | A color image is produced from image data. Color image bit-planes are generated from the image data. Each color image bit-plane represents a time increment for displaying one color of a plurality of colors for each pixel of the color image. For each of the colors, color patterns are displayed in a plurality of image sub-frame locations. The color patterns represent the color image bit-planes. At least the least significant color image bit-planes are displayed in less than all of the image sub-frame locations. | 1. A method for producing a color image from image data, the color image having pixels, the method comprising: generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, a smallest time increment for each color represented by a least significant color image bit-plane; displaying in at least one of a plurality of image sub-frame locations, for each of the plurality of colors, color patterns representing the color image bit-planes; and displaying, for at least one of the colors, at least the least significant color image bit-planes in less than all of the image sub-frame locations. 2. The method of claim 1 wherein the image data includes color values for image frame locations and wherein generating color image bit-planes comprises: generating image sub-frame color values from the color values for the image frame locations; calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes. 3. The method of claim 2 wherein compensating for differences in color comprises: recreating, from the calculated color image bit-planes, image frame color values for the image frame locations; computing a color error map by comparing the recreated color values to the color values from the image data; computing correction factors to offset the error map; and distributing the correction factors to image sub-frame locations. 4. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying at least the least significant color image bit-planes in a single image sub-frame location. 5. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying, for each color, all the bit-planes in a single image sub-frame location. 6. The method of claim 1 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises defining less than the full color depth of at least one of the colors in at least one of the plurality of image sub-frame locations. 7. A display system for producing a color image from image data, the color image having pixels, the display system comprising: a sub-frame generation module configured to generate, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames; a spatial light modulator configured to modulate light beams to generate each of the image sub-frames; a color light source configured to generate light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and a periodic wobbling device configured to provide a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame locations, the image sub-frames. 8. The display system of claim 7 wherein the image data includes color values for image frame locations and wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to: generate image sub-frame color values from the color values for the image frame locations; calculate color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and compensate, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes. 9. The display system of claim 8 wherein the sub-frame generation module configured to compensate for differences in color comprises the sub-frame generation module configured to: recreate, from the calculated color image bit-planes, image frame color values for the image frame locations; compute a color error map by comparing the recreated color values to the color values from the image data; compute correction factors to offset the error map; and distribute the correction factors to image sub-frame locations. 10. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame. 11. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame. 12. The display system of claim 7 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames. 13. A display system for producing a color image from image data, the color image having pixels, the display system comprising: means for generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames; means for modulating light beams to generate each of the image sub-frames; means for generating light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and means for providing a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame locations, the image sub-frames. 14. The display system of claim 13 wherein the image data includes color values for image frame locations and wherein the means for generating color image bit-planes comprises: means for generating image sub-frame color values from the color values for the image frame locations; means for calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and means for compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame locations and the color image bit planes. 15. The display system of claim 14 wherein the means for compensating comprises: means for compensating recreating, from the calculated color image bit-planes, image frame color values for the image frame locations; means for computing a color error map by comparing the recreated color values to the color values from the image data; means for computing correction factors to offset the error map; and means for distributing the correction factors to image sub-frame locations. 16. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame. 17. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame. 18. The display system of claim 13 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames. 19. A method for producing a color image from image data, the color image having pixels, the method comprising: generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, a smallest time increment for each color represented by a least significant color image bit-plane; displaying in at least one of a plurality of image sub-frame periods, for each of the plurality of colors, color patterns representing the color image bit-planes; and displaying, for at least one of the colors, at least the least significant color image bit-planes in less than all of the image sub-frame periods. 20. The method of claim 19 wherein the image data includes color values for image frame periods and wherein generating color image bit-planes comprises: generating image sub-frame color values from the color values for the image frame periods; calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes. 21. The method of claim 20 wherein compensating for differences in color comprises: recreating, from the calculated color image bit-planes, image frame color values for the image frame periods; computing a color error map by comparing the recreated color values to the color values from the image data; computing correction factors to offset the error map; and distributing the correction factors to image sub-frame periods. 22. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises displaying at least the least significant color image bit-planes in a single image sub-frame period. 23. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises displaying, for each color, all the bit-planes in a single image sub-frame period. 24. The method of claim 19 wherein displaying at least the least significant color image bit-planes in less than all of the image sub-frame periods comprises defining less than the full color depth of at least one of the colors in at least one of the plurality of image sub-frame periods. 25. A display system for producing a color image from image data, the color image having pixels, the display system comprising: a sub-frame generation module configured to generate, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames; a spatial light modulator configured to modulate light beams to generate each of the image sub-frames; a color light source configured to generate light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and a periodic wobbling device configured to provide a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame periods, the image sub-frames. 26. The display system of claim 25 wherein the image data includes color values for image frame periods and wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to: generate image sub-frame color values from the color values for the image frame periods; calculate color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and compensate, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes. 27. The display system of claim 26 wherein the sub-frame generation module configured to compensate for differences in color comprises the sub-frame generation module configured to: recreate, from the calculated color image bit-planes, image frame color values for the image frame periods; compute a color error map by comparing the recreated color values to the color values from the image data; compute correction factors to offset the error map; and distribute the correction factors to image sub-frame periods. 28. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame. 29. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame. 30. The display system of claim 25 wherein the sub-frame generation module configured to generate color image bit-planes comprises the sub-frame generation module configured to generate color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames. 31. A display system for producing a color image from image data, the color image having pixels, the display system comprising: means for generating, from the image data, color image bit-planes, each color image bit-plane representing a time increment for displaying one color of a plurality of colors for each pixel of the color image, the smallest time increment for each color represented by a least significant color image bit-plane, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane unequally distributed between the image sub-frames; means for modulating light beams to generate each of the image sub-frames; means for generating light beams in each of the plurality of colors, the color light source disposed to pass the light beams across the spatial light modulator; and means for providing a relative displacement to the image sub-frames for displaying, in a plurality of image sub-frame periods, the image sub-frames. 32. The display system of claim 31 wherein the image data includes color values for image frame periods and wherein the means for generating color image bit-planes comprises: means for generating image sub-frame color values from the color values for the image frame periods; means for calculating color image bit-planes, exclusive of at least the least significant color image bit-plane, from the image sub-frame color values; and means for compensating, with the excluded bit-planes, for differences in color represented by the color values for the image frame periods and the color image bit planes. 33. The display system of claim 32 wherein the means for compensating comprises: means for compensating recreating, from the calculated color image bit-planes, image frame color values for the image frame periods; means for computing a color error map by comparing the recreated color values to the color values from the image data; means for computing correction factors to offset the error map; and means for distributing the correction factors to image sub-frame periods. 34. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for at least one of the colors, at least the least significant color image bit-plane distributed into a single image sub-frame. 35. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, for each color, all the bit-planes distributed into a single sub-frame. 36. The display system of claim 31 wherein the means for generating color image bit-planes comprises means for generating color image bit-planes, the color image bit-planes defining image sub-frames with, less than the full color depth of at least one of the colors defined in at least one of the image sub-frames. | BACKGROUND Sequential display systems produce color image frames by generating a plurality of colors of light in sequence, spatially modulating the colors of light and projecting the spatially modulated colors of light to form the image frames. The colors of light are typically derived from a white light source passed through a color filter wheel, prism, or some other color filter. In order to remain competitive with alternative technologies, there is a continual need for the sequential display systems to improve image quality factors such as the resolution of the image frames. Issues with enhancing resolution can include an impact on system cost or color depth. DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating one embodiment of the present invention display system. FIGS. 2-5 are examples of color filter wheels used with the display system of FIG. 1. FIG. 6 illustrates an exemplary timing diagram for the color filter wheels shown in FIGS. 3-5. FIGS. 7A-C illustrate alternate exemplary timing diagrams for the color filter wheels shown in FIGS. 3-5. FIG. 8 illustrates one example of relative timing of bit-planes for the timing diagram of FIG. 6. FIG. 9 is a block diagram illustrating the display system of FIG. 1, showing one embodiment of the image processing unit in more detail. FIGS. 10A-C illustrate that a number of image sub-frames may be generated for a particular image according to one exemplary embodiment. FIGS. 11A-B illustrate displaying a pixel from the first sub-frame in a first image sub-frame location and displaying a pixel from the second sub-frame in the second image sub-frame location according to one exemplary embodiment. FIGS. 12A-D illustrate that the sub-frame generation function may define four image sub-frames for an image frame according to one exemplary embodiment. FIGS. 13A-D illustrate displaying a pixel from the first sub-frame in a first image sub-frame location, displaying a pixel from the second sub-frame in a second image sub-frame location, displaying a pixel from the third sub-frame in a third image sub-frame location, and displaying a pixel from the fourth sub-frame in a fourth image sub-frame location according to one exemplary embodiment. FIGS. 14A-C illustrate one embodiment of color image bit-planes unequally distributed between image sub-frames. FIG. 15 illustrates, for each color, all the bit-planes displayed in a single image sub-frame location. FIG. 16 is a flow chart illustrating one embodiment of the present invention method for creating color image sub-frames. FIG. 17 is a flow chart illustrating one embodiment of generating a plurality of color image bit-planes. FIG. 18 is a flow chart illustrating one embodiment of compensating for differences in color represented by color values. DETAILED DESCRIPTION OF THE INVENTION Illustrated in FIG. 1 is one embodiment of a display system 2 of the present invention. The term “display system” is used herein and in the appended claims, unless otherwise specifically denoted, to refer to a projector, projection system, image display system, television system, video monitor, computer monitor system, or any other system configured to create a sequence of image frames. The sequence of image frames produces an image that may be a still image, a series of images, or motion picture video. The phrase “sequence of image frames” and the term “image” are used herein and in the appended claims, unless otherwise specifically denoted, to refer broadly to a still image, series of images, motion picture video, or anything else that is displayed by a display system. In the embodiment illustrated in FIG. 1, display system 2 includes image processing unit 4, color light source 6, spatial light modulator (SLM) 8, wobbling device 10, and display optics 12. Display system 2 receives image data 14. In one embodiment, image data 14 is embodied in a data array. Image data 14 defines image 16 to be displayed and display system 2 uses image data 14 to produce displayed image 16. Examples of image data 14 include digital image data, analog image data, and a combination of analog and digital data. While one image 16 is illustrated and described as being processed by display system 2, it will be understood by one skilled in the art that a plurality or series of images 16, or motion picture video display 16, may be processed by display system 2. Color light source 6 is any apparatus or system configured to generate a plurality of colors of light having a color sequence that periodically varies with a characteristic sequential color time period. Color light source 6 is disposed within display device 2 to pass the plurality of colors of light across SLM 8. In one embodiment, color light source 6 includes light source 18 and sequential color device 20. In an alternative embodiment, color light source 6 may include solid state light sources such lasers or light emitting diodes (LEDs) that generate a sequential color signal. In an illustrative example of the alternative embodiment, the LEDs may comprise red, green, and blue LEDs that are activated in sequence (e.g., first red, then green, and finally blue) to provide the color sequence. In one embodiment, color light source 6 generates a light beam carrying a sequence of primary colors and optionally white light. Stated another way, color light source 6 outputs a beam having a spectral distribution that changes with time in a periodic manner. For example, color light source 6 may generate a beam that varies between primary colors red, green, and blue as well as white. Color light source 6 may additionally or alternatively output colors such as cyan, yellow, and magenta or any other color. Reference to a light beam of a particular color indicates that the spectral distribution of the light beam has a peak wavelength that can be characterized as visible light of that color. Color filter elements may be used in some embodiments to alter a white light source to provide such a spectral peak. Light source 18 is any source of light suitable for use in a projector or display device. One example of such a suitable light source 18 is an ultra high-pressure mercury lamp. As shown in FIG. 1, light source 18 provides a beam of light to sequential color device 20. Sequential color device 20 is any apparatus or system configured to sequentially modulate light from light source 18 into a plurality of colors or wavelengths. In one embodiment, a color time period set point may be set to control the color time period of sequential color device 20. Examples of sequential color devices 20 include a color filter wheel 22 (FIGS. 2-5) and a set of rotating prisms. FIGS. 2-5 illustrate several examples of color filter wheels 22. Each color filter wheel 22 includes a plurality of color filters 24. Each color of color filter wheel 22 is a color filter element 24. In the figures, R, G, B, and W refer to red, green, blue, and white color filter elements 24. Color filter wheels 22 operate by rotating to sequentially allow only selected colors or wavelengths of light to pass through each color filter element 24. Although illustrated as having equally sized color filter elements 24 for each color, it is not uncommon for color filter elements 24 to be differently sized. Often the relative sizing of color filter elements 24 is used to accommodate an unbalanced light source 18. For example if light source 18 is red deficient, the red color filter element 24 may be relatively larger than the other color filter elements 24. FIGS. 6 and 7A illustrate the relationship between frame period T and the rotation of a color filter wheel 22. In these figures, R, G, and B, refer to red, green, and blue color sub-frames. Alternatively, as FIGS. 6 and 7A relate to the color filter wheel 22 shown in FIG. 5, R, G, and B refer to red/white, green/white, and blue/white combinations. Although illustrated with the color filter wheels 22 shown in FIGS. 3-5, the graphs shown in FIGS. 6 and 7A could be modified for the color filter wheel shown in FIG. 2 by adding a W after each B within each image sub-frame. The time during which each frame is being output is frame period T. A spatial or image sub-frame period is a portion of frame period T during which each spatial or image sub-frame is being output. A color sub-frame is a portion of frame period T during which the color light source is outputting a particular color or primary color. Frame period T is any suitable frame period T. An example frame period T is about 1/60th of a second. As depicted by FIGS. 6 and 7A a complete set of color sub-frames are generated at least once for each spatial or image sub-frame. Stated another way, color light source 6 generates a complete set of primary colors at least once during a single spatial or image sub-frame. FIG. 6 shows one example of the relationship between frame period T and the rotation of the color filter wheels 22 depicted in FIGS. 3-5. In this example, there are four image sub-frames and the color filter wheel 22 spins with a period equal to one fourth of frame period T, for the color filter wheels 22 of FIGS. 3 and 4, and one half of frame period T, for the color filter wheel 22 of FIG. 5. For example, with frame period T equal to 1/60th of a second, the color filter wheels 22 of FIGS. 3 and 4 spin at 14400 RPM, four complete revolutions during frame period T. The color filter wheel 22 of FIG. 5 spins with a period equal to one half of frame period T but since the color filter wheel 22 of FIG. 5 is an RGBRGB wheel, the effect is the same as the color filter wheel 22 of FIG. 3 spinning twice as fast. At the same frame period T of 1/60th of a second, the color filter wheel 22 of FIG. 5 rotates at 7200 RPM. FIG. 7A shows another example of the relationship between frame period T and the rotation of the color filter wheels 22 depicted in FIGS. 3-5. In this example, there are three image sub-frames and the color filter wheel 22 spins with a period equal to one third of frame period T, for the color filter wheels 22 of FIGS. 3 and 4, and two thirds of frame period T, for the color filter wheel 22 of FIG. 5. A timing diagram for an alternative system is depicted in FIG. 7B. This depicts the relationship between frame period T and the color wheel depicted in FIG. 4 in the event that primary color sub-frames coincide with image sub-frames. In this embodiment, the white component of the color is generated during all three image sub-frames. On the other hand, the remaining red, green, and blue color sub-frames are each distributed into a separate image sub-frame. This lengthens the sub-frame time period for generating 8 bit color for each of the primary colors. In yet another embodiment, the timing diagram of FIG. 7C can be used with the color wheel depicted with respect to FIG. 3. Again, each image sub-frame contains all the bit planes for one primary color. For the embodiments depicted in FIGS. 7B and 7C, the projection system displays the primary color sub-frames displaced with respect to each other. Another aspect of this embodiment is that the color sub-frames coincide with shifted image sub-frames. During the first image sub-frame, the projector system generates pixels of a first primary color such as red at a first array of locations. During the second image sub-frame, the projector system generates pixels of a second primary color such as green at a second array of locations. Finally, during the third image sub-frame, the projector system generates pixels of a third primary color such as blue at a third array of locations. FIG. 8 shows one example of the relative timing relationship between color image bit-planes B0-B7. A color image bit-plane is a time increment for displaying one color for each pixel of a color image. The color image is an entire image or a region of a larger image. Each color image bit-plane B0-B7 represents a time increment for displaying one color of the color filter wheel 22 for each pixel of a color image. With a three color, color filter wheel 22 and four image sub-frames, the total time for each color is one twelfth of the frame period T. Each color sub-frame is defined by the color image bit-planes for that color. Together, all of the color image bit-planes define the image sub-frames. The smallest time increment for each color is represented by a least significant color image bit-plane B0. The largest time increment for each color is represented by a most significant color image bit-plane B7. In the illustrated example, most significant color image bit-plane B7 represents a little over one half of the total time for a color. Each successively smaller color image bit-plane represents one half of the next larger color bit-plane and least significant color image bit-plane B0 represents about 1/255th of the total time for each color. Referring again to FIG. 1, SLM 8 is any apparatus or system configured to modulate light to provide a plurality of image sub-frames for each of the image frames during frame period T. SLM 8 modulates incident light in a spatial pattern corresponding to an electrical or optical input. The incident light may be modulated in its phase, intensity, polarization, or direction by SLM 8. SLM 8 is disposed to spatially modulate light from color light source 6. Light transmitted by color light source 6 is passed onto SLM 8. In one embodiment, the light is focused onto SLM 8 through a lens or through some other device. SLM 8 modulates the light output by color light source 6 based on input from image processing unit 4 to form an image-bearing beam of light. Examples of an SLM 8 are a liquid crystal on silicon (LCOS) array and a micro-mirror array. LCOS and micro-mirror arrays are known in the art and will not be explained in detail in the present specification. One example of an LCOS array is the Philips™ LCOS modulator. One example of a micro-mirror array is the Digital Light Processing (DLP) chip available from Texas Instruments™ Inc. In one embodiment, the modulated light from SLM 8 is eventually displayed by display optics 12 on a viewing surface (not shown). Display optics 12 are any device or system configured to display or project an image. Display optics 12 provide focusing and other optical adjustments, where necessary, for the display of display image 16 by display system 2. One example of display optics 12 includes a lens configured to project and focus displayed image 16 onto a viewing surface. Examples of the viewing surface include a screen, television, wall, or computer monitor. Alternatively, display optics 12 may include a viewing surface onto which displayed image 16 is projected. Periodic wobbling device 10 is any apparatus or system configured to provide a relative displacement of the image sub-frames for each image frame. In one embodiment, before display optics 12 display displayed image 16, the modulated light is passed through wobbling device 10. One example of a wobbling device 10 is a galvanometer mirror. In alternate embodiments, the functionality of the wobbling device 10 is integrated into SLM 8 or some other component of display system 2. Image processing unit 4 performs various functions including controlling the illumination of light source 18 and controlling SLM 8. Image processing unit 4 may be configured to receive and process digital image data, analog image data, or a combination of analog and digital data. In one embodiment, as illustrated in FIG. 9, image processing unit 4 includes frame rate conversion unit 26, resolution adjustment unit 28, sub-frame generation module 30, frame buffer 32, and system timing unit 34. Frame rate conversion unit 26 and image frame buffer 32 receive and buffer image data 14 to create an image frame corresponding to image data 14. Resolution adjustment unit 28 adjusts the resolution of the frame to match the resolution capability of display system 2. Sub-frame generation module 30 processes the image frame data to define two or more image sub-frames corresponding to the image frame. The image sub-frames are displayed by display system 2 to produce displayed image 16. System timing unit 34 synchronizes the timing of the various components of display system 2. Image processing unit 4, including frame rate conversion unit 26, resolution adjustment unit 28, sub-frame generation module 30, and system timing unit 34, include hardware, executable code, or a combination of these. In one embodiment, one or more components of image processing unit 4 are included in a computer, computer server, or other microprocessor-based system capable of performing a sequence of logic operations. In addition, the image processing may be distributed throughout display system 2 with individual portions of image processing unit 4 being implemented in separate system components. Frame rate conversion unit 26 receives image data 14 corresponding to an image that is to be displayed by display system 2 and buffers or stores image data 14 in image frame buffer 32. More specifically, frame rate conversion unit 26 receives image data 14 representing individual lines or fields of the image and buffers image data 14 in image frame buffer 32 to create an image frame that corresponds to the image that is to be displayed by display system 2. Image frame buffer 32 may buffer image data 14 by receiving and storing all of image data 14 corresponding to the image frame. Frame rate conversion unit 26 may generate the image frame by subsequently retrieving or extracting all of image data 14 for the image frame from image frame buffer 32. As such, the image frame is defined to comprise a plurality of individual lines or fields of image data 14 representing an entirety of the image that is to be displayed by display system 2. Thus, the image frame includes a plurality of columns and a plurality of rows of individual pixels representing the image 16 that is to be displayed by display system 2. Frame rate conversion unit 26 and image frame buffer 32 can receive and process image data 14 as progressive image data, interlaced image data, or both progressive image data and interlaced image data. With progressive image data, frame rate conversion unit 26 and image frame buffer 32 receive and store sequential fields of image data 14 for the image. Frame rate conversion unit 26 creates the image frame by retrieving the sequential fields of image data 14 for the image. With interlaced image data, frame rate conversion unit 26 and image frame buffer 32 receive and store the odd fields and the even fields of image data 14 for the image. For example, all of the odd fields of image data 14 are received and stored and all of the even fields of image data 14 are received and stored. As such, frame rate conversion unit 26 de-interlaces image data 14 and creates the image frame by retrieving the odd and even fields of image data 14 for the image. Image frame buffer 32 includes memory for storing image data 14 for one or more image frames of respective images. For example, image frame buffer 32 may comprise non-volatile memory such as a hard disk drive or other persistent storage device or include volatile memory such as random access memory (RAM). By receiving image data 14 at frame rate conversion unit 26 and buffering image data 14 in image frame buffer 32, the input timing of image data 14 can be decoupled from timing requirements of the remaining components in display system 2 (e.g.; SLM 8, wobbling device 10, and display optics 12). More specifically, since image data 14 for the image frame is received and stored by image frame buffer 32, image data 14 may be received at any input rate. As such, the frame rate of the image frame may be converted to the timing requirement of the remaining components in display system 2. For example, image data 14 may be received by image processing unit 4 at a rate of 30 frames per second while SLM 8 may be configured to operate at 60 frames per second. In this case, frame rate conversion unit 26 converts the frame rate from 30 frames per second to 60 frames per second. Resolution adjustment unit 28 receives image data 14 for an image frame and adjusts a resolution of image data 14. More specifically, image processing unit 4 receives image data 14 for the image frame at an original resolution and processes image data 14 to match the resolution that display system 2 is configured to display. Image processing unit 4 increases, decreases, or leaves unaltered the resolution of image data 14 to match the resolution that display system 2 is configured to display. In one embodiment, sub-frame generation module 30 receives and processes image data 14 for an image frame and defines a number of image sub-frames corresponding to the image frame. If the resolution adjustment unit 28 has adjusted the resolution of image data 14, the sub-frame generation module 30 receives image data 14 at the adjusted resolution. Each of the image sub-frames comprises a data array or matrix that represents a subset of image data 14 corresponding to the image that is to be displayed. The data arrays comprise pixel data defining the content of pixels in a pixel area equal to the pixel area of the corresponding image frame. Because, each image sub-frame is displayed in spatially different image sub-frame locations, each of the image sub-frames' data arrays comprise slightly different pixel data. In one embodiment, image processing unit 4 may only generate image sub-frames corresponding to an image that is to be displayed as opposed to generating both an image frame and corresponding image sub-frames. As mentioned, each image sub-frame in a group of image sub-frames corresponding to an image frame comprises a matrix or array of pixel data corresponding to an image to be displayed. In one embodiment, each image sub-frame is input to SLM 8. SLM 8 modulates a light beam in accordance with the sub-frames and generates a light beam bearing the sub-frames. The light beam bearing the individual image sub-frames is eventually displayed by display optics 12 to create a displayed image. However, after light corresponding to each image sub-frame in a group of sub-frames is modulated by SLM 8 and before each image sub-frame is displayed by display optics 12, wobbling device 10 shifts the position of the light path between SLM 8 and display optics 12. In other words, the wobbling device shifts the pixels such that each image sub-frame is displayed by display optics 12 in a slightly different spatial position than the previously displayed image sub-frame. Thus, because the image sub-frames corresponding to a given image are spatially offset from one another, each image sub-frame includes different pixels or portions of pixels. Wobbling device 10 may shift the pixels such that the image sub-frames are offset from each other by a vertical distance, a horizontal distance, or both a vertical distance and a horizontal distance. In one embodiment, each of the image sub-frames in a group of sub-frames corresponding to an image is displayed by display optics 12 at a high rate such that the human eye cannot detect the rapid succession between the image sub-frames. The rapid succession of the image sub-frames appears as a single displayed image. By sequentially displaying the image sub-frames in spatially different positions, the apparent resolution of the finally displayed image is enhanced. In one embodiment, such as for the timing diagrams depicted with respect to FIGS. 6 or 7A, each image sub-frame is an RGB (red, green, and blue) color image sub-frame having with data shifted to be consistent with a particular position defined by the wobbling device 10. In this embodiment, one or more of the less significant color bit planes are distributed to less than all of the image sub-frames to minimize the color error for either each frame or groups of frames. In another embodiment, such as for the timing diagrams depicted with respect to FIG. 7B or 7C, each image sub-frame is generated for a single primary color and optionally white. The data for each primary color is shifted to be consistent with a particular position defined by the wobbling device 10. In this embodiment, all color bit planes (not just the least significant ones) for each primary color are displayed in only one image sub-frame. FIGS. 10-13 illustrate an exemplary spatial displacement of image sub-frames by an exemplary wobbling device. Sequential color is combined with the spatial displacement of the image sub-frames to produce a displayed color image. FIGS. 10A-C illustrate an exemplary embodiment wherein a number of image sub-frames are generated for a particular image. As illustrated in FIGS. 10A-C, the exemplary image processing unit 4 generates two image sub-frames for a particular image. More specifically, image processing unit 4 generates first sub-frame 36 and second sub-frame 38 for the image frame. Although the image sub-frames in this example and in subsequent examples are generated by image processing unit 4, it will be understood that the image sub-frames may be generated by sub-frame generation module 30 or by a different component of display system 2. First sub-frame 36 and second sub-frame 38 each comprise image data of a subset of image data 14 for the corresponding image frame. Although the exemplary image processing unit 4 generates two image sub-frames in the example of FIGS. 10A-C, it will be understood that two image sub-frames are an exemplary number of image sub-frames that may be generated by image processing unit 4 and that any number of image sub-frames may be generated in other embodiments. As illustrated in FIG. 10A, first sub-frame 36 is displayed in first image sub-frame location 40. An image sub-frame location is the relative location in which an image sub-frame is displayed. Each sub-frame location may be spatially distinct from or overlap other sub-frame locations. Second sub-frame 38 is displayed in second image sub-frame location 42 that is offset from first image sub-frame location 40 by vertical distance 44 and horizontal distance 46. As such, second sub-frame 38 is spatially offset from first sub-frame 36 by a predetermined distance. In one illustrative embodiment, as shown in FIG. 10C, vertical distance 44 and horizontal distance 46 are each approximately one-half of one pixel. However, the spatial offset distance between first image sub-frame location 40 and second image sub-frame location 42 may vary as best serves a particular application. In an alternative embodiment, first sub-frame 36 and second sub-frame 38 may only be offset in either the vertical direction or in the horizontal direction. In one embodiment, wobbling device 10 is configured to offset the beam of light between SLM 8 and display optics 12 such that first 36 and second 38 sub-frames are spatially offset from each other. As illustrated in FIG. 10C, display system 2 alternates between displaying first sub-frame 36 in first image sub-frame location 40 and displaying second sub-frame 38 in second image sub-frame location 42 that is spatially offset from first image sub-frame location 40. More specifically, wobbling device 10 shifts the display of second sub-frame 38 relative to the display of first sub-frame 36 by vertical distance 44 and by horizontal distance 46. As such, the pixels of first sub-frame 36 overlap the pixels of second sub-frame 38. In one embodiment, the display system 2 completes one cycle of displaying first sub-frame 36 in first image sub-frame location 40 and displaying second sub-frame 38 in second image sub-frame location 42 resulting in a displayed image with an enhanced apparent resolution. Thus, second sub-frame 38 is spatially and temporally displaced relative to first sub-frame 36. However, the two sub-frames are seen together by an observer as an enhanced single image. FIGS. 11A-B illustrate an exemplary embodiment of completing one cycle of displaying pixel 48 from first sub-frame 36 in first image sub-frame location 40 and displaying pixel 50 from second sub-frame 38 in second image sub-frame location 42. FIG. 11 A illustrates the display of pixel 48 from first sub-frame 36 in first image sub-frame location 40. FIG. 11 B illustrates the display of pixel 50 from second sub-frame 38 in second image sub-frame location 42. In FIG. 11B, first image sub-frame location 40 is illustrated by dashed lines. By generating a first 36 and second 38 sub-frame and displaying the two sub-frames 36, 38 in the spatially offset manner as illustrated in FIGS. 10A-C and FIGS. 11A-B, twice the amount of pixel data is used to create the finally displayed image as compared to the amount of pixel data used to create a finally displayed image without using the image sub-frames. Accordingly, with two-position processing, the resolution of the finally displayed image is increased by a factor of approximately 1.4 or the square root of two. In another embodiment, as illustrated in FIGS. 12A-D, image processing unit 4 defines four image sub-frames for an image frame. More specifically, image processing unit 4 defines first sub-frame 36, second sub-frame 38, third sub-frame 52, and fourth sub-frame 54 for the image frame. As such, first sub-frame 36, second sub-frame 38, third sub-frame 52, and fourth sub-frame 54 each comprise image data of a subset of image data 14 for the corresponding image frame. In one embodiment, as illustrated in FIGS. 12B-D, first sub-frame 36 is displayed in first image sub-frame location 40. Second image sub-frame 38 is displayed in second image sub-frame location 42 that is offset from first image sub-frame location 40 by vertical distance 44 and horizontal distance 46. Third sub-frame 52 is displayed in third image sub-frame location 56 that is offset from first image sub-frame location 40 by horizontal distance 58. Horizontal distance 58 may be, for example, the same distance as horizontal distance 46. Fourth sub-frame 54 is displayed in fourth image sub-frame location 60 that is offset from first image sub-frame location 40 by vertical distance 62. Vertical distance 62 may be, for example, the same distance as vertical distance 44. As such, second sub-frame 38, third sub-frame 52, and fourth sub-frame 54 are each spatially offset from each other and spatially offset from first sub-frame 36 by a predetermined distance. In one illustrative embodiment, vertical distance 44, horizontal distance 46, horizontal distance 58, and vertical distance 62 are each approximately one-half of one pixel. However, the spatial offset distance between the four sub-frames may vary as best serves a particular application. In one embodiment, wobbling device 10 is configured to offset the beam of light between SLM 8 and display optics 12 such that the first 36, second 38, third 52, and fourth 54 sub-frames are spatially offset from each other. In one embodiment, display system 2 completes one cycle of displaying first sub-frame 36 in first image sub-frame location 40, displaying second sub-frame 38 in second image sub-frame location 42, displaying third sub-frame 52 in third image sub-frame location 56, and displaying fourth sub-frame 54 in fourth image sub-frame location 60 resulting in a displayed image with an enhanced apparent resolution. Thus, second sub-frame 38, third sub-frame 52, and fourth sub-frame 54 are spatially and temporally displaced relative to each other and relative to first sub-frame 36. 65 FIGS. 13A-D illustrate an exemplary embodiment of completing one cycle of displaying pixel 48 from first sub-frame 36 in first image sub-frame location 40, displaying pixel 50 from second sub-frame 38 in second image sub-frame location 42, displaying pixel 64 from third sub-frame 52 in third image sub-frame location 56, and displaying pixel 66 from fourth sub-frame 54 in fourth image sub-frame location 60. FIG. 13A illustrates the display of pixel 48 from first sub-frame 36 in first image sub-frame location 40. FIG. 13B illustrates the display of pixel 50 from second sub-frame 38 in second image sub-frame location 42 where first image sub-frame location 40 is illustrated by dashed lines. FIG. 13C illustrates the display of pixel 64 from third sub-frame 52 in third image sub-frame location 56 where first 40 and second 42 image sub-frame location are illustrated by dashed lines. Finally, FIG. 13D illustrates the display of pixel 66 from fourth sub-frame 54 in fourth image sub-frame location 60 where first 40, second 42, and third 56 image sub-frame location are illustrated by dashed lines. By generating four image sub-frames and displaying the four sub-frames in the spatially offset manner as illustrated in FIGS. 12A-D and FIGS. 13A-D, four times the amount of pixel data is used to create the finally displayed image as compared to the amount of pixel data used to create a finally displayed image without using the image sub-frames. Accordingly, with four-position processing, the resolution of the finally displayed image is increased by a factor of two or the square root of four. As shown by the examples in FIGS. 10-13, by generating a number of image sub-frames for an image frame and spatially and temporally displaying the image sub-frames relative to each other, display system 2 can produce a displayed image with a resolution greater than that which SLM 8 is configured to display. In one illustrative embodiment, for example, with image data 14 having a resolution of 800 pixels by 600 pixels and SLM 8 having a resolution of 800 pixels by 600 pixels, four-position processing by display system 2 with resolution adjustment of image data 14 produces a displayed image with a resolution of 1600 pixels by 1200 pixels. In addition, by overlapping pixels of image sub-frames, display system 2 may reduce the undesirable visual effects caused by a defective pixel. For example, if four sub-frames are generated by image processing unit 4 and displayed in offset positions relative to each other, the four sub-frames effectively diffuse the undesirable effect of the defective pixel because a different portion of the image that is to be displayed is associated with the defective pixel in each sub-frame. A defective pixel is defined to include an aberrant or inoperative display pixel such as a pixel which exhibits only an “on” or “off” position, a pixel which produces less intensity or more intensity than intended, or a pixel with inconsistent or random operation. Sub-frame generation module 30 generates color image bit-planes from image data 14. The color image bit-planes are generated so that, for at least one of the colors, at least the least significant color image bit-plane B0 is displayed in less than all of the sub-frame locations or at least the least significant color image bit-plane B0 is unequally distributed between the image sub-frames. FIGS. 14A-14C illustrate one example of color image bit-planes displayed in less than all of the sub-frame locations. FIG. 14A shows least significant bit-plane B0 displayed in only first image sub-frame location 40. Each of the least significant bits B0 for first 40, second 42, third 56, and fourth 60 image sub-frame locations is added together and displayed only in first sub-frame location 40. Hatching on a sub-frame location represents light displayed on the sub-frame location. For example, the hatching on first image sub-frame location 40 represents light displayed, for one color, at first image sub-frame location 40 by each of the bit-planes B0. In FIG. 14B, more than one of the least significant bits are displayed in less than all of the bit plane locations. For example, bit planes B0 and B1, for each of the sub-frame locations, are displayed in only first 40 and second 42 sub-frame locations and not in third 56 and fourth 60 sub-frame locations. Likewise, in FIG. 14C, more than one of the least significant bits are displayed in less than all of the bit plane locations. For example, bit planes B0, B1, and B2, for each of the sub-frame locations, are displayed in only first 40, second 42, and third 56 sub-frame locations and not in fourth sub-frame location 60. FIG. 15 illustrates an alternate embodiment wherein for each color, all the bit-planes are displayed in a single image sub-frame location. In one embodiment, three colors are displayed, red, green, and blue. All of the red bit-planes are displayed in first sub-frame position 68. All of the green bit-planes are displayed in second sub-frame position 70. All of the blue bit-planes are displayed in third sub-frame position 72. This would be consistent with the timing diagrams depicted with respect to FIGS. 7B or 7C. FIG. 16 is a flow chart representing steps of one embodiment of the present invention for producing a color image from image data 14. Although the steps represented in FIG. 16 are presented in a specific order, the present invention encompasses variations in the order of steps. Furthermore, additional steps may be executed between the steps illustrated in FIG. 16 without departing from the scope of the present invention. In one embodiment, steps illustrated in FIG. 16 are performed by sub-frame generation module 30. Color image bit-planes are generated 74 from image data 14. Each color image bit-plane represents a time increment for displaying one color for each pixel of a color image. The smallest time increment for each color is represented by a least significant color image bit-plane. Light beams are generated 76 in each of the colors. For each of the colors, color patterns representing the color image bit-planes are displaying 78 in a plurality of image sub-frame locations. For at least one of the colors, at least the least significant color image bit-plane is displayed 80 in less than all of the image sub-frame locations. In one embodiment, displaying 80 at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying at least the least significant color image bit-planes in a single image sub-frame location. In an alternate embodiment, displaying 80 at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises displaying, for each color, all the bit-planes in a single image sub-frame location as consistent with FIG. 7B or 7C In another embodiment, displaying 80 at least the least significant color image bit-planes in less than all of the image sub-frame locations comprises defining less than the full color depth of at least one of the colors in at least one of the plurality of image sub-frame locations. FIG. 17 is a flow chart representing steps of one embodiment of generating a plurality of color image bit-planes wherein image data 14 includes color values for image frame locations. Although the steps represented in FIG. 17 are presented in a specific order, the present invention encompasses variations in the order of steps. Furthermore, additional steps may be executed between the steps illustrated in FIG. 17 without departing from the scope of the present invention. In one embodiment, steps illustrated in FIG. 17 are performed by sub-frame generation module 30. Image sub-frame color values are generated 82 from the color values for the image frame locations. Color image bit-planes, excluding at least the least significant color image bit-plane, are calculated 84 from the image sub-frame color values. The differences in color represented by the color values for the image frame locations and the color image bit planes are compensated 86 for with the excluded bit-planes. FIG. 18 is a flow chart representing steps of another embodiment of compensating for differences in color represented by color values. Although the steps represented in FIG. 18 are presented in a specific order, the present invention encompasses variations in the order of steps. Furthermore, additional steps may be executed between the steps illustrated in FIG. 18 without departing from the scope of the present invention. Image frame color values for the image frame locations are recreated 88 from the calculated color image bit-planes. A color error map is computed 90 by comparing the recreated color values to the color values from image data 14. Correction factors are computed 92 to offset the error map. The correction factors are distributed 94 to image sub-frame locations. The foregoing description is only illustrative of the invention. Various alternatives, modifications, and variances can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention embraces all such alternatives, modifications, and variances that fall within the scope of the appended claims. | <SOH> BACKGROUND <EOH>Sequential display systems produce color image frames by generating a plurality of colors of light in sequence, spatially modulating the colors of light and projecting the spatially modulated colors of light to form the image frames. The colors of light are typically derived from a white light source passed through a color filter wheel, prism, or some other color filter. In order to remain competitive with alternative technologies, there is a continual need for the sequential display systems to improve image quality factors such as the resolution of the image frames. Issues with enhancing resolution can include an impact on system cost or color depth. | 20040430 | 20060404 | 20051103 | 67133.0 | 0 | RAHMJOO, MANUCHEHR | DISPLAYING LEAST SIGNIFICANT COLOR IMAGE BIT-PLANES IN LESS THAN ALL IMAGE SUB-FRAME LOCATIONS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,603 | ACCEPTED | Ambulatory energy transfer system for an implantable medical device and method therefore | An external power system, system and method for transcutaneous energy transfer to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. An external power source has a primary coil contained in a housing. The external power source is capable of providing energy to the implantable medical device when the primary coil of the external power source is placed in proximity of the secondary coil of the implantable medical device. A holder is adapted to be externally positioned with respect to the patient at a spot in proximity of the location of the implantable medical device and secured at the spot. The holder is attachable to the housing after the holder is secured to the patient. | 1. An external power system for transcutaneous energy transfer to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to said componentry, said implantable medical device adapted to be implanted at a location in a patient, comprising: an external power source having a primary coil contained in a housing; said external power source capable of providing energy to said implantable medical device when said primary coil of said external power source is placed in proximity of said secondary coil of said implantable medical device; and a holder adapted to be externally positioned with respect to said patient at a spot in proximity of said location of said implantable medical device and secured at said spot; said holder being attachable to said housing after said holder is secured to said patient. 2. An external power system as in claim 1 wherein said holder has a surface closest to said implantable medical device and wherein said surface is tacky with respect to said patient. 3. An external power system as in claim 2 wherein said surface has a durometer of about 40 Shore A. 4. An external power system as in claim 1 further comprising a belt coupled to said holder and adapted to secure said holder to said patient. 5. An external power system as in claim 1 wherein said holder comprises: a flexible body portion having a central opening; and a pair of pivot points positioned laterally on either side of a central axis; said pair of pivot points facilitating pivotal attachment of said housing to said holder. 6. An external power system as in claim 1 wherein said external power source further comprises a repositionable magnetic core located in said housing. 7. An external power system as in claim 1 wherein a surface of said housing closest to said secondary coil is thermally conductive. 8. An external power system as in claim 7 wherein said external power source further comprises a temperature sensor thermally coupled to said surface of said housing. 9. An external power system as in claim 8 wherein said external power source further comprises circuitry coupled to said temperature sensor operative to limit said energizing at least in part as a function of said temperature. 10. An external power system as in claim 1 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having a resonant frequency; said circuitry adjusting said carrier frequency to said resonant frequency. 11. An external power system as in claim 1 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having an impedance; said circuitry adjusting said carrier frequency to minimize said impedance. 12. An external power system as in claim 1 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having an energy transfer efficiency; said circuitry adjusting said carrier frequency to increase said energy transfer efficiency of said inductively tuned circuit. 13. An external power system as in claim 1 wherein said implantable medical device has a rechargeable power source operatively couple to said secondary coil and to said componentry. 14. A system for transcutaneous energy transfer, comprising: an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to said componentry, said implantable medical device adapted to implanted at a location in a patient an external power source having a primary coil contained in a housing; said external power source capable of providing energy to said implantable medical device when said primary coil of said external power source is placed in proximity of said secondary coil of said implantable medical device; and a holder adapted to be externally positioned with respect to said patient at a spot in proximity of said location of said implantable medical device and secured at said spot; said holder being attachable to said housing after said holder is secured to said patient. 15. A system as in claim 14 wherein said holder has a surface closest to said implantable medical device and wherein said surface is tacky with respect to said patient. 16. A system as in claim 15 wherein said surface has a durometer of about 40 Shore A. 17. A system as in claim 14 further comprising a belt coupled to said holder and adapted to secure said holder to said patient. 18. A system as in claim 14 wherein said holder comprises: a flexible body portion having a central opening; and a pair of pivot points positioned laterally on either side of a central axis; said pair of pivot points facilitating pivotal attachment of said housing to said holder. 19. A system as in claim 14 wherein said external power source further comprises a repositionable magnetic core located in said housing. 20. A system as in claim 14 wherein a surface of said housing closest to said secondary coil is thermally conductive. 21. A system as in claim 20 wherein said external power source further comprises a temperature sensor thermally coupled to said surface of said housing. 22. A system as in claim 21 wherein said external power source further comprises circuitry coupled to said temperature sensor operative to limit said energizing at least in part as a function of said temperature. 23. A system as in claim 14 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having a resonant frequency; said circuitry adjusting said carrier frequency to said resonant frequency. 24. A system as in claim 14 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having an impedance; said circuitry adjusting said carrier frequency to minimize said impedance. 25. A system as in claim 14 wherein said external power further comprises circuitry, operatively coupled to said primary coil, capable of inductively energizing said secondary coil by driving said primary coil at a carrier frequency when said primary coil of said external power source is externally placed in proximity of said secondary coil creating a tuned inductive circuit having an energy transfer efficiency; said circuitry adjusting said carrier frequency to increase said energy transfer efficiency of said inductively tuned circuit. 26. A system as in claim 14 wherein said implantable medical device has a rechargeable power source operatively couple to said secondary coil and to said componentry. 27. A method of transcutaneous energy transfer from an external power source having a primary coil contained in a housing to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to said componentry, said implantable medical device adapted to implanted at a location in a patient, comprising the steps of: placing a holder with respect to said patient at a spot in proximity of said location of said implantable medical device; securing said holder at said spot; and then attaching said housing to said holder. 28. An external power system as in claim 27 wherein said holder has a surface closest to said implantable medical device and wherein said surface is tacky with respect to said patient. 29. A method as in claim 28 wherein said surface has a durometer of about 40 Shore A. 30. A method as in claim 27 wherein said securing step is accomplished using a belt coupled to said holder. 31. A method as in claim 27 wherein said attaching step comprises pivotally attaching said housing to said holder. 32. A method as in claim 27 further comprising the step of repositioning a magnetic core located in said housing to improve efficiency of said transcutaneous energy transfer. 33. A method as in claim 27 wherein a surface of said housing closest to said secondary coil is thermally conductive. 34. A method as in claim 33 further comprising the step of limiting said energizing at least in part as a function of a temperature of a temperature sensor thermally coupled to said surface of said housing. 35. A method as in claim 27 further comprising the step of adjusting a carrier frequency of said primary coil inductively driving said secondary coil, forming a tuned inductive circuit having a resonant frequency, to said resonant frequency of said tuned inductive circuit. 36. A method as in claim 27 further comprising the step of adjusting a carrier frequency of said primary coil inductively driving said secondary coil, forming a tuned inductive circuit having an impedance, to minimize said impedance of said tuned inductive circuit. 37. A method as in claim 27 further comprising the step of adjusting a carrier frequency of said primary coil inductively driving said secondary coil, forming a tuned inductive circuit having an energy transfer efficiency, to increase said energy transfer efficiency of said tuned inductive circuit. 38. A method as in claim 27 wherein said implantable medical device has a rechargeable power source operatively couple to said secondary coil and to said componentry. | FIELD OF THE INVENTION This invention relates to implantable medical devices and, in particular, to energy transfer devices, systems and methods for implantable medical devices. BACKGROUND OF THE INVENTION Implantable medical devices for producing a therapeutic result in a patient are well known. Examples of such implantable medical devices include implantable drug infusion pumps, implantable neurostimulators, implantable cardioverters, implantable cardiac pacemakers, implantable defibrillators and cochlear implants. Of course, it is recognized that other implantable medical devices are envisioned which utilize energy delivered or transferred from an external device. A common element in all of these implantable medical devices is the need for electrical power in the implanted medical device. The implanted medical device requires electrical power to perform its therapeutic function whether it be driving an electrical infusion pump, providing an electrical neurostimulation pulse or providing an electrical cardiac stimulation pulse. This electrical power is derived from a power source. Typically, a power source for an implantable medical device can take one of two forms. The first form utilizes an external power source that transcutaneously delivers energy via wires or radio frequency energy. Having electrical wires which perforate the skin is disadvantageous due, in part, to the risk of infection. Further, continuously coupling patients to an external power for therapy is, at least, a large inconvenience. The second form utilizes single cell batteries as the source of energy of the implantable medical device. This can be effective for low power applications, such as pacing devices. However, such single cell batteries usually do not supply the lasting power required to perform new therapies in newer implantable medical devices. In some cases, such as an implantable artificial heart, a single cell battery might last the patient only a few hours. In other, less extreme cases, a single cell unit might expel all or nearly all of its energy in less than a year. This is not desirable due to the need to explant and re-implant the implantable medical device or a portion of the device. One solution is for electrical power to be transcutaneously transferred through the use of inductive coupling. Such electrical power or energy can optionally be stored in a rechargeable battery. In this form, an internal power source, such as a battery, can be used for direct electrical power to the implanted medical device. When the battery has expended, or nearly expended, its capacity, the battery can be recharged transcutaneously, via inductive coupling from an external power source temporarily positioned on the surface of the skin. Several systems and methods have been used for transcutaneously inductively recharging a rechargeable used in an implantable medical device. U.S. Pat. No. 5,411,537, Munshi et al, Rechargeable Biomedical Battery Powered Devices With Recharging and Control System Therefor, (Intermedics, Inc.) discloses a hermetically-sealed automatic implantable cardioverter-defibrillator (AICD) or any other bioimplantable device which may be operated on a single rechargeable cell, or a dual power source system, the rechargeable complement being recharged by magnetic induction. Included in the implantable devices are lithium rechargeable chemistries designed to sense the state-of-charge or discharge of the battery; a battery charge controller specifically designed to recharge a lithium battery rapidly to less than 100% full charge, and preferably 90%, more preferably 80%, of full rated charge capacity; and charging means for multi-step charging. The batteries are based on lithium chemistries specially designed to yield higher currents than conventional primary lithium chemistries and to permit long-term performance despite sub-capacity recharging. U.S. Pat. No. 5,690,693, Wang et al, Transcutaneous Energy Transmission Circuit For Implantable Medical Device, (Sulzer Intermedics Inc.) discloses a transcutaneous energy transmission device for charging rechargeable batteries in an implanted medical device. A current with a sinusoidal waveform is applied to a resonant circuit comprising a primary coil and a capacitor. Current is induced in a secondary coil attached to the implanted medical device. Two solid-state switches are used to generate the sinusoidal waveform by alternately switching on and off input voltage to the resonant circuit. The sinusoidal waveform reduces eddy current effects in the implanted device which detrimentally increases the temperature of the implanted device. The batteries are charged using a charging protocol that reduces charging current as the charge level in the battery increases. The controller is constructed as a pulse with modulation device with a variable duty cycle to control the current level applied to the primary coil. An alignment indicator is also provided to insure proper and alignment between the energy transmission device and the implanted medical device. U.S. Pat. No. 5,733,313, Barreras, Sr., FR Coupled Implantable Medical Device With Rechargeable Back-Up Power Source, (Exonix Corporation) discloses an implantable, electrically operated medical device system having an implanted radio frequency (RF) receiving unit (receiver) incorporating a back-up rechargeable power supply and an implanted, electrically operated device, and an external RF transmitting unit (transmitter). RF energy is transmitted by the transmitter and is coupled into the receiver which is used to power the implanted medical device and/or recharge the back-up power supply. The back-up power supply within the receiver has enough capacity to be able to, by itself, power the implanted device coupled to the receiver for at least 24 hours during continual delivery of medical therapy. The receiver is surgically implanted within the patient and the transmitter is worn externally by the patient. The transmitter can be powered by either a rechargeable or non-rechargeable battery. In a first mode of operation, the transmitter will supply power, via RF coupled energy, to operate the receiver and simultaneously recharge the back-up power supply. In a second mode of operation, the receiver can, automatically or upon external command from the transmitter, acquire its supply of power exclusively from the back-up power supply. Yet, in a third mode of operation, the receiver can, automatically or upon command from the transmitter, alternatively acquire it supply of power from either, FR energy coupled into the receiver or the internal back-up power supply. U.S. Pat. No. 6,308,101, Faltys et al, Fully Implantable Cochlear Implant System, (Advanced Bionics Corporation) discloses a fully implantable cochlear implant system and method including an implantable cochlear stimulator unit that is connected to an implantable speech processor unit. Both the speech processor unit and the cochlear stimulator unit are in separate, hermetically-sealed, cases. The cochlear stimulator unit has a coil permanently connected thereto through which magnetic or inductive coupling may occur with a similar coil located externally during recharging, programming, or externally-controlled modes of operation. The cochlear stimulator unit further has a cochlear electrode array permanently connected thereto via a first multi-conductor cable. The cochlear stimulator unit also has a second multi-conductor cable attached thereto, which second cable contains no more than five conductors. The second cable is detachably connected to the speech processor unit. The speech processor unit includes an implantable subcutaneous microphone as an integral part thereof, and further includes speech processing circuitry and a replenishable power source, e.g., a rechargeable battery. U.S. Pat. No. 6,324,430, Zarinetchi et al, Magnetic Shield For Primary Coil of Transcutaneous Energy Transfer Device, (Abiomed, Inc.) discloses a transcutaneous energy transfer device which has a magnetic shield covering the primary winding of the device to reduce sensitivity of the device to conducting objects in the vicinity of the coils and to increase the percentage of magnetic field generated by the primary coil which reaches the secondary coil. The shield is preferably larger than the primary coil in all dimensions and is either formed of a high permeability flexible material, for example a low loss magnetic material and a flexible polymer matrix, with perforations formed in the material sufficient to permit ventilation of the patient's skin situated under the shield, or the shield may be formed of segments of a very high permeability material connected by a flexible, porous mesh material. U.S. Pat. No. 6,516,227, Meadows et al, Rechargeable Spinal Cord Stimulator System, (Advanced Bionics Corporation) discloses a spinal cord stimulation system providing multiple stimulation channels, each capable of producing up to 10 milliamperes of current into a one kilohm load. The system further includes a replenishable power supply, e.g., a rechargeable battery that requires only an occasional recharge, and offers a life of at least 10 years at typical settings. The replenishable power source may be replenished using non-invasive means. The system monitors the state of charge of the internal power source and controls the charging process by monitoring the amount of energy used by the system, and hence the state of the charge of power source. A suitable bidirectional telemetry link allows the system to inform the patient or clinician regarding the status of the system, including the state of the charge, and makes requests to initiate an external charge process. U.S. Pat. No. 6,505,077, Kast et al, Implantable Medical Device With External Recharging Coil Electrical Connection, (Medtronic, Inc.) discloses a rechargeable implantable medical device with an improved external recharging coil electrical connection resistant to corrosion. The electrical connection couples the external recharging coil to a recharge feedthrough. The rechargeable implantable medical device can be a medical device such as a neuro stimulator, drug delivery pump, pacemaker, defibrillator, diagnostic recorder, cochlear implant, and the like. The implantable medical device has a housing, electronics carried in the housing configured to perform a medical therapy, a rechargeable power source, and a recharging coil. European Patent Application 1,048,324, Schallhorn, Medical Li+ Rechargeable Powered Implantable Stimulator, (Medtronic, Inc.) discloses an implantable stimulator having a rechargeable lithium ion power source and delivers electrical stimulation pulses, in a controlled manner, to a targeted site within a patient. The lithium ion power source can supply sufficient power to the implantable stimulator on an exclusive basis over at least about 4 days. The power source includes a high value, small size lithium ion storage unit having a power rating of at least 50 milliamp hours. The implantable stimulator also has an inductor adapted to gather EMF power transmissions. The implantable stimulator can be replenished with electrical power by an electrical power replenisher, external to the implantable stimulator, to replenish the lithium ion power source up to its maximum rated voltage by generating the EMF power transmission near the inductor. PCT Patent Application No. WO 01/83029 A1, Torgerson et al, Battery Recharge Management For an Implantable Medical Device, (Medtronic, Inc.) discloses an implantable medical device having an implantable power source such as a rechargeable lithium ion battery. The implantable medical device includes a recharge module that regulates the recharging process of the implantable power source using closed-loop feedback control. The recharging module includes a recharge regulator, a recharge measurement device monitoring at least one recharge parameter, and a recharge regulation control unit for regulating the recharge energy delivered to the power source in response to the recharge measurement device. The recharge module adjusts the energy provided to the power source to ensure that the power source is being recharged under safe levels. PCT Patent Application No. WO 01/97908 A2, Jimenez et al, An Implantable Medical Device With Recharging Coil Magnetic Shield, (Medtronic, Inc.) discloses a rechargeable implantable medical device with a magnetic shield placed on the distal side of a secondary recharging coil to improve recharging efficiency. The rechargeable implantable medical device can be wide variety of medical devices such as neurostimulators, drug delivery pumps, pacemakers, defibrillators, diagnostic recorders, and cochlear implants the implantable medical device has a secondary recharging coil carried over a magnetic shield and coupled to electronics and a rechargeable power source carried inside the housing electronics are configured to perform a medical therapy. Additionally a method of for enhancing electromagnetic coupling during recharging of an implantable medical device is disclosed, and a method for reducing temperature rise during recharging of an implantable medical device is disclosed. Transcutaneous energy transfer through the use of inductive coupling involves the placement of two coils positioned in close proximity to each other on opposite sides of the cutaneous boundary. The internal coil, or secondary coil, is part of or otherwise electrically associated with the implanted medical device. The external coil, or primary coil, is associated with the external power source or external charger, or recharger. The primary coil is driven with an alternating current. A current is induced in the secondary coil through inductive coupling. This current can then be used to power the implanted medical device or to charge, or recharge, an internal power source, or a combination of the two. For implanted medical devices, the efficiency at which energy is transcutaneously transferred is crucial. First, the inductive coupling, while inductively inducing a current in the secondary coil, also has a tendency to heat surrounding components and tissue. The amount of heating of surrounding tissue, if excessive, can be deleterious. Since heating of surrounding tissue is limited, so also is the amount of energy transfer which can be accomplished per unit time. The higher the efficiency of energy transfer, the more energy can be transferred while at the same time limiting the heating of surrounding components and tissue. Second, it is desirable to limit the amount of time required to achieve a desired charge, or recharge, of an internal power source. While charging, or recharging, is occurring the patient necessarily has an external encumbrance attached to their body. This attachment may impair the patient's mobility and limit the patient's comfort. The higher the efficiency of the energy transfer system, the faster the desired charging, or recharging, can be accomplished limiting the inconvenience to the patient. Third, amount of charging, or recharging, can be limited by the amount of time required for charging, or recharging. Since the patient is typically inconvenienced during such charging, or recharging, there is a practical limit on the amount of time during which charging, or recharging, should occur. Hence, the size of the internal power source can be effectively limited by the amount of energy which can be transferred within the amount of charging time. The higher the efficiency of the energy transfer system, the greater amount of energy which can be transferred and, hence, the greater the practical size of the internal power source. This allows the use of implantable medical devices having higher power use requirements and providing greater therapeutic advantage to the patient and/or extends the time between charging effectively increasing patient comfort. Prior art implantable medical devices, external power sources, systems and methods have not always provided the best possible system or method for allowing the patient to be ambulatory during energy transfer and/or charging. Physical limitations related to the energy transfer and/or charging apparatus and methods as well as necessary efficiencies of operation have effectively limited the patient's ability to move around during such energy transfer and/or charging and have deleteriously affected patient comfort. BRIEF SUMMARY OF THE INVENTION In one embodiment, the present invention provides an external power system for transcutaneous energy transfer to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. An external power source has a primary coil contained in a housing. The external power source is capable of providing energy to the implantable medical device when the primary coil of the external power source is placed in proximity of the secondary coil of the implantable medical device. A holder is adapted to be externally positioned with respect to the patient at a spot in proximity of the location of the implantable medical device and secured at the spot. The holder is attachable to the housing after the holder is secured to the patient. In another embodiment, the present invention provides a system for transcutaneous energy transfer. An implantable medical device has componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. An external power source has a primary coil contained in a housing. The external power source is capable of providing energy to the implantable medical device when the primary coil of the external power source is placed in proximity of the secondary coil of the implantable medical device. A holder is adapted to be externally positioned with respect to the patient at a spot in proximity of the location of the implantable medical device and secured at the spot. The holder is attachable to the housing after the holder is secured to the patient. In a preferred embodiment, a belt is coupled to the holder and adapted to secure the holder to the patient. In a preferred embodiment, the holder has a flexible body portion having a central opening and a pair of pivot points positioned laterally on either side of a central axis. The pair of pivot points facilitate pivotal attachment of the housing to the holder. In a preferred embodiment, the external power source has a repositionable magnetic core located in the housing. In a preferred embodiment, the external power source has circuitry coupled to the temperature sensor operative to limit the energizing at least in part as a function of the temperature. In another embodiment, the present invention provides a method of transcutaneous energy transfer from an external power source having a primary coil contained in a housing to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. A holder is placed with respect to the patient at a spot in proximity of the location of the implantable medical device. The holder is secured at the spot. The housing is then attached to the holder. In a preferred embodiment, the holder has a surface closest to the implantable medical device and wherein the surface has a durometer of about 40 Shore A. In a preferred embodiment, the surface of the holder is constructed of PCABS. In a preferred embodiment, a surface of the housing closest to the secondary coil is thermally conductive. In a preferred embodiment, the external power source has a temperature sensor thermally coupled to the surface of the housing. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having a resonant frequency. The circuitry adjusts the carrier frequency to the resonant frequency. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having an impedance. The circuitry adjusts the carrier frequency to minimize the impedance. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having an energy transfer efficiency. The circuitry adjusts the carrier frequency to increase the energy transfer efficiency of the inductively tuned circuit. In a preferred embodiment, the implantable medical device has a rechargeable power source operatively couple to the secondary coil and to the componentry. In a preferred embodiment, the securing step is accomplished using a belt coupled to the holder. In a preferred embodiment, the attaching step pivotally attaches the housing to the holder. In a preferred embodiment, a magnetic core located in the housing is repositioned to improve efficiency of the transcutaneous energy transfer. In a preferred embodiment, the energizing step is limited at least in part as a function of a temperature of a temperature sensor thermally coupled to the surface of the housing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an implantable medical device implanted in a patient; FIG. 2 is a block diagram of an implantable medical device; FIG. 3 is a detailed block diagram of an implantable medical device implanted subcutaneously and an associated external charging device in accordance with an embodiment of the present invention; FIG. 4 is a perspective view of an internal antenna associated with an implantable medical device; FIG. 5 is a side view of the internal antenna of FIG. 4; FIG. 6 is an exploded perspective view an external antenna and associated bracket in accordance with an embodiment of the present invention; FIG. 7 is a top view of an external antenna in accordance with an embodiment of the present invention; FIG. 8 is a perspective view of an external antenna and bracket combination in accordance with an embodiment of the present invention; FIG. 9 is a cross-sectional side view of an implantable medical device implanted subcutaneously and an associated bracket for use with an external antenna; FIG. 10 is a cut-away top view of view a primary coil and associated magnetic core in accordance with an embodiment of the present invention; FIG. 11 is a cross-sectional view of the primary coil and associated magnetic core of FIG. 10 taken through section line B-B; FIG. 12 is an exploded view a portion of an external antenna constructed in accordance with an embodiment of the present invention showing the magnetic core and a core cup assembly; FIG. 13 is block diagram of an external charging unit and an associated inductively coupled cradle for recharging the external charging unit; FIG. 14 is a detailed block diagram of the external charging unit of FIG. 13; FIG. 15 is a flow chart illustrating a charging process in accordance with an embodiment of the present invention; and FIG. 16 is a schematic diagram of a dual range temperature sensor. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows implantable medical device 16, for example, a drug pump, implanted in patient 18. The implantable medical device 16 is typically implanted by a surgeon in a sterile surgical procedure performed under local, regional, or general anesthesia. Before implanting the medical device 16, a catheter 22 is typically implanted with the distal end position at a desired therapeutic delivery site 23 and the proximal end tunneled under the skin to the location where the medical device 16 is to be implanted. Implantable medical device 16 is generally implanted subcutaneously at depths, depending upon application and device 16, of from 1 centimeter (0.4 inches) to 2.5 centimeters (1 inch) where there is sufficient tissue to support the implanted system. Once medical device 16 is implanted into the patient 18, the incision can be sutured closed and medical device 16 can begin operation. Implantable medical device 16 operates to infuse a therapeutic substance into patient 18. Implantable medical device 16 can be used for a wide variety of therapies such as pain, spasticity, cancer, and many other medical conditions. The therapeutic substance contained in implantable medical device 16 is a substance intended to have a therapeutic effect such as pharmaceutical compositions, genetic materials, biologics, and other substances. Pharmaceutical compositions are chemical formulations intended to have a therapeutic effect such as intrathecal antispasmodics, pain medications, chemotherapeutic agents, and the like. Pharmaceutical compositions are often configured to function in an implanted environment with characteristics such as stability at body temperature to retain therapeutic qualities, concentration to reduce the frequency of replenishment, and the like. Genetic materials are substances intended to have a direct or indirect genetic therapeutic effect such as genetic vectors, genetic regulator elements, genetic structural elements, DNA, and the like. Biologics are substances that are living matter or derived from living matter intended to have a therapeutic effect such as stem cells, platelets, hormones, biologically produced chemicals, and the like. Other substances may or may not be intended to have a therapeutic effect and are not easily classified such as saline solution, fluoroscopy agents, disease diagnostic agents and the like. Unless otherwise noted in the following paragraphs, a drug is synonymous with any therapeutic, diagnostic, or other substance that is delivered by the implantable infusion device. Implantable medical device 16 can be any of a number of medical devices such as an implantable therapeutic substance delivery device, implantable drug pump, cardiac pacemaker, cardioverter or defibrillator, as examples. In FIG. 2, implantable medical device 16 has a rechargeable power source 24, such as a Lithium ion battery, powering electronics 26 and therapy module 28 in a conventional manner. Therapy module 28 is coupled to patient 18 through one or more therapy connections 30, also conventionally. Rechargeable power source 24, electronics 26 and therapy module 28 are contained in hermetically sealed housing 32. Secondary charging coil 34 is attached to the exterior of housing 32. Secondary charging coil 34 is operatively coupled through electronics 26 to rechargeable power source 24. In an alternative embodiment, secondary charging coil 34 could be contained in housing 32 or could be contained in a separate housing umbilically connected to electronics 26. Electronics 26 help provide control of the charging rate of rechargeable power source 24 in a conventional manner. Magnetic shield 36 is positioned between secondary charging coil 34 and housing 32 in order to protect rechargeable power source 24, electronics 26 and therapy module 28 from electromagnetic energy when secondary charging coil 34 is utilized to charge rechargeable power source 24. Rechargeable power source 24 can be any of a variety power sources including a chemically based battery or a capacitor. In a preferred embodiment, rechargeable power source is a well known lithium ion battery. FIG. 3 illustrates an alternative embodiment of implantable medical device 16 situated under cutaneous boundary 38. Implantable medical device 16 is similar to the embodiment illustrated in FIG. 2. However, charging regulation module 42 is shown separate from electronics 26 controlling therapy module 28. Again, charging regulation and therapy control is conventional. Implantable medical device 16 also has internal telemetry coil 44 configured in conventional manner to communicate through external telemetry coil 46 to an external programming device (not shown), charging unit 50 or other device in a conventional manner in order to both program and control implantable medical device and to externally obtain information from implantable medical device 16 once implantable medical device has been implanted. Internal telemetry coil 44, rectangular in shape with dimensions of 1.85 inches (4.7 centimeters) by 1.89 inches (4.8 centimeters) constructed from 150 turns of 43 AWG wire, is sized to be larger than the diameter of secondary charging coil 34. Secondary coil 34 is constructed with 182 turns of 30 AWG wire with an inside diameter of 0.72 inches (1.83 centimeters) and an outside diameter of 1.43 inches (3.63 centimeters) with a height of 0.075 inches (0.19 centimeters). Magnetic shield 36 is positioned between secondary charging coil 34 and housing 32 and sized to cover the footprint of secondary charging coil 34. Internal telemetry coil 44, having a larger diameter than secondary coil 34, is not completely covered by magnetic shield 36 allowing implantable medical device 16 to communicate with the external programming device with internal telemetry coil 44 in spite of the presence of magnetic shield 36. Rechargeable power source 24 can be charged while implantable medical device 16 is in place in a patient through the use of external charging device 48. In a preferred embodiment, external charging device 48 consists of charging unit 50 and external antenna 52. Charging unit 50 contains the electronics necessary to drive primary coil 54 with an oscillating current in order to induce current in secondary coil 34 when primary coil 54 is placed in the proximity of secondary coil 34. Charging unit 50 is operatively coupled to primary coil by cable 56. In an alternative embodiment, charging unit 50 and antenna 52 may be combined into a single unit. Antenna 52 may also optionally contain external telemetry coil 46 which may be operatively coupled to charging unit 50 if it is desired to communicate to or from implantable medical device 16 with external charging device 48. Alternatively, antenna 52 may optionally contain external telemetry coil 46 which can be operatively coupled to an external programming device, either individually or together with external charging unit 48. As will be explained in more detail below, repositionable magnetic core 58 can help to focus electromagnetic energy from primary coil 46 to more closely be aligned with secondary coil 34. Also as will be explained in more detail below, energy absorptive material 60 can help to absorb heat build-up in external antenna 52 which will also help allow for a lower temperature in implantable medical device 16 and/or help lower recharge times. Also as will be explained in more detail below, thermally conductive material 62 is positioned covering at least a portion of the surface of external antenna 52 which contacts cutaneous boundary 38 of patient 18. In a preferred embodiment of internal antenna 68 as shown in FIG. 4 and FIG. 5, secondary coil 34 and magnetic shield 36 are separate from but adjacent to housing 32 encompassing the remainder of implantable medical device 16. Internal antenna 68 is contained in a separate housing 74 which is attachable to housing 32 so that implantable medical device 16 can be implanted by a medical professional as essentially one unit. Secondary coil 34 is electrically attached to charging regulation module 42 through leads 82. In order to achieve efficient inductive coupling between primary coil 54 of external antenna 52 and secondary coil 34, it is desirable to place primary coil 54 of external antenna 52 as close to secondary coil 34 as possible. Typically, external antenna 52 is placed directly on cutaneous boundary 38 and, since the location of implantable medical device 16 is fixed, the distance across cutaneous boundary 38 between primary coil 54 and secondary coil 34 is minimized as long as external antenna 52 is kept adjacent cutaneous boundary 38. In a preferred embodiment, external antenna 52 is attachable to patient 18 with bracket 84 when charging rechargeable power source 24. FIG. 6 is an exploded illustration of a preferred embodiment of external antenna 52 attachable to bracket 84. Primary coil 54 is contained in bobbin assembly 86 which sits in bottom housing 88. Primary coil is connectable to cable 56. The bottom of external antenna 52 is formed from a thermally conductive material 90 surrounded by bottom housing 88. Rotating core cup assembly 92 is held in place by top housing 94. Rotating core cup assembly 92 is rotatable is allowed to rotate within external antenna 52. Detents 96 engage detent spring 98 to position rotatable core cup assembly 92 in one of a plurality of detent positions. External antenna may be secured together, for example, with screws 97 holding top housing 94 and thermally conductive material 90 together. Bracket 84 is adapted to be attached to the body of patient 18 with a belt (not shown) attachable to bracket 84 with belt loops 102. Ears 104 are adapted to mate with tabs 106 in top housing 94 and pivotally secure external antenna 52 in bracket 84 when charging is to be accomplished. Bracket 84 has an opening 108 allowing thermally conductive material 90 of external antenna 52 to contact the skin of patient 18 when external antenna 52 is pivotally secured in bracket 84. As bracket 84 is attached to patient 18 with a belt via belt loops 102, the skin surface of patient 18 is typically not completely flat. For example, if implantable medical device 16 is implantable in the body torso of patient 18, then the belt attached via belt loops 102 will typically pass around the torso of patient 18. Since the torso of patient 18, and especially the torso of patient 18 near the location of implantable medical device 16, bracket 84 may not sit completely flat on patient 18. This may be especially true as patient 18 moves and the torso flexes during such movement. It is preferred that bracket 84 be conformal and flexible in order to conform to the shape of the body of patient 18. However, it is also preferred that bracket 84 be rigid enough so that opening 108 in bracket 84 maintain it shape in order to properly receive external antenna 52. Bracket 84 is preferably constructed of PC/ABS. To maintain the proper position of bracket 84 with the skin of patient 18, the surface of bracket 84 closest to patient 18 contains material 109 constructed from a low durometer, e.g., 40 Shore A, or “sticky” material such as a material known under the tradename of “Versaflex” manufactured by GLS Corp. of McHenry, Ill. Such material is tacky with respect to the skin surface of patient 18 helping limit the movement of external antenna 52 with respect to secondary antenna 24. This will help external antenna to sit more closely to the skin surface of patient 18 and remain there during movements of patient 18 throughout the charge or recharge cycle. In addition, external antenna 52 is allowed to pivot by way of ears 104 on tabs 106. Bracket 84 is configured to allow thermally conductive material 90 to extend through opening 108 and contact the skin surface of patient 18. Allowed pivoting of external antenna 52 and, hence, thermally conductive material 90, permits thermally conductive surface to sit more closely to the skin surface of patient 18. FIG. 7 is a partially cut away top view of external antenna 52 is assembled form and attached to cable 56. Rotatable core cup assembly 92 is shown located inside of primary coil 54 and positionable in selected rotated positions via detents 96 and detent spring 98. In FIG. 7, rotatable core cup assembly is positioned between with detent spring 98 between detents 96 illustrating that while multiple detent positions are available, rotatable core cup assembly can be positioned between detent positions and, indeed, at any rotated position. In FIG. 8, the assembly of external antenna 52 with bracket 84 is shown connected to cable 56. It is preferred that bracket 84 be affixed to patient 18 through belt loops 102 and then, after bracket 84 has been affixed to patient 18, external antenna 52 be attached to bracket 84. Affixing bracket 84 to patient 18 first allows for bracket 84 to be used to laterally position external antenna close to the position of implantable medical device 16. Typical prior art positioning systems rely on the external antenna for lateral positioning. The external antenna is moved around on the body of the patient 18 until the best lateral position is found. When the best lateral position is found, the external antenna is removed from the body and the bottom of the external antenna (the portion of the external antenna) contacting the patient's body) is made to be resistant to lateral movement. As an example, one way is to remove a protective liner exposing a sticky surface allowing the external antenna to be relatively fixed in location. However, the very act of lifting the external antenna in order to remove the protective liner and replacing the external antenna on the body of the patient 18 causes crucial positioning information to be lost. There is no guarantee, and in fact it is not likely, that the external antenna will be replaced in the exact same position as the position previously found to be best. In contrast, bracket 84 of the present invention can be used to roughly find the optimum position for external antenna 52. This can be done relatively easily due to opening 108 in bracket 84. Implantable medical device 16, when implanted, usually leaves an area of the body of patient 18 which is not quite as flat as it was before implantation. That is, implantable medical device 16 usually leaves an area of the skin of patient 18 which bulges somewhat to accommodate the bulk of implantable medical device 16. It is relatively easy for patient, medical professional or other person, to place bracket 84 in the general area of implantable medical device 16 and move bracket 84 around until the bulge caused by implantable medical device 16 is most closely centered in opening 108. As bracket 84 is moved laterally, opening 108 tends to naturally center on the bulge created by implantable medical device 16. Once positioned in this manner, bracket 84 can be secured to the body of patient 18 with belt (not shown) attached via belt loops 102. Securing and/or tightening, by pulling the belt tight or snapping a buckle, for example, can be without removing bracket 84 from the body of patient 16. Thus, bracket 84 can be relatively easily positioned over the general location of implantable medical device 16 and secured in that position without be removed from the body of patient 18. FIG. 9 is cross-sectional view of implantable medical device 16 implanted in patient 18 approximately one centimeter under cutaneous boundary 38 creating bulging area 110, an area of the body of patient 18 in which the skin of patient 18 is caused to bulge slightly due to the implantation of implantable medical device 16. Bulging area 110 is an aid to locating the position of external antenna 52 relative to secondary coil 34. Bracket 84 can be positioned roughly in the area where implantable medical device 16 is implanted. Opening 108 in bracket 84 can aid is establishing the location of implantable medical device. Bracket 84 can be roughly centered over bulging area 110. After external antenna 52 is coupled to bracket 84, then primary coil 54 can be generally centered on implantable medical device 16. However, secondary coil 34 may not be centered with respect to implantable medical device 16. This can occur due to a variety of reasons such as the need for operatively coupling secondary coil 34 to charging regulation module 42. Connections to make this operative coupling may require physical space on one side of internal antenna 68 which may cause secondary coil 34 not to be centered on implantable medical device 16. It is also possible that the attachment of internal antenna 68 to housing 32 can cause secondary coil 34 not to be centered on implantable medical device 16. Regardless of the cause, if secondary coil 34 is not centered on implantable medical device 16, then centering bracket 84 on bulging area 110 may not optimally position primary coil 54 with respect to secondary coil 34. Any offset in the position of primary coil 54 and secondary coil 34 may not result in the most efficient energy transfer from external antenna 52 to implantable medical device 16. A magnetic core 58 is positioned within primary coil 54 in order to focus energy generated by primary coil 54. Magnetic core 58 attracts the magnetic flux lines generated by primary coil 54. The position of magnetic core 58 within primary coil 54 the lateral location of the largest amount of the flux lines generated by primary coil 54. FIGS. 10 and 11 show cut-away top and cross-sectional views of magnetic core 58 used with primary coil 54. Magnetic core 58 is moveable within primary coil 54. Lower portion 122 of magnetic core 58 can be rotated to a plurality of positions within primary coil 58 by rotating core cup assembly 92 (see FIG. 12). In a preferred embodiment, the travel path of magnetic core 58 can be locked in a plurality of discrete positions. In a preferred embodiment, magnetic core 58 is locked in four (4) different positions by detents 96 and detent spring 98 (see FIG. 6). Magnetic core 58 has an upper planar portion 120 and a smaller lower portion 122. As magnetic core 58 is repositioned within primary coil 54, the focus of magnetic flux generated by primary coil 54 is also repositioned. As noted above, external antenna 52 is generally aligned with implanted medical device 16 using palpatory sensation. Moveable magnetic core 58 can then be used to provide a “fine” adjustment to the lateral positioning of external antenna 52 with respect to secondary coil 34. After bracket 84 has been secured to patient 18, external antenna 52 is attached to bracket 84. Magnetic core 58 is then moved until the best lateral alignment with secondary coil 34. Magnetic core 58 is shown positioned within external antenna 52 of FIG. 12. Core cup assembly 92 holds magnetic core 58 within the assembly of external antenna 52. Lower portion 122 (not visible in FIG. 12) of magnetic core 58 fits into recess 124 of core cup assembly 92 while upper portion 120 of magnetic core 58 rests upon ledge 126 of core cup assembly 92. Preferably, magnetic core 58 is a ferrite core. Still more preferably, magnetic core 58 is constructed from MN60LL high performance, low loss ferrite manufactured by Ceramic Magnetics, Inc., Fairfield, N.J. Magnetic core 58 has an initial permeability of 6,500 and a maximum permeability of 10,500 (typical) with a volume resistivity of 500 ohm-centimeters. A surface, preferably the top, of magnetic core 58 is lined with an adhesive coated foam 127 and contained in core cup assembly 92. Magnetic core 58 has a tendency to be brittle. Containing magnetic core 58 is core cup assembly assures that even if magnetic core 58 has one or more fractures, magnetic core 58 will still be properly positioned and continue to function. Foam 127 also helps to hold magnetic core 58 together and minimize gaps between fractured segments of magnetic core 58. Further, foam 127 adds mechanical stability to magnetic core 58 helping to cushion magnetic core 58 against mechanical impacts, such as from dropping external antenna 52 against a hard surface, and helps to prevents audible rattles which may otherwise develop from a fractured magnetic core 58. As shown in FIG. 13, external charging device 48 can be powered either directly from internal (to charging unit 50) batteries 160 or indirectly from desktop charging device 162. Desktop charging device is connectable via power cord 164 to a source of AC power, such as a standard readily available wall outlet. Desktop charging device 162 can be configured as a cradle which can receive charging unit 50. Other forms of connection from desktop charging device 162 to a power source, such as by a dedicated line cable can also be utilized. Desktop charging device 162 can charge and/or recharge batteries 160 in charging unit 50, preferably by inductive coupling using coil 167 positioned in desktop charging device 162 and coil 168 positioned within charging unit 50. Once charged and/or recharged, batteries 160 can provide the power through internal circuitry 168 and cable 56 to external antenna 52. Since charging unit 50 is not, in a preferred embodiment, coupled directly to the line voltage source of AC power, charging unit 50 may be used with external antenna 52 to transfer power and/or charge implanted medical device 16 while desktop charging device 162 is coupled to a line voltage source of AC power. The inductive coupling using coil 167 and coil 168 break the possibility of a direct connection between the line voltage source of AC power and external antenna 52. Batteries 160 also allow charging unit 50 and, hence, external charging device 48, to be used in transferring power and/or charging of implanted medical device 16 while completely disconnected from either a line voltage source of AC power or desktop charging device 162. This, at least in part, allows patient 18 to be ambulatory while transferring power and/or charging implanted medical device 16. FIG. 14 is a block diagram of external charging device 48 controlled by microprocessor 212. Transmit block 214 consists of an H-bridge circuit powered from 12 volt power supply 216. Transmit block 214 drives primary coil 54 in external antenna 52. H-bridge control signals and timing are provided conventionally by microprocessor 212. H-bridge circuit in transmit block 214 is used to drive both primary coil 54, used for power transfer and/or charging, and telemetry antenna 218. Drive selection is done by electronically controllable switch 220. During power transfer and/or charging, H-bridge circuit is driven at 9 kiloHertz. During telemetry, H-bridge circuit is driven at 175 kiloHertz. Receive block 222 is used only during telemetry, enabled by switch 224, to receive uplink signals from implanted medical device 16. Twelve volt power supply 216 is a switching regulator supplying power to transmit block 214 during power transfer and/or charging as well as telemetry downlink. Nominal input voltage to 12 volt power supply 216 is either 7.5 volts from lithium ion batteries 226 or 10 volts from desktop charging device 162 (FIG. 13). Current measure block 226 measures current to 12 volt power supply 216. Current measured by current measure block 226 is used in the calculation of power in along with the voltage of batteries 160. As noted above, power in is used in the calculation of efficiency of power transfer and/or charging efficiency to determine, in part, the best location of external antenna 52 and/or rotating core cup assembly 92. Rotating core cup assembly 92 is rotated in external antenna 52 for better lateral alignment of primary coil 54 and secondary coil 34. A feedback mechanism is used to determine the best rotation of core cup assembly 92. External charging device 48 can determine whether the current position of rotating core cup assembly 92 is optimally aligned for energy transfer and/or charging. External charging device 48 measures the power out of external charging device 48 divided by the power into external charging device 48. This calculation is a measure of the efficiency of external charging device 48. The power out is gauged by the power induced in implantable medical device 16 and is determined by multiplying the voltage of rechargeable power source 24 by the charging current in implantable medical device 16. These values are obtained by telemetry from implanted medical device 16. The power in is gauged by the power generated by charging unit 50 and is determined by multiplying the voltage of the internal voltage of charging unit 50, e.g., the voltage of a battery or batteries internal to charging unit 50, by the current driving external antenna 52. The ratio of power out divided by power in can be scaled displayed to patient 18, or a medical professional or other person adjusting rotatable core cup assembly 92 or positioning external antenna 52. For example, the available efficiency can be divided into separate ranges and displayed as a bar or as a series of lights. The separate ranges can be linearly divided or can be logarithmic, for example. Using efficiency as a measure of effective coupling and, hence, as a measure of proper location of external antenna 52 and rotatable core cup assembly 92 works not only at high charging or power transfer levels but also at reduced charging levels, as for example, when charging at reduced levels toward the end or beginning of a charging cycle. If, after patient 18 or other person has moved rotatable core cup assembly 92 through all of the range of positions on external antenna 52 and can not achieve an acceptable efficiency level, patient 18 or other person can remove external antenna 52 from bracket 84, realign bracket 84 with bulging area 110, reattach external antenna 52 to bracket 84 and restart the alignment and coupling efficiency process. FIG. 15 is a flow chart illustrating an exemplary charging process using external antenna 52. The process starts [block 126] and a charging session begins [block 128] with a test [block 130]. The charging system performs start-up checks [block 132]. If the start-up checks are not performed successfully, the actions taken in Table 1 are performed. TABLE 1 Check Screen/Message System Errors: e.g., stuck key System Error External Charger Battery Status Recharge Complete Battery Low Recharge External Charger External Charger Connected Recharge in Process Icon to External Antenna Antenna Disconnect Connect Antenna If the start-up checks are successful, telemetry with implantable medical device 16 is checked [block 134]. If telemetry is successful, the error messages indicated in Table 2 are generated. TABLE 2 Failure Screen/Message Poor Communication Reposition Antenna External Charger Error Code Response Call Manufacturer Communication Error Communication Error External Charger Fault Call Manufacturer Antenna Disconnect Connect Antenna Antenna Failure Antenna Failure Icon If telemetry checks are successful, external charging device 48 is able to monitor [block 136] charging status. Monitoring charging status can includes providing feedback to an operator to help determine the best rotational position of core cup assembly 92. Charge events are checked [block 138]. If no charge events are noted, the actions indicated in Table 3 are executed. TABLE 3 Event Screen/Message Telemetry Failure (See Messages From Table 2) Implantable Medical Device Battery Low Device Battery Low External Charger Battery Low Charger Battery Low External Charger Battery Depleted Recharge Charger External Charger Recharge Complete External Charger Recharge Complete Implantable Medical Device Recharge Device Will Not Provide Therapeutic Result Until Recharged: Therapy Unavailable/Sleep Mode Antenna Disconnect Connect Antenna If a charge event occurs, then the process checks to determine if charging is complete [block 140]. Once charging is complete, the process terminates [block 142]. As energy is transferred from primary coil 54 of external antenna 52 to secondary coil 34 of implantable medical device 16, heat may also be generated in implantable medical device 16 in surrounding tissue of patient 18. Such heat build-up in tissue of patient 18, beyond certain limits, is undesirable and should be limited as acceptable values. Generally, it is preferable to limit the temperature of external antenna 52 to not more than forty-one degrees Centigrade (41° C.) and to limit the temperature of implanted medical device 16 and the skin of patient 18 to thirty-nine degrees Centigrade (39° C.). In order to ensure that implantable medical device 16 is less than the upper limit of thirty-nine degrees Centigrade (39° C.), it is preferred that the actual temperature of external antenna 52 be less than thirty-nine degrees Centigrade (39° C.). In general, the temperature of external antenna 52 should be maintained to be less than or equal to the desired maximum temperature of implanted medical device 16. While the temperature limits discussed above are preferred under current conditions and regulations, it is recognized and understood that conditions and regulations may change or be different in different circumstances. Accordingly, the actual temperatures and temperature limits may change. In a preferred embodiment, such temperature limits are under software control in charging unit 50 so that any such temperatures or temperature limits can be modified to fit the then current circumstances. Magnetic shield 36 serves to at least partially protect the portion of implantable medical device 16 contained within titanium housing 32 from the effects of energy transfer from external charging device 48 produced through inductive coupling from primary coil 54. Magnetic shield 36 is constructed of Metglas magnetic alloy 2714A (cobalt-based) manufactured by Honeywell International, Conway, S.C. Magnetic shield 36 is positioned between secondary coil 34 and housing 32 of implantable medical device 16 with secondary coil 34 facing cutaneous boundary 38. Magnetic shield does not interfere with the operation of secondary coil 34 because magnetic shield 36 is positioned away from primary coil 54. Also, magnetic shield does not interfere with telemetry between implantable medical device 16 and an external programmer because magnetic shield 36 is smaller than internal telemetry coil 44. That is, internal telemetry coil 44 lies outside of magnetic shield 36. However, the material of magnetic shield 36 substantially limits the electromagnetic energy induced by primary coil 54 from penetrating beyond magnetic shield. Electromagnetic waves induced by primary coil 54 that reach titanium housing 32 will tend to be absorbed by titanium housing 54 and its components and will tend to cause the temperature of titanium housing 54 to rise. As the temperature of titanium housing 54 rises, such temperature increase will be disadvantageously transferred to the surrounding tissue of patient 18. However, any electromagnetic waves which are prevented from reaching titanium housing 32 will not cause such a temperature rise. Thermally conductive material 62 of external antenna 52 is positioned to contact the skin of patient 18 when external antenna 52 is placed for energy transfer, or charging, of implanted medical device 16. Thermally conductive material 62 tends to spread any heat generated at the skin surface and spread any such heat over a larger area. Thermally conductive material 62 tends to make the temperature of the skin surface more uniform than would otherwise be the case. Uniformity of temperature will tend to limit the maximum temperature of any particular spot on the skin surface. The skin itself is a pretty good conductor of heat and initially spreading any heat generated over a larger area of the skin will further assist the skin in dissipating any heat build-up on to surrounding tissue and further limit the maximum temperature of any particular location on the surface of the skin. Thermally conductive material 62 is molded into the surface of external antenna 52 which will contact the skin surface of patient 18 when external antenna 52 provides energy transfer to implanted medical device 16. Since thermally conductive material 62 should pass electromagnetic energy from primary coil 54, thermally conductive material 62 should be constructed from a non-magnetic material. It is desirable that thermally conductive material 62 have a thermal conductivity of approximately 5.62 BTU inch/hour feet2 degrees Fahrenheit (0.81 W/meters degrees Kelvin). In a preferred embodiment, thermally conductive material is constructed from a proprietary composite of approximately forty percent (40%) graphite, seven percent (7%) glass in RTP 199×103410 A polypropylene, manufactured by RTP Company, Winona, Minn. It is also preferable that thermally conductive material not be electrically conductive in order to reduce eddy currents. In a preferred embodiment, thermally conductive material has a volume resistivity of approximately 103 ohm-centimeters and a surface resistivity of 105 ohms per square. Energy absorptive material 62 is placed in and/or around primary coil 54 of external antenna 52 in order to absorb some of the energy generated by primary coil 54. In a preferred embodiment, energy absorptive material 62 fills in otherwise empty space of rotating core cup assembly 92. Heat generated by energy produced by primary coil 54 which is not effectively inductively coupled to secondary coil 34 will tend to cause a temperature rise in other components of external antenna 52 and, possibly, the skin of patient 18. At least a portion of this temperature rise can be blocked through the use of energy absorptive material 62. Energy absorptive material 62 is chosen to absorb heat build-up in surrounding components and tend to limit further temperature increases. Preferably, energy absorptive material 62 is selected to be material which undergoes a state change at temperatures which are likely to be encountered as the temperature of surrounding components rises during energy transfer, e.g., charging, using external antenna 52. If it is a goal to limit the temperature of the skin of patient 18 to thirty-nine degrees Centigrade (39° C.), it is desirable to use of energy absorptive material 62 which has a state change at or near the temperature limit. In this example, the use of an energy absorptive material 62 having a state change in temperature area just below thirty-nine degrees Centigrade (39° C.), preferably in the range of thirty-five degrees Centigrade (35° C.) to thirty-eight degrees Centigrade (38° C.), can help limit the rise in the temperature of the skin of patient 18 to no more than the desired limit, in this example, thirty-nine degrees (39° C.). As the temperature of surrounding components of external antenna 52 rise to a temperature which is just below the temperature at which energy absorptive material 62 changes state, at least a portion of further heat energy generated by primary coil 54 and surrounding components of external antenna 52 will go toward providing the energy necessary for energy absorptive material 62 to change state. As energy absorptive material 62 is in the process of changing state, its temperature is not increasing. Therefore, during the state change of energy absorptive material 62, energy absorptive material 62 is serving to at least partially limit a further rise in the temperature of components of external antenna 52. As the state change temperature of energy absorptive material has been preferably selected to be near or just below the temperature limit of the skin of patient 18, energy absorptive material 62 will tend to limit the temperature components of external antenna 52 from reaching the temperature limit and, hence, will also tend to limit the temperature of the skin of patient 18 from reaching the maximum desired temperature limit. In a preferred embodiment, energy absorptive material 62 is constructed from wax and, in particular, a wax which has change of state temperature of approximately the maximum temperature at which external antenna 52 is desired to reach, such as thirty-eight (38) or thirty-nine (39) degrees Centigrade. Thus, it is preferred that the wax material of which energy absorptive material is constructed melt at that temperature. Inductive coupling between primary coil 54 of external antenna 52 and secondary coil of implantable medical device 16 is accomplished at a drive, or carrier, frequency, fcarrier, in the range of from eight (8) to twelve (12) kiloHertz. In a preferred embodiment, the carrier frequency fcarrier, of external antenna 54 is approximately nine (9) kiloHertz unloaded. However, the inductive coupling between primary coil 54 of external antenna 52 and secondary coil 34 of implantable medical device is dependent upon the mutual inductance between the devices. The mutual inductance depends upon a number of variables. Primary coil 54 is preferably made from a coil of wire that has an inductance L and a series or parallel tuned capacitance C. The values of both inductance L and capacitance C are fixed. For instance, if the desired drive frequency, fcarrier, of the energy transfer system was to be 1 megaHertz and external antenna 52 had an independence of one microHenry, capacitance would be added so that the resonant frequency of the energy transfer system would equal that of the drive frequency, fcarrier. The total capacitance added can be found using the equation fresonate equals one divided by two times pi (π) times the square root of L times C where L is the inductance of the energy transfer system. In this example, the value of capacitance C required to tune external antenna 52 to resonate at the carrier frequency of 1 megaHertz is calculated as approximately 25 nanofarads. However, when the electrical properties of external antenna 52 change, either by the reflected environment or due to a physical distortion or change in the composition of the external antenna 52, the inductance, L, may be altered. The inductance, L, can be altered because it is made up of two separate parts. The first part is the self-inductance, Lself, of external antenna 52 at fcarrier. The second part is the mutual inductance, Lmutual, which is a measure of the change in current driving external antenna 52 and the magnetic effect, or “loading”, which the environment has on external antenna 52. When the electrical characteristics of the environment of external antenna 52 change, Lself remains constant while Lmutual varies. The effect of a change in the overall inductance, whether that change is from Lself or from Lmutual, is a change in the resonant frequency, fresonate. Since C was chosen in order to have the resonant frequency, fresonate, match the drive frequency, fcarrier, in order to increase the efficiency of energy transfer from primary coil 54 of external antenna 52 to secondary coil 34, a change in either or can result in the resonant frequency, fresonate, being mismatched with the drive frequency, fcarrier. The result can be a less than optimum efficiency of energy transfer to implantable medical device 16. As the drive frequency, fcarrier, varies with respect to the resonant frequency, fresonate, apparent impedance of the energy transfer system, as seen by primary coil 54, will vary. The apparent impedance will be at a minimum when the drive frequency, fcarrier, exactly matches the resonant frequency, fresonate. Any mismatch of the drive frequency, fcarrier, from the resonant frequency, will cause the impedance to increase. Maximum efficiency occurs when the drive frequency, fcarrier, matches the resonant frequency, fresonate. As the impedance of the energy transfer system varies, so does the current driving primary coil 54. As the impedance of the energy transfer system increases, the current driving primary coil 54 will decreases since the voltage being applied to primary coil 54 remains relatively constant. Similarly, the current driving primary coil 54 will increase as the impedance of the energy transfer system decreases. It can be seen then that point of maximum current driving primary coil 54 will be at a maximum when the impedance of the energy transfer system is at a minimum, when the resonant frequency, fresonate, matches the drive frequency, fcarrier, and when maximum efficiency occurs. The impedance of the energy transfer system can be monitored since the current driving primary coil 54 varies as a function of drive frequency, fcarrier. The drive frequency can be varied and the current driving primary coil can be measured to determine the point at which the impedance of the energy transfer system is at a minimum, the resonant frequency, fresonate, matches the drive frequency, fcarrier, and when maximum efficiency occurs. In a preferred embodiment, instead of holding the drive frequency, fcarrier, constant for a nominal resonant frequency, fresonate, the drive frequency, fcarrier, is varied until the current driving primary coil 54 is at a maximum. This is not only the point at which the impedance of the energy transfer system is at a minimum but also the point at which maximum efficiency occurs. Maximum efficiency is not as important in systems, such as telemetry systems, which are utilized in a static environment or for relatively short periods of time. In a static environment, the resonant frequency, fresonate, may be relatively invariable. Further, efficiency in not terribly important when energy or information transfer occurs over a relatively short period of time. However, transcutaneous energy transfer systems can be utilized over extended periods of time, either to power the implanted medical device 16 over an extended period of time or to charge a replenishable power supply within implanted medical device 16. Depending upon capacity of the replenishable power supply and the efficiency of energy transfer, charging unit 50 can be utilized for hours and typically can be used as patient 18 rests or over night as patient 18 sleeps. Further, over the extended period of time in which charging unit 50 is utilized, external antenna 52 is affixed to the body of patient 18. As patient 18 attempts to continue a normal routine, such as by making normal movement or by sleeping, during energy transfer, it is difficult to maintain external antenna 52 in a completely fixed position relative to secondary coil 34. Movement of external antenna 52 with respect to secondary coil 34 can result in a change in mutual inductance, Lmutual, a change in impedance and a change in the resonant frequency, fresonate. Further, any change in spatial positioning of the energy transfer system with any external conductive object, any change in the characteristics of external antenna 52, such as by fractures in magnetic core 58, for example, a change in the charge level of rechargeable power source 24 of implantable medical device 16 or a change in the power level of charging unit 50, all can result in a change of mutual inductance, Lmutual. In a preferred embodiment, drive frequency, fcarrier, is varied, not only initially during the commencement of energy transfer, e.g., charging, but also during energy transfer by varying the drive frequency, fcarrier, in order to match the drive frequency, with the resonant frequency, fresonate, and, hence, maintaining a relatively high efficiency of energy transfer. As an example, drive frequency, fcarrier, can be constantly updated to seek resonant frequency, fresonate, or drive frequency, fcarrier, can be periodically updated, perhaps every few minutes or every hour as desired. Such relatively high efficiency in energy transfer will reduce the amount of time charging unit 50 will need to be operated, for a given amount of energy transfer, e.g., a given amount of battery charge. A reduced energy transfer, or charging, time can result in a decrease in the amount of heating of implanted medical device 16 and surrounding tissue of patient 18. In a preferred embodiment, external charging device 48 incorporates temperature sensor 87 in external antenna 52 and control circuitry in charging unit 50 which can ensure that external antenna 52 does not exceed acceptable temperatures, generally a maximum of thirty-eight degrees Centigrade (38° C.). Temperature sensor 87 in external antenna 52 can be used to determine the temperature of external antenna 52. Temperature sensor 87 can be positioned in close proximity to thermally conductive material 62 in order to obtain reasonably accurate information on the temperature of the external surface of external antenna 52 contacting patient 18. Preferably, temperature sensor 87 is affixed to thermally conductive material 62 with a thermally conductive adhesive. Thermally conductive material 62 smoothes out any temperatures differences which otherwise might occur on the surface of external antenna 52 contacting patient 18. Positioning temperature sensor 87 in the proximity or touching thermally conductive material 62 enables an accurate measurement of the contact temperature. Control circuitry using the output from temperature sensor 87 can then limit the energy transfer process in order to limit the temperature which external antenna 52 imparts to patient 18. As temperature sensor 87 approaches or reaches preset limits, control circuitry can take appropriate action such as limiting the amount of energy transferred, e.g., by limiting the current driving primary coil 54, or limiting the time during which energy is transferred, e.g., by curtailing energy transfer or by switching energy transfer on and off to provide an energy transfer duty cycle of less than one hundred percent. When the temperature sensed by the temperature sensor is well below preset temperature limits, it may be acceptable to report the temperature with relatively less precision. As an example, if the temperature sensed by temperature sensor 87 is more than two degrees Centigrade (2° C.) away from a preset limit of thirty-eight degrees Centigrade (38° C.), it may be acceptable to know the temperature with an accuracy of three degrees Centigrade (3° C.). However, when the temperature of external antenna 52 approaches to within two degrees Centigrade (2° C.), it may be desirable to know the temperature with a much greater accuracy, for example, an accuracy of within one tenth of one degree Centigrade (0.1° C.). It is generally difficult, however, to produce a temperature which has a high degree of accuracy over a very broad temperature range. While a temperature sensor can easily be produced to provide a resolution within one-tenth of one degree Centigrade (0.1° C.) over a relatively narrow range temperatures, it can be difficult to produce a temperature sensor providing such a resolution over a broad range of temperatures. In a preferred embodiment, a dual range temperature sensor is utilized. This temperature sensor has a first, broad, less accurate range of measurement from thirty-one degrees Centigrade (31° C.) to forty degrees Centigrade (40° C.) having an accuracy within three degrees Centigrade (3° C.). Further, this temperature sensor has a second, narrow, more accurate range of measurement over four degrees Centigrade (4° C.), from thirty-six degrees Centigrade (36° C.) to forty degrees Centigrade (40° C.), having an accuracy within one-tenth of one degree Centigrade (0.1° C.). FIG. 16 illustrates a preferred embodiment of a dual range temperature sensor utilizing temperature sensor 87. Temperature sensor 87, located in external antenna 52, is coupled to amplifier 170 which has been pre-calibrated to operate only in the range of from thirty-six degrees Centigrade (36° C.) to forty degrees Centigrade (40° C.). Components of amplifier 170 have an accuracy reflecting a temperature within one-tenth of one degree Centigrade (0.1° C.). The analog output of amplifier 170 is sent to analog-to-digital converter 172 producing a digital output 173 having an accuracy of one-tenth of one degree Centigrade (0.1° C.). The analog output of amplifier 170 is also sent to comparator 174 which compares the analog output against a known reference voltage 176 which is set to at a predetermined level to produce a positive output 178 when temperature sensor 87 reflects a temperature of thirty-eight degrees Centigrade (38° C.), the maximum temperature permitted for external antenna 52. Control logic in charging unit 50 can then take appropriate action to limit further temperature increases such as by ceasing or limiting further energy transfer and/or charging. Temperature sensor 87 is also coupled to amplifier 182. Components of amplifier 182 have an accuracy reflecting a temperature within three degrees Centigrade (3° C.), much less accuracy than amplifier 170, but amplifier 182 can operate over the much larger temperature range of thirty-one degrees Centigrade (31° C.) to forty-five degrees Centigrade (45° C.). The output of amplifier 182 is sent to analog-to-digital converter 184 producing a digital output 186 having an accuracy of three degrees Centigrade (3° C.). Some or all of the various features of implantable medical device 16 and charging unit 50 described enable a system for transcutaneous energy transfer having a relatively high efficiency of energy transfer, especially in situations involving some latitude of maladjustment of external antenna 52 with secondary coil 34. High efficiency of energy transfer can enable a rechargeable power source 24 of implantable medical device 16 to be charged, or recharged, within a shorter period of time than would otherwise be possible. Alternatively or in addition, high efficiency of energy transfer can enable transcutaneous energy transfer to occur at higher rate than would otherwise be possible since more of the energy generated by charging unit 50 is actually converted to charging rechargeable power source 24 instead of generating heat in implanted medical device 16 and/or surrounding tissue of patient 18. Alternatively or in addition, high efficiency of energy transfer can result in lower temperatures being imparted to implanted medical device 16 and/or surrounding tissue of patient 18. Alternatively or in addition, high efficiency of energy transfer can enable a greater degree of maladjustment of external antenna 52 with secondary coil 34 effectively resulting in patient 18 being able to be more ambulatory. Thus, embodiments of the external power source for an implantable medical device having an adjustable magnetic core and system and method related thereto are disclosed. One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>Implantable medical devices for producing a therapeutic result in a patient are well known. Examples of such implantable medical devices include implantable drug infusion pumps, implantable neurostimulators, implantable cardioverters, implantable cardiac pacemakers, implantable defibrillators and cochlear implants. Of course, it is recognized that other implantable medical devices are envisioned which utilize energy delivered or transferred from an external device. A common element in all of these implantable medical devices is the need for electrical power in the implanted medical device. The implanted medical device requires electrical power to perform its therapeutic function whether it be driving an electrical infusion pump, providing an electrical neurostimulation pulse or providing an electrical cardiac stimulation pulse. This electrical power is derived from a power source. Typically, a power source for an implantable medical device can take one of two forms. The first form utilizes an external power source that transcutaneously delivers energy via wires or radio frequency energy. Having electrical wires which perforate the skin is disadvantageous due, in part, to the risk of infection. Further, continuously coupling patients to an external power for therapy is, at least, a large inconvenience. The second form utilizes single cell batteries as the source of energy of the implantable medical device. This can be effective for low power applications, such as pacing devices. However, such single cell batteries usually do not supply the lasting power required to perform new therapies in newer implantable medical devices. In some cases, such as an implantable artificial heart, a single cell battery might last the patient only a few hours. In other, less extreme cases, a single cell unit might expel all or nearly all of its energy in less than a year. This is not desirable due to the need to explant and re-implant the implantable medical device or a portion of the device. One solution is for electrical power to be transcutaneously transferred through the use of inductive coupling. Such electrical power or energy can optionally be stored in a rechargeable battery. In this form, an internal power source, such as a battery, can be used for direct electrical power to the implanted medical device. When the battery has expended, or nearly expended, its capacity, the battery can be recharged transcutaneously, via inductive coupling from an external power source temporarily positioned on the surface of the skin. Several systems and methods have been used for transcutaneously inductively recharging a rechargeable used in an implantable medical device. U.S. Pat. No. 5,411,537, Munshi et al, Rechargeable Biomedical Battery Powered Devices With Recharging and Control System Therefor, (Intermedics, Inc.) discloses a hermetically-sealed automatic implantable cardioverter-defibrillator (AICD) or any other bioimplantable device which may be operated on a single rechargeable cell, or a dual power source system, the rechargeable complement being recharged by magnetic induction. Included in the implantable devices are lithium rechargeable chemistries designed to sense the state-of-charge or discharge of the battery; a battery charge controller specifically designed to recharge a lithium battery rapidly to less than 100% full charge, and preferably 90%, more preferably 80%, of full rated charge capacity; and charging means for multi-step charging. The batteries are based on lithium chemistries specially designed to yield higher currents than conventional primary lithium chemistries and to permit long-term performance despite sub-capacity recharging. U.S. Pat. No. 5,690,693, Wang et al, Transcutaneous Energy Transmission Circuit For Implantable Medical Device, (Sulzer Intermedics Inc.) discloses a transcutaneous energy transmission device for charging rechargeable batteries in an implanted medical device. A current with a sinusoidal waveform is applied to a resonant circuit comprising a primary coil and a capacitor. Current is induced in a secondary coil attached to the implanted medical device. Two solid-state switches are used to generate the sinusoidal waveform by alternately switching on and off input voltage to the resonant circuit. The sinusoidal waveform reduces eddy current effects in the implanted device which detrimentally increases the temperature of the implanted device. The batteries are charged using a charging protocol that reduces charging current as the charge level in the battery increases. The controller is constructed as a pulse with modulation device with a variable duty cycle to control the current level applied to the primary coil. An alignment indicator is also provided to insure proper and alignment between the energy transmission device and the implanted medical device. U.S. Pat. No. 5,733,313, Barreras, Sr., FR Coupled Implantable Medical Device With Rechargeable Back-Up Power Source, (Exonix Corporation) discloses an implantable, electrically operated medical device system having an implanted radio frequency (RF) receiving unit (receiver) incorporating a back-up rechargeable power supply and an implanted, electrically operated device, and an external RF transmitting unit (transmitter). RF energy is transmitted by the transmitter and is coupled into the receiver which is used to power the implanted medical device and/or recharge the back-up power supply. The back-up power supply within the receiver has enough capacity to be able to, by itself, power the implanted device coupled to the receiver for at least 24 hours during continual delivery of medical therapy. The receiver is surgically implanted within the patient and the transmitter is worn externally by the patient. The transmitter can be powered by either a rechargeable or non-rechargeable battery. In a first mode of operation, the transmitter will supply power, via RF coupled energy, to operate the receiver and simultaneously recharge the back-up power supply. In a second mode of operation, the receiver can, automatically or upon external command from the transmitter, acquire its supply of power exclusively from the back-up power supply. Yet, in a third mode of operation, the receiver can, automatically or upon command from the transmitter, alternatively acquire it supply of power from either, FR energy coupled into the receiver or the internal back-up power supply. U.S. Pat. No. 6,308,101, Faltys et al, Fully Implantable Cochlear Implant System, (Advanced Bionics Corporation) discloses a fully implantable cochlear implant system and method including an implantable cochlear stimulator unit that is connected to an implantable speech processor unit. Both the speech processor unit and the cochlear stimulator unit are in separate, hermetically-sealed, cases. The cochlear stimulator unit has a coil permanently connected thereto through which magnetic or inductive coupling may occur with a similar coil located externally during recharging, programming, or externally-controlled modes of operation. The cochlear stimulator unit further has a cochlear electrode array permanently connected thereto via a first multi-conductor cable. The cochlear stimulator unit also has a second multi-conductor cable attached thereto, which second cable contains no more than five conductors. The second cable is detachably connected to the speech processor unit. The speech processor unit includes an implantable subcutaneous microphone as an integral part thereof, and further includes speech processing circuitry and a replenishable power source, e.g., a rechargeable battery. U.S. Pat. No. 6,324,430, Zarinetchi et al, Magnetic Shield For Primary Coil of Transcutaneous Energy Transfer Device, (Abiomed, Inc.) discloses a transcutaneous energy transfer device which has a magnetic shield covering the primary winding of the device to reduce sensitivity of the device to conducting objects in the vicinity of the coils and to increase the percentage of magnetic field generated by the primary coil which reaches the secondary coil. The shield is preferably larger than the primary coil in all dimensions and is either formed of a high permeability flexible material, for example a low loss magnetic material and a flexible polymer matrix, with perforations formed in the material sufficient to permit ventilation of the patient's skin situated under the shield, or the shield may be formed of segments of a very high permeability material connected by a flexible, porous mesh material. U.S. Pat. No. 6,516,227, Meadows et al, Rechargeable Spinal Cord Stimulator System, (Advanced Bionics Corporation) discloses a spinal cord stimulation system providing multiple stimulation channels, each capable of producing up to 10 milliamperes of current into a one kilohm load. The system further includes a replenishable power supply, e.g., a rechargeable battery that requires only an occasional recharge, and offers a life of at least 10 years at typical settings. The replenishable power source may be replenished using non-invasive means. The system monitors the state of charge of the internal power source and controls the charging process by monitoring the amount of energy used by the system, and hence the state of the charge of power source. A suitable bidirectional telemetry link allows the system to inform the patient or clinician regarding the status of the system, including the state of the charge, and makes requests to initiate an external charge process. U.S. Pat. No. 6,505,077, Kast et al, Implantable Medical Device With External Recharging Coil Electrical Connection, (Medtronic, Inc.) discloses a rechargeable implantable medical device with an improved external recharging coil electrical connection resistant to corrosion. The electrical connection couples the external recharging coil to a recharge feedthrough. The rechargeable implantable medical device can be a medical device such as a neuro stimulator, drug delivery pump, pacemaker, defibrillator, diagnostic recorder, cochlear implant, and the like. The implantable medical device has a housing, electronics carried in the housing configured to perform a medical therapy, a rechargeable power source, and a recharging coil. European Patent Application 1,048,324, Schallhorn, Medical Li+ Rechargeable Powered Implantable Stimulator, (Medtronic, Inc.) discloses an implantable stimulator having a rechargeable lithium ion power source and delivers electrical stimulation pulses, in a controlled manner, to a targeted site within a patient. The lithium ion power source can supply sufficient power to the implantable stimulator on an exclusive basis over at least about 4 days. The power source includes a high value, small size lithium ion storage unit having a power rating of at least 50 milliamp hours. The implantable stimulator also has an inductor adapted to gather EMF power transmissions. The implantable stimulator can be replenished with electrical power by an electrical power replenisher, external to the implantable stimulator, to replenish the lithium ion power source up to its maximum rated voltage by generating the EMF power transmission near the inductor. PCT Patent Application No. WO 01/83029 A1, Torgerson et al, Battery Recharge Management For an Implantable Medical Device, (Medtronic, Inc.) discloses an implantable medical device having an implantable power source such as a rechargeable lithium ion battery. The implantable medical device includes a recharge module that regulates the recharging process of the implantable power source using closed-loop feedback control. The recharging module includes a recharge regulator, a recharge measurement device monitoring at least one recharge parameter, and a recharge regulation control unit for regulating the recharge energy delivered to the power source in response to the recharge measurement device. The recharge module adjusts the energy provided to the power source to ensure that the power source is being recharged under safe levels. PCT Patent Application No. WO 01/97908 A2, Jimenez et al, An Implantable Medical Device With Recharging Coil Magnetic Shield, (Medtronic, Inc.) discloses a rechargeable implantable medical device with a magnetic shield placed on the distal side of a secondary recharging coil to improve recharging efficiency. The rechargeable implantable medical device can be wide variety of medical devices such as neurostimulators, drug delivery pumps, pacemakers, defibrillators, diagnostic recorders, and cochlear implants the implantable medical device has a secondary recharging coil carried over a magnetic shield and coupled to electronics and a rechargeable power source carried inside the housing electronics are configured to perform a medical therapy. Additionally a method of for enhancing electromagnetic coupling during recharging of an implantable medical device is disclosed, and a method for reducing temperature rise during recharging of an implantable medical device is disclosed. Transcutaneous energy transfer through the use of inductive coupling involves the placement of two coils positioned in close proximity to each other on opposite sides of the cutaneous boundary. The internal coil, or secondary coil, is part of or otherwise electrically associated with the implanted medical device. The external coil, or primary coil, is associated with the external power source or external charger, or recharger. The primary coil is driven with an alternating current. A current is induced in the secondary coil through inductive coupling. This current can then be used to power the implanted medical device or to charge, or recharge, an internal power source, or a combination of the two. For implanted medical devices, the efficiency at which energy is transcutaneously transferred is crucial. First, the inductive coupling, while inductively inducing a current in the secondary coil, also has a tendency to heat surrounding components and tissue. The amount of heating of surrounding tissue, if excessive, can be deleterious. Since heating of surrounding tissue is limited, so also is the amount of energy transfer which can be accomplished per unit time. The higher the efficiency of energy transfer, the more energy can be transferred while at the same time limiting the heating of surrounding components and tissue. Second, it is desirable to limit the amount of time required to achieve a desired charge, or recharge, of an internal power source. While charging, or recharging, is occurring the patient necessarily has an external encumbrance attached to their body. This attachment may impair the patient's mobility and limit the patient's comfort. The higher the efficiency of the energy transfer system, the faster the desired charging, or recharging, can be accomplished limiting the inconvenience to the patient. Third, amount of charging, or recharging, can be limited by the amount of time required for charging, or recharging. Since the patient is typically inconvenienced during such charging, or recharging, there is a practical limit on the amount of time during which charging, or recharging, should occur. Hence, the size of the internal power source can be effectively limited by the amount of energy which can be transferred within the amount of charging time. The higher the efficiency of the energy transfer system, the greater amount of energy which can be transferred and, hence, the greater the practical size of the internal power source. This allows the use of implantable medical devices having higher power use requirements and providing greater therapeutic advantage to the patient and/or extends the time between charging effectively increasing patient comfort. Prior art implantable medical devices, external power sources, systems and methods have not always provided the best possible system or method for allowing the patient to be ambulatory during energy transfer and/or charging. Physical limitations related to the energy transfer and/or charging apparatus and methods as well as necessary efficiencies of operation have effectively limited the patient's ability to move around during such energy transfer and/or charging and have deleteriously affected patient comfort. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>In one embodiment, the present invention provides an external power system for transcutaneous energy transfer to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. An external power source has a primary coil contained in a housing. The external power source is capable of providing energy to the implantable medical device when the primary coil of the external power source is placed in proximity of the secondary coil of the implantable medical device. A holder is adapted to be externally positioned with respect to the patient at a spot in proximity of the location of the implantable medical device and secured at the spot. The holder is attachable to the housing after the holder is secured to the patient. In another embodiment, the present invention provides a system for transcutaneous energy transfer. An implantable medical device has componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. An external power source has a primary coil contained in a housing. The external power source is capable of providing energy to the implantable medical device when the primary coil of the external power source is placed in proximity of the secondary coil of the implantable medical device. A holder is adapted to be externally positioned with respect to the patient at a spot in proximity of the location of the implantable medical device and secured at the spot. The holder is attachable to the housing after the holder is secured to the patient. In a preferred embodiment, a belt is coupled to the holder and adapted to secure the holder to the patient. In a preferred embodiment, the holder has a flexible body portion having a central opening and a pair of pivot points positioned laterally on either side of a central axis. The pair of pivot points facilitate pivotal attachment of the housing to the holder. In a preferred embodiment, the external power source has a repositionable magnetic core located in the housing. In a preferred embodiment, the external power source has circuitry coupled to the temperature sensor operative to limit the energizing at least in part as a function of the temperature. In another embodiment, the present invention provides a method of transcutaneous energy transfer from an external power source having a primary coil contained in a housing to an implantable medical device having componentry for providing a therapeutic output and a secondary coil operatively coupled to the componentry. The implantable medical device is adapted to implanted at a location in a patient. A holder is placed with respect to the patient at a spot in proximity of the location of the implantable medical device. The holder is secured at the spot. The housing is then attached to the holder. In a preferred embodiment, the holder has a surface closest to the implantable medical device and wherein the surface has a durometer of about 40 Shore A. In a preferred embodiment, the surface of the holder is constructed of PCABS. In a preferred embodiment, a surface of the housing closest to the secondary coil is thermally conductive. In a preferred embodiment, the external power source has a temperature sensor thermally coupled to the surface of the housing. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having a resonant frequency. The circuitry adjusts the carrier frequency to the resonant frequency. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having an impedance. The circuitry adjusts the carrier frequency to minimize the impedance. In a preferred embodiment, the external power has circuitry, operatively coupled to the primary coil, capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency when the primary coil of the external power source is externally placed in proximity of the secondary coil creating a tuned inductive circuit having an energy transfer efficiency. The circuitry adjusts the carrier frequency to increase the energy transfer efficiency of the inductively tuned circuit. In a preferred embodiment, the implantable medical device has a rechargeable power source operatively couple to the secondary coil and to the componentry. In a preferred embodiment, the securing step is accomplished using a belt coupled to the holder. In a preferred embodiment, the attaching step pivotally attaches the housing to the holder. In a preferred embodiment, a magnetic core located in the housing is repositioned to improve efficiency of the transcutaneous energy transfer. In a preferred embodiment, the energizing step is limited at least in part as a function of a temperature of a temperature sensor thermally coupled to the surface of the housing. | 20040430 | 20090407 | 20050407 | 94992.0 | 0 | BERTRAM, ERIC D | AMBULATORY ENERGY TRANSFER SYSTEM FOR AN IMPLANTABLE MEDICAL DEVICE AND METHOD THEREFORE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,609 | ACCEPTED | Method for removing Cryptosporidium oocysts from water | A method for stabilizing and removing Cryptosporidium oocysts or Giardia cysts from water. The method comprises adding chitosan, a salt or solution of chitosan to water containing Cryptosporidium oocysts or Giardia cysts and a halogenating agent. The method may also include adding a secondary polyelectrolyte flocculant to the water. The resulting flocs are filtered to remove the Cryptosporidium oocysts or Giardia cysts. | 1. A method for removing Cryptosporidium oocysts or Giardia cysts from water containing a halogenating agent, comprising: adding chitosan to water comprising Cryptosporidium oocysts or Giardia cysts and a halogenating agent, wherein the Cryptosporidium oocysts or Giardia cysts have been exposed to the halogenating agent for a period of time effective to oxidize at least a portion of the Cryptosporidium oocysts or Giardia cysts, before adding the chitosan to the water; allowing the Cryptosporidium oocysts or Giardia cysts and the chitosan to form stabilized flocs in the water; and filtering the flocs of the Cryptosporidium oocysts or Giardia cysts and chitosan to remove the Cryptosporidium oocysts or Giardia cysts from the water. 2. The method of claim 1, wherein the chitosan is in solution. 3. The method of claim 2, wherein the solution comprises acetic acid. 4. The method of claim 1, further comprising adding an anionic or cationic polyelectrolyte flocculant to the water before, during or after adding the chitosan. 5. The method of claim 4, wherein the polyelectrolyte flocculant comprises at least one of alginate, hexametaphosphate, carboxymethylcellulose, pectin, polyaluminum hydroxychloride, polyaluminum silicate sulfate, polyaluminum sulfate or polyacrylamide. 6. The method of claim 4, wherein said polyelectrolyte flocculant is about 5 ppb to about 100 ppm by weight in water. 7. The method of claim 1, wherein the water is in a swimming pool, spa, water park, hot tub, bath, or potable or nonpotable source. 8. The method of claim 1, comprising filtering the flocs in at least one of a sand, cartridge or diatomaceous earth filter. 9. The method of claim 1, further comprising adding an inorganic aluminum coagulant. 10. The method of claim 9, wherein said inorganic aluminum coagulant is aluminum sulfate or polyaluminum chloride. 11. The method of claim 9, wherein the inorganic aluminum coagulant is about 50 ppb to about 100 ppm by weight in water. 12. The method of claim 1, further comprising adding a ferric salt coagulant. 13. The method of claim 12, wherein said ferric salt coagulant is ferric sulfate or ferric chloride. 14. The method of claim 12, wherein said ferric salt coagulant is about 50 ppb to about 100 ppm by weight in water. 15. The method of claim 1, wherein said chitosan is about 5 ppb to about 100 ppm by weight in water. 16. The method of claim 1, wherein the halogenating agent comprises at least one of sodium hypochlorite, calcium hypochlorite, chlorine, hypochlorous acid, bromine, hypobromous acid, N-chlorosuccinimide, sodium hypobromite, pyridinium bromide perbromide, N-bromosuccinimide, chloramine-T, chlorhexadine, biguanides, dichlorodimethylhydantoin, bromochlorodimethylhydantoin dibromodimethylhydantoin, dichloroisocyanurate, or trichloroisocyanurate. 17. The method of claim 1, wherein said halogenating agent is about 1 ppm to about 50 ppm by weight in water. 18. The method of claim 1, wherein said halogenating agent is about 2 ppm to about 20 ppm by weight in water. | FIELD OF THE INVENTION Pathogens, such as Cryptosporidium oocysts and Giardia cysts, are removed from water containing a halogenating agent by the addition of chitosan. The resulting flocs of Cryptosporidium oocysts or Giardia cysts and chitosan are then filtered to remove the Cryptosporidium oocysts or Giardia cysts from the water. BACKGROUND OF THE INVENTION Cryptosporidium is a water-borne parasitic protozoan responsible for the water-borne disease Cryptosporidiosis. Outbreaks of Cryptosporidiosis have been attributed to ingestion of drinking water, recreational water or food containing viable oocysts of Cryptosporidium. Cryposporidium oocysts are typically introduced into the water through contamination of the water with fecal matter from cattle or humans containing oocysts. The oocysts have a hard outer cell wall that renders the oocysts resistant to the effects of chlorine present at concentrations typical of drinking water and recreational water. The oocyts are approximately 4-6 microns in size, which makes them difficult to remove by filtration. Since filtration and chlorination are universally practiced as a means for clarifying and sanitizing drinking water in municipal water treatment facilities and for maintaining the clarity of recreational water such as in swimming pools, water parks, hot tubs and spas, the chlorine resistance and size of the oocysts make it difficult to ensure that water is free of this disease-causing microorganism. A variety of filters and filter medias are used to clarify water in swimming pools, water parks, hot tubs and spas. Sand filters are common for swimming pool use and municipal water treatment. Diatomaceous earth filters are also available for use in swimming pools and water parks. Cartridge filters available to both pools and spas utilize a synthetic fabric enclosed in a plastic cartridge. Different filter media exhibit different capabilities for removing particles that vary in size. Sand filters are capable of filtering out particles in the size range of 20-25 microns, while cartridge filters are typically capable of removing particles in the size range of 5-10 microns. Diatomaceous earth filters exhibit the capability of removing particles in the size range of 1-3 microns, but have to be replaced frequently. Coagulation and flocculation followed by filtration is commonly utilized in the treatment of drinking and recreational water to remove suspended microscopic particles. Non-filterable suspended microscopic particles tend to possess an electrostatic charge that prevents the particles from aggregating into larger filterable aggregates due to charge-charge repulsion. This can be often overcome through the use of coagulants and flocculants. Coagulants are chemicals, that when dissolved in water, form ions of charge opposite to that of the suspended particles. The charge interaction of the coagulant with the particles results in the reduction of the particle's charge or so called zeta potential. Reduction of the particle's zeta potential reduces particles' charge-charge repulsion and allows the particles to come sufficiently close together to form aggregates large enough to be filtered out. The most commonly used coagulants are metal salts such as aluminum sulfate and ferric chloride and their use is highly dependent on both pH and dosage. Flocculants are typically water soluble or water dispersible high molecular weight polyelectrolyte long chain polymers composed of repeating monomeric units that can be categorized into inorganic or organic compounds. The inorganic polyelectrolytes are polymerized metal salts and may include polyaluminum hydroxychloride, polyaluminum silicate sulfate and polyaluminum sulfate. Organic polyelectrolyte flocculants are derived synthetically or obtained from natural sources. The organic polyelectrolytes can exist as charged or uncharged polymers depending on their composition. Flocculants when added to water containing aggregates of microscopic particles or non-aggregated particles exhibit the ability to bind and gather the particles or particle aggregates into even larger aggregates that can be easily filtered. The success of this aggregation is dependent on a variety of properties unique to the particles or particle aggregates and the properties of the particular flocculant being used. The stability of the flocculated particles or aggregated particles can be important to successful removal by filtration. Unstable flocculated particles or particle aggregates may come apart during filtration and pass through the filter while only the more stable aggregates are retained. Aggregate stability can be influenced by the flow rate and pressure across the filter and the turbulence of the water. Previous attempts at removing Cryptosporidium oocysts via filtration from large bodies of water moving at high flow rates have not been successful. Since Cryptosporidium oocysts are negatively charged, coagulants and flocculants such as ferric sulfate, ferric chloride, aluminum sulfate or polyaluminum chloride have been tried unsuccessfully as a means to remove the oocysts from water through the process of aggregation, settling and filtration. Although flocs of oocysts are formed using these particular coagulants, the Cryptosporidium oocyst flocs are unstable and subject to hydrodynamic shear forces that make them susceptible to breaking up and coming apart resulting in their not being retained on filters. The use of anionic or cationic polymeric polyelectrolyte flocculants has been suggested as a means to stabilize Cryptosporidium oocyst-containing flocs against shear. One such study involving dissolved air flotation (DAF) was performed using ferric sulfate as the primary coagulant and LT22, a cationic acrylamide co-polymer. No improvement in oocyst removal over that expected with ferric sulfate coagulant alone was observed. Sand filtration for removing Cryptosporidium oocysts from water has been evaluated with some success. Rapid sand filtration has been reported to remove 3 logs of Cryptosporidium oocysts. Slow sand filtration that utilizes a finer grain of sand and a slower flow rate was reported in a pilot scale study to be fairly good in removing Cryptosporidium oocysts without having to use flocculants or coagulants. The previous coagulants and flocculants cannot be used in conjunction with slow sand filtration because they tend to clog the pores and severely restrict the flow rate. Currently there is no methodology that is effective in stabilizing flocs of Cryptosporidium oocysts for their significant removal from water through aggregation followed by filtration. Accordingly, there is a need to find a flocculant or coagulant or a combination of the two for obtaining significant removal of oocysts that can take advantage of existing filtration technology such as sand, diatomaceous earth or synthetic cartridge filters to provide safe water for recreation and drinking. SUMMARY OF THE INVENTION The present invention relates to a method of removing Cryptosporidium oocysts or Giardia cysts from water containing a halogenating agent. The method includes adding chitosan, chitosan salt, or a solution thereof to water containing Cryptosporidium oocysts or Giardia cysts and a halogenating agent. Before adding the chitosan to the water, the Cryptosporidium oocysts or Giardia cysts have been exposed to a halogenating agent for a period of time that is effective to oxidize at least a portion of the Cryptosporidium oocysts or Giardia cysts. Adding chitosan to the water containing the Cryptosporidium oocysts or Giardia cysts and a halogenating agent will result in flocs that are aggregates of Cryptosporidium oocysts or Giardia cysts and chitosan. Flocs of Cryptosporidium oocysts or Giardia cysts with chitosan are stabililized so that the Cryptosporidium oocysts or Giardia cysts can then be removed from the water by filtering the water in conventional filters. In other embodiments, a polyelectrolyte flocculant, other than the chitosan, and a coagulant can be added to the water before, after, or during the addition of the chitosan to the water. The method according to the invention is particularly useful in water that is presently being treated with a halogenating agent, so that the addition of chitosan is supplemental and subsequent to treatment with a halogenating agent. However, the conventional treatments utilizing halogenating agents alone are ineffective in rendering Cryptosporidium oocysts or Giardia cysts inactive. Treating water in a manner according to the invention will result in the flocculation of these pathogens into stabilized flocs that can then be removed with the use of conventional filters. Pathogen contaminated water can come from swimming pools, water parks, hot tubs, spas, and any potable or nonpotable water sources. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The term “chitosan” as used herein refers to a copolymer having greater than 65% by weight of 2-deoxy-2-aminoglucose monomeric units with the remainder of the monomeric units being 2-deoxy-2-acetamidoglucose units. Chitosan is derived from chitin by hydrolysis of some 2-deoxy-2-acetamidoglucose units to 2-deoxy-2-aminoglucose units. Due to the presence of free amino groups, chitosan is soluble in aqueous acidic solutions and is present in such media as a polycation with some of the protonated amino groups bearing a positive charge. One embodiment of a chitosan solution comprising chitosan and glacial acetic acid for use in the method according to the invention is known under the designation SEA-KLEAR, and is available from Vanson HaloSource, Inc. of Redmond Wash. The term “halogenating agent” as used herein refers to compounds having a halogen atom bound to a strongly electronegative atom such as oxygen, nitrogen, or another halogen, and capable of donating a positively charged halogen atom. Representative halogenating agents include sodium hypochlorite, calcium hypochlorite, chlorine, hypochlorous acid, bromine, hypobromous acid, aqueous chlorine solutions, aqueous bromine solutions, N-chlorosuccinimide, sodium hypobromite, pyridinium bromide perbromide, N-bromosuccinimide, chloramine-T, chlorhexadine, biguanides, dichlorodimethylhydantoin, bromochlorodimethylhydantoin, dibromodimethylhydantoin, dichloroisocyanurate, trichloroisocyanurate, and combinations thereof. Other suitable halogenating agents will be readily apparent to those skilled in the art. Cryptosporidium oocysts (Cryptosporidium parvum) and Giardia cysts (Giardia duodenalis) are generally not inactivated with the levels of chlorine that are typical in swimming pool, hot tub, spa, water park, potable and nonpotable water applications. Accordingly, an alternate method is removal of these pathogens that avoids resorting to such high levels of chlorine that would render the water unusable. However, even if the levels of chlorine are not sufficient to inactivate the pathogens, the levels of chlorine are sufficient to oxidize Cryptosporidium oocysts and Giardia cysts that can then be removed with chitosan through flocculation and filtration. Cryptosporidium oocysts and Giardia cysts are known to have negative charges on their surfaces. However, the typical flocculants mentioned in the background section above have not proven successful for the flocculation and removal of Cryptosporidium oocysts. According to the present invention, chitosan is used to bond with Cryptosporidium oocysts or Giardia cysts to produce stabilized flocs of Cryptosporidium oocysts or Giardia cysts with chitosan. Chitosan has positively charged sites that bond to the negatively charged Cryptosporidium oocysts or Giardia cysts in a manner that produces a stabilized floc that allows for the removal of Cryptosporidium oocysts and Giardia cysts through filtration. The method according to the invention for removing Cryptosporidium oocysts or Giardia cysts from water that already contains a halogenating agent comprises adding a dose of chitosan to the water already containing the halogenating agent. The amount of halogenating agent in water is preferably in the range of about 1 ppm to about 50 ppm by weight in water. More preferably about 2 ppm or about 3 ppm to about 20 ppm by weight in water. Preferably, the chitosan is dissolved in an acidic solvent to increase the positively charged sites that can bond to Cryptosporidium oocysts or Giardia cysts. The situation of a halogenating agent already being present in water occurs in the context of swimming pools, spas, water parks, hot tubs, and any potable or nonpotable water source. Typically halogenating agents will be present in water that is treated on a routine basis for a purpose besides removing Cryptosporidium oocysts or Giardia cysts. One embodiment of the present invention is the subsequent addition of chitosan to water containing a halogenating agent after the halogenating agent has had time to oxidize the Cryptosporidium oocysts or Giardia cysts. While the exact mechanism through which chitosan and the halogenating agent interact with a Cryptosporidium oocyst or Giardia cyst is not fully understood, one embodiment of the invention provides that sites on the Cryptosporidium oocysts or Giardia cysts be oxidized by the halogenating agent before addition of the chitosan. Oxidation is increased the longer that the Cryptosporidium oocysts or Giardia cysts are exposed to the halogenating agent. While the optimum period of time that the halogenating agent should be given to oxidize sites on the Cryptosporidium oocysts or Giardia cysts is difficult to predict for any given situation, any water that has had a halogenating agent added to it before the addition of chitosan will realize some benefit of Cryptosporidium oocysts and Giardia cysts removal. As an approximation, the period of time to allow for oxidation between the Cryptosporidium oocysts and the halogenating agent is from several days to several hours. However, some oxidation will occur even after a short period, such as an hour or less. Even at these shorter times, chitosan will produce flocs of Cryptosporidium oocysts or Giardia cysts that can then be removed through filtration. When chitosan, a chitosan salt or an aqueous solution of a chitosan salt is in the presence of Cryptosporidium oocysts or Giardia cysts that have been oxidized by a halogenating agent, the result will be stabilized aggregates or flocs of the Cryptosporidium oocysts or Giardia cysts with the chitosan that can then be run through filters within a matter of minutes using the existing filters already installed in the water treatment system. Such filters can include sand filters, cartridge filters and diatomaceous earth filters. The flocs of Cryptosporidium oocysts or Giardia cysts with chitosan are stable under conditions of high water flow rates or velocities that may be encountered in swimming pool, hot tub, water park, spa and potable and nonpotable water filters. “Stable” or “stabilized” floc refers to the ability of a floc to substantially remain intact to allow a majority of the floc's removal through filtration under turbulent conditions or high velocities that are encountered in swimming pool, spa, hot tub, water park, potable and nonpotable water filtration systems. Suitable levels of chitosan to cause flocculation of Cryptosporidium oocysts or Giardia cysts in water are about 5 ppb to about 100 ppm by weight. The pH of the water is believed to have an impact on the effectiveness with which any given halogenating agent will oxidize the Cryptosporidium oocysts or Giardia cysts. For example, sodium hypochlorite exists in water as the anionic chlorite ion and the more oxidative hypochlorous acid. The relative amounts of each species depends on the pH of the water. In systems where pH can be adjusted without harmful effects, it may be beneficial to lower the pH in the case of sodium hypochlorite to produce the more oxidative hypochlorous acid. In one embodiment of the present invention, a negatively or positively charged polyelectrolyte flocculant can be added to the water, before, after or during the addition of the chitosan. Representative polyelectrolyte flocculants, in addition to chitosan, include alginate, hexametaphosphate, carboxymethylcellulose, pectin, polyaluminum hydroxychloride, polyaluminum silicate sulfate, polyaluminum sulfate and polyacrylamide. A negatively charged anionic polyelectrolyte flocculant, for example, will combine with the cationic polyelectrolyte chitosan (bound to the Cryptosporidium oocysts or Giardia cysts) to form a polyelectrolyte complex of larger flocs containing aggregates of Cryptosporidium oocysts or Giardia cysts that are removed from the water by entrapment on a filter. This is particularly effective for filters with larger nominal pore sizes. Suitable levels of polyelectrolyte flocculants in water, not including chitosan, are about 5 ppb to about 100 ppm by weight. In another embodiment of the present invention, a coagulant can be added to the water, before, after or during addition of the chitosan, including with or without the polyelectrolyte flocculant. Representative coagulants include inorganic aluminum or ferric salts, such as ferric or aluminum sulfate or chloride. Suitable levels of coagulant in the water are about 50 ppb to about 100 ppm by weight. EXAMPLE 1 Demonstration of Increased Floc Size Using Both Chitosan and Alginate in Water Containing a Halogenating Agent One liter of deionized water was mixed with about 0.03-0.08 grams of dichlor (a chlorine source). A small drop (˜0.02 grams) of NIVEA lotion or 2 grams of a solution consisting of 0.1 gram NIVEA lotion in 9;9 grams of distilled water was then added to the 1 liter of water containing dichlor. A cloudy solution develops upon mixing. Control water contained all ingredients except dichlor (chlorine source). SEA-KLEAR for spas (0.5% chitosan and 0.5% acetic acid in water wt./wt.) was then added dropwise (10 drops ˜0.4 grams) to the test solution and allowed to mix for about 2-5 minutes. Mixing was stopped and small flocs formed within ˜5 minutes in the dichlor-containing water but not the control water that did not contain dichlor. Mixing was started again and 1 drop (0.04 gram) of a 1% (wt./wt.) sodium alginate in water solution was added. Solution was mixed for about 2-5 minutes, stopped and floc size was measured. Floc size increased in comparison to the same solution without sodium alginate. Control solutions without chlorine did not form flocs. Dichlor Presence Chitosan Alginate (chlorine (Primary (Secondary Floc Size source) Flocculant) Flocculant) (nominal) Yes Yes Yes 2,000-4,000 microns Yes Yes No 500 microns No Yes Yes none No Yes No none Results demonstrate that addition of a secondary anionic polymer flocculant to a solution containing chitosan, chlorine and NIVEA lotion can increase the size of flocculated material, which is not observed in non-chlorine containing water. While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Cryptosporidium is a water-borne parasitic protozoan responsible for the water-borne disease Cryptosporidiosis. Outbreaks of Cryptosporidiosis have been attributed to ingestion of drinking water, recreational water or food containing viable oocysts of Cryptosporidium. Cryposporidium oocysts are typically introduced into the water through contamination of the water with fecal matter from cattle or humans containing oocysts. The oocysts have a hard outer cell wall that renders the oocysts resistant to the effects of chlorine present at concentrations typical of drinking water and recreational water. The oocyts are approximately 4-6 microns in size, which makes them difficult to remove by filtration. Since filtration and chlorination are universally practiced as a means for clarifying and sanitizing drinking water in municipal water treatment facilities and for maintaining the clarity of recreational water such as in swimming pools, water parks, hot tubs and spas, the chlorine resistance and size of the oocysts make it difficult to ensure that water is free of this disease-causing microorganism. A variety of filters and filter medias are used to clarify water in swimming pools, water parks, hot tubs and spas. Sand filters are common for swimming pool use and municipal water treatment. Diatomaceous earth filters are also available for use in swimming pools and water parks. Cartridge filters available to both pools and spas utilize a synthetic fabric enclosed in a plastic cartridge. Different filter media exhibit different capabilities for removing particles that vary in size. Sand filters are capable of filtering out particles in the size range of 20-25 microns, while cartridge filters are typically capable of removing particles in the size range of 5-10 microns. Diatomaceous earth filters exhibit the capability of removing particles in the size range of 1-3 microns, but have to be replaced frequently. Coagulation and flocculation followed by filtration is commonly utilized in the treatment of drinking and recreational water to remove suspended microscopic particles. Non-filterable suspended microscopic particles tend to possess an electrostatic charge that prevents the particles from aggregating into larger filterable aggregates due to charge-charge repulsion. This can be often overcome through the use of coagulants and flocculants. Coagulants are chemicals, that when dissolved in water, form ions of charge opposite to that of the suspended particles. The charge interaction of the coagulant with the particles results in the reduction of the particle's charge or so called zeta potential. Reduction of the particle's zeta potential reduces particles' charge-charge repulsion and allows the particles to come sufficiently close together to form aggregates large enough to be filtered out. The most commonly used coagulants are metal salts such as aluminum sulfate and ferric chloride and their use is highly dependent on both pH and dosage. Flocculants are typically water soluble or water dispersible high molecular weight polyelectrolyte long chain polymers composed of repeating monomeric units that can be categorized into inorganic or organic compounds. The inorganic polyelectrolytes are polymerized metal salts and may include polyaluminum hydroxychloride, polyaluminum silicate sulfate and polyaluminum sulfate. Organic polyelectrolyte flocculants are derived synthetically or obtained from natural sources. The organic polyelectrolytes can exist as charged or uncharged polymers depending on their composition. Flocculants when added to water containing aggregates of microscopic particles or non-aggregated particles exhibit the ability to bind and gather the particles or particle aggregates into even larger aggregates that can be easily filtered. The success of this aggregation is dependent on a variety of properties unique to the particles or particle aggregates and the properties of the particular flocculant being used. The stability of the flocculated particles or aggregated particles can be important to successful removal by filtration. Unstable flocculated particles or particle aggregates may come apart during filtration and pass through the filter while only the more stable aggregates are retained. Aggregate stability can be influenced by the flow rate and pressure across the filter and the turbulence of the water. Previous attempts at removing Cryptosporidium oocysts via filtration from large bodies of water moving at high flow rates have not been successful. Since Cryptosporidium oocysts are negatively charged, coagulants and flocculants such as ferric sulfate, ferric chloride, aluminum sulfate or polyaluminum chloride have been tried unsuccessfully as a means to remove the oocysts from water through the process of aggregation, settling and filtration. Although flocs of oocysts are formed using these particular coagulants, the Cryptosporidium oocyst flocs are unstable and subject to hydrodynamic shear forces that make them susceptible to breaking up and coming apart resulting in their not being retained on filters. The use of anionic or cationic polymeric polyelectrolyte flocculants has been suggested as a means to stabilize Cryptosporidium oocyst-containing flocs against shear. One such study involving dissolved air flotation (DAF) was performed using ferric sulfate as the primary coagulant and LT22, a cationic acrylamide co-polymer. No improvement in oocyst removal over that expected with ferric sulfate coagulant alone was observed. Sand filtration for removing Cryptosporidium oocysts from water has been evaluated with some success. Rapid sand filtration has been reported to remove 3 logs of Cryptosporidium oocysts. Slow sand filtration that utilizes a finer grain of sand and a slower flow rate was reported in a pilot scale study to be fairly good in removing Cryptosporidium oocysts without having to use flocculants or coagulants. The previous coagulants and flocculants cannot be used in conjunction with slow sand filtration because they tend to clog the pores and severely restrict the flow rate. Currently there is no methodology that is effective in stabilizing flocs of Cryptosporidium oocysts for their significant removal from water through aggregation followed by filtration. Accordingly, there is a need to find a flocculant or coagulant or a combination of the two for obtaining significant removal of oocysts that can take advantage of existing filtration technology such as sand, diatomaceous earth or synthetic cartridge filters to provide safe water for recreation and drinking. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to a method of removing Cryptosporidium oocysts or Giardia cysts from water containing a halogenating agent. The method includes adding chitosan, chitosan salt, or a solution thereof to water containing Cryptosporidium oocysts or Giardia cysts and a halogenating agent. Before adding the chitosan to the water, the Cryptosporidium oocysts or Giardia cysts have been exposed to a halogenating agent for a period of time that is effective to oxidize at least a portion of the Cryptosporidium oocysts or Giardia cysts. Adding chitosan to the water containing the Cryptosporidium oocysts or Giardia cysts and a halogenating agent will result in flocs that are aggregates of Cryptosporidium oocysts or Giardia cysts and chitosan. Flocs of Cryptosporidium oocysts or Giardia cysts with chitosan are stabililized so that the Cryptosporidium oocysts or Giardia cysts can then be removed from the water by filtering the water in conventional filters. In other embodiments, a polyelectrolyte flocculant, other than the chitosan, and a coagulant can be added to the water before, after, or during the addition of the chitosan to the water. The method according to the invention is particularly useful in water that is presently being treated with a halogenating agent, so that the addition of chitosan is supplemental and subsequent to treatment with a halogenating agent. However, the conventional treatments utilizing halogenating agents alone are ineffective in rendering Cryptosporidium oocysts or Giardia cysts inactive. Treating water in a manner according to the invention will result in the flocculation of these pathogens into stabilized flocs that can then be removed with the use of conventional filters. Pathogen contaminated water can come from swimming pools, water parks, hot tubs, spas, and any potable or nonpotable water sources. detailed-description description="Detailed Description" end="lead"? | 20040430 | 20070102 | 20051103 | 63101.0 | 0 | HRUSKOCI, PETER A | METHOD FOR REMOVING CRYPTOSPORIDIUM OOCYSTS FROM WATER | SMALL | 0 | ACCEPTED | 2,004 |
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10,836,683 | ACCEPTED | Method of processing an acoustic signal, and a hearing instrument | A method of processing an acoustic input signal into an output signal in a hearing instrument includes converting the acoustic input signal into a converted input signal, and applying a gain to the converted input signal to obtain the output signal. According to the invention, the gain is calculated using a room impulse attenuation value being a measure of a maximum negative slope of the a converted input signal power on a logarithmic scale. The calculation of the gain may include evaluating a signal power development value being a measure of the actual converted input signal power attenuation or signal power increase, evaluating a signal-to-reverberation-noise ratio from the signal power development value and the room impulse attenuation value, and calculating, based on a gain rule, said gain from said signal-to-reverberation-noise ratio. | 1. In a hearing instrument, a method of converting an acoustic input signal into an output signal, comprising the steps of converting the acoustic input signal into a converted input signal, determining a converted signal power value from the converted input signal determining a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of a converted signal power value as a function of time, carrying out a gain calculation based on said room impulse attenuation value, which calculation yields a gain, and applying said gain to the converted input signal to obtain the output signal. 2. The method according to claim 1, wherein said gain calculation comprises the steps of evaluating a signal power development value being a measure of the actual converted input signal power attenuation or signal power increase, of evaluating a signal-to-reverberation-noise ratio from the signal power development value and the room impulse attenuation value, and of calculating, based on a gain rule, said gain from said signal-to-reverberation-noise ratio. 3. The method according to claim 2, wherein the gain rule is such that the gain monotonously increases as a function of said signal-to-reverberation-noise ratio. 4. The method according to claim 3, wherein the gain is at a maximum if the difference between the acoustic input signal power and the acoustic input signal power delayed by a delay T is positive and continuously increases as a function of the signal-to-reverberation-noise ratio if the difference between the acoustic input signal power and the acoustic input signal power delayed by a delay T time is negative. 5. The method according to claim 2, wherein said room impulse attenuation value is the absolute value of said maximum negative slope multiplied by a delay time T, and wherein said signal-to-reverberation-noise ratio is the sum of said room impulse attenuation value and the difference between the acoustic input signal and the acoustic input signal delayed by the delay time T. 6. The method according to claim 1, wherein the converted input signal power value is determined and processed in a number of frequency bands, wherein a room impulse attenuation value is calculated in at least one of these frequency bands, and wherein a gain factor is calculated therefrom in at least one of these frequency bands. 7. The method according to claim 6, wherein the frequency band signal signals in the individual frequency bands are obtained in time domain filter banks or transform based filterbanks with uniform or non-uniform frequency band-width distribution. 8. The method according to claim 1, wherein the converted input signal power value is determined and processed in a number of frequency bands, and wherein said gain calculation comprises the steps of calculating in at least one of these frequency bands, a signal power development value being a measure of the actual converted input signal power attenuation or signal power increase, of evaluating, in said at least one frequency band, a signal-to-reverberation-noise ratio from the signal power development value and a room impulse attenuation value, and of calculating, based on a gain rule, a gain factor in said at least one frequency band from said signal-to-reverberation-noise ratio. 9. The method according to claim 1, wherein the converted input signal power is smoothed before the room impulse attenuation value is determined. 10. The method according to claim 9, wherein time constants of filters used for smoothing are chosen dependent on the room impulse attenuation value. 11. The method according to claim 9 wherein dual-slope-filters are used for smoothing. 12. The method according to claim 9, wherein the converted input signal power value is determined and processed in a number of frequency bands, wherein a room impulse attenuation value is calculated in at least one of these frequency bands, and wherein said gain calculation comprises calculating a gain factor from the room impulse attenuation value in said at least one frequency band, and wherein the signals are smoothed in said at least one frequency band, using individual smoothing filter parameters for said at least one frequency band. 13. The method according to claim 12, wherein said gain calculation comprises the steps of evaluating, in said at least one of said frequency bands, a signal power development value being a measure of the actual converted input signal power attenuation or signal power increase in said at least one frequency band, of evaluating, in said at least one frequency band, a signal-to-reverberation-noise ratio from the signal power development value and the room impulse attenuation value, and of calculating, based on a gain rule, said gain factor from said signal-to-reverberation-noise ratio. 14. A hearing instrument comprising an input transducer to convert an acoustic input signal into a converted input signal, at least one gain unit, and an output transducer, wherein the input transducer is operatively connected to the output transducer via the gain unit, and wherein a gain value for the gain unit is adjustable, the hearing instrument further comprising gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value. 15. The hearing instrument according to claim 14, wherein said gain calculating means comprise a gain rule unit operatively connected to the gain unit for providing at least one gain factor, and wherein said room impulse attenuation evaluating unit is operatively connected to said gain rule unit via an adding stage operable to add a difference between an actual signal power and a delayed signal power to the room impulse attenuation value. 16. The hearing instrument according to claim 14 comprising a smoothing stage with at least one filter being arranged upstream of the room impulse attenuation evaluating unit. 17. The hearing instrument according to claim 16, comprising a feedback loop for adjusting time constants of said at least one filter based on room impulse attenuation values. 18. The hearing instrument according to claim 14 comprising frequency band splitting means for splitting the converted input signal in a plurality of input sub-signals in separate frequency bands, and a gain unit and a gain calculating means for at least one frequency band, wherein said gain calculating means are operable to calculate a gain factor in at least one frequency band, respectively. 19. The hearing instrument according to claim 18, wherein said gain calculating means comprise a gain rule unit operatively connected to the gain unit for evaluating a gain factor in said at least one frequency band, and wherein said room impulse attenuation evaluating unit is operatively connected to said gain rule unit via an adding stage operable to add a difference between an actual signal power and a delayed signal power to the room impulse attenuation value in said frequency band. 20. A method for manufacturing a hearing instrument comprising the steps of providing an input transducer to convert an acoustic input signal into a converted input signal, of providing at least one gain unit, of providing output transducer, and of operatively connecting the input transducer to the output transducer via the gain unit, wherein a gain value for the gain unit is adjustable, the method further comprising the steps of providing gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value, and of operatively connecting the gain calculating means with the gain unit. | FIELD OF THE INVENTION This invention is in the field of processing signals in or for hearing instruments. It more particularly relates to a method of converting an acoustic input signal into an output signal, a hearing instrument, and to a method of manufacturing a hearing instrument. BACKGROUND OF THE INVENTION Reverberation is a major problem for hearing impaired persons. The reason is that, in addition to the missing spectral cues for speech intelligibility from the broadening of the auditory filters (i.e. the reduced spectral discrimination ability of the impaired ear, due to defect outer hair cells, resulting in less sharply tuned auditory filters in the impaired ear), the temporal cues also are mitigated by the reverberation. Onsets, speech pauses etc. are no longer perceivable. Thus, severe intelligibility reductions as well as comfort decreases occur. From a technical point of view, reverberation is a filtering (convolution) of the clean signal, for example a speech signal, with the room impulse response (RIR) from the speaker to the hearing impaired person. These room impulse responses tend to be very long, in the order of several hundred milliseconds up to several seconds for large cathedrals or main train stations. The long RIR thus slurs the speech pauses. The immediate technical solution therefore is so called ‘de-convolution’, i.e. the estimation and inversion of the RIR, with which the reverberated signal arriving at the Hearing Instrument (HI) can get filtered and thus perfectly restored to the original clean or ‘dry’ signal. From a mathematical point of view, deconvolution or inversion of a filter response is a well known process. The problems lie in the following points: a.) The fact that the inversion of a real RIR generates an acausal filter, i.e. one which needs information from the future. This can in principle only be eliminated by introducing an appropriate delay into the system, which therefore would have to be several hundred milliseconds long at least. b.) Estimation of the correct RIR (or directly the inverted version of it). Concerning point a.), even when only the first part of the RIR (the one with the highest energies) gets corrected for, far too long delays for hearing instrument (HI) purposes would be required. Even more important though is the correct estimation of the RIR (point b.), which is considered a hard problem in the field to solve, and no completely satisfying and useful solutions exist. For these reasons, instead of deconvolution other approaches are used for dereverberation. One known solution uses multiple microphones or a beamformer to dereverberate the signal. This, however, is of limited use in large rooms, where the sound field is very diffuse. Another known solution tries to dereverberate by transforming the signal first into cepstral domain, where the (estimated) RIR can simply get subtracted, before transforming back into the linear time domain. These solutions are computationally not cheap either, and also require a significant group delay. Also, they are not very robust. A novel solution was presented in K. Lebart et al., acta acustica vol. 87 (2001), p. 359-366. The solution is a method based on spectral subtraction. The principle is that the RIR is modeled to be a zero mean Gaussian noise which decays exponentially: h(t)=b(t)·e−Δt for t≧0 and h(t)=0 for t<0 (1) In the above equation, b(t) denotes a zero mean Gaussian function and Δ = 3 · ln ( 10 ) T r , Tr being the reverberation time, i.e. the time after which the reverberation energy decayes by 60 dB. The reverberation energy at any time t can thus be estimated by Prr(t,f)=e−2ΔT·Pxx(t−T,f) (2) where Pxx(t,f) is the power spectral density of a signal x(n). T is an (arbitrary) delay. In other words, the reverberation power at any time t is equal to the signal power of the speaker at an earlier time t-T, and attenuated by the exponential term e−2ΔT. One can now consider the ratio between the current received signal power and the estimated reverberation signal power as a ‘Signal-to-reverberation-Noise Ratio (SNR)’ and form a spectral subtraction filter like gain function from it. However, musical noise artifacts may get produced and have to be avoided by additional means like averaging or setting a spectral floor. An algorithm based on these findings is of lower complexity than above mentioned direct dereverberation or cepstral methods, but is still computational expensive. In particular, the reverberation time Tr, which is required in order to generate the exponential term in Eq. (2) for the reverberation power estimation, is hard to calculate: First, speech pauses are detected (which is rather difficult in a highly reverberated signal). During speech pauses, the exponential decay corresponds to a linear negative slope on a logarithmic scale. Then, within these signal segments the slope of the smoothed signal power envelope on a dB scale is extracted by linear regression, another quite expensive operation. Further averaging of the found slopes are used to come up with an improved estimate. From the slope estimate and the known sample time, Tr can get extracted. Next to being computationally expensive, the above described method also lacks a certain amount of robustness. This is, among other reasons, due to uncertainties in detecting speech pauses. SUMMARY OF THE INVENTION It is an object of this invention to provide a method and a device for suppressing reverberation, which method is robust, is computationally not expensive, and avoids drawbacks of corresponding prior art methods. More concretely, it is an object of the invention to provide a method of obtaining an output signal from an acoustic input signal, which method causes reverberation contributions to the acoustic input signal to be suppressed in the output signal. The method should be computationally inexpensive, robust and should overcome drawbacks of according prior art methods. An embodiment of the invention provides, in a hearing instrument, a method of converting an acoustic input signal into an output signal. The method comprises the steps of converting the acoustic input signal into a converted input signal, and of applying a gain to the converted input signal to obtain the output signal, and further comprises the steps of determining a converted signal power value from the converted input signal determining a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of a converted signal power value as a function of time, and of carrying out a gain calculation based on said room impulse attenuation value, which calculation yields said gain applied to the converted input signal. Another embodiment of the invention concerns a hearing instrument comprising an input transducer to convert an acoustic input signal into a converted input signal, at least one gain unit, and an output transducer, wherein the input transducer is operatively connected to the output transducer via the gain unit, and wherein a gain value for the gain unit is adjustable, and further comprising gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value. Yet another embodiment of the invention provides a method for manufacturing a hearing instrument. The method comprises the steps of providing an input transducer to convert an acoustic input signal into a converted input signal, of providing at least one gain unit, of providing output transducer, and of operatively connecting the input transducer to the output transducer via the gain unit, wherein a gain value for the gain unit is adjustable, and further comprises the steps of providing gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value, and of operatively connecting the gain calculating means with the gain unit. According to these principles, a room impulse attenuation value is evaluated over a reasonably long observation time period. This is done for a converted acoustic input signal, i.e. a signal provided by a transducer and possibly also digitized, optionally split into frequency bands, smoothed and/or otherwise further processed. The room impulse attenuation value is a value that is determined for the converted input signal and is a measure of the maximum negative slope of its power on a logarithmic scale. Based on this and on a measure of the signal evaluation, a signal-to-reverberation-noise ratio is evaluated by comparing the signal evolution (i.e. its attenuation or increase) with the room impulse attenuation value. This signal-to-reverberation-noise ratio serves as basis for calculating a gain to be applied to the converted input signal, so that an output signal is obtained. This course of action is based on the insight that a signal that attenuates with the maximum attenuation rate is, with a high probability, caused by reverberation. On the other hand, the higher the difference between the actual attenuation and the maximum attenuation rate, the better the signal-to-reverberation-noise-ratio. When applying a gain rule, one may use this insight and suppress the converted input signal whenever said ratio is small. In principle, the gain rule may be regarded to be based on a comparison between the room impulse attenuation being the maximal attenuation in the current environment, and the actually observed observation. A “Comparison” in this context is a mathematical operation operating on two input values (or their absolute values or envelopes, respectively) that yields an output value indicative of the relative size of one of the input values with respect to the other one. Examples of comparisons are a subtraction, a weighed subtraction, a division etc. The terms “signal power” and “logarithm of the signal power” generally denote a value that is indicative of the signal power or signal ‘strength’, or its logarithm respectively. Such a value may be the physical signal power, the signal envelope or the absolute value of the signal etc. The gain as a function of the room impulse attenuation may be a monotonously increasing function. A monotonously increasing function g is a continuous or not continuous function if it fulfills g(x)≧g(y) for all x>y. For example, the gain may be at a maximum if the signal-to-reverberation noise ratio is large and small if the signal-to-reverberation noise ratio is small and may further be continuously and monotonously increasing as a function of the signal-to-reverberation-noise ratio in between. It may, as an alternative also be a monotonously increasing and stepped function of the reverberation signal-to-noise ratio. A measure of the signal evaluation may be obtained by calculating the difference between the converted signal input power and the converted signal input power delayed by a delay T. Then, the room impulse attenuation value may be chosen to be the maximum attenuation during a time span corresponding to T, as observed during a much larger time period I. In other words, the room impulse attenuation value RIatt used is the maximum negative slope multiplied by T. (The negative slope itself is not required and does not have to be calculated, though). Several maximum values during the time period I may get averaged to increase robustness. The delay time T may be set to a value between 5 ms and 100 ms, preferably between 10 ms and 50 ms. The time period I over which the room impulse attenuation value is evaluated, in addition to being larger than the delay T, is preferably also substantially larger than a typical speech pause. It may for example be between 1s and 20 s. The room attenuation value is only slowly time dependent. It gets regularly updated. The time window I, over which the maximum Room impulse attenuation Riatt is evaluated, may, as an alternative to being rectangular, also be exponential or otherwise shaped, i.e. may weight maximum values lying further in the past less then more recent maximum values. The window may also be sliding instead of being fixed. Preferably, the converted input signal power is smoothed before the Room Impulse attenuation value is determined. Smoothing methods as such known in the art may be used for this purpose. Preferably, the time constants for the smoothing operation are smaller than Tr, at least by a factor of 2 and preferably by a factor between 3 and 10. In order to ensure this relation independently of the actual reverberation time, a feedback function may be provided. According to this feedback function, the determined room impulse attenuation value—or a quantity derived therefrom—is fed to the smoothing stage as filter constant setting value. The method according to the invention, although its basic principle is comparable to the one of prior art methods, is surprisingly simple and computationally significantly cheaper. It makes use of quantities often already available in a hearing instrument, such as logarithmic signal power etc. Compared to the above described prior art method by K. Lebart et al., it avoids the explicit complex and computationally expensive estimation of the reverberation time Tr in order to generate the exponential term in eq. (2) for the reverberation power estimation. Next to providing a far simpler solution for the estimation of the reverberation time Tr, or a measure for it, respectively, it also allows to implement a simpler gain rule. Therefore, it is computationally efficient. Computational efficiency is still of prime importance in hearing instruments. By also eliminating the error-prone step of speech pause detection, robustness is improved as well. It is further noted that the sensitivity on RIatt estimation errors is quite low, i.e. significant estimation errors in the order of ca. 20.40% are not readily audible. Thus a simplified inversion algorithm for a calculation of 1/RIatt for a gain rule may get used as well. I.e., the inversion algorithm may be implemented with a simple lookup table with only a few entries and possibly even without interpolation in between. The term “hearing instrument” or “hearing device”, as understood here, denotes on the one hand hearing aid devices that are therapeutic devices improving the hearing ability of individuals, primarily according to diagnostic results. Such hearing aid devices may be Outside-The-Ear hearing aid devices or In-The-Ear hearing aid devices. On the other hand, the term stands for devices which may improve the hearing of individuals with normal hearing e.g. in specific acoustical situations as in a very noisy environment or in concert halls, or which may even be used in context with remote communication or with audio listening, for instance as provided by headphones. The hearing devices addressed by the present invention are so-called active hearing devices which comprise at the input side at least one acoustical to electrical converter, such as a microphone, at the output side at least one electrical to mechanical converter, such as a loudspeaker, and which further comprise a signal processing unit for processing signals according to the output signals of the acoustical to electrical converter and for generating output signals to the electrical input of the electrical to mechanical output converter. In general, the signal processing circuit may be an analog, digital or hybrid analog-digital circuit, and may be implemented with discrete electronic components, integrated circuits, or a combination of both. BRIEF DESCRIPTION OF THE DRAWINGS In the following, principles of the invention are explained by means of a description of preferred embodiments. The description refers to drawings with Figures that are, with the exception of FIGS. 1 and 2, all schematic. The figures show the following: FIG. 1 the signal power of a dry (not reverberated) speech signal, showing the nonlinear negative slopes in the speech pauses. FIG. 2 the signal power of a reverberated speech signal, showing the approximately linear negative slopes in the speech pauses. FIG. 3 an example envelope of a reverberated speech signal with the maximum negative slopes shown with thick lines FIG. 4 a block diagram of an embodiment of a hearing instrument according to the invention FIG. 5 a block diagram of a part of the hearing instrument illustrating the signal processing FIGS. 6a, 6b, and 6c, plots of examples of gain rules FIG. 7 a block diagram of a part of a further embodiment of a hearing instrument according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 depicts, on a logarithmic scale, the signal power of a dry (not reverberated) speech signal as a function of time, showing the nonlinear negative slopes in the speech pauses. In the figure, the speech pauses are pointed out by arrows. FIG. 2 shows the corresponding plot of approximately the same speech signal, which however is reverberated. In the speech pauses, the approximately linear negative slopes may be seen. For hearing instrument users, the blurring of speech pauses by reverberation may decrease speech intelligibility. An important finding of the invention is, that the maximal negative slope found over such a (properly pre-processed) signal envelope is a good indicator of the reverberation time Tr. In other words, even for immediate drops in the (speech) signal, the reverberated signal will never decay faster than given by Tr. FIG. 3 shows this relation. The power Pxx of a reverberated speech signal in a frequency band f (here, f is a discrete variable) is plotted as a function of the time. Thick lines show secants (approximating tangents) at places with maximum negative slopes. RIatt (the Room Impulse ATTenuation) is defined to be the attenuation at places with maximum negative slopes during a time T, as shown in FIG. 3. Typical values of T are between 10 ms and 50 ms, for example 20 ms. RIatt is the attenuation of the room impulse response after a short sound energy burst seen over a time period T when no other significant signal energy is present anymore, determined on a logarithmic scale. It is related to Tr by: RIatt ( f ) = T ( f ) · 60 dB T r ( f ) ( 3 ) where the arbitrary time delay T as well as the actual reverberation time may be frequency dependent. RIAtt is only slowly time variant, the time index t is thus omitted, even though the estimate of it is regularly updated. A, signal-to-reverberation-noise ratio SNR′ in the sense of Eq. (2) is defined as SNR rev ( t , f ) = P xx ( t , f ) P rr ( t , f ) = P xx_dB ( t , f ) - [ P xx_dB ( t - T , f ) - RIatt ( f ) ] ︸ P xx_dB ( t , f ) ( 4 ) In general, logarithmic signal powers or levels used are also used for other purposes in a hearing instrument like gain computation, and are therefore readily available. This makes the above expression for a reverberation signal-to-noise ratio readily calculable. Note that above SNR measure compares the received power PXX with the estimated reverberation power Prr, and thus may theoretically never become negative, if RIatt(f) is properly computed, i.e. if RIatt(f)/T is the maximal negative slope found over a reasonably long observation time period. In other words, the above SNR measure compares the (maximal) attenuation a reverberation signal would have if no other signal were present with the observed signal attenuation (which attenuation would be negative in the event of a signal increase): SNRrev(t,f)=RIatt(f)−(Pxx—dB(t−T,f)−Pxx—dB(t,f)) (4b) The reverberation SNR may be used for adjusting a gain according to an appropriate gain rule: If the observed attenuation comes close to the maximal attenuation, the reverberation portion of the total signal is high, and thus the signal is suppressed. An embodiment of a hearing instrument according to the invention is schematically shown in FIG. 4. An input transducer 1 and an analog-to-digital converter 2 convert the acoustic input signal into a converted input signal S1, which is a digital electric signal. The converted input signal is processed by a digital signal processor (DSP) 3. The output signal SO of the DSP is fed to a Digital-to-Analog converter 4 and, after a possible amplification stage (not shown), fed to an output transducer 5. As depicted in FIG. 5, the signal path in the DSP includes a gain unit 11 for applying a reverberation-SNR dependent gain to the signal. It may include further signal processing stages 12 which may be arranged upstream of a branching point A for gain evaluating means, between the branching point A and the gain unit 11, as very schematically illustrated in the figure, and/or downstream of the gain unit 11. The further signal processing stages may comprise any signal processing algorithms known for hearing aids or yet to be invented. They are not subject of the present invention and will not be described any further here. The gain evaluating means 13 comprise a logarithmic power computing stage 14, preferably including smoothing means. For the smoothing of the envelope, so called, dual-slope-averagers' (DSA) (or dual-slope filters) may be used, which contain different parameters for the attack- and release time constants. DSAs can follow the natural shape of a signal envelope better than normal averagers. Typical attack times for evaluation of speech signals are in the order of 5-10 ms, typical release times in the order of 50 ms. The computation of the logarithmic signal power, the smoothing as well as further steps are preferably carried out in confined frequency bands, as explained in more detail further below. Of course, instead of being fed by the converted signal SI, the logarithmic power computing and smoothing stage 14 may be provided with an already available logarithmic power signal instead. The smoothed logarithmic power signal is supplied to a delay element 16. The thus obtained delayed logarithmic power signal as well as the smoothed logarithmic power signal are fed to a first adder 17, where the delayed logarithmic power, signal is subtracted from the logarithmic power signal. This difference is actual an attenuation value (or may be considered as a signal power development value). It is supplied to a room impulse attenuation evaluating unit 15, which evaluates, over a certain time period I, the maximum attenuation RIatt during the delay T. The calculated Room Impulse Attenuation value RIatt may be stored in a temporary store and continuously output from the room impulse attenuation evaluating unit 15. By a second adder 19, the RIatt value is added to the actual attenuation value obtained by the first adder. According to eq. (4), the thus obtained value is a signal-to-reverberation-noise ratio SNR. This SNR is fed to a gain rule unit 18, which, based on the signal-to-noise ratio and a gain rule, calculates a gain for the gain unit 11. Prior to being fed to a gain rule unit, the computed gain may be converted back into the linear domain for application onto the signal S1 or a therefrom derived signal, as indicated by a conversion unit 20 in the figure. A “Gain unit” in this context, relates to a unit that alters the incoming signal in a manner dependent on the reverberation SNR, for example by multiplying or amplifying it by a factor depending on said reverberation SNR. An example of a simple, but effective gain rule is depicted in FIG. 6a: The gain as a function of the reverberation SNR increases linearly if the reverberation SNR is smaller than RIatt (i.e. if the signal power is constant or if it decreases), and the gain attains a constant maximal value if the signal power increases as a function of time. In the figure, the maximal value is 0 (on a logarithmic scale). Expressed as an equation, the gain rule is as follows: G dB ( t , f ) = min ( 0 , Max Att RIatt ( f ) · ( max ( 0 , SNR rev ( t , f ) ) - RIatt ( f ) ) ) ( 5 ) which may get simplified to: G dB ( t , f ) = min ( 0 , max ( Max att ( f ) Max att ( f ) RIatt ( f ) · ( P xx_dB ( t , f ) - P xx_dB ( t - T , f ) ) ) ) ( 6 ) This equation contains the inversion of RIAtt(f), which can get computed at the same slow tick rate as RIAtt (f) itself, and is therefore computationally not expensive either. Likewise it can get approximated with a course lookup table method. Note also, that the max(.) operation is for robustness only, i.e. for negative values of SNRrev(t,f), which should not occur anyhow. The min(.) operation limits the gains to negative values, i.e. attenuations, such that no positive gains get applied for non-reverberation signals. The computed gain is then either combined with other gains computed for other means (not shown in FIG. 5) or independently converted back into linear domain for application onto the signal SI or a therefrom derived signal. Instead of the above mentioned gain rule, other gain rules may be applied. FIGS. 6b and 6c show examples of further possible gain rules. The gain rule according to FIG. 6b simply cuts the signal off if the reverberation SNR is below a threshold value SNRTHR. “Cut off”, in this context, means attenuation by a maximal attenuation rate MaxAtt. If the reverberation SNR is above the threshold value, the signal is not attenuated (the gain is 0 on a logarithmic scale). Other, more sophisticated stepped functions including a plurality of steps may be applied also. The gain rule according to FIG. 6c is, next to the one of FIG. 6a, an other example of a gain rule where the gain is a continuous function of the reverberation SNR. According to a preferred embodiment of the invention, the logarithmic signal power (or level) as well as the term RIatt is computed in a plurality of frequency bands, and a gain factor is calculated in each band. Equations (1) to (5) are then all to be read as frequency dependent, as indicated by the variables Time domain or transformation based filter banks with uniform or non-uniform frequency band-width distribution for the individual bands may be used to divide the converted input signal into individual signals for each frequency band. Examples of transform based filterbanks comprise, but are not limited to, FFT, DCT, and Wavelet based filterbanks. FIG. 7 very schematically depicts the embodiment where a gain factor is calculated in each frequency band. The converted input signal is fed to the filters 21 of the filterbank yielding a pluraltiy of input subsignals SI(f). In each frequency band, a gain evaluating means 13 of the kind described above calculates a gain factor for a gain unit 11. Individual smoothing filter parameters may be used for each frequency band. Such individual smoothing filter parameters may be adapted to a frequency band specific room impulse attenuation value in each frequency band. The output sub-signals SO(f) obtained in each frequency band are added (or inverse transformed, respectively) by an adding stage 22 to provide an output signal SO. According to a preferred embodiment, the number of frequency bands is chosen to be between 10 and 36, however, the invention applies for any number of frequency bands. Frequency bands may be chosen to be uniformly spaced on a logarithmic scale. Next, different possibilities of obtaining RIatt values are discussed. According to a first embodiment, the following steps are applied. During a time period I, the value Att(t,f)=Pxx—dB(t−T,f)−Pxx—dB(t,f) (7) is measured every T time units. The first measured positive value of Att(t,f) is stored in a temporary store. Each subsequently measured value of Att(t,f) is compared with the stored value. If it is larger, the stored value is replaced by the measured value. The value remaining in the store after the time period I is defined to be RIatt. This procedure is repeated regularly (the repetition rate of the procedure is sometimes denoted “tick rate” in this text), and every time RIatt is evaluated anew. This procedure is founded on the assumption that the power signal is smooth on a time scale corresponding to T. In other words, the time constants of filters of the smoothing stages have to be chosen in the range of T or larger than T. As an alternative, the value Att(t,f) may be the result of an averaging of subsequent difference values. As an alternative to the above evaluation over time periods I, RIatt may be continually updated. Each value of Att(t,f)—evaluated according to (7)—is compared with the stored value as in the above procedure. If the measured value is higher than the stored value, the stored value is replaced by the measured value. The stored value, however, is regularly lowered by an incremental value so that the system may not be trapped once the attenuation value is high, and may adapt to a situation where the hearing instrument user gets into a situation where reverberation is enhanced. Other procedures for updating the room impulse attenuation value may be envisaged. The time constants of the filters (averagers) of the smoothing stage may be adapted to the actual value of RIatt, or, via equation (3) to the value of Tr, respectively. In FIG. 5, this is illustrated by a dashed arrow illustrating a feedback function. More concretely, time constants of the filters may for example be chosen to be proportional to Tr and for example be between ½ and 1/20 of the value of Tr, preferably between ⅓ and 1/10 of the value of Tr. According to a preferred embodiment, dual slope averagers are used, wherein time constants for the dual-slope filters are made adaptive in response to the room impulse attenuation values. Although this invention is described for digital signal processing, it may as well be implemented using analog techniques. Various other embodiments may be envisaged without departing from the scope or spirit of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Reverberation is a major problem for hearing impaired persons. The reason is that, in addition to the missing spectral cues for speech intelligibility from the broadening of the auditory filters (i.e. the reduced spectral discrimination ability of the impaired ear, due to defect outer hair cells, resulting in less sharply tuned auditory filters in the impaired ear), the temporal cues also are mitigated by the reverberation. Onsets, speech pauses etc. are no longer perceivable. Thus, severe intelligibility reductions as well as comfort decreases occur. From a technical point of view, reverberation is a filtering (convolution) of the clean signal, for example a speech signal, with the room impulse response (RIR) from the speaker to the hearing impaired person. These room impulse responses tend to be very long, in the order of several hundred milliseconds up to several seconds for large cathedrals or main train stations. The long RIR thus slurs the speech pauses. The immediate technical solution therefore is so called ‘de-convolution’, i.e. the estimation and inversion of the RIR, with which the reverberated signal arriving at the Hearing Instrument (HI) can get filtered and thus perfectly restored to the original clean or ‘dry’ signal. From a mathematical point of view, deconvolution or inversion of a filter response is a well known process. The problems lie in the following points: a.) The fact that the inversion of a real RIR generates an acausal filter, i.e. one which needs information from the future. This can in principle only be eliminated by introducing an appropriate delay into the system, which therefore would have to be several hundred milliseconds long at least. b.) Estimation of the correct RIR (or directly the inverted version of it). Concerning point a.), even when only the first part of the RIR (the one with the highest energies) gets corrected for, far too long delays for hearing instrument (HI) purposes would be required. Even more important though is the correct estimation of the RIR (point b.), which is considered a hard problem in the field to solve, and no completely satisfying and useful solutions exist. For these reasons, instead of deconvolution other approaches are used for dereverberation. One known solution uses multiple microphones or a beamformer to dereverberate the signal. This, however, is of limited use in large rooms, where the sound field is very diffuse. Another known solution tries to dereverberate by transforming the signal first into cepstral domain, where the (estimated) RIR can simply get subtracted, before transforming back into the linear time domain. These solutions are computationally not cheap either, and also require a significant group delay. Also, they are not very robust. A novel solution was presented in K. Lebart et al., acta acustica vol. 87 (2001), p. 359-366. The solution is a method based on spectral subtraction. The principle is that the RIR is modeled to be a zero mean Gaussian noise which decays exponentially: in-line-formulae description="In-line Formulae" end="lead"? h ( t )= b ( t )· e −Δt for t ≧0 and in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? h(t)=0 for t<0 (1) in-line-formulae description="In-line Formulae" end="tail"? In the above equation, b(t) denotes a zero mean Gaussian function and Δ = 3 · ln ( 10 ) T r , T r being the reverberation time, i.e. the time after which the reverberation energy decayes by 60 dB. The reverberation energy at any time t can thus be estimated by in-line-formulae description="In-line Formulae" end="lead"? P rr ( t,f )= e −2ΔT ·P xx ( t−T,f) (2) in-line-formulae description="In-line Formulae" end="tail"? where P xx (t,f) is the power spectral density of a signal x(n). T is an (arbitrary) delay. In other words, the reverberation power at any time t is equal to the signal power of the speaker at an earlier time t-T, and attenuated by the exponential term e −2ΔT . One can now consider the ratio between the current received signal power and the estimated reverberation signal power as a ‘Signal-to-reverberation-Noise Ratio (SNR)’ and form a spectral subtraction filter like gain function from it. However, musical noise artifacts may get produced and have to be avoided by additional means like averaging or setting a spectral floor. An algorithm based on these findings is of lower complexity than above mentioned direct dereverberation or cepstral methods, but is still computational expensive. In particular, the reverberation time T r , which is required in order to generate the exponential term in Eq. (2) for the reverberation power estimation, is hard to calculate: First, speech pauses are detected (which is rather difficult in a highly reverberated signal). During speech pauses, the exponential decay corresponds to a linear negative slope on a logarithmic scale. Then, within these signal segments the slope of the smoothed signal power envelope on a dB scale is extracted by linear regression, another quite expensive operation. Further averaging of the found slopes are used to come up with an improved estimate. From the slope estimate and the known sample time, T r can get extracted. Next to being computationally expensive, the above described method also lacks a certain amount of robustness. This is, among other reasons, due to uncertainties in detecting speech pauses. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of this invention to provide a method and a device for suppressing reverberation, which method is robust, is computationally not expensive, and avoids drawbacks of corresponding prior art methods. More concretely, it is an object of the invention to provide a method of obtaining an output signal from an acoustic input signal, which method causes reverberation contributions to the acoustic input signal to be suppressed in the output signal. The method should be computationally inexpensive, robust and should overcome drawbacks of according prior art methods. An embodiment of the invention provides, in a hearing instrument, a method of converting an acoustic input signal into an output signal. The method comprises the steps of converting the acoustic input signal into a converted input signal, and of applying a gain to the converted input signal to obtain the output signal, and further comprises the steps of determining a converted signal power value from the converted input signal determining a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of a converted signal power value as a function of time, and of carrying out a gain calculation based on said room impulse attenuation value, which calculation yields said gain applied to the converted input signal. Another embodiment of the invention concerns a hearing instrument comprising an input transducer to convert an acoustic input signal into a converted input signal, at least one gain unit, and an output transducer, wherein the input transducer is operatively connected to the output transducer via the gain unit, and wherein a gain value for the gain unit is adjustable, and further comprising gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value. Yet another embodiment of the invention provides a method for manufacturing a hearing instrument. The method comprises the steps of providing an input transducer to convert an acoustic input signal into a converted input signal, of providing at least one gain unit, of providing output transducer, and of operatively connecting the input transducer to the output transducer via the gain unit, wherein a gain value for the gain unit is adjustable, and further comprises the steps of providing gain calculating means including a room impulse attenuation evaluating unit operable to determine a room impulse attenuation value being a measure of a maximum negative slope of the logarithm of the converted input signal power as a function of time, said gain calculating means being operable to calculate a gain based on said room impulse attenuation value, and of operatively connecting the gain calculating means with the gain unit. According to these principles, a room impulse attenuation value is evaluated over a reasonably long observation time period. This is done for a converted acoustic input signal, i.e. a signal provided by a transducer and possibly also digitized, optionally split into frequency bands, smoothed and/or otherwise further processed. The room impulse attenuation value is a value that is determined for the converted input signal and is a measure of the maximum negative slope of its power on a logarithmic scale. Based on this and on a measure of the signal evaluation, a signal-to-reverberation-noise ratio is evaluated by comparing the signal evolution (i.e. its attenuation or increase) with the room impulse attenuation value. This signal-to-reverberation-noise ratio serves as basis for calculating a gain to be applied to the converted input signal, so that an output signal is obtained. This course of action is based on the insight that a signal that attenuates with the maximum attenuation rate is, with a high probability, caused by reverberation. On the other hand, the higher the difference between the actual attenuation and the maximum attenuation rate, the better the signal-to-reverberation-noise-ratio. When applying a gain rule, one may use this insight and suppress the converted input signal whenever said ratio is small. In principle, the gain rule may be regarded to be based on a comparison between the room impulse attenuation being the maximal attenuation in the current environment, and the actually observed observation. A “Comparison” in this context is a mathematical operation operating on two input values (or their absolute values or envelopes, respectively) that yields an output value indicative of the relative size of one of the input values with respect to the other one. Examples of comparisons are a subtraction, a weighed subtraction, a division etc. The terms “signal power” and “logarithm of the signal power” generally denote a value that is indicative of the signal power or signal ‘strength’, or its logarithm respectively. Such a value may be the physical signal power, the signal envelope or the absolute value of the signal etc. The gain as a function of the room impulse attenuation may be a monotonously increasing function. A monotonously increasing function g is a continuous or not continuous function if it fulfills g(x)≧g(y) for all x>y. For example, the gain may be at a maximum if the signal-to-reverberation noise ratio is large and small if the signal-to-reverberation noise ratio is small and may further be continuously and monotonously increasing as a function of the signal-to-reverberation-noise ratio in between. It may, as an alternative also be a monotonously increasing and stepped function of the reverberation signal-to-noise ratio. A measure of the signal evaluation may be obtained by calculating the difference between the converted signal input power and the converted signal input power delayed by a delay T. Then, the room impulse attenuation value may be chosen to be the maximum attenuation during a time span corresponding to T, as observed during a much larger time period I. In other words, the room impulse attenuation value RIatt used is the maximum negative slope multiplied by T. (The negative slope itself is not required and does not have to be calculated, though). Several maximum values during the time period I may get averaged to increase robustness. The delay time T may be set to a value between 5 ms and 100 ms, preferably between 10 ms and 50 ms. The time period I over which the room impulse attenuation value is evaluated, in addition to being larger than the delay T, is preferably also substantially larger than a typical speech pause. It may for example be between 1s and 20 s. The room attenuation value is only slowly time dependent. It gets regularly updated. The time window I, over which the maximum Room impulse attenuation Riatt is evaluated, may, as an alternative to being rectangular, also be exponential or otherwise shaped, i.e. may weight maximum values lying further in the past less then more recent maximum values. The window may also be sliding instead of being fixed. Preferably, the converted input signal power is smoothed before the Room Impulse attenuation value is determined. Smoothing methods as such known in the art may be used for this purpose. Preferably, the time constants for the smoothing operation are smaller than T r , at least by a factor of 2 and preferably by a factor between 3 and 10. In order to ensure this relation independently of the actual reverberation time, a feedback function may be provided. According to this feedback function, the determined room impulse attenuation value—or a quantity derived therefrom—is fed to the smoothing stage as filter constant setting value. The method according to the invention, although its basic principle is comparable to the one of prior art methods, is surprisingly simple and computationally significantly cheaper. It makes use of quantities often already available in a hearing instrument, such as logarithmic signal power etc. Compared to the above described prior art method by K. Lebart et al., it avoids the explicit complex and computationally expensive estimation of the reverberation time Tr in order to generate the exponential term in eq. (2) for the reverberation power estimation. Next to providing a far simpler solution for the estimation of the reverberation time T r , or a measure for it, respectively, it also allows to implement a simpler gain rule. Therefore, it is computationally efficient. Computational efficiency is still of prime importance in hearing instruments. By also eliminating the error-prone step of speech pause detection, robustness is improved as well. It is further noted that the sensitivity on RIatt estimation errors is quite low, i.e. significant estimation errors in the order of ca. 20.40% are not readily audible. Thus a simplified inversion algorithm for a calculation of 1/RIatt for a gain rule may get used as well. I.e., the inversion algorithm may be implemented with a simple lookup table with only a few entries and possibly even without interpolation in between. The term “hearing instrument” or “hearing device”, as understood here, denotes on the one hand hearing aid devices that are therapeutic devices improving the hearing ability of individuals, primarily according to diagnostic results. Such hearing aid devices may be Outside-The-Ear hearing aid devices or In-The-Ear hearing aid devices. On the other hand, the term stands for devices which may improve the hearing of individuals with normal hearing e.g. in specific acoustical situations as in a very noisy environment or in concert halls, or which may even be used in context with remote communication or with audio listening, for instance as provided by headphones. The hearing devices addressed by the present invention are so-called active hearing devices which comprise at the input side at least one acoustical to electrical converter, such as a microphone, at the output side at least one electrical to mechanical converter, such as a loudspeaker, and which further comprise a signal processing unit for processing signals according to the output signals of the acoustical to electrical converter and for generating output signals to the electrical input of the electrical to mechanical output converter. In general, the signal processing circuit may be an analog, digital or hybrid analog-digital circuit, and may be implemented with discrete electronic components, integrated circuits, or a combination of both. | 20040430 | 20080115 | 20051103 | 82488.0 | 0 | SAUNDERS JR, JOSEPH | METHOD OF PROCESSING AN ACOUSTIC SIGNAL, AND A HEARING INSTRUMENT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,762 | ACCEPTED | Method and apparatus for multi-color printing using a rosette or diamond halftone screen for one or more of the colors | A method and apparatus for processing image data representing a color separation or mono-color image includes processing the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and obtaining results of the processings and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. The resulting print of the composite image data forms relatively pleasing rosettes or diamond structures in the particular color. | 1. An apparatus for processing image data representing a color separation or mono-color image, the apparatus comprising: a processor operative to process the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. 2. The apparatus of claim 1 and wherein the processor is operative to process the color separation image data or mono-color image data in accordance with a dot structure dot growth pattern processing. 3. The apparatus of claim 2 and including a printer responsive to the composite image data for generating a color separation or mono-color image as a rosette. 4. The apparatus of claim 3 and wherein the different screen angles are separated by 30°. 5. The apparatus of claim 3 and wherein the different screen angles are separated by 60°. 6. The apparatus of claim 2 and wherein the processor is operative to process the color separation image data or mono-color image data in accordance with the first and the second and a third halftone screen processings all at different screen angles and combine the results of the processings to generate composite image data. 7. The apparatus of claim 1 and wherein the processor is operative to process the color separation image data or mono-color image data in accordance with a line structure dot growth pattern processing and the apparatus includes a printer responsive to the composite image data for generating a color separation image or mono-color image having a diamond structure. 8. The apparatus of claim 7 and wherein the different screen angles are separated by 60°. 9. The apparatus of claim 7 and wherein the different screen angles are separated by an angle within the range of 53° to 64°. 10. An apparatus for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the apparatus comprising: a screen generator responsive to the color separation image data for generating halftone screens for each color of the color separation image data, and for one color having color separation image data the screen generator being operative to process color separation image data of said one color in accordance with each of two or more halftone screen angles of different angles and combining the results of the processings with two or more screen angles for output to a printer as composite image data of the two or more screen angles. 11. The apparatus of claim 10 and wherein the processor is operative to process the color separation image data of the one color in accordance with a dot structure dot growth pattern processing. 12. The apparatus of claim 11 and including a printer for printing the color separation image data as respective halftone color separation images and for printing said one color as a rosette pattern in response to the composite image data of the two or more screen angles. 13. The apparatus of claim 12 and wherein the printer includes printer components for respectively printing color separation image data in cyan, magenta, yellow, and black. 14. The apparatus of claim 13 and wherein the printer includes additionally a hi-fi printer component for printing the composite image data of the two or more screen angles in a fifth color different from cyan, magenta, yellow, and black. 15. The apparatus of claim 10 and wherein the processor is operative to process the color separation image data of the one color in accordance with two halftone screen angles and with a line structure dot growth pattern processing. 16. The apparatus of claim 12 and wherein the printer is an electrostatographic printer. 17. The apparatus of claim 10 and including a printer for printing the color separation image data as respective halftone screens and for printing said one color as a diamond structure pattern in response to the composite image data of two halftone screen angles. 18. The apparatus of claim 17 and wherein the printer includes printer components for respectively printing color separation image data in cyan, magenta, yellow, and black. 19. The apparatus of claim 18 and wherein the printer includes additionally a hi-fi printer component for printing the composite image data of the two screen angles in a fifth color different from cyan, magenta, yellow, and black. 20. The apparatus of claim 19 and wherein the printer is an electrostatographic printer. 21. A method for processing image data representing a color separation or mono-color image, the method comprising: processing the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and obtaining results of the processings; and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. 22. The method of claim 21 and wherein the color separation image data or mono-color image data is processed in accordance with a dot structure dot growth pattern processing. 23. The method of claim 22 and including printing the composite image data and generating a color separation or mono-color image as a rosette. 24. The method of claim 23 and wherein the different screen angles are separated by 30°. 25. The method of claim 23 and wherein the different screen angles are separated by 60°. 26. The method of claim 22 and wherein the color separation or mono-color image data is processed in accordance with the first and the second and a third halftone screen processing all at different screen angles. 27. The method of claim 21 and wherein the image color separation or mono-color image data is processed in accordance with the first and second halftone screen processings and with a line structure dot growth pattern processing and in response to the composite image data generating a color separation or mono-color image having a diamond structure. 28. The method of claim 27 and wherein the different screen angles are separated by 60°. 29. The method of claim 27 and wherein the different screen angles are separated by an angle within the range of 53° to 64°. 30. A method for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the method comprising: processing the color separation image data for generating halftone screens for the color separation images of some of the colors; and for one of the colors processing the color separation image data of the one color in accordance with each of two or more halftone screen angles and combining the results of the processings for output to a printer as composite image data of the two or more screen angles. 31. The method of claim 30 and wherein the color separation image data of the one color is processed in accordance with a dot structure dot growth pattern processing. 32. The method of claim 31 and including printing the color separation image data as respective halftone screens and printing a rosette structure in response to the composite image data of the two or more screen angles. 33. The method of claim 32 and wherein the color separation image data is printed in cyan, magenta, yellow, and black. 34. The method of claim 33 and wherein the composite image data of the two screen angles is printed in a fifth color different from cyan, magenta, yellow, and black. 35. The method of claim 34 and including printing the multi-color image using an electrophotographic printer. 36. The method of claim 30 and wherein the color separation image data of the one color is processed in accordance with two halftone screen angles processing and with a line structure dot growth pattern processing. 37. The method of claim 36 and including printing the color separation image data as respective halftone screens and printing a diamond structure pattern in response to the composite image data of the two screen angles. 38. The method of claim 37 and wherein the printer includes printer components for respectively printing color separation image data in cyan, magenta, yellow, and black. 39. The method of claim 38 and wherein the printer includes additionally a hi-fi printer component for printing the composite image data of the two screen angles in a fifth color different from cyan, magenta, yellow, and black. 40. The method of claim 39 and including printing the multi-color image using an electrophotographic printer. 41. The method of claim 30 and including printing the multi-color image using an electrophotographic printer. 42. The apparatus of claim 14 and wherein the fifth color is printed as a color separation in a halftone screen with a rosette structure and a complementary color of the fifth color is also printed as a color separation with the same rosette structure. 43. The apparatus of claim 42 and wherein the fifth color is blue and the complementary color of the fifth color is yellow. 44. The apparatus of claim 42 and wherein the fifth color is red and the complementary color of the fifth color is cyan. 45. The apparatus of claim 42 and wherein the fifth color is green and the complementary color of the fifth color is magenta. 46. The apparatus of claim 19 and wherein the fifth color is printed as a color separation in a halftone screen with a diamond structure and a complementary color of the fifth color is also printed as a color separation with the same diamond structure. 47. The method of claim 34 and wherein the fifth color is printed as a color separation in a halftone screen with a rosette structure and a complementary color of the fifth color is also printed as a color separation with the same rosette structure. 48. The method of claim 47 and wherein the fifth color is blue and the complementary color of the fifth color is yellow. 49. The apparatus of claim 47 and wherein the fifth color is red and the complementary color of the fifth color is cyan. 50. The apparatus of claim 47 and wherein the fifth color is green and the complementary color of the fifth color is magenta. 51. The method of claim 39 and wherein the fifth color is printed as a color separation in a halftone screen with a diamond structure and a complementary color of the fifth color is also printed as a color separation with the same diamond structure. 52. The method of claim 51 and wherein the fifth color is blue and the complementary color of the fifth color is yellow. 53. The method of claim 51 and wherein the fifth color is red and the complementary color of the fifth color is cyan. 54. The method of claim 51 and wherein the fifth color is green and the complementary color of the fifth color is magenta. 55. The method of claim 32 and wherein the color separation image data is printed in cyan, magenta and yellow and a fourth color that is a complementary color of one of cyan magenta and yellow and further wherein the fourth color is printed as a color separation in a halftone screen with a rosette structure and the complementary color of the fourth color is also printed as a color separation with the same rosette structure. 56. The method of claim 55 and wherein the fourth color is blue and the complementary color of the fourth color is yellow. 57. The method of claim 55 and wherein the fourth color is red and the complementary at color of the fourth color is cyan. 58. The method of claim 55 and wherein the fourth color is green and the complementary color of the fourth color is magenta. 59. The method of claim 37 and wherein the color separation image data is printed in cyan, magenta and yellow and a fourth color that is a complementary color of one of cyan magenta and yellow and further wherein the fourth color is printed as a color separation in a halftone screen with a diamond structure and the complementary color of the fourth color is also printed as a color separation with the same rosette structure. 60. The method of claim 59 and wherein the fourth color is blue and the complementary color of the fourth color is yellow. 61. A method for printing a multi-color image using color separation image data representing color separation images for each of plural different colors, the method comprising: processing the color separation image data of each of two different colors and generating similar rosette structures for each of the two colors and wherein the two colors are complementary colors to each other. 62. The method of claim 61 and wherein the two colors are blue and yellow. 63. The method of claim 61 and wherein the two colors are red and cyan. 64. The method of claim 61 and wherein the two colors are green and magenta. 65. The method of claim 61 and wherein the two different colors are each processed in accordance with two or more halftone screen processings at different screen angles. 66. A method for printing image data representing a color separation or mono-color image, the method comprising: processing the color separation image data or mono-color image data in accordance with the first and second or more halftone screen processings at different screen angles and obtaining results of each of the processings; and printing the results of the processings in the color to generate a composite image of the first and second or more halftone screen processings. | CROSS-REFERENCE TO RELATED APPLICATION This application is related to U.S. application Ser. No. ______ filed on even date herewith in the names of Tai et al. and entitled, METHOD AND APPARATUS FOR MULTI-COLOR PRINTING USING HYBRID DOT-LINE HALFTONE COMPOSITE SCREENS, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of digital encoding of pictorial information for use in forming color reproductions on display or printing systems. 2. Description Relative to the Prior Art With the advent of printing using digital technology, images may be printed, by rendering the image into a set of pixels. In pure binary printers, the pixel is either on (black) or off (white). Such techniques are well suited to reproducing text because the sizes of the individual pixels that make up the symbols are much smaller than the symbols. Thus, the human eye sees the text as a continuous image even though it is a collection of closely spaced dots. However, most binary print engines and particularly electrophotographic print engines do not provide acceptable levels of gray for other images, such as photographs. Those skilled in the art have used halftone dots to emulate grayscale for reproducing images with continuous tones. One reason for this is that the particles used for forming the printed dots may be larger than is desirable even if the printing system were suited to printing very small binary pixels. In the area of digital printing (the term “printing” is used to encompass both printing and displaying throughout), gray level has been achieved in a number of different ways. The representation of the intensity, i.e., the gray level, of a color by binary displays and printers has been the object of a variety of algorithms. Binary displays and printers are capable of making a mark, usually in the form of a dot, of a given, uniform size and at a specified resolution in marks per unit length, typically dots per inch. It has been well known to place the marks according to a variety of geometrical patterns such that a group of marks when seen by the eye give a rendition of an intermediate color tone between the color of the background (usually white paper stock) and total coverage, or solid density. The effect is such that a group of dots and dot-less blank spots, when seen by the eye, is a rendition of an intermediate color tone or density between the color of the initial paper stock, usually white, and total ink coverage, or solid density halftone dot. It is conventional to arrange the dots in rows, where the distance between rows is known as line spacing, and determines the number of lines per inch (lpi). In the ensuing paragraphs, discussions will be made in terms of white paper stock; it is understood that white paper stock is used as an illustration and not as a limitation of the invention and that other media may be used such as plastics, textiles, coated papers, metals, wood, edible articles, etc. Continuous tone images contain an apparent continuum of gray levels. Some scenes, when viewed by humans, may require more than two hundred and fifty six discrete gray levels for each color to give the appearance of a continuum of gray levels from one shade to another. Halftone pictorial or graphical images lower the high contrast between the paper stock and toned image and thereby create a more visually pleasing image. As an approximation to continuous tone images, pictorial imagery has been represented via binary halftone technologies. In order to record or display a halftone image one picture element of the recording or display surface consists of a j×k matrix or cell of sub-elements where j and k are positive integers. A halftone image is reproduced by printing the respective sub-elements (pixels or pels) or leaving them blank, in other words, by suitably distributing the printed marks within each cell. Another method of producing gray levels is provided by gray level printing. In such a method, each pixel has the capability to render several different dot sizes. In certain electrophotographic printing systems, for example, the dot size for a pixel is a function of the exposure time provided an LED element corresponding to that pixel. The longer the exposure time, the more toner is attracted to that particular pixel. There are two major concerns in rendering a continuous tone image for printing: (1) the resolution of image details, and (2) the reproduction of gray scales. These two fundamental factors compete with each other in a binary representation scheme. The more gray levels that are rendered, the larger is a halftone cell. Consequently, coarse halftone lines screens are provided, with the attendant poor image appearance. Hence, compromises made in rendering between the selection of line resolution in gray scales and binary halftone printing. However, with gray level halftone printing, one can satisfy both resolution and gray level requirements. In gray level printing, the same number of addressable dots are present, and there is attached a choice of dot sizes from one dot size of 1 bit/pixel to for example 255 different dot-sizes of 8 bits/pixel. Although providing higher image quality with respect to line resolution and tone scales, gray level halftone presents its own dot rendering issues. A number of different dot layouts are possible to build gray level dots from a cell template. These gray level dots are the digital representation of the gray level screening, and must be realized through a printing process. It is desirable in gray level screening to layout the dots with the printing process characteristics built into it such that the appearance of the dots are pleasing to the eye: less grainy, stable, less artifacts, less texture (i.e., visible screen and its microstructure). An example of a line screen designed for gray scale rendering is disclosed in U.S. Pat. No. 5,258,850. The arrangement of pixels within a halftone cell is such that growth within a cell to represent increases in density is accomplished through arranging the pixels along lines of growth. Another example of a halftone cell is that shown in U.S. Pat. No. 5,258,849, which features growth of density within a halftone cell by gradual enlargement about a central area within the cell. The halftone cells disclosed in the above two patents are notable in that the pixels we need within each cell may vary in density. This substantially increases the number of gray levels that may be represented by the overall halftone cell from that where the pixels can only be rendered as a binary representation (either black or white with no distinction regarding size). The combination of cells represents a halftone screen. Color printing on halftone printers involves the formation of color separations as halftone screens for each color, which is to be used to form a color image. The halftone screens are laid down on a predetermined overlapping relationship to each other, which results in generation of the desired color image. A well-known problem when overlapping two or more halftone screens is the possibility of developing a moiré pattern or other form of interference, when the screens are not properly positioned. To avoid the moiré or other undesirable patterns, precise angle combinations of the screens are required. It is known that increasing the difference in angle of two overlaid screens will result in a smaller pattern, making the pattern less apparent. However, the prior art teaches, see for example U.S. Pat. No. 6,307,645, the largest possible angle difference between two overlaid screens should be no more than 45° because a 90° screen is essentially the same as 0°, just as a 135° screen is the same as a 45° screen even in the context of attempting to reduce moiré with asymmetrical dots. In color image printing it has been common practice to use at least three process colors and in more cases three process colors and black. In the case of four-color printing the printing industry has generated a standardized combination of four halftone angles. In particular and with reference to FIG. 1, the cyan halftone screen is located at 15°, the black halftone screen at 45°, the magenta halftone screen at 75° and the yellow halftone screen at 0°. Since yellow is the lightest and least noticeable color, it can be set at 0°, even though 0° is a highly noticeable angle, and that is only 15° from the nearest neighbor. In some embodiments, the cyan halftone screen is known to be set at 105°, however, with symmetrical dots this is substantially the same as 15°, and the prior art recognizes that even with asymmetrical dots it does not make a large difference. When the four process colors using the above halftone screen angle combinations are overlaid, the resulting moiré or other interference patterns are as small as possible. A visually pleasing rosette structure is formed when the individual dots grains are oriented 30° apart. The traditional graphics art printing has been made using this 15°/45°/75° angle screen design to form a balanced rosette structure. In the CMYK four-color printing process, the yellow screen is usually designed at 0° or 45°. However, the moiré pattern resulting from the interaction between the yellow screen and the other three individual screens due to mis-registration is not as visually pleasing as a 30° moiré pattern (rosette structure). Yellow is a light color, so this additional moiré is usually acceptable and not very noticeable in most CMYK four-color printing systems. However, careful examination of prints shows that this yellow moiré pattern can be seen in certain composite colors. U.S. Pat. No. 5,808,755 deals with the problem of moiré in a multi-color printer. The patent suggests the use of a screen having a cluster dot growth pattern that varies in a predetermined way such that the centroid of the cluster dot is not situated within an internal region. The screen can be used to induce a variable rosette structure depending upon the intensity level of the original image. The suggested screen pattern does not lend itself easily to currently available screen designs. Where additional colors are used such as in a hi-fi color (for example, a five-color) printing system, there is a need to design a fifth screen on top of the original well-balanced CMYK screen set. This is particularly true where the fifth color screen is blue, the complementary color of yellow, and the blue color screen is placed at the same screen angle and screen frequency as the yellow color screen. The unpleasant moiré, which was not noticeable in the yellow color, will now show up in the blue color. It is thus known that many color printing systems will include five or more printing units using different color colorants. Attempting to incorporate these additional colors is noted to be difficult, especially if each color must have a halftone screen with a unique halftone angle. Particularly, once there are more than four screens with attendant screen angles, which must be laid down, the patterning problems discussed above, are greatly increased. It would thus be desirable to provide for color screen sets for printing which minimize the unpleasant moiré patterns formed including those caused by the interactions of the yellow screen. SUMMARY OF THE INVENTION The foregoing objects are realized by the present invention, which provides an apparatus and method for the generation of halftone images with reduced image artifacts and increased number of gray levels. In accordance with a first aspect of the invention there is provided, an apparatus for processing image data, representing a color separation or mono-color image, the apparatus comprising a processor operative to process the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. In accordance with a second aspect of the invention there is provided an apparatus for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the apparatus comprising a screen generator responsive to the color-separation image data for generating halftone screens for each color of the color separation image data, and for one color having color separation image data the screen generator being operative to process color separation image data of said one color in accordance with each of two or more halftone screen angles of different angles and combining the results of the processings with two or more screen angles for output to a printer as composite image data of the two or more screen angles. In accordance with a third aspect of the invention there is provided a method for processing image data representing a color separation or mono-color image, the method comprising processing the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and obtaining results of the processings; and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. In accordance with a fourth aspect of the invention there is provided a method for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the method comprising processing the color separation image data for generating halftone screens for the color separation images of some of the colors; and for one of the colors processing the color separation image data of the one color in accordance with each of two or more halftone screen angles and combining the results of the processings for output to a printer as composite image data of the two or more screen angles. In accordance with a fifth aspect of the invention there is provided a method for printing a multi-color image using color separation image data representing color separation images for each of plural different colors, the method comprising processing the color separation image data of each of two different colors and generating similar rosette or diamond structures for each of the two colors and wherein the two colors are complementary colors to each other. Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a representation of halftone screen angles in a four-color printing system as known in the prior art; FIG. 2 is a schematic of an electrophotographic print engine that may be used in accordance with the invention to generate multi-color prints; FIGS. 3-6 are respective different diagrams each illustrating a representation of halftone screen angles in a four-color printing system in accordance with four different embodiments of the invention wherein the color yellow is represented by two or more halftone screens at different screen angles; FIGS. 7-10 are respective different diagrams each illustrating a representation of halftone screen angles in a four-color printing system in accordance with four different embodiments of the invention wherein the color black is represented by two or more halftone screens at different screen angles; FIG. 11 illustrates exemplary three-bit gray halftone dot layouts, according to a full dot type embodiment, as known in the prior art and which may be used in accordance with the invention; FIG. 12 illustrates a halftone cell with dots that have been formed in accordance with the full dot type of growth pattern of FIG. 11; FIG. 13 illustrates an exemplary halftone dot mask used for growing the full type dot type of FIG. 11; FIG. 14 is a graphic illustration of the building up within a halftone cell in accordance with a line type dot growth pattern as known in the prior art and which may be used in accordance with the invention; FIGS. 15-20 are respective different diagrams each illustrating a representation of halftone screen angles in a five-color printing system, typically referred to as a hi-fi color printing system, in accordance with ten different embodiments of the invention wherein the hi-fi color is represented by two or more halftone screens at different screen angles; FIG. 21 is an illustration of a rosette resulting from the use of three halftone screens at three different screen angles to generate the halftone color separation image of one color in accordance with the invention; FIGS. 22 and 23 are each respective illustrations of rosettes resulting from the use of two halftone screens at the indicated two different screen angles to generate the halftone color separation image of one color in accordance with the invention; FIG. 24 is an illustration of a rosette density ramp resulting from the use of two or more halftone screens at different screen angles to generate the halftone color separation image of one color in accordance with the invention; FIG. 25 is an illustration of a diamond screen structure formed by the use of two halftone screens at 60° screen angle to generate the halftone color separation image of one color using a line structure dot growth pattern in accordance with the invention; FIG. 26 is an illustration of a density ramp with use of the diamond screen structure of FIG. 24; FIG. 27 is a flowchart for creating a single-color separation image using two halftone screens at two different screen angles; and FIGS. 28-30 are graphs illustrating examples of determination of weight factors for use in the flowchart of FIG. 27. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an elevational view showing the essential portions of an electrophotographic engine suitable for printing of full-color images and incorporating the improvements of the invention. Although one embodiment of the invention involves printing using an electrophotographic engine having repeating sets of single-color image producing stations and arranged in a so-called tandem arrangement other electrostatographic color reproduction apparatus and make use of the invention as well as other types of color printing systems including inkjet, lithography, etc. With reference now to FIG. 2 there is shown a printer apparatus 500 having a number of tandemly arranged electrostatographic image forming modules. Although five-color modules are shown it will be understood that the invention is also suited for multi-color printer apparatus for printing three or more colors. Each module of the printer includes a plurality of electrophotographic imaging subsystems for producing a single-color toned image. Included in each imaging subsystem is a charging subsystem for charging a photoconductive imaging member, an exposure system for image-wise exposing a photoconductive imaging member to form a latent color separation image in the respective color, a development subsystem for toning the image-wise exposed photoconductive imaging member with toner of the respective color, an intermediate transfer subsystem for transferring the respective color separation image from the photoconductive imaging member to an intermediate transfer member and from the intermediate transfer member to a receiver member which receives the respective toned color separation images in superposition to form a composite multi-color image. Subsequent to transfer of the respective color separation images from each of the respective subsystems the receiver member is transferred to a fusing subsystem to fuse the multi-color toner image to the receiver member. Further details regarding the printer 500 are also provided in U.S. Pat. No. 6,608,641, the contents of which are incorporated herein by reference. The five exemplary color modules of printer apparatus 500 are for preferably forming black, cyan, magenta, yellow, and blue color toner separation images. Although blue is illustrated and preferred as the fifth color it will be understood that the fifth color may be other dominant colors such as red or green or orange or violet or that the number of the modules may be increased to print more colors than five. Elements in FIG. 2 that are similar from module to module have similar reference numerals with a suffix of B, C, M, Y, and BE referring to a color module to which it is respectively associated; i.e. black (B), cyan (C), magenta (M), yellow (Y), and blue (BE). Each module (591B, 591C, 591M, 591Y, and 591BE) is of similar construction except that as shown one receiver transport web (RTW) 516 in the form of an endless belt operates with all the modules and the receiver member is transported by the RTW 516 from module to module. Receiver members are supplied from a paper supply unit, thereafter preferably passing through a paper conditioning unit (not shown) before entering the first module in the direction as indicated by arrow A. The receiver members are adhered to RTW 516 during passage through the modules, either electrostatically or by mechanical devices such as grippers, as is well known. Preferably, receiver members are electrostatically adhered to RTW 516 by depositing electrostatic charges from a charging device, such as for example by using a tack-down corona charger 526. Five receiver members or sheets 512a, 512b, 512c, 512d, and 512e are shown (simultaneously) receiving images from modules 591BE, 591B, 591C, 591M, and 591Y. It will be understood as noted above that each receiver member may receive one color image from each module and that in this example up to five-color images can be received by each receiver member. The movements of the receiver member with the RTW 516 is such that each color image transferred to the receiver member at the transfer nip 510B, 510C, 510M, 510Y, and 510BE of each module is a transfer that is registered with the previous color transfer so that a five-color image formed on the receiver member has the colors in registered superposed relationship on the transferee surface of the receiver member. The receiver members are then serially detacked from RTW 516 and sent in a direction indicated by arrow B to a fusing station (not shown) to fuse or fix the dry toner images to the receiver member. The RTW is reconditioned for reuse by providing charge to both surfaces using, for example, opposed corona chargers is 522, 523 which neutralize charge on the two surfaces of the RTW. Each color module includes a primary image-forming member, for example a drum or primary image-forming roller (PIFR) labeled 503B, 503C, 503M, 503Y, and 503BE respectively. Each PIFR 503B, 503C, 503M, 503Y, and 503BE has a respective photoconductive surface structure 507B, 507C, 507M, 507Y, and 507BE having one or more layers, upon which a pigmented marking particle image or a series of different ones of such images is formed (individual layers of PIFRs are not shown). In order to form toned images, the outer surface of the PIFR is uniformly charged by a primary charger such as a corona charging device 505B, 505C, 505M, 505Y, and 505BE respectively, or by other suitable charger such as a roller charger, a brush charger, etc. The uniformly charged surface is preferably exposed by a respective electronic image writer, which exposure device is preferably an LED or other electro-optical exposure device, for example, a laser to selectively alter the charge on the surface of the PIFR. The exposure device creates an electrostatic image corresponding to an image to be reproduced or generated. The electrostatic image is developed, preferably using the well-known discharged area development technique, by application of pigmented marking particles to the latent image bearing photoconductive drum by development station 581B, 581C, 581M, 581Y, and 581BE respectively, which development station preferably employs so-called “SPD”(Small Particle Development) developers. Each of development stations 581B, 581C, 581M, 581Y, and 581BE is respectively electrically biased by a suitable respective voltage to develop the respective latent image, which voltage may be supplied by a power supply, e.g., power supply 552, or by individual power supplies (not illustrated). The respective developer includes toner marking particles and magnetic carrier particles. Each development station has a particular color of pigmented toner marking particles associated respectively therewith for toning. Thus, each module creates a series of different color marking particle images on the respective photographic drum. In lieu of a photoconductive drum, which is preferred, a photoconductive belt may be used. Alternatively, the image may be created by an electrostatic charger that forms respective pixels of charge on an insulating surface directly in response to image information. Each marking particle image formed on a respective PIFR is transferred to a compliant surface of a respective secondary or intermediate image transfer member, for example an intermediate transfer Roller (ITR) labeled 508B, 508C, 508M, 508Y, and 508BE respectively. After transfer, the residual toner image is cleaned from the surface of the photoconductive drum by a suitable cleaning device 504B, 504C, 504M, 504Y, and 504BE, respectively, so as to prepare the surface for reuse for forming subsequent toner images. A logic and control unit (LCU) provides various control signals that control movement of the various members and the timing thereof as well as the appropriate electrical biases for accommodating the various transfers of the respective toner images. Timing signals are also provided to a motor M, which drives a drive roller 513 that drives the RTW 516. The RTW in turn may be used to drive the other components and/or other drivers may be used to control movement of the rollers in the respective modules. Image data for writing by the printer apparatus 500 may be processed by a raster image processor (RIP) 501 which may include a color separations screen generator or generators. The term “generator” or “generators” are used interchangeably herein since a single device may operate serially and be programmed or adjusted to operate differently for each of the different screens. The output of the RIP may be stored in a frame or line buffers 502 for transmission of the color separation print data to each of the respective LED writers 506 BE, 506B, 506C, 506M, and 506Y. The RIP and/or color separations screen generator may be a part of the printer apparatus or remote therefrom. Image data processed by the RIP may be obtained from a color document scanner or a digital camera or generated by a computer or from a memory or network which typically includes image data representing a continuous image that needs to be reprocessed into halftone image data in order to be adequately represented by the printer. The RIP may perform image processing processes including color correction, etc. in order to obtain the desired color print. Color image data is separated into the respective colors and converted by the RIP to halftone dot image data in the respective color using threshold matrices, which comprise desired screen angles and screen rulings. The RIP may be a suitably programmed computer and/or logic devices and is adapted to employ stored or generated threshold matrices and templates for processing separated color image data into rendered image data in the form of halftone information suitable for printing. The invention proceeds from the recognition that a visually pleasing rosette structure is formed when the individual screen orientation angles are spaced 30° apart. The traditional graphics are printing practice is of using 15°/45°/75° angle screens designed to form a balanced cyan, magenta, and black (CMK) rosette structure. In the CMYK four-color printing process, the yellow screen is usually designed at 0° or 45°. However, a moiré pattern resulting from the interaction of the yellow screen with the other three individual screens is not as visually pleasing as a 30° moiré pattern (rosette structure). Yellow is a light color, so this additional moiré is usually acceptable and difficult to notice in the conventional CMYK four-color printing practice. However, with careful examination, this yellow moiré pattern may show up in certain composite colors. The invention therefore proposes that a design of a rosette structure screen for the yellow color may be provided that eliminates the unpleasant moiré pattern caused by the interaction of the yellow screen with the other three screens (C, M, and K). The rosette structure is formed when two or more differently oriented screens are overlaid on top of each other. This rosette structure carries frequency information corresponding to multiple screen rulings and multiple screen angles that diffuse the spectrum into broad distribution instead of sharp peaks that occur in the regular halftone structure. The rosette structure hides the screen structure so that it is less visible to the naked eye and looks smooth even when printed in a single separation color. In the description below reference will be made to separate color separation images of the same color being at different screen angles, however as will be shown with reference to the flowchart of FIG. 27 that a composite of the two screens may be combined electronically before printing and this composite then printed. An illustration of a density ramp for such a rosette structure is illustrated in FIG. 24. With reference now to FIG. 3 there is illustrated a first embodiment of the invention wherein a four-color halftone system is shown in accordance with their respective color screen angles. In each of the color systems to be hereafter described it is assumed that a print job request is for a photographic type of image (as opposed to a text image) and each module of printer apparatus 500 will be caused to generate a halftone screened image in the respective separation color and wherein the cells of the halftone screen are oriented at the angle indicated in the respective figure. The cyan color separation component halftone screen is directed at the same screen angle of 15° as that of a first yellow color halftone separation screen Y1. The black color (K) separation component halftone screen is directed at the usual angle of 45°. The magenta color separation component halftone screen is directed at the usual angle of 75° as is that of a second yellow color halftone separation screen Y2. A rosette structure developed by the two 15°/75° yellow halftone screens is illustrated in FIG. 23. With reference now to FIGS. 4 and 5 there are illustrated second and third embodiments of the invention wherein a four-color halftone screen system has the cyan, black and magenta halftone screens oriented at the usual angles of 15°/45°/75°. In each of these embodiments the two yellow screens, Y1 and Y2, are oriented at angles of 15° and 45° (FIG. 4) and angles 45° and 75° (FIG. 5), respectively. A rosette structure corresponding to the two screen angles for the yellow color separation image of FIG. 4 is illustrated in FIG. 22. With reference now to FIG. 6 there is illustrated a fourth embodiment of the invention wherein a four-color halftone screen system has the cyan, black and magenta halftone screens oriented at the usual angles of 15°/45°/75°. In this embodiment there are three yellow halftone screens, Y1, Y2, and Y3 that are oriented respectively at the screen angles of 15°/45°/75°. The rosette structure corresponding to the three screen angles for the yellow color separation image of FIG. 6 is illustrated in FIG. 21. With reference now to FIGS. 7-10 there are illustrated fifth, sixth, seventh, and eighth embodiments of the invention wherein a four-color halftone screen system has one of the dominant colors such as black which will be formed as a composite of two or three halftone screens at different screen angles. In all the embodiments of FIGS. 7-10 the cyan and magenta halftone screens are oriented at the usual angles of 15°/75°. In FIG. 7 the yellow color halftone separation is at an angle of 45°. As noted above, yellow is typically located at either one of 0° or 45°. In the embodiment of FIG. 7 the two black halftone screens, K1 and K2, are at angles of 15° and 75°, respectively. The rosette structure for the black color for this embodiment is also illustrated in FIG. 23. In the embodiments of FIGS. 8, 9 and 10 the yellow halftone screen is formed at 0°. In the embodiment of FIG. 8 the two black halftone screens, K1 and K2, are at 15° and 45°, respectively. The rosette structure for the black color for the embodiment of FIG. 8 is illustrated in FIG. 22. In the embodiment of FIG. 9 the two black halftone screens are at 45° and 75°, respectively. In the embodiment of FIG. 10 there are three black halftone screens, K1-K3, at the screen angles of 15°/45°/75°. The rosette structure corresponding to the three screen angles for the black color separation image of FIG. 10 is also illustrated in FIG. 21. With reference now to FIGS. 11-13 description will be provided of a dot structure dot growth pattern, which is distinguished herein from the line structure dot growth pattern description of which will be provided hereafter with regard to discussion of FIG. 14. It should be understood that while the preferred embodiments described herein utilize gray level printheads that are adapted to print gray level dots at each pixel location that the invention regarding the use of various screen angles and dot types are also suited for binary printheads that can place either a dot or no dot at a particular pixel location in a halftone cell. As noted above the pixel locations are grouped into cells having cell gray levels. The dots of a cell are formed such that for each increase in cell gray level, a dot at at least one of the pixels in the cell, the core pixel, forms to a larger dot size (or dot density). In an example of one type of growth pattern the dots are sequentially formed at the pixels in the cell in a pre-defined order such that at the lower cell gray levels a dot is formed at a first or core pixel location within the cell and this dot is increased in size (or density) with desired increases in cell density until a maximum dot size is reached before beginning the formation of a dot at an adjacent pixel location within the cell. Thereafter for increasing cell gray levels the dot size is increased at this adjacent pixel location until a maximum dot size is reached at the pixel location. Additional increases in cell density are made similarly with buildup of dots using adjacent pixel locations so that dot growth is from a center or core pixel location gradually outwardly and surrounding the central pixel location. Alternatively, the growth pattern for the dots of the halftone cell may be a “partial dot” dot structure dot growth pattern also described in aforementioned U.S. Pat. No. 5,258,849, the contents of which are incorporated herein by reference. In lieu of the “full dot” dot growth pattern and the “partial dot” dot growth pattern just described as well as described in U.S. Pat. No. 5,258,849, the growth pattern may also be that which is known as a “mixed dot” dot structure dot growth pattern wherein growth of the dot at a core pixel location is to a predetermined level less than a maximum before commencing growth at one or more adjacent pixel locations about the core pixel. Subsequent growth is by additions to the core pixel as well as to the one or more adjacent pixel locations. With reference to FIG. 11 there is illustrated an example of a 3-bits/pixel gray halftone dot layout for a full dot type growth pattern. Also illustrated are seven different pixel dot sizes corresponding to the sizes that each individual pixel dot can obtain. There are 57 possible gray levels for the exemplary aid elements sell 30 shown here. An example of the formation of the cell that is a gray level 12, will now be given. The pixel circled in level one, reference numeral 1, is formed to dot size 1 in level 1. Only one cell will be described, although the pixels in other cells will be changed according to the same layout or growth pattern as shown in FIG. 11. The dot at this pixel grows larger and larger as cell gray levels increase from level 1 to level 2 all the way to cell gray level 7. One can see that the circled pixel increases in value from pixel size (or density) 1 to 7 as the cell gray levels increase. If the desired gray level for the cell 30 is 7, then the formation of dots would be completed once the circled pixel has reached the dot size of 7. In this example, however, the gray level for the cell 30 is desired to be 12. At gray level 7, the circled pixel has reached its maximum dot size, so that a dot at another pixel location in the cell must now start forming. This dot starts forming at an adjacent pixel indicated with a square around it in level 1, with the numeral 8. The dot formation process continues, with the dot at the second pixel growing larger and larger as the levels again increase from level 1 to level 5. The formation process stops at level 5, since the pixel has now reached the value of 12. The halftone cell 30 now contains, as seen in FIG. 12, a dot of dot size 7, and a dot of dot size 5. The extension of this formation process to 57 gray levels is easy to see from this example. Although this example is illustrated with a printer that forms dots in accordance with 3-bits/pixel the invention is suited for use with any gray level printhead that can form pixels at 2 bits/pixel or more as well as with binary printheads wherein the dot growth pattern is around a central or core pixel location. The full dot type process thus involves forming dots at the highest priority pixels to their maximum allowable dot size before beginning the formation of the dots for the next highest priority pixels. An exemplary halftone dot mask 32 with pixel priorities indicated is shown in FIG. 13. Different matrix sizes, cell shapes, and priorities can be used for the cells than that illustrated in FIG. 11. Halftone cells of about 4×4 pixels are known and may be used it being understood that the average number of pixels per cell need not be a whole number. In the electrophotographic process, the full dot type formation process is favored because it forms stable dots and exhibits less granularity (halftone printing noise). The partial dot type is known to carry more information detail than full dot but at the cost of less stable dots in the electrophotographic process. The mixed dot type combines the merits of both the full dot and the partial dot types in gray level halftoning. The above description of the 3-bits/pixel printhead case, may readily be extended to higher numbers of gray levels. In an example of a 4-bits/pixel printhead, each pixel location in the cell may have gray levels from 0 to 15. Also in an example of an 8 bits/pixel printhead each pixel location in the cell may have gray levels from 0 to 255 and the resolution of the printer for printing pixels may be 300 dpi or greater, the example of FIG. 2 being a 600 dpi printer. In the embodiments of FIGS. 3-10 the halftone cells for all the halftone color separation images are grown in density using a dot structure dot growth pattern wherein density increases in the halftone cell are about a central or core dot. With reference now to FIG. 14 and with further reference to U.S. Pat. No. 5,258,850 there is shown a halftone cell wherein the growth pattern of the dots within the cell is a development or creation along a line or lines as opposed to growing of dots about a central or core dot. In the line structure dot growth pattern for lower values of cell density, for example from cell density level 1 to cell density 5, all the pixel locations indicated as having a dot are exposed to form a line of dots or a series dot lines (three dot lines are shown in the FIG. 14). As the lines become solid dot lines due to overlap of adjacent dots as the dots grow in size at the pixel locations along the dot lines further increases in cell density are produced by forming secondary lines adjacent each of the solid lines as shown in the FIG. 14. Thus it can be seen that the line structure dot growth pattern emphasizes creation of stable line structures as opposed to the full or partial or mixed dot type growth structure, which emphasizes stable dot growth. With reference now to FIGS. 15a-18a, there are illustrated the ninth through twelfth embodiments of the invention wherein five colors are accommodated, i.e. a hi-fi color system. For example red, green, blue, orange, or violet color may be the fifth color in a hi-fi color system. In these embodiments for the colors yellow, cyan, black, magenta, the halftone cells are at the usual angles 0°, 15°, 45°, and 75° respectively. The hi-fi color, in this example blue (B), is formed of at least two halftone screens at different respective angles. In the embodiment of FIG. 15a the blue halftone cells (B1 and B2) are at the angles of 15° and 75° respectively. The rosette structure formed by a composite of such screens is also illustrated in FIG. 23. In the embodiment of FIG. 16a the blue halftone cells are at the angles of 15° and 45° and the rosette structure formed by a composite of such screens is also illustrated in FIG. 22. In the embodiment of FIG. 17a the blue halftone cells are at the screen angles of 45° and 75° and a rosette structure is formed by a composite of such screens. In the embodiment of FIG. 18a there are three blue halftone cells that are employed to create the blue color separation image. In the embodiment of FIG. 18a the blue halftone cells (B1, B2, and B3) are at the screen angles of 15°, 45°, and 75° respectively and the rosette structure formed by a composite of such three screens is also illustrated in FIG. 21. With reference now to FIGS. 15b-18b there are illustrated additional alternate embodiments of the invention wherein five colors are accommodated; i.e. a hi-fi color system, except that the hi-fi color and its complementary color are each formed using the same rosette structure. In this regard it will be noted that in FIG. 15b that blue and yellow are each formed using two halftone screen angles with the identical angles, i.e. 15° and 75° and identical screen frequencies and identical type of dot growth pattern such as the dot structure dot growth pattern or a line structure dot growth pattern. The color separation images of cyan, magenta, and black are processed at halftone screen angles typical for these colors. Where the hi-fi color is green its complementary color is magenta and both the green and magenta color separation images may be processed identically using the same number of halftone screen angles (two or three), the identical screen frequencies and identical type of dot growth pattern. Thus, in the examples of FIGS. 15b-18b, the blue color screen angles shown (B1, B2, and B3) could be replaced by a green color (G1, G2, and G3), and the yellow color (Y1, Y2, and Y3) could be changed to magenta color (M1, M2, and M3), so that the same rosette screen can be applied to both complementary colors (green and magenta) in a hi-fi color printing system where cyan, yellow, and the black color have the original screen angles shown in FIGS. 15a-18a. Similarly, if the hi-fi color is red its complementary color is cyan, and both the red and cyan color separation images may be processed identically using the same plural number of halftone screen angles, the identical screen frequencies and identical type of dot growth pattern to obtain the same rosette or diamond structure for each as described for blue and yellow. It will be understood that a four-color system may also be a hi-fi color system wherein cyan, magenta and yellow are used in combination with another color other than black and the other color may be a complementary color of one of cyan, magenta or yellow. Placement of the blue screen at an angle of only 15° from cyan and magenta with all three colors being dominant colors may cause a problem in printing quality. However, where the blue screen is formed in a rosette structure as described herein the problem can be ameliorated. Furthermore, this can be extended to other hi-fi colors so that it is acceptable to use a rosette structure in forming other hi-fi colors as red and green in a hi-fi color printing system. Preferably, where red is the hi-fi color and formed in a rosette pattern, its complement, which is cyan will also be formed in a rosette pattern such as illustrated in FIGS. 21-23 and 25 with red and cyan being processed identically using the same screen angles (two or three angles) and screen frequencies. Similarly, green and its complement magenta can also each be processed to form respective rosette structures. Because there are seldom images having both complementary colors present on the same pixel, lay down of complementary colors on the same pixel produces a gray color which can be replaced at least in part by a black color during printing. In the embodiments of FIGS. 15-18 the halftone cells for all the halftone color separation images are grown in density using a dot structure dot growth pattern wherein density increases in the halftone cell are about a central or core dot. However, it will be understood that the dot growth pattern for the colors other than blue may have instead a line structure dot growth pattern. In this regard it is preferred to have pairs of colors being formed in a line structure dot growth pattern. The rosette structures illustrated in FIGS. 21-23 result from processing of the image data for the color blue (or any single-color separation image or mono-color) using halftone cells having a same dot structure dot growth pattern. As an alternative, a color separation image that is formed using two halftone screen angles can be formed using a line structure dot growth pattern and advantageously one color color-separation image and its complementary color color-separation image can each be formed with the identical diamond structure as described herein. With reference now to FIG. 19 there is illustrated the seventeenth embodiment of the invention wherein five colors are accommodated. The halftone screens for the yellow and black color separations are situated at 0° and 45° respectively and each of these screens employs a dot structure dot growth pattern. The cyan and magenta color separation images have their respective halftone screens at angles of 15° and 75° respectively and each of these halftone screens employs a line structure dot growth pattern. A 60° line structure is thus formed by, the cyan and magenta color separation images, and this 60° rosette or diamond line structure is relatively pleasing. Furthermore, the blue color separation image is formed using a composite of two halftone screens, one being situated at 105° and the other at 165° to provide a 60° separation between the two screens. Both of these blue color separation halftone screens also employ a line structure dot growth pattern. It will be noted that, in the embodiment of FIG. 19, the line structures formed as a result of the B1 halftone cell will be perpendicular to that of the line structures formed in the cyan halftone color separation and the line structures formed as a result of the B2 halftone cell will be perpendicular to that of the line structures formed in the magenta color separation. Therefore, objectionable moiré pattern artifacts will tend to be minimized. Because the halftone screens B1 and B2 are separated by 60° and provided with line structure dot growth patterns the two directions respectively orthogonal to these lines are separated by a 60° angle and also combine to form a “double line” screen in cyan and magenta the white holes of which have a diamond shape, see in this regard the diamond screen pattern shown in FIG. 25. In FIG. 26 there is illustrated a density ramp of the composite “double line” screen with the diamond structure formed by the composite of halftone screens B1 and B2. With reference to FIG. 20 there is illustrated an eighteenth embodiment of the invention wherein five colors are accommodated. The halftone screens of yellow and black are both situated at 45° and both of these screens employ a dot structure dot growth pattern. The cyan and magenta halftone screens are at 18° and 72° respectively and both of these screens employ a line structure dot growth pattern. The blue color separation image is formed using a composite of two halftone screens, one at −18° and the other at −72°, and in accordance with the process illustrated by the flowchart of FIG. 27 each using the line structure dot growth pattern to form the diamond line structure illustrated by FIGS. 25 and 26. With reference to the flowchart of FIG. 27 the actual image that is printed for the blue color separation of the embodiments of FIGS. 15-20 (or of the two yellow halftone screens for the embodiments of FIGS. 3-6 or of the two black halftone screens for the embodiments of FIGS. 7-10) is a composite weighted sum of corresponding pixel locations in each of these two blue (or two yellow, or two black, etc.) color separation screens. Thus as can be seen in the flowchart of FIG. 26 color image data of the blue color separation image (or any color separation image or a mono-color) is input from a color scanner, digital camera, memory or computer or generated from some other combination of colors and may be subject to color correction and other corrections to make the image data color dependent on the characteristics of the printer, step 100. The corrected blue color separation image data is processed by the screen generator or respective generators, at each of the two different halftone screen angles, steps 101 and 102. To do this, threshold values are assigned with each screen and associated with each halftone cell and dependent upon line frequency, dot growth pattern type, halftone cell size, etc., the incoming blue image data is compared with the threshold values to determine whether or not a dot is to be printed at a particular pixel location i,j (binary printing case) or to determine the gray level of the dot at a particular pixel location i,j (gray level printing case). The algorithmically developed gray value for each pixel location i,j is then multiplied by a predetermined weighting value, steps 103, 104, and then the weighted products are summed in step 105. The sum in step 105 represents the rendered pixel value to be sent to the printer for printing by that color module at the pixel location i,j on the receiver sheet, step 106. Further modification of the pixel value may be made for uniformity correction or otherwise as is well known in the art. The resulting image produced has an influence of both screens so that there are a series of dot structures or line structures that appear to be printed along lines at one screen angle and other series of dot structures or line structures that appear to be printed along lines at the second screen angle. In the examples where all the halftone cells for the blue (or any color separation image or mono-color) image provide a dot structure dot growth pattern the rosettes of FIGS. 21-23 will be created and appear relatively pleasing. In the examples where all the halftone cells for the blue (or any color separation or mono-color) image provide a line structure dot growth pattern the diamond screen pattern of FIG. 25 will be created and appear relatively pleasing. Halftone cells comprising the halftone screens form, in response to the image data, a buildup of halftone dots at various locations on each halftone screen wherein the dots appear to be arranged along lines having different respective angles. It will be noted that while each cell comprises plural pixel locations that it is the cell itself that is to be representative of the gray level to be printed at an area on the receiver member. Each halftone screen 101, 102 has a counterpart pixel location that would ordinarily be used to print a pixel at a pixel location i,j on the receiver. The counterpart pixel in each halftone screen is multiplied by a weighting factor associated with each screen and then the sum is taken and sent to the printer for printing at that pixel location i,j on the receiver member. The composite image thus formed for this blue color separation represents pixels arranged along two screen line directions that in effect present a rosette or diamond grid. In the case of where the hi-fi color (or any color separation or mono-color) is rendered using a composite of two halftone screens that employ the line structure dot growth pattern a diamond structured grid pattern having the density ramp of FIG. 26 will result. It has been found that this 60° diamond grid has a relatively pleasing appearance and is the preferred angle for a diamond grid. However, diamond grid angles of 53° to 64° are also appealing. The weighting factors provided when forming the composite of the halftone screens 101, 102 may be adjusted in accordance with providing more weight to one than the other to emphasize one screen angle over the other at certain densities. With reference to FIGS. 28-30 there are illustrated various examples of how a weighting factor implementation might be realized. In the example where a line structure dot growth pattern is employed for a color being produced using the combined processing of two halftone screens at different screen angles the preferred weighting factors to employ is, as shown in FIG. 29, 0.5 for each halftone screen and preferably these screens are of the same screen frequency. However, as noted in FIG. 30 greater weight may be provided to a lower frequency line screen in an example where one color is produced using two halftone screens at different screen angles and at different screen frequencies (measured in lines per inch) and to thereby emphasize one screen angle or screen frequency over the other. In the example where a dot structure dot growth pattern is employed for a color being produced using the combined processing of two halftone screens at different screen angles an example of weighting factors to employ is illustrated in FIG. 28. As this figure illustrates the weighting factors at each pixel location may vary in accordance with the input image density for the local area. Thus, at lower image densities higher weight is given to the lower frequency dot screen. At higher local area image densities greater weight is given to the higher frequency dot screen. There has thus been shown an improved printer and method of printing and method of encoding image data wherein color images may be printed with minimization of artifacts through representation of certain color separation images with a relatively pleasing rosette formed by simulating the generation of a color separation image by using the composite of two or more color separation images of the same color at different screen angles. The calculated composite of the two or more color separation images of the one color may then be printed and overlaid with dots formed by the various halftone screen patterns of the other different color separation images. These dots may be printed on the receiver and may be superimposed on each other at the same pixel location to form various shades of other colors. In the embodiments of FIGS. 3-10 and 15-18 all the halftone screens illustrated may be processed using the dot structure dot growth pattern or alternatively all using the line structure dot growth pattern or further alternatively a mixture of some using the dot structure dot growth pattern and others using the line structure dot growth pattern it being understood that where a single-color is processed using two halftone screen angles the same type of dot growth pattern (line structure or dot structure) be used for both of those two halftone screen angles although as noted above the frequencies of the halftone screens may differ. Typical screen frequencies range from 130 lpi (lines per inch) to 220 lpi. Screen angles referred to herein are nominal values and might very ±0.5° from the recited number. Also as noted above the hi-fi color or other color separation image may be determined using three screen angles and the weighting factors for each adjusted so that the sum of the weighting factors is 1.0. The invention has been described with reference to the preferred embodiments. Obviously, modifications and alternatives will occur to others upon reading the preceding detailed description. For example, as noted above that while the creation of gray level dots in individual pixel locations has been described as the preferred embodiment the invention in its broader aspects also contemplates the use of binary pixels for forming the line structure dot growth patterns in a halftone cell and/or the dot structure dot growth patterns in a halftone cell. It is also contemplated that in lieu of printing image data that is a composite of color separation or mono-color image data processed at two or more different halftone screen angles, that separate printing may be made of the color separation image data of one color at each of two angles and combined on the receiver sheet to form the rosette or diamond structures described herein. For example, some ink jet printers employ redundant inks and may have two or more of at least some colors and such may be used to each generate a screen pattern at one screen angle in a particular color. It is intended therefore that the invention be construed as including all such modifications and alternatives in so far as they come within the scope of the appended claims or the equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to the field of digital encoding of pictorial information for use in forming color reproductions on display or printing systems. 2. Description Relative to the Prior Art With the advent of printing using digital technology, images may be printed, by rendering the image into a set of pixels. In pure binary printers, the pixel is either on (black) or off (white). Such techniques are well suited to reproducing text because the sizes of the individual pixels that make up the symbols are much smaller than the symbols. Thus, the human eye sees the text as a continuous image even though it is a collection of closely spaced dots. However, most binary print engines and particularly electrophotographic print engines do not provide acceptable levels of gray for other images, such as photographs. Those skilled in the art have used halftone dots to emulate grayscale for reproducing images with continuous tones. One reason for this is that the particles used for forming the printed dots may be larger than is desirable even if the printing system were suited to printing very small binary pixels. In the area of digital printing (the term “printing” is used to encompass both printing and displaying throughout), gray level has been achieved in a number of different ways. The representation of the intensity, i.e., the gray level, of a color by binary displays and printers has been the object of a variety of algorithms. Binary displays and printers are capable of making a mark, usually in the form of a dot, of a given, uniform size and at a specified resolution in marks per unit length, typically dots per inch. It has been well known to place the marks according to a variety of geometrical patterns such that a group of marks when seen by the eye give a rendition of an intermediate color tone between the color of the background (usually white paper stock) and total coverage, or solid density. The effect is such that a group of dots and dot-less blank spots, when seen by the eye, is a rendition of an intermediate color tone or density between the color of the initial paper stock, usually white, and total ink coverage, or solid density halftone dot. It is conventional to arrange the dots in rows, where the distance between rows is known as line spacing, and determines the number of lines per inch (lpi). In the ensuing paragraphs, discussions will be made in terms of white paper stock; it is understood that white paper stock is used as an illustration and not as a limitation of the invention and that other media may be used such as plastics, textiles, coated papers, metals, wood, edible articles, etc. Continuous tone images contain an apparent continuum of gray levels. Some scenes, when viewed by humans, may require more than two hundred and fifty six discrete gray levels for each color to give the appearance of a continuum of gray levels from one shade to another. Halftone pictorial or graphical images lower the high contrast between the paper stock and toned image and thereby create a more visually pleasing image. As an approximation to continuous tone images, pictorial imagery has been represented via binary halftone technologies. In order to record or display a halftone image one picture element of the recording or display surface consists of a j×k matrix or cell of sub-elements where j and k are positive integers. A halftone image is reproduced by printing the respective sub-elements (pixels or pels) or leaving them blank, in other words, by suitably distributing the printed marks within each cell. Another method of producing gray levels is provided by gray level printing. In such a method, each pixel has the capability to render several different dot sizes. In certain electrophotographic printing systems, for example, the dot size for a pixel is a function of the exposure time provided an LED element corresponding to that pixel. The longer the exposure time, the more toner is attracted to that particular pixel. There are two major concerns in rendering a continuous tone image for printing: (1) the resolution of image details, and (2) the reproduction of gray scales. These two fundamental factors compete with each other in a binary representation scheme. The more gray levels that are rendered, the larger is a halftone cell. Consequently, coarse halftone lines screens are provided, with the attendant poor image appearance. Hence, compromises made in rendering between the selection of line resolution in gray scales and binary halftone printing. However, with gray level halftone printing, one can satisfy both resolution and gray level requirements. In gray level printing, the same number of addressable dots are present, and there is attached a choice of dot sizes from one dot size of 1 bit/pixel to for example 255 different dot-sizes of 8 bits/pixel. Although providing higher image quality with respect to line resolution and tone scales, gray level halftone presents its own dot rendering issues. A number of different dot layouts are possible to build gray level dots from a cell template. These gray level dots are the digital representation of the gray level screening, and must be realized through a printing process. It is desirable in gray level screening to layout the dots with the printing process characteristics built into it such that the appearance of the dots are pleasing to the eye: less grainy, stable, less artifacts, less texture (i.e., visible screen and its microstructure). An example of a line screen designed for gray scale rendering is disclosed in U.S. Pat. No. 5,258,850. The arrangement of pixels within a halftone cell is such that growth within a cell to represent increases in density is accomplished through arranging the pixels along lines of growth. Another example of a halftone cell is that shown in U.S. Pat. No. 5,258,849, which features growth of density within a halftone cell by gradual enlargement about a central area within the cell. The halftone cells disclosed in the above two patents are notable in that the pixels we need within each cell may vary in density. This substantially increases the number of gray levels that may be represented by the overall halftone cell from that where the pixels can only be rendered as a binary representation (either black or white with no distinction regarding size). The combination of cells represents a halftone screen. Color printing on halftone printers involves the formation of color separations as halftone screens for each color, which is to be used to form a color image. The halftone screens are laid down on a predetermined overlapping relationship to each other, which results in generation of the desired color image. A well-known problem when overlapping two or more halftone screens is the possibility of developing a moiré pattern or other form of interference, when the screens are not properly positioned. To avoid the moiré or other undesirable patterns, precise angle combinations of the screens are required. It is known that increasing the difference in angle of two overlaid screens will result in a smaller pattern, making the pattern less apparent. However, the prior art teaches, see for example U.S. Pat. No. 6,307,645, the largest possible angle difference between two overlaid screens should be no more than 45° because a 90° screen is essentially the same as 0°, just as a 135° screen is the same as a 45° screen even in the context of attempting to reduce moiré with asymmetrical dots. In color image printing it has been common practice to use at least three process colors and in more cases three process colors and black. In the case of four-color printing the printing industry has generated a standardized combination of four halftone angles. In particular and with reference to FIG. 1 , the cyan halftone screen is located at 15°, the black halftone screen at 45°, the magenta halftone screen at 75° and the yellow halftone screen at 0°. Since yellow is the lightest and least noticeable color, it can be set at 0°, even though 0° is a highly noticeable angle, and that is only 15° from the nearest neighbor. In some embodiments, the cyan halftone screen is known to be set at 105°, however, with symmetrical dots this is substantially the same as 15°, and the prior art recognizes that even with asymmetrical dots it does not make a large difference. When the four process colors using the above halftone screen angle combinations are overlaid, the resulting moiré or other interference patterns are as small as possible. A visually pleasing rosette structure is formed when the individual dots grains are oriented 30° apart. The traditional graphics art printing has been made using this 15°/45°/75° angle screen design to form a balanced rosette structure. In the CMYK four-color printing process, the yellow screen is usually designed at 0° or 45°. However, the moiré pattern resulting from the interaction between the yellow screen and the other three individual screens due to mis-registration is not as visually pleasing as a 30° moiré pattern (rosette structure). Yellow is a light color, so this additional moiré is usually acceptable and not very noticeable in most CMYK four-color printing systems. However, careful examination of prints shows that this yellow moiré pattern can be seen in certain composite colors. U.S. Pat. No. 5,808,755 deals with the problem of moiré in a multi-color printer. The patent suggests the use of a screen having a cluster dot growth pattern that varies in a predetermined way such that the centroid of the cluster dot is not situated within an internal region. The screen can be used to induce a variable rosette structure depending upon the intensity level of the original image. The suggested screen pattern does not lend itself easily to currently available screen designs. Where additional colors are used such as in a hi-fi color (for example, a five-color) printing system, there is a need to design a fifth screen on top of the original well-balanced CMYK screen set. This is particularly true where the fifth color screen is blue, the complementary color of yellow, and the blue color screen is placed at the same screen angle and screen frequency as the yellow color screen. The unpleasant moiré, which was not noticeable in the yellow color, will now show up in the blue color. It is thus known that many color printing systems will include five or more printing units using different color colorants. Attempting to incorporate these additional colors is noted to be difficult, especially if each color must have a halftone screen with a unique halftone angle. Particularly, once there are more than four screens with attendant screen angles, which must be laid down, the patterning problems discussed above, are greatly increased. It would thus be desirable to provide for color screen sets for printing which minimize the unpleasant moiré patterns formed including those caused by the interactions of the yellow screen. | <SOH> SUMMARY OF THE INVENTION <EOH>The foregoing objects are realized by the present invention, which provides an apparatus and method for the generation of halftone images with reduced image artifacts and increased number of gray levels. In accordance with a first aspect of the invention there is provided, an apparatus for processing image data, representing a color separation or mono-color image, the apparatus comprising a processor operative to process the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. In accordance with a second aspect of the invention there is provided an apparatus for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the apparatus comprising a screen generator responsive to the color-separation image data for generating halftone screens for each color of the color separation image data, and for one color having color separation image data the screen generator being operative to process color separation image data of said one color in accordance with each of two or more halftone screen angles of different angles and combining the results of the processings with two or more screen angles for output to a printer as composite image data of the two or more screen angles. In accordance with a third aspect of the invention there is provided a method for processing image data representing a color separation or mono-color image, the method comprising processing the color separation image data or mono-color image data in accordance with first and second or more halftone screen processings at different screen angles and obtaining results of the processings; and combining the results of the processings to generate composite image data of the first and second or more halftone screen processings. In accordance with a fourth aspect of the invention there is provided a method for processing color separation image data representing color separation images for each of plural different colors for printing a multi-color image, the method comprising processing the color separation image data for generating halftone screens for the color separation images of some of the colors; and for one of the colors processing the color separation image data of the one color in accordance with each of two or more halftone screen angles and combining the results of the processings for output to a printer as composite image data of the two or more screen angles. In accordance with a fifth aspect of the invention there is provided a method for printing a multi-color image using color separation image data representing color separation images for each of plural different colors, the method comprising processing the color separation image data of each of two different colors and generating similar rosette or diamond structures for each of the two colors and wherein the two colors are complementary colors to each other. Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. | 20040430 | 20101123 | 20051103 | 66520.0 | 0 | ZHU, RICHARD Z | METHOD AND APPARATUS FOR MULTI-COLOR PRINTING USING A ROSETTE OR DIAMOND HALFTONE SCREEN FOR ONE OR MORE OF THE COLORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,836,849 | ACCEPTED | Verification system and method | A verification system has an operational component registry 10 that includes an interface 20, a memory device 30, and a processor 40. Preferably, the interface 20 in the operational component registry 10 communicates the installed identification data 50 from the gaming units 60 to the operational component registry. The memory device 30 preferably stores registered identification data 70 for the gaming units 60. Preferably, the processor 40 in the operational component registry 10 then analyzes the registered identification data 70 and the installed identification data 50 from the gaming units 60, after which enablement of the gaming units is determined based upon the examination of the registered identification data and the installed identification data. An operational component registry 10 may also monitor changes, services, requirements, enablement, and productivity of the gaming units or components of the gaming units. | 1. A verification system utilizing an operational component registry, the verification system comprising: a memory device, wherein the memory device stores registered identification data for one or more gaming units, wherein the gaming units include one or more components, and wherein the components include hardware and software; an interface that communicates the installed identification data from the gaming units to the operational component registry; and a processor that analyzes the registered identification data and the installed identification data of the gaming units; and wherein enablement of the gaming units is determined by examining the registered identification data and the installed identification data. 2. The verification system of claim 1, wherein the registered identification data for the gaming units includes identification data for the components that are supposed to be installed on the gaming units. 3. The verification system of claim 2, wherein the installed identification data for the gaming units includes identification data for the components that are actually installed on the gaming units. 4. The verification system of claim 1, wherein the registered identification data is authenticatible and non-repudiatible. 5. The verification system of claim 3, wherein the registered identification data and the installed identification data for the gaming units includes unique identifiers for each of the components that are supposed to be installed or that are actually installed on a gaming unit. 6. The verification system of claim 5, wherein the registered identification data and installed identification data for the hardware includes data selected from the group of serial numbers, model numbers, part numbers, a manufacture date, location information, an installation date, and a repair date. 7. The verification system of claim 5, wherein the registered identification data and installed identification data for the software includes data selected from the group of globally unique identifiers, version information, licensing information, an installation date, a patch date, a repair date, signature data, hash data, and authentication data. 8. The verification system of claim 1, wherein the operational component registry is resident on a central gaming system to which the gaming units are associated. 9. The verification system of claim 1, wherein the operational component registry is resident on a wide area gaming system to which the gaming units are associated. 10. The verification system of claim 1, wherein the operational component registry is resident on a local area gaming system to which the gaming units are associated. 11. The verification system of claim 1, wherein the operational component registry is resident on a gaming unit. 12. The verification system of claim 1, wherein the operational component registry is utilized in conjunction with additional operational component registries within a system of gaming units. 13. The verification system of claim 1, wherein the operational component registry is remote from the gaming units. 14. The verification system of claim 1, further comprising a update process, wherein the update process includes identification data regarding authorized changes and updates to the components of the gaming units, and wherein the update process is used to amend the operational component registry to include registered identification data for authorized changes and updates to installed components. 15. The verification system of claim 14, wherein the operational component registry is amended at predetermined intervals to include registered identification data for authorized changes and updates to components contained in the update process. 16. The verification system of claim 14, wherein the operational component registry is amended in response to a request to include registered identification data for authorized changes and updates to components contained in the update process. 17. The verification system of claim 1, further comprising a service log, wherein the service log includes information regarding diagnostic and maintenance services performed on components of the gaming units. 18. The verification system of claim 1, further comprising a productivity log, wherein the productivity log includes information regarding productivity of the gaming units. 19. The verification system of claim 1, further comprising a requirements log, wherein the requirements log includes data used to verify whether enablement of a particular component is required for proper operation of the gaming units. 20. The verification system of claim 1, wherein communication of the installed identification data from the gaming units to the operational component registry occurs at predetermined intervals. 21. The verification system of claim 1, wherein communication of the installed identification data from the gaming units to the operational component registry occurs in response to a request. 22. The verification system of claim 1, further comprising at least one user access port, wherein the access port is configured to provide access to the operational component registry. 23. The verification system of claim 1, wherein the processor examines the registered identification data and the installed identification data, determines whether the registered identification data corresponds with the installed identification data, and identifies corresponding and non-corresponding identification data for each component of the gaming units. 24. The verification system of claim 23, wherein an update process is used to update the registered identification data with authorized changes and updates to the components in response to a determination that the registered identification data and the installed identification data do not correspond to each other. 25. The verification system of claim 23, wherein gaming units having components with non-corresponding identification data are not enabled. 26. The verification system of claim 23, wherein gaming units having corresponding identification data for all components are enabled. 27. The verification system of claim 25, wherein the non-enablement of one or more non-corresponding components of a gaming unit initiates a determination of whether enablement of the gaming unit is prevented. 28. The verification system of claim 23, wherein enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit. 29. The verification system of claim 25, further comprising an enablement log, wherein the enablement log includes data regarding enablement or non-enablement of the gaming units and of individual components of the gaming units. 30. The verification system of claim 1, wherein one or more gaming machine system components are assigned identification codes and are grouped together into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. 31. A verification system comprising: a catalog of registered identification data, wherein the registered identification data comprises identification data for components supposed to be installed on one or more gaming units; and a catalog of installed identification data, wherein the installed identification data comprises identification data for components that are actually installed on the gaming units. 32. The verification system of claim 31, further comprising a memory device that stores the registered identification data. 33. The verification system of claim 32, wherein at least one of the registered identification data and the installed identification data is authenticatible and non-repudiatible. 34. The verification system of claim 31, further comprising a processor that analyzes the registered identification data and the installed identification data. 35. The verification system of claim 31 further comprising an interface between the operational component registry and the gaming units. 36. The verification system of claim 23, wherein the interface is a network interface connecting the operational component registry with remote gaming units. 37. The verification system of claim 31, wherein the components include hardware and software, and each gaming unit is comprised of at least one component. 38. The verification system of claim 31, wherein installed identification data is communicated to the operational component registry at predetermined intervals. 39. The verification system of claim 31, wherein installed identification data is communicated to the operational component registry in response to a triggering event. 40. The verification system of claim 31, wherein enablement of the gaming units is determined by examining the registered identification data and the installed identification data. 41. The verification system of claim 31, wherein enablement of individual components on the gaming units is determined by examining the registered identification data and the installed identification data. 42. The verification system of claim 41, wherein the registered identification data and the installed identification data each comprise unique identifiers for each component that is supposed to be installed or that is actually installed on the gaming units. 43. The verification system of claim 42, wherein the registered identification data and the installed identification data are provided for each component, the components including hardware and software, wherein the identification data for the hardware includes at least one of serial numbers, model numbers, part numbers, a manufacture date, location information, an installation date, or repair date; and wherein the identification data for the software includes at least one of globally unique identifiers, version information, licensing information, an installation date, a patch date, a repair date, signature data, hash data, and authentication data. 44. The verification system of claim 31, wherein the operational component registry is resident on a central gaming system. 45. The verification system of claim 31, wherein the operational component registry is resident on a wide area gaming system. 46. The verification system of claim 31, wherein the operational component registry is resident on a local area gaming system. 47. The verification system of claim 31, wherein the operational component registry is resident on a gaming unit. 48. The verification system of claim 31, wherein the operational component registry is utilized in conjunction with additional operational component registries within a system of gaming units. 49. The verification system of claim 31, further comprising an update process, wherein the update process includes identification data regarding authorized changes and updates to components listed therein. 50. The verification system of claim 49, wherein the registered identification data is amended with the update process, and the amended registered identification data reflects authorized changes and updates to registered components. 51. This verification system of claim 50, wherein amendment of the registered identification data occurs at predetermined intervals. 52. The verification system of claim 50, wherein the amendment of the registered identification data occurs in response to a triggering event. 53. The verification system of claim 31, further comprising a service log, wherein the service log includes data regarding diagnostic and maintenance services performed on components. 54. The verification system of claim 53, wherein data on the service log includes installed identification data for installed components, and the installed identification data is communicated to the change log. 55. The verification system of claim 31, further comprising a productivity log, the productivity log including productivity data for the gaming units, wherein the productivity data is searchable, manipulable, and used to generate gaming unit productivity reports. 56. The verification system of claim 31, further comprising a requirements log, the requirements log including requirements data for the gaming units. 57. The verification system of claim 56, wherein the requirements data is used to determine whether enablement of a gaming unit is predicated on enablement of the components in the gaming unit. 58. The verification system of claim 56, wherein the requirements data is used to determine whether enablement of the components is required for proper operation of the gaming units. 59. The verification system of claim 31, wherein the registered identification data and the installed identification data are examined, and corresponding identification data and non-corresponding identification data are identified for each component of the gaming units. 60. The verification system of claim 59, wherein an update process is used to update the registered identification data if non-corresponding identification data is identified for components of the gaming units, and wherein the updated registered identification data and the installed identification data are then re-examined. 61. The verification system of claim 59, wherein gaming units having components with non-corresponding identification data are not enabled, and gaming units having all components with corresponding identification data are enabled. 62. The verification system of claim 59, wherein the non-enablement of one or more non-corresponding components of a gaming unit initiates a determination of whether enablement of the gaming unit is prevented. 63. The verification system of claim 59, wherein enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit. 64. The verification system of claim 31, further comprising an enablement log, the enablement log including data regarding enablement or non-enablement of gaming units, and the enablement log including data regarding enablement or non-enablement of individual components of the gaming units. 65. The verification system of claim 59, wherein components with non-corresponding identification data are not enabled, and a requirements log is used to determine whether gaming units including the non-enabled components may be enabled. 66. A method for verifying components of one or more gaming units using an operational component registry, the method comprising: selecting one or more gaming units for verification; establishing communication with the selected gaming units; receiving installed identification data at the operational component registry from the selected gaming units as to components actually installed on the selected gaming units; and examining the installed identification data and registered identification data stored to determine enablement of the gaming units. 67. The method of claim 66, wherein the gaming units selected for verification include one or more components, and each component includes hardware and software. 68. The method of claim 67, wherein the selected gaming units are remote from the operational component registry. 69. The method of claim 66, wherein the operational component registry is resident on a central gaming system to which at least one of the selected gaming units is connected. 70. The method of claim 66, wherein the operational component registry is resident on a wide area gaming system to which at least one of the selected gaming units is connected. 71. The method of claim 66, wherein the operational component registry is resident on a local area gaming system to which at least one of the selected gaming units is connected. 72. The method of claim 66, wherein the operational component registry is resident on at least one of the selected gaming units. 73 The method of claim 66, wherein the operational component registry is utilized in conjunction with additional operational component registries within a system of gaming units. 74. The method of claim 66, wherein the operational component registry and the selected gaming units communicate via an interface. 75. The method of claim 74, wherein the interface comprises a network interface. 76. The method of claim 66, wherein the installed identification data is communicated to the operational component registry at predetermined intervals. 77. The method of claim 66, wherein the installed identification data is communicated to the operational component registry in response to a request. 78. The method of claim 66, wherein the installed identification data is communicated to the operational component registry in response to a triggering event. 79. The method of claim 66, wherein examination of the installed identification data and the registered identification data is performed by a processor that is associated with the operational component registry. 80. The method of claim 79, wherein at least one of the registered identification data and the installed identification data are authenticatible and non-repudiatible. 81. The method of claim 66, wherein examination of the installed identification data and the registered identification data includes determining whether the registered identification data corresponds to the installed identification data. 82. The method of claim 81, further comprising: determining corresponding and non-corresponding identification data for each component of the gaming units. 83. The method of claim 81, wherein the operational component registry further comprises an update process, wherein the update process is used to update the registered identification data with authorized changes to the registered components on the gaming units; and wherein the updated registered identification data and the installed identification data are then examined. 84. The method of claim 82, wherein gaming units having components with non-corresponding identification data are not enabled, and gaming units having corresponding identification data for all components are enabled. 85 The method of claim 84, wherein enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit, and regardless of whether any components having non-corresponding identification data are non-enabled in the gaming unit. 86. The method of claim 66, further comprising an enablement log, wherein the enablement log includes data regarding the enablement or non-enablement of the gaming units and of individual components of the gaming units. 87. The method of claim 84, further comprising a requirements log, wherein the requirements log is used to determine whether to enable gaming units that include non-enabled components. 88. The method of claim 66, further comprising a service log, wherein the service log includes service data regarding diagnostic and maintenance services performed on components of the gaming units, and wherein the service data is communicated from the gaming units to the operational component registry. 89. The method of claim 88, wherein the service log includes installed identification data for installed components, and wherein the installed identification data is communicated from the gaming units to a service log on the operational component registry. 90. The method of claim 66, further comprising a productivity log, wherein the productivity log includes productivity data for the gaming units, and wherein the productivity data is communicated from the gaming units to the operational component registry. 91. A method for verifying and selectively enabling gaming units, the method comprising: receiving installed identification data from one or more gaming units at an operational component registry through an interface located on the operational component registry; storing registered identification data on a memory device located within the operational component registry; and examining the registered identification data and the installed identification data using a processor located in the operational component registry to determine enablement of the gaming units. 92. The method of claim 91, wherein the operational component registry includes registered identification data and installed identification data for components of the gaming units, wherein the registered identification data includes identification data for components that are supposed to be installed on the gaming units, and wherein the installed identification data includes identification data for components that are actually installed on the gaming units. 93. The method of claim 92, wherein the installed identification data is communicated from the gaming units to the operational component registry via the interface. 94. The method of claim 91, wherein the interface between the operational component registry and the gaming units is a network interface. 95. The method of claim 92, wherein the components include hardware and software, wherein the registered identification data and the installed identification data for the hardware include at least one of serial numbers, model numbers, part numbers, a manufacture date, location information, an installation date or a repair date; and wherein the registered identification data and the installed identification data for the software include at least one of globally unique identifiers, version information, licensing information, an installation date, patch date, a repair date, signature data, hash data, and authentication data. 96. The method of claim 91, wherein one or more operational component registries are resident on at least one of a central gaming system, wide area gaming system, and local area gaming system. 97. The method of claim 91, wherein an operational component registry is utilized in conjunction with additional operational component registries on at least one or more gaming units. 98. The method of claim 91, wherein the memory device that stores the registered identification data is remote from the operational component registry. 99. The method of claim 91, further comprising: determining whether the registered identification data corresponding the installed identification data. 100. The method of claim 91, further comprising: determining corresponding and non-corresponding identification data for each component of the gaming units. 101. The method of claim 99, further comprising providing an update process, wherein the update process includes data regarding authorized changes and updates to the components, wherein data from the update process is used to update the registered identification data, and wherein the updated registered identification data and the installed identification data are then re-examined. 102. The method of claim 101, wherein the registered identification data is updated with the update process data at predetermined intervals. 103. The method of claim 101, wherein the registered identification data is updated with the update process data in response to a request. 104. The method of claim 101, wherein the registered identification data is updated with the update process data in response to a triggering event. 105. The method of claim 101, wherein the registered identification data is updated with the update process data at least once following the determination of non-corresponding identification data for components of the gaming units. 106. The method of claim 99, further comprising: determining whether to enable the gaming units, wherein the corresponding and non-corresponding identification data for the components of the gaming units are used to determine whether to enable gaming units, wherein gaming units having components with non-corresponding identification data are not enabled, and wherein gaming units having components with all corresponding identification data are enabled. 107. The method of claim 99, further comprising: selecting individual gaming units for enablement, wherein the gaming units have corresponding identification data. 108. The method of claim 99, further comprising: selecting individual components of the gaming units for enablement, wherein the components have corresponding identification data. 109. The method of claim 99, further comprising: determining whether to permit enablement of gaming units including one or more components that have non-corresponding identification data and are not enabled. 110. The method of claim 109, wherein enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit. 111. The method of claim 99, further comprising an enablement log, wherein the enablement log includes data regarding enablement or non-enablement of the gaming units and of individual components of the gaming units. 112. The method of claim 99, further comprising a requirements log, wherein the requirements log includes data used to verify whether enablement of non-enabled components is required for proper operation of gaming units, and wherein the requirements log is used to prevent enablement of the gaming units if a non-enabled component is required. 113. The method of claim 99, further comprising: assigning identification codes to gaming machine system components within a gaming unit; binding together one or more gaming machine system components within the gaming unit, including registered identification data and installed identification data, into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group. 114. A verification system utilizing an operational component registry, the verification system comprising: a memory device, wherein the memory device stores registered identification data for one or more gaming units, wherein the gaming units include one or more components, and wherein the components include hardware and software; an interface that communicates the installed identification data from the gaming units to the operational component registry; and a processor that analyzes the registered identification data and the installed identification data of the gaming units; and wherein enablement of the gaming units is determined by examining the registered identification data and the installed identification data; and wherein one or more gaming machine system components are assigned identification codes and are grouped together into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. 115. A verification system utilizing an operational component registry, the verification system comprising: a catalog of registered identification data, wherein the registered identification data comprises identification data for components supposed to be installed on one or more gaming units; and a catalog of installed identification data, wherein the installed identification data comprises identification data for components that are actually installed on the gaming units; and wherein one or more gaming machine system components, including at least one of the catalogs, are assigned identification codes and are grouped together into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group. 116. A method for verifying components of one or more gaming units using an operational component registry, the method comprising: assigning identification codes to gaming machine system components within a gaming unit; binding together one or more gaming machine system components within the gaming unit, including registered identification data and installed identification data, into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group; selecting one or more gaming units for verification; establishing communication with the selected gaming units; receiving installed identification data at the operational component registry from the selected gaming units as to components actually installed on the selected gaming units; and examining the installed identification data and registered identification data to determine enablement of the gaming units. 117. A method for verifying and selectively enabling gaming units, the method comprising: assigning identification codes to gaming machine system components within a gaming unit; binding together one or more gaming machine system components within the gaming unit, including registered identification data and installed identification data, into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group; receiving installed identification data from one or more gaming units at an operational component registry through an interface located on the operational component registry; storing registered identification data on a memory device located within the operational component registry; and examining the registered identification data and the installed identification data using a processor located in the operational component registry to determine enablement of the gaming units. 118. A component bindings verification system for gaming machine system components, the verification system comprising: identification codes, wherein an identification code is assigned to each gaming machine system component; and a protected grouping of gaming machine system components that form component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. 119. The verification system of claim 118, wherein every log entry made on the hard drive and every entry made on the non-volatile RAM, must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. 120. The verification system of claim 118, wherein every log entry that attempts a replacement of any of the gaming machine system components must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. 121. The verification system of claim 118, wherein the identification codes of the gaming machine system components are randomly or pseudo-randomly generated. 122. The verification system of claim 118, wherein a Hashed Message Authorization Code key for authenticating access to the component bindings is produced using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. 123. The verification system of claim 118, wherein the gaming machine system components are secured within the component bindings using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. 124. A verification method for prevention falsification and repudiation of log entries with respect to modifications and replacements gaming machine system components, the verification method comprising: assigning identification codes to gaming machine system components within a gaming unit, wherein the gaming machine system components include at least non-volatile RAM, a cabinet, and a hard drive; binding together one or more gaming machine system components into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group. 125. The verification system of claim 124, wherein every log entry made on the hard drive and every entry made on the non-volatile RAM, must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. 126. The verification system of claim 124, wherein every log entry that attempts a replacement of any of the gaming machine system components must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. 127. The verification system of claim 124, wherein the identification codes of the gaming machine system components are randomly or pseudo-randomly generated. 128. The verification system of claim 124, wherein a Hashed Message Authorization Code key for authenticating access to the component bindings is produced using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. 129. The verification system of claim 124, wherein the gaming machine system components are secured within the component bindings using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. | CROSS REFERENCE TO RELATED DOCUMENTS This application is a continuation-in-part of U.S. patent application Ser. No. 10/243,912, filed, Sep. 13, 2002. U.S. patent application Ser. No. 10/243,912, is hereby incorporated herein by reference. COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. FIELD OF THE INVENTION This invention relates generally to a verification system, and more particularly, to a verification system utilizing an operational component registry that identifies hardware and software components installed on one or more gaming units, and examines the installed components and registered components. The results of the examination are used to determine whether the gaming units and/or individual components of the gaming units are enabled. BACKGROUND OF THE INVENTION There are a wide variety of software, hardware and other types of verification systems that attempt to monitor additions, deletions, changes, and updates, which are routinely performed on gaming machines. Typically, in the gaming field, verification of software or hardware installed on a gaming machine may occur by reviewing the contents of a read-only memory. To ensure that tampering, such as with software codes or hardware devices has not occurred, a simple review of the memory contents and visual inspection of hardware is conducted to verify the gaming application. Such a memory check is performed before start-up of the gaming machine or during game play after a win occurs and by a regulatory field agent's inspection. This type of verification system is typically adequate only if the gaming application is stored in a read-only memory (e.g., the memory is difficult to alter and the standard software verification systems prevent unauthorized access), and if there is little danger that the hardware of the gaming machine will be compromised. For instance, in a casino with 24-hour surveillance, it is likely that any hardware tampering would quickly be noticed. Today, it is becoming more common to connect multiple gaming machines and/or multiple gaming locations to provide many different gaming options. Moreover, there is a desire to operate these multiple gaming machines and/or casinos using a centralized system or network. Accordingly, when multiple gaming machines or multiple casinos are connected over a local area network or a wide area network, it is difficult to quickly and efficiently run the above-described software verifications or to engage in constant surveillance in each location to assure that no hardware tampering is occurring. Additionally, gaming services are evolving to include virtual and networked platforms that permit use of gaming systems and services through non-dedicated, web-based, or remote access points. These virtual and networked games increase the difficulty of monitoring the use of unauthorized software and/or hardware in these remote locations. Still further, the assortment of gaming options and services that are available on a gaming machine and/or a gaming network may vary over time. As the variety of gaming options and services that are available continues to increase, it becomes more difficult to accurately monitor and regulate the software and hardware that are used to implement the different games and gaming applications. Additionally, the registry and tracking systems that are currently in place merely indicate whether or not a component is contained within a registry. Known registry systems do not use the registry to track the requirements for operation and to determine whether or not a gaming unit or a particular component may be enabled. Additionally, known registry systems do not track changes and servicing of the components, and thus, do not allow the registry to be automatically updated with new, authorized component information. Finally, the current systems do not track the productivity of the gaming units. Accordingly, those skilled in the art have long recognized the need for enhanced verification of components and improved security measures that prevent enablement of gaming units and components or unauthorized installation changes. There is also a continuing need for a system that provides additional security from tampering by tracking the installations and changes to software or hardware on a gaming unit, thereby preventing unauthorized enablement of a gaming unit. Further, there is a continuing need for a system that is useful in monitoring and tracking gaming operations and services performed on a gaming machine or its components. The claimed invention clearly addresses these and other needs. SUMMARY OF THE INVENTION Briefly, and in general terms, the claimed invention resolves the above and other issues by providing a verification system and method for identifying all components installed on one or more gaming units, and verifying that these installed components (i.e., the components that are actually installed) correspond to the registered components (i.e., the components that are supposed to be installed). The phrase “gaming machine” as used herein describes typical gaming machines as well as other gaming related, computing systems, such as game servers and the like. Accordingly, the phrase “gaming units” as used herein describes groupings of gaming-related components and associated system components. In this way, the resultant examination of installed component data and registered component data is used to determine whether the gaming units, or individual components of the gaming units, may be enabled before starting or continuing operation. Preferably, the verification system and method also monitors changes and updates to the components of the gaming units, identifies service that has been performed on the components, verifies that the requirements for proper operation of a gaming unit are satisfied by enabled and non-enabled components, and determines the productivity of a gaming unit. In one preferred embodiment, the verification system includes an operational component registry having a memory device, an interface, and a processor. The memory device stores registered identification data and installed identification data for one or more gaming units. The gaming units themselves each include one or more components. Preferably, the components include by way of example only, and not by way of limitation, hardware (e.g., a hard drive, non-volatile RAM, and the like), software, and other gaming machine system components (e.g., a gaming machine cabinet). The interface communicates the installed identification data from the gaming units to the operational component registry. Additionally, the processor analyzes the registered identification data and the installed identification data of the gaming units. The processor then, by examining the registered identification data (i.e., data detailing what is supposed to be installed) with the installed identification data (i.e., data detailing what is actually installed), determines whether or not the gaming units are allowed to be enabled. In accordance with another preferred aspect of the verification system, the registered identification data includes identification data for the components that are supposed to be installed on the gaming units. Preferably, the installed identification data for the gaming units includes identification data for the components that are actually installed on the gaming units. Typically, in a preferred embodiment the registered identification data is authenticatible and non-repudiatible, rather than hidden or otherwise obfuscated (encrypted). Accordingly, the registered identification data and the installed identification data must be authenticated prior to examination by the processor. Non-repudiation is a way to guarantee that the sender of a message cannot later deny having sent the message, and that the recipient cannot deny having received the message. In accordance with another preferred aspect of the verification system, both the registered identification data and the installed identification data for the gaming units include unique identifiers for each of the components that either are supposed to be installed or are actually installed on a gaming unit. Preferably, the registered identification data and installed identification data for the hardware include, by way of example only, and not by way of limitation, one or more of: serial numbers, model numbers, part numbers, location information, manufacture date, installation date, and repair date. Further, in a preferred embodiment the registered identification data and installed identification data for the software include, by way of example only, and not by way of limitation, one or more of: globally unique identifiers, version information, licensing information, installation date, patch date, repair date, signature data, hash data, and authentication data. In accordance with another preferred aspect of the verification system, the operational component registry is resident on a central gaming system to which the gaming units are connected. In another preferred embodiment, the operational component registry is resident on a wide area gaming system to which the gaming units are connected. In still another preferred embodiment, the operational component registry is resident on a local area gaming system to which the gaming units are connected. In yet another preferred embodiment, the operational component registry is resident on a gaming unit. In a further preferred embodiment, the operational component registry is utilized with additional operational component registries within a system of gaming units. In accordance with another aspect of the verification system, the operational component registry further includes an update process. In a preferred embodiment, a change log is produced during the update process that catalogs the results of the update process. Preferably, the change log includes identification data regarding authorized changes and updates that occurred to the components of the gaming units during the update process. Specifically, the update process is used to amend the operational component registry to include registered identification data for authorized changes and updates to installed components. Preferably, technology such as digital signature verification, message authentication code, bindings, and electronic keys (BKEYs) are used to verify, authenticate, and/or authorize the validity of these changes. In one preferred embodiment of the verification system, the operational component registry is amended, at predetermined intervals, using the update process to enable the operational component registry to include the registered identification data for authorized changes and updates to the installed components that were added during the update process. In another preferred embodiment of the verification system, the operational component registry is amended, in response to a request, using the update process to enable the operational component registry to include registered identification data for authorized changes and updates to installed components that were added during the update process. In accordance with another aspect of the verification system, the operational component registry further includes service processes. In one preferred embodiment, a service log is produced during the service processes that catalog the results of the service processes. Preferably, the service log includes information regarding diagnostic and maintenance services performed on components of the gaming units during the service processes. As stated above, the phrase “gaming units” as used herein, describes groupings of gaming related components (e.g., gaming machines, gaming systems, gaming servers, and the like) as well as associated system components. In accordance with another aspect of the verification system, the operational component registry further includes a productivity log. In one preferred embodiment, the productivity log includes information regarding productivity of the gaming units. In accordance with still another aspect of the verification system, the operational component registry further includes a requirements log. In one preferred embodiment, the requirements log includes data used to verify whether enablement of a particular component is required for proper operation of the gaming units. The requirements log preferably includes rules for the processor to use in determining whether or not the gaming units (or subsets of the components comprising the gaming units) are allowed to be enabled, when the processor examines the registered identification data (i.e., data detailing what is supposed to be installed) and the installed identification data (i.e., data detailing what is actually installed). In accordance with another aspect of the verification system, the communication of the installed identification data from the gaming units to the operational component registry occurs at predetermined intervals. In one preferred embodiment, the communication of the installed identification data from the gaming units to the operational component registry occurs in response to a request. Additionally, in one preferred embodiment, the operational component registry further includes at least one user access port that is configured to provide access to the registry in an embodiment where the operational component registry is remotely located. In accordance with one aspect of the verification system, the update process is used to update the registered identification data with authorized changes and updates to the components. In one preferred embodiment, the gaming units have components with non-corresponding identification data that are not enabled. Correspondingly, in this embodiment the gaming units have corresponding identification data for all components that are enabled. Additionally, in one preferred embodiment, the non-enablement of one or more non-corresponding components of a gaming unit initiates a determination process, during which it is established whether enablement of the gaming unit is prevented. Conversely, in another preferred embodiment, enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit. In accordance with another aspect of the verification system, the operational component registry further includes an enablement log. Preferably, the enablement log includes data that is utilized by the processor to assist in determining enablement or non-enablement of the gaming units (as well as of individual components of the gaming units). In another preferred embodiment of the verification system, the operational component registry includes a catalog of registered identification data and a catalog of installed identification data. The term “catalog” as used herein, refers simply to the data files themselves and not to the memory device on which the data files reside. The registered identification data preferably includes identification data for components registered as being installed (i.e., are supposed to be installed) on one or more of the gaming units. Additionally, the installed identification data preferably includes identification data for components that are actually installed on the gaming units. In one preferred embodiment of the verification system, the operational component registry further comprises a memory device that stores a catalog of the registered identification data and a catalog of the installed identification data, a processor that analyzes the registered identification data and the installed identification data, and an interface between the operational component registry and the gaming units. Preferably, the components include both hardware and software. In accordance with another aspect of the verification system, the claimed invention utilizes “component binding” for cryptographic security. In component binding, some components, like the motherboard, the cabinet, the hard drive, and the non-volatile RAM (such as battery-backed Safe RAM), are issued identification numbers. When these numbers are cryptographically secured together collectively in a grouping, this protected grouping is referred to as a “binding.” Each component of the machine contains its portion of the binding. The collected bindings are not stored anywhere. In one such preferred embodiment, every critical log entry made on the hard drive and every critical entry on the non-volatile RAM is signed with a Hashed Message Authorization Code (HMAC) that is based on the entry itself, and on the individual binding codes. In this manner, the security produced by the bindings ensures that log entries that are made cannot be falsified or repudiated. In such an embodiment, even if the hard drive and/or non-volatile RAM are removed from a machine, an entry cannot be falsified unless the binding numbers from the motherboard, and cabinet are all known. In accordance with one preferred embodiment of the verification system, one or more gaming machine system components are assigned identification codes. The components are grouped together into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group. Accordingly, the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. In another preferred embodiment, the component bindings verification system for gaming machine system components includes, the gaming machine system components, identification codes, and a protected grouping of gaming machine system components that form the component bindings. Preferably, the gaming machine system components include at least non-volatile RAM, a cabinet, and a hard drive. Typically, an identification code is assigned to each gaming machine system component. The protected grouping of components form component bindings using cryptographic security procedures and the identification codes of the components in the bindings group. The bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. In accordance with another aspect of the verification system, every log entry made on the hard drive and every entry made on the non-volatile RAM, must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. In the same manner, every log entry that attempts a replacement of any of the gaming machine system components must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. Preferably, the identification codes of the gaming machine system components are randomly or pseudo-randomly generated. In accordance with another aspect of the verification system, a Hashed Message Authorization Code key for authenticating access to the component bindings is produced using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. Additionally, the gaming machine system components are secured within the component bindings using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. Another preferred embodiment of the claimed invention utilizes a method for verifying components of one or more gaming units using an operational component registry. The method includes: selecting one or more gaming units for verification; establishing communication with the selected gaming units; receiving installed identification data into the operational component registry from the selected gaming units regarding components actually installed on the selected gaming units; and examining the installed identification data and registered identification data stored on the operational component registry to determine enablement of the gaming units. Still another preferred embodiment of the claimed invention utilizes a method for verifying and selectively enabling gaming units. This method includes: receiving installed identification from one or more gaming units to an operational component registry through an interface on the operational component registry; storing registered identification data and installed identification data on a memory device located within the operational component registry; and examining the registered identification data and the installed identification data on a processor in the operational component registry to determine enablement via the gaming units. In one preferred embodiment, the verification method prevents falsification and repudiation of log entries with respect to modifications and replacements in gaming machine system components. Preferably, the verification method includes: assigning identification codes to gaming machine system components within a gaming unit, wherein the gaming machine system components include at least non-volatile RAM, a cabinet, and a hard drive; binding together one or more gaming machine system components into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group. Other features and advantages of the claimed invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example, the features of the claimed invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a gaming system that utilizes a verification system having operational component registry, which is resident on the central gaming system, and wherein the operational component registry is connected to a gaming unit having a single gaming machine that includes various hardware and software components; FIG. 2 illustrates a gaming system having a central gaming system, a wide area gaming system, a local area gaming system, wherein the gaming units include single gaming machines, multiple gaming machines, and/or miscellaneous components; FIG. 3 illustrates a gaming system in which the operational component registry is resident on a local gaming system and includes an interface, a processor, and a memory device, as well as a gaming unit having multiple and differing gaming machines grouped therein; FIG. 4 illustrates a gaming system that includes multiple operational component registries; FIG. 5 illustrates the memory device of an operational component registry that preferably includes installed identification data, registered identification data, a change log, a service log, a requirements log, an enablement log, and a productivity log; and FIG. 6 illustrates a method utilizing an operational component registry for checking gaming units and/or individual components, and determining whether to permit enablement of the gaming units and/or individual components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the verification system has an operational component registry that identifies all components installed on one or more gaming units and verifies that these “installed components” correspond to the “registered components.” Otherwise stated, the operational component registry verifies that the components that are actually installed on a gaming machine correspond to the components that are supposed to be installed on that gaming machine. The resultant examination of the installed component data and registered component data is used to determine whether the gaming units, or individual components of the gaming units, may be enabled before starting or continuing operation. Preferably, the verification system also monitors changes and updates to the components of the gaming units, identifies services that have been performed on the components, verifies that requirements for proper operation of a gaming unit are satisfied, and determines the productivity of a gaming unit. Referring now to the drawings, wherein like reference numerals denote like or corresponding parts throughout the drawings, and more particularly to FIGS. 1-6, there is shown a preferred operational component registry 10 of the verification system. As shown in FIG. 1, a preferred embodiment of the verification system has an operational component registry 10 that includes an interface 20, a memory device 30, and a processor 40. Preferably, the interface 20 in the operational component registry 10 communicates the installed identification data 50 from gaming units 60 to the operational component registry. The memory device 30 preferably stores registered identification data 70 and installed identification data 50 for the gaming units 60. In a preferred embodiment, the processor 40 in the operational component registry 10 then analyzes the registered identification data 70 and the installed identification data 50 from the gaming units 60, after which enablement of the gaming units is determined based upon the examination of the registered identification data and the installed identification data. Notably, each gaming unit 60 preferably includes a gaming machine 80 having one or more components 90. Further, the gaming units 60 may include additional components 90 that are not part of a gaming machine 80. Typically, each component 90 is either hardware, software, or some other gaming system related component. In a preferred embodiment, the registered identification data 70 for each gaming unit 60 includes identification data for the components 90 that are supposed to be installed on each gaming unit. Correspondingly, the installed identification data 50 for the gaming units 60 preferably includes identification data for the components 90 that are actually installed on the gaming units. In the preferred embodiment illustrated in FIG. 1, the verification system has an operational component registry 10 that is resident on a central gaming system 100. As discussed above, in one preferred embodiment, the interface 20 is used to communicate the installed identification data 50 from the gaming units 60 and the operational component registry 10. Preferably, the communication of the installed identification data 50 occurs (1) at predetermined intervals, (2) in response to a request, or (3) in response to a triggering event. Additionally, in some embodiments the interface 20 resides on the operational component registry 10, while in other embodiments the interface 20 is remote to the operational component registry. In some embodiments, more than one interface 20 is used to communicate the installed identification data 50 from the gaming units 60 to the operational component registry 10. Further, in some embodiments the interface 20 resides within the operational component registry 10, while in other embodiments the interface is remote to the operational component registry. Examples of the interface 20 include, by way of example only, and not by way of limitation, a serial port, a parallel port, a universal serial bus (USB) port, a RS-232 port, an I2C (Inter-Integrated Circuit) port, an Ethernet port, an infrared port, a binary port, a TTL (transistor-transistor logic) port, an IEEE 1394 “fire wire” port, or a wireless port. Preferably, once the installed identification data 50 has been communicated to the operational component registry 10, the processor 40 performs an analysis of the registered identification data 70 and the installed identification data 50 for each component 90 of the gaming units 60. That is, the registered identification data 70 is compared with the installed identification data 50, and matching and non-matching identification data is determined for each component 90. From the matching and non-matching identification data, the enablement or non-enablement of the gaming units 60 (or of individual components 90 on the gaming units) is determined. Additionally, in some preferred embodiments, the operational component registry 10 is associated with more than one processor 40. Further, in some preferred embodiments, the processor 40 is remote from the operational component registry 40. In the embodiment shown in FIG. 1, a central gaming system 100 is in communication with a gaming unit 60 and its associated gaming machine 80. Preferably, the gaming machine 80 is configured with a variety of components depending on its gaming applications. In one preferred embodiment, a gaming machine 80 includes coin-in and/or bill acceptor devices 91, video and/or audio devices 92, various software applications 93, casino and/or player access/identification devices 94, and miscellaneous input/output devices 95 that are necessary for the proper operation of the gaming machine 80. Referring now to FIGS. 1 and 2, the gaming systems in which the gaming units 60 are contained may be organized in a variety of different configurations. These include, by way of example only, and not by way of limitation, a central gaming system 100, a local gaming system 110, and a wide area gaming system 120. Further, a gaming unit 60 may be defined as including only a single gaming machine 80, multiple gaming machines 80, or a gaming machine 80, as well as other components 90. Typically, a central gaming system 100 is a gaming communication and control system that controls a network of gaming machines 80 and gaming systems. However, in a preferred embodiment, a central gaming system 100 may be used, not for real-time gaming, but rather for the gradual migration of data. Preferably, the central gaming system 100 may be used for material requirements planning. Such a central gaming system 100 may further include capabilities for outcome determination, configured control, jurisdictional optioning, and marketing content distribution. Continuing, a local area gaming system 110 preferably includes a communication and control system that covers gaming machines 80 and gaming systems located over a relatively small geographic area. In contrast, a wide area gaming system 120 is a gaming communication and control system that covers gaming machines and gaming systems located over a wide geographic area. In one preferred embodiment, a wide area gaming system 120 may refer to a gaming system for a specific jurisdictional area. Both central gaming systems 100 and wide area gaming systems 120 may include smaller subsets of gaming systems, such as a local area gaming system 110 or groupings of gaming units 60. As shown in FIG. 2, a gaming unit 60 is shown with multiple additional components that include, by way of example only and not by way of limitation, a communications interface 96, a game controller 97, coin in/bill acceptor devices 91, video/audio devices 92, player access/identification devices 94, miscellaneous input/output devices 95, mechanical game devices 98, and printer/ticket devices 99. Preferably, the components 90 of a gaming unit 60 include hardware and software. Moreover, access ports 150 are preferably provided at multiple locations in a gaming system (e.g., a central gaming system 100, a local area gaming system 110, a wide area gaming system 120, or a single gaming unit 60). Through these access ports 150, a user can access and manipulate the data in the operational component registry 10. Examples of these access ports 150 include, by way of example only, and not by way of limitation, a serial port, a parallel port, a universal serial bus (USB) port, a RS-232 port, an I2C (Inter-Integrated Circuit) port, an Ethernet port, an infrared port, a binary port, a TTL (transistor-transistor logic) port, an IEEE 1394 “fire wire” port, or a wireless port. Referring now to FIGS. 1 and 3, a preferred embodiment of the verification system has an operational component registry 10 that is shown as resident on a local area gaming system 110. In this embodiment, the operational component registry 10 includes at least one memory device 30, at least one processor 40, and at least one interface 20. Connected to the local area gaming system 110 are three gaming units 60. As discussed above, some gaming units 60 include additional (possibly non-gaming) components 90, as well as one or more gaming machines 80. Accordingly, these components 90 may be part of the gaming machine 80, or may not be directly related to gaming. Thus, in one preferred embodiment, the operational component registry 10 is utilized in conjunction with components 90 that are not directly related to gaming, such as vending machines, automated information services, or other electromechanical applications. FIGS. 3 also illustrate a gaming unit 60 that includes multiple differing gaming machines 80. As shown in one embodiment, different types of gaming machines 80 are grouped into a single gaming unit 60. Such differing types of gaming machines 80 include, by way of example only and not by way of limitation, video gaming machines 310, card gaming machines 320, lottery gaming machines 330, and/or slot gaming machines 340. Moreover, in another preferred embodiment of the verification system shown in FIG. 1 and 3, the operational component registry 10 is used to verify the components 90 of only a portion of the gaming unit 60. In one such preferred embodiment, the operational component registry 10 is used to only check the components 90 in the gaming machine 80 portion of a gaming unit 60 and not the additional non-gaming machine components 90. Thus, the operational component registry 10 may be configured to verify the components 90 of an entire system, the components of a particular gaming unit 60, the components of a particular gaming machine 80, or merely a single component. Another preferred embodiment of the verification system utilizes “component bindings” for verification using cryptographic security. In component binding, some components, like the CPU chip and the cabinet, come equipped with unalterable serial numbers. Additionally, components such as the cabinet may also be given another random identification number by the owner. Other components in the system, such as the CMOS memory in the motherboard, the hard drive, and the non-volatile RAM, are also issued random identification numbers. When these numbers are secured together collectively in a grouping, this protected grouping is referred to as a “binding.” Each component of the machine contains its portion of the binding. The collected bindings are not stored anywhere. In one such preferred embodiment, every critical log entry made on the hard drive and every critical entry on the non-volatile RAM is signed with a Hashed Message Authorization Code (HMAC) that is based on the entry itself, and on the individual binding codes. In this manner, the security produced by the bindings ensures that log entries that are made cannot be falsified or repudiated. In such an embodiment, even if the hard drive and/or non-volatile RAM are removed from a machine, an entry cannot be falsified unless the binding numbers from the all of the components in the bindings group (e.g., the CPU, motherboard, and cabinet) are all known. After the critical gaming and/or system components are selected, given individual identifiers, and combined into a protected grouping that is secured using the component “bindings,” any changes to those components will then be detected, authorized, and logged. For example, application log entries on a component within the binding are digitally signed (SHA-1) using the key derived from the bindings. This signature is verified whenever an entry is made to a component within the binding. If the signature is wrong, this security violation and the violator are noted, but typically the entry is not prohibited. Thus, the component binding produce a cryptographic audit trail of the individuals making changes to any of the components within the binding. Moreover, bindings ensure that the critical components of a gaming machine system that have been selected to be components within the binding have not been swapped in an un-authorized manner. Preferably, bindings use unique identification numbers that are assigned to vital parts of the gaming platform including, by way of example only, and not by way of limitation, the cabinet, motherboard, specific software, non-volatile RAM card, and hard drive. These identification numbers combined in a cryptographic manner to form a “binding” that protects and virtually encloses the included components, such that no component within the binding can be modified, removed, or replaced without creating an audit trail and requiring authentication. Thus, for one of these components within the binding to be changed, appropriate authentication is required and a log file entry is made documenting the activity and the identity of the individual making the change. In one preferred embodiment, a specific level of BKEY is required to make the changes. In one preferred embodiment, the Secure Hash Function-1 (SHA-1) is used to compute a 160-bit hash value from the data file or firmware contents. This 160-bit hash value, which is also called an abbreviated bit string, is then processed to create a signature of the game data using a one-way, private signature key technique, called Digital Signature Algorithm (DSA). The DSA uses a private key of a private key/public key pair, and randomly or pseudo-randomly generated integers, to produce a 320-bit signature of the 160-bit hash value of the data file or firmware contents. This signature is stored in the database in addition to the identification number. For example, prior to binding a 256-bit random number is generated and stored for the cabinet. Additionally, a 128-bit random number is generated and stored on the non-volatile RAM. Further, another 128-bit random number is generated and stored on the hard drive. Additionally, yet another 128-bit random number is generated and stored in the CMOS memory of the CPU board. Then, to create the HMAC key and bind the components, a SHA1 hash is produced using all those numbers (i.e., all of the components in the binding group). This 160-bit result is the HMAC key, which is never stored anywhere except for in RAM. Thus, for this embodiment, the cabinet, the CMOS memory of the CPU board, the hard drive, and the non-volatile RAM (i.e., all of the components in the binding group) are all needed to create this key. Without all of these components (and associated component identification codes) the key cannot be created, and without the key signed entries cannot be forged. Referring now to FIG. 4, a verification system is shown that uses multiple operational component registries 100. In this preferred embodiment of the verification system, a central gaming system 100 communicates with a wide area gaming system 120. The wide area gaming system 120 in turn communicates with multiple gaming units 60 and with a local gaming system 110. In this preferred embodiment, the operational component registry 10 is resident on more than one portion of a system. Specifically, the operational component registry 10 is shown as resident on (1) a wide area gaming system 120, (2) a gaming unit 60 comprising a single gaming machine, and (3) a group of gaming units 60. FIG. 5 illustrates a preferred embodiment of the verification system having an operational component registry 10 that includes a plurality of additional data files, including a change log 510, a service log 520, a requirements log 530, an enablement log 540, and a productivity log 550 (as well as the above-discussed installed identification data 50 and registered identification data 70). In one preferred embodiment, each of these additional data files is stored in the operational component registry 10, while in another preferred embodiment, one or more of these data files are transmitted to the operational component registry from another location. Otherwise stated, the change log 510, service log 520, requirements log 530, enablement log 540, and productivity log 550 may each either be initially stored in the operational component registry 10 or transmitted from a remote location to the operational component registry. As discussed above, the registered identification data 70 is typically stored in the operational component registry 10, while the installed identification data 50 is typically transmitted from another location. In a preferred embodiment of the verification system, each of the above-discussed data files in the operational component registry 10 is authenticatible and non-repudiatible, thereby increasing security of the system and helping to prevent unauthorized access. Other forms of authorization and security may also be used. Typically, when data files are made authenticatible and non-repudiatible, it is also necessary to authenticate the data files before processing the data. In a preferred embodiment, at least one of the registered identification data 70 and the installed identification data 50 is authenticatible and non-repudiatible. Accordingly, in such an embodiment, authentication is performed before the registered identification data 70 and the installed identification data 50 are examined. Referring now to FIG. 1 and 5, in a preferred embodiment of the verification system, the registered identification data 70 and the installed identification data 50 in the operational component registry 10 contain unique identifiers for each component 90. As discussed above, these components 90 preferably include hardware and software, each of which has unique data characteristics. In one preferred embodiment, the registered identification data 70 and installed identification data 50 for hardware components 90 include, by way of example only and not by way of limitation, serial numbers, model numbers, part numbers, manufacture date, location information, installation date, repair date, and other unique identifying data. In another preferred embodiment, the registered identification data 70 and installed identification data 50 for software components 90 include, by way of example only and not by way of limitation, globally-unique identifiers, version information, licensing information, installation date, patch or repair date, signature data, hash data, authentication data, and other unique identifying data. Accordingly, any type of data characteristics (or combination of data characteristics) that uniquely identifies a component 90 may be used by the operational component registry 10 for verification purposes. In a preferred embodiment of the verification system, the update process authorizes changes and updates to the components 90 of the gaming units 60. In a preferred embodiment, a change log is produced during the update process that catalogs the results of the update process. Preferably, the update process is used to amend the registered identification data 70 on the operational component registry 10 to include identification data for authorized changes and updates to installed components on the gaming units 60. In preferred embodiments, updates to the registered identification data 70 that are made using the update process occur either at predetermined intervals, in response to a request, or in response to a triggering event. Thus, in one preferred embodiment, the user configures the update process to automatically update the registered identification data 70. In another preferred embodiment, the user sends a request to update the registered identification data 70 through the access port 150 (shown in FIG. 2) or other input device, which results in the initiation of the update process. Finally, in still another preferred embodiment, updates to the registered identification data 70 occur in response to a triggering event, such as the identification of registered identification data 70 and installed identification data 50 that is non-corresponding. A preferred embodiment of the verification system also includes a service log 520. Preferably, the service log 520 includes information regarding diagnostic and maintenance services performed on components 90 of the gaming units 60. In this regard, any service that is performed on a component 90 is recorded in the service log 520. Thus, the service log 520 preferably provides a trackable record of any and all repairs, replacements, and/or tampering with components 90 of the gaming units 60. A preferred embodiment of the verification system further includes a requirements log 530. Preferably, the requirements log 530 contains data that is used to determine the operational requirements for a particular gaming unit 60. In one preferred embodiment, the requirements log 530 is used to determine whether the non-enablement of a component 90 in a gaming unit 60 will prevent the proper operation of that gaming unit. If proper operation of the gaming unit 60 is not possible with the component 90 being non-enabled, the operational component registry 10 prevents the enablement of the gaming unit associated with the non-enabled component. Otherwise stated, the requirements log 530 preferably includes rules for the processor 40 to use in determining whether or not the gaming units 60 (or subsets of the components comprising the gaming units) are allowed to be enabled. In a preferred embodiment, the verification system also includes an enablement log 540. Preferably, the enablement log 540 contains data that is transmitted and stored regarding the enablement or non-enablement of gaming units 60, and/or of individual components 90 of the gaming units. In one preferred embodiment, the enablement log 540 contains an “override” command that is used to permit operation of a gaming unit 60, even though there is non-corresponding data for one or more components 90 of the gaming unit 60, and the components are identified by the requirements log 530 as necessary for the proper operation of the gaming unit. In another aspect of a preferred embodiment, the verification system also includes a productivity log 550 that provides information regarding the productivity of one or more gaming units 60. Preferably, the operational component registry 10 is used to track the performance and productivity of the gaming units 60. In one preferred embodiment, the productivity log 550 of the operational component registry 10 tracks the coin-in, the win ratio, the play time, and various other factors that are potentially indicative of productivity. Referring now to FIG. 6 (as well as FIG. 1), a preferred embodiment method is shown for checking and verifying one or more gaming units 60 (or individual components 90), using an operational component registry 10. A preferred method includes, at Step 600, selecting one or more gaming units 60 for verification. At Step 610 communication is established between the selected gaming units 60 and the operational component registry 10. At Step 620 the installed identification data 50 is requested for components 90 that are installed on the selected gaming units 60. Next, at Step 630, the installed identification data 50 is received by the operational component registry 10 from the selected gaming units 60. Continuing, at Step 640, the installed identification data 50 is examined with respect to the registered identification data 70 stored on the operational component registry 10. Lastly, this preferred method further includes, at Step 650, determining whether to permit enablement of the selected gaming units 60 (or individual components 90), using the results of the examination of the installed identification data 50 with respect to the registered identification data 70. Referring again to FIG. 5 (as well as FIG. 1), in some preferred embodiments, the method also includes determining whether any changes have been made to the installed components. Preferably, this is accomplished by querying the change log 510 and the selected components 90 to determine whether any changes or updates have been made since the last request for installed identification data 50. In a preferred embodiment, if a change or update is found to have occurred to the installed components, the installed identification data 50 is communicated to the operational component registry 10, and the information is updated. The operational component registry 10 then preferably verifies that the changes to the installed components are authorized, and that the requirements for proper operation of the gaming units 60 (or components 90) are satisfied. In this preferred embodiment, the requirements log 530 then confirms that the software change is authorized (e.g., a license is available, the software is the proper version, and the like). Preferably, the requirements log 530 also confirms that the software permits proper operation of the gaming unit 60. After confirming that all of the requirements are satisfied, the operational component registry 10 is amended to include the registered identification data 70 for the changed components. Once the updates have been entered, the installed identification data 50 and the updated registered identification data 70 are the examined. Using the results from this examination, the operational component registry 10 determines whether to permit enablement of the gaming units 60 or the individual components 90 of the gaming units. Furthermore, the various systems and methodologies described above are provided by way of illustration only and should not be construed to limit the invention. Those skilled in the art will readily recognize that various modifications and changes may be made to the claimed invention without departing from the true spirit and scope of the claimed invention. Accordingly, it is not intended that the claimed invention be limited, except as by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>There are a wide variety of software, hardware and other types of verification systems that attempt to monitor additions, deletions, changes, and updates, which are routinely performed on gaming machines. Typically, in the gaming field, verification of software or hardware installed on a gaming machine may occur by reviewing the contents of a read-only memory. To ensure that tampering, such as with software codes or hardware devices has not occurred, a simple review of the memory contents and visual inspection of hardware is conducted to verify the gaming application. Such a memory check is performed before start-up of the gaming machine or during game play after a win occurs and by a regulatory field agent's inspection. This type of verification system is typically adequate only if the gaming application is stored in a read-only memory (e.g., the memory is difficult to alter and the standard software verification systems prevent unauthorized access), and if there is little danger that the hardware of the gaming machine will be compromised. For instance, in a casino with 24-hour surveillance, it is likely that any hardware tampering would quickly be noticed. Today, it is becoming more common to connect multiple gaming machines and/or multiple gaming locations to provide many different gaming options. Moreover, there is a desire to operate these multiple gaming machines and/or casinos using a centralized system or network. Accordingly, when multiple gaming machines or multiple casinos are connected over a local area network or a wide area network, it is difficult to quickly and efficiently run the above-described software verifications or to engage in constant surveillance in each location to assure that no hardware tampering is occurring. Additionally, gaming services are evolving to include virtual and networked platforms that permit use of gaming systems and services through non-dedicated, web-based, or remote access points. These virtual and networked games increase the difficulty of monitoring the use of unauthorized software and/or hardware in these remote locations. Still further, the assortment of gaming options and services that are available on a gaming machine and/or a gaming network may vary over time. As the variety of gaming options and services that are available continues to increase, it becomes more difficult to accurately monitor and regulate the software and hardware that are used to implement the different games and gaming applications. Additionally, the registry and tracking systems that are currently in place merely indicate whether or not a component is contained within a registry. Known registry systems do not use the registry to track the requirements for operation and to determine whether or not a gaming unit or a particular component may be enabled. Additionally, known registry systems do not track changes and servicing of the components, and thus, do not allow the registry to be automatically updated with new, authorized component information. Finally, the current systems do not track the productivity of the gaming units. Accordingly, those skilled in the art have long recognized the need for enhanced verification of components and improved security measures that prevent enablement of gaming units and components or unauthorized installation changes. There is also a continuing need for a system that provides additional security from tampering by tracking the installations and changes to software or hardware on a gaming unit, thereby preventing unauthorized enablement of a gaming unit. Further, there is a continuing need for a system that is useful in monitoring and tracking gaming operations and services performed on a gaming machine or its components. The claimed invention clearly addresses these and other needs. | <SOH> SUMMARY OF THE INVENTION <EOH>Briefly, and in general terms, the claimed invention resolves the above and other issues by providing a verification system and method for identifying all components installed on one or more gaming units, and verifying that these installed components (i.e., the components that are actually installed) correspond to the registered components (i.e., the components that are supposed to be installed). The phrase “gaming machine” as used herein describes typical gaming machines as well as other gaming related, computing systems, such as game servers and the like. Accordingly, the phrase “gaming units” as used herein describes groupings of gaming-related components and associated system components. In this way, the resultant examination of installed component data and registered component data is used to determine whether the gaming units, or individual components of the gaming units, may be enabled before starting or continuing operation. Preferably, the verification system and method also monitors changes and updates to the components of the gaming units, identifies service that has been performed on the components, verifies that the requirements for proper operation of a gaming unit are satisfied by enabled and non-enabled components, and determines the productivity of a gaming unit. In one preferred embodiment, the verification system includes an operational component registry having a memory device, an interface, and a processor. The memory device stores registered identification data and installed identification data for one or more gaming units. The gaming units themselves each include one or more components. Preferably, the components include by way of example only, and not by way of limitation, hardware (e.g., a hard drive, non-volatile RAM, and the like), software, and other gaming machine system components (e.g., a gaming machine cabinet). The interface communicates the installed identification data from the gaming units to the operational component registry. Additionally, the processor analyzes the registered identification data and the installed identification data of the gaming units. The processor then, by examining the registered identification data (i.e., data detailing what is supposed to be installed) with the installed identification data (i.e., data detailing what is actually installed), determines whether or not the gaming units are allowed to be enabled. In accordance with another preferred aspect of the verification system, the registered identification data includes identification data for the components that are supposed to be installed on the gaming units. Preferably, the installed identification data for the gaming units includes identification data for the components that are actually installed on the gaming units. Typically, in a preferred embodiment the registered identification data is authenticatible and non-repudiatible, rather than hidden or otherwise obfuscated (encrypted). Accordingly, the registered identification data and the installed identification data must be authenticated prior to examination by the processor. Non-repudiation is a way to guarantee that the sender of a message cannot later deny having sent the message, and that the recipient cannot deny having received the message. In accordance with another preferred aspect of the verification system, both the registered identification data and the installed identification data for the gaming units include unique identifiers for each of the components that either are supposed to be installed or are actually installed on a gaming unit. Preferably, the registered identification data and installed identification data for the hardware include, by way of example only, and not by way of limitation, one or more of: serial numbers, model numbers, part numbers, location information, manufacture date, installation date, and repair date. Further, in a preferred embodiment the registered identification data and installed identification data for the software include, by way of example only, and not by way of limitation, one or more of: globally unique identifiers, version information, licensing information, installation date, patch date, repair date, signature data, hash data, and authentication data. In accordance with another preferred aspect of the verification system, the operational component registry is resident on a central gaming system to which the gaming units are connected. In another preferred embodiment, the operational component registry is resident on a wide area gaming system to which the gaming units are connected. In still another preferred embodiment, the operational component registry is resident on a local area gaming system to which the gaming units are connected. In yet another preferred embodiment, the operational component registry is resident on a gaming unit. In a further preferred embodiment, the operational component registry is utilized with additional operational component registries within a system of gaming units. In accordance with another aspect of the verification system, the operational component registry further includes an update process. In a preferred embodiment, a change log is produced during the update process that catalogs the results of the update process. Preferably, the change log includes identification data regarding authorized changes and updates that occurred to the components of the gaming units during the update process. Specifically, the update process is used to amend the operational component registry to include registered identification data for authorized changes and updates to installed components. Preferably, technology such as digital signature verification, message authentication code, bindings, and electronic keys (BKEYs) are used to verify, authenticate, and/or authorize the validity of these changes. In one preferred embodiment of the verification system, the operational component registry is amended, at predetermined intervals, using the update process to enable the operational component registry to include the registered identification data for authorized changes and updates to the installed components that were added during the update process. In another preferred embodiment of the verification system, the operational component registry is amended, in response to a request, using the update process to enable the operational component registry to include registered identification data for authorized changes and updates to installed components that were added during the update process. In accordance with another aspect of the verification system, the operational component registry further includes service processes. In one preferred embodiment, a service log is produced during the service processes that catalog the results of the service processes. Preferably, the service log includes information regarding diagnostic and maintenance services performed on components of the gaming units during the service processes. As stated above, the phrase “gaming units” as used herein, describes groupings of gaming related components (e.g., gaming machines, gaming systems, gaming servers, and the like) as well as associated system components. In accordance with another aspect of the verification system, the operational component registry further includes a productivity log. In one preferred embodiment, the productivity log includes information regarding productivity of the gaming units. In accordance with still another aspect of the verification system, the operational component registry further includes a requirements log. In one preferred embodiment, the requirements log includes data used to verify whether enablement of a particular component is required for proper operation of the gaming units. The requirements log preferably includes rules for the processor to use in determining whether or not the gaming units (or subsets of the components comprising the gaming units) are allowed to be enabled, when the processor examines the registered identification data (i.e., data detailing what is supposed to be installed) and the installed identification data (i.e., data detailing what is actually installed). In accordance with another aspect of the verification system, the communication of the installed identification data from the gaming units to the operational component registry occurs at predetermined intervals. In one preferred embodiment, the communication of the installed identification data from the gaming units to the operational component registry occurs in response to a request. Additionally, in one preferred embodiment, the operational component registry further includes at least one user access port that is configured to provide access to the registry in an embodiment where the operational component registry is remotely located. In accordance with one aspect of the verification system, the update process is used to update the registered identification data with authorized changes and updates to the components. In one preferred embodiment, the gaming units have components with non-corresponding identification data that are not enabled. Correspondingly, in this embodiment the gaming units have corresponding identification data for all components that are enabled. Additionally, in one preferred embodiment, the non-enablement of one or more non-corresponding components of a gaming unit initiates a determination process, during which it is established whether enablement of the gaming unit is prevented. Conversely, in another preferred embodiment, enablement of a gaming unit is permitted regardless of whether any components having non-corresponding identification data are identified in the gaming unit. In accordance with another aspect of the verification system, the operational component registry further includes an enablement log. Preferably, the enablement log includes data that is utilized by the processor to assist in determining enablement or non-enablement of the gaming units (as well as of individual components of the gaming units). In another preferred embodiment of the verification system, the operational component registry includes a catalog of registered identification data and a catalog of installed identification data. The term “catalog” as used herein, refers simply to the data files themselves and not to the memory device on which the data files reside. The registered identification data preferably includes identification data for components registered as being installed (i.e., are supposed to be installed) on one or more of the gaming units. Additionally, the installed identification data preferably includes identification data for components that are actually installed on the gaming units. In one preferred embodiment of the verification system, the operational component registry further comprises a memory device that stores a catalog of the registered identification data and a catalog of the installed identification data, a processor that analyzes the registered identification data and the installed identification data, and an interface between the operational component registry and the gaming units. Preferably, the components include both hardware and software. In accordance with another aspect of the verification system, the claimed invention utilizes “component binding” for cryptographic security. In component binding, some components, like the motherboard, the cabinet, the hard drive, and the non-volatile RAM (such as battery-backed Safe RAM), are issued identification numbers. When these numbers are cryptographically secured together collectively in a grouping, this protected grouping is referred to as a “binding.” Each component of the machine contains its portion of the binding. The collected bindings are not stored anywhere. In one such preferred embodiment, every critical log entry made on the hard drive and every critical entry on the non-volatile RAM is signed with a Hashed Message Authorization Code (HMAC) that is based on the entry itself, and on the individual binding codes. In this manner, the security produced by the bindings ensures that log entries that are made cannot be falsified or repudiated. In such an embodiment, even if the hard drive and/or non-volatile RAM are removed from a machine, an entry cannot be falsified unless the binding numbers from the motherboard, and cabinet are all known. In accordance with one preferred embodiment of the verification system, one or more gaming machine system components are assigned identification codes. The components are grouped together into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group. Accordingly, the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. In another preferred embodiment, the component bindings verification system for gaming machine system components includes, the gaming machine system components, identification codes, and a protected grouping of gaming machine system components that form the component bindings. Preferably, the gaming machine system components include at least non-volatile RAM, a cabinet, and a hard drive. Typically, an identification code is assigned to each gaming machine system component. The protected grouping of components form component bindings using cryptographic security procedures and the identification codes of the components in the bindings group. The bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the bindings group. In accordance with another aspect of the verification system, every log entry made on the hard drive and every entry made on the non-volatile RAM, must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. In the same manner, every log entry that attempts a replacement of any of the gaming machine system components must be authenticated by being digitally signed with a Hashed Message Authorization Code that is based on the entry itself and on the individual identification codes of the components in the bindings group. Preferably, the identification codes of the gaming machine system components are randomly or pseudo-randomly generated. In accordance with another aspect of the verification system, a Hashed Message Authorization Code key for authenticating access to the component bindings is produced using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. Additionally, the gaming machine system components are secured within the component bindings using a SHA-1 hash that is generated using the individual identification codes of the components in the bindings group. Another preferred embodiment of the claimed invention utilizes a method for verifying components of one or more gaming units using an operational component registry. The method includes: selecting one or more gaming units for verification; establishing communication with the selected gaming units; receiving installed identification data into the operational component registry from the selected gaming units regarding components actually installed on the selected gaming units; and examining the installed identification data and registered identification data stored on the operational component registry to determine enablement of the gaming units. Still another preferred embodiment of the claimed invention utilizes a method for verifying and selectively enabling gaming units. This method includes: receiving installed identification from one or more gaming units to an operational component registry through an interface on the operational component registry; storing registered identification data and installed identification data on a memory device located within the operational component registry; and examining the registered identification data and the installed identification data on a processor in the operational component registry to determine enablement via the gaming units. In one preferred embodiment, the verification method prevents falsification and repudiation of log entries with respect to modifications and replacements in gaming machine system components. Preferably, the verification method includes: assigning identification codes to gaming machine system components within a gaming unit, wherein the gaming machine system components include at least non-volatile RAM, a cabinet, and a hard drive; binding together one or more gaming machine system components into a protected group of component bindings using cryptographic security procedures and the identification codes of the components in the bindings group, and wherein the bindings prevent falsification or repudiation of log entries with respect to any modifications or replacements of components within the binding group. Other features and advantages of the claimed invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example, the features of the claimed invention. | 20040430 | 20100601 | 20050106 | 80822.0 | 0 | PERUNGAVOOR, VENKATANARAY | VERIFICATION SYSTEM AND METHOD | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,836,905 | ACCEPTED | Portable body massager | The present invention discloses a body massager comprising a portable housing including a backrest and a seat support. A longitudinal guide is provided in the backrest cooperating with a carriage for translation of the carriage within the backrest and a motor drives the carriage along the guide. A pair of massage members are supported by the carriage and extend from the backrest for imparting a massage effect upon the back of the user. The seat support includes a massager therein for imparting another massage effect to the user. | 1. A portable body massager sized to be received and supported by a conventional chair, the massager comprising: a portable housing sized to be received and supported by a backrest of the conventional chair, the housing having a longitudinal axis and an external contact surface for receiving a portion of a body of a user; a longitudinal guide mounted in the housing; a carriage oriented in the housing and cooperating with the guide for limited longitudinal translation in the housing along the guide; a motor supported upon the carriage, the motor having a motor output shaft driven thereby, the motor output shaft being operably coupled to the housing to translate the carriage along the guide; and at least a pair of massage members transversely spaced about the longitudinal axis, each of the at least a pair of massage members being supported by the carriage for rotation relative to the carriage, the at least a pair of massage members extending out of the housing through an aperture formed through the body contacting surface for imparting a massage effect upon the portion of the user's body as the carriage is translated relative to the housing. 2. The portable body massager of claim 1 wherein the at least a pair of massage members are each operably driven by the motor output shaft for rotation relative to the carriage to impart a rotary kneading massage effect to the user. 3. The portable body massager of claim 1 wherein each of the at least a pair of massage members rotates about an axis that is generally perpendicular to both the longitudinal axis of the housing and a transverse axis of the housing. 4. The portable body massager of claim 1 wherein each of the at least a pair of massage members further comprises at least two massage nodes that are not coaxial with an axis of rotation of the massage member, one of the at least two massage nodes extends from the carriage further than the other of the at least two massage nodes, each massage node is axially translatable relative to the carriage between an extended position and a retracted position and each massage member further comprises a spring for biasing the at least two massage nodes towards the extended position. 5. The portable body massager of claim 1 wherein the carriage further comprises at least one roller bearing pivotally supported thereby for engaging a bearing surface provided within the housing for providing bearing support therebetween as the carriage is translated within the housing. 6. The portable body massager of claim 1 wherein the housing provides a structural frame for the guide. 7. The portable body massager of claim 1 further comprising at least a pair of limit switches oriented within the housing to be actuated by the carriage at positions along the guide for providing a signal that causes the motor to reverse rotation, consequently reversing the translation of the carriage along the guide, wherein the limit switches are each adhered to the housing. 8. The portable body massager of claim 1 further comprising: a central processing unit for programming various operations of the massager; and a series of limit switches oriented within the housing to be actuated by the carriage at spaced apart positions along the guide for providing a signal to the central processing unit whereby the user may select a desired range of targeted massage corresponding to any two of the series of limit switches so that the signal from each of the two of the series of limit switches causes the central processing unit to reverse the rotation of the motor, consequently reversing the translation of the carriage along the guide. 9. The portable body massager of claim 1 wherein at least a portion of the guide is formed integrally with the housing by a plastic injection molding process. 10. The portable body massager of claim 1 further comprising a multistage transmission driven by the motor and cooperating with the housing for the translating the carriage along the guide, wherein at least one gear of the multistage transmission rotates about an axis that is generally perpendicular to both the longitudinal axis of the housing and a transverse axis of the housing. 11. The portable body massager of claim 1 further comprising: a worm mounted to and driven by the motor output shaft; at least a pair of worm gears each coupled to one of the at least two massage members for imparting rotation from the motor output shaft to the at least two massage members for providing a rotary massage effect to the user; a pinion gear rotatably mounted to the carriage and operably driven by one of the worm or the at least a pair of worm gears; and a longitudinal rack affixed to the housing and engaged with the pinion gear such that rotation of the pinion gear translates the carriage along the guide. 12. A body massager comprising: a housing having an external contact surface for receiving a portion of a body of a user; a longitudinal guide mounted in the housing; a carriage oriented in the housing and cooperating with the guide for limited longitudinal translation in the housing along the guide; a motor supported upon the carriage, the motor having a motor output shaft driven thereby; at least a pair of massage members each supported by the carriage for rotation relative to the carriage and extending out of the housing through an aperture formed through the body contacting surface, each massage member being operably connected to and driven by the motor output shaft for providing a rotary massage effect to the user; a pinion gear rotatably mounted to the carriage and operably driven by the motor output shaft; a longitudinal rack affixed to the housing engaged with the pinion gear such that rotation of the pinion gear translates the carriage along the guide; and at least a pair of limit switches oriented within the housing to be actuated by the carriage at positions along the guide for providing a signal that causes the motor to reverse rotation, consequently reversing the translation of the carriage along the guide. 13. The body massager of claim 12 further comprising: a worm mounted to and driven by the motor output shaft; and at least a pair of worm gears each coupled to one of the at least a pair of massage members for imparting rotation from the motor output shaft to the at least a pair of massage members; wherein the pinion gear is driven by one of the worm or the at least a pair of worm gears for translating the carriage along the guide. 14. The body massager of claim 12 further comprising a central processing unit for programming various operations of the massager; wherein the at least a pair of limit switches further comprises a series of limit switches oriented within the housing to be actuated by the carriage at spaced apart positions along the guide for providing a signal to the central processing unit whereby the user may select a desired range of targeted massage corresponding to any two of the series of limit switches so that the signal from each of the two of the series of limit switches causes the central processing unit to reverse the rotation of the motor, consequently reversing the translation of the carriage along the guide. 15. The body massager of claim 12 wherein the housing is further defined as a portable housing that is sized to be received and supported by a backrest of a conventional chair. 16. A portable body massager comprising: a longitudinal backrest housing having an external surface sized to receive a back of a user rested thereon; a longitudinal guide mounted in the backrest housing; a carriage oriented in the backrest housing and cooperating with the guide for limited longitudinal translation in the backrest housing along the guide; a motor supported by one of the carriage and the backrest housing, the motor having a motor output shaft driven thereby, the motor output shaft being operably coupled to the other of the carriage and the backrest housing to translate the carriage along the guide; at least a pair of massage members each supported by the carriage for rotation relative to the carriage and extending out of the housing through an aperture formed through the body contacting surface for imparting a massage effect upon the back of the user as the carriage is translated relative to the backrest housing; a seat support housing sized to seat the user thereon, the seat support housing being pivotally connected to the backrest housing at a longitudinal end of the backrest housing, the pivotal connection being generally transverse relative to the backrest housing for permitting user adjustment of an included angle between the backrest housing and the seat support housing; and at least one massager oriented within the seat support housing for imparting another massage effect to the user seated thereon. 17. The portable body massager of claim 16 wherein the backrest housing further comprises a cushion affixed upon the backrest housing external surface for providing resilient support to the back of the user and the seat support housing further comprises a flexible seat cover having a seat cushion retained therein. 18. The portable body massager of claim 16 wherein the pivotal connection of the seat support housing and the backrest housing is provided by flexible material connected to a cover of the seat support housing and a cover of the backrest housing. 19. The portable body massager of claim 16 wherein the backrest housing is sized to be received and supported by a backrest of a conventional chair and the seat support housing is sized to be received and supported by a seat support of the conventional chair. 20. The portable body massager of claim 16 wherein the seat support massager further comprises at least one vibratory massager. 21. A portable body massager sized to be received and supported by a conventional chair, the massager comprising: a portable housing sized to be received and supported by a backrest of the conventional chair, the housing having a longitudinal axis and an external contact surface for receiving a portion of a body of a user; a longitudinal guide mounted in the housing; a carriage oriented in the housing and cooperating with the guide for limited longitudinal translation in the housing along the guide; a motor supported upon the carriage, the motor having a motor output shaft driven thereby, the motor output shaft being operably coupled to the housing to translate the carriage along the guide; and at least a pair of massage members transversely spaced about the longitudinal axis, each of the at least a pair of massage members being supported by the carriage for rotation relative to the carriage for imparting a massage effect upon the portion of the user's body as the carriage is translated relative to the housing; wherein a width of the at least a pair of massage members relative to the longitudinal axis is adjustable by rotation of the at least a pair of massage members relative to the carriage. 22. The portable body massager of claim 21 wherein each of the at least a pair of massage members further comprises: a bracket rotatably mounted to the carriage; a primary massage node rotatably mounted to the bracket about an axis of rotation that is not coaxial with an axis of rotation of the bracket, so that the primary massage node can rotate relative to the bracket to provide a rolling massage effect; a secondary massage node rotatably mounted to the bracket about an axis of rotation that is not coaxial with the axis of rotation of the bracket and the axis of rotation of the primary massage node, so that the secondary massage node can rotate relative to the bracket to provide a rolling massage effect, the secondary massage node being smaller than the primary massage node so that the rolling massage effect of the secondary massage node differs from that of the primary massage node. 23. The portable body massager of claim 21 wherein the operation of the motor further comprises user-selected rotation for translating the carriage to a desired longitudinal orientation. 24. The portable body massager of claim 21 wherein the operation of the motor further comprises continuous rotation within a range of the carriage for providing a massage effect from the at least a pair of massage members. 25. The portable body massager of claim 24 wherein the operation of the motor is controlled from a control pad. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to massagers, particularly to portable body massagers. 2. Background Art The prior art includes body massagers provided within chairs, as well as in portable cushions. These prior art body massagers commonly include a track or guide for moving a massage assembly longitudinally within the chair or cushion. The prior art body massagers are relatively complex and utilize many components, thereby requiring sufficient structure to support the massager and limiting the portability of the massager. Due to the complexities of conventional body massagers, a consumer's ability to procure such massagers is limited due to value and affordability. For example, many prior art body massagers include a complex guide system and frame thereby requiring a housing that is sufficiently robust, such as a chair. Many prior art body massagers require two motors, one for translating the massage mechanism, and the other for imparting the massage effect from the massage mechanism. Accordingly, these drawbacks of the prior art add both cost and weight to the prior art body massagers. A goal of the present invention is to provide a simplified body massager having improvements in massage function, portability and cost in view of the prior art. SUMMARY OF THE INVENTION An aspect of the present invention is to provide a body massager comprising a portable housing having an external contact surface for receiving a portion of a body of a user. A longitudinal guide is mounted in the housing; and a carriage is oriented in the housing and cooperating with the guide for limited longitudinal translation. A motor is supported by the carriage or the housing for translating the carriage along the guide. A pair of massage members are supported by the carriage for rotation relative to the carriage. The massage members extend out of the housing through an aperture formed through the body contacting surface for providing a massage effect to the user. Another aspect of the present invention is to provide a portable body massager comprising a longitudinal backrest housing having an external surface sized to receive a back of a user thereon. A longitudinal guide is mounted in the backrest housing. A carriage is oriented in the backrest housing and cooperating with the guide. A motor is supported by one of the carriage and the backrest housing that is operably coupled to the other of the carriage and the backrest housing for translating the carriage along the guide. Massage members are supported by the carriage for rotation relative to the carriage, and extend out of the housing through an aperture formed to the body contacting surface for imparting a massage effect upon the back of the user as the carriage is translated relative to the backrest housing. A seat support housing is sized to seat the user thereon and is pivotally connected to the backrest housing at a longitudinal end of the backrest housing. A massager is oriented within the seat support housing for imparting another massage effect to the user. The above aspects and other aspects, objects, features, and advantages of the present invention are readily apparent from the following detailed description of the preferred embodiment for carrying out the invention when taken in connection with the accompanying brief description of the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferred embodiment body massager in accordance with the present invention; FIG. 2 is an exploded perspective view of a backrest region of the body massager of FIG. 1; FIG. 3 is a front side elevation view of the backrest region of the body massager of FIG. 1, illustrated with a portion of a housing thereof partially removed; FIG. 4 is an enlarged, front side elevation view of a carriage of the body massager of FIG. 1, illustrated within the backrest housing of the body massager with a cover plate removed therefrom; and FIG. 5 is an exploded perspective view of a seat support region of the body massager of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a preferred embodiment body massager is illustrated in accordance with the present invention and is referenced generally by numeral 10. The body massager 10 includes a backrest region 12 and a seat support region 14. The internal assemblies of the backrest region 12 and the seat support region 14 are collectively retained within a flexible cover 16, which is formed of a high quality vinyl. Of course other materials such as leather may be employed for the cover 16. The cover 16 provides a pivotal connection 18 at a lower longitudinal end of the backrest region 12 and a rearmost end of the seat support region 14. The flexible material of the cover 16 provides a living hinge at the pivotal connection 18 permitting user adjustment of an included angle between the backrest region 12 and the seat support region 14. Massage effects provided by the body massager 10 include a kneading massage effect provided in the backrest support 12, which is operable to provide the kneading massage effect longitudinally along the length of the backrest region 12. The seat support region 14 provides a vibratory massage effect to the user seated thereupon. The backrest region 12 is sized to be received upon a backrest of a conventional chair. Likewise, the seat support region 14 is sized to be received upon a seat support of a conventional chair. Additionally, the body massager 10 is portable due to its compact size and light weight so that the user may place the body massager 10 upon a conventional chair for receiving a massage when seated upon the chair. The adjustability of the included angle between the backrest region 12 and the seat support region 14 accommodates a wide range of angles that may be incorporated in conventional chairs. The backrest region 12 includes a height and width corresponding to the conventional chair and has a thickness that is adequate for housing the massager assembly therein while avoiding disruption of comfort and support provided by the underlying chair. Likewise, the seat support region 14 has a width and a depth corresponding to that of the conventional seat support and has a thickness that is adequate for housing the associated massager assembly while avoiding disruption of comfort and support provided by the underlying chair. Additionally, the backrest region 12 includes a pair of straps 20 mounted from its lateral sides for securing the body massager 10 to the conventional chair. The straps 20 each include one of a hook and loop material for securing the straps 20 about the backrest of the conventional chair. Of course, any engagement mechanism is contemplated, such as a belt buckle, a clip or the like. By way of example, the backrest region 12 has a height of approximately twenty-five inches, an overall width of approximately eighteen inches, and a thickness of approximately two and a half inches. Also, by way of example, the seat support region 14 has a width of approximately sixteen and a half inches, a depth of approximately fourteen and a half inches, and a thickness of approximately one and three quarter inches. Of course, the invention contemplates that the body massager may have dimensions adequate to be received by any conventional chair. However, the dimensions of the preferred embodiment are suitable for most conventional chairs. The seat support region 14 includes a seating surface 22 provided thereon for receiving the user when seated. The backrest region 12 includes a backrest surface 24 for receiving and supporting the back of the user thereupon. The massage assemblies of the backrest region 12 and the seat support region 14 impart the respective massage effects through the backrest surface 24 and seating surface 22 respectively. The cover 16 includes a removable flap 26 mounted to the backrest region 12 along the backrest surface 24. The flap 26 is removably attached by hook and loop material so that the user may remove the flap 26 and expose a woven fabric (not shown). The flexible material of the flap 26 includes dampening characteristics which reduce the massage effect imparted to the backrest surface 24. Accordingly, the user may remove the flap 26 to increase the massage intensity. The body massager further includes a remote 28 connected thereto for controlling the operations of the massager 10. The cover 16 has a pocket 30 mounted to a lateral side of the seat support region 14. The pocket 30 has an opening provided in its rearward end so that the remote 28 may be conveniently retained when not in use. With reference now to FIGS. 2-4, the backrest region 12 is illustrated in greater detail. The backrest region 12 includes a two piece housing provided by an upper housing portion 32 and a lower housing portion 34. The upper housing portion 32 and the lower housing portion 34 are sized and adaptable to be secured together by a plurality of fasteners 36 for retaining components of a massager assembly 38 therein. The massage assembly 38 includes a carriage 40 which cooperates with the lower housing portion 34 for limited longitudinal translation within the backrest region 12. Accordingly, the lower housing portion 34 includes a longitudinal guide 41 mounted therein for cooperating with the carriage 40. The longitudinal direction y is illustrated in FIG. 2 and the housing includes a longitudinal axis yL. The guide 41 includes a series of gibs indicated and referenced as upper gib 42, central gib 44 and lower gib 46. The gibs, 42, 44, 46 of the lower housing portion 34 cooperate with and retain a first longitudinal key 48 formed laterally along the carriage 40. The carriage 40 includes a second longitudinal key 50 formed laterally thereupon in transversely spaced opposition to that of the first key 48. A transverse direction x is illustrated in FIG. 2. The second key 50 is retained relative to the lower housing portion 34 by an elongate retainer gib 52 which is secured to the lower housing portion 34 by a series of fasteners 54. The guide 41 of the lower housing portion 34 further comprises a pair of longitudinal rails 56, 56′ provided within the lower housing portion 34 and extending upward therefrom. A pair of keyways 58, 58′ are formed longitudinally through the carriage 40. The keyways 58,58′ are sized to receive the rails 56, 56′, respectively. The cooperation of the rails 56, 56′ and keyways 58, 58′ provides transverse guidance and support to the carriage 40 as it translates along the guide 41. The carriage 40 includes a plurality of roller bearings 60, which are each pivotally connected to the carriage 48 and are offset from the keyways 58, 58′ and adjacent thereto for engaging a bearing surface provide upon each rail 56, 56′. As the carriage 40 translates along the guide 41, the carriage 40 is bearingly supported by the roller bearings 60 as they engage the surfaces provided by the rails 56, 56′. The lower housing portion 34 includes a series of ribs 62 formed therein for providing cross support to the lower housing portion 34 and the gibs 42, 44, 46, 52. Accordingly, the two piece housing 32, 34 provides both a housing and a structural frame for the massager assembly 38. Both housing portions 32, 34 are each formed from an injection molding process or the like to provide low weight, yet rigid structural members. Additionally, the upper gib 42, central gib 44, lower gib 46 and rails 56, 56′ are integrally formed with the lower housing portion 34 thereby enhancing rigidity and structural cooperation therebetween and minimizing costs in components and assembly. The upper housing portion 32 has a peripheral contour that exceeds the overall dimensions of the lower housing portion 34. This feature is to provide broad lateral support to the user that is distributed directly to the lower housing portion 34. A pair of lateral cushions 64, 64′ are each adhered to lateral undersides of the upper housing portion 32 to provide an overall thickness of the two piece housing that is generally uniform. Additionally, another cushion (not shown) is provided within the cover 16 and attached therein. The cushion is oriented to engage the top side of the upper housing portion 32 about its periphery for providing padded comfort and support to the user as the user rests its back against the backrest surface 24. The cushion is provided within the cover 16 rather than being adhered atop the upper housing portion 32 to permit access to the fasteners 36 that fasten the housing portions 32, 34 together. The massage assembly 38 includes a motor 66, which is mounted to the carriage 40 and retained by a cover plate 68. The cover plate 68 and the carriage 40 collectively define a motor mount for the motor 66 and are fastened together by a plurality of fasteners 70. The motor 66 is operable to impart a massage effect from the massage assembly 38 and translate the carriage 40 along the guide 41 of the lower housing portion 34. The motor 66 includes a motor output shaft 72 extending from the motor 66 and driven thereby. A worm 74 is provided on the motor output shaft 72 and fixed relative to the shaft by a fastener 76. The worm 74 drives a pair of worm gears 78, 78′ in opposed rotational directions. Each worm gear 78, 78′ is secured to a gear shaft 80, 80′ by a fastener 82, 82′. The gear shafts 80, 80′ are each rotatably connected to the carriage 40 and the cover plate 68 so that the worm 74 drives the worm gear 78, 78′ in opposite rotary directions relative one another in a reduced rotation from that of the motor 66. The gear shafts 80, 80′ extend in direction z, which is perpendicular to both the longitudinal direction y and the transverse direction x. Each gear shaft 80, 80′ extends through the cover plate 68 and receives a massage bracket 84, 84′, which are each fastened to the respective gear shaft 80, 80′ by a fastener 86, 86′. The massage brackets 84, 84′ are transversley spaced about the longitudinal axis yL. Each massage bracket 84, 84′ includes a first massage hemispherical node 88, 88′ and a second hemispherical massage node 90, 90′ mounted to the respective bracket. The gear shafts 80, 80′ are oriented perpendicular to the guide 41 and extend in the z direction towards the backrest surface 24. The massage nodes 88, 88′, 90, 90′ each rotate relative to the respective massage bracket 84, 84′ about an axis that is offset from that of the respective gear shaft 80, 80′. The massage nodes 88, 88′, 90, 90′ extend through a corresponding aperture 92, 92′ formed through the housing upper portion 32 for imparting the massage effect to the user through the cover 16. As the massage nodes 88, 88′, 90, 90′ revolve around the corresponding gear shaft 80, 80′ a rotary kneading massage effect is imparted upon the user, which is commonly referred to as a Shiatsu massage. Each massage node 88, 88′, 90, 90′ is rotatably connected to the corresponding massage bracket 84, 84′ to reduce friction generated in the rotary kneading massage effect. Further, each massage node 88, 88′, 90, 90′ is axially translatable relative to the corresponding massage bracket 84, 84′ and is urged to an extended position in the z direction by a spring (not shown) retained between the corresponding massage node 88, 88′, 90, 90′ and the respective massage bracket 84, 84′. The springs cause the massage nodes 88, 88′, 90, 90′ to extend and engage the user, yet permit the respective massage node 88, 88′, 90, 90′ to be urged to a retracted position upon a load provided by the user resting thereagainst thereby enhancing the kneading massage effect by adding axial compliancy to the operation of the rotary massage effect. Additionally, the first massage nodes 88, 88′ have an overall height in the z direction greater than that of the second massage nodes 90, 90′ to extend further from the corresponding massage brackets 84, 84′. The first massage nodes 88, 88′ also have a diameter greater than that of the second massage nodes 90, 90′. These variations are utilized for varying the engagement of the rotary kneading effect with the user, resulting in a kneading effect that is nonsymmetrical and similar to a massage provided by the hands of a skilled massage therapist. The apertures 92, 92′ formed through the upper housing portion 32 are generally elongate for permitting the massage nodes 88, 88′, 90, 90′ to pass therethrough as the carriage 40 is translated relative to the guide 41. Further, the cover plate 68 includes a roller bearing 94 pivotally connected thereto for engaging an underside bearing surface formed within the upper housing portion 32, thus providing bearing support between the carriage 40 and the upper housing portion 32. Accordingly, loading imparted upon the backrest surface 24 is translated through the upper housing portion 32 to the carriage 40 through roller bearing 94, to the lower housing portion 34 through the roller bearings 60 for providing bearing support therebetween and preventing such loading from inhibiting the translation of the carriage 40 along the guide 41. A first pinion gear 96 is mounted upon gear shaft 80′ between the worm gear 78′ and the carriage 40 for being driven by rotation imparted upon the worm gear 78′. A first reduction gear 98 is rotatably mounted upon an intermediate shaft 100 that is supported by the carriage 40 for rotation about an axis in the z direction. A second pinion gear 102 is secured to the first reduction gear 98 and driven by the rotation imparted upon the first reduction gear 98. The second pinion gear 102 is engaged with a second reduction gear 104. The second reduction gear 104 is rotatably coupled to the carriage 40 about a shaft 106, which is supported between the carriage 40 and the cover plate 68 for rotation about an axis in the z direction. A third pinion gear 108 is secured to the second reduction gear 104 and oriented about the shaft 106 between the second reduction gear 104 and the carriage 40. The third pinion gear 108 is engaged to a gear rack 110 formed along the retainer gib 52. The worm 74, worm gear 78′, first pinion gear 96, first reduction gear 98, second pinion gear 102, second reduction gear 104, third pinion gear 108 and gear rack 110 provide a transmission such that rotation from the motor output shaft 72 experiences three stages of reduction for reduced rotation of the third pinion gear 108 relative to the motor output shaft 72 and two stages of reduction relative to the massage nodes 88, 88′, 90, 90′. Since the rack 110 is fixed relative to the guide 41, rotation of the third pinion 108 translates the carriage 40 along the guide 41. Accordingly, the rotation of the motor output shaft 72 results in both a rotary kneading massage effect and translation of the carriage along the guide due to the engagement with the gear rack 110. Due to the translation of the carriage 40 and the motor 66, cord management is necessary to ensure that a power cord 112, which provides power to the motor 66 does not interfere with, nor get damaged by the operations of the massage assembly 38. Accordingly, a longitudinal bar 114 is provided within the backrest region 12 mounted to the lower housing portion 34. The power cord 112 is coiled about the bar 114 for extension and retraction thereabout as the carriage 40 is translated along the guide 41. The motor 66 is directly coupled to the associated transmission for translation of the carriage 40 when the motor 66 is powered. In order to reverse direction of the carriage 40, the rotational direction of the motor 66 is reversed as well. In order to control the reversal of power to the motor 66, a series of limit switches 116a-116f are provided along the guide 41. Each limit switch 116a-116f includes a leaf spring which extends in an unloaded position thereof. Upon actuation of each leaf spring, the respective limit switch 116a-116f sends a signal indicating the actuation. Accordingly, the limit switches 116a-116f are each oriented so that the associated leaf spring extends into the path of travel of the carriage 40 for actuation thereby. The signals provided by the limit switches 116a-116f are processed by a central processing unit provided at a circuit board 118, mounted within the backrest region 12 to the lower housing portion 34 as illustrated in FIG. 3. The user operates the remote 28 to select a desired target range of massage to be imparted to the user's back. The range selected on the remote 28 is processed so that a pair of limit switches 116a-116f provide the range of travel of the carriage 40. For example, if the user selects a range of massage associated with the entire back, the limit switches 116a-116f control this operation. For example, referring to FIG. 3, with the carriage 40 in a position which actuates the limit switch 116a, the motor 66 begins a rotation which provides a rotary kneading massage effect rotating the massage nodes 88, 88′, 90, 90′ and translates the carriage 40 along the guide 41 towards the limit switch 116f. Upon the carriage 40 actuating the limit switch 116f, a signal is sent to the central processing unit, which consequently reverses the rotation of the motor 66. The reversed rotation of the motor 66 provides a reversed rotation of the rotary kneading massage and translates the carriage 40 towards the limit switch 116a. Various ranges of massages are provided by the series of limit switches 116a-116f so that the user may target desired regions of massage upon the back of the user. In order to simplify the manufacture of the backrest region 12, the limit switches 116a-116f are each adhered to the housing lower region 34 by resistance welding, friction welding, adhesives or the like. Briefly, the kneading massage effect is generated from the simplified massage assembly 38 and corresponding support frame and guide 41. Accordingly, the kneading massage effect is provided within the body massager 10 without limiting the portability and weight of the massager 10. Additionally, the motor 66 is provided upon the carriage 40 to overcome short comings of prior art kneading massagers that require either two motors to provide both a massage effect and translation of the massage effect or a complex drive system for providing both effects, which commonly requires a heavy duty frame for supporting the complex drive system. Referring now to FIG. 5, the seat support region 14 is illustrated without the cover 16 and is partially exploded. The seat support region 14 comprises a seat support housing defined by a unitary cushion 120 for providing comfort and resilient support to the user. The cushion 120 includes a pair of vibratory massage assemblies 122, 122′ housed therein. The cushion 120 has a pair of recesses 124, 124′ formed in its underside illustrated in hidden for receiving each of the respective vibratory massage assemblies 122, 122′. Each vibratory massage assembly 122, 122′ includes a motor 126, 126′ for imparting rotary motion to an eccentric weight 128, 128′ for generating an invigorating vibratory massage effect upon the cushion 120, which is received by the user seated thereupon. The vibratory massage assemblies 122, 122′ are spaced transversely apart relative one another to distribute the massage effect upon the cushion 120. Each vibratory massage assembly 122, 122′ includes a bracket 130, 130′ for securing the respective assembly to the underside of the cushion. Specifically, each bracket 130, 130′ may be adhered to the underside of the cushion 120 by an adhesive. Each vibratory massage assembly 122, 122′ includes a motor mount bracket 132, 132′ for securing the respective motor 126, 126′ to the corresponding bracket 130, 130′. The operation of the vibratory massage assemblies 122, 122′ is controlled by the remote 28. Therefore, the vibratory massage effect may be imparted to the user alone or in combination with the rotary kneading massage effect. By way of example, the operation of the vibratory massage assemblies 122, 122′ includes a steady massage, wherein both vibratory massage assemblies 122, 122′ provide a consistent vibratory massage effect to the user. Additionally, a tapping massage effect is provided wherein both vibratory massage assemblies are operated synchronously with a common direction of rotation relative to another so that the user experiences a vibratory massage effect that is generally enhanced rather than merely vibrating. Additionally, a side to side vibratory massage effect is provided wherein each vibratory massage assembly 122, 122′ cycles alternatingly so that the user experiences a vibratory massage effect that is directed from one of the vibratory massage assemblies 122 to the other 122′. The remote 28 provides control of the intensity of the vibratory massage effect such as low, medium and high wherein the intensity is a result of the speed of the motors 126, 126′. In summary, the body massager 10 provides an efficient, portable, lightweight, sturdy massage apparatus which generates two types of massage to two areas of the body with operational variations thereof so that the user may experience a variety of massage effects or a desired targeted massage effect, while minimizing the costs of the overall massager. While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to massagers, particularly to portable body massagers. 2. Background Art The prior art includes body massagers provided within chairs, as well as in portable cushions. These prior art body massagers commonly include a track or guide for moving a massage assembly longitudinally within the chair or cushion. The prior art body massagers are relatively complex and utilize many components, thereby requiring sufficient structure to support the massager and limiting the portability of the massager. Due to the complexities of conventional body massagers, a consumer's ability to procure such massagers is limited due to value and affordability. For example, many prior art body massagers include a complex guide system and frame thereby requiring a housing that is sufficiently robust, such as a chair. Many prior art body massagers require two motors, one for translating the massage mechanism, and the other for imparting the massage effect from the massage mechanism. Accordingly, these drawbacks of the prior art add both cost and weight to the prior art body massagers. A goal of the present invention is to provide a simplified body massager having improvements in massage function, portability and cost in view of the prior art. | <SOH> SUMMARY OF THE INVENTION <EOH>An aspect of the present invention is to provide a body massager comprising a portable housing having an external contact surface for receiving a portion of a body of a user. A longitudinal guide is mounted in the housing; and a carriage is oriented in the housing and cooperating with the guide for limited longitudinal translation. A motor is supported by the carriage or the housing for translating the carriage along the guide. A pair of massage members are supported by the carriage for rotation relative to the carriage. The massage members extend out of the housing through an aperture formed through the body contacting surface for providing a massage effect to the user. Another aspect of the present invention is to provide a portable body massager comprising a longitudinal backrest housing having an external surface sized to receive a back of a user thereon. A longitudinal guide is mounted in the backrest housing. A carriage is oriented in the backrest housing and cooperating with the guide. A motor is supported by one of the carriage and the backrest housing that is operably coupled to the other of the carriage and the backrest housing for translating the carriage along the guide. Massage members are supported by the carriage for rotation relative to the carriage, and extend out of the housing through an aperture formed to the body contacting surface for imparting a massage effect upon the back of the user as the carriage is translated relative to the backrest housing. A seat support housing is sized to seat the user thereon and is pivotally connected to the backrest housing at a longitudinal end of the backrest housing. A massager is oriented within the seat support housing for imparting another massage effect to the user. The above aspects and other aspects, objects, features, and advantages of the present invention are readily apparent from the following detailed description of the preferred embodiment for carrying out the invention when taken in connection with the accompanying brief description of the drawings. | 20040430 | 20061031 | 20051103 | 67041.0 | 1 | THANH, QUANG D | PORTABLE BODY MASSAGER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,115 | ACCEPTED | System and method for flow control in a network | A method for controlling command message flow in a network including a server and a client. A command window, comprising a maximum number of command messages that may be outstanding at the server, is included in messages sent from the server to the client. The value of the command window at the server is modified in accordance with available server resources for receiving command messages. When there are insufficient resources at the server to process one of the command messages delivered to the server, then a pause message is sent to the client indicating which said command message cannot be received; indicia is stored that indicates the command message initially discarded; and subsequent said command messages delivered to the server are discarded until an initially discarded said command message is again delivered to the server. | 1. A method for controlling command message flow in a network including a server and a client comprising the steps of: including a command window, comprising a maximum number of command messages that may be outstanding at the server, in messages sent from the server to the client; modifying the value of the command window at the server in accordance with available server resources for receiving said command messages; sending a plurality of said command messages from the client to the server; when there are insufficient resources at the server to process one of the command messages delivered to the server, then: sending a pause message to the client indicating which said command message cannot be received; storing indicia indicating the command message initially discarded; and discarding subsequent said command messages delivered to the server until an initially discarded said command message is again delivered to the server; ceasing sending said command messages from the client when the number of outstanding said command messages is at least equal to the maximum number of messages indicated by the command window; and when the number of outstanding said command messages is less than the maximum number indicated by the command window, then resuming sending said command messages from the client to the server, starting with the command message initially discarded by the server. 2. The method of claim 1, wherein, after ceasing sending said command messages from the client when the number of outstanding said command messages is at least equal to the maximum number of messages indicated by the command window, the sending of command messages from the client is resumed if the number of outstanding said command messages decreases below the maximum number. 3. The method of claim 1, wherein the command window indicates the maximum number of commands that may be outstanding at the server, for each connection between the client and the server, based upon the availability of resources needed to receive said command messages on a presently established connection, the method including the step of allowing the sum of a plurality of the command windows to exceed the totality of the resources available at the server. 4. The method of claim 1, wherein, when the server sends said pause message, if the command window is larger than a predefined minimum and larger than the number of commands currently outstanding, then the command window is set to the larger of the minimum or the number of commands currently outstanding. 5. The method of claim 1, including the steps of: maintaining for each connection, at the server, a command window request counter, initially set to a predefined initial value; marking as delayed, each said command message that cannot be transmitted by the client because the maximum number of said command messages, as indicated by the command window, are presently outstanding; marking as retransmitted, each said command message that must be retransmitted due to receipt of said pause message; including, in each said command message transmitted, an indication of whether the command message was marked as either delayed or retransmitted; when one of the command messages is received at the server with the indication that it was marked as either delayed or retransmitted, then decrementing the command window request counter by one; and when the command window request counter at the server reaches a value of zero, then resetting the request counter to the initial value; and incrementing the command window value by one, if the command window value is less than a predefined upper limit for the maximum number of said command messages. 6. A method for controlling command message flow in a network including a server and a client comprising the steps of: including a command window, comprising a maximum number of command messages that may be outstanding at the server, in messages sent from the server to the client; modifying the value of the command window at the server in accordance with available server resources for receiving said command messages; when there are insufficient resources at the server to process one of the command messages delivered to the server, then: sending a pause message to the client indicating which said command message cannot be received; storing indicia indicating the command message initially discarded; and discarding subsequent said command messages delivered to the server until an initially discarded said command message is again delivered to the server. 7. The method of claim 6, including: sending a plurality of said command messages from the client to the server; ceasing sending said command messages from the client when the number of outstanding said command messages is at least equal to the maximum number of messages indicated by the command window; and when the number of outstanding command messages is less than the maximum number indicated by the command window, then resuming sending said command messages from the client to the server, starting with the command message initially discarded by the server. 8. The method of claim 6, including the steps of: maintaining for each connection, at the server, a command window request counter, initially set to a predefined initial value; marking as delayed, each said command message that cannot be transmitted by the client because the maximum number of command messages, as indicated by the command window, are presently outstanding; marking as retransmitted, each said command message that must be retransmitted due to receipt of said pause message; including, in each said command message transmitted, an indication of whether the command message was marked as either delayed or retransmitted; when a specific said command message is received at the server with the indication that it was marked as either delayed or retransmitted, then decrementing the command window request counter by one; and when the command window request counter at the server reaches a value of zero, then resetting the request counter to the initial value; and incrementing the command window value by one, if the command window value is less than a predefined upper limit for the maximum number of said command messages. 9. The method of claim 6, wherein the command window indicates the maximum number of commands that may be outstanding at the server, for each connection between the client and the server, based upon the availability of resources needed to receive said command messages on a presently established connection, the method including the step of allowing the sum of a plurality of the command windows to exceed the totality of the resources available at the server. 10. The method of claim 6, wherein, after ceasing sending said command messages from the client when the number of outstanding said command messages is at least equal to the maximum number of messages indicated by the command window, the sending of command messages from the client is resumed if the number of outstanding said command messages decreases below the maximum number. 11. The method of claim 6, wherein, when the server sends said pause message, if the command window is larger than a predefined minimum and larger than the number of commands currently outstanding, then the command window is set to the larger of the minimum or the number of commands currently outstanding. 12. A method for controlling command message flow in a network including a server and a client comprising the steps of: sending a plurality of command messages from the client to the server; receiving, from the server, a message command window, comprising a maximum number of said command messages that may be outstanding at the server, ceasing sending said command messages from the client when the number of outstanding command messages is at least equal to the maximum number of messages indicated by the command window; and when the number of outstanding said command messages is less than the maximum number indicated by the command window, then resuming sending said command messages from the client to the server, starting with the command message initially discarded by the server. 13. The method of claim 12, wherein, after ceasing sending said command messages from the client when the number of outstanding said command messages is at least equal to the maximum number of messages indicated by the command window, the sending of command messages from the client is resumed if the number of outstanding said command messages decreases below the maximum number. 14. The method of claim 12, comprising the steps of: including the command window in messages sent from the server to the client; modifying the value of the command window at the server in accordance with available server resources for receiving said command messages; when there are insufficient resources at the server to process one of the command messages delivered to the server, then: sending a pause message to the client indicating which said command message cannot be received; storing indicia indicating the command message initially discarded; and discarding subsequent said command messages delivered to the server until an initially discarded said command message is again delivered to the server. 15. The method of claim 14, including the steps of: maintaining for each connection, at the server, a command window request counter, initially set to a predefined value; marking as delayed, each said command message that cannot be transmitted by the client because the maximum number of command messages, as indicated by the command window, are presently outstanding; marking as retransmitted, each said command message that must be retransmitted due to receipt of a pause message; including, in each said command message transmitted, an indication of whether the command message was marked as either delayed or retransmitted; when one of the command messages is received at the server with the indication that it was marked as either delayed or retransmitted, then decrementing the command window request counter by one; and when the command window request counter at the server reaches a value of zero, then resetting the request counter to the initial value; and incrementing the command window value by one, if the command window value is less than a predefined upper limit for the maximum number of said command messages. 16. A method for controlling command message flow in a network including a server and a client comprising the steps of: including a command window, comprising a maximum number of command messages that may be outstanding at the server, in each message sent from the server to the client; setting an initial value of the command window via a message from the server to the client during connection establishment therebetween; modifying the value of the command window at the server in accordance with available server resources for receiving said command messages; sending a plurality of said command messages from the client to the server in client command message order until the number of outstanding command messages is equal to the maximum number indicated by the command window; establishing command order at the server based on the order in which said command messages are delivered to the server by the sequenced message transport; when there are insufficient resources at the server to process one of the command messages delivered to the server, then: sending a pause message to the client indicating which said command message cannot be processed; storing indicia indicating the command message initially discarded; and discarding subsequent said command messages delivered to the server until the initially discarded said command message is again delivered to the server; ceasing sending said command messages from the client when the number of outstanding command messages is at least equal to the maximum number of messages indicated by the command window; when the number of outstanding command messages is less than the maximum number indicated by the command window, then resuming sending said command messages from the client to the server, starting with the command message initially discarded by the server, and proceeding to process received command messages in the client command message order; and when the initially discarded said command message is again delivered to the server, then resuming processing of delivered command messages if sufficient server resources are available. 17. The method of claim 16, including the steps of: maintaining for each connection, at the server, a command window request counter, initially set to a predefined initial value; marking as delayed, each said command message that cannot be transmitted by the client because the maximum number of said command messages, as indicated by the command window, are presently outstanding; marking as retransmitted, each said command message that must be retransmitted due to receipt of said pause message; including, in each said command message transmitted, an indication of whether the command message was marked as either delayed or retransmitted; when one of the command messages is received at the server with the indication that it was marked as either delayed or retransmitted, then decrementing the command window request counter by one; and when the command window request counter at the server reaches a value of zero, then resetting the request counter to the initial value; and incrementing the command window value by one, if the command window value is less than a predefined upper limit for the maximum number of said command messages. 18. The method of claim 16, wherein the command window indicates the maximum number of commands that may be outstanding at the server, for each connection between the client and the server, based upon the availability of resources needed to receive said command messages on a presently established connection, the method including the step of allowing the sum of a plurality of the command windows to exceed the totality of the resources available at the server. 19. A system for controlling command message flow in a network including a server and a client comprising: a command window, comprising a maximum number of command messages that may be outstanding at the server, included in each message sent from the server to the client; wherein: an initial value of the command window is set via a message from the server to the client during connection establishment therebetween; the value of the command window at the server is modified in accordance with available server resources for receiving said command messages; a plurality of said command messages are sent from the client to the server in client command message order until the number of outstanding command messages is equal to the maximum number indicated by the command window; command order at the server is established based on the order in which said command messages are delivered to the server by the sequenced message transport; when there are insufficient resources at the server to process one of the command messages delivered to the server, then: a pause message is sent to the client indicating which said command message cannot be processed; indicia is stored indicating the command message initially discarded; and subsequent said command messages delivered to the server are discarded until the initially discarded said command message is again delivered to the server; said command messages from the client cease being sent to the server when the number of outstanding command messages is at least equal to the maximum number of messages indicated by the command window; when the number of outstanding command messages is less than the maximum number indicated by the command window, then resuming sending said command messages from the client to the server, starting with the command message initially discarded by the server, and proceeding to process received command messages in the client command message order; and when the initially discarded said command message is again delivered to the server, then processing of delivered command messages is resumed if sufficient server resources are available. 20. The system of claim 19, including: a command window request counter, maintained at the server, for each connection, and initially set to a predefined value; wherein: each said command message that cannot be transmitted by the client because the maximum number of command messages, as indicated by the command window, are presently outstanding, is marked as delayed; each said command message that must be retransmitted due to receipt of a pause message is marked as retransmitted; an indication of whether the command message was marked as either delayed or retransmitted is included in each said command message transmitted; when one of the command messages is received at the server with the indication that it was marked as either delayed or retransmitted, then the command window request counter is decremented by one; and when the command window request counter at the server reaches a value of zero, then the request counter is reset to the initial value; and the command window value is incremented by one, if the command window value is less than the maximum number of command messages. | RELATED APPLICATIONS This application is related to the following commonly owned and co-filed U.S. patent applications, filed Apr. 30, 2004 and incorporated herein by reference: System For Addressing Network End-Points Using Route Handles, Attorney Docket Number 200209216-1; System For Determining Network Route Quality Using Sequence Numbers, Attorney Docket Number 200209218-1; System For Selecting Routes For Retransmission In A Network, Attorney Docket Number 200209219-1; and System And Method For Message Routing In A Network, Attorney Docket Number 200209220-1. BACKGROUND In a network that employs remote procedure call (RPC) mechanisms, these mechanisms typically use a sequenced message delivery transport (e.g., TCP/IP) to send command and response messages. When a command message is sent to an application by a client, the message arrives at the server and pends in the transport receive queue until the application can receive it. At that point, if the application does not have the necessary resources to complete the requested operation, the command message will languish in the application, consuming receive resources until the remaining resources become available. If no additional receive resources are available that are needed to complete operations already in progress, and the operations already in progress are using all the remaining resources necessary to start the new operation, a deadlock condition exists and no more operations are ever completed. Existing implementations must insure that sufficient resources are available that this resource starvation situation never occurs. This is typically done by dividing the server resources needed to complete commands equally among the connected clients and extending that number of command credits to each client. Clients then limit their number of outstanding commands to their number of command credits. This method is often called pessimistic flow control. Pessimistic flow control works well when a server has a small number of clients or when the rate of command arrival is similar among all clients. However, when a server has a large number of clients and the rate of command arrival varies greatly among clients, then server resource limitations lead to poor network performance because no client is able to keep as many commands outstanding as it needs. SUMMARY A system and method are disclosed for controlling command message flow in a network including a server and a client. A command window, comprising a maximum number of command messages that may be outstanding at the server, is included in messages sent from the server to the client. The value of the command window at the server is modified in accordance with available server resources for receiving command messages. When there are insufficient resources at the server to process one of the command messages delivered to the server, then a pause message is sent to the client indicating which command message cannot be received; indicia is stored that indicates the command message initially discarded; and subsequent command messages delivered to the server are discarded until an initially discarded command message is again delivered to the server. The sending of command messages from the client is ceased when the number of outstanding command messages is equal to or greater than the maximum number of messages indicated by the command window. When the number of outstanding command messages is less than the maximum number indicated by the command window, then the sending command messages from the client to the server is resumed, starting with the command message initially discarded by the server. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing applications, running on end-points, communicating with peer applications via respective ports and Fibre Channel fabrics over a prior art network; FIG. 2 is an exemplary diagram showing the relationship between TCP/IP protocol layering and protocol layering of the present system; FIG. 3 is a diagram showing relationships between exemplary physical components in the present system; FIG. 4 is a diagram showing relationships between exemplary logical objects in the present system; FIG. 5 is a diagram of a route showing half-routes; FIG. 6A is a diagram showing an exemplary relationship between routes and route sets; FIG. 6B is a diagram showing exemplary relationships between a route set management connection, a route set, and application connections; FIG. 6C is an exemplary diagram showing the relationship between a route management connection and pseudo end-points; FIG. 7 is a diagram showing an overview of an exemplary set of steps performed in operation of the present system; FIG. 8 is a diagram showing exemplary steps performed in establishing a path and a route management connection between two ports; FIG. 9 is a diagram showing exemplary steps performed in a full route registration procedure; FIGS. 10A and 10B are flowcharts showing exemplary steps performed in establishing a route set; FIG. 11 is a flowchart illustrating exemplary steps performed in handling a request to establish a connection between end-point applications; FIG. 12A is flowchart illustrating exemplary steps performed in selecting a route for initial transmission; FIG. 12B is flowchart illustrating exemplary steps performed in selecting a route for a retry transmission; FIG. 13 is a diagram showing exemplary steps and queues used in queueing route selection requests; FIG. 14 is a diagram showing an exemplary routing header; FIG. 15 is a diagram illustrating exemplary routing layer processing performed in sending transmissions; FIG. 16 is a diagram illustrating exemplary routing layer processing performed in receiving transmissions; and FIG. 17 is a diagram showing an exemplary routing layer feedback loop used in establishing the transmission rate limit for a particular half route. FIG. 18 is a diagram showing possible relationships between pool buffers in a buffer pool, ports, and application programs; FIG. 19 is a diagram showing an exemplary sequence of transmissions involved in performing command flow control; FIGS. 20A and 20B are flowcharts illustrating exemplary steps performed to implement client command flow-control; FIGS. 21A and 21B are flowcharts illustrating exemplary steps performed in implementing server command flow-control; FIG. 22 is a diagram showing an exemplary request header; FIG. 23 is a flowchart illustrating exemplary steps performed in processing a received request message; and FIG. 24 is a flowchart showing exemplary steps performed in determining initial command window size. DETAILED DESCRIPTION Definitions The following definitions are applicable to the present document: End-point—a locus for execution of applications on a network. End-point Incarnation—the sustained, continuous operation of an end-point without loss of context. Connection—a relationship between two communicating program incarnations, or processes, that is maintained where those processes are running. While the connection is established, the processes may use it to communicate. If either of the communicating processes stops (i.e., fails, exits, etc.) then the connection fails, and if restarted, the programs cannot continue to use the previously existing connection. Within this document, the following examples of connections are described: An application connection is a relationship between two incarnations of an application that is maintained by the end-points where those applications are running and that allows them to communicate reliably. A route set management connection is a relationship between routing layer programs on two end-point incarnations that allows them to communicate route set management information reliably. A route management connection is a relationship between two port layer programs on two port incarnations that allows the reliable communication of route management information. Port—a port comprises all network-specific functionality associated with a specific, single Nx_port (Fibre Channel N_port or NL_port). Also denotes a specific communications protocol layer. Message—A logically contiguous array of bytes sent reliably by the sequenced message transport. A message is sent using one or more transmissions. Transmission—A single-frame Fibre Channel sequence having, at least, a Fibre Channel header, network header, and a routing header. Transmissions are sent on a best-effort basis. Outbound Message—an object that is used to describe a message to be sent. Acronym is OBM. Outbound Sequence—an object that is used to describe a transmission to be sent. Acronym is OBS. Path—a relationship between two port incarnations established by the standard Fibre Channel PLOGI extended link service. Process—an incarnation of the code on a machine that is executing the code. Route—a connection between the processes that represent the two end point incarnations that uses a specific path. A route relates two end-point incarnations and two port incarnations. Half route—the portion of a route that delivers messages in one direction. With respect to an end-point, a half route is either outbound or inbound. A route consists of exactly two half routes. Route set—a relationship between two end-point incarnations that associates the complete set of routes between those incarnations and that indicates the existence (currently, or at some previous time) of one or more routes between the end-points. A route is a member of exactly one route set. A route is established as a member of a specific route set and cannot migrate to any other route set. Termination of a route set terminates all routes belonging to the route set. Introduction FIG. 2 is a diagram showing, as an example, the general correspondence between TCP/IP protocol layering 20 and the protocol layering 200 of the present system. As shown in FIG. 2, each end-point 102 in the present system includes network layer 240, routing layer 230, transport layer 220, request layer 212, and application layer 210 plus a buffer pool management component 270. An API (Application Program Interface) 211 makes network services available to applications 210. Network layer 240 encapsulates one or more ports 103(*) that are local to the network layer's end-point 102 and makes them available to that end-point. In so doing, the network layer 240 hides any physical interface (e.g., a PCI bus) between the end-point 102 and its local ports 103(*). The present system uses a routing layer 230 to effectively glue together the network 240 and transport 220 layers of a networking protocol. Routing layer 230 may be implemented in conjunction with Hewlett-Packard's SCTP (Storage Cluster Transport Protocol), for example. The routing layer 230 provides a routing or steering mechanism to direct outgoing transmissions from a connection onto the proper route, and to direct incoming transmissions (on a particular route) to the proper connection. Transport layer 220 sends and receives messages on connections and provides a sequenced-message delivery service. Request layer 212 provides the command-response service, command flow-control, and the bulk data transfer service. A buffer pool management component 270 manages buffers (not shown) used to receive unsolicited messages directly into application memory. An API (applications programming interface) 211 makes network services available to applications 101 (*). The functionality that is specific to a single port 103 is called the port layer 250. In the present exemplary embodiment, port layer 250 performs the discovery and maintenance of routes, in addition to providing mechanisms for sending and receiving transmissions as described herein. In the present embodiment, each port 103 comprises an ‘Nx_port’, which is a Fibre Channel N_port or NL_port. Each port 103 uses a driver (‘Fibre Channel services’) 260 to abstract the port hardware such that the peculiarities of the Fibre Channel port hardware 261 are hidden from the upper protocol layers. In an exemplary embodiment, an end-point 102 may use several ports 103(*) simultaneously. While the present description is cast in embodiments that are implemented using a Fibre Channel network, the system described herein may also be implemented using other network technologies, such as Ethernet, IP, or the Internet RDMA protocol. As shown in FIG. 2, the application layer 21 in the TCP/IP protocol layering scheme 20 may be considered to correspond to the application and request layers 210/212 of the present system. In the present protocol layering scheme 200, the TCP/IP transport layer 22 is functionally similar to the present transport layer 220; the TCP/IP network layer 24 may be considered to correspond to the combination of the present network layer 240 and port layer 250; and the TCP/IP link layer 25 is effectively implemented within Fibre Channel Services and port hardware layers 260/261. While the TCP/IP protocol does routing within its network layer 24, it does not specifically provide for a distinct formal routing layer. In the present exemplary embodiment, the protocol stack 200 provides a reliable one-way sequenced message delivery service for small messages, a reliable command-response service that uses the sequenced message delivery service to deliver commands and responses, and a reliable, high-performance bulk data transfer service that can be used in conjunction with the reliable command-response service. The transport protocol used to implement transport layer 220 allows two application processes running on end-points 102(*) to establish a connection between them and to use that connection to send one-way sequenced messages. Barring major communication failures, messages sent via the connection are delivered in order and exactly once to the connected process. A command-response service implemented by the request layer 212 (using services provided by the transport layer 220) allows a client process, e.g., application 101(1), to send commands to a server process, e.g., application 101(2), for the server process to return a response to the client process, and for the client and server to perform high-performance bulk data transfers. Commands and responses are sent via a connection established between the client and the server processes, so they are presumed by the request layer to be delivered reliably. As can be seen from FIG. 2, the present system adds a routing layer 230 to an end-point's protocol stack between the transport 220 and network 240 layers. This routing layer 230 is aware of multiple routes and networks to other end-points 102. As described herein, the routing layer 230 organizes the available routes to a given end-point 102(*), measures route quality, and selects the proper route for each outgoing transmission. The present system's transport layer 230 uses different routing layer functions for sending initial transmissions and retry transmissions. This distinction allows the route selection for retry transmissions to differ from route selection for initial transmissions. In addition, transport layer 230 informs the routing layer when a previous transmission may not have arrived in a timely fashion so that the routing layer can avoid the route used by the previous transmission. As an adjunct to the routing process, routing layer 230 monitors the quality of each route. The resulting route quality is used to select routes for outgoing transmissions to avoid routes that are unreliable, congested, or slow. The manner in which the routing layer determines route quality is described in related application; the routing layer's use of route quality measurements and other information to select routes is described herein. Routing layer 230 automatically maintains the routes in a route set (described in detail below), adding newly discovered routes and removing those that have failed. Route Components Physical components governed by the present system include end-points 102(*), ports 103(*), and fabrics 105. Certain relationships between these component objects are summarized in FIG. 3. As shown in FIG. 3, a route 300 comprises a pair of ports, e.g., 103(L,1) and 103(R,j), connected via a fabric 105 through which two end-points, e.g., 102(1) and 102(2), can communicate. In the above figure, there are i*j potential routes 300 between end-point 102(1) and end-point 102(2), j through each port [103(L,1) through 103(L, i)] directly connected to end-point 102(1). One of these routes is shown by the bold line 300. The protocols described herein govern the creation, modification, and deletion of logical objects (structures). These logical objects describe discovered physical ports 103 and end-points 102, and include local port, remote port, local end-point, and remote end-point objects, which are described in detail with reference to FIG. 4. Route, route set, discovered remote end-point, and route management connection objects are used to group and manage instances of these logical objects, as described below. The term ‘local’ is used herein to refer to logical objects that represent physical objects that can be accessed without using Fibre Channel messages. In contrast, the term ‘remote’ is used to refer to objects that are not local. Thus, a remote end-point describes an end-point that can only be accessed across a Fibre Channel, e.g., end-point 102(2) is remote to port 103(L,1), whereas end-point 102(1) is a local end-point relative thereto. FIG. 4 is a diagram showing relationships between exemplary logical component objects (structures) and their location in port memory 420 and end-point memory 421, located in a physical port 103(*) and a physical end-point 102(*), respectively. In the present system, several objects (local port, route, local end-point, and requested remote end-point) are represented by the combination of a master and a proxy. This bifurcation into masters and corresponding proxies allows these objects to be distributed between the port memory/processor and the end-point memory/processor. By maintaining both the masters and proxies, the present system will support either a distributed implementation or a single memory/processor implementation. FIG. 4 is presented at this point to clarify subsequent references made to these system objects throughout this document. A brief description of certain objects shown in FIG. 4 is presented below. Local port objects, comprising local port master 404 and local port proxy 413, describe the state of a directly accessible physical port. Local port objects 404/413 are created automatically at initialization based on physically detected port hardware. Attributes of a local port object describe the physical port hardware and its fabric login state. Remote port object 401 describes the state of a local port's relationship with a physical port that is not directly accessible. Remote port objects 401 are created when they are discovered via Fibre Channel communication. Attributes of the remote port object 401 describe its port ID, port name, a local port through which it can be accessed, and port login state. A local end-point object (e.g., local end-point incarnation master 414 and local end-point incarnation proxy 411) describes the state of a directly accessible end-point. Local end-point incarnation master object 414 is created when it is initialized on that end-point and the local end-point incarnation proxy is created when the local end-point discovers the port. Attributes of the local end-point object include the local end-point's UID (unique identifier) and IID (incarnation identifier). Pseudo local end-point object 402 describes the local end-point for route management connections that is associated with a local port object 404. It is created as a side effect of creating the local port object 404. Likewise, a pseudo remote end-point object 403 is created as a side effect of creating a remote port object 401. Unlike real end-points, pseudo end-points are not addressed by their UIDs; rather, they are addressed by their associated ports during connection establishment and by route handles thereafter. A remote end-point object describes the state of an end-point that is not directly accessible. Discovered remote end-point objects 407 are created when they are discovered through partial route registration, and requested remote end-point master objects 418 are created when a client makes a connect request to a new end-point 102. Requested remote end-point proxy objects 415 are created when either when a client makes a connect request or when a local port 103(L) is discovered. Attributes of the remote end-point include the remote end-point's UID. Attributes of the discovered remote end-point object 407 include references to remote ports that can be used to access the remote end-point. Attributes of the requested remote end-point object (415/418) include references to local end-points that have requested that routes be established to the remote end-point. An end-point incarnation 410/411 is the sustained, continuous operation of an end-point without loss of context. Attributes of an end-point incarnation include its incarnation identifier (IID). The incarnation identifier is assumed unique over all end-point incarnations. Each time an end-point reboots, its old incarnation is destroyed and a new one is created, including a new incarnation identifier. Route management connection object 405 describes a connection that is used to communicate route management information between two pseudo end-points and their corresponding ports. Routing layer connection object 416 is a base class from which a transport layer connection object is derived. Route set object 417 associates the routes from a local end-point incarnation 411 to a remote end-point incarnation 410. Attributes of the route set include a list of routes, a list of clients (connections), and a remote end-point UID and incarnation identifier (IID) (the local end-point is implicit). There are at least two viable route management configurations for the present system. In the first configuration, all local port and end-point objects are stored in a single memory and the processors that implement the local port and end-point methods have a method for synchronizing access to that memory. In the second configuration, the port and end-point objects may be distributed between memory and processors associated with ports 103(*) and end-points 102(*). When the port and end-point objects are distributed, those objects are decomposed into a corresponding master object and its proxies. For example, local end-point incarnation 411 is decomposed into a local end-point incarnation master object 414 in the memory 421 of the end-point 102 and multiple local end-point incarnation proxy objects 412 in the memories 420 of the end-point's local ports 103(L). The local end-point incarnation master 414 is created automatically during the end-point initialization, and the local end-point incarnation proxy 412 is created as a result of end-point registration with a port 103. Similarly, the local port master object 404 is created automatically during port initialization, and the local port proxy object 413 is created during hardware discovery and modified as a result of end-point registration with the port 103. Half Routes Each route 300 comprises two independent, unidirectional, half routes. FIG. 5 is a diagram of a route 300 showing the two component half routes 500(1) and 500(2). From the perspective of an end-point 102(*), one of these components is the outbound half route and the other is the inbound half route. The local end-point's outbound half route is the remote end-point's inbound half route and vice versa. For example, if end-points 102(L) and 102(R) are considered to be the local end-point and remote end-points, respectively, half route 500(1) is the outbound half route for local endpoint 102(L), and half route 500(2) is the inbound half route for local endpoint 102(R). Route Sets FIG. 6A is a diagram showing the relationship between routes 300(*) and a route set 600. A route set 600 specifies the relationship between two end-points 102(*) and catalogs the routes 300(*) between the two end-points. A route set typically contains multiple distinct routes. As shown in FIG. 6A, route set 600 is the set of routes 300(1), 300(2), 300(3), and 300(4) between the two end-points 102(L) and 102(R). A route set 600 thus groups all routes 300 between a local end-point and a remote end-point. Routing layer 230 is responsible for creating, deleting, and maintaining route sets 600. Before application processes on two end-points 102(*) can create a connection, the end-points must first establish a route set between them. A route set 600 may persist while routes are added to or removed from the route set, provided the end-point incarnations 410/411 continue to exist. Route Set Management Connection FIG. 6B is a diagram showing exemplary relationships between a route set management connection (RTSMC) 602, a route set 600, and application connections 601 (1)-601 (3), with application processes P1-P5 running on end-points 102(L) and 102(R) and communicating via application connections 601(1)-601(3) between the processes. A local end-point, e.g., 102(L), creates routes 300, a route set 600, and a route set management connection to a remote end-point, e.g., 102(R), when it finds it necessary to create a first application connection 601(1) with an application on the remote end-point. Route Selection In selecting a route 300 for an outgoing transmission, transport layer 220 implicitly constrains the selection to a route set 600 by specifying a connection on which to send a transmission. Routing layer 230 attempts to select a route 300 from that route set 600 that is reliable, not congested, and fast. When multiple routes 300 appear to be acceptable, then the routing layer 230 distributes traffic among those routes to balance their utilization. Routing layer clients (i.e., transport layer entities) send and receive messages via connections established by the routing layer 230. These connections are base-class connections from which transport layer connections are derived. Routing layer 230 provides functions that clients can use to request and abort connections. A route set management connection 602, is used by the routing layer to manage the routing layer connections established on a route set. Route set management connections 602 are described below in detail with respect to FIGS. 10A, 10B and 10C. Once a routing layer connection is established, the routing layer connection's send and receive functions are available to routing layer clients. Operational Overview FIG. 7 is a diagram showing an exemplary set of high-level operations performed in operation of the present system. Much of the process shown in FIG. 7 is event-driven, and thus the execution of each functional block shown does not occur automatically in response to execution of a previous block in the figure. Configuration Discovery As show in FIG. 7, at step 702, port initialization begins with the fabric login and name server registration as described in the Fibre Channel specification. In order to provide better scaling for the discovery process, the subject protocols allow two classes of Fibre Channel ports 103(*), Class A and Class B. Class A ports register with the fabric name server as two FC4 types, while Class B ports register as only one of these two. In this way, Class A ports autonomously locate all of the Class A and Class B ports by querying the fabric name server for all ports that have registered the FC4 type used by all ports that support the subject protocols. In contrast Class B ports locate only Class A ports by querying only the FC4 type that Class B ports do not register. Class B ports can locate other Class B ports by querying a protocol-specific name server that is implemented by all Class A ports. Once registration is complete, port configuration discovery is performed periodically, at step 705, with each local port 103(*) querying the Fabric name server (logging in if necessary) to discover newly connected ports that have registered the FC4 types used by the ports that support the subject protocols. In the steady state, configuration discovery is performed every 100 seconds, in an exemplary embodiment. However, during startup and whenever there is evidence that the system configuration may have changed, this period is changed, for example, to 10 seconds for 10 periods and then back to 100 seconds. It should be noted that the present system does not require setting the configuration discovery period precisely to the foregoing values. This autonomous configuration discovery must be repeated periodically because fabric name server registrations propagate slowly, configurations change, and state change notifications are not delivered reliably. When repeated periodically, only newly discovered ports 103(*) are processed. This is true because ports that restart or whose IDs change will spontaneously execute portions of autonomous configuration discovery and thus update configuration changes. Port Login Port login is used to establish a shared context between two Fibre Channel ports 103(*). Prior to port login, the ports may only exchange port login transmissions (i.e., PLOGI/PLOGI_ACC transmissions). Successful port login establishes a path between the ports 103(*). Port login is specified by the Fibre Channel specification. Each port maintains a set of remote port objects (structures) 401, each of which describes the relationship between it and another port that it can access via a fabric 105(*). As shown in FIG. 7, at step 710, a port 103(*) creates a path between itself and each remote port 103(*) that it discovered from the Fabric name server. A route management connection 603 (shown in FIG. 6C) is then established between the pseudo end-points 402/403 associated with the ports of a path, at step 715. Route management connection 603 is a sequenced-message connection that provides a one-way sequenced message delivery service used to communicate route management information between two ports 103(*). FIG. 8 is a diagram showing exemplary steps for establishing a path and a route management connection 603 between two ports 103(*), and also for performing a ‘partial route registration’ process. As shown in FIG. 8 (with reference also to FIG. 3), at step 805, local port 103(L) requests that Fibre Channel Services establish a path to remote port 103(R) using a PLOGI transmission. Upon receipt thereof, a path to the remote port 103(R) is established, at step 810, and the remote port responds by sending a PLOGI_ACC transmission to the local port 103(L), at step 815. After receipt of the PLOGI_ACC transmission at the local port, a path from the remote port 103(R) to the local port 103(L) is established, at step 820. At step 825, the local port then uses the Report Node FC-4 Types (RNFT) protocol to learn the set of FC-4 protocols supported by a particular remote port. Receipt of RNFT_ACC from the remote port 103(R) at step 830 indicates that the remote port supports the proper Fibre Channel FC-4 protocol, and causes the local port 103(L) to initiate process login. Route Management Connection Establishment The present system extends every local and remote port object 404/401 by attaching to it a pseudo end-point object 402/403 to provide a terminus for route management connections. FIG. 6C is an exemplary diagram showing the relationship between pseudo end-points 402/403 and a route management connection (RMC) 603. The present process login protocol establishes a route management connection 603 and a route 300 between pseudo end-points 402/403 associated with the ports 103(*) of a path. The route management connection 603 is used to communicate: partial route registration messages, full route registration requests and their responses, and name service queries and their responses. Route management connection 603 behaves slightly differently than other connections. Differences include the following: the two end-points of a route management connection 603 are pseudo-end-points that correspond to ports of a path. the route management connection 603 does not use a route set. Rather, the corresponding path constitutes the sole route used by the route management connection. when a remote Nx_port is implicitly or explicitly logged out, all corresponding route management connections 603 are terminated immediately. The present process login protocol comprises an FC-4 Link Service request (SCPRLI) and an FC-4 Link Service reply (SCPRLI_ACC). The local and remote ports exchange process login protocol transmissions SCPRLI (step 835) and SCPRLI_ACC (step 840) to establish a route management connection 603 between the path's local and remote ports 103(L)/103(R), at step 845. SCPRLI and SCPRLI_ACC correspond to the first two phases of a three-way handshake. Information carried by the SCPRLI/SCPRLI_ACC FC-4 Link Service includes the route management connection's connection identifier (connection ID) and the route's full route handle, which is used to direct messages to a remote end-point 102(*) via a route 300, once established. The first message to be sent on the route management connection is a SCRPR command, at step 850, which completes the three-way handshake and completes establishment of the route management connection 603, at step 855, thus enabling the transmission of messages on the route management connection by the remote port 103(R). More specifically, during process login, a local port 103(L) and a remote port 103(R) perform the steps below to establish a route management connection: (1) On the local port, a route management connection object 405 and pseudo remote end-point object 403 are created that reference the remote port's remote port object 401. (2) On the local port, a route master object 406 is created, and a SCPRLI command is sent to the remote port 103(R), as indicated above. The SCPRLI message contains the inbound full route handle, a connection ID, an initial sequence number, and flags describing the local port 103(L). (3) On the remote port, receipt of a SCPRLI message normally modifies the states of the existing route management connection and route master objects 405/406 to the pseudo remote end-point 403. In the case where SCPRLI is received and those objects do not exist, they are created. Successful completion is signaled by sending a SCPRLI_ACC message containing the remote port's inbound full route handle, a connection ID, an initial sequence number, and flags describing the remote port 103(R). (4) On the local port, receipt of a SCPRLI_ACC message modifies the states of the route management connection and route master objects 405/406 to the pseudo remote end-point 403 and establishes the route management connection 603. Partial Route Registration Register Partial Routes (SCRPR) messages are sent any time there is a change in the set of end-points that are local to a port, to allow end-points 102(*) discover one another. Once process login is complete, a SCRPR message is sent as the first sequenced message on the route management connection 603. The message includes the remote port's inbound full route handle and the connection ID. Each port 103(R)/103(L) uses the route management connection's one-way sequenced message delivery service to supply a list of its local end-points' UIDs and IIDs to the corresponding remote port 103(L)/103(R) using the partial route registration protocol (SCRPR), at steps 850/865. In response, the receiving port creates or modifies a discovered remote end-point object 407 for each listed end-point and registers it in its name server database. Subsequently, an end-point 102(*) local to the receiving port can discover the set of remote end-points 102(*) to which it can communicate via yet-to-be established routes 300 and connections 601. As a side effect of using the route management connection's sequenced message delivery service, each SCRPR message is acknowledged (at steps 860/870); i.e., the route management connection 603 assures that every sequenced message is ACK'd. As shown at step 720 in FIG. 7, one or more routes 300 are established between end-points 102(*) using a full route registration protocol. At step 725, a route set 600 is established between the end-points 102(*). Steps 720 and 725 are described in detail in the immediately following section. Full Route Registration A port 103 uses full route registration protocols to establish and maintain routes 300 between its local end-point incarnations 412 and those remote end-point incarnations 409 that correspond to the logical intersection of discovered remote end-points 407 and requested remote end-points 415. These full route registration protocols include protocols to establish (register) and destroy (deregister) routes 300. Each active route 300 provides a mechanism for delivering transmissions between its two end-points 102(*). Full route registration and deregistration cause the creation and deletion of route objects (route masters 406, route proxies 408, route sets 417, and route set management connections 419). As a side effect, remote end-point incarnation proxy objects 409 may be created and deleted. A remote end-point incarnation proxy object 409 is used to represent the remote end-point incarnation of a full route 300. A remote end-point incarnation may be represented as an attribute of a route master object 406 (described below in detail), but because route master objects are relatively large, it is desirable to share them. Thus, in an exemplary embodiment, a remote end-point incarnation proxy 409 is created whenever a route master's remote end-point incarnation 410 is set to a previously unknown value, and deleted whenever no route master 406 references it. The full route registration protocol comprises sending a Register Full Route message (SCRFR) from a local port 103(L) to a remote port 103(R) and a Register Full Route Response message (SCRFR_RSP) that the remote port returns to the local port. Both the SCRFR and the SCRFR_RSP messages are sent on the route management connection 603 associated with the route's path. FIG. 9 is a diagram showing exemplary steps performed in a full route registration process. As shown in FIG. 9, full route registration is initiated after an end-point 102(L) has expressed a demand for routes to a remote end-point 102(R), at step 905, by issuing a Request Remote End-Point command to a local port 103(*). More specifically, full route registration is triggered either by an end-point 102 issuing a Request Remote End-Point command for an end-point 102 to which a partial route has already been discovered, or by the discovery of a partial route to a remote end-point 102(R) that was previously requested. In the process of establishing a route 300, two ports 103(*) exchange full route handles to use to address messages to the end-points via the route. After full route registration is triggered, the local port 103(L) first checks to see if a route master 406 already exists to the remote end-point incarnation 410 that represents either an established route or a route that is in the process of being established, and if one exists then no further action is taken. Otherwise, a route master 406 is created to track the progress of full route registration and it is linked with the remote end-point incarnation proxy 409 and the route management connection 405. Then, the local port 103(L) changes the route master state to NRO and notifies the local end-point 102(L) that requested the remote end-point 102(R) by sending a New Route Originator (NRO) event, at step 910. The local end-point 102(L) either refuses the new route 300 or approves it and provides the local port 103(L) with the originator's ep_info (end-point information) structure, containing end-point information for the local end-point, to transmit to the remote end-point 102(R). A New Route Originator (NRO) event is generated by the route master object on the port originating the SCRFR to inform the local end-point that a new route to the requested remote end-point 102(R) specified by a remote end-point UID has been discovered through the path specified by the remote port 103(R). When a new route is approved, the local port 103(L) looks up the route master, copies the ep_info and route proxy handle into the route master, and updates the route master state to SCRFR_SENT. The local port then allocates an OBM and uses it to construct a SCRFR message which it sends to the remote port, at step 915 via the route management connection. The SCRFR message conveys the route's local and remote end-point UIDs and IIDs, the originator's ep_info structure generated by the local end-point, and a full route handle that can be used to direct messages from the remote end-point 102(R) to the local end-point 102(L) via the route 300. In the case where the new route is refused, the local port runs down the route master, and no further action is taken. On receipt of the SCRFR message, the remote port 103(R) checks to make sure that the remote end-point 102(R) referenced in the SCRFR message has registered with the port, and if not, an OBM is allocated and prepared with a SCRFR_RSP with BADREP status. Otherwise, the remote port 103(R) creates a route master 406 to track the progress of the full route registration and links it to a remote end-point incarnation proxy 409. If it was not possible to create a route master, then an OBM is allocated and prepared with a SCRFR_RSP with INSRES status to indicate that the remote port has insufficient resources to process the SCRFR. In the case where the route master was created, the remote port 103(R) copies the SCRFR originator's full route handle and ep_info from the SCRFR message into the new route master. In the case where the new route master is the only route master at the remote port that describes this route, the remote port changes the route master's state to NRR and then notifies the remote end-point 102(R) by sending a New Route Responder (NRR) event, at step 917. In the case where the new route master duplicates an existing route master the two ports may be attempting to perform the full route registration protocol concurrently. This will be true if the existing route master is in the SCRFR_SENT state, in which case the UIDs of the route's end-points are compared and the port local to the end-point with the larger UID takes charge by running down the old route master and continuing as before by generating a NRR event at step 917. If the end-point that originated the SCRFR that is being processed has the larger end-point UID, then an OBM is allocated and used to prepare a SCRFR_RSP with DUPLICATE status. Then, if a SCRFR_RSP message was prepared, it is sent on the route management connection and the new route master is run down. The (NRR) event informs the end-point referenced in the SCRFR that a new route 300 to the remote end-point incarnation specified by the remote end-point UID and remote end-point IID (incarnation identifier) is partly established through the path specified by the remote port 103(R). The remote end-point 102(R) either refuses the new route 300, or approves it and provides the port 103(R) with a responder ep_info structure, containing end-point information for the remote end-point 102(R), to transmit to the local end-point 102(L). In either case, the remote port 103(R) sends a SCRFR_RSP message, at step 925, to the local port 102(L) via the route management connection. Refusal causes the SCRFR_RSP status field to be set to REFUSED to indicate that the remote end-point refused the route, and the route's resources are run down. Approval updates the state of the route master 406 to SCRFR_RSP_SENT, sets the SCRFR_RSP status field to SUCCESS, and causes the message to convey the route's local and remote end-point incarnations (UID and IID), the responder's ep_info structure generated by the remote end-point, and a full route handle that can be used to direct messages from the local end-point 102(L) to the remote end-point 102(R) via the route 300. Also in response to receipt of the SCRFR message at step 915, the local port 102(L) sends an ACK 920, either explicitly or piggybacked on the SCRFR_RSP, as part of the route management connection's protocol. Receipt of the SCRFR_RSP with status field SUCCESS sent at step 925 causes the local port 103(L) to record the responder's route handle in the route master 406, change the state of the route master 406 to ACTIVE, and generate a Route Completed Originator (RCO) event at step 927, thus establishing the route at both the local port 103(L) and the local end-point 102(L), at step 930. The Route Completed Originator event informs the end-point that had previously approved the route 300 that the route is now complete and supplies the ep_info provided by the remote end-point. Because full route registration origination is flow controlled on each route management connection, a pending full route registration can now be started. Receipt of the SCRFR_RSP with a status field indicating anything other than SUCCESS causes the local port to run down the route master. In response to receipt of the SCRFR_RSP at step 925, local port 102(L) sends an ACK 933 to remote port 102(R), either explicitly or piggybacked on another available message, as part of the route management connection's protocol. Receipt of that ACK causes the remote port to change the state of the route master 406 from SCRFR_RSP_SENT to ACTIVE and generate a Route Completed Responder (RCR) event at step 935, thus establishing the full route at the remote end-point 102(R) at step 940. More specifically, receipt, by the remote port 103(R), of a SCRFR_RSP ACK (at step 933) or receipt of the first message on the route 300 establishes the route from the local end-point 102(L) to the remote end-point 102(R), at step 940. End-points 102(*) can remove the demand for new routes to a remote end-point by issuing a Derequest Remote End-Point message. A Deregister Full Route protocol is used to terminate a route. The Deregister Full Route process is triggered either by a Delete Route request by one of the route's end-points 102(*) or the failure of one of the route's end-point incarnations 410/411. Route Set and Route Set Management Connection Establishment As shown in FIG. 7, a route set 600 and a route set management connection 602 are established between end-point incarnations 410/411 at steps 725 and 730. Details of these steps are described with respect to FIGS. 10A, 10B and 10C, which are flowcharts showing exemplary steps performed in establishing a route set 600 and a route set management connection 602. Attributes of a route set 600 include a list of connections 601 between processes on the local end-point 102(L) and processes on the remote end-point 102(R) and a list of routes 300 to the remote end-point. A routing layer program running on an end-point 102(*) provides grouping of routes 300 into route sets 600, and uses a route set 600 to find candidate routes 300 to use for transmissions to the routing layer program running on the corresponding remote end-point 1013(*). Route set and route set management connection establishment are driven by the New Route Originator (NRO) 910, New Route Responder (NRR) 917, Route Completed Originator (RCO) 927, and Route Completed Responder (RCR) 935 events that are generated by the ports 103(*) to the end-points 102(*) during full route registration. Thus, route set and route set management connection establishment are done by the end-points 102(*). Ports 103(*) are only involved in that they generate the events and communicate the ep_info data opaquely. As shown in FIG. 10A, at step 1001, the routing layer 230 waits for a New Route Originator (NRO) or New Route Responder (NRR) event. When an NRO or NRR event is detected, a route proxy object 408 is created (at step 1005) that describes the new route 300. The route proxy 408 is described in detail below. If (at step 1007) a new route proxy 408 was not successfully created, then the new route 300 is refused. If a new route proxy 408 was created, then the UID and IID of the route proxy's remote end-point are used to find a corresponding route set among existing route sets 600(*) at step 1010. If a corresponding route set is found, then the new route proxy 408 is grouped with the other route proxies to the same end-point incarnation by attempting to add the route proxy to the found route set 600 at step 1015. If no corresponding route set 600 presently exists, then the local end-point routing layer 230 attempts to create a route set 600 to the remote end-point 102(R) described in the new route event, at step 1012. If (at step 1017) a new route set 600 was successfully created, then the new route proxy is added to that route set at step 1015 as its first member, otherwise the new route 300 is refused, at step 1055. If the attempt to add the new route to the route set 600 (step 1015) failed (test at step 1020) (e.g. the route set was full), the new route proxy 408 is deleted and the new route is refused, at step 1055. If the new route 300 was added in response to an NRR event (at step 1025), then the supplied route index is copied from the supplied ep_info, and the route set management connection (RTSMC) 602 is updated accordingly, at steps 1030 and 1035, respectively. An ep_info structure is then created for the remote end-point 102(*) at step 1040, and processing continues at step 1042, described below. If the new route 300 was added in response to an NRO event, then the route set management connection is updated at step 1027, and an ep_info structure is created for the remote end-point 102(*) at step 1029. When two end-point incarnations 410/411 attempt to establish a route set management connection 602 between them simultaneously, only one RTSMC 602 should be created. When attempted on a single route 300, the SCRFR protocol resolves this conflict and generates a NRR event at only one end-point 102(*). However, when route set management connection establishment is attempted on two separate routes, NRR events will occur at both end-points 102(L)/102(R). To avoid creating two route set management connections 602, end-point UIDs are compared, and only the end-point 102(*) with the higher UID approves the route 300. Note that this UID comparison must be done with the same sense as that done in the SCRFR protocol in order to avoid refusing both attempts to create a route. Thus, at step 1042, if a duplicate route set management connection 602 exists in the requested state and the remote end-point UID has a value which is not greater than the local end-point UID, then the new route proxy 408 is deleted and the new route is refused, at step 1055. Certain event conditions constitute a conflicting route set management connection 602 and thus cause an existing RTSMC 602 to be run down. The corresponding event is then processed as if the existing RTSMC were unknown. Those conditions include the following: A NRR event whose originator and responder end-point UIDs and IIDs match those of an existing route set 600, but whose conn_id_requester does not match the RTSMC's outbound connection_id (field 1408 in the routing header, described below). This implies that a stale RTSMC 602 exists at the responder. A RCO event whose conn_id_acceptor does not match the RTSMCs outbound connection_id. This implies that a stale RTSMC 602 exists at the originator. When one end-point incarnation 410/411 attempts to establish a route set management connection 602 via two routes simultaneously, no special action is needed because both NRR events will reference the same conn_id_requester. An end-point 102 can come up, go down, and then come back up with a new incarnation 410/411 fast enough so that the NRO and NRR events can arrive from the second (new) incarnation before those of the first incarnation. Therefore, both route sets 600 are initially allowed to be established, after which the stale one will fail naturally because it will be unable to deliver messages. When an end-point 102 has a choice of more than one route set 600 to a given end-point destination, preference is given to the last route set to become established. In addition, to accelerate the demise of the stale route set, when an end-point successfully sends a message on a RTSMC 602 and receives a response to that message, then the RTSMC is known to be functioning and any other route sets that exist to other incarnations of that end-point are stale and can be run down. At step 1044, if there is no conflicting established route set management connection 602, then the state of the route proxy 408 is changed to indicate that the corresponding route 300 is in the process of being established, at step 1045. At step 1050, the ep_info structure that was constructed at step 1040 or 1029 (and mentioned in the description of FIG. 9) is passed to the port for transmission to the remote end-point and the route 300 is approved. Included in the ep_info structure are the inbound half route's identifier and the route's local route index (local_route_index), which is the index of the corresponding route proxy 408 in the local route set's route_proxies array (an attribute of the route set object 417, described below). The local route index value is sent to the remote end-point 102(R) during full route registration, where it is used by the remote end-point's routing layer 230 to identify the described route in the routing headers of subsequent messages sent on a particular route set 600. If (at step 1044) there is a conflicting established route set management connection 602, then the new route proxy 408 is deleted at step 1046, the existing route set 600 is run down at step 1048, and an attempt is made to create a route proxy object 408 to describe the new route 300, at step 1005, and the above-described process is repeated. As shown in FIG. 10B, at step 1060, the routing layer 230 waits for a Route Completed Originator (RCO) event or Route Completed Responder (RCR) event. When either an RCO or RCR event is detected, then the corresponding route proxy and route set objects 408/417 are located, at step 1062 as the states of these objects will be changed in response to the RCO/RCR event. If (at step 1063) a Route Completed Originator event was detected, then the supplied route index is recorded from the supplied ep_info structure at step 1066, and the state of the route proxy 408 is changed to active, at step 1067. The route set management connection 602 is then updated accordingly, at step 1068. At this point, the state of the route set management connection 602 may change in response to receiving the RCO event. In the situation wherein the RTSMC 602 is in the ‘requested’ state, and an RCO event is received in conjunction with an unknown connection ID, the state of the RTSMC is changed to established. At step 1069, if there is a conflicting established route set management connection, then the route set is run down, at step 1080, and processing continues at step 1076; otherwise, processing continues at step 1070. If a Route Completed Responder event was detected at step 1063, then the state of the route proxy is changed to active, at step 1064, and the route set management connection is then updated accordingly, at step 1065. Here, the state of the route set management connection 602 may change in response to receiving various events. In the situation wherein the RTSMC 602 is in the ‘accepted’ state, and an RCR event is received, the state of the RTSMC is changed to established. At step 1070, if the route set management connection 602 was successfully established, then a check is made for connections 601 waiting for route sets and their connection establishment process is restarted, at step 1072. If the route set management connection 602 was not successfully established, then step 1072 is skipped. At step 1076, a check is made to see if there are any outbound sequences (OBSs) waiting for an acceptable route and, if so, their route selection process is restarted (see 1325). At step 1078, the ep_info structure is passed to the port for inclusion in the SCRFR_RSP message, as indicated above with respect to FIG. 9. As shown in FIG. 10C, at step 1080, routing layer 230 waits for a Route Deleted event, which is generated to remove a failed route 300 from a route set 600. When the network layer 240 delivers a route deleted event to the routing layer 230, it removes a failed route 300 from a route set 600. In addition, a route set 600 is automatically deleted as a result of events including the following: no connection has existed on the route set 600 for a substantial period, e.g., on the order of an hour. This indicates that there is no demand for the route set; no route has existed within the route set 600 for a substantial period, e.g., on the order of an hour. This indicates the route set cannot be supplied; or no connection exists on the route set 600 and no route exists in the route set. When a Route Deleted event is detected, at step 1082, the corresponding route proxy and route set objects 408/417 are located. At step 1084, the route proxy 408 is removed from the route set 600 and deleted. At step 1086, if the route set 600 is now empty, then (at step 1088) if the route set has no client connections, the route set is deleted, otherwise a timer is started which will delete the route set if no routes 300 are added before the timer expires. If the route set 600 is not empty at step 1086, then Route Deleted event processing terminates, at step 1090. Application Connection Establishment As shown in FIG. 7, a connection 601 between local and remote end-point applications 101 (*) is established at step 735. These application connections are derived from a routing layer connection base class. The aspects of the application connection described in this section are actually those provided by the routing layer connection, and thus only the routing layer connection is described subsequently. As explained above, route set 600 also provides a route set management connection 602 that is used to manage the routing layer connections 601 established on the route set. This includes the communication of Connect Request and Connect Accept messages used to establish the connections as well as the Connect Abort message used to destroy the connections. During routing layer connection establishment, routing layer 230 assigns connection IDs. Once the connection is established, the request layer copies the connection ID into the routing header of each outbound message, and dispatches incoming messages to their proper client based on the connection ID in the received routing header. The routing header (1400) is described in detail with respect to FIG. 14, below. Each routing layer connection 601 is established on a route set 600. The route set 600 defines the set of available routes 300 that can be used by the connection 601. Routing layer 230 relies on the transport layer 220 to send and receive messages on a route set management connection 602. In this role, the routing layer 230 is merely a client making use of transport layer functionality. Thus, the transport layer 220 must allow each connection 601 to have a different client. FIG. 11 is a flowchart illustrating exemplary steps performed in handling a request to establish a connection 601 between end-point applications 101 (*). As described in detail in the present section, the routing layer 230 establishes an application connection 601 with a three-way handshake beginning with a Connect Request message on the route set management connection 602. Receipt of a Connect Accept message completes the handshake at the requester and receipt of either the connect accept ACK or the first message on the routing layer connection 601 completes the handshake at the acceptor. As shown in FIG. 11, at step 1105, when routing layer 230 receives a request to establish a connection 601 to a remote end-point 102(*), the routing layer must first find an established route set 600 to that remote end-point. This is accomplished by a standard software lookup procedure. At step 1110, if no established route set 600 exists, the routing layer will attempt to create a route set 600 by issuing a request remote end-point message to each of the network layer's local ports at step 1120. This triggers an autonomous full route registration process in the network layer's local port, as described above with respect to FIG. 9. From this point on, route establishment and route set establishment are driven by events generated by the network layer 240. At step 1125, a routing layer routine waits for a route set 600 to the requested remote end-point 418 to be established. After the route set 600 and a route set management connection 602 are established to the requested remote end-point 418, then an OBM is allocated by the client wanting to send the message, at step 1130. At step 1110, if an established route set 600 exists to the remote end-point 102(R), then an OBM (outbound message object) is allocated by the client wanting to send the message, at step 1130, and processing continues as described below with respect to step 1135. In the present case, routing layer 230 is the client. An OBM is an object that is shared between the routing layer and its client, and used by the routing layer's client to describe a message that is to be sent by the routing layer. The OBM is passed to the routing layer in various functions that select routes and send messages. In the present case, the routing layer allocates an OBM so that it can send a Connect Request message on a route set management connection. Once the OBM is allocated, the routing layer calls a Make Connect Request virtual function, at step 1135, to allow the routing layer's client to add its information to the Connect Request message being constructed within the OBM, at step 1140. The Connect Request message is then sent on the route set management connection 602 to the remote end-point 102(R), at step 1145. When the Connect Request message is received by routing layer 230 at the remote end-point 102(R), the routing layer delivers it to the transport layer entity to which the message is addressed, at step 1150. The transport (or a higher layer) then determines whether or not a matching Connect Accept message is pending, at step 1155. If there is a pending Connect Accept, then an OBM is allocated by the routing layer, at step 1165, and the routing layer calls a MakeConnectRequest virtual function to allow the routing layer's client to add its information to the Connect Accept message, at step 1170. The Connect Accept message is then sent on the route set management connection 602, at step 1175. If no matching Connect Accept is pending when the Connect Request message arrives at the receiver at the remote end-point 102(R), then the routing layer allocates a OBM and responds with a Connect Reject message, at step 1160. When the Connect Accept message is received, at step 1180, the routing layer application connection 601 becomes established at the requestor, and the routing layer's client is notified with a ConnectRequestDone virtual function associated with the connection. The routing layer application connection 601 becomes established at the acceptor when the ACK to the Connect Accept message is received (step 1185) or the first message is received on the new connection by the remote end-point 102(R) (step 1190). A ConnectAcceptDone virtual function then notifies the routing layer's client that the connection has been successfully established. Route Selection Once a connection, including an application connection 601 or a route set management connection 602, is established between end-points 102(*), the clients of that connection can use it to exchange messages reliably. Each message (e.g., a Connect Request message) is preferably sent via its initial transmission, and retry transmissions are used by the transport layer to assure that messages are delivered reliably in the same manner employed by TCP. In the present system, the transport layer 220 requests that the routing layer 230 send these transmissions and the routing layer selects a route 300 for each transmission and then sends the transmissions via the selected route. The present route selection method is based on the notion of acceptable routes. An acceptable route is one that meets all of the following constraints: the outbound half route 500 is enabled and in the active state; the outbound half route's transmission rate is below its transmission rate limit; and the outbound half route's local port 103(L) has the resources required to send a transmission, including an available outbound sequence (OBS) object, which is the primary object describing a transmission to be sent. As shown in FIG. 7, at step 740, a route 300 between two end-points 102(*) is selected in response to a route selection request. Route selection is done each time the routing layer 230 sends a transmission, which may be the initial transmission of a message, a retry transmission of a message, or an ACK. The route selection process is described in detail with respect to FIGS. 12A and 12B. Before making a route selection request, the routing layer client must first allocate and construct an OBM that describes the outbound message to send, and this OBM must be available for queueing in the case where not acceptable route is available. FIG. 12A is flowchart illustrating an algorithm comprising exemplary high-level steps performed in selecting a route 300 for an initial transmission. As shown in FIG. 12A, when selecting a route for an initial transmission, the last route 300 used within the route set 600 is selected if it is still acceptable (step 1110) and has been used for fewer than some small number of consecutive transmissions CTmax (step 1215). The value of CTmax is selected by the implementer, but is typically approximately 5, and tends to amortize the selection computation over that number of transmissions. At step 1225, a determination is made as to whether there are any acceptable routes 300 in the route set 600. If no acceptable routes are found, then at step 1230, the OBM supplied in the route selection request is queued in the routing layer. If there are a plurality of acceptable routes 300 in the route set 600 that are equally underutilized (step 1235), then a route is selected from these equally underutilized acceptable routes at step 1240, that is next in route set order starting with the last route used; otherwise, the least utilized acceptable route from the route set 600 is selected at step 1245. FIG. 12B is flowchart illustrating exemplary high-level steps performed in selecting a route 300 for a retry transmission. As shown in FIG. 12B, at step 1250, a determination is made as to whether there are any acceptable routes 300 in the route set. If acceptable routes exist, then, at step 1265, the route 300 is selected which is the next acceptable route in route set route order relative to the route used for the previous transmission of the message being retried. This procedure assures that for any given message, all acceptable routes are tried before any are retried. If no acceptable routes 300 exist in the route set 600, then at step 1260, the OBM supplied in the route selection request is queued within the routing layer 230. When a route's state changes such that it may now be acceptable, the route selection algorithm of FIG. 12A/B is executed, and queued route selection requests may complete asynchronously. The passing of time will automatically lower a route's transmission rate below its transmission rate limit and when the other constraints are met, then transmissions will be sent at the route's transmission rate limit. A method of controlling the transmission rate for a given half route 500 is described below with respect to FIG. 17. Queueing FIG. 13 is a diagram showing exemplary steps and queues used in queueing route selection requests. As shown in FIG. 13, when a route selection request is received by the routing layer 230 (FIG. 12A, step 1230, or FIG. 12B, step 1260), a determination is made as to whether any acceptable routes 300 are presently available within the specified route set 600, at step 1305. If an acceptable route 300 exists, then route selection proceeds in accordance with the steps shown in either FIG. 12A or FIG. 12B. When no acceptable routes 300 are available within the specified route set 600, the OBMs supplied in the requests to select routes are queued within the routing layer 230, at step 1315. When a route's state changes such that it may now be acceptable, the route selection algorithm described with respect to FIG. 12A/11B is executed and queued route selection requests may complete asynchronously. Because an acceptable route must have a transmission rate that is below its transmission rate limit, the routing layer is able to control transmission rate using its queueing mechanism. This feature is used to back off transmission rate when a route becomes congested. Each route selection request issued to the routing layer 230 is described by an outbound message (OBM) object that the routing layer may queue. When no acceptable route is available, the request's OBM is placed on one of the following prioritized FIFO queues: 1. A route_proxy.send_specific_route queue 1320 is used to queue requests for which the route has already been determined. Although no route selection is done in this case, route status must be acceptable and an outbound sequence (OBS) must be allocated; these are effectively route selection functions. These requests, for which the route has already been determined, are given highest priority because the delivery of an End_MSE (end multi-sequence exchange) frees resources and because the local resource allocation is constrained. 2. A route_set.send_retry_sfe queue 1321 is used to queue route selection requests for retry SFEs (single frame exchanges). These requests are given second highest priority because they indicate that connection message delivery is probably stalled at the remote end-point. 3. A route_set.send_initial_sfe queue 1322 is used to queue route selection requests for sends of initial SFEs. These requests are given third highest priority because they will stall the connection's message transmission unless satisfied. 4. A route_set.send_start_mse queue 1323 is used to queue route selection requests for Start_MSEs (start multi-sequence exchanges). When a route's state changes such that it may now be acceptable (step 1325), the route selection algorithm of FIG. 11A/11B is executed with the OBMs at the heads of these queues for the corresponding route proxy 408 and route set 600 in the priority order listed above, at step 1330. If the route selection algorithm indicates that a route 300 is acceptable for an OBM, the OBM is dequeued. Then an OBS is allocated from the route's local port 103(L), and after the OBS is prepared it is transmitted via the local port 103(L). When the route selection algorithm determines that a route 300 is unacceptable because no OBS is available on the route's local port 102(L), the corresponding route set 600 is queued to the local port. When an OBS becomes available on that local port, route sets 600(*) are dequeued and their route selection algorithm is run until one consumes the available OBS. Because a route set 600 may need to be queued to several local ports 103(*) simultaneously, the unacceptable route's route proxy 408, instead of the route set, is queued to the local port 103(L). Instead of dequeueing a route set 600, a route proxy 408 is dequeued along with all other route proxies in that route's route set 600 that use the same local port 103(L). Route Order The two end-points 102(*) of a route set 600 each determine an order for the routes 300 in the route set. There are several reasons for route ordering. First, when a route 300 becomes unacceptable, it is desirable to quickly select a next route from the same route set that is largely independent of the old route. Since route independence is relatively static, a next route can be predetermined for each route. In addition, when a series of two or more routes becomes unacceptable, it is desirable to quickly select a next route from the same route set that is largely independent of each route in the series of unacceptable routes. All routes of a route set may be placed in a circular queue to facilitate this route selection. Each end-point 102(*) determines route order independently, using locally available information, and then communicates that order to the corresponding remote end-point. The remotely determined route order is used to select the next route for transmission because it may include information about route independence that is not available locally. When a new route 300 is added to a route set 600 or removed from a route set, the route set's route order changes and the new route order is communicated via a route set management connection message. While changes in route set order may cause transient anomalies in route selection, these anomalies do not cause incorrect network behavior and should disappear quickly. Route Order Report (ROR) messages are sent on the route set management connection 602 to communicate a route set's locally determined route order to the remote end-point 102(R). The ROR is a one-way sequenced message that includes a count field indicating the number of routes 300 in a route set 600 and an array containing an ordered list of the sender's remote_route_index values of the routes in the sender's local route set route order. The remote_route_index comprises indicia of the remote route proxy 408 for a given route 300 in the remote route set object's route_proxies array. Route order determination is not architecturally constrained, because it does not affect correctness of operation. However, route order can have a significant effect on performance. In general, successive routes 300 in a route set 600 should share as few common components or resources as possible. This is desirable in error recovery, to maximize chances of a retry succeeding. It is also desirable for load balancing, where the goal is to spread the load as uniformly as possible across the available components. The manner in which the route ordering is determined is described in a related application. Routing Header All routing layer transmissions include a routing header 1400. The routing layer 230 uses information in the routing header 1400 to monitor transmissions on each half route 500 to determine the half route's quality, by determining whether a half route is delivering transmissions promptly, has lost recent transmissions, or is experiencing delay. Inbound half route quality is computed at the receiving routing layer and converted to a transmission rate limit, which is communicated back to the transmitting routing layer in the routing header where it is used by a route selection algorithm (e.g., the algorithm of FIGS. 12A/B) to choose the best route 300 of a route set 600 for sending future transmissions. Finally, the routing header contains the routing layer connection's connection_id that was discussed in reference to FIG. 11. In an alternative embodiment, the routing layer places information into the routing header of each transmission sent on a route set that describes multiple (or even all) routes of that route set. However, the result is expensive both in transmission header efficiency and processing time to send and receive the transmission. In an exemplary embodiment, the routing layer 230 places monitoring information that describes a single route of the route set in the routing header 1400 of each transmission sent on that route set 600, and in the steady state, the single route described is rotated among the routes of that route set in a round-robin fashion. Thus, the described route may differ from the route used to send the transmission. For a given transmission, the route 300 described in the routing header 1400 is called the described route (DR). In contrast, the route 300 on which the transmission is sent and received is called the receive route (RR). Routing header 1400 includes the following information about the described route: the DR's index, which uniquely identifies the DR to the receiver; the RSN of the last transmission sent on the outbound half DR; the time since the last transmission was sent on the outbound half DR; information that signals that the transmission rate limit (TRL) should be reset on the receiver's inbound half DR; and the computed TRL for the transmitter's inbound half DR. In an exemplary embodiment, the routing header 1400 contains the following fields, which are transmitted in the order listed. All fields except the connection ID describe a route in the route set known as the described route or DR. These fields are organized within an exemplary routing header as shown in FIG. 14, and described below. dr_index_key This 2-bit field (‘key’ 1401 in FIG. 14) is a key that is used to validate the dr_index field at the receiver. Its value is determined by the receiver and is communicated to the transmitter during full route registration. When a transmission is received in which this value does not match the expected value then the described route information in the transmission is ignored. dr_tre This 2-bit field (‘tre’ 1402 in FIG. 14) specifies the transmitter's route epoch for the outbound half DR. The receiver compares this value to the last dr_tre value received for the inbound half DR. If it differs, the receiver resets the inbound half DR's transmit rate limit to one transmission per E_D_TOV (defined in FC-FLA V2.7). dr_rre This 2-bit field (‘rre’ 1403 in FIG. 14) is a copy of the last dr_tre received by the transmitter for its inbound half DR. When this field equals the receiver's outbound half DR route epoch, then the local end-point knows that the remote end-point has received its last route epoch update for the DR. dr_tric This 8-bit field 1404 is a compressed form of the transmit rate Limit (TRL) computed by the transmitter for its inbound half DR. This value is used by the receiver to limit the transmit rate of its outbound half DR. dr_itt This field 1405 contains an 11-bit unsigned integer representing the number of milliseconds that have elapsed since the last transmission on the transmitter's outbound half DR. If the elapsed time exceeds 2047 milliseconds, then this field contains a value of 2047. dr_index This field 1406 contains a 5-bit unsigned integer representing the index of the inbound half DR at the receiver. This index is supplied to the transmitter during full route registration. The receiver uses this value to determine which inbound half route is being described. dr_rsn This field 1407 contains a 32-bit unsigned integer representing the routing sequence number of the transmitters outbound half DR. This value is the number of transmissions sent on the route since it was established, modulo 232. connection_id This field 1408 contains the 32-bit outbound connection ID of the connection on which the message is being sent. The receiver uses this value as an inbound connection ID to find the destination connection. End-points 102(*) monitor the quality of each inbound half route 500 using data supplied by the remote end-point 102(R) via the routing header 1400. The receiving end-point combines all said data into a single metric called the transmission rate limit (TRL). The TRL is indicative of whether a half route is delivering transmissions promptly, has lost recent transmissions, or is experiencing delay. Each TRL computed by the receiving end-point is fed back to the transmitting end-point via a field in the routing header 1400, which, in one embodiment, is sent in compressed form as the dr_trlc field 1404. At the transmitter, the TRL is used to place an upper bound on the rate of transmissions issued on the outbound half route 500 and by a route selection algorithm (e.g., the algorithm of FIGS. 12A/B) to choose the best route 300 of a route set 600 for sending future transmissions. In this capacity, the ratio TR/TRL is used to determine whether a route is acceptable and as a measure of route utilization. These processes are described below in detail with respect to FIGS. 12 and 17. Send Processing FIGS. 15A and 15B are diagrams illustrating exemplary routing layer processing performed in sending transmissions. The routing layer client sends a transmission via a routing layer connection in two phases. First, the routing layer client selects a route 300, and then the routing layer client sends the transmission on that route. The routing layer provides separate procedures for selecting and sending the initial transmission of a message, shown in FIG. 15A, and for selecting and sending retry transmissions of a message, shown in FIG. 15B. As shown in FIG. 15A, the route selection phase for an initial transmission begins at step 1502, in which the routing layer client supplies a reference to the routing layer connection and a outbound message (OBM) structure that describes the message to be transmitted. At step 1505, the routing layer connection state is validated as suitable for sending transmissions, i.e., the connection state must be established. At step 1508, a route is selected for an initial transmission as described in FIG. 12A, queueing for an acceptable route if necessary as described in FIG. 13. Once route selection completes, the routing layer must check to see that a route was indeed selected at step 1511, because it is possible, for example, that the route set failed while the OBM was queued for an acceptable route. In the case where a route was selected, an outbound sequence (OBS) structure must be allocated from the route's local port for describing the transmission at step 1514, and linked to the OBM. The selected route is recorded in that OBS at step 1517, and the selected route is recorded in the OBM as the last route tried for transmissions of the message described therein at step 1520. Finally, at step 1523, the routing layers estimate of the selected route's outbound half route transmission rate is updated and control is returned to the routing layer client at step 1526. Before the routing layer client requests that the routing layer send the initial transmission at step 1529, the routing layer client may update its connection state. For example, the routing layer client might start a timer that triggers a retry transmission if the initial transmission is not acknowledged before the timer expires. When the routing layer client does request that the initial transmission be sent, the routing layer starts by initializing the OBS that was previously linked to the OBM at step 1514. At step 1532, the route's route master handle is inserted in the OBS so that when the OBS is passed into the port layer then the port layer can rapidly find the outbound route. At step 1535, a scatter-gather list (SGL) is copied to the OBS that describes the OBM buffer that holds the transmission's routing, transport, and request layer headers plus the application payload buffer. Thus, the port can transmit all of this data directly from the end-point's buffers without having to first copy it into a contiguous buffer. At step 1538, the described route (DR) is selected, and the routing header described route fields are filled in using data from the selected described route. Next, the routing header's connection ID 1408 is filled in using data from the routing layer connection, at step 1541. The receive route (RR) is then updated by incrementing its RSN at step 1544. Next, the network layer 240 is used to send the transmission via the selected route's local port 103(L), at step 1547. Once the network layer completes its attempt to send the transmission, the status is checked. In the case where the network layer was unable to successfully send the transmission, then the receive route (RR) is updated at step 1550 to indicate that it is seriously congested. Regardless of the send completion status, the OBS is unlinked from the OBM and de-allocated at step 1553 and control is returned to the routing layer client. As shown in FIG. 15B, the route selection phase for a retry transmission begins at step 1564 in which the routing layer client supplies a reference to the routing layer connection and a outbound message (OBM) structure that describes the message to be retransmitted. At step 1567, the routing layer connection state is validated as suitable for sending transmissions, i.e., the connection state must be established. Because this is a retry transmission, it is very likely that the previous transmission of this message failed, thus at step 1570 the TRL of the half route indicated by the OBM's last route tried (set in step 1520) is decreased and the half route's significant event flag is set. At step 1573, a route is selected for a retry transmission as described in FIG. 12B, queueing for an acceptable route if necessary as described in FIG. 13. Once route selection completes the route selection phase for a retry, transmission continues, and the steps shown in bracket 1580 are performed exactly as corresponding steps 1511-1523 (described with respect to FIG. 15A) for an initial transmission. The send transmission phase for a retry transmission begins at step 1587. The routing layer starts by initializing the last OBS that was linked to the OBM. At step 1590, the route's route master handle is inserted in the OBS so that when the OBS is passed into the port layer then the port layer can rapidly find the outbound route. At step 1593, a scatter-gather list (SGL) is copied to the OBS that describes the buffer that holds the transmission's routing, transport, and request layer headers plus the application payload buffer. In contrast to the initial transmission, the SGL for the retry transmission describes a buffer for the headers that is in the OBS instead of the OBM, and the request and transport headers are copied from the OBM to the OBS in step 1596. This allows the routing layer to modify the routing header without risking modifying said header of the initial transmission of the message which may not be complete at the time of the retransmission. Once the header copy completes the send transmission phase for a retry, transmission continues, and the steps shown in bracket 1598 are performed exactly as corresponding steps 1538-1556 (described with respect to FIG. 15A) for an initial transmission. Receive Processing FIG. 16 is a diagram illustrating exemplary routing layer processing performed in receiving transmissions. As shown in FIG. 16, the routing layer performs the following exemplary steps with respect to each received transmission. Initially, at step 1605, context is established from a pool buffer descriptor, which includes indicia of the route over which the transmission was received, and information supplied by the receiving port about how the transmission was received. In an exemplary embodiment of the present system, communicating applications 101 (*) create buffer pools, containing pool buffers, to directly receive messages bound for them. When an application 101 requests or accepts a connection 601, it specifies the buffer pool into which messages received on that connection should be stored. In an exemplary embodiment, end-point memory 421 is used for the buffer pools, as applications 101 are executed in that memory space. However, when a pool buffer (i.e., a buffer within the buffer pool) is posted for receive, a description of that buffer is passed to the associated port 103 and that memory becomes shared between the end-point 102 and the port until the pool buffer is consumed. This allows the port to receive a transmission directly into the pool buffer without the need to copy the data from the port memory 420 to end-point memory 421. Given the route over which the transmission was actually received, the routing layer is able to determine the corresponding RR and the route set 600 at step 1605. The DR is determined at step 1608 from the route set itself and dr_index 1406 and dr_index_key 1401 (in the routing header). At step 1610, the route set, DR, RR, and the routing header data are used to compute a new transmission rate limit (TRL) for the inbound half DR. Next, at step 1615, the transmission rate limit (TRL) for the outbound half DR is updated using the dr_trlc 1404 that was fed back from the other end-point via the routing header. Since updating this TRL may have caused the DR to become acceptable, a check is made for OBMs queued for route selection. Then, at step 1618, the reception rate estimate, round-trip-time estimate, inbound TRL, and expected RSN for RR are updated. The destination routing layer connection whose inbound connection ID matches connection_id 1408 (in the routing header) is then located, at step 1620. At step 1623, if the destination routing layer connection is in the accepted state then transition the routing layer connection to the established state and run down any existing route sets to other incarnations of the same remote end-point. At step 1625, if the destination routing layer connection state is suitable for receiving transmissions (e.g., established), then the transmission is delivered to the routing layer connection's client at step 1630 by passing the pool buffer descriptor to it; otherwise, the transmission is discarded, at step 1635 by returning the pool buffer descriptor to its buffer pool. Route Monitoring The routing layer 230 monitors transmissions on each half route 500(*) to determine the half route's quality. Routing layer 230 determines whether a half route 500 is delivering transmissions promptly, has lost recent transmissions, or is experiencing delay. This route quality information is used by a route selection algorithm (e.g., the algorithm of FIGS. 12A/B) to choose the best route 300 of a route set 600 for sending future transmissions. More specifically, routing layer 230 monitors the quality of each inbound half route 500 using data supplied by the remote end-point's routing layer via the routing header that is included in each transmission. All half route quality information is combined into a single metric called the transmission rate limit (TRL) (See step 1610, FIG. 16). The TRL is computed by the receiving end-point's routing layer and is fed back to the transmitting end-point where it is used by the routing layer to place an upper bound on the rate of transmissions issued on the outbound half route. When not limiting, the rate of transmissions divided by TRL indicates the degree of outbound half route underutilization, a metric the routing layer uses to select a route for an initial transmission. FIG. 17 is a diagram showing an exemplary routing layer feedback loop 1710/1715/1720/1725 that is executed to control the transmission rate for each half route 500 and to supply route quality information to be used by the transmitting routing layer for route selection. In operation, transmissions 1710 are sent from transmitting end-point 102(1) via outbound half route 500 to receiving end-point 102(2). The routing layer at end-point 102(2) monitors the quality of each inbound half route 500 using data supplied by a transmitting end-point 102(1) via the routing header 1400 of each received transmission 1710. In an exemplary embodiment, all half route quality information is combined by the receiving routing layer at block 1715 (see step 1610, FIG. 16) to establish a transmission rate limit (TRL) 1404. Transmission rate limit determination is described in detail in a related application. After TRL 1404 is computed by the receiving end-point 102(2), it is fed back to the transmitting end-point in the dr_trlc field of the routing header 1400, via the next message 1720 that describes that half route 500, where it is used by the routing layer to place an upper bound on the rate of transmissions issued on the outbound half route 500. In an exemplary embodiment, a routing layer program 1703 continually determines a current value for the transmission rate (TR) 1701 on each outbound half route by passing a sequence of inter-transmission times through a low-pass digital filter and inverting the result (see step 1523, FIG. 15A). Block 1725 functions as a limiter in which the transmitting end-point 102(1) compares the current value for TR 1701 with the value of TRL 1404 fed back from the remote end-point 102(2) to determine whether to send the next transmission on that outbound half route or another route within the route set, or to delay it. When the current TR 1701 is no greater than TRL 1404, the transmission is sent without imposition of a delay. In an exemplary embodiment, when the current TR 1701 exceeds TRL 1404, no transmissions will be sent on the outbound half route 500(1) because the route will not be acceptable and thus not selected (see FIG. 12). However, the next transmission may be sent on another route of the route set without delay if another route is acceptable. In the case where no route of the route set is acceptable, the OBM is queued as described in FIG. 13, at step 1315. As time passes, the intertransmission time will increase and thus the transmission rate 1701 of an unacceptable route will decrease until it reaches a value that is equal to or less than the present TRL 1404, at which time the route will become acceptable again. This mechanism effectively limits the transmission rate to be no greater than TRL. To avoid continually computing a half route's transmission rate when its transmission rate exceeds its transmission rate limit, a timer is started whose expiration time is computed to be the time when TR will equal TRL. When the timer expires, TR is updated. Then, if the route is acceptable and OBMs are waiting, route selection is triggered, as described above with respect to FIGS. 12A/B and 13. When not limiting, the transmission rate 1701 divided by the transmission rate limit 1404 indicates the degree of outbound half route underutilization. This metric is used by initial route selection at step 1245, in FIG. 12. In the case where an end-point 102(*) detects a serious problem with an outbound half route, a mechanism is provided for communicating that event to a corresponding remote end-point 102(R). For example, if a transmission sent to the network layer 240 times out because the network layer detects so much congestion on the network that it cannot send the transmission within E_D_TOV (see FIG. 15A, step 1550), this mechanism allows the transmitting end-point to request that the remote end-point 102(R) set the inbound half route's TRL 1702 to one transmission per E_D_TOV. Routing Sequence Numbers The routing layer 230 counts transmissions sent on each outbound half route 500 from the time the full route 300 was established. These counts are called routing sequence numbers (RSNs) and they facilitate monitoring half routes 500. Each transmission on a route set 600 is uniquely identified by the route 300 on which it is sent, its direction or sending end-point 102, and its routing sequence number. The sending end-point 102 knows this information for each transmission. In an alternative embodiment, each transmission includes its own RSN (i.e. the RSN of the outbound half route on which the transmission was sent), which allows both sending and receiving end-points 102 to share knowledge of each transmission's unique identity. In particular, upon receiving a transmission, the end-point 102 can readily determine whether any previous transmissions sent on the same route 300 are missing by comparing the RSN just received to the highest RSN previously received. The above concept may be extended across routes 300 in a route set 600. In an alternative embodiment, each transmission describes not just its own RSN, but the RSN for every outbound half route 500 in the route set 600. These RSNs identify the most recent transmission sent on each outbound half route 500. Together the RSNs identify all transmissions that have been sent in a particular direction on the route set 600 prior to the subject transmission. For each transmission that it receives, a receiving end-point 102 determines which prior transmissions it has received (on all routes of the route set) and which are missing. The receiving end-point 102 cannot always distinguish a missing transmission as lost or delayed; both are transmissions that the receiving end-point 102 expects to receive but has not received. However, because Fibre Channel fabrics (and communication fabrics in general) are unlikely to deliver transmissions out of order when sent via a single route 300, the receiving end-point 102 can use the manner in which it learned of a missing transmission to distinguish those that were probably lost from those that were probably delayed. When evidence of a missing transmission is obtained on the same route 300 as the missing transmission, then the transmission is probably lost. For example, suppose an end-point 102 had received all transmissions through RSN N on route A, and then received RSN N+5 on the same route. The end-point may then conclude that the four transmissions RSN N+1 through RSN N+4 were probably lost. When evidence of a missing transmission is obtained on a different route 300 than the missing transmission, then the transmission is first considered probably delayed, and then after a period of time equal to R_A_TOV, it is considered lost. For example, suppose an end-point 102 has received all transmissions through RSN N on route A, and then received a transmission on route B specifying that the most recent RSN sent on route A was N+10. In this case, the receiving end-point may initially conclude that the ten transmissions N+1 through N+10 are probably delayed. If the end-point next received transmission N+5 on route A, it would then conclude that the four transmissions N+1 through N+4 were probably lost, the transmission N+5 was certainly delayed, and the five transmissions N+6 through N+10 are probably still be delayed. If no further transmissions are received on route A for R_A_TOV, the end-point may then conclude that transmissions N+6 through N+10 are certainly lost. As each transmission is received, the receiving end-point 102 compares an RSN included in the transmission with that expected for the corresponding inbound half route 500. Thus, the end-point must store an expected RSN for each inbound half route. If it were not for lost transmissions, the expected RSN would simply be the count of transmissions received on the inbound half route 500. However, because transmissions may be lost, the expected RSN is estimated using the following procedure. When a transmission is received that includes the RSN of the half route 500 on which the transmission was sent, the inbound half route's expected RSN is updated: If the received RSN is greater than or equal to the inbound half route's expected RSN, the inbound half route's expected RSN is set to one higher than the received RSN. Otherwise, the transmission must have been received out of order and the expected RSN is left unchanged. Because out-of-order delivery on a single route 300 is unlikely, it is not necessary to include, in every transmission, the RSN of the half route 500 on which the transmission is sent. When a transmission is received that does not include the RSN of the half route 500 on which it was sent, the receiver simply increments the inbound half route's expected RSN. Furthermore, because changes in route quality tend to occur infrequently, it is not necessary to include, in every transmission, the RSN of every other outbound half route of the receive route's (RR) route set. In an exemplary embodiment, each transmission sent on outbound route RR includes the RSN of one of the outbound routes, the described route (DR), of the receive route's route set, and the described route is rotated among the routes of the route set. Significant Events Most events that cause changes in half route quality metrics are known as significant events. When a significant event occurs, it becomes desirable to describe the affected route 300 to the remote end-point promptly. Normally, the routes 300 in a route set 600 are described in round-robin order, but following a significant event, the corresponding route is given a higher priority for being described. This is done with a significant_event flag (an attribute of the route proxy object 408) that is set when a significant event occurs on that route 300 and which is cleared when the route is described. The following events are considered to be significant events: The routing layer client indicates that an ACK response timeout occurred on a route 300. In response, the outbound half route's transmission rate limit (TRL) is reduced by half and its significant_event flag is set. Because the ACK may have been sent on any route, the routing layer 230 cannot conclude with certainty that the indicated half route 500 has lost or delayed any transmissions. By changing the outbound half route's TRL, the local end-point 102(L) is immediately discouraged from using that route further, but when the remote end-point 102(R) provides an updated TRL, this change will be dismissed, since the remote end-point has more definitive quality data about the outbound half route 500. Any time the outbound half route 500 selected for an initial transmission differs from the route set's last_rtp. The value for last_rtp indicates the route proxy 408 of the last route 300 that was used to send a transmission on this route set 600; this value is included as a field in the route set object 417, described in detail below. In response, the significant_event flags are set for the selected route 300 and last_rtp, and last_rtp is updated to be the selected route. This is done to describe changes that motivated selecting a new route 300 and to assure that routes describe themselves frequently. Any time the outbound half route 500 selected for a retry transmission differs from the route set's last_rtp. In response, the significant_event flag is set for last_rtp and last_rtp is updated to be the selected route 300. The significant event flag is not set for the selected route so that the route used for the previous try will be described as soon as possible. Any time a half-route's local port changes state, the significant_event flags for all associated outbound half routes are set. In addition, when a local port changes state from link-up to link-down, the TRLs for all associated half-routes are set to zero, and when a local port changes state from link-down to link-up, the TRLs for all associated half routes are set to their default values. Route Master/Proxy Objects The combination of the route master object 406 and the route proxy object 408 describes the state of a route 300 from the local end-point incarnation 411 to a remote end-point incarnation 410. The route master object 406 describes the portion of the route that is important to the local port 103(L) including the associated route management connection 603 [which implies the remote port 103(R)], the full route handle, references to the local and remote end-point incarnations 411/410, state, and a reference to the corresponding route proxy 408. The route proxy object 408 describes the portion of the route that is important to the end-point 102 including a reference to the route's route set 600, the route's index within the route set, the route's order within the route set, the routing sequence number for the outbound half route, the transmission rate limit for the outbound half route, information used to measure the quality of the inbound half route, state, and a reference to the corresponding route master object 406. Route Master Object Each port 103 maintains route master objects 406, each of which describes a relationship between a local end-point incarnation 411, a remote end-point incarnation 410, a remote port 103(R), and (by implication) the local port 103(L). A route master object 406 is created whenever a port 103(*) discovers a unique route 300 between a requested remote end-point 415 and one of the requested remote end-point's local end-point incarnation proxies 412. This may occur because either a new partial route is discovered to an existing requested remote end-point 415, or a local end-point incarnation 411 issues a request remote end-point message to an end-point 102 for which a partial route already exists. A route master object 406 is also created whenever a port 103 receives a Register Full Routes (SCRFR) message. A route master object 406 is deleted whenever any of its references become invalid, which may occur in the following cases: The associated path becomes invalid because either the remote port 103(R) is implicitly logged out (i.e., becomes not usable) or the associated route management connection 603 fails, or a SCRPR arrived on that path that omitted the route master's remote end-point incarnation 410. The associated local end-point incarnation proxy 412 is deleted because the local end-point 102(L) either deregistered or reregistered. The associated route proxy 408 is explicitly deleted. A route master object 406 is also deleted whenever a route 300 is deregistered via SCDFR. Finally, incomplete route master objects 406 are deleted when SCRFR is rejected via a SCRFR_RSP and when the new route event is refused. Exemplary attributes associated with a route master object 406 include the following: full_route_handle The full route handle received in the SCRFR or SCRFR_RSP message used to establish this route 300. It is used to direct messages to the remote end-point 102(R) via the route. local_end_point_incarnation_proxy Handle of the associated local end-point incarnation proxy 412 or pseudo local end-point 402 (the null handle is used to reference the pseudo local end-point). remote_end_point_incarnation_proxy Handle of the associated remote end-point incarnation proxy 409 or pseudo remote end-point 403. remote_port Handle of the associated remote port object 401. route_management_connection Handle of the associated route management connection object 603. route_proxy Handle of the associated route proxy 408. state state of the route master object 406. Values for the route master state include: Unknown: Implies that the route master does not exist. NewRouteOrig: Implies that the route master has generated a new_route_originator event and is awaiting a response. NewRouteResp: Implies that the route master has generated a new_route_responder event and is awaiting a response. SCRFR_Sent: Implies that the route master has sent a SCRFR message and is awaiting a response. SCRFR_RSP_Sent: Implies that the route master has sent a SCRFR_RSP message and is awaiting its ACK. Active implies the normal operational state of the route master. RunDown: Implies that the route master is in the process of being deleted, but still exists because references to it still exist. On explicit creation, the value of this attribute is set to NewRouteOrig. On creation due to receiving a SCRFR message, the value of this attribute is set to NewRouteResp. Route Proxy Object The route proxy object 408 is a structure that describes a single route 300. It is a proxy of the route master object 406. The route proxy object 408 describes the state of a route 300 from the local end-point 102 to the remote end-point 102 through a specific path. Attributes of the route proxy 408 include its route_set, rtp_handle, rtm_handle, local_port_proxy, and state. These attributes are involved in route selection and monitoring. Route proxy objects 408 are created and deleted in response to events (new route originator, new route responder, route deleted) generated by route masters 406 on local ports 103(L). Route proxy objects 408 are also deleted when the local port 103(L) fails. Exemplary attributes associated with a route proxy object 408 include the following: rtp_handle Handle that the route master 406 uses to identify the route proxy object 408. expected_rsn The expected value of the routing sequence number that will be received in the next transmission received on this route that describes itself. highest_described_rsn The highest RSN received that described this route. It is used to calculate transmission delay likelihood. On creation, this value is set to zero subsequently, it is updated each time a transmission is received that describes this route in which the described RSN exceeds this value. inbound_trlc Transmission rate limit of the inbound half 500(1) of this route 300 in compressed form. This value is computed locally and communicated to the remote end-point 102(R) where it is used to limit the transmission rate of the corresponding outbound half route 5000. last_receive_time The time when the last transmission was received on this route. Used to calculate reception_rate_est. last_send_time The time when the last transmission was sent on this route. Used for calculating transmission_rate_est. local_port_proxy The local port proxy 413 for the port 103 that contains this route proxy's route master 406. local_route_epoch This route proxy's route epoch. The route epoch is incremented to cause the remote end-point 102(R) to reset its TRL computation for the inbound half route 500(I). local_route_index Index of this route proxy 408 in the local route set's route_proxies array. This value is sent to the remote end-point 102(R) during full route registration. The remote end-point uses it to identify this route 300 in route headers 1400 that it transmits. local_route_index_key Opaque key used to validate the local_route_index. This value is sent to the remote end-point 103(R) during full route registration and a copy is received in the routing header 1400 when the transmission describes the route 300. When a received transmission's local_route_index_key does not match this attribute, then the described route information is ignored. next_described_route The next route 300 in the route set 600 to describe in the routing header 1400 of a transmission sent on this route. next_route The next route in the route set's route order. It is a forward link in the circular list of all routes 300 of the route set 600. one_shot_flag Used when transmssion_rate_est>decompressed (outbound_tric) to make the route acceptable for one transmission. outbound_trlc Transmission rate limit of the outbound half 500(O) of this route 300 in compressed form. it is used to determine whether a route is acceptable during route selection. On creation, this value is set to SCR_TRLC_DEFAULT. Subsequently, it is updated when a received transmission describes this route. It may also be updated when the local end-point 103(L) suspects that the outbound half route's quality is low. reception_iat_est Estimate of the mean transmission receive inter-arrival time of the outbound half 500(O) of this route 300. On creation, this value is set to scr_irr_scale. Subsequently, it is updated each time a transmission is received on this route. remote_route_epoch The last value of transmitter_route_epoch described for the inbound half 500(I) of this route 300. This value is sent in the routing header 1400 of each transmission that describes this route. On creation, this value is set to zero. Subsequently, it is updated when a received transmission describes this route. remote_route_index Index of the remote route proxy 408 for this route 300 in the remote route set's route_proxies array. It is copied to the routing header 1400 in each transmission that describes this route. remote_route_index_key Opaque key used to validate the remote_route_index. This value is received from the remote end-point 102(R) during full route registration and is transmitted in the routing header 1400 with the remote_route_index. round_trip_time_est Estimate of the round-trip-time for this route 300. Its value is a number of milliseconds*256 expressed as an unsigned 32-bit integer. On creation, this value is set to 256 (1 millisecond). route_set The route set 600 to which the route proxy 408 belongs. On creation, its value is set to null. However, every route proxy 408 is added to a route set 600 immediately after creation and only removed from a route set immediately prior to run-down. rsn The route proxy's routing sequence number. Its value is the count of transmissions originated at this end of the route expressed as an unsigned 32-bit integer. rtm_handle Handle that identifies the route master object 406 that corresponds to this route proxy 408 within the scope of a local port 103(L). Its value is supplied by the route master 406 when the route proxy 408 is created and cannot be modified subsequently. send_specific_route_queue Queue of obms waiting for this route 300 to send a transmission. Used when an allocateobs operation requires a specific route but that route is not acceptable. significant_event A binary flag indicating that the route 300 has experienced a significant event since the route was described. state State of the route proxy object 408. timer A general-purpose timer for the route used for a variety of purposes. transmission_iat_est Estimate of the mean transmission send inter-arrival time of the outbound half 500 of this route. On creation, this value is set to scr_irr_scale. Subsequently, it is updated each time a route selection algorithm selects this route for a transmission. transmission_rate_est Estimate of the transmission rate of the outbound half 500(O) of this route. On creation, this value is set to zero. subsequently, it is updated each time the route selection algorithm selects this route for a transmission. transmissions_received The count of transmissions received at this end of the route expressed as an unsigned 32-bit integer. This attribute is used as a performance counter, i.e., expected_rsn-1-transmissions_received gives the total transmissions lost on this route. Route Set Object A route set object 417 associates the routes 300 from a local end-point incarnation 411 to a remote end-point incarnation 410. Attributes of the route set object 417 include a list of routes 300, a list of clients (connections) 601, and a remote end-point UID and IID (the local end-point 102(L) is implicit). A route set 600 groups the complete set of route proxies 408 that correspond to approved routes 300 between this local end-point incarnation 411 and a remote end-point incarnation 410. The route set object 417 is used to manage the creation and deletion of routes 300 between a pair of end-points 102(*) and groups the routes that exist between those end-points. As indicated above, a route set 600 is created when a route proxy 408 is created to a remote end-point incarnation 410 for which no route set yet exists. A route set 600 is deleted immediately when it has neither route proxies nor client connections. Stale route sets 600 are also deleted using policies based on an empty timeout (SCR_E_TOV) and a demand timeout (SCR_D_TOV). When a route set 600 has clients but no route proxies 408 for a continuous period (SCR_E_TOV) of time, it will enter the rundown state and issue Derequest Remote End-Point commands to each local port 103(L) to stop the creation of new routes 300. In an exemplary embodiment, the value for SCR_E_TOV is 600,000 (i.e., ten minutes). The route set object 417 then generates a route_set_failed event to each of its client connections 601. As each client connection aborts, it will remove its route set reference and thus allow the route set 600 to be deleted. SCR_E_TOV is used to control local policy that recovers resources from empty route sets. Specifically, when a route set 600 has no routes for SCR_E_TOV continuous milliseconds, it may be forced into rundown. Exemplary attributes associated with a route set object 417 include the following: client_list Unordered list of client connections 601 that use this route set 600. demand_timer Timer to time SCR_D_TOV. On creation, this timer is started. It is cancelled when client_list transitions from empty to nonempty. It is restarted when client_list transitions from nonempty to empty. establishment_time Time when the route set's RTSMC 602 entered the established state. This is used to determine the most recently established route set 600 when selecting between multiple route sets to the same remote end-point 102(R). empty_timer Timer to time SCR_E_TOV. On route set creation, this timer is started. It is cancelled when route_proxies transitions from empty to nonempty. It is restarted when route_proxies transitions from nonempty to empty. last_rtp Indicates the route proxy 408 of the last route 300 that was used to send a transmission on this route set 600. On creation, this value is set to NULL. When the first route is added, it becomes a reference to that route. When the last route is removed then it becomes NULL. last_rtp_count Count of the consecutive route set transmissions sent on route last_rtp. On creation, this value is set to zero. The route selection process zeros it each time it changes last_rtp and increments it each time a transmission is sent on the route set. lepim Specifies the local end-point incarnation master 414 to which this object belongs. max_r_a_tov The maximum value of the member routes' local_port_proxy.r_a_tov. remote_end_point_iid Incarnation identifier (IID) of the route set's remote end-point incarnation 410. remote_end_point_UID UID of the route set's remote end-point incarnation 410. route_index_keys Array of opaque keys used to verify dr_index values in received Transmissions. The route_proxy.local_route_index is used to index this array. On creation, the entries in this array are set to zero. When a route proxy 408 is added to the route set 600, the corresponding route_index_keys value is incremented and is copied into route_proxy.local_route_index_key. route_order_is_arbitrary True implies that the routes 300 within the route set 600 have not been ordered since the route membership last changed. On creation, this value is set to false. Subsequently, it is set to true each time a route is added to or remove from the route set. It is cleared when the routes within the route set are assigned an order. route_proxies Array of handles of the route proxies 408 that belong to this route set. The route_proxy.local_route_index is used to index this array. rtsmc The route set's management connection object. It may be stored either as a reference to a transport layer connection or as an object embedded in the route set object 417. send_initial_sfe_queue Queue of OBMs waiting for a route 300 to send an initial SFE on this route set 600. Used for route selection when no acceptable route exists. send_retry_sfe_queue Queue of OBMs waiting for a route 300 to send a retry SFE on this route set 600. Used to select a route when no acceptable route exists. send_start_mse_queue Queue of OBMs waiting for a route 300 to send a Start_MSE on this route set 600. Used to select a route when no acceptable route exists. significant_events Array of bits indicating which routes 300 of the route set 600 have experienced a significant event since the route was described. state State of the route set object 417. Route Management Connection Object The route management connection 603 is a sequenced-message connection that provides a one-way sequenced message delivery service. Each message payload sent on an established route management connection 603 is prefixed with network, routing, and transport headers, as in the case of a ‘plain’ connection. All route management connection message payloads are received in the header buffer portion of a pool buffer. The route management connection object 405 tracks the number of attempts to complete process login with retries_remaining, which, in an exemplary embodiment, is initially set to a value of 8. When retries_remaining reaches zero, the route management connection Connect Request operation fails. In response, route management deletes the corresponding pseudo remote end-point object 403 and remote port object 410. Exemplary attributes associated with a route management connection (RMC) object 405 include a system buffer pool handle, a full route handle, retries_remaining, the RMC connection ID, and the state of the connection. System Buffers FIG. 18 is a diagram showing exemplary relationships between pool buffers 1801, ports 103(*), and applications 101 (*). Pool buffers 1801, stored in a buffer pool 1800, are used to minimize the number of times that data is copied. Communicating applications may create buffer pools 1800 to directly receive messages bound for them. When an application 101(*) requests or accepts a connection, it specifies the buffer pool 1800 into which messages received on that connection should be stored. Buffer pools are created by applications 101(*). Each application specifies the memory to use to receive payloads and the maximum payload size to accommodate. An application can create more than one buffer pool 1800, if needed. Each application associates a buffer pool 1800 with one of its connections. Each connection is associated with a single buffer pool 1800 (established at connection creation time) to receive messages directed to the owning application 101(*). Each buffer pool 1800 has a handle that is unique within the scope of its end-point incarnation 411. This handle is communicated to the remote end-point incarnation 410 during connection establishment so that it can be included in the network header of transmissions sent on that connection. Thus, when a transmission is received by a port 103, it can be directly stored into a pool buffer 1801 having a matching handle. Each pool buffer 1801 comprises a header area, payload area, and a descriptor. The header area receives that portion of a transmission that is consumed by other network functions and is not provided directly to the receiving application 101(*). The payload area receives that portion of a transmission that is provided directly to the receiving application 101. The pool buffer descriptor includes the following information about the pool buffer 1801: the location of the header and payload areas; the received header and payload transmission sizes; the route over which the transmission was received; information about the context in which the transmission was received; and the owner of the pool buffer. Pool buffers 1801 may be unowned, or, as shown in FIG. 18, temporarily owned by entities including a local port 103(*) (queued to receive a transmission), the transport layer 220 (during sequenced delivery), the request layer 212 (for command queuing), or the buffer pool's application 101 (during command processing). Buffer pool management 270 controls the allocation of pool buffers 1800 and enforces quotas on each owner thereof so that one owner does not starve the memory resources of another. Buffer pool management 270 includes the task of determining when additional pool buffers should be queued to each local port 103(L). FIG. 19 is a diagram showing an exemplary sequence of transmissions involved in performing command flow control. In the following description, a remote procedure call (RPC) is termed a ‘request’. Requests are managed by request layer 212. Each request includes a command message transmitted from the client 1901 to the server 1902 followed by a response message transmitted from the server to the client. When a connection is established between client and server applications, a window size for command messages is established as well. This window size indicates the maximum number of requests that may be simultaneously outstanding on this connection at the server. From the point of view of the client 1901, a request is outstanding until the operation is completed. The command window size is communicated in every request header in the cmd_win field 2203. This window size may be adjusted and is communicated in the next request layer message. As shown in FIG. 19, at steps 1905-1925, an application owned by client 1901 attempts to send a plurality of command messages (requests ‘C’ through ‘G’), via request layer 212, to server 1902. At step 1907, the server request layer 1902/212 receives request ‘C’, which it proceeds to process using available server request resources. At step 1912, the server request layer receives command message ‘D’, which it cannot immediately process because it does not have enough server request resources. When a command message for a request arrives at the server request layer 1902/212 and it would cause the number of requests in progress at the server to exceed the current window size, the command message is nevertheless accepted. It is assumed that this situation was caused by changing window size and the client request layer will shortly adjust to the new window size. The command window size is adjusted as described below. When, as in the present example, there are insufficient resources available to begin processing the new request, at step 1916, the server request layer 1902/212 sends a pause message, containing a request ID for request ‘D’, to the client, indicating that the request could not be started. The corresponding request ID is recorded in the server request layer, and this and subsequent command messages (in the present example, requests ‘D’-‘F’, initiated at steps 1910-1925) received at the server 1902 from that paused client 1901 are discarded. The client request layer 1901/210 places all requests in a list (an ‘active request queue’) in the order in which they were started, until they have been completed. At step 1918, when the client request layer receives the pause message, it marks the indicated request in the active request queue. The client request layer 901/210 also sets the command window size from the request header of the pause message. If the window size is equal to or smaller than the number of outstanding requests, the client request layer no longer sends command messages for new RPC calls, but continues to place the new requests in the active request queue (marked as ‘unsent’ and ‘delayed’). In the present example, the command window size in the pause message is smaller than the number of outstanding requests, therefore client request layer 1901 stops sending new command messages to the server 1902, as indicated at step 1926, where request ‘G’ is ‘delayed’. The server request layer 1902/212 continues to send the current command window size to the client 1901. As ‘delayed’ or ‘retransmitted’ command messages are received, the command window size is slowly increased. When the client request layer 1901/212 receives a message that sets the command window size greater than the number of outstanding requests, it locates the marked (paused) request from step 1918 in the active request queue. Beginning with that request and proceeding in order, it resends the command message for the subsequent ‘unsent’ requests in the list until they have all been processed or it has sent the number of commands allowed by the window size. In the present example, at step 1922, a message is sent to client 1901 in which the command window size is greater than the number of outstanding requests, causing the client request layer 1901/212 to commence re-sending the command messages for requests ‘D’-‘G’, beginning at step 1930. If the server request layer 1902/212 has adjusted the command window size downward (due to lack of resources), it is adjusted upwards slowly by successfully receiving subsequent ‘delayed’ or ‘retransmitted’ command messages. Client Command Flow Control Operation FIGS. 20A and 20B are flowcharts illustrating exemplary steps performed in implementing client command flow-control. The client request layer 1901/212 keeps track of the number of requests it may have outstanding in a clnt_cmd_win attribute stored in a Connection object. Each request layer message contains a cmd_win field (2203, shown in FIG. 22) in the request header that is set by the sending server request layer to flow-control the client. When the client request layer receives a message, the cmd_win field in the request header is stored in cint_cmd_win. The request header is shown in FIG. 22, described below. As shown in FIG. 20A, at step 2005, when a new request is initiated by the client request layer 1901/212, a request object is allocated and a Command message is constructed to be sent from the client 1901 to the server 1902, as follows. The request object is marked as ‘unsent’, the ‘delayed’ and ‘retransmitted’ fields are cleared in the request object, and the request is placed in the client's active request queue, at step 2010. At step 2015, if clnt_cmd_win is greater than clnt_num_cmds_out, which is the number of requests that are currently outstanding on the present connection, the Command message is sent to the server, and the ‘unsent’ field in the request header 2200 is cleared at step 2020. Otherwise, the request is marked as ‘delayed’, at step 2025, and the client may not send any more Command messages at step 2030. Once the sequenced message transport layer 220 delivers a command message to the server 1902, the server request layer 1902/212 may or may not accept the new command. As previously indicated, if the new command is not accepted, the server will send a pause message indicating the first request whose command message could not be accepted. As shown in FIG. 20B, at step 2035, when the pause message is received by the client, the indicated request is located in the active request queue, and this request object and all subsequent request objects with ‘unsent’ clear are marked as ‘unsent’ and ‘retransmitted’, indicating that their corresponding command message needs to be retransmitted, at step 2040. At step 2045, the active request queue is rescanned to determine whether additional Command messages may be sent. Command messages may only be sent when clnt_cmd_win for the connection is greater than clnt_num_cmds_out. The value for clnt_num_cmds_out begins at zero, is incremented for each command message sent, and decremented for each request completed or command paused. Rescanning continues until cint_cmd_win is no longer greater than clnt_num_cmds_out, or there are no more requests to start. At step 2050, if the value stored in cint_cmd_win is less than or equal to the value of clnt_num_cmds_out, the client may not presently send additional command messages (block 2055). If, at step 2050, the value stored in clnt_cmd_win is greater than clnt_num_cmds_out, and if, at step 2060, there are pending ‘unsent’ messages, clnt_num_cmds_out is incremented, and the earliest ‘unsent’ request object has the ‘delayed’ and ‘retransmitted’ flags copied to the request header 2200 of its Command message, which is then sent to the server, and the ‘unsent’ status in the request object is cleared, at step 2070. The pause message will typically set clnt_cmd_win at or below clnt_num_cmds_out. When new requests are ready to send their command message, if clnt_cmd_win is no greater than clnt_num_cmds_out, the requests wait. When a request layer message (including a pause message) is received with a cmd_win that is greater than clnt_num_cmds_out, then a number of messages up to the allowed number of command messages may be sent, in order, starting with the first request still needing to send its command message (‘unsent’ set). When a ‘release’ or a ‘response’ message is received by the client request layer 1901/212, at step 2075, the indicated request is located in the active request queue, the request is removed from the queue, clnt_num_cmds_out is decremented, and the associated pool buffer 1801 is freed, at step 2080. Client command flow-control processing then continues at step 2045, described above. Server Command Flow Control Operation The present command flow control system allocates server request objects and pool buffers to each connection dynamically, as command messages arrive. The initial command window size for each connection is computed from the number of free server request objects, the number of free pool buffers, and the number of other connections contending for these resources. As the number of connections contending for resources (established connections) changes, the command window size is recomputed. Computation of command window size is described below. FIGS. 21A and 21B are flowcharts illustrating exemplary steps performed in implementing server command flow-control. As shown in FIG. 21A, when a command message is received by the server request layer 1902/212, at step 2105, if srvr_cmd_paused is zero (at step 2110), and either there are no server request objects or no pool buffers available to deliver the command to the application (at step 2125), then the request ID from the command message is stored in srvr_cmd_paused, making it non-zero, and the current command window size, srvr_cmd_win_cur, is set to the larger of srvr_num_cmds_in and srvr_cmd_win_min, unless it is already smaller, at step 2130. A pause message is then queued to be sent on the connection, at step 2135. Otherwise, at step 2140, a new pool buffer 1801 is allocated from the buffer pool application quota and it becomes owned by the request layer, ownership is swapped with the pool buffer holding the command and the newly allocated pool buffer is freed, a Server Request object is allocated and the Command message associated with it, and, at step 2145, the Command is accepted. If, at step 2110, a command message is received while srvr_cmd_paused is non-zero, and, at step 2115, the requestID in the command message matches the requestID stored in srvr_cmd_paused, then srvr_cmd_paused is set to zero, at step 2117. The command message is then processed as if it had been received with srvr_cmd_paused equal to zero, starting with step 2125. If, at step 2115, the requestID in the command message does not match the requestID stored in srvr_cmd_paused, then at step 2120, commands are still paused, the received command is discarded, and the pool buffer associated with the received command is freed. As shown in FIG. 21B, when a command message is accepted by the server request layer 1902/212 (at step 2145), then at step 2150, if neither ‘delayed’ nor ‘retransmitted’ are set in this Command message, and processing continues at step 2180, described below. Otherwise, at step 2155, srvr_cmd_win_req_counter is decremented. At step 2160, if srvr_cmd_win_req_counter is non-zero, then processing continues at step 2180, described below. Otherwise, if srvr_cmd_win_req_counter is zero, then at step 2165, it is set to a value of SCQ_CMD_WIN_ADJUST_RATE, which in an exemplary embodiment is typically 16. At step 2170, if the value of srvr_cmd_win_cur is less than that of srvr_cmd_win_max, then srvr_cmd_win_cur is incremented; and in either case, processing continues with step 2180. At step 2180, if a Request Receive call is pending, then the Request Receive is de-queued and the corresponding server request is delivered to, and becomes owned by, the application at step 2185, otherwise, the pending Request Receive is added to a queue of pending commands, at step 2190. Received Request Message Processing All request layer messages consist of a request header and optional payload. The presence of a request layer message is indicated by the opcode in the transport header set to a request layer message (opcode==SCTH_SEND_REQ). FIG. 22 is a diagram showing an exemplary request header 2200. In the FIG. 22 diagram, the fields in the header are shown as being included in six larger ‘fields’, each 32 bits in length. In an exemplary embodiment, the request header 2200 includes the following information, where the sizes of the fields may vary with the requirements of a particular implementation. apid This field 2201 indicates the application protocol identifier for the connection on which the message is being sent. opcode This field 2202 indicates what type of request layer message is being sent. cmd_win This field 2203 contains the maximum number of requests that may be outstanding simultaneously. A cmd_win value of zero (0) indicates that no requests may be outstanding. struct flags This field 2204 contains the next five fields described immediately below. flags.cmd_seq (8-bits) Contains the low-order bits of the command sequence number for command messages, used as a consistency check. For other messages, this field is zero (0). flags.param_cnt (2-bits) A count of the number of parameters (0-3) supplied in the request header's 32-bit parameter array 2208. flags.retransmitted (1-bit) When set to one (1), this indicates that this command message was retransmitted due to receipt of a pause that affected it. For non-command messages, this is always zero (0). flags.delayed (1-bit) When set to one (1), this indicates that this command message was delayed at the client due to insufficient command window size. For non-command messages, this is always zero (0). flags.req_pld_siz (11-bits) This is the size of the payload (in bytes) following this header. request_id This field 2205 identifies the associated request context, and allows request specific messages to be associated. The request ID is unique within the scope of a connection on the client. It is allocated as part of command processing and it is deallocated as part of response processing. rel_id_a, rel_id_b These fields 2206/2207 contain the IDs of requests being released. When zero (0), no request is being released. parameters This field 2208 is an array of three 32-bit parameters. The number of parameters that are valid is indicated by flags.param_cnt. FIG. 23 is a flowchart illustrating exemplary steps performed in processing a received Request message. As shown in FIG. 23, at step 2305, a Request message is received by the connection transport. The message is delivered to the request layer, which examines the request header 2200 and performs the following processing: At step 2310, the connection client command window size (clnt_cmd_win) is updated from the window field (cmd_win) in the request header. If, at step 2315, clnt_cmd_win is larger than clnt_num_cmds_out, then the active request queue is rescanned beginning at step 2045 in FIG. 20B, and returns from FIG. 20B step 2055 or 2065. In any case, processing continues in FIG. 23 at step 2325. If any release messages are supplied in the Request message, a Receive(Release) call is made to each specified request ID. Release messages are not separate messages, but rather are piggybacked onto other request layer messages using the rel_id_a or rel_id_b field 2206/2207 of the request header 2200. The rel_id_a and rel_id_b fields 2206/2207 in the request header 2200 contain the IDs of requests being released, if any. For a message request, a release message is sent from the server to the client when the Command message is accepted by the server (at step 2145 in FIG. 21A), and indicates that the request is now complete. For a read data request, a release message is sent from the client to the server. The message indicates that the data indicated by the response was successfully received by the client, and that the request is now complete. In one embodiment of the present system, request state machines implement release delay timers to allow a release to be piggybacked on another request layer message. If the timer expires before the release can be piggybacked, a no-op message is sent to carry the release. More specifically, at step 2325, if any releases are supplied (via rel_id_a 2206 or rel_id_b 2207), a Receive(Release) call is made to each specified Request ID, at step 2330. If the Request ID is not that of an existing client or server request object, this is a protocol error and the associated connection is aborted. Processing then continues at step 2075, in FIG. 20B, and returns from FIG. 20B step 2055 or 2065 to FIG. 23 step 2335. Whether or not releases are supplied in the rel_id_a and rel_id_b header fields 2206/2207, the message type field indicated by the opcode field 2202 is then processed. At step 2335, if the received message is a ‘command’ message, then message processing continues at step 2105 in FIG. 21A, as described above. At step 2340, if the received message is a ‘response’ message, then at step 2345, a Receive(Response) call is made to the Request identified by the request_id header field 2205, and message processing continues at step 2075 in FIG. 20B. At step 2350, if the received message is a ‘pause’ message, then message processing continues at step 2035 in FIG. 20B. Other types of received messages (i.e., messages that do not fall into one of the above categories) are processed at step 2355. No-op messages are sent to carry piggybacked releases (in the rel_id_a and rel_id_b fields) and command window size updates (in the cmd_win field). After processing these fields, the message is discarded. In all cases, once a message has been completely processed, the associated pool buffer is freed. However, the pool buffer for a command message is not freed until the application completes the request of the command messages is discarded because the connections is paused. When the application completes the request, the pool buffer containing the Command message is returned to the buffer pool, thus increasing the available application quota. Initial Command Window Size Computation The present system implements ‘optimistic’ command flow control. This means that the sum of the server command window sizes (srvr_cmd_win_cur) for all connections on an end-point will exceed the resources actually available. The following variables are used to compute the maximum command window size (srvr_cmd_win_max): the total number of server request blocks available to all connections, and the number of pool buffers available to the request layer for each group of connections sharing the same buffer pool. In an exemplary embodiment, command window size quota is distributed across connections in roughly the same proportion as pool buffers are distributed. In addition, past usage is used as a predictor of future usage. Statistics are kept on the recent received command traffic on each connection and used as part of the command window size computation. FIG. 24 is a flowchart showing exemplary steps performed in determining initial command window size and limits. Each connection has maximum, minimum, and current command window parameters. The current command window starts at the maximum and is constrained to vary between that and the minimum. Whenever the number of established connections changes, the maximum, minimum, and current command window are computed for each remaining established connection. The following parameters are used to compute these values: The total number of active connections on the local end-point (‘req_conn_cnt’); The total number of server request objects on the local end-point (‘tot_srvr_req’); The application quota for each buffer pool (‘bp_aquota’); The number of active connections using each buffer pool (‘bp_conn_cnt’); The overdraft fraction allowed (‘OVERDRAFT’, typically 10 percent); The absolute minimum command window size allowed (‘CMD_WIN_MIN’, typically 1). The maximum window value that will fit in a request header (‘HDR_CMD_WIN_MAX’, typically 255); At step 2405, the number of established connections has changed, as a result of a connection becoming established or an established connection being closed or aborted. At step 2410, the minimum and maximum command window sizes allowed by the available server request objects and number of established connections are computed by the following exemplary equations: req—cmd—win_min=min(max(tot—srvr—req/req—conn—cnt,CMD—WIN_MIN),HDR—CMD—WIN_MAX) req—cmd—win_max=req—cmd—win_min+req—cmd—win_min*OVERDRAFT*(req—conn—cnt−1)/100 In block 2415, the command window parameters for each established connection are computed. At step 2420, the minimum and maximum command window sizes allowed by the buffer pool resources available to this connection and number of connections using the buffer pool are computed by the following exemplary equations: bp—cmd—win_min=min(max(bp—aquota/bp—conn—cnt,CMD—WIN_MIN),HDR—CMD—WIN_MAX) bp—cmd—win_max=bp—cmd—win_min+bp—cmd—win_min*OVERDRAFT*(bp—conn—cnt−1)/100 At step 2425, the minimum connection command window size, srvr_cmd_win_min, is then computed by the following equation: srvr—cmd—win_min=min(req—cmd—win_min,bp—cmd—win_min) At step 2430, the maximum connection command window size, srvr_cmd_win_max, is then computed by the following equation: srvr—cmd—win_max=min(req—cmd—win_max,bp—cmd—win_max,HDR—CMD—WIN_MAX) At step 2435, the current connection command window size, srvr_cmd_win_cur, is then set to the maximum connection command window size (srvr_cmd_win_max). Steps 2420 through 2435 are repeated for each established connection. Note that the overdraft computed is a percentage for each connection over one. While the maximum command window size generally remains constant when connections are relatively static, the actual window size used on a connection can be dynamically adjusted between the maximum (srvr_cmd_win_max) and minimum (srvr_cmd_win_min) values for that connection. Proper operation of the presently-described embodiment depends on srvr_cmd_win_cur never becoming zero, since the client would then cease sending command messages and, in the absence of received ‘delayed’ or ‘retransmitted’ command messages, the server would never increase srvr_cmd_win_cur above zero. If a value of zero is used as the predetermined minimum value (CMD_WIN_MIN) the srvr_cmd_win_cur may eventually be set to zero. Thus, the server must have an additional periodic evaluation of connections in this state to eventually set srvr_cmd_win_cur above zero and send a window message (via a ‘No-op’) to the client so that the client may again send command messages to the server. The present embodiment assumes a fixed number of server request objects, allocated at startup. Alternative embodiments are possible where the number of server request objects may change dynamically. In this situation, the command window size parameters should be recomputed when the number of number of server request objects is changed. Certain changes may be made in the above methods and systems without departing from the scope of the present system. It is to be noted that all matter contained in the above description or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. For example, the network shown in FIG. 1 may be constructed to include components other than those shown therein, and the components may be arranged in other configurations. The elements and steps shown in FIGS. 3-24 may also be modified in accordance with the methods described herein, without departing from the spirit of the system thus described. In addition, fabric 105(*) may be any type of switched or non-switched network, including the Internet, local area networks, and point-to-point communications links. | <SOH> BACKGROUND <EOH>In a network that employs remote procedure call (RPC) mechanisms, these mechanisms typically use a sequenced message delivery transport (e.g., TCP/IP) to send command and response messages. When a command message is sent to an application by a client, the message arrives at the server and pends in the transport receive queue until the application can receive it. At that point, if the application does not have the necessary resources to complete the requested operation, the command message will languish in the application, consuming receive resources until the remaining resources become available. If no additional receive resources are available that are needed to complete operations already in progress, and the operations already in progress are using all the remaining resources necessary to start the new operation, a deadlock condition exists and no more operations are ever completed. Existing implementations must insure that sufficient resources are available that this resource starvation situation never occurs. This is typically done by dividing the server resources needed to complete commands equally among the connected clients and extending that number of command credits to each client. Clients then limit their number of outstanding commands to their number of command credits. This method is often called pessimistic flow control. Pessimistic flow control works well when a server has a small number of clients or when the rate of command arrival is similar among all clients. However, when a server has a large number of clients and the rate of command arrival varies greatly among clients, then server resource limitations lead to poor network performance because no client is able to keep as many commands outstanding as it needs. | <SOH> SUMMARY <EOH>A system and method are disclosed for controlling command message flow in a network including a server and a client. A command window, comprising a maximum number of command messages that may be outstanding at the server, is included in messages sent from the server to the client. The value of the command window at the server is modified in accordance with available server resources for receiving command messages. When there are insufficient resources at the server to process one of the command messages delivered to the server, then a pause message is sent to the client indicating which command message cannot be received; indicia is stored that indicates the command message initially discarded; and subsequent command messages delivered to the server are discarded until an initially discarded command message is again delivered to the server. The sending of command messages from the client is ceased when the number of outstanding command messages is equal to or greater than the maximum number of messages indicated by the command window. When the number of outstanding command messages is less than the maximum number indicated by the command window, then the sending command messages from the client to the server is resumed, starting with the command message initially discarded by the server. | 20040430 | 20091201 | 20060209 | 96812.0 | G06F1516 | 0 | MUSA, ABDELNABI O | CONTROLLING COMMAND MESSAGE FLOW IN A NETWORK | UNDISCOUNTED | 0 | ACCEPTED | G06F | 2,004 |
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10,837,243 | ACCEPTED | Apparatus and method for non-invasive measurement of cardiac output | A comparatively light and compact permanent magnet arrangement for an MRI apparatus has a pair of opposed permanent magnet arrays with a shimming system to adjust the uniformity and strength of a magnetic field in a central chamber of the apparatus. The MRI apparatus is used to examine the extremities of a patient to determine cardiovascular characteristics from an analysis of the blood flow through selected arteries in the extremity. The information collected can be used to calculate such characteristics as total cardiac output, blood flow, arterial wall thickness and elasticity and the presence of plaque. | 1. A permanent magnet arrangement for use in apparatus performing MRI analysis of living tissue, said arrangement comprising: a main magnet formed as a right, cylindrical solid having a central axis, an outer wall and first and second opposed faces perpendicular to said main magnet axis; a pole piece formed from ferromagnetic material, said pole piece having a central axis and first and second opposed pole piece faces perpendicular to said pole piece axis, the first of said pole piece faces being positioned at and coextensive with said first main magnet face; a side magnet, said side magnet having an inner opening sized and shaped to match the outer dimensions of said pole piece, said side magnet positioned about the outer periphery of said pole piece; and means for adjusting the magnetic flux created by said magnet arrangement, said adjusting means including at least a first cavity formed in said pole piece, a first shim positioned within said first cavity, and means for positioning said first steel shim at selected orientations and positions within said first cavity. 2. The apparatus as recited in claim 1 wherein said flux adjusting means includes a plurality of said steel shims, each said shim positioned within a correspondingly shaped and sized cavity in said pole piece. 3. The apparatus as recited in claim 1 wherein said first shim is a solid disk and said positioning means comprises a plurality of adjusting bolts, each said bolt rotatably journaled to said shim and axially adjustable with respect to said pole piece. 4. The apparatus as recited in claim 1 wherein said adjusting means comprises first, second and third cavities. said first cavity formed in the shape of a right circular cylinder, each of said second and third cavities formed in the shape of a circular channel, said first, second and third cavities being concentric one with the other and being centered with respect to said pole piece axis; a first shim dimensioned to fit within and positioned within said first cavity, a second shim dimensioned to fit within and positioned within said first cavity, and a third shim dimensioned to fit within and positioned within said third cavity; means for adjusting each said shim with respect to said pole piece, said adjusting means including a plurality of bolts rotatably journaled to each said shim, each said bolt being individually axially adjustable with respect to said pole piece whereby each said shim may be positioned in a direction in to or outward from each said cavity and whereby each said shim may be positioned at a tilt with respect to said pole piece axis. 5. The apparatus as recited in claim 4 wherein said second and third cavities are rectangular in cross-section and said second and third shims are formed as toroidal rings having rectangular cross-sections. 6. The apparatus as recited in claim 4 wherein said first, second and third cavities are formed in said pole piece first face and said adjusting bolts extend from said pole piece second pole piece face to said shims. 7. The apparatus as recited in claim 4 wherein said first, second and third cavities are formed in said pole piece second face and said adjusting bolts extend from said pole piece second pole piece face to said shims. 8. Apparatus for use in performing MRI analysis of living tissue, said apparatus comprising: a cylindrical housing formed from magnetically conductive material, said housing having a housing wall defining a space therewithin and having first and second open ends; a first permanent magnet arrangement comprising a first main magnet formed as a right, cylindrical solid having a central axis, an outer wall and first and second opposed faces perpendicular to said main magnet axis; a pole piece formed from ferromagnetic material, said pole piece having a central axis and first and second opposed pole piece faces perpendicular to said pole piece axis, the first of said pole piece faces being positioned at and coextensive with said first main magnet face; a side magnet, said side magnet having an inner opening sized and shaped to match the outer dimensions of said pole piece, said side magnet positioned about the outer periphery of said pole piece; and means for adjusting the magnetic flux created by said magnet arrangement, said adjusting means including at least a first cavity formed in said pole piece, a first shim positioned within said first cavity, and means for positioning said first steel shim at selected orientations and positions within said first cavity, said first magnet arrangement positioned within said housing proximate said first open end with said first magnet arrangement side magnet contacting said housing wall; a second permanent magnet arrangement comprising a second main magnet formed as a right, cylindrical solid having a central axis, an outer wall and first and second opposed faces perpendicular to said second main magnet axis; a second pole piece formed from ferromagnetic material, said second pole piece having a central axis and first and second opposed pole piece faces perpendicular to said pole piece axis, the first of said pole piece faces being positioned at and coextensive with said second main magnet first face; a second side magnet, said second side magnet having an inner opening sized and shaped to match the outer dimensions of said second pole piece, said second side magnet positioned about the outer periphery of said second pole piece; and means for adjusting the magnetic flux created by said second magnet arrangement, said second adjusting means including at least a first cavity formed in said second pole piece, a first shim positioned within said first cavity, and means for positioning said first shim at selected orientations and positions within said first cavity, said second magnet arrangement positioned within said housing proximate said second open end with said second magnet arrangement side magnet contacting said housing wall; said second magnet arrangement positioned within said housing proximate said second open end with said second side magnet contacting said housing wall; said first and second arrangements spaced apart one from another with said first arrangement second pole piece face facing said second arrangement second pole piece face; said first and second arrangements and said housing wall defining therebetween an air gap;and an access port formed in said housing wall allowing said tissue to be positioned within said air gap. 9. The apparatus as recited in claim 8 wherein said apparatus produces a magnetic field of about 1.0 tesla and said apparatus weighs about 250 kg. 10. The apparatus as recited in claim 8 wherein said housing is about 60 cm. in diameter. 11. The apparatus as recited in claim 8 wherein said first and second magnet arrangements are sufficiently adjustable to provide a magnetic field of uniform field strength and direction across said air gap. 12. The apparatus as recited in claim 11 wherein said first and second magnet arrangements are sufficiently adjustable to form a diagnostic zone located in said air gap and between said first and second magnet arrangements, said diagnostic zone defined by that portion of said magnetic field found to be the most uniform in filed strength and direction. 13. The apparatus as recited in claim 8 further comprising first and second end caps, said first end cap sized and shaped to close off said first open end of said housing, and said second end cap sized and shaped to close off the second open end of said housing. 14. The apparatus as recited in claim 13 wherein said first end cap contacts said second face of said first main magnet and said second end cap contacts said second face of said second main magnet. 15. The apparatus as recited in claim 8 wherein said apparatus further includes a second arrangement of shims to adjust said magnetic field, said second shim arrangement comprising at least one circumferential groove formed on said housing proximate one said magnet arrangement, said groove being coaxial with said main magnet axis; at least one steel shim positioned within said groove; and means for positioning said steel shim at selected orientations and positions within said groove. 16. The apparatus as recited in claim 15 wherein one said second shim arrangement is formed on said housing proximate each said magnet arrangement. 17. The apparatus as recited in claim 8 wherein said apparatus further comprises an array of RF coils disposed within said air gap, selected of said coils acting as transmitters and selected of said coils acting as receivers to pulse and detect electromagnetic signals across said magnetic field. 18. The apparatus as recited in claim 17 wherein said apparatus further comprises means to detect and analyze said signals and to select that combination of coils to pulse and detect said signals that produces the most satisfactory MRI image of said tissue. 19. A method for non-invasively performing an examination to determine selected physical characteristics of the heart and cardiovascular system of a living subject, said method comprising the steps of: selecting an extremity of the subject suitable for conducting said examination; providing an apparatus adapted to conduct MRI analysis of selected blood vessels within said extremity, said MRI apparatus of the type having a housing, first and second opposed permanent magnet arrangements defining an air gap therebetween, an access port in said housing to enable the placement of said extremity within said air gap, and means to create a magnetic field across said air gap with sufficient field strength, uniformity and resolution to perform said examination; providing an array of RF coils to pulse and detect electromagnetic signals within said air gap; pulsing selected of said RF coils and detecting the signals produced thereby; creating an MRI image of said selected blood vessels at selected time intervals to produce information as to selected of said cardiovascular ysytem characteristics; and collecting and analyzing said information. 20. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the cross-sectional area of a selected blood vessel measured at selected times during the beating of said heart. 21. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the flow rate of blood through a selected blood vessel measured at selected times during the beating of said heart. 22. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the total cardiac output of said heart. 23. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the wall thickness of a selected blood vessel. 24. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the elasticity of a selected blood vessel. 25. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the flow mediated dilation of a selected blood vessel. 26. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the presence, type and thickness of plaque in a selected blood vessel. 27. The method as recited in claim 19 including the step of selelcting said cardiovascular characteristic to be the wall thickness of a selected blood vessel. 28. The apparatus as recited in claim 22 including the steps of selecting said extremity to be a human arm and selecting said blood vessels to be the radial and ulnar arteries in said arm, and calculating total cardiac output by determining the volume of blood per unit time flowing through said arteries and comparing said blood volume to tables of known relationships of total cardiac output to blood flow measured through said arteries. 29. The method as recited in claim 19 including the step of pulsing said coils when said heart beats. 30. The method as recited in claim 19 including the step of performing a first said examination for selected of said physical characteristics and storing the results of each said examination for use as a base line to determine subsequent changes in said characteristics. | BACKGROUND OF THE INVENTION This invention relates generally to the measurement of cardiac output and, more particularly, to apparatus and methods for non-invasively measuring cardiac output and claims priority from application Ser. No. 60/467015 of the same title, filed 01 May 2003. Cardiac output is the volume of blood pumped by the heart during a given interval of time. Measuring cardiac output is a diagnostic technique used to evaluate cardiac function and detect the presence of cardiovascular disease or abnormality. Normally, cardiac output varies to meet the body's demand for oxygen and for nutrition. The left side of the heart receives oxygenated blood from the lungs and contracts, pumping the blood through arteries to all parts of the body. Blood flow is affected by such factors as the contractility of the left ventricle, the resistance against which the heart must pump and the volume of blood in the ventricle when pumping occurs. Changes in cardiac output may indicate disease or may be evidence of an abnormality or change in a patient's cardiovascular system. Accordingly, measurement of cardiac output is a useful diagnostic tool and detection of changes in cardiac output may allow a physician to investigate a patient's condition more thoroughly and take measures to prevent serious or permanent damage. Ideally, measurement of cardiac output should be quick, convenient, safe for the patient and should use equipment and techniques which are reliable, easy to operate and accurate. There are a number of known techniques and devices for measuring cardiac output. One is the Fick method based upon work done by Adolph Fick in about 1870. As performed today, the Fick method involves injecting a measured amount of oxygen into an artery and then measuring the concentration of oxygen at a selected site downstream of the injection site. Typically, such a procedure involves the insertion of two catheters into a patient's body, one for the injection of the oxygen and the other for the collection of blood which is then analyzed and the oxygen content determined. While this technique produces satisfactorily accurate results, it does require surgically invasive procedures and the removal of an appreciable amount of blood which must then be analyzed, resulting in a measurement that is not a real time measurement. Whenever an invasive procedure is performed, it carries with it the attendant risk of possible infection. In another technique for measuring cardiac output a dye is injected into the bloodstream and the dye concentration is measured at a point downstream of the injection site. Alternatively, a bolus of a chilled fluid indicator is injected and the temperature of blood withdrawn from a site downstream of the injection site is measured. These and other cardiac output measurement techniques are well represented in the prior art. The following references are representative of known invasive measurement techniques. U.S. Pat. No. 5,797,395 (Martin) teaches and describes a continuous cardiac output derived from arterial pressure wave form using pattern recognition. Martin uses a fluid catheter installed in the bloodstream to measure the arterial pressure of a patient and to digitize the data collected by the sensors. The collected data is then compared to representative data stored in a database with representative wave forms corresponding to various levels of cardiac output. U.S. Pat. No. 6,299,583 (Eggers) teaches and describes monitoring total circulating blood volume and cardiac output. Eggers et al uses a variation of the indicator dilution technique in which a test substance or analyte is injected into the body. As seen in FIG. 1 of Eggers et al, analyte is injected into the bloodstream by way of a catheter inserted into the subclavian vein leading to the heart. A catheter with a sensor is inserted into, for example, the radial artery in one of the patient's arms and is used to detect and measure the concentration of analyte. U.S. Pat. No. 6,186,956 (McNamee) teaches and describes a method and system for continuously monitoring cardiac output without having to inject substances into the patient's body nor withdraw liquids from the body. McNamee does so by using a pressure transducer placed in a patient's mouth or a tracheal cannula in measuring the differential in pressure as the patient breathes in and out. The detection of this signal is then correlated to a table of known values from which cardiac output is deduced. McNamee references the use of MRI as an acceptable non-invasive measurement technique and also states that such techniques typically require large, expensive equipment and highly trained technicians to operate the equipment and interpret the results. U.S. Pat. No. 6,322,518 (Young et al) teaches and describes a method and apparatus for measuring cardiac output which utilizes an esophageal probe inserted down the patient's throat to measure thoracic impedance variations which are then correlated to a measurement of cardiac output. Even minimally invasive procedures require skilled technicians, risk infection and allergic responses, and cause apprehension and discomfort in the patient. The advantages of using non-invasive techniques for measuring cardiac output have been recognized in the prior art. U.S. Pat. No. 6,306,098 (Orr et al) teaches and describes apparatus and method for non-invasively measuring cardiac output. Orr et al use a modification of the Fick approach, measuring the difference in carbon dioxide concentration between the air inhaled and exhaled by a patient through a breathing tube rather than measuring concentration of oxygen at disparate points in the patient's bloodstream. A computer program is used to calculate cardiac output based upon the differential in carbon dioxide concentration. U.S. Pat. No. 5,458,126 (Cline et al) teaches and describes a cardiac finctional analysis system employing gradient image segmentation. Cline et al describe the use of techniques such as computed axial tomography (CAT) and MRI to create a four-dimensional data set to create images of selected portions of the cardiovascular system. Cline et al are representative of the use of complex, expensive and quite large equipment to carry out these measurements. U.S. Pat. No. 5,417,214 (Roberts et al) teaches and describes quantitative blood flow measurement using steady-state transport induced adiabatic fast passage. Again, Roberts et al is representative of the complexity presently experienced in the use of MRI to carry out cardiovascular measurements and evaluation. In particular, at column 5, lines 26 et seq. Roberts et al describe the necessity for precise techniques for gathering the data used in the analysis. U.S. Pat. No. 6,348,038 (Band et al) teaches and describes method and apparatus for the measurement of cardiac output using the wave form created by the measurement of arterial blood pressure in a patient. The collected data is used to determine nominal stroke volume and using this determination to obtain a nominal value for the patient's cardiac output. U.S. Pat. No. 5,360,005 (Wilk) teaches and describes a medical diagnosis device for sensing cardiac activity and blood flow. Wilk uses an acousto-electric transducer as a type of stethoscope to convert heart sounds into electric impulses and then uses a microprocessor to analyze these impulses and correlate them to cardiovascular activity. U.S. Pat. No. 4,509,526 (Barnes et al) teaches and describes method and system for non-invasive ultrasound Doppler cardiac output measurement. Barnes et al teach the positioning of a transducer at separate locations on a patient's body to determine ultrasonically the cross-sectional area of a patient's ascending aorta and to determine the systolic velocity profile of blood flow through the aorta, enabling the calculation of cardiac output. To practice the technique described in Barnes et al the transducer must be accurately positioned by a technician at two separate sites in order to generate the data required to make the calculations necessary to determine cardiac output. U.S. Pat. No. 5,178,151 (Sackner) teaches and describes a system for non-invasive detection of changes of cardiac volumes and aortic pulses. Sackner et al use transducers positioned on the patient's body to send and receive signals which include a wave form characteristic of the ventricular volume and then continuously monitors to detect changes in the wave form. U.S. Pat. No. 5,443,073 (Wang et al) teaches and describes a system and method of impedance cardiography monitoring using body-mounted electrodes to collect EKG signals which are then mathematically processed to predict stroke volume. U.S. Pat. No. 5,423,326 (Wang et al) teaches and describes apparatus and method for measuring cardiac output in which transducers are attached to a patient's body and the signals generated and collected by these transducers are transformed and analyzed to correlate these signals to cardiac output. U.S. Pat. No. 5,309,917 (Wang et al) teaches and describes a system and method of impedance cardiography and heartbeat determination using a combination of thoracic impedance and electrocardiogram signals with the data represented by these signals processed to determine such characteristics as stroke volume and cardiac output. U.S. Pat. No. 5,685,316 (Schookin et al) teaches and describes a non-invasive monitoring of hemodynamic parameters using impedance cardiography. Bioimpedance electrodes are used to collect data across a patient's thoracic region and the data so collected are analyzed and correlated to heart stroke volume from which cardiac output is calculated. Although diagnostically useful, the foregoing art references demonstrate serious drawbacks ranging from the size, complexity and expense of the equipment used to obtain information to the requirement that the instruments used to collect the data. As an example, thoracic impedance systems use EKG leads which must be accurately positioned on and attached to a patient's body in order to effect the collection of data that is later translated into values for cardiac output. In a text entitled “Magnetic Resonance of the Heart and Great Vessels”, edited by J. Bogaert, A. J. Duerinckx and F. E. Rademakers (Springer-Verlag, Berlin 2000) the principles of MRI as applied to cardiology are set forth in Chapter 1, entitled “Techniques for Cardiac MRI”, written by H. Bosmans. MRI examination begins with placing the patient within a strong, static magnetic field which aligns the spins of the protons contained in body tissues and fluids. Thereafter a radio frequency (RF) pulse is used to excite the protons and disturb the alignment of the protons with the magnetic field. A coil or detector is used to capture the signal produced by this change in alignment and return to the original alignment. The signal is influenced by two “relaxation times”, T1 and T2, generally described as measuring the times it takes the longitudinal and transverse components of the “excited” protons to return to the aligned state. The resulting signals are characteristic of the type of tissue being examined and are processed to create an image of the tissues being studied. The use of MRI in cardiac examination is also described in the March 2001 issue of Medica Mundi in an article reprinted from “Heart Care” written by E. Nagel and E. Fleck, beginning at page 23. At page 29 of the article, the use of MRI to determine blood flow velocities is discussed and the need for more accuracy in the equipment used is identified. MRI technology is used to diagnose coronary disease by examining the flow of blood through blood vessels located in the arms. In one such proposed technique, the flow of blood is occluded with an inflatable cuff and MRI is used to measure the dilation of the blood vessels and the shear stress generated by the force of blood flow against the endothelial cells. Under normal circumstances, the endothelial cells will produce the chemical nitric oxide to cause the coronary arteries to widen thus increasing blood flow to the heart and other muscles during times of stress. In a patient with coronary artery disease this effect my be greatly attenuated. Accordingly, the need exists for apparatus and methods to determine cardiac output which are wholly non-invasive, require no leads or other data collection devices to be attached to the patient, utilize recognized accurate diagnostic techniques such as MRI and which may be used in obtaining quick and accurate measurement of cardiac output without requiring significantly complex placement or measurement techniques. A further object of the present invention is to provide an MRI unit which is relatively small and inexpensive yet which provide the precision and resolution necessary to make accurate measurements of cardiac output. A further object is to make such equipment easy to operate without the use of time-consuming or complex diagnostic techniques. A further object is to provide methods for the use of such equipment to make the required measurements carrying out such measurements on a patient's extremities rather than the thoracic cavity or the heart itself. A further object is to avoid the use of drugs, analytes, dyes, tracers and other foreign substances. The present invention is concerned with apparatus and methods to carry out the analysis of blood flow, preferably in the radial and ulnar arteries. The apparatus consists of an MRI unit significantly smaller in size than the fill-body MRI units presently used to conduct cardiovascular examination. A pair of opposed magnet assemblies joined by a magnetically conductive yoke defines an air gap between the assemblies. When a patient's arm is placed within the air gap the unit is used to carry out MRI analysis of the blood vessels in the arm. Internal and peripheral shimming mechanisms allow the uniformity of the magnetic field to be adjusted, and the configuration of the magnets creates a magnetic field of about 1.0 tesla. A preferred configuration of the apparatus will be approximately 60 cm. by 60 cm. in cross-sectional size, about 40 cm. and will weigh about 250 kg. BRIEF DESCRIPTION OF THE DRAWINGS These and firther objects of the present invention will become more apparent upon consideration of the accompanying drawings wherein: FIG. 1 is an illustration showing use of apparatus embodying the present invention to examine the arm of a supine patient; FIG. 2 is an illustration showing use of the present invention to examine the arm of a patient seated at a desk; FIG. 3 is a partial sectional view of a first permanent magnet arrangement designed for use with the present invention; FIG. 4 is a view along 4-4 of FIG. 3; FIG. 5 is a partial sectional view of a second permanent magnet arrangement designed for use with the present invention; FIG. 6 is an enlarged sectional view of an adjustable pole piece shim shown in FIG. 5; FIG. 7 is a view along 7-7 of FIG. 5; FIG. 8 is a cross-section of a patient's arm illustrating measurement of the radial and ulnar arteries; FIG. 9 is a schematic view of an RF coil array used with the present invention; FIG. 10 is a cross-sectional view of a sleeve worn by a user of the present invention; FIG. 11 is a lateral view of a second embodiment of the pole piece of FIG. 1; FIG. 12 is a plan view of the cubic elements making up the pole piece of FIG. 11; FIG. 13 is a partial view of a pole piece segment; and FIG. 14 is a partial lateral view of a second embodiment of the shim rings of FIG. 1. While the following describes a preferred embodiment or embodiments of the present invention, it is to be understood that this description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures. Referring now to FIG. 1, the numeral 10 indicates generally a diagnostic apparatus consisting generally of a cabinet 12 within which a permanent magnet assembly is disposed. Access to the cabinet is via a port 14 through which a patient 16 inserts his or her arm to place the arm within a magnetic field created by the magnet assembly. As seen in FIG. 2, the same apparatus can be used for a patient 18 when in the supine position. Apparatus 10 is relatively lightweight, compact in size and capable of providing real-time data. Referring now to FIG. 3, the numeral 20 indicates generally a sectional view of a first permanent magnet assembly designed for use in diagnostic apparatus 10. Assembly 20 consists of a steel main magnet 22 formed as a solid right circular cylindrical section having a vertical axis A. A circular toroidal side magnet 24 is positioned coaxially with main magnet 22 about axis A and in this preferred embodiment has a rectangular or square cross-section. A steel pole piece 26, formed as a solid right cylindrical section equal in diameter to main magnet 22 is positioned in face-to-face contact with main magnet 22 at main magnet face 28. This entire assembly is positioned within a hollow steel sleeve 30 which is closed off by a steel end cap 32. In a preferred embodiment of the present invention, first permanent magnet assembly 20 is placed in face-to-face relationship with an identical permanent magnet assembly 34 having identical components to and spaced apart from first magnet assembly 20 to form an air gap 36 therebetween. Sleeve 30 extends to enclose magnet assemblies 20,34 and air gap 36. A pair of removable side walls 38,40 allow access to air gap 36 when removed from sleeve 30. Permanent magnet assemblies 20, 34 are opposite in polarity to create a magnetic flux field across air gap 36. A centrally located segment of air gap 36 is identified in FIG. 3 as diagnostic zone 42 across which the magnetic flux is at its most powerful and its most uniform. Magnet assembly 20 includes means for adjusting the flux field across zone 42. In a first embodiment of magnet assembly 20, pole piece 26 has a first centrally located cylindrical cavity 44 formed in interior face 26a. A second, circular cavity 46 is formed coaxial with cavity 44 and a third circular pole piece cavity 48 is similarly formed, coaxial with cavities 44 and 46. Disposed within cavity 44 is a first cylindrical steel shim 50. Disposed within second circular cavity 46 is a toroidal steel shim 52 and disposed within third circular cavity 48 is a second toroidal steel shim 54. Each shim 50, 52, 54 is adjustable along an axis parallel to axis A of permanent magnet assembly 20. A preferred embodiment of the adjusting mechanisms for shim 54 is shown in FIG. 3. A shaft 56 is bored through terminating in a countersink 58 larger in diameter than that of shaft 56 and extending to face 60 of pole piece 26. A threaded fastener, such as a bolt 62, is journalled to shim 54 and shim 54 may be adjusted with respect to face 60 by turning bolt 62 to move shim 54 toward or away from face 60. At least three such bolts are attached to shim 54 and are placed equidistantly about the circumference of shim 54. FIG. 4 is a view taken along 4-4 of FIG. 3 and illustrates the positioning of the shafts and adjusting bolts for each of the shims. In FIG. 4, bolts 62, 64 and 66 are attached to and serve to adjust shim 54. In like fashion, bolts 68, 70 and 72 are attached to and work to adjust first shim 52. Bolts 74, 76 and 78 are journalled to and serve to adjust cylindrical shim 50. In a preferred embodiment of magnet assembly 20, a second set of toroidal steel shims are provided for the purpose of strengthening and adjusting the linearity of the magnetic flux field across air gap 36. As seen in FIG. 3, steel sleeve 30 has a circumferentially extending channel 80, a concentric set of toroidal steel shims 82, 84, 86 are positioned in channel 80 and are supported and adjusted by a series of adjusting bolts such as those described in connection with shims 50, 52 and 54. As seen in FIG. 3, a bore 88 is formed extending through end cap 32 and having a countersink 90 formed at the end thereof. An adjusting bolt 92 is threadedly journaled to sleeve shim 82. A minimum of three such adjusting bolts are provided for each said shim and, as seen in FIG. 4, identical adjusting bolts are provided for sleeve shims 84 and 86. FIG. 4 shows, in section, bolts disposed in bores such as bore 88, with bolts 92, 94 and 96 attached to shim 84, bolts 98, 100 and 102 attached to shim 84 and bolts 104, 106, and 108 attached to shim 86. Referring now to FIG. 5 the numeral 110 indicates generally a sectional view of a second permanent magnet assembly designed for use in diagnostic apparatus 10. Magnet assembly 110 consist of a steel main magnet 112, formed as a solid right circular section having an axis B. A circular toroidal side magnet 114 is positioned coaxially with main magnet 112 about axis B. In the embodiment shown herein, side magnet 114 has a square cross section although cross sections of varying shapes may be selected. A steel pole piece 116, formed as a right solid cylindrical section equal in diameter to main magnet 112 is positioned in face-to-face with main magnet 112 and main magnet face 118. The entire assembly is positioned within a right cylindrical steel sleeve 120 which is closed off by a cylindrical steel end cap 122. As with first magnet assembly 20, and consistent with a preferred embodiment of the present invention, second permanent magnet assembly 110 is placed within sleeve 120 in face-to-face relationship with an identical, mirror image permanent magnet assembly 124 having identical components and construction and spaced apart from second magnet assembly 110 to form an air gap 126 therebetween. Steel sleeve 30 extends to enclose magnet assemblies 110, 124 and air gap 126. A pair of removable side walls 128, 130 allow access to air gap 126 when removed from sleeve 120. Permanent magnet assemblies 110, 124 are opposite in polarity to create a magnetic flux field across air gap 126. A centrally located segment of air gap 126 is identified in FIG. 5 as a diagnostic zone 132 across which the magnetic flux is at its most powerful and uniform. For purposes of illustration, face 118 of main magnet 112 has a north polarity while the corresponding face of the main magnet in magnet assembly 124 has a south polarity. As with magnet assembly 20, magnet assembly 110 includes means for adjusting the linearity of the flux field across air gap 126. In this second permanent magnet assembly embodiment, 110, exterior face 116a of pole piece 116 has a first centrally located cylindrical cavity 134 formed therein. A second, circular cavity 136 is formed coaxial with cavity 134 and a third circular pole piece cavity 138 is similarly formed, coaxial with cavities 134 and 136. As seen in FIG. 5, a first steel shim 140 is disposed within cavity 44. Shim 140 is formed as a solid right cylindrical section or disk. Disposed within second circular cavity 136 is second steel shim 142 formed as a toroid and disposed with a third circular cavity 138 is a third steel shim 144 also formed as a toroid. In the preferred embodiment shown in FIG. 5, shims 142 and 144 are formed with square or rectangular cross-sectional shapes although other shapes may be selected as found desirable or necessary. Each shim 140, 142 and 144 is adjustable along an axis parallel to axis B of permanent magnet assembly 110. A preferred embodiment of the adjusting mechanism for shim 144 is shown in FIG. 6. Shim 144 has a series of tapped or threaded apertures 146 formed parallel to axis B. In a preferred embodiment, apertures 146 are formed midway to the inner and outer diameters of shim 144 and at regularly spaced intervals. For example, three such apertures may be formed displaced one from the other by an angle of 120 degrees. An adjusting screw 148 has a head 150 and a shaft 152, with shaft 152 sized and threaded to engage tapped aperture 146. End 154 of shaft 152 is rotatably journalled to and supported by a support 156, allowing screw 148 to rotate in either a clockwise or counterclockwise direction. As screw 148 is rotated, shim 144 travels along shaft 152 as shaft 152 threads along tapped aperture 146. Referring again to FIG. 5, a series of sleeve shims 252, 254 and 256 are shown concentrically disposed in a circumferentially extending channel 258 formed in sleeve 120. Shims 252, 254 and 256 are axially adjustable in the same manner as sleeve shims 82, 84 and 86 shown in FIG. 3. A representative threaded adjusting bolt 260 passes through a threaded bore 262 with bolt head 264 seated in countersink 266. Bolt end 268 is journaled to sleeve shim 252 in the same manner as shown in FIG. 6 and shim 252 is adjusted axially by threading bolt 260 along bore 262. Preferably, at least three such adjusting bolts are provided for each sleeve shim, spaced at regular intervals. Referring to FIG. 7, shim 144 is shown in cavity 138 and supported by adjusting screws 148, 158 and 160. Similarly, shim 142 is shown in cavity 134 and supported by adjusting screws 162, 164 and 166. Central disk shaped shim 140 is shown in cavity 132 and is supported by adjusting screws 168, 170 and 172. When assembled, the pole piece shims and annular shims described above are adjusted to produce a magnetic field across air gap 36 and air gap 126 with a high degree of uniformity in field strength and field direction. Apparatus 10 is used to practice non-invasive methods of assessing total cardiac output, relative cardiac output, arterial wall thickness and elasticity and flow mediated dilation. Measurement of these finctions is carried out non-invasively on a real-time basis and in a setting which is convenient and comfortable for the patient. These measurements are used for initial examinations and to track changes in the circulatory system before and after a given treatment. Use of apparatus 10 in carrying out MRI examinations is not subject to the variations and results produced using such techniques as ultrasound where personnel must be highly trained to position accurately the probe used during examinations. In a preferred embodiment of the present invention, apparatus 10 is used to perform an MRI examination of the radial and ulnar arteries in a patient's arm. Referring now to FIG. 8, the numeral 174 identifies the arm of a patient shown in a schematic-type cross-section. For the purposes of illustrating the present invention, reference will be made to the permanent magnet arrangement shown in FIG. 3. Arm 174 is placed within apparatus 10 as shown in FIGS. 1 or 2 with arm 174 extending through air gap 36 and positioned within diagnostic zone 42. An RF coil 176 is positioned above arm 174 and a gradient or pickup coil 178 is positioned beneath arm 174 to receive the signal created when RF coil 176 is pulsed. As seen schematically in FIG. 8, the radial and ulnar bones 180, 182 are shown, as are the radial and ulnar arteries 184, 186. As the heart beats, the blood pressure within the body's arterial blood vessels varies from a maximum (systolic) and minimum (diastolic) value. The systolic blood pressure represents pressure within the blood vessel during a heartbeat while the diastolic pressure is that measured when the heart is at rest between beats. Arteries 184, 186 are shown during the diastolic portion of the heartbeat cycle. When the heart beats, arteries such as 184, 186 expand as shown at 188, 190. The apparatus and methods of the present invention measure and record the changes in size of arteries 184, 186 with the heartbeat and between heartbeats. In this fashion, the cross-sectional area of arteries 184, 186 can be determined. It is also known to determine the rate of flow of blood using commonly applicable MRI techniques and the combination of the determination of artery cross-sectional area and rate of flow allows calculation of the portion of the total cardiac output passing through the representative arteries during a heartbeat. This information can be used to establish a baseline cardiac output for a patient with any deviation in output over time operating as an indicator that the patient's cardiac condition has changed. Cardiac output can also be calculated by using known values of the percentage of cardiac output normally passing through the radial and ulnar arteries and using this ratio to estimate total cardiac output. For the purposes of this description, total cardiac output is defined as the volume of blood pumped from the heart with each beat, approximately 12% of which moves through the brachial arteries of each arm with each beat and the detected blood flow volume can be compared to tables of known blood flow ratios for patients of different ages, weights and other variables. MRI allows a cross-section to be taken that includes both arteries 184, 186 simultaneously. In order to create a high resolution image, it may be necessary to reposition the arm within the magnetic field prior to pulsing the RF electrodes. An alternative to physical repositioning is the use of an array of electrodes and a computer program to adjust the pulsing of the electrodes to produce improved images. For purposes of accuracy, pick up coil 178 should be positioned as close as possible to the arteries being measured. Use of the relatively small diagnostic area 42 makes this possible and readings can be taken with the patient's arm extending into apparatus 10 with the palm either facing in the upward or downward position or rotated to produce an optimum image of the arteries. Referring now to FIG. 9, the numeral 192 identifies generally an array of RF coils positioned around a patient's arm 194. RF coils such as those used as electrodes in MRI diagnostic equipment can be used as pulsing or receiving coils or can function as both pulsing and receiving coils. For a single coil to both pulse and receive, an rf signal is pulsed through the coil. This transmission is gated and after it has ceased the coil goes through a period of quiescent or “dead” time where no signal is being sent nor received. Thereafter, the coil is activated to receive the data produced by its own pulsed signal. The data signal is also gated to create a second period of dead time, after which the coil may then again be pulsed to transmit another signal. As seen in FIG. 9, an array of RF coils 196, 198, 200 are positioned equidistantly about the circumference of array perimeter 202. It is possible to pulse these coils in sequence to create a “virtual coila” effectively positioned at selected points about the periphery of perimeter 202. It is also possible to mechanically rotate perimeter 202 to bring coils 196, 198, 200 into a different physical location with respect to arm 194. By performing actual or virtual rotation of the positions of coils 196, 198, 200 and selectively using each coil selectively to pulse energy, receive energy or both it is possible to adjust device 10 to produce the clearest possible image of arm 194. To increase the sensitivity and adjustability of array 192, additional RF coils can be added to the array such as coils 204, 206, and 208 and to control the pulsing and collection capabilities of each coil by computer in order to adjust the received image. Referring now to FIG. 10, the numeral 210 identifies a cross-sectional view of a tubular sleeve within which RF coils 212, 214 and 216 are disposed. Sleeve 210 can be formed of fabric and is intended to be slipped over the patient's arm or other appendage and to thereafter be placed within device 10. Sleeve 10 allows coils 212, 214, 216 to be placed as close to the area of examination as possible and to provide a uniform dispersion of signal transmission and collection independent of the placement of coils within device 10 itself. As described in connection with array 192, sleeve 210 can include any selected number of coils and the arrangement shown in FIG. 10 is by way of example only. Sleeve 210 can be formed as a permanent, flexible and expandable cuff or can be formed as a disposable unit which can be discarded after use. Sleeve 210 can be provided in a range of sizes to accommodate extremities of varying proportions, can be written upon to record patient information, and can contain various numbers and configurations of coils and coil leads that can selectively be connected to provide energy to selected coils. Referring now to FIG. 11, an alternative construction for pole pieces such as pole piece 60 is shown. FIG. 11 is a cross-sectional view of a pole piece 218 constructed as a series of laminae 220, 224, 226, 228 and 230 glued together in a solid array by non-conductive epoxy glue or other well-known well-known permanet adhesives. As seen in FIG. 12, a section of laminae 220 is shown in partial perspective. Each laminae is formed of a series of cubes 232 preferably extruded from ferromagnetic material and glued together with the adhesives described above. In a preferred embodiment of the invention, each cube is approximately 10 mm by 10 mm by 10 mm. When cubes 232 have been solidly glued into a planar array, each such array is stacked and glued to corresponding arrays to produce the structure shown in FIG. 11. The completed array may then be machined to the shape desired to use the completed array as a pole piece. Use of cubic elements are believed to limit the eddy currents created within the ferromagnetic pole piece when the RF coils are pulsed. Referring now to FIG. 13, a top plan view of a segment of pole piece 218 is shown illustrating the appearances of cubes 232 when cemented into the array and shaped to be used as a pole piece. In assembling a laminated pole piece such as 218, cubes 232 are arranged such that the interfaces of adjacent cubes are offset from the interfaces of the cubes in the layers immediately above and below thereby adding strength to the array. Referring now to FIG. 14, the numeral 234 identifies a segment of an alternative construction of the torroidal shim rings such as 54 of FIG. 3. The embodiment of FIG. 14 shows shim 234 assembled from overlapping segments 236, 238 with segment 236 having an upper edge 240 and intermediate land 242 and a lower edge 244 while segment 238 has an upper edge 246 an intermediate land 248 and a lower edge 250. When assembled, edges 240, 246 abut as do lands 242, 248 and lower edges 244, 250. At each of these abutments, an epoxy or other suitable adhesive is used to permanently attach the segments together. It is also contemplated that the torroidal and disk-shaped shims described earlier can also be constructed from laminae in the manner shown in FIGS. 11, 12, and 13. In such constructions, it is contemplated that cubes 232, when used in shim constructions, can be extruded from ferromagnetic metals, non-ferromagnetic metals, non-metallic substances or magnetic material. While not herein specifically shown, it is acknowledged that the use of electromagnetic gradient coils as shims to adjust the linearity and shape of the magnetic field of a permanent magnet array is well known and can be included in the arrangements described herein. Such shim coils can also be used as gradient coils by pulsing the coils to intentionally distort the field of view to aid in distinguishing between tissues of different types. Preferably, separate shim and gradient coils are used to keep voltage to the shim coils constant. The disclosed methods and apparatus offer advantages over prior known MRI diagnostic methods in that a relatively small permanent magnet arrangement is used to produce a high strength uniform and high resolution magnetic field across a very small part of the body. This is a much different approach than that described in the Nagel and Fleck article referenced above in which a patient is “positioned within the bore of a cylindrical superconducting magnet.” The strength of the magnetic field produced by the present invention is estimated in excess of 1.0 tesla and the relatively small size of the body portion being sampled creates an image with a higher signal-to-noise ratio than can be achieved when the entire body is placed within a magnetic field. The resulting high resolution images allow the changes in size of the arteries to be accurately determined. When performing MRI diagnostic procedures, care must be taken to avoid damage to nerves caused by too high a field gradient across the area of the body being examined. For the purposes of this description, the field gradient is described as the strength of the magnetic field divided by the area of the field of view in question. Using the greatly reduced field of view made possible by the present invention, allows for higher gradients to be safely used when examining patients. This results in higher resolution images and more accurate diagnostic information. Total cardiac output can be estimated by relating the radial and ulnar arteries and comparing these measurements to known values of percentages of cardiac output measured through such arteries. Use of the present invention thus allows cardiac functions to be examined in a strong, small magnetic field with a relatively high field gradient. This will also result in the capability of using rapid pulses to produce accurate images showing the changes in size of the arteries in question. The apparatus described herein uses less energy and is less expensive to build than the presently known full body type MRI diagnostic units. In evaluating cardiac function, the RF pulses may be timed to commence with the heartbeat and can be used to track changes in the heartbeat. Alternatively, use of the present invention may be used without using the heartbeat as a trigger or marker with the apparatus being operated through a sufficient number of cycles to guarantee that an entire cycle has been captured and accurately characterized. Use of MRI to create images of arteries 186, 188 is superior to the use of ultrasound because MRI produces a cross-sectional view which allows the system to track the changes in size and configuration of arteries 186, 188. Ultrasound, on the other hand will provide only a lateral view and even though this lateral view can show changes in the apparent diameter of the arteries, it does not provide an accurate view of the actual cross-sectional configuration of the artery. Where an artery is, for example, not perfectly round or in some way impeded, the cross-section will be less than circular. However, MRI will enable the operator to determine the exact shape and, therefore, area of the cross-section and to calculate the blood flow therethrough. Measurement of FMD using the radial and ulnar arteries has been shown to have a 95% correlation with the same measurements when measured at the coronary arteries. Measuring FMD, or endothelial dysfunction, correlates with well-known risk factors used to assess the health of the patient's cardiovascular system Using a multi-spectral or multi-contrast technique allows the technician to accurately determine the presence and thickness of any plaque layers in the artery, another indicator of general cardiovascular health. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates generally to the measurement of cardiac output and, more particularly, to apparatus and methods for non-invasively measuring cardiac output and claims priority from application Ser. No. 60/467015 of the same title, filed 01 May 2003. Cardiac output is the volume of blood pumped by the heart during a given interval of time. Measuring cardiac output is a diagnostic technique used to evaluate cardiac function and detect the presence of cardiovascular disease or abnormality. Normally, cardiac output varies to meet the body's demand for oxygen and for nutrition. The left side of the heart receives oxygenated blood from the lungs and contracts, pumping the blood through arteries to all parts of the body. Blood flow is affected by such factors as the contractility of the left ventricle, the resistance against which the heart must pump and the volume of blood in the ventricle when pumping occurs. Changes in cardiac output may indicate disease or may be evidence of an abnormality or change in a patient's cardiovascular system. Accordingly, measurement of cardiac output is a useful diagnostic tool and detection of changes in cardiac output may allow a physician to investigate a patient's condition more thoroughly and take measures to prevent serious or permanent damage. Ideally, measurement of cardiac output should be quick, convenient, safe for the patient and should use equipment and techniques which are reliable, easy to operate and accurate. There are a number of known techniques and devices for measuring cardiac output. One is the Fick method based upon work done by Adolph Fick in about 1870. As performed today, the Fick method involves injecting a measured amount of oxygen into an artery and then measuring the concentration of oxygen at a selected site downstream of the injection site. Typically, such a procedure involves the insertion of two catheters into a patient's body, one for the injection of the oxygen and the other for the collection of blood which is then analyzed and the oxygen content determined. While this technique produces satisfactorily accurate results, it does require surgically invasive procedures and the removal of an appreciable amount of blood which must then be analyzed, resulting in a measurement that is not a real time measurement. Whenever an invasive procedure is performed, it carries with it the attendant risk of possible infection. In another technique for measuring cardiac output a dye is injected into the bloodstream and the dye concentration is measured at a point downstream of the injection site. Alternatively, a bolus of a chilled fluid indicator is injected and the temperature of blood withdrawn from a site downstream of the injection site is measured. These and other cardiac output measurement techniques are well represented in the prior art. The following references are representative of known invasive measurement techniques. U.S. Pat. No. 5,797,395 (Martin) teaches and describes a continuous cardiac output derived from arterial pressure wave form using pattern recognition. Martin uses a fluid catheter installed in the bloodstream to measure the arterial pressure of a patient and to digitize the data collected by the sensors. The collected data is then compared to representative data stored in a database with representative wave forms corresponding to various levels of cardiac output. U.S. Pat. No. 6,299,583 (Eggers) teaches and describes monitoring total circulating blood volume and cardiac output. Eggers et al uses a variation of the indicator dilution technique in which a test substance or analyte is injected into the body. As seen in FIG. 1 of Eggers et al, analyte is injected into the bloodstream by way of a catheter inserted into the subclavian vein leading to the heart. A catheter with a sensor is inserted into, for example, the radial artery in one of the patient's arms and is used to detect and measure the concentration of analyte. U.S. Pat. No. 6,186,956 (McNamee) teaches and describes a method and system for continuously monitoring cardiac output without having to inject substances into the patient's body nor withdraw liquids from the body. McNamee does so by using a pressure transducer placed in a patient's mouth or a tracheal cannula in measuring the differential in pressure as the patient breathes in and out. The detection of this signal is then correlated to a table of known values from which cardiac output is deduced. McNamee references the use of MRI as an acceptable non-invasive measurement technique and also states that such techniques typically require large, expensive equipment and highly trained technicians to operate the equipment and interpret the results. U.S. Pat. No. 6,322,518 (Young et al) teaches and describes a method and apparatus for measuring cardiac output which utilizes an esophageal probe inserted down the patient's throat to measure thoracic impedance variations which are then correlated to a measurement of cardiac output. Even minimally invasive procedures require skilled technicians, risk infection and allergic responses, and cause apprehension and discomfort in the patient. The advantages of using non-invasive techniques for measuring cardiac output have been recognized in the prior art. U.S. Pat. No. 6,306,098 (Orr et al) teaches and describes apparatus and method for non-invasively measuring cardiac output. Orr et al use a modification of the Fick approach, measuring the difference in carbon dioxide concentration between the air inhaled and exhaled by a patient through a breathing tube rather than measuring concentration of oxygen at disparate points in the patient's bloodstream. A computer program is used to calculate cardiac output based upon the differential in carbon dioxide concentration. U.S. Pat. No. 5,458,126 (Cline et al) teaches and describes a cardiac finctional analysis system employing gradient image segmentation. Cline et al describe the use of techniques such as computed axial tomography (CAT) and MRI to create a four-dimensional data set to create images of selected portions of the cardiovascular system. Cline et al are representative of the use of complex, expensive and quite large equipment to carry out these measurements. U.S. Pat. No. 5,417,214 (Roberts et al) teaches and describes quantitative blood flow measurement using steady-state transport induced adiabatic fast passage. Again, Roberts et al is representative of the complexity presently experienced in the use of MRI to carry out cardiovascular measurements and evaluation. In particular, at column 5 , lines 26 et seq. Roberts et al describe the necessity for precise techniques for gathering the data used in the analysis. U.S. Pat. No. 6,348,038 (Band et al) teaches and describes method and apparatus for the measurement of cardiac output using the wave form created by the measurement of arterial blood pressure in a patient. The collected data is used to determine nominal stroke volume and using this determination to obtain a nominal value for the patient's cardiac output. U.S. Pat. No. 5,360,005 (Wilk) teaches and describes a medical diagnosis device for sensing cardiac activity and blood flow. Wilk uses an acousto-electric transducer as a type of stethoscope to convert heart sounds into electric impulses and then uses a microprocessor to analyze these impulses and correlate them to cardiovascular activity. U.S. Pat. No. 4,509,526 (Barnes et al) teaches and describes method and system for non-invasive ultrasound Doppler cardiac output measurement. Barnes et al teach the positioning of a transducer at separate locations on a patient's body to determine ultrasonically the cross-sectional area of a patient's ascending aorta and to determine the systolic velocity profile of blood flow through the aorta, enabling the calculation of cardiac output. To practice the technique described in Barnes et al the transducer must be accurately positioned by a technician at two separate sites in order to generate the data required to make the calculations necessary to determine cardiac output. U.S. Pat. No. 5,178,151 (Sackner) teaches and describes a system for non-invasive detection of changes of cardiac volumes and aortic pulses. Sackner et al use transducers positioned on the patient's body to send and receive signals which include a wave form characteristic of the ventricular volume and then continuously monitors to detect changes in the wave form. U.S. Pat. No. 5,443,073 (Wang et al) teaches and describes a system and method of impedance cardiography monitoring using body-mounted electrodes to collect EKG signals which are then mathematically processed to predict stroke volume. U.S. Pat. No. 5,423,326 (Wang et al) teaches and describes apparatus and method for measuring cardiac output in which transducers are attached to a patient's body and the signals generated and collected by these transducers are transformed and analyzed to correlate these signals to cardiac output. U.S. Pat. No. 5,309,917 (Wang et al) teaches and describes a system and method of impedance cardiography and heartbeat determination using a combination of thoracic impedance and electrocardiogram signals with the data represented by these signals processed to determine such characteristics as stroke volume and cardiac output. U.S. Pat. No. 5,685,316 (Schookin et al) teaches and describes a non-invasive monitoring of hemodynamic parameters using impedance cardiography. Bioimpedance electrodes are used to collect data across a patient's thoracic region and the data so collected are analyzed and correlated to heart stroke volume from which cardiac output is calculated. Although diagnostically useful, the foregoing art references demonstrate serious drawbacks ranging from the size, complexity and expense of the equipment used to obtain information to the requirement that the instruments used to collect the data. As an example, thoracic impedance systems use EKG leads which must be accurately positioned on and attached to a patient's body in order to effect the collection of data that is later translated into values for cardiac output. In a text entitled “Magnetic Resonance of the Heart and Great Vessels”, edited by J. Bogaert, A. J. Duerinckx and F. E. Rademakers (Springer-Verlag, Berlin 2000) the principles of MRI as applied to cardiology are set forth in Chapter 1, entitled “Techniques for Cardiac MRI”, written by H. Bosmans. MRI examination begins with placing the patient within a strong, static magnetic field which aligns the spins of the protons contained in body tissues and fluids. Thereafter a radio frequency (RF) pulse is used to excite the protons and disturb the alignment of the protons with the magnetic field. A coil or detector is used to capture the signal produced by this change in alignment and return to the original alignment. The signal is influenced by two “relaxation times”, T 1 and T 2 , generally described as measuring the times it takes the longitudinal and transverse components of the “excited” protons to return to the aligned state. The resulting signals are characteristic of the type of tissue being examined and are processed to create an image of the tissues being studied. The use of MRI in cardiac examination is also described in the March 2001 issue of Medica Mundi in an article reprinted from “Heart Care” written by E. Nagel and E. Fleck, beginning at page 23. At page 29 of the article, the use of MRI to determine blood flow velocities is discussed and the need for more accuracy in the equipment used is identified. MRI technology is used to diagnose coronary disease by examining the flow of blood through blood vessels located in the arms. In one such proposed technique, the flow of blood is occluded with an inflatable cuff and MRI is used to measure the dilation of the blood vessels and the shear stress generated by the force of blood flow against the endothelial cells. Under normal circumstances, the endothelial cells will produce the chemical nitric oxide to cause the coronary arteries to widen thus increasing blood flow to the heart and other muscles during times of stress. In a patient with coronary artery disease this effect my be greatly attenuated. Accordingly, the need exists for apparatus and methods to determine cardiac output which are wholly non-invasive, require no leads or other data collection devices to be attached to the patient, utilize recognized accurate diagnostic techniques such as MRI and which may be used in obtaining quick and accurate measurement of cardiac output without requiring significantly complex placement or measurement techniques. A further object of the present invention is to provide an MRI unit which is relatively small and inexpensive yet which provide the precision and resolution necessary to make accurate measurements of cardiac output. A further object is to make such equipment easy to operate without the use of time-consuming or complex diagnostic techniques. A further object is to provide methods for the use of such equipment to make the required measurements carrying out such measurements on a patient's extremities rather than the thoracic cavity or the heart itself. A further object is to avoid the use of drugs, analytes, dyes, tracers and other foreign substances. The present invention is concerned with apparatus and methods to carry out the analysis of blood flow, preferably in the radial and ulnar arteries. The apparatus consists of an MRI unit significantly smaller in size than the fill-body MRI units presently used to conduct cardiovascular examination. A pair of opposed magnet assemblies joined by a magnetically conductive yoke defines an air gap between the assemblies. When a patient's arm is placed within the air gap the unit is used to carry out MRI analysis of the blood vessels in the arm. Internal and peripheral shimming mechanisms allow the uniformity of the magnetic field to be adjusted, and the configuration of the magnets creates a magnetic field of about 1.0 tesla. A preferred configuration of the apparatus will be approximately 60 cm. by 60 cm. in cross-sectional size, about 40 cm. and will weigh about 250 kg. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>These and firther objects of the present invention will become more apparent upon consideration of the accompanying drawings wherein: FIG. 1 is an illustration showing use of apparatus embodying the present invention to examine the arm of a supine patient; FIG. 2 is an illustration showing use of the present invention to examine the arm of a patient seated at a desk; FIG. 3 is a partial sectional view of a first permanent magnet arrangement designed for use with the present invention; FIG. 4 is a view along 4 - 4 of FIG. 3 ; FIG. 5 is a partial sectional view of a second permanent magnet arrangement designed for use with the present invention; FIG. 6 is an enlarged sectional view of an adjustable pole piece shim shown in FIG. 5 ; FIG. 7 is a view along 7 - 7 of FIG. 5 ; FIG. 8 is a cross-section of a patient's arm illustrating measurement of the radial and ulnar arteries; FIG. 9 is a schematic view of an RF coil array used with the present invention; FIG. 10 is a cross-sectional view of a sleeve worn by a user of the present invention; FIG. 11 is a lateral view of a second embodiment of the pole piece of FIG. 1 ; FIG. 12 is a plan view of the cubic elements making up the pole piece of FIG. 11 ; FIG. 13 is a partial view of a pole piece segment; and FIG. 14 is a partial lateral view of a second embodiment of the shim rings of FIG. 1 . detailed-description description="Detailed Description" end="lead"? While the following describes a preferred embodiment or embodiments of the present invention, it is to be understood that this description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures. Referring now to FIG. 1 , the numeral 10 indicates generally a diagnostic apparatus consisting generally of a cabinet 12 within which a permanent magnet assembly is disposed. Access to the cabinet is via a port 14 through which a patient 16 inserts his or her arm to place the arm within a magnetic field created by the magnet assembly. As seen in FIG. 2 , the same apparatus can be used for a patient 18 when in the supine position. Apparatus 10 is relatively lightweight, compact in size and capable of providing real-time data. Referring now to FIG. 3 , the numeral 20 indicates generally a sectional view of a first permanent magnet assembly designed for use in diagnostic apparatus 10 . Assembly 20 consists of a steel main magnet 22 formed as a solid right circular cylindrical section having a vertical axis A. A circular toroidal side magnet 24 is positioned coaxially with main magnet 22 about axis A and in this preferred embodiment has a rectangular or square cross-section. A steel pole piece 26 , formed as a solid right cylindrical section equal in diameter to main magnet 22 is positioned in face-to-face contact with main magnet 22 at main magnet face 28 . This entire assembly is positioned within a hollow steel sleeve 30 which is closed off by a steel end cap 32 . In a preferred embodiment of the present invention, first permanent magnet assembly 20 is placed in face-to-face relationship with an identical permanent magnet assembly 34 having identical components to and spaced apart from first magnet assembly 20 to form an air gap 36 therebetween. Sleeve 30 extends to enclose magnet assemblies 20 , 34 and air gap 36 . A pair of removable side walls 38 , 40 allow access to air gap 36 when removed from sleeve 30 . Permanent magnet assemblies 20 , 34 are opposite in polarity to create a magnetic flux field across air gap 36 . A centrally located segment of air gap 36 is identified in FIG. 3 as diagnostic zone 42 across which the magnetic flux is at its most powerful and its most uniform. Magnet assembly 20 includes means for adjusting the flux field across zone 42 . In a first embodiment of magnet assembly 20 , pole piece 26 has a first centrally located cylindrical cavity 44 formed in interior face 26 a . A second, circular cavity 46 is formed coaxial with cavity 44 and a third circular pole piece cavity 48 is similarly formed, coaxial with cavities 44 and 46 . Disposed within cavity 44 is a first cylindrical steel shim 50 . Disposed within second circular cavity 46 is a toroidal steel shim 52 and disposed within third circular cavity 48 is a second toroidal steel shim 54 . Each shim 50 , 52 , 54 is adjustable along an axis parallel to axis A of permanent magnet assembly 20 . A preferred embodiment of the adjusting mechanisms for shim 54 is shown in FIG. 3 . A shaft 56 is bored through terminating in a countersink 58 larger in diameter than that of shaft 56 and extending to face 60 of pole piece 26 . A threaded fastener, such as a bolt 62 , is journalled to shim 54 and shim 54 may be adjusted with respect to face 60 by turning bolt 62 to move shim 54 toward or away from face 60 . At least three such bolts are attached to shim 54 and are placed equidistantly about the circumference of shim 54 . FIG. 4 is a view taken along 4 - 4 of FIG. 3 and illustrates the positioning of the shafts and adjusting bolts for each of the shims. In FIG. 4 , bolts 62 , 64 and 66 are attached to and serve to adjust shim 54 . In like fashion, bolts 68 , 70 and 72 are attached to and work to adjust first shim 52 . Bolts 74 , 76 and 78 are journalled to and serve to adjust cylindrical shim 50 . In a preferred embodiment of magnet assembly 20 , a second set of toroidal steel shims are provided for the purpose of strengthening and adjusting the linearity of the magnetic flux field across air gap 36 . As seen in FIG. 3 , steel sleeve 30 has a circumferentially extending channel 80 , a concentric set of toroidal steel shims 82 , 84 , 86 are positioned in channel 80 and are supported and adjusted by a series of adjusting bolts such as those described in connection with shims 50 , 52 and 54 . As seen in FIG. 3 , a bore 88 is formed extending through end cap 32 and having a countersink 90 formed at the end thereof. An adjusting bolt 92 is threadedly journaled to sleeve shim 82 . A minimum of three such adjusting bolts are provided for each said shim and, as seen in FIG. 4 , identical adjusting bolts are provided for sleeve shims 84 and 86 . FIG. 4 shows, in section, bolts disposed in bores such as bore 88 , with bolts 92 , 94 and 96 attached to shim 84 , bolts 98 , 100 and 102 attached to shim 84 and bolts 104 , 106 , and 108 attached to shim 86 . Referring now to FIG. 5 the numeral 110 indicates generally a sectional view of a second permanent magnet assembly designed for use in diagnostic apparatus 10 . Magnet assembly 110 consist of a steel main magnet 112 , formed as a solid right circular section having an axis B. A circular toroidal side magnet 114 is positioned coaxially with main magnet 112 about axis B. In the embodiment shown herein, side magnet 114 has a square cross section although cross sections of varying shapes may be selected. A steel pole piece 116 , formed as a right solid cylindrical section equal in diameter to main magnet 112 is positioned in face-to-face with main magnet 112 and main magnet face 118 . The entire assembly is positioned within a right cylindrical steel sleeve 120 which is closed off by a cylindrical steel end cap 122 . As with first magnet assembly 20 , and consistent with a preferred embodiment of the present invention, second permanent magnet assembly 110 is placed within sleeve 120 in face-to-face relationship with an identical, mirror image permanent magnet assembly 124 having identical components and construction and spaced apart from second magnet assembly 110 to form an air gap 126 therebetween. Steel sleeve 30 extends to enclose magnet assemblies 110 , 124 and air gap 126 . A pair of removable side walls 128 , 130 allow access to air gap 126 when removed from sleeve 120 . Permanent magnet assemblies 110 , 124 are opposite in polarity to create a magnetic flux field across air gap 126 . A centrally located segment of air gap 126 is identified in FIG. 5 as a diagnostic zone 132 across which the magnetic flux is at its most powerful and uniform. For purposes of illustration, face 118 of main magnet 112 has a north polarity while the corresponding face of the main magnet in magnet assembly 124 has a south polarity. As with magnet assembly 20 , magnet assembly 110 includes means for adjusting the linearity of the flux field across air gap 126 . In this second permanent magnet assembly embodiment, 110 , exterior face 116 a of pole piece 116 has a first centrally located cylindrical cavity 134 formed therein. A second, circular cavity 136 is formed coaxial with cavity 134 and a third circular pole piece cavity 138 is similarly formed, coaxial with cavities 134 and 136 . As seen in FIG. 5 , a first steel shim 140 is disposed within cavity 44 . Shim 140 is formed as a solid right cylindrical section or disk. Disposed within second circular cavity 136 is second steel shim 142 formed as a toroid and disposed with a third circular cavity 138 is a third steel shim 144 also formed as a toroid. In the preferred embodiment shown in FIG. 5 , shims 142 and 144 are formed with square or rectangular cross-sectional shapes although other shapes may be selected as found desirable or necessary. Each shim 140 , 142 and 144 is adjustable along an axis parallel to axis B of permanent magnet assembly 110 . A preferred embodiment of the adjusting mechanism for shim 144 is shown in FIG. 6 . Shim 144 has a series of tapped or threaded apertures 146 formed parallel to axis B. In a preferred embodiment, apertures 146 are formed midway to the inner and outer diameters of shim 144 and at regularly spaced intervals. For example, three such apertures may be formed displaced one from the other by an angle of 120 degrees. An adjusting screw 148 has a head 150 and a shaft 152 , with shaft 152 sized and threaded to engage tapped aperture 146 . End 154 of shaft 152 is rotatably journalled to and supported by a support 156 , allowing screw 148 to rotate in either a clockwise or counterclockwise direction. As screw 148 is rotated, shim 144 travels along shaft 152 as shaft 152 threads along tapped aperture 146 . Referring again to FIG. 5 , a series of sleeve shims 252 , 254 and 256 are shown concentrically disposed in a circumferentially extending channel 258 formed in sleeve 120 . Shims 252 , 254 and 256 are axially adjustable in the same manner as sleeve shims 82 , 84 and 86 shown in FIG. 3 . A representative threaded adjusting bolt 260 passes through a threaded bore 262 with bolt head 264 seated in countersink 266 . Bolt end 268 is journaled to sleeve shim 252 in the same manner as shown in FIG. 6 and shim 252 is adjusted axially by threading bolt 260 along bore 262 . Preferably, at least three such adjusting bolts are provided for each sleeve shim, spaced at regular intervals. Referring to FIG. 7 , shim 144 is shown in cavity 138 and supported by adjusting screws 148 , 158 and 160 . Similarly, shim 142 is shown in cavity 134 and supported by adjusting screws 162 , 164 and 166 . Central disk shaped shim 140 is shown in cavity 132 and is supported by adjusting screws 168 , 170 and 172 . When assembled, the pole piece shims and annular shims described above are adjusted to produce a magnetic field across air gap 36 and air gap 126 with a high degree of uniformity in field strength and field direction. Apparatus 10 is used to practice non-invasive methods of assessing total cardiac output, relative cardiac output, arterial wall thickness and elasticity and flow mediated dilation. Measurement of these finctions is carried out non-invasively on a real-time basis and in a setting which is convenient and comfortable for the patient. These measurements are used for initial examinations and to track changes in the circulatory system before and after a given treatment. Use of apparatus 10 in carrying out MRI examinations is not subject to the variations and results produced using such techniques as ultrasound where personnel must be highly trained to position accurately the probe used during examinations. In a preferred embodiment of the present invention, apparatus 10 is used to perform an MRI examination of the radial and ulnar arteries in a patient's arm. Referring now to FIG. 8 , the numeral 174 identifies the arm of a patient shown in a schematic-type cross-section. For the purposes of illustrating the present invention, reference will be made to the permanent magnet arrangement shown in FIG. 3 . Arm 174 is placed within apparatus 10 as shown in FIGS. 1 or 2 with arm 174 extending through air gap 36 and positioned within diagnostic zone 42 . An RF coil 176 is positioned above arm 174 and a gradient or pickup coil 178 is positioned beneath arm 174 to receive the signal created when RF coil 176 is pulsed. As seen schematically in FIG. 8 , the radial and ulnar bones 180 , 182 are shown, as are the radial and ulnar arteries 184 , 186 . As the heart beats, the blood pressure within the body's arterial blood vessels varies from a maximum (systolic) and minimum (diastolic) value. The systolic blood pressure represents pressure within the blood vessel during a heartbeat while the diastolic pressure is that measured when the heart is at rest between beats. Arteries 184 , 186 are shown during the diastolic portion of the heartbeat cycle. When the heart beats, arteries such as 184 , 186 expand as shown at 188 , 190 . The apparatus and methods of the present invention measure and record the changes in size of arteries 184 , 186 with the heartbeat and between heartbeats. In this fashion, the cross-sectional area of arteries 184 , 186 can be determined. It is also known to determine the rate of flow of blood using commonly applicable MRI techniques and the combination of the determination of artery cross-sectional area and rate of flow allows calculation of the portion of the total cardiac output passing through the representative arteries during a heartbeat. This information can be used to establish a baseline cardiac output for a patient with any deviation in output over time operating as an indicator that the patient's cardiac condition has changed. Cardiac output can also be calculated by using known values of the percentage of cardiac output normally passing through the radial and ulnar arteries and using this ratio to estimate total cardiac output. For the purposes of this description, total cardiac output is defined as the volume of blood pumped from the heart with each beat, approximately 12% of which moves through the brachial arteries of each arm with each beat and the detected blood flow volume can be compared to tables of known blood flow ratios for patients of different ages, weights and other variables. MRI allows a cross-section to be taken that includes both arteries 184 , 186 simultaneously. In order to create a high resolution image, it may be necessary to reposition the arm within the magnetic field prior to pulsing the RF electrodes. An alternative to physical repositioning is the use of an array of electrodes and a computer program to adjust the pulsing of the electrodes to produce improved images. For purposes of accuracy, pick up coil 178 should be positioned as close as possible to the arteries being measured. Use of the relatively small diagnostic area 42 makes this possible and readings can be taken with the patient's arm extending into apparatus 10 with the palm either facing in the upward or downward position or rotated to produce an optimum image of the arteries. Referring now to FIG. 9 , the numeral 192 identifies generally an array of RF coils positioned around a patient's arm 194 . RF coils such as those used as electrodes in MRI diagnostic equipment can be used as pulsing or receiving coils or can function as both pulsing and receiving coils. For a single coil to both pulse and receive, an rf signal is pulsed through the coil. This transmission is gated and after it has ceased the coil goes through a period of quiescent or “dead” time where no signal is being sent nor received. Thereafter, the coil is activated to receive the data produced by its own pulsed signal. The data signal is also gated to create a second period of dead time, after which the coil may then again be pulsed to transmit another signal. As seen in FIG. 9 , an array of RF coils 196 , 198 , 200 are positioned equidistantly about the circumference of array perimeter 202 . It is possible to pulse these coils in sequence to create a “virtual coila” effectively positioned at selected points about the periphery of perimeter 202 . It is also possible to mechanically rotate perimeter 202 to bring coils 196 , 198 , 200 into a different physical location with respect to arm 194 . By performing actual or virtual rotation of the positions of coils 196 , 198 , 200 and selectively using each coil selectively to pulse energy, receive energy or both it is possible to adjust device 10 to produce the clearest possible image of arm 194 . To increase the sensitivity and adjustability of array 192 , additional RF coils can be added to the array such as coils 204 , 206 , and 208 and to control the pulsing and collection capabilities of each coil by computer in order to adjust the received image. Referring now to FIG. 10 , the numeral 210 identifies a cross-sectional view of a tubular sleeve within which RF coils 212 , 214 and 216 are disposed. Sleeve 210 can be formed of fabric and is intended to be slipped over the patient's arm or other appendage and to thereafter be placed within device 10 . Sleeve 10 allows coils 212 , 214 , 216 to be placed as close to the area of examination as possible and to provide a uniform dispersion of signal transmission and collection independent of the placement of coils within device 10 itself. As described in connection with array 192 , sleeve 210 can include any selected number of coils and the arrangement shown in FIG. 10 is by way of example only. Sleeve 210 can be formed as a permanent, flexible and expandable cuff or can be formed as a disposable unit which can be discarded after use. Sleeve 210 can be provided in a range of sizes to accommodate extremities of varying proportions, can be written upon to record patient information, and can contain various numbers and configurations of coils and coil leads that can selectively be connected to provide energy to selected coils. Referring now to FIG. 11 , an alternative construction for pole pieces such as pole piece 60 is shown. FIG. 11 is a cross-sectional view of a pole piece 218 constructed as a series of laminae 220 , 224 , 226 , 228 and 230 glued together in a solid array by non-conductive epoxy glue or other well-known well-known permanet adhesives. As seen in FIG. 12 , a section of laminae 220 is shown in partial perspective. Each laminae is formed of a series of cubes 232 preferably extruded from ferromagnetic material and glued together with the adhesives described above. In a preferred embodiment of the invention, each cube is approximately 10 mm by 10 mm by 10 mm. When cubes 232 have been solidly glued into a planar array, each such array is stacked and glued to corresponding arrays to produce the structure shown in FIG. 11 . The completed array may then be machined to the shape desired to use the completed array as a pole piece. Use of cubic elements are believed to limit the eddy currents created within the ferromagnetic pole piece when the RF coils are pulsed. Referring now to FIG. 13 , a top plan view of a segment of pole piece 218 is shown illustrating the appearances of cubes 232 when cemented into the array and shaped to be used as a pole piece. In assembling a laminated pole piece such as 218 , cubes 232 are arranged such that the interfaces of adjacent cubes are offset from the interfaces of the cubes in the layers immediately above and below thereby adding strength to the array. Referring now to FIG. 14 , the numeral 234 identifies a segment of an alternative construction of the torroidal shim rings such as 54 of FIG. 3 . The embodiment of FIG. 14 shows shim 234 assembled from overlapping segments 236 , 238 with segment 236 having an upper edge 240 and intermediate land 242 and a lower edge 244 while segment 238 has an upper edge 246 an intermediate land 248 and a lower edge 250 . When assembled, edges 240 , 246 abut as do lands 242 , 248 and lower edges 244 , 250 . At each of these abutments, an epoxy or other suitable adhesive is used to permanently attach the segments together. It is also contemplated that the torroidal and disk-shaped shims described earlier can also be constructed from laminae in the manner shown in FIGS. 11, 12 , and 13 . In such constructions, it is contemplated that cubes 232 , when used in shim constructions, can be extruded from ferromagnetic metals, non-ferromagnetic metals, non-metallic substances or magnetic material. While not herein specifically shown, it is acknowledged that the use of electromagnetic gradient coils as shims to adjust the linearity and shape of the magnetic field of a permanent magnet array is well known and can be included in the arrangements described herein. Such shim coils can also be used as gradient coils by pulsing the coils to intentionally distort the field of view to aid in distinguishing between tissues of different types. Preferably, separate shim and gradient coils are used to keep voltage to the shim coils constant. The disclosed methods and apparatus offer advantages over prior known MRI diagnostic methods in that a relatively small permanent magnet arrangement is used to produce a high strength uniform and high resolution magnetic field across a very small part of the body. This is a much different approach than that described in the Nagel and Fleck article referenced above in which a patient is “positioned within the bore of a cylindrical superconducting magnet.” The strength of the magnetic field produced by the present invention is estimated in excess of 1.0 tesla and the relatively small size of the body portion being sampled creates an image with a higher signal-to-noise ratio than can be achieved when the entire body is placed within a magnetic field. The resulting high resolution images allow the changes in size of the arteries to be accurately determined. When performing MRI diagnostic procedures, care must be taken to avoid damage to nerves caused by too high a field gradient across the area of the body being examined. For the purposes of this description, the field gradient is described as the strength of the magnetic field divided by the area of the field of view in question. Using the greatly reduced field of view made possible by the present invention, allows for higher gradients to be safely used when examining patients. This results in higher resolution images and more accurate diagnostic information. Total cardiac output can be estimated by relating the radial and ulnar arteries and comparing these measurements to known values of percentages of cardiac output measured through such arteries. Use of the present invention thus allows cardiac functions to be examined in a strong, small magnetic field with a relatively high field gradient. This will also result in the capability of using rapid pulses to produce accurate images showing the changes in size of the arteries in question. The apparatus described herein uses less energy and is less expensive to build than the presently known full body type MRI diagnostic units. In evaluating cardiac function, the RF pulses may be timed to commence with the heartbeat and can be used to track changes in the heartbeat. Alternatively, use of the present invention may be used without using the heartbeat as a trigger or marker with the apparatus being operated through a sufficient number of cycles to guarantee that an entire cycle has been captured and accurately characterized. Use of MRI to create images of arteries 186 , 188 is superior to the use of ultrasound because MRI produces a cross-sectional view which allows the system to track the changes in size and configuration of arteries 186 , 188 . Ultrasound, on the other hand will provide only a lateral view and even though this lateral view can show changes in the apparent diameter of the arteries, it does not provide an accurate view of the actual cross-sectional configuration of the artery. Where an artery is, for example, not perfectly round or in some way impeded, the cross-section will be less than circular. However, MRI will enable the operator to determine the exact shape and, therefore, area of the cross-section and to calculate the blood flow therethrough. Measurement of FMD using the radial and ulnar arteries has been shown to have a 95% correlation with the same measurements when measured at the coronary arteries. Measuring FMD, or endothelial dysfunction, correlates with well-known risk factors used to assess the health of the patient's cardiovascular system Using a multi-spectral or multi-contrast technique allows the technician to accurately determine the presence and thickness of any plaque layers in the artery, another indicator of general cardiovascular health. detailed-description description="Detailed Description" end="tail"? | 20040430 | 20100112 | 20050421 | 95229.0 | 0 | RAMIREZ, JOHN FERNANDO | APPARATUS AND METHOD FOR NON-INVASIVE MEASUREMENT OF CARDIAC OUTPUT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,270 | ACCEPTED | Operationally interactive enclosure | A platform for electronic components has a temperature sensing array, a vibration sensing array, a programmable logic device, and one or more cooling fans. The programmable logic device receives temperature data from the temperature sensing array and structure-borne noise data from the vibration sensing array. The programmable logic device analyzes the data, and based on this analysis, maintains the temperature and low level noise requirements of the system by activating, deactivating, speeding up, or slowing down one or more cooling fans. | 1. An operationally interactive enclosure comprising: a housing; one or more thermal sensing devices; one or more transducers; an analog to digital converter; a programmable logic device; and one or more fans; wherein said programmable logic device controls said fans based on data from both said one or more thermal sensing devices and data from said one or more transducers. 2. The operationally interactive enclosure according to claim 1, wherein said data from said one or more thermal sensing devices comprises a temperature; and wherein said data from said one or more transducers comprises a level of structure-borne noise; and further wherein said programmable logic device determines, based on said temperature data and said low level noise data, the operating conditions of said fans. 3. The operationally interactive enclosure according to claim 2, wherein said programmable logic device alters the operating speed of said fans in response to said data from said one or more transducers. 4. The operationally interactive enclosure according to claim 2, wherein the programmable logic device alters the operating speed of a number of fans that is less than the total number of fans mounted on said enclosure. 5. The operationally interactive enclosure according to claim 2, wherein said programmable logic device alters the number of fans that are operating in response to said data from said one or more transducers. 6. The operationally interactive enclosure according to claim 1, wherein said enclosure houses electronic components. 7. The operationally interactive enclosure according to claim 1, wherein said one or more thermal sensing devices comprises thermal sensing arrays. 8. The operationally interactive enclosure according to claim 7, wherein said thermal sensing arrays comprise thermistors. 9. The operationally interactive enclosure according to claim 1, wherein said one or more transducers comprises a vibration sensing array. 10. The operationally interactive enclosure according to claim 1, wherein said one or more thermal sensing devices is positioned equidistantly throughout said enclosure. 11. The operationally interactive enclosure according to claim 1, wherein said thermal sensing devices are logically positioned throughout said enclosure. 12. An operationally interactive platform comprising: one or more thermal sensing devices; one or more transducers; an analog to digital converter; a programmable logic device; and one or more fans; wherein said programmable logic device controls said fans based on data from both said one or more thermal sensing devices and said one or more transducers. 13. The operationally interactive platform according to claim 12, further comprising a housing. 14. The operationally interactive platform according to claim 12, wherein said platform further comprises electronic components. 15. A method to control the temperature and structure-borne noise on an electronic component platform, comprising the steps of: collecting temperature data; collecting structure-borne noise data; converting said temperature data and said structure-borne noise data into a digital format; processing said temperature data and said structure-borne noise data; and modifying the operating condition of one or more cooling fans based on both said temperature data and said structure-borne noise data. 16. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein said temperature data is collected with a thermal sensing array; and wherein said structure-borne noise data is collected with a vibration sensing array; and further wherein said temperature data and said structure-borne noise data is processed within a processing unit. 17. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the operating condition of one or more of said cooling fans is modified. 18. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the speed of one or more fans is modified based on said temperature data and said structure-borne noise data. 19. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein one or more fans are deactivated based on said temperature data and said structure-borne noise data. 20. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein one or more fans are activated based on said temperature data and said structure-borne noise data. 21. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the number of fans operating depends on the criticality of the temperature requirements of a particular section of said platform. 22. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the operating speed of said fans depends on the criticality of the temperature requirements of a particular section of said platform. 23. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the number of fans operating depends on the criticality of the noise requirements of a particular section of said platform. 24. The method to control the temperature and structure-borne noise on an electronic component platform according to claim 15, wherein the operating speed of said fans depends on the criticality of the noise requirements of a particular section of said platform. | FIELD OF THE INVENTION The present invention relates to temperature control and low level noise control in electronic component enclosures and other platforms. BACKGROUND OF THE INVENTION Virtually all commercial and military industries are dependent on integrated processors, computing, and the electronic components associated therewith to carry out their businesses and missions. It is well known that these electronic components, when they are energized and consuming power, produce heat that in most instances must be actively removed by means other than simple radiation-dissipation to the surrounding environment. To accomplish this heat removal, many industrial and military applications use fans and/or blowers to convectively remove the heat produced by energy consuming electronic components. To be most effective, these fans are normally mounted onto the chassis, housing, enclosure or platform that contains the electronic components. Mounting the fans in this manner however can create low level noise problems, since the vibration or structure-borne noise generated by the operating fans may be transmitted to the electronic components, the platform for the electronic components, and the surrounding environment. In some applications, such as military submarine platforms in which stealth is required, it is critical to limit low level noise. Indeed, military standards such as MIL-STD 740-2 detail the measurement and limits of structure-borne low level vibratory noise. One way to limit such noise is to slow down the speed of the fans used to cool the electronic components, or to deactivate one or more of those fans. The cooling of electronic components and the reduction of low level structure-borne noise are, on most if not all platforms, competing critical parameters. They are critical because an elevated temperature within an electronic enclosure may lead to failure of electronic components, and elevated structure-borne noise may lead to a military vehicle such as a submarine becoming detectable by hostile forces. They are competing because to attain or maintain a lower temperature, more fans must be run at greater speeds. However, operating more fans at greater speeds will increase the low level noise associated with the enclosure. Despite the dynamics and interrelatedness between temperature control and noise control, prior art systems are single point solutions—i.e. they address either temperature or noise independently, but not the effect of one on the other. Consequently, the art is in need of a system that can simultaneously and logically control both convective cooling and low level noise reduction so that the two competing interests can be simultaneously addressed. SUMMARY OF THE INVENTION The present invention addresses computing resource allocation and conflicting environmental needs. In one embodiment, a platform or enclosure has on or within it electronic components. The platform or enclosure further contains arrays of heat sensing and vibration sensing devices, both of which are electrically connected to a programmable logic device through an analog to digital converter. The programmable logic device is in turn coupled to one or more cooling fans or blowers. The thermal sensing devices, vibration sensing devices, and fans can be positioned in any manner on or about the platform or enclosure. In operation, the thermal sensing devices detect the heat generated by the electronic components, and activate or deactivate, and/or speed up or slow down, the necessary fan or fans. Similarly, and in conjunction with the temperature sensing devices, the vibration sensing devices monitor the low level noise in the system, much of which is generated by the cooling fans. The programmable logic device contemporaneously and simultaneously analyzes the data from both the thermal sensing devices and the vibration sensing devices, and determines what action needs to be taken to keep the system within the temperature and noise level requirements. Such actions include activating, deactivating, speeding up, and/or slowing down one or more fans. It is therefore an object of a preferred embodiment of the present invention to use both temperature data and vibration data to maintain a system of electronic components within temperature and noise level specifications. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the components of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION, INCLUDING THE BEST MODE FIG. 1 is a block diagram of one embodiment of the present invention, which is an operationally interactive enclosure 10 that contains electronic components 20. The electronic components 20 may include integrated circuits, circuit boards, power supplies, fiber optic switches and other devices or components. While the enclosure 10 will be described herein as an enclosure for electronic components, it need not be so limited, and could be some other platform besides a complete enclosure, and it could support or house any components or materials that have cooling and noise reduction requirements. A thermal sensing array is positioned in the enclosure 10. The thermal array consists of a plurality of sensing devices 22, such as thermistors, dispersed throughout the enclosure 10. In addition to thermistors being placed throughout the enclosure to register the ambient temperature of the enclosure 10, thermal data could also be acquired from sources such as power supplies, heat sinks of integrated circuits, or exhaust air from the enclosure. In the case of heat sinks and power supplies, a proper interface would be required. The sensing devices 22 can be positioned throughout the enclosure in virtually any arrangement and concentration. For example, the devices 22 could be spaced equidistantly throughout the enclosure 10 so that a temperature profile of the entire enclosure is obtained. Alternatively, sensing devices 22 could be concentrated in a critical area of the enclosure. An area could be designated as critical because of the concentration of heat producing components localized there, the presence of a particularly critical piece of hardware, or some other reason. The sensing devices 22 are connected to an analog to digital converter 24. The A/D converter 24 converts the analog output of the sensing devices 22 into digital format, and is connected to programmable logic device 26 (PLD). The PLD 26 is in turn connected to a plurality of fans 30. Like the sensing devices 22, there can be any number of fans 30, and these fans can be placed in proximity to the enclosure 10 in an equidistant arrangement, or placed in proximity to the enclosure 10 based on the cooling requirements of a particular area of the enclosure. Once again, the cooling requirements of a particular portion of the enclosure could be dictated by the number of components in that area, the criticality of a component or components in that area, or some other factor or factors. The enclosure 10 further contains a plurality or network of transducers 40, such as accelerometers, that make up a vibration sensing array and measure the structure-borne or low level noise within the enclosure 10. The transducers 40 are connected to the A/D converter 24, which in turn is connected to PLD 26, and which in turn is connected to the fans 30. The operationally interactive enclosure 10 operates as follows. As detailed supra, temperature sensing devices 22 are placed within the enclosure 10 in virtually any arrangement desired. That is, if it is important that the temperature in all areas of the enclosure be known, the sensing devices 22 may be positioned equidistantly throughout the enclosure. If there are critical areas within the enclosure, sensing devices may be concentrated in that area. Alternatively, physically equidistant sensing devices could be logically controlled by the PLD 26 to concentrate on a certain area of the enclosure, irrespective of the physical arrangement of sensing devices 22. The devices produce an analog output proportional to the temperature in the area of the devices, and this output is converted to digital format by A/D converter 24 for processing by the PLD 26. The logic and data programmed into the PLD 26 determine whether the temperature requirements of the system are being met. If the sensing devices 22 are spread equidistantly throughout the enclosure 10, at least two logic schemes could be implemented. In one embodiment, the temperature readings for all sensors could be averaged, giving an average temperature within the enclosure, and the cooling fans 30 turned on, turned off, sped up or slowed down depending on those readings. In another embodiment, if the temperature control in one area of the enclosure is more critical than in other areas of the enclosure, the sensing devices of that area could be logically isolated from the other areas' sensing devices. This logical isolation would allow the independent control of the fans in that critical area. With such a set up, there would be no need to run fans in non-critical areas of the enclosure, and the fans in the critical area could be run at a higher speed to increase the rate of heat removal. It is preferred that the placement of the sensing devices 22 be capable of modification by the logic of the PLD 26 rather than require a physical alteration, since a logical change is much easier to implement than a physical change. In a similar fashion, instead of being placed equidistant throughout the enclosure, sensing devices 22 may be physically concentrated in a critical area of the enclosure 20. Similarly, the fans 30 may be placed equidistantly around the enclosure, or concentrated in a particular critical area of the enclosure. The PLD 26 could then use the data from these specifically placed sensing devices to control all the fans, fans only in that area, or any combination of the fans. While the sensing devices 22, PLD 26 and fans 30 are monitoring and controlling the temperature of the enclosure, the transducers 40 are monitoring the low level or structure-borne noise associated with the enclosure. The transducers sense vibration and produce an analog signal. The analog signal is converted to a digital signal by the A/D converter 24, the digital signal is sent to the PLD 26 and analyzed, and a decision is made by the PLD 26 as to what course of action to take based on that data. If the PID 26 determines that the structure-borne noise of the system is excessive, corrective action must be taken. One effective manner of reducing that noise is by turning off one or more fans, and/or reducing the speed of one or more fans. However, as outlined supra, while decreasing the number of fans running and/or the speed of those fans will reduce the noise level, this will also increase the heat level of the enclosure by decreasing the amount and rate of heat removal. It is at this point that the logic programmed into the PLD 26 weighs the competing goals of temperature maintenance and noise reduction. Decisions are programmed into the PLD as to the proper course of action to take in light of the present state of the system as indicated by the data. These decisions are based on predeterminations as to the highest noise level that can be tolerated and the highest temperature that the electronic components of the enclosure can withstand. For example, the fan speed could be increased when the low level noise level is not critical (e.g. in non-hostile territories), thereby cooling the electronic components to a level below that of the specifications. Then, when the maintenance of a low level of noise is critical, the speed and/or number of fans can be cut back without as much adverse effect since the components have previously been cooled to below specifications. Moreover, the very design of the system allows for the concurrent addressing of temperature and noise concerns. That is, by permitting the isolation of the critical areas of the enclosure, and in particular the logical isolation of the critical areas of the enclosure, fans in that area may be operated to continue cooling, or even operated at higher speeds, while fans in a non-critical area can be slowed down or turned off to cut down on the low level noise. Consequently, the system allows increased cooling of critical areas of the enclosure 10 without adding to, and perhaps decreasing, the structure-borne noise level of the system. The exact operating conditions, that is the number of fans operating and the speed of the fans, will vary in each particular application, and may be programmed into the PLD 26. While the invention has been described in its preferred and other embodiments, it is to be understood that the words used are words of description rather than limitation and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the invention in its broader aspects. For example, while the technique for simultaneously monitoring and controlling temperature and structure-borne noise has primarily been discussed in connection with enclosures containing electronic components, the present invention could be applied to many other situations and environments that involve enclosures or other platforms, the controlling of temperature, and the controlling of structure-borne low level noise. | <SOH> BACKGROUND OF THE INVENTION <EOH>Virtually all commercial and military industries are dependent on integrated processors, computing, and the electronic components associated therewith to carry out their businesses and missions. It is well known that these electronic components, when they are energized and consuming power, produce heat that in most instances must be actively removed by means other than simple radiation-dissipation to the surrounding environment. To accomplish this heat removal, many industrial and military applications use fans and/or blowers to convectively remove the heat produced by energy consuming electronic components. To be most effective, these fans are normally mounted onto the chassis, housing, enclosure or platform that contains the electronic components. Mounting the fans in this manner however can create low level noise problems, since the vibration or structure-borne noise generated by the operating fans may be transmitted to the electronic components, the platform for the electronic components, and the surrounding environment. In some applications, such as military submarine platforms in which stealth is required, it is critical to limit low level noise. Indeed, military standards such as MIL-STD 740-2 detail the measurement and limits of structure-borne low level vibratory noise. One way to limit such noise is to slow down the speed of the fans used to cool the electronic components, or to deactivate one or more of those fans. The cooling of electronic components and the reduction of low level structure-borne noise are, on most if not all platforms, competing critical parameters. They are critical because an elevated temperature within an electronic enclosure may lead to failure of electronic components, and elevated structure-borne noise may lead to a military vehicle such as a submarine becoming detectable by hostile forces. They are competing because to attain or maintain a lower temperature, more fans must be run at greater speeds. However, operating more fans at greater speeds will increase the low level noise associated with the enclosure. Despite the dynamics and interrelatedness between temperature control and noise control, prior art systems are single point solutions—i.e. they address either temperature or noise independently, but not the effect of one on the other. Consequently, the art is in need of a system that can simultaneously and logically control both convective cooling and low level noise reduction so that the two competing interests can be simultaneously addressed. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention addresses computing resource allocation and conflicting environmental needs. In one embodiment, a platform or enclosure has on or within it electronic components. The platform or enclosure further contains arrays of heat sensing and vibration sensing devices, both of which are electrically connected to a programmable logic device through an analog to digital converter. The programmable logic device is in turn coupled to one or more cooling fans or blowers. The thermal sensing devices, vibration sensing devices, and fans can be positioned in any manner on or about the platform or enclosure. In operation, the thermal sensing devices detect the heat generated by the electronic components, and activate or deactivate, and/or speed up or slow down, the necessary fan or fans. Similarly, and in conjunction with the temperature sensing devices, the vibration sensing devices monitor the low level noise in the system, much of which is generated by the cooling fans. The programmable logic device contemporaneously and simultaneously analyzes the data from both the thermal sensing devices and the vibration sensing devices, and determines what action needs to be taken to keep the system within the temperature and noise level requirements. Such actions include activating, deactivating, speeding up, and/or slowing down one or more fans. It is therefore an object of a preferred embodiment of the present invention to use both temperature data and vibration data to maintain a system of electronic components within temperature and noise level specifications. | 20040503 | 20071204 | 20051103 | 68968.0 | 0 | JIANG, CHEN WEN | OPERATIONALLY INTERACTIVE ENCLOSURE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,284 | ACCEPTED | Aligned extrudate structure | The present invention provides an improved composite material structure having large portions of additive material aligned over a substantial width of a material structure and occupying a larger percentage of the structure volume. The material structure includes a resilient substrate layer or conventional decking having a plurality of elongated rods arranged on a surface of the substrate layer to form at least one rod layer. The spaces between rods are filled with a slurry material which is allowed to set causing the component elements to bond together to form a lightweight durable and high strength composite material structure. | 1. A composite material structure comprising: a resilient substrate layer; a slurry material; and a plurality of elongated rods arranged on said substrate layer to form at least one rod layer, wherein said slurry material fills the spaces between said plurality of rods and bonds said plurality of rods to said substrate layer. 2. The composite material of claim 1 wherein said plurality of rods are formed from a foam extrudate material. 3. The composite material of claim 2 wherein said extrudate material is polystyrene. 4. The composite material of claim 2 wherein said extrudate material comprises at least one carbonate compound. 5. The composite material of claim 1 wherein said substrate layer is formed of expanded polystyrene. 6. The composite material of claim 1 wherein said slurry material is made from an inorganic material. 7. The composite material of claim 6 wherein said slurry material is magnesia cement. 8. The composite material of claim 7 wherein said magnesia cement is a magnesium oxysulfate cement. 9. The composite material of claim 7 wherein said magnesia cement is a magnesium phosphate cement. 10. The composite material of claim 1 further comprising a reflective elastomeric layer disposed on top of said at least one rod layer. 11. The composite material of claim 3 wherein said polystyrene is self sealing. 12. The composite material of claim 1 further comprising at least one rod spacer operative to support said rods symmetrically spaced apart. 13. A roofing installation comprising: a plurality of elongated rods of extruded polymeric material aligned and coated with an inorganic cementitious slurry that fills the spaces between said plurality of rods; an overlying cementitious layer; an insulation board thereover; a second plurality of elongated rods aligned and coated with a cementitious slurry filling the spaces therebetween; and an expanded polystyrene regrind material within a cementitious overlayer. 14. The installation of claim 13 wherein said second plurality of elongated rods are arranged nonparallel to said first plurality of elongated rods. | RELATED APPLICATION This application claims priority of U.S. Provisional Patent Application Ser. No. 60/466,881 filed Apr. 30, 2003, which is incorporated herein by reference. FIELD OF THE INVENTION The present invention generally relates to building material structures and, in particular, to building material structures containing aligned extrudate inclusions. BACKGROUND OF THE INVENTION The choice of a building material structure often involves a compromise between structure strength, weight, durability, cost and handling characteristics. Owing to the difficulties in balancing these disparate requirements in a single structural material such as stone, brick, cement or the like, the building trades increasingly are relying upon composite materials that maintain the desirable properties of the principal component while ameliorating disadvantageous properties of the primary component. Laminated and filler-containing materials are often relied upon as lower cost, higher performance alternatives to monolithic materials. Such fillers have traditionally been in the form of granulate, flakes, chopped fibers and woven webs. The requirement for a comparatively large amount of matrix material to support such additions has limited the range of properties afforded by such materials. Thus, there exists a need for a material structure having large portions of additive aligned over the substantial width of a material structure and occupying a larger percentage of the structure volume. SUMMARY OF THE INVENTION The present invention provides a composite material structure having large portions of additive material being aligned over a substantial width of a material structure wherein the additive material occupies a larger percentage of the structure volume. Particularly, the composite material structure is applied over a resilient substrate layer, conventional roofing decking or wall assembly that provides a rigid base or support surface for forming the composite material structure. A thin layer of slurry material is added to a surface of the substrate layer as an adhesive for securing the additive material to the substrate surface during construction. The slurry material is also operative to provide some rigidity to the composite material once the structure is completely formed. A plurality of elongated rods are arranged on the surface of the substrate layer having the thin layer of slurry material applied thereto. Preferably, the plurality of elongated rods are symmetrically arranged in a parallel fashion such that at least one rod layer is formed on the surface of the substrate layer. Such rods are readily formed as virgin extrudate or from chopped anisotropic foamed debris. The formation of at least one rod layer on the substrate layer enhances the overall structural rigidity of the composite material to be formed as a substitute for the rigidity that would be provided by a composite material having only a substrate layer and a slurry material filler. After the plurality of elongated rod layers have been arranged on the substrate layer in a parallel fashion, the composite material structure is completed by filling the spaces between elongated rods with the slurry material which is then allowed to set and bond the composite material elements together while providing extra rigidity to the composite material structure. Optionally, a spacer is used to control the spacing between the adjacent elongated rods while the slurry material is applied. In this manner a larger percentage of the structural volume of the composite material structure is provided by the elongated rods which may be formed of a desired material having characteristics that provide advantages over existing composite material structure fillers. BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present invention will be had upon reference to the following detailed description when read in conjunction with the accompanying drawings wherein like reference characters refer to like parts in which: FIG. 1 is an elevated view of a roofing installation structure as according to the invention; FIG. 2 exemplifies an arrangement of the component elements of the composite material structure as according to the invention; FIG. 3 illustrates a perspective view of a composite material as according to FIG. 2 further including a spacer for supporting the elongated rods in a symmetrical and spaced-apart fashion; FIG. 4 illustrates a composite material structure formed using extrudate material layers having undulating surfaces; FIGS. 5 and 6 illustrate extrudate rods formed in other exemplary geometric shapes and arranged in stacked configurations; FIG. 7 illustrates a slurry material mixing/dispensing apparatus; FIG. 8 exemplifies a fastener for use with the composite material structure of the present invention; FIG. 9 exemplifies a second fastener for use with the composite material structure of the present invention; FIG. 10 illustrates a power tool for use in installing the fasteners in the composite material structure; and FIG. 11 is an elevated view of an alternative embodiment of an inventive roofing installation. DETAILED DESCRIPTION OF THE INVENTION The present invention has utility as a building structural material operative as siding or roofing assembly. Use is optionally also made herein of waste foamed plastics. In a preferred embodiment, extrudate material operative in the present invention is formed through the compaction of chips or flakes, or other high dimensional aspect ratio forms of waste foamed polymeric material. The waste foamed polymeric material illustratively including plates, food trays, cups, packing peanuts, scrap, and combinations thereof. A process for preparing chopped waste includes washing the waste, if necessary to remove debris that will interfere with cementitious bonding to the foamed polymeric material, followed by feeding the material into a chopper to form particulate having at least one anisotropic axis. It is appreciated that the application of heat in the form of steam will further expand the polymeric material. The chopped polymeric material is then mixed with an inorganic cementitious slurry and compressed to form an oriented polymeric cement board or other preform structure. While it is appreciated that the specific amount of inorganic cementitious slurry necessary to form a chopped foam material structure varies with variables such as anisotropic-shape, -size, -surface area, and cement viscosity. In the instance where a chip has a thickness of 3 millimeters and an average surface area of from 2 to 10 square centimeters, an inorganic cementitious slurry is effective in producing a shredded component structure with the addition of from 5 to 40 volume percent relative to the amount of chip material present. Preferably, the slurry is present from 10 to 30 volume percent for typical roofing installations. The resulting board or other structure is well suited for assembly in the field through coating with inorganic cementitious slurries to form a lightweight roofing material. Additionally, the resulting preform is amenable to machining operations to form more intricate forms such as roofing shakes, siding, or complex shapes preformed to match the contours of a substrate. Alternatively, preformed rods or boards are readily coated with inorganic cementitious slurries upon production to form completed roofing or siding subassembly components such as boards, shakes or the like that are delivered to a structure and immediately applied thereto. The coating of individual rods or boards according to the present invention with an inorganic cementitious slurry with compression of the mass prior to slurry setup is effective in controlling air voids within a preassembled structure according to the present invention. FIG. 1 illustrates a cross section of an inventive roofing installation shown generally at 1. A composite material structure 10 has large portions of additive material aligned over a substantial width of a material structure formed into rods or boards that occupy a large percentage of the structure volume. The structure 10 is formed to fill the flutes of an underlying metal deck D. It is appreciated the distribution of forces over the body of a material structure enhances the structure's load bearing capabilities as compared to applying a concentrated force to a similar body. The present invention relies on this principle in providing a resiliently rigid and durable composite material structure having large portions of additive material symmetrically aligned over a substantial width of a material structure and occupying a large percentage of the structure volume. The composite material structure 10 has utility as building material for use in commercial, residential and/or industrial applications. As best illustrated in FIGS. 1 and 2, the composite material structure 10 as according to the invention includes a resilient layer 12 that provides a base or support surface for the composite material structure. Preferably, the layer 12 is formed from foamed insulated materials and other types of conventional materials known to those skilled in the art may be used which illustratively include rigid lightweight and durable materials such as foamed polystyrene, polyisocyanate, expanded perlite containing insulations, cardboard, polymer compounds, particleboard, and the like. In this case, it is desired for its insulative and shock-absorbing properties as well as its light weight. Plastic foam is exceptionally durable, making it effective as a protective material in a variety of applications such as packing, building and/or insulating material. Typically foam is made up of more than 90% closed cell gaseous volume of air, carbon dioxide, or other gases, and due to its extremely low weight and durability, it is frequently desired as a construction material. Preferably, all the foamed elements used to construct the composite material structure herein are formed from recycled waste material such as disposable lunch trays, packing materials, carpet fibers, beverage cups, and carry-out containers or alternatively, a thermoplastic material having a well defined glass transition temperature is readily melted and extrusion spun into a fiber operative in the present invention. The waste material is recycled according to conventional processes wherein substantially all of the waste material is converted into a usable valuable product rather than landfill. Referring to FIG. 2, a thin layer of slurry material 14 is disposed on a surface of the layer 12 or metal deck D to provide an adhesive layer on which additive materials may be disposed in forming the composite material structure. Preferably, the slurry material 14 is a cementitious material and illustratively includes calcium sulfate hemihydrate (gypsum), Portland, magnesia cements, aluminum calcite, and most preferably, a magnesia cementitious material such as magnesium oxychloride, magnesium oxysulfate (MOS) or magnesium phosphate cement (MAP). It is appreciated that a cement is modified with various conventional additives illustratively including polymeric colloidal particulate, emulsion, surfactants, and air entrainment to yield a variety of physical properties for various applications. The composite material structure 10 includes a plurality of elongated rods 16 as the additive material used to fill the bulk of the volume of the material structure. The elongated rods 16 are arranged on the layer 12 or metal deck D coated with a thin layer of slurry material 14 to form at least one rod layer. Preferably, the elongated rods 16 are made of an extruded foamed plastic material; however, it is appreciated that other materials are optionally substituted therefor, these illustratively include polymer fibers, plastic tubing, metal tubing, and straw. Most preferably, the material used to form the rods 16 comprises a carbonate compound additive that is operative to release carbon dioxide gas upon reaching a decomposition temperature. Accordingly, this would make the elongated rods used in the composite material structure substantially fire resistant. Alternatively, a small percentage of finely ground dolomite can be added to the extrudate resin before expansion such that these powders will be suspended in the cell walls of the foamed extrudate material and will be responsible for the release of carbon dioxide gas from the formed elongated rods 16 in the event of a fire contacting the composite material structure 10. Still further, a post-extrudate fire-resistant powder, e.g. dolomite, calcium carbonate, calcium oxide, talc, or magnesium hydroxide, may be disposed on the surface of the elongated rods of the composite material structure 10. As shown in FIG. 3, the elongated rods 16 may be arranged in spaced-apart symmetrical fashion through the utilization of spacers 22 that support the elongated rods 16 within the composite material 10. After arranging the at least one rod layer on the layer 12 in a spaced-apart fashion, the voids formed between the adjacent rods are filled with the slurry material 14 and allowed to set such that the layer 12 and elongated rods are securely bound together to form the composite material structure. Other materials may be added to the composite material structure 10 to facilitate its use in various applications. As according to FIG. 2, the composite material structure 10 as described above is disposed with a combination of slurry and polyester fabric that forms a resilient shock-absorbing layer that adds to the durability of the composite material. Other materials may be used for such purposes illustratively including synthetic fibers, saw dust, finely ground plastic aggregate, or other lightweight shock-absorbent materials. The structure 10 is overlayered with an inorganic cementitious slurry of a thickness of greater than 0.2 centimeters. Preferably, the overlying slurry 18 has a thickness of between 0.3 and 2 centimeters. Optionally, the overlying slurry 18 incorporates a polymeric fiber, polymeric, mat, inorganic fiber, or inorganic mat in instances where additional strength is required. A foamed or otherwise expanded polystyrene insulation board of conventional design or that formed of waste regrind according to the present invention 19 is applied thereover. The board 19 has a thickness commensurate with the insulation factor desired for the inventive roofing installation 1. The insulation board 19 is overcoated with an additional layer of composite material structure 10A. Preferably, structure 10A is aligned with the elongated rods thereof being nonparallel to those of structure 10. It is appreciated that while the installation 1 depicted in FIG. 1 has only a single insulation board 19 and structure 10A, that these two layers in combination can be repeated multiple times within an inventive installation. In the instance where repetitive insulation board and structure layers 10A are present, it is preferred that the orientation of the rods within each of the layers 10A varies relative to other structure layers 10A. A resilient layer 12A comparable to previously described layer 12 overlies structure 10A. Optionally, a conventional elastomeric layer 20 is applied over layer 12A in order to inhibit water intercalation. While the inventive rods 16 have been depicted as circular in cross section, it is appreciated that this shape is only exemplary and various other cross sections are operative herein illustratively including triangular, rectilinear, pentagonal, hexagonal, non-regular variants thereof, and combinations thereof. In an embodiment depicted in FIG. 4, the elongated rods 16 are formed as a sheet having undulating surfaces that upon stacking interlock inorganic cementitious slurry therebetween to form a structure 10 as detailed above. FIGS. 5 and 6 illustrate two other examples of the many geometric shapes that the extrudate rods may be formed whereby the exterior surfaces of the adjacent rods abut complementarily such that stacking results in the formation of a composite material structure 10. Preferably, the rods 16 undergo a preprocessing step of being wet with a spray of inorganic slurry before being stacked on the substrate layer 12. To aid in handling of wet components, the slurry 14 can be made to set in thin sheets and then milled to granules and optionally combined with a expanded polystyrene (EPS) dust. This mixture can be sprinkled on the surface of the wet rod and EPS board assembly. In this manner the first rod layer can be arranged on the substrate layer 12 in a more precise fashion due to the adhesive properties of the slurry material 14 that coats the surface of each elongated rod 16 and to further aid in field installation to like slurries. Preferably, each elongated rod 16 is one-eighth inch thick; however, other thicknesses may be utilized dependent on the application such that the desired durability and strength is provided. Further, it is preferable that the layer 12 used to form the composite material structures 10 is two feet by four feet, width by length, and of adequate thickness such that the substrate layer 12 provides an adequate support surface for the composite material structure 10. FIG. 7 is illustrative of a mixing/dispensing apparatus 70 for the slurry material used with the composite material structure 10. The apparatus 70 receives dry EPS regrind and inorganic slurry materials through separate delivery channels 71 and 72, respectively in a mixing chamber 73 equipped with a slurry jet 74 to assure regrind wetting. Mixing is accomplished via an auger terminating in a dispensing nozzle 76 that regulates dispensing at a predetermined rate. Preferably, the auger is a pair of twin augers 75 with reversed intermeshed threads to promote regrind wetting and extrusion of the material. FIGS. 8 and 9 illustrate fastening elements 80 and 90 respectively which may be used with the composite material structure 10 in order to secure a foamed insulation board thereto with or without a wet slurry 18 as shown in FIG. 1. FIG. 8 illustrates a fastener 80 having a shaft that includes serrated edges 82 for opposing extraction after insertion and an insulation board cap 84. Preferably, the fastener 80 has a slurry receiving grid 86. FIG. 9 illustrates a fastener 90 having an elongated shaft 92 terminating in a point 94 for ease of insertion into the composite material structure and an H-shaped cross section. The shaft 92 has serrations 93 therealong. The fastener 90 has an insulation board cap 96. In the preferred embodiment depicted in FIG. 9, the cap 96 is a separate piece relative to the shaft 92. The cap 96 has an interior bevel 98 that engages the serrations 93 and preferably a flare 99 extending towards the cap end 100 so as to define a slurry receiving cavity 102. According to the present invention, a fastener is constructed of either metal or plastic, or combination thereof. In the instance of a metal fastener, it is appreciated that adhesion of cementitious materials thereto is facilitated by a polymeric coating. Nitrile plastics are well suited for the formation of a plastic fastener. FIG. 10 depicts an insertion tool suitable for the rapid installation of a fastener 90. The tool is shown generally at 110 and includes a spool 112 of continuous shaft material 92. The shaft material 92 is fed through the core 114 of the elongated tool body 116. A tube 118 is mounted on the body 116 for the storage of caps 96. A spring-mounted lever 120 strips a cap 96 from the tube 118 and places the cap 96 in concentric alignment with the shaft material 92 extending from the base 120 of the body 116. The application of pressure to the footrest 124 ejects a punch 126 through the underlying substrate 12 or decking D to a create a pilot hole concentric with cap 96 and the shaft material 92. The shaft material 92 is then driven into engagement with the cap 96 and the underlying substrate and composite material structure 10. A cutter 128 is activated after placement of the fastener 90 through closure of a lever 129 proximal to a tool handle 130. The alternate embodiment of the inventive roofing installation is depicted in FIG. 11 at 150 where like numerals correspond to those detailed with respect to the aforementioned figures. Conventional foam plastic insulation 152 is secured to an underlying resilient substrate 12 or decking D with the use of an inventive fastener 80 or 90 or a conventional fastener. A layer of inorganic cementitious slurry 18 overlies the foam plastic insulation 152 and serves to adhere an overlying oriented polymeric cement board 154. A second layer of inorganic cementitous slurry 18′ overlying the oriented polymeric cement board 154 adheres a fiber mat material 156, where the fiber mat 156 is either woven or non-woven. The fiber mat 156 is optionally overcoated with an elastomeric roof coating 20. From the foregoing it can be seen that the present invention provides a composite material structure wherein large portions of an additive material are aligned over a substantial width of a material structure whereby a larger percentage of the structure volume is filled by the additive material resulting in a more durable yet lightweight material structure. Having described the invention, however, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The choice of a building material structure often involves a compromise between structure strength, weight, durability, cost and handling characteristics. Owing to the difficulties in balancing these disparate requirements in a single structural material such as stone, brick, cement or the like, the building trades increasingly are relying upon composite materials that maintain the desirable properties of the principal component while ameliorating disadvantageous properties of the primary component. Laminated and filler-containing materials are often relied upon as lower cost, higher performance alternatives to monolithic materials. Such fillers have traditionally been in the form of granulate, flakes, chopped fibers and woven webs. The requirement for a comparatively large amount of matrix material to support such additions has limited the range of properties afforded by such materials. Thus, there exists a need for a material structure having large portions of additive aligned over the substantial width of a material structure and occupying a larger percentage of the structure volume. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a composite material structure having large portions of additive material being aligned over a substantial width of a material structure wherein the additive material occupies a larger percentage of the structure volume. Particularly, the composite material structure is applied over a resilient substrate layer, conventional roofing decking or wall assembly that provides a rigid base or support surface for forming the composite material structure. A thin layer of slurry material is added to a surface of the substrate layer as an adhesive for securing the additive material to the substrate surface during construction. The slurry material is also operative to provide some rigidity to the composite material once the structure is completely formed. A plurality of elongated rods are arranged on the surface of the substrate layer having the thin layer of slurry material applied thereto. Preferably, the plurality of elongated rods are symmetrically arranged in a parallel fashion such that at least one rod layer is formed on the surface of the substrate layer. Such rods are readily formed as virgin extrudate or from chopped anisotropic foamed debris. The formation of at least one rod layer on the substrate layer enhances the overall structural rigidity of the composite material to be formed as a substitute for the rigidity that would be provided by a composite material having only a substrate layer and a slurry material filler. After the plurality of elongated rod layers have been arranged on the substrate layer in a parallel fashion, the composite material structure is completed by filling the spaces between elongated rods with the slurry material which is then allowed to set and bond the composite material elements together while providing extra rigidity to the composite material structure. Optionally, a spacer is used to control the spacing between the adjacent elongated rods while the slurry material is applied. In this manner a larger percentage of the structural volume of the composite material structure is provided by the elongated rods which may be formed of a desired material having characteristics that provide advantages over existing composite material structure fillers. | 20040430 | 20070130 | 20050113 | 71058.0 | 0 | CHANG, VICTOR S | ALIGNED EXTRUDATE STRUCTURE | SMALL | 0 | ACCEPTED | 2,004 |
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10,837,336 | ACCEPTED | Method of fabricating a rat's nest RFID antenna | A method of fabricating a rat's nest radio frequency identification (RFID) antenna is disclosed. The antennas are fabricated on a substrate that includes already fabricated RFID chips. The antennas can be loop antennas. An antenna is connected to a RFID chip in an assembly order and a RFID tag including the antenna and the RFID Chip is removed from a carrier substrate connected with the substrate in a disassembly order. The assembly order and the disassembly order prevent the overlapping antennas from being damaged or entangled upon disassembly. The antenna can be substantially larger than the RFID chip it is connected with and the resulting RFID tag can have a small size and small cost with the enhanced performance of a larger antenna without having to resort to a large off-chip external antenna or a large on-chip antenna that would increase chip area and cost. | 1. A method of fabricating an antenna on a substrate including a plurality of previously fabricated RFID chips, comprising: connecting the substrate with a carrier substrate; singulating the substrate to separate the plurality of RFID chips into a plurality of diesites; connecting in an assembly order, an antenna with a selected RFID chip to form a RFID tag; and repeating as necessary, the connecting of another antenna with another RFID chip in the assembly order with each successively connected antenna overlapping a previously connected antenna. 2. The method as set forth in claim 1 and further comprising: removing each RFID tag from the carrier substrate in a disassembly order. 3. The method as set forth in claim 2, wherein the disassembly order is opposite the assembly order. 4. The method as set forth in claim 2, wherein the removing comprises heating a selected one of the substrate, the carrier substrate, or the substrate and the carrier substrate to effectuate the removing of each RFID tag from the carrier substrate. 5. The method as set forth in claim 2, wherein the removing comprises using a pick-and-place machine to remove the RFID tag from the carrier substrate. 6. The method as set forth in claim 5 and further comprising: using the pick-and-place machine to attach the RFID tag to a host object. 7. The method as set forth in claim 2 and further comprising after the removing: encapsulating the RFID tag. 8. The method as set forth in claim 2 and further comprising after the removing: attaching the RFID tag with a host object. 9. The method as set forth in claim 8 and further comprising after the attaching: encapsulating the RFID tag. 10. The method as set forth in claim 1, wherein the connecting the substrate with the carrier substrate comprises a selected one of adhesively connecting the substrate with the carrier substrate or gluing the substrate and the carrier substrate to each other. 11. The method as set forth in claim 10, wherein the adhesively connecting comprises connecting the substrate with the carrier substrate using a layer of a double sided adhesive material. 12. The method as set forth in claim 1, wherein the connecting the antenna comprises electrically connecting a first node of the antenna with a first node of the RFID chip and electrically connecting a second node of the antenna with a second node of the RFID chip. 13. The method as set forth in claim 12, wherein the connecting comprises using a wire bonding machine to connect the first and second nodes of the antenna with the first and second nodes of the RFID chip. 14. The method as set forth in claim 1, wherein the antenna is a loop antenna. 15. The method as set forth in claim 1, wherein after the connecting, the antenna is positioned entirely within a quadrant defined by a diesite corner. 16. The method as set forth in claim 15, wherein the antenna includes a first portion positioned inside a perimeter of the RFID chip and opposite the quadrant defined by the diesite corner and a second portion positioned outside the perimeter of the RFID chip the antenna is connected with, and the second portion includes an area that is greater than an area of the RFID chip. 17. The method as set forth in claim 1, wherein a selected one of a shape of the antenna, a size of the antenna, or a shape of the antenna and a size of the antenna varies among the diesites. 18. A RFID Tag made according to the method as set forth in claim 1. | FIELD OF THE INVENTION The present invention relates generally to a method of fabricating a rat's nest radio frequency identification (RFID) antenna. More specifically, the present invention relates to a method of fabricating a RFID antenna on a RFID chip die while the die is still attached to a substrate. BACKGROUND OF THE ART Radio frequency identification (RFID) is a technology that has been in use since the 1940's where military aircraft carried large transponders as part of an IFF (Identify Friend-or-Foe) system. The transponder received electrical power from the aircraft and was thus an active RFID transponder. When a radar signal interrogated the transponder the transponder would generate a specific radio frequency signal that identified the aircraft as a “friendly” aircraft. This IFF system prevented otherwise friendly aircraft from being shot down by other friendly aircraft or friendly military forces. State of the art microelectronics technology now make it possible to fabricate very small analog (e.g. RF circuitry) and digital (e.g. Memory) circuits on silicon (Si). As a result, RFID technology is currently being used to obtain information stored on a RFID tag that is a much smaller version of the aforementioned large RFID transponder used for aviation IFF. At its most basic, a RFID system includes a RFID reader and one or more RFID tags that are attached to an object to be identified. The RFID reader transmits a radio frequency signal that creates an electromagnetic field. The RFID tags include electronics that store information about the object the tag is attached to. For example, the object can be a piece of merchandise, a food article, currency, a product, a component passing through a manufacturing process, an automobile, or a piece of luggage. The RFID tag also includes an antenna and electronics connected with the antenna for receiving a specific radio signal and for transmitting the stored information at a specific radio frequency when the RFID tag enters the electromagnetic field generated by the RFID reader. A RFID tag can be an active tag or a passive tag. An active RFID tag includes a power source, such as a battery, for example. Upon entering the electromagnetic field generated by the RFID reader, the active RFID tag extracts data from the electromagnetic field and then transmits its own information carrying radio signal to the RFID reader. In contrast, a passive RFID tag does not include a power source. Instead, the electromagnetic field generated by the RFID reader induces an AC voltage in the antenna of the passive RFID tag and that induced voltage is then rectified to produce a DC voltage that energizes the passive RFID tag. Once energized, the passive RFID tag transmits an information carrying radio signal to the RFID reader. Due to the requirement of a power source, active RFID tags are typically larger and more costly than passive RFID tags. In FIG. 1, a substrate 400 includes a plurality of RFID chips 401 that include an area a1. The substrate 400 can be a wafer of a semiconductor material such as silicon (Si), for example. The substrate 400 can include a wafer flat 400f and scribe lines 402s that delineate the RFID chips 401 and allow the RFID chips 401 to be separated from one another. A designer of an RFID chip 401 is faced with two fundamental choices between using an on-chip antenna 405 as depicted in FIG. 2a or an external antenna (421, 431) as depicted in FIGS. 2b, 3a, and 3b. In FIG. 1, The RFID chip 401 can include the on-chip antenna 405 positioned within an outer perimeter p1 of the chip 401, RFID electronics 403 that occupy a smaller area a2, and conductive traces or bonding wires 413 that electrically connect nodes (415, 417) on the RFID electronics with nodes (407, 409) on the on-chip antenna 405. If the on-chip antenna 405 can be accommodated on-chip without increasing the area a1 of the RFID chip 401, then the RFID chip 401 will offer the lowest possible RFID tag cost because tag cost is directly proportional to the area a1. However, one disadvantage of the on-chip antenna 405 is that unless the chip 401 is large, the on-chip antenna 405 will offer only a very limited range. That is, the chip 401 must be in very close proximity to the RFID reader in order to receive the electromagnetic field and to transmit the information stored on the RFID chip 401 to the RFID reader. The range may be adequate in some cases, but in general more range is better. Another disadvantage of on-chip antennas is that scaling of the RFID chip 401 to smaller chip sizes (i.e. reducing the area a1 thereby reducing tag cost) is largely precluded because shrinking the on-chip antenna 405 will seriously impact the range of the RFID chip 401 and/or reduce a data rate at which the information is transmitted from the RFID chip 401 to the RFID reader. On the other hand, by using an external antenna as depicted in FIGS. 2b, 3a, and 3b, the range of the RFID chip 401 can be greatly increased, but at a substantial increase in tag cost. The increase in tag cost can be attributed in large part to: a cost of manufacturing the external antenna (421, 431); a cost of mounting the RFID chip 401 to a substrate 451 that carries the antenna 431; and a cost of making an electrical connection (between the RFID chip 401 and the external antenna (421, 431). For example, in FIGS. 2b, 3a, and 3b, a wire bonding process can be used to connect a wire 413 with nodes (415, 417) on the RFID chip 401 and with nodes (423, 425) on the external antenna (421, 431). Solder balls 444 or other techniques that are well understood in the microelectronics art (e.g. surface mount technology) can be used to electrically connect the RFID chip 401 with the external antenna (421, 431). The process of connecting the RFID chip with the external antenna is a non-trivial process that increases the cost of the RFID tag, especially when the RFID chip 401 is much smaller than the external antenna (421, 431) as is often the case when large external antennas are used. For example, the μ-chip™ by HITACHI® has a size that is 0.4 mm*0.4 mm, which is much smaller than a grain of rice; however, the external antenna that is connected with the μ-chip™ is substantially larger than the μ-chip™ itself. Much effort has been expended in recent years to develop a low-cost means for connecting a small RFID chip to a large external antenna. As one example, Alien Technology® claims a RFID tag cost of less than $0.10 in high volumes for RFID chips that are connected with a large external antenna using fluidic self assembly (FSA) techniques. HITACHI® with its μ-chip™ and other makers of RFID tags have developed their own approaches to solving the problem of connecting a small RFID chip to a large external antenna. As another example, a current cost per unit area for a RFID chip fabricated on silicon (Si) is on the order of $0.20/sq-mm and with a RFID chip size of 0.4 mm on a side, the cost for the bare RFID chip (i.e. absent the external antenna) would be roughly $0.03 per RFID chip (i.e. $0.20/mm2*[0.4 mm*0.4 mm]=$0.03 per RFID chip). Therefore, the total cost of a complete RFID tag would then be determined by the cost of the large external antenna and the cost of connecting the antenna to the RFID chip. Consequently, there exists a need for a RFID tag with a cost that approaches that of an on-chip antenna, but with a performance approaching that of a separately fabricated and much more expensive external antenna. There is also a need for a low cost method of fabricating a RFID tag with a low cost antenna that uses a low cost means for connecting the antenna with a RFID chip and would add little to a cost of even the smallest RFID chips. SUMMARY OF THE INVENTION The method of the present invention solves the aforementioned needs by connecting a plurality of antenna in an assembly order to a plurality of previously fabricated RFID chips while the RFID chips are still connected with a carrier substrate. The method includes connecting a substrate that carries the previously fabricated RFID chips with a carrier substrate and then singulating the substrate to separate the plurality of RFID chips into a plurality of diesites so that each RFID chip can be processed as a discrete die. In a predetermined assembly order, an antenna is connected with a selected RFID chip to form a RFID tag. A first portion of the antenna is positioned opposite a quadrant defined by a diesite corner of the die the antenna is connected with. A second portion of the antenna is positioned outside a perimeter of the RFID chip. The connecting of additional antenna to additional RFID chips in the assembly order can be repeated as necessary with each successively connected antenna overlapping a previously connected antenna. Essentially, the connected antennas form a rat's nest of antennas. Subsequently, the RFID tags can be removed from the carrier substrate in a disassembly order and optionally attached to a host object. The rat's nest antenna approach falls in between RFID tags with on-chip antenna and RFID tags with external antenna in both cost and performance. The antenna can be connected with the RFID chip using low-cost wire bonding techniques and the antenna can be a wire made from a low cost material such as aluminum (Al) or copper (Cu). Consequently, the rat's nest antenna adds little to the cost of even the smallest RFID chips. Because the antenna can be substantially larger than the RFID chip, the rat's nest antenna overcomes the performance limitations of small on-chip antennas. Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view depicting a prior substrate including a plurality of prior RFID chips. FIG. 2a is a top plan view depicting a prior RFID tag with an on-chip antenna. FIG. 2b is a top plan view depicting a prior RFID tag with an external antenna. FIG. 3a is a top plan view depicting a prior RFID tag mounted on a substrate with an external antenna. FIG. 3b is a cross-sectional view along a line VI-VI of FIG. 3a and depicts an electrical connection between a prior RFID chip and an external antenna. FIGS. 4a and 4b are flow diagrams depicting a method of fabricating an antenna on a substrate. FIGS. 5a and 5b are top plan views depicting a substrate including a plurality of RFID chips. FIG. 6a is cross-sectional view depicting a singulated substrate. FIGS. 6b through 6d are detailed cross-sectional views of a section II of FIG. 6a. FIG. 7 is a cross-sectional view depicting a connecting of a substrate with a carrier substrate. FIG. 8 is a top plan view depicting a RFID chip. FIG. 9 is a top plan view depicting a plurality of diesites on a substrate. FIGS. 10a through 10d and are top plan views depicting a connecting of an antenna to a RFID chip in an assembly order. FIG. 10e is a cross-sectional view along a line III-III of FIG. 10c. FIG. 11a is a top plan view depicting a RFID tag in which an area enclosed by an antenna is greater than an area of an RFID chip the antenna is connected with. FIG. 11b is a top plan view depicting an antenna including an area positioned inside a perimeter and outside a perimeter of a RFID chip. FIGS. 12a through 12c are top plan views depicting a removing of a RFID tag from a carrier substrate in a disassembly order. FIG. 12d is a cross-sectional view depicting a method of removing a RFID chip from a carrier substrate. FIG. 13a is a cross-sectional view depicting antennas that are in contact with one another. FIG. 14a is a top plan view depicting a connecting of nodes on an antenna and a RFID chip. FIG. 14b is a cross-sectional view depicting a connecting of a RFID tag with a host object. FIG. 14c is a cross-sectional view depicting an encapsulated RFID tag. DETAILED DESCRIPTION In the following detailed description and in the several figures of the drawings, like elements are identified with like reference numerals. As shown in the drawings for purpose of illustration, the present invention is embodied in method of fabricating an antenna on a substrate including a plurality of previously fabricated RFID chips. In FIGS. 5a and 5b, a substrate 11 includes a plurality of RFID chips 21 that have been previously fabricated on the substrate 11. Accordingly, one of ordinary skill in the art will appreciate that the RFID chips 21 can be fabricated using processes that are well understood in the microelectronics art and that the RFID chips 21 can include RF circuitry, analog circuitry, and digital circuitry. The substrate 11 can be made from a material including but not limited to a semiconductor material, silicon (Si), and a silicon wafer such as the type commonly used in the fabrication of microelectronic devices. The substrate 11 can have a shape including but not limited to a rectangular shape as depicted in FIG. 5a or a circular shape as depicted in FIG. 5b. The circular shape can be a wafer that includes a wafer flat 12f. In FIG. 6a and referring to the flow diagram of FIG. 4a, at a stage 103, the substrate 11 is connected with a carrier substrate 25. A variety of methods can be used to connect the substrate 11 with the carrier substrate 25. Those methods include but are not limited to using an adhesive to adhesively connect the substrate 11 with the carrier substrate 25 and using a glue to glue the substrate 11 and the carrier substrate 25 to each other. The carrier substrate 25 serves as a stable platform or foundation upon which to carry out additional fabrication steps on the RFID chips 21 as will be described below. In FIG. 7, as one example of how the substrate 11 can be connected with the carrier substrate 25, a layer 23 of a double sided adhesive material including adhesive surfaces 23t and 23b can be used to adhesively connect the substrate 11 with the carrier substrate 25. A bottom surface 11b of the substrate 11 and a top surface 25s of the carrier substrate 25 can be urged U into contact with the adhesive surfaces (23t, 23b) to effectuate the connecting of the substrate 11 with the carrier substrate 25. Preferably, the carrier substrate 25 is a substantially planar along the top surface 25s so that the substrate 11 can be mounted on a flat surface. The carrier substrate 25 can be made from a variety of materials including but not limited to a semiconductor material, a metal, a plastic, a glass, a ceramic, a composite material, quartz, and a borosilicate glass, such as a PYREX™ glass, for example. In FIGS. 6a through 6d, at a stage 105, the substrate 11 is singulated to separate the RFID chips 21 from one another with each RFID chip 21 forming a diesite (see diesites a-p in FIG. 9) that is connected with the carrier substrate 25. The singulating at the stage 105 can be accomplished using a process including but not limited to sawing, etching, cutting, scribing, or the like. For example, it is well understood in the microelectronics art that die on a semiconductor wafer can be either scribed or sawed to separate the die from one another. However, after the stage 105 the diesite 21 are still connected to the carrier substrate 25. The singulating forms a space 12s between adjacent diesites such that the diesites are no longer connected to one another but are still connected with the carrier substrate 25. As one example, the singulating at the stage 105 can be accomplished using a saw to cut the spaces 12s in the substrate 11. The spaces 12s can be cut down to a bottom surface 11b of the substrate as depicted in FIG. 6b or the spaces 12s can be cut partially into or all the way through the layer 23 as depicted in FIG. 6c, where the spaces 12s are cut all the way through the substrate 11 and partially through the layer 23. As another example, in FIG. 6d, the spaces 12s can be cut all the way through the substrate 11 and the layer 23, but only partially through the carrier substrate 25. In FIGS. 8 and 9, after the singulating at the stage 105, each RFID chip 21 comprises a diesite denoted as diesites a through p in FIG. 9. Although only sixteen diesites are depicted, the actual number of diesites will be application specific and may be determined by a total useable number of RFID chips 21 that were previously fabricated on the substrate 11. In FIG. 8, a RFID chip 21 has a perimeter P1 and can include circuitry 30, a first node 31, and a second node 32. One of ordinary skill in the art will appreciate that the circuitry 30 can include RF circuits, analog circuits, digital circuits, memory (e.g. ROM and/or RAM), a power source such as a battery, and other circuitry necessary to implement a passive or an active RFID tag. The first and second nodes (31, 32) can be electrically conductive bonding pads that are electrically connected with the circuitry 30. As will be described below, an antenna will be electrically connected with the first and second nodes (31, 32). In FIGS. 10a through 10d, at a stage 107, an antenna 40 is connected with a selected RFID chip 21 in an assembly order. The assembly order is a predetermined order that is application specific and can be based on several factors including the shape of the substrate 11. For example, the assembly order may be different for the circular (e.g. wafer shaped) substrate 11 of FIG. 5b than the rectangular shaped substrate of FIG. 5a. As an example, in FIG. 10a, the assembly order comprises traversing down the columns of the substrate 11 as depicted by the dashed lines 1, 2, 3, and 4 so that the diesites are connected with the antenna 40 by moving down each column to connect the RFID chips 21 in that column with an antenna 40 and then moving to the next column in a left to right order. Therefore, the assembly order is: a; b; c; and d for the column traversed by dashed arrow 1 (see FIG. 10c); e; f; g and h for the column traversed by dashed arrow 2; i; j; k and l for the column traversed by dashed arrow 3; and m; n; o and p for the column traversed by dashed arrow 4. In FIG. 10b, the antenna 40 is connected with the diesite a. Connecting the antenna 40 with the RFID chip 21 can include connecting a first node 41 and a second node 42 of the antenna 40 with the first and second nodes (31, 32) respectively of the RFID chip 21. For example, a wire bonding machine can be used to connect the first and second nodes (41, 42) of the antenna with the first and second nodes (31, 32) of the RFID chip 21. The first and second nodes (31, 32) can be contact pads such as the type used in ASIC devices for connecting pads on a chip with bonding pads on a lead frame. The antenna 40 can be made from an electrically conductive material including but not limited to copper (Cu), aluminum (Al), or other bare or insulated wire. The antenna 40 can be a loop antenna as depicted in FIG. 10b, or the antenna 40 can have another shape tailored to a specific application. The shape of the antenna 40 will be determined in part by a means used for forming and connecting the antenna 40 to the RFID chip 21. For example, if a wire bonding machine is used, then the accuracy with which the antenna 40 is positioned on the diesite and the shape of the antenna 40 will be determined by the capabilities of the wire bonding machine. The connecting of the antenna 40 is not to be construed as being limited to a wire bonding process and any process suitable for effectuating the connection can be used. It is desirable to prevent entanglement of the antennas 40 with one another as additional antenna 40 are connected to their respective RFID chips 21. Entangled antennas can lead to damage to the antenna 40 and/or the RFID chip 21 when the RFID chip 21 is removed from the carrier substrate 25 as will be described below. One way to prevent entanglement is to control the shape of the antenna 40 and the position of the antenna 40 relative to the diesite. In FIG. 10b, the antenna 40 is positioned entirely within a quadrant Q4 defined by a diesite corner. The diesite corner is defined by the intersection of the x-y axes. In FIGS. 10c through 10d, the positioning of the antenna 40 entirely within the quadrant Q4 prevents entanglement of the antennas 40 with one another as they are connected to their respective RFID chips 21 and allows for the RFID chips 21 to be removed from the carrier substrate 25 in a disassembly order that prevents entanglement of the antennas 40 during a disassembly process to be described below. In FIG. 11a, one advantage of the antenna 40 is that the antenna 40 can be substantially larger than the RFID chip 21 that the antenna 40 is connected with. For example, if the RFID chip 21 has an area A1 determined by a width and a height of the diesite, the antenna 40 can enclose an area A3 that is substantially larger than the area A1. The area A3 is measured between an interior perimeter of the antenna 40 and a dashed line 40″. As an example, if the RFID chip 21 has dimensions of (0.5 mm*0.5 mm) so that the area A1 is 0.25 mm2, then the area A3 enclosed by the antenna 40 can be several times larger than the area A1, such as ten times the area A1 so that A3 is 2.5 mm2 (i.e. 10*0.25 mm2). Accordingly, for a very small RFID chip 21, the antenna 40 can be much larger with the resulting advantages of a low cost per unit of area A1 for the RFID chip 21 and a large, low cost, connected antenna 40 that has the performance advantages of the aforementioned prior large external antenna. In FIG. 11b, another advantage of the antenna 40 is that it includes a first portion (denoted as an area A5) positioned inside the perimeter P1 of the RFID chip 21 and the first portion is positioned opposite the quadrant Q4 defined by the diesite corner (i.e. the x-y axes). The antenna 40 also includes a second portion (denoted as an area A4) that is positioned outside the perimeter of the RFID chip 21 the antenna 40 is connected with. The area A4 of the second portion is greater than the area A5 of the first portion and the area A4 is also greater than the area A1 of the RFID chip 21. Consequently, the area A4 of the antenna 40 that is positioned off-chip (i.e. outside the perimeter of the RFID chip 21) can be substantially larger than the area A1 of the RFID chip 21. In FIGS. 10c and 10d and referring to FIG. 4a, at a stage 109, the process of connecting another antenna 40 with another RFID chip 21 in the assembly order can be repeated as necessary. Each successively connected antenna 40 overlaps a previously connected antenna 40 as depicted in FIGS. 10c and 10d. The connecting process may be used to connect antennas 40 to all of the available diesites a-p (see FIG. 10d) or only a subset of the diesites can have antennas 40 connected therewith. For example, only the diesites a-h can have antennas 40 connected therewith in the assembly order for columns 1 and 2. As depicted in FIGS. 10c and 10d the connected antennas 40 partially overlap one another as they are successively connected in the assembly order. For example, in FIG. 10c, a portion of the antenna 40 at diesite b overlaps the antenna 40 at diesite a. Similarly, a portion of the antenna 40 at diesite c overlaps the antenna 40 at diesite b and a portion of the antenna 40 at diesite d overlaps the antenna 40 at diesite c. Moreover, as additional antenna 40 are connected, the number of antennas 40 that are overlapped by another antenna 40 increases. For example, the antenna 40 at the diesite p overlaps portions of the antennas 40 at diesites o, j, k, l, g, and h; however, the antenna 40 at the diesite p is also positioned above all of the antenna 40 that it overlaps so that is will not become entangled with those antenna 40 when the RFID chip 21 at the diesite p is removed from the carrier substrate 25. In FIG. 10e, a cross-sectional view of the diesites a-d of FIG. 10c, the connected antennas 40 may be spaced apart S from one another such that the antennas 40 are not touching each one another. The antennas 40 may extend substantially a out-of-plane of the surface 11s of the substrate 11 as denoted by an angle α between the antenna 40 and a line IV-IV that is coplanar with the surface 11s. Consequently, the spatial relationship between the antennas 40 allows for a disassembly order that prevents the antennas 40 from entangling with or interfering with one another as they are removed from the carrier substrate 25. Therefore, in FIG. 10e, when diesite d is removed from the carrier substrate 25 prior to the removal of diesite C, the antenna 40 at diesite d will not snag or otherwise interfere with the antenna at diesite c. As was describe above, the actual shape and spatial relationship between the antennas 40 will be determined in part by an accuracy of the means used to connect the antennas 40 with their respective diesites. In contrast, in FIG. 13a, the connected antennas 40 can include a portion that is in contact with an adjacent antenna 40 as denoted by a dashed oval C. The antenna 40 may also lay closer to the plane IV-IV as denoted by an angle β that is closer to the plane IV-IV than the angle α of FIG. 10e. In FIG. 4a, after the stage 109, if all desired diesites have an antenna 40 connected therewith, then the connection process can be terminated at the stage 131. The substrate 11 can then be stored or shipped for later disassembly of the diesites from the carrier substrate 25. The RFID chip 21 with a connected antenna 40 comprises a RFID tag. In FIG. 14a, a RFID tag 10 includes the RFID chip 21, a connected antenna 40, and circuitry 30. The circuitry 30 can have an area A2 that is less than the area A1 of the RFID chip 21 and the circuitry 30 can be electrically connected with the first and second nodes (31, 32) by electrically conductive traces (51, 52). An electrical connection between the first and second nodes (41, 42) of the antenna 40 and the first and second nodes (31, 32) of the RFID chip 21 can be made using solder balls 34 or the like. However, after the connecting process is completed, it may be desirable to disassemble the diesites from the carrier substrate 25. In FIGS. 12a through 12c and referring to FIG. 4b, at a stage 111, each RFID tag 10 is removed from the carrier substrate 25 in a disassembly order denoted by dashed arrows 1-4. Preferably, the disassembly order is opposite the assembly order. Therefore, a disassembly order opposite the assembly order would be: p; o; n; and m for the column traversed by dashed arrow 1 (see FIG. 12b); l; k; j and i for the column traversed by dashed arrow 2; h; g; f and e for the column traversed by dashed arrow 3; and d; c; b and a for the column traversed by dashed arrow 4. Accordingly, in FIG. 12b the first RFID tag 10 to be removed from the carrier substrate 25 is the diesite p. The removing process continues until all desired diesites have been removed from carrier substrate 25. Therefore, in FIG. 12c, diesites p-e have been removed and diesites d-a remain to be removed in the disassembly order denoted by the dashed arrow 4, that is d; c; b and a. The removing at the stage 111 can be accomplished by a variety of methods. For example, in FIG. 12d, if the layer 23 is made from a temperature sensitive material that, melts, softens, or the like when heated, then the substrate 11, the carrier substrate 25, or the substrate 11 and the carrier substrate 25 can be heated H to cause the layer 23 to lose its adhesive or other connecting properties so that the RFID tag 10 at the diesite can be extracted from the carrier substrate 25. One of ordinary skill in the art will appreciate that other methods can be used to remove the RFID tags 10 and the present invention is not limited to the aforementioned heating H. For example, a solvent can be applied to the layer 23 to effectuate the removing at the stage 111. In FIG. 12d, the removing at the stage 111 can include using a pick-and-place machine 70 to remove the RFID tag 10 from the carrier substrate 25. For example, an end effector 71 of the pick-and-place machine 70 can contact the surface 11s of the diesite and apply a vacuum to create suction and a force F can be used to pull the diesite p off of the carrier substrate 25. The present invention is not to be construed as being limited to the use of a pick-and-place machine to effectuate the removing at the stage 111 and other processes for removing a diesite from the carrier substrate 25 can be used. Regardless of the process used, it is important that the process not damage the antenna 40, the RFID chip 21, or adjacent RFID chips 21 and their antenna 40. In FIG. 14b and referring to FIG. 4b, after the removing at the stage 111, at a stage 113, the RFID tag 10 can be attached to a host object 80. The RFID tag 10 and the host object 80 can be urged U into contact with each other. A glue, an adhesive, or the like, can be applied to a surface 80t of the host object and/or the surface 11b of the RFID tag 10 to connect the RFID tag 10 and the host object 80 with each other. The host object 80 can be any object it is desirable to attach the RFID tag 10 to and includes but is not limited to an article of manufacture, a product, a piece of luggage, a vehicle, a food article, an animal, a person, a negotiable instrument, and currency. A pick-and-place machine can be used to attach the RFID tag 10 to the host object 80. The pick-and-place machine can be the same pick-and-place machine 70 used to remove the RFID tag 10 from the carrier substrate 25. In FIG. 14c, at a stage 115, the RFID tag 10 can be attached to a host object 80 as was described above, and then at a stage 117, the RFID tag 10 can be encapsulated. Alternatively, at a stage 119, the RFID tag 10 can be encapsulated 85 prior to being attached to the host object at a stage 121. An encapsulating material 85 can be used to cover, conformally coat, protect, or otherwise electrically insulate the antenna 40 and the RFID chip 21. Suitable encapsulating materials include but are not limited to silicone rubber, polydimethylsiloxane (PDMS), a polymer, and Paralene™. As an example, a PDMS material such as a DuPont® Sylgard™ can be used to form a coating that encapsulates the RFID tag 10. Another advantage to the method described herein is that the antennas 40 need not all be of the same size and shape. Accordingly, the connecting process at the stage 107 can include connecting antennas 40 in the assembly order that vary in size, shape, or size and shape among the diesites a-p. It is important to ensure that the antennas 40 properly overlap one another as described above and that the variations in shape and/or size among the antennas 40 will not lead to entanglement so that at the stage 111, the RFID tags 10 can be removed in the disassembly order without damage to the RFID chips 21 or their respective antennas 40. Moreover, the method described herein is also amendable to connecting an antenna 40 that is slightly larger than the perimeter P1 would allow in those situations in which the size of the antenna 40 must be larger than the prior on-chip antenna due to the upper limit set by P1, but the performance parameters of the antenna 40 don't require that it be substantially larger than the RFID chip 21. Although several embodiments of the present invention have been disclosed and illustrated, the invention is not limited to the specific forms or arrangements of parts so described and illustrated. The invention is only limited by the claims. | <SOH> BACKGROUND OF THE ART <EOH>Radio frequency identification (RFID) is a technology that has been in use since the 1940's where military aircraft carried large transponders as part of an IFF (Identify Friend-or-Foe) system. The transponder received electrical power from the aircraft and was thus an active RFID transponder. When a radar signal interrogated the transponder the transponder would generate a specific radio frequency signal that identified the aircraft as a “friendly” aircraft. This IFF system prevented otherwise friendly aircraft from being shot down by other friendly aircraft or friendly military forces. State of the art microelectronics technology now make it possible to fabricate very small analog (e.g. RF circuitry) and digital (e.g. Memory) circuits on silicon (Si). As a result, RFID technology is currently being used to obtain information stored on a RFID tag that is a much smaller version of the aforementioned large RFID transponder used for aviation IFF. At its most basic, a RFID system includes a RFID reader and one or more RFID tags that are attached to an object to be identified. The RFID reader transmits a radio frequency signal that creates an electromagnetic field. The RFID tags include electronics that store information about the object the tag is attached to. For example, the object can be a piece of merchandise, a food article, currency, a product, a component passing through a manufacturing process, an automobile, or a piece of luggage. The RFID tag also includes an antenna and electronics connected with the antenna for receiving a specific radio signal and for transmitting the stored information at a specific radio frequency when the RFID tag enters the electromagnetic field generated by the RFID reader. A RFID tag can be an active tag or a passive tag. An active RFID tag includes a power source, such as a battery, for example. Upon entering the electromagnetic field generated by the RFID reader, the active RFID tag extracts data from the electromagnetic field and then transmits its own information carrying radio signal to the RFID reader. In contrast, a passive RFID tag does not include a power source. Instead, the electromagnetic field generated by the RFID reader induces an AC voltage in the antenna of the passive RFID tag and that induced voltage is then rectified to produce a DC voltage that energizes the passive RFID tag. Once energized, the passive RFID tag transmits an information carrying radio signal to the RFID reader. Due to the requirement of a power source, active RFID tags are typically larger and more costly than passive RFID tags. In FIG. 1 , a substrate 400 includes a plurality of RFID chips 401 that include an area a 1 . The substrate 400 can be a wafer of a semiconductor material such as silicon (Si), for example. The substrate 400 can include a wafer flat 400 f and scribe lines 402 s that delineate the RFID chips 401 and allow the RFID chips 401 to be separated from one another. A designer of an RFID chip 401 is faced with two fundamental choices between using an on-chip antenna 405 as depicted in FIG. 2 a or an external antenna ( 421 , 431 ) as depicted in FIGS. 2 b, 3 a, and 3 b. In FIG. 1 , The RFID chip 401 can include the on-chip antenna 405 positioned within an outer perimeter p 1 of the chip 401 , RFID electronics 403 that occupy a smaller area a 2 , and conductive traces or bonding wires 413 that electrically connect nodes ( 415 , 417 ) on the RFID electronics with nodes ( 407 , 409 ) on the on-chip antenna 405 . If the on-chip antenna 405 can be accommodated on-chip without increasing the area a 1 of the RFID chip 401 , then the RFID chip 401 will offer the lowest possible RFID tag cost because tag cost is directly proportional to the area a 1 . However, one disadvantage of the on-chip antenna 405 is that unless the chip 401 is large, the on-chip antenna 405 will offer only a very limited range. That is, the chip 401 must be in very close proximity to the RFID reader in order to receive the electromagnetic field and to transmit the information stored on the RFID chip 401 to the RFID reader. The range may be adequate in some cases, but in general more range is better. Another disadvantage of on-chip antennas is that scaling of the RFID chip 401 to smaller chip sizes (i.e. reducing the area a 1 thereby reducing tag cost) is largely precluded because shrinking the on-chip antenna 405 will seriously impact the range of the RFID chip 401 and/or reduce a data rate at which the information is transmitted from the RFID chip 401 to the RFID reader. On the other hand, by using an external antenna as depicted in FIGS. 2 b, 3 a, and 3 b, the range of the RFID chip 401 can be greatly increased, but at a substantial increase in tag cost. The increase in tag cost can be attributed in large part to: a cost of manufacturing the external antenna ( 421 , 431 ); a cost of mounting the RFID chip 401 to a substrate 451 that carries the antenna 431 ; and a cost of making an electrical connection (between the RFID chip 401 and the external antenna ( 421 , 431 ). For example, in FIGS. 2 b, 3 a, and 3 b, a wire bonding process can be used to connect a wire 413 with nodes ( 415 , 417 ) on the RFID chip 401 and with nodes ( 423 , 425 ) on the external antenna ( 421 , 431 ). Solder balls 444 or other techniques that are well understood in the microelectronics art (e.g. surface mount technology) can be used to electrically connect the RFID chip 401 with the external antenna ( 421 , 431 ). The process of connecting the RFID chip with the external antenna is a non-trivial process that increases the cost of the RFID tag, especially when the RFID chip 401 is much smaller than the external antenna ( 421 , 431 ) as is often the case when large external antennas are used. For example, the μ-chip™ by HITACHI® has a size that is 0.4 mm*0.4 mm, which is much smaller than a grain of rice; however, the external antenna that is connected with the μ-chip™ is substantially larger than the μ-chip™ itself. Much effort has been expended in recent years to develop a low-cost means for connecting a small RFID chip to a large external antenna. As one example, Alien Technology® claims a RFID tag cost of less than $0.10 in high volumes for RFID chips that are connected with a large external antenna using fluidic self assembly (FSA) techniques. HITACHI® with its μ-chip™ and other makers of RFID tags have developed their own approaches to solving the problem of connecting a small RFID chip to a large external antenna. As another example, a current cost per unit area for a RFID chip fabricated on silicon (Si) is on the order of $0.20/sq-mm and with a RFID chip size of 0.4 mm on a side, the cost for the bare RFID chip (i.e. absent the external antenna) would be roughly $0.03 per RFID chip (i.e. $0.20/mm 2 *[0.4 mm*0.4 mm]=$0.03 per RFID chip). Therefore, the total cost of a complete RFID tag would then be determined by the cost of the large external antenna and the cost of connecting the antenna to the RFID chip. Consequently, there exists a need for a RFID tag with a cost that approaches that of an on-chip antenna, but with a performance approaching that of a separately fabricated and much more expensive external antenna. There is also a need for a low cost method of fabricating a RFID tag with a low cost antenna that uses a low cost means for connecting the antenna with a RFID chip and would add little to a cost of even the smallest RFID chips. | <SOH> SUMMARY OF THE INVENTION <EOH>The method of the present invention solves the aforementioned needs by connecting a plurality of antenna in an assembly order to a plurality of previously fabricated RFID chips while the RFID chips are still connected with a carrier substrate. The method includes connecting a substrate that carries the previously fabricated RFID chips with a carrier substrate and then singulating the substrate to separate the plurality of RFID chips into a plurality of diesites so that each RFID chip can be processed as a discrete die. In a predetermined assembly order, an antenna is connected with a selected RFID chip to form a RFID tag. A first portion of the antenna is positioned opposite a quadrant defined by a diesite corner of the die the antenna is connected with. A second portion of the antenna is positioned outside a perimeter of the RFID chip. The connecting of additional antenna to additional RFID chips in the assembly order can be repeated as necessary with each successively connected antenna overlapping a previously connected antenna. Essentially, the connected antennas form a rat's nest of antennas. Subsequently, the RFID tags can be removed from the carrier substrate in a disassembly order and optionally attached to a host object. The rat's nest antenna approach falls in between RFID tags with on-chip antenna and RFID tags with external antenna in both cost and performance. The antenna can be connected with the RFID chip using low-cost wire bonding techniques and the antenna can be a wire made from a low cost material such as aluminum (Al) or copper (Cu). Consequently, the rat's nest antenna adds little to the cost of even the smallest RFID chips. Because the antenna can be substantially larger than the RFID chip, the rat's nest antenna overcomes the performance limitations of small on-chip antennas. Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. | 20040430 | 20071204 | 20051103 | 75189.0 | 0 | TRINH, MINH N | METHOD OF FABRICATING A RAT'S NEST RFID ANTENNA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,779 | ACCEPTED | Low noise op amp | The present invention relates amplifiers using metal oxide semiconductor based integrated circuits. The present invention is particularly but not exclusively related to audio application mixed signal chips. The present invention provides an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. Preferably a cascode based op amp structure is implemented. | 1. An analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. 2. A circuit according to claim 1 wherein the first transistor device is arranged in use to have an operating voltage below a predetermined level and wherein the second transistor device is arranged such that in use it is not constrained by the predetermined operating voltage level, and wherein the second oxide thickness is greater than the first oxide thickness. 3. A circuit according to claim 2 wherein the predetermined operating voltage level is 3.6V and the first oxide thickness is 70 nm. 4. A circuit according to claim 2 wherein the second transistor device forms part of a cascode transistor device circuit within said analogue circuit. 5. A circuit according to claim 4 wherein the cascode transistor device circuit is a differential folded cascode op amp circuit. 6. A circuit according to claim 5 wherein the op amp circuit further comprises input, bias, current mirror and constant current sub-circuits and wherein said first transistor device forms part of one of said op amp sub-circuits. 7. A circuit according to claim 6 further comprising a clamp circuit arranged to limit the operating voltage of said first transistor to the predetermined operating voltage level. 8. A mixed signal integrated circuit comprising an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. 9. A method of processing an analogue signal comprising applying the analogue signal to an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the analogue circuit comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness, such that the analogue signal is processed by both said transistor devices. 10. A method according to claim 9 wherein the first transistor device is arranged to have an operating voltage below a predetermined level and wherein the second transistor device is arranged such that it is not constrained by the predetermined operating voltage level, and wherein the second oxide thickness is greater than the first oxide thickness. 11. A method according to claim 10 wherein the second transistor device forms part of a cascode transistor device circuit within said analogue circuit. 12. A method of producing an analogue circuit for processing analogue signals in an integrated circuit; the method comprising providing a number of metal oxide semiconductor transistor devices arranged to implement said analogue circuit, at least a first said transistor device having a first oxide thickness, and at least a second said transistor device having a second and different oxide thickness. 13. A method according to claim 12 further comprising providing a second number of metal oxide semiconductor transistors devices arranged to implement a digital circuit. | FIELD OF THE INVENTION The present invention relates to amplifiers using metal oxide semiconductor based integrated circuits. The present invention is particularly but not exclusively related to audio application mixed signal chips. BACKGROUND OF THE INVENTION Due to the increasing need for miniaturisation of portable devices such as MP3 players, mobile telephones and personal digital assistants, it has become increasingly important to implement both digital processing functions and related analogue, especially audio, processing functions on the same chip or integrated circuit—a so called mixed signal chip. For this reason the implementation of analogue functions on metal oxide semiconductor (MOS) based devices has become increasingly important. A major problem with this technology however is that the digital and analogue circuits require different characteristics from the same semiconductor technology. Digital circuits are fastest and consume least power and chip area when implemented using the shortest channel available in a given manufacturing technology. However this limits the supply voltage that can be applied to this digital circuitry without causing breakdown or premature wear-out of the small devices used. For example digital circuitry on a currently mature process might use a structure with 0.35 um drain-source spacing and 70 nm gate oxide thickness. However most analogue circuits must operate in accordance with legacy standards, for example in order to provide a 2V rms signal for consumer standard audio Line Outputs, or possibly 5V rms for professional applications. Operation at these large signal swings is likely to continue to be necessary for some time in the future, to maintain the ratio of signal power to that of the thermal noise of the op amps and resistors in the signal path: a halving of the signal amplitude would require the noise power to be divided by four, reducing the required circuit impedances by a factor of four, and increasing the power required by the amplifiers, despite the lower supply voltage. Also reducing the signal level would increase the relative importance of extraneous noise and interference coupling into the circuitry. This is likely to require a rail to rail supply as high as 18V. To avoid large electric fields in the device, which cause breakdown or long-term reliability issues such as hot-carrier induced degradation of threshold voltage and transconductance, this requires a larger device structure, with typically a 3 um minimum drain-source spacing and a 350 nm oxide layer thickness. Many widely available semiconductor manufacturing technologies today offer the possibility of selecting a thin or thick gate oxide thickness for selected transistors in each integrated circuit on the basis of additional photographic masking and processing steps. For instance one technology allows 70 nm gate oxides for 3.3V nominal (3.6V maximum) operation for core logic transistors, but 120 nm devices for 5V nominal (5.5V maximum) digital input and output devices. Such technology has been used for mixed signal circuits where the logic operates at 3.3V and all the analogue circuitry operates at 5V. Similarly circuits such as LCD display drivers use 3.3V control logic and 18V nominal (19.8V maximum) (350 nm gate oxide) output stages. Allowing the logic to operate at lower voltage using smaller devices makes these devices smaller in chip area and hence cost and reduces the power consumed by the digital circuitry. High performance audio op amps also require high open loop bandwidth so that the distortion inherent in their open-loop transfer characteristics may be suppressed across the audio band by negative feedback around the amplifier, even when this feedback is relatively light, to provide gain in the signal path. Suppression of distortion is important even at frequencies well above the human hearing limit of approximately 20 kHz. This is because distortion at these higher frequencies, for example up to 100 kHz, have an effect in the audible range (20 Hz-20 kHz). Also audio signals from delta-sigma digital-to-analogue converters have quantisation noise components well above the audio band, which can intermodulate to produce audio band components unless the amplifier retains a linear closed-loop response to these high-frequency components. A wide closed-loop bandwidth is also necessary to avoid relative phase delays across the audio spectrum. One of the major sources of noise in MOS technology is flicker noise. MOS devices such as transistors contain traps, due to impurities and inevitable imperfections in the crystal structure of the silicon, in or near the interface between the silicon and silicon oxide layers. The current in MOS devices typically travels substantially along this interface, and the traps charge and discharge randomly over time. This gives rise to a noise component of charge density at the oxide interface with an approximately 1/f power spectrum, i.e. with higher spectral density at lower frequencies. For circuit analysis, this charge variance ΔQ may be regarded as an equivalent modulation of the gate voltage ΔVG where ΔVG=ΔQ/Cox, Cox being the capacitance from gate to channel across the gate oxide. Cox is inversely proportional to gate oxide thickness, so for the same charge variance, the equivalent gate voltage noise is proportional to gate oxide thickness. In practice, this is found to be the case, i.e. similar processes with different gate oxide thicknesses give gate flicker noise voltages increasing with gate oxide thickness. It is also found that the flicker noise voltage is inversely proportional to the square root of the area of a MOS transistor. So one approach to reducing this noise is to increase the surface area, i.e. to increase the width and length of the transistor. However to improve flicker noise by say 6 dB would require four times the transistor area: significant further improvement in flicker noise rapidly leads to impractically large devices, both in terms of extra parasitic capacitances and in the chip area consumed and hence in cost of manufacture. The contribution of flicker noise of a given transistor to the input-referred noise voltage of an amplifier can also be reduced by altering the gain from the transistor referred to the input, by altering its aspect ratio or altering its bias current. But this makes the design deviate from what would otherwise be considered the optimum in terms of the desired combination of area, power, and performance, and in practice there is again only a small improvement practically achievable without unduly compromising other design objectives. Also chopper-stabilisation techniques could be incorporated to move flicker noise away to higher frequencies, where the noise can either be ignored or filtered out. However this adds to the complexity of the circuit, generally requiring the addition of multiple switches and clock generation and distribution circuitry, and tends to give spurious output signals at the chopping frequency and its harmonics. So in general, for a given circuit topology, circuit specification, and manufacturing technology, there is a practical and economical lower limit to the flicker noise achievable. A known circuit common in high performance audio amplifier applications is the differential folded cascode op amp circuit, a schematic for which is shown in FIG. 1a. This circuit offers low distortion, high gain, and wide bandwidth, which are desirable for hi fidelity sound reproduction. The operation of such circuits is well known to those skilled in the art, however the cascode arrangement essentially utilises a gain transistor (MP1 or MP2) together with a cascode transistor (MNC1 or MNC2) which effectively reduces the variation in voltage across its associated gain transistor (M1 or MP2) in order for this to amplify changes in its input voltage in a linear fashion; thus reducing distortion. This topology also offers high voltage gain to the output lout and wide voltage compliance at this node, either for directly driving an output or to act as the input of a further op amp gain stage. FIG. 1a shows a differential folded cascode amplifier structure using two cascode transistors (MNC1, MNC2) and constant current bias devices MNM1, MNM2. Since bias device MNM2 passes a constant current, all signal current from input device MP2 passes through cascode device MNC2 to the output lout. Similarly, signal current from MP1 passes through cascode device MNC1 rather than bias device MNM1, and is then mirrored by mirror devices MPB1, MPB2 to the output lout. Cascode devices MPC1 and MPC2 are inserted in series with the drains of MPB1, MPB2 to improve the output impedance and accuracy of this current mirror. Suitable bias voltages VCP1, VCN1, VBN1 are derived by other circuitry using standard techniques. The folded cascode structure of FIG. 1b is a variation of this differential folded cascode amplifier. In this case previous bias devices MNM1 and MNM2 are reconnected as mirror devices with MNM1 being drain-gate connected, and cascode device MNC1 is also drain-gate connected, and previous mirror devices MPB1 and MPB2 now operate as constant bias current sources supplied with a suitable bias voltage VBP1. As before, signal current from MP2 flows through cascode device MNC2 to the output. However signal current from MP1 can no longer flow through cascode device MNC1, since this is now forced to operate at the constant current supplied by MPB1, so this signal current now flows though mirror device MNM1, where it is mirrored by MNM2 and thence flows through MNC2 to the output. Whilst in these structures the flicker noise contribution of the cascode transistors MNC1, MNC2, MPC1 and MPC2 is small, in practical implementations of the circuits of FIG. 1a or FIG. 1b, it is found that the flicker noise contributed by MNM1 and MNM2 is one of the dominant components of audio frequency noise, with other flicker noise contributed by input devices MP1 and MP2 and by MPB1 and MPB2. This is particularly the case for high-voltage (say 18V) circuits where the amplifier is implemented with appropriately thick gate oxide (say 350 nm) MOS devices. As discussed above, the designer soon reaches a practical lower limit for this flicker noise. Yet there is an increasing requirement for lower and lower noise audio circuitry with better and better signal-to-noise ratio, i.e. lower noise and higher signal swings. SUMMARY OF THE INVENTION In general terms the present invention provides an analogue circuit arrangement using MOS based technology which reduces flicker noise by reducing the oxide thickness of selected transistor devices, having a low operating voltage, compared with those required to operate with a larger operating voltage in the same circuit. The lower voltage transistors are typically employed for biasing, constant current sources, and current mirrors, whereas the larger voltage transistors are exposed to the necessary large signal swings for hi fidelity audio operation. The reduced oxide thickness reduces the flicker noise contribution to the circuit from these low voltage transistors, and hence the overall flicker noise of the circuit. The cascode transistor(s) will still require a thicker oxide layer in order to handle the higher voltage level, whereas the other circuit transistors can be implemented with thinner oxide layers by arranging the circuit such that they are only required to handle relatively low operating voltages. Advantageously, this dual transistor oxide thickness arrangement can be utilised in a folded cascode op amp circuit in which the transistors required to handle the larger voltages are the cascode transistors, which because of the nature of cascode circuits have a much reduced flicker noise contribution compared with transistors in other circuit configurations. Thus a number of the non-cascode circuit transistors can have thinner oxide layers in order to further minimise their contributions to the flicker noise of the op amp circuit. A further advantage of this arrangement is that the overall chip size can be reduced because of the replacement of thicker oxide layer transistors by thinner oxide transistors. For a given width and length and operating current and voltage, the thinner gate oxide transistor will have high transconductance and higher output impedance: conversely for a given requirement for transconductance or output impedance, the width and length can be scaled, giving a smaller chip area occupied by the transistor. Of course this scaling will also reduce the improvement in flicker noise, but this is a tradeoff available to the designer. When used in mixed-signal mixed-voltage integrated circuits, where the digital circuitry uses thin-oxide transistors and the analogue circuitry uses thick-oxide transistors, there is no incremental cost, either in tooling or actual manufacturing cost in using thin-oxide transistors of the same structure as used in the digital circuitry in selected locations in the analogue circuitry. In particular in one aspect the present invention provides an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. Preferably the first transistor device is arranged in use to have an operating voltage below a predetermined level and the second transistor device is arranged such that in use it is not constrained by this predetermined operating voltage level. This allows the first oxide layer to be thinner than the second oxide layer thickness. For example the predetermined operating voltage level is 3.6V and the first oxide thickness is 70 nm. This compares with an example operating voltage of 19.8V and oxide thickness of 350 nm for the second transistor. Preferably the second transistor device forms part of a cascode transistor device circuit within said analogue circuit. Preferably the cascode transistor device circuit is a differential folded cascode op amp circuit. This reduces the flicker noise contribution of the thicker oxide layer transistors. Preferably the thin oxide transistors are employed in the input, bias and constant current sub-circuits of the op amp circuit. The predetermined operating voltage level may be achieved with the use of a clamp circuit for example. Preferably the analogue circuit is integrated in a mixed signal chip, such as a DAC or ADC chip. The circuit may also be utilised in more complex packages such as system on a chip (SoC), or in a MOS based analogue only integrated circuit. There is also provide a method of processing an analogue signal comprising applying the analogue signal to an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. There is also provide a method of producing an analogue circuit for processing analogue signals in an integrated circuit; the method comprising providing a number of metal oxide semiconductor transistor devices arranged to implement said circuit stage, at least a first said transistor device having a first oxide thickness, and at least a second said transistor device having a second and different oxide thickness. Preferably the integrated circuit is a mixed signal circuit having additionally digital circuits, which preferably use transistors employing the thinner of the two oxide thicknesses BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described with reference to the following drawings, by way of example only and without intending to be limiting; in which: FIG. 1a shows a known differential folded cascode op amp circuit; FIG. 1b shows another known differential folded cascode op amp circuit; FIG. 2 shows a modified differential folded cascode op amp circuit according to an embodiment; FIG. 3 shows a modified differential folded cascode op amp circuit according to a second embodiment; FIG. 4 shows a modified differential folded cascode op amp circuit according to a third embodiment; FIG. 5 shows a modified differential folded cascode op amp circuit according to a fourth embodiment; and FIG. 6 shows a schematic of an integrated analogue circuit comprising two transistor devices having different oxide thicknesses. DETAILED DESCRIPTION Referring initially to FIG. 1b, a typical audio op amp design is shown which utilises a differential folded cascode arrangement. MOS based transistor devices MP1 and MP2 are input transistors. Signal current from MP2 passes through folded cascode device MNC2 to the output. Signal current from MP1 cannot pass through folded cascode device MNC1, since current I(MNC1) is equal to the constant current defined by the constant current source MPB1. The MP1 signal current therefore passes through the current mirror formed by MNM1, MNM2 and then through the cascode device MNC2 to the output. Thus MNM1, MNM2, MNC1, MNC2 act as a single ended to differential converter, as well as contributing a cascode function to increase output impedance of this transconductance stage. Transistors MPC1 and MPC2 serve as cascode devices to bias devices MPB1 and MPB2 to increase their effective output impedance, to maintain the high output impedance at Iout and also to improve power supply rejection. The supply voltage for this circuit block is typically 18V, and so all the transistor devices are “thick” oxide devices, typically 350 nm. Generally NMOS devices contribute more flicker noise than PMOS devices, so the main source of flicker noise in this circuit is MNM1 and MNM2. However the other non-cascode devices (MP1, MP2, MPB1, MPB2) also contribute some noise. To first order the signal current from the drain terminals of cascode devices MNC1, MNC2, MPC1, MPC2 is equal to that into their respective source terminals, so they can not contribute noise. Second order effects due to their non-zero output conductance and the non-zero output conductance of adjacent devices do allow these devices to generate a small output noise contribution, but this is generally negligible compared to contributions of other devices in the circuit. Referring now to FIG. 2, a differential folded cascode op amp according to an embodiment is shown. This circuit comprises the same elements as the circuit of FIG. 1b, in particular input transistor devices MP1 and MP2 which receive the input signal; input bias transistor MPD1; cascode transistors MNC1 and MNC2; constant current source transistors MPB1 and MPB2, and associated cascode transistors MPC1 and MPC2, as well as current mirror transistors MNM1 and MNM2. The circuit operates in the same manner as the circuit of FIG. 1b, however a number of the transistors (circled) have advantageously a thinner oxide layer than the others. In particular, transistors MNM1, MNM2, MPB1 and MPB2 have thin, for example 70 nm, oxide layer thicknesses, whereas the cascode transistors MNC1, MNC2, MPC1 and MPC2, as well as the input transistors MP1, MP2 and MPD1 have thick, for example 350 nm, oxide layers thicknesses. The thicker oxide layers allow these transistors to handle the larger operating voltages imposed upon them by the large signal swing requirement. However the thin oxide layer transistors have lower maximum voltages across their drain-source, gate-drain, and gate-source and so can be implemented with thinner oxide layers, thereby reducing their flicker noise contribution to the circuit. Remaining thick oxide transistors MNC1, MNC2, MPC1 and MPC2 are in cascode configurations so contribute little flicker noise, providing a low noise op amp circuit design. In certain applications, the input transistors MP1 and MP2 may also be made thin oxide, to reduce their flicker noise contribution if the input signals can be “guaranteed” to be within the predetermined operating voltage level, for example 3.6V for a 70 nm oxide layer thickness. Whilst a differential folded cascode op amp circuit is the preferred arrangement, other amplifier designs can also benefit from the dual transistor device oxide layer thickness approach. For example non-differential, non-folded, and non-cascode amplifier circuits could be implemented using MOS transistor devices having more than one thickness. FIG. 3 shows an alternative differential folded cascode op amp circuit according to an embodiment. This circuit is similar to that of FIG. 2, but includes additional circuitry to ensure the operating drain-source, gate-drain, and gate-source voltages for the thin oxide transistors remain below the predetermined voltage level (eg 3.6V) even in overload conditions. Current mirror device MNM1 is diode connected and so never sees more current than the sum of bias currents I(MPD1)+I(MPB1). Therefore its drain-source voltage can be designed to be less than 3.6V. Complementary current mirror device MNM2 is not diode connected, however its gate-source voltage is equal to that of MNM1, and so is again usually limited to 3.6V; thus permitting thin oxide implementation. However in overload conditions where V(INN) is much larger than V(INP), such that I(MP2) is greater than I(MPB2), the source of MNC2 potentially can rise in voltage giving excessive drain-source voltage on MNM2. To overcome this potential problem a clamp circuit is added comprising transistor device MPX, which clamps the drain voltage of MNM2 to a safe voltage during overload to avoid excessive drain-source or drain-gate voltage. The gate of MPX can be biased to a suitable voltage in a number of ways, for example the bias circuit comprising R3, MNN3, MPC3 and MPB3 shown. I(MPB3) passing through diode connected MNN3 and resistor R3 biases the gate in this example. The voltage is chosen such that MPX turns off in normal operation, but clamps the gate bias voltage of MNM2 low enough to avoid exceeding a predetermined level, given by the maximum recommended operating voltage of the thin oxide transistor, in overload conditions. Note the clamp transistor MPX is normally inactive, so MPX and its bias circuit contribute no noise. MPB1 and MPB2 also contribute some flicker noise, albeit less than the NMOS transistors (MNM1, MNM2) and so can be advantageously made thin oxide. In circuits where both input voltages could be guaranteed to stay well below 3.6V, MP1 and MP2 could also be made thin oxide. However this is generally hard to guarantee under all overload or transient conditions. FIG. 4 shows a further alternative op amp circuit according to an embodiment. Here additional input transistor devices MPL1, MPL2, MPE1 and MPE2 are added. Diode-connected devices MPL1 and MPL2 are connected back-to-back in parallel between the gates of the input transistors MP1 and MP2, to limit the input differential voltage, assuming one or both inputs are driven from a significant source impedance (e.g. from feedback resistors around the op amp). Assuming the input voltage applied to the gates is now constrained to a known range, cascode devices MPE1 and MPE2 can be suitably biased and inserted in series with MP1 and MP2 to reduce the maximum drain-source voltage across the input transistors MP1 and MP2. MPE1 and MPE2 are cascode devices, so will contribute little noise, and clamp devices MPL1 and MPL2 will be off, except during short transients, so will not contribute any noise. Note that in addition to requiring that the drain-source, gate-drain, and gate-source voltages are less than the rated maximum voltage, e.g. 3.6V, of the thin-oxide transistors, the drain-bulk and source-bulk voltages must also be limited to the rated maximum voltage. In the circuit of FIG. 4, this condition is satisfied since the bulk of MP1 and MP2 is connected to the common source. If the bulk connection was to the positive supply, this condition would be violated for low input voltages, and the device might break down from drain to bulk. FIG. 5 shows an enhanced arrangement of FIG. 3, to illustrate the use of this technique in a two-stage amplifier, which additionally includes a conventional class A output stage. The class A gain transistor device MN4 is biased by MPD4, with Miller compensation using resistor RC and capacitor CC, as well as a lever shifter MN3. These techniques could be equally applied to the amplifier of FIG. 1a with MNM1, MNM2, MPB1 and MPB2 thin oxide. In this case clamps analogous to MPX would need applying to the sources of MNC1 and MNC2. MP1 and MP2 could be made thin-oxide with the addition of MPE1, MPE2, MPL2, MPL1 as above. Similar adaptations could be made to other similar amplifiers. Though the above has been described to a process with 3.6V and 19.8V transistors available, the concept could obviously be applied to processes with other maximum transistor operating voltages with clamps applied to limit the voltages across thin-oxide transistors to other predetermined voltages. These analogue circuit stages can be used as straightforward audio analogue amplifier stages, or combined with digital circuits for example in a digital to analogue converter (DAC) or an analogue to digital converter (ADC) on a mixed signal integrated circuit. In such an arrangement, the same type of thin oxide transistor devices used in the analogue circuit stage may also be implemented in the digital circuit(s). In principle, the oxide thickness of every noise-contributing transistor could be optimised to minimise flicker noise according to its maximum applied voltage. However each option of oxide thickness requires at least one extra photo mask to be tooled, and one extra photolithographic wafer processing step, and one extra oxide growth wafer processing step, so more than say three different oxide thicknesses becomes expensive in tooling costs and wafer processing costs. Typically just two will be adequate: one for voltage-limited devices, and one for devices which may see the full analogue supply voltage. FIG. 6 shows schematically two MOS transistor devices in the same analogue circuit on an integrated circuit, but with different oxide (SiO2) thicknesses. The oxide layers are not to scale and are merely representative of the above described thick and thin transistor devices. Both devices will be based on a substrate, in the example a p-type substrate. This has two deposits of n-type material to form the source and drain parts of each transistor device. The Silicon Oxide (SiO2) layers at this point are typically thinner than at other parts. The electrical contacts are provided at these thinner regions. Similarly the gate is formed with a contact and a thinning of the oxide layer between the two n type regions. There is however a difference between the two devices in that the oxide layer is thicker on one device (typically 350 nm) at the thinnest part, between gate and channel, compared with the other device (70 nm at the thinnest part). The skilled person will recognise that the above-described apparatus and methods may be embodied as processor control code, for example on a carrier medium such as a disk, CD- or DVD-ROM, programmed memory such as read only memory (Firmware), or on a data carrier such as an optical or electrical signal carrier. For many applications embodiments of the invention could be implemented on a FPGA (Field Programmable Gate Array). Thus the code may comprise for example code for setting up or controlling an FPGA. The code may also comprise code for dynamically configuring re-configurable apparatus such as re-programmable transistor arrays. Similarly the code may comprise code for a hardware description language such as Verilog™ or VHDL (Very high speed integrated circuit Hardware Description Language) which could be used as input to analogue circuit synthesis software. Or analog circuit synthesis software could be written or configured to select appropriate transistors in synthesised amplifiers to be thin-oxide. As the skilled person will appreciate, the code may be distributed between a plurality of coupled components in communication with one another. Where appropriate, the embodiments may also be implemented using code running on a field-(re)programmable analogue array or similar device in order to configure analogue hardware. The skilled person will also appreciate that the various embodiments and specific features described with respect to them could be freely combined with the other embodiments or their specifically described features in general accordance with the above teaching. The skilled person will also recognise that various alterations and modifications can be made to specific examples described without departing from the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Due to the increasing need for miniaturisation of portable devices such as MP3 players, mobile telephones and personal digital assistants, it has become increasingly important to implement both digital processing functions and related analogue, especially audio, processing functions on the same chip or integrated circuit—a so called mixed signal chip. For this reason the implementation of analogue functions on metal oxide semiconductor (MOS) based devices has become increasingly important. A major problem with this technology however is that the digital and analogue circuits require different characteristics from the same semiconductor technology. Digital circuits are fastest and consume least power and chip area when implemented using the shortest channel available in a given manufacturing technology. However this limits the supply voltage that can be applied to this digital circuitry without causing breakdown or premature wear-out of the small devices used. For example digital circuitry on a currently mature process might use a structure with 0.35 um drain-source spacing and 70 nm gate oxide thickness. However most analogue circuits must operate in accordance with legacy standards, for example in order to provide a 2V rms signal for consumer standard audio Line Outputs, or possibly 5V rms for professional applications. Operation at these large signal swings is likely to continue to be necessary for some time in the future, to maintain the ratio of signal power to that of the thermal noise of the op amps and resistors in the signal path: a halving of the signal amplitude would require the noise power to be divided by four, reducing the required circuit impedances by a factor of four, and increasing the power required by the amplifiers, despite the lower supply voltage. Also reducing the signal level would increase the relative importance of extraneous noise and interference coupling into the circuitry. This is likely to require a rail to rail supply as high as 18V. To avoid large electric fields in the device, which cause breakdown or long-term reliability issues such as hot-carrier induced degradation of threshold voltage and transconductance, this requires a larger device structure, with typically a 3 um minimum drain-source spacing and a 350 nm oxide layer thickness. Many widely available semiconductor manufacturing technologies today offer the possibility of selecting a thin or thick gate oxide thickness for selected transistors in each integrated circuit on the basis of additional photographic masking and processing steps. For instance one technology allows 70 nm gate oxides for 3.3V nominal (3.6V maximum) operation for core logic transistors, but 120 nm devices for 5V nominal (5.5V maximum) digital input and output devices. Such technology has been used for mixed signal circuits where the logic operates at 3.3V and all the analogue circuitry operates at 5V. Similarly circuits such as LCD display drivers use 3.3V control logic and 18V nominal (19.8V maximum) (350 nm gate oxide) output stages. Allowing the logic to operate at lower voltage using smaller devices makes these devices smaller in chip area and hence cost and reduces the power consumed by the digital circuitry. High performance audio op amps also require high open loop bandwidth so that the distortion inherent in their open-loop transfer characteristics may be suppressed across the audio band by negative feedback around the amplifier, even when this feedback is relatively light, to provide gain in the signal path. Suppression of distortion is important even at frequencies well above the human hearing limit of approximately 20 kHz. This is because distortion at these higher frequencies, for example up to 100 kHz, have an effect in the audible range (20 Hz-20 kHz). Also audio signals from delta-sigma digital-to-analogue converters have quantisation noise components well above the audio band, which can intermodulate to produce audio band components unless the amplifier retains a linear closed-loop response to these high-frequency components. A wide closed-loop bandwidth is also necessary to avoid relative phase delays across the audio spectrum. One of the major sources of noise in MOS technology is flicker noise. MOS devices such as transistors contain traps, due to impurities and inevitable imperfections in the crystal structure of the silicon, in or near the interface between the silicon and silicon oxide layers. The current in MOS devices typically travels substantially along this interface, and the traps charge and discharge randomly over time. This gives rise to a noise component of charge density at the oxide interface with an approximately 1/f power spectrum, i.e. with higher spectral density at lower frequencies. For circuit analysis, this charge variance ΔQ may be regarded as an equivalent modulation of the gate voltage ΔVG where ΔVG=ΔQ/Cox, Cox being the capacitance from gate to channel across the gate oxide. Cox is inversely proportional to gate oxide thickness, so for the same charge variance, the equivalent gate voltage noise is proportional to gate oxide thickness. In practice, this is found to be the case, i.e. similar processes with different gate oxide thicknesses give gate flicker noise voltages increasing with gate oxide thickness. It is also found that the flicker noise voltage is inversely proportional to the square root of the area of a MOS transistor. So one approach to reducing this noise is to increase the surface area, i.e. to increase the width and length of the transistor. However to improve flicker noise by say 6 dB would require four times the transistor area: significant further improvement in flicker noise rapidly leads to impractically large devices, both in terms of extra parasitic capacitances and in the chip area consumed and hence in cost of manufacture. The contribution of flicker noise of a given transistor to the input-referred noise voltage of an amplifier can also be reduced by altering the gain from the transistor referred to the input, by altering its aspect ratio or altering its bias current. But this makes the design deviate from what would otherwise be considered the optimum in terms of the desired combination of area, power, and performance, and in practice there is again only a small improvement practically achievable without unduly compromising other design objectives. Also chopper-stabilisation techniques could be incorporated to move flicker noise away to higher frequencies, where the noise can either be ignored or filtered out. However this adds to the complexity of the circuit, generally requiring the addition of multiple switches and clock generation and distribution circuitry, and tends to give spurious output signals at the chopping frequency and its harmonics. So in general, for a given circuit topology, circuit specification, and manufacturing technology, there is a practical and economical lower limit to the flicker noise achievable. A known circuit common in high performance audio amplifier applications is the differential folded cascode op amp circuit, a schematic for which is shown in FIG. 1 a . This circuit offers low distortion, high gain, and wide bandwidth, which are desirable for hi fidelity sound reproduction. The operation of such circuits is well known to those skilled in the art, however the cascode arrangement essentially utilises a gain transistor (MP 1 or MP 2 ) together with a cascode transistor (MNC 1 or MNC 2 ) which effectively reduces the variation in voltage across its associated gain transistor (M 1 or MP 2 ) in order for this to amplify changes in its input voltage in a linear fashion; thus reducing distortion. This topology also offers high voltage gain to the output lout and wide voltage compliance at this node, either for directly driving an output or to act as the input of a further op amp gain stage. FIG. 1 a shows a differential folded cascode amplifier structure using two cascode transistors (MNC 1 , MNC 2 ) and constant current bias devices MNM 1 , MNM 2 . Since bias device MNM 2 passes a constant current, all signal current from input device MP 2 passes through cascode device MNC 2 to the output lout. Similarly, signal current from MP 1 passes through cascode device MNC 1 rather than bias device MNM 1 , and is then mirrored by mirror devices MPB 1 , MPB 2 to the output lout. Cascode devices MPC 1 and MPC 2 are inserted in series with the drains of MPB 1 , MPB 2 to improve the output impedance and accuracy of this current mirror. Suitable bias voltages VCP 1 , VCN 1 , VBN 1 are derived by other circuitry using standard techniques. The folded cascode structure of FIG. 1 b is a variation of this differential folded cascode amplifier. In this case previous bias devices MNM 1 and MNM 2 are reconnected as mirror devices with MNM 1 being drain-gate connected, and cascode device MNC 1 is also drain-gate connected, and previous mirror devices MPB 1 and MPB 2 now operate as constant bias current sources supplied with a suitable bias voltage VBP 1 . As before, signal current from MP 2 flows through cascode device MNC 2 to the output. However signal current from MP 1 can no longer flow through cascode device MNC 1 , since this is now forced to operate at the constant current supplied by MPB 1 , so this signal current now flows though mirror device MNM 1 , where it is mirrored by MNM 2 and thence flows through MNC 2 to the output. Whilst in these structures the flicker noise contribution of the cascode transistors MNC 1 , MNC 2 , MPC 1 and MPC 2 is small, in practical implementations of the circuits of FIG. 1 a or FIG. 1 b , it is found that the flicker noise contributed by MNM 1 and MNM 2 is one of the dominant components of audio frequency noise, with other flicker noise contributed by input devices MP 1 and MP 2 and by MPB 1 and MPB 2 . This is particularly the case for high-voltage (say 18V) circuits where the amplifier is implemented with appropriately thick gate oxide (say 350 nm) MOS devices. As discussed above, the designer soon reaches a practical lower limit for this flicker noise. Yet there is an increasing requirement for lower and lower noise audio circuitry with better and better signal-to-noise ratio, i.e. lower noise and higher signal swings. | <SOH> SUMMARY OF THE INVENTION <EOH>In general terms the present invention provides an analogue circuit arrangement using MOS based technology which reduces flicker noise by reducing the oxide thickness of selected transistor devices, having a low operating voltage, compared with those required to operate with a larger operating voltage in the same circuit. The lower voltage transistors are typically employed for biasing, constant current sources, and current mirrors, whereas the larger voltage transistors are exposed to the necessary large signal swings for hi fidelity audio operation. The reduced oxide thickness reduces the flicker noise contribution to the circuit from these low voltage transistors, and hence the overall flicker noise of the circuit. The cascode transistor(s) will still require a thicker oxide layer in order to handle the higher voltage level, whereas the other circuit transistors can be implemented with thinner oxide layers by arranging the circuit such that they are only required to handle relatively low operating voltages. Advantageously, this dual transistor oxide thickness arrangement can be utilised in a folded cascode op amp circuit in which the transistors required to handle the larger voltages are the cascode transistors, which because of the nature of cascode circuits have a much reduced flicker noise contribution compared with transistors in other circuit configurations. Thus a number of the non-cascode circuit transistors can have thinner oxide layers in order to further minimise their contributions to the flicker noise of the op amp circuit. A further advantage of this arrangement is that the overall chip size can be reduced because of the replacement of thicker oxide layer transistors by thinner oxide transistors. For a given width and length and operating current and voltage, the thinner gate oxide transistor will have high transconductance and higher output impedance: conversely for a given requirement for transconductance or output impedance, the width and length can be scaled, giving a smaller chip area occupied by the transistor. Of course this scaling will also reduce the improvement in flicker noise, but this is a tradeoff available to the designer. When used in mixed-signal mixed-voltage integrated circuits, where the digital circuitry uses thin-oxide transistors and the analogue circuitry uses thick-oxide transistors, there is no incremental cost, either in tooling or actual manufacturing cost in using thin-oxide transistors of the same structure as used in the digital circuitry in selected locations in the analogue circuitry. In particular in one aspect the present invention provides an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. Preferably the first transistor device is arranged in use to have an operating voltage below a predetermined level and the second transistor device is arranged such that in use it is not constrained by this predetermined operating voltage level. This allows the first oxide layer to be thinner than the second oxide layer thickness. For example the predetermined operating voltage level is 3.6V and the first oxide thickness is 70 nm. This compares with an example operating voltage of 19.8V and oxide thickness of 350 nm for the second transistor. Preferably the second transistor device forms part of a cascode transistor device circuit within said analogue circuit. Preferably the cascode transistor device circuit is a differential folded cascode op amp circuit. This reduces the flicker noise contribution of the thicker oxide layer transistors. Preferably the thin oxide transistors are employed in the input, bias and constant current sub-circuits of the op amp circuit. The predetermined operating voltage level may be achieved with the use of a clamp circuit for example. Preferably the analogue circuit is integrated in a mixed signal chip, such as a DAC or ADC chip. The circuit may also be utilised in more complex packages such as system on a chip (SoC), or in a MOS based analogue only integrated circuit. There is also provide a method of processing an analogue signal comprising applying the analogue signal to an analogue circuit for processing analogue signals in an integrated circuit comprising a number of metal oxide semiconductor transistor devices, the circuit stage comprising a first said transistor device having a first oxide thickness, and a second said transistor device having a second and different oxide thickness. There is also provide a method of producing an analogue circuit for processing analogue signals in an integrated circuit; the method comprising providing a number of metal oxide semiconductor transistor devices arranged to implement said circuit stage, at least a first said transistor device having a first oxide thickness, and at least a second said transistor device having a second and different oxide thickness. Preferably the integrated circuit is a mixed signal circuit having additionally digital circuits, which preferably use transistors employing the thinner of the two oxide thicknesses | 20040504 | 20060926 | 20050922 | 74183.0 | 0 | MOTTOLA, STEVEN J | LOW NOISE OP AMP | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,891 | ACCEPTED | Variable formatting of digital data into a pattern | A method of formatting digital data and a method of decoding the formatted digital data. User selectable format parameters vary the dimensions and other attributes of spots and the cells containing those spots as well as other features which the formatting process formats into a pattern. A method of encoding the formatted digital data using these format parameters allows for encoding a substrate optimally for any given printer or scanner. One embodiment provides for markers to facilitate determination of cell locations. In one embodiment the decoding process achieves a pyramid gain of knowledge by locating a landmark (801), which is located in a known position relative to a metasector (802), which contains information about the encoding process used to encode the main body of data (803), which the decoding process decodes to recover the original digital data. Further embodiments include encryption, transmission by facsimile, inclusion of human readable information, and automatic launches of computer files. | 1. A method of accessing data comprising: producing digital instructions for accessing data, formatting into a pattern the series of digital data values representing said digital instructions for accesing data, distributing the pattern of formatted digital data, decoding the pattern of formatted digital data, and activating the digital instructions for accessing data, whereby the data is accessed. 2. The method of accessing data of claim 1 wherein said digitial instructions for accessing data consists of hyperlinks to information extraneous to said formatted digital data. | This is a dvisional of application Ser. No. 09/382,173, now pending, which is a divisional of application Ser. No. 08/609,549 now U.S. Pat. No. 6,098,882. COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. RELATED APPLICATIONS This application is related to patent application Ser. No. 09/382,173, titled Variable Formatting of Digital Data into a Pattern, filed Aug. 23, 1999, and U.S. Pat. No. 6,098,882, titled Variable Formatting of Digital Data into a Pattern, filed Aug. 23, 1999, which are both hereby incorporated by reference into this application. BACKGROUND OF THE INVENTION This invention relates to the formatting of digital data into a pattern, encoding that pattern onto a substrate where appropriate, and decoding that pattern to reconstruct the digital data. While computers have substantially enhanced the manner in which society conveys and works with information, paper remains the favored manner of conveying information. Indeed, the proliferation of personal computers has resulted in a proliferation of paper. Yet, no technology to date has significantly integrated the digital environment of the computer with the visual environment of written media. Instead, computers primarily direct human readable information to be placed on paper. It would be greatly advantageous to have digital data placed on paper and other media currently used for human readable information. Such a method would link the largely separate environments of paper and computers. The method could store and convey digital data with greater efficiency, ease, speed, and lesser cost than any other available method. The method would have the further advantage of being the only significant method to integrate digital data with visual media. As described below, the prior art discloses methods for placing machine readable information on media such as paper. However, none of these prior art methods, and, to the best of the inventors' knowledge, no other technology currently available to personal computer users allows for the placement of a significant amount of machine readable information on the media. Other practical limitations of these prior art methods forestall significant commercial success. One example of digital information being stored on paper is the use of bar codes. Because standard bar codes are one dimensional, they are severely limited in the number of bars that may be used to store digital information. The limits are somewhat greater in the case of two-dimensional bar codes but these limits are still far more restrictive than the theoretical limits of any particular printer, and bar codes are designed for use with specialized scanners. For more information on bar codes, see “Information Encoding with Two-Dimensional Bar Codes,” authored by T. Pavlidis, J. Schwartz and Y. Wang, COMPUTER, June 1992. U.S. Pat. No. 5,245,165, issued to Zhang, discloses a self-clocking glyph code for encoding dual bit digital values of a logically ordered sequence of wedge-shaped glyphs that are written or otherwise recorded on a hardcopy recording medium in accordance with a predetermined spatial formatting rule. The dual bit values are encoded in the relative rotations of the glyphs. The glyphs are decoded by determining a bounding box for each glyph and determining either which quadrant of the box contains its center of mass or by comparing the relative locations of the shortest and longest runs of ON pixels. To reliably present a single bit of data, each glyph comprises a large number of pixels, and thus this technology requires considerable space on the recording medium. The technology does not optimize the use of space or computational resources by presenting a bit in the most compact fashion. U.S. Pat. No. 5,337,362, issued to Gormish, discloses a method for transferring digital information to and from plain paper. The method involves storing data in at least one box on the paper, the box including a frame or border having alternating pixels along the left and right edges for use in determining the current location of a horizontal line of pixels when reading the data and having pixels in corners of the frame to determine horizontal spacing between pixels within the box. Binary data is formatted in rows within the box, wherein a bit of digital data is depicted by the presence or absence of an ink dot. The method disclosed by Gormish provides the ability to represent 60 kilobytes of data on a single page. Although Gormish allows for the storage of more data on a page than can currently be stored in text form, it has several problems which prevent it from being useful in a commercial environment. For example, Gormish requires a thick frame to be placed around the entire data box in order to locate the box, which limits the ability to place the data in convenient shapes and sizes on a substrate. Also, Gormish requires placement of pixels in a rigid fashion, without provision of guideposts to determine where to search for the presence or lack of a dot other than on the borders of the boxes. Further, Gormish provides ink placement in an ink dot that covers an entire square and that square covers an area 16 times larger than the finest optical resolution of any given scanner (e.g., Gormish discloses printing dots at 50 dpi while scanning is performed at 200 dpi), thereby limiting the density of data which can be represented on each page. In addition, although the method disclosed in Gormish may be suited for certain printers and scanners of great precision it does not adequately accommodate for deviations from perfection in printing and scanning found in off-the-shelf printers and scanners designed for use with personal computers. Operating in an environment of personal computers and their peripherals, this rigidity ultimately translates into loss of data density, higher error rates, slower processing speed, all of these deficiencies, or, worse yet, complete inability to use the method in given computer environments. Other known methods disclose manners in which a single cell contains more than one bit of information through the use of gray scales. One such method is disclosed in U.S. Pat. No. 5,278,400, issued to J. Appel (1994). This patent discloses the encoding of multiple bits in a single cell by marking, preferably by binary marking, a predetermined number of pixels in a cell irrespective of the location of the pixels within the cell. The number of pixels marked corresponds to the data to be encoded. The markings on the substrate are decoded by detecting the gray scale level at each pixel of the cell, converting that gray scale level to a corresponding digital signal and summing all of the digital signals corresponding to all of the pixels in the cell. This method requires discrete determination of where the cell begins and ends. The gains from encoding multiple values in a single cell are lost by requiring larger cells, relative to straightforward binary printing. Gormish also discloses the encoding of multiple values in one cell through the use of gray scale inks. This method employs rigid formatting and printing described above and similarly relies on rigid decoding mechanisms that may be optimized for a particular combination of a printer and a scanner, but not for all such combinations. These methods give back the data density and savings in computational resources that the use of multiple colors should provide. U.S. Pat. No. 5,329,107, issued to D. Priddy and R. Cymbalski (1994), discloses a method to dynamically vary the size, format, and density of machine readable binary code. The method disclosed in that document provides a code formed of a matrix and allows variation in the amount of data in the matrix by printing on two sides of the perimeter of the matrix broken line patterns of alternating darkened and lightened areas. The method determines the amount of data in the matrix from the product of the number of lightened areas and darkened areas of the first side and the number of lightened areas and darkened areas of the second. The method determines size of the matrix by measuring the other two sides of the perimeter, formed of two solid black lines. While the method allows the encoder of information some flexibility in accommodating the different potentials of higher and lower resolution scanners, the method is rigid in darkening entire square cells. The method also lacks regular reference markers and generally limits information about the encoding, conveyed in the matrix, to size and density. The method therefore lacks the flexibility needed to address the peculiarities of every combination of printer and scanner. Hence the method can not produce the greatest density of data or the most efficient manner of decoding for every combination of printer and scanner. There is a need to substantially increase the amount of data that can be stored within a given amount of paper in order to compete with other channels of storage and communication such as floppy disks and digital communication by telephone. Employing binary printing (i.e., storing one bit per cell), the most basic and least dense printing process, the invention is capable of storing data at densities several times as great as any other paper based method known to the inventors. Utilizing printing methods which store more than one bit per cell, such as color printing, the theoretical density limits increase substantially. While Gormish discloses the ability to store 60 kilobytes on a single page using a 400 dpi scanner, the invention is capable of encoding and decoding over 160 kilobytes of data error free (i.e., by utilizing error correction) using just a 300 dpi scanner. With the aid of compression, this single page can contain over 500 kilobytes of text. With a 600 dpi printer and a 600 dpi flatbed scanner, the invention can encode data in cells {fraction (1/200)} inch square (i.e., 0.005 inch×0.005 inch), successfully encoding and decoding over 300 kilobytes of data before the benefit of any compression, in excess of 1 megabyte of text with the aid of compression. Utilizing more precise printing processes and a 600 dpi flatbed scanner, the invention encodes and decodes over 7,000 bytes per square inch (over 1,100 bytes/cm2), over 20,000 bytes of text using compression. Utilizing an ordinary thermal fax machine as a scanner (achieving a binary scan of approximately 200 dpi), the invention encodes and decodes over 50 kilobytes of data, over 150 kilobytes of text with the aid of compression. All of the above densities are accomplished utilizing binary printing. The invention also conveys advantages for any particular printer. For example, using an ordinary thermal fax machine the invention can print over 230 kilobytes of data, over 675 kilobytes of text with compression, on an 8.5 by 11 in. piece of thermal fax paper. The invention can then successfully decode that data error free. SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems discussed above present in prior art systems for representing digital data on a substrate. It is another object of the present invention to greatly increase the density at which digital data can be represented on a substrate. It is another object of this invention to overcome the limitations of prior art through a method that writes and reads digital data on paper and other media using off-the-shelf personal computers and peripherals, and achieves the full carrying capacity these off-the-shelf components can sustain. It is another object of the invention to determine and enable the features and parameters that contribute to density of information on a printed substrate, and to enable full generality in formatting and decoding along the dimensions identified. This satisfies in turn the ultimate, practical goal: achieving the maximum density possible for any particular combination of printer and scanner. This comes about because that point of maximum density can always be found in the multi-dimensional space so defined. It is another object of the present invention to provide flexibility in printing digital data onto a substrate along with other information. These and other objects of the invention are achieved by a method of formatting digital data into a pattern where the pattern comprises a number of cells (i.e., predetermined spaces in the pattern) with known dimensions where each cell conveys at least one bit of data by expressing one of at least two logical states where one logical state is expressed by the presence of spot with a given set of attributes in the cell and a second logical state is expressed by the absence of a spot with those attributes from the cell, and where the size of spots may be different from the size of cells containing the spots. Generally speaking, in accordance with the invention, a method of formatting data into a pattern in an optimal fashion is provided. The preferred embodiment of the invention provides for the placement of ink on paper. The preferred embodiment allows the person providing data to format the placement of digital data. This flexibility in formatting the placement of digital data allows the person providing data to optimize for any particular combination of encoding device and scanner. The method of encoding allows the person providing data to format the placement of ink in a fashion that best reflects the printer's capabilities to place ink in a designated area. The method of encoding also allows for formatting designed to consider the strengths and limitations of the target audience of scanners. The features that support encoding information on the printed substrate, and its effective decoding via a scanner, fall under two heads. First, there are dark regions on the substrate, which the current invention terms “spots,” whose presence or absence in a specified region represents digital bits. Second, there are guideposts, which the present invention terms “markers,” that serve to identify the location of spots on the printed substrate—a function known in the art as “clocking.” The present invention explicitly decouples these two features, allowing them to be varied independently, so that each may be optimally configured for its distinct purpose. The current invention also permits each to be varied across all the dimensions (e.g., those defining size, spacing, and frequency) that affect the density of information on the printed substrate, while supporting its effective decoding. This full generality allows the optimum match for a particular printer and scanner always to be selected, formatted, and decoded. The method of the present invention allows the person or computer encoding data to select the size, in pixels, of both the cell containing a bit of information and the size of the printed spot where a spot is required. The preferred embodiment of the method of encoding provides a bit of one value by placing a spot of the chosen size in the cell of the chosen size. The method provides a bit of the opposite value by leaving the cell of the chosen size blank. In accordance with the invention, the size of the spots and of the cells can be varied in both the width and height directions. The method of the present invention also allows the person or computer system encoding data to select the size and locations of markers. In accordance with the invention, the size and location of the markers can be flexibly altered to achieve reliable clocking with the minimum amount of space and computation time. The method of the preferred embodiment provides information about the encoding process through use of a “metasector”, a header physically separate from the main body of data. The purpose of providing a metasector is to facilitate decoding the main body of data. In this embodiment, the metasector is itself an instance of the general pattern by which information is stored in the invention. This metasector is preferably printed at a resolution which can be easily and reliably scanned and interpreted. It is also given a predictable and relatively rigid format, which makes it straightforward to decode in the absence of detailed information about the printing process and environment which generated the encoded data. This metasector contains information about the printing process and environment that is then used to decode the main body of data. The somewhat rigid format of the metasector frees the main body of the data from rigidity in its own format, allowing it the greatest flexibility in achieving maximum density. The metasector, encoded at a relatively low resolution, contains information communicated to the remainder of the method in order to decode information at a higher resolution. The information included in the metasector includes, inter alia, the size of the data spots printed, the size of the cells containing data spots, the printing process used to print spots and the size and relative location of markers, if any. Allowing flexibility in the size and placement of data spots in cells greatly increases density of data and improves the speed and accuracy of determining whether a bit is on or off. The fundamental purpose behind defining spot size independently is twofold—first, to compensate for printer deficiencies and, second, to compensate for scanner deficiencies. Within types of printers, such as 300 dot-per-inch (“dpi”) laser printers, there is variation in both the ability to place ink at a given location and the ability to keep ink within the spot designated by that location. For example, printers have varying degrees of “dot gain”—the tendency of most printers to place ink beyond the purported boundaries of the pixel. Dot gain, and the problems it causes, can be exacerbated when the printing process employed goes through multiple steps. If, for example, the printing process involves producing film from a print, a plate from film, and copies from the plate, increasing amounts of dot gain can occur in each step. A spot is preferably allowed to be defined to be smaller than its cell (i.e., the space that is supposed to contain the spot) simply to prevent spots from spilling over to adjacent cells. Even with perfect printing, however, it would be important to allow smaller spots than cells, because of a second phenomenon. Scanners characteristically “leak” dark intensities from one pixel to a directly adjacent pixel. That is, if a pixel is directly over a dark region on the printed substrate, and an adjacent pixel is not, the intensity of the adjacent pixel is nonetheless suppressed to a darker value. When spots completely fill in their cells, the cells must be made larger to compensate for this tendency of scanners. If they are not made larger, the neighboring cell when blank may not differ enough in intensity from the dark cell to be discriminated as blank. Making it possible to configure spots to be smaller than cells generally allows cells to be smaller while supporting correct discrimination between dark and white cells. Of course, it is possible in principle that a given printer (or a like device) may characteristically print smaller spots than defined, or a given scanner (or a like device) may “leak” bright intensities—in which case it would be useful to define spots to be marginally larger than the cells they occupy (or, alternatively, to print spots in reverse video.) Between types of scanners or types of printers, such as between a 360 dpi inkjet printer and a 600 dpi laser, the degree of variation expands significantly. Laser printers have a greater precision in the placement of ink, and 600 dpi printers place ink more accurately than a 360 dpi printer. The invention provides a method critical to optimization of ink placement based on these variations. The ability to vary the dimensions of spots and cells in both horizontal and vertical directions also serves to maximize the density of information. For example, with a 200 dpi thermal fax printer, and a 400 dpi scanner, the invention can encode and decode a pattern with cells of 1×2 pixels containing spots of 1×2 pixels, thus encoding over 100 kilobytes of data on a single page. However, a 400 dpi scanner cannot reliably decode a pattern with spots of 1×1 pixels printed at 200 dpi. Since the next step up from 1×1 is 1×2 (or, equivalently, 2×1), the most compact representation is employing the 1×2 cells. If the technology could allow for only square cells, the next step up would be 2×2 cells, which would be only half as compact. A powerful use of the invention, beyond its ability to communicate and store information (documents, software, graphics, etc.), is as an enabling technology for other technologies. One of the great limiting factors in permitting most consumers to fully exploit their PCs is that the PC possesses simply too many distinct functionalities that must be learned. This is indeed a problem that promises to get only worse as the PC itself develops greater capabilities. Even today, a PC user may have fax and data communication software on the user's PC, and access to the Internet, and the ability to use the PC as a telephone, and many other functionalities. Yet it is a rare user who will know how to utilize all of these functionalities. The present invention can be used to encode on paper an arbitrarily complicated batch file, script file, application file, or executable file that can effectively navigate the user through all the complexities involved in each function the PC can perform. By a simple scan of a datatile, for instance—as easy as running a copier—all such functions can be invoked. A datatile can contain both the identity of the application to be invoked—e.g., data communication, fax communication, Internet access—and the sequence of actions and data that that function requires—e.g., the phone number that must be dialed, the account number of the user, the password that must be entered, the particular address on the Internet sought, and/or a flag for the particular function that should be performed when access is granted. In effect, the datatile enables paper to become the user interface, instructing the user as to the functions that will be performed—e.g., a bill will be paid over the Internet, or a fax back will be initiated. The scan becomes the single thing that the user must learn to do: all other functions can be performed automatically. This spares the unsophisticated user the perhaps overwhelming task of learning how to invoke these functions, and saves the sophisticated user from the tedium of entering the point clicks and detailed information any of these functions demand. Several features of the invention's methods of encoding and decoding make practical for the first time the enabling of many further, simplifying, technologies. The ability to significantly increase density of data allows far more complicated instructions to be placed in any given amount of space. The ability to accommodate a wide audience of printers and scanners allows access to the greatest number of potential users. The ability to vary the shape, dimensions, and location of the encoded digital data on the substrate allows the greatest flexibility in formatting the digital data alongside other information (such as text or graphics) on the substrate. Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing descriptions. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of the preferred embodiments of the invention which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only. FIG. 1 is a block diagram describing the overall process for transmitting digital data pursuant to one embodiment. FIG. 2 is a block diagram describing the method of encoding digital data onto a substrate, according to the preferred embodiment. FIG. 3 is an enlarged portion of a digitally encoded substrate illustrating how the method of encoding converts a series of digital data values into a pattern. FIG. 4 is an enlarged portion of a digitally encoded substrate illustrating an embodiment of the method of encoding where markers are light areas inside dark bars. FIG. 5 is a dialog box for establishing shapes for spots and cells. FIG. 6 is a dialog box for determining how cell shapes fit together and the sequence in which cells are created and each bit in the series of digital data values encoded. FIG. 7 is a block diagram describing one implementation of the process for selecting format parameters. FIG. 8 is an enlarged digitally encoded substrate produced by the method of encoding, where the substrate, in this instance, is paper encoded with the placement of ink. FIG. 9 illustrates a substrate produced by a further embodiment of the invention in which both machine readable encoded digital data and human readable text and graphics is placed on the substrate. FIG. 10 illustrates a substrate produced by an embodiment of the invention in which parts of a datatile are placed in noncontiguous regions of the substrate instead of being placed as a whole in one region of the substrate. FIG. 11 illustrates a digitally encoded substrate containing multiple datatiles, each of which has been enlarged for illustration purposes. FIG. 12 illustrates a digitally encoded substrate containing multiple datatiles, shown at their actual sizes. FIG. 13 is an enlarged view of a portion of a digitally encoded substrate illustrating an embodiment in which each cell contains one bit of digital data expressed by spots with different attributes, where the difference in attributes is a difference in spot size. FIG. 14 is an enlarged digitally encoded substrate produced by a further embodiment of the invention in which each cell represents a plurality of bits where spots of different sizes and colors express different logical states. FIG. 15 is an enlarged view of a portion of a digitally encoded substrate illustrating an embodiment of the method of encoding in which one spot size and two cell sizes are defined. FIG. 16 is a block diagram describing the method of decoding for decoding digital data contained on a digitally encoded substrate, according to the preferred embodiment. FIG. 17 is a block diagram describing the decoding process for deriving a series of digital data values from an image of a digitally encoded substrate. FIG. 18 is a block diagram describing the recovery process for deriving a series of digital data values from the image of that portion of a digitally encoded substrate that lies between markers. FIG. 19 is an enlarged view of a portion of a digitally encoded substrate illustrating one embodiment of the recovery process used to recover digital data. FIG. 20 is a block diagram illustrating a further embodiment of the method of encoding in which the digital data is subjected to encryption prior to encoding. FIG. 21 is a block diagram illustrating the addition of decryption to the method of decoding where the method of encoding included encryption prior to encoding. FIG. 22 is a block diagram describing a method of transmitting digital data. FIG. 23 is a block diagram describing a method of transmitting digital data involving immediate use of the digital data transmitted on the substrate. FIG. 24 is a block diagram describing a further embodiment of a method of transmitting digital data, including transmission of a digitally encoded substrate, that method being by facsimile transmission. FIG. 25 illustrates a further embodiment of the invention in which both machine readable encoded digital data and human readable text and graphics are placed on the substrate and in which the encoded digital data is designed to cause a computer to reproduce on the computer's display the human readable text and graphics placed on the substrate as well as allow context sensitive interaction with the computer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described herein with reference to the drawings in the Figures and the source code of the digital data encoding and decoding software (“DEDS”) program contained in the Appendix, which is incorporated in and forms part of this application. The method and system of the preferred embodiments are generally incorporated in the DEDS program. The DEDS program does not yet include, however, all aspects of the preferred embodiment. For example, the format parameters of the preferred embodiment (as described by reference to FIG. 2) include Ink Colors and Ink Types, while the DEDS program does not yet include these parameters. Because inclusion of these additional parameters is advantageous, a future version of the software should include them. In the preferred embodiment, the DEDS program is designed to operate on a personal computer having an 80386 model microprocessor or higher, at least 4 MB RAM, using the Windows® operating system available from Microsoft Corporation of Redmond, Wash., and available hard disk space of at least 10 MB. The DEDS program supports inkjet and laser printers, grayscale flatbed, handheld, and sheetfed scanners, and thermal, inkjet, and laser fax machines. Of course, one skilled in the art will recognize that the method and system of the present invention can be implemented on any computer system using any appropriate operating system. FIG. 1 illustrates the overall process of transmitting digital data, according to one embodiment of the invention, it being understood that the details of the invention itself are described below. The data source comprises digital data. The source, preferably being computer files stored on a personal computer's fixed disk, may also be from a floppy drive, visual images input by a scanner, digital data input by a scanner, files stored in memory, as might be the case, for example, of a word processing document input through a keyboard, or any other source capable of producing digital data. The program encodes this digital data on a substrate, step 101, producing a substrate with the digitally encoded data. The program then places the digitally encoded substrate in the hands of the ultimate user of the digital data, step 102. The ultimate user scans and decodes the digitally encoded substrate, step 103, which results in the reconstruction of the original computer files or other digital data. The overall result of the process described in FIG. 1 is the transmission or storage of digital data, with a substrate such as paper being the medium for that storage or transmission. Each of these steps will now be described in greater detail. Encoding FIG. 2 illustrates the method of encoding of the preferred embodiment of the invention. Selection step 201 requires selection of various format parameter values. The parameters include the height and width in printer pixels of each printed data spot, the height and width in printer pixels of each cell, the height and width in printer pixels of the markers, and Marker to Spot, the distance in printer pixels between markers and the data spots. Markers, the function of which is described more fully below as part of the decoding process, are guideposts contained in the preferred embodiment that allow for more precise determination of the center of rows and columns of data spots. The person encoding data may also vary the number of cells between markers. The Spots per Segment parameter establishes the number of cells (and thereby the maximum number of possible spots) located horizontally between columns of markers while Rows Per Marker establishes the number of cells located vertically between markers. Hence, the preferred embodiment allows the person encoding data complete flexibility in formatting spots, cells and markers. The preferred embodiment contains further parameters, allowing flexibility in the formatting of datasectors and allowing the person encoding data to indicate the type of printer to be used. A datasector of the invention is a subdivision of a datatile and a datatile is an overall pattern of digital data complete with all components needed by the method of decoding. A datasector represents the smallest accumulation of data cells which, when decoded, can reconstruct a stream of digital data without errors, by employing error correction. That is, a stream of data of a certain length is first transformed into a sequence of codewords, with redundancy for error correction. The bits composing this sequence of codewords may, in principle, be distributed anywhere in a datasector, but they must all, by convention, be located somewhere within one datasector. The original stream can be reconstructed only after the entire datasector has been examined. The person encoding data may establish the parameter Data Segments, a measure of the number of data segments located across each datasector. A data segment is a row of cells located between columns of markers with the number of cells in the row determined by the Spots per Segment parameter. Hence, the parameter Data Segments varies the number of columns of markers within a datasector. The person encoding data may also establish the number of Datasectors Across and the number of Datasectors Down the datatile. In the preferred embodiment, the person encoding data must explicitly override the Datasectors Down parameter, that value being otherwise calculated automatically. The Printer Type parameter does not directly influence the formatting process in the preferred embodiment and, in that sense, may be considered something other than a format parameter. The Printer Type parameter allows the person encoding data to communicate information describing the printing process used to print the datatile. This information is preferably established automatically by reference to the printer currently selected in the computer's operating system, but may be overridden by the user. The Ink Colors and Ink Types parameters are set in the preferred embodiment to black and normal, respectively, but may be varied in other embodiments using different colors or types of ink. A cell represents a part of the area covered by a datatile. A cell should be understood as being a space that should contain no more than one spot and a cell should be understood as ordinarily being a space large enough to contain an entire spot. In the preferred embodiment, defining a cell size determines the size of the space that may contain no more than one spot, while defining a spot size determines the size of any spot in the cell. It should be understood that a cell of the preferred embodiment is a conceptual construct with no physical manifestation other than the space it occupies. The DEDS program applies the concepts of cell and spot by determining an array of pixels, with dimensions equal to the cell size, and determining within that array a subarray with dimensions equal to the spot size. If a spot is called for, the DEDS program prints dots (i.e., the placement of ink at a given printer pixel location) at each of the pixels within the subarray. The DEDS program does not print dots at any remaining pixels in the array representing the cell. Hence, a cell differs physically from a spot contained in the cell only by virtue of pixels that the printer skips over and only then if the cell has dimensions larger than the spot. Thus, if a cell is defined with dimensions M pixels wide by N pixels high, and a spot is defined with dimensions X pixels wide by Y pixels high, X should ordinarily be smaller than, or equal to M and Y should ordinarily be smaller than, or equal to N. It should be understood that M, N, X, and Y are labels for numbers, where M is intended to express the width of a cell, N the height of a cell, X the width of a spot and Y the height of a spot. Of course, because they are labels, M, N, X, and Y could be replaced by any other labels, or the underlying dimensions could be expressed without labels, to accomplish the same effect. If at least one of the dimensions X or Y is defined as being less than the corresponding dimensions M or N, the spot will be smaller than its corresponding cell. If the dimensions X and Y are defined with different values, the spot will not be square. If the dimensions M and N are defined with different values, the cell will not be square. These possibilities allow greater flexibility to accommodate particular printers and scanners. In step 202 of the preferred embodiment the person encoding data would select the computer file or files to be printed as spots on paper. The computer files would preferably reside on the encoding computer's hard disk. In other embodiments, the digital data to encode would come from other sources, such sources being limited only by the requisite ability to produce digital data. For example, digital data can be a stream of data that comes from an on-line source, such as might exist on the Internet, and be directly formatted by the method of encoding without the intermediate step of saving data from that stream of data as a file on the computer of the person encoding data. The digital data from step 202 then passes compression processing 203, if any. It should be noted that in the present invention, compression may or may not be performed. If compression is performed, various forms may be utilized, including both lossy and lossless compression techniques depending on whether the compressed data must be recreated in the exact form as the original. In the preferred embodiment, the invention will decode the printed pattern to produce an error free stream of data. This allows compression techniques to be employed that do not require reconstruction from somewhat corrupted data of as much of the original information as feasible. In the DEDS program, standard compression into ZIP files is employed. In some instances, the impact of compression, such as increased data density, is so minimal that compression is not warranted. A further embodiment allows a user to circumvent compression. Once any desired compression of the digital data has taken place (processing block 203), error correction encoding (processing block 204) may be performed. Since the substrate is used (along with the target scanner) as a digital channel, the error correction of the present invention can be viewed as just another box with digital input and digital output. Error correction encoding comprises adding correction or “parity” bits to the digital information. The method of error correction encoding can be any one of many methods known to those skilled in communications theory. The technique of error correction employed in the preferred embodiment is a straightforward and standard technique that derives from the Hamming distance theorem in communication theory. In the preferred embodiment, the coding technique allows for the correction of at least two bit errors in any given codeword. The precise amount of redundancy is user or system selectable. It is useful to allow for the correction of at least two bit errors, since a given codeword might be subject to more than one bit error even if its bits are distributed throughout a datasector to reduce the effects of localized defects. If only one bit error could be corrected, even a single case of a codeword with two bit errors in the entirety of a printed pattern would effectively corrupt the entire pattern. The preferred embodiment uses one method of error detection and correction (with user selectable degrees of redundancy) and one method of compression. In the DEDS program the degree of redundancy selected is information conveyed in the metasector. In other embodiments other methods are used. Some of these further embodiments allow the user to select the methods of error detection and correction and compression from a variety of possibilities. In one embodiment, for example, the user can choose, as a further format parameter, between lossy (e.g., MPEG) and lossless methods of compression. In one such embodiment, the user can choose, also a further format parameter, between various methods of error detection and correction, including one that requires perfect digital accuracy, one that allows up to a selected degree of errors, and one that requires perfect digital accuracy for some data but allows up to a selected degree of errors for other data. The methods of error detection and correction and compression of these further embodiments are widely known to those skilled in the art. It should be understood that compression can occur before any of the steps in FIG. 2. If so desired, the user can choose to employ any available compression technique to convert one computer file or data stream into a compressed computer file. For example, a stream of audio from a microphone connected to a computer's sound card can be stored as an Adaptive Differential Pulse Code Modulation (“ADPCM”) compressed file. This already compressed file can then be selected in step 202. In a further embodiment, the user can choose whether to skip step 203 which would employ a second compression process. Note that there is an advantage to using information about the formatting parameters to set the parameters for error correction. The organization of codeword bits on the printed page can be optimized using this information to reduce certain common types of defects introduced in printing, faxing, and scanning. In the present embodiment, the bits are separated within a datasector. In this manner, error correction results where the plain paper starts with defects, sustains damage or the printing or scanning processes introduce defects. The DEDS program allows the user to vary the degree of error correction to reflect the quality of the target scanner or other circumstances encountered or anticipated by the user. For example, a hand held scanner would typically require greater error correction than a flatbed scanner of the same resolution. Once the digital data has undergone compression processing 203, if any, and error correction processing 204, the digital data goes through formatting process 205. Formatting process 205 is done in accordance with all values selected for format parameters. Formatting process 205 of the preferred embodiment first creates a landmark—2 dark bars which facilitate determining the location and orientation of the datatile as discussed more fully below in regard to the method of decoding. Formatting process 205 then creates a metasector. The metasector indicates the format parameters used in the method of encoding. Formatting process 205 is then responsible for changing a digital bit sequence into a pattern which is readable by the printer and from which printed pixels can be produced such that the printed pattern can be accurately scanned. In the preferred embodiment, the formatting process produces a bitmap file which is then printed by any printer capable of printing bitmap files. The formatting process begins by exclusive-ORing the bit sequence with a known random sequence to create a relatively uniform appearance in the pattern on the printed page. The uniform appearance created can render a more aesthetically pleasing effect for the printed pattern, which can be important if the pattern is integrated with certain human readable material, such as an advertisement. The digital data is then formatted into black and white pixels, in which a “0” bit is stored as a blank or a white space and a “1” is stored as a black spot with the dimensions in printer pixels as previously specified. In other embodiments, the digital data is formatted into different colors. Varying levels of gray scale is here regarded as one form of color formatting. In one such embodiment, gray scale formatting is accomplished through binary printing by printing a known number of pixels (i.e., the number of pixels needed to achieve a given level of gray scale) at arbitrary locations within the subarray of pixels that constitutes a spot. In further embodiments, the digital data is formatted into differing levels of electric charge, as in the use of substrates capable of holding electrical charges, differing levels of magnetism, as in the use, for example, of magnetic inks, and differing levels of non-visible (e.g., infrared) reflectivity, as in the use of inks with non-visible light qualities, it being understood that the invention is not limited to these particular types of formatting or materials. Data formatted through step 205 is output onto a substrate, step 206. In a preferred embodiment, the step of outputting, step 206, includes communicating the formatted image from a personal computer to an off-the-shelf laser printer, preferably a laser printer with a high resolution. In other embodiments, the printer is an inkjet, dot-matrix, or LED printer, or any other printer capable of accepting graphic input from a computer. Further embodiments involve outputting digital data on substrates through means other than just communicating data from a personal computer to a connected printer. In one embodiment, a digitally encoded substrate produced, for example, by a laser printer connected to a personal computer, is photocopied through commercially available photocopiers. In a further embodiment, a digitally encoded substrate is printed in colors, such as light blue, by offset or other printing processes, which such colors can be scanned by a color scanner but not effectively photocopied with most photocopiers, thus preventing improper photocopying. In a further embodiment, printing presses produce the digitally encoded substrates, either directly from the formatted image or indirectly by copying a digitally encoded substrate. In a yet further embodiment, a rubber stamp or other solid material, produced in the likeness of a datatile, is used to place ink or other substance on paper. The paper used for printing can be any paper capable of accepting and holding the placement of ink including, for example, postcards, business reply cards, business cards, newsprint, magazine paper, self-adhesive paper notes, labels, forms, envelopes, cardboard, and checks. In the case of business cards, the digital information could include a database or additions to a database consisting of a person's name, telephone number, address, e-mail address, picture, audio file (e.g., a sound clip of the person speaking his or her name) and other pertinent information together with computer instructions that initiate a telephone call to the included telephone number. In still further embodiments, the outputting of digital data on a substrate involves processes other than printing ink on paper and outputting step 206 should be understood to include any means for outputting digital data onto a substrate. In one embodiment, the outputting involves placing the encoded digital data on paper by changing the characteristics of the paper such as occurs when a facsimile machine prints using thermal fax paper or when the paper is burned (through the use of lasers or otherwise) or when holes are produced in the paper. In one embodiment, reflective substances are placed on such non-paper substrates as cloth (e.g., shirts, towels, bags), ceramics (e.g., mugs, glasses, and plates), and buttons. In one embodiment, the outputting of digital data occurs through photographic processes that place the digital data on a photographic print or slide. In another embodiment, the outputting occurs by producing plastic objects (e.g., plastic labels, and cards) containing a datatile. In a further embodiment, the outputting occurs by selectively magnetizing a substrate capable of retaining such a charge. In a still further embodiment, the outputting occurs through processes that act upon a substrate of biological agents capable of being differentiated in discrete locations in at least two separate states. For example, the hide or skin of animals (or their internal organs) and the surface of plant matter can be marked, such as with tattoos or branding, with datatiles. In a yet further embodiment, the outputting occurs not through the placement of substances on a substrate but by the removal of substances from a substrate as occurs through, for example, etching of metals, plastics or other materials, or the creation of pits in a compact disk. It should be understood that printing step 206 is not limited to the embodiments described above, but could include any means of outputting digital data on a substrate of any type capable of being differentiated in at least two different states in each of a plurality of locations on such substrate. FIG. 3 is an enlarged view of a portion of a digitally encoded substrate. FIG. 3 illustrates how the method of encoding takes a series of digital data values (i.e., bit values) and, using those format parameters applicable to spots, cells, markers, and rows, produces a pattern. The format parameter values used for producing the digitally encoded substrate of FIG. 3 are: Spot Height=3, Spot Width=3, Cell Height=4, Cell Width=4, Marker Height =3, Marker Width=4, Marker to Spot=6, Spots per Segment=7, and Rows per Marker=3. The series of bit values for the first row of cells are: 1, 0, 1, 1, 1, 0, and 0. FIG. 3 reflects the bit values and format parameters selected, as illustrated in markers 301, distance from the first marker to the first spot 302, spot 303, and cells 304, 305, 306, 307, and 308. Each of the markers 301 is 4 pixels wide by 3 pixels high, consistent with a Marker Width value of 4 and a Marker Height value of 3. Consistent with a Rows per Marker value of 3, there are three rows of cells for each marker, the first row being immediately to the right of the first marker. Distance from the first marker to the first spot 302 is 6 pixels, consistent with a Marker to Spot value of 6. Each spot, such as spot 303, is 3 pixels high by 3 pixels wide, consistent with a Spot Height value of 3 and a Spot Width value of 3. Each cell, such as cell 304, is 4 pixels high by 4 pixels wide, consistent with a Cell Height value of 4 and a Cell Width value of 4. The embodiment of the method of encoding utilized to produce the digitally encoded substrate of FIG. 3 reflects each bit in the series of bit values by expressing one bit in each cell through two different logical states, where one state is represented by the presence of a spot and the other logical state is represented by the absence of a spot from the cell. In this instance, a spot represents a 1 and a blank cell represents a 0. Accordingly, cells 304, 305, 306, 307, and 308 are spotted, blank, spotted, spotted, spotted, blank and blank, reflecting the series of bit values 1, 0, 1, 1, 1, 0, and 0. Similarly, the second row reflects the series of bit values 1, 1, 0, 0, 0, 0, and 0, the third row reflects the series of bit values 0, 0, 1, 1, 0, 0, and 0, and the fourth row reflects the series of bit values 0, 1, 0, 0, 0, 1, and 1. In the preferred embodiment of the method of encoding, a marker consists of a dark rectangular array of pixels. Series of markers are located in columns, with a number of white pixels vertically separating one marker from the next marker down the column, such number of pixels being a function of the values for format parameters Cell Height, Rows per Marker and Marker Height. Similarly, each marker is horizontally separated from the nearest possible spots by a number of white pixels, such number being determined by the value for the format parameter Marker to Spot. FIG. 3 illustrates markers according to this preferred embodiment. It is well recognized in the area of the invention that it is important to have a “clocking” mechanism to allow a precise mapping from image pixel locations to printed pattern locations. The present invention allows the clocking mechanism, which always demands some overhead in terms of space, to be configured so that it can maximize the density of information on the printed substrate. The clocking mechanism assumes the most compact form that allows it to represent spatial information: periodic dark interrupting white, or periodic white interrupting dark. The area occupied by this mechanism is fully configurable: both the frequency with which it occurs, and the size of each occurrence can be fully modified. Moreover, the clocking mechanism “wraps around” so that the clocking region provides spatial information for data cells on both sides. It is important that the amount of clocking apparatus on the substrate be configurable. If there is too much, then density is lost due to the space occupied by the clocking mechanism itself. If there is not enough, then spatial inaccuracies creep in, and this brings about either erratic behavior, or loss in density if the spots must be made larger to accommodate the inaccuracies. Somewhere between there is an optimum amount of clocking, and this amount may vary considerably from one combination of printer/scanner to another. The clocking is performed by markers, currently implemented as dark rectangles on a white vertical column. These markers capture both horizontal and vertical location. The horizontal information is carried essentially by counting the number of marker columns over, and multiplying that count by a determinable horizontal displacement between columns; the vertical information is carried by counting the number of markers down, and multiplying that count by a determinable vertical displacement between markers. In principle the markers could be arranged in strips that run horizontally across the direction of the scan. Yet the distortions in a scanned image are almost always in the vertical dimension, since this is governed by mechanical factors of paper moving down a document feeder, or of a scan head moving down. It is more important therefore to keep track of the variations along the vertical dimension, which vertical strips of markers more effectively do. (Of course it would be also possible in the current invention to have both horizontal and vertical strips, if significant distortions were introduced in both directions.) Rather than have the markers the same size and periodicity as the spots—which a number of technologies do—it is far better to make their size and periodicity independent, since the role they play is quite different. The principle that must guide the dimensions and periodicity of the markers is that they must be laid down by the printing process so that they rarely are absent, are clearly identifiable in the scan, and have absolutely reliable physical location. This is a general constraint on any clocking mechanism in any technology that encodes digital information on a substrate and decodes it by means of a scan. When the amount of overhead that the clocking mechanism incurs is decreased, by decreasing the clocking features in size and/or frequency, the amount of data that can be affected by each imperfection (or aggregation of imperfections) in the printing or scanning of the clocking features increases. It is important therefore to be able to configure the clocking mechanism so as to minimize defects in the printing or scanning of the clocking features. The optimal configuration depends on the imperfections peculiar to the particular printer and scanner. Considerable imperfection can be tolerated in data spots, since any individual defect can compensated for by error correction. Yet a single spatial inaccuracy arising from a marker can affect any number of rows of spots—which may in turn comprehend perhaps hundreds of spots, thereby corrupting large quantities of data. In general, these constraints imply that markers should be larger than spots, and better separated from other features, including both spots and each other. The absence of this capability in other technologies limits their ability to achieve highest densities and reliability. The concept of “wrap around” in the current invention also plays a key role. It means that the same set of guideposts that provides spatial information about a grouping of data cells on one side also provides it for a grouping on the other. Alternative technologies which divide data into separated blocks demand not only a new, effectively redundant, set of guideposts for the nearby side of the neighboring block, but also a separation of white space (and perhaps other paraphernalia—e.g., a thick bar), between the blocks so that the location of each block itself can be determined. The unnecessary overhead all of this introduces can severely reduce the density of information on the substrate. Other embodiments utilize markers other than rectangular arrays of dark spots set in a light background. In one such embodiment, the markers consist of a grouping of dark pixels in nonrectangular shapes such as circles, ellipses or triangles. In a further embodiment, markers consist of groupings of light pixels against a dark background. FIG. 4 illustrates this further embodiment. FIG. 4 contains an enlarged view of a portion of a datatile that is identical to that illustrated in FIG. 4 except for the markers. Each column of markers 401 consists of a dark bar that preferably extends the entire length of the column of markers 401 plus a few pixels on top and bottom. The number of additional pixels on top and bottom would preferably be between one and two times the value for the format parameter Marker Height. The bar would have a width that can preferably be varied by the person encoding data so that the user can optimize the width for the particular printers and scanners anticipated or such other circumstances the user might encounter. Thus, this embodiment would preferably have a further format parameter, Marker Bar Width. Similar to the datatile in FIG. 3, the horizontal distance from each marker to the nearest edges of possible spots is 6 pixels (i.e., the value for Marker to Spot equals 6). The dark bar for each column of markers 401 is 8 pixels wide, consistent with a value of 8 for Marker Bar Width. Thus, the distance from the dark bar to the nearest edges of possible spots is 4 pixels. Within each dark bar are the markers themselves—arrays of white pixels that are 4 pixels wide and 3 pixels high. It is important for the technology to come to terms with the basic fact that the defined dimensions of a spot may be very different from the actual dimensions of the spot produced on a substrate by a printer. The precision of defined dimensions of a spot usually well exceeds the true precision of a printer. When pushed close to their theoretical resolution, printers rarely can produce on a substrate a dark region filled in exactly to the bounds defined, and typically exceed and/or fall short of these bounds. One effect of this is that the notion of “shape” of a spot largely breaks down. For example, at these resolutions, the defined squareness (or rectangularity) of a spot is in great measure lost, and the spot becomes effectively a roughly circular (or oval) “blob.” It is likewise true that scanners when pushed close to their resolutions cannot distinguish the shapes of even perfectly printed shapes on the substrate, and effectively reduce all small shapes to “blobs” which vary only in darkness and, to a degree, size. From the standpoint of ability to encode data, the real issue becomes: in a given space, how many such “blobs” can be separately printed so that they can be distinguished by a scanner? For this reason, even if the defined shapes of these microscopic entities on the printed page differ from one case to another, it is, for the purposes of the technology, effectively the same representation. In the preferred embodiment, cells and spots are rectangular or essentially rectangular with the cells placed in horizontal rows and vertical columns in the datatile. In another embodiment, cells are formatted as diagonal spaces and series of cells are formatted diagonally into the datatile. In one embodiment spots are likewise formatted as nonrectangular spots. Formatting spots as nonrectangular shapes may be particularly advantageous where placing dots in all pixels of a rectangular spot results in too much ink spreading beyond the spot's theoretical limits (i.e., dot gain) while placing dots at less than all pixels (as might be accomplished with a nonrectangular spot shape) reduces the encroachment over a rectangular spot's borders while still giving good definition within the borders. In one embodiment, nonrectangular cells and spots are chosen through a dialog box that includes an array of squares, each square representing a pixel. The person encoding data selects those squares in the array that represent a cell and within those squares, the squares that represent a spot. Each of a plurality or all of the cells and spots in a datatile would have the shapes selected. FIG. 5 and FIG. 6 illustrate dialog boxes according to this embodiment FIG. 5 illustrates a dialog box for establishing the shapes for a spot and a cell. FIG. 6 illustrates a dialog box for determining how nonrectangular cell shapes fit together, and the sequence in which those cells are created and each bit in the series of digital data values is encoded. In FIG. 5, the user has 7 options, 5 represented by radio buttons and 2 by icons. Matrix 501 represents the printer pixels available for formatting spots and cells, where each square in the matrix represents one printer pixel. The user selects Add to Spot. When this button is selected, the user moves the mouse cursor over desired squares in matrix 501 and clicks those squares. In FIG. 5, squares that have been selected as part of the spot are black. Pixel 502 illustrates a square that is part of the spot. If the user desires to revise pixels selected for the spot, the user selects Delete from Spot, moving the mouse cursor over previously selected squares and clicks, thereby removing those pixels from the spot (in an alternative dialog box, there is no separate Delete from Spot and Delete from Cell radio buttons—clearing previous selections is instead performed done by clicking a second time on previously selected squares). The user also selects Add to Cell. When this button is selected, the user moves the mouse cursor over desired squares in matrix 501 and clicks those squares. In FIG. 5, squares that have been selected as part of the cell are those that either hatched or selected as part of a spot. Pixel 503 illustrates a square selected to be part of the cell but not part of the spot. All squares not selected as part of either the spot or the cell remain blank. Square 504 illustrates a square that is neither part of the spot nor the cell. The user selects Change Matrix Size if the user desires to either increase or decrease the array of printer pixels available for selection as part of the spot and cell. When the user completes the selection of spot and cell shapes, the user selects DONE or, if the user wishes to abort the selection process, the user selects CANCEL. In FIG. 6, the user has 3 options in addition to DONE and CANCEL (DONE and CANCEL have functions comparable to the similarly named icons in FIG. 5). Matrix 601 depicts the cell shape chosen in the CONFIGURE SPOT/CELL SHAPE dialog box illustrated in FIG. 5. The CONFIGURE CELL PLACEMENT dialog box preferably pops up following completion of selection in the CONFIGURE SPOT/CELL SHAPE dialog box. The cell previously selected is illustrated as area 602—i.e., the area not composed of squares. Matrix 603 represents the printer pixels available for placing cells, where each square represents one printer pixel. The user selects Add Another Square, moves the mouse cursor over area 602 representing the cell shape, and leaving the mouse button clicked, moves (i.e., drags) an image of the cell shape to the desired location in matrix 603. Inappropriate selections are ignored by the computer in the dialog box, including selections that effectively change the shape of cells by leaving unfilled squares in gaps between cells of the chosen. shape. The user selects Delete Cell to revise a previous selection (in an alternative dialog box the Delete Cell radio button does not exist and instead, the user clicks a second time on a previously placed cell). The user then selects Set Sequence, and moves the mouse cursor over cell shapes in matrix 603 in the order desired, clicking on each cell shape as the cursor moves. The sequence is indicated in the dialog box by the numerals in the cell shapes. The sequence selected determines the order in which bits from the series of digital data values are encoded in the cell, proceeding in the order selected to the border of the datasector then moving to the next line in the datasector. In matrix 603, the order selected is a line of cells extending from upper left to lower right. Cell shape 604 was selected as the first in the series followed by cell shapes 605, 606, and 607. The method of encoding would encode cells in this sequence starting at the left border of the datasector moving down and to the right to the other border of the datasector. Once the lower border has been reached, the sequence goes back to the first cell of the next line, depicted in matrix 603 as cell shape 608. This embodiment preferably determines a sequence of cells by default if none is selected by the user. One such default sequence would generally follow the sequence of the preferred embodiment—i.e., generally from left to right. In the preferred embodiment the format parameters are selected through a combination of input, automatic selection and default values. FIG. 7 describes this selection process as applied to each format parameter. The step of inputting, 701, can encompass a user inputting a value for a format parameter. Inputting is performed using a keyboard, mouse, or other input device, to select values in a dialog box. After allowing adequate time for inputting but before the method of encoding commences formatting, the selection process determines whether a value has in fact been input, step 702. If a value has been input, the selection process sets the format parameter equal to that value, step 703. If a value has not been input, the selection process then determines whether information otherwise available bears on the selection of a format parameter value, step 704. For example, if the encoding process is being performed by a computer, the computer's operating system may have stored information in the printer driver concerning the default printer used by the computer. This information could include the printer's make, model, and resolution. Printer resolution can be particularly useful in automatic selection of format parameter values. Another source of information can be information input by the user other than values for the format parameters themselves. For example, the user can input information concerning the types and resolutions of printer and intended scanners for a given datatile. While this information does not directly establish format parameter values (other than the Printer Type parameter which preferably does not directly influence the formatting process), the information clearly bears on the selection of these values. The correct setting for these parameters can be established by experimentation with desired printers and scanners. The results of these experiments are then captured in lookup tables for the parameters that are stored in the software. In the source code, the lookup tables for the preferred embodiment can be found in the setdefs.c file. If information is available, from whatever source, that bears on the selection of a format parameter value, then the selection process establishes the value consistent with that information, step 705. Otherwise, the selection process sets the format parameter equal to a predefined default value, step 706. The preferred default values are intended to be reliable no matter what printer or scanner is used. While the selection process of the preferred embodiment provides for user input as at least one manner of selecting format parameters, other embodiments have other ways of selecting format parameters with no user input. One such embodiment selects format parameter values as part of the process of developing computer code for the instructions to be executed by a computer and attached printer. In accordance with this embodiment, format parameter values are selected for a particular printer or set of printers, where the values are preferably optimized for the particular printer or printers. It is therefore possible to include the selected format parameter values as part of printer drivers—i.e., the set of computer instructions directing a particular printer to print and the manner in which to print. In other embodiments, format parameter values are varied without user input by reference to information available without user input In one such embodiment, the format parameter values are selected by reference to information known about attached printers, possible scanners, or a combination of such factors. FIG. 8 illustrates a digitally encoded substrate as produced by a preferred embodiment of the method of encoding. More particularly, the digitally encoded substrate illustrated in FIG. 8 consists of one datatile. It should be understood that the preferred embodiment produces one or a plurality of datatiles depending on the amount of digital data, the density of data produced by the formatting process, the size of the substrate and user preferences for datatile size and quantity. The datatile in FIG. 8, enlarged for illustration purposes, consists of three main components, a landmark 801, a metasector 802, and a main body of data 803. In this embodiment, landmark 801 consists of two bars—i.e., two rectangular regions composed entirely of pixels in the same state. The landmark 801 consists of two bars that are entirely black. One such rectangle is elongated vertically while the other is elongated horizontally. The basic purpose of these landmarks, as further described in the decoding process below, is twofold. First, the landmark provides information about the orientation of the pattern within the image, and in particular the orientation of the metasector. The metasector and the horizontal bar of the landmark are both much longer than they are high. Furthermore, they are both designed to be printed at the same orientation—i.e., the horizontal aspects of each should be printed perfectly horizontal. The skew of the landmark in the scanned image therefore gives a very good approximation of the skew of the metasector. Second, the landmark provides information about the scale of the pattern within the image, and the scale of the metasector in particular. In the DEDS program, the dimensions of the vertical bar and horizontal bar are standardized based on the sizes they assume when printed on a 300 dpi laser and configured for a 400 dpi scanner—i.e., these settings are treated by the DEDS program to be the “base” case. In particular, the vertical bar is printed with width of 6 printed pixels, and height of 32 printed pixels. The horizontal bar is printed with length of 64 pixels, and height of 16 pixels. These relative proportions are observed no matter what the resolution of a printer and scanner might be. If the pattern is to be scanned in by a 300 dpi scanner, and printed on a 300 dpi laser, then the number of pixels is half again as much in each dimension (i.e., vertical bar 9 pixels wide by 48 pixels high, horizontal bar 96 pixels wide by 24 pixels high). And a 600 dpi laser will precisely double the number of pixels in each dimension for the two cases—i.e., for a 300 dpi scanner the vertical bar is printed at 18 pixels wide by 96 pixels high and the horizontal bar is printed at 192 pixels wide by 48 pixels high, while for a 400 dpi scanner the vertical bar is printed at 12 pixels wide by 64 pixels high and the horizontal bar is printed at 128 pixels wide by 32 pixels high. The vertical bar in landmark 401 has dimensions 9 pixels wide by 48 pixels high, while the horizontal bar has dimensions 96 pixels wide by 24 pixels high. The scale can generally vary widely depending on the resolution of the printer and the scanner. In the DEDS program, the landmark is in precise scale to the metasector, which also has a rigid format. The width of the horizontal bar is precisely 16 times the width and 32 times the height of a marker in the metasector. Likewise, the dimensions in printer pixels of the metasector itself will be a multiple of the “base” case printer pixels. Thus, the metasector's markers, spots, and distances will, for example, precisely double if printed on a 600 dpi printer instead of a 300 dpi printer. The multiple used is encoded within the metasector. This allows a precise understanding of the ratio of printed pixels to image pixels. This understanding enables the algorithm to decode the data portion of the pattern, since distances and dimensions of markers and spots are defined in the metasector in terms of printed pixels In other embodiments, the method of encoding produces digitally encoded substrates with landmarks other than two bars consisting of pixels of the same state. Potential shapes for landmarks should be distinctive so that they are not easily confused with other possible features in the scanned image. They should also bear a predictable orientation with respect to the metasector, as well as a predictable scale (or limited set of scales.) In still further embodiments, the method of encoding produces digitally encoded substrates with no landmarks. In general, the landmarks perform a function that can be achieved through further computational steps. Such a process locates the left side of the printed pattern by examining the image for horizontal sequences of white pixels followed to the right by dark pixels, and reconstructing the vertical left side for the pattern by assembling into a straight line the points at which the dark pixels first occur. At the top of the left side of the pattern lies the metasector, and an algorithm locates the predictable number of vertical markers in the metasector (typically three) that occurs at the extreme left side. From the size and relative location of these markers, the orientation of the metasector as well as its scale can be well approximated. The known pattern (or one of a series of known patterns) for the metasector markers virtually precludes mistaking some other graphical image as a metasector, thus allowing both a datatile and human readable graphics and text on the same page. Metasector 802 of the present embodiment consists of two basic elements, metasector markers and metasector data cells. These two basic elements are differentiated in the present embodiment by relative size and placement. Each metasector marker of metasector 802 is 3 pixels high by 6 pixels wide. These metasector markers are placed in groups of three, stacked vertically and separated from each other by 9 blank pixels. Metasector 802 contains 9 groups of three metasector markers, including one group at the leftmost region of metasector 802 and one group at the rightmost region of metasector 802. Each metasector data cell of metasector 802 is 6 pixels high by 6 pixels wide. These cells are grouped together between the groups of metasector markers, with any spots in the cells closest to the metasector markers being 6 pixels horizontally removed from the metasector markers. The groups of metasector cells are 8 cells wide by 5 cells high. Each cell within a group may contain a spot that is black or may be blank (white) depending on the bit value being encoded within that cell. Each black spot in a metasector cell, where called for, is 3 pixels wide by 3 pixels high. The data cell that may contain a spot is most perspicuously to be understood as locating such a spot precisely in its center. That is, if a spot is 3 pixels by 3 pixels, and its containing cell is 6 pixels by 6 pixels, then the border of that cell should be understood as extending 1.5 pixels above, below, to the right of, and to the left of the spot. Understanding the notion of a cell in this way allows all cells to be treated equally and symmetrically—in particular, the cells at the extreme right and extreme left of a contiguous aggregation of cells are equally distant from the markers at the border of the aggregation. While the notion that a spot is located precisely at the corresponding cell's center facilitates understanding of the construct of a cell, it should be further understood that the spot could be located anywhere in the array of pixels that defines a cell and achieve the same effect. The importance of a notion of a cell from the point of view of understanding the invention is that a cell captures the separation of a potential spot from the neighboring potential spots. This separation is important to the invention, because, one, printed spots typically extend beyond their defined boundaries, and, two, when a dark spot is scanned, the darkness typically extends (beyond its physical bounds) into neighboring image pixels. These two phenomena demand that spots be defined with separation from each other if they are to be most effectively determined to be “on” or “off.” Taking advantage of this can greatly increase the density of information on the page. The main body of data 803 of the present embodiment consists of two basic elements, markers and data cells. These two basic elements are differentiated in the present embodiment by relative size and placement. Each marker is 3 pixels by 3 pixels, these dimensions having been determined by setting the parameters Marker Height and Marker Width each equal to 3. The markers are arranged in columns, with each column being one marker wide and as high as the main body of data 803. The beginning of each marker within a column is separated vertically from the beginning of the next marker by 9 pixels, this distance being determined by (and is a product of) setting the parameter Cell Height equal to 3 and the parameter Rows per Marker equal to 3. The main body of data 803 contains 10 columns of markers and 9 groupings of data cells between those columns of markers. The 9 groupings of data cells across results from (and is a product of ) setting the parameter Datasectors Across equal to 3 and the parameter Data Segments equal to 3. The first three groupings for instance, located between columns of markers 804 and 805, constitutes the first datasector (note Datasectors Down equals 1). Each grouping of data cells is 15 cells wide and extends the height of the main body of data 803. The number of cells across each grouping is 15 as a result of setting the parameter Spots per Segment equal to 15. Each grouping contains, in addition to data cells, a calibration pattern such as calibration pattern 806. A calibration pattern contains spotted and blank cells arranged in a checkerboard pattern. The calibration patterns facilitate the decoding process by providing information on the darkness of the scanned image. The manner in which the calibration pattern facilitates the decoding process is further disclosed in the source code for the DEDS program. Each data cell is 4 pixels wide by 3 pixels high, these dimensions having been determined by setting the parameter Cell Width equal to 4 and the parameter Cell Height equal to 3. Each data cell of the main body of data 803 contains either a black spot or is blank (white), depending on the bit value being encoded within that cell. Each black spot is 3 pixels wide by 2 pixels high, these dimensions having been determined by setting the parameter Spot Width equal to 3 and the parameter Spot Height equal to 2. The column of markers is horizontally separated from the closest possible spots in the data cells by 5 pixels, this distance having been determined by setting the parameter Market to Spot equal to 5. The height of the main body of data 803 is a function of the amount of data to encode, the parameter Datasectors Down, and the width of the main body of data 803, such width having been determined as indicated above. In a further embodiment of the method of encoding, information recorded on a substrate includes digital data as well as other information such as human readable text and graphics. FIG. 9 illustrates an example of a substrate according to this embodiment. The substrate in FIG. 9 includes human readable text, graphics (i.e., a drawing of a cat's face), and a datatile containing digital data relevant to the human readable information (the datatile in FIG. 9 illustrates an embodiment that does not include a landmark). The substrate illustrated in FIG. 9 thus conveys how a further embodiment of the invention can be used for such purposes as advertising, thus providing further evidence of the invention's value. The invention's unique advantages (relative to other known technologies), including the ability to store far greater amounts of data in a limited space, the ability to determine locations of data through use of metasectors, and the ability to determine cell locations by utilizing formattable series of markers, make the embodiment of FIG. 9 commercially practical for the first time. In other embodiments, involving photographic materials and processes, encoded digital data is placed inside, alongside or on the back of images captured from normal photographic processes. In further embodiments involving digital photography, encoded digital data is placed inside, alongside or in back of printouts of the digitally captured and recorded image, or inside, alongside or in back of printouts of scanned and digitized images captured from normal photographic processes. A further embodiment of the invention serves as a substitute for optical character recognition (“OCR”). The datatile in FIG. 9 could, for example, contain (whether or not in addition to the indicated list of information and phone numbers) the underlying file or files for the printed text and graphics. The datatile could further contain instructions to not perform OCR on the printed text. An embodiment that includes both OCR capability and the ability to decode datatiles first attempts to find and decode a datatile. If successful in decoding a datatile (one that contains instructions not to perform OCR) the invention does not perform OCR on the printed text but instead stores the file contained in the datatile. If no datatile is present on a printed document (or if the datatile is not successfully decoded) this further embodiment performs OCR on the document. The result in either case is a digital representation of the document. In light of current deficiencies in OCR, the first possibility—deriving a perfect digital representation from a datatile—is clearly preferable. While FIG. 9 includes human readable information in addition to digital data, it should be understood that further embodiments of the invention combine digital data as well as other information that is not or is not primarily human readable through visual inspection. Thus, one further embodiment combines the encoded digital data with braille so that digital data can be transmitted by substrate to the visually impaired. For example, computer audio files can be transmitted on paper and the recipient can read the braille on the substrate to determine the contents of the computer audio files. In further embodiments, the machine readable digital data produced by the present process is combined with machine readable digital data of other processes such as those that utilize bar codes or characters written in magnetic ink. These further embodiments allow existing installed bases of technologies to initially sort or otherwise make determinations using existing equipment and processes in place. In a further embodiment of the method of encoding, the digitally encoded substrate contains at least one datatile where parts of the datatile are located in noncontiguous regions of the substrate instead of the whole datatile being located in one region of the substrate. The regions not occupied by parts of the datatile may contain other printable matter including human readable text or graphics, blank space, or parts or all of other datatiles. FIG. 10 illustrates an example of a substrate produced in accordance with this embodiment. This substrate contains parts of a single datatile, a landmark 801, a metasector 802, and a main body of data 1003. The substrate also contains human readable text 1004. Parts of the datatile are in noncontiguous regions of the substrate. Landmark 801 and metasector 802 are located together at the top of the substrate. Main body of data 1003 is divided into 2 parts, each of which is physically separate from each other and from landmark 801 and metasector 802. Human readable text 1004 occupies space between the noncontiguous parts of the datatile. In one embodiment of the method of encoding, the metasector contains information indicating or otherwise assisting in the determination of the location of the various parts of the main body of data 1003 while in a further embodiment, a part or parts of the main body of data 1003 contains information indicating or otherwise assisting in the determination of the location of the other parts of the main body of data 1003, while in a still further embodiment, the various parts of the main body of data 1003 are located without reference to information provided by either metasector 802 or other parts of the main body of data 1003. Of these various embodiments, the preferred method places in the metasector the location information for at least the first grouping of cells of the main body of data. If less than all location information is placed in the metasector, the preferred method would place in the main body of data's first grouping of cells the location information for at least the next grouping of cells. Determination of the landmark and metasector locations therefore facilitates determination of locations of a series of non-contiguous parts of the main body of data. Location of cells within non-contiguous parts of the main body of data is aided by another aspect of the invention—i.e., the intermittent series of formattable markers. In some embodiments, the number and size of the separate parts of the main body of data 1003 are fixed by information contained in metasector 802 or other parts of the main body of data 1003. In other embodiments, the number and/or size of the separate parts of the main body of data 1003 are not fixed. The method of decoding continues searching for additional parts until no more are found, either because the entire substrate has been searched or because the succession of location references from part to subsequent part ceases. While the result of the method of encoding is sometimes a single digitally encoded substrate, in some instances the preferred embodiment produces a plurality of digitally encoded substrates from one or more computer files or series of digital data values. Utilization of multiple substrates may be called for particularly when the amount of data or the size of one or more computer files exceeds the limits of what can be encoded on a single substrate. Thus, computer files or other digital data of virtually unlimited sizes can be encoded. In a further embodiment, a plurality of datatiles are encoded onto a single digitally encoded substrate. The encoding into multiple datatiles may be particularly called for to facilitate in the navigation to particular digital data. For example, a newspaper page might contain several articles with a separate datatile alongside each article with digital data (such as a digital representation of the article itself) relevant to the particular article. Multiple datatiles on one substrate may also be used such that each is decoded in sequence in order to provide a steady stream of data once the first datatile is decoded instead of waiting for an entire page to be decoded. In some embodiments this steady stream of data is used for some further application, where the computer decodes datatiles and executes this further application on such a substantially contemporaneous basis as to be transparent to the user. In one such embodiment, the method of decoding is integrated with application software that displays video clips and plays audio files such that datatiles are decoded, video displayed, and audio played on a substantially contemporaneous basis. FIG. 11 illustrates a digitally encoded substrate containing multiple datatiles, each originally produced by the DEDS program and then enlarged 250% in each dimension for illustration purposes. The first two datatiles, 1101 and 1102, were intended to be decoded by using a fax machine as a scanner. The third datatile, 1103, was intended to be decoded by using a flatbed scanner with an optical resolution of no less than 300 dpi scanning 256 levels of gray scale. Datatiles 1101 and 1102 are two datatiles that together contain one computer file. Datatile 1103 contains one whole computer file. The one computer file contained in datatiles 1101 and 1102 contains 1,866 bytes of text while the one computer file contained in datatile 1103 contains 3,112 bytes of text. While a flatbed 300 dpi scanner can successfully decode the originals (i.e., at their original size) of all three datatiles, 1101, 1102, and 1103, using a fax machine as a scanner, the invention can successfully decode only datatiles 1101 and 1102 (at their original size). Thus, FIG. 11 illustrates another feature of the invention—the ability to convey a base amount of data to all recipients regardless of their scanners' capabilities by formatting at least one datatile using the lowest common denominator while providing significantly more data to those with more powerful scanners. FIG. 12 illustrates a digitally encoded substrate containing multiple datatiles, all produced by the DEDS program, all depicted at their actual, original size. The first two datatiles, 1201 and 1202, are intended to be decoded by using a fax machine as a scanner. The third datatile, 1203, is intended to be decoded by using a flatbed scanner with an optical resolution of no less than 300 dpi scanning 256 levels of gray scale. Datatiles 1201 and 1202 are two datatiles that together contain one computer file. Datatile 1203 contains one whole computer file. The one computer file contained in datatiles 1201 and 1202 contains 28,371 bytes of text while the one computer file contained in datatile 1203 contains 48,102 bytes of text. The method of encoding of the preferred embodiment is capable of producing multiple datatiles (or series of datatiles) each of which contains the identical file or files and are distinguished from each other by their unique identification tag. This capability allows each datatile to contain a unique password, for example, while minimizng the amount of computing necessary to format each datatile. Each of the formatted patterns represented by the datatiles are preferably identical to each other except for that part of the pattern expressing the unique identification tag. In this fashion, a multiplicity of datatiles conveying the same data can be formatted using as a template a pattern containing everything but the identification tag and, for each datatile, completing the datatile by adding to the template a second (and much smaller) pattern representing the identification tag. In the preferred embodiment, the identification tag is added to the main body of data at the end (i.e., in the lower right corner of the datatile, following the file or files intended to be conveyed). In a further embodiment, the identification tag is added to the metasector—one grouping of metasector cells 8 cells wide by 5 cells high is capable of expressing 240 unique identifications. In still further embodiments, the identification tag is a pattern near but not within the metasector or main body of data of the datatile. This last embodiment facilitates first photocopying the template pattern then adding the identification tag in a second step. Because the identification tag is not part of the metasector or main body of data of the datatile, the embodiment is more tolerant of any misregistration caused by outputting in 2 steps. One embodiment would express different logical states for each cell by the placement of spots with different attributes. Depending on the embodiment, the attributes that could vary to express different logical states include spot size, spot color, ink type, and spot shape. In one such embodiment, illustrated in FIG. 13, each cell contains a spot. Each spot has one of two sizes. Markers 301, bordering the data cells, are 4 pixels wide by 3 pixels high. Each data cell contains one bit of information expressed by two logical states. A first logical state, exemplified by spot 1302, is expressed by a spot 3 pixels wide by 3 pixels high. A second logical state, exemplified by spot 1303, is expressed by a spot 1 pixel wide by 1 pixel high. In this fashion, each cell contains a spot of one of the two sizes. In instances where a self-clocking mechanism is called for, this embodiment would have the advantage of providing such a mechanism. In a further embodiment, each cell represents more than one bit where a plurality of bits are expressed by spots of different sizes and colors. FIG. 14 is an enlarged view of a substrate produced by such an embodiment containing markers 301 and cells 1402, 1403, 1404, 1405, 1406, 1407, 1408, and 1409. Markers 301 are of uniform size, 4 pixels wide by 3 pixels high, and color, black. FIG. 14 contains cells each of which represents 3 bits in a series of digital data values. Each cell has one of eight different logical states with one logical state expressed by the absence of a spot and each of the other logical states expressed by a spot with either a size or color different from a spot expressing any other logical state. Cell 1402 contains a black spot 3 pixels wide by 3 pixels high. Cell 1403 contains a black spot 2 pixels wide by 2 pixels high. Cell 1404 contains a black spot 1 pixel wide by 1 pixel high. Cell 1405 is blank. Cell 1406 contains a gray spot 3 pixels wide by 3 pixels high. Cell 1407 contains a gray spot 2 pixels wide by 2 pixels high. Cell 1408 contains a gray spot 1 pixel wide by 1 pixel high. Cell 1409 contains a black spot 1 pixel wide by 1 pixel high surrounded by a gray border 1 pixel wide on all sides. Hence, cells 1402, 1403, 1404, 1405, 1406, 1407, 1408, and 1409 are examples of each of the eight different logical states that a cell can express. FIG. 15 illustrates the use of more than one cell size in the same datatile. A user of the invention may desire to select such a configuration when, for example, one cell size is too small and the next larger cell size wastes space. If a user determines that dot gain prevents a smaller cell size from accurately conveying data, this embodiment allows the user to alternate cell sizes between a smaller size and the next larger size to overcome the problem while making the most efficient use of space. It is a reasonable inference that the technique of different cell sizes can increase the density of information. Any spot either within a larger cell, or within a smaller cell contiguous to a larger cell, will enjoy greater separation from at least one neighboring spot than it would if all spots were within smaller cells. This will serve to reduce the bit errors that will be introduced in decoding, since the number of bit errors depends critically on the separation. The reduction of bit errors in turn can allow the correct decoding of the information in cases in which it would be impossible if all cells were of the smaller size. FIG. 15 references markers 301, and spots 1502, 1503, 1504, and 1505. The elements in FIG. 15 are enlarged for purposes of illustration and explanation. While spots are considered in FIG. 15 to occupy the upper left corners of cells for illustration purposes, it should be understood that this is just one possible embodiment—another embodiment, for example, places a spot in the center of cells. Markers 301 are 4 pixels wide by 3 pixels high. Each of the spots is 3 pixels wide by 3 pixels high. The first column is formatted to include cells that are 3 pixels wide and 4 pixels high and, accordingly, spots 1502 and 1503 are in cells 3 pixels wide and 4 pixels high. The second column is formatted to include cells that are 4 pixels wide by 4 pixels high and, accordingly, spot 1504 is in a cell 4 pixels wide by 4 pixels high. Because the first column has been formatted such that its width equals the width of any spot, a spot in the first column directly adjoins a spot in the same row in the second column, as illustrated by spots 1503 and 1504, which together appear to be one spot twice as wide as high, but are in fact two distinct spots. Because the second column has been formatted to be wider than any spot, any spots in the same row in the third column will not directly adjoin spots in the second column. Accordingly, spot 1504 does not directly adjoin spot 1505. Decoding Formatted digital data produced by the invention must be decoded in order to reconstruct the original computer files or other digital data. The manner in which the preferred embodiment accomplishes the decoding is illustrated in FIGS. 16, 17, 18, and 19. FIGS. 16, 17, and 18 are block diagrams describing processes relating to decoding, while FIG. 19 is an enlarged portion of a digitally encoded substrate used to illustrate the steps diagrammed in FIG. 18. FIG. 16 describes the method of decoding—i.e., the broad perspective of how a digitally encoded substrate is decoded. Included in the steps according to this broad perspective is step 1602, the decoding process. FIG. 17 describes the preferred embodiment of the decoding process. Included in the steps according to this preferred embodiment are steps 1704 and 1706, both of which involve decoding a grouping of contiguous cells. Decoding a grouping of contiguous cells involves a process of recovering digital data values from the grouping. FIG. 18 is a block diagram describing the preferred embodiment of that recovery process. Thus, FIGS. 16, 17, and 18 should be understood as illustrating increasing detail of the manner in which the preferred embodiment reconstructs the original computer files or other digital data. The overall method of decoding a substrate comprises, at a minimum, the steps of scanning (i.e., creating an electronic image of the substrate) and decoding. In the preferred embodiment, the method of decoding further comprises the steps of error correction, error detection, and decompression. This embodiment is illustrated in FIG. 16. The digitally encoded substrate is first scanned (processing block 1601). In a preferred embodiment, this scanning occurs using a flatbed scanner attached to a personal computer. In further embodiments, the scanning occurs using a handheld scanner, a sheet-fed page scanner, a business card scanner, a drum scanner or another type of scanner attached to a personal computer. It should be understood that the universe of scanners which may be used is not limited to those attached to personal computers but could include any scanner capable of producing an electronic image. In a still further embodiment, a facsimile machine is used as a scanner, whereby a digitally encoded substrate is fed through the facsimile machine to produce a scan of the datatile. The fax machine may connect to the computer through telephone lines (i.e., by the normal process of transmitting a facsimile from one facsimile device to another by causing the facsimile machine to place a telephone call to a fax/modem attached to the computer), through a device connected to both the facsimile machine and the fax/modem (connected to the computer) which simulates a telephone line, or directly by a telephone wire connected to both the facsimile machine and a fax/modem which is connected to the computer. The result of the scanning is an image of the digitally encoded substrate, such image residing in the memory, fixed drive or other storage component of the personal computer. The image is preferably stored as a bitmap image. Note that the stored image only approximates the pattern placed on the digitally encoded substrate produced by the encoding process. Errors produced by the scanning process, such as misregistration, artifacts due to crimps and folds, skew, and scanner defects, may prevent the stored image from exactly representing the digitally encoded substrate. The stored image is then decoded (processing block 1602). The decoding process identifies cells (i.e., the locations of possible spots) in the stored image and determines for each cell, at a minimum, the presence or absence of a spot. The aggregation of these determinations results in a series of digital data values. Further embodiments make additional determinations that may include the color and size of a spot present, if any. These further embodiments depend on embodiments of the encoding process that provide for encoding of spots that vary in color or size. The result of these further embodiments is likewise, a series of digital data values, but each cell represents more than one bit of that series of digital values. The series of digital data values resulting from decoding process 1602 is then subjected to error correction and detection processing (processing block 1603). This step 1603 is the inverse of the error correction encoding which occurred during encoding (FIG. 2). The error detection and correction occurs by using the codewords with redundant parity bits added during encoding (FIG. 2) to correct errors which may have occurred. The error correction compensates for the loss of data due to damage to the paper or due to the failure to predict the cell location correctly. The errors may be attributed to staples, hole punches, folds, crumples, paper discolorations, technical problems, imperfections introduced in the scanning process or other imperfections. Once any required error correction is performed, the stream of digital data values is decompressed (processing block 1604). The decompression performed depends on the compression performed during encoding and is performed to restore the data to its original form. After decoding processing block 1602), error detection and correction (processing block 1603) and decompression (processing block 1604), the reconstructed computer files or other digital data can be stored on a disk, displayed, or otherwise used by the computer doing the decoding. Decoding process 1602 of the preferred embodiment of the invention (FIG. 8, described above, illustrates a digitally encoded substrate produced by the preferred embodiment) takes advantage of the wealth of information provided in the encoding process. Decoding process 1602 of this preferred embodiment achieves a pyramid gain of knowledge: finding the landmark conveys knowledge on where to find the metasector, as well as its dimensions, the metasector conveys knowledge on where to find the main body of data and how precisely to extract data from that main body of data, and the main body of data conveys the underlying computer files or other digital data. While the method of decoding is described above by reference to a single datatile, the preferred embodiment allows the same steps to be applied to each of a series of datatiles. In one such instance, multiple substrates contain, in the aggregate, more than one datatile while in a further instance, a single substrate contains multiple datatiles, as illustrated in FIG. 11 and FIG. 12. The method of decoding of the preferred embodiment applied to multiple datatiles first scans all datatiles and then applies all of the remaining steps (1602, 1603, and 1604) to each datatile before proceeding to the next datatile. Another embodiment applies all of the steps of FIG. 16 to each datatile before proceeding to the next datatile. A further embodiment applies each step to all datatiles before proceeding to the next step. With each possibility, an automatic document feeder attached to a scanner facilitates the creation of images which are then subject to the decoding process. It should be understood that the method of decoding can also be applied to multiple datatiles not encoded on substrates but, instead, are always in electronic form, as in the case of a facsimile transmission of datatiles from a fax/modem to a fax/modem. FIG. 17 illustrates the decoding process achieving a pyramid gain of knowledge according to the preferred embodiment. The process may be generally described as one in which the locations of metasector cells are determined, the information in the metasector cells is derived, the locations of cells in the main body of data are determined and the data in the cells of the main body of data is derived. The steps of determining the locations of cells in the main body of data and deriving the data from those cells is performed by using the information conveyed by the metasector cells. In the case of multiple datatiles forming one series of digital data values, the entire sequence of steps of FIG. 17 are preferably applied to one datatile before proceeding to the next datatile. First, the decoding process finds the landmark (processing block 1701). In a digitally encoded substrate produced by the preferred embodiment of the invention (as illustrated in FIG. 8, described above), this landmark consists of two dark bars located at the upper left corner of the datatile, with the first dark bar having a height significantly greater than its width and a second dark bar located near the first dark bar with the second dark bar having a width significantly greater than its height. The decoding process can find the two bars due to their unique characteristics. The decoding process looks for a series of contiguous dark pixels. Having found such a series of contiguous dark pixels, the decoding process tests whether a series of contiguous dark pixels of a calculated number extends in the orthogonal direction, with the calculated number determined by reference to the number of pixels extending in the first direction and the predefined ratios of width to height. The decoding process then attempts to determine the orientation of the first bar—i.e., whether the image has been skewed resulting in the first bar being skewed. Determination of orientation is accomplished by locating the corners of the first bar and judging skew by the relative location of these corners. Location of the corners of what might be a first bar further aids determination of whether the first bar has in fact been found. The corners of the first bar should be a certain angle and distance in pixels from each other. If the decoding process locates the appropriate angle and distance in pixels between corners, the decoding process assumes for purposes of further testing that it has found a first bar of the landmark. The decoding process then determines whether a second bar exists at a location determined by reference to the first bar. Existence of a second bar is accomplished by likewise locating a calculated number of consecutive dark pixels extending in one direction, and a second calculated number of dark pixels extending in the other direction, with the calculated numbers of pixels in each direction determined by reference to the size of the first bar and the predefined ratios of heights and widths. It should be understood that while the process described assumes certainty in the relative size and location of the bars comprising the landmark, the preferred embodiment allows for some latitude. The degree of latitude involves a tradeoff, with too much flexibility introducing the possibility of the decoding process concluding that it has found a landmark, where none in fact exists, and too little flexibility forcing the conclusion that it can find no landmark, where a landmark in fact exists. An appropriate degree of flexibility is provided in the source code of the DEDS program. It should be further understood that in other embodiments of the invention, landmarks of a different size, shape or appearance are used, or no landmark at all is used. In each of these further embodiments, the steps described above are modified or omitted. The next step toward knowledge acquisition comprises locating the metasector (processing block 1702). As illustrated in FIG. 8, described more fully above, the metasector of the preferred embodiment is located at a predefined location relative to the landmark, that location being generally to the right of the landmark. Having already located the landmark, processing block 1701, the decoding process knows where the metasector should be in the image of the digitally encoded substrate. The decoding process determines the distance of the metasector from what it knows about the landmark. Once it determines the width and height of the landmark's horizontal and vertical bars in image pixels, it can calculate the ratio of image pixels to printed pixels in the “base” case described earlier by reference to FIG. 8. This allows it to calculate the displacement in number of image pixels of the first column of metasector markers from the landmark, for the other columns of markers in the metasector, and the expected size and distances, in image pixels, of these markers and of the spots. The decoding process finds the metasector by finding the first column of metasector markers based on what is known about the location of the landmark in the image, the relative location of the metasector to the landmark in printed pixels and the ratio of image pixels to printed pixels. The decoding process preferably allows some degree of latitude in making this determination of location and dimensions. Having found the metasector (processing block 1702) the decoding process then finds the metasector markers, processing block 1703. In the preferred embodiment (as illustrated in FIG. 8 described above) the metasector includes 27 metasector markers, 9 columns of 3 evenly spaced markers, with one column of markers bordering each of the left and right sides of the metasector. In addition to having predefined locations, the metasector markers of the preferred embodiment have a size predefined to be different from the metasector data spots. The decoding process determines where the metasector markers should be and then confirms those locations or adjusts to the actual locations as necessary. Because the number of metasector markers and the number of cells between these markers is fixed in the preferred embodiment, this determination is straightforward (as described more fully below with reference to FIG. 18). Another embodiment of the invention provides for an abbreviated metasector, such an abbreviated metasector being warranted when, for example, customary practice of consumers limits the variety of formats actually used. The metasector format in the preferred embodiment expresses enough information to allow the main body of data to assume a vast variety of formats. Yet after considerable experimentation by consumers, it may be that only a relatively small number of such formats enters widespread use. These formats may be adequately captured by a much abbreviated metasector, that only permits these commonly used formats to be specified. In a further embodiment there are a finite number of possible formats for the metasector. Each of these is searched for, until one is found that conforms to a known possibility. This can be safely done, since it will be certain whether the metasector has been correctly interpreted. Each metasector has a checksum associated with it that can guarantee, to any specified level of certainty, that the information decoded is wholly correct. And of course the metasector might also be in the form of a standard linear barcode, with its own notion of error detection. It is likewise true that the main body of data might have a finite number of expected formats, which are the most commonly used formats, and even in the absence of a metasector, could be correctly decoded simply by cycling through the possibilities until one is found that works. The correctness of the choice would again be assured by a checksum in the main body of data. The decoding process then decodes the data contained in the metasector (processing block 1704), such information being located in cells in between the metasector markers. The preferred method of decoding the metasector is as illustrated in FIG. 18, described below. The result of the decoding process is primarily information relating to the encoding process. The decoding process uses this information to decode the main body of data (processing block 1706). The metasector can also contain information not used in the decoding process, such as the time and date the datatile was created. This information, as well as other information not directly related to the decoding, can likewise be contained in the main body of data. The penultimate step in knowledge acquisition involves locating the main body of data, processing block 1705. As illustrated in FIG. 8 described above, a preferred embodiment places the main body of data at a predefined location relative to the landmark and the metasector. The decoding process pursuant to this embodiment searches for a first marker of the main body of data at or near this predefined location in the image of the digitally encoded substrate. The final step in knowledge acquisition is decoding the main body of data, processing block 1706. The decoding process preferably accomplishes this by employing the same basic process used to decode the metasector, as illustrated in FIG. 18. The mechanics differ primarily to reflect the peculiarities of the main body of data relative to the metasector. In particular, the mechanics of decoding the main body of data take advantage of the wealth of information provided in the metasector. While the metasector has preferably been encoded in a rigid or semi-rigid fashion with each metasector having the same or largely the same format as any other metasector produced by the method of encoding, the main body of data is preferably encoded in a user selectable format which can vary widely. For example, while every metasector is preferably encoded with cells of a constant or largely constant low resolution, the main body of data may be encoded with cells whose size can vary greatly among datatiles. The mechanics of the decoding process for the main body of knowledge considers the flexibility allowed by the method of encoding, with the details of the encoding process contained in the metasector and communicated by the pyramid gain of knowledge approach of the preferred embodiment. The manner in which the decoding process uses these details is illustrated in FIG. 19, and discussed below. The metasector, when present, should generally contain at least the version number, the multiple of the “base” printed dimensions of the landmark and metasector, the width and height of the markers, the number of rows of spots per marker, the distance between markers and spots, the horizontal distance between spots (i.e., the difference between Cell Width and Spot Width), the distance between rows of spots (i.e., the difference between Cell Height and Spot Height), the width and height of the spots, the type of checksum in the data sectors, the type of printer (e.g., laser or inkjet), the type and degree of error correction, and finally a checksum to guarantee the correctness of the information. In the DEDS program the metasector contains, in addition to the above information, the number of data segments per datasector, the number of datasectors down, the number of datasectors across, and the size of the data contained in the data portion of the pattern. However, in another embodiment this additional data is instead placed in the main body of data of the pattern by placing it in the top rows of the first portion of the main body of data. The version of the metasector indicates the precise format and nature of the data fields contained within the metasector. It may also be used to indicate peculiarities of the format of the main body of data of the pattern—for example, the size of the header information in the main body of data. The result of the decoding process is a series of digital data values. This series of digital data values is the unprocessed data stream from which the method of decoding derives the original computer files or other digital data after applying decompression and, possibly, decryption processing. The basic process for recovering data from cells is preferably the same whether the cells are contained in the metasector or in the main body of data. FIG. 18 illustrates this recovery process as applied to an image of a digitally encoded substrate produced by a preferred embodiment of the invention, an example of which is illustrated in FIG. 8. The recovery process sequentially finds the point in each cell representing the center of where a spot might be printed and for each cell determines whether a spot exists at that location. In the first step, processing block 1801, the recovery process locates the first marker in the image of the metasector or the main body of data, as the case may be. The recovery process then locates the center at that first marker, processing block 1802. The recovery process then locates the center of the nearest marker displaced horizontally, preferably the marker to the immediate right, and the nearest marker displaced vertically, preferably the marker immediately down from the first marker, processing block 1803. The markers are found by first locating the topmost, leftmost marker. This is done by examining the region where the marker is expected, looking through vertical strips of pixels from right to left until all the vertical strips are “white.” This will determine where the leftmost dark pixels in the marker are. Next, horizontal strips are examined from bottom to top, noting where all the strips turn white. This determines where the topmost dark pixels in the marker are. The precise center of the marker is then determined by finding all the contiguous dark pixels, and finding the centroid of this group of pixels. Once the top left marker is found, the top marker for the next column is determined in the preferred embodiment by moving the known displacement across the image, and finding the precise top of the marker by repeating the process described for finding the top of the top, left marker. Again, the precise center is found by finding the centroid of the contiguous dark pixels. The markers down the column are found by the preferred embodiment by progressing down the image from a previously determined marker, examining horizontal strips of pixels, and detecting when the combined intensities of the pixels in the strip dips significantly, as is characteristic when a new marker is encountered. In another embodiment, markers down are determined by first moving down a known displacement to determine the approximate location of the next marker, then searching for the centroid pixel of the marker. The recovery process then determines for each cell in between the first marker and the next nearest markers displaced vertically and horizontally the point in the cell representing the center of where a spot might be printed. The centers of spot locations are determined by locating the lines across the centers of the rows where spots might be printed in between the first marker and the next marker displaced vertically, processing block 1804, and then locating the lines down the centers of the columns where spots might be printed in between the first marker and the next marker displaced horizontally, processing block 1805. Each spot is preferably thought of as occupying the precise center of its corresponding cell. Accordingly, determining the lines across the centers of rows where spots might be printed equates to finding the lines through the centers of rows of cells. Likewise, determining lines down the centers of the columns where spots might be printed equates to finding the lines through the centers of columns of cells. Having found the centers of possible spot locations in between the first marker and the next nearest markers, the recovery process determines whether each cell is “on” or “off” by determining whether a spot is present or absent at each of the possible spot locations, and accumulates these determinations. The recovery process accomplishes this subprocess by looping through a series of steps for each cell; processing block 1806 establishes the loop for each cell. For each cell, the recovery process determines whether a spot exists at the point representing the center of where a spot would be if printed, processing block 1807. The center is determined as the intersection of the central line through the column and the central line through the row containing any such spot. It should be understood that the preferred embodiment makes more than a simple “yes” or “no” determination of whether a spot exists at a particular pixel. The preferred embodiment determines the level of gray scale of the center pixel and, depending on the gray scale level, determines that the cell contains a spot, determines that the cell does not contain a spot, or determines the need for further processing if it is too close to call. If it is too close to call, information about whether surrounding dots or spots are present or absent may be used to settle whether the spot is to be considered on or off. If surrounding the region of a potential spot, the neighboring potential spots appear to be mostly present, the intensity of the region of the potential spot is generally depressed (i.e., darker). This is compensated for in the DEDS program by adding predetermined values to the intensity found in the region of the potential spot (i.e., the DEDS program assumes that the region of the potential spot is lighter than what was actually found in the image). If a spot is determined to be present in the cell the recovery process starts (or, in subsequent iterations, adds to) a series of digital data values with a value of 1, processing block 1808. If, alternatively, a spot is determined to be absent from the cell, the recovery process starts (or, in subsequent iterations, adds to) a series of digital data values with a value of 0, processing block 1809. The next step, processing block 1810, determines whether to continue the loop. If all cells between the first marker and the next nearest markers have been tested for spots, the recovery process proceeds to processing block 1811. If cells remain to be tested for spots, the recovery process returns to the beginning of the loop at 1806, reiterating steps 1807 through 1810 for each cell. For each further marker or set of markers, the recovery process repeats the process described and illustrated in steps 1801 through 1810. The recovery process first determines whether an additional marker exists, processing block 1811. The recovery process determines this by calculating the number of markers encountered, and comparing this number with the number of markers expected. The number of markers expected by the DEDS program is based on a calculation derived from the number of datasectors down, the number across, the number of spots across a single row in a single datasector, the number of rows of spots per marker, and the total size of the information in the printed pattern. If an additional marker exists, additional cells with data need processing to recover their data. The recovery process is repeated by first treating an adjacent marker as the primary marker of reference (described above as the first marker), processing block 1812, and then repeating steps 1801 through 1811. The preferable manner of choosing an adjacent marker is systematically. A preferred embodiment recovers an entire datasector before moving on to the next datasector. A row of datasectors (i.e., all datasectors across a datatile) are recovered before moving to the next row of datasectors. Within a datasector, the markers are chosen in a similar fashion—markers are sequentially chosen across an entire row, with rows sequentially chosen down the datasector. In the preferred embodiment, all datasectors within a datatile are decoded in order to recover all data encoded in that datatile. In another embodiment, less than all datasectors are decoded. This further embodiment might be preferable when, for example, a particular application requires some, but not all data conveyed in a datatile and the datatile is designed such that data is encoded in a predetermined organized fashion and the particular application accesses particular datasectors to seek particular data. Such an embodiment would save time and computational resources relative to decoding the entire datatile. Such an embodiment can also be employed to supply a steady stream of data to an application such that datasectors are decoded and the application software is executed both on such a substantially contemporaneous basis as to be transparent to the user (e.g., where the application software is a video player, the video player displays a continuous stream of video derived from the datatiles). In one such embodiment, a substrate is scanned to create an image of the datatile and the locations of all markers in the datatile are determined and stored in the fashion described above by reference to the preferred embodiment. The further steps of locating cell centers and spots are performed only as to the currently desired datasector or datasectors. In the preferred embodiment, the recovery process first exclusive-ORs the sequence of bits with precisely the same random sequence of bits that was employed in the encoding process, described above by reference to FIG. 2. Whether or not the sequence of bits is thus altered, the recovery process now reconstructs codewords from the sequence. The codewords are interpreted to produce the original data. The ultimate result of the recovery process is, then, a series of digital data values. The information expressed by this series of digital data values depends on the source of the recovery. In the case of recovery of data from a metasector, the series of digital data values represents the information contained in the metasector, primarily the format parameters used to encode the main body of data In the case of the main body of data, the series of digital data values produced is the unprocessed data from which the method of decoding produces the original computer files or other digital data after further processing that includes decompression and, possibly, decryption. The recovery process has further embodiments reflecting the different embodiments of the method of encoding. Where the method of encoding places multiple bits in each cell through the use of multiple colors (such as varying levels of gray), the recovery process preferably determines the centers of cells (i.e., the centers of possible spots) in a fashion described above but then determines not merely the presence of a spot at the cell's center but also the color of any spot present. Where the method of encoding places multiple bits in each cell through the use of multiple spot sizes, the recovery process again preferably determines the centers of cells in a fashion described above but then determines not merely the presence of a spot at the cell's center but also the size of any spot present. In one embodiment, the size of a possible spot is preferably determined by first testing the center pixel of a cell (i.e., the pixel at the intersection of the lines through the column and row of the possible spot) to determine whether a spot exists. If a spot exists, this method of decoding then tests all contiguous pixels (i.e., pixels one pixel removed from the center pixel) and then, depending on the maximum size of possible spots, tests all pixels 2 pixels removed from the center pixel, and then retest pixels even further removed. This methodology can be applied to the datatile a portion of which is illustrated in FIG. 14. Cell 1409 contains a spot with a dark center and a gray border on all sides. The method first tests the center pixel, finding a dark spot. Depending on the printer/scanner resolution ratio, the method may continue to find dark pixels emanating out from the center pixel in the scanned image. Eventually, the method would encounter gray pixels. Having found both dark pixels at the center and gray pixels at the periphery, the method determines that the spot in cell 1409 represents the logical state expressed by a spot with a dark center and gray periphery. Spots such as those in cells 1402 and 1403 are determined by the dark pixels at the center and dark pixels on the periphery with the difference between the two spots determined by the number of pixels that are dark. Spots such as those in cells 1406 and 1407 are determined in a like fashion to the spots in cell 1402 and 1403 except that gray is found in the center and surrounding pixels. Adjustments obvious to those skilled in the art are made where the pixel determined to be at a possible spot's center is not in fact at the spot's exact center. For example, if the centroid pixel of a spot differs from the pixel determined to be at the intersection of the column and row containing the spot, the centroid pixel is used as the starting point instead of the pixel at the intersection. In another embodiment, which can be applied where the datatile encodes multiple bits per cell by varying the size of spots or both the size and color of spots (other than variations of color based solely on intensity such as varying levels of gray scale), the method of decoding determines the intensity of each image pixel that may contain all or part of a particular spot, accumulates those intensities and compares the aggregate intensity to ranges of intensities that correspond to varying spot sizes to determine the size of the spot. Where various colors were also used in encoding (e.g., cyan, magenta, yellow and black), the method of decoding determines both an aggregate intensity and color. Where the method of encoding employs multiple spot and cell sizes the recovery process is adjusted so as to determine each cell's center. The manner in which cell centers are determined would generally follow the recovery process described above except as adjusted to reflect the various sizes. Likewise, the recovery process is adjusted to reflect each of the other embodiments of the method of encoding where these requisite adjustments should be apparent to those skilled in the art of imaging. FIG. 19 illustrates the recovery process as applied to a portion of an image of a digitally encoded substrate produced by one embodiment of the invention. It should be understood that FIG. 19 represents a substantially enlarged view for the purpose of illustrating the process. FIG. 19 references the following parts: columns 1901 of markers, the distance from markers to the closest possible spots 1902, spot 1903, cell 1904, center 1905 of the first marker, center 1906 of the next marker displaced horizontally, center 1907 of the next marker displaced vertically, line 1908 through the center of the top row of possible spots, line 1909 through the center of the second row of possible spots, line 1910 through the center of the first column of possible spots, line 1911 through the center of the third row of possible spots, and line 1912 through the center of the last column of possible spots. The substrate has markers located in the image of FIG. 19 in columns 1901 consisting of 4 markers at the right and left perimeters of the image. These markers have dimensions 3 printer pixels wide by 3 printer pixels high. The distance from markers to the closest possible spots 1902 equals 5. Each spot, such as spot 1903, is 3 printer pixels wide by 2 printer pixels high contained in a cell, such as cell 1904, which is 4 printer pixels wide by 3 printer pixels high. Each spot should be understood as occupying the precise center of its corresponding cell. Accordingly, each cell containing a spot has a blank border 0.5 printer pixels wide along the right, left, bottom, and top of the cell. Also, the lines through the centers of any rows or columns of possible spots are the same as the lines through the centers of any corresponding rows or columns of cells. The number of spots per segment, 15, is illustrated in FIG. 19 by the 15 cells, some with spots, some blank, located between the 2 columns of markers. There are 3 rows of possible spots between markers displaced vertically. The information concerning printer pixel sizes and distances, the number of rows between markers and the number of spots per segment is conveyed by the metasector of the preferred embodiment and is therefore known to the recovery process. Having found the first marker, the recovery process finds the center of that first marker, here located at 1905. In the preferred embodiment, pixels are determined to be part of the marker by virtue of having a gray scale level below a threshold. The coordinates of the pixels contained in the marker are averaged after being weighted to determine the center of the marker. The recovery process then determines the center 1906 of the next marker displaced horizontally and the center 1907 of the next marker displaced vertically through the process described above in steps 1802 and 1803 of FIG. 18. Having determined the centers of three reference point markers, the recovery process of the preferred embodiment uses that information, as well as information conveyed by the metasector, to determine the lines through the centers of the columns and rows of possible spot locations. If an image has no skew, the line 1908 through the center of the top row of possible spots is determined to be one-half printer pixel higher than the vertical pixel coordinates of the center 1905 of the first marker and the center 1906 of the next marker displaced horizontally. This determination of the central line through the row is made due to a number of factors First, the top of the first row of possible spots in FIG. 19 is known to be at the same location as the top of the highest markers in FIG. 19, this feature having been established as a convention of the preferred embodiment. Second, while the markers are known to be 3 printer pixels high any spots are known to be 2 printer pixels high—both heights are conveyed by the metasector. The recovery process can accordingly infer that the vertical centers of any possible spots in the first row should be 1 printer pixel down from the tops of the spots (a spot height of 2 printer pixels divided in half) while the vertical centers of markers should be 1.50 printer pixels down from the tops of the markers (a marker height of 3 printer pixels divided in half). Because the tops of the spots are known to be at the same location as the top of the markers, the recovery process can accordingly infer that the vertical centers of the row of possible spots is 0.50 (i.e., 1.50-1.00) printer pixels higher than the markers' centers. Because the adjustment of one-half pixel is expressed in printer pixels and the vertical pixel coordinates of the marker centers 1905 and 1906 are expressed in image (e.g., scanner) pixels, and printer pixel size may differ from image pixel size, the adjustment of one-half must be first multiplied by the image to printer pixel ratio to determine the actual adjustment in image pixels. The ratio of image pixels to printed pixels is determined immediately after decoding the metasector. The dimensions of the metasector in image pixels (e.g., its overall length) are known after decoding it. In addition, the metasector internally expresses the multiple the metasector dimensions are, in printed pixels, of the “base” case (by convention, configured to be printed at 300 dpi, and scanned in at 400 dpi.). The ratio of image pixels to printer pixels is therefore the length of the metasector in image pixels, divided by the product of the multiple and the length of a metasector in printed pixels in the base case. The recovery process determines the centers of subsequent rows of possible spots by reference to the relative printer pixel displacement from the top marker to the next marker displaced vertically. The recovery process first determines the printer pixels down from the center 1905 of the first marker to the center of each such subsequent row of possible spots. The recovery process determines this printer pixel distance by adding one-half the printer pixel spot height, the product of multiplying the printer pixel cell height by the number of rows down a particular row is from the top row, and subtracting one-half the printer pixel marker height. The recovery process would then determine the total printer pixels down from the center 1905 of the first marker to the center 1907 of the next marker displaced vertically. This is here determined to be 9 by multiplying the number of rows of possible spots between markers of 3 by the cell height of 3. A ratio of printer pixels down for each row to the total printer pixels down between centers 1905 and 1907 is then computed. The recovery process then determines the image pixels down between the centers of the first marker and of the next marker displaced vertically, 1905 and 1907, respectively. For each row, the recovery process multiplies the printer pixel ratio for the row by the total image pixels between centers 1905 and 1907. The result is the image pixels down for the central line through each such subsequent row. If for example, the digitally encoded substrate was printed at 300 dpi and scanned at 600 dpi with no skew or imperfections, the line 1909 through the center of the second row of possible spots would be 5 image pixels down from the center 1905 of the first marker. The line 1909 through the center of the second row of possible spots is 2.5 printer pixels down from the center 1905 of the first marker. The recovery process determines this by adding 1 (one-half the printer pixel spot height of 2) plus 3 (printer pixel cell height of 3 multiplied by 1, the number of rows down from the first row to the second row), and then subtracting 1.5 (one-half the printer pixel marker height of 3). The total printer pixels down from the center 1905 of the first marker to the center 1907 of the next marker displaced vertically equals 9, rows per marker of 3 multiplied by cell height of 3. These conclusions regarding printer pixels are inferred from information conveyed in the metasector and therefore known by the recovery process. The ratio of the printer pixels down from the center 1905 of the first marker to the line 1909 through the center of the second row of possible spots to the total printer pixels down between the center 1905 of the first marker and center 1907 of the next marker displaced vertically equals 2.5:9. This ratio is then multiplied by the image pixels down between the centers 1905 of the first marker and 1907 of the next marker displaced vertically. The image pixels down between the centers 1905 of the first marker and 1907 of the next marker displaced vertically should equal 18 (a 600 dpi scan should produce a distance in image pixels double the printer pixels produced by a 300 dpi printer). Multiplying the ratio 2.5:9 by 18 image pixels results in a determination that the line 1909 through the center of the second row is 5 image pixels down from the center 1905 of the first marker. Thus, for example, if the center 1905 of the first marker has a vertical image pixel coordinate of 70 (i.e., 70 image pixels below the top edge of the image produced by the scanner), then the line 1909 through the center of the second row has a vertical image pixel coordinate of 75. Having determined the lines through the centers of the rows of possible spots, the recovery process determines the line 1910 through the center of the first column of possible spots. The line through the center of each column of possible spots is determined by reference to two factors, first, the ratio of the printer pixel distance of that column's central line from the center 1905 of the first marker to the printer pixel distance from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally, and second, the image pixel distance from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally. The recovery process determines the line 1910 through the center of the first column of possible spots to be 8 printer pixels to the right of the center 1905 of the first marker. The recovery process makes this determination by using information conveyed in the metasector. The Marker Width parameter was set at 3, the Marker to Spot parameter was set at 5, and the Spot Width parameter was set at 3. Accordingly, the horizontal distance from the center 1905 of the first marker to the line 1910 through the center of the first column should equal the sum of one-half the marker width, 3×0.5=1.5, the marker to spot distance of 5 and one-half of the spot width, 3×0.5=1.5. This sum equals 8. For each subsequent column, the recovery process adds to this printer pixel distance of 8 the product from multiplying the printer pixel cell width of 4 by the number of columns the subsequent column is displaced from the first column. The recovery process then computes the total distance in printer pixels from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally. This computation is performed by summing the following distances measured in printer pixels as communicated by the metasector: the distance from the center 1905 of the first marker to the center of the first spot, 8 (8=0.5×printer pixel marker width of 3+the distance from markers to the closest possible spots 1902 of 5+0.5×printer pixel spot width of 3), the distance of 56 from line 1910 through the center of the first column of possible spots to the line 1912 through the center of the last column of possible spots (56=cell width of 4×14, the number of columns separating the centers of the first and last columns determined by subtracting 1 from the Spots per Segment of 15), and the distance from the center of the last spot to the center 1906 of the next marker displaced horizontally from the first marker of 8 (8=0.5×printer pixel marker width of 3+the distance from markers to the closest possible spots 1902 of 5+0.5×printer pixel spot width of 3). This sum equals 72. The recovery process then determines the total distance in image pixels from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally. The lines through the centers of the columns of possible spots, in image pixels displaced from the center 1905 of the first marker, are then determined by multiplying this total distance in image pixels by the ratio of the printer pixels from the center 1905 of the first marker to the line through the center of each column of possible spots to the total printer pixel distance from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally. If, for example, the digitally encoded substrate was printed with a 300 dpi printer, scanned with a 600 dpi scanner, and the printing and scanning processes had no imperfections, the line 1910 through the center of the first column of possible spots should be 16 image pixels to the right of the center 1905 of the first marker. Thus, if the horizontal image pixel coordinate of the center 1905 of the first marker is, for example, 110 image pixels to the right of the leftmost edge of the image produced by the scanner, the line 1910 through the center of the first column of possible spots would have a horizontal image pixel coordinate of 126. The total distance from the center 1905 of the first marker to the center 1906 of the next marker displaced horizontally should be 144 image pixels, double the printer pixel distance of 72, because the scanned image should twice as large in pixels as the printout due to a scanner with twice the resolution. This distance of 144 image pixels is multiplied by the ratio 8:72 to determine the horizontal distance in image pixels from the center 1905 of the first marker to the line 1910 through the center of the first column of possible spots. The product, 16 image pixels, is added to the horizontal image pixel coordinate of 110 of the center 1905 of the first marker to produce the horizontal image pixel coordinate of 126 for the line 1910 through the center of the first column of possible spots. A similar methodology is employed to determine the lines through the centers of each subsequent column of possible spots. Having determined the lines through the centers of rows of possible spots and the lines through the centers of columns of possible spots, the recovery process can then look to the intersection of the row and column central lines for each possible spot to determine if a spot is in fact present or absent. Accordingly, the recovery process can thereby determine one bit of the series of digital data values. These determinations may depend on contextual information. Thus, if all the spots in all surrounding cells are present (i.e., “on”), it may very well be that the cell is relatively dark, even though no spot is present. In such a case, an adjustment in the threshold for calling a bit on or off may reduce bit errors. The source code contains one methodology for making these determinations and adjustments. If a nonrectangular spot has been defined, the center of that spot is preferably determined by looking to the centroid of the pixels of any such spot which might exist in a cell. If a nonrectangular cell has been defined, the center is preferably found by locating the cell in a manner similar to locating the center of a rectangular cell, discussed above (including adjustments made for cells placed diagonally), adjusting such determination where the centroid pixel of any spot in such cell is expected (based on what is known about how the cells and spots were formatted) to be different from the center pixel otherwise determined. It should be understood that determining the centers of rows of possible spots and the centers of columns of possible spots can also be determined not by reference to the image pixel/printer pixel ratio but by reference to the ratios determined by dividing the number of rows or columns, as the case may be, that a particular row or column is displaced from a first reference marker by the total rows or columns, as the case may be, between markers. This ratio for each row or column is then multiplied by the total image pixel distance between markers to determine the image pixel displacement of each row or column from the reference markers. This method of determining the center of each row and each column performs most efficiently with an embodiment where there is no distance between markers and the nearest cells—i.e., the Marker to Spot parameter equals 0. For example, where the digitally encoded substrate is formatted and encoded such that there are 3 rows between markers (i.e., Rows per Marker equals 3), the total image pixel distance between the top of a first marker and the top of the next marker displaced vertically equals 21, the top of the first row of possible spots has the same vertical pixel coordinate as the top of the first marker, the image pixel distance between the top and bottom of each spot equals 6 and the vertical pixel image coordinate of the top of the first marker equals 156, the centers of each of the 3 rows can be determined by multiplying 21 by the ratios 0:3, 1:3, and 2:3, the products being 0, 7, and 14, and adding those products to 159 (the vertical pixel coordinate of the top of the first marker plus 50% of the image pixel distance from the top to the bottom of each spot). Thus, the centers of the 3 rows would be at vertical image pixel coordinates 159, 166, and 173. While the recovery process preferably determines the centers of cells and the existence of spots through processes rendered by a computer from an electronic image of a datatile, it should be understood that the recovery process can be employed without reference to an electronic image. Instead, the distinct features of a datatile (e.g., markers and spots) are determined by measuring distances. Distances are preferably determined entirely through automatic means (i.e., without any human intervention). In one such embodiment, a microscope coupled with a measuring device constitutes a mechanical means that automatically determines distance by sensing areas of differing reflectivity. Visual inspection of a datatile provides information from which to conclude the locations of datatile features such as landmarks, markers, cells, and spots, and these conclusions are then used to derive the series of digital data values which can, if appropriate, be used to manually derive some further information, such as text. Visual inspection follows the steps described in FIG. 18, and generally follows that part of the process described by reference to FIG. 19 that involves distances generally and not printer or image pixels or conversions of printer pixel coordinates and distances to image pixel coordinates and distances, it being understood that in a visual inspection embodiment there is no image of a datatile other than the printed datatile itself, and determination of printer pixels (instead of actual markers, spots, etc.) by visual inspection may be cumbersome and unnecessary. A method of decoding employing measurement of distances enjoys many of the same benefits of the preferred embodiment, including use of the metasector to communicate the format parameters used for encoding. A visual inspection embodiment of the method of decoding preferably determines the lines through the centers of rows and columns by reference to actual distances, such as distances in microns. According to this embodiment, and assuming the top of the first row of possible spots next to a first marker has the same vertical coordinate as the top of that first marker, the lines through the centers of rows are determined by first measuring the distance from the top of that first marker to the next marker displaced vertically and dividing that measurement by the number of known rows of cells between each marker and the next marker displaced vertically. The result of this division is multiplied by the number of rows that a row is down from the first row next to the first marker. That product is then added to the sum of one half the spot height plus the vertical coordinate of the top of the first marker. If the assumption that the top of the first row of possible spots has the same vertical coordinate as the top the first marker is invalid, appropriate adjustments are made for each row by adding the distance between the top of the first marker and the top of the first row of possible spots. Lines through the centers of the leftmost and rightmost columns are preferably determined by visual inspection—through mechanical means locating the vertical centers of the top and bottom spots in each of those columns and drawing, physically or conceptually, a line through those spot centers. The lines through the centers of columns in between the first and last columns are determined by measuring the distance between the lines through the centers of the first column of possible spots and the last column of possible spots, dividing that distance by the result derived by subtracting one from the known number of columns between markers, and multiplying that product by the number of columns that each column is horizontally displaced from the first column. The product from that multiplication indicates the distance that the line through the center of each column is horizontally displaced from the center of the first column of possible spots. This system of determining column centers more accurately accounts for printing distortions. Determinations of the numbers of rows and columns known to exist between markers can be made either through visual inspection by mechanical means or, preferably, by first decoding information conveyed by the metasector. The visual inspection embodiment as described in general above can be understood more particularly as following a series of steps applied for each grouping of cells between markers. The steps below are applied to a datatile where a known number of rows exists between the top of each marker and the top of the next marker displaced vertically, and where a known number of columns exists between the left side of each marker and the left side of the next marker displaced horizontally, this knowledge being best conveyed by the metasector. 1. Locate a first marker bordering a first grouping of contiguous cells. 2. Determine the vertical coordinate of the top of the first marker. 3. Locate a second marker being the nearest marker displaced vertically from the first marker. 4. Measure the distance from the top of the first marker to the top of the first row of spots. 5. Locate a third marker being the nearest marker displaced horizontally from the first marker. 6. Determine the height of each spot. This knowledge may also be conveyed by the metasector. 7. Determine the lines through the centers of each of the rows of cells by measuring the distance from the top of the first marker to the top of the second marker, dividing that distance by the number of rows of cells known to exist between markers, and for each of the known number of rows, adding to the vertical coordinate of the top of the first marker the sum of one-half the height of each spot plus the distance from the top of the first marker to the top of the spots in the first row, plus, for each row of cells, the product from multiplying the result of the division by the number of rows that that row of cells is vertically displaced from the first row of cells. 8. Determine the lines through the centers of each of the columns of cells by determining the lines through the centers of the rightmost and leftmost columns of cells located between the first marker and the third markers, determining the horizontal coordinate of the line through the center of the leftmost column of cells, determining the distance between the lines through the centers of the rightmost and leftmost columns of cells between the first marker and the third marker, dividing that distance by the result derived by subtracting one from the number of columns known to exist between markers, and, for each column, multiplying the result of that division by the number of columns that the column is horizontally displaced from the leftmost column, and adding that product to the horizontal coordinate of the line through the center of the leftmost column of cells. 9. For each cell, determine the location of the cell as being the intersection of the lines through the centers of the cell's corresponding row and column. Thus, the location of each cell located between each set of markers (a set of markers being three markers—a marker and the next marker displaced vertically and the next marker displaced horizontally) can be determined through the above steps. These steps would be applied for each set of markers in the datatile. Having determined the locations of all cells, the method of decoding would then determine the contents of the cells to determine the series of digital data values. The above methodology can be applied to the enlarged portion of a digitally encoded substrate illustrated in FIG. 19. If, for example, the distance between the top of the first marker and the next marker displaced vertically equals 900 microns, that distance is divided by 3, the number of rows known to exist between markers, that number being known by virtue of being communicated in the metasector. The result, 300 microns, is multiplied by the number of rows that each row is down from the first row next to the first marker—i.e., 0 for the first row, 300 microns for the second row, and 600 microns for the third row. If each spot is known to have a height of 200 microns, one-half of this height, i.e., 100 microns, is added to the products for each row to determine the distance that the lines through the centers of rows are from the top of the first marker. Accordingly, the line 1908 through the center of the first row of possible spots is 100 microns below the vertical coordinate for the top of the first marker. Line 1909 through the center of the second row of possible spots is 400 microns below the vertical coordinate of the top of the first marker. Line 1911 through the center of the third row of possible spots is 700 microns below the vertical coordinate of the top of the first marker. The embodiment then determines the lines through the centers of columns of possible spots. Visual inspection through mechanical means should determine the line 1910 through the center of the first column of possible spots and the line 1912 through the center of the last column of possible spots. If, for example, the distance between lines 1910 and 1912 equals 5,600 microns, that distance is divided by 14, the number of known columns between markers, 15, less one. The result of that division, 400 microns, is multiplied by the number of columns that each column is horizontally displaced from the first column of possible spots. Accordingly, lines through the centers of the first five columns of possible spots, for example, are 0, 400, 800, 1,200, and 1,600 microns horizontally displaced from the line 1910 through the center of the first column of possible spots. Other embodiments of the method of decoding involving visual inspection determine the lines through the centers of possible rows and columns through other means. In one such embodiment, the centers are determined entirely by visual inspection—e.g., by visually observing through mechanical means patterns of spots, the location of each cell is possible and determination of the presence or absence of a spot is thereby possible without measuring distances. The process above for recovering data from a digitally encoded substrate, a portion of an example of which is illustrated in FIG. 19, assumes that cells have been formatted into horizontal rows and vertical columns and that the printing and scanning processes produced little or no skew. The recovery process of the preferred embodiment makes adjustments for diagonal formatting or unintended skew. The recovery process makes such adjustments by determining the lines through the centers of rows of possible spots and the centers of columns of possible spots where both such lines are diagonal or skewed, expressed as having both vertical and horizontal displacements. The method of determining relative distances in printer pixels is the same as though no skew existed. These ratios are then applied to displacements between markers that are both vertical and horizontal. The line through the center of a row of possible spots is a diagonal or skewed line parallel to a line between the centers of a first marker and the next marker displaced primarily horizontally, but partially vertically. The line through the center of a column of possible spots would be a diagonal or skewed line parallel to a line between the centers of a first marker and the next marker displaced primarily vertically, but partially horizontally. In the case where cells are at perfect 45 degree angles to each other, the recovery process treats series of cells as though occurring in rows and columns, where the lines through the centers of rows and columns have equal horizontal and vertical displacements. In a further embodiment, encryption and decryption may be integrated into the methods of encoding and decoding of the invention. FIG. 20 illustrates the method of encoding of this further embodiment. Note that in one embodiment of the method of encoding, this would occur after the compression of the digital data (processing block 2003). Note that each of the processing blocks in FIG. 20 are performed as their similarly named counterparts in FIG. 2, with the exception of encryption processing block 2004. In one embodiment, encryption is provided by exclusive-ORing the initial data with a pseudo-random sequence generated using a secret key as a seed. Note that in this case, the decryption process (as described below) is simply exclusive-ORing the data with the same pseudo-random sequence. Note that this type of encryption process is not a perfectly secure method of data encryption because of the short key length used to seed pseudo-random sequences and the fact that the same key is likely to be used on more than one message. There are well-known methods to attack this type of encryption. In order to obtain secure data through encryption, a one time pad can be employed in place of the pseudo-random sequence. A one time pad comprises a series of randomly generated bits that are known to both parties (i.e., the “encrypting” party and the “decrypting” party) and is only used once in the encryption process. In a one time pad, the key length is equal to the message length and may be more than 100,000 bits. Since the one time pad is used once, it is not susceptible to the same attacks which are used on pseudo-random sequences. In another embodiment, encryption processing could be performed using the digital encryption standard (DES) or the RSA algorithm In the RSA algorithm, digital data is encrypted using two prime numbers which are multiplied together, as is well-known in the art. It should be noted that any digital encryption method may be employed with the present invention. In the preferred embodiment, one method of encryption is used. In a further embodiment, the user can choose, as a further format parameter, from a variety of encryption methods. If encryption is integrated into the method of encoding, then decryption must be included in the method of decoding. One embodiment of the method of decoding of the present invention that includes decryption is shown in FIG. 21. Note that each of the processing blocks in FIG. 21 are performed in the same manner as their similarly named counterparts in FIG. 16, with the exception of decryption processing block 2104. After error detection and correction, the data undergoes decryption (processing block 2104). The decryption processing 2104 is the inverse of the encryption applied in the method of encoding (FIG. 20). In one embodiment, the decryption process requires the use of the same key used during encryption. By using the same key, the original data is recreated. When the methods of encryption (and decryption) of the present invention are being integrated into the methods of encoding and decoding, the present invention also provides data information to be transferred using plain paper in a manner which preserves its privacy, authentication and/or limited accessibility. In the present invention, this privacy can easily be obtained through the use of a key or code known to the user(s) when encryption and decryption of a document occurs. Another useful application of the present invention is the authentication of a document. Specifically, the present invention could be used to authenticate signatures on paper documents or facsimile transmissions. A further use of the present invention is to limit access to a selected audience. Information could be widely published, as in, for example, newspapers or other mass media, with access limited to those designated to receive the secret key where such designation could occur before or after the encryption process. These keys could be distributed, for example, pursuant to subscriptions or some other method of raising revenue. Methods of Transmitting Digital Data FIG. 22 is a block diagram illustrating a method of transmitting digital data. A data source provides computer files or other digital data. The method of transmitting digital data selects format parameters (step 2201) for the formatting 2202 of the computer files or other digital data. Formatting 2202 formats the computer files or other digital data into a series of digital data values and formats that series of digital data values into a series of cells where each cell contains at least one bit of information from that series of digital data values. Formatting 2202 is done in accordance with the format parameters selected in step 2201. In the preferred embodiment formatting 2202 includes defining a cell size (i.e., width and height), and a spot size (i.e., width and height), such sizes defined as pixels of the encoding device, whether a printer, a facsimile machine, a fax/modem using facsimile software, or some other encoding device. The dimensions of a cell in the preferred embodiment are at least as large as the corresponding dimensions of any spot that might occupy the cell. It should be understood that the details concerning the computer files or other digital data, selection of format parameters (step 2201), and formatting 2202, are generally the same as the method of encoding described and illustrated above, including as described by reference to FIG. 2. Formatted digital data is then distributed, step 2203. The manner of distribution may include any manner for the distribution of digital data in electronic or physical form. Embodiments of electronic distribution include facsimile, satellite transmission, telephonic transmission, cable transmission, and high speed line transmission (such as T1 or ISDN). Embodiments of physical distribution include postal delivery, hand delivery, courier or other contract delivery service as well as any other means for moving the digitally encoded substrate. In the case of physical distribution, the formatted digital data is first encoded onto a substrate, where the manner of producing the substrate is as described above, including as illustrated in and described by reference to FIG. 2. Step 2201 preferably selects format parameters optimal for the means of distribution used. The DEDS program source code stores the appropriate format parameters in lookup tables in the setdefs.c file. Transmission by facsimile machine typically requires larger spot and cell sizes than transmission by fax modem. Where the manner of distribution is more likely to introduce damage to the formatted digital data, format parameters should reflect larger spot and cell sizes than less damaging means of distribution. Distribution by printing and physical distribution may require larger or smaller spot and cell sizes than electronic distribution, depending on the printer/scanner combination, the electronic distribution method or other factors. Thus, the selection of format parameters allows flexibility to consider not only the manner of encoding and decoding but also the manner of distribution. Once the formatted digital data is distributed, the recipient decodes that formatted digital data, step 2204. The details of the decoding are as described above in the method of decoding, including as illustrated in and described by reference to FIGS. 16, 17, 18, and 19. In the case of physical distribution and in the case of facsimile transmission to a facsimile machine, step 2204 of the preferred embodiment includes first scanning the digitally encoded substrate to produce an image which is then decoded. In the case of electronic distribution of the formatted digital data, step 2204 of the preferred embodiment does not require an initial scan because the digital data is already in electronic form. In any case, step 2204 of the preferred embodiment decodes the formatted digital data from an electronic image of that formatted digital data. A preferred embodiment of decoding step 2204 is that method described by reference to and illustrated in FIGS. 17, 18, and 19, and, where formatted digital data has been placed on a substrate, FIG. 16. The result derived from step 2204 is the original computer files or other digital data. FIG. 23 illustrates in further detail the preferred embodiment of a method of transmitting digital data. The initial processes are similar to the steps illustrated in FIG. 22 and described above. The initial source of digital data is preferably computer files stored on the fixed disk drive of a personal computer, but could also be other sources of digital data such as a floppy disk, or another digitally encoded substrate. The computer files contemplated include data files not associated with any particular application software, data files associated with a particular application software, and executable files, i.e., files that perform functions once invoked. The method of transmitting digital data then provides for selection of format parameters, step 2301, and formatting, step 2302, these steps being the same as those described as steps 2201 and 2202, above. The formatted digital data is then distributed (step 2303). The recipient of the digitally encoded substrate then subjects the digitally encoded substrate to decoding process 2304. Decoding process 2304, comparable to step 2204 discussed above, is as described in detail and illustrated above. The preferred embodiment of the method of transmitting digital data then determines process step 2305) whether the original digital data included a computer file designed to be run automatically following decoding. Whether a computer file is designed to be run automatically is a matter originally determined by the person creating the original file, quite possibly the person producing the formatted digital data. If it is an independently executable DOS/Windows® file (Windows is a product of Microsoft Corporation of Redmond, Wash.), then it has a distinct file name extension, such as “.exe”. Furthermore, the program will be automatically executed if a flag in the header portion of the first datasector is so set. In the preferred embodiment, the person producing the formatted digital data has the option to select setting of this flag. For example, the computer file may be communications software that activates the recipient computer's modem, places a telephone call to a predesignated electronic bulletin board (or other remote computer such as a network server or Internet service provider), establishes a connection between the recipient's computer and the electronic bulletin board (or other remote computer), and downloads a further computer file from the electronic bulletin board (or other remote computer) to the recipient's computer. If process step 2305 determines that the original digital data includes a computer file designed to be run automatically, step 2306 commences execution of that computer file. Execution of the computer file may also follow or precede the storing on the recipient computer's fixed disk other computer files contained within the datatile, possibly including files available for the automatically executed file. It should be understood that an application launched automatically may be stored and operated solely on the recipient's computer, or may be an application all or part of which involves establishing communication with other computers. Thus, for example, the application launched automatically may be a communications program that activates the recipient computer's modem to telephone a remote computer and establish a connection with that remote computer, and then turn. control over to the recipient of the datatile for further action. As a further example, a datatile contains both a computer file of a document and instructions to automatically print the document on the printer attached to the recipient's computer. Thus, the recipient gets a hardcopy printout of the underlying document through a minimum of effort. If, alternatively, the datatile does not include a computer file designed to be launched automatically, the method of transmitting digital data determines whether the datatile contains files associated with a particular application (process step 2307). A file can be associated with a particular application when that file has been created by a particular application software or can be run by a particular application software. If the file is intended to be executed as input into an application, the appropriate application is also determined in Windows by the file name extension, along with standard mappings from extensions to applications (this mapping is stored in the win.ini file). For example, a file with the name “letter.wri” is typically assumed to be a Microsoft® Write document, as it ends with the extension “.wri”, and that is usually mapped in win.ini to Microsoft Write. Similar to the process for automatically executing a file, if a file is intended to be launched as part of an application, a flag in the header portion of the first datasector is set, with the setting preferably being selected by the user. For example, a word processing software package is an application software that creates files containing documents. If that document file is associated with the word processing software and if the word processing software is pre-installed, choosing to open the document file actually launches the word processing software and then loads (i.e., opens within the word processing software for further processing) the document file. If the datatile contains a file associated with a particular application, and if the recipient's computer has that particular application software pre-installed, and if the recipient chooses to launch the application software (process step 2308) then step 2309 commences execution of the application software and loads the associated file contained in the datatile. Alternatively, the recipient's computer produces the original computer files or other digital data for purposes such as being stored on the recipient computer's fixed disk. FIG. 24 is a block diagram of a further embodiment of the method of transmitting digital data, one which includes facsimile transmission. The data source can be computer files or other digital data. It should be understood that the nature of computer files or other digital data is not limited in scope and can include any source described previously for other embodiments such as files that can be launched automatically or files associated with a particular application software that can be launched automatically. The method of decoding then provides for selection of format parameters, step 2401, and formatting, step 2402, these steps being the same as those described as steps 2201 and 2202, above. The present embodiment, contemplating transmission of digital data by facsimile transmission, then determines in step 2403 whether the person transmitting digital data transmits by facsimile machine or, alternatively, by fax/modem connected to a computer. If the transmission is by fax/modem, the digital data as formatted in step 2402 is transmitted over a telephone line consistent with the method of transmitting any computer generated image by fax/modem. If, alternatively, the person transmitting digital data uses a fax machine, the digital data formatted in step 2402 is printed onto a substrate, step 2404. That digitally encoded substrate is then processed in step 2405 through a facsimile machine, the processing comprehending those same substeps exercised in any facsimile machine transmission: feeding the document, in this instance the digitally encoded substrate, into the facsimile machine, entering the telephone number and causing the facsimile machine to dial the inputted number. Whether by facsimile machine or through a fax/modem, the transmission sent over a telephone line is fundamentally the same—an image of a datatile one example of which is illustrated in FIG. 8. It should be noted, however, that minor differences might occur as a result of different format parameters. It should also be noted that a further embodiment comprehends, based on the sender's knowledge (or information available to the sender's computer), determined in advance or determined contemporaneously, of the recipient's currently activated equipment, the possibility of direct transmission of digital data from modem to modem. In those instances where possible and advantageous, this further embodiment employs direct modem to modem transmission in order to achieve transmission speeds faster than by facsimile transmission through a fax/modem. The digital data sent pursuant to this further embodiment is either the formatted digital data or the original computer files or other digital data. The image of formatted digital data having been sent by facsimile transmission, process step 2406 of the present embodiment then determines, at the recipient's end, whether the recipient receives facsimile transmissions by facsimile machine or, alternatively, through a fax/modem connected to a computer. If the recipient receives facsimile transmissions by fax machine, the formatted digital data as transmitted through the telephone line is printed by the facsimile machine, producing a digitally encoded substrate 2407. Digitally encoded substrate 2407 is then scanned, process step 2408, using a scanner connected to a computing device capable of producing an image in electronic form of the digitally encoded substrate 2407 (the scanner used for this purpose may include the fax machine itself where the fax machine first receives a transmission and prints the substrate and the recipient then feeds the substrate back through the fax machine sending an image of the substrate to a computer through the computer's fax/modem). The image of the digital data, whether produced by facsimile machine and scanned into electronic form or instead received by fax/modem directly in electronic form, is decoded in step 2409, such decoding being as described and illustrated above, including the method illustrated in and described by reference to FIGS. 16, 17, 18, and 19. In the present embodiment the result of the decoding process 2409 is the reconstruction of the original computer files or other digital data. In further embodiments, the result is the automatic launching of executable files or the automatic launching of an application software with the transmitted file loaded within that application software, it being understood that the embodiment illustrated in FIG. 24 involves additional means of transmitting digital data that does not in any way limit what can be done with that digital data once decoded. In a further embodiment of a method of transmitting digital data incorporating the facsimile transmission in accordance with the method illustrated by FIG. 24, digital data is sent through a fax back system. In accordance with this embodiment, a person desiring to receive digital data telephones a number established by a person that desires to distribute the digital data. The person desiring to transmit digital data connects the telephone line to a fax/modem connected to a computer or other means capable of both receiving input from a touch tone telephone and then sending out a facsimile transmission. The person desiring to receive digital data, having established a telephone connection, inputs information by use of touch tone telephone signals, such information including, at a minimum, the facsimile number of the person desiring to receive digital data and, if a choice is available, the digital data desired. The computer or other means capable of both receiving touch tone telephone input and transmitting facsimile transmission, then telephones (without further human intervention) the facsimile telephone number of the person desiring to receive digital data and establishes a facsimile connection with the facsimile means of the person desiring digital data. Having established this facsimile connection, the computer or other means capable of both receiving touch tone telephone input and transmitting facsimile transmission, transmits an image of the formatted digital data in accordance with embodiments of the invention described previously. A similar embodiment employs a fax-on-demand capability—the image of formatted digital data is transmitted by facsimile during the telephone call placed by the person desiring to receive digital data. In a further embodiment of the method of transmitting data, information recorded on a substrate includes digital data as well as human readable information where the digital data includes one or both of data needed to have the computer display appear the same or similar to the human readable information appearing on the substrate and data that causes information to appear on the computer display together with hyperlinks to further sources of information. FIG. 25 illustrates an example of a substrate and the process according to this embodiment. A paper substrate 2501 has printed upon it human readable text and graphics as well as encoded digital data Paper substrate 2501 represents how the embodiment might be used for marketing purposes as in marketing flyers, advertising appearing in print media or other marketing materials. More particularly, the printed paper has three main components. First, at top, human readable text informs the reader of the purpose of the marketing material and the contents of the encoded digital data. Second, in the middle of paper substrate 2501, surrounded by a dashed line, an entry form prompts the reader for the information needed to enter a contest. Third, at the bottom, a datatile 2502 includes encoded digital data. The reader of paper substrate 2501 may then process (step 2503) the datatile, it being understood that the reader may also proceed to enter the contest by manually completing the entry form as printed without use of a computer and without processing 2503 of the datatile. Processing 2503 includes the substeps of scanning, decoding and running of the datatile, which substeps are as further described and illustrated above. Datatile 2502 in paper substrate 2501 would preferably include a computer file designed to be run automatically upon completion of the decoding process of the invention. The computer file could be composed using, for example, hypertext markup language (HTML). Datatile 2502, once scanned, produces an image 2504 on the computer display (e.g., 2504 represents a computer monitor with the image as the user would see it). Image 2504 has two primary components. First, image 2504 duplicates on the computer display the entry form appearing on paper substrate 2501. Datatile 2502 preferably contains or invokes word processing software allowing the reader to enter and edit through keyboard input the information needed to enter the contest. Second, image 2504 contains at its bottom a series of “icons”, delineated areas of the display which, if the user selects by click of a mouse or otherwise, causes the computer to commence some further action. The datatile is encoded with digital data that includes means for navigating to the subsets of information indicated by each icon illustrated in image 2504. In the instance of image 2504, there are 4 icons. The first, labeled “CONTEST RULES”, will, when selected by the user, cause the computer to erase the current image on the display and in its stead produce an image of the contest rules. The second, labeled “ACME COMP. DEALERS”, will, when selected by the user, cause the computer to erase the current image on the display and in its stead place an image of a list of Acme computer dealers on the display. The third, labeled “FAX ENTRY FORM”, will, when selected by the user, cause the computer to activate its fax/modem and send a facsimile transmission of an image of the entry form appearing on the display, as altered by the user with keyboard input. The fourth, labeled “PRESIDENTS VIDEO CLIP”, will, when selected by the user, cause the computer to erase the current image on the display and in its stead commence a video clip on the display. Thus, FIG. 25 illustrates an embodiment including both automatic links to further sources of data and “reverse WYSIWYG”—i.e., instead of printing on paper the image appearing on a computer display (What You See Is What You Get), the image printed on paper appears on the computer's display. This feature is accomplished by virtue of the datatile being encoded with instructions such that displaying means will display an image comparable to the human readable information printed on substrate 2501. It should be understood that the digital data of each underlying icon application may derive from the datatile, from some other source including other digitally encoded substrates, remote computers connected telephonically by modem, compact disks, hard disk, floppy disk, or from a combination of the datatile and another source. For example, referring back to FIG. 25, selecting “CONTEST RULES” may cause the computer to produce on its display a list of contest rules derived from the datatile while selecting “PRESIDENT'S VIDEO CLIP” may cause the computer to access a video clip from a compact disk, or to instead search for and access the video clip from various alternative sources—for example, first determining whether the video clip exists on the computer's hard disk, looking next on a compact disk, then invoking telephonic communication with an online service, bulletin board, an internal or external network or the Internet, accessing the video clip from the fist available source. In one embodiment, uniform resource locators (URLs) are used in the instructions directing the computer to access digital data. It should be further understood that because the invention acts as a channel for digital communication the ability to link the printed page to the electronic world can be accomplished in any manner in which instructions can be digitized. Thus, while FIG. 25 illustrates the use of icons, automatic links to further data sources can also occur through hypertext—i.e., specially formatted text which when selected by the click of a mouse button causes a jump to some further source of data. Also, HTML is just one method known to those skilled in programming for accomplishing the linking of paper to the electronic world. Other methods include the object linking and embedding (“OLE”) facility of Windows® Version 3.1 produced by Microsoft Corporation of Redmond, Wash. and the facility of Microsoft Plus® for Windows 95® to place an icon in a document which, when selected by click of a mouse button, automatically activates the host computer's modem and Internet access software, calls and establishes contact with the host computer's Internet access provider, and navigates to the URL specified for the icon (i.e., the URL specified by the person creating the icon for the document). The linking of paper with the electronic world is preferably accomplished using the methods of encoding and decoding described above. These methods of encoding and decoding make the linking feasible due to many of the unique and advantageous features including the density of data possible and the wide range of acceptable printers and, more importantly, acceptable off-the-shelf scanning devices. It should be further understood that while the invention serves as a link between paper and the electronic world, the electronic connection can also be just a digital path to an analog source. For example, the digital data can include a way of navigating, a priori, through a voice mail system where the digital data includes a company's main telephone number, a directory of employees of a company, the particular telephone extensions for each of those employees and computer instructions to activate a calling device (such as a modem) place a telephone call to the company's main number and navigate through the company's voice mail system to the telephone of the employee selected by the user before the call is made. By decoding the digital data, activating the program contained in the digital data, and making a selection of employee, the user can avoid the usual time consuming method of navigating a company's voice mail system. The method is especially advantageous for subsequent calls to the same company because the digital data would presumably be stored on hard disk after decoding. Thus, the digital data serves as a link between two analog sources—the user and the company employee. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to the formatting of digital data into a pattern, encoding that pattern onto a substrate where appropriate, and decoding that pattern to reconstruct the digital data. While computers have substantially enhanced the manner in which society conveys and works with information, paper remains the favored manner of conveying information. Indeed, the proliferation of personal computers has resulted in a proliferation of paper. Yet, no technology to date has significantly integrated the digital environment of the computer with the visual environment of written media. Instead, computers primarily direct human readable information to be placed on paper. It would be greatly advantageous to have digital data placed on paper and other media currently used for human readable information. Such a method would link the largely separate environments of paper and computers. The method could store and convey digital data with greater efficiency, ease, speed, and lesser cost than any other available method. The method would have the further advantage of being the only significant method to integrate digital data with visual media. As described below, the prior art discloses methods for placing machine readable information on media such as paper. However, none of these prior art methods, and, to the best of the inventors' knowledge, no other technology currently available to personal computer users allows for the placement of a significant amount of machine readable information on the media. Other practical limitations of these prior art methods forestall significant commercial success. One example of digital information being stored on paper is the use of bar codes. Because standard bar codes are one dimensional, they are severely limited in the number of bars that may be used to store digital information. The limits are somewhat greater in the case of two-dimensional bar codes but these limits are still far more restrictive than the theoretical limits of any particular printer, and bar codes are designed for use with specialized scanners. For more information on bar codes, see “Information Encoding with Two-Dimensional Bar Codes,” authored by T. Pavlidis, J. Schwartz and Y. Wang, COMPUTER, June 1992. U.S. Pat. No. 5,245,165, issued to Zhang, discloses a self-clocking glyph code for encoding dual bit digital values of a logically ordered sequence of wedge-shaped glyphs that are written or otherwise recorded on a hardcopy recording medium in accordance with a predetermined spatial formatting rule. The dual bit values are encoded in the relative rotations of the glyphs. The glyphs are decoded by determining a bounding box for each glyph and determining either which quadrant of the box contains its center of mass or by comparing the relative locations of the shortest and longest runs of ON pixels. To reliably present a single bit of data, each glyph comprises a large number of pixels, and thus this technology requires considerable space on the recording medium. The technology does not optimize the use of space or computational resources by presenting a bit in the most compact fashion. U.S. Pat. No. 5,337,362, issued to Gormish, discloses a method for transferring digital information to and from plain paper. The method involves storing data in at least one box on the paper, the box including a frame or border having alternating pixels along the left and right edges for use in determining the current location of a horizontal line of pixels when reading the data and having pixels in corners of the frame to determine horizontal spacing between pixels within the box. Binary data is formatted in rows within the box, wherein a bit of digital data is depicted by the presence or absence of an ink dot. The method disclosed by Gormish provides the ability to represent 60 kilobytes of data on a single page. Although Gormish allows for the storage of more data on a page than can currently be stored in text form, it has several problems which prevent it from being useful in a commercial environment. For example, Gormish requires a thick frame to be placed around the entire data box in order to locate the box, which limits the ability to place the data in convenient shapes and sizes on a substrate. Also, Gormish requires placement of pixels in a rigid fashion, without provision of guideposts to determine where to search for the presence or lack of a dot other than on the borders of the boxes. Further, Gormish provides ink placement in an ink dot that covers an entire square and that square covers an area 16 times larger than the finest optical resolution of any given scanner (e.g., Gormish discloses printing dots at 50 dpi while scanning is performed at 200 dpi), thereby limiting the density of data which can be represented on each page. In addition, although the method disclosed in Gormish may be suited for certain printers and scanners of great precision it does not adequately accommodate for deviations from perfection in printing and scanning found in off-the-shelf printers and scanners designed for use with personal computers. Operating in an environment of personal computers and their peripherals, this rigidity ultimately translates into loss of data density, higher error rates, slower processing speed, all of these deficiencies, or, worse yet, complete inability to use the method in given computer environments. Other known methods disclose manners in which a single cell contains more than one bit of information through the use of gray scales. One such method is disclosed in U.S. Pat. No. 5,278,400, issued to J. Appel (1994). This patent discloses the encoding of multiple bits in a single cell by marking, preferably by binary marking, a predetermined number of pixels in a cell irrespective of the location of the pixels within the cell. The number of pixels marked corresponds to the data to be encoded. The markings on the substrate are decoded by detecting the gray scale level at each pixel of the cell, converting that gray scale level to a corresponding digital signal and summing all of the digital signals corresponding to all of the pixels in the cell. This method requires discrete determination of where the cell begins and ends. The gains from encoding multiple values in a single cell are lost by requiring larger cells, relative to straightforward binary printing. Gormish also discloses the encoding of multiple values in one cell through the use of gray scale inks. This method employs rigid formatting and printing described above and similarly relies on rigid decoding mechanisms that may be optimized for a particular combination of a printer and a scanner, but not for all such combinations. These methods give back the data density and savings in computational resources that the use of multiple colors should provide. U.S. Pat. No. 5,329,107, issued to D. Priddy and R. Cymbalski (1994), discloses a method to dynamically vary the size, format, and density of machine readable binary code. The method disclosed in that document provides a code formed of a matrix and allows variation in the amount of data in the matrix by printing on two sides of the perimeter of the matrix broken line patterns of alternating darkened and lightened areas. The method determines the amount of data in the matrix from the product of the number of lightened areas and darkened areas of the first side and the number of lightened areas and darkened areas of the second. The method determines size of the matrix by measuring the other two sides of the perimeter, formed of two solid black lines. While the method allows the encoder of information some flexibility in accommodating the different potentials of higher and lower resolution scanners, the method is rigid in darkening entire square cells. The method also lacks regular reference markers and generally limits information about the encoding, conveyed in the matrix, to size and density. The method therefore lacks the flexibility needed to address the peculiarities of every combination of printer and scanner. Hence the method can not produce the greatest density of data or the most efficient manner of decoding for every combination of printer and scanner. There is a need to substantially increase the amount of data that can be stored within a given amount of paper in order to compete with other channels of storage and communication such as floppy disks and digital communication by telephone. Employing binary printing (i.e., storing one bit per cell), the most basic and least dense printing process, the invention is capable of storing data at densities several times as great as any other paper based method known to the inventors. Utilizing printing methods which store more than one bit per cell, such as color printing, the theoretical density limits increase substantially. While Gormish discloses the ability to store 60 kilobytes on a single page using a 400 dpi scanner, the invention is capable of encoding and decoding over 160 kilobytes of data error free (i.e., by utilizing error correction) using just a 300 dpi scanner. With the aid of compression, this single page can contain over 500 kilobytes of text. With a 600 dpi printer and a 600 dpi flatbed scanner, the invention can encode data in cells {fraction (1/200)} inch square (i.e., 0.005 inch×0.005 inch), successfully encoding and decoding over 300 kilobytes of data before the benefit of any compression, in excess of 1 megabyte of text with the aid of compression. Utilizing more precise printing processes and a 600 dpi flatbed scanner, the invention encodes and decodes over 7,000 bytes per square inch (over 1,100 bytes/cm 2 ), over 20,000 bytes of text using compression. Utilizing an ordinary thermal fax machine as a scanner (achieving a binary scan of approximately 200 dpi), the invention encodes and decodes over 50 kilobytes of data, over 150 kilobytes of text with the aid of compression. All of the above densities are accomplished utilizing binary printing. The invention also conveys advantages for any particular printer. For example, using an ordinary thermal fax machine the invention can print over 230 kilobytes of data, over 675 kilobytes of text with compression, on an 8.5 by 11 in. piece of thermal fax paper. The invention can then successfully decode that data error free. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to solve the problems discussed above present in prior art systems for representing digital data on a substrate. It is another object of the present invention to greatly increase the density at which digital data can be represented on a substrate. It is another object of this invention to overcome the limitations of prior art through a method that writes and reads digital data on paper and other media using off-the-shelf personal computers and peripherals, and achieves the full carrying capacity these off-the-shelf components can sustain. It is another object of the invention to determine and enable the features and parameters that contribute to density of information on a printed substrate, and to enable full generality in formatting and decoding along the dimensions identified. This satisfies in turn the ultimate, practical goal: achieving the maximum density possible for any particular combination of printer and scanner. This comes about because that point of maximum density can always be found in the multi-dimensional space so defined. It is another object of the present invention to provide flexibility in printing digital data onto a substrate along with other information. These and other objects of the invention are achieved by a method of formatting digital data into a pattern where the pattern comprises a number of cells (i.e., predetermined spaces in the pattern) with known dimensions where each cell conveys at least one bit of data by expressing one of at least two logical states where one logical state is expressed by the presence of spot with a given set of attributes in the cell and a second logical state is expressed by the absence of a spot with those attributes from the cell, and where the size of spots may be different from the size of cells containing the spots. Generally speaking, in accordance with the invention, a method of formatting data into a pattern in an optimal fashion is provided. The preferred embodiment of the invention provides for the placement of ink on paper. The preferred embodiment allows the person providing data to format the placement of digital data. This flexibility in formatting the placement of digital data allows the person providing data to optimize for any particular combination of encoding device and scanner. The method of encoding allows the person providing data to format the placement of ink in a fashion that best reflects the printer's capabilities to place ink in a designated area. The method of encoding also allows for formatting designed to consider the strengths and limitations of the target audience of scanners. The features that support encoding information on the printed substrate, and its effective decoding via a scanner, fall under two heads. First, there are dark regions on the substrate, which the current invention terms “spots,” whose presence or absence in a specified region represents digital bits. Second, there are guideposts, which the present invention terms “markers,” that serve to identify the location of spots on the printed substrate—a function known in the art as “clocking.” The present invention explicitly decouples these two features, allowing them to be varied independently, so that each may be optimally configured for its distinct purpose. The current invention also permits each to be varied across all the dimensions (e.g., those defining size, spacing, and frequency) that affect the density of information on the printed substrate, while supporting its effective decoding. This full generality allows the optimum match for a particular printer and scanner always to be selected, formatted, and decoded. The method of the present invention allows the person or computer encoding data to select the size, in pixels, of both the cell containing a bit of information and the size of the printed spot where a spot is required. The preferred embodiment of the method of encoding provides a bit of one value by placing a spot of the chosen size in the cell of the chosen size. The method provides a bit of the opposite value by leaving the cell of the chosen size blank. In accordance with the invention, the size of the spots and of the cells can be varied in both the width and height directions. The method of the present invention also allows the person or computer system encoding data to select the size and locations of markers. In accordance with the invention, the size and location of the markers can be flexibly altered to achieve reliable clocking with the minimum amount of space and computation time. The method of the preferred embodiment provides information about the encoding process through use of a “metasector”, a header physically separate from the main body of data. The purpose of providing a metasector is to facilitate decoding the main body of data. In this embodiment, the metasector is itself an instance of the general pattern by which information is stored in the invention. This metasector is preferably printed at a resolution which can be easily and reliably scanned and interpreted. It is also given a predictable and relatively rigid format, which makes it straightforward to decode in the absence of detailed information about the printing process and environment which generated the encoded data. This metasector contains information about the printing process and environment that is then used to decode the main body of data. The somewhat rigid format of the metasector frees the main body of the data from rigidity in its own format, allowing it the greatest flexibility in achieving maximum density. The metasector, encoded at a relatively low resolution, contains information communicated to the remainder of the method in order to decode information at a higher resolution. The information included in the metasector includes, inter alia, the size of the data spots printed, the size of the cells containing data spots, the printing process used to print spots and the size and relative location of markers, if any. Allowing flexibility in the size and placement of data spots in cells greatly increases density of data and improves the speed and accuracy of determining whether a bit is on or off. The fundamental purpose behind defining spot size independently is twofold—first, to compensate for printer deficiencies and, second, to compensate for scanner deficiencies. Within types of printers, such as 300 dot-per-inch (“dpi”) laser printers, there is variation in both the ability to place ink at a given location and the ability to keep ink within the spot designated by that location. For example, printers have varying degrees of “dot gain”—the tendency of most printers to place ink beyond the purported boundaries of the pixel. Dot gain, and the problems it causes, can be exacerbated when the printing process employed goes through multiple steps. If, for example, the printing process involves producing film from a print, a plate from film, and copies from the plate, increasing amounts of dot gain can occur in each step. A spot is preferably allowed to be defined to be smaller than its cell (i.e., the space that is supposed to contain the spot) simply to prevent spots from spilling over to adjacent cells. Even with perfect printing, however, it would be important to allow smaller spots than cells, because of a second phenomenon. Scanners characteristically “leak” dark intensities from one pixel to a directly adjacent pixel. That is, if a pixel is directly over a dark region on the printed substrate, and an adjacent pixel is not, the intensity of the adjacent pixel is nonetheless suppressed to a darker value. When spots completely fill in their cells, the cells must be made larger to compensate for this tendency of scanners. If they are not made larger, the neighboring cell when blank may not differ enough in intensity from the dark cell to be discriminated as blank. Making it possible to configure spots to be smaller than cells generally allows cells to be smaller while supporting correct discrimination between dark and white cells. Of course, it is possible in principle that a given printer (or a like device) may characteristically print smaller spots than defined, or a given scanner (or a like device) may “leak” bright intensities—in which case it would be useful to define spots to be marginally larger than the cells they occupy (or, alternatively, to print spots in reverse video.) Between types of scanners or types of printers, such as between a 360 dpi inkjet printer and a 600 dpi laser, the degree of variation expands significantly. Laser printers have a greater precision in the placement of ink, and 600 dpi printers place ink more accurately than a 360 dpi printer. The invention provides a method critical to optimization of ink placement based on these variations. The ability to vary the dimensions of spots and cells in both horizontal and vertical directions also serves to maximize the density of information. For example, with a 200 dpi thermal fax printer, and a 400 dpi scanner, the invention can encode and decode a pattern with cells of 1×2 pixels containing spots of 1×2 pixels, thus encoding over 100 kilobytes of data on a single page. However, a 400 dpi scanner cannot reliably decode a pattern with spots of 1×1 pixels printed at 200 dpi. Since the next step up from 1×1 is 1×2 (or, equivalently, 2×1), the most compact representation is employing the 1×2 cells. If the technology could allow for only square cells, the next step up would be 2×2 cells, which would be only half as compact. A powerful use of the invention, beyond its ability to communicate and store information (documents, software, graphics, etc.), is as an enabling technology for other technologies. One of the great limiting factors in permitting most consumers to fully exploit their PCs is that the PC possesses simply too many distinct functionalities that must be learned. This is indeed a problem that promises to get only worse as the PC itself develops greater capabilities. Even today, a PC user may have fax and data communication software on the user's PC, and access to the Internet, and the ability to use the PC as a telephone, and many other functionalities. Yet it is a rare user who will know how to utilize all of these functionalities. The present invention can be used to encode on paper an arbitrarily complicated batch file, script file, application file, or executable file that can effectively navigate the user through all the complexities involved in each function the PC can perform. By a simple scan of a datatile, for instance—as easy as running a copier—all such functions can be invoked. A datatile can contain both the identity of the application to be invoked—e.g., data communication, fax communication, Internet access—and the sequence of actions and data that that function requires—e.g., the phone number that must be dialed, the account number of the user, the password that must be entered, the particular address on the Internet sought, and/or a flag for the particular function that should be performed when access is granted. In effect, the datatile enables paper to become the user interface, instructing the user as to the functions that will be performed—e.g., a bill will be paid over the Internet, or a fax back will be initiated. The scan becomes the single thing that the user must learn to do: all other functions can be performed automatically. This spares the unsophisticated user the perhaps overwhelming task of learning how to invoke these functions, and saves the sophisticated user from the tedium of entering the point clicks and detailed information any of these functions demand. Several features of the invention's methods of encoding and decoding make practical for the first time the enabling of many further, simplifying, technologies. The ability to significantly increase density of data allows far more complicated instructions to be placed in any given amount of space. The ability to accommodate a wide audience of printers and scanners allows access to the greatest number of potential users. The ability to vary the shape, dimensions, and location of the encoded digital data on the substrate allows the greatest flexibility in formatting the digital data alongside other information (such as text or graphics) on the substrate. Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing descriptions. | 20040503 | 20121009 | 20050210 | 72247.0 | 38 | LE, THIEN MINH | VARIABLE FORMATTING OF DIGITAL DATA INTO A PATTERN | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,837,908 | ACCEPTED | Spray coating device for spraying coating material, in particular coating powder | A spray apparatus for coating material, in particular for coating powders, contains a spray outlet (4) spraying the coating material, a shaping air outlet (10) in the form of a plurality of holes (14) shaping the spray jet (8) and an ambient-air passage (50) radially configured between the spray outlet (4) and the holes (14) to aspirate ambient air by means of the flow suction effect of the spray jet (8) and/or of the shaping air flow (11). | 1. Spray apparatus for coating materials (6), in particular for coating powders, containing a coating powder duct (2); a spray outlet (4) at the downstream end of the coating material duct (2) used to spray the coating material (6) onto an object to be coated; a shaping air outlet (10) for shaping compressed air, said outlet (10) running near the spray outlet (4) and around the flow path of the coating material (6), apart from the flow path, and being designed to generate from compressed air, a shaping air flow (11) enclosing the coating material spray jet (8); where the shaping air outlet (10) is constituted by a large number of holes (14) in a body (16), said holes being configured in distributed manner around the flow path of the coating material (6) and separated from latter and point forward to the coating material spray jet (8), characterized by an ambient-air passage (50) which is radially inwardly offset relative to the holes (14) and which runs from an ambient-air inlet (52) situated behind the body (16) containing the holes (14) to an air outlet (54) situated in front of the body (16) containing the holes (14); and which further runs in the form of a single component or in the form of several apertures around and apart from the flow path of the coating material (6), whereby the ambient air (56) can be aspirated from the rear air inlet (52) through the ambient-air passage (50) toward the forward air outlet (54) by means of the flow suction effect of the coating material spray jet (8) and/or the flow suction effect of the shaping air flow (11). 2. Spray apparatus as claimed in claim 1, characterized in that the body (16) is undivided at the holes (14). 3. Spray apparatus as claimed in either of claim 1, characterized in that there are at least ten or more holes (14). 4. Spray apparatus as claimed in claim 1, characterized in that the mutual distance (18) between adjacent holes (14) as seen in the circumferential direction around the flow path of the coating material (6) is larger by a factor of at least five or more, preferably at least ten or more than the aperture size of the holes (14) in said circumferential direction. 5. Spray apparatus as claimed in at claim 1, characterized in that the aperture cross-section of each hole (14) is less than 2 mm2, preferably less than 1.0 mm2, more preferred yet less than 0.5 mm2 or less than 0.3 mm2. 6. Spray apparatus as claimed in claim 1, characterized in that the holes (14) exhibit a circular cross-section. 7. Spray apparatus as claimed in claim 1, characterized in that the body (16) is a hose or a tube enclosing the flow path of the coating material (6) while being apart from it, and in that the holes (14) are present in the wall of the hose resp. the tube. 8. Spray apparatus as claimed in claim 1, characterized in that the outlet end of the holes (14) is configured in rearwardly offset manner relative to the spray outlet (4) at the upstream side. 9. Spray apparatus as claimed in claim 1, characterized in that all holes (14) or sets of holes (14) are each pneumatically connected to a compressed-air manifold duct (34) which is fitted with at least one compressed-air inlet aperture (62). 10. Spray apparatus as claimed in claim 9, characterized in that the aperture cross-section of the manifold duct (34) and the aperture cross-sections of the holes (14) are mutually matched in a manner that the same quantity of compressed air per unit time may issue from all holes (14). | The present invention relates to a spray apparatus for coating materials, in particular for coating powders, as defined in the preamble of claim 1. In particular the present invention relates to a spray apparatus comprising at least one high-voltage electrode electrostatically charging the coating material. However it also applies to spray apparatus which are not designed to electrostatically charge coating materials. Spray apparatus of this kind are known for instance from the patent documents U.S. Pat. No. 4,324,361; DE 34 12 694 A1; U.S. Pat. No. 4,505,430; U.S. Pat. No. 4,196,465; U.S. Pat. No. 4,347,984 and U.S. Pat. No. 6,189,804. Spray apparatus fitted with shaping-air outlets of annular gap geometry incur the drawback that if said gap is supported along its longitudinal direction at several places, manufacturing constraints will preclude uniform gap size. Such a drawback however is averted by using boreholes instead of an angular gap, especially if the body containing said boreholes remains undivided at the borehole site. Illustratively such spray apparatus are shown in the patent documents EP 0 767 005 B1; EP 0 744 998 B1 and DE 34 31 785 C2. The objective of the present invention is to attain equal or better efficiency in controlling the coating material spray flow and the quantity of coating material required for such coating while using less shaping air per unit time. This problem is solved by the features of claim 1 of the present invention. Accordingly the present invention relates to a spray apparatus for coating materials, in particular coating powder, said spray apparatus comprising a coating material duct; a spray outlet at the downstream end of the coating material duct to spray the coating material onto an object to be coated; a shaping air outlet for compressed shaping air, said outlet being configured near the spray outlet and around the flow path of the coating material, said outlet being separate from the flow path and designed to generate from compressed air a shaping air flow enclosing the coating material spray jet; the shaping outlet being constituted by a large number of holes in a body, said holes being configured in distributed manner around the coating material flow path and being apart from latter and pointing toward the coating material spray jet, characterized by an ambient air passage which is configured a distance from said holes and is radially offset inward, said passage extending from an ambient air intake situated behind the body containing said holes to an air outlet situated in front of said body, said passage running integrally or in the form of several apertures around and separately of said flow path, so that, on account of flow suction caused by the coating material spray jet and/or caused by the flow suction of the shaping air flow, the ambient air may be aspirated from the rearward air intake through the ambient air passage into the forward air outlet Other features are defined in the dependent claims. The present invention is elucidated below by an illustrative and preferred embodiment and in relation to the appended drawings. FIG. 1 schematically shows a cutaway view of the invention (not to scale), FIG. 2 is a front view of the spray apparatus of FIG. 1 in the direction of the arrows II. FIGS. 1 and 2 show only one of many embodiment modes of the present invention. The spray apparatus shown in FIGS. 1 and 2 is designed to spray coating powder, though it may also be used to spray liquid coating materials. The spray apparatus contains a coating material duct 2; a spray outlet 4 at the downstream end of said coating material duct 2 in order to spray the coating material 6 in the form of a flow 8 onto an (omitted) object to be coated, and a shaping air outlet 10 of compressed shaping air 12, said outlet 10 running around and apart from the flow path of the coating material 6 in order to generate from the compressed shaping air 12 a shaping air flow 11 enclosing the coating material spray jet 8. The shaping air outlet 10 consists of a large number of holes 14 through the body 16 which is undivided at said holes, these holes being distributed around and apart from the flow path of the coating material 6. In the embodiment shown in FIGS. 1 and 2, all the holes 14 are configured at identical circumferential distances 18 from one another and concentrically with the axial center axis 20 of the flow path of the coating material 6. Instead of being circular, said holes also may assume other geometries, for instance being ovally or polygonally framed, around the axial center axis 20 in order to generate a particular cross-sectional form of the spray flow 8. The equidistant space 8 between the holes 14 is sufficiently small that the shaping air jets 22 exiting from them will converge into a cross-sectionally annular shaping air flow, preferably immediately after the holes 14 and before they impact the spray flow 8, but at the latest at the point of impact with the spray flow 8. Seen in the direction of coating material spraying, the holes 14 point forward and preferably parallel to the axial center axis 20, and preferably they are present in a forward pointing end face. In another embodiment mode they also may point obliquely to the axial center axis 20, either toward or away from it. The cross-sectional shape and size of the spray flow 8 may be adjusted by the direction of the holes 14 relative to the axial center axis 20 and by the pressure of the compressed air 12. One or preferably several electrodes, for instance 23, 24 and/or 25 are configured in or near the coating material flow path or at or near the spray outlet 4 and is/are connected to a high voltage generator 26 for the purpose of electrostatically charging the coating material 6. The high voltage generator 26 may be mounted outside the spray apparatus or, as shown in FIG. 1, within it. From AC, said voltage generator produces a high DC voltage for instance in the range of 4 kv to 150 kv. The spray apparatus is fitted with a low AC connector 28 to apply a low voltage AC to the high voltage generator 26; further with a coating material connector 30 to apply coating material to the coating material duct 2; and a shaping compressed air connector 32 to apply compressed shaping air 12 to a manifold duct 34 mutually connecting the holes 14 on their upstream side. At least ten or more holes 14 are present, for instance at least twenty, thirty or forty, or any arbitrary large number. The circumferential equidistant spacing 18 between the holes 14 is at least twice as large as or larger than the aperture size 38 of the holes 14 as seen in the circumferential direction about the axial center axis 20. Preferably however such a multiplying factor shall be larger, illustratively being five or more, for instance ten or more. The cross-section of the aperture of each hole 14 is less than 2 mm2, for instance being less than 1.0 mm2 or even better less than 0.5 mm2 or less than 0.3 mm2. The holes should be made as small as possible in practice in order to generate thereby the least possible quantity per unit time of shaping air flow with which to attain a rapidly moving, high-energy shaping air jet 22 at each hole 14 and hence a rapidly moving, high-energy shaping air flow 11. As a result, with low quantities of air per unit time, the cross-sectional shape and size of the spray flow 8 can be effectively controlled. Because the cross-section of the particular holes 14 is very small, a uniform quantity of flowing shaping air per unit time shall be attained at all holes even when all holes 14 exhibit the same size cross-section and the manifold duct 34 and the cross-section of exhibits a constant cross-section over its full length. The small cross-section of the holes 14 implements uniform distribution of compressed air over the full length of the manifold duct 34. The sum of all the cross-sections of all holes 14 is less, for instance being only half as large, as the flow cross-section of the manifold duct 34. Preferably the holes 14 each shall be circular in cross-section though they also may exhibit a different cross-section, for instance being cross-sectionally polygonal. The holes 14 may be manufactured during the making of the body 16 of which they are part while the latter is being produced, illustratively by injection molding the body 16 and simultaneously manufacturing the holes 14. In another preferred embodiment mode, the holes 14 are made by being drilled into the body 16. The body 16 may be made of a rigid material, for instance being a metallic or a plastic tube, or it may be made of an elastic or flexible material, for instance a hose illustratively made of rubber or plastic. In the embodiment of FIGS. 1 and 2, the body 16 is a hose or a tube into which were drilled the holes 14 and of which the inside space constitutes the manifold duct 34. The body 16 may be part of the housing 40 or it may be a housing component affixed to this housing 40 of the spray apparatus 2, or, as indicated in FIGS. 1 and 2, it may be an additional body 16. This additional body 16 is mounted in the spray apparatus housing 40, though it also may be mounted on another element in turn affixed to the housing, for instance on a front terminal component 42 constituting the spray outlet 4 or containing it and affixed to the housing 40. In the preferred embodiment mode, the discharge end of the holes 14 is offset backward upstream of the spray outlet 4. In other embodiment modes, however, the discharge ends of the holes 14 may be situated in the same transverse plane or downstream of this transverse plane wherein is also contained the spray outlet 4. The essential point is that the shaping air flow 11 shall enclose the spray flow 8 so tightly at the spray outlet 4 that no coating material particles may escape from the flow of coating material radially outward or rearward onto the spray apparatus's outer surfaces. The holes 14 can be manufactured with substantially greater accuracy at a given size than can be gaps circumferentially running about the axial center axis 20. Moreover the holes are less exposed to the danger of thermal changes in size and external mechanical effects such as shocks when impacting other objects. The body 16 fitted with the holes 14 is affixed by one or several elements 44—preferably by mechanical webs with spaces between them, directly or by intermediate means—to the housing 40, as a result of which the body 16 rests on the housing 40. In a preferred embodiment mode of the present invention, an ambient air passage 50 is mounted at a radially inward offset from the holes 14 and runs from an ambient air intake 52 situated behind the body 16 fitted with holes 14 to an air exit 54 situated in front of the body 16, said passage 50 being in the form of one or more slots or other apertures and running around but apart from the flow path of the coating material 6, and therefore also around the axial center axis 20, as a result of which ambient air 56 may be aspirated through said ambient air passage 50 on account of the suction caused by the coating material spray flow 8 and/or by the suction caused the compressed shaping jets 22 and the shaping air flow 11 from the rear air inlet 52 to the forward air outlet 54. This ambient air passage 50 precludes the coating material particles from flowing back onto the spray apparatus's outer surfaces and on its body 16 fitted with the holes 14. In this manner said component are protected against soiling. In the above shown embodiment mode, all holes 14 are connected for (pneumatic) flow by means of the compressed air manifold duct 34 to a compressed air inlet aperture 62. In an omitted embodiment mode, two or more sets of such holes 14 may be mutually connected for flow by means of a segment of the manifold duct 34, the said segments being isolated as regards flow from one another and each segment being fitted with its own compressed air intake aperture 62. The latter design allows finer adjustment of the quantity of compressed air per unit time issuing from the holes 14, preferably to the extent that the same rate issues from all holes, or, in yet another embodiment mode, that defined and different rates shall issue. In both embodiment modes, the aperture cross-section of the manifold duct 34 (or its mutually separate segments) and the aperture cross-sections of the holes 14 are matched to each other in a manner that the same quantity of compressed air per unit time may issue from all holes 14. The quantity of compressed air per unit time issuing from the holes 14 depends on the flow impedance in the manifold duct 34 between the intake aperture 62 and the particular hole 14. Identical quantities of compressed air per unit time may be attained at all holes 14 in that either the manifold duct 34 sees an ever lesser impedance in the direction from the nearest hole 14 to the most remote hole 14 or preferably in that as the distance between the hole and the compressed air intake aperture 62 increases, said holes shall exhibit a larger aperture cross-section. In this instance that hole 14 subtending the shortest flow path from the inlet aperture 62 shall exhibit the smallest aperture cross-section and that hole 14 which is the most remote shall exhibit the largest aperture cross-section. However such designs are laborious and expensive. Still they may be used in the present invention. On the other hand the aperture cross-sections of the invention are so small as discussed above that even in the absence of such designs an identical or nearly identical shaping air flow is attained at all holes 14. The embodiment modes of the present invention are applicable to all kinds of coating material spray apparatus, especially those for powder coating materials, illustratively spray apparatus comprising a spray outlet in the form of a circularjet nozzle or a fan jet nozzle, those assuming cylindrical or funnel-like geometries, with or without baffles 60, and also to spray apparatus of which the spray outlet 4 is fitted with a rotary element or consist of such. Moreover the present invention is applicable to corona spray apparatus generating corona discharges at least one of the high voltage electrodes 23, 24, 25, and furthermore so-called tribo spray apparatus wherein the particles of the spray coating material are electrostatically charged by being rubbed within the coating material duct 2. The present invention allows attaining homogeneous air distribution of the shaping compressed air around the spray flow 8. Only a small quantity of compressed air per unit time is required for that purpose. The shaping air flow 11 produced in the manner of the present invention stabilizes the spray flow 8 which assumes the form of a spray cloud rather than a spray jet. This spray flow or spray cloud 8 is substantially less sensitive to air flows in a coating cabin than in the state of the art. This feature offers the further advantage that the coating powder's efficiency of deposition for a given object to be coated and the quality of coating, i.e. coating uniformity, shall be substantially raised. Spray apparatus of this kind are conventionally denoted as “spray guns”, both when they comprise a grip for manual operation and when they are designed as straight or angled automated spray guns held by an appropriate support, for instance a robot, a stand or a fixed support. | 20040504 | 20090120 | 20050106 | 60911.0 | 1 | NGUYEN, DINH Q | SPRAY COATING DEVICE FOR SPRAYING COATING MATERIAL, IN PARTICULAR COATING POWDER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,837,919 | ACCEPTED | Security cover for passive restraint buckle | A security cover is provided for a belt-type passive restraint system including a buckle with a tab and a receiver. The cover includes a slot for receiving the buckle tab and an enclosure for receiving the buckle receiver. An optional retainer assembly can be provided for retaining the cover on the buckle receiver or the belt. The buckle is released by inserting a key through a corresponding keyhole formed in a tab end of the cover. | 1. A security cover for a belt-type passive restraint system with a buckle including a tab attached to a first belt and a receiver attached to a second belt and selectively engageable with the tab and including a release button for disengaging same, which cover comprises: a body with a tab end and a buckle end; said body forming an enclosure adapted to receive the receiver; said body tab end including a slot for said tab and a keyhole; and said keyhole being generally aligned with said release button with said receiver positioned in said enclosure. 2. The security cover according to claim 1, which includes: a retainer selectively connected to send cover and to one of said receiver and said second belt, said retainer selectively retaining said receiver within said cover enclosure. 3. The security cover according to claim 2, which includes: said cover including an aperture in proximity to said buckle end; said retainer comprising a pin with a proximate end mounting a head and a distal end; and said retainer further comprising a lock mounted on said cover in proximity to its receiver end and adapted for selectively capturing said retainer pin distal end with said buckle receiver in said cover enclosure and said retainer pin in an inserted positioned thereof. 4. The security cover according to claim 3, which includes: said second belt forming a loop attached to said buckle receiver and receiving said retainer pin in its inserted positioned. 5. The security cover according to claim 4, which includes: said keyhole comprising a first keyhole; and said cover body having a second keyhole in proximity to said receiver end and located in proximity to said retainer pin lock and adapted for providing access thereto. 6. The security cover according to claim 2 wherein said retainer includes: a cable with a proximate end fixedly attached to said cover and a distal end; and a retainer cable lock mounted on said cover receiver end and adapted for selectively locking said cable distal end with said cable extending through said belt second portion. 7. The security cover according to claim 2, which includes: said retainer comprising a bolt and a nut threadably mountable thereon; and a pair of bolt apertures located in the post relation on said cover body in proximity to its receiver end and adapted for selectively receiving said bolt in its inserted positioned. 8. The security cover according to claim 1 wherein said retainer includes: said cover body having a base and an access lid hingedly mounted on the base and movable between a closed position retaining said buckle receiver in said cover enclosure and an open position releasing same. 9. The security cover according to claim 10, which includes: said cover body having a front panel located at said tab end, a back panel located at said receiver end, a top panel, a bottom panel and opposite side panels; said back panel including a notch adapted for selectively receiving said belt first portion with said buckle receiver located in said enclosure; and said access lid including portions of said top and side panels. 10. The security cover according to claim 9, which includes: said access lid being hingedly mounted on said cover base portion along one of said side panels; an access lid lock mounted on said cover body and located in proximity to said cover receiver end; and an access lid lock keyhole in said cover in proximity to said access lid lock and adapted for providing access thereto. 11. The security cover according to claim 9, which includes: said access lid being hingedly mounted on said cover base portion along one of said side panels; an access lid lock mounted on said cover body and located in proximity to said cover receiver end; and an access lid lock keyhole in said cover in proximity to said access lid lock and adapted for providing access thereto. 12. The security cover according to claim 2, which includes: said cover body having a front panel located at said tab end, a back panel located at said receiver end, a top panel, a bottom panel and opposite side panels; said cover including an aligned pair of lock hasp apertures in said side panels and in proximity to the cover receiver end; and said retainer comprising a padlock with a hasp selectively receivable in said hasp apertures. 13. The security cover according to claim 2, which includes: said cover body having a front panel located at said tab end, a back panel located at said receiver end, a top panel, a bottom panel and opposite side panels; said cover including an aligned pair of lock hasp apertures in said top and bottom panels and in proximity to the cover receiver end; and said retainer comprising a padlock with a hasp selectively receivable in said hasp apertures. 14. The security cover according to claim 2, which includes: said cover body having a front panel located at said tab end, a back panel located at said receiver end, a top panel, a bottom panel and opposite side panels; a pair of aligned apertures in said side panels; and said retainer comprising a chain with a closure link adapted for selectively closing said chain in a continuous configuration; and said chain extending through said aligned apertures and through said belt receiver portion with said retainer in a retaining positioned thereof. 15. The security cover according to claim 2, which includes: said cover body having a front panel located at said tab end, a back panel located at said receiver end, a top panel, a bottom panel and opposite side panels; a pair of apertures in one of said side panels and in said top panel in proximity to said body receiver end; and said retainer comprising a flexible locking tie strap with a closure adapted for closing same; and said tie strap extending through said apertures and through said belt receiver portion with said retainer in a retaining positioned thereof. 16. The security cover according to claim 2, which includes: a key with a generally cylindrical configuration; and said keyhole having a generally round configuration adapted to receive said key. 17. The security cover according to claim 2, which includes: a key with a generally cylindrical shaft and a lever extending radially therefrom; and said keyhole having a configuration with a circular portion adapted to receive said shaft and a slot adapted to receive said lever. 18. A security cover for a belt-type passive restraint system with a buckle including a tab attached to a first belt and a receiver attached to a second belt and selectively engageable with the tab and including a release button for disengaging same, which cover comprises: a body with a tab end and a buckle end; said body forming an enclosure open at said buckle end and adapted to receive the receiver; said body tab end including a slot for said tab and a keyhole positioned above said slot; said body including a pair of side panels, a top panel and bottom panel; a retainer assembly including a retainer pin with a proximate end, an enlarged head mounted on said proximate end and a distal end with a slot; said body having a retainer pin receiver in one of said side panels, said retainer pin receiver selectively receiving said retainer pin; said retainer assembly including a retainer pin lock associated with the other said side panel and adapted for capturing the distal end of said retainer pin; said retainer pin being adapted for extending through or across said belt adjacent to said buckle receiver for retaining said buckle receiver within said security cover enclosure; and said tab end keyhole being generally aligned with said release button with said receiver positioned in said enclosure. 19. The security cover according to claim 18 wherein: said retainer pin receiver comprises a first retainer pin receiver; said body includes a second retainer pin receiver located in the other said side panel and transversely aligned with said first retainer can receiver; said retainer pin includes an aperture in its distal end; and said retainer assembly includes a flexible spring clip selectively receivable in said retainer pin distal end aperture adjacent to said other side panel with said retainer pin extending through said retainer pin receivers whereby said retainer pin is retained in said body adjacent to its receiver end. 20. A security cover for a belt-type passive restraint system with a buckle including a tab attached to a first belt and a receiver attached to a second belt and selectively engageable with the tab and including a release button for disengaging same, which cover comprises: a body with a tab end and a buckle end; said body forming an enclosure adapted to receive the receiver; said body tab end including a slot for said tab and a tab end keyhole positioned above said slot; said tab end keyhole including a round portion and a slot extending radially from said round portion; said body including a pair of side panels, a top panel and bottom panel said buckle end including a panel with a belt opening adapted to selectively receive said second belt with said buckle receiver positioned in said cover enclosure; said body including a lid comprising at least a portion of said a top panel and said side panels; a hinge mounting said lid on said top panel or a respective side panel; a lid lock mounted on said body and adapted for locking said lid and a close positioned thereof; said body including a lid keyhole aligned with said lid lock with said cover and its lock position and adapted for receiving a key for releasing said lid lock cover; said tab end keyhole being generally aligned with said release button with said receiver positioned in said enclosure; and a key including a generally cylindrical shaft receivable in said keyhole round portion and a lever extending radially from said shaft and receivable in said keyhole slot. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to vehicle safety equipment, and in particular to a security cover for seat belt buckles. 2. Description of the Related Art Passive restraints for occupants are standard safety equipment in many vehicles. They generally include seatbelts, shoulder harnesses and other equipment, which restrain the occupants for protection from “secondary” collisions. Various combinations and configurations of seat belts and shoulder harnesses have been developed, generally with the objectives of providing safety, comfort and convenience to the occupants. For example, both separate and combined seatbelts and shoulder harnesses have been provided in vehicles. Such belt-type passive restraints generally include buckles comprising tabs and receivers, which are selectively engaged by the occupants when securing and releasing same upon entering and exiting the vehicle. Vehicles are often used for transporting individuals with special security considerations. Law enforcement officers are often required to transport individuals in custody under security conditions requiring restraint in order to prevent escape. Incidents have arisen wherein criminal suspects, convicted inmates and accomplices have involved law enforcement officers in serious and even deadly altercations in the course of being transferred between detention facilities, courthouses, etc. It is therefore desirable to provide vehicle operators and others who are responsible for the safety and security of such passengers with locking restraints. Criminal suspects and inmates are commonly handcuffed during such procedures, but nevertheless pose serious hazards of escape and flight while in transit. Another criteria for such equipment is portability from vehicle-to-vehicle and adaptability to a wide range of vehicles. For example, in connection with extradition and other proceedings requiring travel to other jurisdictions, law enforcement officers are often required to use locally-available vehicles. A compact, universally-adaptable, portable restraint locking system would be highly beneficial to officers in connection with discharging such duties. However, heretofore there has not been available a passive restraint locking system with the advantages and features of the present invention. SUMMARY OF THE INVENTION In the practice of the present invention, a security cover is provided for a belt-type passive restraint system including a buckle with a tab selectively received in a tab receiver. The tab receiver includes a release button for releasing the tab whereby the passive restraint system is opened. The security cover includes a slot for receiving the tab and a keyhole located thereover for passing a key to the release button for releasing same. An optional restraint assembly can be provided for retaining the security cover on the belt receiver. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 show a prior art security cover for the buckle of a belt-type passive restraint system. FIG. 3 is a prospective view of a security cover for the buckle of a belt-type passive restraint system, including a retaining pin. FIG. 3A is a perspective view of a modified retaining pin for the security cover. FIG. 4 is a perspective view of a security cover comprising another aspect of the invention, including a retaining cable. FIG. 5 is a perspective view of a security cover comprising another aspect of the invention. FIG. 5A is a longitudinal, cross-sectional view of the security cover shown in FIG. 5, installed on a seatbelt and shoulder harness buckle. FIG. 6 is a perspective view of a security cover comprising another aspect of the invention, including a retaining bolt and nut. FIG. 7 is a perspective view of a security cover comprising another aspect of the invention, with a hinged lid. FIG. 8 is a perspective view of a security cover comprising another aspect of the invention, with another type of hinged lid. FIG. 9 is a perspective view of a security cover comprising another aspect of the invention, with a padlock. FIG. 10 is a perspective view of a security cover comprising another aspect of the invention, with another type of padlock. FIG. 11 is a perspective the end of a security cover comprising another aspect of the invention, including a chain retainer. FIG. 12 is a perspective view of a security cover comprising another aspect of the invention, including a cable-tie type retainer. FIG. 13 is a perspective view of a key and a keyhole. FIG. 14 is a perspective view of a key and a keyhole with alternative configurations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Introduction and Environment As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, down, front, back, right and left refer to the invention as oriented in the view being referred to. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning. Referring to the drawings in more detail, the reference numeral 2 generally designates a security cover embodying the present invention. Without limitation on the generality of useful applications of the security cover 2, it is shown with a belt-type passive restraint system 4 including a buckle receiver 6 mounted on the end of a belt 8, which forms a loop 10. The receiver 6 includes a release button 12, which can be pressed to release a buckle tab (not shown) from the receiver 6 for releasing the passive restraint system 4. The passive restraint system 4 can comprise a seatbelt, a shoulder harness, a combined seatbelt-and-shoulder harness or some other type of system with a buckle. The buckle receiver 6 can also be mounted on a semi-rigid cable or attached directly to the body of a vehicle. Moreover, other configurations of passive restraint systems, buckles and release buttons can be accommodated by different aspects of the present invention. II. Security Cover Preferred Embodiments FIG. 3 shows the security cover 2, which includes an open receiver end 14, a tab end 16 with a tab slot 18 and a keyhole 44, opposite side panels 20, a top panel 22 and a bottom panel 24, which collectively define an enclosure 26. A retainer assembly 28 includes a retaining pin 30 with a proximate end 32 mounting an enlarged head 34 and a notched distal end 36. The retaining pin 30 is adapted for passing through a retaining pin aperture 38 and one of the side panels 20 and into a retaining pin lock 40 mounted in the enclosure 26 adjacent to the receiver end 14. A retainer keyhole is provided in the top panel 22 for actuating the retaining pin lock 40. In operation, the buckle receiver 6 is inserted into the cover enclosure 26 and the retaining pin 30 is inserted through the aperture 38, the belt loop 10 and into the retaining pin lock 40. Alternatively, the retaining pin 30 can be positioned over or under the belt loop 10 and retain the buckle receiver 6 within the cover enclosure 26. The seatbelt or shoulder harness tab is inserted through the slot 18 to secure the restraint system 4. Releasing the restraint system 4 is accomplished by inserting a key 42 through a keyhole 44 formed in the cover tab end 16 above the slot 18. FIG. 3A shows a flexible clip 46 adapted for insertion through a flexible clip aperture 48 whereby the retaining pin 30 can be releasably secured in the cover 2 and through the belt loop 10, as an alternative to the retaining pin lock 40. FIG. 4 shows another aspect of the invention with a retaining cable 52 attached at a proximate end 54 to a respective cover side panel 20. A cable distal end 56 mounts a hook 58 selectively receivable and a cable lock 60 actuated through a lock keyhole 62. FIG. 5 shows another aspect of the invention with an unsecured cover 64, adapted for placement over the buckle receiver 6 and retained in place by the buckle tab. FIG. 5A shows the cover 64 positioned on the buckle receiver 6 with a buckle tab 63 locked therein. A key 65 is inserted through a keyhole 67 and is pushing the release button 12 whereby the tab 63 will be released from the buckle receiver 6. FIG. 6 shows another aspect of the invention with a retaining bolt 66 threadably mounting a retaining nut 68 and adapted for placement through aligned apertures 70 formed in the top and bottom panels 22, 24. The retaining bolt 66 is adapted for selectively retaining buckle receiver 6 within the cover enclosure 26. FIG. 7 shows another aspect of the invention with a modified cover including a base 74 hingedly mounting a lid 76 and collectively forming a belt opening 78 adapted for selectively capturing the belt 8. The lid 76 can be selectively locked in a closed position by a suitable lid lock 80 adapted for actuation through a lid keyhole 82. FIG. 8 shows a cover 84 comprising another aspect of the invention with a modified lid 86. FIG. 9 shows another aspect of the invention including a padlock 88 with a hasp 90 extending through aligned hasp apertures 92 in the cover side panels 20. FIG. 10 shows another aspect of the invention including a padlock 94 with a hasp 96 extending through aligned apertures 98 in the cover top and bottom panels 22, 24. Fig 11 shows another aspect of the invention including a chain 102 with a connecting link 104 and multiple apertures 106 formed in the cover whereby various combinations of the apertures 106 can receive the chain 102 for securing same to a buckle receiver 6 or belt 8. FIG. 12 shows a similar aspect of the invention with a flexible plastic cable or wire tie 108 in place of the chain 102. FIG. 13 shows a key 110 with a generally cylindrical configuration and a keyhole 112 with a corresponding round configuration. FIG. 14 shows an alternative key 114 with a generally cylindrical shaft 1 16 and a lever 118 extending radially therefrom. An alternative configuration keyhole 120 includes a round portion 122 adapted to receive the key shaft 116 and a slot 124 adapted to receive the lever 118. The key 114 can comprise the type widely used by law enforcement officials for handcuffs. Other alternative configurations can be utilized for the keys and keyholes, including various geometric shapes. It is to be understood that the invention can be embodied in various forms, and is not to be limited to the examples discussed above. Other components and configurations can be utilized in the practice of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to vehicle safety equipment, and in particular to a security cover for seat belt buckles. 2. Description of the Related Art Passive restraints for occupants are standard safety equipment in many vehicles. They generally include seatbelts, shoulder harnesses and other equipment, which restrain the occupants for protection from “secondary” collisions. Various combinations and configurations of seat belts and shoulder harnesses have been developed, generally with the objectives of providing safety, comfort and convenience to the occupants. For example, both separate and combined seatbelts and shoulder harnesses have been provided in vehicles. Such belt-type passive restraints generally include buckles comprising tabs and receivers, which are selectively engaged by the occupants when securing and releasing same upon entering and exiting the vehicle. Vehicles are often used for transporting individuals with special security considerations. Law enforcement officers are often required to transport individuals in custody under security conditions requiring restraint in order to prevent escape. Incidents have arisen wherein criminal suspects, convicted inmates and accomplices have involved law enforcement officers in serious and even deadly altercations in the course of being transferred between detention facilities, courthouses, etc. It is therefore desirable to provide vehicle operators and others who are responsible for the safety and security of such passengers with locking restraints. Criminal suspects and inmates are commonly handcuffed during such procedures, but nevertheless pose serious hazards of escape and flight while in transit. Another criteria for such equipment is portability from vehicle-to-vehicle and adaptability to a wide range of vehicles. For example, in connection with extradition and other proceedings requiring travel to other jurisdictions, law enforcement officers are often required to use locally-available vehicles. A compact, universally-adaptable, portable restraint locking system would be highly beneficial to officers in connection with discharging such duties. However, heretofore there has not been available a passive restraint locking system with the advantages and features of the present invention. | <SOH> SUMMARY OF THE INVENTION <EOH>In the practice of the present invention, a security cover is provided for a belt-type passive restraint system including a buckle with a tab selectively received in a tab receiver. The tab receiver includes a release button for releasing the tab whereby the passive restraint system is opened. The security cover includes a slot for receiving the tab and a keyhole located thereover for passing a key to the release button for releasing same. An optional restraint assembly can be provided for retaining the security cover on the belt receiver. | 20040503 | 20060124 | 20051103 | 97533.0 | 1 | SANDY, ROBERT JOHN | SECURITY COVER FOR PASSIVE RESTRAINT BUCKLE | MICRO | 0 | ACCEPTED | 2,004 |
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10,837,966 | ACCEPTED | CONNECTOR ELEMENTS INCLUDING PROTECTIVE MEMBER FOR PREVENTING CONNECTION TO CERTAIN CONNECTOR ELEMENTS | An electrical device includes a power supply that is switchable between a first mode and a second mode. The power supply includes a first connector element of the power supply, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively. The power supply also includes a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. The electrical device also includes electrical equipment powered through the power supply. | 1. A power supply arrangement for an electrical device, comprising: a power supply that is switchable between a first mode and a second mode; a first connector clement of the power supply, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively; and a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. 2. The power supply arrangement as set forth in claim 1, further comprising a switch for switching the power supply between the first mode and the second mode, the guard member being movable between the first and the second positions upon moving the switch between first and second switch positions corresponding to the first and second modes. 3. The power supply arrangement as set forth in claim 2, wherein the guard member includes a protrusion that blocks a portion of the first connector element. 4. The power supply arrangement as set forth in claim 3, wherein the first connector element includes a female connector element and the second connector element includes a male connector element, and wherein the second connector element is specially configured by providing a recessed area to receive the protrusion. 5. The power supply arrangement as set forth in claim 3, wherein the first connector element includes a male connector element and the second connector element includes a female connector element, and wherein the second connector element is specially configured by providing a recessed area to receive the protrusion. 6. The power supply arrangement as set forth in claim 1, wherein the guard member includes a protrusion that blocks a portion of the first connector element. 7. The power supply arrangement as set forth in claim 1, wherein the first mode is a 220V mode, and the second mode is a 110V mode. 8. The power supply arrangement as set forth in claim 7, wherein the specially configured second connector element includes a 110V power cord. 9. The power supply arrangement as set forth in claim 8, wherein the guard member includes a protrusion that blocks a portion of the first connector element. 10. The power supply arrangement as set forth in claim 9, wherein the second connector element is specially configured by providing a recessed area to receive the protrusion. 11. The power supply arrangement as set forth in claim 1, wherein the first mode is a first voltage mode, and the second mode is a second voltage mode lower than the first voltage mode. 12. The power supply arrangement as set forth in claim 11, wherein the specially configured second connector element includes a power cord for use at the voltage of the second voltage mode. 13. An electrical device, comprising: a power supply that is switchable between a first mode and a second mode, the power supply including: a first connector element, the first connector element being a female connector element defining a socket; a corresponding second connector element, the second connector element being a male connector element for being removably insertable into the socket of the female connector element for mating with the first connector element; and a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode; wherein at least a portion of the guard member extends into the socket of the first connector element when the guard member is in the second position of the guard member and no portion of the guard member extends into the socket of the first connector element when the guard member is in the first position of the guard member; and electrical equipment powered through the power supply. 14. A connector element assembly, comprising: a connector element, the connector element being one of a wale and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively; and a guard member disposed on the connector element, the guard member being movable in a substantially linear movement between a first position in which the connector element is adapted to mate with any corresponding mating connector elements and a second position in which the connector element is only adapted to mate with specially configured mating connector elements. 15. The connector element assembly as set forth in claim 14, wherein the guard member is associated with a switch and is movable between the first and the second positions upon moving the switch between first and second switch positions. 16. The connector element assembly as set forth in claim 15, wherein the guard member includes a protrusion that blocks a portion of the connector element. 17. The connector element assembly as set forth in claim 16, wherein the connector element includes a female connector element and the mating connector element includes a male connector element, and wherein the mating connector element is specially configured by providing a recessed area to receive the protrusion. 18. The connector element assembly as set forth in claim 16, wherein the connector element includes a male connector element and the mating connector element includes a female connector element, and wherein the mating connector element is specially configured by providing a recessed area to receive the protrusion. 19. The connector element assembly as set forth in claim 14, wherein the guard member includes a protrusion that blocks a portion of the connector element. 20. A connector element assembly, comprising: a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively; and a configuration on the connector element for cooperating with a guard member disposed on the mating connector element, the configuration permitting the connector element to mate with the mating connector element, the guard member preventing the mating connector element from mating with connector elements not having the configuration; wherein the guard member includes a protrusion that, when the guard member is in a blocking position blocks a portion of the mating connector element to prevent the mating connector element from mating with connector elements not having the configuration, and wherein the protrusion, when the guard member is in a non-blocking position, does not block the portion of the mating connector element to permit the mating connector element to mate with connector elements not having the configuration. 21. (canceled) 22. (canceled) 23. The connector element assembly as set forth in claim 20, wherein the mating connector element includes a power cord. 24. The connector element assembly as set forth in claim 20,.wherein the configuration includes a recess. 25. The power supply arrangement as set forth in claim 1, wherein the second position of the guard member is characterized by a portion of the guard member engaging the second connector element when the first connector element and the second connector element are in a mated condition, and the first position of the guard member is characterized by the guard member being free of any engagement with the second connector element when the first connector element and the second connector element are in a mated condition. 26. The power supply arrangement as set forth in claim 1, wherein the guard member is movable in a substantially linear movement between the first position and the second position. 27. The power supply arrangement as set forth in claim 1, wherein the guard member is slidable between the first position and the second position. 28. The power supply arrangement as set forth in claim 1, additionally comprising a switch having a ridge extending outwardly for being engaged by fingers of a user to move the guard member. 29. The power supply arrangement as set forth in claim 1, wherein the first connector element defines a socket, and wherein the guard member reduces an area of the socket when the guard member is moved from the first position to the second position. | BACKGROUND AND SUMMARY The present invention relates to connector elements, such as those used with power supplies for personal computers and the like, and, more particularly, to connector elements that provide protection against connecting the connector elements to certain other connector elements, such as inadvertently connecting a 110V power supply connector element to a 220V power cord. Power supplies such as are typically found in devices such as personal computers mostly presently use switcher technology to convert AC power input to lower DC voltages. For example, in personal computers, input AC power is usually either 110V, e.g., in the U.S., or 220V, e.g., in most European countries. The computer's digital circuits typically use 3.3V and 5V, and 12V is used to run motors in disk drives and fans. Many power supplies are adapted to operate at either 110V or 220V. For example, an electrical device used in the U.S. operates with 110V AC input power. For some devices, if the user travels abroad and plugs the computer into 220V AC input power, internal circuitry will automatically accommodate the different input power. For other devices, the user manually operates a switch on the power supply so that the correct circuitry will be used depending upon what the input voltage is. The automatic circuitry tends to be more expensive than the manual switch. If an electrical device that is set up to operate with 110V AC input voltage is plugged into 220V AC, the electrical device may be seriously damaged. Users of electrical devices having manual switches will often accidentally fail to set the switch on the device properly, often leading to damage of such devices. Accordingly, it is increasingly common for electrical devices to be provided with the internal circuitry necessary to automatically accommodate whatever type of power is input, adding to the cost of the devices. It is desirable to provide low cost protection against connection of electrical device power supplies to the wrong type of input power. According to an aspect of the present invention, a power supply arrangement for an electrical device includes a power supply that is switchable between a first mode and a second mode, a first connector element of the power supply, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, and a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. According to another aspect of the present invention, an electrical device includes a power supply that is switchable between a first mode and a second mode, the power supply including a first connector element, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, the power supply also including a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode, and electrical equipment powered through the power supply. According to yet another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a guard member disposed on the connector element, the guard member being movable between a first position in which the connector element is adapted to mate with any corresponding mating connector elements and a second position in which the connector element is only adapted to mate with specially configured mating connector elements. According to still another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a configuration on the connector element for cooperating with a guard member disposed on the mating connector element, the configuration permitting the connector element to mate with the mating connector element, the guard member preventing the mating connector element from mating with connector elements not having the configuration. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention are well understood by reading the following detailed description in conjunction with the drawings in which like numerals indicate similar elements and in which: FIG. 1 is a schematic, partially perspective view of an electrical device with a power supply arrangement including connector elements according to an embodiment of the present invention; FIG. 2A is a plan view of a mating end of a male connector element including a recess; FIG. 2B is a plan view of a mating end of a female connector element including a guard in place to mate with a recessed male connector element of the type shown in FIG. 2A; FIG. 2C is a plan view of a mating end of a male connector element that does not include a recess and is prevented from mating with a female connector element of the type shown in FIG. 2B; and FIG. 2D is a plan view of a mating end of a female connector element not including a guard, the female connector element of FIG. 2D being adapted to mate with a recessed male connector element of the type shown in FIG. 2A and an unrecessed male connector of the type shown in FIG. 2C. DETAILED DESCRIPTION A power supply arrangement 21 for an electrical device 23 is seen in FIG. 1. The electrical device 23 includes electrical equipment 25 that is powered through the power supply, such as the various components of a personal computer such as the digital circuits, disk drives, and fans. The power supply arrangement 21 includes a power supply 27 that is switchable between a first mode and a second mode. The first mode may be, for example, a higher voltage, such as a 220V mode, and the second mode may be lower voltage, such as a 110V mode. The power supply arrangement 21 may include conventional circuitry (not shown) for automatically preventing damage to the power supply if it is set at a second, e.g., 110V, mode but plugged into a 220V power source, such as often occurs by accident. However, the power supply arrangement 21 need not include such protective circuitry. The power supply arrangement 21 includes a first connector element 29 for the power supply 27. The first connector element 29 may be one of a male and a female connector element for mating with a corresponding second or mating connector element 31, the second connector element being the other type of connector, i.e., a female and a male connector element, respectively. For example, in conventional power supply arrangements, the first connector element is a female electrical socket and the second connector element is a power cord with a male plug end for mating with the female socket. In the embodiments illustrated here, the first connector element 29 is a female element and the second connector element 31 is a male element. It will be appreciated that the first connector element 29 may be a female element and the second connector element 31 may be a male element. Additionally, the first and second connector elements do not necessarily have to be male or female elements. The power supply arrangement 21 also includes a guard member 33 disposed on the first connector element 29. In the embodiment seen in FIG. 1, the guard member 33 is movable between a first position in which the first connector element 29 is adapted to mate with any corresponding second connector elements 31 and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. In the embodiment illustrated in FIG. 1, the specially configured second connector element 31 can be part of a 110V power cord while a second connector element 31a (FIG. 2C) that is not specially configured is part of a 220V power cord. By providing a special configuration for the second connector element 31 that is part of a 110V power cord, the inadvertent use of a 220V power cord that has no special configuration, like the second connector element 31a, cannot mate with the first connector element 29, thus reducing the risk of damaging the electrical device by providing power at too high of a voltage. In the embodiment shown in FIG. 1, the guard member 33 includes a protrusion 35 that blocks a portion of the first connector element 29. The second connector element 31 can, in this case, be specially configured by providing a recessed area 37 to receive the protrusion 35. Thus, a second connector element 31 configured to include such a recessed area 37, as seen in FIG. 2A, can mate with the first connector element 29 when the guard member 33 blocks a portion of the first connector element of the type seen in FIG. 2B. A second connector element 31a that is not configured to include a recessed area as seen in FIG. 2C will be prevented from mating with the first connector element 29 by the guard member 33. When the guard member 33 is moved so that it does not block the portion of the first connector element 29, as seen in FIG. 2D, either the second connector element 31 shown in FIG. 2A or the second connector element 31 a shown in FIG. 2B can mate with the first connector element. As seen in FIG. 1, a switch 39 is provided for switching the power supply 27 between the first mode and the second mode, as in conventional power supplies. The guard member 33 may be coupled to the switch 39 by a variety of suitable means, such as by an arm 41 extending from the switch, by multi-component linkages, electromagnetically, or otherwise. The guard member 33 does not need to be coupled to the switch at all, however, when the switch 39 is moved between first and second switch positions corresponding to the first and second modes, the guard member 33 will also be moved between the first and the second positions. The guard member 33 may, of course, be moved by some means other than the switch 39, such as by a motor or piston device whose operation is controlled by the switch. The invention is described here largely in connection with an application for power supplies. It will be appreciated that the invention has applications in a variety of other areas where it is occasionally desired or necessary to limit the types of connectors with which another connector can mate. For example, connectors that can be selectively prevented from mating with certain other connectors may be useful in mechanical structures. Connectors according to the present invention might, for example, be used to ensure that only specially adapted load bearing members such as cables capable of bearing particular weights are connected to connection points of an object to be borne while a more extensive array of cables can be connected to connection points of another, less heavy object. While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims. | <SOH> BACKGROUND AND SUMMARY <EOH>The present invention relates to connector elements, such as those used with power supplies for personal computers and the like, and, more particularly, to connector elements that provide protection against connecting the connector elements to certain other connector elements, such as inadvertently connecting a 110V power supply connector element to a 220V power cord. Power supplies such as are typically found in devices such as personal computers mostly presently use switcher technology to convert AC power input to lower DC voltages. For example, in personal computers, input AC power is usually either 110V, e.g., in the U.S., or 220V, e.g., in most European countries. The computer's digital circuits typically use 3.3V and 5V, and 12V is used to run motors in disk drives and fans. Many power supplies are adapted to operate at either 110V or 220V. For example, an electrical device used in the U.S. operates with 110V AC input power. For some devices, if the user travels abroad and plugs the computer into 220V AC input power, internal circuitry will automatically accommodate the different input power. For other devices, the user manually operates a switch on the power supply so that the correct circuitry will be used depending upon what the input voltage is. The automatic circuitry tends to be more expensive than the manual switch. If an electrical device that is set up to operate with 110V AC input voltage is plugged into 220V AC, the electrical device may be seriously damaged. Users of electrical devices having manual switches will often accidentally fail to set the switch on the device properly, often leading to damage of such devices. Accordingly, it is increasingly common for electrical devices to be provided with the internal circuitry necessary to automatically accommodate whatever type of power is input, adding to the cost of the devices. It is desirable to provide low cost protection against connection of electrical device power supplies to the wrong type of input power. According to an aspect of the present invention, a power supply arrangement for an electrical device includes a power supply that is switchable between a first mode and a second mode, a first connector element of the power supply, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, and a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. According to another aspect of the present invention, an electrical device includes a power supply that is switchable between a first mode and a second mode, the power supply including a first connector element, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, the power supply also including a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode, and electrical equipment powered through the power supply. According to yet another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a guard member disposed on the connector element, the guard member being movable between a first position in which the connector element is adapted to mate with any corresponding mating connector elements and a second position in which the connector element is only adapted to mate with specially configured mating connector elements. According to still another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a configuration on the connector element for cooperating with a guard member disposed on the mating connector element, the configuration permitting the connector element to mate with the mating connector element, the guard member preventing the mating connector element from mating with connector elements not having the configuration. | <SOH> BACKGROUND AND SUMMARY <EOH>The present invention relates to connector elements, such as those used with power supplies for personal computers and the like, and, more particularly, to connector elements that provide protection against connecting the connector elements to certain other connector elements, such as inadvertently connecting a 110V power supply connector element to a 220V power cord. Power supplies such as are typically found in devices such as personal computers mostly presently use switcher technology to convert AC power input to lower DC voltages. For example, in personal computers, input AC power is usually either 110V, e.g., in the U.S., or 220V, e.g., in most European countries. The computer's digital circuits typically use 3.3V and 5V, and 12V is used to run motors in disk drives and fans. Many power supplies are adapted to operate at either 110V or 220V. For example, an electrical device used in the U.S. operates with 110V AC input power. For some devices, if the user travels abroad and plugs the computer into 220V AC input power, internal circuitry will automatically accommodate the different input power. For other devices, the user manually operates a switch on the power supply so that the correct circuitry will be used depending upon what the input voltage is. The automatic circuitry tends to be more expensive than the manual switch. If an electrical device that is set up to operate with 110V AC input voltage is plugged into 220V AC, the electrical device may be seriously damaged. Users of electrical devices having manual switches will often accidentally fail to set the switch on the device properly, often leading to damage of such devices. Accordingly, it is increasingly common for electrical devices to be provided with the internal circuitry necessary to automatically accommodate whatever type of power is input, adding to the cost of the devices. It is desirable to provide low cost protection against connection of electrical device power supplies to the wrong type of input power. According to an aspect of the present invention, a power supply arrangement for an electrical device includes a power supply that is switchable between a first mode and a second mode, a first connector element of the power supply, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, and a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode. According to another aspect of the present invention, an electrical device includes a power supply that is switchable between a first mode and a second mode, the power supply including a first connector element, the first connector element being one of a male and a female connector element for mating with a corresponding second connector element, the second connector element being one of a female and a male connector element, respectively, the power supply also including a guard member disposed on the first connector element, the guard member being movable between a first position in which the first connector element is adapted to mate with any corresponding second connector elements and the power supply is in the first mode and a second position in which the first connector element is only adapted to mate with specially configured second connector elements and the power supply is in the second mode, and electrical equipment powered through the power supply. According to yet another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a guard member disposed on the connector element, the guard member being movable between a first position in which the connector element is adapted to mate with any corresponding mating connector elements and a second position in which the connector element is only adapted to mate with specially configured mating connector elements. According to still another aspect of the present invention, a connector element assembly includes a connector element, the connector element being one of a male and a female connector element for mating with a corresponding mating connector element, the mating connector element being one of a female and a male connector element, respectively, and a configuration on the connector element for cooperating with a guard member disposed on the mating connector element, the configuration permitting the connector element to mate with the mating connector element, the guard member preventing the mating connector element from mating with connector elements not having the configuration. | 20040503 | 20051213 | 20051103 | 64887.0 | 0 | HYEON, HAE M | CONNECTOR ELEMENTS INCLUDING PROTECTIVE MEMBER FOR PREVENTING CONNECTION TO CERTAIN CONNECTOR ELEMENTS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,838,022 | ACCEPTED | COMPRESSED GAS-POWERED GUN SIMULATING THE RECOIL OF A CONVENTIONAL FIREARM | A compressed gas powered gun provides recoil simulating the recoil of a gun firing gunpowder propelled projectiles. The valve assembly provides both consistent shot to shot pressure, and rearward gas pressure for generating recoil. Preferred embodiments of the compressed gas powered gun may include means for adjusting the amount of recoil provided. A trigger mechanism permitting semi-automatic operation, or full automatic operation at a user selectable cyclic rate, is provided. The air gun provides consistent gas pressure behind the projectile from shot to shot. A magazine and magazine indexing system for loading projectiles into the firing chamber in a manner contributing to the accuracy of the air gun is also provided. | 1. A trigger assembly for a gas powered gun, comprising: a trigger having a finger-engaging portion and a selector-engaging portion; a selector, comprising: a first surface dimensioned and configured to abut said selector-engaging portion of said trigger and to resist movement of said trigger; a second surface dimensioned and configured to abut said selector-engaging portion of said trigger and to permit a first distance of movement of said trigger; a third surface dimensioned and configured to abut said selector-engaging portion of said trigger and to permit a second distance of movement of said trigger, said second distance of movement being greater than said first distance of movement; a channel dimensioned and configured to permit a third distance of movement of said trigger, said third distance of movement being greater than said second distance of movement; and said selector is dimensioned and configured to permit said first surface, second surface, third surface, and channel to be selectively positioned to engage said trigger's selector-engaging portion. 2. The trigger assembly according to claim 1, wherein said first surface corresponds to safe, said second surface corresponds to semiautomatic operation, said third surface corresponds to full automatic operation at a first cyclic rate, and said channel corresponds to full automatic operation at a second cyclic rate, said second cyclic rate being faster than said first cyclic rate. 3. The trigger assembly according to claim 1, further comprising a sear trip operatively associated with said trigger. 4. The trigger assembly according to claim 3, further comprising a sear, said sear having a first end dimensioned and configured to selectively engage and release a bolt, and a second end dimensioned and configured to engage said sear trip said sear being spring-biased into engagement with said bolt, said sear being secured to a receiver by a sliding pivot. 5. The trigger assembly according to claim 4, wherein said sear trip further comprises an end having an upper step and a lower step, with said upper step and lower step each having a radiused corner. | CROSS REFERENCE TO RELATED APPLICATION This application is a divisional of U.S. patent application Ser. No. 10/289,021, entitled, “Compressed Gas-Powered Gun Simulating The Recoil of a Conventional Firearm,” filed Nov. 6, 2002, which is a divisional of U.S. patent application Ser. No. 09/756,891, filed Jan. 9, 2001. BACKGROUND OF THE INVENTION 1. Field of the Invention This application relates to compressed gas powered guns. More specifically, the invention relates to training guns duplicating various characteristics of guns firing gunpowder propelled projectiles. 2. Description of the Related Art Guns firing projectiles propelled by compressed air or gas are commonly used for recreational target shooting or as training devices for teaching the skills necessary to properly shoot guns firing gunpowder propelled projectiles. Ammunition for air guns is significantly less expensive than gunpowder propelled ammunition. A typical gas powered projectile has significantly lower velocity and energy than a gunpowder propelled projectile, making it much easier to locate a safe place to shoot an air gun, and much less expensive to construct a suitable backstop. Additionally, the low velocity and energy of air powered projectiles makes air guns significantly less useful as weapons than guns firing gunpowder propelled projectiles. Lack of usefulness as a weapon is an important factor in making air guns available in regions where national or local governments regulate firing gunpowder propelled projectiles (firearms). To be an effective training tool, an air gun must duplicate the characteristics of a firearm as closely as possible. These characteristics include size, weight, grip configuration, trigger reach, type of sights, level of accuracy, method of reloading, method of operation, location of controls, operation of controls, weight of trigger pull, length of trigger pull, and recoil. The usefulness of a gas powered gun as a training tool is limited to the extent that any of the above listed characteristics cannot be accurately duplicated. Presently available air guns increasingly tend to have an exterior configuration resembling that of a gun firing a powder propelled projectile. Presently available air guns may be used in a semi-automatic (one shot per pull of the trigger) or very rarely full automatic (more than one shot per pull of the trigger) mode of fire, although the cyclic rate of full automatic fire typically does not duplicate the cyclic rate of a full automatic firearm firing a projectile powered by gunpowder. The vast majority of presently available airguns which are advertised as being semiautomatic are actually nothing more than double-action revolver mechanisms disguised within an outer housing that simply looks like a semiautomatic gun. However, because they are true double-action mechanisms, the weight of trigger pull is much heavier than the weight of trigger pull of the present invention, which has a true single-action trigger. Presently available air guns have also been designed to simulate the trigger pull and reloading of guns firing gunpowder propelled projectiles. Presently available air guns do not duplicate the recoil of a gun firing a powder propelled projectile. The inability to get a trainee accustomed to the recoil generated by conventional firearms is one of the greatest disadvantages in the use of air guns as training tools. Additionally, although presently available air guns can be made extremely accurate, variations in gas pressure can cause differences in shot placement from shot to shot, or from the beginning of a gas cartridge to the end. Further, duplication of the cyclic rate of a conventional firearm within an air gun would enable a trainee to learn how to properly depress the trigger to fire short bursts of approximately three shots in full automatic mode of fire using an air gun. Because recoil is significantly more difficult to control during full automatic fire than during semi-automatic fire, an air gun simulating both recoil and the cyclic rate of a conventional firearm would be particularly useful as a training tool. Accordingly, there is a need for an air powered gun duplicating the recoil of a conventional firearm. Additionally, there is a need for an air powered gun maintaining a consistent compressed gas pressure behind the projectile from shot to shot, thereby maintaining a constant velocity, energy, and point of impact for each projectile. Further, there is a need for an air gun duplicating the full automatic cyclic rate of a conventional full automatic firearm. There is also a need to combine these characteristics into an air gun that is not particularly useful as a weapon, thereby facilitating safe use by inexperienced trainees, making training facilities easier and more economical to construct, lowering the cost of ammunition and training, reducing noise levels, and broadening the legality of ownership. SUMMARY OF THE INVENTION The preferred embodiment of the invention is an air or gas powered gun providing a recoil similar to that of a gun firing a powder propelled projectile. The compressed gas powered gun includes an improved magazine and magazine indexing system, contributing to the accuracy of the gun. The compressed gas powered gun preferably also duplicates many other features of a conventional firearm, for example, the sights, the positioning of the controls, and method of operation. One preferred embodiment simulates the characteristics of an AR-15 or M-16 rifle, although the invention can easily be applied to simulate the characteristics of other conventional firearms. The operation of a compressed gas powered gun of the present invention is controlled by the combination of a trigger assembly, bolt, buffer assembly and valve. Preferred embodiments will be capable of semi-automatic fire, full automatic fire at a low cyclic rate, and full automatic fire at a high cyclic rate. One of the two full automatic cyclic rates preferably approximately duplicates the cyclic rate of a conventional automatic rifle, for example, an M-16 rifle. The trigger assembly includes a trigger having a finger-engaging portion and a selector-engaging portion, a selector switch, a trigger bar, a sear trip, and a sear. The selector switch will preferably by cylindrical, having three bearing surfaces corresponding to safe, semi-automatic fire, and full automatic fire at a low cyclic rate, and a channel corresponding to full automatic fire at a high cyclic rate. These surfaces and channel of the selector bear against the selector engaging portion of the trigger, permitting little or no trigger movements if safe is selected, and increasing trigger movement for semi-automatic fire, low cyclic rate full automatic fire, and high cyclic rate full automatic fire, respectively. The sear is mounted on a sliding pivot, and is spring-biased towards a rearward position. The sear has a forward end for engaging the sear trip, and a rear end for engaging the bolt. The bolt preferably contains a floating mass, and reciprocates between a forward position and a rearward position. Although the bolt is spring-biased towards its forward position, the bolt will typically be held in its rearward position by the sear except during firing. The valve assembly includes a reciprocating housing containing a stationary forward valve poppet, a sliding rear valve poppet, and a spring between the front and rear valve poppets. The spring pushes the rear valve poppet rearward, causing the rear poppet to bear against the housing, thereby closing the rear valve and pushing the housing rearward. Pushing the housing rearward causes the housing to bear against the front valve poppet, thereby closing the front valve. Before the trigger is pulled, the trigger is in its forwardmost position, the bolt is held to the rear by its engagement with the sear, and the sear, although spring-biased rearward, is pushed towards its forwardmost position by the bolt. Pulling the trigger causes the trigger bar to move rearward, pivoting the sear trip upward. The upward movement of the sear trip pushes upward on the forward end of the sear, causing the rearward end of the sear to move down. The bolt is then free to travel forward, where the bolt strikes the rear valve, thereby moving the rear valve relative to the housing and opening the rear valve. Air pressure between the O-ring on the bolt face and the O-ring on the rear of the valve housing causes the housing to move forward, thereby opening the forward valve. Opening the forward valve dispenses pressurized gas to a position directly behind the projectile, causing the projectile to exit the barrel. Opening the rear valve supplies air pressure to the bolt face, thereby causing the bolt to return to its rearward position. If semi-automatic fire is selected, the limited movement of the sear trip, combined with the rearward spring-bias on the sear, causes the sear to move backwards on its pivot to a position where the sear trip can no longer apply upward pressure to the forward portion of the sear. The rear portion of the sear therefore pivots upward. The bolt will be propelled rearward to a point slightly behind the position wherein it engages the sear. As the bolt returns forward, the sear, which is no longer held in place by the sear trip, will engage the bolt, preventing further forward movement. From this position of the components, the trigger must be released before it can be pulled to fire another shot. If full automatic fire at a slow cyclic rate is selected, the trigger may be pulled slightly farther to the rear before it engages the selector, thereby causing the sear trip to pivot slightly higher. Whereas the upper bearing surface of the sear trip pushes the sear up to initially release the bolt, here, the lower end bearing surface of the sear trip pushes the sear up sufficiently so that, when the bolt catches the sear, there is only about {fraction (1/32)}nd inch of engagement between the sear and bolt. The floating mass bolt is thereby momentarily held in its rearward position by the sear, which cams forward off the sear trip as the forward motion of the bolt pushes the sear from its rearward position to its forward position. If full automatic fire at a high cyclic rate is selected, the trigger is allowed to travel to its maximum rearward position. The sear trip is thereby pivoted upward to its maximum extent, causing the lower end bearing surface of the sear trip to push the sear completely out of the way of the bolt. Therefore, as soon as the spring behind the bolt driver overcomes the rearward momentum of the bolt, the bolt will simply return forward and again actuate the valve. A compressed gas powered gun of the present invention preferably includes a magazine and magazine indexing assembly configured to facilitate precise alignment of the firing chambers with the barrel. A preferred embodiment of the magazine is a cylinder. The term “cylinder” as used herein does not necessarily mean a perfect geometrical cylinder, but is used to denote a generally cylindrical magazine wherein a plurality of firing chambers are located around its circumference, as known to those skilled in the art of revolvers. A preferred cylinder will have six chambers, although this number may vary. The exterior surface of the cylinder will preferably include a plurality of flutes, with the flutes located between the chambers, and with an equal number of chambers and flutes. One preferred embodiment of the cylinder aligns the chamber with the barrel in the three o'clock position when viewed from the rear or the nine o'clock position when viewed from the front. A spring-biased bearing preferably engages the flutes, thereby precisely aligning the cylinder with the barrel. A preferred bearing will have a larger radius than the radius of the flutes, thereby maximizing the precision with which the chamber and barrel may be aligned. This arrangement permits the barrel and chamber to be aligned with such precision that a forcing cone is not needed at the breach of the barrel. Indexing of the cylinder is controlled by the forward and backward movements of the bolt. A spring-biased pawl mounted on a pawl carrier is located directly behind the cylinder. The pawl carrier reciprocates between a left most position and a right most position, with the left most position corresponding to the engagement of the pawl with one chamber of the cylinder, and the right most position corresponding to engagement of the pawl with another chamber of the cylinder. An operating rod extends forward from the bolt, overlapping the pawl carrier. The bottom surface of the operating rod includes an angled slot, dimensioned and configured to guide an upwardly projecting pin on the pawl carrier. With the bolt in its rear most position, the pawl carrier pin is located in the forwardmost portion of the operating rod's angled slot. The pawl carrier and pawl are therefore in their right side position. The pawl is spring-biased forward to engage the chamber in the one o'clock position when viewed from the rear, or the eleven o'clock position when viewed from the front. As the operating rod moves forward due to forward travel of the bolt, the pawl carrier is moved from its right side position to its left side position. The left side of the pawl includes a ramped surface which permits the pawl to be pushed rearward by the cylinder wall, against the bias of the spring, allowing the pawl to move from the top right side chamber to the top left side chamber. When the bolt returns to its rearward position, the pawl and pawl carrier are moved from their left side position to their right side position. The right side of the pawl is parallel to the inside of the cylinder wall, so that movement of the pawl from left to right will cause the cylinder to index in a clockwise direction when viewed from the rear, or a counterclockwise direction when viewed from the front. The bearing will be biased out of the current flute, and will bear against the next flute at the completion of indexing, thereby properly aligning the next firing chamber with the barrel. Another preferred embodiment includes a tubular magazine in addition to the cylinder. The tubular magazine is aligned with one chamber of the cylinder whenever another chamber of the cylinder is aligned with the barrel. The tubular magazine includes a spring-biases follower for pushing projectiles rearward into the cylinder. Whenever the cylinder is indexed, another projectile will thereby be pushed into an empty chamber of the cylinder as that chamber is aligned with the tubular magazine. If no tubular magazine is present, or if use of only the cylinder is desired, a preferred method of reloading the compressed gas powered gun is to remove the cylinder, place a single pellet into each chamber, and then replace the cylinder. If the tubular magazine is used, a preferred method of loading the compressed gas powered gun includes retracting the follower using a finger tab secured to the follower and extending outside the gun, opening a loading gate, and pouring projectiles into the tubular magazine. Preferred projectiles for use of a tubular magazine include spherical pellets. Preferred projectiles for use with the cylinder alone include spherical pellets or conventional air gun pellets. A compressed gas powered gun of the present invention uses a recoiled buffer system for biasing the bolt forward, and for providing a recoil for the shooter. A preferred buffer system includes a floating mass bolt driver, and an air resistance bolt driver, with a spring disposed therebetween. This assembly is located in a tube within the air gun's shoulder stock, which is preferably a cylindrical tube. The buffer assembly may be oriented so that either the air resistance bolt driver or the floating mass bolt driver is positioned directly behind the bolt, with the other bolt driver placed at the rear of the stock. The forward bolt driver will thereby abut the rear of the bolt, pushing the bolt forward. If the air resistance bolt driver is positioned directly behind the bolt, light recoil results. The air resistance bolt driver has less mass than the floating mass bolt driver, resulting in less mass reciprocating back and forth. Additionally, the air resistance bolt driver will trap air behind it as it reciprocates, thereby slowing travel of the reciprocating mass. Conversely, positioning the floating mass bolt driver behind the bolt results in heavier recoil, due to the increased reciprocating mass and the lack of the ability of the floating mass bolt driver to trap air. The shooter may therefore select the desired level of recoil to correspond with the recoil of the conventional firearm the shooter wishes to simulate. It is therefore an aspect of the present invention to provide a compressed gas powered gun simulating the recoil of a conventional firearm. It is another aspect of the present invention to provide a compressed gas powered gun wherein the level of recoil provided to the shooter may be selected by the shooter. It is further aspect of the present invention to provide a compressed gas powered gun capable of simulating the operation of a conventional firearm. It is another aspect of the present invention to provide a compressed gas powered gun capable of both semi-automatic and full automatic operation. It is a further aspect of the present invention to provide a compressed gas powered gun wherein different cyclic rates of full automatic fire may be utilized. It is another aspect of the present invention to provide a compressed gas powered gun utilizing a magazine and magazine indexing system providing precise alignment of the firing chambers with the barrel. It is a further aspect of the present invention to provide a compressed gas powered gun capable of utilizing multiple types of projectiles. It is another aspect of the present invention to provide a compressed gas powered gun for providing training that accurately simulates shooting a conventional firearm. It is a further aspect of the present invention to provide a compressed gas powered gun that may be legally owned and utilized in locations where conventional firearms are heavily restricted. Theses and other aspects of the present invention will become apparent through the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a compressed gas powered gun according to the present invention. FIG. 2 is a side view of a four-position selector switch according to the present invention. FIG. 3 is a side view of a four-position selector switch according to the present invention, rotated 90° from the position of FIG. 2. FIG. 4 is a side cross-sectional view of a trigger assembly, valve assembly and bolt of a gas powered gun according to the preset invention, showing the position of the components before the trigger is pulled. FIG. 5 is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a gas powered gun according to the present invention, showing the position of the components at the moment of firing. FIG. 6 is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a gas powered gun according to the present invention, showing the position of the parts after firing and with the trigger still depressed during semi-automatic fire. FIG. 7 is a side cross-sectional view of a trigger assembly, valve assembly, a bolt of a gas powered gun according to the present invention, showing the position of the components after the bolt has returned and with the trigger still pulled during full automatic fire at a slow cyclic rate. FIG. 8 is a side cross-sectional view of a trigger assembly, valve assembly and bolt of a gas powered gun according to the present invention, showing the position of the components with the bolt retracted and trigger depressed during full automatic fire at a high cyclic rate. FIG. 9 is a top cross-sectional view of one preferred embodiment of a magazine assembly for a gas powered gun according to the present invention, showing the location of the components when the bolt is in the forward position. FIG. 10 is a top cross-sectional view of a magazine assembly of FIG. 9 for a gas powered gun according to the present invention, showing the position of the components when the bolt is in the rearward position. FIG. 11 is a top cross-sectional view of another preferred embodiment of a magazine assembly, with the operating rod deleted for clarity, illustrating the position of the components with the bolt in the forward position. FIG. 12 is a front cross-sectional view of a magazine assembly for a gas-powered gun according to the present invention. FIG. 13 is a top cross-sectional view of a magazine assembly of FIG. 1, showing the position of the components with the bolt in the rearward position. FIG. 14 is a top cross-sectional view of the magazine assembly of FIG. 11, showing the position of the components with the bolt in the forward position. FIG. 15 is a front cross-sectional view of an additional alternative embodiment of a magazine for a gas-powered gun of the present invention. FIG. 16 is a bottom view of an operating rod for a gas-powered gun according to the present invention. FIG. 17 is a side partially cut away view of a bolt, operating rod, and front portion of a bolt driver for a gas powered gun according to the present invention. FIG. 18 is a side view of a bolt and bolt driver for a gas powered gun according to the present invention. FIG. 19 is a side view of an air resistance bolt driver and floating mass bolt driver for a gas-powered gun according to the present invention. FIG. 20 is a side cut away view of a buffer assembly for a gas powered gun according to the present invention, showing the components configured for low recoil. FIG. 21 is a side cut away view of a buffer assembly for a gas-powered gun according to the present invention, showing the components configure for high recoil. FIG. 22 is a side cross-sectional view of a trigger assembly, valve assembly and bolt for a compressed gas gun of the present invention, showing an alternative preferred valve assembly. FIG. 23 is an exploded view of a captive assembly of a forward valve poppet, rear valve poppet, and spring for a gas powered gun according to the present invention. Like reference numbers denote like elements throughout the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention is a compressed gas powered gun that simulates the recoil of a conventional firearm discharging a powder propelled projectile. Referring to FIG. 1, a preferred embodiment of the compressed gas powered gun 10 is illustrated. The illustrated embodiments of the compressed gas powered gun simulates an AR-15 or M-16 rifle. The rifle 10 includes an action portion 12, a barrel 14, and a stock portion 16. The stock portion 16 includes a shoulder stock 18 and a pistol grip 20. The action portion 12 includes an upper receiver portion 22, to which the barrel 14 is secured, and a lower receiver portion 24, to which the shoulder stock 18 and pistol grip 20 are secured. A trigger 26 is located just ahead of the pistol grip 20 within the lower receiver portion 24. The lower receiver portion 24 also includes at least one compressed gas container 28, and may include a pressure gauge 30. The upper receiver portion 22 includes a sight mounting rail 32 on its top surface, upon which the electronic dot sight 34 is illustrated. Any conventional sight may be substituted for the electronic dot sight 34, including telescopic sights, or standard post front, aperture rear iron sights. Referring to FIGS. 2-8, 17-18, and 22, the trigger assembly 36, bolts 38, and valve assembly 40 are illustrated. The trigger 26 is pivotally secured within the lower receiver portion 24 at pivot 42, and is biased towards its forward position by the trigger return spring 44. The trigger 26 includes a finger-engaging portion 48, and a selector-engaging portion 50. The selector-engaging portion 50 is dimensioned and configured to abut a selector 46 when the trigger 26 is pulled rearward. The selector 46 is best illustrated in FIGS. 2-3. The selector 46 includes an actuator 52 for permitting the shooter to rotate the selector 46 as explained below, and a trigger-engaging portion 54. The trigger-engaging portion 54 includes a first surface 56, corresponding to safe. A second surface 58 of the trigger-engaging portion 54 corresponds to semi-automatic fire. A third surface 60 of the trigger-engaging portion 54 corresponds to full automatic fire at a slow cyclic rate. This surface 60 is different from selectors used in firearms in that it is cut to a different geometry to be used as a cam stop for the trigger as opposed to a surface that controls disconnectors. It is therefore sufficiently different that it cannot be used in a firearm. Lastly, the trigger-engaging portion 54 defines a channel 62, corresponding to full automatic fire at a high cyclic rate. Referring back to FIGS. 4-8, the trigger 26 is pivotally secured to one end of a trigger bar 64, with the other end of the trigger bar 64 secured to a sear trip 66. The sear trip 66 includes a sear-engaging end 68, having an upper radius surface 70 and a lower radius surface 72. The sear 74 is pivotally secured within the lower housing 24 by the sliding pivot 76. The sear 74 includes a front end 78, dimensioned and configured to engage the sear trip 66, and a back end 80, dimensioned and configured to mate with a notch 82 defined within the bolt 38. A spring 75 biases the sear rearward, and the front end 78 downward. The bolt 38 contains floating mass 39, and includes a bolt key 83, dimensioned and configured to secure an operating rod (described below). A spring-biased bolt driver is located directly behind the bolt 38, as will also be explained below. The forward portion of the bolt preferably includes an O-ring 84 around its circumference. The valve assembly 40 includes a housing 86, a forward valve 88, a rear valve 90, and a spring 92 between the forward valve 88 and rear valve 90. The front valve 88 is stationary. The housing 86 reciprocates between a forward position and a rearward position, with the inward flange 94 bearing against the front O-ring 96 to close the front valve 88 when the housing 86 is in its rearward position, and with the forward position of the housing 86 corresponding to the front valve being opened. The rear valve 90 reciprocates within the housing 86, with the rearward position of the valve 90 bringing the O-ring 98 against the housing's rear flange 100, thereby closing the rear valve. When the rear valve 90 moves forward relative to the housing 86, the rear valve 90 is opened. Compressed gas is supplied to the valve assembly 40 through the hose 102, connected between the valve 40 and the compressed gas channels 104 within the lower receiver 24. The compressed gas container 28 is secured to the compressed gas channels 104, thereby supplying compressed gas through the channels 104, hose 102 to the valve assembly 40. The rear end of the housing 86 also includes an O-ring 106. Referring to FIGS. 9-14 and 16-17, a preferred embodiment of a magazine assembly 108 is illustrated. A preferred magazine is a cylinder 110, located immediately in front of the valve assembly 40, and directly behind the barrel 14. A cylinder is defined herein as a rotary magazine similar to that used in a revolver wherein a plurality of firing chambers are arranged around the circumference, and is not necessarily a perfect geometrical cylinder. Cylinder 110 rotates about a central axis (not shown, and well known in the art) and has a plurality of chambers 112, parallel to the central axis, and bored around the circumference. A preferred and suggested number of firing chambers 112 is six, although a different number may easily be used. The firing chambers 112 are each dimensioned and configured to receive one projectile, with the projectile positioned so that compressed air from the valve 88 will be positioned behind the projectile. The cylinder 110 also includes a plurality of flutes 114 around its circumference, with the flutes 114 located between the chambers 112, and equal in number to the number of chambers 112. A spring-biased bearing 116 preferably engages the flutes 114 to precisely align a chamber 112 of the cylinder 110 with the barrel 14. The bearing 116 preferably has a radius larger than the radius of the flutes 114, thereby facilitating more precise alignment. Indexing of the cylinder 110 is controlled by movement of the bolt 38. The bolt key 83 secures an operating rod 118 to the bolt 30, so that as the bolt 38 reciprocates, the operating rod 118 will reciprocate with the bolt 38. The operating rod 118, shown in phantom for maximum clarity, defines an angled slot 120 along its bottom surface. A pawl assembly 122 is located directly behind the cylinder 110. The pawl assembly 122 includes a pawl carrier 124, having a spring-biased pawl 126. The pawl carrier 124 includes a pin 128, dimensioned and configured to fit within the angled slot 120 of the operating rod 118. The pawl 126 includes a reloading tab 130, and a cylinder-engaging end 132 having a pusher surface 134 and ramp surface 136. The cylinder-engaging end 132 is biased into one of chambers 112 by the spring 138. The magazine assembly 108 may also include a magazine tube 140, aligned with one of the chambers 112 of the cylinder 110. The magazine tube 140 is dimensioned and configured to contain a plurality of spherical projectiles. The magazine tube 140 includes a spring-biased follower 142, and has a loading gate 144 at its forward end. In one preferred embodiment, the chamber 112 in the three o'clock position when viewed from the rear is aligned with the barrel 14, and the chamber in the eleven o'clock position when viewed from the rear is aligned with the magazine tube 140. Additionally, in one preferred embodiment, the pawl 126 acts on the chambers in the eleven o'clock and one o'clock positions when viewed from the rear, as will be explained below. An alternative embodiment of a magazine assembly 108 is illustrated in FIG. 15. The cylinder 110 has been replaced by an elongated bar 146, having a plurality of chambers 148, indexing holes 150, and flutes 152 along its bottom surface. At least one spring-biased bearing 116 engages a flute 152 to align the chambers 148 with the barrel 14. A pair of slots 154, 154 permit the rod 146 to be inserted into the rifle 10 by accommodating the pawl 126. As will be seen below, indexing of the magazine 146 is very similar to the indexing of the cylinder 110. Referring to FIGS. 18-21, the buffer system 158 is illustrated. A preferred buffer system 158 includes an air piston bolt driver 160, a floating mass bolt driver 162 having a floating mass 164 therein, and a spring 166 disposed therebetween. The air piston bolt driver may preferably be made of two pieces, a forward portion 168 and rear portion 170. The buffer system 158 is located directly behind the bolt 38, and is housed within a buffer tube 172 within the shoulder stock 18. Depending on the length of the buffer tube 172, the forward portion 168 of the air resistance bolt driver may either be attached or removed from the rear portion 170 of the air piston bolt driver 158. Referring to FIGS. 22 and 23, an improved valve assembly 174 is illustrated. As before, this valve includes a housing 176, a forward valve 178, a rear valve 180, and a spring therebetween 182. The valve assembly 174 is a captive assembly, permitting easy disassembly and reassembly. The front valve 178 and rear valve 180 include mating male and female components 184, 186 forming a telescoping spring guide. As before, moving the valve housing 176 forward with respect to the front valve 178 opens the front valve, and moving the rear valve 180 forward with respect to the housing 176 open the rear valve 180. The spring 182 biases the rear valve 180 and housing 176 rearward, closing both valves. To use the rifle 10, a gas cartridge 28 is first secured to the compressed gas channel 104. At least one gas cartridge 28 must be used, and more than one may be used. If desired, a pressure gauge 30 may also be connected to the compressed gas channels 104. The gas selected may be either compressed air, or any compressed gas commonly used for air guns. One example is carbon dioxide. Next, projectiles are loaded into the magazine. If a rotary magazine or cylinder 110 is used, any projectile suitable for use in an air gun may be used, including spherical projectiles, conventional pellets, darts, etc. The cylinder 110 is loaded by first depressing the bearing 116 so that it does not block removal of the cylinder 110, and then pushing forward on the reloading tab 130, thereby retracting the pawls end 132 from the chamber. The cylinder 110 is now free to exit the rifle 10. The projectiles are pushed into place through the front portion of the chambers, and secured with friction. After loading all six chambers, the cylinder 110 may be inserted back into place within the rifle 10, after which the shooter re-engages the bearing 116 with the magazine flute 114. If a tubular magazine is used, preferred projectiles include spherical projectiles. These may be loaded by first retracting the follower 142 using a finger tab secured to the follower (not shown and well known in the art), opening the loading gate 144, and pouring spherical projectiles into the magazine tube. Releasing the follower 102 will push the first spherical projectile into the chamber 112 aligned with the tubular magazine 140. Compressed air will be supplied from the compressed air container 28, through the compressed air channels 104 and hose 102 to the center portion of the valve assembly 40 between the forward valve 88 and rear valve 90. Before firing, the trigger mechanism 36, valve assembly 40 and bolt 38 are in the positions illustrated in FIG. 4. The bolts 38, although biased forward by pressure from the spring 166, is held in its rear position by the rear end 80 of the sear 74 engaging the notch 82. Pressure from the spring 75 holds the sear 74 in this position, forward pressure from the bolt 38 against the sear 74 pushes the sear towards its forwardmost position on the sliding pivots 76. The trigger spring 44 holds the trigger 26 in its forwardmost position. The selector 46 may be rotated to the appropriate position, corresponding to safe, semi-automatic, or full automatic at a low or high cyclic rate. FIG. 5 depicts the location of the parts when the trigger is pulled in semi-automatic mode. Trigger 26 has been pulled rearward until the selector-engaging portion 50 engages the surface 58 of the selector 46. The trigger bar 64 moves rearward, thereby pivoting the end 68 of the sear's trip 66 upward so that the radiused surface 70 pushes the sear's forward end 78 upward, thereby pivoting the sear's back end 80 downward, releasing the bolt 38 to travel forward. During the forward travel of the bolt 38, the operating rod 118 moves from the rearward position depicted in FIGS. 10 and 13 to the forward position depicted in FIGS. 9 and 14. The pawl carrier 124 is thereby moved from its right side position of FIGS. 10 and 13 to its left side position of FIGS. 9 and 14. The pawl's end 132 is pushed out of the chamber 112 in the one o'clock position when viewed from the rear (FIGS. 10 and 13) to the eleven o'clock position of FIGS. 9 and 14, without rotating the cylinder 110. When the bolt 38 reaches its forwardmost position, air pressure between the bolt 38 and valve housing 86, enhanced by the O-rings 84 and 106, causes the valve housing 86 to move forward, thereby opening the forward valve 88. This releases compressed air to a position immediately behind the projectile in the chamber 112 aligned with the barrel 14, thereby discharging the projectile. At the same time, the bolt 38 strikes the rear valve 90, thereby moving the rear valve 90 forward to open the rear valve 90, thereby releasing compressed air to the bolt 38. The bolt 38 is thereby pushed to its rearward position as the pressure from the compressed air overcomes the bias of the spring 166. At the same time, the operating rod 118 is pulled from its forward position of FIGS. 9 and 14 to its rearward position of FIGS. 10 and 13. The pawl carrier 24 is thereby moved from its left most position to its right most position. As the pawl carrier 124 moves, the surface 134 of the pawl 126 engages the wall of a cylinder 112, thereby pushing the cylinder 110 so that the next chamber 112 is aligned with the barrel 14. The bearing 116 is briefly biased out of the flute 114, engaging the next flute 114 once the appropriate 112 chamber is aligned with the barrel 14. The above portion of the firing sequence, although based on semi-automatic fire, is identical for full automatic fire. The subsequent portion of the firing sequence changes depending on whether semi-automatic or full automatic fire is selected, and the rate of full automatic fire selected. FIG. 6 depicts the location of the components after firing a shot in semi-automatic mode, with the trigger still depressed. The spring 75 has pulled the sear 74 to the rear, where the end 78 slips off the radiused surface 70, permitting the sear to rotate so that the rear end 80 rotates upward. The bolt 38 is retracted to a position slightly behind the point where the notch 82 engages the sear 74. As the bolt 38 returns forward under pressure from spring 166, the notch 82 and sear 74 engage each other, thereby arresting forward travel of the bolt 38. At this point, releasing the trigger 26 is necessary to fire another shot. FIG. 7 depicts the position of the parts when the rifle 10 is discharged in full automatic mode at a slow rate of fire. In this mode of operation, the selector 46 is rotated so that the surface 60 engages the selector-engaging portion 50 of the trigger 26. The trigger 26 is thereby permitted to move back farther than in semi-automatic mode. As before, gas pressure forces the bolt 38 back to a position slightly behind the point wherein it engages the sear 74. The sear trip 66 is thereby rotated slightly higher, so that the lower radius 72 pushes upward on the front end 78 of the sear 74. The sear is pulled towards its rear most position on the sliding pivot 76 by the spring 75, and is thereby also pulled so that the rear end 80 of the sear 74 is rotated upward. As the bolt 38 returns forward under pressure from spring 166, about {fraction (1/32)}nd inch of the rear end 80 of the sear 74 catches the notch 82 of the bolt 38. The floating mass 39, which at this point will be located in the rear portion of the bolts 38, has slowed the bolt 38 sufficiently so that it will momentarily catch on the sear 74. When the bolt 38 engages the sear 74, forward pressure applied to the sear 74 by the bolt 38 will cause the sear 74 to cam off the radiused surface 70 as it moves towards its forwardmost position on the sliding pivot 76, rotating the sear 74 out of the path of the bolt 38. The bolt 38 is then free to travel forward to discharge another shot. FIG. 8 depicts the location of the parts if full automatic fire is selected. The selector 46 is rotated so that the selector-engaging portion 50 of the trigger 26 corresponds to the channel 62 within the selector 46, permitting the trigger 26 to travel to its maximum rearward position. The sear trip 66 is thereby rotated to its maximum upward position, thereby rotating the sear 74 completely out of the way of the bolt 38. When the bolt 38 travels rearward sufficiently for the spring 166 to overcome the air pressure from the valve 90, there is nothing to impede the forward motion of the bolt. This results in a maximum cyclic rate. A typical cyclic rate for full automatic fire with the low cyclic rate is approximately 600 rounds per minute. A typical cyclic rate for a full automatic fire at a high cyclic rate is approximately 900 rounds per minute, approximately simulating the cyclic rate of an M-16 rifle. Upon reading the above description, it becomes obvious that a magazine 146 may be substituted for the cylinder 110 without changing the basic operation of the rifle 10. As the bolt 38 travels forward, the pawl carrier 124 will move from right to left as before, indexing the pawl 126 from one indexing chamber 150 to the next indexing chamber 150. As the bolt 38 travels rearward, the pawl carrier 124 will move from left to right as before, causing the pawl 126 to index the magazine 146 so that the next firing chamber 148 is aligned with the barrel 14. As before, the bearings 116 will fit within the corresponding flutes 152 to align the chambers 148 precisely with the barrel 14. The airgun 10 has two accuracy-enhancing features. The combination of the bearing 116 and smaller radius flutes 114 ensures that the chamber 112 of the cylinder 110 aligns with the barrel 14 so precisely that a forcing cone at the breech end of the barrel is not required. This provides a totally straight path for the projectile throughout the chamber 112 and barrel 14. Additionally, as compressed gas pressure from the container 28 decreases, the bolt 38 will push the valve 90 further inward as it strikes the valve 90, thereby increasing the gas flow within the valve assembly 40. This ensures that each projectile will have a substantially consistent velocity. Therefore, the projectile will have a substantially consistent energy and trajectory. While a specific embodiment of the invention has been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalence thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This application relates to compressed gas powered guns. More specifically, the invention relates to training guns duplicating various characteristics of guns firing gunpowder propelled projectiles. 2. Description of the Related Art Guns firing projectiles propelled by compressed air or gas are commonly used for recreational target shooting or as training devices for teaching the skills necessary to properly shoot guns firing gunpowder propelled projectiles. Ammunition for air guns is significantly less expensive than gunpowder propelled ammunition. A typical gas powered projectile has significantly lower velocity and energy than a gunpowder propelled projectile, making it much easier to locate a safe place to shoot an air gun, and much less expensive to construct a suitable backstop. Additionally, the low velocity and energy of air powered projectiles makes air guns significantly less useful as weapons than guns firing gunpowder propelled projectiles. Lack of usefulness as a weapon is an important factor in making air guns available in regions where national or local governments regulate firing gunpowder propelled projectiles (firearms). To be an effective training tool, an air gun must duplicate the characteristics of a firearm as closely as possible. These characteristics include size, weight, grip configuration, trigger reach, type of sights, level of accuracy, method of reloading, method of operation, location of controls, operation of controls, weight of trigger pull, length of trigger pull, and recoil. The usefulness of a gas powered gun as a training tool is limited to the extent that any of the above listed characteristics cannot be accurately duplicated. Presently available air guns increasingly tend to have an exterior configuration resembling that of a gun firing a powder propelled projectile. Presently available air guns may be used in a semi-automatic (one shot per pull of the trigger) or very rarely full automatic (more than one shot per pull of the trigger) mode of fire, although the cyclic rate of full automatic fire typically does not duplicate the cyclic rate of a full automatic firearm firing a projectile powered by gunpowder. The vast majority of presently available airguns which are advertised as being semiautomatic are actually nothing more than double-action revolver mechanisms disguised within an outer housing that simply looks like a semiautomatic gun. However, because they are true double-action mechanisms, the weight of trigger pull is much heavier than the weight of trigger pull of the present invention, which has a true single-action trigger. Presently available air guns have also been designed to simulate the trigger pull and reloading of guns firing gunpowder propelled projectiles. Presently available air guns do not duplicate the recoil of a gun firing a powder propelled projectile. The inability to get a trainee accustomed to the recoil generated by conventional firearms is one of the greatest disadvantages in the use of air guns as training tools. Additionally, although presently available air guns can be made extremely accurate, variations in gas pressure can cause differences in shot placement from shot to shot, or from the beginning of a gas cartridge to the end. Further, duplication of the cyclic rate of a conventional firearm within an air gun would enable a trainee to learn how to properly depress the trigger to fire short bursts of approximately three shots in full automatic mode of fire using an air gun. Because recoil is significantly more difficult to control during full automatic fire than during semi-automatic fire, an air gun simulating both recoil and the cyclic rate of a conventional firearm would be particularly useful as a training tool. Accordingly, there is a need for an air powered gun duplicating the recoil of a conventional firearm. Additionally, there is a need for an air powered gun maintaining a consistent compressed gas pressure behind the projectile from shot to shot, thereby maintaining a constant velocity, energy, and point of impact for each projectile. Further, there is a need for an air gun duplicating the full automatic cyclic rate of a conventional full automatic firearm. There is also a need to combine these characteristics into an air gun that is not particularly useful as a weapon, thereby facilitating safe use by inexperienced trainees, making training facilities easier and more economical to construct, lowering the cost of ammunition and training, reducing noise levels, and broadening the legality of ownership. | <SOH> SUMMARY OF THE INVENTION <EOH>The preferred embodiment of the invention is an air or gas powered gun providing a recoil similar to that of a gun firing a powder propelled projectile. The compressed gas powered gun includes an improved magazine and magazine indexing system, contributing to the accuracy of the gun. The compressed gas powered gun preferably also duplicates many other features of a conventional firearm, for example, the sights, the positioning of the controls, and method of operation. One preferred embodiment simulates the characteristics of an AR-15 or M-16 rifle, although the invention can easily be applied to simulate the characteristics of other conventional firearms. The operation of a compressed gas powered gun of the present invention is controlled by the combination of a trigger assembly, bolt, buffer assembly and valve. Preferred embodiments will be capable of semi-automatic fire, full automatic fire at a low cyclic rate, and full automatic fire at a high cyclic rate. One of the two full automatic cyclic rates preferably approximately duplicates the cyclic rate of a conventional automatic rifle, for example, an M-16 rifle. The trigger assembly includes a trigger having a finger-engaging portion and a selector-engaging portion, a selector switch, a trigger bar, a sear trip, and a sear. The selector switch will preferably by cylindrical, having three bearing surfaces corresponding to safe, semi-automatic fire, and full automatic fire at a low cyclic rate, and a channel corresponding to full automatic fire at a high cyclic rate. These surfaces and channel of the selector bear against the selector engaging portion of the trigger, permitting little or no trigger movements if safe is selected, and increasing trigger movement for semi-automatic fire, low cyclic rate full automatic fire, and high cyclic rate full automatic fire, respectively. The sear is mounted on a sliding pivot, and is spring-biased towards a rearward position. The sear has a forward end for engaging the sear trip, and a rear end for engaging the bolt. The bolt preferably contains a floating mass, and reciprocates between a forward position and a rearward position. Although the bolt is spring-biased towards its forward position, the bolt will typically be held in its rearward position by the sear except during firing. The valve assembly includes a reciprocating housing containing a stationary forward valve poppet, a sliding rear valve poppet, and a spring between the front and rear valve poppets. The spring pushes the rear valve poppet rearward, causing the rear poppet to bear against the housing, thereby closing the rear valve and pushing the housing rearward. Pushing the housing rearward causes the housing to bear against the front valve poppet, thereby closing the front valve. Before the trigger is pulled, the trigger is in its forwardmost position, the bolt is held to the rear by its engagement with the sear, and the sear, although spring-biased rearward, is pushed towards its forwardmost position by the bolt. Pulling the trigger causes the trigger bar to move rearward, pivoting the sear trip upward. The upward movement of the sear trip pushes upward on the forward end of the sear, causing the rearward end of the sear to move down. The bolt is then free to travel forward, where the bolt strikes the rear valve, thereby moving the rear valve relative to the housing and opening the rear valve. Air pressure between the O-ring on the bolt face and the O-ring on the rear of the valve housing causes the housing to move forward, thereby opening the forward valve. Opening the forward valve dispenses pressurized gas to a position directly behind the projectile, causing the projectile to exit the barrel. Opening the rear valve supplies air pressure to the bolt face, thereby causing the bolt to return to its rearward position. If semi-automatic fire is selected, the limited movement of the sear trip, combined with the rearward spring-bias on the sear, causes the sear to move backwards on its pivot to a position where the sear trip can no longer apply upward pressure to the forward portion of the sear. The rear portion of the sear therefore pivots upward. The bolt will be propelled rearward to a point slightly behind the position wherein it engages the sear. As the bolt returns forward, the sear, which is no longer held in place by the sear trip, will engage the bolt, preventing further forward movement. From this position of the components, the trigger must be released before it can be pulled to fire another shot. If full automatic fire at a slow cyclic rate is selected, the trigger may be pulled slightly farther to the rear before it engages the selector, thereby causing the sear trip to pivot slightly higher. Whereas the upper bearing surface of the sear trip pushes the sear up to initially release the bolt, here, the lower end bearing surface of the sear trip pushes the sear up sufficiently so that, when the bolt catches the sear, there is only about {fraction (1/32)} nd inch of engagement between the sear and bolt. The floating mass bolt is thereby momentarily held in its rearward position by the sear, which cams forward off the sear trip as the forward motion of the bolt pushes the sear from its rearward position to its forward position. If full automatic fire at a high cyclic rate is selected, the trigger is allowed to travel to its maximum rearward position. The sear trip is thereby pivoted upward to its maximum extent, causing the lower end bearing surface of the sear trip to push the sear completely out of the way of the bolt. Therefore, as soon as the spring behind the bolt driver overcomes the rearward momentum of the bolt, the bolt will simply return forward and again actuate the valve. A compressed gas powered gun of the present invention preferably includes a magazine and magazine indexing assembly configured to facilitate precise alignment of the firing chambers with the barrel. A preferred embodiment of the magazine is a cylinder. The term “cylinder” as used herein does not necessarily mean a perfect geometrical cylinder, but is used to denote a generally cylindrical magazine wherein a plurality of firing chambers are located around its circumference, as known to those skilled in the art of revolvers. A preferred cylinder will have six chambers, although this number may vary. The exterior surface of the cylinder will preferably include a plurality of flutes, with the flutes located between the chambers, and with an equal number of chambers and flutes. One preferred embodiment of the cylinder aligns the chamber with the barrel in the three o'clock position when viewed from the rear or the nine o'clock position when viewed from the front. A spring-biased bearing preferably engages the flutes, thereby precisely aligning the cylinder with the barrel. A preferred bearing will have a larger radius than the radius of the flutes, thereby maximizing the precision with which the chamber and barrel may be aligned. This arrangement permits the barrel and chamber to be aligned with such precision that a forcing cone is not needed at the breach of the barrel. Indexing of the cylinder is controlled by the forward and backward movements of the bolt. A spring-biased pawl mounted on a pawl carrier is located directly behind the cylinder. The pawl carrier reciprocates between a left most position and a right most position, with the left most position corresponding to the engagement of the pawl with one chamber of the cylinder, and the right most position corresponding to engagement of the pawl with another chamber of the cylinder. An operating rod extends forward from the bolt, overlapping the pawl carrier. The bottom surface of the operating rod includes an angled slot, dimensioned and configured to guide an upwardly projecting pin on the pawl carrier. With the bolt in its rear most position, the pawl carrier pin is located in the forwardmost portion of the operating rod's angled slot. The pawl carrier and pawl are therefore in their right side position. The pawl is spring-biased forward to engage the chamber in the one o'clock position when viewed from the rear, or the eleven o'clock position when viewed from the front. As the operating rod moves forward due to forward travel of the bolt, the pawl carrier is moved from its right side position to its left side position. The left side of the pawl includes a ramped surface which permits the pawl to be pushed rearward by the cylinder wall, against the bias of the spring, allowing the pawl to move from the top right side chamber to the top left side chamber. When the bolt returns to its rearward position, the pawl and pawl carrier are moved from their left side position to their right side position. The right side of the pawl is parallel to the inside of the cylinder wall, so that movement of the pawl from left to right will cause the cylinder to index in a clockwise direction when viewed from the rear, or a counterclockwise direction when viewed from the front. The bearing will be biased out of the current flute, and will bear against the next flute at the completion of indexing, thereby properly aligning the next firing chamber with the barrel. Another preferred embodiment includes a tubular magazine in addition to the cylinder. The tubular magazine is aligned with one chamber of the cylinder whenever another chamber of the cylinder is aligned with the barrel. The tubular magazine includes a spring-biases follower for pushing projectiles rearward into the cylinder. Whenever the cylinder is indexed, another projectile will thereby be pushed into an empty chamber of the cylinder as that chamber is aligned with the tubular magazine. If no tubular magazine is present, or if use of only the cylinder is desired, a preferred method of reloading the compressed gas powered gun is to remove the cylinder, place a single pellet into each chamber, and then replace the cylinder. If the tubular magazine is used, a preferred method of loading the compressed gas powered gun includes retracting the follower using a finger tab secured to the follower and extending outside the gun, opening a loading gate, and pouring projectiles into the tubular magazine. Preferred projectiles for use of a tubular magazine include spherical pellets. Preferred projectiles for use with the cylinder alone include spherical pellets or conventional air gun pellets. A compressed gas powered gun of the present invention uses a recoiled buffer system for biasing the bolt forward, and for providing a recoil for the shooter. A preferred buffer system includes a floating mass bolt driver, and an air resistance bolt driver, with a spring disposed therebetween. This assembly is located in a tube within the air gun's shoulder stock, which is preferably a cylindrical tube. The buffer assembly may be oriented so that either the air resistance bolt driver or the floating mass bolt driver is positioned directly behind the bolt, with the other bolt driver placed at the rear of the stock. The forward bolt driver will thereby abut the rear of the bolt, pushing the bolt forward. If the air resistance bolt driver is positioned directly behind the bolt, light recoil results. The air resistance bolt driver has less mass than the floating mass bolt driver, resulting in less mass reciprocating back and forth. Additionally, the air resistance bolt driver will trap air behind it as it reciprocates, thereby slowing travel of the reciprocating mass. Conversely, positioning the floating mass bolt driver behind the bolt results in heavier recoil, due to the increased reciprocating mass and the lack of the ability of the floating mass bolt driver to trap air. The shooter may therefore select the desired level of recoil to correspond with the recoil of the conventional firearm the shooter wishes to simulate. It is therefore an aspect of the present invention to provide a compressed gas powered gun simulating the recoil of a conventional firearm. It is another aspect of the present invention to provide a compressed gas powered gun wherein the level of recoil provided to the shooter may be selected by the shooter. It is further aspect of the present invention to provide a compressed gas powered gun capable of simulating the operation of a conventional firearm. It is another aspect of the present invention to provide a compressed gas powered gun capable of both semi-automatic and full automatic operation. It is a further aspect of the present invention to provide a compressed gas powered gun wherein different cyclic rates of full automatic fire may be utilized. It is another aspect of the present invention to provide a compressed gas powered gun utilizing a magazine and magazine indexing system providing precise alignment of the firing chambers with the barrel. It is a further aspect of the present invention to provide a compressed gas powered gun capable of utilizing multiple types of projectiles. It is another aspect of the present invention to provide a compressed gas powered gun for providing training that accurately simulates shooting a conventional firearm. It is a further aspect of the present invention to provide a compressed gas powered gun that may be legally owned and utilized in locations where conventional firearms are heavily restricted. Theses and other aspects of the present invention will become apparent through the following description and drawings. | 20040503 | 20050405 | 20050407 | 63514.0 | 0 | RICCI, JOHN A | COMPRESSED GAS-POWERED GUN SIMULATING THE RECOIL OF A CONVENTIONAL FIREARM | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,838,112 | ACCEPTED | Enhanced wireless handset, including direct handset-to-handset communication mode | A wireless handset is provided with enhanced features and capabilities. The wireless handset may be embodied as a full-featured handset that is capable of operating either within a wireless network (such as a cellular or PCS network) or in a direct handset-to-handset communication mode that is independent of the wireless network. Alternatively, the wireless handset may be embodied as a special purpose handset, that is capable of simply operating in a direct handset-to-handset communication mode. The wireless handset may additionally include features for supporting and enhancing direct communication between handsets. Such features may include a find feature that permits a user to determine which objects, including other wireless handset users, are located within a predetermined operating range of the wireless handset. A memorize feature may also be provided to permit handsets and other objects exchange information by wireless transmission. | 1. An electronic apparatus including a wireless transmitter having a wireless communications range, the electronic apparatus comprising: a system that initiates a find feature to determine if at least one object is within the wireless communications range; a detector to detect a message from the at least one object; and an indicator responsive to the detector, the indicator comprising a recorder to record information to a found list based on detection of the message and a display to display the found list to indicate each object that has been detected within the wireless communications range of the electronic apparatus. 2. A method for locating objects that are within a wireless communication range of an electronic apparatus, the objects including devices capable of communicating with the electronic apparatus, the method comprising: initiating a find feature to determine if at least one of the objects is within the wireless communication range of the electronic apparatus; detecting a first message from a first detected object within the wireless communication range; detecting a second message from a second detected object within the wireless communication range; recording information to a found list based on the first detected message to indicate that the first object is within range of the electronic apparatus and based on the second detected message to indicate that the second object is within range of the electronic apparatus; and displaying the found list on a display of the electronic apparatus to allow user selection of communicating wirelessly with at least one of the first and the second object. 3. The method of claim 2, further comprising receiving a user selection of an entry in the found list to specify a selected object identified in the found list and communicating a data message with the selected object. 4. A method of operating an electronic apparatus, the method comprising: initiating a find feature to determine if at least one object is within wireless communication range of the electronic apparatus; detecting a message from at least one object; indicating, based on the message detected, that the at least one object is within range of the electronic apparatus; recording information relating to the object to a found list based on the message; and displaying the found list to indicate each object including the at least one object, that is within range of the electronic apparatus. 5. The method of claim 4, wherein the information that is recorded comprises at least one of an ID associated with the at least one object and a channel for communicating with the at least one object. 6. The method of claim 5, further comprising detecting a second message from a second object, modifying the found list by recording information to the found list relating to the second object based on the second message to add a second entry to the found list corresponding to the second object and displaying the modified found list with the second entry identifying the second object. 7. A method for locating objects that are within range of an electronic device, the method comprising: initiating a find feature to determine if at least one specified object is within range of the electronic device; tuning to a registry channel based on the initiation of the find feature; receiving a registry message on the registry channel from the at least one specified object; recording information based on the registry message received from the at least one specified object; and providing a find list comprising a plurality of entries, each of the plurality of entries including information specifying at least one object, the information of an entry of the find list comprising an ID of an object. 8. An electronic device to identify a proximally located object within a proximity wireless coverage area, the electronic device comprising: a short-range wireless transmitter to transmit an inquiry data packet according to a wireless protocol; a receiver operable to receive a response data packet including an object identifier, the response data packet identifying the proximally located object within the proximity wireless coverage area, the proximally located object configured to communicate using the wireless protocol associated with the inquiry data packet; and a computing system responsive to the short-range wireless transmitter and responsive to the receiver, the computing system configured to add the object identifier associated with the proximally located object to a dynamically generated find list of detected objects located within the proximity wireless coverage area. 9. The electronic device of claim 8, wherein the computing system is operable to provide a page data packet to the proximally located object. 10. The electronic device of claim 8, further comprising a graphical user interface to display the dynamically generated find list of detected objects. 11. A method of discovering proximally located objects within a proximity wireless coverage area, the method comprising: transmitting an inquiry data packet according to a wireless protocol using a short-range wireless transmitter; transmitting the inquiry data packet using the short-range wireless transmitter; receiving a first response data packet including a first object identifier, the first response data packet identifying a first proximally located object within the proximity wireless coverage area; receiving a second response data packet including a second object identifier, the second response data packet identifying a second proximally located object within the proximity wireless coverage area; and dynamically generating a list of detected objects located within the proximity wireless coverage area, the dynamically generated list of detected objects including the first object identifier and the second object identifier. 12. The method of claim 11, further comprising displaying the dynamically generated list of detected objects using a graphical user interface. 13. The method of claim 11, further comprising synchronizing communication with at least one of the first proximally located object and the second proximally located object. 14. A method of discovering a proximally located object within a proximity wireless coverage area, the method comprising: transmitting an inquiry message according to a wireless protocol using a short-range wireless transmitter; receiving a response message including an object identifier, the response message identifying the proximally located object within the proximity wireless coverage area; and adding the object identifier associated with the proximally located object to a found list of detected objects located within the proximity wireless coverage area. 15. The method of claim 14, further comprising providing a page message to the proximally located object. 16. The method of claim 14, further comprising displaying the found list of detected objects. | CROSS REFERENCE TO RELATED APPLICATION This is a continuation application of U.S. patent application Ser. No. 09/968,856 filed on Oct. 3, 2001 which is a divisional application of U.S. patent application Ser. No. 09/094,600 filed on Jun. 15, 1998 (U.S. Pat. No. 6,484,027), the contents of both of which are expressly incorporated herein by reference in their entirety. BACKGROUND OF INVENTION The present invention generally relates to the field of communications and the use of wireless handsets. More particularly, the present invention relates to wireless handsets with enhanced functionality, including the ability to operate within a wireless network and in a direct handset-to-handset communication mode. Acronyms The written description provided herein contains acronyms which refer to, for example, various communication services, components and techniques, as well as features relating to the present invention. Although some of these acronyms are known, use of these acronyms is not strictly standardized in the art. For purposes of the written description herein, acronyms will be defined as follows: Citizens Band (CB). Complimentary Metal Oxide Semiconductor (CMOS) Customer Premise Equipment (CPE) Electronically Erasable Programmable Read Only Memory (EEPROM) Federal Communications Commission (FCC) Group System for Mobile Communications (GSM) Interim Standard (IS) Liquid Crystal Display (LCD) Mobile Identification Number (MIN) Mobile Switching Center (MSC) Mobile Telephone Switching Office (MTSO) Number Assignment Module (NAM) Personal Access Communication System (PACS) Personal Communications Network (PCN) Personal Communications Services (PCS) Personal Handyphone Systems (PHS) Public Land Mobile Network (PLMN) Plain Old Telephone Service (POTS) Public Switched Telephone Network (PSTN) Random Access Memory (RAM) System Access List (SAL) Supervisory Audio Tone (SAT) System Identification Code (SID) Subscriber Identity Module (SIM) System Operator Code (SOC) Signal Strength (SS) Transmission Control Protocol/Internet Protocol (TCP/IP) Time Division Multiple Access (TDMA) BACKGROUND AND MATERIAL INFORMATION Traditionally, wireless handsets have been provided to facilitate mobile communications. Such handsets are typically assigned a unique wireless or mobile identification number. By dialing the number assigned to the handset, a user may attempt to access a wireless handset user through the wireless network infrastructure. The wireless network may facilitate communications between two mobile wireless handset users, or between a user located at a fixed location (such as, for example, a Plain Old Telephone Service (POTS) station location) and a wireless handset user. In addition, the wireless network may comprise a cellular network or a mobile telephone network to facilitate communication. Wireless networks enable mobile station users to roam over large geographic areas while maintaining immediate access to communication services. Mobile station users often carry their handsets or have them installed in their vehicle(s). Mobile stations comprising cellular telephones or wireless handsets may be operable in cooperation with cellular or Personal Communications Services (PCS) communications systems. Cellular communication systems typically provide service to a geographic area by dividing the area into many smaller areas or cells. Each cell is serviced by a radio transceiver (i.e., a transmitter-receiver base station or cell site). The cell sites or base stations may be connected to Mobile Telephone Switching Offices (MTSOs) or Mobile Switching Centers (MSCs) through landlines and/or other communication links. The MSCs may, in turn, be connected via landlines to the Public Switched Telephone Network (PSTN). FIG. 1 illustrates the main components of a conventional cellular network. As shown in FIG. 1, a wireless handset 38 may place or receive calls by communicating with a cell site 30 or a cell site 40, depending upon the location of the wireless handset and the cell coverage area that is provided by each cell site (i.e., cell coverage area 35 of cell site 30 or cell coverage area 45 of cell site 40). For purposes of illustration, wireless handset 38 is depicted in FIG. 1 as being able to communicate with either cell site 30 or cell site 40, even though the wireless handset is not illustrated as being located within cell coverage area 35 or cell coverage area 45. Under normal operating conditions, the extent to which wireless handset 38 will be able to communicate with cell site 30 or cell site 40 will depend on the geographic location of the wireless handset and the size of the cell coverage area of each cell site. Further, although only two cell sites are depicted in FIG. 1, the entire cellular network may include, for example, more than two cell sites. In addition, more than one cell site may be connected to each MSC and more than one wireless handset 38 may be operating within each cell site. Wireless handset 38 may include a conventional cellular telephone unit with a transceiver and antenna (not shown) to communicate by, for example, radio waves with cell sites 30 and 40. Various air-interface technologies may be implemented to facilitate communication between each wireless handset and the cell sites. Cell sites 30 and 40 may both include a radio transceiver (not shown) and be connected by landlines 16 or other communication links to MSCs 24, 28. A PSTN 12 is also connected to each of the MSCs 24, 28 by landline 16 or other communication links. PSTN 12 may also be connected to fixed Customer Premise Equipment (CPE) 6 (which may include telephone equipment) by communication or trunked lines 10. The MSCs 24, 28 may be conventional digital telephone exchanges that control the switching between PSTN 12 and the cell sites 30 and 40 to provide wireline-to-mobile, mobile-to-wireline and mobile-to-mobile call connectivity. Each MSC may perform various functions, including: (i) processing mobile station status data received from the cell site controllers; (ii) handling and switching calls between cells; (iii) processing diagnostic information; and (iv) compiling billing information. The transceiver (not shown) of each cell site 30 and 40 provides communications, such as voice and data, with each wireless handset 38 while it is present in its geographic domain. The MSCs 24, 28 may track and switch wireless handset 38 from cell site to cell site, as the wireless handset passes through various coverage areas. When wireless handset 38 passes from one cell to another cell, the MSC of the corresponding cell may perform a “hand-off” that allows the wireless handset to be continuously serviced. In the current North American cellular system, any given area may be serviced by up to two competing service providers of cellular airtime communication services. By Federal Communications Commission (FCC) regulations, the two competing cellular service providers are assigned different groups of frequencies within the 800-900 MHZ region through which services are provided. A frequency set typically includes control channels and voice channels. The control channels are used for preliminary communications between a mobile station and a cell site for setting up a call, after which a voice channel is assigned for the mobile station's use on that call. The assigned frequency sets are generally referred to as “A band frequencies” and “B band frequencies”. Typically, the A band frequencies are reserved for non-wireline service providers, while the B band frequencies are reserved for wireline service providers. While each frequency set for a given cellular service area is assigned to only one service provider, in different service areas the same frequency set may be assigned to different service providers or companies. Cellular service providers often charge usage fees for airtime since they have to purchase or license the wireless bandwidth over which cellular calls take place, and because they have to maintain their wireless network. The FCC, however, has also designated unlicensed bands in Northern America which do not require a license to operate on if the transmit power is sufficiently low. For example, the 902-928 MHZ Industrial, Scientific and Medical band is unlicensed in the United States. This band is commonly used for home cordless telephones and is well suited for voice communications at limited distances. Depending upon which cellular service provider is subscribed to by the user of the wireless handset, the home frequency set of the user may correspond to the A frequency band or the B frequency band. Whenever a call is placed by the mobile station or wireless handset, the unit will ordinarily attempt to use the home frequency set to establish the call. If a call is handled outside of the user's home network area, then the unit is said to be “roaming” and service will be attempted through a frequency set of the preferred service provider in that area. Typically, the user's home service provider will have a roaming agreement or reciprocal billing arrangement with the non-home service provider to permit service to be extended to the user's wireless unit when it is roaming in the non-home service provider's service area. The wireless handset may include a memory device, such as a number assignment module (NAM), in which an assigned phone number (MIN) and a system identification code (SID) is stored to uniquely identify the home service provider for the unit. In addition, the wireless handset may store a unique Electronic Serial Number (ESN) that is assigned to the wireless handset. In the North American cellular system, each cellular market or provider is assigned a distinct, fifteen bit SID. In Europe, on the other hand, the Global System for Mobile Communications (GSM) standard (see, for example, Recommendation GSM 02.11, Service Accessibility, European Telecommunications Standards Institute, 1992) defines a process for network selection based on the wireless handset reading the GSM equivalent of the SID, called the Public Land Mobile Network (PLMN) identity. The SID or equivalent system identification number is broadcast by each service provider or cellular provider and is used by the wireless handset to determine whether or not the wireless handset is operating in its home network or if it is operating in a roaming condition. The wireless handset makes this determination by reading the SID that is broadcast in the cellular market in which it is located, and comparing it to the home SID stored in the NAM of the cellular phone unit. If the SIDs do not match, then the wireless handset is roaming, and the mobile station must attempt to gain service through a non-home service provider. Due to the imposition of a fixed surcharge or higher per unit rate, the airtime charges when the mobile station is roaming are customarily higher than when it is operating within its home network. When a wireless handset is switched ON, the handset scans the group of control channels to determine the strongest cell site or base station signal. Control channels are primarily involved in setting up a call and moving it to an unused voice channel. When a telephone call is placed, a signal is sent to the cell site or base station. The MSC usually dispatches the request to all base stations in the cellular system. The MIN which is assigned as the phone number to the wireless handset is then broadcast as a paging message throughout the cellular system. When the wireless handset receives the page, the handset identifies itself to the base station it received the page from (usually the strongest base station) and informs the MSC of the “handshake”. The MSC then instructs the base station to move the call to an unused channel. As noted above, the MSC may also provide access to the PSTN once a channel is established. Operation under a roaming condition is often under the control of the wireless handset user. The user can select whether the mobile station will operate in a Home System Only, A Band Only, B Band Only, A Band Preferred, or B. Band Preferred operating mode. The user typically controls the system preference and mode operation through menu choice or selection. This current method of roaming control is conventionally known as “Preferred System Selection”. In the most common roaming situation, the wireless handset remains on the same band as the home cellular network. That is, if the wireless handset is homed to a cellular network with an odd numbered SID (which is normally assigned to an A band cellular service provider), then the wireless handset will obtain service from the A band cellular service provider when roaming. In addition to conventional cellular network systems, Personal Communications Services (PCS) systems are also available. PCS covers a broad range of individualized communication services. However, providing cellular or PCS services is costly. To recover these costs, a subscriber is normally required to pay a monthly fee and additional fees may be charged for time spent talking on the wireless handset (often referred to as airtime). Some service plans may give a subscriber a certain number of minutes of airtime free per month and then charge for every minute over that allotment. Other plans may charge for every minute spent using the wireless handset. In addition, the subscriber is often required to purchase the wireless handset or sign a multi-year service contract. Additional charges may also be incurred for service features (such as voice mail) or using the wireless handset in other service markets. Roaming charges can be costly, especially where preferred roaming carriers are not available. Forms of wireless or mobile communication that do not incur these fees are also available. For example, cordless phone systems, land mobile radio systems, CB radios and walkie-talkies are available. Cordless phone technologies are often utilized in home or office environments and operate over unlicensed bands to provide wireless or cordless phone capabilities via a cordless phone base station. Cordless phone units typically employ a manufacturer's proprietary protocol to manage full duplex communications between the handset and a single cordless phone base station connected to a phone line. Further, land mobile radio systems, CB radios, walkie-talkies and radios using the new family band provide half duplex (push-to-talk) wireless voice comminations over extended ranges (e.g., at ranges up to 2 miles). These devices communicate directly by broadcasting voice signals over channels that are shared with anyone who buys a similar device and desires to listen in to the conversation. Such technologies do not incur fees, since they do not rely upon a wireless network infrastructure or service provider, such as with cellular or PCS units. However, these devices also suffer from several drawbacks. For example, cordless phone systems operate over limited ranges and do not support direct handset-to-handset communication, since all calls are handled through the cordless phone base station. Cordless phone units also have limited capabilities and operating features that restrict their usefulness. Further, while land mobile radio systems, CB radios, walkie-talkies and other radio systems provide direct communication between units over extended ranges, such devices do not provide any level of privacy since all signals are broadcasted by the units and may be received by other parties. In addition, radio devices only provide half-duplex communications and require that users manually select similar operating channels. In recent years, Personal Handyphone System (PHS) handsets have been provided as an alternative and more economical solution for wireless communications. PHS systems utilize low powered handsets and a micro-cell network architecture including a large number of cell stations to provide coverage. Each cell station picks up a carrier at random from those available and selects a carrier on the basis of least interference. A traffic channel is then allocated to provide wireless communications. PHS systems also provide other features, such as user authentication, location registration and seamless handover during calls. PHS systems, however, have not been commercially successful in many developed countries (including the United States and Germany) and have limited handset features. In view of the foregoing, there is presently a need for a full-featured wireless handset that includes enhanced features or capabilities to provide a user with greater flexibility and optimum performance. For example, many users would benefit from a full-featured wireless handset that is capable of operating within a wireless network (such as a cellular phone, PCS or PHS network), as well as operating in a direct handset-to-handset mode within a limited range but without the utilization of a wireless network. Since direct handset-to-handset calls avoid the use of a wireless network, users would be provided with the benefit of being able to place calls free of the wireless network and with little or no airtime charges (i.e., monthly service or use charges could be applied to the user by the supplier of the wireless handset). A full-featured wireless handset with such functionality would have broad appeal to many users and could be applied to many applications to permit users to reduce their cellular phone charges. There is also a need for an improved wireless handset that has enhanced features, and which does not suffer from the drawbacks of existing communication devices, such as those described herein. For example, a wireless handset that is capable of operating in a direct handset-to-handset communication mode would be beneficial if it included enhanced features, such as full-duplex, private communication, dynamic channel allocation and handset locating capabilities. Such features would eliminate the need for users to prearrange or manually select operating channels (which is a common drawback in radio systems such as CB radios) and provide full duplex communication free of a communication network and without incurring substantial airtime charges. Various user groups and industries would benefit from such an enhanced wireless handset. For example, the functionality of such a wireless handset is currently needed by mobile crews, on-site mobile personnel, businesses, teachers, teenagers and families. Mobile crew workers, including contractors, electricians, plumbers, tow truck drivers and caterers, have a strong need for such a wireless handset to enable such personnel to keep in contact with one another at various job sites and to facilitate collaboration on projects at a substantial cost savings. On-site mobile personnel, such office building employees and personnel, security personnel, and warehouses, as well as teachers and other faculty members would also benefit from such a wireless handset, by enabling them to keep contact with other personnel and departments while spending much of their day in transit or in remote locations of the job site. In addition, there is a need for an enhanced, wireless handset communication device by teenagers and families which wish to keep in contact with one another during social events or vacations. Such a device would also provide an inexpensive solution for locating one another and preventing parties from being lost or separated. SUMMARY OF THE INVENTION In view of the foregoing, the present invention, through one or more of its various aspects, embodiments and/or specific features or subcomponents thereof, is thus intended to bring about one or more of the objects and advantages as discussed below. An object of the present invention is to provide a fully featured, wireless handset that provides greater flexibility and operating capabilities for users. In addition, an object of the invention is to provide a wireless handset that is inexpensive to operate and that includes enhanced features and capabilities. A further object of the invention is to provide a wireless handset that is capable of operating in a direct handset-to-handset communication mode. Another object of the present invention is to provide a wireless handset that has enhanced operating features, including the capability of operating either within a wireless network or outside of a wireless network in a direct handset-to-handset communication mode. Still another object of the present invention is provide a wireless handset that is capable of providing full-duplex communication and performing dynamic channel allocation to establish communication with another handset. Yet another object of the present invention is to provide a wireless handset with enhanced features, such as a find feature that assists a handset operator in determining what objects, including other handset users, are located within the handset's operating range. Another object of the invention is to provide a wireless handset that includes a memorize feature, which permits a wireless handset to exchange information conveniently and securely with another handset or object by wireless transmission. In addition, an object of the invention is to provide a plurality of enhanced features for a wireless handset, including find features, memorize features, conference call features and short range messaging features. Accordingly, an enhanced wireless handset is provided that is capable of operating within a traditional wireless network or in a direct handset-to-handset communication mode. The wireless handset includes enhanced operating features, including find features for locating objects, including other wireless handsets, paging devices and beeping devices or clips attached to items (such as keys, tools, pets, etc.), that are within range of the wireless handset. In order to provide such features, the wireless handset is implemented with: means for initiating a find feature to determine if at least one specified object is within range of the wireless handset; means for generating a query message over a control channel based on the initiation of the find feature; means for detecting a positive response message from the specified object in reply to the query message; and means for indicating, based on the positive response message being detected by the detecting means, that the specified object is within range of the wireless handset. According to an aspect of the invention, the wireless handset may include a find list that comprises a plurality of entries, wherein each of the entries includes information for specifying at least one object. The information of each entry in the find list may include the name and/or ID associated with the object specified by the entry. The initiating means may initiate a find feature based on the information of at least one entry of the find list. The wireless handset may also include means for selecting an entry in the find list to specify an object, whereby the initiating means initiates a specific find request based on the object specified by the entry of the find list selected with the selecting means to determine if the selected object is within range of the wireless handset. When no entry in the find list is selected with the selecting means, the initiating means may initiate a general find request based on each object specified by the plurality of entries of the find list in order to determine which objects on the find list are within range of the wireless handset. In accordance with another aspect of the invention, the indicating means may comprise means for recording information to a found list based on the positive response message and means for displaying the found list to indicate that the specified object is within range of the wireless handset. The wireless handset may also include means for detecting when a response has not been received, within a predetermined wait time, from the specified object in reply to the query message, and means for alerting that the object was not found when the detecting means detects that a response has not been received. The query message may comprise an ID of the specified object and an ID of the wireless handset that generated the query message. Means for detecting a signal strength of the positive response message may also be provided, and the indicating means may indicate the detected signal strength of the positive response message to the user of the wireless handset. In accordance with another aspect of the invention, a method is provided for locating objects, such as other wireless handsets, paging devices and beeping devices or clips, that are within range of a wireless handset. The method comprises: initiating a find feature to determine if at least one specified object is within range of the wireless handset; generating a query message over a control channel based on the initiation of the find feature; detecting a positive response message from the specified object in reply to the query message; and recording information to a found list based on the positive response message to indicate that the specified object is within range of the wireless handset. The method may further comprise providing a find list comprising a plurality of entries, and initiating a find feature based on information of at least one entry of the find list, wherein the information of each entry in the find list specifies at least one object to be located. The method may also provide selecting an entry in the find list to specify an object and initiating a find feature based on the object specified by a selected entry of the find list to determine if the selected object is within range of the wireless handset. When it is detected that no entry in the find list has been selected, a general find request may be initiated based on each object specified by the plurality of entries of the find list to determine which objects on the find list are within range of said wireless handset. The present invention also relates to a wireless handset with enhanced operating features, including find features for locating objects (such as other wireless handsets) that are within range of the wireless handset. In accordance with an aspect of the invention, the wireless handset comprises: means for initiating a find feature to determine if at least one specified object is within range of the wireless handset; means for tuning to a registry channel based on the initiation of the find feature; means for receiving a registry message on the registry channel from the at least one specified object in response to the query message; and means for recording information based on the registry message received from the at least one specified object. The information that is recorded by the recording means may include the name and/or ID associated with the specified object. Further, the recording means may record the information to a found list to indicate that the specified object is within range of the wireless handset. Alternatively, the information that is recorded by the recording means may comprise the ID associated with the specified object and a channel for contacting the specified object. In such a case, the recording means may record the information to a temporary list of the wireless handset. Further, means for generating a query message over the channel for contacting the specified object may be provided, as well as means for detecting a positive response message from the specified object in reply to the query message. The wireless handset may also comprise means for indicating, based on the positive response message detected by the detecting means, that the specified object is within range of the wireless handset, means for recording information to a found list based on the positive response message, and means for displaying the found list to indicate that the specified object is within range of the wireless handset. In this case, the information that is recorded by the recording means may indicate a channel for contacting the specified object and a slot time for contacting the specified object on the channel. In accordance with another aspect of the invention, a method is provided for locating objects that are within range of a wireless handset. The objects to be located may comprise other wireless handsets, paging devices and beeping devices or clips attached to items. In general, the method may comprise: initiating a find feature to determine if at least one specified object is within range of the wireless handset; tuning to a registry channel based on the initiation of the find feature; receiving a registry message on the registry channel from the at least one specified object in response to the query message; and recording information based on the registry message received from the at least one specified object. The information that is recorded may include the name and/or ID associated with the specified object. Further, in the disclosed method, information may be recorded to a found list to indicate that the specified object is within range of the wireless handset. According to another aspect of the invention, a wireless handset with enhanced operating features is provided, wherein the enhanced operating features comprise a memorize feature for exchanging information with objects, including other wireless handsets that are capable of operating in a communication mode with the wireless handset. To implement the memorize feature, the wireless handset may comprise: means for initiating a memorize feature with at least one object; means for generating a query message based on the initiation of the memorize feature to request a response from the at least one object; means for receiving a positive response message from the at least one object in reply to the query message; and means for recording information based on the positive response message received from the at least one object. The information that is recorded by the handset may include an ID or number associated with the at least one object. Further, the generating means may generate the query message at a reduced power level when the at least one object is in close proximity to the wireless handset, so that the query message is not received by other objects. The above-listed and other objects, features and advantages of the present invention will be more fully set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described in the detailed description which follows, by reference to the noted plurality of drawings by way of non-limiting examples of preferred embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: FIG. 1 illustrates the basic components of a conventional cellular network system; FIG. 2 illustrates exemplary components of a network infrastructure for supporting wireless communication between enhanced wireless handsets, according to an aspect of the present invention; FIG. 3 illustrates, in accordance with another aspect of the present invention, a direct handset-to-handset communication mode between wireless handsets; FIG. 4A is an exemplary block diagram of the main components of a wireless handset, in accordance with an aspect of the present invention; FIG. 4B illustrates, in accordance with an aspect of the invention, exemplary features of a wireless handset; FIG. 5 illustrates a state transition diagram of a wireless handset, in accordance with an aspect of the invention; FIGS. 6A, 6B, 6C, 6D and 6E are exemplary flowcharts of the various processes and operations that may be performed by a wireless handset of the invention when operating in an Idle state and responding to messages from other handsets; FIGS. 7A and 7B illustrate exemplary flowcharts of the various processes and operations in an Paging state, according to an aspect of the invention; FIG. 8 illustrates an exemplary flowchart of the various processes and operations in a Conversation state, according to an aspect of the invention; FIGS. 9A and 9B are exemplary flowcharts of the various processes and operations that may be carried out for performing a general find request with a separate or dedicated tuner; FIGS. 10A and 10B are exemplary flowcharts, in accordance with another embodiment of the invention, of the various processes and operations that may be carried out for performing a general find request with a predefined control channel; FIGS. 11A and 11B are exemplary flowcharts of the various processes and operations that may be carried out for performing a general find request, in accordance with yet another embodiment of the invention; FIG. 11C is an illustration of the manner in which handsets may register sequentially on a control channel; FIGS. 12A and 12B are exemplary flow charts of another embodiment of the invention for performing a general find request; FIGS. 13A and 13B are exemplary flowcharts of the various processes and operations that may be carried out for performing a specific find request with a separate or dedicated tuner; FIGS. 14A and 14B are exemplary flowcharts, in accordance with another embodiment of the invention, of the various processes and operations that may be carried out for performing a specific find request to locate a specific object, such as another wireless handset user, with a predefined control channel; FIGS. 15A and 15B are exemplary flowcharts of the various processes and operations that may be carried out for performing a specific find request, in accordance with yet another embodiment of the invention; FIGS. 16A and 16B are exemplary flow charts of another embodiment of the invention for performing a specific find request; FIGS. 17A and 17B are exemplary flow charts of an embodiment for performing a memorize feature of the present invention; FIGS. 18A, 18B and 18C illustrate an embodiment for providing three-way conferencing through the use of time domain multiplexing; FIGS. 19A and 19B illustrate an embodiment for locating a non-transmitting object, such as a paging or clip device attached to an item; FIGS. 20A and 20B illustrate an embodiment for locating a transmitting object, such as a paging or clip device attached to an item; FIGS. 21A and 21B illustrate an embodiment for locating a transmitting object, such as a paging or clip device attached to an item, and causing the device to emit an audible beep; FIGS. 22A and 22B are exemplary flowcharts of the various processes and operations that may be carried out by a wireless handset (i.e., handset A) when a free call is to be initiated and set up with another handset (i.e., handset B); FIGS. 23A and 23B are exemplary flowcharts of the various operations and procedures that may be carried out by handset B when responding to the call request from handset A; FIGS. 24A and 24B are exemplary flowcharts of the functions and procedures carried out by handset A when negotiating a channel for the call with handset B, wherein handset A acts as the originator or originating party for the channel negotiation; FIGS. 25A and 25B are exemplary flowcharts of the various procedures and operations carried out by handset B when negotiating the channel for the call with handset A wherein handset B acts as the recipient for the channel negotiation; FIGS. 26A and 26B are exemplary flowcharts of the various processes and operations carried out by handset A for initiating a call with handset B, when handset B is on a call with another handset (i.e., handset C); FIGS. 27A and 27B are exemplary flowcharts of the various processes and operations that may be carried out by handset B to handle the call request from handset A, while handset B is on a call with handset C; FIG. 27C is an exemplary flowchart of the various processes and operations that may be carried out by handset C when it is placed on hold by handset B to accept the call request from handset A; FIG. 28 is an exemplary flowchart of the various processes and operations that may be carried out by handset A to initiate a call request and establish a free call with handset B through the use of a dedicated channel; FIG. 29 illustrates the various operations and procedures that may be carried out by handset B when responding to the call request from handset A; FIGS. 30A and 30B are exemplary flowcharts of the various processes and operations that may be carried out by handset A when negotiating a channel with handset B, with handset A acting as the originator or originating party; FIGS. 31A and 31B are exemplary flowcharts of the various processes and operations that may be carried out by handset B when negotiating a channel with handset A, with handset B acting as the recipient or receiving party; FIG. 32 is an exemplary flowchart of the various processes and operations carried out by handset A for initiating a call with handset B, when handset B is on a call with another handset (i.e., handset C); FIG. 33 is an exemplary flowchart of the various processes and operations that may be carried out by handset B to handle the call request from handset A, while handset B is on a call with handset C; FIG. 34 is an exemplary flowchart of the various processes and operations that may be carried out by handset C when it is placed on hold by handset B to accept the call request from handset A; FIG. 35 is an exemplary block diagram of the main components of a non-transmitting clip device, in accordance with an aspect of the present invention; FIG. 36 is an exemplary block diagram of the main components of a transmitting clip device, in accordance with another aspect of the present invention; FIGS. 37 and 38 are exemplary flowcharts, in accordance with an aspect of the invention, of the various processes and operations that may be carried out by handset A and handset B, respectively, to establish a free call through the utilization of a dedicated control channel; FIGS. 39A and 39B illustrate exemplary flowcharts of the various processes and operations in a Find Request state, according to an aspect of the invention; FIGS. 40A and 40B illustrate exemplary flowcharts of the various processes and operations in a Memorize Request state, according to another aspect of the invention; and FIGS. 41A and 41B illustrate exemplary flowcharts of the various processes and operations in an Short Range Messaging state, according to still another aspect of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, a detailed description of the preferred embodiments and features of the present invention will be provided. The present invention relates to a wireless handset that includes enhanced features to provide greater flexibility and optimum performance. According to an aspect of the present invention, a wireless handset is provided that permits a user to operate either within a wireless network or to communicate with another user in a direct handset-to-handset operating mode. The direct handset-to-handset communication mode provides full-duplex, two-way communication without utilizing a wireless network infrastructure. In addition, as further described herein, the wireless handset of the present invention includes features that enhance the operability and functionality of the handset. Such features include a find or locate feature that assists a handset operator in determining what other handset users are located within the operating range of the wireless handset. These and other features and aspects of the present invention will now be described in greater detail with reference to the accompanying drawings. The wireless handset of the present invention may be implemented as a fully featured handset that is capable of operating in a wireless network, such as a cellular or PCS network, and/or to operate independent of a wireless network in a direct handset-to-handset communication mode. FIGS. 2 and 3 illustrate the main operating modes of the wireless handset of the invention. While it is preferred that the handset is provided with this dual capability or functionality, it is possible to implement the wireless handset and features of the present invention in the form of a special purpose handset that is capable of only operating in a direct handset-to-handset communication mode. Such a special purpose handset may communicate with other special purpose handsets and/or with full-featured handsets that are also capable of operating within a wireless network. In addition, it is also possible to implement the wireless handset of the present invention in the form of a handset that is capable of operating in a direct handset-to-handset communication mode and that can function as a cordless phone in cooperation with a cordless phone base station. Such a wireless handset may also be provided with the capability to operate within a wireless network, such as a cellular or PCS network. Other modifications and implementations may be realized according to the needs of the wireless handset user. FIG. 2 illustrates a wireless network operating mode of a wireless handset, according to an aspect of the present invention. As shown in FIG. 2, wireless handsets 42A, 42B may communicate with one another via a wireless network infrastructure 132. Wireless network infrastructure 132 may be implemented utilizing conventional cellular or PCS technology. In the exemplary embodiment of FIG. 2, wireless handset 42A may establish wireless communication with wireless handset 42B under the control of mobile switching center (MSC) 124. Assuming that wireless handset 42A is operating within a cell coverage area 145 of base station or cell site 140, a call may be completed to wireless handset 42B operating within cell coverage area 135 of base station or cell site 130 by use of conventional air interface technology and landlines 116 connecting the base stations to the MSC 124. A call may also be completed if both wireless handsets 42A and 42B are operating within the same cell coverage area (e.g., area 135 or 145), in which case only one base station is involved. When operating within wireless network infrastructure 132, calls initiated by either wireless handset 42A or 42B are normally assessed airtime charges or fees according to the service plans subscribed to by the users. In addition, fees may also be assessed if either handset 42A or 42B is roaming outside of its home market area or if certain service options are enabled. When operating in a direct handset-to-handset communication mode, the wireless handsets 42A, 42B of the present invention directly establish communication between one another without use of a wireless network infrastructure. As a result, airtime charges may be avoided when the wireless handsets 42A, 42B are functioning in a direct handset-to-handset mode and independently of a network. As illustrated in FIG. 3, when communicating in a direct handset mode, wireless handsets 42A, 42B can directly communicate with one another without the use of a base station or MSC. As further described herein, the selection and setup of a channel for providing communication between the handsets may be established through the use of a dynamic channel allocation technique or process. In such a case, predefined channels may be allocated and searched, with a channel being selected based on the channel having the least detected interference level or the first located channel providing sufficient signal strength. In addition, other channel selection and setup techniques may be utilized to avoid the need for manual channel selection and coordination by each user or operator. As discussed above, the wireless handset of the present invention may be configured and implemented according to the level of functionality and operability that is required (e.g., direct handset mode only or with dual communication mode capabilities). FIGS. 4A and 4B illustrate exemplary components and features of a wireless handset that is capable of operating both within a wireless network and outside of a wireless network in a direct communication mode. The construction and features of wireless handset 42 in FIGS. 4A and 4B may be utilized to construct the wireless handsets 42A or 42B illustrated in FIGS. 2 and 3 and further described herein. As illustrated in the exemplary block diagram of FIG. 4A, wireless handset 42 may be implemented as a full featured wireless handset that comprises a control system 61, an antenna 62, a transceiver or tuner 63, a speaker 64, a display 65, a keypad 66, a microphone 67, and memory 70. An input/output (I/O) port 69 may also be provided for facilitating communication with various devices (such as a portable computer, modem, printer, etc.) and for downloading or loading information into memory 70. Wireless handset unit 42 may be configured to provide all the features of a conventional cellular handset unit, in addition to the unique programming and memory configurations and contents for implementing the direct handset communication mode and other operating features of the present invention. By way of non-limiting example, speaker 64 may comprise a conventional speaker for converting electrical audio signals received by antenna 62 into acoustic audio signals, and microphone 67 may comprise a conventional microphone for converting voice utterances of a user from acoustic audio signals into electric audio signals for transmission by antenna 62. In addition, display 65 and keypad 66 may be implemented by conventional display and keypad devices for displaying and permitting entry of alphanumeric and other information. For instance, display 65 may comprise dedicated status lights and/or a liquid crystal display (LCD) to indicate (through flashing lights, alphanumeric messages, symbols, icons, etc.) the status of the wireless handset unit and the operating mode. Further, keypad 66 may comprise menu selection buttons and/or a conventional 12-button, alphanumeric keypad for initiating and receiving calls, and programming or selecting operating conditions for the wireless handset. The keys of keypad 66 may include dedicated keys which initialize or select certain functions of the handset or enter alphanumeric data when pressed. The keys of keypad 66 may also include “soft keys” which provide multiple functionality depending on the operating state or mode of the handset. For example, a soft key may be provided which functions as both a power (i.e., ON/OFF) switch as well as an end call (i.e., On-Hook) switch. FIG. 4B illustrates an exemplary embodiment of the external construction and arrangement of the main components of wireless handset 42, including antenna 62, speaker 64, display 65, keypad 66, and microphone 67. The arrangement of these components may of course be modified or enhanced according to the needs of the user and the type of features incorporated into the handset. In addition, as discussed above, wireless handset 42 may also include an I/O port 69 (illustrated as being provided on a side surface of wireless handset 42 in FIG. 4B) to facilitate the loading and downloading of information into memory 70 of the wireless handset 42. I/O port 69 may comprise, for example, a data port, a Subscriber Identity Module (SIM) card slot and/or other types of ports or slots. Memory 70 of wireless handset 42 may store the MIN, programming and other operational information to implement the various features and aspects of the invention. Memory 70 may comprise a read-write memory device that has an independent power supply or whose contents will not be effected by power downs of ordinary duration. By way of non-limiting example, memory 70 may be implemented by a programmable Electronically Erasable Programmable Read Only Memory (EEPROM), a Complimentary Metal Oxide Semiconductor (CMOS) memory chip, or a conventional Random Access Memory (RAM) with an independent power supply. As illustrated in the exemplary architecture arrangement of FIG. 4A, antenna 62 may be connected to transceiver or tuner 63, which in turn is connected to a control system 61. Although transceiver 63 is illustrated as a single unit in FIG. 4A, a separate transmitter and receiver may also be provided to provide the functionality of transceiver 63. Control system 61 may be implemented as a microprocessor-based control system and may be programmed to carry out the various features of the invention. The programming of control system 61 may be carried out by any suitable combination or use of software, hardware and/or firmware. Control system 61 may control the various components of the wireless handset 42 to permit a user to send and receive calls and program the wireless handset. In addition, control system 61 may have access to memory 70, in which the MIN and other programming information is stored, for directing operation of the wireless handset. A more detailed description of the various processes and functions of the operating features and modes of the invention is provided below with reference to the accompanying drawings. As discussed above, the wireless handset of the present invention may be a full-featured wireless handset that is capable of operating within a wireless network (e.g., a cellular or PCS network) or in a direct handset-to-handset communication mode that functions independently of a wireless network. As such, the wireless handset of the present invention may be embodied as a full featured wireless handset capable of making traditional wireless calls and that has the additional functionality of enabling the handset to place direct calls to other handsets. Since direct calls do not access a wireless network, such calls will operate free of the wireless network and with little or no airtime charges (i.e., a monthly service or use charge may be charged to the user by the provider of the wireless handset). Direct calls that are placed without access to a network are referred to as “free calls” herein. According to an aspect of the present invention, the wireless handset may be provided with traditional or conventional wireless features, as well as the specific features and functionality of the present invention. Generally, the features of the wireless handset may be classified into the following categories: Traditional Wireless features; Free Call Control features; Find features; List Maintenance features; Conference Call features; Short Range Messaging features; and Accessory-Related features. Each of these features will be discussed in greater detail below. If the wireless handset is embodied to provide Traditional Wireless features and call functionality, then the wireless handset may be implemented with traditional analog and/or digital wireless features. Such features may include: Caller ID; Caller ID Log; Short Message Service (SMS); Auto Answer; Choice of Alerts; Vibration Alert; Call Mute; Large, Scrollable Speed Dial List; Headset (with microphone accessory); and Computer Connectivity and Control. Any combination of these features, as well as additional features, may be embodied in the wireless handset to facilitate traditional analog and/or digital wireless connectivity. Of course, as discussed above, it is possible that the wireless handset be provided as a special purpose handset with only direct handset-to-handset functionality. In such a case, the above-described features may be eliminated or may be modified and provided to support direct handset communication. As indicated above, calls made in a direct handset communication mode with the wireless handset are referred herein to as “free calls”, since such calls are made free of the wireless network and with little or no airtime charges. Free Call Control features may be provided to enhance the operation of the wireless handset when calls are placed directly from one handset to another. These features may encompass both call initiate and call receive features, and call in progress and alert features. Various call initiate feedback features may also be provided for Free Call Control. For example, when a user initiates a free call with the handset, the status or progress of the call may be indicated to the user through the use of predetermined messages and/or icons that are displayed on the handset and/or the generation of predetermined audible tones that are transmitted to the user through the speaker of the handset. For example, the display of the handset may indicate the name or ID of the handset to which the call is directed, and one or more icons or messages may be displayed on the handset to indicate the progress of the call (e.g., on-hook, off-hook, ringing, etc.). The status and progress of the initiated call may also be indicated to the user through the use of predetermined audible tones (e.g., dialing, ringing, busy, etc.). Messages may also be displayed on the handset to provide feedback to the user as to whether the offered call was not responded to or received by the called party. With such features, a user will be better equipped to handle and control direct handset calls with other users. As indicated above, the handset of the present invention may also be provided with various Find features. These features may be provided to permit a user to determine all objects, including other handset users, that are within range or to determine if a specific handset or object is within range of the user. As further described below, the handset of the user may have a prestored find list of other handsets or objects that can be located with the Find features. A user may be given the option to locate a specific handset or object on the list or to initiate a general find function such that each of the handsets or objects on the list are queried to determine if they are within range. In order to maintain privacy, each handset or object may only respond to a query if they have the querying handset on a list and they are in range of the user. As a result, only handsets or objects that have given the querying handset permission to find them will respond to a find query. The wireless handset of the present invention may also include a set of List Maintenance features. These features may be provided to permit a user to add and delete handsets or objects to one or more lists stored in the handset, such as a speed dialing list for initiating calls, a find list for locating other handsets or objects, and/or a privacy list for blocking find queries from specific handsets so that privacy may be maintained. With the List Maintenance features, a user may be permitted to add, delete and view each list stored in their handset. In accordance with an aspect of the present invention, a single list may be stored in each handset to function as a master list for all direct handset calls. In such a case, the master list may serve as a speed dial list, a find list and a privacy list. That is, the master list serves as a speed dial list when a direct handset call is initiated by a user, and also serves as a querying or find list when a find function is initiated by a user to locate all handsets or objects, or a specific handset or object that is within range. The List Maintenance features may also include a memorize feature which permits two handsets to update their respective master list, find list or privacy list with the ID of the other handset. The memorize feature may be activated when handsets are brought in close proximity to each other or their respective antennas are brought into contact, and users press a predetermined key or button within a short time window. As further discussed below, the memorize feature may also permit a user to memorize other objects, such as an accessory or device that is capable of being queried (such as a beeping clip or paging device) by activating the memorize function on the object in order to automatically add the object to the find list. Other features that may be provided with the wireless handset include Conference Call features, Short Range Messaging features, and Accessory-Related features. The Conference Call features may permit “free call” conferencing between three handset users. The three-way conferencing may be enabled through time domain multiplexing and, as further described below, may utilize either a fixed controlled time slot or a variable controlled time slot to permit conferencing. The Short Range Messaging features may include features to permit short range messages to be sent directly from one handset to another handset when both handsets are idle or during a controlled time slot if the receiving handset is on a call. Further, Accessory-Related features may be provided to enhance the wireless handset of the present invention. For example, computer connectivity may be provided to enable downloading of lists and configuration data. Further, beeping clips or other paging devices may be provided that can be attached or secured to items (such as keys, wallets, tools, etc.) in order to facilitate finding those items through the Find features of the invention. In order to implement the wireless handset of the present invention with such functionality, the wireless handset may be embodied with any suitable combination of hardware, software, logic and/or programmed code to perform the required functions. FIG. 5 illustrates a state transition diagram of the functionality that may be embedded in the wireless handset to provide direct handset-to-handset communication and free call capability. The exemplary state transition diagram of FIG. 5 illustrates the various states and trigger conditions to transition between each state. As discussed above, this functionality may be provided in a special purpose wireless handset or preferably may be embodied or bundled with a wireless handset which also has cellular or PCS capability. A wireless handset having both capabilities would provide a user with nearly ubiquitous coverage, either handset-to-handset or via a wireless network. In addition, such a wireless handset can also share circuitry to reduce costs over having two separate wireless handsets. For example, the handset-to-handset communication capability can use the same 10 Kbps data circuitry used in conventional analog cellular phones. The same voice processing circuitry could also be used, as well as the same housing, keypad, display, antenna, microphone, speaker, etc. by both functions. Referring to FIG. 5, when the wireless handset is powered or turned ON, the wireless handset may initialize and enter an Idle state. When in an Idle state, the wireless handset is waiting for a call. Calls may be placed in a direct handset-to-handset communication mode by dialing the assigned directory or telephone number of the handset. If a wireless handset is provided with dual functionality, the telephone number of the analog or digital handset (i.e., the MIN) may be the same number used for placing free calls to the wireless handset in a direct communication mode. In a direct communication mode, full duplex handset-to-handset call setup and call states are provided using frequency domain duplexing. In an Idle state, the receiver of the wireless handset may monitor a higher range of the duplex band to search for pages directed to its internally stored directory number or MIN. Free calls may be set up and handled over a non-cellular or unlicensed band. For example, direct handset-to-handset communication may be provided by utilizing a non-cellular, unlicensed band such as the 930 MHZ Industrial, Scientific and Medical band that is authorized under Part 15 of the FCC Rules. As further discussed below with reference to FIGS. 6A-6E, when a wireless handset is in an Idle state, the receiver of the handset may scan a predetermined set of frequencies (i.e., f.sub.1, fsub.2, . . . f.sub.N). When the receiver or transceiver of the wireless handset tunes to a frequency, the handset may dwell long enough to measure the signal strength, obtain synchronization and decode a paging message, if available. If the signal strength is below a set threshold, or if no message is being sent, or a paging message directed to a different mobile station or wireless handset is decoded, the wireless handset may tune to the next frequency and repeat the process. If a paging message directed to the wireless handset is decoded, then the responding handset may send a page response on a lower range of the duplex band corresponding to the frequency to which the receiver is tuned. While paging, the originating wireless handset receiver listens for a page response on the lower associated duplex frequency (Paging state in FIG. 5). If the receiver decodes the response without error, then the wireless handset will switch to a voice mode on the same duplex frequency pair and enter a Conversation state. This is illustrated in FIG. 5 by condition f (page received and user answers). If the page response is not decoded after a predetermined number of attempts (i.e., M page attempts), the originating handset may provide a reorder alert (e.g., a reorder tone in the speaker or earpiece) and not enter into a Conversation state. “M” may be selected to ensure that a handset in the Idle mode will scan and decode the frequency at least once. Under this condition, the originating wireless handset which sent the paging message will return to an Idle state from a Paging state. This transition is illustrated in FIG. 5 by condition c (no page response received). In an Idle state, the paged wireless handset may respond a predetermined number of times (e.g., L times) when paged by an originating wireless handset. “L” may be greater than one to increase the reliability that the message will be received without errors. The paged wireless handset will then switch to a voice mode and enter a Conversation state when the user indicates that the call should be answered (i.e., a user may press an answer key to indicate that the call should be received). This transition is indicated in FIG. 5 by condition f (page received and user answers). Otherwise, if the user does not answer, the paged wireless handset will eventually time out and stay in an Idle state. FIGS. 6A-6E are exemplary flowcharts of the various processes and operations that may be performed by a wireless handset of the invention when operating in an Idle state and responding to various messages from other handsets. According to an aspect of the present invention, N frequency pairs may be assigned to the wireless handset. The higher frequency associated with the duplex channel “i” is designated as F.sub.hi. Further, in the illustrated embodiment, the lower frequency is designated as F.sub.li. Essentially, up to N simultaneous calls can be supported assuming adequate adjacent channel selectively in the wireless handsets. FIG. 6A illustrates a sequential scan of the N channels. Alternative arrangements, however, may be provided. For example, a quick search based on signal strength could be implemented. In such a case, only channels exceeding a predetermined or programmed signal strength threshold would be evaluated for synchronization and paging messages. Further, the signal strength ranking would be updated periodically. In the exemplary embodiment of FIG. 6A, when a wireless handset enters an Idle state, the receiver of the wireless handset is switched to a predetermined higher band of the duplex pass band (see step S.2). Further, at step S.2, the transmitter is switched to a predetermined lower band of the duplex pass band. Thereafter, at step S.4, a counter i is set to 1. At step S.6, the receiver of the wireless handset is tuned to the high frequency F.sub.hi. After tuning the receiver to the frequency F.sub.hi, the handset waits for a synchronization signal. At step S.8, it is determined whether a synchronizing signal is received. If synchronization is received, then logic flow proceeds to step S.12. Otherwise, at step S.10, the counter i is modified according to the following formula: i=(i+1)mod N. Following step S.10, logic flow returns to step S.6, where the receiver of the handset is returned to the next high frequency F.sub.hi. At step S.12, the wireless handset determines whether a page message has been received. If a page message is not received within a predetermined period of time, then logic flow proceeds to step S.16, where the handset determines whether another type of message has been received. Otherwise, at step S.14, the called party directory number DNr is decoded by the receiver based on the page message that is received and it is determined whether the directory number DNp stored in the wireless handset is the same as or corresponds to the called party directory number DNr. If it is determined at step S.14 that DNr=DNp, then at step S.1600 (see FIG. 6B) the transmitter of the wireless handset is tuned to the lower frequency F.sub.li. Otherwise, logic flows back to step S.10, so that i is modified and the receiver is tuned to a different high frequency. As shown in FIG. 6B, following step S.1600, the receiving wireless handset sends a page response message at step S.1618. In accordance with an aspect of the present invention, the page response message may be sent back to the originating wireless handset repetitively to ensure receipt of the same. For this purpose, the page response message may be sent a predetermined number of times (e.g., L times). Thereafter at step S.1620, the receiving wireless handset may activate an alerter of the receiving handset so as to provide an alert indication to the user of the incoming call. The alert indication provided by the alerter may comprise an alerting signal or tone (such as a ringing signal or tone) or activation of a vibration mechanism to cause the wireless handset to vibrate. Other alerting indications may be provided and may be activated by the user. As further shown in FIG. 6B, at step S.1622, the wireless handset determines whether the user has indicated to answer the incoming call in response to the generation of the alert indication. In accordance with an aspect of the present invention, the user may be given a predetermined amount of time (i.e., T.sub.alert seconds) to respond to and to indicate whether a call should be answered. If the wireless handset user indicates to answer the call within the predetermined time (e.g., by pressing an answer or talk button on the wireless handset), the wireless handset may switch to a voice mode at step S.1624 and enter into a Conversation state to provide full duplex communication between the wireless handsets. Otherwise, at step S.1626, the wireless handset may display an indication to the wireless handset user that the call was received but not answered and, thereafter, enter into an Idle state. Referring again to FIG. 6A, if it is determined that a page message was not received at step S.12, then at step S.16 the handset will determine whether a find message has been received from another handset. As disclosed herein, the wireless handsets of the present invention may include a find feature that permits a handset to locate objects, including other wireless handsets, that are within range. If a find message has been received at step S.16, then logic flow proceeds to step S.18. Otherwise, if a find message has not been received at step S.16, the handset proceeds to step S.20 to determine if another type of message has been received. At step S.18, the called party directory number DNr is decoded by the receiver of the handset based on the find message that is received and it is determined whether the directory number DNp stored in the wireless handset is the same as or corresponds to the called party directory number DNr. If it is determined at step S.18 that DNr=DNp, then at step S.1630 (see FIG. 6C) the wireless handset will determine whether the requesting handset that sent the find message is on its Find list. Otherwise, logic flows back to step S.10, so that i is modified and the receiver is tuned to a different high frequency. As illustrated in FIG. 6C, at step S.1630 it is determined whether the requesting DN is on the Find list of the handset. The determination at step S.1630 may be made by comparing the directory number DN or ID of the requesting handset provided in the find message that was received with the entries in the Find list of the wireless handset. As further described below, this determination may be made in order to maintain privacy and limit the find capability to only authorized handset users. If the requesting DN is on the Find list, then at step S.1632 the transmitter of the wireless handset is tuned to the lower frequency F.sub.li. Otherwise, the find request may be ignored and the handset may enter back into the Idle state following step S.1630. After tuning the transmitter at step S.1632, the receiving wireless handset sends a found response message to the requesting handset at step S.1634. In accordance with an aspect of the present invention, the found response message may be sent back to the requesting wireless handset repetitively to ensure receipt of the same. For this purpose, the found response message may be sent a predetermined number of times (e.g., L times). Thereafter, at step S.1636, the receiving wireless handset may activate a found alerter of the receiving handset so as to provide an alert indication to the user of the find request. The alert indication provided by the alerter may comprise an alerting signal or tone (such as a ringing signal or tone) and/or a message that is displayed on the handset. In addition, at step S.1638, the receiving handset may update a Found list so as to indicate that the requesting handset is within range. Following step S.1638, the wireless handset may enter an Idle state. Referring once again to FIG. 6A, if it is determined that a find message was not received at step S.16, then at step S.18 the handset will determine whether a memorize message has been received from another handset. As disclosed herein, the wireless handsets of the present invention may include a memorize feature that permits handsets to exchange handset information, including handset DN or ID, and corresponding name. If a memorize message has been received at step S.20, then logic flow proceeds to step S.22. Otherwise, if a memorize message has not been received at step S.20, the handset proceeds to step S.24 to determine if another type of message has been received. At step S.22, the called party directory number DNr is decoded by the receiver of the handset based on the memorize message that is received and it is determined whether the directory number DNp stored in the wireless handset is the same as or corresponds to the called party directory number DNr. If it is determined at step S.22 that DNr-DNp, then at step S.1640 (see FIG. 6D) the wireless handset will set the value of a timer i to zero. Otherwise, logic flows back to step S.10, so that i is modified and the receiver is tuned to a different high frequency. As illustrated in FIG. 6D, at step S.1640 the value of a timer i is initialized and set to zero. Thereafter, the handset determines at step S.1642 whether the user has responded by pressing an appropriate key or button on the handset (e.g., a memorize key) so as to activate the memorize feature. In accordance with an embodiment of the memorize feature described herein, the memorize feature must be activated by both handsets within a predetermined time window to permit the exchange of information to occur. If the memorize feature is not activated at step S.1642, then the handset will increment the timer i by one at step S.1644 and determine at step S.1646 whether the value of the timer i is greater than or equal to a predetermined time limit i.sub.max. If the value of the timer i.sub.max, is less than i.sub.max, then logic flow loops back to step S.1642 to again determine whether the memorize feature has been activated. Otherwise, if the timer i is not less than i.sub.max, then the time limit for activating the memorize feature has been exceeded and the memorize request is ignored, with the handset entering the Idle state. If the user responds and activates the memorize feature at step S.1642, then at step S.1648 the transmitter of the wireless handset is tuned to the lower frequency F.sub.li. Further, after tuning the transmitter at step S.1648, the wireless handset sends a memorize response message to the requesting handset at step S.1650. In accordance with an aspect of the present invention, the response message may be sent back to the requesting wireless handset repetitively to ensure receipt of the same. For this purpose, the memorize response message may be sent a predetermined number of times (e.g., L times). Thereafter, at step. S.1652, the receiving wireless handset may activate a memorize success alerter so as to provide an indication to the user of that the memorize feature has been invoked with the requesting handset. The alert indication provided by the alerter may comprise an alerting signal or tone (such as a ringing signal or tone) and/or a message that is displayed on the handset. Following the successful exchange handset information, at step S.1654 the handset may update the speed dial and/or find lists of the handset with the handset information of the handset that sent the memory request. Following step S.1654, the wireless handset may enter an Idle state. As shown in FIG. 6A, if it is determined that a memorize message was not received at step. S.20, then at step S.24 the handset will determine whether a short range message has been received from another handset. As disclosed herein, the wireless handsets of the present invention may include a short range messaging feature that permits handsets to send and receive short range messages. If a short range message has been received at step S.24, then logic flow proceeds to step S.21. Otherwise, if a memorize message has not been received at step S.24, logic flow loops back to step S.10, so that i is modified and the receiver is tuned to a different high frequency. At step S.26, the called party directory number DNr is decoded by the receiver of the handset based on the short range message that is received and it is determined whether the directory number DNp stored in the wireless handset is the same as or corresponds to the called party directory number DNr. If it is determined at step S.26 that DNr-DNp, then at step S.1660 (see FIG. 6E) the wireless handset will tune the transmitter of the handset to the lower frequency F.sub.li. Otherwise, logic flows back to step S.10, so that i is modified and the receiver is tuned to a different high frequency. At step S.1660, the transmitter of the wireless handset is tuned to the lower frequency F.sub.li. As illustrated in FIG. 6E, after tuning the transmitter at step. S.1660, the wireless handset sends a short range message response message to the transmitting handset at step S.1662 to confirm receipt of the short range message. In accordance with an aspect of the present invention, the response message may be sent back to the originating wireless handset repetitively to ensure receipt of the same. For this purpose, the short range message response message may be sent a predetermined number of times (e.g., L times). Thereafter, at step S.1664, the receiving wireless handset may activate an alerter so as to provide an indication to the user of that a short range message has been received. The alert indication provided by the alerter may comprise an alerting signal or tone (such as a ringing signal or tone) and/or a message (e.g., “Short Range Message Received”) that is displayed on the handset. Following step S.1664, the handset may decode the short range message at step S.1668 and, display and/or store the decoded message with the handset. The decision to display or store the message may be optional and/or controlled by the user. Following step S.1668, the wireless handset may enter an Idle state. As illustrated in FIG. 5, the wireless handset will transition between an Idle state and a Conversation state under condition f; that is, when a page message is received and the user answers, the wireless handset will transition from an Idle state to a Conversation state. In a Conversation state, the wireless handset will operate in a voice mode to provide full duplex communication between the wireless handsets. The wireless handset may return to an Idle state under various conditions. For example, as further illustrated in FIG. 5, the wireless handset will return to an Idle state from a Conversation state under condition d (when the user indicates that the call is to be ended by pressing, for example, an end key). A transition from a Conversation state to an Idle state may also occur where a supervisory signal is lost (this is indicated by condition e in FIG. 5). When an originating wireless handset initiates a call, the originating wireless handset will transition from an Idle state to a Paging state. The transition from an Idle state to the Paging state occurs under condition a, when a user indicates to initiate or start a free call by pressing a send or free key on the wireless handset. In the Paging state, the wireless handset essentially functions in a state where it pages another wireless handset based on the directory number or telephone number entered by the user. Normally, the Paging state is entered from the Idle state according to the conditions described above. More specifically, the trigger to enter the Paging state is when a valid handset or object is chosen and the appropriate key (such as a send button or free call button) is pressed by the user. As illustrated in FIG. 5, the wireless handset may transition back to the Idle state under various conditions. Condition b and condition c in FIG. 5 illustrate two such examples. In condition b, the wireless handset will transition from the Paging state to the Idle state when the called party does not answer the call request. Additionally, the transition from the Paging state to the Idle state will occur under condition c, when no page response has been received by the originating wireless handset. If a page is successfully received and the call request is answered by the called party, then the wireless handset will transition from a Paging state to the Conversation state. This condition is depicted in FIG. 5 by condition h (i.e., page response received and called party answers). As described above, in a Paging state, the wireless handset pages another wireless handset with the appropriate directory number or phone number. FIGS. 7A and 7B illustrate an exemplary flowchart of the various processes and operations that may be carried out during a Paging state. Generally, in a Paging state, the wireless handset swaps the transmit and receive frequencies so that other wireless handsets in an Idle state can listen for pages. If a page is responded to and the called party enters the Conversation state, the call is set up. Prior to selecting a channel, the wireless handset may check the channel for possible interference based on, for example, signal strength. The exemplary flowchart of FIGS. 7A and 7B illustrate that such checks may be made until a channel is located that has a signal strength less than or equal to a predetermined threshold level, THR.sub.rssi. As an additional measure, the wireless handset may be configured such that it will terminate analysis of channels for signal strength after a predetermined period of time and provide a warning tone to the user to indicate that no channels are available. More particularly, as illustrated in FIG. 7A, when entering a Paging state, a wireless handset will first prepare or gather the handset phone number at step S.30. The called party digits may correspond to the directory or phone number of the wireless handset of the called party. At step S.32, the wireless handset will then switch the receiver to the lower frequency band of the duplex pass band and will switch the transmitter to the higher frequency band. At step S.34, the handset will initialize a counter i to 1. Then, at step S.36, the receiver of the handset will be set to the low frequency F.sub.li and the transmitter will be tuned to the higher frequency F.sub.hi. After tuning the receiver and transmitter, the wireless handset will determine at step S.38 whether there is interference in the channel. Interference may be analyzed by determining whether the signal strength of the channel is not greater than a predetermined threshold. For example, at step S.38, the wireless handset may determine whether the received signal strength of the channel is less than or equal to a threshold level THR.sub.rssi. If it is not, then at step S.40, the count i may be modified according to the following equation: i=(i+1)mod N After i is reset, logic flow proceeds back to step S.36 so that another channel is tuned to and analyzed for interference. If the signal strength of the channel is determined to be appropriate, then at step S.42 a counter m is initialized and set to 0. Thereafter at step S.44 (see FIG. 7B), a synchronization signal is sent by the wireless handset, as well as a paging message at step S.46. The paging message may contain the directory phone number of the called party, as well as the calling party name or number for caller ID purposes. If caller ID is not equipped in the system, then sending of the calling party name and number is not necessary in or processed from the paging message. At step S.48, it is determined whether a page response message has been received indicating that the called party's wireless handset is within range. If no page response message is received, then at step S.50 the counter m is incremented by one and at step S.52 it is determined whether m has exceeded a predetermined limit L. If m is less than or equal to the predetermined limit L, then logic flow proceeds back to step S.44 so that a synchronizing signal and the paging message may be resent. Otherwise, at step S.54, a reorder indication is provided to the user to indicate that the call request was unsuccessful and that the call request should be placed at another time. Following step S.54, the wireless handset transitions from the Paging state back to the Idle state. As illustrated in FIG. 7B, if a page response message is received at step S.48, then at step S.56, a ring back tone or another form of signal is provided to the user to indicate that the call request was received. In accordance with conventional wireless handsets, the ring back tone may be an audible tone that is provided at the earpiece of the speaker of the wireless handset. At step S.58, the originating mobile station determines whether the called party has answered within a predetermined amount of time. For example, a predetermined amount of time (designated as T.sub.alert seconds in FIG. 7B) may be designated to permit the called party to answer within a certain number of seconds (for example, 20-30 seconds). If it is determined at step S.58 that the called party has not answered within the predetermined period, then the originating phone may return to an Idle state. Otherwise, if the called party answers within the predetermined time, then the phone may enter into a Conversation state to permit full duplex voice communication to be carried out between the parties. FIG. 8 illustrates an exemplary flowchart of the various processes and operations that may be carried out by a mobile station when it is in a Conversation state. As indicated in FIG. 5, the mobile handset may transition into the Conversation state from either an Idle state (under condition f) or from a Paging state (under condition h). A transition from an Idle state to a Conversation state will occur under condition f, when a page has been received and the user answers. A transition from a Paging state to a Conversation state will occur under condition h, when a page response is received and the called party answers. Therefore, both the originating and answering mobile station may enter into a Conversation state. The originating handset may transmit on a frequency that the answering mobile station is tuned to receive and vice versa, in accordance with the previous descriptions. At step S.60, the wireless handset that has entered into a conversation state switches circuitry to transmit and receive voice communication signals. Thereafter, at step S.62, a supervisory signal is sent. The supervisory signal may be based on the supervisory audio tone (SAT) encoding/decoding circuitry employed by cellular phones. At step S.64, the mobile station then initializes a counter t.sub.s to 0. Thereafter, the supervisory signal is decoded at step S.66. At step S.68, the mobile station determines whether the supervisory signal is still present. If the supervisory signal is still present, then the received audio is unmuted at the handset's earpiece at step S.69 and the mobile handset determines whether an end key is pressed by the user to indicate end of the conversation at step S.78. If the end key is pressed by the user or another appropriate key is pressed by the user to indicate end of the conversation or call, then at step S.80 the handset switches back to the data circuitry and stops sending the supervisory signal. Subsequent to step S.80, the mobile handset returns to the Idle state. If, at step S.78, it is determined that the end key has not been pressed by the user, then logic flow proceeds back to step S.64 where the counter t.sub.s is initialized to 0 once again. If, at step S.68, it is determined that the supervisory signal is not present, then at step S.70 the received audio is muted at the handset's earpiece and at step S.72 t.sub.s is incremented by 1. Thereafter, at step S.74, it is determined whether a corrupted signal is received for a time period that exceeds a predetermined interval or time. That is, at step S.74, it is determined whether t.sub.s is greater than or equal to the maximum interval or time T.sub.Hi. If t.sub.s is greater than or equal to T.sub.Hi then at step S.76 a reorder indicator or tone is provided to the user to indicate that the signal has been lost. Thereafter, at step S.80, the mobile station switches back to the data circuitry and stops sending the supervisory signal. This permits the wireless handset to transition back to the Idle state. If, however, at step S.74 it is determined that t.sub.s is not greater than or equal to T.sub.Hi, then logic flow proceeds back to step S.66 where the wireless handset attempts to decode the supervisory signal. Thereafter, the mobile station determines whether the supervisory signal is present at step S.68 and, if so, then the Conversation state proceeds as normal (see step S.78). If, however, the supervisory signal is still not located, then the received audio is muted at step S.70 and the counter t.sub.s is incremented again by 1. (see, for example, step S.72). The logic flow then proceeds as discussed above. In the Conversation state, the mobile station operates on the same frequencies being used prior to entering the Conversation state. The modulating circuitry of the mobile station is switched from the data mode to voice mode so that normal voice-band information is transmitted. A supervisory signal that is easily filtered out of the audio information is also transmitted to indicate when the link is active or broken. As discussed above, one example of a supervisory tone or signal that may be used by the mobile station is the SAT (supervisory audio tone) that is used in analog cellular phones. Another supervisory signal that may be utilized is the sub-audible data stream used in narrow band AMPS (IS-91). If the supervisory tone is corrupted for a prolonged period of time (i.e., a period of time greater than or equal to T.sub.Hi) then it is assumed that the communication path has been lost. In this case, a reorder indication in the form of, for example, an audible and/or visual indication, is provided to the user to warn of the situation and the lost communication path. As discussed above with respect to FIG. 8, when the Conversation state is terminated or ended, the data circuitry of the mobile station is switched back in and the mobile station returns to the Idle state. As further shown in FIG. 5, the mobile station may transition from the Conversation state to the Idle state under different conditions. That is, under condition d, the mobile station will transition from the Conversation state to the Idle state when the end key is pressed by the user to indicate that the conversation has ended. This condition is tested at step S.78 in FIG. 8. The mobile handset will also transition from the Conversation state to the Idle state when the supervisory signal is lost, as indicated by condition e in FIG. 5. The testing of the supervisory signal is performed at steps S.68-S.74 in FIG. 8. After entering the Idle state, the mobile station may reenter the Paging state or the Conversation state depending on the operational mode or state of the mobile station. In addition, the mobile station may enter into other feature states depending on the manner in which the mobile station is controlled or operated by the user. That is, when the phone is in the Idle state, as shown in FIG. 5, the mobile station may transition to one or more feature states under various conditions. In the exemplary state diagram of FIG. 5, condition i is provided to represent the condition where a user selects an additional function or state of the wireless handset. These features, including the Traditional Wireless features, Free Call Control features, Find features, List Maintenance features, Conference Call features and other features to be described hereinafter, may be selected by the user to perform various functions. Under such conditions, the handset will enter one of the feature states to permit various functions to be carried out under the command of the user. In FIG. 5, three exemplary feature states are shown for purposes of illustration. The illustrated feature states include a Find Request state, a Memorize Request state, and a Short Range Message state. Aspects and exemplary embodiments of these features are further described below with reference to FIGS. 39-41. The Find Request state, the Memorize Request state, and the Short Range Message state may be entered into from the Idle state when the user selects or activates one of these features, as represented by conditions j, l and n in FIG. 5, respectively. Termination of the feature states and transition back to the Idle state will occur when the feature or function is completed under normal conditions or when it is terminated by the user (e.g., when the user indicates to exit or end the function or mode). In FIG. 5, this is represented by conditions k, m and o for the Find Request state, the Memorize Request state, and the Short Range Message state, respectively, and by condition g for the other feature state(s) that may be provided in the handset. One of the feature states that may be selected by the user is a feature state for Traditional Wireless features, which may include all of the features and functions required of and included in analog or digital wireless handsets. The set of features that are provided in the wireless handset may, of course, vary depending upon the needs of the handset user. With such features, the handset may be permitted to operate in accordance with traditional analog or digital wireless communication protocols, or a more enhanced wireless handset may be provided that is capable of operating in both analog and digital wireless networks. As described above, the set of features provided as part of the Traditional Wireless features for the handset may include: Caller ID; Caller ID Log; Short Message Service (SMS); Auto Answer; Choice of Alerts; Vibration Alert; Call Mute; and Large, Scrollable Speed Dial List. Other features may be provided including Computer Connectivity and Control, and Headset (with microphone accessory). Any combination of these features may be embodied in the wireless handset to facilitate traditional analog and/or digital wireless connectivity. It is also possible that the wireless handset of the invention be provided as a special purpose handset with only direct handset-to-handset functionality, in which case the above-noted features may be eliminated or modified and provided to support direct handset communication. Similar features or overlapping features may also be provided for free call control and other general features for direct handset-to-handset communication, as further described below. When placing a free call, the wireless handset does not use a cellular or digital network. Instead, such calls are placed directly from one handset to another, as illustrated in FIG. 3. Free Call Control features may be provided to enhance and control the operation of the wireless handset in connection with direct handset communication. One or more of these features could also be utilized in connection with a handset operating through Free Call Control features that may encompass both call initiate and call receive features, as well as various call initiate feedback features. Table 1 illustrates an exemplary set of call receive features that may be implemented with the wireless handset. Further, Table 2 illustrates an exemplary set of call initiate features, and Table 3 illustrates an exemplary set of call initiate feedback features that may also be provided. Depending on the needs of the user, these features may be modified or only various combinations of these features may be provided. TABLE 1 CALL RECEIVE FEATURES Call Intitiate Features Description Call All calls can be accepted by presenting a predefined key (e.g., Accep- RCV or TALK) or by pressing almost any key on the tance handset, with the exception of main function keys (e.g., END, PWR). Auto All calls will be automatically answered by the wireless Answer handset Caller ID The name and number (ID) of the originator of the call will appear on the display of the receiving handset. Call The user will be alerted that another call has been received Waiting while the user is using the handset. The alerting signal (e.g., visual or audible) may be selected by the user. The user will also be able to switch over to the other call and then back to the original call. Call Mute The call alerting signal for the incoming calls will be muted without notifying the originator that the receiver's handset is not providing an alerting signal. Call The alerting signal for an incoming call is muted and the Reject originator of Message the call is notified via a short message With that the call was not accepted. The message may be user Message defined or multiple predefined messages may be selected. Network The incoming call is rejected with a short message sent to the Voice Message originator indicating the number of the network Mail voice mail which the originator can call by pressing a key Message (e.g., SEND or TALK) on their handset. TABLE 2 CALL INITIATE FEATURES Call Receive Features Description FREE A FREE call can be initiated by entering the number of the Button recipient and pressing a key (e.g., a FREE key) of the handset. A traditional wireless call using the network may be initiated by using a separate key (e.g., a SEND key). Auto The handset will redial a call to another handset (that is FREE initially out of range) until that handset comes into range, or Redial for a specified period of time, or until the user cancels this feature. Speed The speed dial list can be scrolled through using arrow keys Dial List on the handset. When an entry is highlighted, the user can press the FREE key to place a direct handset-to-handset call. For traditional wireless network calls, a separate speed dial list may be maintained or such a list may be integrated with the speed dial list for free calls. Speed By typing the first characters of names, the user may quickly Dial List navigate the speed dial list by having the list jump and Spell-Out display, in alphabetical order, those names in the list beginning with the typed characters. Found The Found list is a list of users who have compatible wireless List handsets that are within range to enable free calls. The list can be scrolled through using the arrow keys on the handset and a call can be placed to a user highlighted on the list by pressing the FREE key. Emergen- When activated, this feature will place a call to the closest cy Call handsets automatically to alert those people of an emergency. TABLE 3 CALL INITIATE FEEDBACK FEATURES Call Initiate Feedback Features Description Unavailable A message (e.g., “Unavailable”) will be displayed on the screen of the call originator handset if the call receive handset is out of range or is turned off. The option to simply hit a key (e.g., SEND) and place the call using the wireless network will then be given. Ringing A ringing tone will be heard in the earpiece of the call originating handset if the call receive handset is in range and can accept the call. The call will continue to ring until it is answered or until the call originator ends the call or until a predetermined timer expires. The ringing tone for a free call may have a different sound then the ringing associated with a traditional wireless connection. Busy A busy signal will be heard in the earpiece of the call originating handset if the call receive handset cannot accept the call because it is in use. Call Reject A message that the call was not accepted will be Message presented on the handset display if the Call Reject With Message was used by the call receive handset. An alert will be heard in the earpiece of the call originating handset to signal that the message is on the display. In addition to the above-noted features, other features may be provided to facilitate use and operation of the wireless handset. For example, a set of Call In Progress features may be provided for supporting free or direct handset-to-handset calls. Such features may include a signal strength or distance indicator which will display the strength of the free call during the progress of the call, so as to provide to the user an approximate indication of signal strength or distance. Strong signals may indicate that the two handsets are close together physically, while weak signals may indicate that the two handsets are far apart physically. In addition, a very weak signal alert may be provided, in the form of a beep emitted from both handsets, to indicate that the signal is very weak and may be dropped. Such an alert may be accompanied by an option to reconnect the call using the wireless network by pressing the SEND key. Other features that may be accessible during call progress may include: Call Waiting; Memorize; Spontaneous Conferencing; and Short Range Message (including the alerting and retrieval of messages). As indicated above, the wireless handset of the present invention may be implemented with Find features which enable the user to determine which handsets or users are within range for placing a free call. The Find features may include a Find list that is stored in the handset. The Find list may comprise a list of objects (including other wireless handsets and items with paging devices or beeping clips) that the handset user wants to find. As further discussed below, the objects on the Find list may be grouped or categorized. For privacy reasons, when performing a Find request, the user of the requesting handset will not be able to detect if another handset is within range unless that other handset is on the Find list of the requesting handset and the requesting handset is on the Find list of the other handset. Should a handset receive a Find request where the requesting handset is not on its Find list, a message may be displayed to the receiving handset's user asking if the user wishes to add the originating handset to their Find list. If the user accepts, then they will be “found” at that moment and the originating handset will be added to the receiver's Find list, as well as the receiver's Speed Dial List, if separate. If the user does not respond to a Find query or message, the message may be kept as a short range message and the user can respond or delete the message in the future, as desired. Should the receiving handset's user decline, this message will not be displayed again upon subsequent requests from that originating handset. In this case, if the originating handset is ever in future added to the receiving handset's list and then deleted, the message will be displayed if that Find request is received again from the handset. In order to perform a Find request, the wireless handset may be equipped with a FIND button or key. When pressed, this button may return a list of objects (including other wireless handsets) that are on the Find list and that are within range to perform (if possible) a free call. This list, which is returned after performing a Find request, is referred to herein as the Found list. The Found list may display the signal strength of each object that is within range. If the FIND button is pressed by the user with an object or a group highlighted on the Speed Dial List or the Find list, then the handset will only search for that specific object or objects in that group and return the results in the Found list. With the Find request feature of the present invention, which is further described below with reference to the accompanying figures, a Find request may take no longer than approximately four seconds to determine if twenty objects are within range. In accordance with an aspect of the present invention, a user may wish to configure their handset to automatically perform a Find request at preset or predetermined intervals. For this purpose, the Find features may include Auto Find and Auto Find Object features which permit a Find request to be performed at preset intervals. These options may be selectively turned ON or OFF by the user. With Auto Find, the wireless handset will automatically perform a Find request at preset intervals and update the Found list. Additional options may be provided to inform the user when there is a change to the Found List through a beeping tone, vibration, a ringing tone, or a change on the display. The Auto Find feature may be interruptible to permit a user to make or receive a call or short message. With Auto Find Object, the user may select a specific object on the list and automatically perform a find request at preset intervals that will alert the user if that particular object has recently come into range. An additional option will permit the user to be automatically alerted if that object has recently gone out of range. The Auto Find Object feature may also be interruptible to permit a user to make or receive a call or short message. As discussed above, the wireless handset of the present invention may perform a general Find request whereby all objects on the user's Find list are queried or the handset may perform a specific object Find request whereby a specific object or group of objects highlighted on the Find list by the user is queried to determine if they are within range. Various techniques may be utilized for implementing the general find and specific object find features of the present invention. For example, all handsets may be equipped with a separate or dedicated tuner which is always on a dedicated channel or sets of channels to perform Find requests. In the alternative, each handset may register on a control channel at predetermined intervals when the handset is idle or when the handset is on a call. In such a case, a separate tuner may not be provided. In accordance with another embodiment, the handset requesting a Find may transition from an Idle state to a Find Request state, as shown in FIG. 5. While in the Find Request state, the requesting handset may utilize a technique similar to the Paging state to indicate the objects that are being queried. The queried objects may check for Find messages while in the Idle state. In this state, a procedure similar to; that illustrated in FIGS. 6A-6B may be used to indicate that it is within range. Other embodiments and variations are also possible. FIGS. 39A and 39B illustrate exemplary flowcharts of the various processes and operations in a Find Request state, according to an aspect of the invention. As illustrated in FIG. 5, when initiating a Find request to locate an object, the wireless handset will transition from an Idle state to a Find Request state. The transition from an Idle state to the Find Request state occurs under condition j, when a user indicates to initiate or start a Find request to locate a specified object (e.g., another wireless handset) by pressing an appropriate key or button on the wireless handset. If the user wishes to determine if a specific wireless handset is within range, the ID or directory number DN of the handset should be entered or selected through the handset. In the Find Request state, the wireless handset will attempt to locate the specified handset by transmitting a find message and waiting for a response from the specified handset. The wireless handset may transition back to the Idle state from the Find Request state (represented by condition k in FIG. 5) after successfully locating the specified object or after failing to locate the specified object. FIGS. 39A and 39B illustrate exemplary flowcharts of the various processes and operations that may be performed in a Find Request state when attempting to locate a specified object, such as an another wireless handset. In particular, as illustrated in FIG. 39A, when entering a Find Request state the wireless handset will first switch and/or initialize the transceiver of the handset at step S.1200 for the Find request. That is, similar to the embodiment of FIG. 6A, N frequency pairs may be assigned to the wireless handset for performing a Find request, with the higher frequency associated with a duplex channel “i” being designated as F.sub.hi and the lower frequency being designated as F.sub.li. After initializing the transceiver, the wireless handset will collect or gather the information specifying the handset or object to be located at step S.1202. The collected information may include the directory number or ID of the wireless handset that the user specified for the Find request. At step. S.1204, the wireless handset will switch the receiver to the lower frequency band of the duplex pass band and switch the transmitter to the higher frequency band. Then, as shown in FIG. 39A, the handset will initialize the value of a counter i to 1 at step S.1206. Following step S.1206, the receiver of the handset will be set to the low frequency F.sub.li and the transmitter will be tuned to the higher frequency F.sub.hi at step. S.1208. After tuning the receiver and transmitter, the wireless handset will determine at step S.1210 whether there is interference in the channel. Interference may be analyzed by determining whether the signal strength of the channel is not greater than a predetermined threshold. For example, at step S.1210, the wireless handset may determine whether the received signal strength of the channel is greater than a threshold level THR.sub.rssi. If it is determined that the threshold has been exceeded and that there is interference on the channel, then at step S.1212 the value of the count i may be modified according to the following equation: i=(i+1)mod N After the value of the counter i is reset, logic flow proceeds back to step S.1208 so that another channel is tuned to and analyzed for interference. If the signal strength of the channel is determined to be acceptable at step S.1210, then a counter m may be initialized and set to 0 and at step S.1214 (see FIG. 39B) a synchronization signal may be sent by the wireless handset. After synchronization, the wireless handset may transmit a find message over the channel at step S.1216. The find message may include the directory number of the object or handset that is being queried. In addition, the find message may include the directory number of the requesting handset and/or the name of the user that requested the find request. Following step S.1216, the wireless handset will wait for a response to determine if the queried object is within range. In particular, at step S.1218, the wireless handset will determine whether a find response message has been received indicating that the queried object is within range. If no find response message is received, then at step S.1220 the counter m is incremented by one and at step S.1224 it is determined whether m has exceeded a predetermined limit L. If m is less than or equal to the predetermined limit L, then logic flow proceeds back to step S.1214 so that a synchronizing signal and the find message may be resent. Otherwise, at step S.1226, a find failure indication may be provided to the user to indicate that the find request was unsuccessful. Following step S.1226, the wireless handset may transition from the Find Request state back to the Idle state, as illustrated on FIG. 39B. If a find response message is received at step S.1218, then at step S.1228 the requesting handset will update the status of the queried object in the handset's Found list in order to indicate that the queried object is within range. Further, at step S.1230, the handset will measure the signal strength of the response message from the queried object and update the corresponding signal strength information in the Found list. The found status of the specified object and the measured signal strength may also be indicated or displayed to the user of the requesting handset to notify the user of this information. Following step S.1230, the find routine may terminate and the handset may transition from the Find Request state back to the Idle state. In accordance with other embodiments of the invention, FIGS. 9-12 are exemplary flowcharts of the various processes and operations that may be performed for carrying out a general Find request for other wireless handsets. In addition, FIGS. 13-16 illustrate various embodiments for carrying out a specific object Find request for a specific wireless handset user with the present invention. Each of these embodiments are described in greater detail below. In particular, FIGS. 9A and 9B are exemplary flowcharts of the various processes and operations that may be carried out for performing a general Find request by utilizing a dedicated separate tuner. According to the embodiment of FIGS. 9A and 9B, each handset is equipped with a separate tuner that is always on a predetermined dedicated channel. Such a tuner is provided in addition to a tuner for establishing and providing communication with other handsets. FIG. 9A illustrates an exemplary logic flow for a handset (i.e., handset “A”) that initiates the general Find request. FIG. 9B illustrates the exemplary logic flow of operations performed by each handset that is on the Find list of handset A. In the exemplary flowcharts of FIGS. 9A and 9B, list_count represents or designates to an entry in the Find list of handset A, and ID#list_count is the ID of the handset or object stored in an entry of the Find list. As shown in FIG. 9A, a general find request is initiated by the user of handset A at step S.90 when the user A presses a predetermined key on the handset (hereinafter referred to as a “FIND key”) with no object or handset specifically highlighted or selected on the Find list. In response, at step S.92, the value of a list_count is initialized and set to one. Further, at step S.94, the handset initializes the value of a wait_clock to 0. After initializing the values of the counters, the handset A queries the first entry in the Find list. In one embodiment, the handset includes a separate tuner that is always on a dedicated channel, the find request or query is sent or transmitted by the tuner on the dedicated channel. The find query may include the ID of the handset specified by the entry in the Find list corresponding to the value of the list_count (initially set to one) and also includes the ID of handset A to indicate that the query is from handset A. The find query message may be transmitted based on any message structure protocol that is suitable for carrying and supporting such information elements. Further, the message structure that is utilized may incorporate parity bits or other techniques for error detection and correction. In another embodiment, the handset enters the Find Request state from the Idle state (see FIG. 5). While in the Find Request state, the requesting handset searches for an interference-free channel to send the query. As further shown in FIG. 9A, the handset at step S.98 determines whether a response has been received. In accordance with an aspect of the present invention, handset A may dwell and wait for a predetermined time for a response from the queried handset before moving on to the next entry in the Find list. As such, if a response is not received at step S.98, then at step S.100 it is determined whether the value of the wait_clock is greater than or equal to the value of a predetermined wait time. If the wait time is not exceeded at step S.100, then logic flow loops back to step S.98. Otherwise, if the value of the wait_clock is greater than or equal to the wait time, then logic flow proceeds to step S.104. If it is determined that a response is received at step S.98, then at step S.102 the Found list of handset A is updated with the ID of the handset that responded. In addition to indicating the ID number of the handset, the name of the handset and the signal strength (SS) of that handset may be indicated and stored in the Found list. The relative signal strength may be indicated by a numeric value, code or symbol. Further, various conventional techniques may be utilized for detecting and preparing the signal strength. The Found list may be actively displayed and updated for viewing by the user as each response is received or the Found list may be displayed only after each entry in the Find list has been queried. After updating the Found list at step S.102, the handset determines at step S.104 whether all of the entries in the Find list have been queried. That is, at step S.104, the handset determines if the value of the list_count equals the end of the Find list. If the end of the Find list has not been reached, then at step S.106 the value of the list_count is incremented by 1 and logic flow proceeds back to step S.94. Otherwise, if the list_count equals the end of the Find list, then at step S.108 the entire and complete Found list is displayed to the user A. At step S.108, an alerting signal (e.g., a beep or message on the display) may be provided to alert the user that the find request has been completed. After displaying the Found list at step S.108, the find request routine terminates at step S.110. As mentioned above, FIG. 9B is an exemplary flowchart of the various processes and operations that are carried out by each handset when receiving a find query or request from handset A. In one embodiment, each handset includes a separate or dedicated tuner that is always on a predetermined channel and that monitors the same for find requests. Steps S.112 through S.120 generally represent the functions performed by a responding handset. In particular, at step S.112, the handset is active and performing other functions according to the features implemented by the user. If the dedicated tuner detects that a find request or query has been received at step S.114, then at step S.116 the handset will temporarily store the ID (i.e., the ID of handset A) in memory. The ID of handset A is then compared with the Find list of the handset to determine if the particular ID is on the list. If it is determined at step S.118 that the ID of handset A is on the Find list, then a positive response is transmitted at step S.120 by the tuner on the dedicated channel. The response message that is transmitted at step S.120 may include the ID of the responding handset and the ID of the handset to which the positive response is directed. The positive response message may be transmitted based on any message structure and protocol that supports these information elements. In another embodiment, the same or a similar functional process is implemented. However, a group of channels are scanned and a channel having acceptable interference levels is selected in accordance, for example, with the procedures described herein with reference to FIGS. 5, 6A, 6B, 30A and 30B. This embodiment is better suited for use with the handset when it is implemented with analog cellular handset circuitry. As further shown in FIG. 9B, after transmitting a positive response at step S.120, logic flow proceeds back to step S.112, so that other handset functions may be performed. Logic flow will also return to step S.112 when a find request is not detected at step S.114 or when it is determined that the ID of the querying handset (i.e., handset A) is not on the Find list at step S.118. In the embodiment of FIGS. 9A and 9B, each handset utilizes a separate tuner which is always on a dedicated channel. When a find command is given, the handset uses the dedicated channel to contact all other handsets sequentially to determine if they are within range. Only handsets that are on the list of the handset A will be queried to determine if they are in the area. Further, only handsets that are on the list of handset A, have handset A on their list, and are within range will respond to the query, as indicated above. As such, only handsets that have given handset A permission to find them will respond. Further, according to this embodiment, since the handset utilizes a dedicated or separate tuner, find queries can occur when the handset is on a call with another handset without disruption of any call. Thus, in the exemplary flowchart of FIG. 9B, each handset may check to determine if a find query has been received on the dedicated channel even if other handset functions are being performed at the same time. That is, step S.112 may be performed concurrently with the operations performed at steps S.114 through S.120 in FIG. 9B. Further, in this embodiment, handset A may query all handsets on the Find list sequentially and, therefore, the total query time will be dependent upon the length of the Find list of handset A. In accordance with another embodiment of the present invention, FIGS. 10A and 10B are exemplary flowcharts for performing a general find query. The embodiment of FIGS. 10A and 10B does not require the use of a dedicated or separate tuner. Instead, according to this embodiment, all handsets register on a control channel at predetermined time intervals (e.g., every “x” minutes or seconds). This registration on the control channel may occur when the handset is idle and when the handset is on a call. Registering during a free call will disrupt the call for a short period of time, since the handset utilizes the same tuner required for the free call. The registry message may include the ID of the registering handset and a list of other handset IDs that are on the Find list of the registering handset. When user A initiates a find query by pressing the FIND key, the handset of user A will tune to the registry channel and listen for the predetermined time interval (i.e., for “x” minutes or seconds). For those handsets that are on the Find list of handset A, handset A will check to ensure that handset A is on their list. FIG. 10A is an exemplary flowchart of the various processes and operations that may be performed by handset A (i.e., the handset originating the find request), and FIG. 10B is an exemplary flowchart of the processes and operations that may be carried out by each of the handsets that are on the Find list of handset A. As shown in FIG. 10A, at step S.124 a general find request is initiated by user A when the FIND key is pressed on the handset with no specific object or handset on the Find list being selected or highlighted. In response to the FIND key being pressed at step S.124, the handset A will initialize and set the value of a cycle_clock to zero at step S.126. Thereafter, at step S.128, the handset tunes to the predetermined control or registry channel. At step S.130, the handset then determines whether a response or message is received on the registry channel. As indicated above, according to this embodiment, all handsets register on the control or registry channel in accordance with a predetermined cycle time (e.g., every “x” minutes or seconds). As such, the handset of user A will dwell and wait for the duration of one cycle time to determine if each entry in the Find list is within range. Thus, if it is determined at step S.130 that a response has not been received, then at step S.132 it will be determined if the cycle_clock is greater than or equal to the predetermined cycle time. The cycle_clock may be incremented in accordance with an internal system clock of the wireless handset. The value of the cycle_clock will, thus, maintain the elapsed time of the find query. If it is determined that the cycle time has not been elapsed at step S.132, then logic flow proceeds back to step S.130. If a response is detected at step S.130, then at step S.134 the registry message of the handset that sent the response (i.e., “handset X”) is recorded. In particular, at step S.1314, the registry message is temporarily recorded, including the ID of the handset X and the list of other handset IDs that are on the Find list of handset X. In addition, the measured signal strength (SS) of the registry signal may be recorded by handset A. Thereafter, at step S.136, it is determined whether the ID of handset X is on the Find list of handset A. If handset X is on the Find list of handset A, then at step S.138 it is determined whether the ID of handset A is on the Find list of handset X based on the information recorded from the detected registry message. If it is determined that handset A is on the list of handset X, then at step S.140 the ID of handset X is added to the Found list of handset A, along with the corresponding name for user X and the signal strength (SS). Thereafter, logic flow returns to step S.132. If the cycle time has not expired at step S.132, then additional responses that are received from other users on the registry or control channel are analyzed and (if proper) added to the Found list in accordance with steps S.134 through S.140. When the cycle time has elapsed or been exceeded at step S.132, logic flow proceeds to step S.142 where the complete Found list is displayed to the user A. Once again, an alerting signal (such as an audible beep tone or message on the handset display) may be provided to the user to indicate that the general find query has been completed. Alternatively, the information from the Found list could be updated and displayed to the user after every successful find query by adding a “found” icon or message next to each item on the Find list as they are located or by creating a second list of those objects that were found. Following step S.142, logic flow proceeds to step S.144 where the routine terminates. FIG. 10B is an exemplary flowchart of the various processes and operations that may be carried out by each handset (i.e., handset X) registering on the registry control channel. As discussed above, in the embodiment of FIGS. 10A and 10B, all handsets register on a predetermined control channel every x minutes or seconds. Each handset maintains a cycle_clock, which monitors the elapsed time and is used to determine when the cycle time or period has elapsed. More particularly, as shown in FIG. 10B, when not registering on the registry channel, the handset X performs other functions at step S.150. Concurrently with the performance of other handset functions or upon completion of a handset function, the handset determines at step S.152 whether the value of the cycle_clock is greater than or equal to the predetermined cycle time. If the cycle time has elapsed or been exceeded, then at step S.154 the handset will tune to the registry channel and transmit the ID of the handset and the list of other handset IDs that are on the Find list for the handset. As indicated above, the registration on the registry control channel may occur when the handset X is idle or when the handset is on a call. As such, registering during a free call will disrupt the call for a short period of time since the same handset utilizes the tuner required for the call. Following step S.154, the handset X at step S.156 will reset the value of the cycle_clock to zero. Thereafter, the cycle_clock will be incremented in accordance with the system clock of the handset so as to keep track of the elapsed time and so that the value of the cycle_clock may be evaluated to determine each cycle period. Following step S.156, logic flow proceeds back to step S.150 and the operations at steps S.152 through S.156 are repeated. As further shown in FIG. 10B, logic flow will loop back to step S.150 whenever it is determined at step S.152 that the cycle_clock is not greater than or equal to the predetermined cycle time. In the embodiment of FIGS. 10A and 10B, a dedicated tuner is not required for each handset. However, each handset is required to register on a registry channel in accordance with a predetermined cycle time (i.e., every x minutes or seconds). The total time required to perform a find request is approximately equivalent to the cycle time, no matter how long or short the Find list is for the handset, unless the handset tunes to the registry channel while idle. The length of the cycle time may be preset or variably set by the user or by elements in the wireless network. In either case, the length of the cycle time should be set based on the number of handsets that could be registering in a particular area and the size of the list that each handset could be transmitting on the registry channel. By requiring all handsets to transmit their associated Find lists, comparisons between the lists can be made to ensure that handset A is on the list of handset X and vice versa, without having to contact handset X directly. For registrations that occur during a free call, two potentially long disruptions may occur. These disruptions are required while each handset registers and transmits its list on the registry channel every cycle period. The length of the disruption is dependent upon the length of the list transmitted. Various modifications may be made to the embodiment of FIGS. 10A and 10B. For example, a procedure may be included in FIGS. 10A and 10B to provide for collision detection and/or collision correction. A collision may occur when one handset tries to register while another handset is registering on the registry channel. As further described below, by monitoring and listening to the registry channel, each handset may avoid some collisions by ceasing transmission and waiting a random predetermined period of time and retransmitting whenever a collisions is detected on the registry channel. Another feature may be added whereby an idle handset can tune to the registry channel and maintain updates on the handsets on its lists so that when the FIND key is pressed, the handset is able to immediately inform the user of the list update. Such a feature could also enhance the operation of the find procedure. FIGS. 11A and 11B illustrate another embodiment for providing a general find request. The embodiment of FIGS. 11A and 11B combines the advantages of the embodiment of FIGS. 9A and 9B and the embodiment of FIGS. 10A and 10B. As further discussed below, in the embodiment of FIGS. 11A and 11B, all handsets register on a control channel every x minutes or seconds. The registry occurs when the handset is idle and when the handset is on a call. Registering during a free call will disrupt the call for a short period of time, since the handset utilizes the tuner required for the free call and does, not include a separate or dedicated tuner for performing the registration. The registry includes the ID of the handset and the frequency at which the handset can be contacted. If the handset is on a free call, the registered frequency will be the frequency of the call. If the handset is idle or on a cellular or PCS call, the registry frequency will be the frequency of the dedicated control channel. When user A initiates a general find request by pressing the FIND key, the handset will tune to the registry or control channel and will listen for a duration corresponding to the cycle time (i.e., x minutes or seconds). For those handsets that are registered on the registry channel, handset A will contact them directly on the frequency specified in the registry. Only handsets that are on the list of handset A and that are on the registry channel will be queried. Further, only handsets that are queried, have handset A on their Find list, and are within range will respond to the query. Thus, only handsets that have given handset A permission to find them will respond. FIG. 11A is an exemplary flowchart of the various processes and operations that may be performed by the handset performing the general find request (i.e., handset A), and FIG. 11B is an exemplary flowchart of the various processes and operations that may be performed by each handset that registers on the dedicated control channel (i.e., handset X). As shown in FIG. 11A, the general find request is initiated at step S.160 when user A presses the FIND key of the handset with no specific object or person selected on the Find list. Thereafter, at step S.162, the handset tunes to the registry or control channel. Then, at step S.164, the value of the cycle_clock is initialized and set to 0. Following step S.164, the handset A listens to the control channel for responses at step S.166. If a handset registry response is not received at step S.168, then at step S.174 the handset checks to see if the predetermined cycle time has elapsed or been exceeded. In particular, the value of the running cycle_clock is compared with the cycle time, to determine if the value of the cycle_clock is greater than or equal to the cycle time. If the cycle_clock is less than the cycle time, then logic flow loops back to step S.168 to once again determine if a registry message has been received. When a handset registry response is received at step S.168, then logic flow proceeds to step S.170 where the registry information is analyzed. In particular, at step S.170 it is determined whether the ID of the handset X (which registered) is on the Find list of the handset A. If user X is not on the Find list, then logic flow proceeds to step S.174. If, however, user X is on the Find list, then at step S.172 the ID of user X and the frequency or channel number contained in the registry are temporarily recorded in a separate list. As noted above, information in the registry may include the ID of the handset which registered, as well as the frequency at which that handset can be contacted. Following step S.172, logic flow proceeds back to step S.174. After the cycle time has elapsed or been exceeded at step S.174, the handset will set the value of a list_count to one at step S.176. The value of the list_count represents an entry in the temporary list of the handset A. As shown in FIG. 11A, following step S.176 the handset will attempt to directly query and contact each of the handsets in the list which registered on the registry channel based on the frequency that was specified. Thus, only the handsets that are on the Find list of handset A and that are detected to be on the registry channel will be queried. Further, as discussed below with reference to FIG. 11B, only handsets that are queried, have handset A on their Find list, and are within range will respond to the query. In particular, at step S.178 in FIG. 11A, the handset will tune to the specified channel or frequency of the handset identified by the value of the list_count in the Find list or temporary list of user A. Then, at step S.180 the handset will be queried with the ID of handset A being specified. The value of a wait_clock is then set to zero at step S.182 and it is determined at step S.184 whether a response message is received from the queried handset. The handset A will wait for a predetermined time to see if a response is received. Thus, if a response is not received at step S.184, logic flow proceeds to step S.186 where the value of the wait_clock is compared with the predetermined wait time. The wait_clock may be stored in the handset and incremented in accordance with the system clock to keep a running count of the wait time. If the value of the wait_clock is less than the wait time, then logic flow proceeds back to step S.184. When a response is received at step S.184, the response is recorded along with the detected signal strength (SS) at step S.188. Thereafter, at step S.190, the ID of the responding handset X and the corresponding name for the user X with the signal strength is updated to the Found list. Logic flow then proceeds to step S.192, as shown in FIG. 11A. When it is detected at step. S.186 that the value of the wait_clock is greater than or equal to the predetermined wait time, logic flow proceeds to step S.192 where it is determined whether the end of the list has been reached. In particular, at step S192 the value of the list_count is compared with the number of entries in the Find list or temporary list stored in handset A. If the list_count equals the end of the list, then the complete Found list is displayed to the user at step S.196. Thereafter, the routine terminates at step S.198. If, however, the end of the list is not reached at step S.192, logic flow proceeds to step S.194 where the value of the list_count is incremented by one and logic flow proceeds back to step S.178, so that other handsets on the list may be directly queried. Thereafter, logic flow proceeds as described above at steps S.178 through S.192. FIG. 11B is an exemplary flowchart of the processes and operations that may be performed by each queried handset (i.e., handset X). In particular, after performing other handset functions at step S.200, the handset X checks to determine if the cycle time has elapsed at step S.202. In this regard, a cycle_clock may be maintained that keeps a running time in accordance with an internal system clock of the handset. When it is detected that the cycle_clock is greater than or equal to the predetermined cycle time, then at step S.204 the handset X will tune to the registry channel. Then at step S.206, registration will be performed by transmitting the ID of the handset X and the channel or frequency at which the handset can be contacted. As described above, if the handset is on a free call when performing a registration, the frequency that is specified may be the frequency of the call. If, however, the handset is idle or on a cellular or PCS call, the specified frequency may be the frequency of a dedicated control channel. After registering on the registry channel, the handset X will tune back to the original or previous channel at step S.208. Thereafter, at step S.210, the cycle_clock will be reset to zero so as to count another cycle time (e.g., another x minutes or seconds). Following step S.210, logic flow proceeds to step S.212. Further, as shown in FIG. 11B, logic flow will proceed to step S.212 from step S.202 whenever it is determined that the cycle_clock is less than the predetermined cycle time. At step S.212, the handset X will evaluate and determine whether a find query has been received on the frequency or channel that was specified by the handset in the registry message. If a find query is not detected, then logic flow proceeds back to step S.200 where other handset functions are performed. If, however, a find query is received, then at step S.214 the handset X determines if the ID of handset A (which is contained in the find query) is on the Find list of the handset X. If handset A is on the Find list, then a positive response is transmitted at step S.216. The positive response may include the ID of handset X. Following step S.216, logic flow proceeds back to step S.200. Further, if handset A is not on the Find list of handset X, then logic flow will also proceed back to step S.200 from step S.214. Although not depicted in the flow charts of FIGS. 11A and 11B, if two handsets (for example, handset A and handset B) are on a free call, the handsets may register sequentially on the control channel. FIG. 11C illustrates this principle. That is, since most of the time to register is occupied in tuning to the registry channel, synchronizing with the registry channel, and then tuning back to the voice channel of the free call, conversational time can be saved by registering sequentially. In FIG. 11C, handset A and handset B are represented as sequentially registering on a control channel relative to time, with handset B registering sequentially to handset A. As a result, the total time spent away from the conversation and the free call is the total time to tune twice, sync twice and register twice. If the tune and sync times were not overlapped as illustrated in FIG. 11C, the total time spent away from a conversation would be the required time to tune four times, sync four times and register twice. As a result, by registering sequentially, the disruption of the free call can be minimized. As discussed above, free calls that are established with handset-to-handset communication may utilize time domain multiplexing. Therefore, when handset A needs to find another handset (e.g., handset B) that is on a free call, handset A will tune to the channel in which handset B is conducting a voice conversation. As explained above, this channel will be specified by the handset when registering on the registry or control channel. When directly contacting handset B, handset A will transmit on a control time slot of the specified channel a request to handset B to check its Find list, and receive on the control time slot of the channel the response if handset A is on the Find list of handset B. Further information regarding time domain multiplexing and control time slots is provided below with reference, for example, to the description of the conferencing features of the present invention. Various additional procedures or modifications may be made to the embodiment of FIGS. 11A and 11B. For example, an idle handset can tune to the registry channel and maintain updates on the handsets on its Find list, so that when the FIND key is pressed by the user, the direct queries of the handsets can be performed while shortening the time required for a find procedure. Further, as discussed above with reference to the embodiment of FIGS. 10A and 10B, procedures for collision detection and/or collision correction may be included in the embodiment of FIGS. 11A and 11B. As detailed above, the embodiment of FIGS. 11A and 11B does not require a dedicated or separate tuner to be provided in each of the handsets. Instead, handsets register on a control channel according to a cycle time (e.g., every x minutes or seconds). A registry occurs when the handset is idle and when the handset is on a call. A disruption on a free call is required while both handsets register and sequentially transmit their frequency on the registry channel every cycle period. The length of this disruption should be less than that in the embodiment of FIGS. 10A and 10B, since the Find list of the handset does not need to be transmitted. Further, conversational time is improved if two handsets on a free call register sequentially. The registry message may include the ID of the handset and the frequency on which the handset can be contacted. Time domain multiplexing also allows the handsets on a free call to be queried directly on the channel while the call is occurring. With time domain multiplexing a control time slot may be utilized for querying the handset. The total time required for a find procedure includes the cycle period plus the time required to directly contact the other handsets that are within range, unless the handset tunes to the registry channel while idle. In such a case, the time required for a find procedure is only the time to directly contact the handsets that are within range. FIGS. 12A and 12B illustrate another embodiment of the present invention for performing a general find request. The embodiment of FIGS. 12A and 12B combines the advantages of using a registry and a dedicated channel. In particular, the embodiment does not require a dedicated or separate tuner, but instead each handset registers on a control or registry channel according to a predetermined cycle time (i.e., every x minutes or seconds). This registry occurs when the handset is idle and when the handset is on a call. The registry consists of the ID of the handset, the frequency at which that handset can be contacted, and the time slot in which the handset can be contacted if it is on a call. The onset of this time slot is communicated as an offset from the time that the registration occurred. If the handset is on a free call, the specified frequency will be the frequency of the call and the time slot will be the time that the other handset registers. If the handset is idle or on a cellular or PCS call, the specified frequency will be the frequency of the dedicated control channel and the time slot will be any time. In the embodiment of FIGS. 12A and 12B, when user A presses the FIND key on the wireless handset, the handset will tune to the registry channel and listen for a duration equal to the cycle time (i.e., for x minutes or seconds). Each handset that is registered on the registry channel will be contacted directly by the handset A based on the frequency and time frame specified in the registry message. Only handsets that are on the Find list of handset A and that are on the registry channel will be queried. Further, only handsets that are queried, have handset A on their respective Find list, and are within range will respond to the query. As such, only handsets that have given handset A permission to find them will respond. FIG. 12A is an exemplary flowchart of the various processes and operations that may be performed by the handset that initiates the general find procedure (i.e., handset A). Further, in accordance with an aspect of the invention, FIG. 12B is an exemplary flowchart of the processes and operations carried out by each handset (i.e., handset X) to register on the control channel and to respond to find queries. A detailed description of FIGS. 12A and 12B will now be provided. As shown in FIG. 12A, a general find request is initialized when user A presses the FIND key of the handset at step S.220, with no object or handset selected or highlighted on the Find list. Thereafter at step S.224, the handset tunes to the registry channel. Further, at step S.226, the value of a cycle_clock is initialized and set to zero. Thereafter, the cycle clock may be incremented in accordance with an internal system clock of the handset, so that the elapsed time can be monitored. At step S.228, the handset listens to the registry channel to detect other handsets which have registered. At step S.230, it is determined whether a handset response is received over the registry channel. If a handset registry is not received, then logic flow proceeds to step S.236. At step S.236, the cycle_clock is compared with the predetermined cycle time. If it is determined that the cycle time has elapsed or has been exceeded, then logic flow proceeds to step S.238. Otherwise, logic flow loops back to step S.230, where the handset continues to listen and determine whether a handset registry response is received. When a handset response is received, handset A first checks to determine whether the ID of the handset X (which registered on the control channel) is on the Find list of the handset A. If the handset X is not on the Find list, then logic flow proceeds back to step S.236, where the cycle time is again evaluated. If, however, the handset X is on the Find list, then at step S.234 the registry message is temporarily recorded. In particular, at step S.234, the ID of handset X and the specified channel or frequency at which the handset X can be contacted is temporarily stored in memory in a separate temporary list. Further, the specified time slot (if present in the registry message) is recorded at step S.234. Following completion of step S.234, logic flow proceeds back to step S.236, where the cycle time is again evaluated. When the value of the cycle_clock is equal to or greater than the cycle time, logic flow proceeds from step S.236 to step S.238. At this point, the handset A will set the value of a list_count to one and then proceed to step S.240 to tune to the specified frequency or channel for the handset of the entry of the Find list or temporary list corresponding to the value of the list_count (initially, the first entry in the list). Then, at step S.242, the handset A will query the handset identified by the list_count. The query message may include the ID of the handset A, and may be transmitted in accordance with the specified time slot (if required). At step S.244, the handset will set the value of a wait_clock to zero and thereafter wait for predetermined time at steps S.246 and S.248 for a positive response. The wait_clock may be incremented in accordance with an internal system clock of the handset to keep track of the elapsed time. If the value of the wait_clock is greater than or equal to the predetermined wait time, then logic flow will proceed from step S.248 to S.254. Otherwise, the handset will return and again test at step S.246 as to whether a response to the query is received. When a positive response is received from handset X, the handset A will record the response and the detected signal strength (SS) at step S.250. The Found list will then be updated at step S.252 with the ID of the responding handset (i.e., the ID of handset X) and the corresponding name of the user X with the detected signal strength (SS). Following step S.252, logic flow will proceed to step S.254. At step S.254, it is determined whether the end of the temporary list has been reached. This determination is made by the handset by comparing the value of the list_count to the total number of entries in the List. If the list_count equals the end of the list, then the complete Found list is displayed to the user A at step S.257. Thereafter, the general find routine terminates at step S.259. If it is determined that the list_count does not equal the end of the list at step S.254, then logic flow proceeds to step S.256, where the value of the list_count is incremented by one so that additional handsets which registered and are on the List may be directly queried. Logic flow then proceeds to step S.240, where the handset tunes to the specified channel for the next handset to be directly queried. Logic flow then proceeds at steps S.242 through S.259, as described above. FIG. 12B is an exemplary flowchart of the operations that may be performed by each handset (i.e., handset X) that registers on the control channel and transmits positive responses to handset A. When directly queried at step S.260, the handset X performs other functions. After performing other handset functions or concurrently with performance of other handset functions, the handset X detects whether the value of a cycle_clock is greater than or equal to the predetermined cycle time at step S.262. As noted above, each handset will register on the control channel in accordance with a predetermined cycle time (i.e., every x minutes or seconds). The cycle_clock may be maintained to keep track of the elapsed time and may be incremented in accordance with an internal system clock of the handset. When it is determined that the cycle time has elapsed or has been exceeded, logic flow proceeds to step. S.264 where the handset tunes to the control or registry channel. Thereafter, at step. S.266, registration is performed by transmitting the D of the handset X and specifying the channel or frequency at which the handset can be contacted. At step S.266, the handset may also transmit the time slot in which the handset can be contacted if it is in on a call. As described above, the onset of the time slot may be communicated as an offset from the time that the registration occurred. Following step S.266, the handset X tunes to the previous channel of the call (if not idle) at step S.268 and, at step S.270, the value of the cycle_clock is set to zero. Logic flow then proceeds to step S.272. Further, as shown in FIG. 12B, logic flow will proceed to step S.272 from step S.262 when it is determined that the cycle time has not elapsed. At step S.272, the value of the cycle_clock is compared with the value of the slot start time and the slot end time. In particular, at step S.272, it is determined whether the cycle_clock is greater than or equal to the slot start time and less than or equal to the slot end time. If both of these conditions are satisfied, then at step S.274 the handset determines whether a find query has been received on the specified channel during the required time slot. If a find query has been received, then at step S.276 it is determined whether the ID of the handset A (provided in the find query message) is on the Find list of the handset X. If handset A is on the Find list of handset X, then a positive response is transmitted at step S.278. Thereafter, logic flow loops back to step S.260, whereby the entire procedure is repeated. As shown in FIG. 12B, logic flow will also proceed back to step S.260 if any of the conditions in steps S.272, S.274 and S.276 are not satisfied. Further, step S.272 may be skipped when a time slot has not been specified by handset X in the registry. In the embodiment of FIGS. 12A and 12B, registering during a free call will disrupt the call for a short period of time, since the handset utilizes the same tuner required for the free call. In particular, two disruptions on a free call are required while each handset registers and transmits its frequency and slot time on the registry channel. The length of each disruption should be less than that required in the embodiment of FIGS. 10A and 10B, since the handset does not need to transmit its Find list. As described above, the registry message may include the ID of the handset, the specified frequency for contacting the handset, and the time slot (offset) when the handset can be contacted. Unlike the embodiment in FIGS. 11A and 11B, two handsets on a free call may not register sequentially. Further, time domain multiplexing is not required. Generally, the time required for a general find procedure to be executed is the time of the cycle time (x minutes or seconds) plus the time to directly contact the handsets that are within range, unless the handset tunes to the registry channel while idle. In such a case, the time required for a find is only the time to directly contact the handsets that are within range. In particular, an idle handset can tune to the registry channel and maintain updates on other handsets on its Find list, so that when the FIND key is pressed, the direct queries of the handsets can begin without listening for the predetermined cycle time; and, thus, shortening the overall time required for a find procedure. As explained above, in the embodiment of FIGS. 12A and 12B, the handsets may not register sequentially. Instead, handsets that are on a call should register at non-overlapping times during the cycle time in order to provide the time required to respond to find queries of other handsets during the time slot. During a call set-up, the two handsets may exchange the time they will each register. Further, the time that the other handset registers may be defined as the slot time. If a collision occurs, the registry time, slot time and the cycle time will need to be renegotiated. The main advantage of this technique is that time domain multiplexing is not required. However, as indicated above, two disruptions will occur during the cycle time instead of only one. In addition to performing a general find request for all objects on the Find list of a handset, the wireless handsets of the present invention may also be implemented to perform a specific find request. A specific find request may be performed to determine if a specific handset is within range. To perform a specific find request, a user may press the FIND key of the handset with one of the entries in the Find list being highlighted. As with the general find request, the specific find request may be implemented by utilizing a dedicated or separate tuner or through the use of a registry channel. FIGS. 13-16 illustrate various embodiments and implementations for performing a specific find request. In order to perform the various functions and operations outlined in the FIGS. 13-16, each handset may be implemented with any suitable combination of hardware, firmware, programmed logic, and/or software. A detailed description of each of the embodiments for performing a specific find request will now be described. FIGS. 13A and 13B illustrate an embodiment of the invention for performing a specific find request with a dedicated tuner. That is, for this embodiment, each handset is equipped with a separate or dedicated tuner that is always on and tuned to a predetermined control channel. FIG. 13A is an exemplary flowchart of the various processes and operations carried out by a handset (i.e., handset A) which performs a specific find request with respect to another handset (i.e., handset B). FIG. 13B is an exemplary flowchart of the various processes and operations performed by handset B that is queried by handset A. As shown in FIG. 13A, a specific handset find request is initialized at step S.280 when the user presses the FIND key of the handset A with handset B being selected or highlighted on the Find list. In response to the initialization of the specific find request, handset A initializes and sets the value of a wait_clock to zero at step S.282. The wait_clock may be provided to monitor the elapsed time and may be incremented in accordance with an internal system clock of the handset. After setting the wait_clock, the handset A queries handset B on the dedicated control channel at step. S.284. The find query may include the ID of handset B and the ID of handset A, which sent the query. At step S.286, handset A determines whether a response has been received over the control channel. Handset A may wait and dwell for a predetermined time or wait time to determine if a response has been received from handset B. Thus, if a handset response is not received at step S.286, then handset A will determine at step S.288 whether the wait time has elapsed or been exceeded. In particular, the handset will determine if the value of the wait_clock is greater than or equal to the wait time. If the wait time has not elapsed, then logic flow loops back to step S.286 to check again whether a response has been received. When a response has not been received within the wait time, then at step S.292 it is assumed that handset B is out of range or not available, and the handset A will show or indicate to the user that handset B was not found. In this regard, the ID and/or name of handset B may be shown to the user A as not being found on the display of the wireless handset. If a positive response is received for the handset query at step S.286, then logic flow proceeds to step S.290. As shown in FIG. 13A at step S.290, the handset A will show the handset B as being found to the user. In this regard, the ID and/or name of handset B may be displayed on the display of the handset to user A, along with the detected signal strength (SS) and an indication that the handset was found (e.g., “Found”). Following steps S.290 and S.292, the handset find request terminates at step S.294. FIG. 13B illustrates the various functions and operations that are performed by handset B, which was queried by handset A. At step S.360, handset B may perform other handset functions. Upon completion of the handset functions or concurrently with performance of handset functions, handset B determines at step S.302 whether a find query has been received on the dedicated control channel. As noted above, each handset includes a separate tuner which is always on and actively listens to a dedicated control channel to determine whether a find query has been received. If no find query is received at step S.302, then logic flow flows back to step S.300. If, however, a find query is received at step S.302, then steps S.304 through S.308 are performed. In particular, at step S.304, the contents of the query message is temporarily stored in order to evaluate the same and determine whether the query has been received from a handset on the Find list of user B. Therefore, at step S.304 the ID of handset A (which sent the query) is temporarily stored. Then at step S.306, it is determined whether handset A is on the Find list of handset B. That is, the ID associated with handset A (which was contained in the find query) is compared with the entries in the Find list of handset B. If handset A is not on the Find list of handset B, then logic flow loops back to step S.300. Otherwise, if handset A is on the list of handset B, then at step S.308 a positive response is transmitted back to handset A on the dedicated control channel. The positive response message may include the ID of handset B and the ID of handset A (to which the positive response is directed). Following step S.308, logic flow then returns to step S.300. In the embodiment of FIGS. 13A and 13B, a separate tuner is required in each of the handsets which is always on and tuned to a dedicated control channel. When a find command is given for a specific handset user, the handset uses the dedicated control channel to contact the specified handset to determine if it is within range. Since the handset has a separate or dedicated tuner for this function, the find queries can occur when the handset is on a call with another handset without disruption of the call. If the queried handset (i.e., handset B) is within range and has the querying handset (i.e., handset A) on its Find list, then a positive response message will be sent back to the querying handset over the dedicated channel. FIGS. 14A and 14B illustrate another embodiment of the invention for implementing a specific find request for a handset. In the embodiment of FIGS. 14A and 14B, a separate tuner is not required, since all handsets register on the control channel in accordance with a predetermined cycle time (i.e., every x minutes or seconds). This registry occurs when the handset is idle and when the handset is on a call. Registering during a free call will disrupt the call for a period of time, since the handset utilizes the same tuner required for the call. The querying handset (i.e., handset A) will tune to the control or registry channel and listen for the duration of one cycle time (i.e., for x minutes or seconds). For those handsets that are on the list of handset A, handset A will check to ensure that it is on their corresponding list, which is provided as part of each registry message. FIG. 14A is an exemplary flowchart of the various processes and operations performed by handset A when querying a specific handset (i.e., handset B). FIG. 14B is an exemplary flowchart of the various processes and operations performed by handset B that registers on the control channel. A detailed description of each of these figures will now be provided. As illustrated in FIG. 14A, a specific handset request is initiated at step S.310 when user A presses the FIND key, with handset B being selected or highlighted on the Find list. Thereafter, the value of a cycle_clock is initialized and set to zero at step S.312 and the handset A tunes to the predetermined control or registry channel at step S.314. The cycle_clock may be provided to monitor the elapsed time and determine when the predetermined cycle time has elapsed. The cycle_clock may be incremented in accordance with an internal system clock of the handset. The handset A may dwell and wait at the registry channel for the duration of the cycle time to detect whether the selected handset (i.e., handset B) registers on the control channel and, thus, is within range. Thus, at step S.316, handset A determines whether a response has been received on the registry channel. The registry response message may include the ID and the Find list of the handset. If a registry response is detected, then at step S.320 the ID of the handset that registered is recorded, along with the detected signal strength (SS) and the Find list of the registering handset. Thereafter, at step S.322, it is determined whether the ID of the registering handset (handset X) corresponds to the ID of the handset which was highlighted or designated by the user A (i.e., handset B). If the handset that registered is handset B, then at step S.324 it is determined whether handset A is on the Find list of handset B. That is, the Find list that was contained in the registry message is analyzed to determine whether the ID of user A is contained on the Find list of handset B. If user A is on the list of handset B, then at step S.328 the handset displays the ID of user B, along with the corresponding name and signal strength (SS) as being found (e.g., by displaying a “Found” message). Thereafter, the specific handset find routine terminates at step S.330. If it is determined at step S.322 that the registering handset is not handset B, then logic flow proceeds to step S.318. Logic flow will also proceed to step S.318 from step S.316 when it is determined that handset response has not been received, as shown in FIG. 14A. At step S.318, the value of the cycle_clock is compared with the cycle time. If the cycle time has not elapsed or been exceeded based on the value of the cycle_clock, then logic flow loops back to step S.316, whereby handset listens and again determines whether a handset response has been received. If, however, the cycle_clock is greater than or equal to the cycle time at step S.318, then logic flow proceeds to step S.326. At step S.326, the handset will display and indicate to the user that the handset B was not found. In this case, the ID and/or name of the user B may be displayed to the user of handset A, along with an appropriate message (e.g., “Not Found”). Step S.326 will also be performed when it is determined at step S.324 that the Find list of handset B does not include the ID for handset A. Following step S.326, logic flow proceeds to step S.330, where the specific handset find routine terminates. FIG. 14B illustrates an exemplary flowchart of the operations and processes carried out by each handset (including handset B) for registering on the control channel. In particular, at step S.332, the handset performs other handset functions. Upon completion of a handset function or concurrently with the performance of other handset functions, the handset checks at step S.334 whether the cycle time has been lapsed or been exceeded. In this regard, a cycle_clock is maintained which is incremented in accordance with an internal system clock of the handset. When the value of the cycle_clock is greater than or equal to the predetermined cycle time, then it is time for handset to register on the control channel. In particular at step S.336, the handset will transmit the ID of the handset and its associated Find list on the registry channel. Thereafter, at step S.340, the cycle_clock will be reset to zero and logic flow will proceed back to step S.332. As further shown in FIG. 14B, logic flow will also loop back to step S.332 when it is determined at step S.334 that the value of the cycle_clock is less than the cycle time. In the embodiment of FIGS. 14A and 14B, no dedicated or separate tuner is required. Instead, each handset registers on a predetermined control or registry channel every cycle period (i.e., every x minutes or seconds). The registration during a free call will interrupt the call for a period of time, since the handset utilizes the tuner required for the free call. The registry message may include the ID of the registry handset and the list of other handset IDs that are on the registering handsets Find list. By requiring all handsets to transmit their corresponding Find list, analysis of the list can be made to ensure that the querying handset (handset A) is on the list of specified handsets (handset. B) and vice versa, without having to contact the specified handset directly. Once again, it is possible to provide procedures for collision detection and/or collision correction to prevent or correct the handset from trying to register at the exact same time as another handset. A more detailed discussion of an exemplary embodiment for detecting and correcting collisions is provided below. Various modifications may be made to the embodiment of FIGS. 14A and 14B to improve the efficiency of the specific handset find procedure. In particular, an idle handset can tune to the registry channel and maintain updates on the handsets on its list, so that when a specific find request is made, the handset is able to immediately inform the user of the Found list update. FIGS. 15A and 15B illustrate another embodiment of the present invention for providing a specific find request. The embodiment of FIGS. 15A and 15B combines the advantages of registering and having a dedicated control channel. In this embodiment, all handsets register on a predefined control or registry channel every cycle period (i.e., every x minutes or seconds). The registry occurs when the handset is idle and when the handset is on a call. The registry includes the ID of the handset that is registering and the frequency at which the handset can be contacted. If the handset is on a free call, then the identified or specified frequency will be the frequency of the call. If, however, the handset is idle or on a cellular or PCS call, the indicated frequency in the registry will be the frequency of the dedicated control channel. FIG. 15A is an exemplary flowchart of the various processes and operations that may be performed by a handset (i.e., handset A) which performs a specific request for another handset (i.e., handset B). FIG. 15B is an exemplary flowchart of the various processes and operations that are carried out by each handset (including handset B) for registering on the control channel and responding to find queries. Detailed descriptions of each of these figures will now be provided. As shown in FIG. 15A, a specific find request is initialized at step S.350 when the user of handset A presses the FIND key with the handset B being selected or highlighted on the Find list. Thereafter, at step S.352, handset A tunes to the predefined control or registry channel and at step S.354, sets the value of a cycle_clock to zero. Thereafter, the handset A listens for registry responses at step S.356 on the registry channel. At step. S.358, it is determined whether a handset response is received on the registry channel. If a handset registry message is not received, then at step S.360 it is determined whether the value of the cycle_clock is greater than or equal to the predetermined cycle time. As described above, the cycle_clock may be incremented in accordance with an internal system clock of the wireless handset and may be utilized to determine when the cycle time has elapsed. If the value of the cycle_clock is less than the cycle time at step. S.360, then control loops back to step S.358 where the handset A again tests whether a handset response is received. If a handset response is received at step S.358, then at step S.362 the handset A determines whether the ID of the handset which registered is equal to the ID of the handset which was highlighted by user A. That is, at step S.362, the handset A determines whether the ID of the registering handset (i.e., handset X) corresponding to the ID of handset B. If a handset other then handset B made the registry, then logic flow returns to step S.360 where the value of the cycle_clock is evaluated once again. Otherwise, if the ID corresponds to the ID for handset B, then at step S.364 the detected signal strength (SS) of the handset B is recorded. Further, at step S.366, handset A tunes to the specified channel or frequency for contacting handset B. As noted above, the registry message that is sent by each handset may include the frequency or channel at which the handset can be contacted. Following step S.366, handset A will send a find query to handset B at step S.368 with the ID of handset A being specified in the query message. The queried message will be sent on the specified frequency or channel for contacting handset B directly. At step S.370, handset A will also initialize the value of the wait_clock to zero. At step S.372, it is determined whether a response has been received from the direct query. Handset A may dwell and wait for a predetermined wait time to detect a response from handset B. Thus, if no response is received at step S.372, then at step S.374 it is determined whether the value of the wait_clock is greater than or equal to the predetermined wait time. The wait_clock may keep track of the elapsed time and be incremented in accordance with an internal system clock of the handset in order to keep track of the elapsed time. If the wait time has not elapsed, then logic flow returns to step S.372. Otherwise, when the wait time has elapsed or been exceeded, logic flow proceeds to step S.380, which is described in greater detail below. If it is determined at step S.372 that a positive response has been received from handset B, then at step S.376 the response is recorded along with the detected signal strength (SS). Further, at step S.378, handset A indicates to the user that handset B has been found. This indication may be displayed on the display of the handset and may include the ID of handset B, the corresponding name of user B and/or the detected signal strength (SS). An appropriate message (e.g., “Found”) may also be displayed to the user. Following step S.378, the specific handset find request terminates at step S.382. If a response to the direct query is not detected within the predefined wait time at step S.374, then at step S.380 handset A will assume that handset B is out of range or unavailable and indicate to the user that handset B was not found. In particular, at step S.380 the ID of user B, along with the corresponding name of user B and/or a message (e.g., “Not Found”) will be displayed to the user. Step S.380 will also be performed when it is determined at step S.360 that handset B did not register within the predetermined cycle time. FIG. 15B is an exemplary flowchart of the manner in which each handset (including handset B) may register on the control or registry channel and respond to direct find queries. In particular, at step S.390, the handset may perform other handset functions. Since a separate tuner is not provided in this embodiment, disruptions may occur to a call when the handset determines it is time to register. At step S.392, the handset will check to see if it is time to register on the control channel. That is, at step S.392, the value of the cycle_clock will be compared with the predetermined cycle time. If the cycle_clock is greater than or equal to the cycle time, then at step S.394 the handset will tune to the control or registry channel. Further, at step S.396, the handset will register by transmitting the ID of the handset and the channel or frequency at which the handset can be contacted. If the handset is on a free call, the specified frequency or channel will be the frequency of the call. If, however, the handset is idle or on a cellular or PCS call, then the specified frequency will be the frequency of the dedicated control channel. Following step S.396, the handset tunes back to the original or previous channel at step S.398. As shown in FIG. 15B, at step S.400 the handset will set the value of a cycle_clock to zero and then proceed to step S.402. Logic flow will also proceed to step S.402 from step S.392 when it is determined that the cycle time for registering has not elapsed. At step S.402, it is determined whether a find query has been received over the specified frequency or channel for the handset. If a direct find query has not been received at step S.402, then logic flow proceeds back to step S.390. Otherwise, when a direct find query is received at step S.402, the handset then proceeds to step S.404 where it is determined whether the ID of the querying handset (i.e., the ID of handset A) is on the Find list for the handset (i.e., handset X, which may be the handset of user B or another handset user). If it is determined at step S.404 that handset A is not on the Find list, then logic flow proceeds back to step S.390. If, however, handset A is on the Find list, then permission exists for transmitting a positive response to the find query. Accordingly, at step S.406 the handset will transmit a positive response back to handset A. Following step S.406, logic flow proceeds back to step S.390. With the embodiment of FIGS. 15A and 15B, no dedicated or separate tuner is required. However, a disruption on a free call may exist while both handsets register. As such, both handsets that are on a free call may register sequentially to minimize the disruption to the free call. In any event, the disruption to the conversation is minimized since each handset does not need to transmit their Find list when registering. Instead, the registry message only includes the ID of the handset and the frequency at which the handset can be contacted. Time domain multiplexing also allows the handsets on a free call to be queried directly on the channel where the call is occurring. Thus, when handset A needs to find handset B that is on a free call, handset A will tune to the channel on which handset B is conducting a voice conversation. It will then transmit the query on the control time slot of the channel to request handset B to check its list and receive from the control time slot of the channel the response if handset A is on the list of handset B. In the embodiment of FIGS. 15A and 15B, an idle handset can tune to the registry channel and maintain updates on the handsets on its lists so that when a find request is pressed, the direct queries of a specified handset can begin. Such a modification will reduce the total time required for performing a find request in the embodiment of FIGS. 15A and 15B. In addition, procedures may be implemented in FIGS. 15A and 15B to detect collisions and/or correct collisions. As explained above, a collision may occur when one handset tries to register at the exact same time as another handset. FIGS. 16A and 16B illustrate another embodiment of the present invention for implementing a specific find request for another handset. This embodiment is similar to the embodiment of FIGS. 12A and 12B in that the registry message includes not only the ID of the registering handset and the frequency at which it can be contacted, but also the time slot in which the handset can be contacted if it is on a call. By providing the time slot information, time domain multiplexing is not required in order to directly query a handset that is on a free call. FIG. 16A illustrates an exemplary flowchart of the various processes and operations that may be performed by a querying handset (i.e., handset A) which is attempting to find a specific handset (i.e., handset B) which was selected by the user. FIG. 16B is an exemplary flowchart of the various processes and operations performed by each handset (including handset B) for registering on the control channel and responding to direct find queries. A detailed description of each of these figures will now be provided below. As shown in FIG. 16A, a specific find request is initialized at step S.410 when user A presses the FIND key with the handset B selected on the list. At step S.412, handset A tunes to the control or registry channel and at step S.414 sets the cycle_clock to zero. Thereafter, at step S.416, the handset listens to the registry channel in order to detect a handset registry or response. If a handset response is received at step S.418, then at step S.422 it is determined whether the ID of the registering handset (i.e., handset X) corresponds to the ID of handset B, specified by user A for the specific find request. If it is determined at step S.422 that the responding handset is handset B, then at step S.424 the detect signal strength (SS) of the response is recorded and, at step S.426, the handset A tunes to the channel specified for contacting handset B. As noted above, the registry message includes the frequency at which the handset can be contacted and the time slot during which the handset can be contacted if it is on a call. At step S.428, handset A directly queries handset B on the specified channel. The direct find query will include the ID of the handset A to indicate the source of the query. Further, if handset B is on a free call, handset A will contact and send the query on the specified frequency and based on the specified time frame. Following step S.428, the handset A will set the value of the wait_clock to zero at step S.430 and, at step S.432, determine whether a response has been received from the handset B. If a positive response is received from handset B, then at step S.436 the response is recorded along with the detected signal strength (SS) of the response. Thereafter, at S.438, the handset will indicate to the user that handset B was found. In this regard, handset A may display the ID of user B, along with the name of user B and/or the detected signal strength (SS). Following step S.438, the specific find request terminates at step S.442. If a response is not received at step S.432, then logic flow will proceed to step S.434 to determine whether the predetermined wait time has elapsed. The handset may wait for the predetermined wait time to see if the directly queried handset responds. The value of the wait_clock may be incremented in accordance with an internal system clock of the handset to detect the elapsed time and to monitor the wait time. If the wait time has not been exceeded at step S.434, then logic flow will loop back to step S.432 so that the handset will again check to see whether a response has been received. Otherwise, if a response is not received and the predetermined wait time has been exceeded, then at step S.440, the handset will indicate that user B was not found. In this regard, handset A may display the ID of user B, along with the corresponding name of user B and/or an appropriate message (i.e., “Not Found”). Following step S.440, the specific find request will terminate at step S.422. Referring again to step S.418 in FIG. 16A, handset A will listen to the registry channel for the duration of one cycle time to detect whether handset B registers on the predefined control or registry channel. Thus, when a handset response is not received at step S.418, logic flow will proceed to step S.420 to check whether the cycle time has elapsed. As described above, the cycle_clock may be maintained to keep track of the elapsed time and to monitor when the cycle time has elapsed. As long as the cycle time has not elapsed, logic flow will loop back to step S.418 to check whether a handset response has been received. If, however, handset B is out of range or is not detected as registering on the control channel within the cycle time, then logic flow proceeds from step S.420 to step S.440 so that the handset A may indicate to the user that handset B was not found. FIG. 16B illustrates an exemplary logic flow of the various procedures and operations that may be carried out by each handset (including handset B) to register on the control channel and to respond to direct find queries. At step S.450, the handset performs other handset-related functions. These functions may include maintaining a free call or performing a memory-related function. At step S.452, it is determined whether the value of a cycle_clock is greater than or equal to the cycle time. Upon detection of the lapse of the cycle time, the handset then determines that it is necessary to register on the control or registry channel. Thus, at step S.452, if the cycle_clock is greater than or equal to the cycle time, logic flow proceeds to step S.454 where the handset tunes to the registry channel. Thereafter, at step S.456, the handset transmits the ID of the handset as well as the channel or frequency at which it can be contacted. If the handset is on a free call, the handset will also specify in the registry message the time slot in which the handset can be contacted. The onset of this time slot may be communicated as an offset from the time that the registration occurred. If the handset is idle or on a cellular or PCS call, the specified frequency to contact the handset will be the frequency of the dedicated control channel and the time slot will be any time. Following step S.456, logic flow proceeds to step S.458 where the handset tunes to the previous channel. Thereafter, the cycle_clock is reset to zero. Logic flow then proceeds from step S.460 to step S.462. As shown in FIG. 16B, logic flow will also proceed to step S.462 from step S.452 when it is determined that the cycle time has not elapsed. At step S.462 the value of the cycle_clock is compared with the slot start time and slot end time. In particular at step S.462, it is determined whether the cycle_clock is greater than or equal to the slot start time and less than or equal to the slot end time. If these conditions are satisfied, then logic flow proceeds to step S.464, where the handset determines whether a direct find query has been received during the specified time frame. If the conditions of step S.462 are not met (i.e., the value of the cycle_clock is outside of the specified time frame) or a find query is not received at step S.464, then logic flow will loop back to step S.450, as shown in FIG. 16B. When a direct find query is received at step S.464, the handset will check to see if the ID of the querying handset (i.e., handset A) is on the list of the handset (i.e., the Find list of handset X, which may be handset B or another handset). If the ID of handset A is on the Find list, then a positive response is transmitted at step S.470. Thereafter, logic flow returns to step S.450. If, however, there is no permission to respond to the find query since handset A is not on the Find list of the handset, then logic flow will proceed directly back to step S.450 from step S.468. In the embodiment of FIGS. 16A and 16B, when the querying handset (i.e., handset A) is initialized to perform a specific find request with respect to another handset (i.e., handset B), handset A will tune to the registry channel and listen for the duration of the cycle time. When it is detected that handset B registers on the registry channel, handset A will contact handset B directly on the frequency specified in the registry and in the time frame specified (if necessary). If handset B is within range, detects the find query from handset A and determines that handset A is on its corresponding Find list, then handset B will be able to respond to the query from handset A. During call setup, two handsets may exchange the time that they will each register. The time that the other handset registers may be defined as the slot time. Therefore, in the embodiment of FIGS. 16A and 16B, handsets may not register sequentially. Instead, handsets on a call may register at non-overlapping times during the cycle time in order to provide the time required to respond to find queries of other handsets during the slot time. If a collision occurs, then the registry time, slot time, and cycle time should be renegotiated. While two disruptions on a free call are required (since each handset registers and transmits its frequency and slot time on the registry channel), each disruption is minimized since the Find list of each handset does not need to be transmitted. Further, this embodiment includes the advantage of not requiring time domain multiplexing. As discussed above, the wireless handset of the present invention may also be implemented with a set of List Maintenance features. Generally, each wireless handset may store and maintain one or more lists of numbers and/or IDs of other handset users. According to a preferred embodiment of the invention, each handset is equipped with three lists of numbers, including a Speed Dial list, a Find list and a Found list. The Speed Dial list contains the names and numbers of all the people the user would like to call without having to dial the number directly. The Find list contains the names and number of all of the people that are on the Speed Dial list that have a wireless handset that is capable of operating in a direct handset-to-handset communication mode. Further, as described above, the Found list is the list of people or users that are on the Find list of the handset and that are within range of the user's wireless handset. The Found list is generated by pressing, for example, a FIND button on the handset and executing a find request. Each wireless handset may be implemented such that changes to any one of these lists will automatically be reflected in the other lists. In addition, these lists (i.e., the Find, Speed Dial and Found lists) do not need to be provided separately in the wireless handset. For example, two lists or all three lists may be combined in the handset. The List Maintenance features of the present invention may include features which permit a user to add, delete and modify entries to each list of the handset. In particular, according to an aspect of the present invention, the List Maintenance features may allow users to add entries identifying other handset users to their Speed Dial list and Find list. For example, a program feature may be provided which allows a user to program, with the buttons or keypad of the handset, the name and number of a person into either the Speed Dial list or the Find list. Such a feature may be similar in functionality to that used for programming speed dials in to conventional wireless handsets. However, the program feature of the invention may additionally require that the user indicate whether the number being programmed belongs to a compatible wireless handset that is capable for performing direct handset-to-handset communication. Another feature which may be provided with the List Maintenance features is a delete feature. With the delete feature, a user may be given an option to delete an entry from either the Speed Dial List or the Find list. When deleting an entry, both the name and number of the user will be deleted. In addition to the delete feature, a group feature may also be provided to permit a user to group objects into sublists. This feature may be useful when grouping family members, co-workers or friends into sublists. Grouping items on the Speed Dial list may also automatically cause entries to be grouped on the Find list, and vice versa. When items are grouped, their members will continue to be available on the list, as well as the group as a whole. According to an additional aspect of the present invention, the List Maintenance features of the wireless handset includes a memorize feature which provides an easy way for handset users to trade names and numbers with one another. The memorize feature may be invoked when two handset users are near each other (e.g., within an arm's reach or the same room) or are talking to each other on a free call. As illustrated in FIG. 5, a wireless handset may transition from an Idle state to a Memorize Request state when invoking the memorize feature. By invoking the memorize function at approximately the same time, the two handsets will exchange names and numbers, and enter those names and numbers into their respective Find list. By way of a non-limiting example, FIGS. 40A and 40B are exemplary flowcharts of the various processes and operations in a Memorize Request state, according to an aspect of the invention. As illustrated in FIG. 5, when initiating the memorize feature to exchange information with an object, the wireless handset will transition from an Idle state to a Memorize Request state. The transition from an Idle state to the Memorize Request state may occur under condition 1, when a user indicates to initiate or start a memorize request to exchange information with another object (e.g., another wireless handset) by pressing an appropriate key or button on the wireless handset. In the Memorize Request state, the wireless handset will attempt to exchange information (including ID or directory number information) with another handset or object that is located within range. The wireless handset may transition back to the Idle state from the Memorize Request state (represented by condition m in FIG. 5) after successfully exchanging information with another object or handset or after failing to complete the memorize function. More particularly, as illustrated in FIG. 40A, when entering a Memorize Request state the wireless handset will first switch and/or initialize the transceiver of the handset at step S.1300 for the memorize request. That is, N frequency pairs may be assigned to the wireless handset for performing a memorize function, with the higher frequency associated with a duplex channel “i” being designated as F.sub.hi and the lower frequency being designated as F.sub.li. Therefore, at step S.1302, the wireless handset will switch the receiver to the lower frequency band of the duplex pass band and switch the transmitter to the higher frequency band. As further shown in FIG. 40A, the handset will also initialize and set the value of a counter i to 1 at step S.1304. Following step S.1304, the receiver of the handset will be set to the low frequency F.sub.li and the transmitter will be tuned to the higher frequency F.sub.hi at step S.1306. After tuning the receiver and transmitter, the wireless handset will determine at step S.1308 whether there is interference in the channel. Interference may be analyzed by determining whether the signal strength of the channel is not greater than a predetermined threshold. For example, at step S.1308, the wireless handset may determine whether the received signal strength of the channel is greater than a threshold level THR.sub.rssi. If it is determined that the threshold has been exceeded and that there is interference on the channel, then at step S.1310 the value of the count i may be modified according to the following equation: i=(i+1)mod N After the value of the counter i is reset, logic flow proceeds back to step S.1306 so that another channel is tuned to and analyzed for interference. If the signal strength of the channel is determined to be acceptable at step S.1308, then a counter m may be initialized and set to 0 and at step S.1312 (see FIG. 40B) a synchronization signal may be sent by the wireless handset. After synchronization, the wireless handset may transmit a memorize message over the channel at step S.1314. The memorize message may include information associated with the handset, including the directory number DN and/or name associated with the wireless handset. Following step S.1314, the wireless handset will wait for a response at step S.1316 to determine if the object or other wireless handset responds by sending a memorize response message to complete the exchange of information. Ideally, the memorize feature should be invoked when both handsets are in close proximity to each other, so that memorize messages can be sent and received without interference (e.g., by calls or memorize messages transmitted between other wireless handsets in the area). In addition, the memorize messages may be transmitted at a reduced power level and within a short time window in order to avoid the messages from being received by other handsets or objects in the area. As such, the requesting handset that transmits the memorize message may wait for a predetermined period of time (e.g., a few seconds) to determine if a memorize response message has been received, before attempting to retransmit on another channel or determining that the memorize request has failed. If a memorize response message is not received at step S.1316, then the counter m is incremented by one at step S.1318 and at step S.1320 the requesting handset determines whether m has exceeded a predetermined limit L. If m is less than or equal to the predetermined limit L, then logic flow proceeds back to step S.1312 so that a synchronizing signal and the memorize message may be resent. Otherwise, at step S.1326, the handset will assume that the memorize request has failed and a find failure indication will be provided to the user to indicate that the memorize request was unsuccessful. Following step S.1326, the wireless handset may transition from the Memorize Request state back to the Idle state, as illustrated on FIG. 40B. If a memorize response message is received at step S.1316, then the wireless handset will check and analyze the signal strength of the memorize response message to determine if it was transmitted by the responding handset that is within close proximity or next to the transmitting handset. That is, at step S.1324, the handset may compare the signal strength with a predetermined threshold RD.sub.rssi to confirm that the memorize response message was sent at a reduced power level. If the signal strength is greater than the predetermined threshold RD.sub.rssi, then the attempt to exchange information has failed and at step S.1326 a find failure indication will be provided to the user to indicate that the memorize request was unsuccessful. Thereafter, the handset may return to an Idle state. If, however, the signal strength is determined to be at the expected reduced power level, then the memorize response message has been received successfully and the information associated with the responding handset (including directory number and/or name) will be decoded. Further, at step S.1328, a memorize success alerter will be activated to notify the user that the memorize request was successful. This indication may comprise providing an audible tone and/or message to the user with the handset. Following step S.1328, the handset will store and update the decoded information in the handset. The information may be stored in the speed dial and Find lists of the handset, so that the user may initiate call requests and find requests with the stored information. Thereafter, the wireless handset may transition from the Memorize Request state back to the Idle state, as illustrated on FIG. 40B. In accordance with another embodiment of the invention, FIGS. 17A and 17B represent an additional, exemplary implementation of the memorize feature that may be provided in a handset. In particular, FIG. 17A is an exemplary flowchart of the various processes and operations that may be performed by a handset (i.e., handset A) when invoking the memorize function to exchange name and number information with another handset (i.e., handset B) that is nearby. FIG. 17B illustrates an exemplary flowchart of the various processes and operations performed by the handset B that is near handset A and that is also invoked to perform a memorize procedure. Each of these figures will now be discussed in greater detail. As shown in FIG. 17A, the memorize procedure is initialized by user A at step S.500 when the memorize feature is selected on the handset with the other handset or object B being nearby. Since the memorize procedure is performed with the handsets being set at reduced power, handset B should be in close proximity to handset A in order to receive the transmitted handset information. Generally, the handsets should be approximately an arm's length away from one another or should be in the same room. Further, although step S.500 illustrates user A as initializing the memorize procedure, it is of course possible that handset B initializes the memorize procedure by activating the memorize feature before user A. At step S.502, handset A sets the value of a wait_clock to zero. The wait_clock may be a counter stored in the handset which is incremented in accordance with an internal system clock to keep track of the elapsed time. Following step S.502, the handset at step S.504 tunes to a predetermined control channel at a very low or reduced power. As discussed above, since the memorize information is exchanged at a reduced power level, handset A and handset B should be in close proximity to one another so that the information may be detected and received. The power level should be reduced to a level so as to prevent other handsets in the area from receiving the signal. Preferably, the handset units should be operated within several feet of one another or within one arm's reach. At step S.506, handset A queries handset B over the control channel for a memorize confirmation. The memorize query message sent from handset A may include the ID and corresponding name for user A. Following step S.506, the handset A determines at step S.508 whether a positive response or confirmation has been received. If a response is not received, then at step S.510, the handset determines whether a predetermined wait time has expired. In accordance with an aspect of the present invention, each handset may wait for a predetermined wait time for a memorize confirmation from the other handset. The value of the wait_clock may be compared with the wait time to determine the amount of lapsed time since initializing the memorize procedure. If it is determined that the wait_clock is less than the wait time, then logic flow loops back to step S.508. Otherwise, if a memorize confirmation is not received within the wait time and, at step S.510, it is determined that the wait time has elapsed or been exceeded, then logic flow proceeds to step S.516 where the memorize routine is terminated. If it is determined at step S.508 that a memorize confirmation has been received, then at step S.512 it is determined whether user A confirms that the ID and name of user B should be memorized. In this regard, user A may be prompted by the display of the handset to confirm that the memorize procedure should be completed by storing the ID and name of user B to the list. If user A does not confirm the saving of user B to the list, then logic flow proceeds to step S.516 where the routine terminates. If user A confirms the completion of the memorize procedure, then at step S.514 the ID and name of user B (which was included in the memorize confirmation message from handset B) is stored in the Find list for handset A. Following step S.514, the procedure terminates at step S.516. FIG. 17B illustrates the various processes and operations that may be carried out by handset B when performing a memorize procedure with handset A. Specifically, at step S.520, handset B performs other handset related functions. Thereafter, at step S.522, handset B detects whether a memorize query has been received over the control channel. In accordance with an aspect of the present invention, the tuner for handset B may periodically check for responses received over the control channel, including whether a memorize query has been received. If it is determined that a memorize query is not received at step S.522, then logic flow loops back to step S.520. If, however, a memorize query is received in the control channel at step S.522, then the query message is analyzed at step S.524. In particular, handset B temporarily records the ID and name of user A at step S.524. As discussed above, the ID and corresponding name of user A is included with the memorize query from handset A. Following step S.524, handset B sets and initializes the value of a wait_clock to zero. The wait_clock may be stored in handset B and is utilized to monitor the elapsed time. For this purpose, the wait_clock may be incremented in accordance with an internal system clock of the handset. At step S.528, the handset determines whether user B has pressed the memorize button or selected the memorize feature. That is, upon receipt of the memorize query from user A (which initialized the memorize procedure), user B may be prompted by the display of the handset to activate the memorize feature. Alternatively, the handset may not provide a prompt and user B may simply press or activate the memory feature with the handset after user A initializes the memorize procedure on his/her handset. If the memorize procedure is not activated by the user B, then at step S.530, it is determined whether a predetermined wait time has been exceeded. For this purpose, the value of the wait_clock is compared with the wait time. If the wait_clock is less than the wait time, then logic flow loops back to step S.528. Further, if the memorize feature is not activated at step S.528 and the wait time has been determined to be exceeded at step S.530, then the entire memorize procedure is skipped and logic flow returns to step S.520. If it is determined at step S.528 that the memorize feature has been activated by user B, then at step S.532 a memorize confirmation message is sent back to handset A over the control channel. In this regard, handset B operates at a reduced power and includes the ID and name of user B with the memorize confirmation message. Following step S.532, handset B determines at step S.534 whether the user confirms to complete the memorize procedure by saving the ID and name of user A (which was included in the memorize query from handset A). User B may be prompted to confirm the storing of the ID and name of user A by a message prompt on the handset. If user B confirms that user A is to be memorized, then at step S.536 the ID and name of user A is added to the Find list of handset B. Following step S.536, the routine ends and logic flow loops back to step S.520, so that other handset functions can be performed. Logic flow will also return to step S.520 from step S.534 if user B does not confirm that user A is to be added to the Find list. Successful completion of the memorize procedure results in handset B showing on the Find list of handset A, and vice versa. The Speed Dial list of handsets A and B may also be updated in accordance with the information added to the Find list. In addition to two handsets exchanging information, other objects (such as tracking devices, including a paging device or a beeping clip attached to an item) can be memorized by having the user press the memorize button or activate the memorize feature on the object. Objects, however, can also be manually programmed into a Find list of a handset, thus alleviating the need for a memorize button on the object. As discussed above, since the memorize procedure is performed with the handsets operating at a reduced power and for transmitting only for a short period of time, users must invoke the function in close proximity to one another and close together in time. Additional procedures may be incorporated into the logic flow of FIGS. 17A and 17B to detect collisions and/or correct collisions. A more detailed discussion of procedures for detecting and correcting collisions if provided below. The memorize features of the present invention may also be used in connection with other objects, such as a tracking devices or clip. The memorize procedure may operate in a similar fashion to that for memorizing between two handsets. For example, when the memorize feature is invoked by a handset on a clip, the ID of the clip may be automatically transferred and stored in the Find list of the handset. The user of the handset may then be given an opportunity to associate a name with the clip or object. Such a feature may save a user from having to enter both the name and the ID into the handset. Another set of features which may be implemented in the wireless handset of the present invention is a set of Conference Call features. Conference Call features may enable the user of the wireless handset to place conference calls to other compatible handsets through direct handset-to-handset communication, as long as all parties are within range of the conference initiator. Various methods may be provided for initiating a conference call. For example, a Spontaneous Conference Call feature may be provided to permit a user to add another person to an existing call (similar to three-way calling) to establish a conference call. This type of conferencing may be available during other types of conferencing. Further a Static Talk Group feature may be provided which enables the user to create a group of people in the Speed Dial list or the Find list to which the user would like to place a conference call. To establish a conference call, the user may select the group of people through the display of the handset, press the FREE button and the handset will simultaneously place a call to all members of that group. Should some of the users in the group not be available or reject the call, the conference may still be initiated, but without those members. Further, this conference feature will not continue to try to bring the missing members into the call. However, spontaneous conferencing may be available during this type of conference to permit the user to selectively add other users or try to contact the missing members of the group. Other Conference Call features may be provided. For example, a Temporary Talk Group feature may be provided that allows a user to specify two or more people to place a call by selecting those people from the Speed Dial list, Find list, or Found list individually and then hitting the FREE button on the handset. Should some of the users from the group not be available or reject the call, the conference will still be initiated, but without those members. This conference call feature will not try to bring these missing persons into the call, but the user may try to add these persons during the conference with the spontaneous conferencing feature. Another feature that may be provided as part of the set of Conference Call features is a Conference Call Channel. In accordance with an aspect of the present invention, a Conference Channel may be a predefined channel which is open to all wireless handsets that are implemented according to the aspects of the present invention. Such a Conference Channel may function similar to a channel of a CB radio. Spontaneous conferencing may be made available with this type of conferencing to permit other members to be added to the conference call. Various techniques may be utilized to implement and establish conference calls through direct handset-to-handset communication. According to an aspect of the present invention, time domain multiplexing is utilized to establish three-way conferencing and other types of conference calls. For three-way conferencing established through time domain multiplexing, three time slots per frame may be defined. In general, one time slot is utilized to carry control data and the other two time slots are utilized to carry voice data between any two handsets. FIGS. 18A, 18B and 18C illustrate embodiments of providing three-way conferencing through the use of time domain multiplexing, in accordance with aspects of the present invention. In particular, FIG. 18A schematically represents a three-way conferencing scenario between handset A, handset B and handset C. In FIG. 18A time domain multiplexing may be utilized to implement three-way conferencing with the handsets communicating in a direct handset-to-handset communication mode. As mentioned above, three time slots per time frame are provided, with two of the time slots carrying voice data. To support bi-directional communication, the voice data may be transmitted by either party. For example, with respect to handsets A and B, handset A may transmit with handset B receiving (ATBR), or handset B may transmit voice data with handset A receiving (BTAR). Further, with respect to handsets A and C, handset A may transmit with handset C receiving (ATCR), or handset C may transmit with handset A receiving (CTAR) the voice data. Similarly, with respect to handsets B and C, handset B may transmit with handset C receiving (BTCR), or handset C may transmit with handset B receiving (CTBR) the voice data. In addition to the two slots per time frame that are utilized to carry voice, one slot per frame may be dedicated for carrying control data. Various implementations may be utilized for allocating the three time slots per frame. FIGS. 18B and 18C illustrate two embodiments of the invention for time slot allocation. In FIG. 188B, the first, second and third time slots (TS1, TS2 and TS3) are defined, wherein the first time slot TS1 is dedicated for control data (C). In this embodiment, the first time slot TS1 may have a length that is as small or as large as needed for supporting the control data. The second time slot TS2 and the third time slot TS3 in FIG. 188B are provided to carry voice. In FIG. 18C, the first, second and third time slots (TS1, TS2 and TS3) are defined differently with respect to the control data time slot. That is, in FIG. 18C, any time slot can carry voice. Therefore, the control data (C) may be carried in any time slot. However, in the embodiment of FIG. 18C, the length of the time slot carrying the control data must be the same length as the voice channel or time slots. In any event, for both of the embodiments of FIGS. 188B and 18C, an additional framing bit may be provided at the beginning of each frame to help the receiving equipment synchronize. As illustrated in FIGS. 18A-18C, three-way conferencing may be implemented and provided in the wireless handset of the present invention through the use of time domain multiplexing and a time frame including a plurality of time slots (preferably three slots). In the embodiment of FIG. 18B, the time slot carrying the control data may be of any required length, whereas in the embodiment of FIG. 18C the control data time slot must be the same length of the voice channel. Further, in the embodiment of FIG. 18C, only one handset has access to the transmit and receive control time slot at a time. Thus, handset specific data must either be sent over multiple time slots, or the proper time slot for each handset must be known. In contrast, in the embodiment of FIG. 188B, control data that applies to any or all of the handsets can be sent at one time and all handsets can receive the same. Since the first time slot TS1 is dedicated for carrying the control data, no prior knowledge of the proper time slot is required. While the embodiments of FIGS. 18B and 18C have been provided, other variations on the number of time slots per frame and the allocation of what is transmitted and received in each time slot may be provided. The present invention has been described with reference to facilitating and supporting voice communication between handsets. In addition to supporting voice communication, the wireless handsets of the present invention may also be implemented so as to permit short range messages (including alphanumeric text, etc.) between handsets when communicating in a direct handset-to-handset communication mode. For this purpose, a set of Short Range Messaging features may be provided with the handset of the present invention. Such features may facilitate the sending of short range messages from one handset to another handset, as along as both handsets are within range. The types of messages that may be supported can include both numeric and alphanumeric messages. Short range messages can be sent directly from one handset to another if they are both idle, or can be received during the control time slot if the receiving handset is on a call. When sending a short range message, the sending handset may check a registry or control channel to determine if the handset is within range (i.e., the handset should perform a specific find request), and to identify the proper frequency on which to send the message. Short range messaging should be restricted if a user tries to initiate the same during a call. Traditional short range messaging techniques and features may be utilized to provide short range messaging in the wireless handset of the present invention. That is, traditional message structures for sending messages (such as that used in short message service—SMS) may be used for sending short messages between handsets. However, since handsets are capable of communicating with one another without the use of a network infrastructure, a separate message center is not necessary to handle transmission of the short messages. Further, since the wireless handsets of the present invention are capable of communicating in a direct handset-to-handset mode, short range messages may be received by a handset during a call. The set of Short Range Messaging features may provide various functionalities and capabilities to the user of the wireless handset. For example, a user may be able to enter custom messages, including numeric or alphanumeric messages, by typing them in using the keypad of the wireless handset. Once a message is typed in, the user will be given the option to store that message in a Saved Messages list. The Saved Messages list may store a predetermined number of messages, each of which is permitted to have a maximum length. When the limit of the Saved Messages list is reached, old messages may be deleted to provide sufficient room for additional or new messages. Further, the user may be given the ability to select message from the Saved Messages list to easily use and resend the messages without having to type those messages again. These messages may include basic alphanumeric messages (e.g., “Let's go to lunch”) or other types of messages that are frequently sent by the user. In order to send a message, the Speed Dial list, Find list or Found list can be utilized by the user to select a person or group to send the message. A message can be sent or broadcast to a group by selecting a defined group from the Speed Dial list or the Find list. In addition, the user can specify two or more recipients of a message by selecting those people or groups from the Speed Dial list, Find list or Found list. With respect to header information, the sender of the message, time and date the message was received will be displayed at the beginning of the message. An optional feature may also be provided which permits the display of all recipients of a broadcast message when this feature is selected. Various types of feedback may be provided to the user when a message is sent. For example, if the receiving handset is out of range or turned off, a message stating this fact may be presented on the display of the sender's handset (e.g., “Unavailable”). Further, if the receiving handset is in use and cannot receive a message, then a message stating that the handset is busy may be presented on the sender's handset display (e.g., “Busy”). If the receiving handset confirms reception of the message, then a message stating this fact may be displayed (e.g., “Delivered”). Another feature that may be provided is a Query Message Read feature which allows users to ask the handset that received the message if that message was read. If the handset is in range, the handset will respond automatically without asking the user. In addition, a Read Feedback feature may be provided which, when selected, will automatically send a message back to the originator of the message that the message was read by the receiver (as indicated by the receiver scrolling to that message). If the originator is out of range, the handset will not continue to try to deliver this acknowledgment. For incoming short range messages, various features may be provided for alerting and displaying the incoming messages. For example, a variety of message alert features may be provided which enable the handset to alert the user of an incoming message by the choice of a ringing signal, vibrating signal, blinking display, beeping signal (only once) or with no alerting signal. The choice of message alert may be selectable and an independent choice than that made for traditional wireless network calls or incoming handset-to-handset calls. When an incoming message is received, a note on the screen may be displayed to the user to inform the user of the received message. The message display may indicate the number of messages received. When a message is received, the user may then be able to access that message and scroll through it using the arrow keys on the handset. For reply features, a one function reply to a message can be invoked. The reply can be numeric, alphanumeric or a message chosen from the Saved Messages list. The reply message may contain the quoted text of the original message. As discussed above, users may also be given the ability to delete messages, including messages stored in the Saved Messages list. By way of a non-limiting example, FIGS. 41A and 41B illustrate exemplary flowcharts of the various processes and operations that may be performed by a handset when sending a short range message in a Short Range Message state. That is, as illustrated in FIG. 5, a wireless handset may transition from an Idle state to a Short Range Message state when the handset is invoked by the user to transmit a short range message. This transition state is represented by condition n in FIG. 5. In the Short Range Message state, the wireless handset may transmit the short range message to a specified handset or object. Upon the successful transmission of the short range message or after determining that the short range message request has failed, the handset may transition back to the Idle state from the Short Range Message state (as represented by condition o in FIG. 5). In particular, as illustrated in FIG. 41A, when entering a Short Range Message state the wireless handset will first collect the short range message entered by the user at step S.1400. The short range message may be entered by the user through the keypad of the handset. The handset may include pre-stored messages that the user may select and/or modify. At step S.1400, the short range message that is collected may be stored in a memory buffer of the handset. Then, at step S.1402, the handset will switch and/or initialize the transceiver in preparation of transmitting the short range message request. The handset may be implemented to sent the short range message over a dedicated control channel or a registry channel. Alternatively, in accordance with the embodiment of FIGS. 41A and 41B, N frequency pairs may be assigned to the wireless handset for transmitting short range messages. In such case, the higher frequency associated with a duplex channel “i”may be designated as F.sub.hi and the lower frequency designated as F.sub.li. Therefore, at step S.1402, the wireless handset will switch the receiver to the lower frequency band of the duplex pass band and switch the transmitter to the higher frequency band. As further shown in FIG. 41A, the handset initializes and set the value of a counter i to 1 at step S.1404. Following step S.1404, one of the assigned frequency pairs is selected based on the value of the counter i, with the receiver of the handset being set to the low frequency F.sub.li and the transmitter will be tuned to the higher frequency F.sub.hi. After tuning the receiver and transmitter, the wireless handset will determine at step S.1308 whether there is interference in the channel. Interference may be analyzed by determining whether the signal strength of the channel is not greater than a predetermined threshold. For example, at step S.1408, the wireless handset may determine whether the received signal strength of the channel is greater than a threshold level THR.sub.rssi. If it is determined that the signal strength exceeds the threshold and that there is interference on the channel, then at step S.1410 the value of the count i may be modified according to the following equation: i=(i+1)mod N After the value of the counter i is reset, logic flow proceeds back to step S.1406 so that another channel is tuned to and analyzed for interference. If the signal strength of the channel is determined to be acceptable at step S.1408, then a counter m may be initialized and set to 0 and at step S.1412 (see FIG. 41B) a synchronization signal may be sent by the wireless handset. After synchronization, the wireless handset may transmit and send the short range message over the selected channel at step S.1414. The short range message include the directory number DN and/or name associated with the wireless handset or object that the short range message is directed to. Following step S.1414, the wireless handset will wait for a response at step S.1416 to determine if the short range message has been received. The handset that transmits the short range message may wait for a predetermined period of time (e.g., a few seconds) to determine if a short range message response has been received before attempting to retransmit on another channel or determining that the memorize request failed. If a short range message response is not received at step S.1416, then the counter m is incremented by one at step S.1418 and at step S.1420 the handset determines whether m has exceeded a predetermined limit L. If m is less than or equal to the predetermined limit L, then logic flow proceeds back to step S.1412 so that a synchronizing signal and the short range message may be resent. Otherwise, at step S.1426, the handset will assume that the short range message was not received and a short range message (SMR) send failure indication will be provided to the user to indicate that the memorize request was unsuccessful. Following step S.1426, the wireless handset may transition from the Short Range Message state back to the Idle state, as illustrated on FIG. 41B. If a short range message response is received at step S.1416, then at step S.1424 a short range message (SMR) send success indication will be provided to the user to indicate that the short range message was sent successfully. Following step S.1424, the wireless handset may transition from the Short Range Message state back to the Idle state, as illustrated on FIG. 41B. In addition to providing Short Range Messaging features, the wireless handset of the present invention may be implemented with various Accessory-Related features. Various accessories may be provided with the wireless handset of the present invention. For example, the wireless handset may be provided with a port or connection to support computer connectivity. Computer connectivity features may be implemented in the wireless handset to enable downloading of large lists (e.g., Speed Dial lists, Find lists, Short Messages lists, etc.) and standard configurations. In addition, computer control of handset features, such as find features, may be available so that such features are performed automatically when they are required to perform other handset functions. The computer connectivity features may also permit handset data (e.g., the results of a find query) to be uploadable to a computer or other computer-based device. Another accessory which may be provided with the wireless handset of the present invention is a tracking device, such as a beeping clip device or paging device that is secured to an item. Beeping clip and paging devices may be attached to items such as keys, wallets and tools to facilitate the locating of those items. These devices may be clipped onto the item or attached by other suitable means (e.g., an adhesive surface, a clasp, a chain, etc.). Further, these devices may be embedded in the item with other components (e.g., as part of a remote lock or key ring) or provided in another form. In any event, the word “clip” is used herein as a way of generally referring to all types of tracking devices. Accordingly, a beeping clip that clips to an item is an exemplary embodiment only and the word “clip” should not be construed as limiting the type of tracking device that may be utilized in the invention. Each tracking device may have a unique ID and may be entered with other objects into the Speed Dial list and Find list of the handset by performing a memorize function or by entering the same manually. The user may also be given the option to individually name each item and to automatically group items together. By pressing a predetermined key or button on the handset with an item (which, for example, has a beeping clip or paging device attached thereto) being highlighted on the display, the selected item will be instructed to beep if it is within range. This will then permit the user to locate the item without difficulty. Items with attached clips can also be selected, as with persons and other objects, to make the items beep or ring whenever the items start in range but then exceed range, to facilitate ensuring that those items are not left behind (such as a tool or wallet) or do not wander away from the user (e.g., a toddler or a pet). In connection with the Accessory-Related features and the use of clips, various features may be implemented for locating these type of objects. In general, clips may be transmitting or non-transmitting in type. That is, the clips may include the capability to transmit a response or beacon when queried by a handset (i.e., transmitting in type) or may be limited to only emitting an audible beep without transmitting a beacon or response signal (i.e., non-transmitting in type). FIGS. 19A and 19B illustrate an exemplary embodiment for locating a non-transmitting clip. Further, FIGS. 20A and 20B represent the manner by which a transmitting clip can be located by causing the clip to emit a beacon, in accordance with another embodiment of the invention. Moreover, in accordance with yet another embodiment of the invention, FIGS. 21A and 21B represent the manner by which a transmitting clip can be located by causing the clip to respond with a beacon signal and emit an audible beep. The various processes and operations represented in the flowcharts of FIGS. 19-21 may be implemented by any suitable combination of hardware, software, programmed logic and/or firmware. A detailed description of each of these embodiments will now be provided. As noted above, FIGS. 19A and 19B represent an embodiment for locating a non-transmitting clip. In particular, FIG. 19A is an exemplary flowchart of the various processes and operations performed by a handset (i.e., handset A) which is attempting to locate at non-transmitting clip (i.e., object B). FIG. 19B illustrates an exemplary logic flow of the various processes and operations that may be performed by object B when queried by handset A. In the embodiments of FIGS. 19A and 19B, the non-transmitting clip only transmits an audible beep tone when queried, since it is incapable of transmitting a beacon or response signal. Referring to FIG. 19A, a non-transmitting clip (i.e., object B) is queried or called when user A presses the call or send button at step S.600 with the object B selected or highlighted on the list. Thereafter, at step S.602, handset A queries object B based on the ID of object B at step S.602. The query at step S.602 includes a beep request so that the object B will emit an audible beep if it is within range of handset A. If the object B is not within range of handset A, then the query will not be received and object B will not emit a beep tone. In the embodiment of FIG. 19A, a predefined object or control channel may be provided for querying object B. Following step S.602, the procedure terminates at step S.604. FIG. 19B illustrates the various processes and operations carried out by the specified clip (object B) when responding to a query from handset A. In particular, at step S.610 other object functions are performed. Thereafter, at step S.612, object B determines whether a query message with a beep request has been received from a handset that is within range. A dedicated tuner or device may be provided for detecting when a beep request is received over the object channel. The monitoring of the channel by object B may be performed concurrently with the performance of other functions at step S.610. If a beep request is not received at step S.612, then logic flow loops back to step S.610. Otherwise, if a query with a beep request is received at step S.612, then at step S.614 object B emits an audible beep, noise or signal. If object B is heard by the user of handset A, then the object can be located. Following step S.614, logic flow returns to step S.610. In the embodiment of FIGS. 19A and 19B, the object that is called is a non-transmitting type of clip that will only emit an audible beep when queried by the handset. Since the non-transmitting clip is not capable of transmitting a beacon or response signal, the querying handset will be prevented from measuring its relative signal strength and/or proximity. The non-transmitting clip, however, should be less expensive than a transmitting-type of clip, and may or may not include a memorize button for permitting the object to be memorized by a handset. FIGS. 20A and 20B represent an exemplary embodiment for locating a transmitting-type of clip. In this embodiment, the clip (i.e., object B) is queried by the handset (i.e., handset A) to transmit a positive response or beacon without emitting a beep noise. FIG. 20A is an exemplary flowchart of the various processes and operations that may be performed by handset A when querying object B for a beacon signal. Further, FIG. 20B is an exemplary logic flow diagram of the processes and operations carried out by the clip B when queried by handset A. As shown in FIG. 20A, the procedure for finding object B is initialized at step S.620 when user A presses the FIND button on a handset with the clip or object B being selected or highlighted on the Find list. Thereafter, at step S.622, the handset sets the value of the wait_clock to zero. The wait_clock may monitor the elapsed time and may be incremented in accordance with an internal system clock of the handset. Following steps S.622, handset A queries object B at step S.624 based on the ID associated with object B. This query may be sent on a predefined object or control channel for object B. At step S.626, handset A determines whether a response or beacon signal has been received. If no response is received at step S.626, then at step S.628 it is determined whether a predetermined wait time has been exceeded. In this regard, the value of the wait_clock may be compared with the wait time. If the wait_clock is less than the wait time, then logic flow loops back to step S.626 to again determine whether a response has been received. Otherwise, if a response has not been received and the wait time has been exceeded at step S.628, then at step S.634 the handset A displays to the user that object B was not found. In this regard, an appropriate message (i.e., a “Not Found” message) may be displayed on the handset for viewing by the user. Following step S.634, the procedure terminates at step S.636. If a response or beacon signal is received within the wait time at step S.626, then at step S.630 the signal strength (SS) of the response is measured and recorded. Conventional or standard techniques may be utilized to measure the signal strength of the beacon signal received from the object B. Following step S.630, the handset at step S.632 will indicate to the user that object B was found. In this regard, handset A may display the ID and/or name associated with object B along with a message (i.e., “Found”) indicating that the object was found. In addition, handset A may also indicate and display the detected signal strength (SS) of the beacon signal. The signal strength may be indicated on the display by use of a numeric value or a sequence of bar segments. Following step S.634, the procedure terminates at step S.636. FIG. 20B illustrates the various procedures and functions carried out by the clip (i.e., object B) when being queried by handset A. In particular, at step S.640 object B performs other functions. Concurrently with the performance of these functions or following the completion of these functions, object B determines at step S.642 whether a find query has been received on the predefined object or control channel. In this regard, a dedicated tuner or transceiver may be provided in the clip device to constantly monitor the channel for find queries. If it is determined at step S.642 that a find query was received, then at step S.644 the object B will transmit a positive response or beacon signal back to the handset A. Further, since the find query from handset A did not instruct the object B to emit a beep noise, no audible beep will be emitted by the object. Following step S.644, logic flow loops back to step S.640. Logic flow will also loop back to step S.640 if it is determined at step S.642 that a find query has not been received over the object channel. In the embodiment of FIGS. 20A and 20B, a simple beacon or response signal is emitted by the object to permit the querying handset to detect and measure the signal strength of the signal. The receipt of the beacon or response signal from object B will serve to indicate to the querying handset that the object is within range. Further, the detected signal strength will also provide a means by which the user of the querying handset may determine the relative distance to the object. The beacon or response signal that is emitted by object B may contain the ID of the object or the response may take the form of a direct synchronous connection to the handset (possibly containing the ID of the object) which is used to measure the signal strength. As noted above, object B does not emit a beep tone and, in fact, may or may not be capable of emitting such an audible beep. That is, in the embodiment of FIGS. 20A and 20B, a find query is performed in such a case where the user want to know if the object is within range, without making the object beep. Although the clip device is a transmitting type of clip and, therefore, is more complicated and expensive than the non-transmitting clip of FIGS. 19A and 19B, the clip for this embodiment may or may not have a memorize button (an object without a memorize button should be less complicated and expensive). If a user wishes to determine if an item with an attached beeping clip is within range and to cause the object to beep, then a query of the object may be performed to measure the signal strength and to cause the object to emit an audible beep. FIGS. 21A and 21B illustrate an exemplary embodiment for carrying out such a function. In particular, FIG. 21 is an exemplary flowchart of the various processes and operations that may be performed by a handset (i.e., handset A) to locate a transmitting-type clip (i.e., object B) and to cause the object to emit a beep. FIG. 21B is an exemplary logic flow of the various processes and operations carried out by the object B which has been queried by handset A. FIGS. 21A and 21B are further discussed below. In particular, as shown in FIG. 21A, a query to object B is initialized at step S.650 when user A presses the call or send button of the handset with the object B being highlighted or selected on the handset. Following step S.650, handset A sets and initializes the value of a wait_clock to zero. The wait_clock may be provided to keep track of the elapsed time and may be incremented in accordance with an internal system clock of the handset. After resetting the wait_clock, handset A queries object B at step S.654. The query that is sent at step S.654 may include the ID of object B and may be sent on a predefined object or control channel. Further, this query message means include a beep request which will cause object B to emit an audible tone or noise. At step S.656, handset A determines whether a positive response or beacon signal has been received from object B. If no response is received at step S.656, then at step S.658 the handset determines whether the predetermined wait time has been exceeded. This may be performed by comparing the value of the wait_clock to the wait time. If the wait_clock is less than the wait time, then logic flow loops back to step S.656 where it is again determined whether the response has been received. Otherwise, if a response has not been received from the object within the wait time, then at step S.664 the handset A indicates to the user that object B was not found. In this regard, the handset may display a message (i.e., “Not Found”) and/or the ID and name corresponding to object B. Following step S.664, the procedure terminates at step. S.668. If it is determined at step S.656 that a response has been received within the wait time, then the response signal or beacon signal is analyzed and the signal strength is detected and measured. Further, the detected signal strength (SS) is recorded at step S.660 and then at step S.662 the handset indicates to the user that object B was found. At step S.662, the handset A may display a message (i.e., “Found”) and the signal strength (SS) of the response received from object B. As indicated above, the signal strength may be indicated with a numeric value or through the aid of a bar segment display. Following step S.664, the procedure terminates at step S.668. The basic procedures and functions performed by the clip device queried by handset A are illustrated in FIG. 21B. In particular, at step S.670, object B performs other functions. Concurrently with the performance of these functions or after the performance of a function, object B determines at step S.672 whether a query has been received on the object or control channel. In this regard, object B may include a dedicated tuner or device that is constantly monitoring the object channel for queries and beep requests. If it is determined at step S.672 that a query with a beep request has been received, then at step S.674 a positive response or beacon signal is sent back to handset A and at step S.676 object B emits an audible beep noise. Following step S.676, logic flow loops back to step S.670. Logic flow will also return to step S.670 if it is determined at step. S.672 that a beep request has not been received. With the embodiment of FIGS. 21A and 21B, the paged clip device will respond with a beacon signal and emit an audible beep tone. The response may take the form of a beacon signal containing the ID of the object or the response may simply be a direct synchronous connection to the handset (possibly containing the ID of the object) which is used to measure the signal strength. The transmitting-type clip of FIGS. 21A and 21B includes the ability to respond with a positive response signal and to emit an audible beeping tone. The clip device, however, may or may not have a memorize button to facilitate adding the object to the listed handset. As detailed above, clip devices that are provided as accessories with a wireless handset may be transmitting or non-transmitting in type. Whether the clip is implemented as a transmitting type object or a non-transmitting type object, a preferred embodiment of the invention does not require the objects to include a memorize button. By not requiring the memorize button, a user will have to manually program the clip into the list of the handset. However, without the memorize button, clip devices will be less complicated and expensive to implement and provide as an accessory. Further, for the transmitting type of clip device, a preferred embodiment of the invention utilizes the beacon transmission as a response, since this requirement is also believed to be less expensive than the alternative of providing a direct synchronous connection to the handset. In accordance with aspects of the present invention, FIGS. 35 and 36 are exemplary block diagrams of the main components of a non-transmitting clip device and a transmitting clip device, respectively. In particular, as illustrated in the exemplary block diagram of FIG. 35, non-transmitting clip device 2000 may be implemented through various components, including a control system 2040, an antenna 2005, a transducer 2010, a receiver 2015, and a memory unit 2020. An input/output (I/O) interface 2030 may also be provided for facilitating communication with the other components of the clip device 2000, including the control system 2040. The I/O 2030 may also be configured to permit downloading and/or uploading of information from memory 2020. In addition, transducer 2010 may be implemented as a speaker, horn, or another type of device that is capable of generating an audible beep tone in response to a beep request that is received through antenna 2005 and receiver 2015. Further, since clip device 2000 is a non-transmitting type of object, a transmitter is not required in the device. In contrast, as indicated by reference numeral 3015 in FIG. 36, a transmitting clip device 3000 should include a transmitter as well as a receiver. These components may be provided as a single transceiver which is capable of receiving and responding to requests and queries from other objects, including wireless handsets. The other components provided in transmitting clip device 3000 may be similar to that provided in the non-transmitting clip device 2000. For example, as illustrated in the exemplary block diagram of FIG. 36, transmitting clip device 3000 may also comprise a control system 3040, an antenna 3005, a transducer 3010, a memory unit 3020, and an input/output (I/O) interface 3030 for interfacing with the components of the clip device. In the embodiment of FIG. 36, transducer 3010 may be implemented as a speaker, horn, or another type of device that is capable of generating an audible beep tone in response to beep requests. The clip device configurations of FIGS. 35 and 36 may be modified to include additional features or components. For example, in order to facilitate the activation of features, one or more buttons or a keypad may also be provided in the clip device. Through the use of a keypad or button, a user may be permitted to initiate various features, such as the memorize feature of the invention to exchange information with another object or handset. As discussed above, the wireless handset of the present invention may be implemented with additional procedures or routines to improve the operation of the handset. In this regard, separate procedures and routines may be provided for detecting and correcting collisions. A collision may occur when one handset tries to register at the exact same time as another handset on the registry channel. To detect collisions, each handset may be required to first listen on the registry channel before transmitting registry information. If the channel is not open, then the handset may wait until the channel is open before transmitting information and registering. Further, if another signal is detected during transmission on a channel, then all handsets transmitting during that interval may invoke a routine which causes them to wait a random period of time and then retransmit information. Such procedures will ensure future collisions with the same handset do not occur. In addition, the clock cycles will be reset to synchronize with the new interval. In addition, other procedures and routines may be provided to prevent channels or conversations from interfering. For example, it is possible for two handsets (i.e., handsets H1 and H2) on a call to occupy a channel (i.e., F1) and that for two other handsets (i.e., H3 and H4) on a call but out of range of H1 and H2, to occupy that same channel, F1. If H3 and H4 are moving, and come within range of H1 and H2, then their conversations will interfere. Upon detection of interference on the channel, the control time slot may be used to renegotiate a new channel for either H1 and H2 or H3 and H4. Alternatively, both H1 and H2 and H3 and H4 may renegotiate a new channel by transmitting a randomly selected new channel and indicating the same with control data during the control time slot. Further, during the control time slot, all four handsets may recognize that there is interference and decide which handsets will move to a different channel. Various embodiments are disclosed herein for initiating and establishing a call between wireless handsets in a direct handset-to-handset communication mode (see, e.g., FIGS. 5-8). It is of course possible to provide other implementations and embodiments to support direct handset-to-handset connectivity between wireless handsets. By way of non-limiting examples, FIGS. 22-25 illustrate exemplary flowcharts of the operations and processes that may be carried out for initiating and establishing a free call between wireless handsets, in accordance with the present invention. These embodiments utilize a registry channel for initiating and establishing a free call. Call waiting features may also be enabled in the wireless handsets of the invention, exemplary embodiments of which are described below with reference to FIGS. 26-27. In particular, FIGS. 22A and 22B are exemplary flowcharts of the various processes and operations that may be carried out by a wireless handset (i.e., handset A) when a free call is to be initiated and set up with another handset (i.e., handset B). FIGS. 23A and 23B illustrate the various operations and procedures that may be carried out by handset B when responding to the call request from handset A. In addition, FIGS. 24A and 24B are exemplary flowcharts of the functions and procedures carried out by handset A when negotiating a channel for the call with handset B, wherein handset A acts as the originator or originating party for the channel negotiation. Further, FIGS. 25A and 25B are exemplary flowcharts of the various procedures and operations carried out by handset B when negotiating the channel for the call with handset A, wherein handset B acts as the recipient for the channel negotiation. As shown in FIG. 22A, the call initiation process is started at step S.700 when the user of handset A presses the appropriate key on the handset (e.g., a FREE call button) with handset B being selected or dialed. When the call is initiated by handset A, handset B may or may not be on a call with another handset. To facilitate access, each handset may be equipped with call waiting features to permit a user of a handset to switch between free calls. An embodiment for providing call waiting is discussed below with reference to FIGS. 26-27. However, in order to facilitate description of the embodiment of FIGS. 22A and 22B, it will be assumed that handset B is not on a call when the call request is initiated by handset A. At step S.702, the transmitter/receiver or tuner of handset A is tuned to a predetermined registry channel. The registry channel may be similar to the registry channel that is utilized for performing the Find features of the invention. Alternatively, a separate registry channel may be established for initiating and establishing a call. After tuning to the registry channel, handset A sets the value of a cycle_clock to 0 at step S.704. Similar to the other embodiments disclosed herein, the cycle_clock may be implemented as a counter that is incremented in accordance with an internal system clock of the handset and may be utilized to monitor the elapsed time. At step S.706, handset A will monitor and listen to the registry channel in order to determine whether handset B is within range. As further discussed below, in this embodiment each handset (including handset B) will register on the registry channel every predetermined cycle time (i.e., every times minutes or seconds). The registry message may include the ID of the registering handset, as well as the status (e.g., Idle or On Call) of the handset. Handset A will wait and listen to the registry channel for approximately one predetermined cycle time in order to determine if handset B is within range. Thus, at step S.708, handset A will determine whether a response has been received on the registry channel. If no response is received, then at step S.710 it will be determined whether the value of the cycle_clock is greater than or equal to the predetermined cycle time. If the cycle_clock is less than the cycle time, then logic flow loops back to step S.708 to determine again whether a handset response has been received. Otherwise, if no response is detected within the predetermined cycle time, then logic flow will proceed to step S.714. At step S.714, handset A will indicate to the user that handset B is out of range. This notification may take the form of displaying the ID and/or corresponding name of handset B, along with a predetermined message (e.g., “Out of Range”). In addition, at step S.714 handset A may prompt the user to inquire as to whether a network call should be placed in order to contact handset B. If the user decides to contact handset B through a network call, then handset A may place a network call in accordance with conventional methods or techniques. Following step S.714, operation of the call initiate routine may terminate at step S.715, as shown in FIG. 22A. When a handset response is detected at S.708 within the cycle time, handset A will determine at step S.712 whether the ID of the registering handset corresponds to that of handset B. If the handset of the registering handset does not correspond to the ID of handset B, then logic flow proceeds to step S.710, where it is determined whether the cycle time has elapsed. If, however, the ID of the registering handset corresponds to that of handset B, then handset B is within range and handset A may analyze the status information contained in the registry message at step S.716 to determine if handset B is idle or on a call. This step may be provided when a separate call waiting feature is enabled in the handset. In such a case, when it is determined that handset B is on a call, then logic flow may proceed to step S.717 where the appropriate call waiting routine is performed by handset A. An exemplary embodiment of such a call waiting routing is provided below with reference to FIGS. 26A and 26B. If it is determined at step S.716 that handset B is not on a call, then logic flow proceeds to step S.718. Further, if call waiting features are not enabled in the handset, then step S.716 in FIG. 22A may be eliminated and logic flow may proceed directly from step S.712 to step S.718. In accordance with an aspect of the invention, the above-described routine of steps S.700-S.715 may be performed on an on-going basis by handset A such that when the user initiates a call, the handset already knows if handset B is in range and/or if handset B is on a call or not. In such a case, handset A may keep track and store the status of all other handsets on the Find list of handset A. Further, with this embodiment, a handset on the list may be required to miss a predetermined number of sequential registrations before being recorded as unavailable by handset A. Referring again to FIG. 22A, at step S.718, handset A transmits a call request message to handset B over the registry channel. The call request may include the ID of handset A, as well as the ID of the intended recipient of the call request (i.e., the ID of handset B). An appropriate code may also be provided in the message to indicate that a call request is being made. If the call request is received by handset B, then at step S.720 handset A will attempt to negotiate a channel for the call with handset B. For channel negotiation, handset A will act as the originator or originating party, with handset B acting as the recipient or receiving party. An exemplary embodiment of the various operations and processes that may be carried out by handset A to negotiate a channel is discussed below with reference to FIGS. 24A and 24B. Following step S.720, handset A will set the value of a wait_clock to 0 at step S.722. That is, after successfully negotiating a channel with handset B, handset A will wait for a predetermined wait time to determine if the user of handset B responds to the call request from handset A. For this purpose, the wait_clock may be a counter that is incremented in accordance with an internal system clock of the handset to monitor the elapsed time and determine when the wait time has been exceeded. After tuning to the channel negotiated for the call, handset A will listen and determine whether a response has been received from handset B at step S.724. As further discussed below, a response message may be sent by handset B when it is determined that the user of handset B has responded to the call request from handset A. The user of handset B may respond to the call request by accepting the call or requesting special handling or forwarding of the call (e.g., call forwarding to voice mail or another handset or number). If no response is received from handset B as step S.724, then at step. S.726 handset A will check and determine if the value of the wait_clock is greater than or equal to the predetermined wait time. If the value of the wait clock is less than the wait time, then logic flow loops back to step S.724. If, however, the wait time has elapsed or been exceeded, then at step S.728 handset A will assume that the call request was not responded to by the user of handset B and will notify the user of handset A that handset B is unavailable. In this regard, the notification to the user may take the form of a message that is displayed on the display panel of handset A This display may include the ID and/or name of handset B, along with an appropriate message to indicate that handset B is unavailable (e.g., “Unavailable”). At this point, handset A may also prompt or ask the user (e.g., through the display panel of the handset) if the call should be placed through a network. If the user determines to place the call through a network, then conventional techniques and methods may be performed to send the call request through the network. Following step S.728, the free call initialization routine may terminate at step S.729, as shown in FIG. 22A. If a positive response is received over the negotiated channel at step S.724, then logic flow will proceed to step S.730 (see FIG. 22B), where it will be determined whether the user of handset B has responded to the call request by accepting the call. The determination at step S.730 may be made by analyzing the response message received from handset B. The response message may include a code indicating whether the call has been accepted or forwarded/transferred. If the call is determined as being accepted by handset B, then the user of handset A may initiate a conversation with the user of handset B at step S.736. Further, handset A will then perform other handset functions, at step S.738, including handset registration and listening for queries or requests from other handsets. If it is determined that the call was not accepted by the user of handset B at step S.730, then at step S.732 handset A will notify that the call was rejected. This notification may take the form of a message on the display panel (e.g., “Call Rejected”). Further, this notification may be generated based on the notification selected by the user of handset B from a number of user definable messages. For example, the user of handset B may send a “Call Back Later” message in response to one call request, while replying with a “I'll Call You Back” message in response to another call request. The selected message may be transmitted from handset B as part of the response message sent to handset A. In addition, handset A may provide a prompt to indicate other options that may be performed by the user of handset A based on the response from handset B. For example, an option may be provided to send a request to handset B which forwards the call to a voice mail network or perform some other function based on the response received from handset B. Following step. S.732, the routine terminates at step S.734, as shown in FIG. 22B. FIGS. 23A and 23B are exemplary flowcharts of the various operations and processes that may be carried out by handset B when responding to a call request from handset A. As noted above, in this embodiment each handset registers on a predetermined registry or control channel every cycle time (e.g., every times minutes or seconds). Accordingly, as shown in FIG. 23A, after performing other handset functions at step S.740, handset B will determine at step S.742 whether the predetermined cycle time has elapsed. This is performed by comparing the value of a cycle_clock with the predetermined cycle time. If the cycle time has elapsed, then it is time for handset B to register on the registry channel. As such, at step S.744, handset B will register on the registry channel by transmitting the ID of handset B and transmitting status information. The status information may include a code to indicate whether handset B is idle or on a call. Following step S.744, handset B will initialize and set the value of the cycle_clock to 0 at step S.746 and then proceed to step S.748. Logic flow will also proceed to step S.748 when it is determined at step S.742 that the cycle_clock is less than the predetermined cycle time. At step S.748, handset B will check to determine whether a call request has been received. As noted above, call request may be transmitted over the registry or control channel, with the call request including the ID of the requesting handset (i.e., the ID of handset A). If a call request is not detected at step S.748 because, for example, the requesting handset is out of range or has not transmitted the call request, then logic flow loops back to step S.740. If, however, a call request message is received at step S.748, then handset B will negotiate a channel for the call at step S.752, with handset B acting as the receiving party. More particularly, in response to the receipt of a call request from handset A, handset B will negotiate a channel for the call at step S.752, with handset A acting as the originator or originating party. Since handset A initiated the call request and is acting as the originating party, handset B will negotiate the channel for the call as the recipient or receiving party. An exemplary embodiment of the various processes and operations that may be carried out by handset B at step S.752 to negotiate a channel is described below with reference to FIGS. 25A and 25B. Following the successful negotiation of a channel for the call at step S.755, handset B will query the user of handset B at step S.754 so as to notify the user of the presence of the call request from handset A. This query may take the form of providing an alerting tone (such as a ringing tone, etc.), as well as displaying a message (e.g., “Incoming Call”) and/or the ID and/or name of handset A. In response to the query, the user of handset B may respond to the call request (e.g., by accepting the call, forwarding the call, etc.) or ignore and not respond to the call request. At step S.756, it is determined whether the user of handset B has decided to respond to the call. If the user of handset B has responded to the call, then at step S.758 a response message is transmitted by handset B to handset A. The response message may be transmitted over the channel negotiated for the call. Thereafter, at step S.760, logic flow proceeds depending on the manner in which the user of handset B has decided to respond to the call. That is, if the user of handset B did not accept the call, then logic flow proceeds from step S.760 to step. S.750, where handset B tunes back to the registry channel. As shown in FIG. 23A, logic flow will also proceed to step S.750 when it is determined that the user has not responded to the call request at step S.756. Following step S.750, logic flow loops back to step S.740 so that other handset functions may be performed. If it is determined at step S.760 that the user has accepted the call, then the user of handset B may be permitted to initiate the conversation with the user of handset A at step S.762 (see FIG. 23B). At step S.762, handset B will transmit and receive voice data over the negotiated channel with handset A. In addition, at step S.764, handset B will perform other handset functions, including registration on the registry channel and listening for queries and requests from other handsets. As discussed above, handset A will negotiate with handset B to select a channel for the free call after transmitting the call request to handset B (see step S.720 in FIG. 22A). Various procedures and routines may be implemented to facilitate channel negotiation. Channel negotiation may also be utilized to select a new channel for a free call when interference has arisen from other handsets that have moved within range while occupying the same channel for the free call or when other interference occurs. FIGS. 24A and 24B illustrate an exemplary embodiment of the manner in which handset A can negotiate a channel when acting as the originator or originating party. More specifically, as represented at step S.770 in FIG. 24A, handset A needs to negotiate a channel for a free call with handset B, where handset A is acting as the originator or originating party. In order to negotiate a channel, handset A will tune to a predetermined registry channel at step S.772. The registry or control channel may be the same as that utilized for detecting handsets through registry messages. Alternatively, a separate registry channel may be provided for negotiating channels. In any event, after tuning to the registry channel, handset A transmits a hold request over the registry channel to handset B at step S.774. The hold request message, which may include the ID of handset A as the originator and the ID of handset B as the recipient, may be sent to notify to handset B that handset A wishes to negotiate a channel. In response, handset A will wait or expect for a hold confirmation message to be sent back from handset B. Alternatively, this hold request confirmation step may be bypassed in favor of a faster overall negotiation process. For this purpose, handset A will set the value of a wait_clock to 0 at step S.776 and determine at step S.778 whether the hold confirmation has been received over the registry channel from handset B. The wait_clock may be a counter that is incremented with an internal system clock of the handset to detect whether the hold confirmation message has been received from handset B within a predetermined wait time. If the hold confirmation is not received at step S.778, handset A will determine at step S.780 whether the value of the wait_clock is greater than or equal to the predetermined wait time or period. If the wait time has not been exceeded, then logic flow will loop back to step S.778. However, if the hold confirmation is not received within the wait time, then at step. S.790 the user of handset A will be alerted that the call request has failed. This alert or notification may include providing a displayed message and/or tone to the user of handset A to signify that the call has failed. Following step. S.790, the call negotiation procedure or routine may terminate at step S.792. As further shown in FIG. 24A, if a hold confirmation is received at step S.778, then handset A will proceed and attempt to locate an empty or clear channel for the call. Various methods may be employed to locate a channel. According to an aspect of the invention, a predetermined number or set of channels may be available for setting up the call. The handset acting as the originator for the channel negotiation (in this case handset A) may be given a predetermined number of attempts to locate an empty or clear channel to support the call. Channel frequencies may be selected sequentially, randomly or by a specific algorithm or some other method, and then tested to determine activity and use of the channel by other handsets that are within range. Once a clear channel is detected, the originating handset (i.e., handset A) will transmit over the registry channel to the recipient handset (i.e., handset B) the frequency or number of the free channel to notify the other handset of the proposed channel. The recipient handset may then test and confirm as to whether the proposed channel is acceptable. A channel count may be maintained in order to determine the number of attempts to find a clear channel and to determine when the maximum permissible number of tries has been exceeded. When the maximum number of tries has been exceeded, the call negotiation procedure will fail and terminate. As illustrated in FIG. 24A, at step S.782, handset A will initialize and set the value of a channel_count to 0. Then, at step S.784, handset A will compare the value of the channel_count to the predetermined maximum number of tries that is permitted. (which is represented by the value of “max_tries” in FIG. 24A). If the channel_count is less than the max_tries, then at step S.788 handset A will select a channel (i.e., channel x) for monitoring. The selection of the channel may be random, sequential, or based on any other method. After selecting a candidate channel, handset A will listen to the channel for activity at step S.794. Essentially, handset A will determine if the candidate channel is suitable for handling and supporting the free call between handset A and handset B. Handset A may determine that the channel is not clear if other handsets within the area are using the channel for a call or if there is unacceptable level of noise on the channel. If the handset determines that the channel is not clear at step S.796, then the value of the channel_count is incremented by one (i.e., channel_count=channel_count+1) and logic flow will loop back to step S.784 to again compare the value of the channel_count to the value of the max_tries permitted. If a clear channel cannot be obtained within the predetermined maximum number of permissible tries or attempts, then logic flow will proceed to step S.786 and handset A will notify handset B that the call attempt has failed. For this purpose, a call fail notification may be sent as a message over the registry or control channel to handset B at step S.786. Following step S.786, logic flow proceeds to step S.790 where the user of handset A is alerted that the call failed. The user of handset A may be alerted by generating an appropriate message (e.g., “Call Failed”) and/or tone. Thereafter, the call negotiation routine may terminate at step S.792, as shown in FIG. 24A. If a clear channel is detected at step S.796, then handset A will notify handset B of the proposed channel (i.e., channel x) that has been selected. For this reason, handset A will tune to the registry channel at step S.798 and then transmit the channel frequency or number of the proposed channel to handset B at step S.800 (see FIG. 24B). Handset A will then wait for a confirmation message from handset B that the proposed channel is suitable for supporting the free call. As such, handset A will set the value of a wait_clock to 0 at step S.801 and determine whether a confirmation response has been received from handset B at step S.802. Handset A may monitor the registry channel for a response for a predetermined wait time before determining that the call negotiation has failed. Thus, if the value of the wait_clock is less than the predetermined wait time at step S.804, then logic flow will loop back to step S.802 to determine again if a response has been received. If a response is not received within the wait time, then logic flow will proceed to step S.808 where handset A will alert the user that the call has failed. Thereafter, the call negotiation routine may terminate at step S.809. If a response is received within the wait time from handset B at step S.802, then at step S.806 handset A will determine whether the selected channel (i.e., channel x) has been confirmed by handset B. If the channel is confirmed by handset B as being suitable for the free call at step S.806, then at step S.810 handset A will tune to the selected channel to permit the user of handset A to initiate conversation with the user of handset B at step S.812. Further, at step S.814, handset A may perform other handset functions, including the periodic registration on the registry channel and monitoring for queries or requests (e.g., find queries and/or call requests). If, however, the channel selected by handset A was not cleared or confirmed by handset B, then logic flow will proceed from step S.806 back to step S.784 (see FIG. 24A) and the value of the channel_count will be incremented by one. Handset A will then attempt to locate another clear channel if the maximum number of permissible tries has not been exceeded. Logic flow then proceeds after step S.784 as detailed above. Handset B also performs various operations and procedures when negotiating a channel with handset A for a free call. In the above-described example, handset B is acting as the recipient or receiving party of the call request and is negotiating a channel with handset A (see, for example, step S.752 in FIG. 23A). Various procedures and routines may be implemented to permit handset B to negotiate a channel with handset A. FIGS. 25A and 25B illustrate an exemplary embodiment for handset B to negotiate a channel when acting as the recipient or receiving party. As represented at step S.816 in FIG. 25A, handset B needs to negotiate a channel with handset A, while acting as the recipient or receiving party. Since a hold request from handset A is transmitted over the registry channel, handset B will tune to the registry channel at step S.818 to determine whether such a hold request has been received within a predetermined wait time. For this purpose, the value of a wait_clock may be initialized to 0 at step S.820 and, thereafter, incremented in accordance with an internal system clock of the handset. Further, handset B determines whether a hold request has been received over the registry channel at step S.821. If a hold request is not determined as being received at step S.821, then at step S.822 handset B will determine whether the value of the wait_clock is greater than or equal to the predetermined wait time. So long as the wait_clock is less than the wait time, logic flow will loop back to step S.821 to determine if the hold request has been received over the registry or control channel. If a hold request is not received within the wait time, then the call negotiation routine has failed and logic flow will proceed to step S.825. As shown in FIG. 25A, at step S.825 handset B will determine whether handsets A and B are continuing on an interrupted call. That is, as discussed above, it is possible that the need to negotiate a channel for a free call may arise when interference occurs on a channel that is being used to support a current call. In such a case, the decision to negotiate a new channel for the free call may be performed automatically by either handset. In addition, the users of handset A and handset B may be given the ability to determine when it is necessary to negotiate a new channel for the free call. Thus, in addition to negotiating a channel based on a new call request, handset B may also need to negotiate a new channel (e.g., while acting as a recipient or receiving party) for an existing call that has been interrupted (e.g., due to other handsets occupying the same channel or unacceptable noise levels on the channel). The call negotiation procedures of the invention may thus be utilized in either case. If handsets A and B are continuing on an interrupted call, then logic flow may proceed to step S.826 where the user of handset B is alerted that the call has failed. Thereafter, logic flow may proceed to step S.827 where the call negotiation routine will terminate. If, however, handset A and handset B are not continuing on an interrupted call, then the user of handset B does not need to be notified of the failure of the call request and negotiation, and logic flow may proceed directly from step S.825 to step S.827 where the call negotiation routine terminates. As further shown in FIG. 25A, if a hold request is received at step S.821, then at step S.824 handset B will transmit a hold confirmation message back to handset A. The hold confirmation message may be transmitted over the registry channel from handset B to handset A. Thereafter, handset B will wait for handset A to further respond with a selected or proposed channel for the call. More particularly, as shown in FIG. 25B, handset B will set the value of a wait_clock2 to 0. The wait_clock2 may be a counter that is incremented in accordance with an internal system clock of handset B. The value of the wait_clock2 may be monitored to determine whether a predetermined wait time has elapsed without receiving a response from handset A. This predetermined wait time should be set in accordance with the maximum number of tries that handset A is permitted to locate a suitable channel. At step. S.830, handset B will determine whether a response has been received from handset A over the registry channel. If a response is not received, then at step. S.832 the value of the wait_clock2 will be compared with the predetermined wait time. If the value of the wait_clock2 is less than the wait time, then logic flow will loop back to step S.830 to again determine whether a response has been received. If a response has been received within the predetermined wait time, then at step. S.833 handset B will check to determine whether handset A has indicated in the response message that the attempt to locate a free channel has failed. If a call fail notification message is received, then logic flow proceeds to step S.834. Logic flow will also proceed to step S.834 if it is determined that a response has not been received from handset A within the predetermined wait time at steps S.830 and S.832. At step S.834, handset B will determine whether handsets A and B are continuing on an interrupted call. If handsets A and B are continuing on an interrupted call, then at step S.837 handset B will be alerted that the call has failed. Thereafter, logic flow proceeds to step S.838 where the routine may terminate. If, however, handset A and handset B are not continuing on an interrupted call, then the user of handset B does not need to be notified of the failure of the call request and negotiation, and logic flow may proceed directly from step S.834 to step S.838 where the call negotiation routine terminates. As further shown in FIG. 25B, if handset A has not sent a call fail notification, then handset A has sent the selected or proposed channel (i.e., channel x) and handset B will tune to the proposed channel at step S.835. Handset A may indicate the number or frequency of the selected channel in the response message after detecting that the channel is clear, as described above. Handset B will then confirm that the selected channel is clear and suitable to support the call. Thus, following step S.835, handset B will determine whether the channel is clear by listening for activity on the channel at step S.836. Handset B may check whether the selected channel has become occupied by other handsets within the area or whether the noise level of the channel is at an unacceptable level. After listening for activity on the channel, handset B will tune to the registry channel at step. S.839 in preparation of transmitting a response message back to handset A. If channel B determines that the selected channel is clear at step. S.840, then at step S.842 handset B will transmit a message to handset A to indicate that the selected channel (i.e., channel x) is suitable for setting Up the call. If, however, handset B determines that the selected channel has become corrupted or is not clear, then at step S.844 a message will be transmitted to handset A to indicate that the proposed channel is bad or unacceptable for setting up the call. Following step S.844, logic flow will loop back to step S.828 to wait for an additional response from handset A (i.e., another selected channel or a call fail notification message). If the proposed channel was determined as being clear and handset A was notified that the channel is clear at step S.842, then handset B will tune to the confirmed channel at step S.843. Thereafter, at step S.846, handset B will determine whether handsets A and B are continuing on an interrupted call. If this is not the case, then the call negotiation routine may terminate at step S.847. Thereafter, the call initialization procedure for handset B may continue as indicated, for example, in FIGS. 23A and 23B (see, e.g., the steps following step S.752). If, however, handsets A and B are continuing on an interrupted call, then at step S.848 handset B will permit the user to initiate and continue the conversation with the user of handset A. In addition at step S.849, handset B will perform other handset functions, including handset registration on the registry channel and listening for queries and requests on the registry channel. As described above, the call negotiation procedures of the present invention may be implemented for negotiating a channel when establishing a free call between wireless handsets. In particular, the embodiments of FIGS. 24 and 25 may be utilized as part of the overall procedures of FIGS. 22 and 23 for establishing a handset-to-handset call. In addition, the channel negotiation procedures of the invention may be utilized to negotiate a new channel to avoid interference during a free call. That is, the embodiments of FIGS. 24 and 25 may be utilized by wireless handsets on a free call to select a new channel when the current channel that is supporting the free call has become corrupted due to noise or interference caused by other wireless handsets that have come into range and that are occupying the same channel or due to other causes. As indicated above, the wireless handset of the present invention may be configured to include call waiting features, which permit a wireless handset to switch between calls from other wireless handsets. FIGS. 26-27 illustrate exemplary embodiments for establishing a free call between wireless handsets that are enabled with call waiting features, and for switching between free calls. In particular, FIGS. 26A and 26B are exemplary flowcharts of the various processes and operations carried out by handset A for initiating a call with handset B, when handset B is on a call with another handset (i.e., handset C). FIGS. 27A and 27B are exemplary flowcharts of the various processes and operations that may be carried out by handset B to handle the call request from handset A, while handset B is on a call with handset C. Lastly, FIG. 27C is an exemplary flowchart of the various processes and operations that may be carried out by handset C when it is placed on hold by handset B to accept the call request from handset A. In the embodiments of FIGS. 26-27 a predetermined registry channel is provided, similar to that provided in the embodiments of FIGS. 22-25. As represented at step S.850 in FIG. 26A, the user of handset A initiates a free call to handset B, while handset B is on a call with handset C. The initiation of the free call may be caused by the user of handset A by pressing a predetermined key (i.e., a free call key) on the handset, with handset B being dialed or selected through the keypad and/or display screen of the handset. In response to the free call being initiated, handset A will tune to the predetermined registry or control channel at step S.851. Further, at step S.852, the value of a cycle_clock will be set to 0. Thereafter, handset A will listen and monitor the registry channel at step S.853 to determine if handset B is within range of the handset A. In accordance with an aspect of the invention, handset A may listen to and monitor the registry channel for a predetermined cycle time. The cycle time may correspond to the cycle period by which each handset registers on the registry channel. That is, when a handset is idle or on a call, the handset may register on the registry channel every predetermined cycle time (e.g., every x minutes or seconds). At step S.854, handset A will first determine if there is a handset response or registration. If no handset response is detected at step S.854, then at step S.855 handset A will determine whether the value of the cycle_clock is greater than or equal to the predetermined cycle time. The cycle_clock may be incremented in accordance with an internal system clock of the handset, after being initialized in order to keep track of and monitor the elapsed time of listening to the registry channel. If the value of the cycle_clock is less than the cycle time, then logic flow loops back to step S.854. Thereafter, handset A may again check to see if a response is received on the registry channel at step S.854. If no handset response is received within the cycle time, then logic flow will proceed to step S.857, as shown in FIG. 26A. At step S.857, handset A will assume that handset B is out of range or unavailable. As such, handset A may alert the user that handset B is out of range or unavailable by displaying the ID and/or name of handset B along with an appropriate message (e.g., “Out of Range”). In addition, at step S.857, handset A may give the user the option as to whether the call should be continued by placing the call to handset B through a network. Following step S.857, the procedure may terminate at step S.865. If a handset registration is detected at step S.854, then handset A will determine whether the ID of the registering handset corresponds to that for handset B, at step S.856. If the ID in the registry message corresponds to a different handset, then logic flow proceeds to step S.855. Otherwise, if the registration was performed by handset B, then at step S.858 handset A will determine the status of handset B. The status of handset B may be indicated in the registry message which comprises a code for indicating whether the handset is idle or on a call. If handset B is not on a call, then a separate routine may be performed at step S.859. That is, operations and procedures similar to that discussed above with reference to FIGS. 22A and 22B may be performed for establishing a free call with handset A when handset B is not on a call. If, however, handset B is determined to be on a call at step S.858, then the call waiting aspects of the invention may be utilized. In particular, at step S.860, handset A will tune to the channel that is indicated in the registry message for contacting handset B. Since handset B is on a call with handset C, the channel to contact handset B may be the same channel that supports the free call between handset B and handset C. Further, the registry message may indicate a time slot for contacting handset B. With this information, handset A may transmit a call waiting request to handset B over the channel during the designated time slot at step S.861. The call waiting request may include the ID of handset A. Thereafter, handset A will wait for a response from handset B. In particular, handset A will set the value of a wait_clock to 0 at step S.862 and then determine whether a response has been received from handset B over the contact channel at step S.863. Handset A may wait for such a response for a predetermined wait time. The value of the wait_clock may be incremented in accordance with an internal system clock of the handset to determine when the predetermined wait time has elapsed. Thus, at step S.864, the value of the wait_clock may be compared with the wait time when it is determined that a response has not been received at step S.863. If the wait_clock is less than the wait time, then logic flow will loop back to step S.863. Otherwise, at step S.866, handset A will assume that handset B is unavailable and will notify the user of the unavailability of handset B. This notification may take the form of displaying the ID and/or name of handset B along with an appropriate message (e.g., “Unavailable”). Handset A may also ask the user whether the call should be continued by attempting to contact handset B through a network. Following step S.866, the procedure or routine may terminate at step. S.867. If a response is received from handset B at step S.863, then handset A will determine whether the user of handset B has accepted the call at step S.870 (see FIG. 26B). The determination at step S.870 may be made based on the response message received from handset B, which may include data indicating whether the call has been accepted. If the call is not accepted, then at step S.871 a call rejection message (e.g., “Call Rejected”) may be provided to the user of handset A. In addition, an option to send a request to handset B which forwards the call to a voice mail network to leave a message to handset B may be provided to the user of handset A or another appropriate message may be provided based on the response received from handset B. Following step S.871, the procedure may terminate at step S.872. If it is determined that the user of handset B has responded and accepted the call request at step S.870, then at step S.873 handset A permits the user to initiate the conversation with the user of handset B. This conversation may take place over the channel previously occupied by handset B and C. In addition, at step S.874, handset A will perform other handset functions, including registering on the registry channel and listening for query or request messages. FIGS. 27A and 27B are exemplary flowcharts of the various processes and operations that may be carried out by handset B for receiving the call request from handset A, while handset B is on another call with handset C. In this embodiment, each handset (including handset B) registers on a predetermined registry channel every cycle time. Thus, after performing other handset functions at step S.876, handset B will determine whether the predetermined cycle time has elapsed at step S.877, as shown in FIG. 27A. This may be performed by comparing the value of a cycle_clock to that of the cycle time. The cycle_clock may be maintained as a counter and incremented in accordance with an internal system clock of the handset. If the value of the cycle_clock is less than the cycle time, then logic flow proceeds to step S.884. Otherwise, as shown in FIG. 27A, logic flow proceeds to step S.878. When it is time to register on the registry channel, handset B will tune to the registry channel, as indicated at step S.878. Thereafter, at step S.879, handset B will transmit the channel number or frequency at which handset B can be contacted, as well as the ID of handset B. When handset B is on a free call, the channel to contact handset B may be the channel of the free call. Handset B may also transit at step S.879 the beginning and ending time of a time slot for contacting handset B or the time domain multiplexing control time slot. Following step S.879, handset B tunes to the previous channel (i.e., the channel on which the call with handset C is being supported) as shown at step S.880. Following step S.880, handset B initializes the value of the cycle_clock to 0 at step S.882. Logic flow then proceeds to step S.884. At step S.884, handset B determines whether the value of the cycle_clock corresponds to a time within the indicated control time slot. This determination may be performed by determining whether the value of the cycle_clock is greater than or equal to the slot start time and whether the cycle_clock is also less than or equal to the slot end time. This time could also be the control time slot used if time domain multiplexing is utilized by the handsets for contacting one another. In any event, if both of these conditions are not satisfied, then logic flow loop backs to step S.876. If, however, the value of the cycle_clock corresponds to the control slot time, then handset B will determine whether a call waiting request has been received at step S.885. In particular, at step S.885 handset B determines whether a call waiting request has been received from another handset. If a call waiting request is not received, then logic flow loops back to step S.876 so that handset B may perform other handset functions. If a call waiting request is detected at step S.885, then handset B will analyze the call waiting request information and, based on this analysis, query the user of handset B to notify the user that a call request has been received at step S.886. This query or notification may include the displaying of a message containing the ID of the handset that sent the call waiting request (e.g., the ID of handset A) and/or the generation of an appropriate tone to indicate that a call waiting request has been received. Following step S.886, it is determined at step S.887 whether the user of handset B has decided to respond to the call waiting request. The user of handset B may respond to the call waiting request by pressing an appropriate key on the handset to signify the acceptance of the call waiting request and to indicate that handset C should be placed on hold. By pressing other keys on the handset, the user of handset B may also respond to the call waiting request by transferring or forwarding handset A to a voice mail system or to a different handset or location, or by sending a call reject message. If it is determined that the user of handset B has not responded at step S.887 within a predetermined amount of time, then logic flow may loop back to step S.876. If the user does respond, then at step S.888 handset B will transmit a response message to handset A based on the manner on which the user has responded to the call waiting request. The response message may include information indicating whether the user of handset B has determined to accept the call or to place/forward handset A to a voice mail system, etc. If the user of handset B decided not to accept the call but to forward handset A to a voice mail system or another location, then logic flow will loop back to step S.876 where other appropriate handset functions may be performed. If the user of handset B accepted the call request from handset A, then at step S.890 (see FIG. 27B) handset B will transmit to handset C a request to hold the present call. This hold request to handset C may be transmitted during a defined time slot (i.e., the control time slot available for control functions in a time domain multiplexing system, or the time slot that the other handset uses to register when time domain multiplexing is not used). In addition, the hold request may designate a channel at which handset C is to switch to and wait for a possible further call request from handset B. This channel may be the registry channel or another predetermined channel. Following step S.890, the user of handset B is permitted to initiate and conduct a conversation with the user of handset A at step S.892. Handset B will also perform other handset functions at step S.894, including periodic registration on the registry channel and listening for queries and requests from other handsets. With the call waiting features of the present invention, the user of handset B may determine to reestablish or switch back to a call with handset C after completing or while conducting the call with handset A. As illustrated at step S.895 in FIG. 27B, handset B may periodically check to see if the user of handset B has requested to recontact with handset C. The user of handset B may indicate a request to recontact with handset C by pressing an appropriate key or button on the handset. If there is no request to recontact, then logic flow will loop back to step S.894 from step S.895. Otherwise, when a request to recontact has been detected, logic flow proceeds from step S.895 to step S.896. At step S.896, handset B will transmit to handset A a hold request message. This request will indicate to handset A that it should switch and wait for a possible recontact request from handset B on another channel. This channel may be the registry channel, or another predetermined channel. Following step S.896, handset B will tune to the registry channel or another predetermined channel at step S.897 and then initiate a new call request with handset C at step S.898. The call may then be setup and supported over the same channel for the previous call between handset A and handset B. The procedures performed at step S.898 may include the initiation/negotiation procedures for a new call in accordance with any one of the embodiments disclosed herein that utilize a registry channel, if deemed appropriate by the handsets (e.g., for interference reasons). Following step S.898, the user of handset B will have the option of completing the call with handset C and/or switching back to the call with handset A to continue the conversation with the user of handset A. In the above-described embodiment, a call request is sent from handset A to handset B, while handset B is on a call with handset C. In accordance with the call waiting features of the present invention, handset C may be placed on hold while handset B switches between the call with handset C and handset A. While handset C is placed on hold, handset C can also accept call requests from other handsets that are within range. FIG. 27C is an exemplary flowchart of the various processes and operations that may be carried out by handset C for enabling the call waiting features of the invention. In the embodiment of FIG. 27C, a registry or control channel is provided. As represented at step S.900 in FIG. 27C, handset C is in conversation and on a call with handset B, when handset B receives a call request from handset A. If the user of handset B determines to respond to and accept the call waiting request, then handset B will place handset C on hold by transmitting a hold request message. Thus, at step S.902, handset C determines whether a hold request message has been received from handset B. As indicated above, the hold request may be transmitted during the defined time slot on the channel supporting the call between handset B and handset C. The hold request message from handset B may indicate a channel on which handset C is to wait and hold for further response from handset B. This channel may be a predetermined channel, such as the registry channel, or another appropriate channel. If a hold request is received at step S.902, then at step S.904 handset C will tune to the registry channel. If a hold request is not received at step S.902, then logic flow loops back to step S.900, where handset C is permitted to perform other handset functions and the call between handset B and handset C is maintained. After receiving a hold request message and tuning to the registry channel at step S.904, handset C will monitor and listen for a recontact request from handset B or a call request from another handset. Thus, at step S.905, handset C will listen to the registry channel and determine whether a call request has been received. If no call request has been received at step S.905, then at step S.906 handset C will continue to perform other handset functions, including periodic registration on the registry channel and listening for other queries. Handset C will also continue to check at step S.905 whether a call request has been received. When a call request has been received at step S.905, handset C will determine at step S.907 whether the call request was from handset B. Specifically, handset C determines whether the request is a recontact request from handset B. If the request is not from handset B, then the call request was sent from another handset and at step S.908 handset C may receive the call request from the other handset while acting as a recipient of the call request. Various procedures and operations may be performed at step S.908, such as those described above with reference to FIGS. 23A and 23B, for handling a new call request. If the user of handset C decides to receive the call request and initiate a conversation with the user of the other handset, then handset C may negotiate a channel for the call (while acting as the receiving party) with the other handset. If the user of handset C decides to refuse the call request, then logic flow will return to step S.904, where handset C tunes back to the registry channel and again listens for call request or recontact request. If it is determined that a recontact request was received from handset B at step S.907, then at step S.910 a channel is negotiated with handset B to set up and reestablish the direct handset-to-handset communication between handset B and handset C. The user of handset C may then initiate a conversation with the user of handset B at step S.912. Thereafter, at step S.914, handset C may perform other handset functions, including registration and listening for queries and requests. The call waiting features of the present invention may be modified or enhanced to provide other capabilities. For example, it is possible to modify the above-described embodiments of FIGS. 26-27 so that a user is permitted to place more than one handset on hold, since a handset (such as handset C) is not physically placed on hold to seize a particular channel or line when a call waiting request is accepted. With this feature, the handset may display to the user a list of the handsets that have been placed on hold, so that the user may freely select and recontact with handsets that have been placed on hold. The process of switching between handsets may continue indefinitely and with an unlimited number of handsets. Further, the user of the handset may be permitted to receive and respond to more than one call waiting request to provide enhanced operating capabilities. The above-described embodiments of FIGS. 22-27 are based upon the use of a registry or control channel. In such a case, a separate or dedicated tuner is not required for each of the handsets, since a single tuner may be utilized for supporting calls and periodically registering on the registry channel. It is of course possible to provide modified embodiments corresponding to that of FIGS. 22-27, in which a separate tuner is provided in each handset that is tuned to a dedicated control channel. Through the use of such a dedicated channel, a free call may be initiated and established between handsets, and various call waiting features may be enabled. By way of non-limiting examples, FIGS. 28-31 are exemplary embodiments for handling call requests and negotiating channels for free calls through the use of a dedicated channel. In particular, FIG. 28 is an exemplary flowchart of the various processes and operations that may be carried out to initiate a call request and establish a free call through the use of a dedicated channel. In FIG. 28, it is assumed that handset A has initiated a call request and is attempting to establish a direct handset-to-handset call with handset B. Further, it is assumed that handset B is not on call with another handset. FIG. 29 illustrates the various operations and procedures that may be carried out by handset B when responding to the call request from handset A. In addition, FIGS. 30A and 30B are exemplary flowcharts of the functions and procedures carried out by handset A when negotiating a channel for the call with handset B, wherein handset A acts as the originator or originating party for the channel negotiation. Further, FIGS. 31A and 31B are exemplary flowcharts of the various procedures and operations carried out by handset B when negotiating the channel for the call with handset A, wherein handset B acts as the recipient for the channel negotiation. As represented at step S.918 of FIG. 28, the call request procedure is initiated when the user of handset A presses the appropriate key or button on the handset (e.g., the free call button) with handset B being selected or dialed through the keypad and/or display screen of the handset. Following step S.918, handset A will transmit a call request to handset B at step S.920. As noted above, it is assumed that handset B is not on a call when the call request is initiated. The call request message may include the ID of handset A as well as the ID of handset B to indicate the handset to which the call request is directed. In addition, the call request may be transmitted from handset A to handset B over a dedicated control channel. That is, in the embodiment of FIG. 28, each handset is equipped with a separate tuner which is always tuned to a dedicated control channel. As a result, handsets are not required to periodically register on a registry channel and interruptions to calls (for registering, etc.) is eliminated. After transmitting the call request, handset A will then attempt to negotiate a channel with handset B for establishing the call at step S.921. Since handset A initiated the call request, handset A will act as the originating party when negotiating a channel with handset B. Various procedures and operations may be performed for negotiating a channel. An exemplary embodiment for negotiating a channel through the use of a dedicated control channel is discussed below with reference to FIGS. 30A and 30B. In FIGS. 30A and 30B, handset A negotiates a channel with handset B, while handset A acts as the originator. Following the successful selection of a channel, handset A then awaits for a response from handset B to determine whether the user of handset B has responded and accepted the call request. In particular, as illustrated in FIG. 28, handset A will set the value of a wait_clock to 0 at step S.922 and then determine at step S.923 whether a response from handset B has been received. Handset A may monitor and listen to the dedicated control channel for a predetermined wait time to receive a response from handset B. To monitor the wait time, the value of the wait_clock may be incremented in accordance with an internal system clock of the handset and the value of the wait_clock may be periodically compared with the predetermined wait time. Thus, if a response is not received at step S.923, handset A will determine at step S.924 whether the value of the wait_clock is greater than or equal to the wait time. If the wait time has not elapsed, then logic flow loops back to step S.923 where handset A again determines whether a response has been received. If a response from handset B has not been received within the predetermined wait time, then at step S.925 handset A assumes that handset B is unavailable or out of range. As such, handset A will notify the user that handset B is unavailable. This notification may be performed by displaying the ID and/or name of handset B along with an appropriate message (e.g., “Unavailable”). In addition, at step S.925 handset A may prompt the user as to whether the call should be attempted through the use of a network. If the user decides to place a network call, then handset A may place a network call to handset B using conventional methods or techniques. Following step S.925, the procedure may terminate at step S.926. If a response from handset B is received over the dedicated control channel at step S.923, then at step S.928 handset A determines whether the user of handset B has accepted the call. The determination at step S.928 may be made by evaluating the response message received from handset B. The response message may indicate whether the user of handset B has responded to the call by accepting the call or by requesting special handling of the call (e.g., by transferring to a voice mail system or call forwarding). If it is determined at step S.928 that the user of handset B has decided to accept the call, then at step S.932 handset A permits the user to initiate a conversation with the user of handset B. In addition, at step S.934, handset A proceeds by performing other handset functions, including listening for queries or requests over the dedicated control channel. If it is determined at step S.928 that the user of handset B has responded to the call without accepting the call, then at step S.930 handset A notifies the user that the call has been rejected. This notification may take the form of displaying an appropriate message (e.g., “Call Rejected”). In addition, depending on the response from handset B and the manner in which the user of handset B has responded to the call request, handset A may also prompt the user for various options (e.g., transferring to the voice mail system of handset B or forwarding the call to another handset or location). Following step S.930, the procedure may terminate at step S.931. FIG. 29 is an exemplary flowchart of the various processes and operations and may be carried out by handset B when responding to a call request from handset A over a dedicated control channel. In particular, following the performance of other handset functions at step S.938, handset B may determine at step S.940 whether a call request has been received over the dedicated control channel. For this purpose, handset B may have a separate tuner that constantly listens and monitors the dedicated control channel for call requests. Handset B may perform this function simultaneously with the performance of other handset functions. If a call request is not received, then logic flow loops back to step S.938. Otherwise, if a call request has been received at step S.940, then logic flow proceeds to step S.942, as shown in FIG. 29. At step S.942, handset B negotiates a channel for setting up the call with handset A. Since handset B has received the call request that was initiated by handset A, handset B acts as the receiving party when negotiating the channel. Various procedures and operations may be performed by handset B to negotiate a channel with handset A. For example, the exemplary embodiment of FIGS. 31A and 31B may be utilized by handset B to negotiate a channel with handset A through the use of a dedicated control channel. In the embodiment of FIGS. 31A and 31B, handset B negotiates a channel with handset A, while handset B acts as the receiving party. Following the successful negotiation of a channel for the call, handset B will then determine if the user wishes to respond to the call request from handset A. In particular, at step S.944, handset B will query the user regarding the presence of a call request from handset A. This query or notification may include the displaying of a message indicating the ID and/or name of handset A and/or the generating of an appropriate tone. Following step S.944, handset B will determine whether the user has responded to the call request at step S.946. This determination may be made by determining whether one or more appropriate keys or buttons on the handset have been pressed by the user to respond to the call request. If the user of handset B does not respond to the call request, then logic flow loops back to step S.938 from step S.946. However, if the user of handset B does respond to the call request, then at step S.948 handset B will transmit an appropriate response message to handset A over the dedicated control channel based on the manner in which the user responded to the call request. As discussed above, the response message from handset B may indicate whether the user of handset B has responded to the call by accepting the call or by rejecting the call and requesting specialized handling of the call (i.e., forwarding to a voice mail system or to a different handset or location). Further, handset B will respond depending on whether the user has accepted the call. That is, if it is determined at step S.950 that the user has not accepted the call, then logic flow will proceed back to step S.938. However, if the user has accepted the call, then logic flow will proceed from step S.950 to step S.952. At step S.952, handset B will permit the user to initiate a conversation with the user of handset A by supporting the call over the negotiated channel. In addition, at step S.954 handset B will perform other handset functions, including listening for queries or requests over the dedicated control channel. As discussed above with reference to FIGS. 28 and 29, handsets A and B will negotiate a channel when setting up a free call. The exemplary flowcharts of FIGS. 30-31 illustrate embodiments for negotiating a channel through the use of a dedicated control channel. In particular, FIGS. 30A and 30B are exemplary flowcharts of the various processes and operations that may be carried out by handset A when negotiating a channel with handset B. In the embodiment of FIGS. 30A and 30B, handset A acts as the originator or originating party. In addition, FIGS. 31A and 31B are exemplary flowcharts of the various processes and operations that may be carried out by handset B when negotiating a channel with handset A. In FIGS. 31A and 31B, handset B acts as the recipient or receiving party when negotiating the channel with handset A. As indicated above, handset A will negotiate with handset B to select a channel for the call after transmitting the call request to handset B (see step S.921 in FIG. 28). Various procedures and routines may be implemented to facilitate channel negotiation. FIGS. 30A and 30B illustrate an exemplary embodiment of the manner in which handset A can negotiate a channel when acting as the originator of the call request. More specifically, as represented at step S.960 in FIG. 30A, handset A needs to negotiate a channel for the call with handset B, where handset A is acting as the originator or originating party. In order to negotiate a channel, handset A may utilize the dedicated control channel to communicate with handset B. Thus, following step S.960, handset A may transmit a hold request over the dedicated control channel to handset B at step S.961. The hold request message, which may include the ID of handset A (acting as the originator) and the ID of handset B (acting as the recipient), may be sent to signify to handset B that handset A wishes to negotiate a channel. In response, handset A will anticipate and wait for a hold confirmation message to be sent back from handset B. For this purpose, handset A will set the value of a wait_clock to 0 at step S.962 and then determine at step S.963 whether the hold confirmation has been received over the dedicated control channel from handset B. The wait_clock may be a counter that is incremented in accordance with an internal system clock of the handset to detect whether the hold confirmation message has been received within a predetermined wait time. Thus, if the hold confirmation is not received at step S.963, handset A will determine at step S.964 whether the value of the wait_clock is greater than or equal to the predetermined wait time or period. If the wait time has not been exceeded, then logic flow will loop back to step S.963. However, if the hold confirmation is not received within the wait time, then at step S.972 the user of handset A will be alerted that the call request has failed. This alert or notification may include a displayed message and/or audible tone that is provided to the user by handset A to signify that the call has failed. Following step S.972, the call negotiation procedure or routine may terminate at step S.973. Alternatively, the hold request confirmation step may be bypassed in favor of a faster overall negotiation process. As further shown in FIG. 30A, if a hold confirmation is received from handset B at step S.970, then handset A will proceed and attempt to locate an empty or clear channel for the call. Various methods may be employed to locate a channel. According to an aspect of the invention, a predetermined number or set of channels may be available for setting up the call. The handset acting as the originator for the channel negotiation (in this case handset A) may be given a predetermined number of attempts to locate an empty or clear channel to support the call. Channel frequencies may be selected sequentially, randomly or by another method, and then tested to determine activity and possible use of the channel by other handsets that are within range. Once a clear channel is detected, the originating handset (i.e., handset A) will transmit to the recipient handset (i.e., handset B) the channel frequency or number of the clear channel over the dedicated control channel to notify the other handset of the proposed channel. A channel count may be maintained in order to determine the number of attempts to find a clear channel and to determine when the maximum permissible number of tries has been exceeded. When the maximum number of tries has been exceeded, the call negotiation procedure will fail and terminate. For this purpose, the value of a channel_count is set to 0 at step S.966 and then handset A compares the value of the channel_count with the maximum number of tries that is permitted at step S.966 (represented by max_tries in FIG. 30A). If the channel_count is less than the max_tries, then at step S.970 handset A will select a channel (i.e., channel x) for monitoring. The selection of the channel may be random, sequential, or based on any other method. After selecting a candidate channel, handset A will listen to the channel for activity at step S.970. Essentially, handset A will determine if the candidate channel is suitable for handling the call between handset A and handset B. Handset A may determine that the channel is not clear if other handsets within the area are using the channel for a call or if there is unacceptable noise on the channel. If the handset determines that the channel is not clear at step S.974, then the value of the channel_count is incremented by one and logic flow loops back to step S.967 to again compare the value of the channel_count to the max_tries permitted. If a clear channel cannot be obtained within the maximum number of permissible tries or attempts, then logic flow will proceed to step S.968 and handset A will notify handset B that the call attempt has failed. That is, a call fail notification may be sent by handset A as a message over the dedicated control channel to handset B at step S.968. Following step S.968, logic flow proceeds to step S.964 where handset A will alert the user that the call failed. The call negotiation routine will then terminate at step S.973. If a clear channel is detected at step S.974, then handset A will notify handset B of the channel (i.e., channel x) that has been detected. For this reason, handset A will transmit the channel frequency or number of the proposed channel to handset B over the dedicated control channel at step S.976 (see FIG. 30B). Handset A will then wait for a confirmation message from handset B that the proposed channel is suitable for setting up the call. As such, handset A will set the value of a wait_clock to 0 at step S.977 and determine whether a confirmation response has been received from handset B at step S.978. Handset A may monitor the dedicated control channel for a confirmation response for a predetermined wait time before determining that the call negotiation has failed (e.g., due to handset B going out of range, etc.). Thus, if the value of the wait_clock is less than the predetermined wait time at step S.980, then logic flow will loop to step S.978 to determine again if a response has been received. If a response is not received within the wait time, then logic flow will proceed to step S.981 where handset A will alert the user that the call has failed. Thereafter, the call negotiation routine may terminate at step S.982, as shown in FIG. 30B. If a response is received from handset B within the wait time at step S.978, then at step S.984 handset A will determine whether the selected channel (i.e., channel x) has been confirmed by handset B. This determination may be made by analyzing the response from handset B and whether the proposed channel was confirmed by handset B as being clear. If the channel is confirmed as being suitable by handset B at step S.984, then at step S.985 handset A will tune to the selected channel to permit the user of handset A to initiate conversation with the user of handset B at step S.985. Further, at step S.986, handset A may perform other handset functions, including monitoring for queries and requests (e.g., find queries and/or call request queries from other handsets). If, however, the channel selected by handset A was not cleared or confirmed by handset B, then logic flow will proceed from step S.984 back to step S.967 (see FIG. 30A) and the value of the channel_count will be incremented by one. Handset A will then attempt to locate another clear channel if the maximum number of permissible tries has not been exceeded. Logic flow then proceeds after step S.967 as detailed above. Handset B also performs various operations and procedures when negotiating a channel with handset A. In the above-described example, handset B is acting as the recipient or receiving party of the call request and is negotiating a channel with handset A (see, for example, step S.942 in FIG. 29). Various procedures and routines may be implemented to permit handset B to negotiate a channel with handset A. FIGS. 31A and 31B illustrate an exemplary embodiment for handset B to negotiate a channel when acting as the recipient or receiving party. As represented at step S.990 in FIG. 31A, handset B needs to negotiate a channel with handset A, while acting as the recipient or receiving party. For this purpose, the value of a wait_clock may be initialized to 0 at step S.992 and thereafter incremented in accordance with an internal system clock of the handset. If a hold request is not determined as being received over the dedicated control channel at step S.994, then at step S.995 handset B will determine whether the value of the wait_clock is greater than or equal to the predetermined wait time. So long as the wait_clock is less than the wait time, logic flow will loop back to step S.994 to again check if a hold request has been received over the dedicated control channel. If a hold request is not received within the wait time, then logic flow will proceed to step S.998 where it is determined whether handset A and/or handset B are continuing an interrupted call. That is, as discussed above, it is possible that the need to negotiate a channel for a free call may arise when interference occurs on a channel that is being used to support a current call. In such a case, either handset may automatically determine that it is necessary to negotiate a new channel for the call. In addition, the users of handset A and handset B may be provided with the ability to determine when to negotiate a new channel for the free call. Thus, in addition to negotiating a channel based on a new call request, handset B may also need to negotiate a new channel (e.g., while acting as a recipient or receiving party) for an existing call that has been interrupted (e.g., due to other handsets occupying the same channel or unacceptable noise levels on the channel). The call negotiation procedures of the invention may thus be utilized in either case. If handsets A and B are continuing on an interrupted call, then logic flow may proceed to step S.999 where the user of handset B is alerted that the call has failed. Thereafter, logic flow may proceed to step S.1000 where the call negotiation routine will terminate. If, however, handset A and handset B are not continuing on an interrupted call, then the user of handset B does not need to be notified of the failure of the call request and negotiation, and logic flow may proceed directly from step S.998 to step S.1000 where the call negotiation routine terminates. As further shown in FIG. 31A, if a hold request is received at step S.994, then at step S.996 handset B will transmit a hold confirmation message back to handset A over the dedicated control channel. Thereafter, handset B will wait for handset A to further respond with the proposed channel for the call within a predetermined wait time. More particularly, as shown in FIG. 31B, handset B will set the value of a wait_clock2 to 0. The wait_clock2 may be a counter that is incremented in accordance with an internal system clock of handset B. The value of the wait_clock2 may be monitored to determine whether the predetermined wait time has elapsed. The predetermined wait time should be set in accordance with the maximum number of tries that handset A is permitted to locate a suitable channel. At step S.1004, handset B will determine whether a response has been received from handset A over the dedicated control channel. If a response is not received, then at step S.1005, the value of the wait_clock2 will be compared with the predetermined wait time. If the value of the wait_clock2 is less than the wait time, then logic flow will loop back to step S.1004 to again determine whether a response has been received. If a response has been received within the predetermined wait time, then at step S.1006 handset B will determine whether handset A has indicated in the response message that the attempt to locate a free channel has failed. If a call fail notification is received, then logic flow proceeds to step S.1008. Logic flow will also proceed to step S.1008 if it is determined that a response has not been received from handset A within the predetermined wait time at steps S.1004 and S.1005 of FIG. 31B. At step S.1008, handset B will determine whether handsets A and B are continuing on an interrupted call. If handsets A and B are continuing on an interrupted call, then at step S.1011 handset B will be alerted that the call has failed. Thereafter, logic flow proceeds to step S.1012 where the routine may terminate. If, however, handset A and handset B are not continuing on an interrupted call, then the user of handset B does not need to be notified of the failure of the call request and negotiation, and logic flow may proceed directly from step S.1008 to step S.1012 where the call negotiation routine terminates. As further shown in FIG. 31B, if handset A has not sent a call fail notification, then handset B will tune to the proposed channel (i.e., channel x) at step S.1010 and listen for activity on the channel. As described above, handset A will indicate the number or frequency of the proposed channel in the response message after detecting that the channel is clear. Handset B will then test and confirm as to whether proposed channel is clear for supporting the call. Handset B may check whether the selected channel has become occupied by other handsets within the area or whether the noise over the channel has risen to an unacceptable level. If handset B determines that the selected channel is clear at step S.1014, then at step S.1016 handset B will transmit a message to handset A to indicate that the selected channel (i.e., channel x) is suitable for setting up the call. If, however, handset B determines that the selected channel has become corrupted or is not clear, then at step S.1018 a message will be transmitted to handset A to indicate that the proposed channel is bad or unacceptable for setting up the call. Following step S.1018, logic flow will loop back to step S.1002 to wait for an additional response from handset A (i.e., another selected channel or a call fail notification message). Following step S.1016, handset B will determine whether handset A and handset B are continuing on an interrupted call at step S.1020. If handset A and B are not continuing on an interrupted call, then the call negotiation routine may terminate at step S.1021. If, however, handsets A and B are continuing on an interrupted call, then at step S.1022 handset B will permit the user to initiate a conversation with the user of handset A on the selected channel. In addition at step S.1024, handset B will perform other handset functions, including listening for additional queries or messages on the dedicated control channel. As described above, the call negotiation procedures of the invention may be implemented for negotiating a channel when establishing a free call between wireless handsets. In particular, the embodiments of FIGS. 30-31 may be utilized as part of the overall procedures of FIGS. 28 and 29 for establishing a handset-to-handset call. In addition, the channel negotiation procedures of the invention may be utilized to negotiate a new channel to avoid interference during a free call. That is, the embodiments of FIGS. 30-31 may be utilized by wireless handsets on a free call to select a new channel when the current channel that is supporting the free call has become corrupted due to noise or interference caused by other wireless handsets that have come into range and that are occupying the same channel. The embodiments of FIGS. 28-31 may be modified and/or adapted to enable call waiting features. Such call waiting features, as described above, may permit handset users to be notified when a call request has been received during a call with another handset user, and to permit handset users to selectively switch between calls. FIGS. 32-34 illustrate exemplary embodiments for establishing a free call between wireless handsets that are provided with call waiting features. In each of these embodiments, a dedicated control channel is utilized with each handset including a separate tuner that is always tuned to the dedicated control channel. In particular, FIG. 32 is an exemplary flowchart of the various processes and operations carried out by handset A for initiating a call with handset B, when handset B is on a call with another handset (i.e., handset C). Further, FIG. 33 is an exemplary flowchart of the various processes and operations that may be carried out by handset B to handle the call request from handset A, while handset B is on a call with handset C. Lastly, FIG. 34 is an exemplary flowchart of the various processes and operations that may be carried out by handset C, when it is placed on hold by handset B to accept the call request from handset A. In the embodiments of FIGS. 32-34, it is assumed that a dedicated tuner and predetermined control channel are provided, similar to that provided in the embodiments of FIGS. 28-31. As represented at step S.1030 in FIG. 32, handset A is attempting to establish a call with handset B, while handset B is on a call with handset C. A free call may be initiated by the user of handset A by pressing a predetermined key or button (i.e., the free call button or key) after dialing or selecting handset B. If handset B is on a call, a call waiting request may be transmitted over the dedicated control channel. That is, at step S.1032, handset A transmits a call waiting request to handset B over the dedicated control channel, with the request containing the ID of handset A. The ID of handset B may also be included in the call waiting request message to indicate to which handset the call waiting request is directed. Following step S.1032, handset A sets the value of a wait_clock to 0 at step S.1034 and listens to the dedicated control channel for a response from handset B. In particular, at step S.1036, handset A determines whether a response has been received from handset B. If no response is detected, then at step S.1038 the value of the wait_clock is compared to a predetermined wait time. If handset A determines that the value of the wait_clock, which may be incremented in accordance with an internal system clock of the handset, is less than the predetermined wait time, then logic flow loops back to step S.1036. Handset A will then again determine whether a response has been received. If a response is not received from handset B within the predetermined wait time, then at step S.1042 handset A will assume that handset B is unavailable or out of range. Thus, handset A will notify the user that handset B is unavailable. This notification may be performed by handset A by displaying of the ID and/or name of handset B, along with an appropriate message (e.g., “Unavailable”). In addition, handset A may prompt the user as to whether the call should be attempted over a network. Following step S.1042, the procedure may terminate at step S.1046, as shown in FIG. 32. When a response from handset B is detected as being received over the dedicated control channel, handset A will determine at step S.1040 whether the user of handset B has responded to the call waiting request by accepting the call. This determination may be made by analyzing the response message received from handset B. If the user of handset B has accepted the call, then at step S.1048 handset A will set up the call to permit the user of handset A to initiate conversation with the user of handset B. The free call between handset A and handset B may be set up on a new channel (through channel negotiation, etc.) or may be carried out on the same channel that was utilized for the call between handset B and handset C (whereby handset A is notified of the channel of the call through the response message from handset B). In either case, handset C will be requested to hold the call and to wait for a re-contact request from handset B over the dedicated control channel. Following step S.1048, handset A may perform other handset functions at step. S.1050, including listening for queries or requests on the dedicated control channel. If it is determined at step S.1040 that the user of handset B has responded to the call waiting request by rejecting the call, then at step S.1044 handset A will notify the user that the call has been rejected. This notification may include displaying an appropriate message (e.g., “Call Rejected”), along with the ID and/or name of handset B. In addition, depending upon the manner in which the user of handset B has responded to the call waiting request, handset A may prompt the user for various options (e.g., forwarding to a voice mail system or to a different handset or location). Following step S.1044, the procedure may terminate at step S.1046, as shown in FIG. 32. As described above, FIG. 33 is an exemplary flowchart of the various operations and procedures that may be performed by handset B to handle a call waiting request form handset A, while on a call with handset C. In particular, after performing other handset functions at step S.1052, handset B determines at step S.1054 whether a call waiting request has been received over the dedicated control channel. If a call waiting request has not been received, then logic flow proceeds back to step S.1052 where handset B may perform other handset functions. When a call waiting request is detected as being received at step S.1054, handset B will query the user to indicate that a call waiting request has been received at step S.1056. At step S.1056, handset B may query the user by displaying the ID and/or name of handset A to indicate the source of the call waiting request. This query may also include the generation of an appropriate tone to alert the user of handset B, during the call with handset C, as to the presence of the call waiting request. At step S.1058, handset B determines whether the user has responded to the call waiting request query. If the user of handset B ignores the query, then logic flow will loop back to step S.1052. However, if the user responds to the call waiting request, then at step S.1060 handset B will transmit a response message to handset A over the dedicated control channel based on the manner in which the user responded to the call waiting request. Depending on the manner in which the user of handset B has responded to the call waiting request, handset B may cause a new call to be established with handset A or may maintain the call with handset C. That is, at step S.1062, handset B will determine whether the user has decided to respond to the call by accepting the call. If the user did not decide to accept the call, then logic flow will loop back to step S.1052 and the call with handset C will not be interrupted. However, if the user has indicated to accept the call (e.g., by pressing an appropriate key or button on the handset), then logic flow will proceed to step S.1064. At step S.1064, handset B will transmit to handset C a call hold request message. This request message may be transmitted over the dedicated control channel or may be transmitted during a defined control time slot on the channel supporting the call between handset B and handset C. As further discussed below, when handset C receives the hold request, handset C will place the call on hold and wait for a re-contact request from handset B or a call request from another handset. Following step S.1064, handset B will set up the call to permit the user of handset B to initiate conversation with the user of handset A at step S.1066. Once again, the call between handset B and handset A may be maintained on the same channel that was used between handset B and handset C, or handset B may negotiate a new or different channel with handset A to set up the free call. Following step S.1066, handset B may perform other handset functions at step S.1068, including listening for queries or requests over the dedicated control channel. With handset C placed in hold, the user of handset B may carry out communication with handset A and, when desired, switch back and re-contact with handset C. Thus, as represented at step S.1070, handset B may periodically check whether the user of handset B has requested to re-contact with handset C. The determination at step S.1070 may be made based on the detection of the activation of a predetermined key or button on the handset by the user. If a request to re-contact has been made by the user, then at step S.1072 handset B will transmit a hold request to handset A and then initiate a new call or re-contact request to handset C at step S.1074. As a result, handset A will be placed on hold and the user of handset B may conduct a conversation with the user of handset C. Thereafter, the user of handset B can continue to switch between calls with handset A and handset C, and complete calls as desired. FIG. 34 is an exemplary flowchart of the various processes and operations that may be carried out by handset C in accordance with the call waiting features of the invention and that may be used in connection with the embodiments of FIGS. 32 and 33. As represented at step S.1076 in FIG. 34, handset C is in conversation with handset B, when handset B receives a call request from handset A. If the user of handset B determines to respond to the call waiting request, then handset B will put handset C on hold. Thus, at step S.1078, handset C determines whether a hold request message has been received from handset B. The hold request may be transmitted during a control time slot on the channel supporting the call between handset B and handset C, or may be transmitted over the dedicated control channel. As discussed above with reference to the embodiment of FIG. 33, the hold request message from handset B may indicate a channel on which handset C is to wait and hold for a further request from handset B. This channel may be a predetermined channel, such as the dedicated control channel, or another appropriate channel. If a hold request is not received at step S.1078, then logic flow loops back to step S.1076, where handset C performs other handset functions, including maintaining the call between handset B and handset C. If a hold request is received from handset B at step S.1076, then handset C will tune to the dedicated control channel and wait for a re-contact request message for handset B or a call request from another handset at step S.1080. If no call request has been received at step S.1080, then at step S.1082 handset C will continue to perform other handset functions, including listening for other queries or requests (e.g., find queries, etc.). Handset C will also continue to check at step S.1080 whether a call request has been received. When a call request has been received at step S.1080, then at step S.1084 handset C determines whether the call request is from handset B. Specifically, handset C determines whether the request is a re-contact request from handset B. If the request-is not from handset B, then at step S.1086 handset C may receive the call request from the other handset while acting as a recipient of the call request. Various procedures and operations may be performed at step S.1086, such as those described above with reference to FIGS. 29, 31A, 31B, and/or 33. Thus, if the user of handset C decides to receive the call request and initiate a conversation with the user of the other handset, then handset C may negotiate a channel for the call (while acting as the receiving party) with the other handset. If the user of handset C decides to refuse the call request, then logic flow will turn to step S.1080, where handset C again listens for call requests on the dedicated control channel. If a re-contact request is received from handset B at step S.1084, then at step S.1088 handset C will negotiate a channel for the call with handset B to again establish the direct handset-to-handset communication between handset B and handset C. After successfully negotiating a channel, the user of handset C may initiate a conversation with the user of handset B at step S.1090. Thereafter, at step S.1092, handset C may perform other handset functions, including listening for other queries or requests on the dedicated control channel. Modifications to the embodiments of FIGS. 28-34 may be provided without departing from the main features and objects of the invention. For example, FIGS. 37 and 38 are exemplary flowcharts of the various processes and operations that may be carried out by handset A and handset B, respectively, to establish a free call through the utilization of a dedicated control channel. The embodiments of FIGS. 37 and 38 incorporate call waiting features to permit a call request from handset A to be received even if handset B is on a call. In FIG. 37, it is assumed that handset A has initiated a call request and is attempting to establish a direct handset-to-handset call with handset B. Further, for the embodiments of FIGS. 37 and 38 it is assumed that each handset B includes a separate tuner that is always tuned to a dedicated control channel. FIG. 38 illustrates the various operations and procedures that may be carried out by handset B when responding to the call request from handset A. As represented at step S.1100 of FIG. 37, the call request procedure is initiated when the user of handset A presses the appropriate key or button on the handset (e.g., the free call button) with handset B being selected or dialed through the keypad and/or display screen of the handset. Following step S.1100, handset A will transmit a call request to handset B at step S.1102. The call request message may include the ID of handset A, as well as the ID of handset B to indicate the handset to which the call request is directed. In addition, the call request may be transmitted from handset A to handset B over a dedicated control channel. As a result, handsets are not required to periodically register on a registry channel and interruptions to calls (for registering, etc.) is eliminated. Following step S.1102, handset A will set the value of a wait_clock to 0 at step S.1104 and then wait for a response from handset B. The wait_clock may be incremented in accordance with an internal system clock of handset A and may be provided to determine if a response has been received within a predetermined wait time. If a response is not received within the predetermined wait time, then handset A may assume that handset B is unavailable or out of range. At step. S.1106, handset A will determine if a response to the call request has been received from handset B over the dedicated control channel. If no response is received, then at step S.1108 the value of the wait_clock is compared with the predetermined wait time. If the wait_clock is less than the wait time, then logic flow returns to step S.1106 so that the receipt of a response from handset B may be checked. Otherwise, when the wait time has expired, logic flow proceeds from step S.1108 to step S.1120, as illustrated in FIG. 37. If a response message is received at step S.1106, then at step. S.1110 handset A determines the status of handset B. (e.g., Idle or On Call). The determination at step S.1110 may be made based on status information provided in the response message from handset B. If handset B is determined to be on a call at step S.1110, then logic flow proceeds to step S.114 where handset A waits to determine if the user of handset B responds to the call request from handset A. As further described below with reference to FIG. 38, if handset B detects a call request from handset A when handset B is on a call with another handset, handset B may automatically provide a call waiting notification to the user of handset B to alert the user of the presence of the call request from handset A. The user of handset B may then respond to the call request from handset A by accepting the call request or rejecting the same. In either case, handset B may transmit a further response message to handset A to indicate whether the call request has been accepted or rejected. If it is determined at step S.1110 that handset B is not on a call, then at step S.1112 handset A will then attempt to negotiate a channel with handset B for establishing the call. Since handset A initiated the call request, handset A will act as the originating party when negotiating a channel with handset B. Various procedures and operations may be performed for negotiating a channel, such as the exemplary embodiment for negotiating a channel through the use of a dedicated control channel, as discussed above with reference to FIGS. 30A and 30B. In FIGS. 30A and 30B, handset A negotiates a channel with handset B, while handset A acts as the originator. Following the successful selection of a channel, logic flow proceeds to step S.1114 and handset A then awaits for a response from handset B to determine whether the user of handset B has responded and accepted the call request. As further illustrated in FIG. 37, handset A may initialize and set the value of the wait_clock to 0 at step S.1114 and then determine at step S.1116 whether a response message from handset B has been received. Handset A may monitor and listen to the dedicated control channel for a predetermined wait time to receive a response from handset B. Thus, if a response is not received at step. S.1116, handset A will determine at step S.1118 whether the value of the wait_clock is greater than or equal to the wait time. If the wait time has not elapsed, then logic flow loops back to step S.1116 where handset A again determines whether a response has been received. If a response from handset B has not been received within the predetermined wait time, then at step S.1120 handset A assumes that handset B is unavailable or out of range. As such, handset A will notify the user that handset B is unavailable. This notification may be performed by displaying the ID and/or name of handset B along with an appropriate message (e.g., “Unavailable”). In addition, at step S.1120 handset A may prompt the user as to whether the call should be attempted through the use of a network. If the user decides to place a network call, then handset A may place a network call to handset B using conventional methods or techniques. Following step S.1120, the procedure may terminate at step S.1122. If a response from handset B is received over the dedicated control channel at step S.1116, then at step S.1124 handset A determines whether the user of handset B has accepted the call. The determination at step S.1124 may be made by evaluating the response message received from handset B. The response message may indicate whether the user of handset B has responded to the call by accepting the call or by requesting special handling of the call (e.g., by transferring to a voice mail system or call forwarding). If it is determined at step S.1124 that the user of handset B has decided to accept the call, then at step S.1128 handset A permits the user to initiate a conversation with the user of handset B. In addition, at step S.1130, handset A proceeds by performing other handset functions, including listening for queries or requests over the dedicated control channel. If it is determined at step S.1124 that the user of handset B has responded to the call without accepting the call, then at step S.1126 handset A notifies the user that the call has been rejected. This notification may take the form of displaying an appropriate message (e.g., “Call Rejected”). In addition, depending on the response from handset B and the manner in which the user of handset B has responded to the call request, handset A may also prompt the user for various options (e.g., transferring to the voice mail system of handset B or forwarding the call to another handset or location). Following step S.1126, the procedure may terminate at step S.1122. As indicated above, FIG. 38 is an exemplary flowchart of the various processes and operations and may be carried out by handset B when responding to a call request from handset A over a dedicated control channel. In particular, following the performance of other handset functions at step S.1140, handset B may determine at step S.1142 whether a call request has been received over the dedicated control channel. For this purpose, handset B may have a separate tuner that constantly listens and monitors the dedicated control channel for call requests. Handset B may perform this function simultaneously with the performance of other handset functions. If a call request is not received, then logic flow loops back to step S.1140. Otherwise, if a call request has been received at step S.1142, then logic flow proceeds to step S.1144, as shown in FIG. 38. At step S.1144, handset B transmits a response message to handset A to confirm the receipt of the call request. As indicated above with respect to FIG. 37, the response message may include status information to indicate to handset A the status of handset B (e.g., Idle or On Call). After transmitting the response message at step S.1144, handset B notifies or queries the user of handset B of the receipt of the call request from handset A. This notification may include generating an appropriate tone and/or displaying a message including the ID and/or name of handset A. The type of notification that is provided may depend on the status of handset B. If handset B is not on a call, an audible ringing tone may be provided, as well as displaying an appropriate message with the ID of handset A. If, however, handset B is on a call, a quick or periodic beep tone may be provided in the earpiece of the handset to notify the user of the call waiting request. An appropriate message with the ID of handset A may also be displayed to the user of handset B during the call, so that the user can determine where the call request originated and whether to accept the new call. After providing the query to the user at step S.1146, handset B performs additional operations depending on the status of the handset. That is, if it is determined at step. S.1148 that handset B is on a call then logic flow proceeds to step S.1152, to determine if the user responds to the call request. If, however, it is determined at step S.1148 that handset B is not on a call, then logic flow proceeds to step S.1150. At step. S.1150, handset B negotiates a channel for setting up the call with handset A. Since handset B has received the call request that was initiated by handset A, handset B acts as the receiving party when negotiating the channel. Various procedures and operations may be performed by handset B to negotiate a channel with handset A, such as operations of the exemplary embodiment of FIGS. 31A and 31B. In the embodiment of FIGS. 3A and 31B, handset B negotiates a channel with handset A, while handset B acts as the receiving party. Following the successful negotiation of a channel for the call, handset B will then determine if the user wishes to respond to the call request from handset A at step S.1152. As illustrated in FIG. 38, at step S.1152 handset B will determine whether the user has responded to the call request. This determination may be made by determining whether one or more appropriate keys or buttons on the handset have been pressed by the user to respond to the call request. If the user of handset B does not respond to the call request, then logic flow loops back to step S.1140 from step S.1152. However, if the user of handset B does respond to the call request, then at step S.1154 handset B will transmit an appropriate response message to handset A over the dedicated control channel based on the manner in which the user responded to the call request. As discussed above, the response message from handset B may indicate whether the user of handset B has responded to the call by accepting the call or by rejecting the call and requesting specialized handling of the call (i.e., forwarding to a voice mail system or to a different handset or location). Further, handset B will respond depending on whether the user has accepted the call. That is, if it is determined at step S.1156 that the user has not accepted the call, then logic flow will proceed back to step S.1140. However, if the user has accepted the call, then logic flow will proceed from step S.1156 to step S.1158. At step S.1158, handset B will permit the user to initiate a conversation with the user of handset A by supporting the call over the negotiated channel. In addition, at step S.1160 handset B will perform other handset functions, including listening for queries or requests over the dedicated control channel. While the invention has been described with reference to exemplary embodiments, it is understood that the words which have been used herein are words of description and illustration, rather then words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its various aspects. For example, group lists of beeping clips may be defined in the handset so that a user may page (with or without a beep request) each clip in the group list with a single CALL function. In such a case, the user may select a predefined group list of clips and then press the CALL button on the handset. In response, the handset may then page each clip in the group list and provide information to the user (e.g., via the handset display) as each clip is paged. Such a feature may facilitate a user in locating a group of items (such as tools, pets, children, etc.) with a simple activation of the CALL function. In addition, modifications may be made to the disclosed embodiments of the invention in order to reduce collisions or interferences. For instance, for each of the embodiments of the invention that utilize a registry, the predetermined cycle time for registering may be reset to a random number (e.g., between 0 and y minutes or seconds) after each registration. By changing the cycle time in this manner, two handsets that are out of range of one another but both in range of a third handset can avoid colliding with one another more than once. Other modifications to the disclosed embodiments of the invention may also be made. For example, modifications may be made so that the wireless handsets do not need to sequentially register during a free call. That is, one handset could register for both handsets on the free call by transmitting its own ID and channel number first, and then transmitting the ID of the other handset and the channel number to contact the other handset. In addition, the wireless handset of the present invention may be provided with call-waiting features. For instance, where a control time slot is defined (see, e.g., the embodiments of FIGS. 1A and 1B and FIGS. 12A and 12B), the control time slot may be utilized to transmit a call-waiting signal. Such a call-waiting signal may comprise Caller ID information and/or the frequency or number at which to contact the calling party (which may include other wireless handset users). Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein. Instead, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. | <SOH> BACKGROUND OF INVENTION <EOH>The present invention generally relates to the field of communications and the use of wireless handsets. More particularly, the present invention relates to wireless handsets with enhanced functionality, including the ability to operate within a wireless network and in a direct handset-to-handset communication mode. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing, the present invention, through one or more of its various aspects, embodiments and/or specific features or subcomponents thereof, is thus intended to bring about one or more of the objects and advantages as discussed below. An object of the present invention is to provide a fully featured, wireless handset that provides greater flexibility and operating capabilities for users. In addition, an object of the invention is to provide a wireless handset that is inexpensive to operate and that includes enhanced features and capabilities. A further object of the invention is to provide a wireless handset that is capable of operating in a direct handset-to-handset communication mode. Another object of the present invention is to provide a wireless handset that has enhanced operating features, including the capability of operating either within a wireless network or outside of a wireless network in a direct handset-to-handset communication mode. Still another object of the present invention is provide a wireless handset that is capable of providing full-duplex communication and performing dynamic channel allocation to establish communication with another handset. Yet another object of the present invention is to provide a wireless handset with enhanced features, such as a find feature that assists a handset operator in determining what objects, including other handset users, are located within the handset's operating range. Another object of the invention is to provide a wireless handset that includes a memorize feature, which permits a wireless handset to exchange information conveniently and securely with another handset or object by wireless transmission. In addition, an object of the invention is to provide a plurality of enhanced features for a wireless handset, including find features, memorize features, conference call features and short range messaging features. Accordingly, an enhanced wireless handset is provided that is capable of operating within a traditional wireless network or in a direct handset-to-handset communication mode. The wireless handset includes enhanced operating features, including find features for locating objects, including other wireless handsets, paging devices and beeping devices or clips attached to items (such as keys, tools, pets, etc.), that are within range of the wireless handset. In order to provide such features, the wireless handset is implemented with: means for initiating a find feature to determine if at least one specified object is within range of the wireless handset; means for generating a query message over a control channel based on the initiation of the find feature; means for detecting a positive response message from the specified object in reply to the query message; and means for indicating, based on the positive response message being detected by the detecting means, that the specified object is within range of the wireless handset. According to an aspect of the invention, the wireless handset may include a find list that comprises a plurality of entries, wherein each of the entries includes information for specifying at least one object. The information of each entry in the find list may include the name and/or ID associated with the object specified by the entry. The initiating means may initiate a find feature based on the information of at least one entry of the find list. The wireless handset may also include means for selecting an entry in the find list to specify an object, whereby the initiating means initiates a specific find request based on the object specified by the entry of the find list selected with the selecting means to determine if the selected object is within range of the wireless handset. When no entry in the find list is selected with the selecting means, the initiating means may initiate a general find request based on each object specified by the plurality of entries of the find list in order to determine which objects on the find list are within range of the wireless handset. In accordance with another aspect of the invention, the indicating means may comprise means for recording information to a found list based on the positive response message and means for displaying the found list to indicate that the specified object is within range of the wireless handset. The wireless handset may also include means for detecting when a response has not been received, within a predetermined wait time, from the specified object in reply to the query message, and means for alerting that the object was not found when the detecting means detects that a response has not been received. The query message may comprise an ID of the specified object and an ID of the wireless handset that generated the query message. Means for detecting a signal strength of the positive response message may also be provided, and the indicating means may indicate the detected signal strength of the positive response message to the user of the wireless handset. In accordance with another aspect of the invention, a method is provided for locating objects, such as other wireless handsets, paging devices and beeping devices or clips, that are within range of a wireless handset. The method comprises: initiating a find feature to determine if at least one specified object is within range of the wireless handset; generating a query message over a control channel based on the initiation of the find feature; detecting a positive response message from the specified object in reply to the query message; and recording information to a found list based on the positive response message to indicate that the specified object is within range of the wireless handset. The method may further comprise providing a find list comprising a plurality of entries, and initiating a find feature based on information of at least one entry of the find list, wherein the information of each entry in the find list specifies at least one object to be located. The method may also provide selecting an entry in the find list to specify an object and initiating a find feature based on the object specified by a selected entry of the find list to determine if the selected object is within range of the wireless handset. When it is detected that no entry in the find list has been selected, a general find request may be initiated based on each object specified by the plurality of entries of the find list to determine which objects on the find list are within range of said wireless handset. The present invention also relates to a wireless handset with enhanced operating features, including find features for locating objects (such as other wireless handsets) that are within range of the wireless handset. In accordance with an aspect of the invention, the wireless handset comprises: means for initiating a find feature to determine if at least one specified object is within range of the wireless handset; means for tuning to a registry channel based on the initiation of the find feature; means for receiving a registry message on the registry channel from the at least one specified object in response to the query message; and means for recording information based on the registry message received from the at least one specified object. The information that is recorded by the recording means may include the name and/or ID associated with the specified object. Further, the recording means may record the information to a found list to indicate that the specified object is within range of the wireless handset. Alternatively, the information that is recorded by the recording means may comprise the ID associated with the specified object and a channel for contacting the specified object. In such a case, the recording means may record the information to a temporary list of the wireless handset. Further, means for generating a query message over the channel for contacting the specified object may be provided, as well as means for detecting a positive response message from the specified object in reply to the query message. The wireless handset may also comprise means for indicating, based on the positive response message detected by the detecting means, that the specified object is within range of the wireless handset, means for recording information to a found list based on the positive response message, and means for displaying the found list to indicate that the specified object is within range of the wireless handset. In this case, the information that is recorded by the recording means may indicate a channel for contacting the specified object and a slot time for contacting the specified object on the channel. In accordance with another aspect of the invention, a method is provided for locating objects that are within range of a wireless handset. The objects to be located may comprise other wireless handsets, paging devices and beeping devices or clips attached to items. In general, the method may comprise: initiating a find feature to determine if at least one specified object is within range of the wireless handset; tuning to a registry channel based on the initiation of the find feature; receiving a registry message on the registry channel from the at least one specified object in response to the query message; and recording information based on the registry message received from the at least one specified object. The information that is recorded may include the name and/or ID associated with the specified object. Further, in the disclosed method, information may be recorded to a found list to indicate that the specified object is within range of the wireless handset. According to another aspect of the invention, a wireless handset with enhanced operating features is provided, wherein the enhanced operating features comprise a memorize feature for exchanging information with objects, including other wireless handsets that are capable of operating in a communication mode with the wireless handset. To implement the memorize feature, the wireless handset may comprise: means for initiating a memorize feature with at least one object; means for generating a query message based on the initiation of the memorize feature to request a response from the at least one object; means for receiving a positive response message from the at least one object in reply to the query message; and means for recording information based on the positive response message received from the at least one object. The information that is recorded by the handset may include an ID or number associated with the at least one object. Further, the generating means may generate the query message at a reduced power level when the at least one object is in close proximity to the wireless handset, so that the query message is not received by other objects. The above-listed and other objects, features and advantages of the present invention will be more fully set forth hereinafter. | 20040503 | 20100406 | 20050721 | 57575.0 | 6 | TRAN, TUAN A | ENHANCED WIRELESS HANDSET, INCLUDING DIRECT HANDSET-TO-HANDSET COMMUNICATION MODE | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,838,149 | ACCEPTED | Reservation gift card | A method of using a stored-value card to reserve an item includes providing a stored-value card to a customer prior to the release date of an item, adding value to the stored-value card prior to the release date of the item, and reserving the item with the stored-value card. Other method and product embodiments are disclosed. | 1. A method of using a stored-value card to reserve an item, comprising: providing a stored-value card to a customer prior to the release date of an item; adding value to the stored-value card prior to the release date of the item; and reserving the item with the stored-value card. 2. The method of claim 1, wherein the providing comprises displaying the stored-value card to multiple customers. 3. The method of claim 2, wherein the displaying includes supporting multiple stored-value cards simultaneously on a display in a retail store. 4. The method of claim 1, wherein the providing comprises releasably affixing the stored-value card to a substrate. 5. The method of claim 1, wherein the adding comprises presenting the stored-value card to an employee of a retail store. 6. The method of claim 1, wherein the adding comprises updating a record of a monetary balance for the card in an electronic database. 7. The method of claim 1, further comprising, on or after the release date, receiving the stored-value card from a bearer of the stored-value card. 8. The method of claim 7, further comprising providing the reserved item to the bearer. 9. The method of claim 8, further comprising receiving additional value from the bearer in connection with providing the reserved item to the bearer. 10. The method of claim 7, further comprising applying the value added to the card for purchase of an item other than the reserved item. 11. The method of claim 1, further comprising applying the value added to the card for purchase of an item other than the reserved item. 12. The method of claim 1, further comprising holding the reserved item for the customer or customer's designee for a predetermined period of time after the release date. 13. The method of claim 12, further comprising ceasing to hold the reserved item after the predetermined period of time. 14. The method of claim 13, wherein the ceasing to hold comprises reducing the value loaded on the stored-value card. 15. The method of claim 1, further comprising adding additional value to the stored-value card for purchase of one or more items other than the reserved item. 16. The method of claim 1, wherein the providing comprises providing to a customer a stored-value card having zero initial value. 17. The method of claim 16, wherein the adding comprises activating the stored-value card. 18. The method of claim 1, wherein the adding comprises adding a deposit that is less than a full purchase price for the item. 19. The method of claim 1, further comprising providing a receipt to the customer for the added value. 20. A method of tracking pre-sales of a new release, comprising: providing a reservation card to a customer prior to a release date of the new release; having the customer load monetary value on the card toward purchase of the new release; and tracking the number of reservation cards loaded with the monetary value, to track pre-sales of the new release. 21. The method of claim 20, wherein the providing comprises providing a zero-initial-value reservation card to the customer. 22. The method of claim 20, wherein the providing comprises displaying the reservation card in a retail store with unrestricted access to the card by multiple customers. 23. The method of claim 20, further comprising determining order quantities from a vendor of the new release in view of the tracked pre-sales. 24. The method of claim 20, further comprising tracking redemption of the reservation cards. 25. A reservation gift card assembly, comprising: a substrate; a reservation gift card supported by the substrate, the reservation gift card defining an activation area adapted for loading of the reservation gift card with monetary value; and indicia on the reservation gift card and/or the substrate directing a purchaser of the reservation gift card to make a down payment to reserve a pre-release item and to present the reservation gift card to pick up the reserved item. 26. The reservation gift card assembly of claim 25, further comprising indicia on the reservation gift card and/or the substrate indicating that the reserved item will be held for a predetermined period of time after a release date for the item. 27. The reservation gift card assembly of claim 25, further comprising indicia on the reservation gift card and/or the substrate indicating that the reservation gift card can be used to purchase one or more items other than the reserved item. 28. The reservation gift card assembly of claim 25, further comprising indicia on the reservation gift card and/or the substrate indicating that the reservation gift card has no value until the down payment is made. 29. A method of making a reservation gift card assembly, comprising: providing a substrate; supporting a reservation gift card on the substrate, the reservation gift card defining an activation area adapted for loading of the reservation gift card with monetary value; and providing indicia on the reservation gift card and/or the substrate directing a purchaser of the reservation gift card to make a down payment to reserve a pre-release item and to present the reservation gift card to pick up the reserved item. 30. A reservation stored-value card assembly, comprising: a reservation stored-value card defining means for loading the reservation stored-value card with monetary value; and means for directing a purchaser of the reservation stored-value card to make a down payment to reserve a pre-release item and to present the reservation stored-value card to pick up the reserved item. | BACKGROUND OF THE INVENTION Some merchant areas, e.g. video games and books, are at distinct disadvantage competitively in the marketplace when it comes to pre-selling new releases. Current pre-sale methods using pre-loaded and/or pre-specified dollar-amount coupons, normally stored in a drawer or under lock-and-key at an electronics counter or other location in a retail store, result in shortage and accounting reconciliation issues. Also, because such coupons are pre-loaded and kept behind display glass or elsewhere, merchandising options are limited. Stored-value cards and other financial-transaction cards come in many forms. A gift card, for example, is a type of stored-value card that includes pre-loaded or selectably loaded monetary value. In one example, a customer buys a gift card having a specified value for presentation as a gift to another person. In another example, a customer is offered a gift card as an incentive to make a purchase. A gift card, like other stored-value cards, can be “recharged” or “reloaded” at the direction of the bearer. The balance associated with the card declines as the card is used, encouraging repeat visits to the retailer or other provider issuing the card. Additionally, the card generally remains in the user's purse or wallet, serving as an advertisement or reminder to revisit the associated retailer. Gift cards provide a number of advantages, to both the customer and the retailer. SUMMARY OF THE INVENTION A method of using a stored-value card to reserve an item includes providing a stored-value card to a customer prior to the release date of an item, adding value to the stored-value card prior to the release date of the item, and reserving the item with the stored-value card. Other method and product embodiments are disclosed. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will be described with respect to the figures, in which like reference numerals denote like elements, and in which: FIG. 1 is a front view of a gift card assembly, according to an embodiment of the invention. FIG. 2 is a rear view of the FIG. 1 assembly. FIG. 3 is a flow chart showing a method according to an embodiment of the invention. FIG. 4 is a flow chart showing a method according to an embodiment of the invention. FIG. 5 is a flow chart showing a method according to an embodiment of the invention. DETAILED DESCRIPTION Embodiments of the invention relate to a gift card or other stored-value card that is used not only in the manner of a typical gift card, but also to reserve an in-demand item prior to a date or time when the item becomes generally available. For example, embodiments of the invention are used to reserve a copy of a book, prior to the release date of that book. Embodiments of the invention are particularly, though not exclusively, advantageous when pre-release demand for the item is extraordinary and the release date is a long-awaited event. Items that are reservable according to embodiments of the invention include not just books, but other merchandise, such as video games, videos, music, CD's, and DVD's, to name several non-exclusive examples. Reservable items according to embodiments of the invention also include services that are not scheduled to be available until a certain date or time. Referring to FIGS. 1-2, stored-value card assembly 10 includes substrate 15. Substrate 15, which also may be called a backing, comprises a single layer or multiple layers of paper or plastic material, for example, generally in the form of a relatively stiff but bendable/flexible card. Other materials are also contemplated. Substrate 15 supports stored-value card or other financial-transaction card 20. Card 20 is releasably secured to substrate 15 by adhesive or an adherence layer. Card 20 is, for example, a card used by a merchant to issue a spending credit to a customer. The merchant provides the card in exchange for money received, merchandise returned or other consideration. The card is “loadable” with monetary value, for example a dollar value that the merchant's customer can use or give to another individual. A record of the monetary balance on the card optionally is maintained on a database, other electronic or manual record-keeping system, or, in the case of “smart” cards, for example, on a chip or other electronics or devices on the card itself. Substrate 15 defines window or opening 30 for displaying activation area 35 of card 20. According to the illustrated embodiment, activation area 35 includes bar code 40. Alternatively, or additionally, activation area 35 may include a magnetic strip, a smart chip or other electronic device, a radio frequency identification device, or other identification device or indicia, such as a card number and event number. Bar code 40 or other activation-area feature optionally represents an account number or otherwise serves to link card 20 to a database or other electronic or manual storage device or system. In the case of a stored-value card, activation area 35 is adapted for loading of the stored-value card with monetary value. Substrate 15 is a bi-fold substrate defining fold line 50, about which substrate 15 is foldable roughly in half. In FIGS. 1-2, substrate 15 is unfolded, i.e. is in an open configuration. According to one embodiment, FIG. 1 illustrates surfaces 55, 60 of substrate 15 that will be on the outside of assembly 10 when substrate 15 is folded about fold line 50, and FIG. 2 illustrates surfaces 65, 70 of substrate 15 that will be on the inside of assembly 10 when substrate 15 is folded about fold line 50. Folding substrate 15 in the manner described yields a folded substrate 15, i.e. a substrate 15 in a closed configuration, with card 20 supported on front outer surface 60 thereof. According to one embodiment, the length of surfaces 70, 55 is slightly greater than the length of surfaces 60, 65, such that a slight underlap area at the right-hand side (as viewed in FIG. 2) of surface 70 is defined when substrate 15 is folded about fold line 50. Substrate 15 also defines a cut, forming flap 80. If desired, the right-hand edge (as viewed in FIG. 1) of surface 60 may be tucked behind flap 80 to hold assembly 10 in the closed configuration. Folded substrate 15 and card 20 together define a compact package. The package, e.g. one or both of substrate 15 and card 20, displays graphics or text information, e.g. brand indicia, advertising, promotional information, directions, or other information. For example, as illustrated on inside surface 65 of substrate 15, indicia 100 (alone or in combination with other indicia on card 20) directs a purchaser of stored-value or gift card 20 to give a store employee, at a location within a retail store, a down payment to reserve a pre-release item. Alternatively, indicia 100 directs the purchaser to make a down payment in a different way, e.g. at an in-store or other kiosk, over the Internet, or in some other manner. Indicia 100 also directs the purchaser to keep card 20, and a receipt, and to present card 20 to pick up a reserved copy of the pre-release item, which is identified by title, for example. Indicia 100 also indicates that the reserved pre-release item will be held at a location within the retail store for a predetermined period of time, e.g. seven days, after a release date, e.g. the national release date, for the pre-release item. The national release date may be specifically identified by day, month and year. Surface 65 includes additional indicia 105, which optionally indicates one or more of the following: that card 20 is redeemable toward the price of the reserved item, that card 20 is redeemable only at the specific retail store location where purchased, that the reserved item will be held for a predetermined period of time, e.g. seven days, after the release date of the item, that after the predetermined period of time, the retail store will not be responsible for holding the reserved item, that if a reserved item is unavailable then card 20 may be used for other items (e.g. merchandise or services) at the retail store, at another retail store in a common chain of retail stores, at an Internet site, etc., that card 20 is not redeemable for cash or credit except where required by law, that a lost, damaged or stolen card can be reported by telephone so that the retail store can replace the remaining value upon presentation of the original purchase receipt, and that card 20 has no value until purchased, i.e. until a down payment on the reserved item is made. Surface 70 of substrate 15 includes indicia 110, which optionally are directed to a store employee and optionally indicate one or more of the following: that the employee should scan bar code 40, that card 20 then processes in the store's computer or POS system like a normal gift card, that a down payment amount, for example $10.00, should be keyed in to the computer or POS system, that it should be explained to the purchaser that card 20 will reserve a copy of the pre-release item, such as a book, at that particular retail store location for a predetermined period of time after the national release date, and that the value of card 20 may be applied towards the purchase of the reserved book. Front surface 60 of substrate 15 includes indicia 1115, which optionally indicate one or more of the following: an encouragement to the purchaser to reserve a pre-release item, e.g. “Reserve Your Copy!”, that card 20 may be obtained, a deposit paid, and then card 20 returned on or after a certain date, e.g. a national release date for the pre-release item, and that the purchase price balance then may be paid for the purchaser to receive their pre-release item. Card 20 itself optionally includes indicia 120 indicating the title of a book, video game, or other pre-release item, and/or additional text or graphics, including promotional material, advertising, brand identifiers, or the like. Any of indicia 100, 105, 110, 115, 120, or other indicia, optionally may appear anywhere on substrate 15 and/or card 20. Additional information besides that specifically described and illustrated herein also may be included. For example, such indicia optionally appear on a back surface of card 20, a portion of which is visible through opening 30 in FIG. 2. According to one embodiment, indicia appearing on the back of card 20 are generally identical to indicia 105 on surface 65 of substrate 15. According to embodiments of the invention, then, assembly 10 is an example of a reservation stored-value card assembly including a reservation stored-value card 20 defining means for loading the reservation stored-value card with monetary value, e.g. bar code 40 or other indicia or apparatus tied to a database or other record-keeping system, a smart chip, etc., and means for directing a purchaser of card 20 to make a down payment to reserve a pre-release item and to present card 20 to pick up the reserved item. Method embodiments according to the invention are illustrated in FIGS. 3-5. FIG. 3 shows method 150 of using a stored-value card to reserve an item, the method comprising providing, at 155, a stored-value card to a customer, e.g. a customer shopping at a retail store, prior to the release date of an item. Providing 155 optionally includes displaying the stored-value card to multiple customers, e.g. supporting multiple stored-value cards simultaneously on a display in an area of a retail store that is open to the public. Providing 155 optionally includes providing a stored-value card 20 having zero initial value. Because such cards 20 have no value until purchased or “loaded”, according to embodiments of the invention, cards 20 are not limited to being kept under lock-and-key behind display glass or elsewhere. Merchandising options are expanded to include open displays and other free-access modes. Providing 155 also optionally includes releasably affixing card 20 to substrate 15, for example with adhesive or an adhering layer. Method 150 also includes adding value, at 160, to stored-value card 20, prior to the release date of the item. Adding 160 optionally includes presenting card 20 to an employee of a retail store, for example a cashier at a department counter or at the general checkout lanes. Adding 160 also optionally includes updating a record of a monetary balance for card 20 in an electronic database, maintained e.g. at the store, at a central headquarters for a chain of stores or at another centralized or remote location. Adding 160 also optionally includes activating card 20, and/or adding a deposit that is less than a full purchase price for the item. Method 150 also includes, at 165, reserving the item for the customer (or the customer's designee, if the customer wishes to give card 20 to another party, for example). Method 150 additionally includes receiving, at 170, card 20 from a bearer of card 20. Receiving 170 occurs on or after the release date of the item, e.g. on or after the national release date of a book or other item of merchandise. Receiving 170 occurs at the retail store where card 20 was originally purchased, according to embodiments of the invention. It is also possible that receiving 170 occurs at a different location. A store employee or other individual receives card 20; receiving 170 also optionally occurs without direct human intervention, e.g. at a kiosk in a retail store or over the Internet on the store's website, for example. Providing 155 also optionally occurs in this manner. If the reserved item is available and still desired by the customer, as indicated at 175, method 150 also optionally includes, at 180, providing the reserved item to the bearer of card 20. In the case where the value originally added to card 20 at 160 is a down payment, i.e. only a portion of the purchase price of the item, for example, method 150 also includes receiving, at 185, additional value from the bearer—the difference between the down payment and the full purchase price, for example. In the case where the value originally added to card 20 at 160 is sufficient to cover the purchase price of the item, then receiving 180 need not occur. If the reserved item is unavailable and/or not desired by the customer, as indicated at 175, method 150 also optionally includes, at 190, applying the value originally added to the card at e.g. 160 for purchase of one or more items other than the reserved item. For example, as indicated by indicia 105 in the above-described embodiment, the reserved item might not be held by the retail store longer than a predetermined period after the release date, e.g. a week after the release date, and might therefore be unavailable as a reserved item. Alternatively, the purchaser of card 20 might change their mind and no longer desire the reserved item, or the bearer of card 20 might not want the reserved item. In such cases, card 20 is useable as a typical gift card or stored-value card, where the value stored on card 20 is used to purchase other items at the retail store. Card 20 also can be recharged, reloaded, and otherwise used as a typical gift card. Method 150 thus optionally includes adding, at 195, additional value to card 20 for purchase of one or more items other than the reserved item. FIG. 4 illustrates an additional method 200 according to an embodiment of the invention. Method 200 includes providing 155, adding 160 and reserving 165 as described previously. Method 200 also includes, at 205, holding the reserved item for the customer or the customer's designee for a predetermined period of time after the release date of the item. Method 200 also includes, at 210, ceasing to hold the reserved item after the predetermined period of time. In the case of high customer demand, for example, it may desirable to open up all reserved copies for purchase by others, after a certain period of time elapses. Ceasing 210 optionally includes reducing the value loaded on card 20 if the predetermined period of time elapses without the reserved item being picked up or purchased, e.g. in the manner of administrative charge. On the other hand, it may be more advantageous to the retail store if the customer is assured that there will be no value lost if the item is not picked up or purchased within the predetermined period of time, and, indeed, that the customer can apply the down payment amount to any other item of merchandise or service offered by the retail store. Embodiments of the invention also provide advantages for the retail store offering the new release. In addition to encouraging not only sales of the pre-release item but also other merchandise and services offered by the store, embodiments of the invention allow the store to more easily track pre-sales, redemption rates, vendor-order quantities, and other information. In that regard, FIG. 5 illustrates method 250 according to an embodiment of the invention. Method 250 includes, at 255, providing reservation card 20 to a customer prior to a release date of a new release. Providing 255 optionally includes providing a zero-initial-value reservation card to the customer, e.g. a card that is not pre-loaded with any value but instead needs to be loaded or activated in connection with receipt of payment by the customer. Accordingly, providing 255 also optionally includes displaying the reservation card in a retail store with unrestricted access to the card by multiple customers. Method 250 also includes, at 260, having the customer load monetary value on card 20 toward purchase of the new release, e.g. having the customer direct that a certain monetary value be added to card 20. Method 250 also includes, at 265, tracking the number of reservation cards loaded with the monetary value, to track pre-sales of the new release. At 270, method 250 includes determining order quantities from a vendor of the new release in view of the tracked pre-sales. Instead of having to blindly estimate the number of items that will be sold, embodiments of the invention allow retailers to more accurately forecast how many of the items will be needed to meet customer demand. Method 250 also includes, at 275, tracking redemption of the reservation cards, e.g. tracking how many cards are redeemed and applied toward purchase of the released item, how many cards are applied toward purchase of other items at the retailer, how many cards are reloaded, and/or how many cards are never redeemed. Thus, embodiments of the invention enable merchants to track pre-sale of merchandise by store, by requiring the customer to put a specified monetary amount on reservation card 20 and then requiring that the customer bring the card back on the date/week of the product release to pick up their reserved/set aside product. This gift card platform tracks the number of reservation cards by store, so that the merchant knows how much quantity of the product to set aside on a per-store basis. Using this platform corrects shortage/theft and accounting-reconciliation issues and allows for more merchandising options. Because the reservation card is not pre-loaded, but only activated at a cashier's station or other location, theft of the reservation card is minimized. Further, as referenced earlier herein, because the reservation card is not pre-loaded, it can be sold out in the open instead of from behind the counter, allowing more marketing and merchandising options with the pre-sale offer. This technology platform then tracks sales and redemption information for the card. Depending on the number of reservation cards sold, the merchant knows “pre-sales” for the product and can determine order quantities accordingly with the vendor of the item. Reservation cards are tracked at redemption to know what percentage of the reservation cards were redeemed back in a specific department of the retail store, e.g. whether they were redeemed for the item that was pre-sold or used for another item or purpose. Embodiments of the invention also extend to a method of making reservation gift card assembly 10, the method including providing substrate 15, supporting reservation gift card 20 on substrate 15, reservation gift card 20 defining activation area 35 adapted for loading of the reservation gift card with monetary value, and providing indicia 100, 105, 110, 115, and/or 120 on reservation gift card 20 and/or substrate 15 directing a purchaser of reservation gift card 20 to make a down payment to reserve a pre-release item and to present reservation gift card 20 to pick up the reserved item. Stored-value cards come in many forms, according to embodiments of the invention. A gift card, for example, includes pre-loaded or selectably loaded monetary value. In one example, a customer provides consideration in the amount of the card value, or is offered the gift card as an incentive to make a purchase, and then either keeps the card for use or provides the card as a gift to a recipient. The gift card, like other stored-value cards, can be “recharged” or “reloaded” at the direction of the original customer, the gift recipient, or a third party. The balance associated with the card declines as the card is used, encouraging repeat visits. The card remains in the user's purse or wallet, serving as an advertisement or reminder to re-visit the associated merchant. Gift cards according to embodiments of the invention provide a number of advantages to both the customer and the merchant. Other stored-value cards according to embodiments of the invention include loyalty cards, merchandise return cards, electronic gift certificates, employee cards, frequency cards, pre-paid cards, and other types of cards associated with or representing purchasing power or monetary value, for example. Although the invention has been described with respect to particular embodiments, such embodiments are for illustrative purposes only and should not be considered to limit the invention. Various alternatives and changes will be apparent to those of ordinary skill in the art. For example, card 20 optionally is a physical card made of plastic, paper, generally stiff paper, other substrate, or the like. Card 20 also optionally is a virtual or electronic card accessible on a retailer's website, other Internet location, kiosk, or elsewhere. Adding value to card 20 optionally includes adding either a fixed amount or an amount that can be chosen by the customer. The release date of an item optionally is its national release date, a local release date or release date within another geographic region, a release date within a particular store or group of stores, or otherwise a date or time when an item becomes generally available, and/or available in a less-restricted form than at a previous time. Other modifications within the scope of the invention in its various embodiments will be apparent to those of ordinary skill. | <SOH> BACKGROUND OF THE INVENTION <EOH>Some merchant areas, e.g. video games and books, are at distinct disadvantage competitively in the marketplace when it comes to pre-selling new releases. Current pre-sale methods using pre-loaded and/or pre-specified dollar-amount coupons, normally stored in a drawer or under lock-and-key at an electronics counter or other location in a retail store, result in shortage and accounting reconciliation issues. Also, because such coupons are pre-loaded and kept behind display glass or elsewhere, merchandising options are limited. Stored-value cards and other financial-transaction cards come in many forms. A gift card, for example, is a type of stored-value card that includes pre-loaded or selectably loaded monetary value. In one example, a customer buys a gift card having a specified value for presentation as a gift to another person. In another example, a customer is offered a gift card as an incentive to make a purchase. A gift card, like other stored-value cards, can be “recharged” or “reloaded” at the direction of the bearer. The balance associated with the card declines as the card is used, encouraging repeat visits to the retailer or other provider issuing the card. Additionally, the card generally remains in the user's purse or wallet, serving as an advertisement or reminder to revisit the associated retailer. Gift cards provide a number of advantages, to both the customer and the retailer. | <SOH> SUMMARY OF THE INVENTION <EOH>A method of using a stored-value card to reserve an item includes providing a stored-value card to a customer prior to the release date of an item, adding value to the stored-value card prior to the release date of the item, and reserving the item with the stored-value card. Other method and product embodiments are disclosed. | 20040503 | 20130813 | 20051103 | 82563.0 | 0 | VAN BRAMER, JOHN W | RESERVATION GIFT CARD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,838,272 | ACCEPTED | Protection circuit for electro static discharge | An electro static discharge (ESD) protection circuit employing a field-effect transistor (FET) having no silicide block disposed thereon. It is connected with an internal circuit so as to prevent the internal circuit from the influence of an ESD event, wherein the internal circuit has at least a signal input end. The ESD protection circuit includes: an ESD clamp circuit for providing an ESD grounding path as an ESD occurs; and at least a pair of p-n junction diodes. The p-n junction diodes are stacked so that one of the p-n junction diodes has a n-type end coupled to the signal input end and the other one has a p-type end coupled to the signal input end as well. The ESD clamp circuit has at least a FET, whose drain has no silicide block disposed thereon. | 1. An electro static discharge (ESD) protection circuit, comprising: a pair of p-n junction diodes having a signal input end to receive an input signal of the ESD protection circuit; and an ESD clamp circuit electrically connecting to the pair of p-n junction diodes, the ESD clamp circuit having a transistor, which has a drain without a silicide block disposed thereon; thereby, as an ESD occurs, the ESD clamp circuit providing a grounding path to drain the ESD current so as to prevent a circuit from damage. 2. The protection circuit as claimed in claim 1, wherein the ESD clamp circuit comprises a RC retarder; and an inverter electrically connecting with the RC retarder and the transistor; thereby, as the ESD occurs, the RC retarder controlling the inverter to bias the transistor so as to turn the transistor on to provide the grounding path between the drain and a source of the transistor. 3. The protection circuit as claimed in claim 1, wherein the transistor of the ESD clamp circuit comprises at least a field-effect transistor (FET), which has the drain without the silicide block disposed thereon. 4. The protection circuit as claimed in claim 1 further comprising a first power line and a second power line, which are connected to the drain and a source of the transistor. 5. The protection circuit as claimed in claim 4, wherein one of the first and second power lines is grounded. 6. The protection circuit as claimed in claim 4, wherein the ESD clamp circuit provides the grounding path formed between the first and second power lines. 7. The protection circuit as claimed in claim 1, wherein the ESD clamp circuit further comprises a coupling capacitor, one of its ends is coupled to a gate of the transistor. 8. The protection circuit as claimed in claim 7, as the ESD occurs, a corresponding ESD voltage being induced to bias the gate of the transistor via the coupling capacitor. 9. An ESD protection circuit employing a FET without a silicide block disposed on a drain of the FET, the protection circuit being electrically connected with a internal circuit, the protection circuit comprising: an ESD clamp circuit having the FET and a coupling capacitor, the FET having the drain without the silicide block disposed thereon, one end of the coupling capacitor being coupled to a gate of the FET; and at least a pair of p-n junction diodes forming an input end of the ESD protection circuit and being coupled to the ESD clamp circuit; thereby, as an ESD occurs, the ESD clamp circuit providing a grounding path to drain off a corresponding ESD current. 10. The protection circuit as claimed in claim 9, wherein the ESD clamp circuit comprises; a RC retarder; and an inverter electrically connecting with the RC retarder and the FET; thereby, as the ESD occurs, the RC retarder controlling the inverter to bias the FET so as to turn the FET on to provide the grounding path between the drain and a source of the FET. 11. The protection circuit as claimed in claim 9 further comprising a first power line and a second power line, which are connected to the drain and a source of the transistor. 12. The protection circuit as claimed in claim 11, wherein one of the first and second power lines is grounded. 13. The protection circuit as claimed in claim 11, wherein the ESD clamp circuit provides the grounding path formed between the first and second power lines. | FIELD OF THE INVENTION The present invention is directed to a protection circuit for electro static discharge (ESD), and more particularly, to a protection circuit employing a metal-oxide semiconductor field-effect transistor (MOSFET) having no silicide block disposed on its drain. BACKGROUND OF THE INVENTION In accordance with the prior art, it is well known that ESD is a main factor to cause electronic devices or systems to be damaged by electrical overstress (EOS). ESD may make semiconductor devices and computer systems be damaged permanently, hence it can influence functions of integrated circuits (IC) and make the electronic devices operate abnormally. In most situations, ESD is induced artificially, but it is still hard to avoid this effect. The reason is that the static electricity would accumulate in human bodies, instruments and store equipments during the processes of manufacturing, producing, assembling, storing or moving of the electronic devices and systems. Even the electronic devices would accumulate static electricity itself. In some circumstances, due to contacting the electronic devices with human bodies, instruments and store equipments unknowingly, it may form a path of ESD and make the electronic devices or systems be damaged unexpectedly. In order to prevent the electronic devices from being damaged by the ESD current effectively, the ESD protection circuits used to drain the ESD current away become necessary. Up to now, a lot of technology about used components or manufacturing improvement of the components in the ESD protection circuits has been accumulated for successor' reference. In general, the components of the ESD protection circuits may include reverse-biased diode, bipolar transistor, MOS component and silicon-controlled rectifier (SCR), etc. In these ESD protection circuits, most of them use the components that can operate at first breakdown region to drain out the ESD current. In the first breakdown region, the component of the ESD protection circuits wouldn't be damaged. However, there is still a limit. It is so-called secondary breakdown region. When the components operate at the second breakdown region due to the additional EOS current or voltage, they will be damaged permanently. Further, these components can also be turned on, such as turning on a FET component to form a current grounding path between its source and drain, to make the ESD current be passed to the ground via the current grounding path. In general, the ESD protection circuits are designed according to the human body model (HBM) and machine model (MM). However, as the deep sub-micron techniques became the main stream of the market, the ESD of the charge device model (CDM) can cause the damage of gate oxide very easily when the thickness of the gate oxide is only 50A made by 0.25 micro manufacturing processes. The so-called HBM or MM indicates that the static electricity of external human bodies or machines is passed to internal circuits via pins of IC. Hence, the ESD protection circuits are usually disposed beside the input or output boding pad of the internal circuits directly to drain off the ESD current. On the other hand, the static charges are stored in the substrate of electronic components, when a pin is grounded, these charges will be discharged via the grounded pin. The ESD of CDM can make the gate of input end be punched through very easily. Even if the ESD protection circuit is already applied to the gate of the input end, in most situations, it still cannot be turned on timely to drain off the immediately generated ESD current of CDM. Please refer to FIG. 1, which is a schematic diagram of a conventional ESD protection circuit. The ESD protection circuit 10 includes a primary ESD clamp circuit 12, secondary ESD clamp circuit 14 and resistor 16. The resistor 16 first connects with the secondary ESD clamp circuit 14 in series and then connects with the primary ESD clamp circuit 12 in parallel. The ESD protection circuit 10 is disposed beside the input boding pad 19 to prevent the internal circuit 21 from the influence due to the ESD current 25 induced by the external ESD voltage 23 damages the complementary MOS transistors 18. When ESD of HBM or MM is induced at the input boding pad 19, the external ESD voltage 23 would bias the gates of the complementary MOS transistors 18. Hence, the main function of the secondary ESD clamp circuit 14 is to resist the exceeding ESD voltage 23 so as to prevent the complementary MOS transistors 18 from being damaged by the ESD voltage 23. In general, the secondary ESD clamp circuit 14 is carried out by employing a short-channel NMOS component, which can't bear high ESD voltage 23. Hence, the resistor 16 and the primary ESD clamp circuit 12 should be added to prevent the exceeding ESD current 25 from passing the secondary ESD clamp circuit 14 composed of the NMOS component. The ESD current 25 is mainly drained off by the primary ESD clamp circuit 12, hence the primary ESD clamp circuit 12 should be composed of the components that can bear large current. These components have high turn-on voltage and slow turn-on speed generally, hence the primary ESD clamp circuit 12 should cooperate with the secondary ESD clamp circuit 14 for effectively protecting the gates of the complementary MOS transistors 18. However, the ESD protection circuit 10 is equivalent to a combination of large resistors and capacitors. It has large RC delay time for the input signal and is not suitable for applications with high-frequency signals or current input signals. Please refer to FIG. 2, which is a schematic diagram of another conventional ESD protection circuit. In order to improve the shortcoming of the ESD protection circuit 10 in the applications with high-frequency signals or current input signals, the ESD protection circuit 50 only employs the NMOS transistor 51 for resisting the ESD effect without additional ESD clamp circuit and shout resistor. Hence, the equivalent input resistor of the input end is decreased so that the ESD protection circuit 50 is more suitable than the ESD protection circuit 10 shown in FIG. 1 for the applications with high-frequency signals or current input signals. However, the ESD protection circuit 50 is composed of the NMOS transistor 51, whose gate is grounded, without the shout resistor 16 shown in FIG. 1. Its robustness is avoidably challenged by the ESD current passed through the NMOS transistor 51. When the ESD voltage 54 is induced, the ESD current 58 is first passed to the ESD protection circuit 50 via the input boding pad 56 so that the analog circuit 52 will not be damaged directly. However, as the advanced manufacturing processes, such as light doped drain (LDD) and silicided diffusion processes, are employed, the compact degree of integrated circuits (IC) and the calculation speed are increased, but the ESD resisting ability of the IC (including the internal circuits and ESD protection circuits) is decreased. In order to overcome the problem regarding the decreasing of the ESD resisting ability of the LDD structure, the ESD-implant process is developed. Its method is to make two different kinds of NMOS components in a complementary MOS (CMOS) manufacturing process; one is of the LDD structure used for the internal circuit with the and the other isn't of the LDD structure used for the input/output stage. In order to make these two kinds of components together in the manufacturing process at a time, an additional ESD-implant mask and some additional processing steps are necessary in the original process. Furthermore, due to the NMOS components made by the ESD-implant process is different from the NMOS components with the LDD structure, it needs some additional processes and design to obtain their SPICE parameters to facilitate the simulation and design of circuits. As per the silicided diffusion process, its main objective is to reduce the stray resistances of the drain and source of the MOS component to increase the operation speed of the MOS component for high-frequency applications. Since the stray resistances are very small, as the ESD occurs, the ESD current is easily passed to the LDD structure of the MOS components to damage them. Even if the MOS component with large width/length (W/L) ratio is used as output stage, the ESD resisting ability still can't be improved. In order to increase the ESD resisting ability of the output stage the silicided diffusion blocking process is developed. It removes part of the silicide layer of the output-stage MOS component to make the source and drain resistances of the MOS increased to improve the ESD resisting ability of the MOS component. Please refer to FIGS. 3a and 3b, which are schematic diagrams of MOS components with and without a silicide block respectively according to the prior art. In order to disopose the silicide block, the spacing between the drain and source should be large enough. Although the silicide block is used to increase the resistance between the drain and the ploy gate to restrict the electric current and hence improve the ESD resisting ability of this kind of MOS component, it increases the occupying area of the MOS due to the increase of the spacing between the source and drain. Hence, the number of the MOS components able to be made in a single wafer would be influenced. Further, in the viewpoint of input end, the increase of resistance would increase the RC delay time of the input signal. Hence, this kind of components is not suitable for the inputs with high-frequency signal or current signals. Please refer to FIG. 4, which is a schematic diagram of an ESD protection circuit disclosed in U.S. 2002/0130390. Both of the ESD protection circuit 100 and the internal circuit 102 are at least connected with two power lines 103 and 104. Therein, the power lines 103 and 104 are preferable to be a power supply line and ground line, respectively. The ESD protection circuit 100 includes an ESD restricting circuit 110 disposed between the power lines 103 and 104, which is composed of a CMOS inverter 112 and a RC retarder 113. It can make the ESD current induced by the ESD voltage obtain an ESD path formed by a forward-biased diode pair (D1, 2 or D3, 4) or a substrate-triggered MOS transistor 117 of the ESD restricting circuit 110 disposed between the power lines that is operated at the first breakdown region (or snapback breakdown region). The CMOS inverter 112 is used to trigger the substrate-triggered MOS transistor 117. The gate of the substrate-triggered MOS transistor 117 is connected with the power line 104 via a resistor R2 so that the substrate-triggered MOS transistor 117 is turned off in the situation without ESD. The ESD protection circuit 100 is directly disposed between the input bonding pad 115 and the internal circuit 102 for providing the ESD path. The diodes D1˜4 are equivalent to capacitances Cjn1˜4. They are connected in series so that the total equivalent capacitance is decreased as the number of the diodes increases. In the ESD protection circuit 100 shown in FIG. 4, all of the MOS components in the substrate-triggered MOS transistor 117, CMOS inverter 112 and RC retarder 113 (the capacitor C is carried out by employing a MOS component) has the silicide blocks disposed in their drains as mentioned above. With the silicide blocks, the ESD resisting ability can be improved certainly, but the increased equivalent input resistance would restrict the application of this kind of component in high-frequency field. Further, the occupying area of this kind of MOS components is larger that of the MOS components with silicide block. Hence, the number of the MOS components able to be made in a single wafer would be decreased. Accordingly, as discussed above, the conventional ESD protection circuit still has some drawbacks that could be improved. The present invention aims to resolve the drawbacks in the prior art. SUMMARY OF THE INVENTION A main objective of the present invention is to provide an ESD protection circuit, which employs a FET component having no silicide block. As ESD occurs, an ESD clamp circuit of the ESD protection circuit turns on the FET component to provide an ESD grounding path for draining off the ESD current so as to prevent the internal circuit from damage. The portion of the present invention different from the prior art is that the ESD protection circuit complied with the present invention employs a FET component having no silicide block so that the equivalent resistance between the drain and source can be reduced. Hence, the ESD protection circuit of the present has an equivalent input resistance and capacitance that is suitable for high-frequency input signals or current input signals. Meanwhile, it also can reduce the occupied area of a single FET component. Besides, its ESD resisting ability for HBM or MM is the same as that of the prior art. For reaching the objective above, the present invention provides an ESD protection circuit, including an ESD clamp circuit for providing an ESD grounding path as an ESD occurs, and at least a pair of p-n junction diodes. One of the p-n junction diodes has a n-type end coupled to the signal input end and the other one has a p-type end coupled to the signal input end. The ESD clamp circuit has at least a FET, whose drain has no silicide block disposed thereon. As the ESD occurs, the FET of the ESD clamp circuit used to provide the ESD grounding path is operated at turn-on status. Numerous additional features, benefits and details of the present invention are described in the detailed description, which follows. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a conventional ESD protection circuit. FIG. 2 is a schematic diagram of another conventional ESD protection circuit. FIG. 3a is a schematic diagram of a MOS component without a silicide block according to the prior art. FIG. 3b is a schematic diagram of a MOS component with a silicide block according to the prior art. FIG. 4 is a schematic diagram of an ESD protection circuit disclosed in U.S. 2002/0130390. FIG. 5 shows a schematic diagram of an ESD protection circuit complied with the present invention. DETAILED DESCRIPTION Please refer to FIG. 5, which shows a schematic diagram of an ESD protection circuit complied with the present invention. The ESD protection circuit has an ESD clamp circuit and at least a pair of p-n junction diodes 203 to prevent the internal circuit 205 from damaged by the ESD (mainly in HBM or MM) induced at the signal input end. The ESD clamp circuit 202 includes a CMOS inverter (Mp and Mn) 2022, a RC retarder 2024 (the capacitor C1 is carried out by using a MOS component), a coupling capacitor 2025 (C2) and a FET 2027 (M). Therein, the coupling capacitor C2 is coupled to the FET M. Meanwhile, the drain of the FET M has no silicide block disposed thereon (as shown in FIG. 3a). In the conventional ESD protection circuit, in order to increase the resistance between the drain and source of a FET to restrict the ESD current, the FET must have the silicide block (as shown in FIG. 3b). The ESD protection circuit complied with the present invention has no silicide block and it still can bear 7 kV and 450 kV ESD voltages in HBM and MM, respectively. As the ESD occurs, the CMOS inverter 2022 turns on the FET M to provide a grounding path formed between the drain and source of the FET M for the ESD current. Besides, the coupling capacitor C2 is used to increase the turn-on effect of the FET M. The reason is that the coupling capacitor C2 can couple the ESD voltage appeared on the first power line to the gate of the FET M. The first and second power lines are coupled to the drain and source of the FET M, respectively. Therein, one of the first and second power lines is preferred to be a grounding line. The ESD clamp circuit 202 is located between the first and second power lines for providing an ESD path. One of the p-n junction diodes 203 has a n-type end coupled to the signal input end the other one has a p-type end coupled to the signal input end. Each of the p-n junctions of the diodes 203 is equivalent to a junction capacitor. These two capacitors are connected in series so that the total capacitance is reduced. As the number of the p-n junction diode pairs is increased, the equivalent input capacitance is reduced deservedly. In the present invention, the number of the p-n junction diode pairs is not limited. As the ESD protection circuit 200 is tested complied with the HBM or MM, since the accumulated static electricity at the signal input end can be positive or negative charges, the testing input signal can be positive or negative pulse selectively. Further, one of the first and second power lines also can be grounded selectively. Hence, there are four modes for testing, named PS, NS, PD and HD respectively. Of course, there are various ESD tests between the signal pins (not necessary to be the signal input end) or between the first and second power lines. If there are differential pairs existed in the internal circuit, there are more tests able to be performed. These tests can verify that the ESD protection circuit can form a corresponding ESD grounding path for draining the ESD current to the ground as the real ESD occurs. As no ESD occurs, the p-n junction diodes are reverse biased, but not under breakdown status. Hence, the signals from the input signal end can be passed to the internal circuit. As ESD occurs, the p-n junction diodes are forward biased. The RC retarder 2024 is used to control the CMOS inverter 2022 to make it bias the FET M. The FET M has no silicide block as shown in FIG. 3a. In general, the FET applied for an ESD protection circuit is used to drain the ESD current (it can operate under drain-source turn-on status or reverse breakdown status), hence employing silicide block to increase resistance so as to reduce the current passed through the FET to prevent the FET from damage is a very important technique in the prior art. However, as mentioned above, due to the restriction in size, the number of the components able to be made in a single wafer would be decreased, as the silicide block is disposed in the FET to increase the occupied area of the FET. Comparing with the prior art, the FET for providing an ESD grounding path in the ESD protection circuit of the present invention has not silicide block disposed thereon. Besides, it is operated by turning on the itself to form the ESD grounding path between its drain and source. Without the silicide block, the occupied area of the FET is reduced and the number of the components able to be made in a single wafer would be increased. Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are embraced within the scope of the invention as defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>In accordance with the prior art, it is well known that ESD is a main factor to cause electronic devices or systems to be damaged by electrical overstress (EOS). ESD may make semiconductor devices and computer systems be damaged permanently, hence it can influence functions of integrated circuits (IC) and make the electronic devices operate abnormally. In most situations, ESD is induced artificially, but it is still hard to avoid this effect. The reason is that the static electricity would accumulate in human bodies, instruments and store equipments during the processes of manufacturing, producing, assembling, storing or moving of the electronic devices and systems. Even the electronic devices would accumulate static electricity itself. In some circumstances, due to contacting the electronic devices with human bodies, instruments and store equipments unknowingly, it may form a path of ESD and make the electronic devices or systems be damaged unexpectedly. In order to prevent the electronic devices from being damaged by the ESD current effectively, the ESD protection circuits used to drain the ESD current away become necessary. Up to now, a lot of technology about used components or manufacturing improvement of the components in the ESD protection circuits has been accumulated for successor' reference. In general, the components of the ESD protection circuits may include reverse-biased diode, bipolar transistor, MOS component and silicon-controlled rectifier (SCR), etc. In these ESD protection circuits, most of them use the components that can operate at first breakdown region to drain out the ESD current. In the first breakdown region, the component of the ESD protection circuits wouldn't be damaged. However, there is still a limit. It is so-called secondary breakdown region. When the components operate at the second breakdown region due to the additional EOS current or voltage, they will be damaged permanently. Further, these components can also be turned on, such as turning on a FET component to form a current grounding path between its source and drain, to make the ESD current be passed to the ground via the current grounding path. In general, the ESD protection circuits are designed according to the human body model (HBM) and machine model (MM). However, as the deep sub-micron techniques became the main stream of the market, the ESD of the charge device model (CDM) can cause the damage of gate oxide very easily when the thickness of the gate oxide is only 50A made by 0.25 micro manufacturing processes. The so-called HBM or MM indicates that the static electricity of external human bodies or machines is passed to internal circuits via pins of IC. Hence, the ESD protection circuits are usually disposed beside the input or output boding pad of the internal circuits directly to drain off the ESD current. On the other hand, the static charges are stored in the substrate of electronic components, when a pin is grounded, these charges will be discharged via the grounded pin. The ESD of CDM can make the gate of input end be punched through very easily. Even if the ESD protection circuit is already applied to the gate of the input end, in most situations, it still cannot be turned on timely to drain off the immediately generated ESD current of CDM. Please refer to FIG. 1 , which is a schematic diagram of a conventional ESD protection circuit. The ESD protection circuit 10 includes a primary ESD clamp circuit 12 , secondary ESD clamp circuit 14 and resistor 16 . The resistor 16 first connects with the secondary ESD clamp circuit 14 in series and then connects with the primary ESD clamp circuit 12 in parallel. The ESD protection circuit 10 is disposed beside the input boding pad 19 to prevent the internal circuit 21 from the influence due to the ESD current 25 induced by the external ESD voltage 23 damages the complementary MOS transistors 18 . When ESD of HBM or MM is induced at the input boding pad 19 , the external ESD voltage 23 would bias the gates of the complementary MOS transistors 18 . Hence, the main function of the secondary ESD clamp circuit 14 is to resist the exceeding ESD voltage 23 so as to prevent the complementary MOS transistors 18 from being damaged by the ESD voltage 23 . In general, the secondary ESD clamp circuit 14 is carried out by employing a short-channel NMOS component, which can't bear high ESD voltage 23 . Hence, the resistor 16 and the primary ESD clamp circuit 12 should be added to prevent the exceeding ESD current 25 from passing the secondary ESD clamp circuit 14 composed of the NMOS component. The ESD current 25 is mainly drained off by the primary ESD clamp circuit 12 , hence the primary ESD clamp circuit 12 should be composed of the components that can bear large current. These components have high turn-on voltage and slow turn-on speed generally, hence the primary ESD clamp circuit 12 should cooperate with the secondary ESD clamp circuit 14 for effectively protecting the gates of the complementary MOS transistors 18 . However, the ESD protection circuit 10 is equivalent to a combination of large resistors and capacitors. It has large RC delay time for the input signal and is not suitable for applications with high-frequency signals or current input signals. Please refer to FIG. 2 , which is a schematic diagram of another conventional ESD protection circuit. In order to improve the shortcoming of the ESD protection circuit 10 in the applications with high-frequency signals or current input signals, the ESD protection circuit 50 only employs the NMOS transistor 51 for resisting the ESD effect without additional ESD clamp circuit and shout resistor. Hence, the equivalent input resistor of the input end is decreased so that the ESD protection circuit 50 is more suitable than the ESD protection circuit 10 shown in FIG. 1 for the applications with high-frequency signals or current input signals. However, the ESD protection circuit 50 is composed of the NMOS transistor 51 , whose gate is grounded, without the shout resistor 16 shown in FIG. 1 . Its robustness is avoidably challenged by the ESD current passed through the NMOS transistor 51 . When the ESD voltage 54 is induced, the ESD current 58 is first passed to the ESD protection circuit 50 via the input boding pad 56 so that the analog circuit 52 will not be damaged directly. However, as the advanced manufacturing processes, such as light doped drain (LDD) and silicided diffusion processes, are employed, the compact degree of integrated circuits (IC) and the calculation speed are increased, but the ESD resisting ability of the IC (including the internal circuits and ESD protection circuits) is decreased. In order to overcome the problem regarding the decreasing of the ESD resisting ability of the LDD structure, the ESD-implant process is developed. Its method is to make two different kinds of NMOS components in a complementary MOS (CMOS) manufacturing process; one is of the LDD structure used for the internal circuit with the and the other isn't of the LDD structure used for the input/output stage. In order to make these two kinds of components together in the manufacturing process at a time, an additional ESD-implant mask and some additional processing steps are necessary in the original process. Furthermore, due to the NMOS components made by the ESD-implant process is different from the NMOS components with the LDD structure, it needs some additional processes and design to obtain their SPICE parameters to facilitate the simulation and design of circuits. As per the silicided diffusion process, its main objective is to reduce the stray resistances of the drain and source of the MOS component to increase the operation speed of the MOS component for high-frequency applications. Since the stray resistances are very small, as the ESD occurs, the ESD current is easily passed to the LDD structure of the MOS components to damage them. Even if the MOS component with large width/length (W/L) ratio is used as output stage, the ESD resisting ability still can't be improved. In order to increase the ESD resisting ability of the output stage the silicided diffusion blocking process is developed. It removes part of the silicide layer of the output-stage MOS component to make the source and drain resistances of the MOS increased to improve the ESD resisting ability of the MOS component. Please refer to FIGS. 3 a and 3 b , which are schematic diagrams of MOS components with and without a silicide block respectively according to the prior art. In order to disopose the silicide block, the spacing between the drain and source should be large enough. Although the silicide block is used to increase the resistance between the drain and the ploy gate to restrict the electric current and hence improve the ESD resisting ability of this kind of MOS component, it increases the occupying area of the MOS due to the increase of the spacing between the source and drain. Hence, the number of the MOS components able to be made in a single wafer would be influenced. Further, in the viewpoint of input end, the increase of resistance would increase the RC delay time of the input signal. Hence, this kind of components is not suitable for the inputs with high-frequency signal or current signals. Please refer to FIG. 4 , which is a schematic diagram of an ESD protection circuit disclosed in U.S. 2002/0130390. Both of the ESD protection circuit 100 and the internal circuit 102 are at least connected with two power lines 103 and 104 . Therein, the power lines 103 and 104 are preferable to be a power supply line and ground line, respectively. The ESD protection circuit 100 includes an ESD restricting circuit 110 disposed between the power lines 103 and 104 , which is composed of a CMOS inverter 112 and a RC retarder 113 . It can make the ESD current induced by the ESD voltage obtain an ESD path formed by a forward-biased diode pair (D 1 , 2 or D 3 , 4 ) or a substrate-triggered MOS transistor 117 of the ESD restricting circuit 110 disposed between the power lines that is operated at the first breakdown region (or snapback breakdown region). The CMOS inverter 112 is used to trigger the substrate-triggered MOS transistor 117 . The gate of the substrate-triggered MOS transistor 117 is connected with the power line 104 via a resistor R 2 so that the substrate-triggered MOS transistor 117 is turned off in the situation without ESD. The ESD protection circuit 100 is directly disposed between the input bonding pad 115 and the internal circuit 102 for providing the ESD path. The diodes D 1 ˜ 4 are equivalent to capacitances Cjn 1 ˜ 4 . They are connected in series so that the total equivalent capacitance is decreased as the number of the diodes increases. In the ESD protection circuit 100 shown in FIG. 4 , all of the MOS components in the substrate-triggered MOS transistor 117 , CMOS inverter 112 and RC retarder 113 (the capacitor C is carried out by employing a MOS component) has the silicide blocks disposed in their drains as mentioned above. With the silicide blocks, the ESD resisting ability can be improved certainly, but the increased equivalent input resistance would restrict the application of this kind of component in high-frequency field. Further, the occupying area of this kind of MOS components is larger that of the MOS components with silicide block. Hence, the number of the MOS components able to be made in a single wafer would be decreased. Accordingly, as discussed above, the conventional ESD protection circuit still has some drawbacks that could be improved. The present invention aims to resolve the drawbacks in the prior art. | <SOH> SUMMARY OF THE INVENTION <EOH>A main objective of the present invention is to provide an ESD protection circuit, which employs a FET component having no silicide block. As ESD occurs, an ESD clamp circuit of the ESD protection circuit turns on the FET component to provide an ESD grounding path for draining off the ESD current so as to prevent the internal circuit from damage. The portion of the present invention different from the prior art is that the ESD protection circuit complied with the present invention employs a FET component having no silicide block so that the equivalent resistance between the drain and source can be reduced. Hence, the ESD protection circuit of the present has an equivalent input resistance and capacitance that is suitable for high-frequency input signals or current input signals. Meanwhile, it also can reduce the occupied area of a single FET component. Besides, its ESD resisting ability for HBM or MM is the same as that of the prior art. For reaching the objective above, the present invention provides an ESD protection circuit, including an ESD clamp circuit for providing an ESD grounding path as an ESD occurs, and at least a pair of p-n junction diodes. One of the p-n junction diodes has a n-type end coupled to the signal input end and the other one has a p-type end coupled to the signal input end. The ESD clamp circuit has at least a FET, whose drain has no silicide block disposed thereon. As the ESD occurs, the FET of the ESD clamp circuit used to provide the ESD grounding path is operated at turn-on status. Numerous additional features, benefits and details of the present invention are described in the detailed description, which follows. | 20040505 | 20090512 | 20050120 | 96012.0 | 0 | WILLOUGHBY, TERRENCE RONIQUE | PROTECTION CIRCUIT FOR ELECTRO STATIC DISCHARGE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,838,549 | ACCEPTED | COMPACT BROADBAND ANTENNA | A compact broadband antenna. The antenna includes a first mechanism for receiving input electromagnetic energy. A second mechanism provides radiated electromagnetic energy upon receipt of the input electromagnetic energy. The radiated electromagnetic energy is provided via an antenna element having one or more angled surfaces. A third mechanism directs the radiated electromagnetic energy in a specific direction. In a more specific embodiment, the third mechanism includes a reflective backstop that is selectively positioned behind the second mechanism to reflect back-radiated energy forward of the second mechanism, thereby causing reflected electromagnetic energy to combine in phase with forward-radiated energy from the second mechanism. The third mechanism further includes plural layers of dielectric material. One or more of the plural layers of dielectric material partially surround an angled radiating surface of the second mechanism, which is implemented via a substantially conical transmit element in the specific embodiment. | 1. A compact broadband antenna comprising: first means for receiving input electromagnetic energy; second means for providing radiated electromagnetic energy upon receipt of said input electromagnetic energy, said radiated electromagnetic energy provided via a conical antenna element; and third means for directing said radiated electromagnetic energy in a specific direction, said third means including a back-reflector selectively positioned behind said second means whereby a longitudinal axis of said antenna element is approximately parallel to said back-reflector to reflect back-radiated energy forward of said second means, thereby causing reflected electromagnetic energy to combine in phase with forward-radiated energy from said second means. 2. (canceled) 3. The system of claim 1 wherein said third means further includes plural layers of dielectric material. 4. The system of claim 3 wherein one or more of said plural layers of dielectric material partially surround an angled radiating surface of said second means. 5-6. (canceled) 7. The system of claim 1 wherein said conical antenna element is supported by and partially surrounded by a first layer of dielectric material. 8. The system of claim 7 wherein a top portion of said conical antenna element lacks dielectric material. 9. The system of claim 7 wherein said first layer of dielectric material includes one or more beveled surfaces. 10. The system of claim 7 wherein said first means includes an antenna feed having an input stripline transmission line that is coupled to a coaxial feed transmission line or wire, which is coupled to a vertex of said conical antenna element. 11. The system of claim 10 wherein said stripline transmission line includes a center conductor having a tapered section. 12. The system of claim 11 wherein said stripline transmission line includes dielectric material between a top ground plane and a bottom ground plane, said dielectric material accommodating a stripline center conductor. 13. The system of claim 12 wherein said dielectric material between said top ground plane and said bottom ground plane include antenna tuning holes therethrough. 14. The system of claim 13 wherein said antenna tuning holes partially surround a transition between said stripline center conductor and said coaxial feed transmission line or wire. 15. The system of claim 12 further including a second dielectric layer between said top ground plane and said first dielectric layer. 16. The system of claim 10 further including a mounting system upon which said antenna is mounted, said mounting system having a longitudinal axis that is approximately parallel to radiation transmitted by said antenna. 17. The system of claim 1 wherein said back-reflector is positioned relative to said conical element to produce a directional beam. 18. A compact broadband antenna comprising: an antenna feed; a substantially conical antenna element in communication with said antenna feed; one or more layered dielectrics supporting said conical antenna element and accommodating said antenna feed; and a back-reflector having a reflecting surface positioned approximately parallel to a longitudinal axis of said conical antenna element and facing forward of said antenna. 19. (canceled) 20. The system of claim 18 wherein said one or more layered dielectrics include one or more antenna-tuning holes therethrough. 21. The system of claim 20 wherein said antenna feed includes a coaxial feed transmission line that connects to a vertex of said conical antenna element. 22. The system of claim 21 wherein said antenna feed includes a stripline transmission line supported by one or more of said layered dielectrics, said stripline transmission line connected between an input transmission line and said coaxial feed transmission line. 23. A compact directional antenna comprising: a conical antenna element having longitudinal axis; an antenna feed section connected to a feed end of said antenna element; a structure positioned relative to said antenna element, said structure facilitating directing a transmit beam in a direction having a component perpendicular to said longitudinal axis in response to a feed signal input to said antenna feed section; and a back-reflector having a surface that is approximately parallel to said longitudinal axis of said antenna element. 24 (canceled) 25. The system of claim 23 wherein said antenna element has a diameter that increases in diameter from a feed end of said antenna element to an open end of said antenna element. 26. The system of claim 25 wherein said antenna element is approximately symmetric about said longitudinal axis. 27. The system of claim 25 wherein said antenna element includes conductive walls that are supported by dielectric material. 28. The system of claim 27 wherein said back-reflector is supported by said dielectric material. 29. The system of claim 28 wherein said dielectric material includes a blend of layered dielectrics sufficient to facilitate antenna tuning within a desired band and to facilitate directing said beam in desired direction. 30. The system of claim 28 wherein said antenna element includes a solid conical structure. 31. The system of claim 30 wherein said solid conical structure includes copper. 32. The system of claim 28 wherein said antenna element includes a hollow conical structure having said feed end near a vertex of said hollow conical structure and said open end at an opposite end of said hollow conical structure. 33. The system of claim 32 wherein said conical structure includes nickel-plated and/or copper surfaces. 34. The system of claim 32 wherein said back-reflector includes nickel-plated and/or copper surfaces. 35. The system of claim 32 wherein said antenna feed includes a coaxial-to-stripline transition positioned on a first feed layer. 36. The system of claim 35 further including one or more additional layers positioned on top of said first feed layer, said one or more additional layers having one or more holes therein sufficient to couple electromagnetic energy from a stripline to said antenna element. 37. The system of claim 36 wherein said one or more additional layers include one or more dielectric layers. 38. The system of claim 37 further including a mounting system upon which said antenna is mounted, said antenna mounted so that a beveled output facet of said antenna forward toward a nose of said mounting system and approximately parallel to a longitudinal axis of said mounting system. 39. A method for radiating electromagnetic energy comprising the steps of: receiving input electromagnetic energy; providing radiated electromagnetic energy upon receipt of said input electromagnetic energy, said radiated electromagnetic energy provided via a unitary antenna element having a diameter that increases from a feed end to an open end thereof; and directing said radiated electromagnetic energy in a predetermined direction with a back-reflector having a reflecting surface position approximately parallel to a longitudinal axis of said antenna element and facing forward relative thereto. 40. A compact broadband antenna comprising: first means for receiving input electromagnetic energy; second means for providing radiated electromagnetic energy upon receipt of said input electromagnetic energy, said radiated electromagnetic energy provided via a unitary antenna element having a diameter that increases from a feed end to an open end thereof; third means for directing said radiated electromagnetic energy in a specific direction said third means including a back-reflector mounted to reflect energy radiated from said antenna element in a direction normal to a longitudinal axis thereof. 41-42. (canceled) 43. The invention of claim 40 wherein said antenna element is conical. 44-46. (canceled) 47. The invention of claim 40 wherein said antenna element is hollow. | This invention was made with Government support under Contract No. N00024-96-C-5204 ERGM. The Government may have certain rights in this invention. BACKGROUND OF THE INVENTION 1. Field of Invention: This invention relates to antennas. Specifically, the present invention relates to systems and methods for selectively directing or receiving a beam of energy. 2. Description of the Related Art: Systems for directing beams of energy are employed in various demanding applications including microwave, radar, ladar, laser, infrared, and sonar sensing and targeting systems. Such applications demand space-efficient and cost-effective receivers and antennas with sufficient gain and bandwidth characteristics for optimal sensing. Efficient and accurate systems for directing electromagnetic energy are particularly important in projected munition guidance and fusing applications, where collateral damage must be avoided. Smart munitions, such as a smart artillery shells, often incorporate electronics and accompanying fuses to time munition detonation. Such electronics may include sensors for detecting target location and selectively triggering detonation when the munition is within a predetermined range of the target. The sensors may include directional antennas, often called end-fire antennas, which aim beams of electromagnetic energy forward of the projected munitions. The directed beams may reflect from targets, yielding return beams. Sensors may detect and time target return beams to determine target range and closing rate. Unfortunately, various conventional antennas, such as doorstop, patch, and monopole antennas have various shortcomings, making their use in projected munition applications problematic. Doorstop antennas are often too large to efficiently incorporate into compact munition designs. Patch antennas often insufficiently direct electromagnetic energy and exhibit undesirable bandwidth constraints. Monopole antennas often lack sufficient gain or bandwidth characteristics. Hence, a need exists in the art for a compact and efficient antenna that exhibits excellent beam-directing, bandwidth, and gain characteristics and that is suitable for munitions applications. SUMMARY OF THE INVENTION The need in the art is addressed by the compact broadband antenna of the present invention. In the illustrative embodiment, the antenna is an end-fire antenna adapted for use in munitions applications. The antenna includes a first mechanism for receiving input electromagnetic energy. A second mechanism provides radiated electromagnetic energy upon receipt of the input electromagnetic energy. The radiated electromagnetic energy is provided via an antenna element having one or more angled surfaces. A third mechanism directs the radiated electromagnetic energy in a specific direction. In a more specific embodiment, the third mechanism includes a reflective backstop that is strategically positioned behind the second mechanism to reflect back-radiated energy forward of the second mechanism, thereby causing reflected electromagnetic energy to combine in phase with forward-radiated energy from the second mechanism. The third mechanism further includes plural layers of dielectric material. One or more of the plural layers of dielectric material partially surround an angled radiating surface of the second mechanism. In the specific embodiment, the second mechanism includes a conical antenna element. The longitudinal axis of the antenna element is approximately parallel to the surface of the back-reflector. The conical antenna element is supported by and partially surrounded by first a layer of dielectric material. A top portion of the conical antenna element lacks dielectric material. The first mechanism includes an antenna feed having an input stripline transmission line that is coupled to a coaxial feed transmission line or wire, which is coupled to a vertex of the conical antenna element. The stripline transmission line includes a center conductor having a tapered section. A dielectric material having mode-suppression holes therethrough, is positioned between a top ground plane and a bottom ground plane, which have corresponding antenna tuning holes, of the stripline transmission line. The dielectric material accommodates a stripline center conductor. A second dielectric layer is positioned between the top ground plane and the first dielectric layer. The novel design of the present invention is facilitated by the second and third mechanisms, which enable a compact, high-gain, antenna with broadband performance. An embodiment of the present invention, wherein the second mechanism includes a substantially conical transmit element, and the third mechanism includes a back-reflector, is particularly efficient for end-fire applications that must withstand significant acceleration and thermal loads. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a compact broadband antenna according to an embodiment of the present invention. FIG. 2 is a more detailed exploded view of the compact broadband antenna of FIG. 1. FIG. 3 is an exploded cross-sectional view of the compact broadband antenna of FIG. 2. FIG. 4 shows the bottom stripline groundplane surface of the first layer section of the compact broadband antenna of FIG. 2. FIG. 5 shows the top surface of the first layer section of the compact broadband antenna of FIG. 2. FIG. 6 shows the bottom surface of the third layer section of the compact broadband antenna of FIG. 2. FIG. 7 shows the top stripline groundplane surface of the third layer section of the compact broadband antenna of FIG. 2. FIG. 8 is a diagram of an exemplary mounting system adapted for use with the compact broadband antenna of FIG. 2. DESCRIPTION OF THE INVENTION While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility. FIG. 1 is a diagram of a compact broadband antenna 10 according to an embodiment of the present invention. For clarity, various features, such as power supplies, frequency generators, network analyzers, and so on, have been omitted from the figures. However, those skilled in the art with access to the present teachings will know which components and features to implement and how to implement them to meet the needs of a given application. The compact broadband antenna 10 includes a input coaxial connector 12 that is connected to base layer sections 14 via connector pins 60, which include a coaxial-to-stripline center conductor transition 16 to a stripline center conductor 18. The base layer sections 14 accommodate a stripline transmission line having the center conductor 18. The stripline transmission line center conductor 18 is coupled to a coaxial feed transmission line, 22, which together form a feed network 20. The coaxial feed transmission line 22 is coupled to a vertex 24 of a conical antenna element 26, which is strategically positioned adjacent to a back-reflector 28. The antenna element 26 has selectively angled sidewalls 27, which provide an efficient radiating surface. The feed network 20, conical antenna element 26, and back-reflector 28 are supported by various layer sections 30, which include support layers, bond layers, and dielectric layers, including a top chamfered dielectric 32, and the base layer sections 14, as discussed more fully below. Those skilled in the art will appreciate that while the conical antenna element 26 is employed as a radiating element in the present embodiment, the element 26 may act as a receiving element and/or a transmitting element, depending on the application. In the present specific embodiment, the conical antenna element 26 is oriented relative to the back-reflector 28 and the various layer sections 30 so that a longitudinal axis 34 of the conical antenna element 26 is approximately perpendicular to the various layer sections 30 and parallel to the surface of the back-reflector 28. The top chamfered dielectric 32 includes various facets 36-42 including a right facet 36, a left facet 38, an output facet 40, and the top facet 42. The various facets 36-42 enhance the compact form factor of the broadband antenna 10 and may facilitate beam shaping. Beam shaping, mode selection, and broadband performance are further facilitated by strategic selection of layer sections 30, including dielectric layer sections, as discussed more fully below. Beam mode selection is also facilitated by features of the feed network 20, including mode-suppression holes 44, which are positioned through the layer sections 30 and strategically placed about the coaxial feed transmission line 22 that feeds the conical antenna element 26. In the present specific embodiment, the through holes 44 are separated by approximately 30° of angular separation. The mode-suppression holes 44 may facilitate tuning the antenna 10 so that the resulting radiation pattern includes a lobe that extends forward in the direction of a beam 46. Additional mounting holes 48 are positioned in the base layer sections 14 to facilitate mounting the antenna 10. The mounting holes 48 are positioned to minimize their effect on the output beam 46. Those skilled in the art will appreciate that the exact dimensions and angles of the facets 36-42 are application-specific and may be determined by those skilled in the art to meet the needs of a given application without undue experimentation. Furthermore, the facets 36-42 may be vertical facets without departing from the scope of the present invention. In the present embodiment, the side facets 36, 38 are beveled at approximately 22.4°, while front facet is angled approximately 10.4° relative to the top surface 42. In operation, electromagnetic energy of a desired frequency is input to the stripline transmission line formed by the center conductor 18 via the input coaxial connector 12. Input electromagnetic energy propagates along the stripline center conductor 18 between groundplanes formed via the layers 14 and then couples to the coaxial feed transmission line 22. The energy then propagates from the coaxial feed transmission line 22 to the conical antenna element 26. As the input electromagnetic energy propagates through the feed network 20 and to the conical antenna element 26, various features, such as the mode-suppression holes 44, and dielectric constants of the layer sections 30 facilitate tuning of the electromagnetic energy in preparation for transmission from the conical antenna element 26. When the electromagnetic energy reaches the conical antenna element 26, the energy radiates from the angled surface 27, which is angled approximately 27° relative to the longitudinal axis 34 in the present embodiment. Partially due to the back-reflector 28 and the beam-shaping effects of the layered sections 30, including the top chamfered dielectric section 32, most energy will radiate forward from the output facet 40, forming a directional output beam 46. The output beam 46 propagates in a direction that is approximately perpendicular to the longitudinal axis 34 of the conical antenna element 34. By strategically positioning the back-reflector 28 relative to conical antenna element 26 and by selecting appropriate element 26 and reflector 28 dimensions for a particular application and input frequency, additional gain is achieved. Appropriate use of the back-reflector 28 may result in gains of 5 dBi or greater, as energy propagating backward from the conical antenna element 26 is reflected forward, combining in phase with energy 46 radiating forward from the conical antenna element 26. The peak of the resulting beam 46 is forward of the compact broadband antenna 10. In the present specific embodiment, the back-reflector 28 is formed from a flat plate of nickel and/or copper or is painted or plated with a silver layer. The back-reflector 28 is cut so that edges of the back-reflector 28 align with the right chamfered facet 36 and the left chamfered facet 38 of the top dielectric layer 32. The back-reflector 28 may be another shape other than flat without departing from the scope of the present invention. For example, the back-reflector 28 may be curved, such as parabolic-shaped and oriented so that the parabola opens in the direction of the conical antenna element 26 to facilitate focusing electromagnetic energy forward of the antenna 10. The conical antenna element 26 is substantially hollow or solid and may be constructed via well-known lithographic techniques. For example, a conic depression may be formed in the layers 30 and then plated with nickel or painted with a silver metallic conductive paint. Alternatively, the conical antenna element 26 is solid, such as solid copper. The conical antenna element 26 may be another shape. For example, the element 26 may have parabolic or trapezoidal vertical cross-section or a multi-faceted horizontal cross-section, without departing from the scope of the present invention. Use of a cone or other appropriate antenna element that increases in diameter from the input end 24 to a top surface 42 as a primary radiation source may provide greater bandwidth than conventional antennas used to create directional beams. In some implementations, the coaxial feed transmission line 22 may be omitted, and instead, the conical antenna element 26 may directly couple to the stripline center conductor 18, without departing from the scope of the present invention. Furthermore, various features of the feed network 20, including the stripline 18, the input coaxial connector 12, and mode-suppression holes 44 are application-specific and may be modified, omitted, or replaced by other types of feed networks to meet the needs of a given application without departing from the scope of the present invention. Electric fields radiate radially outward from the center conductor 56 and terminate on the mode-suppression holes 44, which occurs when current is flowing up the center conductor 56. However, this only occurs where mode-suppression holes 44 are present in layers. As the fields reach layers 62-70 and 32, the electric fields begin to expand into the dielectric regions (see layer 32) and are shaped by those dielectrics and by bouncing off the plated back wall 28 of the top chamfered dielectric section 32 until they collimate and exit the antenna 10 as the beam 46. Furthermore, in the present embodiment, the mode-suppression holes 44 are spaced such that gaps between them are much smaller than 1/10 of a wavelength. While transmit operations of the broadband antenna 10 are discussed with reference to FIG. 1, those skilled in the art will appreciate that the broadband antenna 10 may also be employed for receive functions. FIG. 2 is a more detailed exploded view of the compact broadband antenna 10 of FIG. 1. The base layer sections 14 include a first layer section 50, a second layer section 52, and a third layer section 54. The first layer section 50 accommodates the stripline transmission line center conductor 18. The first layer section 50 includes a groundplane disposed on a bottom surface and the metallic stripline center conductor 18 disposed on a top surface 76 and supported by core dielectric material, as discussed more fully below. In the present specific embodiment, the core dielectric material is Rogers 3003 dielectric. The mode-suppression holes 44 have plated walls, i.e., they are plated through-holes that extend through the first layer section 50 and are strategically placed about a center coaxial feed conductor 56, which terminates one end of the stripline transmission line center conductor 18. Another end of the stripline transmission line center conductor 18 terminates at coaxial connector holes 58. The coaxial connector holes 58 are designed to accommodate the input coaxial connector 12 and accompanying pins 60 so that energy from the coaxial connector 12 will efficiently couple to the stripline transmission line formed via the center conductor 18 and accompanying ground planes, as discussed more fully below. The second layer section 52 acts as a bond layer and facilitates bonding the first layer section 50 to the third layer section 54. The second layer section 52 may be constructed from Dupont Bond Film (Part No. FEP 200 C-20). The second layer section 52 also includes the strategically placed through holes 44, which align with the corresponding through holes 44 in the first layer section 44 and the third layer section 54. The various base layer sections 14 (50-54) have coaxial connector holes 58, some of which are plated and some of which are not plated. Those skilled in the art will know which of the coaxial connector holes 58 to plate and which holes to leave clear without undue experimentation. Furthermore, the exact dimensions of the various antenna features, including mode-suppression holes 44, the thickness of the various layers 30, and so on, are application-specific and may be determined by one skilled in the art to meet the needs of a given application without undue experimentation. The third layer section 54 includes a metallic groundplane top surface 78 and a bottom surface 92, which are supported by a dielectric core, as discussed more fully below. In the present specific embodiment, the dielectric core is Rogers 3003 dielectric, and the groundplane 78 is implemented via Rogers ElectroDeposited Copper (EDC) foil with nickel plating. A fourth layer 62 acts as a bond layer between the third layer 54 and a fifth layer 64. The fifth layer 64 is a strategically-place dielectric layer that facilitates antenna tuning and associated broadband antenna performance and beam shaping. In the present specific embodiment, the fifth layer 64 is implemented via Rogers 3006 unclad dielectric. The fifth layer 64 is unclad, lacking any plating on top or bottom surfaces of the layer 64. A sixth layer 66 acts as a bond layer and is positioned atop the fifth layer 64 and beneath a seventh layer 68. The bond layer 66 may be constructed from Rogers 3001 bond film. The seventh layer 68 is a second special dielectric layer that facilitates antenna tuning and associated broadband antenna performance. The seventh layer 68 may also be constructed from unclad Rogers 3006 dielectric. An eighth layer 70 acts as a bond layer and is positioned atop the seventh dielectric layer 68 and beneath the top chamfered dielectric 32. The eighth layer 70 may be implemented via Rogers 3001 bond film. The ninth layer, corresponding to the top chamfered dielectric 32, is implemented via Rogers TMM4 unclad dielectric in the present specific embodiment. A tenth layer 71 acts as a stiffening structure and is positioned atop the fifth layer 64 and adjacent to the seventh layer 68 and the tenth layer 71. The stiffening tenth layer 71 may be constructed of aluminum or various materials known in the art. Additional stiffening layers may be added or removed from the antenna 10 without departing from the scope of the present invention. In the present specific embodiment, an electrically conductive adhesive 72, such as Ablebond™, is employed to secure the conic antenna element 26 in a conical hole 74 in the top chamfered dielectric 32. The conical antenna element 26 is shown connected to the coaxial feed transmission line center conductor 56. The coaxial feed transmission line center conductor 56 and the conical antenna element 26 may be implemented as one piece, wherein the center conductor 56 of the coaxial feed transmission line is bonded to an input end, i.e., vertex end 24 of the conical antenna element 72. The coaxial feed transmission line center conductor 56 extends through the various layers 30 and couples to the stripline transmission line center conductor 18 at the center coaxial feed transmission line conductor 56 in the first layer 50. The mode suppression holes 44 only extend through the base layer sections 14. FIG. 3 is an exploded cross-sectional view of the compact broadband antenna 10 of FIG. 2. The first layer section 50 includes a first stripline groundplane surface 90 and a top center stripline conductor surface 76. The first stripline groundplane surface 90 is constructed from a metal, such as nickel-plated copper. The top center stripline conductor surface 76 is primarily dielectric material, but includes the conductive stripline center conductor 18 of FIG. 2, which may be made from copper. The stripline surfaces 76, 90 are supported by a dielectric core, which may be constructed from Rogers 3003 dielectric. The third layer section 54 includes the conductive groundplane surface 78, which is implemented via nickel-plated copper in the present embodiment. The ground plane surface 78 is formed on a dielectric core, which also provides the bottom surface 92 of the third layer section 54. The fifth layer 64, seventh layer 66, and the ninth chamfered dielectric layer 32, which are separated by bonding layers 66, 70, represent layered dielectrics that facilitate beam-shaping and antenna tuning. Layer thickness and dielectric constants may be adjusted by those skilled in the art to meet the needs of a given application without undue experimentation. In the present specific embodiment, the fifth layer section 64 and the seventh layer section 68 are approximately 0.025 inches thick. The chamfered dielectric layer 32 is approximately 0.26 inches thick. The longitudinal axis 34, which corresponds to the centerline of the radiating element 2, is positioned approximately 0.2 inches from the metallic back-reflector 28. The conical hole 74, which accommodates the adhesive 72 and conical antenna element 26 has sidewalls that are angled approximately 27° relative to the longitudinal axis 34 of the antenna element 26. In the present embodiment, the groundplanes 90, 78 are at least 0.0015 inches thick copper with a nickel overplate that is that is approximately 150 microinches thick. The various transmission line feed holes that accommodate the center conductor 56 and outer conductor 82 may include padding or dielectric to facilitate accommodating the coaxial feed transmission line (see 22 of FIG. 1) formed by the outer conductor 82 and center conductor 56. The exact type of padding or dielectric is application-specific and may be omitted without departing from the scope of the present invention. FIG. 4 shows the bottom stripline groundplane surface 90 of the first layer section 50 of the compact broadband antenna 10 of FIG. 2. The bottom groundplane surface 90 includes the plated mode-suppression holes 44, which are partially distributed about the center coaxial feed section 22, which shows a cross-section of the inner coaxial feed conductor 56 that passes through the outer coaxial feed conductor, which is implemented via the groundplane 90. The bottom groundplane surface 90 also includes coaxial connector holes 58 for accommodating a standard coaxial cable connector and accompanying pins 60, which may be implemented via a Coming GPO RF connector, part No. A008-L35-02. The coaxial connector holes 58 include a center hole 86 that accommodates a center conductor of the input coaxial connector 12 of FIGS. 1 and 2. In the present embodiment, the groundplane surface 90 is implemented via 0.0015 inch thick copper that is overplated with nickel that is at least 150 microinches thick. FIG. 5 shows the top surface 76 of the first layer section 50 of the compact broadband antenna 10 of FIG. 2. The top surface 76 includes the stripline center conductor 18 that connects to a center coaxial cable connector (see center pin of pins 60 of FIG. 1) at the center coaxial connector hole 86 at the coaxial-to-stripline center conductor transition 16. The stripline center conductor 18 connects to the center conductor 56 of the coaxial feed transmission line 22 at a stripline-to-coaxial center conductor transition 84. The stripline center conductor 18 includes a first leg 94 that connects to a telescoping leg 96 at a ninety-degree bend 98 having a forty-five degree bevel 100. The telescoping leg 96 includes a wider section 102 that extends into a narrower section 104. In the present specific embodiment, the first leg 94 and the wider section 102 of the telescoping leg 96 are approximately 0.026 inches wide, while the narrower section 104 is approximately 0.021 inches wide. The telescoping section 96 facilitates antenna tuning. FIG. 6 shows the bottom surface 92 of the third layer section 54 of the compact broadband antenna 10 of FIG. 2. The bottom surface 92 includes the metal-walled mode-suppression holes 44 and the coaxial feed transmission line section 22 with the inner conductor 56. The surface 92 also accommodates the coaxial connector 58. FIG. 7 shows the top groundplane surface 78 of the third layer section 54 of the compact broadband antenna 10 of FIG. 2. The coaxial connector holes 58 and the mode-suppression holes 44 terminate at the top groundplane surface 78. The coaxial feed section 22 extends through the surface 78 to the top chamfered dielectric 32 of FIG. 2, where it terminates. The center conductor 56 extends partially into the conical antenna element 26 or is bonded to the vertex of the conical antenna element 26 in implementations wherein the conical antenna element 26 is solid or is substantially hollow. FIG. 8 is a diagram of an exemplary mounting system 110 adapted for use with the compact broadband antenna 10 of FIG. 2. The antenna 10 is mounted to a surface of the mounting system 110 and oriented so that energy 46 from the antenna 10 emanates forward and approximately parallel to a system longitudinal axis 112. The mounting system 110 may also accommodate other antennas, such as a Global Positioning System (GPS) antenna 104. The mounting system 110 represents the front end of a projected munition with its radome cover removed. In various embodiments disclosed herein, Rogers materials were selected for their ability to withstand temperature without losing thermal stability, hence alleviating concerns that the antenna would expand unduly with heat and thereby de-tune the antenna. The effects of G-forces are further alleviated with the aluminum stiffeners (see 71 of FIG. 2). Those skilled in the art will appreciate that the antenna 10 of FIGS. 1 and 2 may be caused to operate at a lower or higher frequency by scaling all components in size while maintaining component aspect ratios. Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications, and embodiments within the scope thereof. It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention. Accordingly, | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention: This invention relates to antennas. Specifically, the present invention relates to systems and methods for selectively directing or receiving a beam of energy. 2. Description of the Related Art: Systems for directing beams of energy are employed in various demanding applications including microwave, radar, ladar, laser, infrared, and sonar sensing and targeting systems. Such applications demand space-efficient and cost-effective receivers and antennas with sufficient gain and bandwidth characteristics for optimal sensing. Efficient and accurate systems for directing electromagnetic energy are particularly important in projected munition guidance and fusing applications, where collateral damage must be avoided. Smart munitions, such as a smart artillery shells, often incorporate electronics and accompanying fuses to time munition detonation. Such electronics may include sensors for detecting target location and selectively triggering detonation when the munition is within a predetermined range of the target. The sensors may include directional antennas, often called end-fire antennas, which aim beams of electromagnetic energy forward of the projected munitions. The directed beams may reflect from targets, yielding return beams. Sensors may detect and time target return beams to determine target range and closing rate. Unfortunately, various conventional antennas, such as doorstop, patch, and monopole antennas have various shortcomings, making their use in projected munition applications problematic. Doorstop antennas are often too large to efficiently incorporate into compact munition designs. Patch antennas often insufficiently direct electromagnetic energy and exhibit undesirable bandwidth constraints. Monopole antennas often lack sufficient gain or bandwidth characteristics. Hence, a need exists in the art for a compact and efficient antenna that exhibits excellent beam-directing, bandwidth, and gain characteristics and that is suitable for munitions applications. | <SOH> SUMMARY OF THE INVENTION <EOH>The need in the art is addressed by the compact broadband antenna of the present invention. In the illustrative embodiment, the antenna is an end-fire antenna adapted for use in munitions applications. The antenna includes a first mechanism for receiving input electromagnetic energy. A second mechanism provides radiated electromagnetic energy upon receipt of the input electromagnetic energy. The radiated electromagnetic energy is provided via an antenna element having one or more angled surfaces. A third mechanism directs the radiated electromagnetic energy in a specific direction. In a more specific embodiment, the third mechanism includes a reflective backstop that is strategically positioned behind the second mechanism to reflect back-radiated energy forward of the second mechanism, thereby causing reflected electromagnetic energy to combine in phase with forward-radiated energy from the second mechanism. The third mechanism further includes plural layers of dielectric material. One or more of the plural layers of dielectric material partially surround an angled radiating surface of the second mechanism. In the specific embodiment, the second mechanism includes a conical antenna element. The longitudinal axis of the antenna element is approximately parallel to the surface of the back-reflector. The conical antenna element is supported by and partially surrounded by first a layer of dielectric material. A top portion of the conical antenna element lacks dielectric material. The first mechanism includes an antenna feed having an input stripline transmission line that is coupled to a coaxial feed transmission line or wire, which is coupled to a vertex of the conical antenna element. The stripline transmission line includes a center conductor having a tapered section. A dielectric material having mode-suppression holes therethrough, is positioned between a top ground plane and a bottom ground plane, which have corresponding antenna tuning holes, of the stripline transmission line. The dielectric material accommodates a stripline center conductor. A second dielectric layer is positioned between the top ground plane and the first dielectric layer. The novel design of the present invention is facilitated by the second and third mechanisms, which enable a compact, high-gain, antenna with broadband performance. An embodiment of the present invention, wherein the second mechanism includes a substantially conical transmit element, and the third mechanism includes a back-reflector, is particularly efficient for end-fire applications that must withstand significant acceleration and thermal loads. | 20040504 | 20071016 | 20070816 | 59493.0 | H01Q1300 | 0 | CHEN, SHIH CHAO | COMPACT BROADBAND ANTENNA | UNDISCOUNTED | 0 | ACCEPTED | H01Q | 2,004 |
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10,838,868 | ACCEPTED | Associating a wireless station with an access point | A station associates with an access point in a wireless local area network conforming to, e.g., an IEEE 802.11 standard. The station measures the signal-to-noise ratio (SNR) for the downlink from each of the access points sending either a beacon or a probe response, and forms a first list of access points in decreasing order of received downlink SNR. The station transmits a link test request to each access point to query the access point for the SNR of the link test request received at the corresponding access point. Access points respond to the link test request with corresponding link test responses containing the corresponding SNR. The station i) forms a second list of access points in decreasing order of received uplink SNR and ii) compares the first and second lists to determine which access point to associate with based on overall quality of the uplink and downlink channels. | 1. A method of associating a station to one of a plurality of access points in a wireless local area network (WLAN), the method comprising the steps of: (a) measuring a downlink signal quality of a message received in a signal from each of one or more access points; (b) transmitting a test link request to each of the one or more access points; (c) receiving a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; (d) comparing the corresponding uplink and downlink signal qualities of the one or more access points; and (e) selecting the one of the plurality of access points based on the comparison of step (e). 2. The invention as recited in claim 1, wherein the method further comprises the step of transmitting, when in an active mode, a probe request, and, for step (a), the message in the signal from the one or more access points is a probe response. 3. The invention as recited in claim 1, wherein the method further comprises the step of detecting, when in a passive mode, a beacon, and, for step (a), the message in the signal from the one or more access points is the beacon. 4. The invention as recited in claim 1, wherein, for step (a), each message conforms to a MAC layer frame format in accordance with one or more versions of an Institute of Electrical Engineers (IEEE) 802.11 standard for telecommunications and information exchange between systems. 5. The invention as recited in claim 4, wherein, for steps (c) and (d), the link test request and the link test response conform to the MAC layer frame format in accordance with one or more editions of the IEEE 802.11 standard. 6. The invention as recited in claim 1, wherein, for steps (b) and (d), the measured signal quality is one or more of a signal-to-noise ratio (SNR), a bit-error rate (BER), a power level, and a burst error rate. 7. The invention as recited in claim 1, wherein the method is embodied as processing steps in a processor of an integrated circuit. 8. The invention as recited in claim 1, wherein the method is embodied as processing steps in a processor of a station operating in accordance with one or more editions of an Institute of Electrical Engineers (IEEE) 802.11 standard for telecommunications and information exchange between systems. 9. A method of associating a station to one of a plurality of access points in a wireless local area network (WLAN), the method comprising the steps of: (a) transmitting a test link request to each of the one or more access points; (b) receiving a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; (c) measuring a downlink signal quality of the corresponding access point for each test link response; (d) comparing the corresponding uplink and downlink signal qualities of the one or more access points; and (e) selecting the one of the plurality of access points based on the comparison of step (e). 10. A method of associating a station to one of a plurality of access points in a wireless local area network (WLAN), the method comprising the steps of: (a) receiving, by an access point, a test link request from the station; (b) measuring an uplink signal quality of the corresponding station for the test link request; and (c) forming a test link response for the test link request, the test link response including the uplink signal quality to the corresponding access point. 11. The invention as recited in claim 10, wherein the method further includes the step of (d) transmitting the test link response to the station. 12. Apparatus for associating a station to one of a plurality of access points in a wireless local area network (WLAN), the apparatus comprising: a detector adapted to measure a downlink signal quality of a message received in a signal from each of one or more access points; a transmitter adapted to transmit a test link request to each of the one or more access points; a receiver adapted to receive a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; a comparator adapted to compare the corresponding uplink and downlink signal qualities of the one or more access points; and a selector adapted to select the one of the plurality of access points based on the comparison of the corresponding uplink and downlink signal qualities of the one or more access points. 13. The invention as recited in claim 12, wherein the apparatus further comprises a transmitter adapted to transmit, when in an active mode, a probe request, and the message in the signal from the one or more access points is a probe response. 14. The invention as recited in claim 12, wherein the apparatus further comprises a detector adapted to detect, when in a passive mode, a beacon, and the message in the signal from the one or more access points is the beacon. 15. The invention as recited in claim 12, wherein each message conforms to a MAC layer frame format in accordance with one or more versions of an Institute of Electrical Engineers (IEEE) 802.11 standard for telecommunications and information exchange between systems. 16. The invention as recited in claim 15, wherein the link test request and the link test response conform to the MAC layer frame format in accordance with one or more editions of the IEEE 802.11 standard. 17. The invention as recited in claim 12, wherein the measured signal quality is one or more of a signal-to-noise ratio (SNR), a bit-error rate (BER), a power level, and a burst error rate. 18. The invention as recited in claim 12, wherein the apparatus is embodied in a processor of an integrated circuit. 19. The invention as recited in claim 12, wherein the apparatus is embodied in the station operating in accordance with one or more editions of an Institute of Electrical Engineers (IEEE) 802.11 standard for telecommunications and information exchange between systems. 20. Apparatus for associating a station to one of a plurality of access points in a wireless local area network (WLAN), the apparatus comprising: a transmitter adapted to transmit a test link request to each of the one or more access points; a receiver adapted to receive a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; a detector adapted to measure a downlink signal quality of the corresponding access point for each test link response; a comparator adapted to compare the corresponding uplink and downlink signal qualities of the one or more access points; and a selector adapted to select the one of the plurality of access points based on the comparison of the uplink and downlink signal qualities of the one or more access points. 21. Apparatus for associating a station to one of a plurality of access points in a wireless local area network (WLAN), the apparatus comprising the steps of: (a) a receiver adapted to receive, by an access point, a test link request from the station; (b) a detector adapted to measure an uplink signal quality of the corresponding station for the test link request; and (c) a processor adapted to form a test link response for the test link request, the test link response including the uplink signal quality to the corresponding access point. 22. The invention as recited in claim 21, wherein the apparatus further comprises a transmitter adapted to transmit the test link response to the station. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to communication networks, and, more particularly, to associating a station with an access point in a wireless local area networks. 2. Description of the Related Art Wireless local area networks (WLANs) include one or more non-fixed stations (or mobile terminals) such as cell phones, notebook (laptop) computers, and hand-held computers, equipped with generally available, WLAN PC cards that enable communication among themselves as well as through a network server. An example of a WLAN network is a network that conforms to standards developed and proposed by the Institute of Electrical and Electronic Engineers (IEEE) 802.11 Committee (i.e., a network operating in accordance with one or more editions of the IEEE 802.11 standard for telecommunications and information exchange between systems). In WLANs operating in accordance with the IEEE 802.11 standard, a network server provides support for communication between stations in different service sets (SSs), which are associated with different access points (APs). An AP is a terminal or other device that provides connectivity to other networks or service areas, and also, in some cases, coordinates communication directly between stations. An AP may be either fixed or mobile, but for most applications is fixed. Such WLAN networks allow stations to be moved within a particular service area without regard to the connections among the stations within that service area. Most networks are organized as a series of layers, each one built upon its predecessor. The purpose of each layer is to offer services to the higher layers, shielding those layers from implementations details of lower layers. Between each pair of adjacent layers is an interface that defines those services. The International Standards Organization has developed a layered-network architecture called the Open Systems Interconnection (OSI) Reference model that has seven protocol layers: application, presentation, session, transport, network, data link, and physical. The function of the lowest level, the physical layer, is to transfer bits over a communication medium. The function of the data link layer is to partition input data into data frames and transmit the frames over the physical layer sequentially. Each data frame includes a header that contains control and sequence information for the frames. The interface between the data link layer and the physical layer includes a medium access control (MAC) device and a physical layer signaling control device, called a PHY device. The purpose of the MAC device and the PHY device is to ensure two network stations are communicating with the correct frame format and protocol. In a WLAN, a radio is the physical device, and free space is the physical communications medium. The IEEE 802.11 standard for WLANs defines the communication protocol between the MAC device and the PHY device. For the WLAN data communication protocol, each data frame transferred between the MAC and the PHY devices has a PHY header, a MAC header, MAC data, and error checking fields. The PHY header includes a preamble that is used to indicate the presence of a signal, unique words, frame length, etc. The MAC header includes frame control, duration, source (i.e., MAC) and destination address, and data sequence number. Typically, messages transmitted among the stations associated with the same AP (termed an extended service set, or ESS) in such WLAN networks are transmitted to the access point (AP) rather than being directly transmitted between the stations. Such centralized wireless communication provides significant advantages in terms of simplicity of the communication link as well as in power savings. One primary operation of the WLAN is the process by which a station associates (establishes a communication connection) with an AP. When a station associates with an AP, a basic service set (BSS) is formed. Association is typically initiated by the station, and may occur in either an active mode or a passive mode. In passive mode, the station listens for periodic control messages, called beacons, sent by an AP that indicate the service set identification (SSID) of the AP. In active mode, the station sends a probe request, and each AP receiving the probe request transmits a probe response to the station with its SSID. In the IEEE 802.11 standard, the station has signal quality information pertaining only to the link from the AP to the station. This signal quality information, such as received power or signal-to-noise ratio (SNR), is measured by the station. The station then associates to the AP based on the strongest received power level. The station associates to the AP using one or more control messages to, and with appropriate acknowledgment messages from, the AP. SUMMARY OF THE INVENTION The present invention relates to association of a station association with an access point in a wireless local area network conforming to, e.g., an IEEE 802.11 standard. The station measures link quality, such as the signal-to-noise ratio (SNR), for the downlink channel from each of the access points sending a message, and forms a first list of the access points in decreasing order of received downlink channel SNR The station transmits a link test request to each access point to query the access point for the link quality (e.g., SNR) of the link test request received at the corresponding access point. Access points respond to the link test request with corresponding link test responses containing the corresponding uplink SNR. The station i) forms a second list of the access points in decreasing order of received uplink SNR and ii) compares the first and second lists to determine which access point to associate with based on overall quality of the uplink and downlink channels. In accordance with exemplary embodiments of the present invention, a station is associated to one of a plurality of access points in a wireless local area network (WLAN) by (a) measuring a downlink signal quality of a message received in a signal from each of one or more access points; (b) transmitting a test link request to each of the one or more access points; (c) receiving a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; (d) comparing the corresponding uplink and downlink signal qualities of the one or more access points; and (e) selecting the one of the plurality of access points based on the comparison. BRIEF DESCRIPTION OF THE DRAWINGS Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which: FIG. 1 shows a wireless local area network employing station association in accordance with an exemplary embodiment of the present invention; and FIG. 2 shows a method of station association in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION FIG. 1 shows a wireless local area network (WLAN) 100 employing station association in accordance with an exemplary embodiment of the present invention. WLAN 100 is a network operating in accordance with, for example, one or more versions (or editions) of the IEEE 802.11 standard. Station STA1 desires to form a basic service set (BSS) with one of first and second access points AP1 and AP2. A BSS is a connection for the transfer of data between station STA1 and another device (not necessarily shown in FIG. 1) through the associated one of the access points AP1 and AP2. STA1 might be a wireless client or mobile terminal, such as a cell phone, hand-held computer, or notebook (laptop) computer. Access points AP1 and AP2 are typically fixed receivers, such as fixed radio receiver sets. For convenience, messages sent from the access point to the station are transmitted in a channel termed a “downlink channel,” and messages sent from the station to the access point are transmitted in a channel termed an “uplink channel.” In accordance with embodiments of the present invention, station association employs a measured signal level in each of the uplink and downlink channels to determine which access point a station should associate with when forming a BSS. Each access point communicates with an average transmit level, which is shown in FIG. 1 for AP1 as the dashed circle with 20 dBm power and for AP2 as the dashed circle with 14 dBm power. Because of the greater transmit power of AP1, the coverage area of AP1 is bigger than AP2. Other factors may contribute to one access point having a greater coverage area than another access point, such as atmospheric conditions, buildings or other objects in the coverage area, or high background noise conditions. Association in WLAN 100 is typically initiated by station STA1, and may occur in either an active mode or a passive mode. In passive mode, STA1 listens for periodic control messages, called beacons, in a downlink channel sent by access points AP1 and AP2 that indicate the service set identification (SSID) of the corresponding access point. In active mode, STA1 sends a probe request in an uplink channel, and each of the access points AP1 and AP2 receiving the probe request transmits a probe response to the station with its SSID. When wireless station STA1 initiates association in passive mode, STA1 receives beacons from both AP1 and AP2. When wireless station STA1 initiates association in active mode, STA1 receives beacons and probe responses from both AP1 and AP2. The SNR of the signal (e.g., either a beacon or a probe response) received from AP1 is better than that received from AP2 because of, for example, the greater transmit power of AP1 and the position of STA1 in relation to AP1 and AP2. Because of, for example, limited power available to STA1 for transmission, AP2 receives the signal (of, e.g. the probe request) from STA1 “better” than AP1 because STA1 is “closer” to AP2. To one skilled in the art, “better” may be a given metric, such as signal-to-noise ratio (SNR), bit-error rate (BER), or burst error rate, and “closer” might not be in terms of physical distance, but in terms of the metric (SNR or BER) for the signal transmitted by the station or access point. In general, each access point will transmit with greater power than the station transmits. Consequently, if the station associates with the access point having the higher transmit power (AP1), the station may have to transmit with much higher power to this access point. When the station receives a first access point signal better than a second access point signal, but the second access point receives the station's signal better than the first access point's signal, it might be preferable for STA1 to associate with AP2 when forming the BSS rather than associate to AP1. In accordance with the present invention, the station measures the SNR of each access point's signal received by the station, and also queries each access point for the SNR of the station's signal that the access point receives. The query message sent by the station to an access point may be termed a link test request message. The response of the access point to the query message may be termed a link test response. Given the SNR information of both uplink and downlink channels, the station determines with which access point to associate. The station uses standard IEEE 802.11 association procedure messaging compliant with, for example, MAC and PHY layer control to implement the method of association in accordance with exemplary embodiments of the present invention. FIG. 2 shows a method of station association in accordance with an exemplary embodiment of the present invention. At step 201, a test determines whether the station is in Active Mode. If the test of step 201 determines that the station is in active mode, then, at step 202, the station transmits one or more probe requests. At step 203, the station receives probe responses each with access point SSID. At step 204, the station computes the SNR of the signal for each received probe response, which is the downlink SNR for the corresponding access point. From step 204, the method advances to step 205. SNR might be measured by any one of a number of techniques known in the art, such as by measuring average noise power during periods when no signal is present and measuring average noise power when the signal with added noiose is present. If the test of step 201 determines that the station is not in active mode (e.g., in passive mode), then, at step 209, the station listens for one or more beacon messages with the SSID of each transmitting access point. At step 210, the station computes the SNR of the signal for each beacon (downlink SNR). From step 210, the method advances to step 205. At step 205, the station sends a link test request message to each access point from which it received a valid SSID. The link test request message is a request to the access point to return to the station the SNR of the link test request message. At step 206, the station receive a link test response message from one or more of the access points to which a corresponding link test request message was sent. Each link test response message contains the SNR of the corresponding link test request message (the uplink SNR). At step 207, the station then considers the uplink and downlink SNR values for each access point SSID as a measure of the overall bi-directional communication link quality. The station might form a list of all the access point SSIDs in decreasing order of downlink SNR values. After receiving the link test responses, the station might form a list of all the access point SSIDs in decreasing order of uplink SNR values. Based on a given evaluation criterion, at step 207, the station determines the “best” access point to associate with. Many types of evaluation criterion are known in the art. For example, the station might associate to the access point returning the highest uplink SNR whose downlink SNR is above a predetermined threshold. At step 208, the station associates with the access point determined in step 207 that provides the best overall link quality. In an alternative embodiment of the present invention, a station operating in active mode might omit the steps of 201 through 204 in FIG. 2, and simply initiate association by sending a link test request message at step 205. Each access point receiving the link test request message then returns a link test request response with the corresponding SSID and uplink SNR, and the station calculates the downlink SNR for each access point from the corresponding link test response message at step 206. The station then implements steps 207 and 208 to associate with the access point with the best overall link quality. While the exemplary embodiment of the present invention is described for WLANs operating in accordance with one or more versions of the IEEE 802.11 standard, the present invention is not so limited. One skilled in the art may extent the teachings herein to other types of wireless local area communication networks. The present invention may allow for the following advantages. A given implementation allows for an improved quality of IEEE 802.11 wireless connection in an environment where access points operate with different power levels (or other difference in signal quality), or in an environment where communication between access points and a station occurs with large differences in power levels between uplink and downlink channels. In addition, a given implementation may be compliant with current IEEE 802.11 standards, allowing for upgrade of existing systems. The present invention can be embodied in the form of methods and apparatuses for practicing those methods. The present invention can also be embodied in the form of program code embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. The present invention can also be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a unique device that operates analogously to specific logic circuits. It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the principle and scope of the invention as expressed in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to communication networks, and, more particularly, to associating a station with an access point in a wireless local area networks. 2. Description of the Related Art Wireless local area networks (WLANs) include one or more non-fixed stations (or mobile terminals) such as cell phones, notebook (laptop) computers, and hand-held computers, equipped with generally available, WLAN PC cards that enable communication among themselves as well as through a network server. An example of a WLAN network is a network that conforms to standards developed and proposed by the Institute of Electrical and Electronic Engineers (IEEE) 802.11 Committee (i.e., a network operating in accordance with one or more editions of the IEEE 802.11 standard for telecommunications and information exchange between systems). In WLANs operating in accordance with the IEEE 802.11 standard, a network server provides support for communication between stations in different service sets (SSs), which are associated with different access points (APs). An AP is a terminal or other device that provides connectivity to other networks or service areas, and also, in some cases, coordinates communication directly between stations. An AP may be either fixed or mobile, but for most applications is fixed. Such WLAN networks allow stations to be moved within a particular service area without regard to the connections among the stations within that service area. Most networks are organized as a series of layers, each one built upon its predecessor. The purpose of each layer is to offer services to the higher layers, shielding those layers from implementations details of lower layers. Between each pair of adjacent layers is an interface that defines those services. The International Standards Organization has developed a layered-network architecture called the Open Systems Interconnection (OSI) Reference model that has seven protocol layers: application, presentation, session, transport, network, data link, and physical. The function of the lowest level, the physical layer, is to transfer bits over a communication medium. The function of the data link layer is to partition input data into data frames and transmit the frames over the physical layer sequentially. Each data frame includes a header that contains control and sequence information for the frames. The interface between the data link layer and the physical layer includes a medium access control (MAC) device and a physical layer signaling control device, called a PHY device. The purpose of the MAC device and the PHY device is to ensure two network stations are communicating with the correct frame format and protocol. In a WLAN, a radio is the physical device, and free space is the physical communications medium. The IEEE 802.11 standard for WLANs defines the communication protocol between the MAC device and the PHY device. For the WLAN data communication protocol, each data frame transferred between the MAC and the PHY devices has a PHY header, a MAC header, MAC data, and error checking fields. The PHY header includes a preamble that is used to indicate the presence of a signal, unique words, frame length, etc. The MAC header includes frame control, duration, source (i.e., MAC) and destination address, and data sequence number. Typically, messages transmitted among the stations associated with the same AP (termed an extended service set, or ESS) in such WLAN networks are transmitted to the access point (AP) rather than being directly transmitted between the stations. Such centralized wireless communication provides significant advantages in terms of simplicity of the communication link as well as in power savings. One primary operation of the WLAN is the process by which a station associates (establishes a communication connection) with an AP. When a station associates with an AP, a basic service set (BSS) is formed. Association is typically initiated by the station, and may occur in either an active mode or a passive mode. In passive mode, the station listens for periodic control messages, called beacons, sent by an AP that indicate the service set identification (SSID) of the AP. In active mode, the station sends a probe request, and each AP receiving the probe request transmits a probe response to the station with its SSID. In the IEEE 802.11 standard, the station has signal quality information pertaining only to the link from the AP to the station. This signal quality information, such as received power or signal-to-noise ratio (SNR), is measured by the station. The station then associates to the AP based on the strongest received power level. The station associates to the AP using one or more control messages to, and with appropriate acknowledgment messages from, the AP. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to association of a station association with an access point in a wireless local area network conforming to, e.g., an IEEE 802.11 standard. The station measures link quality, such as the signal-to-noise ratio (SNR), for the downlink channel from each of the access points sending a message, and forms a first list of the access points in decreasing order of received downlink channel SNR The station transmits a link test request to each access point to query the access point for the link quality (e.g., SNR) of the link test request received at the corresponding access point. Access points respond to the link test request with corresponding link test responses containing the corresponding uplink SNR. The station i) forms a second list of the access points in decreasing order of received uplink SNR and ii) compares the first and second lists to determine which access point to associate with based on overall quality of the uplink and downlink channels. In accordance with exemplary embodiments of the present invention, a station is associated to one of a plurality of access points in a wireless local area network (WLAN) by (a) measuring a downlink signal quality of a message received in a signal from each of one or more access points; (b) transmitting a test link request to each of the one or more access points; (c) receiving a corresponding test link response for one or more of the test link requests, the test link response including an uplink signal quality to the corresponding access point; (d) comparing the corresponding uplink and downlink signal qualities of the one or more access points; and (e) selecting the one of the plurality of access points based on the comparison. | 20040504 | 20110906 | 20060622 | 57575.0 | H04B700 | 0 | TRAN, TUAN A | ASSOCIATING A WIRELESS STATION WITH AN ACCESS POINT | UNDISCOUNTED | 0 | ACCEPTED | H04B | 2,004 |
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10,838,889 | ACCEPTED | Method and system for caching at secure gateways | A computer gateway for an intranet of computers, including a scanner for scanning incoming files from the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform, a file cache for storing files, a security profile cache for storing security profiles for files, and a security policy cache for storing security policies for client computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. A method and a computer-readable storage medium are also described and claimed. | 1. A computer gateway for an intranet of computers, comprising: a scanner for scanning incoming files from the Internet and deriving security profiles therefor, and the security profiles being lists of computer commands that the files are programmed to perform; a file cache for storing files; a security profile cache for storing security profiles for files; and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. 2. The computer gateway of claim 1 wherein security policies include at least one alternate action to take when transmission of a file to an intranet computer is restricted. 3. The computer gateway of claim 1 wherein the file cache indexes files according to their Universal Resource Identifiers (URIs). 4. The computer gateway of claim 1 wherein the file cache indexes files according to file IDs. 5. The computer gateway of claim 4 wherein the file IDs are hash values of files. 6. The computer gateway of claim 5 wherein the file IDs are used to ensure that duplicate files are not cached more than once. 7. The computer gateway of claim 5 wherein the file IDs are used to ensure that a file is not re-scanned if its security profile is already resident in the security profile cache. 8. The computer gateway of claim 1 wherein the security profile cache indexes security profiles according to URIs of corresponding files. 9. The computer gateway of claim 1 wherein the security profile cache indexes security profiles according to files IDs of corresponding files. 10. The computer gateway of claim 9 wherein the file IDs are hash values of files. 11. The computer gateway of claim 1 wherein the security policy cache indexes security policies according to groups of intranet users. 12. A method for operation of a network gateway for an intranet of computers, comprising: receiving a request from an intranet computer for a file on the Internet; determining whether the requested file resides within a file cache at the network gateway; if said determining is affirmative: retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; and if said determining is not affirmative: retrieving the requested file from the Internet; scanning the retrieved file to determine computer commands that the file is programmed to perform; deriving a security profile for the retrieved file; storing the retrieved file within the file cache; and storing the security profile for the retrieved file within a security profile cache; retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 13. The method of claim 12 wherein security policies include at least one alternate action to take when transmission of a file to an intranet computer is restricted, the method further comprising taking such an alternative action if said comparing determines that transmission of the requested file to the intranet computer is to be restricted. 14. The method of claim 12 further comprising indexing the file cache so that files are indexed according to their Universal Resource Identifiers (URIs). 15. The method of claim 12 further comprising indexing the file cache so that files are indexed according to file IDs. 16. The method of claim 15 wherein the file IDs are hash values of files. 17. The method of claim 16 further comprising managing the file cache using the file IDs so that duplicate files are not cached more than once. 18. The computer gateway of claim 16 further comprising ensuring that a file is not re-scanned if its security profile is already resident in the security profile cache, using the file IDs. 19. The method of claim 12 further comprising indexing the security profile cache so that security profiles are indexed according to URIs of corresponding files. 20. The method of claim 12 further comprising indexing the security profile cache so that security profiles are indexed according to file IDs of corresponding files. 21. The method of claim 20 wherein the file IDs are hash values of files. 22. The method of claim 12 wherein the security policy cache indexes security policies according to groups of intranet users. 23. The method of claim 12 further comprising synchronizing the file cache and the security profile cache. 24. A computer-readable storage medium storing program code for causing a computer to perform the steps of: receiving a request from an intranet computer for a file on the Internet; determining whether the requested file resides within a file cache at the network gateway; if said determining is affirmative: retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; and if said determining is not affirmative: retrieving the requested file from the Internet; scanning the retrieved file to determine computer commands that the file is programmed to perform; deriving a security profile for the retrieved file; storing the retrieved file within the file cache; and storing the security profile for the retrieved file within a security profile cache; retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 25. A method for operation of a network gateway for an intranet of computers, comprising: receiving a request from an intranet computer for a file on the Internet; retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 26. The method of claim 25 further comprising: retrieving the requested file from a file cache at the network gateway; and transmitting the requested file to the intranet computer if said comparing determines that transmission of the requested file to the intranet computer is not to be restricted. 27. The method of claim 25 further comprising synchronizing the file cache and the security profile cache. 28. The method of claim 25 wherein security policies include at least one alternate action to take when transmission of a file to an intranet computer is restricted, the method further comprising taking such an alternative action if said comparing determines that transmission of the requested file to the intranet computer is to be restricted. 29. A computer-readable storage medium storing program code for causing a computer to perform the steps of: receiving a request from an intranet computer for a file within the Internet; retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; retrieving a security policy for the client computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 30. A method for operation of a network gateway for an intranet of computers, comprising: retrieving a requested file from the Internet; scanning the retrieved file to determine computer commands that the file and the web objects are programmed to perform; deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform; storing the retrieved file within a file cache; and storing the security profile for the retrieved file within a security profile cache. 31. The method of claim 30 further comprising indexing the file cache so that files are indexed according to their Universal Resource Identifiers (URIs). 32. The method of claim 30 further comprising indexing the file cache so that files are indexed according to file IDs. 33. The method of claim 32 wherein the file IDs are hash values of files. 34. The method of claim 33 further comprising managing the file cache using the file IDs so that duplicate files are not cached more than once. 35. The computer gateway of claim 33 further comprising ensuring that a file is not re-scanned if its security profile is already resident in the security profile cache, using the file IDs. 36. The method of claim 30 further comprising indexing the security profile cache so that security profiles are indexed according to URIs of corresponding files. 37. The method of claim 30 further comprising indexing the security profile cache so that security profiles are indexed according to file IDs of corresponding files. 38. The method of claim 37 wherein the file IDs are hash values of files. 39. A computer-readable storage medium storing program code for causing a computer to perform the steps of: retrieving a requested file from the Internet; scanning the retrieved file to determine computer commands that the file is programmed to perform; deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform; storing the retrieved file within a file cache; and storing the security profile for the retrieved file within a security profile cache. 40. A computer gateway for an intranet of computers, comprising: a file cache for storing files; a security profile cache for storing security profiles for files, the security profiles being lists of computer commands that the files are programmed to perform; and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. 41. A method for operation of a network gateway for an intranet of computers, comprising: receiving a request from an intranet computer for a file on the Internet; determining whether the requested file resides within a file cache at the network gateway; if said determining is affirmative: retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; and if said determining is not affirmative: retrieving the requested file from the Internet; storing the retrieved file within the file cache; and storing a security profile for the retrieved file within a security profile cache; retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 42. A computer-readable storage medium storing program code for causing a computer to perform the steps of: receiving a request from an intranet computer for a file on the Internet; determining whether the requested file resides within a file cache at the network gateway; if said determining is affirmative: retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform; and if said determining is not affirmative: retrieving the requested file from the Internet; storing the retrieved file within the file cache; and storing a security profile for the retrieved file within a security profile cache; retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer; and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. 43. A computer gateway for an intranet of computers, comprising: a scanner for scanning outgoing files from an intranet to the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform; and a security policy cache for storing security policies for recipient computers within the Internet, the security policies including a list of restrictions for files that are transmitted to recipient computers. 44. A method for operation of a network gateway for an intranet of computers, comprising: receiving a file from an intranet computer for transmission to a recipient computer on the Internet; scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform; retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers; and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. 45. A computer-readable storage medium storing program code for causing a computer to perform the steps of: receiving a file from an intranet computer for transmission to a recipient computer on the Internet; scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform; retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers; and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. | CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of assignee's pending U.S. patent application Ser. No. 09/539,667, filed on Mar. 30, 2000, and entitled SYSTEM AND METHOD FOR PROTECTING A COMPUTER AND A NETWORK FROM HOSTILE DOWNLOADABLES, which is a continuation of U.S. patent application Ser. No. 08/964,388 (now U.S. Pat. No. 6,092,194), filed on Nov. 6, 1997 and entitled SYSTEM AND METHOD FOR PROTECTING A COMPUTER AND A NETWORK FROM HOSTILE DOWNLOADABLES. FIELD OF THE INVENTION The present invention relates to computer security and network gateways. BACKGROUND OF THE INVENTION A network gateway computer conventionally serves as a proxy between a group of inter-connected computers, referred to as an intranet, such as a corporate intranet or customers of an Internet service provide, and the myriads of server computers on the Internet. The gateway computer is networked with the intranet computers in such a way that outgoing requests and responses from the intranet computers to the Internet, and incoming requests and responses from the Internet to the intranet computers are routed through the gateway computer. Typically, a request is issued as an HTTP protocol request that includes a URI for a file, such as an HTML page, a JPEG image or a PDF document, residing on one or more server computers on the Internet. Similarly, a response is typically an HTTP response including a requested file, sent back to a client in response to a request. Network gateways are generally connected to an intranet with high-speed lines, so that the bandwidth between the intranet computers and the gateway computer is much higher than the bandwidth between the gateway computer and rest of the Internet. Two important functions of computer gateways are (i) to restrict outsiders from unauthorized access to a computer intranet, and (ii) to protect the intranet computers from software containing computer viruses and from spam. Computer gateways may contain conventional firewall software that restricts outside communication with the intranet, anti-virus software that identifies computer viruses residing within files retrieved from the Internet, and anti-spam software that filters out unwanted content. Current gateway systems cause latency because clients do not access websites directly, and because current gateway systems apply security protocols to protect intranet members. Accordingly, systems and methods for reducing network access latency without compromising network safety are needed. SUMMARY OF THE INVENTION The present invention provides a method and system for improving performance of gateway computers. Specifically, the present invention mitigates network latency caused by processing time at a gateway computer. There is thus provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a scanner for scanning incoming files from the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform, a file cache for storing files, a security profile cache for storing security profiles for files, and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. There is further provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative then retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative then retrieving the requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, storing the retrieved file within the file cache, and storing the security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative then retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative then retrieving the requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, storing the retrieved file within the file cache, and storing the security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is moreover provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is additionally provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including retrieving a requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform, storing the retrieved file within a file cache, and storing the security profile for the retrieved file within a security profile cache. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of retrieving a requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform, storing the retrieved file within a file cache, and storing the security profile for the retrieved file within a security profile cache. There is moreover provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a file cache for storing files, a security profile cache for storing security profiles for files, the security profiles being lists of computer commands that the files are programmed to perform, and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. There is additionally provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative retrieving the requested file from the Internet, storing the retrieved file within the file cache, and storing a security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative retrieving the requested file from the Internet, storing the retrieved file within the file cache, and storing a security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is moreover provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a scanner for scanning outgoing files from an intranet to the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform, a security policy cache for storing security policies for recipient computers within the Internet, the security policies including a list of restrictions for files that are transmitted to recipient computers. There is additionally provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a file from an intranet computer for transmission to a recipient computer on the Internet, scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers, and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a file from an intranet computer for transmission to a recipient computer on the Internet, scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers, and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: FIG. 1 is a simplified block diagram for a network gateway, in accordance with a preferred embodiment of the present invention; FIG. 2 is a simplified flowchart for operation of a network gateway, in accordance with a preferred embodiment of the present invention; and FIG. 3 is a simplified block diagram for a network gateway that control outgoing traffic, in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The present invention provides a system and method for optimizing performance of network gateways that perform security-based functions. Reference is now made to FIG. 1, which is a simplified block diagram for a network gateway, in accordance with a preferred embodiment of the present invention. Shown in FIG. 1 is a network gateway computer 110, which serves as a proxy between an intranet of clients and servers, and the Internet. Specifically in FIG. 1, gateway computer 110 intervenes between requests for web pages originating from an intranet 120 of clients 123, 125 and 127, and responses originating from Internet servers 133, 135 and 137. Typically, web pages include text, executable scripts and one or more links to web objects that must be retrieved in order to completely render the web page. Such web objects include inter alia images, sounds, multimedia presentations, video clips and also active code that runs on the client computer. Executable scripts and active code components are a security concern, since they may contain computer viruses that maliciously harm client computers. In fact, most viruses today are transmitted as active web objects or as e-mail attachments. Preferably, gateway computer 110 includes a code scanner 140, for scanning incoming web pages and web objects in order to detect the presence of malicious executable scripts or active code. Preferably when gateway 110 receives a web page, it also retrieves the web objects referenced by the web page, and scanner 140 scans the web page and the web objects that may be malicious. For example, a web page, P, requested by a client computer, may contain references to web objects O1, O2, O3 and O4. Generally, the web page, P, and the web objects it references, O1, O2, O3 and O4 are stored as files within the Internet. When the web page, P, first arrives at gateway computer 110, gateway computer 110 preferably retrieves objects O1, O2, O3 and O4. Gateway computer 110 then decides which of web page P and objects O1, O2, O3 and O4 may potentially be malicious, and scanner 140 scans each of the potentially malicious files. Determination of which files may be potentially malicious may be based on numerous criteria—for example, multimedia objects such as images and video clips may be deemed safe, whereas Visual Basic scripts and Java applets may be deemed potentially malicious. In accordance with a preferred embodiment of the present invention, scanner 140 analyzes each file it scans to determine the nature of computer operations that the file is programmed to perform, and derives a security profile therefor, summarizing potentially malicious computer operations. Thus scanner 140 may determine inter alia that a file is programmed to access a computer file system, or a computer operating system, or open a network socket. Table I below indicates a typical scan analysis, in accordance with a preferred embodiment of the present invention. As can be seen from Table I, web page P and web objects O1 and O4 are deemed potentially malicious. Web objects O2 and O3 are deemed safe. The security profile for web page P includes security profiles for JavaScript within page P, and for web objects O1 and O4 referenced by page P. Web objects O2 and O3 are not scanned, since they are deemed to be safe. TABLE I Security Profile for Web Page P Security Profile Malicious? File System Operating System Network Potentially Commands Commands Commands Web Page P Yes None None Issue HTTP request; References objects O1, O2, O3 and O4 Includes JavaScript Web Object O1 Yes Open file F1; Open registry; None Java applet Write file F2; Edit registry Delete file F1 Web Object O2 No Still image Web Object O3 No Audio clip Web Object O4 Yes Open file F1; None Open socket; ActiveX Control Copy file F1 FTP send In accordance with a preferred embodiment of the present invention, web page security profiles are stored in a security profile cache 150, and the web page and the web objects that the page references are stored in a web cache 160. Security profile cache 150 preferably includes a table as indicated in Table II. TABLE II Structure of Security Profile Cache 150 Web Content ID Web Content Security Profile Web content ID is preferably a has ID that serves as a key for Table II. Similarly, web content cache 160 preferably includes a table as indicated in Table III. TABLE III Structure of Web Content Cache 160 Web Content URI Web Content ID Web Content Web content URI serves as a key for Table III, and Web Content ID is a foreign key that can be used to join Table II with Table III. It may be appreciated that the same web page or web object may be stored at multiple locations and, as such, multiple URIs may correspond to the same web content. In a preferred embodiment of the present invention, web cache 160 is managed so as to avoid caching duplicate web content. Use of a hash ID for web pages and web objects serves to identify web content duplicates, and to determine if web content on the Internet has changed since it was earlier cached within web content cache 160. In case web content has changed, then preferably the more recent web content is cached instead of the older web content, and the newer web content is scanned by code scanner 140, in order to update its security profile within security profile cache 150. Preferably, when a client computer requests a web page, P, from a server computer, the request is first transmitted to gateway computer 110, which checks whether or not the web page is already resident within web cache 160. If not, then computer gateway forwards the request to the server computer, which in turn sends the requested web page, P, to gateway computer 110 within a response. Requests and responses are typically formatted according to the HTTP protocol. Upon receipt of the requested web page, gateway computer 110 (i) fetches the web objects referenced by page P, such as web objects O1, O2, O3 and O4 hereinabove; (ii) determines which files to scan; (iii) determines security profiles for the scanned files; (iv) caches the security profiles for web page P in security profile cache 150; and (v) caches web page P and web objects O1, O2, O3 and O4 in web cache 160. After gateway computer 110 has stored web page P in web cache 160, and has stored its corresponding security profile in security profile cache 150, it determines whether or not to send web page P to the client computer that requested it. If web page P may perform malicious operations to the client computer, then gateway computer 110 may not transmit web page P. The decision whether or not to transmit web page P to the requesting client computer is preferably based on a security policy for the client computer. A security policy indicates suspicious operations that are to be blocked from a client computer. Thus by comparing the operations within a security profile for a web page, P, vis a vis the operations listed within a security policy that are to be blocked, a determination can be made whether or not to transmit web page P to a client computer. Preferably, security policies are stored within a security policy cache 170 on gateway computer 110. Use of security profiles and security policies are described in applicant's U.S. Pat. No. 6,092,194 entitled SYSTEM AND METHOD FOR PROTECTING A COMPUTER AND A NETWORK FROM HOSTILE DOWNLOADABLES, U.S. Pat. No. 6,154,844 entitled SYSTEM AND METHOD FOR ATTACHING A DOWNLOADABLE SECURITY PROFILE TO A DOWNLOADABLE, U.S. Pat. No. 6,167,520 entitled SYSTEM AND METHOD FOR PROTECTING A CLIENT DURING RUNTIME FROM HOSTILE DOWNLOADABLES, and U.S. Pat. No. 6,480,962 entitled SYSTEM AND METHOD FOR PROTECTING A CLIENT DURING RUNTIME FROM HOSTILE DOWNLOADABLES. It may be appreciated that the various caches within gateway computer 110—security profile cache 150, web cache 160 and security policy cache 170, must be managed in order to be kept current as files on the Internet are replaced with newer versions, and in order to appropriately purge items from cache when cache memory is full and new items arrive for storage. Typically, web cache 160 is the cache that fills up, since web objects such as applets and multimedia files tend to be very large. In accordance with a preferred embodiment of the present invention, caches 150 and 160 are synchronized, so that when a file is purged from web cache 160, its corresponding security profile is purged from cache 170. Methodologies for keeping caches 150 and 160 current include inter alia: replacing cached files regularly on a periodic basis, such as every 24 hours, and re-scanning them to derive updated security profiles; replacing files based on expiration dates and times included within the file headers, and re-scanning them to derive updated security profiles; and checking the Internet to determine whether cached files are current whenever they are requested by an intranet computer. Methodologies for purging files when cache 160 is full include inter alia: purging the oldest files; purging the least accessed files; and purging the files that have not been accessed for the longest time; i.e., last recently used (LRU). It may be appreciated that although web content is purged from cache 160 in order to free up memory, the security profile of the purged content need not be purged from security profile cache 150. In such a case, if the purged web content is subsequently re-cached and has not changed, then code scanner 140 need not re-scan the content. Preferably, the web content ID is used to determine if web content re-entering the cache is identical to previously cached web content. Security policies are typically specified by a system administrator and, as such, security policy cache 170 is controlled by the system administrator. It may be appreciated by those skilled in the art that code scanner 140 may be updated from time to time. In accordance with a preferred embodiment of the present invention, when code scanner 140 is updated, cached web content is re-scanned to update the corresponding security profiles, in order to maintain synchronization between security profile cache 150 and web content cache 160. Reference is now made to FIG. 2, which is a simplified flowchart for operation of a network gateway, in accordance with a preferred embodiment of the present invention. All of the steps shown in FIG. 2 are performed by a network gateway computer, except for steps 205, 225 and 230, which are performed by an intranet client computer. As shown in FIG. 2, at step 205 an intranet client computer requests an Internet web page. Typically, the web page is designated by a Universal Resource Identifier (URI), which is a conventional identifier including both an IP address for an Internet server computer and a file location within the server computer's file system. The client request is routed through a network gateway, which acts as a proxy between a group of client computers and the Internet. Thus at step 210 a network gateway computer receives the client request. At step 215 the gateway computer determines whether or not the requested web page is already resident within its web cache. Preferably, the web cache is indexed by URI, so that the gateway computer can readily determine whether or not the requested web page is available. If the requested web page is already available in the web cache, processing continues at step 255. Otherwise, at step 220 the gateway computer retrieves the requested web page from the Internet, using the web page's URI to determine its location. At step 225 the client computer receives the requested web page from the gateway computer, and at step 230 the client computer identifies the web objects referenced within the web page it receives and requests them from the gateway computer. Typically, web objects are referenced by individual URIs. Thus web objects O1, O2, O3 and O4 above typically each have their own URIs, say, URI1, URI2, URI3 and URI4. At step 235 the gateway computer retrieves the referenced web objects from the Internet, using their individual URIs to determine their locations. It may be appreciated that although the requested web page is not available in the web cache at step 215, it is possible that one or more of the web objects it references are nevertheless available in cache. As such, the gateway computer may not be required to retrieve all of the referenced web objects at step 235. At step 240 the gateway computer determines which of the web page and its referenced web objects are deemed potentially malicious, and scans those files that are so deemed. In accordance with a preferred embodiment of the present invention, the scans operate to identify computer commands that a file is programmed to carry out, and record potentially malicious commands in a list that serves as a security profile. Typically, the list includes commands that operate on a computer file system or operating system, and commands that perform network operations such as opening of a network socket or transmission of data. At step 245 the gateway computer stores the retrieved web page and the retrieved web objects within its web cache, and at step 250 the gateway computer stores the corresponding security profiles that it derived within its security profile cache. Preferably, security profiles within the security profile cache are indexed by URIs, similar to the way web pages and web objects are indexed within the web cache. If the requested web page is determined to be resident within the gateway computer's web cache at step 215, then gateway computer simply retrieves a security profile for the requested web page from its security profile cache at step 255. In this case, it is not necessary to retrieve the web page and its web objects from the Internet and derive the security profile, as was done in steps 220-250. At step 260 the gateway computer retrieves a security policy for the intranet client computer that requested the web page at step 205. Preferably, security profiles are indexed by user groups; i.e., a security profile for an intranet computer depends on which group of users the user of the computer belongs to. At step 265 the gateway computer analyzes the web page security profile vis a vis the client computer security policy. At step 270 the gateway computer determines, based on the results of the analysis at step 265, whether or not to block the web page from being transmitted to the requesting intranet computer, in order to protect the intranet computer from potentially malicious software. If the gateway computer determines that the web page is permitted, then at step 275 the gateway computer transmits the web page to the requesting intranet computer, closing the request-response cycle that began at step 205. It may be appreciated that when client computer receives the requested web page and renders it, it subsequently requests the web objects referenced within the web page, and the request is handled by the gateway computer, which has the web objects within its web cache. Typically, web objects can be large files, so the caching of web objects within the gateway computer's web cache eliminates significant network latency for client computers. Otherwise, if the gateway computer determines at step 270 that the web page is to be blocked, then at step 280 the gateway computer takes an alternate action. Preferably, the alternate action is defined within the client computer's security profile, and includes alternatives such as sending a notification to the client computer, sending a notification to a system administrator, sending only a portion of the requested web page, or allowing the intranet computer to decide whether or not to trust the suspicious web page. In the embodiment of the present invention described with reference to FIGS. 1 and 2, the system and method are used to control incoming traffic from outside of an enterprise intranet to within the intranet. In an alternative embodiment the present invention can be used to control outgoing traffic; i.e., for scanning outgoing web pages and web objects to control content that is sent from within an enterprise intranet to computers outside of the intranet. Reference is now made to FIG. 3, which is a simplified block diagram for a network gateway that control outgoing traffic, in accordance with an alternative embodiment of the present invention. Shown in FIG. 3 is a gateway computer 310 that serves as a proxy for content being sent from client computers 323, 325 and 327 within an intranet 320, to recipients 333, 335 and 337 located outside of the intranet. A code scanner 340, situated within gateway computer 310 scans content and determines a profile of commands that the content is programmed to perform. Preferably, gateway computer 310 includes a policy cache 370, which caches policies that restrict content from being sent from within intranet 320 to recipients outside of the intranet, based on groupings of recipients. For example, a first group of recipients may include customers of the enterprise, a second group of recipients may include legal and professional counsel of the enterprise and a third group of recipients may include everyone else. More generally, it may be appreciated that FIG. 1 and FIG. 3 may be combined to provide a system in accordance with the present invention that controls bi-directional traffic; i.e., both incoming and outgoing content. Additional Considerations In reading the above description, persons skilled in the art will realize that there are many apparent variations that can be applied to the methods and systems described. Several variations are described in what follows. 1. The gateway computer described hereinabove may be embodied by a plurality of computers. Thus, for purposes of load balancing, a load balanced set of computers may serve as a gateway. 2. Although the above description follows a paradigm whereby the gateway first receives a request for a web page containing references to web objects, in some instances the gateway may receive a request for a web object without having received a request for a web page that references them. For example, in a network with a load balanced set of computers, one of the computers may receive a request for a web page, and another computer may receive a request for a web object. For another example, client software other than a web browser may download web objects directly from the Internet. 3. Although the above description mentions HTTP as a protocol for sending requests and responses, it may be appreciated that other transport protocols may be used instead. With non-HTTP protocols, it is not necessary to reference a web object from within a different request. 4. Regarding FIG. 2, in an alternative embodiment, the gateway computer may pre-fetch web objects referenced within a web page, in which case step 230 is eliminated. 5. Code scanner 140 in FIG. 1 is not required to reside within gateway computer 110. Code scanner 140 may reside instead in a different computer than gateway computer 110, and gateway computer 110 may accordingly retrieve profiles from another computer. Similarly, code scanner 340 in FIG. 3 is not required to reside within gateway computer 310. 6. Although the web content used in the above description includes web pages and web objects, in an alternative embodiment web pages may be treated as web objects themselves. Similarly, the present invention applies to non-web content as well. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific exemplary embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | <SOH> BACKGROUND OF THE INVENTION <EOH>A network gateway computer conventionally serves as a proxy between a group of inter-connected computers, referred to as an intranet, such as a corporate intranet or customers of an Internet service provide, and the myriads of server computers on the Internet. The gateway computer is networked with the intranet computers in such a way that outgoing requests and responses from the intranet computers to the Internet, and incoming requests and responses from the Internet to the intranet computers are routed through the gateway computer. Typically, a request is issued as an HTTP protocol request that includes a URI for a file, such as an HTML page, a JPEG image or a PDF document, residing on one or more server computers on the Internet. Similarly, a response is typically an HTTP response including a requested file, sent back to a client in response to a request. Network gateways are generally connected to an intranet with high-speed lines, so that the bandwidth between the intranet computers and the gateway computer is much higher than the bandwidth between the gateway computer and rest of the Internet. Two important functions of computer gateways are (i) to restrict outsiders from unauthorized access to a computer intranet, and (ii) to protect the intranet computers from software containing computer viruses and from spam. Computer gateways may contain conventional firewall software that restricts outside communication with the intranet, anti-virus software that identifies computer viruses residing within files retrieved from the Internet, and anti-spam software that filters out unwanted content. Current gateway systems cause latency because clients do not access websites directly, and because current gateway systems apply security protocols to protect intranet members. Accordingly, systems and methods for reducing network access latency without compromising network safety are needed. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a method and system for improving performance of gateway computers. Specifically, the present invention mitigates network latency caused by processing time at a gateway computer. There is thus provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a scanner for scanning incoming files from the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform, a file cache for storing files, a security profile cache for storing security profiles for files, and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. There is further provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative then retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative then retrieving the requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, storing the retrieved file within the file cache, and storing the security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative then retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative then retrieving the requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, storing the retrieved file within the file cache, and storing the security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is moreover provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is additionally provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions on files that can be transmitted to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including retrieving a requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform, storing the retrieved file within a file cache, and storing the security profile for the retrieved file within a security profile cache. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of retrieving a requested file from the Internet, scanning the retrieved file to determine computer commands that the file is programmed to perform, deriving a security profile for the retrieved file, the security profile including a list of at least one computer command that the retrieved file is programmed to perform, storing the retrieved file within a file cache, and storing the security profile for the retrieved file within a security profile cache. There is moreover provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a file cache for storing files, a security profile cache for storing security profiles for files, the security profiles being lists of computer commands that the files are programmed to perform, and a security policy cache for storing security policies for intranet computers within an intranet, the security policies including a list of restrictions for files that are transmitted to intranet computers. There is additionally provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative retrieving the requested file from the Internet, storing the retrieved file within the file cache, and storing a security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a request from an intranet computer for a file on the Internet, determining whether the requested file resides within a file cache at the network gateway, if the determining is affirmative retrieving a security profile for the requested file from a security profile cache at the network gateway, the security profile including a list of at least one computer command that the file is programmed to perform, and if the determining is not affirmative retrieving the requested file from the Internet, storing the retrieved file within the file cache, and storing a security profile for the retrieved file within a security profile cache, retrieving a security policy for the intranet computer from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to the intranet computer, and comparing the security profile for the requested file vis a vis the security policy for the intranet computer, to determine whether transmission of the requested file to the intranet computer is to be restricted. There is moreover provided in accordance with a preferred embodiment of the present invention a computer gateway for an intranet of computers, including a scanner for scanning outgoing files from an intranet to the Internet and deriving security profiles therefor, the security profiles being lists of computer commands that the files are programmed to perform, a security policy cache for storing security policies for recipient computers within the Internet, the security policies including a list of restrictions for files that are transmitted to recipient computers. There is additionally provided in accordance with a preferred embodiment of the present invention a method for operation of a network gateway for an intranet of computers, including receiving a file from an intranet computer for transmission to a recipient computer on the Internet, scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers, and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. There is further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving a file from an intranet computer for transmission to a recipient computer on the Internet, scanning the received file to derive a security profile for the received file, the security profile including a list of at least one computer command that the file is programmed to perform, retrieving a security policy from a security policy cache at the network gateway, the security policy defining restrictions for transmitting files to recipient computers, and comparing the security profile for the received file vis a vis the security policy, to determine whether transmission of the requested file to the recipient computer is to be restricted. | 20040503 | 20080826 | 20050106 | 68120.0 | 7 | REVAK, CHRISTOPHER A | METHOD AND SYSTEM FOR CACHING AT SECURE GATEWAYS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,839,113 | ACCEPTED | Serial self-adaptable transmission line | A self-adaptable transmission line (SATL) according to the present invention is implemented as a single signal path coupled between an SATL transmitter and an SATL receiver. The SATL transmitter controls the process of transmission in an SATL architecture. Data to be sent by the SATL transmitter are first encoded to the appropriate symbol before being serialized and transmitted on the SATL. A symbol transfer starts with an event known as a start-of-symbol (SOS) event, which can be, for example, a low-to-high transition. The SATL receiver samples and deserializes the incoming bitstream, and then decodes the symbol thus received. Upon detection of an SOS by the SATL receiver, the SATL receiver's logic is reset to its initial state, ready to receive the next symbol. | 1. A receiver comprising: a symbol decoder; and a start-of-symbol detector, coupled to receive a start-of-symbol signal from said symbol decoder. 2. The receiver of claim 1, wherein said symbol decoder comprises: a counter; a first comparator, coupled to said counter; and a second comparator, coupled to said counter. 3. The receiver of claim 2, wherein said symbol decoder further comprises: a first storage unit, coupled to said first comparator; and a second storage unit, coupled to said second comparator. 4. The receiver of claim 3, wherein said first storage unit is configured to store a HighWaterMark, and said second storage unit is configured to store a LowWaterMark. 5. The receiver of claim 2, wherein said symbol decoder further comprises: a first storage unit, coupled to said first comparator; and a second storage unit, coupled to said second comparator 6. The receiver of claim 5, wherein said counter is configured to maintain a setSampleCnt, said first storage unit is configured to store a HighWaterMark, said second storage unit is configured to store a LowWaterMark, said first comparator is configured to determine if said setSampleCnt is greater than said HighWaterMark, and said second comparator is configured to determine if said setSampleCnt is greater than said LowWaterMark. 7. The receiver of claim 6, wherein said symbol decoder further comprises: signal logic, wherein said signal logic is coupled to said first comparator and said second comparator, and said signal logic is configured to generate a SyncDetect signal. 8. The receiver of claim 6, wherein said signal logic is further configured to generate a BitLine signal, said BitLine signal is equal to an output of said first comparator, if said setSampleCnt is greater than said HighWaterMark, and said BitLine signal is equal to an output of said second comparator, if said setSampleCnt is not greater than said LowWaterMark. 9. The receiver of claim 7, wherein said signal logic is configured to generate a SyncDetect signal, and said SyncDetect signal is asserted if said setSampleCnt is not greater than said HighWaterMark and said setSampleCnt is greater than said LowWaterMark. 10. The receiver of claim 6, wherein said symbol decoder further comprises: a symbol decoder controller, wherein said symbol decoder controller is coupled to said first comparator and said second comparator, said symbol decoder controller is configured to generate a DataValid signal, and said DataValid signal is asserted if said setSampleCnt is greater than said HighWaterMark or said setSampleCnt is not greater than said LowWaterMark. 11. The receiver of claim 1, wherein said symbol decoder is configured to receive a symbol, indicate said symbol is a synchronization symbol, if said symbol is said synchronization symbol, and generate a data value, if said symbol is not a synchronization symbol. 12. The receiver of claim 11, wherein said symbol decoder is configured to receive a symbol, indicate said symbol is a synchronization symbol, if said symbol is said synchronization symbol, and generate a data value, if said symbol is not a synchronization symbol. 13. The receiver of claim 12, wherein said symbol comprises a plurality of symbol elements, each of a first number of said symbol elements is set to a first logical value, if said data value is equal to a first value, each of a second number of said symbol elements is set to said first logical value, if said data value is equal to a second value, and each of a third number of said symbol elements is set to said first logical value, if said symbol is said synchronization symbol. 14. The receiver of claim 13, wherein said first number is greater than said second number, said third number is not equal to said first number, and said third number is not equal to said second number. 15. The receiver of claim 14, wherein said third number is less than said first number, and said third number is greater than said second number. 16. The transmitter of claim 15, wherein each of a fourth number of said symbol elements is set to a second logical value, if said data value is equal to said first value, each of a fifth number of said symbol elements is set to said second logical value, if said data value is equal to said second value, and each of a sixth number of said symbol elements is set to said second logical value, if said symbol is said synchronization symbol. 17. The receiver of claim 1, further comprising: a synchronizer, coupled to said symbol decoder and said symbol decoder; and a parallel unit, coupled to said symbol decoder and said symbol decoder. 18. The receiver of claim 17, wherein said symbol decoder is configured to provide a SyncDetect signal, a BitLine signal and a DataValid signal to said parallel unit. 19. The receiver of claim 17, wherein said synchronizer is a dual-rank synchronizer. 20. A transmitter comprising: an encoder, wherein said encoder is configured to generate a symbol based on a value of information received by said encoder, said symbol comprises a plurality of symbol elements, said encoder is further configured to set each of a first number of said symbol elements to a first logical value, if said value is equal to a first value, said encoder is further configured to set each of a second number of said symbol elements to said first logical value, if said value is equal to a second value, said encoder is further configured to set each of a third number of said symbol elements to said first logical value, if said encoder is to generate a synchronization symbol, said first number is greater than said second number, said third number is not equal to said first number, and said third number is not equal to said second number. 21. The transmitter of claim 20, wherein said third number is less than said first number, and said third number is greater than said second number. 22. The transmitter of claim 21, wherein said encoder is further configured to set each of a fourth number of said symbol elements to a second logical value, if said value is equal to said first value, said encoder is further configured to set each of a fifth number of said symbol elements to said second logical value, if said value is equal to said second value, and said encoder is further configured to set each of a sixth number of said symbol elements to said second logical value, if said encoder is to generate said synchronization symbol. 23. The transmitter of claim 22, wherein said fourth number is less than said fifth number, said sixth number is not equal to said fourth number, and said sixth number is not equal to said fifth number. 24. The transmitter of claim 23, wherein said sixth number is greater than said fourth number, and said sixth number is less than said fifth number. 25. The transmitter of claim 24, wherein each of said symbol elements is a bit, said first logical value is a logical one, and said second logical value is a logical zero. 26. The transmitter of claim 20, further comprising: a SendSync signal input, wherein said encoder is further configured to receive a SendSync signal at said SendSync signal input and to generate said synchronization symbol upon an assertion of said SendSync signal. 27. The transmitter of claim 26, wherein said third number is less than said first number, and said third number is greater than said second number. 28. The transmitter of claim 27, wherein said encoder is further configured to set each of a fourth number of said symbol elements to a second logical value, if said value is equal to said first value, said encoder is further configured to set each of a fifth number of said symbol elements to said second logical value, if said value is equal to said second value, and said encoder is further configured to set each of a sixth number of said symbol elements to said second logical value, if said encoder is to generate said synchronization symbol. 29. The transmitter of claim 26, further comprising: a serializer, coupled to said encoder. 30. A method comprising: receiving a symbol; incrementing a count in response to said symbol; decrementing said count in response to said symbol; comparing said count to a first limit; and generating a data value, wherein said generating is based on said comparing said count to said first limit. 31. The method of claim 30, further comprising: comparing said count to a second limit, wherein said generating is further based on said comparing said count to said second limit. 32. The method of claim 31, further comprising: receiving a start-of-symbol. 33. The method of claim 32, further comprising: causing said comparing said count to said first limit and said comparing said count to said second limit to be performed upon said receiving said start-of-symbol. 34. The method of claim 32, wherein said count is reset in response to said receiving said start-of-symbol. 35. The method of claim 34, wherein said count is reset to a middlePoint value. 36. The method of claim 31, wherein said first limit is a HighWaterMark, and said second limit is a LowWaterMark. 37. The method of claim 36, wherein said generating said data value comprises: generating a first data value, if said count is greater than said HighWaterMark, and generating a second data value, if said count is not greater than said LowWaterMark. 38. The method of claim 37, wherein said first data value is a logic “1”, and said second data value is a logic “0”. 39. The method of claim 36, further comprising: indicating that said symbol is a synchronization symbol, if said count is not greater than said HighWaterMark and greater than said LowWaterMark. 40. The method of claim 30, wherein said receiving said symbol comprises: sampling a signal, wherein said signal represents said symbol. 41. The method of claim 40, wherein said sampling is performed on each cycle of a receive clock. 42. The method of claim 40, further comprising: incrementing said count for each cycle of a receive clock, while said signal is equal to a first value; and decrementing said count for each cycle of said receive clock, while said signal is equal to a second value. 43. The method of claim 40, wherein said sampling generates a plurality of sample values, and further comprising: incrementing said count for each of said sample values that is equal to a first value; and decrementing said count for each of said sample values that is equal to a second value. 44. The method of claim 43, further comprising: receiving a start-of-symbol. 45. The method of claim 44, further comprising: resetting said count to a middlePoint value in response to said receiving said start-of-symbol; and causing said comparing said count to said first limit and said comparing said count to said second limit to be performed upon said receiving said start-of-symbol. 46. The method of claim 40, wherein said sampling is performed using a receive clock, said signal is generated using a transmit clock, and a receive clock frequency of said receive clock is greater than a transmit clock frequency of said transmit clock. 47. The method of claim 46, wherein a ratio of said receive clock frequency to said transmit clock frequency is greater than 1:1 and not greater than a maxClockRatio. 48. The method of claim 46, further comprising: receiving a start-of-symbol; and resetting said count to a middlePoint in response to said receiving said start-of-symbol, wherein said symbol comprises a plurality of symbol elements, and said middlePoint is greater than a number of said symbol elements plus a serialBitMargin, multiplied by said maxClockRatio. 49. The method of claim 30, wherein said symbol comprises a plurality of symbol elements, said symbol represents a logic “1” if a first number of said symbol elements are a first value, and said symbol represents a logic “0” if a second number of said symbol elements are said first value. 50. The method of claim 49, wherein said symbol is a synchronization symbol if a third number of said symbol elements are a first value, said third number is not greater than said first number, and said third number is greater than said second number. 51. A computer program product comprising: a first set of instructions, executable on a computer system, configured to receive a symbol; a second set of instructions, executable on said computer system, configured to increment a count in response to said symbol; a third set of instructions, executable on said computer system, configured to decrement said count in response to said symbol; a fourth set of instructions, executable on said computer system, configured to compare said count to a first limit; a fifth set of instructions, executable on said computer system, configured to generate a data value, wherein said fifth set of instructions use a result of said fourth set of instructions; and a set of instructions, executable on said computer system, configured to computer readable media, wherein said computer program product is encoded in said computer readable media. 52. The computer program product of claim 51, further comprising: a sixth set of instructions, executable on said computer system, configured to compare said count to a second limit, said sixth set of instructions use a result of said fourth set of instructions. 53. The computer program product of claim 52, further comprising: a seventh set of instructions, executable on said computer system, configured to receive a start-of-symbol. 54. The computer program product of claim 53, further comprising: an eighth set of instructions, executable on said computer system, configured to cause said fourth set of instructions and said sixth set of instructions to be performed upon said start-of-symbol being received. 55. The computer program product of claim 51, wherein said count is reset in response to said receiving said start-of-symbol. 56. The computer program product of claim 51, further comprising: a sixth set of instructions, executable on said computer system, configured to sample a signal, wherein said signal represents said symbol. 57. The computer program product of claim 56, wherein said sixth set of instructions are further configured to perform said sampling on each cycle of a receive clock. 58. The computer program product of claim 56, further comprising: a seventh set of instructions, executable on said computer system, configured to increment said count for each cycle of a receive clock, while said signal is equal to a first value; and an eighth set of instructions, executable on said computer system, configured to decrement said count for each cycle of said receive clock, while said signal is equal to a second value. 59. The computer program product of claim 56, wherein said sixth set of instructions generates a plurality of sample values, and further comprising: a seventh set of instructions, executable on said computer system, configured to increment said count for each of said sample values that is equal to a first value; and an eighth set of instructions, executable on said computer system, configured to decrement said count for each of said sample values that is equal to a second value. 60. The computer program product of claim 59, further comprising: a seventh set of instructions, executable on said computer system, configured to receive a start-of-symbol; an eighth set of instructions, executable on said computer system, configured to reset said count to a middlePoint value in response to said start-of-symbol being received; and a ninth set of instructions, executable on said computer system, configured to cause said fourth set of instructions and said sixth set of instructions to be performed upon said start-of-symbol being received. 61. The computer program product of claim 51, wherein said symbol comprises a plurality of symbol elements, said symbol represents a logic “1” if a first number of said symbol elements are a first value, and said symbol represents a logic “0” if a second number of said symbol elements are said first value. 62. The computer program product of claim 61, wherein said symbol is a synchronization symbol if a third number of said symbol elements are a first value, said third number is not greater than said first number, and said third number is greater than said second number. 63. An apparatus comprising: means for receiving a symbol; means for incrementing a count in response to said symbol; means for decrementing said count in response to said symbol; means for comparing said count to a first limit; and means for generating a data value, wherein said means for generating uses an output of said means for comparing said count to said first limit. 64. The apparatus of claim 63, further comprising: means for comparing said count to a second limit, wherein said means for generating is further based on an output of said means for comparing said count to said second limit. 65. The apparatus of claim 64, further comprising: means for receiving a start-of-symbol. 66. The apparatus of claim 65, further comprising: means for causing said means for comparing said count to said first limit and said means for comparing said count to said second limit to operate in response to said start-of-symbol being received. 67. The apparatus of claim 65, wherein said count is reset in response to said start-of-symbol being received. 68. The apparatus of claim 63, wherein said means for receiving said symbol comprises: means for sampling a signal, wherein said signal represents said symbol. 69. The apparatus of claim 68, wherein said means for sampling is configured to perform sampling on each cycle of a receive clock. 70. The apparatus of claim 68, further comprising: means for incrementing said count for each cycle of a receive clock, while said signal is equal to a first value, and means for decrementing said count for each cycle of said receive clock, while said signal is equal to a second value. 71. The apparatus of claim 68, wherein said means for sampling generates a plurality of sample values, and further comprising: means for incrementing said count for each of said sample values that is equal to a first value; and means for decrementing said count for each of said sample values that is equal to a second value. 72. The apparatus of claim 71, further comprising: means for receiving a start-of-symbol. 73. The apparatus of claim 72, further comprising: means for resetting said count to a middlePoint value in response to said start-of-symbol being received; means for causing said means for comparing said count to said first limit to compare said count to said first limit upon said start-of-symbol being received; and means for causing said means for comparing said count to said second limit to compare said count to said second limit upon said start-of-symbol being received. 74. The apparatus of claim 68, wherein said means for sampling is configured to receive a receive clock, said signal is generated using a transmit clock, and a receive clock frequency of said receive clock is greater than a transmit clock frequency of said transmit clock. 75. The apparatus of claim 74, wherein a ratio of said receive clock frequency to said transmit clock frequency is greater than 1:1 and not greater than a maxClockRatio. 76. The apparatus of claim 74, further comprising: means for receiving a start-of-symbol; and means for resetting said count to a middlePoint in response to said start-of-symbol being received, wherein said symbol comprises a plurality of symbol elements, and said middlePoint is greater than a number of said symbol elements plus a serialBitMargin, multiplied by said maxClockRatio. 77. The apparatus of claim 63, wherein said symbol comprises a plurality of symbol elements, said symbol represents a logic “1” if a first number of said symbol elements are a first value, and said symbol represents a logic “0” if a second number of said symbol elements are said first value. 78. The apparatus of claim 77, wherein said symbol is a synchronization symbol if a third number of said symbol elements are a first value, said third number is not greater than said first number, and said third number is greater than said second number. 79. A method comprising: generating a first number of a first plurality of symbol elements of a first symbol, wherein said first symbol is a synchronization symbol, and each of said first number of said first plurality of symbol elements have a first logical value; and generating a second number of a second plurality of symbol elements of a second symbol, wherein said second symbol represents a data value of data encoded in said second symbol, each of said second number of said second plurality of symbol elements have said first logical value, said first number is not equal to said second number, said second number is equal to a third number, if said data value is equal to a first value, said second number is equal to a fourth number, if said data value is equal to a second value, and said third number is greater than said fourth number. 80. The method of claim 79, further comprising: generating a fifth number of a third plurality of symbol elements of said first symbol, wherein each of said fifth number of said third plurality of symbol elements have a second logical value; and generating a sixth number of a fourth plurality of symbol elements of said second symbol, wherein each of said sixth number of said fourth plurality of symbol elements have said second logical value, said fifth number is not equal to said sixth number, said second number is equal to a seventh number, if said data value is equal to said first value, said second number is equal to a eighth number, if said data value is equal to said second value, and said seventh number is less than said eighth number. 81. The method of claim 80, further comprising: transmitting said first plurality of symbol elements; transmitting said third plurality of symbol elements after said first plurality of symbol elements are transmitted, transmitting said second plurality of symbol elements, and transmitting said fourth plurality of symbol elements after said second plurality of symbol elements are transmitted. 82. The method of claim 80, wherein said first number is less than said third number, said first number is greater than said fourth number, said fifth number is greater than said seventh number, and said fifth number is less than said eighth number. 83. The method of claim 80, wherein each of said first plurality of symbol elements is a bit, each of said second plurality of symbol elements is a bit, each of said third plurality of symbol elements is a bit, each of said fourth plurality of symbol elements is a bit, said first logical value is a logical one, and said second logical value is a logical zero. 84. The method of claim 83, wherein said first number is not greater than said third number, and said first number is greater than said fourth number. 85. A computer program product comprising: a first set of instructions, executable on a computer system, configured to generate a first number of a first plurality of symbol elements of a first symbol, wherein said first symbol is a synchronization symbol, and each of said first number of said first plurality of symbol elements have a first logical value; and a second set of instructions, executable on said computer system, configured to generate a second number of a second plurality of symbol elements of a second symbol, wherein said second symbol represents a data value of data encoded in said second symbol, each of said second number of said second plurality of symbol elements have said first logical value, said first number is not equal to said second number, said second number is equal to a third number, if said data value is equal to a first value, said second number is equal to a fourth number, if said data value is equal to a second value, and said third number is greater than said fourth number; and computer readable media, wherein said computer program product is encoded in said computer readable media. 86. The computer program product of claim 85, further comprising: a third set of instructions, executable on said computer system, configured to generate a fifth number of a third plurality of symbol elements of said first symbol, wherein each of said fifth number of said third plurality of symbol elements have a second logical value; and a fourth set of instructions, executable on said computer system, configured to generate a sixth number of a fourth plurality of symbol elements of said second symbol, wherein each of said sixth number of said fourth plurality of symbol elements have said second logical value, said fifth number is not equal to said sixth number, said second number is equal to a seventh number, if said data value is equal to said first value, said second number is equal to a eighth number, if said data value is equal to said second value, and said seventh number is less than said eighth number. 87. The computer program product of claim 86, further comprising: a fifth set of instructions, executable on said computer system, configured to transmit said first plurality of symbol elements; a sixth set of instructions, executable on said computer system, configured to transmit said third plurality of symbol elements after said first plurality of symbol elements are transmitted; a seventh set of instructions, executable on said computer system, configured to transmit said second plurality of symbol elements; and a eighth set of instructions, executable on said computer system, configured to transmit said fourth plurality of symbol elements after said second plurality of symbol elements are transmitted. 88. The computer program product of claim 86, wherein said first number is less than said third number, said first number is greater than said fourth number, said fifth number is greater than said seventh number, and said fifth number is less than said eighth number. 89. The computer program product of claim 86, wherein each of said first plurality of symbol elements is a bit, each of said second plurality of symbol elements is a bit, each of said third plurality of symbol elements is a bit, each of said fourth plurality of symbol elements is a bit, said first logical value is a logical one, and said second logical value is a logical zero. 90. The computer program product of claim 89, wherein said first number is not greater than said third number, and said first number is greater than said fourth number. 91. An apparatus comprising: means for generating a first number of a first plurality of symbol elements of a first symbol, wherein said first symbol is a synchronization symbol, and each of said first number of said first plurality of symbol elements have a first logical value; and means for generating a second number of a second plurality of symbol elements of a second symbol, wherein said second symbol represents a data value of data encoded in said second symbol, each of said second number of said second plurality of symbol elements have said first logical value, said first number is not equal to said second number, said second number is equal to a third number, if said data value is equal to a first value, said second number is equal to a fourth number, if said data value is equal to a second value, and said third number is greater than said fourth number. 92. The apparatus of claim 91, further comprising: means for generating a fifth number of a third plurality of symbol elements of said first symbol, wherein each of said fifth number of said third plurality of symbol elements have a second logical value; and means for generating a sixth number of a fourth plurality of symbol elements of said second symbol, wherein each of said sixth number of said fourth plurality of symbol elements have said second logical value, said fifth number is not equal to said sixth number, said second number is equal to a seventh number, if said data value is equal to said first value, said second number is equal to a eighth number, if said data value is equal to said second value, and said seventh number is less than said eighth number. 93. The apparatus of claim 92, further comprising: means for transmitting said first plurality of symbol elements; means for transmitting said third plurality of symbol elements after said first plurality of symbol elements are transmitted, means for transmitting said second plurality of symbol elements, and means for transmitting said fourth plurality of symbol elements after said second plurality of symbol elements are transmitted. 94. The apparatus of claim 92, wherein said first number is less than said third number, said first number is greater than said fourth number, said fifth number is greater than said seventh number, and said fifth number is less than said eighth number. 95. The apparatus of claim 92, wherein each of said first plurality of symbol elements is a bit, each of said second plurality of symbol elements is a bit, each of said third plurality of symbol elements is a bit, each of said fourth plurality of symbol elements is a bit, said first logical value is a logical one, and said second logical value is a logical zero. 96. The apparatus of claim 95, wherein said first number is not greater than said third number, and said first number is greater than said fourth number. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field of data communications, and more particularly to a method and system for operating a serial self-adaptable transmission line that provides communications between devices. 2. Description of the Related Art Today's integrated circuits (ICs) are typically implemented using hundreds of input, output, input/output (I/O), power and ground pins, generically referred to as simply “pins”. As will be appreciated, the larger number of pins, the greater complexity in the design, manufacture and use of such ICs. IC designers therefore often go to great lengths to minimize the number of pins required by the various modules of a given design, in order to reduce the overall number of pins required to implement the given IC. Moreover, ICs sometimes required alternate paths of communication that can be called into service in the event of a failure or other situation. For example, the internal states of today's ICs are typically programmed using a processor interface. Such a processor interface can include, for example, a 32-bit data bus, a 16-bit address bus and various control signals. However, it is often desirable to program certain internal registers prior to an IC's processor interface becoming operational. For example, a PLL generating the IC's core clock may be programmed in different ways (changing bias values, frequency ratios and so on). However, that same clock may be used to operate the processor interface. Thus, the processor interface cannot be used to program the PLL, because the processor interface cannot be used until the PLL is programmed. Instead, the PLL needs to be programmed via another interface. This alternate interface should be independent from the PLL itself, and should, as noted, employ a low pin-count technique. Another application of such a low-pin-count interface is as an output to drive a set of 16-bit LEDs. As will be appreciated, it is desirable to employ an interface can drive such LEDs without the IC being required to generate and output 16 different signals, due to the number of pins that would be required by such an approach. As will be appreciated, then, the need for low-pin count interfaces appears in many situations in today's devices. This need has led to the development of a variety of interface standards, such as asynchronous serial communications (e.g., RS-232) and other such approaches (e.g., the inter-IC (I2C) bus). Unfortunately, such interfaces are not without their infirmities. Such interfaces may require a certain frequency relationship between the receiver and the transmitter for proper operation, potentially limiting the devices that are able to communicate with one another. Moreover, such interfaces are sometimes proprietary in nature. Often, such interfaces require more than one input or output pin on an IC implementing the given technique. More specifically, a communications link between ICs typically requires a minimum of two signal lines, one signal line for the clock signal, and one signal line for the serialized datastream, although other solutions require many more signal lines (e.g., RS-232). The I2C-bus is an example of a serial protocol that employs two wires. Such techniques provide a relatively low-pin count solution, and so are very attractive in pin-limited designs. However, it is desirable to allow flexibility in clocking relationships, as well as to further reduce the pin-count required and to avoid proprietary technology. What is desired, then, is to reduce the number of communication lines to a single communications line, in order to further reduce the pin count of ICs employing such a technique, as well as the area consumed by printed circuit board layouts in such designs. It is also desirable to keep the logic used to implement such a communications protocol simple, in order to minimize the area required on the integrated circuit. Moreover, as noted, such a technique should allow flexibility in the relationship between the transmitter and receiver clocks. SUMMARY OF THE INVENTION In one embodiment, a receiver is disclosed. This receiver includes a symbol decoder and a start-of-symbol detector. The start-of-symbol detector is coupled to receive a start-of-symbol signal from the symbol decoder In another embodiment, a transmitter is disclosed. This transmitter includes an encoder. The encoder is configured to generate a symbol based on a value of information received by the encoder. The symbol comprises a plurality of symbol elements. The encoder is further configured to set each of a first number of the symbol elements to a first logical value, if the value is equal to a first value. The encoder is further configured to set each of a second number of the symbol elements to the first logical value, if the value is equal to a second value. The encoder is further configured to set each of a third number of the symbol elements to the first logical value, if the encoder is to generate a synchronization symbol. The first number is greater than the second number, the third number is not equal to the first number, and the third number is not equal to the second number. In yet another embodiment, a method is disclosed. This method includes receiving a symbol, incrementing a count in response to the symbol, decrementing the count in response to the symbol, comparing the count to a first limit, and generating a data value. The generating thus performed is based on comparing the count to the first limit. In still another embodiment, a method is disclosed. This method includes generating a first number of a first number of symbol elements of a first symbol and generating a second number of a second number of symbol elements of a second symbol. The first symbol is a synchronization symbol, and each of the first number of the first number of symbol elements have a first logical value. The second symbol represents a data value of data encoded in the second symbol. Each of the second number of the second number of symbol elements have the first logical value, and the first number is not equal to the second number. The second number is equal to a third number, if the data value is equal to a first value, and the second number is equal to a fourth number, if the data value is equal to a second value. The third number is greater than the fourth number. The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. FIG. 1 is a block diagram illustrating the use of a self-adaptable transmission line (SATL) according to the present invention. FIG. 2 is a block diagram showing an example of the components within a transmitting device and a receiving device in an embodiment of the present invention. FIG. 3 is a graph depicting a waveform representation of a scheme according to the present invention. FIG. 4 is an illustration of an encoded bitstream, encoded according to the present invention. FIG. 5 is a graph illustrating the receipt and conversion of an SATL data stream according to the present invention. FIG. 6 is a block diagram of an SATL transmitter according to the present invention. FIG. 7 is a block diagram illustrating an SATL transmitter according to the present invention in greater detail. FIG. 8 is a block diagram illustrating an SATL receiver according to the prevent invention. FIG. 9 is a block diagram illustrating the elements of an SATL receiver according to the present invention in greater detail. FIG. 10 is a block diagram illustrating a symbol encoder according to the present invention. FIG. 11 is a flow diagram illustrating a process of transmitting a data word according to the present invention. FIG. 12 is a flow diagram of a process reflecting one example of the operations performed by a symbol decoder according the present invention. FIG. 13 is a flow diagram illustrating a process for decoding a symbol according to the present invention. The use of the same reference symbols in different drawings indicates similar or identical items. DETAILED DESCRIPTION The following is intended to provide a detailed description of an example of the invention and should not be taken to be limiting of the invention itself. Rather, any number of variations may fall within the scope of the invention which is defined in the claims following the description. Introduction A self-adaptable transmission line (SATL) according to the present invention is implemented as a single signal path (e.g., wire) coupled between an SATL transmitter and an SATL receiver. The SATL transmitter controls the process of transmission in an SATL architecture. Data to be sent by the SATL transmitter are first encoded to the appropriate symbol before being serialized and transmitted on the SATL. A symbol transfer starts with an event known as a start-of-symbol (SOS) event, which can be, for example, a low-to-high transition. The SATL receiver samples and deserializes the incoming bitstream, and then decodes the symbol thus received. Upon detection of an SOS by the SATL receiver, the SATL receiver's logic is reset to its initial state, ready to receive the next symbol. An Example Architecture Employing a Self-Adaptable Transmission Line FIG. 1 is a block diagram illustrating the use of a self-adaptable transmission line (SATL) according to the present invention. Shown in FIG. 1 is an SATL signal 100 coupling a transmitting device 110 and a receiving device 120. Transmitting device 110 receives a transmit clock (TCLK) 130, which is used to time the data transmitted by transmitting device 110 as SATL signal 100. In a similar fashion, receiving device 120 receives a receive clock (RCLK) 140, which is used to time the receipt of the signal carried by SATL signal 100. Also shown are the power (VCC) and ground connections for transmitting device 110 and receiving device 120. It will be appreciated that, while multiple SATL lines can be used in conjunction with one another, a primary advantages are the reduction in pin count and circuit complexity. FIG. 2 is a block diagram showing an example of the components within transmitting device 110 and receiving device 120 in one embodiment of the present invention. In this embodiment, transmitting device 110 receives outgoing data 200. Outgoing data 200 is typically presented to transmitting device 110 as a bus (i.e., a word of parallel bits of some appropriate width). Because SATL signal 100 is typically a single serial channel, a word width of some number of bits requires that a parallel-to-serial conversion be performed. Thus, transmitting device 110 includes, in the embodiment depicted in FIG. 2, a shift register 210 that receives and stores the outgoing data word received as outgoing data 200. Shift register 210 which receives and stores the outgoing data word (received as outgoing data 200). Shift register 210 provides this outgoing data word to an encoder 220 by shifting out the bits of the outgoing data word, in a serial fashion. Encoder 220 encodes the outgoing data word as per the protocol described subsequently in connection with FIGS. 11, 12, and 13. Encoder 220 thus creates a symbol for each bit of outgoing data 200, and presents the symbols thus created to a serializer 230, which takes in each symbol and outputs the symbol elements of each symbol (typically, the bits of each symbol) in a serial fashion. Thus, as will be appreciated, two parallel-to-serial conversions are performed by the elements of transmitting device 110, the first being within shift register 210 and the second being within serializer 230. In the former case, serializer 230 serializes the parallel bits of each symbol generated by encoder 220 into a bitstream for transmission as SATL signal 100. In corresponding fashion, receiving device 120 receives SATL signal 100 at a deserializer 240, which performs a serial-to-parallel conversion on the bits of SATL signal 100. Deserializer 240 provides the symbols thus generated to a decoder 250. Decoder 250 generates an incoming data stream 260 by decoding the symbols received from deserializer 240 from symbols into the actual data bits those symbols represent. As will be appreciated, incoming data stream 260 is a bitstream, and so corresponds to the output of shift register 210. In the typical case, outgoing data 200 has a word width of some number of bits, and so incoming data stream 260 is deserialized to reconstruct the counterpart of outgoing data 200. This serial-to-parallel conversion is performed by a shift register 270, which generates incoming data 280. Thus, in the manner of transmitting device 110, receiving device 120 performs two serial-to-parallel conversions (corresponding to the two parallel-to-serial conversions performed by the elements of transmitting device 110). As a result, incoming data 280 has a word width of some number of bits, and typically, the same number of bits as outgoing data 200. As will be appreciated, this need not be the case, and a different number of bits can therefore be used for incoming data 280, if such is desirable. A protocol compatible with the present invention sets the default parameters: 1) Number of symbols; 2) Maximum clock ratio between the transmitter and the receiver (1≦RCLK/TCLK≦X); and 3) Serial bit margin (serialBitMargin) between symbols. In an embodiment of the present invention, each symbol has a value indicating how long the SATL signal is set to a logic “1” after an SOS, using the following notation: A±1 where A indicates the length of SATL=1 for that symbol, and ±1 represents the asynchronous interface between the transmitter and receiver clocks (one SATL=1 or SATL=0 may not be latched properly by the receiver). The lowest symbol starts at 2±1 instead of 1±1, because the receiver needs to detect a low-to-high transition (signifying an SOS event). Thus: symbol [ 0 ] = 2 ± 1 symbol [ i ] min = symbol [ i - 1 ] max + serialBitMargin = symbol [ i - 1 ] + 1 + serialBitMargin serialBitLength ≥ symbol [ n ] max + serialBitMargin As will be appreciated, keeping both serialBitMargin and the serial-bit length (serialBitLength) to power-of-two values simplifies implementation of this embodiment in hardware by allowing the use of shift registers, rather than multipliers and dividers. One embodiment of the present invention employs three symbols with a serialBitMargin of 2. The transmitter-to-receiver clock ratio ranges from 1 to 20. Each symbol is 16 bits long, and is represented as shown in Table 1 below. TABLE 1 An example symbol table. Symbol Encoding “0” 11110000_00000000 “SYNC” 11111111_00000000 “1” 11111111_11110000 FIG. 3 is a graph depicting a waveform representation of the above scheme is employed. As can be seen, each symbol (here, the symbols being “0”, “SYNC”, and “1”, as in Table 1) consumes 16 bit times. As can also be seen, the symbol “0” includes four bit times (the first four) of logic ones (in contrast to the “1” symbol), followed by 12 bit times of logic zeroes (in contrast to the “0” symbol). Similarly, the synchronization (“SYNC”) symbol includes eight bit times of logic ones, followed by eight bit times of logic zeroes. Finally the symbol “1” includes 12 bit times of logic ones and four bit times of logic zeroes. As will be appreciated, the encoding scheme presented in connection with FIG. 3, and elsewhere herein, is but one example of an encoding scheme according to the present invention. The data values represented by each symbol need not be encoded as noted herein, but can be encoded using other representations. For example, the graph of FIG. 3 might be interpreted as representing another sequence of symbols, such as “0”-“1”-“SYNC”, “SYNC”-“0”-“1”, or some other sequence. Moreover, the sequences of bits representing each symbol need not be evenly distributed. For example, a bit pattern of 11111111—11111100 could be used for a “1” symbol, once again a bit pattern of 11111111—00000000 could be used for a “SYNC” symbol, and a bit pattern of 11000000—00000000 could be used for a “0” symbol. In fact, as will be appreciated, any number of variants of the basic concepts presented herein can be implemented according to the present invention. For example, the sequences of bits representing each symbol need not be contiguous. Because the main goals are to use a certain overall count (within certain bounds, at least) to represent a given symbol and to examine/reset that count at a certain point in time (e.g., at SOS) in order to determine the current symbol and prepare for the next symbol, any approach that employs bit patterns that provide such information are acceptable. For example, a bit pattern of 11111100—11111100 could be used for a “1” symbol, once again a bit pattern of 11110000—11110000 could be used for a “SYNC” symbol, and a bit pattern of 11000000—11000000 could be used for a “0” symbol. In such an implementation, a mechanism is provided to distinguish an SOS from a similar transition that occurs within a symbol (e.g., using a predefined sequence of symbols at the start of a transmission, comparing the first and second halves of the current symbol or the like), although the counting would still be performed as described elsewhere herein (e.g., a sample of logic “1” would cause the count to increase, and a sample of logic “0” would cause the count to decrease). It will be appreciated that the minimum clock ratio may affect the bit patterns that can be successfully employed. For example, the fewer samples/bit time that are taken by the receiver, the longer the string of logic “1'”s (or logic “0'”s) needs to be, in order for the symbol to be correctly identified by the receiver. It will be further appreciated that these and other variations will be apparent to one of skill in the art, in light of the present description, and so are considered to be within the scope of the present invention. The serialBitLength is determined for this example based on the following default parameters, in the manner described previously: 1) Number of symbols=3 2) Minimum clock ratio=1 3) SerialBitMargin=2 The minimum encoding scheme is determined by the following calculations: symbol[0]=2±1 symbol[1]min=symbol[0]max+serialBitMargin=3+2=5 symbol[1]=6±1 symbol[2]min=symbol[1]max+serialBitMargin=7+2=9 symbol[2]=10±1 Thus, the minimum serialBitLength is equal to 11 plus the serialBitMargin. As will be appreciated, using a serialBitLength of 16 bits in this case meets these requirements, while simplifying the design and implementation of the hardware employed in realizing a system according to the present invention. It will also be appreciated that, for a given serialBitLength (e.g., 16 bits), several different numbers of symbols may be able to be implemented (e.g., for a serialBitLength of 16 bits, the number of symbols can be 3, 5 or 7, for example). Again, if a non-contiguous bit pattern is used, some mechanism for distinguishing between an SOS and a similar transition within a symbol is mandated. FIG. 4 is an illustration of a bitstream that reflects symbols encoded according to the present invention. As can be seen, interspersed among the symbols representing the data are periodic “SYNC” symbols, which are sent regularly, to ensure synchronization of the receiver. Thus, in the example depicted in FIG. 4, a “SYNC” symbol is sent followed by the symbols for “0110” (depicted in FIG. 4 as “0”, “1”, “1”, and “0”). After the four symbols are sent, another “SYNC” symbol is sent and the process repeats with the symbols for the next four data bits (the first two of which are shown in FIG. 4; “1” and “0”). As will be appreciated, a “SYNC” symbol allows an SATL receiver to synchronize itself with the incoming bitstream by providing a symbol that, nominally, will result in the same number of logic ones and logic zeroes being sampled from the incoming symbol's bitstream (although, given the potential for sampling noise, some sort of noise margin is typically employed that allows some acceptable deviation from this ideal, while still identifying the symbol as a “SYNC” symbol). Thus, the logic-one-to-logic-zero transition (in contrast to an SOS, which is just the opposite (a logic-zero-to-logic-one transition), in the embodiment discussed here) is centered between SOS events. This basically provides a 50% duty cycle signal at the transmit clock's frequency divided by the serialBitLength (here, 16 bits), providing the maximum distance between the logic-one-to-logic-zero transition, and the preceding/following SOSs (logic-zero-to-logic-one transitions). Logic designed to implement the present invention requires a few parameters, counters and variables to deserialize and decode the data stream. Parameters are typically a hard-coded value, which determine the working range of the transmitter-receiver pair. As will be appreciated (and as described subsequently), such information can also be programmed into registers, allowing a transmitter-receiver pair according to the present invention to be reconfigured, as desired. These parameters, counters and variables, as well as their meaning and their values, are given in Table 2. TABLE 2 An example of variables, counters and parameters. Name Description Type Value serialBitLength Number of serial bits parameter specified per symbol. maxClockRatio Maximum clock ratio. parameter specified (TCLK/RCLK) maxSampleSetCnt Maximum value of the parameter serialBitLength * maxClockRatio sample set counter. serialBitMargin Margin in bit for the parameter specified “SYNC” symbol. middlePoint The middle point from parameter middlePoint > maxSampleSetCnt + which incrementing serialBitMargin * starts, upon receipt of maxClockRatio) an SOS (in the example given here). sampleSetCnt S-bit counter to count counter middlePoint, at SOS the number of samples +1 if SATL = 1 between two SOS −1 if SATL = 0 events for which the S formula: value of SATL = 1. (2S/2) > middlePoint; or 2(S−1) > middlePoint sampleCnt (S-1)-bit counter to counter 0 when SOS count the number of +1 otherwise samples between two SOSs. clockRatio Ratio between the variable sampleCnt/serialBitLength, receiver clock and the at SOS transmitter clock. lowWaterMark Low water mark, the variable middlePoint − (LWM) lower limit of (serialBitMargin * clockRatio) setSampleCnt at (or below) which a symbol “0” is detected. highWaterMark High water mark, the variable middlePoint + (HWM) upper limit of (serialBitMargin clockRatio) setSampleCnt at (or beyond) which a symbol “1” is detected. A protocol according to the present invention is scalable in a number of ways, including changes to: 1) Number of symbols (by increasing the serial-bit length: bitPerSymbol), 2) Maximum clock ratio (by increasing sample counter size: sampleSetCnt), and 3) Minimum clock ratio (by increasing both the serial-bit length and the sample counter size: bitPerSymbol and sampleSetCnt). All three of these variables (clockRatio, lowWaterMark and highWaterMark) allow the receiver to self-adjust to the incoming data stream, and in fact, allow such adjustment to occur on every SOS event. The watermarks for the current symbol can actually be based on the result of the previous symbol and SOS. The present invention's self-adaptability is advantageous in several respects. As will be appreciated, the present invention largely decouples the receive clock (RCLK) from the transmit clock (TCLK) by employing a sampling technique that requires only the identification of certain points in the incoming SATL signal. In fact, in certain embodiments, only one point need be identified: the SOS, which is used both to identify the point at which the count is to be evaluated and to reset the count in preparation for decoding the next symbol. The only information regarding the relationship between TCLK and RCLK that is needed is the maximum ratio of TCLK to RCLK (i.e., maxClockRatio, from Table 2). As will be appreciated, the theoretical lower limit of the range of ratios of TCLK to RCLK is 1:1, which is the minimum needed to ensure that the SATL receiver generates a bit for each bit transmitted by the SATL transmitter. However, this assumes that the SATL signal generated using TCLK, is sampled at a point at which aliasing is not an issue. To ensure this is the case, one would have to employ some mechanism that would allow the SATL receiver to know when to sample (i.e., some mechanism that defines the phase relationship between TCLK and RCLK (as the frequency relationship would already be known, that being 1:1)). Thus, in implementing a communications system according to the present invention, it is desirable to employ a minimum ratio of TCLK to RCLK of more than 1:1 (i.e., RCLK>TCLK). In so doing, the SATL signal is effectively over-sampled, thus allowing such a system to tolerate an erroneous sample. By selecting a minimum ratio of more than 1:1, the SATL receiver is thus able to generate the correct symbol. The parameter serialBitMargin, noted above, is related to this concept, in that serialBitMargin defines the system's tolerance for “sampling noise”. This sampling noise is the number of samples that such a system can count in the case of a synchronization symbol, above or below the middlePoint, and still decode the symbol being sampled as a synchronization symbol (“Sync” symbol). Thus, the watermarks are set using the serialBitMargin, and allow such a system to tolerate a given amount of noise. This is also advantageous because no synchronization circuitry is required. By avoiding the need for phase-locked loops (PLLs) and the like, implementation of a SATL transmitter and receiver is simplified. Moreover, the resulting receiver design is smaller, thus consuming less IC area and reducing IC cost. The area requirements of such a design are also minimized by limiting the size of the counter used in the SATL receiver (for setSampleCount) to S bits, where: 2(S−1)>middlePoint middlePoint>maxSampleSetCnt+(serialBitMargin*maxClockRatio) Since, maxSampleSetCnt=serialBitLength*maxClockRatio Then, 2(S−1)>middlePoint>(serialBitLength+serialBitMargin)*maxClockRatio 2(S−1)>(serialBitLength+serialBitMargin)*maxClockRatio S>SQRT((serialBitLength+serialBitMargin)*maxClockRatio)+1 The above calculation can be taken to imply that S is an integer, such that the size of the setSampleCnt counter is sized to some power of 2. As will also be appreciated from the above calculation, S is therefore proportionally related to the maxClockRatio. Once the maxClockRatio is selected, the size of the setSampleCnt counter can then be set. This allows the IC designer to use their judgment as to the tradeoff between the IC area consumed by the design, and the clock ratios to be supported. In a converse sense, RCLK and/or TCLK (and so maxClockRatio) can be set to avoid sampling the SATL signal at a rate that could overflow the SATL receiver's setSampleCnt counter. This allows a circuit designer to choose appropriate values for RCLK and/or TCLK in light of the architectural choices made by the IC designer. Thus, TCLK can be, and typically is, completely independent of RCLK, and vice versa. It will This ability to tolerate variations in the frequency and phase relationship between TCLK and RCLK is also advantageous because their relationship can vary dynamically. Once a range of clock ratios is determined, a system according to the present invention can be programmed to use any clock ratio within that range, by properly selecting serialBitLength, maxClockRatio and serialBitMargin. This information can be changed dynamically, at each data word, or even at each symbol, in order to account for changes in clock frequencies, environmental effects (e.g., altering the maximum transmission frequency) and other such conditions. FIG. 5 is a graph illustrating the value of sampleSetCnt as an SATL data stream is received and converted. As can be seen in FIG. 5, sampleSetCnt begins at a middlePoint and is incremented as logical 1's are detected by the SATL receiver. This continues until logical 0's are detected, at which point sampleSetCnt is decremented for each 0 received by the SATL receiver. This continues until a start-of-symbol (SOS) is detected, that being a logical 0 to logical 1 transition, in the implementation described herein. Upon the detection of an SOS, the SATL receiver determines the value of the sampleSetCnt, and how it compares with the HighWaterMark (HWM) and LowWaterMark (LWM). If the sampleSetCnt is greater than the HighWaterMark, a symbol “1” has been detected; if the sampleSetCnt is below the LowWaterMark, a “0” symbol has been detected; and if the sampleSetCnt is between the LowWaterMark and the HighWaterMark, a “SYNC” symbol has been detected. Thus, the example depicted in FIG. 5, the first starter symbol results in the detection of a “SYNC” symbol, the second starter symbol results in the detection of a “0” symbol, and the detection of the third starter symbol results in the detection of a “1” symbol. The variables, counters and parameters discussed above are best illustrated by an example. Table 3 provides a configuration example for the receiver for TCLK=20 MHz and RCLK=200 MHz. TABLE 3 Receiver configuration example. Name Value Note serialBitLength 16 maxClockRatio 20 maxSampleSetCnt 16 * 20 = 320 serialBitMargin 2 middlePoint 320 + (2 * 20) = 360 sampleSetCnt depends on the symbol 2S/2 > 360, so S = 10 sampleCnt 16 * 10 = 160 S − 1 = 9 clockRatio 160/16 = 10 lowWaterMark 360 − (2 * 10) = 340 highWaterMark 360 + (2 * 10) = 380 It is to be understood that the serialBitMargin is 2, in this example, as a result of MIN(symbol[1]=6±1)−MAX(symbol[0]=2±1)=5−3=2. FIG. 6 is a block diagram of an SATL transmitter 600 according to the present invention. As before (in FIG. 1), the SATL transmitter (SATL transmitter 600) receives a transmit clock (TCLK) 610. SATL transmitter 600 also receives data 620, which corresponds to outgoing data 200 of FIG. 2. In order to put SATL transmitter 600 into a known state, SATL transmitter 600 also receives a reset signal 630. In turn, SATL transmitter 600 generates and transmits an SATL signal 640 that corresponds to SATL signal 100 of FIG. 1. FIG. 7 is a block diagram illustrating SATL transmitter 600 in greater detail. As before, SATL transmitter 600 receives transmit clock 610, data 620, and reset signal 630, and generates SATL signals 640. As depicted in FIG. 7, SATL transmitter 600 includes a transmit controller 700, which is configured to control the various elements of SATL transmitter 600 and in so doing, effect the protocol according to the present invention. Transmit controller 700 receives reset signal 630, and in turn, resets the elements of SATL transmitter 600. Transmit controller 700 also distributes clocking signals to the various elements of SATL transmitter 600, having received transmit clock 610. Data 620 is received by a register 710, which stores the value of the data value (e.g., a data word of one or more data bits) presented as data 620. Register 710 then presents this data to a multiplexer 720. Multiplexer 720, under the control of transmit controller 700 selects bits from the data held in register 710 for presentation to an encoder 730. As part of implementing a protocol according to the present invention, transmit controller 700 generates a sendSync signal 740. Transmit controller 700 provides sendSync signal 740 to encoder 730 in order to indicate to encoder 730 that encoder 730 should not encode a data bit during the current symbol time, but should instead encode the symbol for a “SYNC” symbol. Thus, transmit controller 700 controls the stream of symbols generated by encoder 730. Encoder 730 provides these symbols to a shift register 750, which serializes the bits of the given symbol, under the control of transmit controller 700 and in a manner synchronous with transmit clock 610. In so doing, shift register 750 creates the bitstream that is presented as SATL signal 640. FIG. 8 is a block diagram illustrating an SATL receiver 800 according to the prevent invention. SATL receiver 800 receives an SATL signal 810, which corresponds to the SATL signal generated by an SATL transmitter such as SATL transmitter 600 (e.g., SATL signal 640). SATL receiver 800 also receives a receive clock (RCLK) 820, which is used to clock the elements of SATL receiver 800 and to sample SATL signal 810 at the appropriate times. By sampling SATL signal 810 at the appropriate times and processing the information thus received, SATL receiver 800 is able to recover the data thus transmitted, which appears at an output of SATL receiver 800 as data 830. SATL receiver 800 also receives a reset signal 840, which allows SATL receiver 800 to be initialized. FIG. 9 is a block diagram illustrating the elements of SATL receiver 800 in greater detail. As before, SATL receiver 800 receives SATL signal 810, and detects and decodes the data in SATL signal 810 by sampling SATL signal 810 using receive clock 820, thus generating data 830. In a manner similar to that transmitter 600, SATL receiver 800 includes a receive controller 900, which controls various aspects of the operation of the SATL receiver 800. Under the control of receive controller 900, a dual-rank synchronizer 910 receives SATL signal 810 and synchronizes SATL signal 810 to be sampled using receive clock 820. Dual-rank synchronizer 910 provides this synchronized signal to both a start-of-symbol (SOS) detector 920 and a symbol decoder 930. As its name implies, SOS detector 920 detects the start of a given symbol. For example, SOS detector 920 can be configured to detect a low-to-high transition in the synchronized signal generated by dual-rank synchronizer 910. SOS detector 920 provides this indication to symbol decoder 930, in order to allow symbol decoder 930 to recognize the point at which the current symbol begins. Symbol decoder 930 then consumes an appropriate number of bits (i.e., the number of bits used to represent a symbol), and generates an output bit corresponding to the data bit represented by the symbol received. This decoded symbol (i.e., data bit) is presented as BitLine signal 940. BitLine signal 940 is received by a parallel unit 950, which converts the data bits received via bit line signal 940 into a data word, which can then be output as data 830. It will be understood that, in fact, parallel unit 950 need not perform parallel-to-serial conversion, so long as the data input to the corresponding SATL transmitter is also a serial bitstream. As will be appreciated, one approach to implementing parallel unit 950 is through the use of a shift register. Symbol decoder 930, in order to synchronize its operations with those of parallel unit 950, also provides other signals than enable parallel unit 950 to discern when its operations should be performed. Symbol decoder 930 thus generates a DataValid 960 in order to indicate to parallel unit 950 that the data bit presented as BitLine signal 940 is valid, and can be shifted into parallel unit 950. Symbol decoder 930 also provides a SyncDetect signal 970 to parallel unit 950, to indicate the boundary between data words. Thus, at the point at which symbol decoder 930 decodes a “SYNC” symbol, symbol decoder 930 generates SyncDetect signal 970 to re-initialize parallel unit 950. This also indicates to parallel unit 950 that the bit available on BitLine signal 940 is complete and can be shifted into parallel unit 950. Once a sufficient number of bits is shifted into parallel unit 950, the resulting data word is output as data 830, and parallel unit 950 shifts in the bits of the next data word. FIG. 10 is a block diagram illustrating symbol encoder 930 in greater detail. As before, symbol decoder 930 provides a data value (e.g., one or more data bits) at BitLine signal 940, and provides DataValid signal 960 and SyncDetect signal 970 to parallel unit 950 in order to allow parallel unit 950 to determine the various extents of the data received by parallel unit 950. Symbol decoder 930 is controlled by a symbol decoder controller 1000, which provides control and clocking signals to various elements of symbol decoder 930. Symbol decoder controller 1000, among other tasks, is responsible for setting various parameters within symbol decoder 930, to allow for the proper operation of symbol decoder 930, and thus provide for the proper decoding of the symbols received thereby. In configuring symbol decoder 930, symbol decoder controller 1000 receives control signals (control signals 1005) that determine the manner in which symbol decoder controller 1000 programs symbol decoder 930 for operation. Thus, under the control of control signals 1005, symbol decoder controller 1000 stores a LowWaterMark value in a LowWaterMark register 1010 and a HighWaterMark value in a HighWaterMark register 1015. As will be appreciated, LowWaterMark register 1010 and HighWaterMark register 1015 can, in fact, be implemented using any suitable type of storage unit. Symbol decoder controller 1000 receives control signals 1005 from receive controller 900 (as shown in FIG. 9). Symbol decoder controller 1000 also receives an SOS signal 1020 from the SOS detector of SATL receiver 800 (depicted as SOS detector 920 in FIG. 9). As noted, SOS signal 1020 indicates to symbol decoder 930 (and, more particularly, symbol decoder controller 1000) that a start-of-symbol has been received. In certain embodiments of the present invention, this function is performed by detecting a low-to-high transition in SATL signal 810. This event has a number of effects. Upon receipt of an SOS, symbol decoder controller 1000 resets a sample set counter 1030 to an initial value (e.g., middlePoint). Sample set counter 1030 maintains a count of the values of samples of the signal received by symbol decoder 930 (depicted in FIG. 10 as a synchronized SATL signal 1040). Upon the receipt of an SOS indication via SOS signal 1020, symbol decoder controller 1000 also causes a HighWaterMark (HWM) comparator 1050 to compare the value (or count) held in sample set counter 1030 with the HighWaterMark value held in HWM register 1015. More specifically, HWM comparator 1050 determines if the count (in fact, setSampleCnt) is greater than the HWM held in HWM comparator 1050. Similarly, symbol decoder controller 1000, upon the receipt of an SOS indication, causes an LWM comparator 1060 to compare the value (count) held in sample set counter 1030 with the LWM held in LWM register 1010. More specifically, LWM comparator 1060 determines if the count (setSampleCnt) is greater than the LWM. As will be appreciated, the actual value of the HWM and/or the actual value of the LWM can be included or excluded from the range of values that generate a logic “1” or logic “0” on BitLine signal 940, as well as those that assert SyncDetect signal 970, by choosing an appropriate comparison to make (e.g., selecting a relationship such as greater than, greater than or equal to, less than, less than or equal to, or the like). The results of the foregoing comparisons are then provided to signal logic 1070, which in turn generates BitLine signal 940 and SyncDetect signal 970. Signal logic 1070 includes an inverter 1072, an AND gate 1074 and an AND gate 1076. Inverter 1072 and AND gate 1074 combine the outputs from HWM comparator 1050 and LWM comparator 1060 in order to generate SyncDetect signal 970. SyncDetect signal 970 indicates to parallel unit 950 that a “SYNC” symbol was received, and that the data word being shifted into parallel unit 950 is now complete and can be presented as data 830. SyncDetect signal 970 can also be used to re-align (i.e., synchronize) parallel unit 950, in the case where SATL receiver 800 has lost synchronization with SATL signal 810. In a similar fashion, AND gate 1076 performs a logical AND between the output of HWM comparator 1050 and LWM comparator 1060 in order to generate BitLine signal 940. BitLine signal 940 provides the value of the current data bit for shifting into parallel unit 950. Symbol decoder controller 1000 also generates a DataValid signal 960, which indicates a point in time at which BitLine signal 940 presents a valid data bit. It will be appreciated that if DataValid signal 960 is not asserted, BitLine signal 940 is ignored. This can also be characterized in terms of BitLine signal 940 being ignored if SyncDetect signal 970 is asserted. The foregoing signals and their values, in terms of the earlier example, are given in Table 4, which reflects the states of SATL receiver 800 during normal operation, in which SATL receiver 800 synchronized with SATL signal 810. TABLE 4 Certain signals within SATL receiver 800 and their values. Signal Symbol = “1” Symbol = “SYNC” Symbol = “0” HWM comparator 1 0 0 1050 (output) LWM comparator 1 1 0 1060 (output) BitLine 1 0 0 signal 940 DataValid 1 0 1 signal 960 SyncDetect 0 1 0 signal 970 FIG. 11 is a flow diagram illustrating a process of transmitting a data word according to the present invention. The process begins with an SATL transmitter such as SATL transmitter 600 receiving a data word (step 1100). The SATL transmitter then serializes the data word (as is performed in FIG. 7 by register 710 and multiplexer 720) (step 1110). Next, a “SYNC” symbol is generated by the SATL transmitter's transmit controller sending a SendSync signal to the SATL transmitter's encoder (step 1120). The encoder inserts the “SYNC” symbol in the datastream, as the bits that represent the “SYNC” symbol are generated (step 1130). The SATL transmitter sends the “SYNC” symbol by transmitting those bits (depicted in FIG. 7 via a shift register (shift register 750) being loaded with, and then shifting out, the requisite bits) (step 1140). The process of transmitting the data word received by the SATL transmitter is then begun. This portion of the process begins with the encoding of a bit of the data word into a symbol representing the bit's value (step 1150). Next, the symbol for that bit is inserted into the datastream (step 1160). The bits that make up the symbol for the bit of the data word are transmitted serially (step 1170). A determination is then made as to whether bits of the data word remain to be encoded and transmitted in the manner just described (step 1180). If further bits of the data word remain, those bits are encoded (step 1150), the bits of the symbol representing the bit of the data word are then inserted into the datastream (step 1160) and those bits transmitted (step 1170). If the current data word's bits have been encoded and transmitted, the SATL transmitter is then ready to accept the next data word (step 1100). As will be appreciated, the process of encoding and transmitting the bits of the current data word can be repeated any number of times, although it may be desirable to send a “SYNC” symbol with greater frequency than one “SYNC” symbol per data word, if the length of the data word becomes relatively large (e.g., in the case where the period between “SYNC” symbols becomes so great as to make the probability of losing synchronization unacceptably high). Moreover, it will be appreciated that the operations of encoding and transmitting a data word can be overlapped with the receipt (and, optionally, storage) of another data word, as is possible with others of the operations described herein. FIG. 12 is a flow diagram of a process reflecting one example of the operations performed by a symbol decoder, such as symbol decoder 930 of SATL receiver 800 in FIG. 9, according the present invention. As noted, symbol decoder 930 is shown in greater detail in FIG. 10, and the operations now discussed are best understood with reference to the elements of FIG. 10. The process begins with the detection of a start-of-symbol (step 1200). So long as a start-of-symbol (SOS) is not detected, the process loops, awaiting an SOS. Once an SOS is detected, the sample set counter (e.g., sample set counter 1030) is loaded with a value equal to the middlepoint value (step 1210). This prepares the sample set counter to count the samples of the zeroes and ones that make up the symbols received by the SATL receiver. Next, the incoming signal is sampled (step 1220). A determination is then made as to the sample's value (step 1230). If the sample indicates that the value of the incoming signal is a logic “1,” the sample set counter (represented by the variable sampleSetCnt) is incremented (step 1240). Alternatively, if the logical value of the incoming signal is “0” at the sampling point, the sample set counter is decremented (step 1250). A determination is then made as to whether another SOS has been detected (step 1260). If an SOS has not been detected, indicating that the current symbol is not yet complete, the process loops to again sample the incoming symbol (step 1220), and determine whether the sample set counter should be incremented or decremented (steps 1230, 1240, and 1250). If an SOS is detected, the received symbol's value is then determined (step 1270), and the process of receiving the next symbol begins (step 1210). The process of determining the value of the received symbol (step 1270) is discussed in greater detail in connection with FIG. 13, below. As will be appreciated, in one embodiment, sampleSetCnt first undergoes a number of increment operations, followed by number of decrement operations (as demonstrated in the example previously discussed). Thus, the branch in the flow diagram containing step 1240 is taken some number of times, followed by the branch in the flow diagram containing step 1250 being taken some number of times. The number of times each is taken reflects the symbol received. As will also be appreciated, in another embodiment, such a process is implemented by starting with the detection of an SOS (which can be equated with the first sampling of a logic 1). Next, the value of sampleSetCnt is incremented on each clock cycle of RCLK, until a logic 0 is detected (ideally, this is co-incident with the high-to-low transition in the SATL signal, but more likely, is simply the first sample that indicates a logic 0). The value of sampleSetCnt is then decremented on each clock cycle of RCLK, until the next SOS. Sampling in this case is only used to determine when the sampled value changes. This could also be implemented using two counters, one configured to count only when the sample value indicates a logic 1 and the other configured to count only when the sample value indicates a logic 0, although greater resources might be consumed by such an implementation. FIG. 13 is a flow diagram illustrating a process for decoding a symbol according to the present invention. As will be appreciated, the process depicted in FIG. 13 is an example of a process according to the present invention that can be carried out by the symbol decoder of FIG. 10 (symbol decoder 930). The process begins with a comparison of setSampleCnt with the HWM (step 1300). A similar comparison is made between setSampleCnt and the LWM value held in LWM register 1010 by LWM comparator 1060. As will be appreciated, if setSampleCnt is greater than HWM, setSampleCnt will also be greater than LWM. Thus, if setSampleCnt is greater than HWM, the symbol received is taken to be a “1” (step 1310). This indicates that the number by which setSampleCnt is incremented from the middlePoint, less the number by which setSampleCnt is decremented, is above the middlePoint by at least the serialBitMargin. Otherwise, the value of setSampleCnt is compared to the LWM (step 1320) in a manner similar to the previous comparison. If setSampleCnt is greater than the LWM, setSampleCnt is between the LWM and the HWM (step 1320). If such is the case, the symbol decoded is a “SYNC” symbol (step 1330). Otherwise, if setSampleCnt is less than the LWM (it being axiomatic that if setSampleCnt is less than the LWM, setSampleCnt will be less than the HWM), the symbol is a “0” (step 1340). As will be appreciated, the process of FIG. 13 can also be discussed in terms of the symbol decoder of FIG. 10 (symbol decoder 930). The comparison of the value held in sample set counter 1030 (setSampleCnt) with the HWM value stored in HWM register 1015 is performed by HWM comparator 1050 (step 1300). As noted, a similar comparison, between setSampleCnt and the LWM value held in LWM register 1010, is made by LWM comparator 1060 (step 1320). The results of these comparisons are then combined by signal logic 1070, in order to identify the symbol indicated by these comparisons (steps 1310, 1330 and 1340). More specifically, if setSampleCnt is greater than the HWM (and so greater than the LWM), the output of HWM comparator 1050 is a logical “1”, as is the output of LWM comparator 1060. Alternatively, if setSampleCnt is not greater than the LWM (and so not greater the HWM), the output of LWM comparator 1060 is a logical “0”, as is the output of HWM comparator 1050. The outputs of HWM comparator 1050 and LWM comparator 1060 are then AND'ed together by AND gate 1076 to produce BitLine signal 940, which indicates a logic “1” in the former case, and a logic “0” in the latter case. As noted previously, DataValid signal 960 indicates the point in time at which the value indicated of BitLine signal 940 is valid. If, however, setSampleCnt is not greater than the HWM, but is greater than the LWM, the output of HWM comparator 1050 is a logical “0”, while the output of LWM comparator 1060 is a logical “1”. The output of HWM comparator 1050 is thus inverted by inverter 1072, in order to properly detect this case. The output of inverter 1072 (the inverted output of HWM comparator 1050) and the output of LWM comparator 1060 are then AND'ed together by AND gate 1074 to produce SyncDetect signal 970, which indicates a logic “1” in the case where a “SYNC” symbol is detected, and a logic “0” otherwise. In the former case, setSampleCnt is between the LWM and the HWM (step 1320), and the symbol decoded is a “SYNC” symbol (step 1330). Although the present invention has been described in connection with several embodiments, the invention is not intended to be limited to the specific forms set forth herein. On the contrary, it is intended to cover such alternatives, modifications, and equivalents as can be reasonably included within the scope of the invention as defined by the appended claims. While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Moreover, while the invention has been particularly shown and described with reference to these specific embodiments, it will be understood by those skilled in the art that the foregoing and other changes in the form and details may be made therein without departing from the spirit or scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to the field of data communications, and more particularly to a method and system for operating a serial self-adaptable transmission line that provides communications between devices. 2. Description of the Related Art Today's integrated circuits (ICs) are typically implemented using hundreds of input, output, input/output (I/O), power and ground pins, generically referred to as simply “pins”. As will be appreciated, the larger number of pins, the greater complexity in the design, manufacture and use of such ICs. IC designers therefore often go to great lengths to minimize the number of pins required by the various modules of a given design, in order to reduce the overall number of pins required to implement the given IC. Moreover, ICs sometimes required alternate paths of communication that can be called into service in the event of a failure or other situation. For example, the internal states of today's ICs are typically programmed using a processor interface. Such a processor interface can include, for example, a 32-bit data bus, a 16-bit address bus and various control signals. However, it is often desirable to program certain internal registers prior to an IC's processor interface becoming operational. For example, a PLL generating the IC's core clock may be programmed in different ways (changing bias values, frequency ratios and so on). However, that same clock may be used to operate the processor interface. Thus, the processor interface cannot be used to program the PLL, because the processor interface cannot be used until the PLL is programmed. Instead, the PLL needs to be programmed via another interface. This alternate interface should be independent from the PLL itself, and should, as noted, employ a low pin-count technique. Another application of such a low-pin-count interface is as an output to drive a set of 16-bit LEDs. As will be appreciated, it is desirable to employ an interface can drive such LEDs without the IC being required to generate and output 16 different signals, due to the number of pins that would be required by such an approach. As will be appreciated, then, the need for low-pin count interfaces appears in many situations in today's devices. This need has led to the development of a variety of interface standards, such as asynchronous serial communications (e.g., RS-232) and other such approaches (e.g., the inter-IC (I 2 C) bus). Unfortunately, such interfaces are not without their infirmities. Such interfaces may require a certain frequency relationship between the receiver and the transmitter for proper operation, potentially limiting the devices that are able to communicate with one another. Moreover, such interfaces are sometimes proprietary in nature. Often, such interfaces require more than one input or output pin on an IC implementing the given technique. More specifically, a communications link between ICs typically requires a minimum of two signal lines, one signal line for the clock signal, and one signal line for the serialized datastream, although other solutions require many more signal lines (e.g., RS-232). The I 2 C-bus is an example of a serial protocol that employs two wires. Such techniques provide a relatively low-pin count solution, and so are very attractive in pin-limited designs. However, it is desirable to allow flexibility in clocking relationships, as well as to further reduce the pin-count required and to avoid proprietary technology. What is desired, then, is to reduce the number of communication lines to a single communications line, in order to further reduce the pin count of ICs employing such a technique, as well as the area consumed by printed circuit board layouts in such designs. It is also desirable to keep the logic used to implement such a communications protocol simple, in order to minimize the area required on the integrated circuit. Moreover, as noted, such a technique should allow flexibility in the relationship between the transmitter and receiver clocks. | <SOH> SUMMARY OF THE INVENTION <EOH>In one embodiment, a receiver is disclosed. This receiver includes a symbol decoder and a start-of-symbol detector. The start-of-symbol detector is coupled to receive a start-of-symbol signal from the symbol decoder In another embodiment, a transmitter is disclosed. This transmitter includes an encoder. The encoder is configured to generate a symbol based on a value of information received by the encoder. The symbol comprises a plurality of symbol elements. The encoder is further configured to set each of a first number of the symbol elements to a first logical value, if the value is equal to a first value. The encoder is further configured to set each of a second number of the symbol elements to the first logical value, if the value is equal to a second value. The encoder is further configured to set each of a third number of the symbol elements to the first logical value, if the encoder is to generate a synchronization symbol. The first number is greater than the second number, the third number is not equal to the first number, and the third number is not equal to the second number. In yet another embodiment, a method is disclosed. This method includes receiving a symbol, incrementing a count in response to the symbol, decrementing the count in response to the symbol, comparing the count to a first limit, and generating a data value. The generating thus performed is based on comparing the count to the first limit. In still another embodiment, a method is disclosed. This method includes generating a first number of a first number of symbol elements of a first symbol and generating a second number of a second number of symbol elements of a second symbol. The first symbol is a synchronization symbol, and each of the first number of the first number of symbol elements have a first logical value. The second symbol represents a data value of data encoded in the second symbol. Each of the second number of the second number of symbol elements have the first logical value, and the first number is not equal to the second number. The second number is equal to a third number, if the data value is equal to a first value, and the second number is equal to a fourth number, if the data value is equal to a second value. The third number is greater than the fourth number. The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below. | 20040505 | 20081118 | 20051110 | 67619.0 | 0 | TRAN, KHANH C | SERIAL SELF-ADAPTABLE TRANSMISSION LINE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,839,134 | ACCEPTED | Method for rapidly dispatching H.323 packets | A method of rapidly dispatching H.323 packets is disclosed, which is executed after an H.225 protocol connection and before a physical connection of audio/video multimedia data delivery are established between the caller and the callee, and uses Network Address & Port Translation (NAPT) to provide a changed connection port number to H.245 packets between a caller and a callee. A unique connection port number selected by the NAPT is applied to change an original connection port number for packets controlled by the H.245 protocol, thereby providing the changed connection port number as a memory index for add or delete operation and further increasing H.323 packet dispatching rate by directly and quickly comparing memory address through the memory index when searching. | 1. A method for rapidly dispatching H.323 packets, implemented in a network address and port translation (NAPT) with a first network address, comprising: an H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 connect message packet including a data content having a first connection port number for an H.245 connection; a connection port number changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 connect message packet and thus generate a changed message packet for a first termination; an H.245 connection packet receiving step, which uses the NAPT to receive an H.245 connection packet sent by the first termination, the H.245 connection packet including a source content having both a third connection port number and a second network address and a destination content having both the second connection port number and a third network address; a connection port number changing step, which uses the NAPT to change the third connection port number by means of the second connection port number for generating a changed H.245 connection packet, record the second and third connection port numbers for producing an index relation, and send the changed H.245 connection packet to the second termination; an H.245 connection responding step, which uses the second termination to send a response packet to the second connection port number of the NAPT in accordance with the changed H.245 connection packet, the response packet including a source content having both the third network address and the first connection port number; a packet translation forwarding step, which uses the NAPT to forward the response packet to the first termination based on the index relation and translate firstly the first connection port number in the source content of the response packet into the second connection port number, then the first network address and the first connection port number into the first termination's second network address and the third connection port number and finally the response packet into the third connection port number of the first termination; and a connection message exchanging step, which exchanges packets between the first termination and the second termination through the NAPT and the second connection port number. 2. The method as claimed in claim 1, wherein in the H.245 connection port number changing step, the second connection port number is an unique port number selected by the NAPT. 3. The method as claimed in claim 1, wherein the H.245 connection port number changing step is performed by an H.323 application layer gateway (ALG) unit included in the NAPT which also has a dispatcher. 4. The method as claimed in claim 3, wherein in the connection message exchanging step, when the first termination sends at least one first connection message packet to the second connection port number of the second termination and the second termination sends at least one second connection message packet to the second connection port number of the NAPT, the dispatcher receives the connection message packets and directly dispatches the connection message packets to the H.323 ALG unit in accordance with the index relation between the second and third connection port numbers, thereby increasing packet dispatching rate. 5. The method as claimed in claim 1, wherein the second connection port number is a memory direct addressing index value for direct comparison to a memory when searching, thereby increasing H.323 packet dispatching rate. 6. A method for rapidly dispatching H.323 packets, implemented in a network address and port translation (NAPT) with a first network address, comprising the steps of: a H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 connect message packet including a data content having a first connection port number for an H.245 connection; and a connection port changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 connect message packet and thus generate a changed message packet for a first termination, in order to translate corresponding packet address and connection port number through the second connection port number and the NAPT in subsequent H.245 connection protocol and connection message exchange, thereby rapidly dispatching H.323 packets. 7. The method as claimed in claim 6, wherein the second connection port number is an unique port number selected by the NAPT. 8. The method as claimed in claim 6, wherein the H.245 connection protocol includes: an H.245 connection packet receiving step, which uses the NAPT to receive an H.245 connection packet sent by the first termination, the H.245 connection packet including a source content having both a third connection port number and a second network address and a destination content having both the second connection port number and a third network address; a connection port number changing step, which uses the NAPT to change the third connection port number by means of the second connection port number for generating a changed H.245 connection packet, record the second and third connection port numbers for producing an index relation, and send the changed H.245 connection packet to the second termination; an H.245 connection responding step, which uses the second termination to send a response packet to the second connection port number of the NAPT in accordance with the changed H.245 connection packet, the response packet including a source content having both the third network address and the first connection port number; and a packet translation forwarding step, which uses the NAPT to forward the response packet to the first termination based on the index relation and translate firstly the first connection port number in the source content of the response packet into the second connection port number, then the first network address and the first connection port number into the first termination's second network address and the third connection port number and finally the response packet into the third connection port number of the first termination. 9. The method as claimed in claim 6, wherein the connection message exchange is performed between the first and second termination via the NAPT and the second connection port number. 10. The method as claimed in claim 8, wherein the H.245 connection port number changing step is performed by an H.323 application layer gateway (ALG) unit included in the NAPT which also has a dispatcher to directly dispatch connection packets to the H.323 ALG unit in accordance with the index relation between the second and third connection port numbers. 11. The method as claimed in claim 6, wherein the second connection port number is a memory direct addressing index value for direct comparison to a memory when searching, thereby increasing H.323 packet dispatching rate. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet dispatching method and, more particularly, to a method for rapidly dispatching H.323 packets. 2. Description of Related Art Currently, a hardware chip or a system on chip (SoC) generally has a plurality of chips, functional blocks, or models, each having a specific function, so as to gain pipeline or parallel processing effect. FIG. 1 shows a schematic diagram of the essentially functional blocks of a Network Address & Port Translation system on chip (NAPT SoC). In FIG. 1, the NAPT SoC consists of a dispatcher 11, a basic NAPT module 12, at least one NAPT Application Layer Gateway module (ALG module) 13 and a forwarding module 14, etc. The dispatcher 11 receives a packet and determines what kind of the packet is. Accordingly, the packet is dispatched to the basic unit 12 or the ALG unit 13 for further processing. The basic NAPT module 12 is a general NAPT module which translates network address or port number. The ALG module 13 processes the content of specific application data in the Application Layer, such as H.323, File Transfer protocol (FTP), Session Initial Protocol (SIP), and so on. Therefore, there are plural ALG units 13 in general. The forwarding module 14 forwards packets after processed by the basic unit 12 or the ALG unit 13. FIG. 2 shows a schematic diagram of packet dispatch from the dispatcher 11. As show in FIG. 2, the dispatcher 11 has a look up table 111 with a protocol field 1111, a port number field 1112 and a corresponding process field 1113 for the dispatcher 11 to complete packet dispatching in accordance with the look up table 111. For example, when the dispatcher 11 receives a packet with TCP protocol and port number 1720, the packet is known as an H.323 control message packet in accordance with the look up table 111, and thus the dispatcher 11 sends the packet to an H.323 ALG module 131 to process. Alternately, when the packet applies TCP protocol and has port number 21, the packet is known as an FTP control message packet in accordance with the look up table 111, and thus the dispatcher 11 sends the packet to the FTP ALG module 132 to process. Alternately, when the packet applies TCP or UDP protocol and has port number 5060, the packet is known as an SIP control message packet in accordance with the look up table 111, and thus the dispatcher 11 sends the packet to the SIP ALG module 133 to process. However, H.323 has many sub-protocols such as Q.931/call signaling (H.225) and control signaling (H.245). Therefore, the dispatcher at front end requires dynamic add and delete functions for associated H.323 information. Namely, the look up table 111 initially established in the dispatcher records only a port number 1720 used by H.225. However, a caller or a callee in H.245 provides dynamic port number (not fixed). For example, an H.245 connection port number provided by the callee can be 1092, whereas the caller may provide port numbers 2002, 2003 to proceed multimedia data transmission for Real-Time Protocol (RTP)/Real-Time Control Protocol (RTCP) after H.245 connection is complete and the callee may provide port numbers 1092, 1093 to proceed RTP/RTCP multimedia data transmission. However, the cited port numbers 2002, 2003, 1092, 1093 are not recorded in the table 111 initially established. Accordingly, the dispatcher 11 requires dynamic add and delete functions for real-time recording new port number(s) used in H.323, so as to determine a packet type currently received according to the new port number(s). An example of using the NAPT to establish an H.323 connection is described as follows. FIG. 3 shows a chart of message flows between end users E1 and E2 through the NAPT N1 under H.323 protocol. As shown in FIG. 3, the end user E1 applies a virtual network address A1 and a port number P0 in order to establish an H.225 connection to a port number 1720 of the end user E2. The translator N1 changes the virtual network address A1 into a public network address A0 belong to the translator N1 and the port number P0 into a port number P10 selected by the translator N1. The cited data changed is stored in a look up table 31 and subsequently a connection message is sent to the end user E2. The end user E2 applies a virtual network address A2 and the port number 1720 to respond the connection message to the port number P10 belong to the translator N1. After the translator N1 receives a packet with the port number 1720, the packet is sent to the H.323 ALG module to process due to the port number 1720. The packet after being processed is sent to the end user E1 with the address A1 and port number P0, thereby completing the H.225 connection. Next, the end user E2 separately issues ‘Alerting’ and ‘Connect’ control message packets to the end user E1. The ‘Connect’ control message packet dynamically provides data including its address A2 and port number P100, to inform the end user E1 of H.245 connection data to be proceeded later. Packets to be delivered by the end user E2 are forwarded to the end user E1 through the translator N1. Next, the end user E1 provides the port number P1 to proceed H.245 connection to the port number P100 of the end user E2. The translator N1 determines the internal basic NAPT module or H.323 ALG module (not shown) to process a received packet sent from the end user E1, in accordance with the packet's destination port number. However, the packet's port number P100 (e.g., 1920) is not recorded in the look up table, so that the translator N1 first needs time to dynamically add or delete the port number P100, then translates the packet's address and port into its network address A0 and a selected port number P11, and finally sends the packet translated to the end user E2. Subsequently, H.245 control messages are exchanged between the end users E1 and E2 through the translator N1, thereby establishing a connection for delivering multimedia data such as RTP/RTCP and the like. As cited, when H.225 and H.245 connections are establishing, the dispatcher 11 of the translator N1 dispatches packets to other functional block(s) for further processing in accordance with its built-in look up table. At this point, however, only port number 1720 for establishing an H.225 connection is recorded in the look up table while port number for establishing an H.245 connection is not pre-recorded in the look up table. Furthermore, the translator N1 determines required connection port number when a substantial outward connection occurs (at H.245 connection setup or a physical connection for delivering multimedia data such as RTP/RTCP and the like). Thus, the dispatcher of the translator N1 wastes much time on packet dispatching when processing H.323 packets. A typical dispatcher mostly uses a linear-based or hash-based table to determine if a packet to be processed belongs to the H.323 ALG module. If a linear way is applied for the search, it consumes a lot of time and requires maintaining blank fields of the table for add or delete data anytime. If a hash way is applied for the search, it requires a lot of memory space to store a hash table, which may not be available for an environment with limited hardware or SoC. In addition, a content addressable memory (CAM) can be used to speed up required searching, whereas this costs much and is not practical. Therefore, it is desirable to provide an improved method for the cited front-end dispatcher to mitigate and/or obviate the aforementioned problems, thereby avoiding slow determination caused by supporting H.323 processes and further slowing down entire performance. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for rapidly dispatching H.323 packets, which can increase the determination speed of a front-end dispatcher. Another object of the present invention is to provide a method for rapidly dispatching H.323 packets, which can easily maintain a look up table and simplify hardware implementation. According to a feature of the present invention, a method for rapidly dispatching H.323 packets is provided and implemented in a network address and port translation (NAPT) with a first network address. The method includes the steps: an H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 message packet including a data content having a first connection port number for an H.245 connection; a connection port number changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 connect message packet and thus generate a changed message packet for a first termination; an H.245 connection packet receiving step, which uses the NAPT to receive an H.245 connection packet sent by the first termination, the H.245 connection packet including a source content having both a third connection port number and a second network address and a destination content having both the second connection port number and a third network address; a connection port number changing step, which uses the NAPT to change the third connection port number by means of the second connection port number for generating a changed H.245 connection packet, record the second and third connection port numbers for producing an index relation, and send the changed H.245 connection packet to the second termination; an H.245 connection responding step, which uses the second termination to send a response packet to the second connection port number of the NAPT in accordance with the changed H.245 connection packet, the response packet including a source content having both the third network address and the first connection port number; a packet translation forwarding step, which uses the NAPT to forward the response packet to the first termination based on the index relation and translate first the first connection port number in the source content of the response packet into the second connection port number, then the first network address and the first connection port number into the first termination's second network address and the third connection port number and final the response packet into the third connection port number of the first termination; and a connection message exchanging step, which interchanges packets between the first termination and the second termination through the NAPT and second connection port number. According to another feature of the present invention, a method for rapidly dispatching H.323 packets is provided and implemented in a network address and port translation (NAPT) with a first network address. The method includes the steps: an H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 connect message packet including a data content having a first connection port number for an H.245 connection; and a connection port changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 message packet and thus generate a changed message packet for a first termination, in order to translate corresponding packet address and connection port number through the second connection port number and the NAPT in the following H.245 connection protocol and message interchange, thereby rapidly dispatching H.323 packets. Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic diagram of essentially functional blocks of a Network Address & Port Translation system on chip (NAPT SoC); FIG. 2 shows a schematic diagram of packet dispatch from the typical dispatcher of FIG. 1; FIG. 3 is a flowchart of H.323 message interchange through the NAPT of FIG. 1; and FIG. 4 is a message flowchart of a method for rapidly dispatching H.323 packets according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 4 shows a message flowchart in accordance with a preferred embodiment of the invention. As shown in FIG. 4, a caller E3 proceeds a connection to a callee E4 through an NAPT NO which is a translator. An internal configuration of the translator N0 can also refer to functional blocks shown in FIG. 1. The inventive method is implemented essentially by the translator N0, and is executed after H.225 connection and before multimedia data delivery, such as delivering RTP/RTCP and the like. The method for rapidly dispatching H.323 packets through the translator N0 is described below with reference to the message flowchart of FIG. 4. First, the caller E3 sends an H.225 connection packet to the callee E4 for establishing a connection (step S401). The H.225 connection packet is originated from a source of virtual network address A1 representing the caller E3 and port number P0 provided by the caller E3. The H.225 connection packet first passes through the translator N0 and then is forwarded to a destination of virtual network address A2 representing the caller E4 and port number 1720 provided by the callee E4. The translator N0 changes the virtual network address A1 belong to the caller E3 into a public network address A0 owned by the translator N0 and the port number P0 provided by the caller E3 into a port number P10 selected by the translator N0. Thus, a translated H.225 connection packet is formed. After the translator N0 stores corresponding translated data in a look up table 41, the translator N0 forwards the translated H.225 connection packet to the callee E4. Because the cited destination for the H.225 connection packet has a constant connection port number 1720, the look up table in the dispatcher of the translator N0 can create a mapping relation of the connection port number to the H.323 ALG module. Accordingly, when the translator N0 receives the cited packet, the cited packet can quickly be dispatched to the H.323 ALG module according to the TCP and the connection port number 1720 for packet processing. The connection control message packet is subsequently forwarded to the callee E4. In step S402, the callee E4 responds the port number P10 of the translator N0 with its network address A2 and port number 1720. After the translator N0 receives packet having the port number 1720, the packet is sent to the H.323 ALG module to process in accordance with the packet's TCP and port number 1720. The packet after being processed is sent to the callee E3 having the network address A1 and port number P0. In step S403, the callee E4 sends an Alerting message. In step S404, the callee E4 issues a ‘Connect’ control message packet to the caller E3. The ‘Connect’ control message packet has the network address A2 belong to the callee E4 and a connection port number P100 to be used by the H.245 protocol. The ‘Connect’ control message packet is forwarded to the caller E3 through the translator N0. After the translator N0 receives the ‘Connect’ control message packet, it changes the connection port number P100 included in the H.225 ‘Connect’ control message packet to a selected unique connection port number such as P11. The translator N0 records the original connection port number P100 and the changed connection port number P11 to thus create an index relation and stores associated H.245 connection message sent by the callee E4 in a corresponding position of the connection port number P11. The H.225 ‘Connect’ control message packet is subsequently forwarded to the caller E3. In step S405, the caller E3 sends an H.245 connection packet to the connection port number P11 of the callee E4 at the network address A2 according to address port data included in the H.225 (Connect) connection control message packet received. The H.245 connection packet has network address A1 representing the caller E3 and connection port number P1 provided by the caller E3. A connection packet sent by the caller E3 first passes through the translator N0 and is forwarded to the callee E4. The translator N0 receives the H.245 connection packet sent by the caller E3 and determines to apply the internal H.323 ALG module to process the packet according to destination port number P11 included in the packet. Therefore, the translator N0 can directly extract corresponding H.245 connection message of the callee E4 at related position indicated by the port number P11 in view of the aforementioned index relation and accordingly dispatch the connection packet to the H.323 ALG module to process for changing source address, destination address, source connection port number and destination connection port number included in the packet. As cited, source address and source connection port number are changed into network address A0 representing the translator N0 and connection port number P11 selected by the translator N0 respectively. Destination address and destination connection port number are changed into network address A2 representing the callee E4 and connection port number P100 provided by the callee E4 respectively. Thus, a changed connection packet is generated. Subsequently, the translator N0 applies an internal forwarding module (FIG. 1) to forward the changed connection packet to the callee E4 to complete H.245 control connection establishment. Subsequently, negotiation of physical connection data for multimedia data transmission between the caller E3 and the callee E4 is proceeded over the H.245 connection established. Connection messages are exchanged through port number P11 provided by the translator N0. Namely, the caller E3 sends connection packets directly to port number P11 of the callee E4 as well as the callee E4 sends connection packets to port number P11 of the translator N0. The caller E3 is communicated with the callee E4 via the translator N0. Therefore, subsequent H.245 message packets are forwarded through the translator N0 and connection port number P11, such that when the translator N0 receives H.245 packets, transmission data at associated position can be directly and quickly taken only from connection port number P11 (i.e., of the callee E4 or the translator N0) by indexing, thereby increasing packet dispatching rate to the H.323 ALG module. The translator N0 can apply connection port number P11 as a memory direct addressing index value to add or delete because it is included in associated H.245 connection message of the callee E4 that is stored in position (memory) relative to the connection port number P11 pre-taken, so as to relatively reduce maintenance cost for the aforementioned front-end table stored in the dispatcher. Further, when searching, the connection port number P11 can be regarded as an index value directly referring to memory address for direct and quick comparison and thus effectively increase H.323 packet dispatching rate. Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a packet dispatching method and, more particularly, to a method for rapidly dispatching H.323 packets. 2. Description of Related Art Currently, a hardware chip or a system on chip (SoC) generally has a plurality of chips, functional blocks, or models, each having a specific function, so as to gain pipeline or parallel processing effect. FIG. 1 shows a schematic diagram of the essentially functional blocks of a Network Address & Port Translation system on chip (NAPT SoC). In FIG. 1 , the NAPT SoC consists of a dispatcher 11 , a basic NAPT module 12 , at least one NAPT Application Layer Gateway module (ALG module) 13 and a forwarding module 14 , etc. The dispatcher 11 receives a packet and determines what kind of the packet is. Accordingly, the packet is dispatched to the basic unit 12 or the ALG unit 13 for further processing. The basic NAPT module 12 is a general NAPT module which translates network address or port number. The ALG module 13 processes the content of specific application data in the Application Layer, such as H.323, File Transfer protocol (FTP), Session Initial Protocol (SIP), and so on. Therefore, there are plural ALG units 13 in general. The forwarding module 14 forwards packets after processed by the basic unit 12 or the ALG unit 13 . FIG. 2 shows a schematic diagram of packet dispatch from the dispatcher 11 . As show in FIG. 2 , the dispatcher 11 has a look up table 111 with a protocol field 1111 , a port number field 1112 and a corresponding process field 1113 for the dispatcher 11 to complete packet dispatching in accordance with the look up table 111 . For example, when the dispatcher 11 receives a packet with TCP protocol and port number 1720 , the packet is known as an H.323 control message packet in accordance with the look up table 111 , and thus the dispatcher 11 sends the packet to an H.323 ALG module 131 to process. Alternately, when the packet applies TCP protocol and has port number 21 , the packet is known as an FTP control message packet in accordance with the look up table 111 , and thus the dispatcher 11 sends the packet to the FTP ALG module 132 to process. Alternately, when the packet applies TCP or UDP protocol and has port number 5060 , the packet is known as an SIP control message packet in accordance with the look up table 111 , and thus the dispatcher 11 sends the packet to the SIP ALG module 133 to process. However, H.323 has many sub-protocols such as Q.931/call signaling (H.225) and control signaling (H.245). Therefore, the dispatcher at front end requires dynamic add and delete functions for associated H.323 information. Namely, the look up table 111 initially established in the dispatcher records only a port number 1720 used by H.225. However, a caller or a callee in H.245 provides dynamic port number (not fixed). For example, an H.245 connection port number provided by the callee can be 1092 , whereas the caller may provide port numbers 2002 , 2003 to proceed multimedia data transmission for Real-Time Protocol (RTP)/Real-Time Control Protocol (RTCP) after H.245 connection is complete and the callee may provide port numbers 1092 , 1093 to proceed RTP/RTCP multimedia data transmission. However, the cited port numbers 2002 , 2003 , 1092 , 1093 are not recorded in the table 111 initially established. Accordingly, the dispatcher 11 requires dynamic add and delete functions for real-time recording new port number(s) used in H.323, so as to determine a packet type currently received according to the new port number(s). An example of using the NAPT to establish an H.323 connection is described as follows. FIG. 3 shows a chart of message flows between end users E 1 and E 2 through the NAPT N 1 under H.323 protocol. As shown in FIG. 3 , the end user E 1 applies a virtual network address A 1 and a port number P 0 in order to establish an H.225 connection to a port number 1720 of the end user E 2 . The translator N 1 changes the virtual network address A 1 into a public network address A 0 belong to the translator N 1 and the port number P 0 into a port number P 10 selected by the translator N 1 . The cited data changed is stored in a look up table 31 and subsequently a connection message is sent to the end user E 2 . The end user E 2 applies a virtual network address A 2 and the port number 1720 to respond the connection message to the port number P 10 belong to the translator N 1 . After the translator N 1 receives a packet with the port number 1720 , the packet is sent to the H.323 ALG module to process due to the port number 1720 . The packet after being processed is sent to the end user E 1 with the address A 1 and port number P 0 , thereby completing the H.225 connection. Next, the end user E 2 separately issues ‘Alerting’ and ‘Connect’ control message packets to the end user E 1 . The ‘Connect’ control message packet dynamically provides data including its address A 2 and port number P 100 , to inform the end user E 1 of H.245 connection data to be proceeded later. Packets to be delivered by the end user E 2 are forwarded to the end user E 1 through the translator N 1 . Next, the end user E 1 provides the port number P 1 to proceed H.245 connection to the port number P 100 of the end user E 2 . The translator N 1 determines the internal basic NAPT module or H.323 ALG module (not shown) to process a received packet sent from the end user E 1 , in accordance with the packet's destination port number. However, the packet's port number P 100 (e.g., 1920 ) is not recorded in the look up table, so that the translator N 1 first needs time to dynamically add or delete the port number P 100 , then translates the packet's address and port into its network address A 0 and a selected port number P 11 , and finally sends the packet translated to the end user E 2 . Subsequently, H.245 control messages are exchanged between the end users E 1 and E 2 through the translator N 1 , thereby establishing a connection for delivering multimedia data such as RTP/RTCP and the like. As cited, when H.225 and H.245 connections are establishing, the dispatcher 11 of the translator N 1 dispatches packets to other functional block(s) for further processing in accordance with its built-in look up table. At this point, however, only port number 1720 for establishing an H.225 connection is recorded in the look up table while port number for establishing an H.245 connection is not pre-recorded in the look up table. Furthermore, the translator N 1 determines required connection port number when a substantial outward connection occurs (at H.245 connection setup or a physical connection for delivering multimedia data such as RTP/RTCP and the like). Thus, the dispatcher of the translator N 1 wastes much time on packet dispatching when processing H.323 packets. A typical dispatcher mostly uses a linear-based or hash-based table to determine if a packet to be processed belongs to the H.323 ALG module. If a linear way is applied for the search, it consumes a lot of time and requires maintaining blank fields of the table for add or delete data anytime. If a hash way is applied for the search, it requires a lot of memory space to store a hash table, which may not be available for an environment with limited hardware or SoC. In addition, a content addressable memory (CAM) can be used to speed up required searching, whereas this costs much and is not practical. Therefore, it is desirable to provide an improved method for the cited front-end dispatcher to mitigate and/or obviate the aforementioned problems, thereby avoiding slow determination caused by supporting H.323 processes and further slowing down entire performance. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is to provide a method for rapidly dispatching H.323 packets, which can increase the determination speed of a front-end dispatcher. Another object of the present invention is to provide a method for rapidly dispatching H.323 packets, which can easily maintain a look up table and simplify hardware implementation. According to a feature of the present invention, a method for rapidly dispatching H.323 packets is provided and implemented in a network address and port translation (NAPT) with a first network address. The method includes the steps: an H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 message packet including a data content having a first connection port number for an H.245 connection; a connection port number changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 connect message packet and thus generate a changed message packet for a first termination; an H.245 connection packet receiving step, which uses the NAPT to receive an H.245 connection packet sent by the first termination, the H.245 connection packet including a source content having both a third connection port number and a second network address and a destination content having both the second connection port number and a third network address; a connection port number changing step, which uses the NAPT to change the third connection port number by means of the second connection port number for generating a changed H.245 connection packet, record the second and third connection port numbers for producing an index relation, and send the changed H.245 connection packet to the second termination; an H.245 connection responding step, which uses the second termination to send a response packet to the second connection port number of the NAPT in accordance with the changed H.245 connection packet, the response packet including a source content having both the third network address and the first connection port number; a packet translation forwarding step, which uses the NAPT to forward the response packet to the first termination based on the index relation and translate first the first connection port number in the source content of the response packet into the second connection port number, then the first network address and the first connection port number into the first termination's second network address and the third connection port number and final the response packet into the third connection port number of the first termination; and a connection message exchanging step, which interchanges packets between the first termination and the second termination through the NAPT and second connection port number. According to another feature of the present invention, a method for rapidly dispatching H.323 packets is provided and implemented in a network address and port translation (NAPT) with a first network address. The method includes the steps: an H.225 message packet receiving step, which uses the NAPT to receive an H.225 connect message packet sent by a second termination, the H.225 connect message packet including a data content having a first connection port number for an H.245 connection; and a connection port changing step, which uses the NAPT to select a second connection port number to replace the first connection port number of the H.225 message packet and thus generate a changed message packet for a first termination, in order to translate corresponding packet address and connection port number through the second connection port number and the NAPT in the following H.245 connection protocol and message interchange, thereby rapidly dispatching H.323 packets. Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. | 20040506 | 20071211 | 20050407 | 67484.0 | 0 | CHURNET, DARGAYE H | METHOD FOR RAPIDLY DISPATCHING H.323 PACKETS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,839,293 | ACCEPTED | Emulsion aggregation black toner and developer with superior image quality | A black toner of toner particles including at least one binder, at least one black colorant, and a package of external additives is described, wherein the at least one binder includes a styrene acrylate binder and wherein the external additives include each of a first silica having an average particle size of from about 35 to about 45 nm, a second silica having an average particle size of from about 135 to about 160 nm, and a titania having an average particle size of from about 35 to about 45 nm. Also described is a developer that includes the black toner and carrier particles comprising a core of ferrite coated with a coating comprising a polymethyl methacrylate polymer and fluoro-copolymer, carbon black and melamine beads. The black toner and developer are preferably used in a semiconductive magnetic brush development system. | 1. A black toner comprising toner particles comprised of at least one binder, at least one black colorant, and a package of external additives, wherein the at least one binder includes a styrene acrylate binder including a cross-linked styrene acrylate gel content of from 0% to about 15% by weight of the binder, and wherein the external additives include from about 0.2 to about 5.0% by weight of the toner particles of a first silica having an average particle size of from about 35 to about 45 nm, from about 0.2 to about 3.0% by weight of the toner particles of a second silica having an average particle size of from about 135 to about 160 nm, and from about 0.2 to about 5.0% by weight of the toner particles of a titania having an average particle size of from about 35 to about 45 nm. 2. The black toner according to claim 1, wherein the external additives further include from about 0.2 to about 5.0% by weight of the toner particles of a third silica having an average particle size of from about 8 to about 20 nm. 3. The black toner according to claim 1, wherein the at least one black colorant includes carbon black. 4. The black toner according to claim 1, wherein the second silica of the external additives is a sol-gel silica. 5. The black toner according to claim 1, wherein the styrene acrylate binder is an emulsion aggregation styrene acrylate binder. 6. The black toner according to claim 1, wherein the toner particles have an average particle size of from about 4 to about 7 μm. 7. The black toner according to claim 1, wherein the toner particles further comprise from about 2 to about 25% by weight of the toner particles of a wax. 8. The black toner according to claim 1, wherein the cross-linked styrene acrylate gel content of the styrene acrylate binder is from about 5% to about 11% by weight of the binder. 9. The black toner according to claim 1, wherein the black toner has, following triboelectric contact with carrier particles comprising a core of ferrite coated with a polymethyl methacrylate polymer or copolymer, carbon black and melamine beads, a triboelectric charge of from about −25 to about −80 μC/g. 10. A developer comprising the black toner of claim 1 and carrier particles comprising a core of ferrite coated with a coating comprising a polymethyl methacrylate polymer or copolymer, carbon black and melamine beads, wherein the developer comprises from about 1 part to about 25 parts by weight of the black toner and from about 75 parts to about 99 parts by weight of the carrier particles. 11. The developer according to claim 10, wherein the carrier particles have an average diameter of from about 30 to about 55 μm. 12. The developer according to claim 10, wherein the coating on the carrier particles includes from about 70 to about 80% by weight of the polymethyl methacrylate polymer, from about 6 to about 12% by weight of the carbon black and from about 8 to about 12% by weight of the melamine beads. 13. The developer according to claim 12, wherein the coating on the carrier particles further includes from about 3 to about 9% of a fluoro-copolymer. 14. The developer according to claim 10, wherein the melamine beads have a size of from about 100 to about 300 nm. 15. An electrophotographic image forming apparatus comprising a photoreceptor, a semiconductive magnetic brush development system, and a housing in association with the semiconductive magnetic brush development system for containing a developer comprising the black toner according to claim 1. | BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to black toner, developer containing the black toner, and a method of forming images with the developer utilizing a semiconductive magnetic brush development system. More in particular, the invention relates to black toner having specific toner particle and external additive compositions and properties such that the toner, following triboelectric contact with a carrier, exhibits a triboelectric charge of from about 35 to about 75 μC/g so as to provide a black toner image of superior image quality when used to develop electrostatic images in a semiconductive magnetic brush development system. 2. Description of Related Art U.S. Pat. No. 5,545,501 describes an electrostatographic developer composition comprising carrier particles and toner particles with a toner particle size distribution having a volume average particle size (t) (such that 4 μm≦t≦12 μm and an average charge (absolute value) per diameter in femtocoulomb/10 μm (CT) after triboelectric contact with said carrier particles such that 1 fC/10 μm≦CT≦10 fC/10 μm characterized in that (i) said carrier particles have a saturation magnetization value, Msat, expressed in Tesla (T) such that Msat≧0.30 T, (ii) said carrier particles have a volume average particle size (Cavg) such that 30 μm≦Cavg≦60 μm, (iii) said volume based particle size distribution of said carrier particles has at least 90% of the particles having a particle diameter C such that 0.5 Cavg≦C≦2 Cavg, (iv) said volume based particles size distribution of said carrier particles comprises less than b % particles smaller than 25 μm wherein b=0.35×(Msat)2×P with Msat=saturation magnetization value, Msat, expressed in T and P=the maximal field strength of the magnetic developing pole expressed in kA/m, and (v) said carrier particles comprise a core particle coated with a resin coating in an amount (RC) such that 0.2% w/w≦RC≦2% w/w. See the Abstract. This patent describes that such developer achieves images of offset-quality in systems in which a latent image is developed with a fine hair magnetic brush. See column 4, lines 7-17 of the patent. U.S. Pat. No. 6,319,647 describes a toner of toner particles containing at least one binder, at least one colorant, and preferably one or more external additives that is advantageously formed into a developer and used in a magnetic brush development system to achieve consistent, high quality copy images. The toner particles, following triboelectric contact with carrier particles, exhibit a charge per particle diameter (Q/D) of from 0.6 to 0.9 fC/μm and a triboelectric charge of from 20 to 25 μC/g. The toner particles preferably have an average particle diameter of from 7.8 to 8.3 microns. The toner is combined with carrier particles to achieve a developer, the carrier particles preferably having an average diameter of from 45 to 55 microns and including a core of ferrite substantially free of copper and zinc coated with a coating comprising a polyvinylidenefluoride polymer or copolymer and a polymethyl methacrylate polymer or copolymer. U.S. Pat. No. 6,416,916 describes a toner of toner particles containing at least one binder, at least one colorant, and an external additive package comprised of zinc stearate and at least one of silicon dioxide or titanium dioxide, wherein the amount of zinc stearate is limited to about 0.10 percent by weight or less of the toner. It is reported that when the amount of zinc stearate is so limited, a developer formed from the toner exhibits excellent triboelectric charging and stability and excellent developer flow. When the developer is used in a magnetic brush development system, consistent, high quality copy images are formed substantially without any depletion defects over time. What is still desired is a black toner for use in semiconductive magnetic brush development systems, which toner is able to develop a large number of pages per minute with substantially reduced emissions and high print quality. SUMMARY OF THE INVENTION This and other objects are achieved in the present invention with a toner comprised of toner particles of at least one binder, at least one black colorant, and a package of external additives, wherein the at least one binder includes a styrene acrylate binder including a cross-linked styrene acrylate gel content of from 0% to about 15% by weight of the binder, and wherein the external additives include from about 0.2 to about 5.0% by weight of the toner particles of a first silica having an average particle size of from about 35 to about 45 nm, from about 0.2 to about 3.0% by weight of the toner particles of a second silica having an average particle size of from about 135 to about 160 nm, and from about 0.2 to about 5.0% by weight of the toner particles of a titania having an average particle size of from about 35 to about 45 nm. In embodiments, the toner particles may further include a third silica having an average particle size of from about 8 to about 20 nm, and in the amount of from about 0.2 to about 5% by weight of the toner particles. In embodiments, the invention further relates to a developer comprising the aforementioned black toner and carrier particles comprised of a core of ferrite coated with a coating comprising a polymethyl methacrylate polymer or polymethyl methacrylate and fluoro-copolymer mixture, carbon black and melamine beads, wherein the developer comprises from about 1 part to about 25 parts by weight of the black toner and from about 75 parts to about 99 parts by weight of the carrier particles. In still further embodiments, the invention relates to an electrophotographic image forming apparatus comprising a photoreceptor, a semiconductive magnetic brush development system, and a housing in association with the semiconductive magnetic brush development system for containing a developer comprising the black toner of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Generally, the process of electrophotographic printing includes charging a photoconductive member to a substantially uniform potential to sensitize the surface thereof. The charged portion of the photoconductive surface is exposed to a light image from, for example, a scanning laser beam, an LED source, etc., and of an original document being reproduced. This records an electrostatic latent image on the photoconductive surface of a photoreceptor. After the electrostatic latent image is recorded on the photoconductive surface, the latent image is developed with a toner or developer containing a toner. In the present invention, a two-component developer is used for development. A typical two-component developer comprises magnetic carrier particles with toner particles triboelectrically attracted thereto. During development of the latent image, the toner particles are attracted to the latent image, forming a toner powder image on the photoconductive surface. The toner powder image is subsequently transferred to an image transfer medium, e.g., a sheet of paper or a transparency. Finally, the toner powder image is heated to permanently fuse it to the image transfer medium. A commonly known way of developing the latent image on the photoreceptor is by use of one or more magnetic brushes. See, for example, U.S. Pat. Nos. 5,416,566, 5,345,298, 4,465,730, 4,155,329 and 3,981,272, incorporated herein by reference. The toner of the developer may be formulated to carry either a negative or positive charge, and is in any case selected vis-a-vis the carrier so that the toner particles acquire the proper operating charge with respect to the latent electrostatic image being developed. Thus, when the developer is brought into operative contact with the photoconductive surface of the photoreceptor, the greater attractive force of the discharged image causes the toner particles to leave the carrier particles and adhere to the image portion of the photoconductive surface. The previously mentioned magnetic brush typically is comprised of a roll having a tube-like member or sleeve, which is rotatably supported. The sleeve is preferably made from a non-magnetic material, more preferably stainless steel, which is conductive and allows less eddy currents than aluminum so that localized heating is reduced. One or more magnets are mounted inside the sleeve. The roll is disposed so that a portion of the sleeve is immersed in or in contact with a supply of developer comprising the carrier particles and the toner particles. As a result, the developer is made to be attracted to the surface of the sleeve and arranges thereupon in the form of a brush, e.g., as bristles of a brush. Thus, when the photoreceptor bearing the latent electrostatic image thereon is brought into physical contact with the brush, the attractive force of the electrostatic charge on the photoreceptor surface in the image areas, which is greater than the force holding the toner particles is association with the brush, draws the toner particles from the magnetic brush roller and onto the image areas to render the image visible. The electrophotographic marking process given above is ideal for single color images, i.e., conventional black toner images. In such process, the toner particles are colored black by way of a black colorant included in the toner particles. This invention describes the aspects of novel black toners and developers that operate in the restrictive semiconductive magnetic brush development environment to achieve image qualities superior to prior art toners and developers with the capability of forming a large number of prints per minute with reduced emissions. As a result of the reduced emissions with the toner of the present invention, solid and halftone areas are uniform and stable in density and color, and text is crisp with well-defined edges regardless of font size or type. In addition, background toner in non-image areas is reduced and machine dirt and contamination is minimized. The black toner of the present invention is comprised of at least one resin binder, at least one black colorant and an external additive package comprised of one or more particulate additives. Suitable and preferred materials for use in preparing the black toner of the invention will now be discussed. In the black toner of the present invention, the resin binder of the toner particles is preferably comprised of an acrylate binder, more preferably a styrene acrylate binder, most preferably of an emulsion aggregation styrene acrylate binder. The emulsion aggregation styrene acrylate binder may be prepared by any suitable emulsion aggregation process. As one example, reference is made to U.S. Pat. No. 6,120,967, incorporated herein by reference in its entirety. The styrene acrylate binder may be made to include some amount of cross-linked gel portions therein. These cross-linked gel portions are comprised of cross-linked binder distributed as microgel particles throughout the linear portions of the binder. Such cross-linked gel portions have a volume average particle size of from, for example, 0.1 μm or less, preferably about 0.005 to about 0.1 μm, as determined by scanning electron microscopy and/or transmission electron microscopy. The binder resin preferably has a weight fraction of the microgel (cross-linked gel portion content) in the range from 0 to about 15% by weight of the binder, preferably from about 1 to about 12% by weight of the binder, more preferably from about 5 to about 11% by weight of the binder, most preferably about 10% by weight of the binder. The linear portion is comprised of base resin, preferably styrene acrylate, in the range from about 50 to about 100% by weight of the binder, and preferably in the range from about 65 to about 100% by weight of the binder. The linear portion of the binder resin preferably comprises low molecular weight reactive base resin that did not cross-link during a cross-linking reaction. The molecular weight distribution of the styrene acrylate binder resin is thus bimodal, having different ranges for the linear and the cross-linked portions of the binder resin. The binder may also include some amount of additional binder materials such as comprised of, for example, vinyl polymers such as styrene polymers, acrylonitrile polymers, vinyl ether polymers, acrylate and methacrylate polymers; epoxy polymers; diolefins; polyurethanes; polyamides and polyimides; polyesters such as the polymeric esterification products of a dicarboxylic acid and a diol comprising a diphenol, crosslinked polyesters; and the like. The binder of the toner particles is melt blended or otherwise mixed with at least one black colorant. Various black colorants may be used without limitation, and the colorant may be a pigment, dye or mixture thereof. Example black colorants include, for example, carbon black such as REGAL 330 carbon black (Cabot), acetylene black, lamp black, aniline black and mixtures thereof. Most preferably, the colorant is a carbon black pigment having a suitable particle size such as, for example, about 50 to about 250 nm, and may be in the form of a dispersion, for example an aqueous dispersion. The black colorant is preferably included in the toner composition in an amount of from about 1% to about 25% by weight of the toner particles, preferably from about 5% to about 15% by weight of the toner particles, most preferably from about 8 to about 12% by weight of the toner particles. The toner particles of the present invention may also include several additional optional additives within the toner particles (e.g., internal additives). For example, as required, the toner particles may also include charge control additives, surfactants, emulsifiers, pigment dispersants, flow additives, and the like. A wax, such as polyethylene, polypropylene, and/or paraffin wax, can also be included in or on the toner composition as fusing release agents. The toner particles of the present invention preferably have a small size. In particular, the toner particles preferably have an average particle size of from about 3 μm to about 10 μm, preferably from about 4 μm to about 7 μm, most preferably from about 5 μm to about 6 μm. The toner particles also must have an external additive package on the surface of the toner particles. Preferably, the external additive package comprises at least a first silica having an average particle size of from about 35 to about 45 nm, a second silica having an average particle size of from about 135 to about 160 nm, and a titania having an average particle size of from about 35 to about 45 nm. The first silica (also known as SiO2 or silicon dioxide) is preferably present in the toner particles in an amount of from about 0.2 to about 5.0% by weight of the toner particles, preferably from about 0.5 to about 2.0% by weight of the toner particles. This first silica particle preferably has an average particle size of about 40 nm. In general, silica is applied to the toner surface for toner flow, triboelectric enhancement, admix control, improved development and transfer stability and higher toner blocking temperature. It has been found that the aforementioned amounts of the sized first silica in the toner particles can increase the toner particles triboelectric charge in use and can also increase the charge per particle diameter (q/d) of the toner in use. Silica particles of the aforementioned size range are commercially available, for example from DeGussa. The second silica is preferably present in the toner particles in an amount of from about 0.2 to about 3.0% by weight of the toner particles, preferably from about 0.6 to about 2.4% by weight of the toner particles. This second silica particle preferably has an average particle size of about 140 nm to about 150 nm. It has been found that this second silica may increase the cohesion of the toner particles, but not to an extent that is unacceptable within the aforementioned amount ranges. The second silica does not negatively affect the triboelectric charging or q/d properties of the toner particles. The presence of these ultra large size second silica particles is desirable in order to prevent impaction of the smaller sized external additives into the toner particles during use of the toner. During use, carrier particles knock into the toner particles, and such impacts can force smaller external additives to become undesirably impacted into the surface of the toner particles. The larger sized second silica particles absorb the impacts, and are of a sufficiently large size themselves to be less susceptible to complete impaction into the toner particles. The presence of the second silica particles thus ensures maintained development and transfer performance of the toner over time. The second silica particles are preferably sol-gel silica particles. The second silica particles are commercially available, for example from Shin-Etsu. The titania particles (also known as TiO2 or titanium dioxide) is preferably present in the toner particles in an amount of from about 0.2 to about 5.0% by weight of the toner particles, preferably from about 0.2 to about 1.2% by weight of the toner particles. This titania particles preferably have an average particle size of about 40 μm. In general, titania is added to the surface of the toner particles for improved relative humidity (RH) stability, triboelectric control and improved development and transfer stability. Titania particles of the aforementioned size range are commercially available, for example from Tayca. Optionally, a third silica may be present in the toner particles in an amount of from about 0.2 to about 5.0% by weight of the toner particles. This third silica particle preferably has an average particle size of about 8 nm to about 20 nm. The third silica may contribute to improved charging and flowability. Example suitable silicas in the size range of 8 nm to 20 nm and are commercially available from Degussa and Cabot Corporation. Additional external surface additives may also be included in the external surface additive package. For example, the external additive package may also include ZnSt (zinc stearate). Zinc stearate provides lubricating properties, provides developer conductivity and triboelectric enhancement, both due to its lubricating nature, and can enable higher toner charge and charge stability by increasing the number of contacts between toner and carrier particles. Calcium stearate and magnesium stearate may also be added to provide similar functions. A suitable commercially available zinc stearate is known as Zinc Stearate L made by Ferro Corporation, Polymer Additives Division. The aforementioned external additives may be rendered hydrophobic, if necessary, by surface treatments to reduce the humidity sensitivity of the toner charging. The first silica and titania, for example, may be treated with PDMS (polydimethyl siloxane). The second silica may be treated with, for example, an organic silane. For further enhancing the positive charging characteristics of the developer compositions described herein, and as optional components there can be incorporated into the toner or on its surface charge enhancing additives inclusive of alkyl pyridinium halides, reference U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference; organic sulfate or sulfonate compositions, reference U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference; distearyl dimethyl ammonium sulfate; bisulfates, and the like and other similar known charge enhancing additives. Also, negative charge enhancing additives may also be selected, such as aluminum complexes, like BONTRON E-88, and the like. These additives may be incorporated into the toner in an amount of from about 0.1 percent by weight to about 20 percent by weight, and preferably from 1 to about 3 percent by weight, of the toner particles. The following Table 1 sets forth several preferred toner compositions of the present invention. All amounts are percentages by weight, based on the total weight of the toner particles. TABLE 1 First small Second large Example size silica size silica Titania 1 0.57 0.74 0.37 2 1.71 0.74 0.37 3 0.57 0.74 1.10 4 1.71 0.74 1.10 5 0.57 2.22 0.37 6 1.71 2.22 0.37 7 0.57 2.22 1.10 8 1.71 2.22 1.10 The toner composition of the present invention can be prepared by a number of known methods, for example including melt blending the toner resin particles, colorants and optional internal additives followed by mechanical attrition. Other methods include those well known in the art such as spray drying, melt dispersion, dispersion polymerization, suspension polymerization, emulsion aggregation and extrusion. The toner is preferably made by first mixing the binder, preferably comprised of both the linear resin and the cross-linked resin as discussed above, and the colorant together in a mixing device. The toner is then classified to form a toner with the desired volume median particle size. Care should be taken in the method in order to limit the coarse particles, grits and giant particles. Subsequent toner blending of the external additives is preferably accomplished using a mixer or blender, for example a Henschel mixer, followed by screening to obtain the final toner product. Following formation, the toner particles may optionally be washed with an acid, e.g., calcium chloride. Such acid washing can improve the relative humidity sensitivity of the toner particles but can also lower triboelectric charging values of the toner particles. Water washing, which does not substantially affect the toner particle properties, may alternatively be used. The charge of a toner is described in terms of the charge/particle diameter, q/d, in fC/μm following triboelectric contact of the toner with carrier particles. The charge per particle diameter (q/d) of the toner particles preferably has an average value of from, for example, 0.1 to 1.0 fC/μm, corresponding to a 5.5 μm toner tribo of 10 μcoul/gram to 80 μcoul/gram. This charge should remain stable throughout the development process in order to insure consistency in the richness of the images obtained using the toner. The measurement of the average q/d of the toner particles can be done by means of a charge spectrograph apparatus as well known in the art. See, for example, U.S. Pat. No. 4,375,673, incorporated herein by reference. The spectrograph is used to measure the distribution of the toner particle charge (q in fC) with respect to a measured toner diameter (d in μm). In a most preferred embodiment of the present invention, the toner particles exhibit a triboelectric value (as measured by the known Faraday Cage process), after triboelectric contact with carrier particles, of from, for example, about −25 to about −80° C./g, more preferably about −38 to about −50° C./g as measured in 70° F. and 50% relative humidity, as well as exhibits triboelectric stability over the life of the developer. The toner is most preferably incorporated into a two component developer composition as discussed above by mixing with appropriate carrier particles. Suitable and preferred materials for use as carriers used in preparing developers containing the above-discussed toners of the invention that possess the properties discussed above will now be discussed. The toner particles triboelectrically associate and/or adhere to the surface of the carrier particles. Illustrative examples of carrier particles that can be selected for mixing with the toner composition prepared in accordance with the present invention include those particles that are capable of triboelectrically obtaining a charge of opposite polarity to that of the toner particles. Illustrative examples of suitable carrier particles include granular zircon, granular silicon, glass, steel, nickel, ferrites, iron ferrites, silicon dioxide, and the like. Other suitable carriers are disclosed in U.S. Pat. Nos. 4,937,166 and 4,935,326, the disclosures of which are hereby totally incorporated by reference. In a preferred embodiment, the carrier core is comprised of ferrite particles. Any commercially available ferrite carrier may be used without restriction. Preferably, the carrier core may be comprised of a manganese magnesium ferrite core, such as commercially available from Powder Tech. The ferrite particles to be used as carrier cores in the developer composition preferably have an average particle size (diameter) of from, for example, 10 to 100 μm, preferably 20 to 70 μm, most preferably 25 to 40 μm, as determined by standard laser diffraction techniques. The selected carrier particles can be used with or without a coating. In a preferred embodiment of the developer composition, the carrier particles are coated with a polymethyl methacrylate polymer or copolymer. In another preferred embodiment, the ferrite carrier particles are coated with a mixture of at least two dry polymer components, which dry polymer components are preferably not in close proximity thereto in the triboelectric series, and most preferably of opposite charging polarities with respect to the toner selected. The electronegative polymer, i.e., the polymer that will generally impart a positive charge on the toner with which it is contacted, is preferably comprised of a polyvinylidenefluoride polymer or copolymer. Such polyvinylidenefluoride polymers are commercially available, for example under the tradename KYNAR. The electropositive polymer, i.e., the polymer that will generally impart a negative charge on the toner with which it is contacted, is preferably comprised of a polymer or copolymer of polymethyl methacrylate (PMMA), optionally having carbon black or another conductive material dispersed therein. PMMA by itself is an insulative polymer. To obtain a conductive carrier coating, a conductive component, for example carbon black, is dry blended with the PMMA and any other carrier coating constituents. The mixture is then tumbled onto the core and fused. The PMMA may be copolymerized with any desired comonomer, so long as the resulting copolymer retains a suitable particle size. Suitable comonomers can include monoalkyl, or dialkyl amines, such as a dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diisopropylaminoethyl methacrylate, t-butylaminoethyl methacrylate, and the like. If the PMMA polymer has carbon black dispersed therein, it is preferably formed in a semisuspension polymerization process, for example as described in U.S. Pat. No. 5,236,629, incorporated by reference herein in its entirety. In a preferred embodiment of the invention, the carrier is coated with a PMMA coating such as described in U.S. Pat. No. 5,847,030, incorporated herein by reference in its entirety. Preferably, such PMMA is made by an emulsion polymerization process and has a narrow particle size distribution with polymer particles in the 100 to 200 nm size range, preferably about 150 nm. This small size is desirable to provide uniform coverage on the small ferrite core. The percentage of each polymer present in the carrier coating can vary depending on the specific components selected, the coating weight and the properties desired. For example, the ratios of the two polymers may be varied in order to adjust the triboelectric characteristics of the carrier in order to meet the particular requirements of a given printing device. Generally, the coated polymer mixtures used contain from about 3 to about 97 percent of the electronegative polymer, and from about 97 to about 3 percent by weight of the electropositive polymer. Preferably, there are selected mixtures of polymers with from about 3 to 25 percent by weight of the electronegative polymer, and from about 97 to 75 percent by weight of the electropositive polymer. Most preferably, there are selected mixtures of polymers with from about 5 to 15 percent by weight of the electronegative polymer, and from about 95 to 85 percent by weight of the electropositive polymer. In a most preferred embodiment, the coating on the carrier particles includes from about 70 to about 80% by weight of a polymethyl methacrylate polymer, from about 6 to about 12% by weight of carbon black and from about 8 to about 12% by weight of melamine beads, and most preferably the coating further includes from about 3 to about 9% of a fluoro-copolymer. As noted above, the coating on the ferrite carrier particles preferably also includes melamine beads, for example melamine beads having an average particles size of from about 100 nm to about 300 nm. Such beads are commercially available from, for example, Nippon Shokubai. The melamine beads may comprise of from about 5 to about 15% by weight of the total coating, more preferably from about 8 to about 12% by weight of the total coating. The melamine beads may provide charging and conductivity stability. The carrier particles may be prepared by mixing the carrier core with from, for example, between about 0.05 to about 10 percent by weight, most preferably between about 0.3 percent and about 5.0 percent by weight, based on the weight of the coated carrier particles, of the coating composition until adherence thereof to the carrier core by mechanical impaction and/or electrostatic attraction. The mixture of carrier core particles and polymers is then heated to an elevated temperature for a period of time sufficient to melt and fuse to the coating polymers to the carrier core particles. The coated carrier particles are then cooled and thereafter classified to a desired particle size. The coating preferably has a coating weight of from, for example, 0.1 to 5.0% by weight of the carrier, preferably 0.1 to 3.0% by weight. Various effective suitable methods can be used to apply the polymer mixture coatings to the surface of the carrier core particles. Examples of typical methods for this purpose include combining the carrier core material and the coating composition by cascade roll mixing, or tumbling, milling, shaking, electrostatic powder cloud spraying, fluidized bed, electrostatic disc processing, and an electrostatic curtain. The coated carrier particles preferably have a size of from about 25 μm to about 40 μm, more preferably of about 35 μm. In a preferred embodiment, it is desirable to maintain a ratio of carrier volume median diameter to toner volume median diameter of approximately 5:1 to 9:1. Two component developer compositions of the present invention can be generated by mixing the carrier core particles with the toner composition discussed above. The carrier particles can be mixed with the toner particles in various suitable combinations. However, best results are obtained when from about 1 part to about 25 parts by weight of the black toner and from about 75 parts to about 99 parts by weight of the carrier particles, are mixed. The toner concentration in the developer initially installed in a xerographic development housing is thus preferably between, for example, about 1 to about 20% by weight based on the total developer weight. The developers of the invention exhibit superior black image quality, reduced emissions, and enable the device to print a large number of pages per minute (ppm), for example on the order of 40 to 200 ppm or more, without quality problems arising. Table 2 below summarizes the triboelectric and cohesion properties obtained for the Example toners identified in Table 1 above. TABLE 2 Tribo (15 min PS) Tribo (60 min PS) Example (μC/g) (μC/g) Cohesion 1 −36.1 −27.2 73 2 −41.9 −36.4 82 3 −35.5 −26.6 38 4 −39.2 −35.2 65 5 −33.6 −22.4 33 6 −43.5 −27.2 57 7 −29.5 −21.9 18 8 −32.4 −23.6 40 To determine the tribo, a 0.5 gram sample of developer is placed in a Faraday cage. Pressurized air is blown through the cage that has screens at each end. The screen size allows toner to escape and retains carrier. 25 micron screen works best for 35 micron carrier and 5.5 micron toner. An electrometer is attached to the cage and monitors charge change as toner exits the cage. The weight change is measured from before to after blowoff and toner mass is obtained. Tribo is defined as toner charge/toner mass. PS means paint shake. Developer is placed in a glass jar. The glass jar with developer is placed in a paint shaker and agitated for 15 mins and 60 mins. The action of the paint shaker mimics the abuse experienced by a toner in a developer sump in a machine. Tribo generally falls with time as toner constituents move to the carrier and the surfaces become more alike and as additives are impacted into the toner surface. The object of toner design is to minimize the change in tribo with time. Thus, of the 8 designs above, design 4 is most advantaged for tribo stability. Cohesion is measured with a Hosokawa Cohesion tester. This consists of 3 screens with different meshings—53 microns/45microns/38 microns. The screens are placed one atop the other and vibrated for 1 minute. The amount of toner remaining in each screen is an indication of the stickiness (cohesiveness) the toner. Cohesion is a relative value. A cohesion of 0 means liquid flow (no toner remained on any screen) while a cohesion of 100 means no toner moved through any screen. The toner is 5.5 μm and the screens are 53/45/38 microns, so the most cohesive the toner, the larger the toner agglomerates that cannot pass through the mesh openings. The goal in toner design is to have as low a cohesion as possible when the toner is released from the additive blending operation—and to have that cohesion remain as low as possible as the toner is aged in a developer housing in a machine. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention This invention relates to black toner, developer containing the black toner, and a method of forming images with the developer utilizing a semiconductive magnetic brush development system. More in particular, the invention relates to black toner having specific toner particle and external additive compositions and properties such that the toner, following triboelectric contact with a carrier, exhibits a triboelectric charge of from about 35 to about 75 μC/g so as to provide a black toner image of superior image quality when used to develop electrostatic images in a semiconductive magnetic brush development system. 2. Description of Related Art U.S. Pat. No. 5,545,501 describes an electrostatographic developer composition comprising carrier particles and toner particles with a toner particle size distribution having a volume average particle size (t) (such that 4 μm≦t≦12 μm and an average charge (absolute value) per diameter in femtocoulomb/10 μm (CT) after triboelectric contact with said carrier particles such that 1 fC/10 μm≦C T ≦10 fC/10 μm characterized in that (i) said carrier particles have a saturation magnetization value, M sat , expressed in Tesla (T) such that M sat ≧0.30 T, (ii) said carrier particles have a volume average particle size (C avg ) such that 30 μm≦C avg ≦60 μm, (iii) said volume based particle size distribution of said carrier particles has at least 90% of the particles having a particle diameter C such that 0.5 C avg ≦C≦2 C avg , (iv) said volume based particles size distribution of said carrier particles comprises less than b % particles smaller than 25 μm wherein b=0.35×(M sat ) 2 ×P with M sat =saturation magnetization value, M sat , expressed in T and P=the maximal field strength of the magnetic developing pole expressed in kA/m, and (v) said carrier particles comprise a core particle coated with a resin coating in an amount (RC) such that 0.2% w/w≦RC≦2% w/w. See the Abstract. This patent describes that such developer achieves images of offset-quality in systems in which a latent image is developed with a fine hair magnetic brush. See column 4, lines 7-17 of the patent. U.S. Pat. No. 6,319,647 describes a toner of toner particles containing at least one binder, at least one colorant, and preferably one or more external additives that is advantageously formed into a developer and used in a magnetic brush development system to achieve consistent, high quality copy images. The toner particles, following triboelectric contact with carrier particles, exhibit a charge per particle diameter (Q/D) of from 0.6 to 0.9 fC/μm and a triboelectric charge of from 20 to 25 μC/g. The toner particles preferably have an average particle diameter of from 7.8 to 8.3 microns. The toner is combined with carrier particles to achieve a developer, the carrier particles preferably having an average diameter of from 45 to 55 microns and including a core of ferrite substantially free of copper and zinc coated with a coating comprising a polyvinylidenefluoride polymer or copolymer and a polymethyl methacrylate polymer or copolymer. U.S. Pat. No. 6,416,916 describes a toner of toner particles containing at least one binder, at least one colorant, and an external additive package comprised of zinc stearate and at least one of silicon dioxide or titanium dioxide, wherein the amount of zinc stearate is limited to about 0.10 percent by weight or less of the toner. It is reported that when the amount of zinc stearate is so limited, a developer formed from the toner exhibits excellent triboelectric charging and stability and excellent developer flow. When the developer is used in a magnetic brush development system, consistent, high quality copy images are formed substantially without any depletion defects over time. What is still desired is a black toner for use in semiconductive magnetic brush development systems, which toner is able to develop a large number of pages per minute with substantially reduced emissions and high print quality. | <SOH> SUMMARY OF THE INVENTION <EOH>This and other objects are achieved in the present invention with a toner comprised of toner particles of at least one binder, at least one black colorant, and a package of external additives, wherein the at least one binder includes a styrene acrylate binder including a cross-linked styrene acrylate gel content of from 0% to about 15% by weight of the binder, and wherein the external additives include from about 0.2 to about 5.0% by weight of the toner particles of a first silica having an average particle size of from about 35 to about 45 nm, from about 0.2 to about 3.0% by weight of the toner particles of a second silica having an average particle size of from about 135 to about 160 nm, and from about 0.2 to about 5.0% by weight of the toner particles of a titania having an average particle size of from about 35 to about 45 nm. In embodiments, the toner particles may further include a third silica having an average particle size of from about 8 to about 20 nm, and in the amount of from about 0.2 to about 5% by weight of the toner particles. In embodiments, the invention further relates to a developer comprising the aforementioned black toner and carrier particles comprised of a core of ferrite coated with a coating comprising a polymethyl methacrylate polymer or polymethyl methacrylate and fluoro-copolymer mixture, carbon black and melamine beads, wherein the developer comprises from about 1 part to about 25 parts by weight of the black toner and from about 75 parts to about 99 parts by weight of the carrier particles. In still further embodiments, the invention relates to an electrophotographic image forming apparatus comprising a photoreceptor, a semiconductive magnetic brush development system, and a housing in association with the semiconductive magnetic brush development system for containing a developer comprising the black toner of the invention. detailed-description description="Detailed Description" end="lead"? | 20040506 | 20070102 | 20051110 | 75028.0 | 0 | GOODROW, JOHN L | EMULSION AGGREGATION BLACK TONER AND DEVELOPER WITH SUPERIOR IMAGE QUALITY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,839,373 | ACCEPTED | Hierarchical data collection network supporting packetized voice communications among wireless terminals and telephones | A packet-based, hierarchical communication system, arranged in a spanning tree configuration, is described in which wired and wireless communication networks exhibiting substantially different characteristics are employed in an overall scheme to link portable or mobile computing devices. The network accommodates real time voice transmission both through dedicated, scheduled bandwidth and through a packet-based routing within the confines and constraints of a data network. Conversion and call processing circuitry is also disclosed which enables access devices and personal computers to adapt voice information between analog voice stream and digital voice packet formats as proves necessary. Routing pathways include wireless spanning tree networks, wide area networks, telephone switching networks, internet, etc., in a manner virtually transparent to the user. A voice session and associate call setup simulates that of conventional telephone switching network, providing well-understood functionality common to any mobile, remote or stationary terminal, phone, computer, etc. | 1-21. (Canceled) 22. A multi-mode data communication system comprising: a communication terminal capable of selectively exchanging data via a first wireless communication network, the communication terminal comprising identifying information; a first transceiver communicatively coupled to the communication terminal, the first transceiver capable of selectively exchanging data via a second wireless communication network; a second transceiver capable of selectively exchanging data with the first transceiver via the second wireless communication network, the first and second transceivers adapted to exchange data wirelessly within a premises; at least one processor communicatively coupled to the second transceiver, the at least one processor capable of exchanging data via a wired network; and the system selecting exchange of data via one of the first and second wireless communication networks based upon at least one operating condition of one of the first and second wireless communication networks. 23. The system of claim 22 wherein the identifying information comprises a unique number. 24. The system of claim 22 wherein the communication terminal comprises a cellular telephone. 25. The system of claim 22 wherein the first wireless communication network comprises a cellular communication network. 26. The system of claim 22 wherein the wired network comprises a packet network. 27. The system of claim 22 wherein the wired network comprises the Internet. 28. The system of claim 22 wherein the second wireless communication network comprises a wireless local area network. 29. The system of claim 22 wherein the second wireless communication network operates at a frequency of approximately 2.4 gigahertz. 30. The system of claim 22 wherein the second wireless communication network uses a spread spectrum communication technique. 31. The system of claim 30 wherein the spread spectrum technique comprises a direct sequence spread spectrum technique. 32. The system of claim 30 wherein the spread spectrum technique comprises a frequency hopped spread spectrum technique. 33. The system of claim 22 wherein the at least one operating condition comprises the first and second transceivers being within a predefined communication range. 34. A method of multi-mode data communication employing a communication terminal capable of operating on a plurality of wireless communication links and an access device capable of wireless communication with the communication terminal, the access device communicatively coupled to a wired network, the method comprising: establishing wireless communication between the communication terminal and the access device via a first of the plurality of wireless communication links, if at least one predefined operating condition exists; exchanging data between the communication terminal and a destination on the wired network via the access device using the first of the plurality of wireless communication links, if the at least one predefined operating condition exists; establishing wireless communication between the communication terminal and the destination on the wired network via a second of the plurality of wireless communication links, if the at least one predefined operating condition does not exist; and automatically arranging communication of data between the communication terminal and the wired network via one of the first and the second of the plurality of wireless communication links depending at least upon whether or not the at least one predefined operating condition exists. 35. The method of claim 34 wherein the communication terminal comprises a cellular telephone. 36. The method of claim 34 wherein the plurality of wireless communication links comprises a cellular communication network. 37. The method of claim 34 wherein the wired network comprises a packet network. 38. The method of claim 34 wherein the wired network comprises the Internet. 39. The method of claim 34 wherein the plurality of wireless communication links comprises a wireless local area network. 40. The method of claim 34 wherein at least one of the plurality of wireless communication links operates at a frequency of approximately 2.4 gigahertz. 41. The method of claim 34 wherein at least one of the plurality of wireless communication links uses a spread spectrum communication technique. 42. The method of claim 41 wherein the spread spectrum technique comprises a frequency hopped spread spectrum technique. 43. The method of claim 41 wherein the spread spectrum technique comprises a direct sequence spread spectrum technique. 44. The method of claim 34 wherein the at least one operating condition comprises the communication terminal and access device being within a predefined communication range. 45. The method of claim 34 wherein the at least one operating condition comprises the cost of communication via the first of the plurality of wireless communication links being less that the cost of communication via the second of the plurality of wireless communication links. 46. A multi-mode data communication system comprising: a communication terminal capable of exchanging data via a first wireless communication network; at least one processor capable of exchanging data via a wired network; at least two transceivers, a first of the at least two transceivers communicatively coupled to the communication terminal and a second of the at least two transceivers communicatively coupled to the at least one processor, each of the first and second transceivers capable of direct wireless communication of data with the other via a second wireless communication network; and at least one of the at least two transceivers functioning to detect communication signals of another of the at least two transceivers, the system automatically establishing communication of data between the communication terminal and the wired network via one of the first and second wireless networks based upon at least one predetermined parameter. 47. The system of claim 46 wherein the communication terminal comprises a cellular telephone. 48. The system of claim 46 wherein the first wireless communication network comprises a cellular communication network. 49. The system of claim 46 wherein the wired network comprises a packet network. 50. The system of claim 46 wherein the wired network comprises the Internet. 51. The system of claim 46 wherein the second wireless communication network comprises a wireless local area network. 52. The system of claim 46 wherein at least one of the first and second wireless communication networks operates at a frequency of approximately 2.4 gigahertz. 53. The system of claim 46 wherein at least one of the first and second wireless communication networks uses a spread spectrum communication technique. 54. The system of claim 53 wherein the spread spectrum communication technique comprises a frequency hopping spread spectrum technique. 55. The system of claim 53 wherein the spread spectrum communication technique comprises a direct sequence spread spectrum technique. 56. The system of claim 46 wherein the at least one predetermined parameter comprises a communication range. 57. The system of claim 46 wherein the at least one predetermined parameter comprises a cost of communication via at least one of the first wireless communication network and the second wireless communication network. 58. The system of claim 46 wherein the communication terminal comprises unique numeric identifier. | CROSS REFERENCE TO RELATED APPLICATIONS Claiming Benefit Under 35 U.S.C. 120 This application is a continuation in part of U.S. Ser. No. 08/487,609, filed Jun. 7, 1995 (Attorney Docket Nos. 10082US12 and DN37998XE), which is a continuation in part of U.S. application Ser. Nos. a) 08/279,148, filed Jul. 22, 1994 (Attorney Docket Nos. 10082US11; DN37998XD); b) 07/876,629, filed Apr. 30, 1992 (Attorney Docket Nos. 92P275; DN36837D); and c) 08/267,758, filed Jul. 5, 1994 (Attorney Docket Nos. 10554US02; DN37613A). The application U.S. Ser. No. 08/279,148 is a continuation-in-part of: PCT Application Serial No. PCT/US94/05037 filed May 6, 1994 (Attorney Docket Nos. 10082WO08; DN37998XAX); U.S. application Ser. No. 08/205,639 filed Mar. 4, 1994. (Attorney Docket Nos. DN37139XXA; 10458US03); and U.S. application Ser. No. 08/275,821, filed Jun. 10, 1994 (Attorney Docket Nos. 10082US10; DN37998XC). PCT Application Serial No. PCT/US94/05037 is based on U.S. application Ser. No. 08/198,404, filed Feb. 22, 1994 (Attorney Docket Nos. 10082US07; DN37998XA), which is itself a continuation of U.S. application Ser. No. 08/198,452, filed Feb. 18, 1994 (Attorney Docket Nos. 10082US06; DN37998X), which is in turn a continuation-in-part of U.S. application Ser. No. 08/168,478, filed Dec. 16, 1993 (Attorney Docket Nos. 10092US06; DN37998E), and PCT Application Serial No. PCT/US93/12628 filed Dec. 23, 1993 (Attorney Docket Nos. DN37967C and 10082WO01). The application U.S. Ser. No. 08/168,478 is a continuation-in-part of U.S. application Ser. No. 08/147,377 filed Nov. 3, 1993 (Attorney Docket No. DN37998D), which is a continuation-in-part of U.S. application Ser. No. 08/101,254 filed Aug. 3, 1993 (Attorney Docket No. DN37998C), which is itself a continuation-in-part of U.S. application Ser. No. 08/085,662 filed Jun. 29, 1993 (Attorney Docket No. DN37998B), which is itself a continuation-in-part of U.S. application Ser. No. 08/076,340 filed Jun. 11, 1993 (Attorney Docket No. DN37998A), which is in turn a continuation-in-part of U.S. application Ser. No. 08/062,457, filed May 11, 1993 (Attorney Docket No. DN37998). PCT Application Serial No. PCT/US93/12628 is based on pending U.S. application Ser. No. 08/027,140 filed Mar. 5, 1993 (Attorney Docket Nos. DN37967B; 10082US05), which is itself a continuation-in-part of U.S. application Ser. 07/997,693 filed Dec. 23, 1992 (Attorney Docket Nos. DN37967A; 10005US02), now abandoned, which is a continuation-in-part of U.S. application Ser. No. 07/982,292 filed Nov. 27, 1992 (Attorney Docket Nos. DN37967; 92 P 837), now abandoned, which is itself a continuation-in-part of U.S. application Ser. No. 07/700,704 filed May 14, 1991 (Attorney Docket Nos. DN37834X; 91P383), now abandoned, which is itself a continuation-in-part of U.S. application Ser. No. 07/699,818 filed May 13, 1991 (Attorney Docket Nos. DN37834; 91P862), now abandoned. The application U.S. Ser. No. 08/205,639 is a continuation-in-part of U.S. application Ser. No. 07/735,128 filed Jul. 22, 1991 (Attorney Docket Nos. DN37139XX; 91P326), which is itself a continuation-in-part of U.S. application Ser. No. 07/467,096 filed Jan. 18, 1990 (Attorney Docket Nos. DN37139), now U.S. Pat. No. 5,052,020. U.S. application Ser. No. 08/062,457 is a continuation in part of U.S. Ser. No. 07/876,776, filed Apr. 28, 1992 (Attorney Docket Nos. 92P334; DN366949XZB), which is itself a continuation in part of U.S. Ser. No. 07/854,115, filed Mar. 18, 1992 (Attorney Docket Nos. 92P241; DN36649XZA), which is in turn a continuation in part of U.S. Ser. No. 07/558,895, filed Jul. 25, 1990 (Attorney Docket Nos. 91P387; DN36649XZ). U.S. Ser. No. 07/558,895 is a continuation in part of U.S. Ser. No. 07/529,353, filed May 25, 1990 (Attorney Docket Nos. 91P869; DN36649XY), which is itself a continuation in part of U.S. Ser. No. 07/347,602, filed May 3, 1989 (Attorney Docket Nos. 91P386; DN36649XX), which is itself a continuation of U.S. Ser. No. 07/345,771, filed May 2, 1989 (Attorney Docket Nos. 91P844; DN36649Y), which is itself a continuation of U.S. Ser. No. 07/345,200, filed Apr. 28, 1989 (Attorney Docket Nos. 91P423; DN36649X), which is itself a continuation of U.S. Ser. No. 07/305,302, filed Jan. 31, 1989 (Attorney Docket Nos. 91P422; DN36649). The application U.S. Ser. No. 07/876,629 is also a continuation in part of U.S. Ser. No. 07/854,115, filed Mar. 18, 1992 (Attorney Docket No. DN36649XZA), with its parentage as listed above. The application U.S. Ser. No. 08/267,758 is a continuation in part of U.S. Ser. No. 07/748,150, filed Aug. 21, 1991 (Attorney Docket Nos. 10554US01; DN37613), now issued as U.S. Pat. No. 5,349,678 on Sep. 20, 1994. INCORPORATION BY REFERENCE The above referenced applications, PCT Application No. PCT/US92/08610 filed Oct. 1, 1992, as published under International Publication No. WO 93/07691 on Apr. 15, 1993, together with U.S. Pat. No. 5,070,536, by Mahany et al., U.S. Pat. No. 4,924,426, by Sojka, and U.S. Pat. No. 4,910,794, by Mahany, are incorporated herein by reference in their entirety, including drawings and appendices, and hereby are made a part of this application. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to data communication networks having a plurality of wired and/or S wireless access servers configured to support remote processing, data storage and voice communication. More specifically, this invention relates to the intelligent routing of packetized voice communication between telephones and radio terminals through wireless and hardwired channels in a data processing network. While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility. 2. Description of Related Art To support data collection, multiple radio base station networks have been developed to overcome a variety of problems with single radio base station networks such as spanning physical radio wave penetration barriers, wasted transmission power by portable Computing devices, etc. However, multiple radio base station networks have their own inherent problems. For example, in a multiple base station network employing a single shared channel, each base station transmission is prone to collision with neighboring base station transmissions in the overlapping coverage areas between the base stations. Therefore, it often proves undesirable for each base station to use a single or common communication channel. In contradistinction, to facilitate the roaming of portable or mobile devices from one coverage area to another, use of a common communication channel for all of the base stations is convenient. A roaming device may easily move between coverage areas without loss of connectivity to the network. Such exemplary competing commonality factors have resulted in tradeoff decisions in network design. These factors become even more significant when implementing a frequency hopping spread spectrum network. Frequency hopping is a desirable transmission technique because of its ability to combat frequency selective fading, avoid narrowband interference, and provide multiple communications channels. Again, however, changing operating parameters between coverage areas creates difficulties for the roaming devices which move therebetween. In particular, when different communication parameters are used, a portable or mobile device roaming into a new base station coverage area is not able to communicate with the new base station without obtaining and synchronizing to the new parameters. This causes a communication backlog in data collection networks. Such data collection networks and their communication protocols have been specifically designed for data collection and forwarding through wireless and hardwired links. They are designed in attempts to optimize overall data flow through the network. Among other flow optimizing techniques used, the data is segmented and packetized in preparation for transmission. Packet by packet, the data is transmitted as channel bandwidth becomes available. Thus, instead of disabling a channel by dedicating bandwidth to service only a pair of participants exchanging potentially large amounts of data (data possibly having no immediate need), the channel is shared by many participants, each sending segments of data in packets whenever an opening in the channel occurs. In contrast, to support the delivery of real time voice, alternate network design constraints must be considered. For example, such networks often dedicated bandwidth to voice transmission exchanges. However, by dedicating channel bandwidth to voice, efficient communication of data through such networks is seriously impacted. Data communication would have to wait for longer periods of time until dedicated voice bandwidth has been released. Similarly, data communication would have to be immediately discontinued upon requests for voice bandwidth. Thus, there is a need for a communication network that provides efficient distribution and utilization of network resources in support of both data and voice delivery. An object of the invention is to provide a method and apparatus wherein seamless voice and data communication is provided among both roaming devices within wireless portions of a communication network and stationary devices within hardwired portions of the network. Another object of the present invention is to provide a hierarchical communications system for providing an efficient communication pathway for both data and voice. Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. SUMMARY OF THE INVENTION The present invention solves many of the foregoing problems in a variety of embodiments. For example, in one embodiment, a communication network is disclosed which operates to support voice and data communication within a premises. The communication network comprises a plurality of mobile network devices, a stationary network device, a wireless network, a hardwired network and a telephone. Each mobile network device has a buffer that stores incoming digital voice information for a predetermined queuing period before beginning voice reproduction from the stored digital voice information. Each mobile network device uses the wireless network to selectively exchange voice and data packets with other mobile network devices. Similarly, the hardwired network is connected to both said stationary network device and the wireless network, and is used to route voice and data packets between the stationary network device and the plurality of mobile network devices which participate via the wireless network. The telephone, which is connected to the stationary network device, captures, delivers, receives and reproduces voice in an analog voice stream form. The stationary network device also has a buffer that stores digital voice information, received from the wireless network, for a predetermined queuing period before converting it into an analog voice stream. After conversion, the stationary network device delivers the analog voice stream to the telephone. In addition, the stationary network device converts analog voice streams received from the telephone into voice packets for delivery via the hardwired and wireless networks to a selected one of the mobile network devices. Further detail regarding this embodiment and variations thereof are also disclosed. For example, the predetermined queuing period can be determined through examining delays found in test signal routing. The stationary network device can be a computer. The wireless network may utilize a polling protocol and spanning tree routing. The stationary network device can provide call setup assistance for the telephone. Moreover, the communication network may further comprise a telephone switching network, connected to the stationary network device, which selectively routes analog voice streams received from the telephone onto the telephone switching network. The stationary network device may also selectively route analog voice streams received from the telephone switching network to the telephone. Further detail regarding the present invention (and embodiments thereof) may be found in reference to the claims below, in view of the following detailed description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagrammatic illustration of a hierarchal communication system built in accordance with the present invention. FIG. 1B is a diagrammatic illustration of another hierarchal communication system built in accordance with the present invention. FIG. 1C is a diagrammatic illustration of still another hierarchal communication system built in accordance with the present invention. FIG. 2 illustrates an embodiment of a basic access interval structure used by a hierarchical network of the present invention. FIGS. 3A and 3B illustrate the frequency of operation periodically changing corresponding to access interval boundaries in a frequency hopping communication protocol of the present invention. FIGS. 4A and 4B illustrate more than one access interval being used per hop in a frequency hopping communication protocol of the present invention. FIG. 5A illustrates an embodiment of an access interval used by the hierarchical network of the present invention wherein a reservation phase is Idle Sense Multiple Access. FIG. B illustrates an embodiment of an access interval used by the hierarchical network of the present invention wherein a device response follows a reservation poll. FIG. 6A illustrates an embodiment of an access interval used by the hierarchical network of the present invention having multiple reservation slots for transmission of a Request For Poll signal. FIG. 6B illustrates an embodiment of an access interval used by the hierarchical network of the present invention wherein general devices contend for channel access. FIG. 7A illustrates a sequence in an access interval used by the hierarchical network of the present invention for transferring data from a remote device to a control point device. FIG. 7B illustrates a sequence in an access interval used by the hierarchical network of the present invention for transferring data from a control point device to a remote device. FIG. 8 illustrates a preferred embodiment of an access interval used by the hierarchical network of the present invention. FIGS. 9A and B conceptually illustrate how multiple NETs may be employed in an idealized cellular-type installation according to the present invention. FIG. 10 illustrates an access point coverage contour overlap for the multiple NETs Infrastructured Network of FIG. 1. FIG. 11 illustrates hopping sequence reuse in a multiple NET configuration of the present invention. FIG. 12 illustrates a hierarchical infrastructured network of the present invention wherein a wireless link connects access points on separate hard wired LANs. FIG. 13 illustrates a hierarchical infrastructured network of the present invention including a wireless access point. FIG. 14 illustrates conceptually access points communicating neighboring access point information to facilitate roaming of portable/mobile devices. FIG. 15 illustrates a secondary access interval used in the MicroLAN or peripheral LAN in the hierarchical communication network according to the present invention. FIG. 16 is a flow chart illustrating the selection of an access point by a mobile computing device for communication exchange. FIG. 17 is a flow chart illustrating a terminal maintaining synchronization with the network after it has gone to sleep for several access intervals. FIG. 18 is a flow chart illustrating a terminal that maintains or achieves synchronization with the network after it has gone to sleep for several seconds. FIGS. 19A and 19B are flow charts illustrating an access interval during inbound communication. FIGS. 20A and 20B are flow charts illustrating an access interval during outbound communication. FIG. 21 illustrates a sequence in an access interval used in the hierarchical communication network of the present invention with Time Division Multiple Access slots positioned at the end of the access interval. FIG. 22 illustrates a sequence in an access interval used by the hierarchical network of the present invention with the Time Division Multiple Access slots positioned immediately following the SYNC. FIG. 23 illustrates a sequence in an access interval used by the hierarchical network of the present invention with the Time Division Multiple Access slots positioned immediately following the SYNC and Reservation Poll. FIG. 24 illustrates another sequence in an access interval used by the hierarchical network of the present invention with the Time Division Multiple Access slots positioned immediately following the SYNC. FIG. 25 illustrates a portion of an access interval including the preamble, SYNC and Reservation Poll. FIG. 26 illustrates the information contained in a sample SYNC message. FIG. 27 illustrates the information contained in a sample Reservation Poll. FIG. 28A illustrates a warehouse environment incorporating a communication network which maintains communication connectivity between the various network devices according to the present invention. FIG. 28B illustrates other features of the present invention in the use of a vehicular LAN which is capable of detaching from the premises LAN when moving out of radio range of the premises LAN to perform a service, and reattaching to the premises LAN when moving within range to automatically report on the services rendered. FIG. 28C illustrate other features of the present invention in the use of a vehicular LAN which, when out of range of the premises LAN, is still capable gaining access to the premises LAN via radio WAN communication. FIG. 29A is a diagrammatic illustration of the use of a peripheral LAN supporting roaming data collection by an operator according to the present invention. FIG. 29B is a diagrammatic illustration of another embodiment of a peripheral LAN which supports roaming data collection by an operator according to the present invention. FIG. 30 is a block diagram illustrating the functionality of RF transceivers built in accordance with the present invention. FIG. 31 is a diagrammatic illustration of an alternate embodiment of the peripheral LAN shown in FIG. 2. FIG. 32 is a block diagram illustrating a channel access algorithm used by peripheral LAN slave devices in accordance with the present invention. FIG. 33A is a timing diagram of the protocol used according to the present invention illustrating a typical communication exchange between a peripheral LAN master device having virtually unlimited power resources and a peripheral LAN slave device. FIG. 33B is a timing diagram of the protocol used according to the present invention illustrating a typical communication exchange between a peripheral LAN master device having limited power resources and a peripheral LAN slave device. FIG. 33C is also a timing diagram of the protocol used which illustrates a scenario wherein the peripheral LAN master device fails to service the peripheral LAN slave devices. FIG. 34 is a timing diagram illustrating the peripheral LAN master device's servicing of both the higher power portion of the premises LAN as well as the lower power peripheral LAN subnetwork with a single or plural radio transceivers. FIGS. 35 and 36 are block diagrams illustrating additional power saving features according to the present invention wherein ranging and battery parameters are used to optimally select the appropriate data rate and power level of subsequent transmissions. FIG. 37 illustrates an exemplary block diagram of a radio unit capable of current participation on multiple LANs according to the present invention. FIG. 38 illustrates an exemplary functional layout of the frequency generator of FIG. 37 according to one embodiment of the present invention. FIG. 39 illustrates further detail of the receiver RF processing circuit of FIG. 37 according to one embodiment of the present invention. FIG. 40 illustrates further detail of the receiver signal processing circuit of FIG. 37 according to one embodiment of the present invention. FIG. 41 illustrates further detail of the receiver signal processing circuit of FIG. 37 according to another embodiment of the present invention. FIG. 42 illustrates further detail of the memory unit of FIG. 37 according to one embodiment of the present invention. FIG. 43 illustrates a software flow chart describing the operation of the control processor in controlling the battery powered radio unit to participate on multiple LANs. FIG. 44 is an alternate embodiment of the software flow chart wherein the control processor participates on a master LAN and, when needed, on a slave LAN. FIG. 45 illustrates another embodiment of the communication system of the present invention as adapted for servicing a retail store environment. FIGS. 46a-b illustrate a further embodiment of the communication system of the present invention which illustrate the use of access servers that support local processing and provide both data and program migration. FIG. 47a is a flow diagram which illustrates the functionality of the access servers of FIGS. 46a-b in handling data, processing and direct routing requests. FIG. 47b is a flow diagram utilized by the access servers of FIGS. 46a-b to manage the migration of data and program code from a source storage and/or processing device toward an end-point device. FIG. 48 is a schematic diagram of the access servers of FIGS. 46a-b illustrating an exemplary circuit layout which supports the functionality described in relation to FIGS. 47a-b. FIG. 49 is a specific exemplary embodiment of an access point in a multi-hop communication network utilized for remote processing of 2-D (two-dimension) code information. FIG. 50 is a schematic diagram similar to that shown in FIG. 48 which illustrates the circuit layout used in the access point of FIG. 49 to process the 2-D code information. FIGS. 51a-b are flow diagrams illustrating the operation of the 2-D code processing access point of FIGS. 49-50. FIG. 52 illustrates the structuring of 2-D code information so as to support a hierarchical recognition strategy as used by the access point of FIGS. 49-50. FIG. 53 is a diagram illustrating an exemplary 2-D code wherein the hierarchical structure of FIG. 52 is implemented. FIG. 54 is a flow diagram illustrating the functionality of the access point of FIGS. 49-50 in carrying out the hierarchical recognition strategy of FIG. 52. FIG. 55a is a diagram illustrating the overall flow of both data and voice through another embodiment of the hierarchical communication network of the present invention. FIG. 55b is a diagram which illustrates a summary of the various types of communication pathways for setting up voice sessions between a source and destination network device. FIG. 56a illustrates an embodiment of the conversion circuitry contained within a computer card 5601 which plugs into the computer 5515 of FIG. 55a. FIG. 56b illustrates an alternate embodiment of the conversion circuitry of FIG. 56a wherein instead of using an analog subtraction process to separate outgoing voice signals from the combined incoming and outgoing signals, a digital subtraction process is used (at a subtraction circuit 5653). FIG. 57 is an illustration of the back of the telephone 5525 (also illustrated in FIG. 55a) as built in accordance with the present invention. FIG. 58 is a schematic block diagram which illustrates the implementation of one embodiment of the conversion circuitry within the telephone 5525 of FIGS. 55 and 57. FIG. 59 is a block diagram illustrating the packet processing functionality of the access devices illustrated in FIG. 55a. FIG. 60 is a flow diagram illustrating the functionality of a source device in the setup of a voice session. FIG. 61 is a flow diagram illustrating the functionality of the source device (or assisting access device) when performing call setup. FIG. 62 is a flow diagram illustrating ongoing voice session processing performed by a source device (or its assisting access device if needed) and destination device (or its assisting access device if needed). FIG. 63 is a diagram which illustrates further application of the present invention in an embodiment which transparently utilizes internet connectivity to support low-cost voice sessions. DETAILED DESCRIPTION OF THE INVENTION FIG. 1A illustrates a hierarchical communication system 10 within a building in accordance with the present invention. The illustrated hierarchical communication system 10 includes a local area network (LAN) for maintaining typical communication flow within the building premises, herein referred to as a premises LAN. The premises LAN is designed to provide efficient end-to-end routing of information among hardwired and wireless, stationary aid roaming devices located within the hierarchical communication system 10. The premises LAN consists of an infrastructure network comprising radio base stations, i.e., wireless access points 15, and a data base server 16 which may be part of a more extensive, wired LAN (not shown). Herein, base stations which participate in routing and relaying data throughout the communication network are referred to as “access points.” If they also participate in the storage or migration of data and program code or in local processing, the base stations are referred to herein as “access servers.” As will become apparent below, an access point may be modified with additional circuitry and/or programming resources to become an access server. Additionally, access servers and access points are both referred to herein as “access devices.” The access points 15 may communicate with each other via hardwired links, such as Ethernet, RS232, etc., or via wireless (radio frequency) links. A plurality of roaming terminal devices, such as a roaming computing device 20, participate in the premises LAN of the hierarchical communication network 10 to exchange information with: 1) other roaming computing devices; 2) the data base server 16; 3) other devices which might be associated with data base server 16 (not shown); and 4) any other devices accessible via the premises LAN (not shown). A roaming computing device can be, for example, a hand-held computer terminal or vehicle mounted computer terminal (vehicle terminal). In most circumstances, the premises LAN provides a rather optimal solution to the communication needs of a given network. However, in some circumstances, to serve a variety of particular communication needs, the premises LAN does not offer the optimal solution. Instead of relying on the premises LAN for such communications, when and where beneficial, alternate LANs are spontaneously created by (or with) network devices, such as the roaming computing device 20, within the hierarchical communication system 10. Such spontaneously created LANs are referred to herein as spontaneous LANs. After the immediate benefits end, i.e., a task has been completed, or if the participants of the spontaneous LAN move out of range of each other, the spontaneous LAN terminates operation. An exemplary spontaneous. LAN involves the use of peripheral devices as illustrated in FIG. 1A. Although bulk data transfer destined for a peripheral device 23, such as a printer, from the roaming computing device 20 might be communicated through the premises LAN, a more direct interconnection proves less intrusive, saves power, and offers a lower cost solution. Specifically, instead of communicating through the premise LAN, the roaming computing device 20 needing to print: 1) identifies the presence of an available printer, the peripheral device 23; 2) establishes an RF link (binds) with the peripheral device 23; 3) directly begins transferring the bulk data for printing; and 4) lastly, when the roaming terminal finishes the transfer, the spontaneous LAN with the peripheral device 23 terminates. A spontaneous LAN created between the computing devices and peripheral devices is herein referred to as a peripheral LAN. Other types of spontaneous LANs, such as vehicular LANs, are also possible. Embodiments described below identify vehicular LANs and wide area radio networks (WANs) which are part of the hierarchical communication system according to the present invention. Although a spontaneous LAN may operate completely independent of the premises LAN, it is more likely that there will be some degree of coordination between the two. For example, while participating in the peripheral LAN, the roaming computing device 20 may terminate participation in the premises LAN, and vice versa. Alternately, the roaming computing device 20 may only service the peripheral LAN when specific participation on the premises LAN is not required, or vice versa. Moreover, the roaming computing device 20 may attempt to service each peripheral LAN as necessary in a balanced time-sharing fashion, placing little priority upon either LAN. Thus, based on the protocols and hardware selected, a spontaneous LAN can be configured so as to exist hierarchically above, below, at the same level, or independent of the premises LAN. Generally, to design a given LAN configuration, only the characteristics of that LAN are considered for optimization purposes. However, in the hierarchical communication system of the present invention, the operation of other LANs must also be taken into account. For example, because of the roaming computing devices participation in both the premises and peripheral LANs, the requirements and operation of the premises LAN must be taken into consideration when defining the peripheral LAN, and vice versa. Thus, the hierarchical communication system of the present invention provides a series of tightly coupled radio LANs and WANs with radio transceiver and communication protocol designs which take into consideration such factors as cost, weight, power conservation, channel loading, response times, interference, communication flow, etc., as modified by a primary factor of multiple participation. The peripheral LAN replaces hardwired connection between a roaming computing device and associated peripherals. In a typical configuration, a peripheral LAN will consist of one or more peripherals slaved to a single master roaming computing device, although multiple master roaming computing devices are possible. Peripheral devices may be printers, code scanners, magnetic card readers, input styluses, etc. Each of the peripheral devices 22 has a built-in radio transceiver to communicate with the roaming computing devices 20. The roaming computing devices 20 are configured with built-in radio transceivers capable of communicating on both the peripheral and premises LAN. The access points is may be configured with radio transceivers only capable of communicating in the premises LAN. In alternate embodiments, as described below, the access points 15 might instead be configured to participate on both the premises and peripheral LANs. In particular, the peripheral LAN is intended to provide communications between two or more devices-operating within near proximity, e.g., distances of a few tens of feet. The majority of constituents of the peripheral LAN are generally devices that do not require access to resources outside their immediate group, or which can suffice with indirect access through devices which participate outside their immediate peripheral LAN group. In contradistinction, the premises LAN is intended to provide communications between relatively many devices operating across great distances throughout a building. The characteristics of the peripheral LAN permit the use of radio transceivers of lower cost, lower power consumption, and generally more simplistic operation than permitted by the premises LAN. However, the operation of the peripheral LAN is adapted for integration with the premises LAN so that a radio transceiver and protocol designed for operation on the premises LAN includes features which allow concurrent or sequentially concurrent operation on the peripheral LAN. For example, by selecting similar communication hardware characteristics and integrating protocols, communication within the premises and peripheral LANs may be achieved with a single radio transceiver. In one embodiment, radio communication through the premises LAN, i.e., among the access points 15 and the roaming computing device 20, utilizes relatively higher-power spread-spectrum frequency-hopping communication with a reservation access protocol. The reservation access protocol facilitates frequency-hopping and supports adaptive data rate selection. Adaptive data rate selection is based upon the quality of communication on the premises LAN radio channel. Radio communication through the peripheral LAN utilizes a relatively lower-power single frequency communication also with a reservation access protocol. As more fully described below, the coordinated use of reservation access protocols in the peripheral and premises LANs maximize information flow while minimizing conflicts between devices participating in the two LANs. Referring to FIG. 1B, a small hierarchal communication system 30 built in accordance with the present invention is shown. An access point 33 and two roaming or mobile computing devices 35 and 36 form a premises LAN 37. The premises LAN 37 provides for communication among the mobile computing devices 35 and 36 and a host computer 34. The mobile computing devices 35 and 36 can roam anywhere within the range of the access point 33 and still communicate with the host computer 34 via the access point 33. Two peripheral LANs 40 and 41 allow for wireless communication between each mobile computing device 35 and 36 and its respective peripheral devices 43, 44 and 45 when the mobile computing device is not communicating on the premises LAN 37. Specifically, the peripheral LAN 40 consists of the mobile computing device 35 and the peripheral device 43, while the peripheral LAN 41 consists of the mobile computing device 36 and the two peripheral devices 44 and 45. FIG. 1C illustrates another embodiment according to the present invention of a larger hierarchal communication system 50. The host computer 55 is connected to access points 56, 57, 58 and 59. The host computer 55 and the access points 56, 57, 58 and 59 provide the infrastructure for the premises LAN. The access points need not be hardwired together. For example, as illustrated in FIG. 1C, the access points 56, 57 and 58 access each other and the host computer 55 via a hardwired link, while the access point 59 accomplishes such access via a wireless link with the access point 58. The access points 56, 58 and 59 can support multiple mobile computing devices. For example, the access point 56 uses a frequency-hopping communication protocol for maintaining communication with mobile computing devices 61 and 62. Moreover, each of the mobile computing devices may roam out of range of the access point with which they have been communicating and into the range of an access point with which they will at least temporarily communicate. Together, the host computer 55 and the access points 56, 57, 58 and 59 and mobile computing devices 61, 62, 64, 65 and 66 constitute a premises LAN. More particularly, each access point operates with a different set of communication parameters. For example, each access point may use a different frequency hopping sequence. Additionally, different access points may not employ a common master clock and will not be synchronized so as to have the frequency hopping sequences start at the same time. Mobile computing devices 61, 62, 64, 65 and 66 are capable of roaming into the vicinity of any of the access points SE, 58 and 59 and connecting thereto. For example, mobile computing device 62 may roam into the coverage area of access point 58, disconnecting from access point 56 and connecting to access point 58, without losing connectivity with the premises LAN. Each mobile computing device 61, 62, 64, 65 and 66 also participates with associated peripherals in a peripheral LAN. Each peripheral LAN is made up of the master device and its slave device. Similarly, as illustrated, the access point 57 is shown as a direct participant in not only the premises LAN but also in the peripheral LAN. The access point 57 may have either limited or full participation in the premises LAN. For example, the access point 57 may be configured as a mobile computing device with the full RF capability of transmission in both the premises and peripheral LANs. Instead, however, participation in the premises LAN may be limited to communicating through the hardwired link, effectively dedicating the access point 57 to the task of servicing peripherals. Although the use of a plurality of built-in radio transceivers could be used so as to permit simultaneous participation by a single device, factors of cost, size, power and weight make it desirable to only build-in a single radio transceiver capable of multiple participation. Furthermore, even where a plurality of radio transceivers are built-in, simultaneous participation may not be possible depending upon the potential transmission interference between transceivers. In fact, full simultaneous participation may not be desirable at least from a processing standpoint when one transceiver, servicing one LAN, always or usually takes precedence over the other. Justification for such precedence generally exists in a premises LAN over a peripheral LAN. For example, communication flow in most premises LANs must be fast, efficient and rather robust when considering the multitude of participants that operate thereon. In the peripheral LAN, however, response times and other transmission related delays are generally more acceptable—even adding extra seconds to a peripheral printer's print time will usually not bother the user. Thus, in such communication environments, it may be desirable to design the transmitters and associated protocols so that the premises LAN takes precedence over the peripheral LAN. This may yield a communication system where fully simultaneous participation in both the premises and peripheral LANs does not exist. In communication environments wherein fully simultaneous participation does not exist or is not desired, transmitter circuitry might be shared for participation in both the premises and peripheral LANs. Similarly, in such environments, the communication protocol for the peripheral LAN can be tightly coupled with the protocol for the premises LAN, i.e., integrated protocols, so as to accommodate multiple participation. Moreover, one protocol might be designed to take precedence over the other. For example, the premises LAN protocol might be designed so as to minimize participation or response time in the peripheral LAN. As described in more detail below, such transceiver and protocol analysis also takes place when considering additional multiple participation in the vehicular LAN and WAN environments. FIG. 2 illustrates an embodiment of a communication protocol for the premises LAN which uses a basic Access Interval 200 (“AI”) structure according to the present invention. Generally, an Access Interval is the basic communication unit, a fixed block of time, that allocates bandwidth to synchronization, media access, polled communications, contention-based communications, and scheduled services. The Access Interval in FIG. 2 includes a SYNC header 201 generated by a Control Point (“CP”) device of a NET. The term NET describes a group of users of a given hopping sequence or a hopping sequence itself. The Control Point device is generally the access point 15 referenced above with regard to FIG. 1. The SYNC header 201 is used by constituents of the NET to attain and maintain hopping synchronization. A reservation phase 203 follows permitting a reservation poll, which provides the NET constituents an opportunity to gain access to media. A sessions frame 205 is next allocated for communication protocol. A frame 207 follows for optional time division multiple access (“TDMA”) slots in order to accommodate scheduled services. Scheduled services, for example, real time voice or slow scan video, are such that a dedicated time slot may be required to provide acceptable quality of service. However, as described in more detail below in relation to FIG. 55, for example, acceptable real-time voice support is possible without dedicating time slots. The function of frames 201, 203, 205 and 207 will be discussed in greater detail below. FIG. 21 illustrates a sequence in an access interval 2100 with the Time Division Multiple Access slots 2113 positioned at the end of the access interval 2100. In the present example, if this were also a HELLO interval, the HELLO would immediately follow the SYNC 1201. Location of the Time Division Multiple Access slots at such a position provides certain advantages including, for example, 1) the SYNC 2101, HELLO (not shown), Reservation Poll 2103, may all be combined into a single transmission (concatenated frames); 2) hopping information may be moved to or included in the Reservation Poll 2103 allowing for a shorter preamble in the SYNC 2101; and 3) the HELLO messages will occur early in the Access Interval 2100 providing for shorter periods during which a sleeping terminal's receiver is on. The Time Division Multiple Access slots may also be located at different points within the access interval positioning the Time Division Multiple Access slots allow for various systemic advantages. Referring now to FIG. 22, an access interval 2200 is illustrated showing the Time Division Multiple Access slots 2203 immediately following the SYNC 2201. Location of the Time Division Multiple Access slots 2203 at this position provides certain advantages including, for example, 1) better timing accuracy is achieved when the Time Division Multiple Access slots 2203 immediately follow the SYNC 2201; 2) session overruns do not interfere with the Time Division Multiple Access slots 2203; 3) devices which do not use the Time Division Multiple Access slots 2203 do not necessarily need to be informed of the Time Division Multiple Access slot allocation; and 4) HELLO message may follow Time Division Multiple Access slots 2203, Reservation Slots 2207 or Reservation Resolution Poll 2209. Referring now to FIG. 23, an access interval 2300 is illustrated showing the Time Division Multiple Access slots 2305 immediately following the SYNC 2301 and the Reservation Poll 2303. In the present example, if this were a HELLO interval, a HELLO message would immediately follow the Reservation Resolution Poll 2309. Location of the Time Division Multiple Access slots 2305 at the position shown in FIG. 23 provides certain advantages including, for example, 1) the Time Division Multiple Access slot timing is keyed to SYNC 2301 for better accuracy; 2) the number of Time Division Multiple Access slots 2305 may be indicated in SYNC 2301 or the Reservation Poll 2303, providing greater flexibility; 3) session frame overuns do not interfere with Time Division Multiple Access slots 2305; 4) only one maintenance transmission is required per Access Interval 2300; and 5) hopping information may be moved to or included in the Reservation Poll 2303, permitting a shorter preamble in SYNC 2301. In the access interval 2300 configuration shown in FIG. 23, it is possible that the Time Division Multiple Access slots 2305 and the response slots 2307 could be the same. The Reservation Poll 2303 would allocate the correct number of slots and indicate which are reserved for Time Division Multiple Access. For example, to use Idle Sense Multiple Access 1 slot) with 1 inbound and 1 outbound Time Division Multiple Access slots, three slots would be allocated with the first two slots reserved. The appropriate Time Division Multiple Access slot duration is 80 bits at a hop rate of 200 hops per second which is just about the expected duration of a Request for Poll. At slower hop rates, multiple slots could be allocated to Time Division Multiple Access allowing the Time Division Multiple Access slot duration to be constant regardless of hop rate. Referring now to FIG. 24, another access interval 2400 is illustrated showing the Time Division Multiple Access slots 2403 immediately following the SYNC 2401. In this example the Poll Message Queue 2405 immediately follows the Time Division Multiple Access slots 2403. The configuration shown in FIG. 24 provides for certain advantages including, for example, 1) the Time Division Multiple Access slot timing is keyed to SYNC 2401 for better accuracy; and 2) session frame overruns do not interfere with Time Division Multiple Access slots 2403. The configurations shown in FIG. 21 and in FIG. 23 are preferred because they allow the Reservation Poll messages to be transmitted immediately following the SYNC and because of the power management and interference reduction advantages. In one embodiment of the Access Interval structure, all message transmissions use standard high-level data link control (“HDLC”) data framing. Each message is delimited by High-Level Data Link Control Flags, consisting of the binary string 01111110, at the beginning of the message. A preamble, consisting of a known data pattern, precedes the initial FLAG. This preamble is used to attain clock and bit synchronization prior to the start of data. Receiver antenna selection is also made during the preamble for antenna diversity. A CRC for error detection immediately precedes the ending FLAG. Data is NRZ-I (differentially) encoded to improve data clock recovery. High-Level Data Link Control NRZ-I data is run-length-limited to six consecutive bits of the same state. Alternatively, a shift register scrambler could be applied instead of differential encoding to obtain sufficient transitions for clock recovery. Data frames may be concatenated, with two or more frames sent during the same transmission, with a single FLAG separating them. An example of this is SYNC, followed by a HELLO or Reservation Poll (SYNC, HELLO and Reservation Poll are discussed more fully below). While much of the following discussion centers on the use of frequency hopping in the premises LAN, the Access Interval structure of the present invention is also suitable for single channel and direct sequence spread spectrum systems. The consistent timing of channel access, and the relative freedom from collisions due to channel contention, provide desirable benefits in systems that support portable, battery powered devices regardless of modulation type or channelization. Functions that are unique to frequency hopping may be omitted if other channelization approaches are used. FIGS. 3a and 3b illustrate the frequency of operation periodically changing corresponding to Access Interval boundaries in a frequency hopping system. Frequency hopping systems use a hopping sequence, which is a repeating list of frequencies of, length (n) selected in a pseudo random order and is known to all devices within a coverage area. FIG. 3a illustrates a frequency hopping system having one Access Interval 301 per frequency hop (the hop occurring every 10 milliseconds) and a length of 79. FIG. 3b illustrates a frequency hopping system having one Access Interval 303 per frequency hop (the hop occurring every 20 milliseconds) and a length of 79. The 20 ms time frame is preferred for a protocol stack that uses a maximum network layer frame of up to 1536 bytes payload while maintaining two real time voice communications channels. Access interval duration may be optimized for other conditions. Access Interval length is communicated to the NET during the SYNC portion of the Access Interval. This allows Access Interval duration, and other NET parameters to be adjusted without reprogramming every device within the NET. The Access Interval is a building block. The length of the Access Interval can be optimized based on network layer packet size, expected mix of Bandwidth on Demand (“BWOD”) and Scheduled Access traffic, expected velocities of devices within the NET, acceptable duration of channel outages, latency or delay for scheduled services, etc. The preferred Access Interval duration of 20 ms (and maximum packet length of 256 Bytes at 1 MBIT/sec) represents a value chosen for systems with device velocities up to 15 MPH, and a mix between Bandwidth On Demand and scheduled service traffic. Within a frequency hopping network, one or more Access Intervals may be used during each dwell in a frequency hopping system. A dwell is the length of time (d) each frequency in the hopping sequence is occupied by the system. For example, FIGS. 4a and 4b show illustrations of cases where more than one 20 ms Access Interval 401 is used per hop. This may be appropriate for some instances where it is undesirable to hop at higher rates because of relatively long frequency switching times of the radio hardware, where import, export, or regulatory restrictions disallow hopping at a faster rate, or in some applications where it is desirable to maintain operation on each channel for a longer period. An example of the latter is the case where larger files or data records are transferred routinely. In a frequency hopping operation, the Access Interval 200 of FIG. 2 begins with a SYNC header 201. As mentioned above, the SYNC is generated by the Control Point (CP) device of the NET. The SYNC is used by constituents of the NET to attain and maintain hopping synchronization. Included in the SYNC are the following. 1. The address of the Control Point device. 2. Identification of the Hopping Sequence, and index of the current frequency within the hop table. 3. Identification of the hop rate, number of Access Intervals per hop, and Access Intervals before next hop. 4. A timing character for synchronization of device local clocks to the NET clock contained within the Control Point device. 5. Status field indicating reduced SYNC transmissions due to low NET activity (Priority SYNC Indicator). 6. Status field indicating if the Access Interval will contain a broadcast message to all devices within the NET. 7. Status field indicating premises or spontaneous LAN operation. 8. The SYNC field information is optionally encrypted using a block encryption algorithm, with a key provided by the network user. A random character is added to each SYNC message to provide scrambling. However, there are two circumstances during which a SYNC message is not transmitted: 1) co-channel interference; and 2) low NET utilization. With regard to co-channel interference, before issuing a SYNC message, the Control Point device performs channel monitoring for a brief interval. If the Received Signal Strength Indicator (RSSI) level indicates an ON channel signal greater than the system defer threshold, then the Access Interval is skipped. Alternatively, a strong ON channel signal may dictate a reduction in Control Point device power to limit the interference distance of the net for the duration of the Access Interval. A system defer threshold 30 dB above the receiver sensitivity is a preferred choice. Communication within the NET is deferred for the duration of the Access Interval if SYNC is not transmitted due to co-channel interference. In times of low system utilization, SYNC and Reservation Poll messages are reduced to every third Access Interval. The SYNC message includes a status field indicating this mode of operation. This allows devices to access the NET, even during Access Intervals where SYNC is skipped, by using an Implicit Idle Sense algorithm. If the hopping sequence is 79 frequencies in length as shown in FIGS. 3a and 3b, use of every third Access Interval guarantees that a SYNC message will be transmitted on each frequency within the hopping sequence once each three cycles of the sequence, regardless of whether 1, 2 or 4 Access Intervals occur each hop dwell. This addresses US and European regulatory requirements for uniform channel occupancy, and improves the prospects for synchronization of new units coming into the NET during periods when the NET is otherwise inactive. SYNC messages that are on multiples of 3 Access intervals are labeled as priority SYNC messages. “Sleeping” terminals use priority SYNCs to manage their internal sleep algorithms. Sleeping terminals and Implicit Idle Sense are discussed in more detail below. It should be noted that SYNC messages are preceded by dead time, which must be allocated to account for timing uncertainty between NET clocks and local clocks within NET constituents. In frequency hopping systems, the dead time must also include frequency switching time for the RF modem. The Reservation Poll frame 203 immediately follows the SYNC header 201. The two messages are concatenated High-Level Data Link Control frames separated by one or more Flags. The reservation poll provides NET constituents an opportunity to gain access to the media. It includes the following. 1. A field specifying one or more access slots. 2. A field specifying a probability factor between 0 and 1. 3. A list of addresses for which the access points have pending messages in queue. 4. Allocation of Time Division Multiple Access slots for scheduled services by address. 5. Control Point device Transmitted Power level for SYNC and Reservation Polls. The number of access slots, -n, and the access probability factor, p, are used by the Control Point device to manage contention on the channel. They may each be increased or decreased from Access Interval to Access Interval to optimize access opportunity versus overhead. If the NET is lightly loaded, the pending message list is short, and the NET is not subject to significant interference from other nearby NETs, the control point device will generally specify a single slot 501 as shown in FIG. 5a, with a p factor <1. In this case, the reservation phase is Idle Sense Multiple Access (“ISMA”). Devices with transmission requirements that successfully detect the Reservation Poll will transmit a Request for Poll (“RFP”) with probability p and defer transmission with probability 1−p. FIG. 5b shows a device response address 65 503 following the reservation poll. In cases when the transmission density is higher, n multiple reservation slots will be specified, generally with a probability factor p of 1. In this case a device will randomly choose one of n slots for transmission of their Request for Poll. The slotted reservation approach is particularly appropriate in instances where many NETs are operating in near proximity, since it diminishes reliance on listen before talk (“LBT”) (explained more fully below) The number of slots n is determined by a slot allocation algorithm that allocates additional slots as system loading increases. FIG. 6a shows multiple slots 601. In cases where NET loading is extreme, the Control Point may indicate a number of slots, e.g., not more than 6, and a probability less than 1. This will cause some number of devices to defer responding with a Request for Poll in any of the slots. This prevents the control point device from introducing the overhead of a large number of slots in response to heavy demand for communications, by dictating that some units back off until demand diminishes. A pending message list is included in the Reservation Poll. The pending message list includes the addresses of devices for which the Control Point device has messages in queue. Devices receiving their address may contend for the channel by responding with a Request-For Poll (RFP) in the slot response phase. FIG. 6b shows several devices 603, 605 and 607 contending for channel access. Messages that the. Control Point device receives through the wired infrastructure that are destined for Type 1 devices, and inactive Type 3 devices whose awake window has expired, are immediately buffered, and the device addresses are added to the pending message list. When a message is received through the infrastructure for a Type 2 device, or an active Type 3 device, their address is prioritized at the top of the polling queue. (Device Types and the polling queue are described below.) The pending message list is aged over a period of several seconds. If pending messages are not accessed within this period, they are dropped. Devices with transmission requirements respond in slots with a Request for Poll. This message type includes the addresses of the Control Point device and requesting device, the type and length of the message it has to transmit, and a field that identifies the type of device. Devices that detect their address in the pending message list also contend for access in this manner. As mentioned above, devices may be Type 1, Type 2, or Type 3. Type 1 devices are those which require critical battery management. These may be in a power saving, non-operational mode much of the time, Only occasionally “waking” to receive sufficient numbers of SYNC and Reservation Poll messages to maintain connectivity to the NET. Type 2 devices are those that are typically powered up and monitoring the NET at all times. Type 3 units are devices that will remain awake for a window period following their last transmission in anticipation of a response. Other device types employing different power management schemes may be added. Slot responses are subject to collision in both the single and multiple slot cases. Collisions may occur when two or more devices attempt to send Request for Polls in the same slot. However, if the signal strength of one device is significantly stronger than the others, it is likely to capture the slot, and be serviced as if it were the only responding unit. FIG. 6b shows two devices 605, address 111, and 607, address 02, that may be subject to collision or capture. The Control Point device may or may not be able to detect collisions by detecting evidence of recovered clock or data in a slot, or by detecting an increase in RF energy in the receiver (using the Received Signal Strength Indicator, (“RSSI”)) corresponding to the slot interval. Collision detection is used in the slot allocation algorithm for determining addition or deletion of slots in upcoming Reservation Polls. As an optional feature to improve collision detection in the multiple slot case, devices that respond in later slots may transmit the addresses of devices they detect in earlier slots as part of their Request for Poll. Request for Polls which result in collisions at the Control Point device often are captured at other remote devices, since the spatial relationship between devices that created the collision at the base does not exist for other device locations within the NET. The duration of the response slots must be increased slightly to provide this capability. If the Control Point device receives one or more valid Request for Polls following a Reservation Poll, it issues a Reservation Resolution (“RR”) Poll and places the addresses of the identified devices in a polling queue. The Reservation Resolution message also serves as a poll of the first unit in the, queue. Addresses from previous Access Intervals and addresses of intended recipients of outbound messages are also in the queue. If the Polling Queue is empty, then no valid Request for Polls were received or collision detected and no Reservation Resolution poll is issued. If within this scenario a collision is detected, a CLEAR message indicating an Explicit Idle Sense (explained more fully below) is transmitted containing a reduced probability factor to allow colliding units to immediately reattempt NET access. Outbound messages obtained through the network infrastructure may result in recipient addresses being prioritized in the queue, that is, if the recipients are active devices—Type 2 devices or Type 3 devices whose awake window has not expired. This eliminates the need for channel contention for many outbound messages, improving efficiency. Messages for Type 1 devices are buffered, and the recipient address is placed in the pending message list for the next Access Interval. Generally the queue is polled on a first in first out (FIFO) basis. The polling order is as follows: a. addresses of active units with outbound messages; b. addresses from previous Access Intervals; and c. addresses from the current Access interval. Since propagation characteristics vary with time and operating frequency, it is counterproductive to attempt retries if Poll responses are not received. If a response to a Poll is not received, the next address in the queue is polled after a short response timeout period. Addresses of unsuccessful Polls remain in the queue for Polling during the next Access Interval. Addresses are aged, so that after several unsuccessful Polls they are dropped from the queue. Addresses linked to outbound messages are added to the pending message list. Devices with inbound requirements must reenter the queue through the next reservation phase. Data is transferred in fragments. A maximum fragment payload of 256 bytes is used in the preferred implementation. If transfer of network packets larger than of 256 bytes is required, two or more fragments are transferred. Fragments may be any length up to the maximum, eliminating the inefficiency that results when messages that are not integer multiples of the fragment length are transmitted in systems that employ fixed sizes. The sequence for transferring data from a remote device to the control point device is illustrated in FIG. 7a. It is assumed that address 65 is the first address in the polling queue. The Reservation Resolution poll 701 from the control point device includes the device address and the message length that device 65 provided in its initial Request for Poll. A first fragment 703 transmitted back from device 65 is a full length fragment. Its header includes a fragment identifier and a field providing indication of the total length of the message. Length information is included in most message types during the sessions period to provide reservation information to devices that may wish to attempt to access the NET following an Explicit Idle Sense (explained more fully below). Following successful receipt of the first fragment, the Control Point device sends a second poll 705, which both acknowledges the first fragment, and initiates transmission of the second. The length parameter is decremented to reflect that the time required for completion of the message transfer is reduced. A second fragment 707 is transmitted in response, and also contains a decremented length field. Following receipt of the second fragment 707, the Control Point device sends a third poll 709. This pattern is continued until a final fragment 711 containing an End of Data (EOD) indication is received. In FIG. 7, the final fragment is shorter than a maximum length fragment. The Control Point device sends a final Acknowledge (ACK), and the device sends a final CLEAR 713 to indicate conclusion of the transmission. The CLEAR message contains a probability factor p for Explicit Idle Sense (explained more fully below). The value of p is determined by the Control Point device in the ACK and echoed by the device termination communication. A p of zero indicates that the control point device will be initiating other communications immediately following receipt of the CLEAR message. A probability other than 0 indicates an Explicit Idle Sense. If for some reason a fragment is not successfully received, the next poll from the Control Point device would indicate a REJECT, and request re-transmission of the same fragment. The length field would remain fixed at the previous value, prolonging reservation of the channel for the duration of the message. After a fragment is transmitted more than once without successful reception, the Control Point device may suspend attempts to communicate with the device based upon a retry limit, and begin polling of the next address in the queue. A flow chart depicting how inbound messages are received during an access interval is shown in FIGS. 19A and 19B. A flow chart depicting how outbound messages are transmitted during an access interval is shown in FIGS. 20A and 20B. Outbound messages are transmitted in a similar fashion as inbound messages, with the Control Point and device roles largely reversed as illustrated in FIG. 7b. When the Control Point reaches an address in the queue for which it has an outbound message, the Control Point transmits a Request for Poll 721 identifying the address of the device and the length of the message. The response back from the device would be a poll with an embedded length field. The same POLL/FRAGMENT/ACK/CLEAR structure and retry mechanisms as described above with regard to inbound messages in reference to FIG. 7a are maintained. The CLEAR from the device indicates a probability p of zero. If the polling queue is empty, the Control Point may send a final or terminating CLEAR 723 containing a probability for Explicit Idle Sense. All terminating ACK or CLEAR messages contain fields to aid in synchronization of new units to the NET. The content of these fields is identical to that in the SYNC message, except that the timing character is deleted. Synchronization is discussed more fully below. Broadcast. Messages intended for groups of addresses, or all addresses within a NET may be transmitted during the sessions period. Broadcast messages are not individually acknowledged. These messages may be communicated at intervals over the course of several Access Intervals to provide reliable communication. Messages such as SYNC and Reservation Polls are specialized broadcast messages, with dedicated bandwidth in the Access Interval structure. Security of payload data is left to the higher protocol layers. Application programs resident in portable/mobile devices may employ encryption or other means of providing protection against undesired use of transmitted data. Portable/mobile devices may employ transmitter power control during the sessions period to reduce potential interference with other NETs that may occasionally be on the same or adjacent channels. These devices will use Received Signal Strength Indicator readings from outbound messages to determine if transmitter power may be- reduced for their inbound transmission. Because of the need to maintain channel reservations and Listen Before Talk capabilities, the Control Point device does not use transmitter power control. Since Control Point devices are generally part of an installed system infrastructure, they are likely to be physically separated from devices operating in other NETs. They are therefore less likely to cause interference to devices in other NETs than portable devices, which may operate in proximity to devices in other NETs. Often, control point devices will empty the polling queue before the conclusion of the access interval. Two mechanisms within the Access Control Protocol, Explicit and Implicit Idle Sense, are provided to improve bandwidth utilization. These supplemental access mechanisms often provide means for devices that failed to gain reservations during the reservation phase to gain access to the NET within the Access Interval. To assume an Explicit or Implicit Idle Sense, a device must have detected a valid SYNC and Reservation Poll in the current Access Interval. The incorporation of a probability factor p≠D in the final (terminating) ACK or CLEAR from the control point device provides the function of an Explicit Idle Sense (mentioned above). Devices with transmission requirements solicit Request for Polls using the same rules normally used for a single slot Reservation Poll. Successfully identified addresses are placed in the polling queue, and are polled immediately or in the next Access Interval depending on the time remaining in the current Access Interval. The p factor for Explicit Idle Sense is subject to the same optimization algorithm as the Reservation Poll probability. Communication of channel reservations, in the form of the length fields in Polls and Message Fragments is useful to units seeking to access the NET through Explicit Idle Sense. Reservations allow devices to predictably power down during the period that another device has reserved the NET to conserve battery power, without losing the ability to gain access to the NET. Implicit Idle Sense provides an additional means of channel access. An Implicit Idle Sense is assumed whenever a device detects a quiet interval period greater than or equal to the duration of a Poll plus the maximum fragment length after a channel reservation has expired. Detection based upon simple physical metrics, such as a change in Received Signal Strength Indicator or lack of receiver clock recovery during the quiet interval, are preferred methods of ascertaining channel activity. Algorithms based upon these types of indicators are generally less likely to provide a false indication of an inactive channel than those that require successful decoding of transmissions to determine channel activity. False invocation of an Implicit Idle Sense is the only mechanism by which data transmissions are subject to collision within the NET. Thus, the Implicit Algorithm must be conservative. Quiet interval sensing may begin at the following times within the Access Interval: a. any time after the last reservation slot following a Reservation Poll; b. any time after a terminating ACK or CLEAR indicating an Explicit Idle Sense; c. following an unsuccessful response to a single Slot Reservation Poll; or d. any time prior to reserved Time Division Multiple Access time slots at the end of the Access Interval. It is preferable that devices detecting a quiet. interval use a p persistent algorithm for channel access to avoid collisions. The probability factor for Implicit Idle Sense Access will generally be less than or equal to the factor in Explicit Idle Sense. A device must receive the SYNC and Reservation Polls at the beginning of an Access Interval to use Implicit Idle Sense. The Reservation Poll provides indication of guaranteed bandwidth allocation to scheduled services at the end of the Access Interval, which may shorten the period available for Bandwidth On Demand communications. Devices that require scheduled services must contend for the channel in the same fashion as those requiring Bandwidth On Demand access. When polled, these initiating devices will initiate a connection request that indicates the number of inbound and outbound Time Division Multiple Access slots required for communication, and the address of the target device with which communication is desired. The network infrastructure will then attempt to establish the connection to the target device. Once the connection is established, the Control Point device will signal the allocation of slots to the initiating device. Time Division Multiple Access slots are relinquished by transmitting a disconnect message to the control point device in the Time Division Multiple Access slot until the disconnect is confirmed in the next Reservation Poll. The transmission requirements of speech and slow scan video (scheduled services) are similar. In one embodiment, Time Division Multiple Access slots are allocated as multiples of 160 bits payload at 1 MIT/sec, plus overhead for a total of 300 μs. For 10 ms access intervals, acceptable voice communication can be obtained by allocating 1 Time Division Multiple Access slot each for inbound and outbound communication per access interval. For 20 ms access intervals, two slots each way is required. A system employing 10 ms access intervals at 100 hops per second may improve transmission quality by using two or three slots each Access Interval and sending information redundantly over two or three access intervals using interleaved block codes. Scheduled transmissions are generally not subject to processing or validation by the control point device, and are passed through from source to destination. Use of interleaved error correction coding or other measures to improve reliability is transparent to the NET. The selection of certain system parameters is important when considering scheduled services. As an example, since speech is quantized over the duration of the access interval and transmitted as a burst, the length of the access interval translates directly into a transport delay perceptible to the recipient of that speech. In real time “full-duplex” voice communications, delays longer than 20 ms are perceptible, and delays longer than 30 ms may be unacceptable. For real time “half-duplex” voice communications, much longer delays often prove acceptable. Real time full-duplex voice communication delays sometimes prove too excessive where the premises LAN is interconnected with the public switched telephone network (“PSTN”), which introduces its own delays. Two way services (i.e., full-duplex services) such as voice communications are the most sensitive to transport delay because delay impacts the interaction of the communicating parties. One way services (i.e., half-duplex services) are less sensitive to transport delay. One way services are good candidates for interleaving or other forms of redundant transmission. Similarly, the selection of hop rate is important, as hop rate determines the duration of outages that may occur. If one or more frequencies in the hop sequence are subject to interference, for instance, scheduled transmissions during those hops will be disrupted. In a system that hops slowly, detrimental outages of hundreds of milliseconds will occur resulting in poor transmission quality. Occasional losses of smaller durations, e.g., 10 ms or 20 ms, are generally less perceptible, indicating that faster hop rates are desirable if the NET is to offer real time voice transport. Scheduled service intervals may also be used for data transport on a scheduled or priority basis. Telemetry, data logging, print spooling, modem replacement, or other functions are possible. For these activities, a few Time Division Multiple Access slots scheduled for example every fourth, eighth, or sixteenth Al are necessary. Because of multipath and dispersion issues with 2.4 GHz transmission at relatively high data rates, the ability of the NET to adaptively switch between two or more data rates desirable. In one embodiment, implementation of data rate switching may be accomplished by selecting a standard rate of communications, e.g., 250 KBPS and a high rate of communications of 1 Mbit/sec. Messages that contain system status information, including SYNC, Reservation Polls, Reservation Resolution Polls (Request for Polls), Polls, ACKs and CLEARS are transmitted at the standard rate. These messages are generally short, and the time required for transmission is largely determined by hardware overhead, e.g., transmitter receiver switching time. The incremental overhead introduced by transmitting these messages at the lower rate is therefore small in comparison to the total length of an access interval. The reliability of reception of these messages will increase, which will eliminate unnecessary retries in some instances where fragments are received successfully, but acknowledgments or polls are missed. A test pattern at the higher data rate is inserted in each Poll (not in Reservation Polls, however). The Poll recipient evaluates signal quality based on the high data rate test pattern, Received Signal Strength Indicator, and other parameters to determine whether to transmit a fragment at the high rate or the low rate. Fragment lengths are selected such that high and low rate maximum fragment lengths are the same duration. In other words, a fragment at the low rate conveys approximately ¼ the payload of a fragment for the case where the data rate is four times greater. This method is generally suitable for transaction-oriented communications, which frequently require short message transmissions. Alternatively, the length field in Polls and messages can be used to allow different fragment lengths for the two data rates while still providing channel reservation information to other devices in the NET. This method also provides for forward migration. As modulation and demodulation methods improve, newer products can be added to old networks by upgrading Control Points devices. Both new and old devices share the ability to communicate at a common low data rate. An alternate embodiment uses signaling messages such as SYNC, Reservation Polls, Request for Polls, etc., at the higher rate with fall back operation to the standard rate for the communications sessions only. SYNC and Reservation Polls at the high rate constitute a high data rate test message. The Request for Poll response to the Reservation Poll at the high rate may include a field indicating that sessions communications should take place at the fall back, standard rate. Signal quality measures such as signal strength and clock jitter are appropriate. Data rate selection information is included with the device address in the polling queue. When the device is polled, it will be polled at the rate indicated in the Request for Poll. Channel reservation information in the Reservation Resolution Poll will indicate the reservation duration based upon the data rate indicated. In this alternate embodiment, the fact that SYNC and Reservation Polls must be detectable at the high data rate prioritizes access to the NET for those devices that have acceptable connectivity during the current access interval. This general approach has desirable characteristics in a frequency hopping system, as the propagation characteristics between devices may change significantly as the NET changes from frequency to frequency within the hopping sequence, or over several Access Intervals during the dwell time on a single frequency. Reduction in data rate in this system is primarily intended to remedy the data smearing (inter-symbol interference) effects of dispersion due to excess delay, rather than temporarily poor signal to noise ratio due to frequency selective fading. Devices that receive high data rate transmissions with acceptable signal strength but high jitter are likely to be experiencing the effect of dispersion. The concept of allowing Polls and message fragments to occur at an either high or low data rate could create difficulties for other NET constituents that need to be able to monitor the channel for reservation information. Two embodiments for solving this problem are the use of auto-discriminating receivers or the use of fixed data rate headers for system communications. Auto discrimination requires the receiver to process messages sent at either data rate, without necessarily having prior knowledge of the rate. Given a high rate of 1 MBIT/SEC, and a low Rate of 250 KBPS, i.e., one being a binary multiple of the other, it is possible to devise preambles that can be received at either rate. Consider that 01 and 110 sent at the low rate correspond to 00001111 and 111111110000 at the high rate. These preambles are transmitted continuously before the transmission of the High-Level Data Link Control FLAG character at the correct data rate indicating the start of a message. In this example, a preamble of 20 bits of 01 at the low rate indicates operation at the high rate. A preamble of 30 bits of 110 indicates operation at the low rate. A receiver tuned to either rate is capable of receiving both types of preambles and initiating the proper decoding mechanisms for the intended rate of transmission. This general technique, with appropriate selection of preamble content, is applicable to binary modulation schemes, for example, a frequency modulated system where a common frequency deviation value is used for both data rates. It is also applicable to systems where switching occurs between binary and multilevel modulation, such as disclosed in pending U.S. application Ser. No. 07/910,865, filed Jul. 6, 1992. Referring now to FIG. 25, a preamble 2501, a SYNC 2503 and a Reservation Poll 2505 are illustrated. The preamble 2501 starts at the beginning of the Access Interval 2500 and is applied to an RF modem while it is switching frequencies. Since the switching time is a worst case, this causes the preamble 2501 to be present and detectable prior to the allocated 150 μsec period in some instances. It would be equally appropriate to begin preamble transmission 50 or 100 μsec into the switching period if that would be more convenient. The timing has been selected to allow 100 μsec. Referring to FIG. 26, a sample SYNC message 2600 is shown. Referring to FIG. 27, a sample Reservation Poll 2700 is shown. In these examples, the hopping synchronization information has been positioned in the Reservation Poll 2700. With auto-discrimination, it is possible to change data rates on a per-poll basis, thereby adjusting for channel temporal dynamics. Since all devices in the NET have auto discrimination capabilities, and channel reservation information is included in message headers as a length field, the bandwidth reservation features of the NET are preserved. The maximum fragment duration may be maintained at a fixed value, meaning that low data rate fragments convey less data than their high rate counterparts, or may be scaled in the ratio of the data rates to allow consistent fragment data payloads. An alternative to auto-discrimination is the use of headers to communicate system information. This embodiment is less preferred, but may be appropriate if economics, size, or power constraints dictate a simpler design than that required for auto-discrimination. In this embodiment, any transmission at the lower data rate is preceded by a header at the high data rate that conveys NET management information, i.e., channel reservation status. Devices other than those directly involved in polling or fragment transmission need only monitor at the high rate for channel reservation information. The header at the high rate and the following transmission at the low rate are concatenated High-Level Data Link Control frames, with an appropriate preamble for low rate clock recovery synchronization inbetween. For the communicating devices, the header can serve the additional purpose of acting as a test pattern at the high rate. For example, if a device is polled at the low rate, but successfully decodes the high rate header with adequate signal quality, it may indicate back to the polling unit to poll again at the high rate. In a premises LAN as discussed in reference to FIG. 1, many NETs may be distributed geographically to provide enhanced coverage or additional system capacity. The wired portion of the network infrastructure, such as Ethernet or Token Ring, provides a means for coordination of NETs to achieve optimum system performance. An equally important role of the wired infrastructure is to allow resource sharing. Portable devices with limited memory capacities, processing power, and relatively small batteries may access large data bases on, or remotely initiate processing capabilities of, larger AC powered computer systems Portable/mobile devices may also share communication with other like devices which are serviced by other NETs well beyond the radio coverage range of their own NET. The basic method for communication of status information regarding the premises LAN is the HELLO message. HELLO messages are sent routinely, but relatively infrequently, for example, every 90 Access Intervals. The HELLO transmission interval is tied to the Priority SYNC interval, so that the HELLO interval corresponds to Access Intervals where SYNC is transmitted if the network is lightly utilized. In an alternate embodiment, HELLOs could be inserted as a broadcast message at the beginning of the Sessions period. FIG. 8 illustrates a preferred Access Interval embodiment where a HELLO message 801 is inserted between a SYNC 803 and a Reservation Poll 805. The SYNC frame at the beginning of the Access Interval indicates that the Access Interval will contain a HELLO, allowing power managed devices to remain awake to receive the HELLO. HELLO messages may also contain information regarding pending changes in the local NET. If the local NET is changing Access Interval durations or hop sequences, for instance, changes may be communicated in several consecutive HELLOs so that the information is reliably communicated to all NET constituents, permitting all devices to make the change in coordinated fashion. Further discussion of HELLO message content is provided below. For purposes of channel management in the Access Interval structure, the maximum transmission duration by a device should be limited to the time that the device moving at a maximum expected velocity can traverse ¼ wavelength of the maximum carrier frequency. The duration may be further reduced to compensate for link bit error rate characteristics or expected duration or frequency of interference bursts. A maximum transmission duration of 2.5 ms is suitable for 1 MBIT/SEC transmission, with a device velocity of 15 mph, in a multiple NET environment. Use of spatial or polarization antenna selection diversity is also desirable in indoor propagation environments. First, the receiving unit makes an antenna diversity decision during the preamble portion of each transmission. The antenna used for reception for each device address is then recorded in memory so that the correct antenna will be used for response messages to each address. While diversity selection is only valid for a short time, it is not necessary to age this information, because antenna selection is equi-probable even after diversity information is no longer valid. The Access Interval structure of the present invention also inherently provides routine channel sounding for each hop. This is important in a frequency hopping system, as channel conditions will vary considerably from frequency to frequency within the hopping sequence. NET constituents must, in most cases, be able to receive SYNC and Reservation Poll transmissions from the Control Point device to attempt inbound access in an Access Interval. This provides a positive indication that the device is not experiencing a channel outage, allowing power saving and eliminating possible channel contention. Channel sounding does not need to be employed during periods where the NET is not busy since contention is unlikely in this situation. Channel sounding for Outbound messages is accomplished through a Request for Poll/Poll cycle where handshaking messages with short time out periods must be successfully communicated before longer message transmissions may be attempted. As discussed above with regard to FIG. 1, a premises LAN consists of several access points 15 located throughout an environment requiring wireless communications, e.g., a building or other facility, or a campus comprising several buildings. The access points 15 are placed to provide coverage of intended usage areas for the roaming portable or mobile computing devices 20. Coverage areas must overlap to eliminate dead spots between coverage areas. The access points 15 may be interconnected via industry standard wired LANs, such as IEEE 802.3 Ethernet, or IEEE 802.5 Token Ring. Access points may be added to an existing LAN without the need to install additional LAN cable. Alternatively, it may be desirable to install access points on dedicated LAN segments to maximize performance of both the radio network and other collocated computer devices. Access points within the premises LAN provide Control Point functions for individual NETs. NETs employ different hopping sequences to minimize potential interference between NETs. Regulatory restrictions generally preclude synchronization of multiple NETs to a single master clock, requiring that individual NETs operate independently from one another. The lack of the ability to coordinate timing or frequency usage between NETs introduces the potential for collisions between independent NETs with overlapping coverage areas. FIGS. 9a and b conceptually illustrate how multiple NETs may be employed in an idealized “cellular” type installation. Each hexagon 901 and 903 in FIG. 9a represents the primary coverage area of a given NET. Coverage areas are modeled as circles 905 based upon some reliability criterion, for example a 5% mean fragment retry rate (on average 95% of fragments are successfully communicated on the first attempt). Typical coverage areas are determined by physical attributes of the area in which the NET operates. As illustrated in FIG. 9b for the hexagon (NET) 903 of FIG. 9a, an actual coverage area 907 meeting the reliability criterion is likely to be irregular. This may require access points to be offset significantly from the hexagonal grid. FIG. 10 illustrates a coverage contour overlap for the multiple −NETs in the premises LAN of FIG. 1. Darken shaded areas 1001 indicate areas where access point coverage overlaps. Because the coverage distance of a radio system on an instantaneous basis greatly exceeds the coverage that can be provided on average to sustain a given quality of service, the overlap at any instant may be significantly greater than the coverage contours indicate. FIG. 11 illustrates hopping sequence reuse in a multiple NET configuration. Hopping sequence reuse may be necessary if there are physical constraints on the number of hopping sequences that can be supported. For example, devices may have limited memory available for hopping sequence storage. Use of a smaller set of sequences also simplifies the task of determining sets of sequences that have acceptable cross correlation properties. In FIG. 12, 7 hopping sequences 1 through 7 are used throughout the coverage area. Other NETs may reuse the same hopping sequence at some distance removed. While 7 NETs are illustrated, larger numbers, such as 9 or 15 may provide a better compromise between minimizing the number of hopping sequences used, and reuse distance between NETs using the same sequence. Reuse requires coordination of hopping sequence assignment—either the system installer can coordinate the installation, or the system may include automated management features to assign hopping sequences to individual NETs. Since NETs are not synchronized, different NETs that use the same hopping sequence are likely to interfere during periods where oscillator drift causes them to be temporarily synchronized. At other times, they may only interfere due to imperfect channelization For example, for a worst case 100 ppm frequency error between two NETs using the same 79 frequency sequence at one Access Interval per hop and so hops per second, NETs will partially or fully overlap for a duration of 10 minutes every 4.3 hours. Typically the frequency error will be 25% to 50% of the worst case, leading to longer overlap periods occurring less frequently. NETs using the same hopping sequence must be physically isolated from one another to reduce interference to an acceptable level. Extensive hopping sequence reuse generally requires site engineering and optimization of access point placement. Using more hopping sequences reduces the need for critical system engineering during installation. Fifteen hopping sequences is a preferred number -for hopping sequence reuse, allowing simplified installation and minimal coordination. NETs that use different hopping sequences will also temporarily synchronize in timing relationships that cause mutual co-channel interference on common channel frequencies. Since the number of channels that must be used in a sequence is a significant fraction of the total number of channels available, all sequences will share some number of frequencies in common. When sequences are time aligned so that a common frequency is used simultaneously, interference can occur. Optimization of sets of sequences for low cross correlation is necessary to prevent various time alignments of sequences from having more than one or two frequencies in common. Optimization of hopping sequences for multiple NETs must also include analysis of imperfect channelization. The performance characteristics of the RF modems may not, for economic or power consumption reasons, provide sufficient transmitter spectral containment, receiver dynamic range, or receiver selectivity to guarantee that devices operating on different frequencies in proximity to one another will not interfere. In selecting hopping sequences for desirable cross correlation properties, adjacent and alternate adjacent channel interference must be considered. Protocol retry mechanisms for fragments lost to adjacent channel interference or limited dynamic range may be randomized to prevent continued disruption of communications in the affected NET. Often in campus environments where systems must provide coverage in several buildings, the cost of wiring LAN cable between access points is prohibitive. To establish connectivity between access points in a premises LAN, it may be necessary to provide wireless links between groups of access points connected to separate LAN segments. FIG. 12 illustrates a wireless link 1201 connecting groups of access points 1203 and 1205. The access points 1203 and 1205 are connected on separate LAN segments 1207 and 1209. In one embodiment, the access points 1203 and 1205 may be configured in a wireless point to point mode, wherein one access point serves as a control point device while the others operate in a slave mode dedicated to point to point data transfer. Slave access points are configured to operate as portable/mobile devices, and forward communications to master bases by sending Request for Polls during reservation opportunities or Implicit Idle Sense periods. Because of the potential high traffic of point to point links, separate NETs may be allocated for this. purpose, with a master communicating with one or more slave units. Master units may also communicate with other portable/mobile devices. The COST weighing (discussed below) in a slave's HELLO transmission is preferably set to a high value, to force portable/mobile devices which can connect to another NET to do so. In another embodiment, it may also be desirable to support wireless access points. Wireless access points serve as control points, but are not connected to the infrastructure through a LAN cable. As illustrated in FIG. 13, a wireless access point 1301 participates in the premises LAN through a wireless link 1303 to an access point 1305 that is connected to a LAN 1307. Wireless access points operate as slave devices to master access points which are connected to the wired infrastructure. The wired and wireless access points share the same hopping sequence, and are synchronized as a common NET. Because they are not connected to the Infrastructure, wireless access points must be used as store and forward devices. Each transmission to a wireless base must be retransmitted to the intended destination device, doubling the number of transmissions occurring in the NET. Wireless access points are preferably used for supplementing coverage area of the premises LAN. For example, a wireless access point might provide spot coverage of isolated “dead spots” where data traffic is limited or where providing a wired LAN connection is difficult. Wireless access points may also serve as emergency spares to provide coverage in the event of a failure of a primary access point. In this role, the wireless access point may be either permanently installed in selected locations, or stored in a maintenance area and quickly positioned and connected to AC or battery power to provide communications while repairs are made to the primary wired access point. Moreover, permanently installed wireless access points might also be used for redundancy, i.e., to monitor an associated access point and to take over when a breakdown is detected The preferred wireless access point embodiment uses interleaved access intervals. The parent wired access point and secondary wireless access point coordinate Access Intervals, the wired access point deferring every third or sixth access interval to the wireless base. Since the wired access point transmits priority SYNC messages every third Access Interval, the wireless access point may routinely be allocated one of the two intervening Access Intervals for priority SYNC communications with devices that are attached to it. Communication between the wired and wireless access points may occur during Access Intervals initiated by either access point. Wireless access points may also communicate with devices during an Access Interval using Implicit or Explicit Idle Sense. This embodiment provides predictable access for devices attached to the wireless NET, and allows the same power management algorithms to be used regardless of whether the access point is wired or wireless. The wireless access point may transmit its own priority SYNC and HELLO messages. Also, devices seeking communications with the wireless access point will automatically be synchronized with the wired base as well, allowing immediate improved access to the network if their mobility has put them within range of the wired base. Because of the constraint of sharing bandwidth with a wired access point, connectivity of wireless access points is normally limited to one per-wired access point. However, in cases where system loading is predictably and consistently light, multiple wireless access points could share a single wired base, e.g., each transmitting in turn in the Access Intervals between the Wired Base Priority SYNC Access Intervals. Wireless access points are capable of supporting scheduled traffic. However, since each transmission to a wireless access point must be forwarded, scheduled transmissions through wireless access points use twice the bandwidth as those through wired access points. In other words, twice the number of Time Division Multiple Access slots must be allocated. To avoid introducing excessive delay, communications must be forwarded during the same Access Interval that they are received, or shorter Access Intervals must be used. Scheduled traffic slot assignments must be common to all wireless bases operating within a single NET. Wireless access points require reliable communication with their wired counterparts. This dictates smaller coverage contours for wireless access points. If a wired access point provides 80,000 square feet of coverage area, a wireless base can be predicted to provide only an additional forty percent coverage improvement, due to overlap with the wired access point Frequently, access points are mounted at ceiling level, providing a relatively clearer transmission path between access points than exists between bases and portable/mobile devices located in more obstructed areas near the floor. With careful site engineering and installation, a wireless access point can provide somewhat better than the forty percent predicted improvement, but still less than the coverage of an additional wired base. As discussed above, HELLO messages are used to communicate NET and premises LAN status messages. They facilitate load leveling and roaming within the premises LAN and allow sequence maintenance to improve security and performance within the NET. HELLO messages occur periodically in Access Intervals that contain priority SYNC messages. HELLOs are sent periodically relative to the sequence length, for instance, every 90 Access Intervals. HELLOs, like SYNC information, are optionally encrypted to provide greater security. Each HELLO message includes a field for COST. COST is a measure of the access point to handle additional traffic. A device determining which of two or more access points having adequate signal strength to register which will select the base with the lowest COST factor. The base computes COST on the basis of how many devices are attached to the NET, the degree of bandwidth utilization, whether the base is wired or wireless, the number of frequencies experiencing consistent interference within the sequence, and the quality of the connection the base has within the premises LAN. FIG. 14 illustrates the concept of access points communicating neighboring access point information through HELLO messages to facilitate roaming of portable/mobile devices. In a premises LAN, access points 1401, 1403 and 1405 communicate SYNC information amongst themselves via wired backbone (LAN) 1407. In addition, a wireless access point 1409 (discussed above) similarly communicates with the access points 1401, 1403 and 1405 via a wireless link 1411. A portable/mobile device 1413 is initially registered with access point 1401, which acts as a control point for the portable/mobile device 1413. HELLO messages transmitted by access point 1401 to portable/mobile device 1413 contain fields for neighboring access points 1403, 1405 and 1409. These fields may indicate, for example, addresses of the neighboring bases, their COST; the hopping sequences, hopping sequence indices, number of Access Intervals per hop, and NET clock. The portable/mobile device 1413 detects the HELLOs transmitted from access point 1401 and uses the information for coarse synchronization with the other access points 1403, 1405 and 1409. This permits the portable/mobile device to roam between access point coverage areas (i.e., between different NETs) without going through a full acquisition phase. Roaming of portable/mobile devices is discussed in more detail below. Simply put, communication of neighbors' information permits each access point to advise its associated portable/mobile devices (i.e., those having common communication parameters) on how to capture HELLO messages from neighboring access points having different communication parameters. Such communication parameters may include, for example, hopping sequences, spreading codes, or channel frequencies. For example, neighbors' information transmission is appropriate in any case where the system uses more than a single channel. For instance, in a direct sequence architecture, a single spreading code is often used. Capacity can be added to such a network by employing different spreading codes at each access point. The neighbors' information included in the HELLO message from a given access point would include the spreading sequences of access points providing coverage in adjacent coverage areas. Likewise, in a multiple frequency channelized system, HELLO messages would include the channel frequencies of adjacent access points. In addition to facilitating roaming, communication of neighbors' information may also facilitate the initial selection of an access point by a portable/mobile device attaching to the premises LAN for the first time. Access point HELLO messages may also facilitate adaptive access point transmitter power control. For example, each access point HELLO transmission could specify the transmitter power level being used by the access point. If a given attached portable/mobile device notes that the current access point transmitter power level is unnecessarily high (creating the possibility of interference with other access points), the portable/mobile unit could send a message to the access point indicating as such, and the access point could adjust the transmitter power level accordingly. HELLO messages also enable communication of information indicating to all devices that certain changes in the NET are required. For example, the NET may switch hopping sequences periodically to improve security, or to avoid interference sources that consistently interfere with one or two frequencies within a given sequence. Interference may result from outside sources, or from other NETs. Changes to the NET are communicated over the course of several HELLO messages (with a countdown) before the change occurs, so that all devices are likely to be aware of changes and synchronize at the instant of change. In addition, if encryption is used, the encryption key may be periodically changed in HELLOs. Like hopping sequence changes, KEY changes are sent over several HELLOs, and are encrypted using the existing key until the change goes into effect. As mentioned above, roaming portable and mobile computing devices operating in the premises LAN will routinely move between access point coverage areas. At the maximum device velocity and expected coverage area per access point, a mobile device may be expected to cross a NET coverage contour in several seconds. Because of the use of multiple, non-synchronized frequency hopping NETs, it is more difficult to provide for simple hand-off between access points than it would be in a system that used cellular techniques with a single frequency per cell. The premises LAN makes special provisions for roaming by transmitting coarse frequency hopping synchronization information in HELLO messages. The premises LAN uses a spanning tree algorithm to maintain current information regarding the general location of mobile devices within the network. When a device changes registration from one NET Control Point to another, routing information is updated throughout the infrastructure. Wired access points may broadcast spanning tree updates to attached wireless access points. In the premises LAN, roaming portable and mobile devices initially select and register with an access point Control Point on the basis of link quality, i.e., signal quality, signal strength and COST information transmitted within HELLO messages. A device will remain attached to a particular access point until the link quality degrades below an acceptable level, then it will attempt to determine if an alternative NET is available. Different device operating scenarios dictate different roaming strategies, discussed below. An idle device monitors SYNC and HELLO messages from the Control Point device to maintain NET connectivity. Type 2 devices do not employ power management, and always maintain their receivers in an active state. They monitor all SYNC messages. Type 1 and Type 3 devices typically employ power management, operating in standby or sleep modes of operation for many Access Intervals before activating their receivers for monitoring SYNC and HELLO messages. Control Points are guaranteed to send Priority SYNC frames every third Access Interval. HELLOs occur every 30th Priority SYNC frame. Power managed devices employ sleep algorithms synchronized to wake for the minimum period necessary to guarantee receipt of priority SYNC, HELLO, and Pending Message transmissions before resuming SLEEP. Type 2 devices are typically operated from high capacity vehicular power systems, eliminating the need for power management. These devices may travel at velocities near the maximum system design specification, dictating more frequent roaming. Type 2 devices will initiate a search for an alternative NET if SYNC messages are consistently received at signal strengths below a Roaming Threshold or if reception errors are consistently detected. Because of the effects of frequency selective fading, signal strength information is averaged over the course of several hops within the hopping sequence. If roaming is indicated, the device initiates a Roaming Algorithm, using Neighbors' information from the most recent HELLO to attempt synchronization with another candidate NET. If SYNC is not detected within 6 hops, another candidate from the Neighbors list will be selected, and the process repeated. Once SYNC is attained on an alternative NET, the device will monitor signal strength and data errors for several hops to determine link quality. If link quality is acceptable, the device will continue monitoring until a HELLO is received. If COST is acceptable, it will then register with the new NET. The Control Point device will update the spanning tree over the wired backbone (or by RF if a wireless base). If link quality or COST is unacceptable, another candidate from the Neighbors list is selected and the process repeated. This continues until an acceptable connection is established. If a connection cannot be established, the device must return to the original NET or employ the initial acquisition algorithm. Type 2 devices also have the option of monitoring other NETs before degradation of their NET connection. They may do so by monitoring their own NET for the SYNC and pending message list transmissions, then scanning other candidate NETs during the Sessions period of their NET. Other type devices may do so less frequently. Type 1 and Type 3 devices may sleep extensively when idle, preferably activating every nine Access Intervals to resynchronize and check pending messages. Successful reception of at least one SYNC during three monitoring periods is necessary to maintain fine synchronization to the NET clock. Failure to receive two of three SYNC frames, or receipt of two or three SYNC messages with poor signal strength are possible indications of the need to further test link quality by remaining active for several consecutive SYNC transmissions. If signal strength or data errors over several hops indicates that link quality is poor, or if a received HELLO message indicates high COST, the roaming algorithm is initiated, and alternative NETs are evaluated, as in the case of Type 2 devices. Some battery powered devices may sleep for periods of time more than nine Access Intervals. For example, devices with extremely limited battery capacity may sleep between HELLOS, or several HELLO periods, after which they must remain active for several consecutive Access Intervals to regain fine synchronization and assess whether to initiate roaming. A Type 1, Type 2, or Type 3 device that has inbound message requirements immediately activates its receiver and waits for a SYNC and subsequent Reservation Opportunities. A device that does not detect SYNC messages over the course of six Access Intervals immediately initiates the Roaming Algorithm. Outbound messages for devices that have changed coverage areas, but which have not yet registered with a new Control Point device, are problematic. For example, in the premises LAN, messages will be forwarded to the access point that the device had previously been attached to. The access point may attempt to poll the device during one or more Access Intervals, then transmit the unit address in the pending message list periodically for several seconds before disregarding it. Once the unit attaches to a base, the message must be transferred from the previous access point for delivery to the unit. All of these activities require transmission bandwidth on either the backbone or RF media, waste processing resources within the premise LAN, and result in delayed delivery. As this premises LAN embodiment is designed, the network has no means of distinguishing messages it cannot deliver due to roaming from messages that should be retried due to signal propagation characteristics, interference, or sleeping devices. For this reason, the roaming algorithm may be designed to allow devices to quickly detect that they have lost connectivity within their current NET, and re-attach to a more favorably located access point. Some improvement in delivering pending messages to roaming terminals can be obtained by routinely propagating pending message lists over the wired backbone. When a device attaches to an access point, that base is able to immediately ascertain that the device has a pending message, and initiate forwarding of the message for delivery to the device. In the preferred frequency hopping embodiment of the present invention, the hopping sequence consists of 3m±1 frequencies, where m is an integer. 79 frequencies are preferred. This embodiment will support hopping rates of 100, 50 hops per second at 1 Access Interval per dwell, 25 hops per second at 2 frames per dwell, and 12.5 hops per second at 4 frames per dwell. Other rates can be supported for other Access Interval Durations. For example, if the Access Interval is optimized to 25 ms, hop rates of 80, 40, 20, and 10 hops per second would be supported. All devices within the NET may have one or more hopping tables that contain potential hopping sequences that may be used. Up to 64 sequences may be stored in each device. Each sequence has an identifier, and each frequency in each sequence has an index. The sequence identifier and index are communicated in the SYNC transmission. All SYNC transmissions may be block encrypted to prevent unauthorized devices from readily acquiring hopping synchronization information. To facilitate encryption, the encryption key may initially be factory set to a universal value in all devices. Users would then have the option of changing this key, by providing a new key to each device in the system. This may be accomplished through keyboard entry or other secure means. Keys may also be changed through the NET. To facilitate hopping management, a hopping control portion of a protocol controller will download a hopping table to a radio modem, and will signal the radio modem when to hop. This approach consolidates timing functions in the protocol controller, while not requiring the controller to be concerned with conveying frequency selection data to the modem each hop. The NET may switch hopping sequences periodically to improve security, or to avoid interference sources that consistently interfere with one or two frequencies within a given sequence. As mentioned above, changes to the NET are communicated over the course of several HELLO messages before the change occurs so that all devices are likely to be aware of changes. Initial synchronization requires devices to ascertain the hopping sequence, the hop rate, and the specific frequency from the hopping sequence currently in use. Synchronization information is contained in two types of routine messages. The SYNC field at the beginning of an Access Interval contains synchronization information including the hopping sequence, the index of the current frequency within the sequence, the number of Access Intervals per hop, and the length of the Access Interval. It also contains a timing character that communicates the NET master clock to all listening devices. Termination messages in the Sessions period, ACK and CLEAR, contain the same information, but do not contain the timing character. The simplest method for attaining synchronization is to Camp—select a quiet frequency that is likely to be within a sequence in use—and listen for valid synchronization information. If a SYNC message is detected, the listening device immediately has both coarse and fine synchronization, and can begin the registration process. If SYNC is not detected, but a termination message is, then the device has acquired coarse synchronization. The particulars of the hopping sequence are known, but the boundaries of the dwells are not. To acquire fine synchronization; it begins hopping at the indicated hopping rate, listening for SYNC. If SYNC is not detected after a reasonable number of hops, preferably 12 or 15, the device reverts to camping. The worst case scenario for synchronization is to synchronize to a single NET that is idle. Given a 79 frequency hopping sequence, one Access Interval per hop, and SYNC transmissions every third Access Interval if the NET is idle, it may take nine cycle times to guarantee that a SYNC transmission will be detected with 99.5% probability. At 50 hops per second, synchronization could require as long as 14 seconds. At 100 hops per second, 7 seconds is required. At 2 Access Intervals per hop, a SYNC transmission is guaranteed to occur every frequency over 2 cycles of the hopping sequence. Six cycles are required for 99.5% probability of acquisition, corresponding to 19 seconds at 25 hops per second. At 4 Access Intervals per hop, at least one SYNC is guaranteed to occur each hop. Three cycles of the hopping sequence are required for 99.5% acquisition probability. At 12.5 hops per second, this also requires 19 seconds. This illustrates the advantage of scalability. A device that uses an acquisition algorithm suitable for 2 or 4 Access Intervals per hop will also acquire a NET that hops at 1 Access Interval per hop. The algorithm may be as follows: 1. The device scans candidate frequencies until it finds one with no Received Signal Strength Indicator indication. 2. The device remains on the frequency for 6.32 seconds 2 Access Interval/hop @ 25 Hops/second×2, or 4 Access Interval/hop @ 12.5 hops/second×1, or until it detects a SYNC message or a valid termination message. 3. If SYNC is detected, the device synchronizes its internal clock to the SYNC, and begins hopping with the NET for the next 11 hops. It may attempt registration after detecting valid SYNC and any Reservation Opportunity. If synchronization is not verified by detection of SYNC within the 11 hops, the acquisition algorithm is reinitialized. 4. If a message termination. (either an ACK or CLEAR) is detected, the device immediately hops to the next frequency in the sequence and waits for the SYNC. It is coarsely synchronized to the NET but has a timing offset from the NET clock. When the next SYNC is received, the device synchronizes its clock to the NET clock and initiates registration. If SYNC is not received within a dwell time, the device hops to the next frequency in sequence. This continues until SYNC is attained, or until 15 hops have passed without receiving SYNC, after which the acquisition sequence is restarted. 5. If coarse acquisition is not obtained within 6.3 seconds, the device selects another frequency and repeats the process beginning with step 2. Camping provides a worst case acquisition performance that is perceptibly slow to the human user of a portable device. The preferred approach has the receiver scan all potential frequencies in ascending order, at 125 μsec increments. When the highest frequency is reached, the search begins again at the lowest frequency. The 125 μs sampling rate is much faster than the 250 μsec channel switching time specification of the RF modem. This is possible because the overall switching time specification applies to worst case frequency switching intervals, i.e., from the highest to the lowest operating frequency. By switching a single channel at a time, switching may be maintained over frequency intervals very near a synthesizer phase detectors' phase lock range, allowing nearly instantaneous frequency switching. The change from highest to lowest frequency at the end of the scan requires the standard 250 μsec. The 125 μsec monitoring interval allows 85 μs to ascertain if receive clock has been detected prior to switching to the next frequency. The monitoring interval should be selected to be non-periodic with respect to the access interval. For example, the 125 μsec interval allows the entire hopping sequence to be scanned 2 (n+1) times in a 20 ms access interval. If clock is recovered at any frequency, the receiver remains on frequency for a Reservation Opportunity and initiates channel access through the procedure described above. The scanning approach is less deterministic in terms of acquisition probability than camping, but the search time required for 99.5% acquisition probability is about 80 Access Intervals, or three times faster than that for camping. A hybrid approach that scans only three or four consecutive frequencies incorporates the deterministic aspects of camping with some of the improved performance of the scanning algorithm. For scanning over a small number of frequencies an up/down scan is preferred, i.e., 1,2,3,2,1,2,3 since all frequency changes can be accomplished at the faster switching rate. The end frequencies are visited less often than those in the center. The number of frequencies used, e.g., 3 or 4, is selected so that all can be scanned during the preamble duration of a minimum length transmission. All devices are required to have unique 48 bit global addresses. Local 16 bit addresses will be assigned for educed overhead in communications, Local addresses will not be assigned to devices whose global addresses are not on an authentication list maintained in each access point and routinely updated over the infrastructure. Once a device has attained synchronization, it must register with the control point to be connected with the NET. It initiates this by sending a Request for Poll indicating a registration request, and including its global address. The control point will register the device, and provide a short Network Address as an outbound message. The Control point will generate the short address if it is a single NET, or exchange the global address for a short Network Address with a Network Address Server if the NET is part of a larger infrastructured network of a premises LAN. Once a device is synchronized to a NET, it must periodically update its local clock to the NET clock communicated in the SYNC message. The SYNC message contains a character designated as the SYNC character that transfers the NET clock synchronization. This may be the beginning or ending FLAG in the SYNC message, or a specific character within the message. The maximum expected frequency error between NET and device local clocks is 100 parts per million. To maintain a 50 μs maximum clock error, the local device clock must be re-synchronized at 500 ms intervals. At 20 ms per access interval, a non-sleeping device has up to 26 SYNC opportunities within that period in which to re-synchronize and maintain required accuracy. As mentioned above, it is desirable that battery powered devices have the capability to sleep, or power off, for extended periods of time to conserve power. The term sleeping terminal in this instance may refer to a device that powers down its radio communication hardware to save power while maintaining other functions in an operational state, or a device that power manages those functions as well. In the power managed state, the device must maintain its hop clock so that full acquisition is not required every time power management is invoked. Devices that must sleep to manage their power consumption use Priority SYNC Messages to maintain synchronization. Priority SYNC Messages occur every three Access Intervals. In times of low NET activity, non-priority SYNC messages are omitted. By coordinating power management with Priority SYNC Messages, power managed devices can be guaranteed to wake up for Access Intervals where SYNCs will be present, even if the NET activity is low during the sleep period. A sleeping device with no transmission requirements may sleep for eight 20 ms access intervals, and wake only for the SYNC and Reservation Poll at the beginning of the ninth Access Interval to monitor pending messages before returning to the sleep state, for a duty cycle of less than 5%. This provides three opportunities to synchronize to the NET clock within a 540 ms window. A flow chart depicting a device sleeping for several access intervals is shown in FIG. 17. Devices may also sleep for longer periods of time, at the risk of losing fine synchronization. They may compensate by advancing their local clocks to account for the maximum timing uncertainty. For example, a terminal could sleep for 5 seconds without re-synchronizing by waking up 500 microseconds before it expects an Access Interval to begin, and successfully receive SYNC messages. This technique is valid for extended periods of time, up to the point where the maximum timing error approaches 50% of an Access Interval. A flow chart depicting a device sleeping for several seconds is shown in FIG. 18. A power managed device that requires communication during a sleep period may immediately wake and attempt access to the NET at the next available Reservation Opportunity. A device that requires communications may be able to register with one of several NETs operating in its vicinity, with transmissions occurring on many frequencies simultaneously. A good strategy is to synchronize to a NET that provides an acceptable communication link, then monitor HELLO messages to determine other candidate NETs before attaching to a particular NET by registering with the control point device. As described above, a spontaneous wireless local area network or spontaneous LAN is one that is established for a limited time for a specific purpose, and which does not use the premises LAN to facilitate communications between devices or provide access to outside resources. Use of spontaneous LAN allows portable devices to share information, files, data, etc., in environments where communication via the premises LAN is not economically justifiable or physically possible. A spontaneous LAN capability also allows portable/mobile devices to have an equally portable network. Peripheral and vehicular LANs are examples of such spontaneous LANs. Requirements for spontaneous LAN differ from an infrastructured premises LAN in several significant areas. The number of devices in a spontaneous LAN is likely to be smaller than the number that a single NET in a premises LAN must be capable of supporting. In addition, coverage areas for spontaneous LANs are typically smaller than coverage areas for an access point participating in the premises LAN. In a spontaneous LAN, communication often takes place over relatively short distances, where devices are within line of sight of each other. In an premises LAN, the majority of communications are likely to involve accessing communication network resources. For example, portable devices with limited processing capabilities, memory, and power supplies are able to access large databases or powerful computing engines connected to the AC power grid. Access points within the premises LAN are well suited to the role of Control Points for managing synchronization and media access within each NET. In a spontaneous LAN, however, communications are limited to exchanges with spontaneous NET constituents. Additionally, NET constituents may potentially leave at any time, making it difficult to assign control point responsibilities to a single device. A shared mechanism for synchronization and media access is preferable in most cases. In a spontaneous LAN, battery power limitations may preclude assignment of a single device as a control point. The routine transmission of SYNC and access control messages places a significant power drain on a portable, battery powered device. Also, the control point architecture dictates that transmissions intended for devices other than the control point be stored and forwarded to the destination device, further increasing battery drain, and reducing system throughput. Moreover, the use of scheduled transmission in a premises LAN is likely to differ from use in a spontaneous LAN. For example, unlike the premises LAN, in the spontaneous LAN, applications such as massaging and two way (i.e., full-duplex) voice communications may only occasionally be used, whereas video transmission and telemetry exchange may be prevalent. To promote compatibility and integration with the premises LAN, operational differences required by multiple participating devices should be minimized. For example, selecting relatively close frequency bands for each LAN assists the design of a multiple LAN transceiver, reducing circuitry, cost, power, weight and size while increasing reliability. Similarly, selecting communication protocols so that the spontaneous LAN protocol constitutes a subset or superset of premises LAN may enable a given device to more effectively communication in both LANs, while minimizing both the overall protocol complexity and potentially limited memory and processing power. Use of frequency hopping is desirable in premises LAN because of its ability to mitigate the effects of interference and frequency selective fading. In the case of the latter, frequency hopping allows systems to be installed with less fade margin than single frequency systems with otherwise identical radio modem characteristics, providing improved coverage. The potentially smaller coverage area requirement of spontaneous LANS, however, allows single frequency operation to be considered for some applications, e.g., such as a peripheral LAN. Regulatory structures are in place in some countries to allow single frequency operation in the same bands as frequency hopping systems, providing that single frequency devices operate at reduced power levels. The lower transmit power of single frequency operation and elimination of periodic channel switching are desirable methods of reducing battery drain. The choice of single frequency or frequency hopped operation is dictated by the coverage requirements of the network, and may be left as an option to device users. As noted earlier, the basic Access Interval structure is suited to single frequency operation as well as to frequency hopping. SYNC messages in a single frequency system substitute a single frequency indication in the hopping sequence identifier field. A spontaneous LAN comes into existence when two or more devices establish communications, and ceases when its population falls to less than two. Before a spontaneous LAN can be established, at least two devices must agree upon a set of operating parameters for the network. Such agreement may be preprogrammed else exchanged and acknowledged prior to establishing the spontaneous LAN. Once the spontaneous LAN is established, other devices coming into the network must be able to obtain the operating parameters and acquire access. More specifically, to establish a spontaneous LAN, a computing device must first identify at least one other network device with which spontaneous LAN communication is desired. To identify another network device, the computing device may play an active or passive role. In an active role, the computing device periodically broadcasts a request to form spontaneous LAN with either a specific network device or, more likely, a specific type of network device. If a network device fitting the description of the request happens to be in range or happens into range and is available, it responds to the periodic requests to bind with the computing device, establishing the spontaneous LAN. Alternately, the network device may take a passive role in establishing the spontaneous LAN. In a passive role, the computing device merely listens for a request to form a spontaneous LAN transmitted by the appropriate network device. Once such a network device comes into range, the computing device responds to bind with the network device, establishing the spontaneous LAN. The choice of whether a device should take a passive or active role is a matter of design choice. For example, in one embodiment where peripheral devices have access to AC power, the roaming computer terminals take a passive role, while the peripheral devices take a more active role. Similarly, in another embodiment where a vehicle terminal has access to a relatively larger battery source, an active role is taken when attempting to form a spontaneous LAN, i.e., a vehicular LAN, with a hand-held computing device. Binding, a process carried out pursuant to a binding protocol stored in each network device, may constitute a very simple process such as might exist when creating a spontaneous LANs that operates on a single frequency channel. Under such a scenario, a simple acknowledge handshake between the computing terminal and the other network device may be sufficient to establish a spontaneous LAN pursuant to commonly stored, preprogrammed operating parameters. However, more complex binding schemes may also be implemented so as to support correspondingly more complex spontaneous LANs as proves necessary. An example of a more complex binding scheme is described below. It is desirable in some large spontaneous LANs for one device to be designated as a fully functional control point, providing identical NET operation to a single NET in the premises LAN. Providing that all devices share a hopping table and encryption key, the designated device would initiate control point activities, and other devices would synchronize to the designated unit. A device with greater battery capacity, or one that can be temporarily connected to AC power is best suited to the dedicated control point function. This architecture is applicable to Client-Server applications (where the server assumes the control point function), or to other applications where a single device is the predominant source or destination of communications. A portable device used as a dedicated control point is required to have additional programming and memory capacity to manage reservation based media access, pending message lists, and scheduled service slot allocations. In embodiments where communication requirements of a spontaneous LAN are largely peer to peer, there may be no overwhelming candidate for a dedicated Control Point. Thus, in such cases, the Control Point function is either distributed among some or all the devices within the spontaneous LAN. In such scenarios, the interleaved Access Interval approach used for wireless access points is employed. Initially, control point responsibilities are determined during the binding process. Users may designate or redesignate a Control Point device when several candidates are available. For spontaneous LANs, access intervals may be simplified to reduce power consumption, program storage and processing power requirements for portable devices used as control points. Control Point devices transmit SYNC, pending message lists, and Time Division Multiple Access slot reservations normally, but only use the single slot reservation Poll (Idle Sense Multiple Access). The reservation poll contains a field indicating reduced control point functionality. This places other devices in a point-to-point communication mode, using the Implicit Idle Sense Algorithm. The probability factor p communicated in the reservation poll is used for the Implicit Idle Sense algorithm. Control point devices may use the deferred SYNC mechanism for light system loading, transmitting Priority SYNC every third Access Interval to further decrease their transmission requirements. Control point devices must monitor the reservation slot for messages addressed to them, but may sleep afterwards. Request for Polls initiated under Implicit Idle Sense use point-to-point addressing, indicating the address of the destination device directly, rather than the control point device. This eliminates the need for the Control Point device to store and forward transmissions within the spontaneous LAN. The device detecting its address in a Request for Poll begins a session, after employing the Implicit Idle Sense algorithm, by Polling the source address identified in the Request for Poll. The terminating ACK and CLEAR messages contain an Explicit Idle Sense probability factor equal to that in the original reservation poll. To allow for power managed devices, the Control Point device maintains a pending message list. Devices that have been unable to establish communication with a sleeping device initiate a session with the Control Point device to register the pending message. Upon becoming active, the sleeping device will initiate a Poll to the device originating the pending message. The Control Point device will eliminate the pending message indication by aging, or by receipt of communication from the destination device clearing the pending message. Control point devices are not required to store pending messages, only addresses. As mentioned above, HELLO messages are broadcast to indicate changes in NET parameters. HELLO messages may be omitted to simplify the Control Point function in spontaneous LANs. Devices are assigned local addresses upon registration with the Control Point device. Devices may communicate an alias that identifies the device user to other users to the Control Point device where it is stored in an address table. The address table may be obtained by other network constituents by querying the Control Point device. A peripheral LAN is a type of spontaneous LAN which serves as a short range interconnect between a portable or mobile computing device (MCD) and peripheral devices. Designers of portable products are constantly challenged with reducing size, weight, and power consumption of these devices, while at the same time increasing their functionality and improving user ergonomics. Functions that may be used infrequently, or which are too large to fit within the constraints of good ergonomic design may be provided in peripheral devices, including printers, measurement and data acquisition units, optical scanners, etc. When cabled or otherwise physically connected to a portable product, these peripherals often encumber the user, preventing freedom of movement or mobility. This becomes more problematic when use of more than one peripheral is required. A second consideration for portable product design is communication docking. A communication dock is a device that holsters or houses a portable unit, and provides for communication interconnection for such tasks as program downloading, data uploading, or communication with large printers, such as those used for printing full sized invoices in vehicular applications. Communication docking of a portable unit may also involve power supply sharing and/or charging. The requirement for communication docking capability forces newer portable product designs to be mechanically compatible with older docking schemes, or may require that new docks, or adapters, be developed for each new generation of portable device. Product specific docking approaches movement over a radius of operation, forward and backward compatibility between portable units and peripherals, and potential communications among products manufactured by different vendors. Constituents within a peripheral LAN generally number six or fewer devices. One roaming computing device and one or two peripherals comprise a typical configuration. Operating range is typically less than fifty feet. Because the computing devices generally control the operation of peripheral devices, in a peripheral LAN a master/slave type protocol is appropriate. Moreover, roaming computing devices serving as master are well suited to the role of Control Points for managing synchronization and media access within each peripheral LAN. All peripheral communications are slaved to the master. In a peripheral LAN, roaming mobile or portable computing devices and wireless peripherals may all operate from battery power. Operating cycles between charging dictate use of power management techniques. Although all participants in a peripheral LAN might also be configured to directly participate in the premises LAN, the tradeoff in cost, power usage and added complexity often weighs against such configuration. Even so, participants within a peripheral LAN can be expected to function in a hierarchical manner, through a multiple participating device, with the premises LAN. Thus, the use of a much simpler, lower-power transceiver and associated protocol may be used in the peripheral LAN. As previously described, a roaming computing device serving as a master device may itself be simultaneously attempting to participate in other networks such as the premises or vehicular LANs. Considerable benefits arise if the radio and processing hardware that supports operation within the wireless network can also support such operation. For example, a device that is capable of frequency hopping is inherently suited to single frequency operation. If it can adjust transmitter power level and data rate to be compatible with the requirements of the peripheral LAN, it can function in both systems. The major benefits of common transceiver hardware across LANs include smaller product size, improved ergonomics, and lower cost. Specifically, in one embodiment, radio communication on the premises LAN, as described herein, takes place using radio transceivers capable of performing frequency-hopping. To communicate on a peripheral LAN, such transceivers could also utilize frequency-hopping at a lower power. However, such transceivers are relatively expensive in comparison to a lower power, narrow-band, single frequency transceivers. Because of the cost differential, it proves desirable to use the single frequency transceivers for all peripheral devices which will not participate in the premises LAN. Therefore, the more expensive, frequency-hopping transceivers which are fitted into roaming computing devices are further designed to stop hopping and lock into the frequency of the single frequency transceiver, allowing the establishment of peripheral LANs. Instead of frequency hopping, the peripheral LAN may also use narrow-band, single frequency communication, further simplifying the radio transceiver design for commonality. In another embodiment of the peripheral LAN transceivers, operation using one of a plurality of single frequency channels is provided. Thus, to overcome interference on one channel, the transceiver might select from the remaining of the plurality an alternate, single operating frequency with lesser channel interference. To accommodate the plurality of single frequency channels, the peripheral LAN transceivers may either communicate an upcoming frequency change so that corresponding peripheral LAN participants can also change frequency, or the transceivers may be configured to use frequency synthesis techniques to determine which of the plurality a current transmission happens to be. The Access Interval structure is also an appropriate choice for peripheral LAN operations. In one embodiment, to provide for simplicity and tighter integration, the Access Interval for the peripheral LAN is a subset of the Access Interval used in the premises LAN. HELLO messages, Implicit Idle Sense, Data Rate Switching, and scheduled services are not implemented. Peripheral devices normally sleep, activate their receivers for SYNC transmissions from the participating master device, and resume sleeping if no pending messages are indicated and they have no inbound transmission requirements. Access Intervals occur at regular intervals, allowing for power management. Access Intervals may be skipped if the master has other priority tasks to complete. To initialize the peripheral LAN, a device desiring initialization, a master device, selects a single operating frequency by scanning the available frequencies for one with no activity. A typical master device might be a roaming computing device desiring access to a local peripheral. Default values for other parameters, including Access Interval duration, are contained within each participant's memory. Such parameters may be preadjusted in each participant to yield specific performance characteristics in the peripheral LAN. Once a master device identifies a single frequency, slaves, which are generally peripherals, are brought into the peripheral LAN through a process called binding. Binding is initiated by the master device by invoking a binding program contained therein. Slaves, such as peripherals, are generally programmed to enter a receptive state when idle. Thus, in one embodiment, the master device accomplishes binding by transmitting Access Intervals of known duration sequentially on a series of four frequencies spread throughout the available frequency range. The specific frequencies and Access Interval durations used are stored as parameters in all potential participating devices. A 250 KBPS transfer rate is appropriate in some embodiments of the peripheral LAN, reflecting a balance between performance and complexity in peripheral devices. A slave, e.g., a peripheral, responds to the binding attempts by the master device on a given frequency until the slave successfully receives and establishes communication with the master device. If they do not establish communication after four Access Intervals, the slave switches to the next frequency for four Access Interval periods. Once communication is established, the slave registers with the master and obtains the master device's selected operating frequency and related communication parameters. When all slave devices have been bound, the master terminates the binding program and normal operation at the selected single frequency may begin. Referring to FIG. 15, in a hierarchical network, peripheral LAN masters use a secondary access interval 1501 that is synchronized to the Access Interval of a parent (premises) LAN control point. Peripheral LAN Access Intervals occur less frequently than premises LAN Access Intervals, e.g., every other or every third Priority SYNC Access Interval. During the premises LAN Access Interval, the peripheral LAN master device monitors the premises LAN control point for SYNC 1503 reservation poll 1505 and exchanges inbound and outbound message according to the normal rules of the access protocol. The master switches to the peripheral LAN frequency, and transmits its own SYNC frame 1507 during the session period 1509 of its parent control point allowing communication with its peripherals. The peripheral LAN Access Interval is generally shorter than the premises LAN Access Interval, so that it does not extend beyond the premises LAN Access Interval boundary. At the end of the peripheral LAN Access Interval 1501, the master switches to the premises LAN frequency for the next SYNC 1503. The secondary SYNC 1507 may only be transmitted if the peripheral LAN master is not busy communicating through the premises LAN. If a communication session is occurring, the master must defer SYNC, preventing communication with its peripherals during that Access Interval. The master must also defer SYNC if the current frequency in the LAN is prone to interference from the peripheral LAN frequency, i.e., they are the same frequency or adjacent frequencies. If two consecutive SYNCs are deferred, peripherals will activate their receivers continuously for a period of time, allowing the master to transmit during any Access Interval. This approach is also applicable when the master roams between frequency hopping NETs. Since NETs are not synchronized to one another, the devices in the peripheral LAN adjust Access Interval boundaries each time the master roams. If peripherals do not detect SYNC within a timeout period, they may duty cycle their reception to conserve battery power. Referring to FIG. 16, a Roaming Algorithm Flow Diagram illustrates how a roaming computing device will select a suitable access point. Roaming computing devices operating in the infrastructured network environment formed by the access points will routinely move between access point coverage areas. The roaming computing devices are able to disconnect from their current access point communication link and reconnect a communication link to a different access point, as necessitated by device roaming. Access points transmit HELLO messages to devices in their coverage area. These HELLO messages communicate to roaming computing devices the cost of connection through the access point, addresses of neighboring access points, and the cost of connection through these neighboring access points. This information allows roaming computing devices to determine the lowest cost connection available and to connect to the access point with the lowest cost. In addition, access point HELLO message may include communication parameters of neighboring access points, such as frequency hopping sequences and indices, spread spectrum spreading codes, or FM carrier channel frequencies. This. information allows roaming computing devices to roam and change access point connections without going through a full acquisition phase of the new access point's parameters. Roaming computing devices initially select and register with an access point control point on the basis of link quality: signal strength and cost information transmitted within HELLO messages. A device will remain attached to a particular access point until the link quality degrades below an acceptable level; then it will attempt to determine if an alternative access point connection is available. The device initiates a roaming algorithm, using neighbors information from the most recent HELLO message to attempt connection with another candidate access point. If connection fails, another candidate from the neighbors list will be selected, and the process repeated. Once connection is made with an alternative access point, the device will monitor signal strength and data errors to determine link quality. If link quality is acceptable, the device will continue monitoring until a HELLO message is received. If the cost is acceptable, it will register with the new access point, and the access point will update the spanning tree over the infrastructure. If link quality or cost is unacceptable, another candidate from the neighbors list is selected and the process repeated. This continues until an acceptable connection is established. If one cannot be established, the device must return to the original access point connection or employ the initial acquisition algorithm. FIG. 28a illustrates an embodiment of the hierarchical communication system according to the present invention communication is maintained in a warehouse environment. Specifically, a worker utilizes a roaming computing device, a computer terminal 3007, and a code reader 3009 to collect data such as identifying numbers or codes on warehoused goods, such as the box 3010. As the numbers and codes are collected, they are forwarded through the network to a host computer 3011 for storage and cross-referencing. In addition, the host computer 3011 may, for example, forward cross-referenced information relating to the collected numbers or codes back through the network for display on the terminal 3007 or for printing on a printer 3013. The host computer 3011 can be configured as a file server to perform such functions. Similarly, the collected information may be printed from the computer terminal 3007 directly on the printer 3013. Other exemplary communication pathways supported include message exchanges between the computer terminal 3007 and other computer terminals (not shown) or the host computer 3011. The host computer 3011 provides the terminal 3007 with remote database storage, access and processing. However, the terminal 3007 also provides for local processing within its architecture to minimize the need to access the remote host computer 3011. For example, the terminal 3007 may store a local database for local processing. Similarly, the terminal 3007 may run a variety of application programs which never, occasionally or often need access to the remote host computer 3011. Many of the devices found in the illustrative network are battery powered and therefore must conservatively utilize their radio transceivers. For example, the hand-held computer terminal 3007 receives its power from either an enclosed battery or a forklift battery (not shown) via a communication dock within the forklift 3014. Similarly, the code reader 3009 operates on portable battery power as may the printer 3013. The arrangement of the communication network, communication protocols used, and data rate and power level adjustments help to optimize battery conservation without substantially degrading network performance. In the illustrated embodiment shown in FIG. 28a, the hierarchical communication system of the present invention consists of a premises LAN covering a building or group of buildings. The premises LAN in the illustrated embodiment includes a hardwired backbone LAN 3019 and access points 3015 and 3017. A host computer 3011 and any other non-mobile network device located in the vicinity of the backbone LAN 3019 can be directly attached to the backbone LAN 3019. However, mobile devices and remotely located devices must maintain connectivity to the backbone LAN 3019 through either a single access point such as the access point 3015, a multi-hop network of access points such as is illustrated by the access points 3015 and 3017. The access points 3015 and 3017 contain a relatively higher power transmitter, and provide coverage over the entire warehouse floor. Although a single access point may be sufficient, if the warehouse is too large or contains interfering physical barriers, the multi-hop plurality of access points 3017 may be desirable. Otherwise, the backbone LAN 3019 must be extended to connect all of the access points 3017 directly to provide sufficient radio coverage. Through the premises LAN, relatively stable, longer range wireless and hardwired communication is maintained. Because roaming computing devices, such as the hand-held computer terminal 3007, cannot be directly hardwired to the backbone LAN 3019, they are fitted with RF transceivers. To guarantee that such a network device can directly communicate on the premises LAN with at least one of the access points 3015 and 3017, the fitted transceiver is selected to yield approximately the same transmission power as do the access points 3015 and 3017. However, not all roaming network devices require a direct RF link to the access points 3015 and 3017, and some may not require any link at all. Instead, with such devices, communication exchange is generally localized to a small area and, as such, only requires the use of relatively lower power, short range transceivers. The devices which participate in such localized shorter range communication form spontaneous LANs. For example, the desire by a roaming terminal to access peripheral devices such as the printer 3013 and modem 3023, results in the roaming terminal establishing a peripheral LAN with the peripheral devices. Similarly, a peripheral LAN might be established when needed to maintain local communication between a code scanner 3009 and the terminal 3007. In an exemplary embodiment, the printer 3013 are located in a warehouse dock with the sole assignment of printing out forms based on the code information gathered from boxes delivered to the dock. In particular, as soon as the code reader gathers information, it relays the information along a peripheral LAN to the terminal 3007. Upon receipt, the terminal 3007 communicates via the premises LAN to the host computer 3011 to gather related information regarding a given box. Upon receipt of the related information, the terminal 3007 determines that printing is desired with the printer 3013 located at the dock. When the forklift 3014 enters the vicinity of the dock, the terminal 3007 establishes a peripheral LAN with the printer 3013 which begins printing the collected code information. To carry out the previous communication exchange, the printer 3013 and code reader 3009 are fitted with a lower power peripheral LAN transceivers for short range communication. The computer terminal 3007 transceiver is not only capable of peripheral LAN communication, but also with the capability of maintaining premises LAN communication. In an alternate exchange however, the code reader 3009 might be configured to participate on both LANs, so that the code reader 3009 participates in the premises LAN to request associated code information from the host computer 3011. In such a configuration, either the code. reader 3009 or terminal 3007 could act as the control point of the peripheral LAN. Alternately, both could share the task. With capability to participate in the peripheral LAN only, the code reader 3009, or any other peripheral LAN participant, might still gain access to the premises LAN indirectly through the terminal 3007 acting as a relaying device. For example, to reach the host computer 3011, the code reader 3009 first transmits to the computer terminal 3007 via the peripheral LAN. Upon receipt, the computer terminal 3007 relays the transmission to one of the access points 3015 and 3017 for forwarding to the host 3011. Communication from the host 3011 to the code reader 3009 is accomplished via the same pathway. It is also possible for any two devices with no access to the premises LAN to communicate to each other. For example, the modem 3023 could receive data and directly transmit it for printing to the printer 3013 via a peripheral LAN established between the two. Similarly, the code reader 3009 might choose to directly communicate code signals through a peripheral LAN to other network devices via the modem 3023. In an alternate configuration, a peripheral LAN access point 3021 is provided which may be directly connected to the backbone LAN 3019 (as shown), acting as a direct access point to the backbone LAN 3019, or indirectly connected via the access points 3015 and 3017. The peripheral LAN access point 3021 is positioned in the vicinity of other peripheral LAN devices and thereafter becomes a control point participant. Thus, peripheral LAN communication flowing to or from the premises LAN avoids high power radio transmissions altogether. However, it can be appreciated that a stationary peripheral LAN access point may not always be an option when all of the peripheral LAN participants are mobile. In such cases, a high power transmission to reach the premises LAN may be required. FIG. 28b illustrates other features of the present invention in the use of spontaneous LANs in association with a vehicle which illustrate the capability of automatically establishing a premises and a peripheral LAN when moving in and out of range to perform services and report on services rendered. In particular, like the forklift 3014 of FIG. 28a, a delivery truck 3033 provides a focal point for a spontaneous LAN utilization. Within the truck 3033, a storage terminal 3031 is docked so as to draw power from the truck 3033's battery supply. Similarly, a computer terminal 3007 may either be docked or ported. Because of greater battery access, the storage terminal 3031 need only be configured for multiple participation in the premises, peripheral and vehicular LANs and in a radio WAN, such as RAM Mobile Data, CDPD, MTEL, ARDIS, satellite communication, etc. The storage terminal 3031, although also capable of premises and peripheral LAN participation, need only be configured for vehicular LAN participation. Prior to making a delivery, the truck enters a docking area for loading. As goods are loaded into the truck, the information regarding the goods is down-loaded into the storage terminal 3031 via the terminal 3007 or code reader 3009 (FIG. 28a) via the premises or peripheral LAN communications. This loading might also be accomplished automatically as the forklift 3014 comes into range of the delivery truck 3033, establishes or joins the peripheral LAN, and transmits the previously collected data as described above in relation to FIG. 28a. Alternately, loading might also be accomplished via the premises LAN. As information regarding a good is received and stored, the storage terminal 3031 might also request further information regarding any or all of the goods via the peripheral LAN's link to the host computer 3011 through the premises LAN. More likely however, the storage terminal 3031 if appropriately configured would participate on the premises LAN to communicate directly with the host computer 3011 to retrieve such information. The peripheral LAN access point 3021 if located on the dock could provide a direct low power peripheral LAN connection to the backbone LAN 3019 and to the host computer 3011. Specifically, in one embodiment, the access point 3021 is located on the dock and comprises a low power (“short hop”) radio operating in a frequency hopping mode over a 902-928MHz frequency band. However, the access point 3021 can instead be configured to communicate using, for example, infrared, UHF, 2.4 GHz or 902 MHz spread spectrum direct sequence frequencies. Once fully loaded and prior to leaving the dock, the storage device 3031 may generate a printout of the information relating to the loaded goods via a peripheral LAN established with the printer 3013 on the dock. In addition, the information may be transmitted via the peripheral LAN modem 3023 to a given destination site. As illustrated in FIG. 28c, once the storage terminal 3031 and hand-held terminal 3007 moves out of range of the premises and peripheral LANs, i.e., the truck 3033 drives away from the dock, the vehicular LAN can only gain access to the premises LAN via the more costly radio WAN communication. Thus, although the storage terminal 3031 might only be configured with relaying control point functionality, to minimize radio WAN communication, the storage terminal 3031 can be configured to store relatively large amounts of information and to provide processing power. Thus, the terminal 3007 can access such information and processing power without having to access devices on the premises LAN via the radio WAN. Upon reaching the destination, the storage terminal 3031 may participate in any in range peripheral and premises LAN at the delivery site dock. Specifically, as specific goods are unloaded, they are scanned for delivery verification, preventing delivery of unwanted goods. The driver is also informed if goods that should have been delivered are still in the truck. As this process takes place, a report can also be generated via a peripheral or premises LAN printer at the destination dock for receipt signature. Similarly, the peripheral LAN modem on the destination dock can relay the delivery information back to the host computer 3011 for billing information or gather additional information needed, avoiding use of the radio WAN. If the truck 3033 is used for service purposes, the truck 3033 leaves the dock in the morning with the addresses and directions of the service destinations, technical manuals, and service notes which have been selectively downloaded from the host computer 3011 via either the premises or peripheral LAN to the storage terminal 3031 which may be configured with a hard drive and substantial processing power. Upon pulling out of range, the storage terminal 3031 and the computer terminal 3007 automatically form an independent, detached vehicular LAN. Alternately, the terminals 3007 and 3031 may have previously formed the vehicular LAN before leaving dock. In one embodiment, the vehicular LAN operates using frequency hopping protocol much the same as that of the premises LAN, with the storage terminal 3031 acting much like the premises LAN access points. Thus, the radio transceiver circuitry for the premises LAN participation may also be used for the vehicular LAN and, as detailed above, a peripheral LAN. similarly, if the radio WAN chosen has similar characteristics, it may to be incorporated into a single radio transceiver. At each service address, the driver collects information using the terminal 3007 either as the data is collected, if within vehicular LAN transmission range of the storage terminal 3031, or as soon as the terminal 3007 comes within range. Any stored information within storage terminal 3031 may be requested via the vehicular LAN by the hand-held terminal 3007. Information not stored within the vehicular LAN may be communicated via a radio WAN as described above. Referring again to FIG. 28b, upon returning to the dock, the storage terminal 3031, also referred to herein as a vehicle terminal, joins in or establishes a peripheral LAN with the peripheral LAN devices on the dock, if necessary. Communication is also established via the premises LAN. Thereafter, the storage terminal 3031 automatically transfers the service information to the host computer 3011 which uses the information for billing and in formulating service destinations for automatic downloading the next day. FIG. 29a is a diagrammatic illustration of another embodiment using a peripheral LAN to supporting roaming data collection by an operator according to the present invention. As an operator 3061 roams the warehouse floor, he carries a peripheral LAN comprising the terminal 3007, code reader 3009 and a portable printer 3058 with him. The operator collects information regarding goods, such as the box 3010, with the code reader 3009 and the terminal 3007. If the power resources are equal, the terminal 3007 may be configured and designated to also participate in the premises LAN. Corresponding information to the code data must be retrieved from the host computer 3011. The collected code information and retrieved corresponding information can be displayed on the terminal 3007. After viewing for verification, the information can be printed on the printer 3058. Because of this data flow requirement, the computer terminal 3007 is selected as the peripheral LAN device which must also carry the responsibility of communicating with the premises LAN. If during collection, the operator decides to power down the computer terminal 3007 because it is not needed, the peripheral LAN becomes detached from the premises LAN. Although it might be possible for the detached peripheral LAN to function, all communication with the host computer 3011 through the premises LAN is placed in a queue awaiting reattachment. As soon as the detached peripheral LAN comes within range of an attached peripheral LAN device, i e., a device attached to the premises LAN, the queued communications are relayed to the host. It should be clear from this description that the peripheral LAN may roam in relation to a device attached to the premises LAN (“premises LAN device”) Similarly, the premises LAN device may roam in relation to the peripheral LAN. The roaming constitutes a relative positioning. Moreover, whenever a peripheral LAN and a master device move out of range of each other, the peripheral LAN may either poll for or scan for another master device for attachment. The master device may constitute a premises LAN device, yet need not be. To avoid detachment when the terminal 3007 is powered down, the code reader 3009 may be designated as a backup to the terminal 3007 for performing the higher power communication with the premises LAN. As described in more detail below in reference to FIG. 33c regarding the idle sense protocol, whenever the code reader 3009 determines that the terminal 3007 has stopped providing access to the premises LAN, the code reader 3009 will take over the role if it is next in line to perform the backup service. Thereafter, when the computer terminal 3007 is powered up, it monitors the peripheral LAN channel, requests and regains from the code reader 3009 the role of providing an interface with the premises LAN This, however, does not restrict the code reader 3009 from accessing the premises LAN although the reader 3009 may choose to use the computer terminal 3007 for power conservation reasons. In addition, if the computer terminal 3007 reaches a predetermined low battery threshold level, the terminal 3007 will attempt to pass the burden of providing premises LAN access to other peripheral LAN backup devices. If no backup device exists in the current peripheral LAN, the computer terminal 3007 may refuse all high power transmissions to the premises LAN. Alternatively, the computer terminal 3007 may either refuse predetermined select types of requests, or prompt the operator before performing any transmission to the premises LAN. However, the computer terminal 3007 may still listen to the communications from the premises LAN and inform peripheral LAN members of waiting messages. FIG. 29b is a diagrammatic illustration of another embodiment of a peripheral LAN which supports roaming data collection by an operator according to the present invention. An operator is equipped with a peripheral LAN 3065 comprising a housing 3067, which incorporates a printer 3069 and a dock 3071, a roaming computing terminal 3073, and a code reader 3075. The operator may roam a warehouse floor or a shipping dock and collect and retrieve data using the peripheral LAN 3065 as discussed above with respect to FIG. 29a. In this embodiment, the operator may elect to leave the housing 3067, and hence the printer, in one area of the warehouse, or on the truck, and carry only the code reader 3075 and terminal 3073. In addition, the operator may also elect to dock the terminal 3073 in the dock 3071 and carry only the code reader 3075. In any event, the terminal is capable of communicating data to the printer 3069 via RF signals or via the dock 3071. The housing 3067 may optionally include a cigarette lighter power input cable 3077 to power the printer 3069, and recharge the battery of the terminal 3073 via the dock 3071. The housing 3067 may also optionally include a wide area network radio to permit communication with a remote warehouse or station 3079. In addition, the housing 3067 may also be configured to include the functionality of the storage terminal 3031 discussed above with respect to FIGS. 28b and 28c. The peripheral LAN embodiments of FIGS. 29a and 29b may, of course, function when detached from the premises LAN. This feature is particularly desirable in situations where attachment to the premises LAN may be more costly, such as, for example, during the remote pickup or delivery of goods by a driver. In the situation where a driver is picking up goods, the driver may, for example, use the code reader and terminal to collect and/or enter information regarding the goods, such as their origin, destination, weight, etc. The terminal may then encode the information, and transmit it to the printer so that the driver can label each box appropriately with a bar or other type of code for later identification and routing of the goods. Once information regarding a particular pickup has been stored, either in the terminal or storage terminal, the driver may download the stored data using the WAN radio to the premises LAN host computer at the remote warehouse or station 3079 so that the information may be used to pre-schedule further routing of the goods before the driver even arrives. Because WAN communication is costly, however, the information may instead be automatically transferred wirelessly to the premises LAN host once the driver comes into range of the premises LAN, as discussed above with respect to FIG. 28b. Alternatively, or as a check to verify information previously transmitted to the premises LAN wirelessly, the information may be downloaded from the terminal to the premises LAN host via a docking system 3081 located at the warehouse or station 3079. The docking system 3081 may also be used to recharge the terminals 3073. Once the host computer has the information regarding the goods picked up by the driver(s), the host can download the data via RF or the docking system 3081 to any number of terminals 3073 used by warehouse personnel who unload the trucks. While unloading, these personnel can, for example, use a terminal 3073 and a code reader 3075 to build containers for further distribution of the goods to various destinations. Specifically, as a container is unloaded, the label previously placed on the container by the driver is scanned by the code reader 3075, and destination information is displayed on the terminal 3073. The box may then be taken to and loaded into the container headed for the same destination. Each container may also have a label which can be scanned to verify the destination of that particular container. FIG. 30 is a block diagram illustrating the functionality of RF transceivers built in accordance with the present invention. Although preferably plugging into PCMCIA slots of the computer terminals and peripherals, the transceiver 3110 may also be built-in or externally attached via available serial, parallel or ethernet connectors for example. Although the transceivers used by potential peripheral LAN master devices may vary from those used by peripheral LAN slave devices (as detailed below), they all contain the illustrated functional blocks. In particular, the transceiver 3110 contains a radio unit 3112 which attaches to an attached antenna 3113. The radio unit 3112 used in peripheral LAN slave devices need only provide reliable low power transmissions, and are designed to conserve cost, weight and size. Potential peripheral LAN master devices not only require the ability to communicate with peripheral LAN slave devices, but also require higher power radios to also communicate with the premises LAN. Thus, potential peripheral LAN master devices and other non-peripheral LAN slave devices might contain two radio units 3112 or two transceivers 3110—one serving the premises LAN and the other serving the peripheral LAN—else only contain a single radio unit to service both networks. In embodiments where cost and additional weight is not an issue, a dual radio unit configuration for potential peripheral LAN master devices may provide several advantages. For example, simultaneous transceiver operation is possible by choosing a different operating hand for each radio. In such embodiments, a 2.4 GHz radio is included for premises LAN communication while a 27 MHz radio supports the peripheral LAN. Peripheral LAN slave devices receive only the 27 MHz radio, while the non-potential peripheral LAN participants from the premises LAN are fitted with only the 2.4 GHz radios. Potential peripheral LAN master devices receive both radios. The low power 27 MHz peripheral LAN radio is capable of reliably transferring information at a range of approximately 40 to 100 feet asynchronously at 19.2 KBPS. An additional benefit of using the 27 MHz frequency is that it is an unlicensed frequency band. The 2.4 GHz radio provides sufficient power (up to 1 Watt) to communicate with other premises LAN devices. Another benefit of choosing 2.4 GHz or 27 MHz bands is that neither requires FCC licensing. Many different frequency choices could also be made such as the 900 MHz band, UHF, etc. Alternatively, infrared communication may be used in situations where line of sight may be achieved between devices on the network. In embodiments where cost and additional weight are at issue, a single radio unit configuration is used for potential peripheral LAN master devices. Specifically, in such embodiments, a dual mode 2.4 GHz radio supported both the peripheral LAN and premises LANS. In a peripheral LAN mode, the 2.4 GHz radio operates at a single frequency, low power level (sub-milliwatt) to support peripheral LAN communication at relatively close distances 20-30 feet). In a high power (up to 1 Watt) or main mode, the 2.4 GHz radio provides for frequency-hopping communication over relatively long distance communication connectivity with the premises LAN. Although all network devices might be fitted with such a dual mode radio, only peripheral LAN master devices use both modes. Peripheral LAN slave devices would only use the low power mode while all other premises LAN devices would use only the high power mode. Because of this, to save cost, peripheral LAN slave devices are fitted with a single mode radio operating in the peripheral LAN mode. Non-peripheral LAN participants are also fitted with a single mode (main mode) radio unit for cost savings. Connected between the radio unit 3112 and an interface 3110, a microprocessor 3120 controls the information flow between through the transceiver 3110. Specifically, the interface 3115 connects the transceiver 3110 to a selected computer terminal, a peripheral device or other network device. Many different interfaces 3115 are used and the choice will depend upon the connection port of the device to which the transceiver 3110 will be attached. Virtually any type of interface 3110 could be adapted for use with the transceiver 3110 of the present invention. Common industry interface standards include RS-232, RS-422, RS-485, 10BASE2 Ethernet, 10BASE5 Ethernet, 10BASE-T Ethernet, fiber optics, IBM 4/16 Token Ring, V.11, V.24, V.35, Apple Localtalk and telephone interfaces. In addition, via the interface 3115, the microprocessor 3120 maintains a radio independent, interface protocol with the attached network device, isolating the attached device from the variations in radios being used. The microprocessor 3120 also controls the radio unit 3112 to accommodate communication with the premises LAN, the peripheral LAN, or both (for dual mode radios). Moreover, the same radio might also be used for vehicular LAN and radio WAN communication as described above. For example, a radio located in a vehicle or in a hand held terminal can be configured to communicate not only within a local network, but might also be capable of receiving paging messages. More specifically, in a main mode transceiver, the microprocessor 3120 utilizes a premises LAN protocol to communicate with the premises LAN. Similarly, in a peripheral LAN mode transceiver, the microprocessor 3120 operates pursuant to a peripheral LAN protocol to communicate in the peripheral LAN. In the dual mode transceiver, the microprocessor 3120 manages the use of and potential conflicts between both the premises and peripheral LAN protocols. Detail regarding the premises and peripheral LAN protocols can be found in reference to FIGS. 33-36 below. In addition, as directed by the corresponding communication protocol, the microprocessor 3120 controls the power consumption of the radio 3112, itself and the interface 3115 for power conservation. This is accomplished in two ways. First, the peripheral LAN and premises protocols are designed to provide for a low power mode or sleep mode during periods when no communication involving the subject transmitter is desired as described below in relation to FIGS. 33-34. Second, both protocols are designed to adapt in both data rate and transmission power based on power supply (i.e., battery) parameters and range information as described in reference to FIGS. 35-36. In order to insure that the proper device is receiving the information transmitted, each device is assigned a unique address. Specifically, the transceiver 3110 can either have a unique address of its own or can use the unique address of the device to which it is attached. The unique address of the transceiver can either be one selected by the operator or system designer or one which is permanently assigned at the factory such as an IEEE address. The address 3121 of the particular transceiver 3110 is stored with the microprocessor 3120. In the illustrated embodiments of FIGS. 28-29b, the peripheral LAN master device is shown as being either a peripheral LAN access point or a mobile or portable computer terminal. From a data flow viewpoint, in considering the fastest access through the network, such choices for the peripheral LAN master devices appear optimal. However, any peripheral LAN device might be assigned the role of the master, even those that do not seem to provide an optimal data flow pathway but may provide for optimal battery usage. For example, in the personal peripheral LAN of FIG. 29a, because of the support from the belt 3059, the printer might contain the greatest battery capacity of the personal peripheral LAN devices. As such, the printer might be designated the peripheral LAN master device and be fitted with either a dual mode radio or two radios as master devices require. The printer, or other peripheral LAN slave devices, might also be fitted with such required radios to serve only as a peripheral LAN master backup. If the battery-power on the actual peripheral LAN master, i.e., the hand-held terminal 3007 (FIG. 29a) drops below a preset threshold, the backup master takes over. FIG. 31 is a drawing which illustrates an embodiment of the personal peripheral LAN shown in FIG. 29a which designates a printer as the peripheral LAN master device. Specifically, in a personal peripheral LAN 3165, a computer terminal 3170 is strapped to the forearm of the operator. A code reader 3171 straps to the back of the hand of the user, and is triggered by pressing a button 3173 with the thumb. Because of their relatively low battery energy, the computer terminal 3170 and code reader 3171 are designated peripheral LAN slave devices and each contains a peripheral LAN transceiver having a broadcast range of two meters or less. Because of its greater battery energy, the printer 3172 contains a dual mode radio, and is designated the peripheral LAN master device. FIG. 32 is a block diagram illustrating a channel access algorithm used by peripheral LAN slave devices according to the present invention. At a block 3181, when a slave device has a message to send, it waits for an idle sense message to be received from the peripheral LAN master device at a block 3183. When an idle sense message is received, the slave device executes a back-off protocol at a block 3187 in an attempt to avoid collisions with other slave devices waiting to transmit. Basically, instead of permitting every slave device from repeatedly transmitting immediately after an idle sense message is received, each waiting slave is required to first wait for a pseudo-random time period before attempting a transmission. The pseudo-random back-off time period is generated and the waiting takes place at a block 3187. At a block 3189, the channel is sensed to determine whether it is clear for transmission. If not, a branch is made back to the block 3183 to attempt a transmission upon receipt of the next idle sense message. If the channel is still clear, at a block 3191, a relatively small “request to send” type packet is transmitted indicating the desire to send a message. If no responsive “clear to send” type message is received from the master device, the slave device assumes that a collision occurred at a block 3193 and branches back to the block 3183 to try again. If the “clear to send” message is received, the slave device transmits the message at a block 3195. Several alternate channel access strategies have been developed for carrier sense multiple access (CSMA) systems and include 1-persistent, non-persistent and p-persistent. Such strategies or variations thereof could easily be adapted to work with the present invention. FIG. 33a is a timing diagram of the protocol used according to one embodiment the present invention illustrating a typical communication exchange between a peripheral LAN master device having virtually unlimited power resources and a peripheral LAN slave device. Time line 3201 represents communication activity by the peripheral LAN master device while time line 3203 represents the corresponding activity by the peripheral LAN slave device. The master periodically transmits an idle sense message 3205 indicating that it is available for communication or that it has data for transmission to a slave device. Because the master has virtually unlimited power resources, it “stays awake” for the entire time period 3207 between the idle sense messages 3205. In other words, the master does not enter a power conserving mode during the time periods 3207. The slave device uses a binding protocol (discussed below with regard to FIG. 33c) to synchronize to the master device so that the slave may enter a power conserving mode and still monitor the idle sense messages of the master to determine if the master requires servicing. For example, referring to FIG. 33a, the slave device monitors an idle sense message of the master during a time period 3209, determines that no servicing is required, and enters a power conserving mode during the time period 3211. The slave then activates during a time period 3213 to monitor the next idle sense message of the master. Again, the slave determines that no servicing is required and enters a power conserving mode during a time period 3215. When the slave activates again during a time period 3217 to monitor the next idle sense message, it determines from a “request to send” type message from the master that the master has data for transmission to the slave The slave responds by sending a “clear to send” type message during the time period 3217 and stays activated in order to receive transmission of the data. The master is thus able to transmit the data to the slave during a time period 3219. Once the data is received by the slave at the end of the time period 3221, the slave again enters a power conserving mode during a time period 3223 and activates again during the time period 3225 to monitor the next idle sense message. Alternatively, the slave may have data for transfer to the master. If so, the slave indicates as such to the master by transmitting a message during the time period 3217 and then executes a backoff algorithm to determine how long it must wait before transmitting the data. The slave determines from the backoff algorithm that it must wait the time period 3227 before transmitting the data during the time period 3221. The slave devices use the backoff algorithm in an attempt to avoid the collision of data with that from other slave devices which are also trying to communicate with the master. The backoff algorithm is discussed more fully above in reference to FIG. 32. The idle sense messages of the master may also aid in scheduling communication between two slave devices. For example, if a first slave device has data for transfer to a second slave device, the first slave sends a message to the master during the time period 3209 requesting communication with the second slave. The master then broadcasts the request during the next idle sense message. Because the second slave is monitoring the idle sense message, the second slave receives the request and stays activated at the end of the idle sense message in order to receive the communication. Likewise, because the first slave is also monitoring the idle sense message, it too receives the request and stays activated during the time period 3215 to send the communication. FIG. 33b is a timing diagram of the protocol used according to one embodiment of the present invention illustrating a typical communication exchange between a peripheral LAN master having limited power resources and a peripheral LAN slave device. This exchange is similar to that illustrated in FIG. 33a except that, because it has limited power resources, the master enters a power conserving mode. Before transmitting an idle sense message, the master listens to determine if the channel is idle. If the channel is idle, the master transmits an idle sense message 3205 and then waits a time period 3231 to determine if any devices desire communication. If no communication is desired, the master enters a power conserving mode during a time period 3233 before activating again to listen to the channel. If the channel is not idle, the master does not send the idle sense message and enters a power saving mode for a time period 3235 before activating again to listen to the channel. Communication between the master and slave devices is the same as that discussed above in reference to FIG. 33a except that, after sending or receiving data during the time period 3219, the master device enters a power conserving mode during the time period 3237. FIG. 33c is also a timing diagram of one embodiment of the protocol used according to the present invention which illustrates a scenario wherein the peripheral LAN master device fails to service peripheral LAN slave devices. The master device periodically sends an idle sense message 3205, waits a time period 3231, and enters a power conserving mode during a time period 3233 as discussed above in reference to FIG. 33b. Similarly, the slave device monitors the idle sense messages during time periods 3209 and 3213 and enters a power conserving mode during time periods 3211 and 3215. For some reason, however, the master stops transmitting idle sense messages. Such a situation may occur, for example, if the master device is portable and is carried outside the range of the slave's radio. During a time period 3241, the slave unsuccessfully attempts to monitor an idle sense message. The slave then goes to sleep for a time period 3243 and activates to attempt to monitor a next idle sense message during a time period 3245, but is again unsuccessful. The slave device thereafter initiates a binding protocol to attempt to regain synchronization with the master. While two time periods 3241 and 3245 are shown, the slave may initiate such a protocol after any number of unsuccessful attempts to locate an idle sense message. With this protocol, the slave stays active for a time period 3247, which is equal to the time period from one idle sense message to the next, in an attempt to locate a next idle sense message. If the slave is again unsuccessful, it may stay active until it locates an idle sense message from the master, or, if power consumption is a concern, the slave may enter a power conserving mode at the end of the time period 3247 and activate at a later time to monitor for an idle sense message. In the event the master device remains outside the range of the slave devices in the peripheral LAN for a period long enough such that communication is hindered, one of the slave devices may take over the functionality of the master device. Such a situation is useful when the slave devices need to communicate with each other in the absence of the master. Preferably, such a backup device has the ability to communicate with devices on the premises LAN. If the original master returns, it listens to the channel to determine idle sense messages from the backup, indicates to the backup that it has returned and then begins idle sense transmissions when it reestablishes dominance over the peripheral LAN. FIG. 34 is a timing diagram illustrating one embodiment of the peripheral LAN master device's servicing of both the high powered premises LAN and the low powered peripheral LAN subnetwork., with a single or plural radio transceivers, in accordance with present invention. Block 3251 represents typical communication activity of the master device. Line 3253 illustrates the master's communication with an access point on the premises LAN while line 3255 illustrates the master's communication with a slave device on the peripheral LAN. Lines 3257 and 3259 illustrate corresponding communication by the access point and slave device, respectively. The access point periodically broadcasts HELLO messages 3261 indicating that it is available for communication. The master device monitors the HELLO messages during a time period 3263, and, upon determining that the base does not need servicing, enters a power conserving mode during a time period 3265. The master then activates for a time period to monitor the next HELLO message from the base. If the master has data to send to the base, it transmits the data during a time period 3271. Likewise, if the base has data to send to the master, the base transmits the data during a time period 3269. Once the data is received or sent by the master, it may again enter a power conserving mode. While HELLO message protocol is discussed, a number of communication protocols may be used for communication between the base and the master device. As may be appreciated, the peripheral LAN master device acts as a slave to access points in the premises LAN. Generally, the communication exchange between the master and the slave is similar to that described above in reference to FIG. 33b. Block 3273, however, illustrates a situation where the master encounters a communication conflict, i.e., it has data to send to or receive from the slave on the peripheral LAN at the same time it will monitor the premises LAN for HELLO messages from the base. If the master has two radio transceivers, the master can service both networks. If, however, the master only has one radio transceiver, the master chooses to service one network based on network priority considerations. For example, in block 3273, it may be desirable to service the slave because of the presence of data rather than monitor the premises LAN for HELLO messages from the base. On the other hand, in block 3275, it may be more desirable to monitor the premises LAN for HELLO messages rather than transmit an idle sense message on the peripheral LAN. FIGS. 35 and 36 are block diagrams illustrating additional power saving features according to the present invention, wherein ranging and battery parameters are used to optimally select the appropriate data rate and power level for subsequent transmissions. Specifically, even though network devices such as the computer terminal 3007 in FIGS. 28-29b have the capability of performing high power transmissions, because of battery power concerns, such devices are configured to utilize minimum transmission energy. Adjustments are made based on ranging information and on battery parameters. Similarly, within the peripheral LAN, even though lower power transceivers are used, battery conservation issues also justify the use of such data rate and power adjustments. This process is described in more detail below in reference to FIGS. 35 and 36. More specifically, FIG. 35 is a block diagram which illustrates a protocol 3301 used by a destination peripheral LAN device and a corresponding protocol 3303 used by a source peripheral LAN device to adjust the data rate and possibly the power level for future transmission between the two devices. At a block 3311, upon receiving a transmission from a source device, the destination device identifies a range value at a block 3313. In a low cost embodiment, the range value is identified by considering the received signal strength indications (RSSI) of the incoming transmission. Although RSSI circuitry might be placed in all peripheral LAN radios, the added expense may require that only peripheral LAN master devices receive the circuitry. This would mean that only peripheral LAN master devices would perform the function of the destination device. Other ranging techniques or signal quality assessments can also be used, such as measuring jitter in received signals, by adding additional functionality to the radios. Finally, after identifying the range value at the block 3313, the destination device subsequently transmits the range value to the slave device from which the transmission was received, at a block 3314. Upon receipt of the range value from the destination device at a block 3321, the source peripheral LAN device evaluates its battery parameters to identify a subsequent data rate for transmission at a block 3323. If range value indicates that the destination peripheral LAN device is very near, the source peripheral LAN device selects a faster data rate. When the range value indicates a distant master, the source device selects a slower rate. In this way, even without adjusting the power level, the total energy dissipated can be controlled to utilize only that necessary to carry out the transmission. However, if constraints are placed on the maximum or minimum data rates, the transmission power may also need to be modified. For example, to further minimize the complexity associated with a fully random range of data rate values, a standard range and set of several data rates may be used. Under such a scenario, a transmission power adjustment might also need to supplement the data rate adjustment. Similarly, any adjustment of power must take into consideration maximum and minimum operable levels. Data rate adjustment may supplement such limitations. Any attempted modification of the power and data rate might take into consideration any available battery parameters such as those that might indicate a normal or current battery capacity, the drain on the battery under normal conditions and during transmission, or the fact that the battery is currently being charged. The latter parameter proves to be very significant in that when the battery is being charged, the peripheral LAN slave device has access to a much greater power source for transmission, which may justify the highest power transmission and possibly the slowest data rate under certain circumstances. Finally, at a block 3325, an indication of the identified data rate is transmitted back to the destination device so that future transmissions may take place at the newly selected rate. The indication of data rate may be explicit in that a message is transmitted designating the specific rate. Alternately, the data rate may be transferred implicitly in that the new rate is chose and used by the source, requiring the destination to adapt to the change. This might also be done using a predefined header for synchronization. In addition, at the block 3325, in another embodiment, along with the indication of the identified data rate, priority indications are also communicated. Whenever battery power is detected as being low, a radio transmits a higher priority indication, and each receiver thereafter treats the radio as having a higher protocol priority than other such radios that exhibit normal power supply energy. Thus, the remaining battery life is optimized. For example, in a non-polling network, the low power device might be directly polled periodically so to allow scheduled wake-ups and contention free access to a receiver. Similarly, in an alternate embodiment, priority indications not need to be sent. Instead, the low battery power device itself exercises protocol priority. For example, for channel access after detecting that the channel is clear at the end of an ongoing transmission, devices with normal energy levels are required to undergo a pseudo-random back-off before attempting a transmission (to avoid collision). The low power device may either minimize the back-off period or ignore the back-off period completely. Thus, the low power device gains channel access easier than other normal power level devices. Other protocol priority schemes may also be assigned by the receivers to the low power device (via the indication), else may he taken directly by the low power device. FIG. 36 illustrates an alternate embodiment for carrying out the data rate and possibly power level adjustment. At a block 3351 upon binding and possibly periodically, the source peripheral LAN device sends an indication of its current battery parameters to the destination peripheral LAN device. This indication may be each of the parameters or may be an averaged indication of all of the parameters together. At a block 3355, upon receipt, the destination peripheral LAN device 355 stores the battery parameters (or indication). Finally, at a block 3358, upon receiving a transmission from the source device, based on range determinations and the stored battery parameters, the destination terminal identifies the subsequent data rate (and possibly power level). Thereafter, the new data rate and power level are communicated to the source device either explicitly or implicitly for future transmissions. FIG. 37 illustrates an exemplary block diagram of a radio unit 3501 capable of concurrent participation on multiple LAN's. To transmit, a control processor 3503 sends a digital data stream to a modulation encoding circuit 3505. The modulation encoding circuit 3505 encodes the data stream in preparation for modulation by frequency translation circuit 3507. The carrier frequency used to translate the data stream is provided by a frequency generator circuit 3509. Thereafter, the modulated data stream is amplified by a transmitter amplifier circuit 3511 and then radiated via the one of a plurality of antennas 3513 that has been selected via an antenna switching circuit 3515. Together, the modulation encoding circuitry 3505, translator 3507, amplifier 3511 and associated support circuitry constitute the transmitter circuitry. Similarly, to receive data, the RF signal received by the selected one of the plurality of antennas 3513 is communicated to a receiver RF processing circuit 3517. After performing a rather coarse frequency selection, the receiver RF processing circuit 3517 amplifies the RF signal received. The amplified received signal undergoes a frequency shift to an IF range via a frequency translation circuit 3519. The frequency translation circuit 3519 provides the center frequency for the frequency shift. Thereafter, a receiver signal processing circuit receives the IF signal, performs a more exact channel filtering and demodulation, and forwards the received data to the control processor 3503, ending the process. Together, the receiver signal processing 3521, translator 3517, receiver RF processing 3517 and associated support circuitry constitute the receiver circuitry. The control processor 3503 operates pursuant to a set of software routines stored in memory 3522 which may also store incoming and outgoing data. Specifically, the memory 3522 contains routines which define a series of protocols for concurrent communication on a plurality of LANs. As part of such operation, the control processor 3503 provides for power savings via a power source control circuit 3523, i.e., whenever the participating protocols permit, the control processor 3503 causes selective power down of the radio transceiver circuitry via a control bus 3525. Also, via the bus 3525, the control processor sets the frequency of the frequency generator 3509 so as to select the appropriate band and channel of operation required by a correspondingly selected protocol. Similarly, the control processor 3503 selects the appropriate antenna (via the antenna switching circuitry 3515) and channel filtering in preparation for operation on a selected LAN. Responding to the software routines stored in the memory 3522, the control processor 3503 selects the appropriate LANs to establish participation, detaches from those of the selected LANs in which participation is no longer needed, identifies from the selected LANs a current priority LAN in which to actively participate, maintains a time-shared servicing of the participating LANs. Further detail regarding this process follows below. In one embodiment, the control processor 3503 constitutes a typical microprocessor on an independent integrated circuit. In another embodiment, the control processor 3503 comprises a combination of distributed processing circuitry which could be included in a single integrated circuit as is a typical microprocessor. Similarly, the memory 3522 could be any type of memory unit(s) or device(s) capable of software storage. The radio circuitry illustrated is designed with the frequency nimble frequency generator 3509 so as to be capable of operation on a plurality of LANs/WANs. Because each of the plurality may be allocated a different frequency band, more than one antenna may be desirable (although a single antenna could be used, antenna bandwidth limitations might result in an unacceptable transmission-reception inefficiency). Thus, to select the appropriate configuration, the control processor 3503 first identifies the LAN/WAN on which to participate and selects the corresponding radio configuration parameters from the memory 3521. Thereafter, using the configuration parameters and pursuant to control routines stored in the memory 3522, the control processor 3503 sets the frequency of the generator 3509, selects the appropriate antenna via the antenna switching circuit 3515, and configures the receiver RF and signal processing circuits 3517 and 3521 for the desired LAN/WAN. More particularly, the antenna switching circuit 3515 comprises a plurality of digitally controlled switches, each of which is associated with one of the plurality of antennas 3513 so as to permit selective connection by the control processor 3503 of any available antenna to the transceiver circuitry. FIG. 38 illustrates an exemplary functional layout of the frequency generator 3509 of FIG. 37 according to one embodiment of the present invention. Basically, the frequency generator 3509 responds to the control processor 3503 by producing the translation frequency necessary for a selected LAN/WAN. The illustrated frequency generator comprises a voltage controlled oscillator (VCO) 3601. As is commonly known, for a VCO, the center frequency FVCO tracks the input voltage. However, because typical VCO's are subject to drift, the VCO is stabilized by connecting it in a phase locked loop to a narrowband reference, such as a crystal reference oscillator 3603. The oscillator 3603 outputs a signal of a fixed or reference frequency FREF to a divide-by-R circuit 3605, which divides as its name implies the reference frequency FREF by the known number R. A phase detector 3609 receives the divided-by-R output of the circuit 3609 and the feedback from the output of the VCO 3601 via a divide-by-N circuit 3607. Upon receipt, the phase detector 3609 compares the phase of the outputs from the circuits 3605 and 3607. Based on the comparison, a phase error signal is generated and applied to a lowpass loop filter 3611. The output of the filter 3611 is applied to the input of the VCO 3601 causing the center frequency of the VCO 3601 to lock-in. Therefore, if the output of the VCO 3601 begins to drift out of phase of the reference frequency, the phase detector 3609 responds with a corrective output so as to adjust the center frequency of the CO 3601 back in phase. With the illustrated configuration, the center frequency of the VCO 3601 is a function of the reference frequency as follows: FVCO=(FREF*N)/R Thus, to vary the center frequency of the VCO 3601 to correspond to a band of a selected LAN/WAN in which active participation is desired, the control processor 3503 (FIG. 37) need only vary the variables “R” and “N” and perhaps the frequency of the reference oscillator. Because the output FREF of the reference oscillator 3603 is quite stable, the phase lock loop as shown also keeps the output frequency FVCO of the VCO 3601 stable. More specifically, although any other scheme might be implemented, the value R in the divide-by-R circuit 3605 is chosen so as to generate an output equal to the channel spacing of a desired LAN/WAN, while the value N is selected as a multiplying factor for stepping up the center frequency of the VCO 3601 to the actual frequency of a given channel. Moreover, the frequency of the reference oscillator is chosen so as to be divisible by values of R to yield the channel spacing frequencies of all potential LANs and WANs. For example, to participate on both MTEL Corporation's Two Way Paging WAN (operating at 900 MHz with 25 KHz and 50 KHz channel spacings) and ARDIS Corporation's 800 MHz specialized mobile radio (SMR) WAN (operating at 25 KHz channel spacings centered at multiples of 12.5 KHz), a single reference frequency may be chosen to be a whole multiple of 12.5 KHz. Alternately, multiple reference frequencies may be chosen. Moreover, the value N is chosen to effectively multiply the output of the divide-by-R circuit 3605 to the base frequency of a given channel in the selected WAN. For frequency hopping protocols, the value of R is chosen so as to yield the spacing between frequency hops. Thus, as N is incremented, each hopping frequency can be selected. Randomizing the sequence of such values of N provides a hopping sequence for use by an access point as described above. Pluralities of hopping sequences (values of N) may be stored in the memory 3522 (FIG. 37) for operation on the premises LAN, for example. In addition to the single port phase locked loop configuration for the frequency generator 3509, other configurations might also be implemented. Exemplary circuitry for such configurations can be found in U.S. patent application Ser. No. 08/205,639 (Attorney Docket Nos. DN37139XXA; 10458US03), filed Mar. 4, 1994 by Mahany et al., entitled “Method of and Apparatus For Controlling Modulation of Digital Signals in Frequency-Modulated Transmissions”. This application is incorporated herein in its entirety. FIG. 39 illustrates further detail of the receiver RF processing circuit 3517 of FIG. 37 according to one embodiment of the present invention. Specifically, a preselector 3651 receives an incoming RF data signal from a selected one of the plurality of antennas 3513 (FIG. 37) via an input line 3653. The preselector 3651 provides a bank of passive filters 3657, such as ceramic or dielectric resonator filters, each of which provides a coarse filtering for one of the LAN/WAN frequencies to which it is tuned. One of the outputs from the bank of passive filters 3657 is selected by the control processor 3503 via a switching circuit 3655 so as to monitor the desired one of the available LANs/WANs. Thereafter, the selected LAN/WAN RF signal is amplified by an RF amplifier 3659 before translation by the frequency translation circuit 3519 (FIG. 37). FIG. 40 illustrates further detail of the receiver signal processing circuit 3521 of FIG. 37 according to one embodiment of the present invention. In particular, digitally controlled switching circuits 3701 and 3703 respond to the control processor 3503 by selecting an appropriate pathway for the translated IF data signal through one of a bank of IF filters 3705. Each IF filter is an analog crystal filter, although other types of filters such as a saw filter might be used. The IF filters 3705 provide rather precise tuning to select the specific channel of a given LAN/WAN. After passing through the switching circuit 3703, the filtered IF data signal is then amplified by an IF amplifier 3707. The amplified IF signal is then communicated to a demodulator 3709 for demodulation. The control processor retrieves the incoming demodulated data signal for processing and potential storage in the memory 3522 (FIG. 37). FIG. 41 illustrates further detail of the receiver signal processing circuit 3521 of FIG. 37 according to another embodiment of the present invention. Specifically, the IF signal resulting from the translation by the frequency translator circuitry 3519, enters the receiver signal processing circuit via an input 3751. Thereafter, the IF signal passes through an anti-aliasing filter 3753, and is amplified by a linear amplifier 3755. An IF oscillator 3757 supplies a reference signal fREF for translation of the incoming IF signal at frequency translation circuits 3759 and 3761. A phase shift circuit 3763 provides for a 90-degree shift of fREF, i.e., if fREF is considered a SINE wave, then the output of the circuit 3763 is the COSINE of fREF. Both the SINE and COSINE frequency translation pathways provide for channel selection of the incoming data signal. Thereafter the data signals are passed through corresponding low pass filters 3765 and 3767 in preparation for sampling by analog to digital (A/D) converters 3769 and 3771. Each A/D converter forwards the sampled data to a digital signal processor 3773 which provides for further filtering and demodulation. The digital signal processor 3773 thereafter forwards the incoming data signal to the control processor 3503 (FIG. 37) via an output line 3775. Moreover, although the digital signal processor 3773 and the control processor 3507 are discrete components in the illustrated example, they may also be combined into a single integrated circuit. FIG. 42 illustrates further detail of some of the storage requirements of the memory 3522 of FIG. 37 according to one embodiment of the present invention. To control the radio, the control processor 3503 (FIG. 37) accesses the information in the memory 3522 needed for radio setup and operation on a plurality of LANs/WANS. Among other information, the memory 3522 stores: 1) a plurality of software protocols, one for each LAN/WAN to be supported, which define how the radio is to participate on the corresponding LAN; and 2) an overriding control set of routines which govern the selection, use and interaction of the plurality of protocols for participation on desired LANs/WANs. Specifically, in the memory unit 3522, among other information and routines, software routines relating to the media access control (MAC) sublayer of the communication protocol layers can be found. In general, a MAC sublayer provides detail regarding how communication generally flows through a corresponding LAN or WAN. Specifically, the MAC sublayer handles functions such as media access control, acknowledge, error detection and retransmission. The MAC layer is fairly independent of the specific radio circuitry and channel characteristics of the LAN or WAN. As illustrated, premises LAN, peripheral LAN, vehicular LAN and WAN MAC routines 3811, 3813, 3815 and 3817 provide definition as to how the control processor 3503 (FIG. 37) should operate while actively participating on each LAN or WAN. Although only the several sets of MAC routines are shown, many other sets might also be stored or down-loaded into the memory 3522. Moreover, the sets of MAC routines 3811-17 might also share a set of common routines 3819. In fact, the sets of MAC routines 3811-17 might be considered a subset of an overall MAC which shares the common MAC routines 3B19. Below the MAC layer in the communication hierarchy, hardware and channel related software routines and parameters are necessary for radio control. For example, such routines govern the specific switching for channel filtering and antenna selection required by a given LAN or WAN. Similarly, these routines govern the control processor 3503's selection of parameters such as for R and N for the frequency generator 3509 (FIG. 38), or the selective power-down (via the power source control circuitry 3503—FIG. 37) of portions or all of the radio circuitry whenever possible to conserve battery power. As illustrated, such routines and parameters are referred to as physical (PHY) layer control software 3821. Each of the sets of MAC routines 3811-17 and 3819 provide specific interaction with the PHY layer control software 3821. A set of MAC select/service routines 3823 govern the management of the overall operation of the radio in the network. For example, if participation on the premises LAN is desired, the MAC select/service routines 3823 direct the control processor 3503 (FIG. 37) to the common and premises MAC routines 3819 and 3811 respectively. Thereafter, if concurrent participation with a peripheral LAN is desired, the select/service routines 3823 direct the control processor 3503 to enter a sleep mode (if available). The control processor 3503 refers to the premises LAN MAC routines 3811, and follows the protocol necessary to establish sleep mode on the premises LAN. Thereafter, the select/service routines 3823 directs the control processor 3503 to the peripheral LAN MAC routines 3813 to establish and begin servicing the peripheral LAN. Whenever the peripheral LAN is no longer needed, the select/service routines 3823 direct a detachment from the peripheral LAN (if required) as specified in the peripheral LAN MAC routines 3813. Similarly, if, during the servicing of the peripheral LAN, an overriding need to service the premises LAN arises, the processor 3503 is directed to enter a sleep mode via the peripheral LAN MAC routines 3813, and to return to servicing the premises LAN. Although not shown, additional protocol layers as well as incoming and outgoing data are also stored with the memory 3522, which, as previously articulated, may be a distributed plurality of storage devices. FIG. 43 illustrates a software flow chart describing the operation of the control processor 3503 (FIG. 37) in controlling the radio unit to participate on multiple LANs according to one embodiment of the present invention. Specifically, at a block 3901, the control processor first determines whether the radio unit needs to participate on an additional LAN (or WAN). If such additional participation is needed, at a block 3903, the radio unit may register sleep mode operation with other participating LANs if the protocols of those LANs so require and the radio unit has not already done so. Next, at a block 3905, the control processor causes the radio unit to poll or scan to locate the desired additional LAN. If the additional LAN is located at a block 3907, participation of the radio unit on the additional LAN is established at a block 3909. If additional participation is not needed at block 3901, or if the additional LAN has not been located at block 3907, or once participation of the radio unit on the additional LAN has been established at block 3909, the control processor next determines at a block 3911 whether any of the participating LANs require servicing. If any given participating LAN requires servicing, at a block 3913, the radio unit may be required by the protocol of the given LAN to reestablish an active participation status on that LAN, i.e., indicate to the given LAN that the radio unit has ended the sleep mode. Next, at a block 3915, the radio unit services the given LAN as needed or until the servicing of another LAN takes priority over that of the given LAN. At a block 3917, the radio unit may then be required to register sleep mode operation with the given LAN if the LAN's protocol so requires. At that point, or if no participating LAN needs servicing at block 3911, the control processor determines at a block 3919 whether the radio needs to detach from any given participating LAN. If so, the radio unit may implicitly detach at a block 3923 if the protocol of the LAN from which the radio wishes to detach requires no action by the radio unit. However, at a block 3921, the radio unit may be required to establish active participation on the LAN in order to explicitly detach at block 3923. For example, such a situation may arise when a portable terminal desires to operate on a shorter range vehicular LAN and detaches from a premises LAN. The portable terminal may be required by the protocol of the premises LAN to establish active communication on the premises LAN to permit the radio unit to inform the premises LAN that it is detaching and can only be accessed through the vehicular LAN. Once the radio unit is detached at block 3923, or if the radio unit does not need to detach from any participating LANs at block 3919, the control processor returns to block 3901 to again determine whether the radio unit needs to participate on an additional LAN, and repeats the process. FIG. 44 is an alternate embodiment of the software flow chart wherein the control processor participates on a master LAN and, when needed, on a slave LAN. Specifically, at a block 3951, the control processor causes the radio unit to poll or scan in order to locate the master LAN. If the master LAN has not been located at a block 3953, polling or scanning for the master LAN continues. Once the master LAN is located, participation with the master is established at a block 3955. At a block 3957, the radio unit participates with the master LAN until the need for the radio unit to participate on the slave LAN takes precedence. When that condition occurs, the control processor determines at a block 3959 whether participation of the radio unit on the slave network is established. If not, such participation is established at a block 3961. Next, at a block 3963, the radio unit services the slave LAN as needed or until the servicing of the master LAN takes priority. If the control processor determines at a block 3965 that servicing of the slave LAN has been completed, the radio unit detaches from the slave LAN at a block 3967 and returns to block 3957 to continue participation on the master LAN. However, if the control processor determines at block 3965 that servicing has not been, or may not be, completed, the radio unit does not detach from the slave LAN. In that case, before returning to block 3957 to service the master LAN, the radio unit may be required by the protocol of the slave LAN to register sleep mode operation with the slave LAN at a block 3969. In another embodiment, shown in FIG. 45, the overall communication system of the present invention has been adapted to service the environment found, for example, in a retail store. As illustrated, the premises of the retail store are configured with a communication network to provide for inventory control. Specifically, the communication network includes a backbone LAN 4501, an inventory computer 4511, and a plurality of cash registers located throughout the store, such as cash registers 4503 and 4505. As illustrated, the backbone LAN 4501 is a single wired link, such as Ethernet. However, it may comprise multiple sections of wired links with or without wireless link interconnects. For example, in another embodiment, each cash register 4503 and 4505 is communicatively interconnected with the inventory computer via an infrared link. The inventory computer 4511, which can range from a personal to main frame computer, provides central control over the retail inventory by monitoring the inventory status. Thus, the inventory computer 4511 must monitor both sales and delivery information regarding inventoried goods. To monitor sales information, the cash registers 4503 and 4505 include code scanners, such as tethered code scanners 4507 and 4509, which read codes on product labels or tags as goods are purchased. After receiving the code information read from the scanners 4507 and 4509, the cash registers 4503 and 4505 communicate sales information to the inventory computer 4511 via the backbone LAN 4501. To monitor delivery information, when the truck 4513 makes a delivery, the information regarding the goods delivered is communicated to the inventory computer 4511 via the access point 4517. As illustrated, the access point 4517 acts as a direct access point to the backbone LAN 4501, even though a series of wireless hops might actually be required. Upon receiving the sales information from the cash registers 4503 and 4505, the inventory computer 4511 automatically debits the inventory count of the goods sold. Similarly, upon receiving the delivery information, the inventory computer 4511 automatically credits the inventory count of the goods delivered. With both the sales and delivery information, the inventory computer 4511 accurately monitors the inventory of all goods stocked by the retail store. From the inventory information, the inventory computer 4511 generates purchase orders for subsequent delivery, automating the entire process. In particular, the inventory computer 4511 receives sales information from the cash registers 4503 and 4505 as detailed above. Whenever the restocking process is initiated, the inventory computer 4511 checks the retail inventory for each item sold to determine if restocking is needed. If restocking proves necessary, the inventory computer 4511, evaluating recent sales history, determines the quantity of the goods needed. From this information, an “inventory request” is automatically generated by the inventory computer 4511. Once verified (as modified if needed), the inventory request is automatically forwarded by the inventory computer 4511 to the warehouse 4519. This forwarding occurs via either a telephone link using a modem 4521, or a WAN link using the backbone LAN 4501, access point 4517, and an antenna tower 4523. At the remote warehouse 4519, the delivery truck 4513 is loaded pursuant to the inventory request received from the inventory computer 4511. After loading, the truck 4513 travels to the premises of the retail store. When within range of the access point 4517, the radio terminal 4515 in the truck 4513 automatically gains access to the retail premises LAN via the access point 4517 (as detailed above), and communicates an anticipated delivery list (a “preliminary invoice”), responsive to the inventory request, to the inventory computer 4511. In response, dock workers can be notified to prepare for the arrival of the delivery truck 4513. In addition, any rerouting information can be communicated to the terminal 4515 in the delivery truck 4513. If a complete rerouting is indicated, the truck 4513 may be redirected without ever having reached the dock. While unloading the delivery truck 4513, codes are read from all goods as they are unloaded using portable code readers, which may be built into or otherwise communicatively attached to the radio terminal 4515. The codes read are compared with and debited against the preliminary invoice as the goods are unloaded. This comparing and debiting occur either solely within the terminal 4515 or jointly within the terminal 4515 and the inventory computer 4511. If the codes read do not correspond to goods on the inventory request, or if the codes read do correspond but are in excess of what was required by the inventory request, the goods are rejected. Rejection, therefore, occurs prior to the actual unloading of the goods from the delivery truck 4513. At the dock, the goods received from the delivery truck 4513 undergo a confirmation process by a dock worker who, using a radio terminal 4525 configured with a code reader, reads the codes from the goods on the dock to guarantee that the proper goods, i.e., those requested pursuant to the inventory request, were actually unloaded. This extra step of confirmation can be eliminated, however, where the dock worker directly participates in the code reading during the unloading process in the delivery truck 4513. Similarly, the code reading within the delivery truck 4513 could be eliminated in favor of the above described on-dock confirmation process, but, reloading of any wrongly unloaded goods would be required. Upon confirmation of the delivery by the dock worker, a verified invoice is automatically generated by the radio terminal 4515 and routed to the inventory computer 4511 for inventory and billing purposes. In addition, the verified invoice is routed to the warehouse 4519. Such routing may occur as soon as the delivery truck returns to the warehouse 4519. However, to accommodate rerouting in situations where goods have been turned away at the retail store, the radio terminal 4515 communicates the final invoice immediately to the warehouse 4519. The warehouse 4519, upon receiving the final invoice, checks the final invoice with the list of goods loaded in the delivery truck 4513, and determines whether delivery of the remaining goods is possible. If so, the warehouse 4519 reroutes the truck 4513 to the next delivery site. The communication of the final invoice and the rerouting information between the warehouse 4519 and the terminal 4515 may utilize a low cost communication pathway through the telephone link in the premises network of the retail store. In particular, the pathway for such communication utilizes the access point 4517, backbone LAN 4501, inventory computer 4511 and modem 4521. Alternately, the communication pathway might also utilize the WAN directly from the radio terminal 4515 to the warehouse 4519 via the antenna tower 4523. Moreover, the antenna tower 4523 is merely representative of a backbone network for the WAN. Depending on the specific WAN used, the tower 4523 may actually comprise a plurality of towers using microwave links to span the distance between the retail premises and the warehouse 4519. Similarly, satellite relaying of the communications might also be used. FIGS. 46a-b illustrate a further embodiment of the communication system of the present invention which illustrate the use of access servers that support local processing and provide both data and program migration. Specifically, as with the previous figures, FIG. 46a illustrates a wireless and hardwired communication network which uses a spanning tree protocol to provide ubiquitous coverage throughout a premises. For example, if any network device, e.g., an end-point device such as a wireless, hand-held computer terminal 4601, desires to communicate with another network device, e.g., a hardwired computer 4603, a routing request is constructed which specifically identifies the destination device. After construction, the routing request is transmitted through a spanning tree pathway to the destination device. In particular, the terminal 4601 formulates a routing request identifying the computer 4603. The routing request may also contain, for example, a message or data to be delivered or a request for data or program code. The terminal 4601 transmits the routing request downstream (toward the root of the spanning tree) to an access device 4605. The access device 4605 examines its spanning tree routing table entries, attempting to locate an upstream path to the destination device identified by the request. Because no entry exists, the access device 4605 transmits the routing request downstream to an access device 4607. After finding no routing table entry, the access device 4607 routes the request to a root access device 4609. Finding no routing table entry for the computer 4603, the access device 4609 transmits the routing request onto a wired LAN 4610. Using its routing table which has an entry for the computer 4603, a root access device 4611 fields the routing request and transmits the request upstream to an access device 4613. Likewise, the access device 4613, having an entry, sends the routing request to an access device 4617. Upon receipt, the access device 4617 forwards the routing request to the computer 4603. When a network device, an end-point device for example, has a need for remotely stored program code (i.e., program objects) or data (i.e., data objects) such as a schematic diagram, delivery address or repair manual, the end-point device formulates a code or data request and sends it in a downstream spanning tree pathway. Unlike a routing request, data and code requests do not have a specific destination designated. Instead, data/code requests (data requests and/or code request) only identify the specific data or code needed. This is because the requesting device need not know the destination of the data or code needed, promoting dynamic, spanning tree migration—as will become apparent below. In addition, where possible, program code will be reduced to an interpretive form. Common libraries of program objects (in an object code form, i.e., executable form) are stored at each network terminal, computer or access server. Upon any request for an application program, for example, first, the sequence of calls to each program object is delivered along with a list of all program objects that are needed to fully execute the application program. Thereafter, if the specific underlying code for any of the delivered objects is not found locally, a renewed request for the executable code for those program objects is made. Upon delivery, the application program may be executed. Moreover, the movement of the program application and other specific program objects are tracked and migrated as described above in relation to generic data. For example, the terminal 4667 typically operates using an application program directed to an exemplary installation and service industry. A driver of a vehicle 4666 enters the premises via a dock. Upon establishing a link with the network, the terminal 4667 reports its status. In response, the terminal 4667 receives a command to load a docking application from the computer 4652 via the premises network. After determining that it does not have the docking application stored locally, the terminal 4667 transmits a program code request specifying the application. Because of previous activity, for example, the access device 4659 (which receives the transmission) happens to have the program code stored locally. It fields the request, sending the list of program objects along with the “interpretive” program object sequence. Upon receipt, the terminal 4667 might identify that all program object executable code is stored locally, and, therefore, begins to execute the application program. Otherwise, if certain program object executable is not locally stored, the terminal 4667 transmits a subsequent request. This time, the access device 4659 might not currently store the executable program object code. Thus, the access server 4659 routes the request downstream toward a device which does store the code. Once located, the code is delivered upstream to the terminal 4667 for execution. Requested data or program code may reside in one or more of those of the access devices 4605, 4607, 4609, 4611, 4613, 4615, 4617, 4619 and 4621 which happen to be configured as access servers. Otherwise, the data or code may be residing in one or more of the computers 4603, 4621, 4623 or 4625, if they are configured as servers. For example, assuming that the access device 4619 has been configured as an access server and happens to store data needed by the terminal 4601, the terminal 4601 would begin the process of retrieving the data by formulating a data request. As previously mentioned, the data request does not identify the access device 4619, but only identifies the needed data. After formulation, the terminal 4601 routes the request downstream to the access device 4605. Upon receipt, the access device 4605 determines that it does not store the requested data, and fails to identify the requested data in a routing table entry. Thus, the access device 4605 forwards the data request to the access device 4607. As with device 4605, the access device 4607 cannot identify the requested data and routes the request to the access device 4609. Upon receipt, the access device 4609 consults its routing table and identifies an entry for the requested data. The entry lists the next device in an upstream path to the data, i.e., the access device 4619 is listed. Thus, the access device 4609 forwards the data request upstream to the access device 4619. The access device 4619 responds to the data request by: 1) locating the stored data; 2) formulating a routing request (containing the data) destined for the requesting device, the terminal 4601; and 3) sending the routing request downstream to the access device 4609. Using its routing table, the access device 4609 identifies the terminal 4601, and sends the routing request (with attached data) upstream to the access device 4607. Likewise, the access device 4607 sends the routing request upstream to the access device 4605. Finally, the access device 4607 sends the routing request to the destination, the terminal 4601, completing the process. Program code (e.g., program objects) may be similarly stored, requested and delivered. Similarly, when remote processing is required, a network device formulates a processing request which identifies the specific remote processing needed, yet need not identify a processing destination. After formulation, the processing request is transmitted downstream toward an access server or computer server capable of performing the requested processing. For example, the access device 4617 fields processing requests from the computer 4603. After determining that it cannot perform the processing, the access device 4617 consults its spanning tree routing table, yet finds no upstream entry for any network device capable of performing the processing. Thus, the access device 4617 routes the processing request downstream to the access server 4613. Although the access device 4613 has not been configured for such processing, the access device 4613 does find an entry identifying a first network device, the access device 4615, in an upstream pathway to a location where such processing is handled. The access device 4613 forwards the processing request to the access device 4615 which is configured as an access server to handle the processing. Thereafter, the requested processing is carried out by the access device 4615, with any associated intercommunication with the computer 4603 needed via the same pathway using routing requests. Thus, each spanning tree routing table not only includes entries for all upstream network devices, each also includes entries for all upstream data, program code and processing resources. Moreover, each such entry only identifies the next network device through which forwarded requests are to made in the pathway to the request destination. Each spanning tree table also contains an entry designating a downstream route for use when no upstream entry can be located. In the communication network of the present invention, program code, data and local processing capabilities dynamically migrate through the network to optimize network performance. Specifically, each of the access devices 4605, 4607, 4609, 4611, 4613, 4615, 4617, 4619 and 4621 is configured as an access server. However, a specific data object in high demand is not initially stored in any of the access devices. Instead, the data object in high demand is originally stored on the computer 4623, configured as a server. Upon encountering a first data request by the terminal 4601 for the data object in high demand, each of the intermediate access servers, the access devices 4605, 4607 and 4609, fail to identify the data object which results in the sequential forwarding of the data request to the computer 4623. However, each of the intermediate access servers record entries for the data in their routing tables with a downstream destination. Thereafter, each time that a network device, such as the terminal 4601, requests the data object, the intermediate access servers which receive the request bump up a count stored in the routing table entry. To make a determination of whether to migrate the data object or not, upon encountering a data request, each intermediate access server considers: 1) the associated count entry; 2) the duration of time over which the count entry has accumulated; 3) the cost of retrieving the data from the downstream source; 4) the size of the data object; and 5) its own resource availability (e.g., remaining storage space). For example, after receiving a high number of recent requests for the data object and having a relatively high cost in extracting the downstream object, the access device 4605 determines that migration of a copy of the data object into its own available storage could improve network performance. Thus, instead of sending the data request downstream to the access device 4607, the access device 4605 substitutes and forwards a migration request instead of the data request. Upon receiving the migration request, the remaining intermediate access servers, the access devices 4607 and 4609 merely forward the migration request to the computer 4623. In response, the computer 4623 records the migration event, i.e., the data object migrated and the migration destination (the access device 4605), for future updating control. The computer 4623 also forwards a copy of the data object to the access device 4609 for relaying to the access device 4605 via the access device 4607. Upon receipt, the access device 4605 stores the data object locally, and forwards a further copy back to the requesting network device, the terminal 4601. Thereafter, instead of relaying each data request for that data object downstream, the access device 4605 responds by sending a copy of the locally stored data object toward the requesting device. In other words, the access device 4605 has effectively intercepted a copy of the data for local storage, and, thereafter, forwards a copy of the locally stored copy to service any incoming requests. In addition, upon forwarding the data object from the source, the computer 4623, to the destination, the terminal 4601, the data object size and link cost associated with reaching a given intermediate access device is recorded. For example, if a wired communication link between the computer 4623 and the access device 4609 is assigned a cost of “1”, after fielding the data request, the computer 4623 constructs a data response which not only includes the requested data object, but also includes a link cost entry of “1” and an indication of the data object size. In turn, the access device 4609 identifies the cost to the access device 4607, for example a cost of “3”, the access device adds the “1” to the pending cost entry in the data response, and forwards the response to the access device 4607. Similarly, the access device 4607 assesses a cost of “1” for the communication link to the access device 4605, adds the “3” to the pending cost entry of “4”, and forwards the data response to the access device 4605. After assessing a cost for the link to the terminal 4601, for example a cost of “4”, the data response is delivered to the terminal 4601. Thus, the terminal 4601 sees that to access the data again, it will most likely result in “1” units of communication cost. Moreover, for example, the terminal 4607 considers the cost of “3” when determining whether to migrate the data object or not. Similarly, when a migration of a data object occurs, is all intermediate access devices record the cost of the upstream link to the copy of the data object. Thereafter, upon receiving a data request for the data object, an intermediate access device can compare the cost of the upstream pathway to the copy with the downstream pathway to the original data object to choose the pathway with the lesser cost. A notification of deletion of a copy of a data object destined for a downstream source is also noted by each intermediate access devices, requiring deletions of the entries for the “copied then deleted” data object. For example, if a locally stored copy of the data fails to be used for a period of time determined by the access device 4605 to be too long to justify local storage (in view of the communication link costs back to the original source, the size of the data object, and potentially dwindling local resources), the access device 4605 deletes the locally stored copy of the data, and routes to the computer 4623 an indication that the local copy of the data object has been deleted. Upon receiving the indication for relaying, the intermediate access devices 4607 and 4609, in turn, remove from their routing tables the entries to the recently deleted upstream copy. Upon receipt of the indication, the computer 4623 records the deletion, completing the purging process. Although data objects were used above to describe the migration process, program code (or program objects) are similarly migrated to and deleted from local storage. In addition, to prevent instability, a certain amount of hysteresis must be built in to prevent vacillating migration and purging decisions. In assigning cost units to the various communication links, comparisons between factors such as actual monetary costs, bandwidths, delays, loading and power consumption are taken into consideration. Moreover, such costs are stored as sub-entries in the spanning tree routing tables. Although only migration of a copy from a source to a single destination was previously described, if a data or program object proves to be in high enough demand, several, or even all, access devices in the network might store a copy. All that is required is that each access device experience a significant and sustained quantity of requests for a common data object (or program code/object) to justify the storage of a local copy in view of communication link costs and available local resources. Processing resources are similarly migrated and purged. To service a processing request, an access device must be configured not only with sufficient hardware resources but must also store the programming code and associated data necessary to perform the requested processing. For example, if the terminal 4601 desires to search prior sales information but can store neither the information nor the necessary search program routines because of limited local resources, the terminal 4601 formulates a processing request which it routes downstream to the access device 4605. In the illustrated embodiment, the access device 4609 is originally configured with the hardware and software necessary to perform the processing request. In particular, the access device 4609 uses bulk storage devices to store past sales data, and executes a search program in response to received processing requests. Although the intermediate access server 4607 is configured with appropriate processing and storage resources, originally, it does not store the search program or the past sales data. Thus, while receiving repeated processing requests from the terminal 4601 via the intermediate access device 4605, the access device 4607 initially logs the request in its routing table and forwards the request downstream to the access device 4609 which fields, processes and responds to the requests. Because the frequency of the requests, costs and available local resources, when not busy, the access device 4607 sends a migration inquiry downstream to the access device 4609. Upon receipt, the access device 4609 responds by sending an indication of the volume of the potential transfer upstream, to the access device 4607. Based on the indication along with the aforementioned other migration factors, the access device 4607 may or may not pursue the migration. If migration is chosen, the access device 4607 assembles a migration request identifying the desired processing, and routes the request downstream to the access device 4609. In response, the access device 4609, records the migration (for future updating) and begins to transfer a copy of the program (or programming object(s)) and the past sales information to the access device 4607, preferably occurs during periods of low network traffic. Although intermediate access devices between the source and destination of the processing migration are not shown in the exemplary illustration above, any intermediate access devices that do occur follow the same procedures previously set forth in reference to data object migration, recording and purging routing table entries to upstream and downstream processing devices. As may be appreciated in view of the foregoing, in many instances, migration does not always flow immediately to the access device nearest a requesting network device. Instead, for example, an access device which receives the same data or program code requests from a plurality of different terminals will perform migration before any upstream access device unless upstream link costs are comparatively much higher. FIG. 46b is a diagram which further illustrates the migration and purging process. In particular, a premises network consists of computers 4651 and 4652—configured as servers, a wired LAN 4653, and access devices 4655, 4657, 4659, 4661 and 4663—configured as access servers. A portable computer terminal 4664 participates in the premises network which exhibits migration and purging as described above in reference to FIG. 46a. In addition, a vehicular network is shown which consists of a mobile access server 4665 and a portable computer terminal 4667. As illustrated, each of the access devices 4655 and 4659 are configured for long distance, wireless communication with the access server 4665 via a second higher power radio and associated antenna, e.g., WAN, paging, cellular, etc. The corresponding first radio and associated antenna are used for relatively lower power premises network communication. Because of the much higher cost associated with the communication link between the access server 4665 and the access device 4659, the access servers 4.665 is much more likely to engage in the dynamic migration of data/code objects or processing resources than the other access servers located within the premises network. With a link cost assessed at “20” for example, the mobile access server 4665 rapidly decides to migrate, while slowly deciding to purge migrated data. The migration/purging process used is the same as that described above in reference to the premises network of FIG. 46a. In addition, because of the high link cost, the mobile access server 4665 is also configured to provide anticipatory migration, and responds to direct migration commands from the terminal 4667 or other controlling network devices. Specifically, anticipatory migration may occur in two ways. First, if a driver is preparing to leave the premises to service a specific appliance, for example, the schematic diagram of the appliance may be migrated to the mobile access server 4665 in anticipation of future use. This form of anticipatory migration may be directed from a controlling device downstream in the premises network, e.g., the computer 4652 which also stores the schematic diagram, from the terminal 4667 upstream, or from the access server 4665 itself upon analysis of the work order. A second form of anticipatory migration originates at the access server 4665 (although the resulting migration control could originate either up or downstream). The access server 4665 anticipates future migration needs through the storage and analysis of previous requests for data/code objects or processing resources. For example, if the access server 4665 determines that nearly every time the terminal 4667 requests a given program code or program object, the terminal 4667 follows that request a short time thereafter with further requests for specific data objects. In such circumstances, instead of repeatedly initiating, requesting and delivering portions of data over the communication the higher cost link, the requested and anticipated requests are all handled in one communication session, saving money and time. Similarly, the terminal 4667, through program design or through request monitoring, can also participate in anticipatory migration. For example, the terminal 4667 can be programmed to make all upcoming requests at one time, and often in advance of leaving the low power radio range of the premises network. The terminal 4667 can also be specifically programmed to issue direct migration and purging commands to the access server 4665, permitting further control of the migration process and system resources of the mobile access server 4665. Moreover, the terminal 4667 may be configured to historically monitor all requests so as to anticipate subsequent requests in the manner described above in reference to the access server 4665. In addition, the terminals 4664 and 4667 are configured to receive keyed, voice and pen input. Other types of input such as video or thumbprint image capture might also be added. The terminals 4664 and 4667 can also be configured with code reading/image capturing devices, or be configured to receive input from external code reading/image capturing devices (via tethering or low power wireless links). Each terminal also provides voice and LCD (liquid crystal display) output for the user. Thus, it can be appreciated that there are many types of data to be delivered to and from the terminals 4664 and 4667. The data may take on the forms of keyed or penned in command information, penned images or signatures, captured images of 2-D codes, signatures, etc. and voice signals, for example. Each type of data handled by the terminals 4664 and 4667 places specific requirements on the communication network. For example, when communicating voice information, a communication channel or link providing acceptable real time voice delivery may be required. Dedicated bandwidth may be reserved for such communications through the spanning tree network illustrated, or established via a cellular link with the access device 4655. Moreover, if the network conditions are favorable, dedicated bandwidth need not be provided at all (see, e.g., discussion regarding FIG. 55 below). Cellular radios may be built into the terminals 4664 and 4667 (via PCMCIA slots, for example) or via tethered cellular phones. Similarly, an access device can be configured with a cellular radio to provided cellular service to mobile terminal devices via either dedicated or time-shared wireless bandwidth through the spanning tree, for example. If postprocessed signature images require at most a delayed delivery of a plurality of such images over inexpensive and possibly slower or less convenient communication links. Alternately, such images may be delivered as a background task when network communication or channel traffic is low. Further, relatively small packages of one way communication to the terminal 4667 may travel through a lower cost paging network for delivery. They may also travel through the spanning tree network, cellular networks, or through other higher cost, two way WANs. Because programs cannot always anticipate all of the available communication channels through which the different types of data may flow (availability which not only changes from one network installation to another, but also changes within a given installation due to terminal and device configurations and their locations within the network), the routing tables within each network device subdivide routing information based on the type of data to be forwarded. For example, in an oversimplification of the process described in more detail below in reference to FIG. 55a, the access device 4665 receives a communication from the terminal 4667. The communication takes the form of a requested link for voice signal data destined for the computer 4651. In response, the access device 4665 consults its routing table, determines that voice data can take one of two pathways: through either a cellular radio or WAN route to the access device 4655. In response, the access device 4665 delivers the communication route options to the terminal 4667 for user and/or software consideration. If the request is not aborted and the cellular route is selected, the access device 4665 establishes a cellular link with the access device 4655, and requests a voice session with the computer 4651. In response, the access point 4655 consults its routing table, and, for voice data to the computer 4651, it identifies the need to use the wired LAN 4653 to communicate with the computer 4651. In addition, the access point 4655 also determines whether dedicated bandwidth is needed (based on timing considerations), or whether packet based time-shared voice data delivery is sufficient. Either way, the access device 4655 responds by placing the request on the wired LAN 4653. In response, the computer 4651 communicates an acknowledge message which is routed through the access device 4655 to the access device 4665. The access device 4665 delivers the acknowledge message to the terminal 4667. At that point, the terminal 4667 begins sending the voice data to the computer 4651 through the designated route. If the cellular link to the access device 4655 is in use or the end-to-end link otherwise proves unavailable, the access device 4665 reports the status, again offering the remaining communication route via the WAN. If selected, the access device 4665 establishes the pathway to the access device 4659 via WAN communications. In turn, the pathway is established through the access device 4657, access device 4655 and the computer 4653. With a returned acknowledge from the computer 4653, the terminal 4667 begins voice communication. Similarly, a communication pathway between any other two network devices, such as from the computer 4651 to the terminal 4664, can be established. For example, if the computer 4651 desires the user of the terminal 4664 to obtain and compare a penned signature image for comparison with an authenticated signature stored at the computer 4651, the computer 4651 first attempts to communicate the request and image data to the terminal 4664 via the premises network. If the terminal 4664 happens to be out of range of the premises network, the computer 4651 attempts to page the terminal 4664 with the comparison request. In response, the terminal 4664 considers the data type via its routing table, identifies the route(s) available, and offers the route options to the user and/or program at the terminal 4664. If selected, the terminal 4664 establishes the selected communication link for the delivery of the associated comparison image. Moreover, because of the high cost associated with the communication link from the access device 4665 to the premises network, the access device 4665 stores several types of lower priority data until such time or data storage size justifies delivery. Such deliver may not occur until the vehicle returns to the premises network, e.g., to a dock at the premises. In addition, requests for communication may also include specific limitations. For example, the need for voice data only in real time full-duplex (i.e., two-way) mode can be specified, and will result in no consideration by any intermediate network device of other half-duplex or pseudo real time link options. Lowest cost delayed delivery can alternatively be specified if delivery speed is not an issue. Requests specifying high priority result in the selection of the fastest communication link regardless of cost. Moreover, the terminals 4664 and 4667 can be configured to operate running application software under the DOS, Windows or OS/2 operating system environments. Communication between the terminal 4667 and the access device 4665 occurs via an infrared link if the terminal 4667 is docked within the vehicle. Routing tables within the access device 4665 and terminal 4667 both contain dual entries for communication exchange pathways. First, the infrared link is attempted, if available. Otherwise, a lower power RF communication transmission is used. Although a wired docking arrangement might be used instead of infrared, infrared is preferred inside the vehicle for ease of installation and to minimize wire clutter. Such infrared installations also provide support for communicating with printers, scanners and other peripheral devices within the vehicle, i.e., the vehicular LAN preferably operates via infrared except when communicating with a remotely located terminal 4667 or with other remotely located network devices. In another embodiment illustrated by FIG. 46b, service personnel use the vehicle 4666 for visiting customer sites. At the site, the terminal .4667 is carried within the customer's premises. Ordinarily, communication with the premises network would take place via relatively low power radio transmissions between the terminal 4667 and the access device 4665. However, communication can be achieved via a telephone jack link at the customer site, if: 1) the customer site blocks such transmissions; 2) the transmission range is exceeded; or 3) link costs or channel speed so justify. Once plugged into the telephone jack, the terminal 4667 automatically activates inactive routing table entries (by setting a flag therein) corresponding to possible telephone jack links. Thereafter, communication attempts to either the vehicular or premises LAN will offer routes via the customer's telephone jack link. FIG. 47a is a flow diagram which more specifically illustrates the functionality of the access servers of FIGS. 46a-b in handling data, processing and routing requests. At a block 4701, an access server awaits incoming communications which take the form of several types of previously mentioned requests such as data, object, processing, migration and routing requests. In addition at the block 4701, the access server awaits the need to perform migration evaluation and processing, i.e., a time out period to lapse which occurs once every fifteen (15) minutes. This period may be modified (lengthened or shortened) as proves necessary depending on channel loading conditions. Upon receiving a routing request as indicated at the event block 4703, the access server accesses its routing table, at a block 4705, in an attempt to identify the destination of the routing request in an upstream path. If the destination is identified, the access server forwards the routing request to the next network device in the upstream path toward the destination, at a block 4707. Otherwise, if the destination is not identified in the routing table at the block 4705, at the block 4707 the access server transmits the routing request to the next network device in the downstream path. Thereafter, the access server returns to the block 4701 to await another event. At the block 4701, upon receiving and logging a migration request, the access server vectors from an associated event block 4709 to determine whether it stores the requested migration information (e.g., the requested code or data or the program code and/or data associated with a processing resource migration request) locally or not at a block 4711. If not, the access point branches to the block 4705 to identify the closest (or any) network device in the spanning tree pathway. For example, if the routing table carries no entries for the migration information, the access server routes the migration request to the next downstream network device. Otherwise, if the routing table carries only an upstream or a downstream entry, the access server routes the request as specified by the routing table. However, if more than one entry exists for the requested migration information, the access server routes the migration request along the lowest cost spanning tree pathway (as indicated in the routing table). However, if, at the block 4711, the access server determines that it stores the migration information locally, the access server: 1) retrieves the migration information and records the migration event for update control, at a block 4713; 2) accesses its routing table to identify the forwarding pathway, at the block 4705; 3) forwards the retrieved migration information, at the block 4707; and 4) returns to the block 4701 to await another event. After receiving and logging (counting the occurrence of) a processing request at the block 4701, the access server branches via an event block 4715 to determine whether the requested processing can be performed locally or not at a block 4717. If not, the access server forwards the processing request at the block 4707 per routing table instruction at the block 4705. Afterwards, the access server returns to await another event at the block 4701. However, if the access server determines that it can perform the requested processing at the block 4717, the access server performs the processing at a block 4719, generates a response at a block 4721, routes the response back to the requesting network device at the block 4707 per routing table instruction at the block 4705, and, finally, returns to the block 4701 to await another event. Upon receiving and logging a data or code request at the block 4701, the access server vectors via an event block 4723 to determine whether the requested data or code is stored locally at a block 4725. If so, the access server branches to a block 4727 to retrieve the data or code from storage. Thereafter, the data or code is forwarded at the block 4707 per routing table instruction at the block 4705. Once forwarded, the access server branches to the block 4701 to await another event. At the block 4725, if the access server determines that the requested data or code is not stored locally, the access server considers whether it should migrate the data at a block 4729. The access server analyzes the overall link cost, the size of the requested data or code, the frequency of such requests, available local storage resources (some of which it may determine to recapture by purging other locally stored data, code or processing resources). Specifically, if sufficient local resources are (or can be made) available, the access server determines the weighted average frequency of the requests for that data or code. The frequency is then multiplied by a predetermined fraction (50%) of the overall link cost for retrieving the data or object to the access server from the current source. The resulting number is then compared to a migration threshold number, for example “10”. If, at the block 4729, the access server determines that the threshold number is greater than the resulting number, the access server, deciding not to migrate, branches to route the data/code request per routing table instruction at the blocks 4705 and 4707. Alternatively, if the access server determines that the threshold number is equal or less than the resulting number at the block 4729, the access server decides to migrate. Thus, at a block 4731, the access server creates and sends a migration request (instead of merely forwarding the data/code request) and awaits delivery of the requested code or data. Upon receipt, at a block 4733, the access server stores the data or code. Thereafter, the data/code is retrieved at the block 4727 for routing to the requesting network device via the blocks 4705 and 4707. Once routing is complete, the access server again returns to the block 4701 to await another event. Finally, upon receiving a time out event signifying the periodic need to perform migration evaluation and processing, the access server branches to execute migration procedures at a block 4737, as described in more detail below. FIG. 47b is a flow diagram utilized by the access servers of FIGS. 46a-b to manage the migration of data and program code from a source storage and/or processing device toward an end-point device. More specifically, the exemplary flow diagram illustrates the migration and purging procedures represented by the block 4737 of FIG. 47a. Upon encountering a timeout event (occurring every 15 minutes), an access server begins the illustrated procedure of FIG. 47b. At a block 4751, the access server retrieves a data/code entry from its routing table for which it provides local storage. At a block 4753, the current count recorded (indicating the number of requests for that data/code entry during the current time out interval) is multiplied by two thirds (⅔) and added to one third (⅓) the value of the previously recorded weighted frequency. The access server records the result as the new weighted frequency in the routing table entry. This weighting of frequency constitutes “aging” of the data/code routing table entry. At a block 4755, fifty percent (50%) of the overall cost of the link, i.e., from the access server to another source of the locally stored data/code, is multiplied by the newly recorded weighted frequency. The access server compares the results of the multiplication with a hysteresis threshold at a block 4757. The hysteresis threshold is also referred to herein as a purging threshold. In premises network locations, for example, the hysteresis threshold is set at five (5) units below the migration threshold of the block 4729 in FIG. 47a. However, the migration and hysteresis thresholds may need be modified in alternate network embodiments, such as may be found in vehicular network installations. If the hysteresis threshold is exceeded, the access server determines that it should continue to store the data/code, and branches to a block 4759 to determine whether there are any remaining entries for locally stored data/code which have not yet been considered for purging. Alternatively, if the hysteresis threshold is not exceeded, the access server determines that the data/code item should be purged, and does so at a block 4761. Thereafter, the access server branches to the block 4759. If, at the block 4759, other data/code items which have not yet been considered for purging, the access server repeats the purging consideration of the blocks 4751 through 4759 until all locally stored data/code items have been considered. At that point, the access server branches to block 4763 to begin migration and purging consideration of processing resources. First, the access server retrieves a routing table entry relating to processing resources, i.e., supporting program code and any associated data. At a block 4765, the access server ages the entry, i.e., performs the aforementioned weighted frequency averaging. Thereafter, fifty percent (50%) of the overall link cost is multiplied with the new weighted frequency at a block 4767. If the entry indicates local storage of the processing resources at a block 4769, the access server compares the results with the hysteresis threshold at a block 4771. If above the hysteresis threshold, the access server continues to store the processing resources, branching to consider any remaining processing resource entries at a block 4775. Otherwise, the access server purges the stored resources at a block 4773 before considering any remaining entries at the block 4775. Alternately, if the routing table entry indicates that the processing resources are not stored locally, at a block 4777, the access server determines whether it has been configured with the hardware necessary to perform the processing. If not, the access server branches to the block 4775 to consider other entries. Otherwise, at a block 4779, the access server compares the migration threshold with the result, i.e., 50% of the link cost multiplied by the new weighted frequency. If the result does not exceed the migration threshold, the access server branches to the block 4775 to consider other entries. If the result exceeds the migration threshold, the access server formulates and routes a migration request for the processing resources, awaits the responsive delivery and stores the resources locally at a block 4781, before branching to the block 4775. At the block 4775, if the access server determines that other processing resource entries have not been considered for purging or migration, it repeatedly branches back to the block 4763 to carry out the consideration cycle until complete. Thereafter, the migration/purging procedure ends, and the access point returns to the block 4701 of FIG. 47a to await the occurrence of another event. FIG. 48 is a schematic diagram of the access servers of FIGS. 46a-b illustrating an exemplary circuit layout which supports the functionality described in reference to FIGS. 47a-b. In particular, a typical access server, an access server 4801, is configured with transceiver circuitry 4803 and associated antenna 4805 for participating in the premises, peripheral and/or wide area networks. In addition, another transceiver, a transceiver circuit 4807, and associated antenna 4809 might be added, for example, to support WAN or cellular communications. Although not shown, interface circuitry for other wireless or wired communication links may be included in the access server configuration when needed. Processing circuitry 4811 provides at least three processing functions for the access server by managing or performing: 1) communication processing functionality; 2) migration and purging; and 3) local resource processing. Although in most embodiments, the processing circuitry 4811 comprises a single microprocessor, it may comprise several. Moreover, if the processing circuitry 4811 is not configured to perform migration and local resource processing, the illustrated access device operates as an access point. The processing circuitry 4811 utilizes a memory 4813 for short term and long term bulk storage. The memory 4813 comprises hard drive storage, dynamic RAM (random access memory), flash memory, and ROM (read only memory). However, all other types of memory circuits or devices might alternately be used. Specific hardware configurations needed to accommodate specialized processing requests are represented by a circuit/device block 4815. However, such hardware need not be present to service relatively basic processing requests. Additionally, access servers may either be battery powered although, if the network configuration permits, AC (alternating current) power is preferred. FIG. 49a is a specific exemplary embodiment of an access server in a multi-hop communication network utilized for remote processing of 1-D (one dimensional) or 2-D (two-dimensional) code information. In this embodiment, a code reader 4901 is used to capture and transmit code information for further processing, including decoding, by a remote access server in a premises LAN. Specifically, a user brings the code reader 4901, which preferably is a CCD (charged coupled device) type reader, into a reading relationship with a 2-D code 4903 located on a container 4905. Light reflected from the code 4903 is received by the code reader 4901 and directed onto the CCD located within the reader to “capture” the code image. To enable the CCD to operate properly, however, it may first be necessary for the reader to focus the image on the CCD. Such focusing can, for example, be performed by conventional techniques known in the camera art. As another example, one or more spotter beams are presently used to ensure that the user is holding the reader the proper distance from the code to enable the CCD to properly capture the image. Once captured, the code image may then be digitized within the reader to create a digital signal representative of the code image, which is then transferred, via RF transmissions, to other network devices for further processing. Alternatively, the reader 4901 may transmit a modulated analog signal representative of the code image to other network devices for further processing. In any event, the code reader 4901, an end-point device, forwards the code image signal downstream in the premises LAN to the first access server in the network that has the capability of decoding the signal into the usable information represented by the code 4903. As discussed above, any one or all of the access devices 4907-4913 may be an access server and contain the digital signal processing circuitry necessary to decode the code image signal. For example, the network may be designed such that the access device 4907 is an access server which performs decoding for all code readers, such as the code reader 4901, being used in a designated area. If, however, the access device 4907 is merely an access point, or is an access server but does not have decoding capability, then the access device 4907 relays the code image signal downstream. More specifically, and as discussed more completely above, the code reader 4901 sends a processing request downstream to the access device 4907. If the access device 4907 is an access point, the processing request is simply relayed downstream to the access device 4909. If the access device 4907 is an access server, it looks up in its table to determine whether it has the capability to perform the type of processing requested, i.e., decoding. If it does, the access device 4907 sends an acknowledge and the code reader 4901 forwards the code image signal to the access device 4907 for decoding. Once decoded, the information may be re-transmitted to the code reader 4901 for display on a screen (not shown). In addition, or alternatively, the access device 4907 may send a good read signal to the code reader 4901 to indicate to the user that the reading operation has resulted in a valid reading. The decoded information may also be transmitted to a host computer 4915 or other network device for further processing. If the access device 4907 does not find decode capability listed in its table, it forwards the processing request downstream to access device 4909. Likewise, if access device 4909 is an access point or an access server without decode capability, the processing request is forwarded downstream to the access device 4913. Once access device 4913 receives the processing request, it also examines its table to determine whether it, or any device upstream of it (such as, for example, access device 4911), has the capability to service the processing request. If it does locate such capability, it sends an acknowledge upstream to the code reader 4901 which forwards the code image signal to the access device 4913 for decoding thereby or for routing to the upstream access device having that capability. If the access device 4913 does not locate decode capability in its table, it forwards the processing request to host computer 4915 for decoding thereby or so that the host computer 4915 can locate a device having the capability to service the processing request. Of course, as mentioned above, the network could be configured such that each one of the access devices 4907-4913 is an access server having the circuitry necessary for decoding. While a CCD type code reader is preferred with respect to the embodiment of FIG. 49a, other types of code readers, including laser scanners, are also contemplated. Furthermore, while the above description places the decoding circuitry in a device external to the code reader 4901, the code reader 4901 may house such decoding circuitry and may transmit decoded data to external network devices for further processing. However, there are many advantages to placing the decoding circuitry external to the code reader 4901. For example, because the code reader is a portable device and likely battery-powered, power conservation as well as reader size and weight become important design considerations. By placing the decoding circuitry in a device external to the reader 4901, the reader uses less power and may be smaller and lighter than if the decode circuitry is placed in the code reader 4901. Further, in an environment where numerous code readers are used, placing the decode circuitry in one or a few external devices rather than all readers, which are often dropped by users, reduces the chances that the decode circuitry will be damaged. In addition, such a configuration reduces the amount of circuitry used and consequently results- in lower reader manufacturing costs. In addition, the code reader 4929 is configured to collect signature, printed text and handwriting images for further processing. Although further processing can be performed onboard within the reader 4929, in one embodiment it occurs within an access server. Either way, such processing first involves the identification of the type of information contained within the image. If the user does not simplify the process by identifying the type of image captured, automatic identification is invoked. This occurs by first attempting to identify the image as a 2-D code. If this fails, the processing involves an attempt at character recognition to identify any printed text that might exist within the image. If no text is found, an analysis is performed to determine whether the image is a handwritten signature. Finally, if all else fails, the image is generically classified as a picture. Several examples of pictures include: a) images of bakery shelf space in a given store for subsequent collection and evaluation of ones competition; b) images of broken equipment for transmission to remote experts for service advice; and c) images of metering or monitoring displays for billing or usage verification. After identification, each type of data receives yet further processing. Decoded 2-D code information is forwarded and acknowledged. Handwritten signatures are compared with known authentic counterparts. Other types of images may be associatively forwarded, stored, displayed and/or acknowledged. FIG. 49b is an alternate embodiment of FIG. 49a wherein communication between the 2-D code reader and the access devices takes the form of modulated infrared transmissions. Specifically, as discussed above with respect to FIG. 49a, a user uses a code reader 4917 to read a 2-D code 4919 on a container 4921. The user then points the code reader 4917 at an infrared transceiver 4923 of an access device 4925 and transmits a processing request to the access device 4925 using infrared transmissions. To facilitate receipt of the infrared transmissions by the infrared transceiver 4923, the reader may disperse its transmissions, say, for example, four inches over a distance of ten feet. Such dispersion allows a user to be less accurate in aiming the code reader 4917 at the infrared transceiver 4923. The infrared transceiver 4923 may be, for example, a phototransistor/photodiode pair. As above, if the access device 4925 is simply an access point, the processing request is simply relayed downstream, via either RF or infrared transmissions, to a further access device downstream. If the access device 4925 is an access server, it looks up in its table to determine whether it has the capability to perform the type of processing requested. If it does, the access device 4925 sends an acknowledge via infrared transmissions to the code reader 4917 and the code reader 4917 forwards the code image signal to the access device 4925 via infrared transmissions for decoding. The access device 4925 may then transmit the decoded information to the code reader 4917 for display on a screen and/or forward the decoded information to a host computer 4927 for further processing. If the access device 4925 does not find decode capability listed in its table, the access device 4925 forwards the processing request to one of the access devices 4924, 4926, or 4928 to locate such decoding capability similarly as discussed above with respect to FIG. 49a. When such a device is located, the code reader, via infrared transmissions, performs a batch forwarding of the stored image data to the access device 4925 for eventual decoding by one of the access devices 4924, 4926, or 4928 or by a host computer 4927 or another device in the premises LAN (i.e., whichever is the first device located that has the decoding capability). In this embodiment, communication between access devices may be achieved using either RF or infrared transmissions. Furthermore, a user may choose to directly communicate with any specific access device in the network simply by pointing the code reader 4917 at that device and transmitting a processing request. FIG. 49c is an alternate embodiment of FIG. 49a wherein indirect communication between the 2-D code reader and the access servers takes place via holstering or docking access servers. Specifically, as discussed above with respect to FIG. 49a, a user uses a code reader 4929 to read a 2-D code on container. The user then places the reader 4929 in a holster access device 4931. The user may support the holster access device 4931 by a shoulder strap 4933 and belt 4935 to facilitate portability. In one embodiment, the holster access device 4931 may be configured to perform decoding so that when the code reader 4929 is placed inside the holster access device 4931, the code reader 4929 may transmit the code image data to the holster access device 4931 for immediate decoding thereby. Alternatively, if the holster access device 4931 does not house the necessary decoding circuitry, the holster access device 4931 transmits a processing request downstream to one of access devices 4937-4943 to locate such decoding capability similarly as discussed above with respect to FIG. 49a. In a scenario where numerous codes 4945 are to be read successively by the code reader 4929, the code reader 4929 may store the read image data and perform a batch transmission to the holster access device 4931 for immediate decoding thereby if the holster access device 4931 is configured with decoding circuitry. In another embodiment where the holster access device 4931 is not so configured, the code reader 4929 transmits a processing request to the holster access device 4931 via infrared transmissions. The holster access device 4931 in turn forwards the processing request downstream via RF transmission to one of the access devices 4937-4943 to locate such decoding capability similarly as discussed above with respect to FIG. 49a. When such a device is located, the code reader, via the holster access device 4931, performs a batch forwarding of the read image data for eventual decoding by one of the access devices 4937-4943 or by a host computer 4947 or another device in the premises LAN (i.e., whichever is the first device located that has the capability). In an alternate embodiment, batch transmission of stored image data may be performed via a docking access server 4949. When a user has completed his code reading tasks, he docks the code reader 4929 in a bay 4951 of the docking access server 4949. Other users, when their tasks are completed, may similarly dock their code readers in other bays of the docking access server 4949. In one embodiment, similarly as discussed above with respect to the holster access device 4931, once a code reader is docked in the docking access server 4949, the code reader performs a batch transmission of its stored code image data to the docking access server 4949 for immediate decoding thereby if the docking access server 4949 is configured with decoding circuitry. In another embodiment where the docking access server 4949 is not so configured, the code reader 4929 transmits a processing request to the docking access server 4949 via infrared transmissions. The docking access server 4949 in turn forwards the processing request downstream via RF transmission to one of the access devices 4937-4943 to locate such decoding capability similarly as discussed above with respect to FIG. 49a. When such a device is located, the code reader, via the docking access server 4949, performs a batch forwarding of the stored image data for eventual decoding by one of the access devices 4937-4943 or by a host computer 4947 or another device in the premises LAN (i.e., whichever is the first device located that has the decoding capability). In the embodiments of FIGS. 49b or 49c wherein a number of codes are read and the captured image data is stored within the code reader for batch transmission at a later time, it may be desirable to configure the network such that decoding is performed first within the code reader. Specifically, when a user successively reads a plurality of codes, a user can ensure that each reading operation is successful or valid when the decoding is done immediately within the reader and the user is provided some sort of good read acknowledgment by the reader. On the other hand, if the image data is simply stored for later decoding by an off-site device, the user cannot be sure that each reading operation resulted in a valid read. Such a situation may not be a problem, however, if the code and reader are highly reliable or if simple information, such as a signature, is being read which may not require a validity determination. FIG. 50 is a schematic diagram similar to that shown in FIG. 48 which illustrates the circuit layout used in an access server of FIG. 49 to process the 2-D code information. Specifically, in an access point 5001, a processing circuitry 5003 manages 2-D code processing functionality as indicated by a block 5005. Although migration processing functionality is also present, in some embodiments such as those which use a single access server, the migration processing need not be present. In a memory 5007, the access point 5001 also stores a database of known 2-D images in an image database 5009. To further support 2-D code processing, digital signal processing circuitry 5011 has been added. As configured, the signal processing circuitry 5011 assists the exact decoding of 2-D images, and may also be used in the image comparison process of received 2-D images with the database 5009 of stored images. FIGS. 51a-b are flow diagrams illustrating the operation of the 2-D code processing access servers of FIGS. 49-50. In FIG. 51a, when the access server receives image data via its LAN transceiver, it first attempts at a block 5101 to exactly identify the code information from the received code image data. Specifically, the access server uses its code processing circuitry to perform an analysis of the received image data using a decoding algorithm specifically designed for decoding the type of code which was read. A number of 2-D code types exist, including, for example PDF-417, Maxicode, etc., which have specific corresponding decoding algorithms or rules. After its analysis is complete, the access server next determines whether the exact identification was successful at a block 5103. Determining whether an identification was successful often depends on the type of code used. If enough redundancy is built into the code, then the loss of a number of bits of data resulting, for example, from a partially blurred image may not be fatal to a successful exact identification. If, on the other hand, the type of 2-D code being read is less “tolerant,” then even the loss of a single bit might result in a failed exact identification. In any event, if the exact identification is successful, at a block 5105, the access server sends the identified code information to a predetermined destination for further processing, and acknowledges the successful identification. If the exact identification is not successful, however, the access point performs a further analysis of the image data to attempt to identify the corresponding code information. At blocks 5107 and 5109, the access server compares the received image to stored images located in its image database and attempts to locate the closest or best match. Although grey scale considerations and image-shifting correlation techniques are contemplated, in a relatively simple embodiment, such a comparison involves a process of scaling the received image to correspond to the stored images, then performing an “exclusive OR” of the received image with the stored images. More exact matches will yield an overall sum value nearer to zero. After the access point completes its comparison and has identified the closest or best match between the received image data and the stored images, the access point then determines at a block 5111 if the overall value resulting from the best match comparison is above a predetermined accuracy threshold. Such an accuracy threshold may vary depending on, again, the type of code that was read, and the level of importance associated with a good read. If the overall value is below the predetermined threshold, the access server, as above, sends the identified code information (corresponding to the best match stored image) at a block 5105 to a predetermined destination for further processing, and acknowledges the successful decode. If the overall value of the best match comparison is above the predetermined threshold, then, at a block 5113, the access server forwards a bad read or retry message to the code reader to indicate to the user to reread the code. FIG. 51b is similar to FIG. 51a except that the comparison of the received image with stored images is performed before any exact identification is attempted. Specifically, the access server first compares the received image to the stored images at a block 5115, identifies the closest match at a block 5117, and determines whether the overall value of the comparison is above a predetermined accuracy threshold at a block 5119. If the overall value is below the threshold, the code information relating to the best match stored image is simply forwarded at a block 5121 to a predetermined destination for further processing. If the overall value is below the threshold, then the access server attempts the exact identification and determines success at blocks 5123 and 5125. If such exact identification is successful, then the access device forwards the code information at block 5121. If it is not successful, the access device forwards a retry message to the code reader at block 5127. FIG. 52 illustrates the structuring of 2-D code information so as to support a hierarchical recognition strategy as used by the access server of FIGS. 49-50. In the image database of an access server, each known image is stored and hierarchically organized in sections. Each section of image contains information relating to a specific category of information. For example, as shown, images may include a main category followed by further and further subcategories. Thus, the image database stores all of the images in the main or first category at a top level in the hierarchy. Under each main category image, the image database stores only those subcategory images which coexist with the main category image on known complete 2-D code images. Similarly, under each subcategory image, the image database only stores sub-sub-category images which coexist with the main category image and the subcategory image. FIG. 53 is a diagram illustrating an exemplary 2-D code 5301 wherein the hierarchical structure of FIG. 52 is implemented. From left to right, top to bottom, the illustrated 2-D code provides image portions of categories separated by five bit line borders, such as a border 5303. As shown, the main category image represents “grocery”. The subcategory represents “beans”, and so on for the further subcategories. Using such a hierarchical categorization, the access server can more rapidly perform the process of image comparisons. For example, at a main category level in the hierarchy, a grocery image, an office supply image and general merchandize image might be the only three types of main category images known to the access point. If after comparing the received and the stored main categorization images, no acceptable match is found, the attempted comparison ends without ever having to compare the remainder of the potentially thousands of remaining images stored in the image database. Similarly, if a main level match is found with the stored office supply image, no comparison need be made with the plethora of remaining images under the grocery image main category. Further detail of the efficiency of such a hierarchical organization can be found below in reference to FIG. 54. In addition, although the 2-D code illustrated in FIG. 53 is not necessarily a current 2-D code standard, the principle of hierarchical organization can be utilized in current 2-D code standards to take advantage of the image comparison efficiencies involved. FIG. 54 is a flow diagram illustrating the functionality of the access server of FIGS. 49-50 in carrying out the hierarchical recognition strategy of FIGS. 52 and 53. The access server begins the hierarchical image comparison process, and, at a block 5401, extracts from the received 2-D image a first subcategory image portion, i.e., the main category image indicating “grocery” for example. At a block 5403, the access server compares the extracted image with each of the main category images stored in the image database. If the closest comparison fails to fall within an accuracy threshold at a block 5405, the access. server indicates that the comparison has failed at a block 5407, and ends the process. Otherwise, if the comparison is within the accuracy threshold at the block 5405, the comparison process continues with the access server checking to see if there are any further subcategories at a block 5409. Because other subcategories exist, the access point branches to repeat the process beginning at the block 5401. This time, the access server extracts from the received image the image portion relating to the first subcategory (beans) for comparison at the block 5403 with only those first known subcategory images having “grocery” as the main category. Again if no match within the threshold is found, the access point vectors to indicate failure at the block 5407, and terminates the process. However, if a subcategory match is found, the access point branches to handle the sub-sub-category in a similar way. If, at the block 5409 after successfully repeating the comparison a number of times, the access point concludes that there are no further subcategories to compare, the access point delivers the 2-D code information stored in the image database and associated with the matching stored image, and successfully ends the code identification process; The known image database is supplemented by exact decoding as illustrated for example in FIG. 51b, wherein any successful exact decode is used to provide both categorized image and information portions for subsequent decoding through comparison. In addition, although the hierarchical structuring described herein offers many advantages, it need not be implemented to carry out the comparison process. FIG. 55a is a diagram illustrating the overall flow of both data and voice through another embodiment of the hierarchical communication network of the present invention. Specifically, a premises network associated with a premises 5501 comprises a hardwired backbone LAN 5503 and a wireless network of access devices 5505, 5507, 5509, 5511 and 5513. While the backbone LAN 5503 preferably comprises a coaxial or twisted-pair ethernet link, it may alternately constitute, for example, a token ring, fiber optic, infrared, serial or parallel link. A variety of network devices also participate in the premises network. Computers 5515 and 5517, the access device 5505 and a telephone access device 5519 directly participate in the backbone LAN 5503. Mobile terminals 5521, 5522 and 5523 and stationary phone 5525 also participate wirelessly via any of the access devices 5505, 5509, 5507, 5511 and 5513 which happen to be within range. A wireless phone 5527 is configured to communicate with an independent radio channel associated with the access device 5507. The access device 5507 is configured with a second radio transceiver for that purpose. Stationary phones 5529, 5530, 5531 and 5533 indirectly participate in the premises network via hardwired links to the telephone access device 5519, the computers 5515 and 5517 and the access device 5511, respectively. Supporting both voice and data transport, telephone lines 5535, 5536, 5537, 5539 and 5541 provide dedicated communication links to conventional telephone switching networks for delivering voice or data to devices inside and outside of the premises 5501. Associated with a vehicle 5557, a vehicular network 5551 comprises an access device 5553 and mobile terminals 5555 and 5559. Although not shown, other vehicular network devices such as printers, plotters, fax machines, etc., may also be located within the vehicle 5557. Such other devices participate directly or indirectly on the vehicular network 5551 via wireless or hardwired interconnection. Devices within the vehicular network 5551 can. communicate via a WAN having selective operation between the access device 5553 and the access device 5513. To support the WAN, both of the access devices 5553 and 5513 are configured with a higher power transceiver dedicated to WAN communications. In addition, communication between the vehicular and premises networks also occurs when the vehicle 5557 drives within range of the premises network. At that point, the vehicular network effectively merges with the premises network for free communication flow between the two networks. Thus, the devices within the vehicular and premises network store non-critical messages and information destined for devices within the other network until they are in range and merged. Critical messages and information may be immediately communicated via the relatively higher cost WAN. Similarly, at a remote site 5561 located some distance away from the premises 5501, a stationary phone 5563 may communicate via a telephone line 5565 (and associated telephone switching network) to the various network devices participating in the premises or vehicular networks. At a remote site 5571, a wired and wireless network also exists. An access device 5573 participates in a wireless network and in a hardwired backbone LAN 5575. A telephone access device 5577 participates on the backbone LAN 5575, providing access to and from a telephone line 5579. A mobile terminal 5581 participates in wireless communication with the access device 5573. Thus, through the telephone line 5579 and the associated telephone switching network (not shown), the network at the remote site 5571 can be communicatively coupled to the overall network at the premises 5501. Data flows through the illustrated communication system in the same manner as described above in reference to FIGS. 1-54. To summarize, data is segmented into packets (herein “data packets”) which are routed per spanning tree table specification through the wireless network and backbone LAN 5503. Data is also routed as need be through a conventional telephone switching network (not shown) via the telephone lines 5535, 5536,.5537, 5539, 5541 and 5579. Data routed through the telephone switching network takes the form of a serial data stream using commonly known hardwired modem technology. Voice signals are similarly routed. Voice or other audio signals (herein “voice signals”) traveling through the wireless pathways of the premises network typically flow in a digital, packetized form (herein “voice packets”). However, voice signals in an analog form may also be modulated and transmitted in a non-packetized form such as with communication between the wireless phone 5527 and the access device 5507. Voice signals travel through the wired backbone LAN 5503 are also packetized, i.e., they travel in voice packets. Voice signals traveling through the telephone switching network (not shown) may either remain in a continuous, non-packetized form (herein a “voice stream”) as captured, for example, by a microphone, or be routed as voice packets using known modem technology. The option used here is dependent on the form of the voice signals upon entering the telephone switching network, and the desired form of the voice signals upon exiting the telephone switching network. For example, voice signals flowing between the telephones 5531 and 5563 take the form of a voice stream, because both of the telephones 5531 and 5563 capture voice in and attempt to reproduce voice from a voice stream form. Alternately, for example, voice signals flowing between the mobile terminals 5521 and 5581 (between premises) take the form of voice packets while traveling through the telephone switching network via the telephone lines 5579 and 5539. Although a voice stream might be used, it is not preferred in this configuration because the mobile terminals 5581 and 5521 both communicate voice signals in a voice packet form. Converting between forms (and back again) along this pathway offers little value. Conversion between forms along a communication path between, for example, the mobile terminal 5523 and the telephone 5563 does take place, however. Specifically, the mobile terminal 5523 transmits a call route request packet which includes the identity of the destination device, the telephone 5563. Upon receiving the route request packet, the access device, consulting its routing table, concludes that it does not have a telephone line pathway (or any other pathway) to the telephone 5563. Thus, the access device 5513 sends the request toward the root access device 5505, i.e., to the access device 5509. Upon receipt, the access device 5509 consults its routing table, discovers that it has access to the telephone line 5541 and records the availability of the telephone line 5541 in the route request packet. Thereafter, the access device 5509 transmits the route request packet toward (and to) the root access device 5505. Upon receiving the packet, the root device 5505 consults its routing table yet identifies no lower cost telephone line access than that provided by the access device 5509 as was previously recorded in the route request packet. Therefore, the root access device 5505 converts the route request packet into a reply packet and forwards it back to the terminal 5523 via the access devices 5509 and 5513. Upon receipt of the reply packet, the terminal 5523 offers to the user and/or software of the terminal 5523 the telephone line routing pathways (in this case only one) identified in the reply packet. Upon selecting the offered pathway, the terminal 5523 sends a call setup packet to the access device 5513 which forwards the setup packet to the access device 5509. Upon receipt, the access device 5509 must determine from the setup packet whether the destination of the call expects a voice stream or voice packet transfer. If the setup packet indicates a destination identifier which is not the telephone number being dialed, the access device 5509 will use voice packet transfer. Alternatively, which is the case in this example, the setup packet indicates that the destination identifier is the telephone number being dialed, and the access device 5509 concludes that it must send a voice stream. Thereafter, the access device 5509 interfaces between the mobile terminal 5523 and the telephone 5563. Particularly, the access device 5509 dials the telephone number of the telephone 5563. If a busy signal is detected, the access device 5509 hangs up, and delivers a busy message to the mobile terminal 5523 via the access device 5513. If a ringing signal is detected, the access device 5509 sends a ringing message to the mobile terminal via the access device 5513. Upon detecting a pickup, the access device 5509 delivers a connect message to the mobile terminal 5523. The mobile terminal 5523 may then begin sending voice packets to the access device 5509. Similarly, a voice stream from the telephone 5563 arrives at the access device 5509. In addition to providing call setup assistance, the access device 5509 also assists in conversion between voice stream and voice packet forms. Specifically, the access device queues up the voice packets received from the mobile terminal 5523 then begins converting them through a digital to analog conversion process into a voice stream form which it delivers to the telephone 5563. Upon receiving the voice stream, the telephone 5563 reproduces the voice which originated from mobile terminal 5581. The access device 5509 also receives the voice stream from the telephone 5563 and, begins converting it through an analog to digital conversion process into a sequence of voice packets. As the voice packets are generated, they are routed toward the mobile terminal 5523. Upon receipt of the voice packets, the mobile terminal 5523 queues up the packets then performs a digital to analog conversion process to generate a voice stream. The mobile terminal uses the generated voice stream to reproduce (via a speaker) the voice which originated at the telephone 5525. Further detail regarding this process can be found below. In the exemplary illustration of FIG. 55a, the circuitry for converting voice signals between the voice stream and voice packet forms, hereinafter “conversion circuitry”, can be found in the telephone access devices 5519 and 5577, mobile terminals 5521, 5523, 5555 and 5581, computer 5517, telephone 5525 and access devices 5507, 5509, 5511 and 5553. Similarly, the circuitry for handling basic call setup and processing, hereinafter “call processing circuitry”, can be found in the access devices 5507 and 5509 and the telephone access devices 5519 and 5577. Because they are not configured with conversion circuitry, the mobile terminals 5522 and 5559 communicate in a manner similar to the wireless phone 5527, i.e., they communicate voice signals in a voice stream form (e.g., through microphone pickup, amplification, modulation and transmission without packetization) on a communication channel preferably independent of colocated packet-based communication channels. Thus, the access devices 5507, 5511 and 5553 are configured to not only participate on the packetized communication channel(s), but also to participate in voice stream exchanges with the mobile phone 5527, mobile terminals 5522 and 5559, respectively. For example, voice communication with the mobile terminal 5559 typically requires assistance from the access device 5553. Such assistance involves packetizing voice streams received from the mobile terminal 5559, and converting voice packets to voice streams for delivery to the terminal 5559. Generally, the access device 5553 does not have to invoke its conversion circuitry when communicating voice to and from the terminal 5555 (unless, for example, the voice session involves communication between the mobile terminals 5555 and 5559). Moreover, although the telephone switching network might change the form of the voice stream, such as through time multiplexing, modulation multiplexing or packetization, for example, such changes are transparent to the illustrated network and are ignored herein. Thus, whether such changes occur or not, a voice stream flowing through a telephone switching network is still referred to herein as a voice stream. FIG. 55b is a diagram which illustrates a summary of the various types of communication pathways that may be used for setting up voice sessions between a source and destination network device. For example, nearly all of the pathways shown in FIG. 55a can be summarized with reference to FIG. 55b. Network devices, such as mobile terminals or telephones, are typically capable of operating as a source device (a call origination point) or a destination device (a call destination point). Thus, as illustrated, the “source” and “destination” designations merely identify which of the network devices originates the call and which device receives the call. A source device 5583 may establish a voice session with a destination device 5585 via a variety of types of pathways should such pathways be available. However, many of the types of pathways require the assistance of conversion circuitry when conversion between voice packets and voice streams is required. Many types of pathways also require call processing circuitry for interfacing with telephone switching networks. For example, a network device which only captures and transceives voice streams (such as a conventional telephone) can communicate with any other such device without assistance so long as the pathway between the two provides voice stream transport, and the two devices have access to a protocol for establishing the voice session. Such is the case when the source and destination devices 5583 and 5585 are both conventional telephones that use the telephone switching network 5596 for call setup and voice stream routing. However, should the pathway between the two telephones comprise a hardwired connection 5598, the telephones require assistance in, at a minimum, setting up the call. Such setup consists of simulating a connection with the telephone switching network by providing dial tones, busy signals, ring signals, etc., to each telephone. While the voice session is in progress, no assistance is needed and the telephones exchange voice streams over the hardwired link 5598. Depending on the nature of the hardwired link 5598, however, such assistance may not be sufficient if the hardwired link 5598 also operates pursuant to another protocol, such as a packet-based TCP/IP, for example, which may or may not require the sharing of the hardwired link 5598 with other network devices. If such is the case, assistance to the two telephones also involves capturing full use of the hardwired link 5598 (through a request for a full bandwidth voice session), or adapting the voice stream into a form which may be transferred over the hardwired link 5598. Any level of assistance needed by the source and destination devices 5583 and 5885 is provided by corresponding assisting access devices 5587 and 5589. For example, if the source device 5583 is a conventional device such as a typical telephone, it requires the assistance of an access device 5587 to establish a voice session via a packet-based wireless link (or network) 5597. Such assistance involves both the use of conversion circuitry in the access device for adapting to the packet-based requirements of the wireless link 5597, and use of call processing circuitry to establish the call through the wireless link 5597. If, however, the source device 5583 is configured with conversion and call processing circuitry, the assisting access device 5587 would not be needed. Similarly, if the destination device has conversion circuitry, the assisting access device 5589 is also not needed. The dashed line borders surrounding the assisting access devices 5587 and 5589 are representative of the fact that they may or may not be needed depending on the nature of the pathway and the nature of the source and destination devices 5583 and 5585. If assistance is required, the pathway for communicating between the source device 5583 and its assisting access device 5587 may involve: 1) a telephone switching network 5590; 2) a hardwired link 5591, such as an ethernet LAN, RS232, or-telephone wire connection; or 3) a wireless link 5592, involving, for example, cellular phone transmissions or shorter range, relayed or point to point voice stream transmissions such as may be found in typical wireless phone transmissions to its base unit. In addition, the assisting access device 5587 may assist in basic voice session setup and control. For example, to establish a voice session, the assisting access device 5587 may simulate a typical telephone switching system by delivering dial tones, performing touch tone detection and delivering destination ringing and busy signal indications to the source device 5583. Moreover, if necessary, the assisting access device 5587 will adapt the analog audio/voice signals captured by the source device 5583 (i.e., the voice stream) for transport toward the destination device 5585, and adapt received voice information for transport to the source device 5583 for playback. No assisting access device 5587 is needed, for example, where the source device 5583 has been configured to: 1) capture and adapt a voice stream into a packet-based form (via conversion circuitry) for transport to the destination device 5585, 2) adapt incoming voice packets from the destination device 5585 into a voice stream form (via conversion circuitry) for playback; and 3) generate and respond to call setup and session processing control. Similarly, if the assisting access device 5589 is required, the pathway for communicating between the destination device 5587 and the assisting access device 5589 may involve: 1) a telephone switching network 5593; 2) a hardwired link 5594; or 3) a wireless link 5592. The assisting access device 5589 may also assist in basic voice session setup and control by, for example, simulating a typical telephone switching system. If necessary, the assisting access device 5589 will also adapt voice streams for packetized transport toward the source device 5583, and adapt voice packets received for transport to the destination device 5585 for playback. No assisting access device 5589 is needed, for example, where the destination device 5583 has been configured to perform the assisting functionality. No assisting access device 5589 is needed, for example, where the destination device 5585 has been configured to: 1) adapt captured audio/voice signals for packet-based transport via the communications network toward the source device 5583; 2) adapt incoming audio/voice packets into an analog form for playback; and 3) generate and respond to call setup and processing control packets. The source device 5583, with or without assistance from the assisting access device 5587, may establish a voice session with the data device 5585 (itself with or without assistance from the assisting access device 5589) through a variety of pathways. For example, the session may be established directly through a telephone line link to the telephone switching network 5596. The session may also be established through a wireless link 5597 or hardwired link 5598. Otherwise, the voice session pathway may require routing assistance via one or more “non-assisting” access devices 5599. For example, as illustrated in FIG. 55a, the non-assisting access devices are arranged in spanning tree configurations to route voice session packets back and forth between source and destination devices (via assisting access devices where necessary). Links between the source device 5583 (via the assisting access device when needed) and the one or more non-assisting access devices 5599 may consist of a hardwired, telephone switching network or wireless link as illustrated. Similarly, links between the one or more non-assisting access devices 5599 and the destination device 5585 comprise a hardwired, telephone line or wireless link. FIG. 56a illustrates an embodiment of the conversion and call processing circuitry contained within a computer card 5601 (preferably a PCMCIA card although IDE, PCI, etc. type cards might alternately be used). The computer card 5601 plugs into a host device such as an access device or computer. Through plugging the card 5601 into the host device, the control and data bus 5613 of the card becomes available to the host device's processing unit. To complete installation of the card 5601, the host device is loaded with configuration, maintenance and device driver software. The configuration software is used to configure the card 5601 to operate in different configurations such as is illustrated in FIG. 55a or 55b. For example, when installed in the computer 5515, the computer card 5601 must be configured to function with a conventional telephone, the telephone 5530 of FIG. 55a, in a line sharing arrangement. The dual-line phone 5531 associated with the computer 5517 receives a similar software configuration but does not require a line sharing arrangement. The maintenance software permits the user of the host device to add or modify instructional voice messages to be delivered, and (as will be discussed in reference to FIG. 63 below) various telephone numbers of remote sites with cross-referenced internet addresses in a cross-reference database. The device driver software allows the host device and the computer card 5601 to selectively interact to perform various joint functionality. Thus, when needed, the computer card 5601 has access to the host device's processing unit, associated storage devices and other resources. With reference to the specific configuration of the computer 5515 (FIG. 55a), the telephone 5530 (FIG. 55a) connects to a switching circuit 5607 via a phone input line 5603. A telephone switching network also attaches to a switching input line 5605 of the switching circuit 5607 via the telephone line 5536 (FIG. 55a). The switching circuit 5607 senses a pickup of the telephone 5532 (FIG. 55a) by monitoring the phone input line 5603. Upon sensing the pickup event, the switching circuit 5607 communicates the event to a control processing circuit 5609. The control processing circuit 5609 responds by directing the delivery of a dial tone through the switching circuit 5607 to the telephone 5532 (FIG. 55a) attached to the phone input line 5603. After delivering the dial tone, the switching circuit 5607 waits for a number to be dialed. The switching circuit 5607 forwards the received dialed digits to the control processing circuit 5609. Upon receiving the phone number and through activation of the device driver, the control processing circuit 5609 sends the number along the control and data bus 5613 to the host device in which the computer card 5601 is plugged, in this case the computer 5515 (FIG. 55a). The host device compares the received telephone number with the cross-reference database it stores. If the telephone number has an entry in the database, the host device will look to see if the user has indicated therein the desire to: a) always use the telephone switching network; b) always use an internet routing path; c) always attempt an internal routing path; or d) prompt the user each time a call attempted made. Otherwise, if no entry is found, the host device adds the number to the database with a “d)” type cross-reference, permitting the user to later modify the setting. Thereafter, the host device responds to the computer card 5601 per the cross-reference entry identified. If “a)” is identified, the host device directs the control processing circuit 5609 to automatically dial the number on the telephone switching network via the switching input line 5605, and then interconnect the lines 5605 and 5603 to permit a conventional telephone-based call setup and voice session to begin. If the host identified “b”, indicating that an internet pathway is required, the card 5601 attempts to establish an internet connection through the telephone switching network via the input line 5605. Alternately, in a preferred internet route embodiment, an auxiliary input line 5604 is used to maintain continuous internet connectivity via a dedicated line to the telephone switching network. Further detail regarding this configuration and process can be found in reference to FIG. 63 below. If the host device identifies a “c)” type entry in its cross-reference database, the host device informs the control processing circuit 5609 to pursue a voice session through an internal route. The control processing circuit 5609 responds by attempting to setup a voice session with assistance from the host device. Specifically, upon identifying the need to gain access to the premises network on which the host device participates, the host device accesses the premises network to setup the call. The host device uses its own resources, i.e., its own ethernet card in the case of the computer 5515, to establish and maintain the internally routed call. The control processing circuit 5609 provides call setup simulation (busy, ringing, hang up, etc. signals to the telephone 5530) and conversion processing as needed to establish and maintain the voice session. If the host device identifies a “d)” type entry for the telephone number, the host device delivers a voice message through the conversion circuitry of the computer card 5601 and to the user of the telephone 5530 (FIG. 55a) via the input line 5603. The message prompts the user to select a desired pathway via touch tone entry on the telephone 5530 (FIG. 55a), and permits the user to set that pathway as a permanent default. The user's selection is forwarded to the control processing unit 5609 which responds appropriately to the users request. For example, if the user selected the telephone switching network and requested that route be made a permanent option, the control processing circuit 5609 would route the call as described above as if the host identified an entry type “a)” in its cross-reference database. In addition, the control processing circuit 5609 forwards the request to the host device to change the entry to type “a)” for future calls. In addition, if during setup the host device is informed that no conventional device such as a telephone is attached to the input line 5603 or that no switching network access is available, etc., the host device and computer card 5601 interact to provide for any alternate configurations such as those illustrated in FIG. 55a. For example, when a computer card 5601 is placed into the access device 5509, the access device 5509 and the control processing circuit 5609 coordinate to service the routing of voice packets in a voice stream form through the telephone switching network attached to the telephone line 5541. Likewise, they coordinate to service routing of voice stream information from the telephone line 5541 into the premises network in a packet-based form. In addition, the host device and computer card 5601 can be merged into one package such as the telephone access device 5519. Therein, the functionality of the host processing and control processing unit 5609 are merged. The telephone access device 5519 is also configured with an ethernet (10base2 or 10baseT) interface providing for internal routing through the premises. In the specific configuration of the computer 5515 of FIG. 55a, the computer 5515 (FIG. 55a) can use the dialed number to establish a voice session through the premises network. To do this, the computer 5515 (FIG. 55a) delivers a call setup request packet, which includes the dialed number, onto the backbone LAN 5503 (FIG. 55a). As previously discussed, the setup request packet is then routed through the spanning tree network to a destination device. If the call cannot be established because the destination device cannot be found, the control processing circuit 5609 delivers (via its conversion processing circuits) to the telephone 5530 (FIG. 55a) a message indicating that the destination device is off-line and prompts for a voice mail message. Similarly, if the call cannot be established because the destination is currently engaged in voice communication or has responded to the call setup request with a “do not disturb” indication, the control processing circuit 5609 delivers a message indicating the status and prompts for voice mail. If a user hangs up prior to initiating a voice mail recording, the control processing and switching circuits 5609 and 5605 are reset to await another event. Otherwise, voice mail recording begins after a tone delivered at the end of the voice mail prompt. After delivering the tone, the control processing circuit 5609 directs the switching circuit 5607 to interconnect the lines 5603 and 5611. The control processing circuit 5609 also directs an A/D (analog to digital) conversion circuit 5621 to begin digitizing the voice message received via a subtraction circuit 5631. Because the control processing circuit 5609 disables a D/A (digital to analog) conversion circuit 5625 during the digitization process, the subtraction circuit 5631 subtracts nothing from the incoming voice message. Thus, the entire voice message captured by the telephone 5515 (FIG. 55a) is routed to the A/D conversion circuit 5621. The A/D conversion circuit 5621 produces digital samples of the voice message, and delivers each sample to an output buffer 5623. The control processing circuit 5609 interfaces with the computer 5515 (FIG. 55a) via the loaded device driver to coordinate storage and delivery of the voice mail to the destination device as soon as delivery is warranted and possible. If call setup proves successful, the control processing circuit 5609 directs the switching circuit 5607 to interconnect the lines 5603 and 5611, connecting the telephone with the conversion circuitry. Incoming voice signals from the destination device arrive at the computer 5515 via the backbone LAN 5503 (FIG. 55a) in a voice packet form. In response, the computer 5515 (FIG. 55a) strips out routing information from the packets, and coordinates with the control processing circuit 5609 to deliver the remaining digitized voice information (hereinafter “voice data”) to a queue time buffer 5627 via control and data bus 5613. The control processing circuit 5609 waits a predetermined queuing period of time before beginning playback of a group of voice data. Groups of voice data are defined by a group identifier contained in each voice packet received. For example, conversion circuitry which converts voice streams into voice packets adds group identifiers after identifying a group. To identify a group, the conversion circuitry monitors incoming voice streams for gaps in voice input, i.e., it attempts to identify the difference between captured speech and background noise. Upon identifying the lack of speech for a predefined gap time of about one second, the conversion circuitry assigns a different (pseudo-random) group identifier to subsequent voice packets. Likewise, upon identifying another gap, the conversion circuitry assigns another group identifier to voice packets generated thereafter. Thus, for each group of data (each group of voice data extracted from voice packets having a common group identifier), the control processing circuit 5609 begins to wait the predetermined queuing time before beginning conversion. Thereafter, no queuing time is required until the next group of voice packets begin. By using the queuing time in such a manner, the control processing circuit 5609 can reasonably ensure continuous voice delivery of a voice group to the telephone 5530 (FIG. 55a) under most circumstances without, if possible, introducing a delay that is so long as to be noticeable. When the buffer 5627 has sufficiently “queued up” a voice group, the control processing circuit 5609 directs the delivery of the digital voice data from the buffer 5627 to a D/A conversion circuit 5625 at the same sampling rate used to generate the voice packets. From the voice data, the D/A conversion circuit 5621 generates an analog voice signal, i.e., a voice stream, representing the voice captured by the destination device. The voice stream is then delivered to the telephone 5530 (via a buffer 5629, interconnect 5611, switching circuit 5611 and the input line 5603) for listening by the user. The generated voice stream is also subtracted by a subtraction circuit 5631 from the combined voice stream signals on the interconnect 5611. In this way, the voice stream sampled by the A/D conversion circuit. 5621 for delivery to the destination device consists only of the voice signals captured by the telephone 5530 (FIG. 55a). Supporting this process, the buffer 5629 isolates the incoming voice stream from the incoming voice stream combined with the outgoing voice stream so that the subtraction process can be realized. The A/D conversion circuit 5621 converts the voice stream captured by the telephone 5530 (FIG. 55a) into a digitally sampled form (voice data) which is packetized with routing information and a voice group identifier for delivery by the host device (the computer 1515 of FIG. 55a) to the destination device. Specifics regarding packetization of the voice data are managed between the control processing circuit 5609 and the host device in view of the requirements of the delivery route at issue. In an exemplary embodiment, for internal network routing, each voice packet contains a 20 ms (millisecond) time period of compressed voice data samples. Thus, not considering routing delays, a received voice packet has a built-in 20 ms delay. In that embodiment, upon receipt of a first of a group of such voice packets, a 200 ms queuing time is invoked before the first of such voice packets will be played back. This should ensure that 10 packets of a given group should be waiting at the destination for playback at any time, making it unlikely that any extraordinary delays associated with the routing of any one or several voice packets could result in an empty queue during attempted playback of the given group. So long as the overall delay, i.e., the voice packet delivery delay (as determined by round trip test packets sent during call setup) plus the 200 ms queuing time, do not exceed a predetermined threshold value of, for example, 500 ms, full duplex (two-way) voice communication should be possible with relatively unnoticeable delays. If required queuing and delivery time delays prove too long, e.g., to a point where they might annoy a calling party, the control processing circuit 5609 can disable full duplex communication by selectively inhibiting the output of the D/A conversion circuit 5626 and the input of the A/D conversion circuit 5621 to provide communication connectivity to only one speaker at a time, i.e., half duplex connectivity. Queuing times are identified during call setup and may be modified during the course of the call. Queuing should be as short as possible so that the parties involved cannot detect the overall delay. It should also be long enough to prevent detectable gaps in the reproduced voice signals during most channel loading conditions. The queuing time is generated from a combination of the maximum routing time expected between the source and destination devices less the nominal routing time, and that result plus a one hundred percent (100%) safety margin, i.e., twice the result. In a first embodiment wherein packet routing times remain fairly constant, the maximum and nominal routing times are fixed and based on overall channel characteristics (routing delivery times and variations thereof) established during network setup. In an alternate embodiment wherein packet routing times exhibit relatively slow variation, as previoiusly mentioned, routing times are calculated from round trip routing times of test signals transmitted between the source and destination during call setup (while the destination device is “ringing”). This embodiment is preferable where routing time shows little variation throughout a calling session. If routing times vary much over the course of a single calling session, in a third embodiment, round trip test signals are interspersed with voice packets and decisions made regarding queuing times and full or half duplex considerations are reevaluated for further voice session support. Upon receiving an incoming call from the telephone switching network via the switching input line 5605, if not in use, the control processing circuit 5609 first attempts to identify the type of call incoming. If it is a facsimile or modem transmission destined for the host device, the control processing circuit 5609 directs the switching circuit 5607 to interconnect the line 5605 with a modem/fax processing circuit 5633. If the incoming call on the line 5605 constitutes a voice packet transmission destined for the telephone 5530, the control processing circuit 5609 and switching circuit 5607 deliver a busy signal onto the line 5603, and deliver a ringing message packet along the line 5605. If the switching circuit 5607 detects a pickup on the line 5603, a connect message packet is delivered onto the line 5605 to the sending device. Thereafter, the voice stream delivered via the phone input line 5603 is converted as described above into a voice packet form for delivery via the switching input line 5606 to the source device. Similarly, the voice packets received along the line 5606 are processed by the conversion circuitry (as described above) and delivered onto the phone input line 5603. If, however, the call designates a different destination device than the device attached to the phone input line 5603, the voice packets are relayed by the host device for further routing, e.g., the computer 5515 receives the voice packets to route them onto the backbone LAN 5503. Alternately, if the incoming call on the switching input line 5605 is a voice stream call (e.g., a conventional phone call), the control processing device 5609 will direct the switching device to deliver a ring signal onto the line 5603. Upon detecting a pickup on the line 5603, the switching circuit is directed to interconnect the lines 5605 and 5603 for the duration of the voice session. In addition, modem and facsimile transmissions originating from the host device (such as the computer 5515 of FIG. 55a) are received and processed by the modem/fax processing circuit 5633 for routing through the switching circuit 5607 to the telephone switching network via the line 5605. Voice messages delivered to the user are stored in a digital form by the host device. The control processing circuit 5609 interacts to load the voice messages into a buffer 5627 as they are needed. The control processing circuit 5609 also directs the D/A conversion circuit 5625 to begin converting the digital messages into a voice stream for delivery via the buffer 5629 and the switching circuit 5607 to either the line 5603 or 5605. With exception to the modem/fax processing circuit 5633, the telephone access device 5519 (FIG. 55a) also utilizes the circuitry shown in FIG. 56a, and has the same functionality described above in relation thereto. The telephone access device 5519 (FIG. 55a) is configured to communicate on the backbone LAN 5503, and to take on the functionality provided by the computer 5515 as described above. Similarly, the same circuitry and functionality are contained within the telephone access device 5577. However, the device 5577 is shown having no telephone connected thereto. In such configurations, the telephone access device 5577 acts only as an access device from the telephone line 5579 into and out of the remote premises. The computer 5517 also utilizes a computer card 5601 (FIG. 56a). However, in the configuration illustrated, the telephone 5531 is a two-line phone with a first line being connected to an outside telephone line, the line 5537, and the second being connected to the card computer 5601. When the user desires to place an outside call, the first line is chosen and vice versa. In this configuration the line 5605 of the card 5601 is not, and need not be, connected to anything. Through setup, the host device (the computer 5517) takes the missing switching network link into consideration when determining routing options to select, offer, etc. Each of the access devices 5507, 5509, 5511 and 5553 also contain a computer card such as the computer card 5601. In particular, with the card 5601, the access device 5507 provides communication pathways via: 1) the telephone line 5539; 2) the wireless network via the access device 5505; 3) the mobile terminal 5521 via a first transceiver serving the wireless network; and 4) the wireless phone 5527 via a dedicated, second transceiver. The access device 5509 provides pathways via the telephone line 5541 and a transceiver servicing the wireless network. The access device 5511 illustrates that a telephone 5533 can be attached to the card 5601 to provide access through the wireless network to any local or remote device, without having direct access to the telephone switching network. Furthermore, the access device 5533 illustrates that the computer card 5601 need not be connected to either a telephone or a telephone switching network to provide operational functionality. In particular, instead of connecting an outside telephone line, the access device 5553 delivers voice streams captured by and received from the mobile terminal 5559 to the conversion circuitry of the computer card 5601 for digitizing (by the A/D conversion circuit 5621), storing and routing as voice packets back to the premises, for example. Voice packets received from the mobile terminal 5555 (which contains its own conversion circuitry) receive the same storage and routing treatment without conversion assistance. FIG. 56b illustrates an alternate embodiment of the conversion circuitry of FIG. 56a wherein instead of using an analog subtraction process to separate outgoing voice signals from the combined incoming and outgoing signals, a digital subtraction process is used (at a subtraction circuit 5653). In addition, the use of a delay element 5651 is shown to compensate for the D/A and A/D conversion time pathway via circuits 5625 and 5621 respectively. FIG. 57 is an illustration of the back of the telephone 5525 of FIG. 55a as built in accordance with the present invention. Unlike the conventional telephones 5530, 5529, 5531, 5533 and 5561 (FIG. 55a), the telephone 5525 is configured with built in conversion circuitry. In particular, the telephone 5525 contains a phone line jack 5701 for connecting to an available outside telephone line, although in need not be connected to operate (as illustrated in FIG. 55a). The power adapter jack 5703 provides power to the telephone 5525 via a typical A/C to D/C converter. Although not shown, an alternate embodiment of the telephone 5525 also utilizes internal, rechargeable battery power. Lastly, the telephone 5525 is configured to receive PCMCIA cards into slots 5705. For example, the PCMCIA card 5707 is a radio transceiver card which provides wireless access from the telephone 5525 to the access device 5509 (FIG. 55a) Alternately or in addition, an ethernet PCMCIA card may be added for direct ethernet connectivity to, for example, the backbone LAN 5503 (FIG. 55a). The telephone 5525 provides a semi-stationary source for placing phone calls inside or outside of the premises without requiring new telephone line wiring. It also avoids incurring charges associated with other conventional mobile phone services. FIG. 58 is a schematic block diagram which illustrates the implementation of, one embodiment of the conversion circuitry within the telephone 5525 of FIGS. 55 and 57. In particular, a control processing circuit 5801 functions as described above in reference to FIG. 56a with one significant difference—there is no need for a subtraction circuit. This is because the control processing circuit 5801 already has access to the outgoing voice stream separate from that incoming. Incoming voice streams via the jack 5701 (FIG. 57) are delivered (along with outgoing voice streams captured by a microphone 5805) to a speaker 5807 and to the other calling party. A microphone/phone processing circuit 5809 manages the call processing and delivers the outgoing voice stream per direction from a control processing circuit 5801. To support voice packet communication, the processing circuit 5801 directs an A/D conversion circuit 5817 to process the outgoing voice stream. The resultant voice data is stored in an output buffer 5819 in a voice packet form. By attaching a PCMCIA card or cards (see FIG. 57) to the output buffer 5819, the control processing circuit 5801 can direct the delivery of the voice packets onto an ethernet LAN, telephone switching network, wireless network, etc., depending on the nature of the PCMCIA card(s) installed. Similarly, by attaching an input line 5811 to a PCMCIA card or cards (see FIG. 57) incoming voice packets can be delivered via a media defined by the attached PCMCIA card(s). Although not shown, the control processing circuit 5801 also maintains a direct interface with the attached PCMCIA cards to provide appropriate routing, call setup and control as proves necessary. In addition, after queuing group voice data contained in incoming voice packets in a queue time buffer 5813, a D/A conversion circuit 5815 begins converting the queued data into a voice stream form. For half duplex communication, the conversion is delayed until any pending group of outgoing communication has finished. For full duplex (2-way) communication, the incoming voice stream is added to outgoing voice signals from the microphone 5805 for delivery to the speaker 5807. FIG. 59 is a block diagram illustrating the packet processing functionality of the access devices illustrated in FIG. 55a. At a block 5901, an access device waits in an idle state for receipt of any type of communication packet. Upon receipt of a communication packet, the access device examines an identifier field within the packet to determine the packet type. If the packet is determined to be a call route request packet as indicated at an event block 5903, the access device begins an attempt to identify potential phone call pathways. Alternatively, if the packet is a call setup packet as indicated at an event block 5905, the access device either attempts to set up the call (if directly connected to the destination and setup services are needed) or forwards the setup packet toward the destination. Otherwise, if the access device receives any other type of communication packet at an event block 5911, other routines are executed at a block 5913 to appropriately service the received packet. More specifically, a call request packet contains an identifier field—for storing a packet type indicator, a destination field—for storing a destination phone number, a base cost field—for indicating the routing cost incurred by the calling device to reach a current access device, and an internal call routing field—for storing the lowest cost routing pathway (along with its cost), if any, which does not use an outgoing telephone line, and an external call routing field—for storing the lowest cost routing pathway (along with its cost), if any, utilizing an outgoing telephone line. Upon receiving a call setup request packet as indicated by the event block 5903, the access device first attempts to find a lowest cost external routing pathway for the call. At a block 5917, the access device consults its routing table to identify the lowest cost direct or upstream access to an available outgoing telephone line. If no access is found, the access device branches to begin internal call route processing. However, if an outgoing telephone line is identified, the access device determines whether to replace an external routing pathway stored in the external call routing field at a block 5919. In particular, the access device compares the cost of the currently stored external routing pathway with the cost of the access device's own lowest cost external pathway at the block 5919. If the access device has identified a lower cost external pathway, the access device replaces the current external call routing field entry (if any) with the lower cost pathway along with the associated cost at a block 5921, and branches to a block 5923 to begin internal call route processing. However, if no phone line access is available or its cost is not lower, the access device branches immediately branches to the block 5923 for internal call route processing. The term “cost” being compared at the block 5919 consists of the sum of the routing cost involved in routing a packet from the source (the call initiator) to the current access point and the routing cost involved in routing a packet from the current access point to the access device which provides direct access to the available outgoing telephone line. Routing cost not only takes into account actual costs that may be incurred, but also takes into account the media, e.g., its bandwidth, reliability, time delays and traffic levels. After considering the external routing pathway, the access device begins internal routing pathway processing at the block 5923. Specifically, at the block 5923, the access device determines whether the internal routing field contains an entry. If the field is empty, the access device attempts to identify a routing table entry for the telephone number of the destination device at a block 5925. If a routing table entry is found, at a block 5927 the access device inserts the table entry along with the overall cost from the source to destination into the internal routing field. Thereafter, the access device branches to a block 5929 to begin either root processing or further forwarding. The access device also branches to the block 5929 if an entry is found in the internal routing pathway field at the block 5923 or a routing table entry is not found at the block 5925. At the block 5929, the access device considers whether it is a root device in the spanning tree. If it is not a root device, the access device increments the base cost field entry by the cost of reaching the next device in the pathway toward the root access device (as indicated by the cost entry in the routing table), routes the updated route request packet to the next device in the pathway toward the root, and returns to the idle state at the block 5901. Otherwise, if the access device is a root device, the access device converts the call route request packet to a call reply packet (by changing the packet type indicator) at a block 5933, and routes the reply packet back toward the source. Upon receipt of the call reply packet, among other processing illustrated in reference to FIG. 60 below, the source device (the “calling device”) is offered the internal and external call pathway options (if available) for establishing the call. The source device may offer the user the pathway options, or, if so programmed, automatically select the most appropriate pathway for placing the call. Having selected a pathway from the offered options, the source device generates a call setup packet and routes it toward the destination. Upon receiving a call setup packet as indicated at an event block 5905, the access device responds at a block 5937 by first considering whether the access device has a direct link to: 1) the destination device—either a hardwired or wireless link; or 2) a telephone line which is to be used in the communication pathway to or toward to destination device. If neither direct link exists, the access device routes the call setup packet toward the destination per routing table specification at a block 5939, and, thereafter, returns to the idle state at the block 5901. Otherwise, if either or both direct links, the access device determines whether further processing assistance is required at a block 5941. In particular, if the access device identifies that the destination device is directly connected thereto, the access device consults its routing table to determine if the destination device requires call setup assistance. When the destination device is available and not in use, setup assistance by the access devices involves: 1) the dialing of destination devices connected via a telephone line of a telephone switching network to the access device; 2) the delivery of a ring signal to conventional destination devices connected directly to the access device via hardwiring, for example; 3) sending a ringing message back toward the source device; 4) detecting a pickup at the destination device; and 5) sending a pickup message toward the source device so that the call can proceed. If the destination device is busy (“in use”), the access device sends a busy message toward the source device. If setup assistance is not needed, the access device merely forwards the call setup packet to the destination device. Upon receipt, if not busy, the destination device sends a ringing message toward the destination, signals the user to answer the incoming call, and responds to a pickup by delivering a pickup message toward the source device. Otherwise, if busy, the destination device sends a busy message through the spanning tree network toward the source device. Upon receipt of a pickup message, the source device begins to capture audio signals which are routed toward the destination. Similarly, upon pickup, the destination device begins capturing audio signals which are routed toward the source device. In addition, if captured audio signals are to be routed through the wireless spanning tree network and/or through the associated hardwired networks within the communication network, the audio signals must first be converted to a packetized form (i.e., a “call voice packet” form) and then reconstructed for playback. For example, if an access device directly receives captured audio signals but must route the signals through the network, the access device converts the audio signals into voice packets, screens out all audio signals falling below a predetermined threshold level (to avoid the wasted bandwidth associated with the transmission of interleaving background noise), and forwards the call voice packets through the network. Similarly, if it has the capability of performing the packetization processing, a source or destination device connected directly to a wired or wireless network will generate call voice packets for delivery through the network. Upon receiving a call voice packet at the block 5901 as represented by the block 5907, the access device first determines whether it has a direct link to the destination of the voice packet at a block 5937. If so, the access device considers whether call processing assistance is needed at a block 5941. If needed, the access device performs the processing assistance at the block 5943. In particular, the processing assistance in this situation consists of converting the call voice packets back into an audio signal form (analog form) for delivery to the destination of the voice packets. In addition, as described in more detail below, the access device delays the audio signals for a predetermined queuing time before delivery to promote continuous delivery of the overall segment of captured voice. If no direct link is available at the block 5937 or no call processing assistance is needed at the block 5941, the call voice packets are routed toward the destination at the block 5939. Thereafter, the access device reenters the idle processing state at the block 5901. FIG. 60 is a flow diagram illustrating the functionality of a source device in the setup of a voice session. The flow diagram also applies to an access device assisting a source device in the setup of a voice session whenever such assistance is needed. Specifically, when a user attempts to initiate a voice session to a destination device, the source device (or assisting access device where applicable) responds by first determining whether it has direct telephone line access to an outside public telephone switching network. Such access may be via a telephone line, through a direct wireless telephone link to a telephone base unit having telephone line access, or through a cellular radio. If direct telephone line access routing exists, the source device offers the route(s) along with associated cost(s) to the user (or user software) for selection at a block 6603. If such a route is selected, the source device branches to conventional call setup routines as indicated at a block 6007. Alternately, if direct telephone line access is rejected or unavailable, the source device generates a call route request packet at a block 6009. Thereafter, the source device routes the request packet toward the root device of the spanning tree at the block 6011, and awaits a reply packet at a block 6013. As described in relation to FIG. 59 above in more detail, as the call route request packet is routed toward a root device of the spanning tree, each intermediate access device along the route selectively supplements the route request packet with lowest cost routing information. Upon receipt of the packet, the root device also selectively supplements the call route request packet, converts the packet into a reply packet, and routes the reply packet back toward the source device. Upon receiving the reply packet, at a block 6015 the source device examines the reply packet for voice session routing options. If no session options are available, the attempt is aborted at a block 6021. If routing options are indicated, they are offered along with their associated costs at a block 6017. If the user of the source device (or associated software) rejects the offered routes, the voice session is aborted as indicated at the block 6021. If an offered route is accepted, the source device branches to perform call setup at the block 6007. FIG. 61 is a flow diagram illustrating the functionality of the source device (or assisting access device) when performing call setup. The source device begins the setup functionality at a block 6101. If the source device intends to deliver voice mail, as determined at a block 6103, the source device prompts for the voice message and captures the message at a block 6105. Once the voice message is captured, the source device waits at a block 6107 for a predetermined time period before attempting to deliver the captured voice message. During the wait, the source device may have queued up other voice messages such that they may all be processed in a time and money saving batch mode. In addition, while waiting, other voice sessions might be conducted, and, during such time, delivery of the captured and queued voice mail takes place. Thus, in effect, the delivery of voice mail messages can be delayed to optimize communication resources. In an alternate embodiment, voice mail is treated no differently than any other voice session. In addition, if the voice message cannot be delivered because the destination device is busy or otherwise unavailable, delivery is periodically reattempted. Thus, to deliver voice mail or establish a real-time voice session, at a block 6109, the source device generates and routes toward the destination device a call setup packet at a block 6109, with the pathway for the routing having been defined by one of the routing options previously offered and selected. At a block 6111, the source device waits for a response regarding the attempted setup. If a busy message is received, the source device concludes that the path is currently unavailable at a block 6113, and delivers a busy signal to the user of the source device at a block 6115. If the busy message results from a busy destination device, the source device concludes that no other pathway need be considered at a block 6117, and ends the session setup attempt at a block 6119. However, if the busy message indicates a busy pathway, the source device considers whether other pathways are available at the block 6117 through analysis of the previously received reply packet. If other pathways exist, the source device offers such other routes at the block 6130 to the user. If selected, the source device repeats the processing of the blocks 6103-6117 until either no other voice session paths are available, or the destination device or assisting access device responds with a ring message packet. In particular, upon receiving a setup request packet, an available destination device (or assisting access device) responds by delivering a ring signal to the user, and by generating and routing a ring message packet toward the source device. Upon call pickup, the destination device (or assisting access device) generates and routes a connect packet toward the source device. Thus, at the block 6113, when the ring message packet is received, the source device responds in one embodiment at a block 6121 by attempting to adjust the queuing time of the audio information received. This is accomplished by sending a series of round trip test packets which are sent from the source to the destination and back while ringing is taking place so as to identify the approximate delay time of the network. The overall queue time consists of a worst case relay time plus a tolerance factor generated through statistical analysis of the mean and median of the test packet round trip times. However, in an alternate embodiment, a predetermined default queue time is selected, and no test packets are delivered. At a block 6123, the source device delivers a ringing signal to its user, indicating that the destination device is ringing. Thereafter, if the user of the source device happens to hang up, the voice session attempt ends at a block 6127. Otherwise, the source device continues to indicate ringing at the destination device until a connect packet is received. Upon receipt of the connect packet, the source device concludes that the destination device has answered the call at a block 6128 and branches to begin voice session processing at a block 6129, as further described below in reference to FIG. 62. FIG. 62 is a flow diagram illustrating ongoing voice session processing performed by a source device (or its assisting access device if needed) and destination device (or its assisting access device if needed). Once a connect message is generated, the destination device (or its assisting access device) enters the idle state 6201. Upon receiving the connect message, the source device also enters the idle state at a block 6201. Any device waiting in an idle state at the block 6201 responds to several types of ongoing call processing events. If a voice packet is received as indicated by a block 6203, the device queues up the incoming digital voice data contained within the voice packet, and thereafter returns to the idle state. If the incoming queue contains queued up information, as indicated by a block 6211, the device must consider whether full duplex operation is possible or not. To do so, at a block 6213, the device first determines whether a potential conflict with outgoing voice information might occur. If no outgoing transmission is in progress, the device evaluates whether the queuing time is greater than a predetermined threshold value at a block 6215. If it is greater, only half duplex communication is desired because the delay between the generation and playback of the incoming voice information in queue is so long that it might be detectable by the listener. In such circumstances, half duplex communication is preferred, therefore, at a block 6217, an indication is provided to the user that half duplex communication being utilized, and the device reenters the idle state, to again vector through the event block 6211 and blocks 6213 and 6215 until the outgoing transmission ends. If no outgoing transmission is taking place or the queue time is less than the predetermined queuing threshold, the device begins playback of the queued, digital voice information through D/A conversion at a block 6219. If voice capture is detected, as indicated by a block 6221, an A/D conversion, packetization and queuing process takes place at a block 6223. Thereafter, the device reenters the idle state at the block 6201, only to vector on an “outgoing queue not empty” event indicated by a block 6225. At the block 6225, the device vectors to a block 6227 to send a queued, outgoing voice/audio packet to the other device involved in the voice session exchange. After sending the voice packet, the device reenters the idle state at the block 6201. If a local hang is detected, as indicated at an event block 6231, the device sends a remote hangup packet to the other participating device at a block 6233, and ends the voice session at a block 6239. If a remote hangup packet is detected by the device while in the idle state, as indicated by an event block 6235, the device delivers a click and dial tone to the user at a block 6237, and also ends the voice session at the block 6239. Finally, if an error in the queuing time is detected, as indicated by an event block 6241, the queuing time is adjusted at a block 6243 before reentering the idle state at the block 6201. In particular, if the selected “preset” queuing time for storing incoming signals proves to be too short, the queue time is adjusted up to avoid clicking sounds associated with gaps in incoming voice signals. However, the adjusted queuing time is only implemented with future groups of voice packets, i.e., not the current group. FIG. 63 is a diagram which illustrates further application of the present invention in an embodiment which transparently utilizes internet connectivity to support low-cost voice sessions. In particular, as with convention internet services, personal computers 6301 and 6303 participate on internet via dial up service to internet providers 6305 and 6307, respectively. Such service providers typically require the computers 6301 and 6303 to communicate via modem through a telephone line, such as telephone lines 6309 and 6311 via a TCP/IP protocol. The internet providers 6305 and 6307 participate along with other providers and participants in an overall network of internet servers and routers, as represented by a block 6315. The internet functions as a distributed information source which can be accessed by either of the computers 6301 or 6303. In addition, internet provides a pathway for exchanging data between the computers 6301 and 6303. Beyond the typical internet functionality, the computers 6301 and 6303 are also configured with a computer card such as the card 5601 of FIG. 56a so that they can also handle voice sessioning. In addition, a two-line telephone 6321 is also provided with a first line attached to the computer card and a second line to a telephone line 6325. Via the telephone line 6325, which attaches to a conventional telephone switching network (not shown), the telephone 6321 provides typical dialing functionality outside of the internet network. On the first line, the telephone 6321 interfaces with the computer card in the computer 6301 to place phone calls through the internet. Similarly, a single-line telephone 6323 is also attached to computer card such as the card 5601 of FIG. 56a. Through interfacing with the computer card within the computer 6303, the telephone 6323 can place calls either through a conventional telephone network via a telephone line 6327 or through the internet network via the telephone line 6311. More specifically, to communicate from the telephone 6321 to the telephone 6323, the user first picks up the telephone 6321. If the user selects the first line, the telephone 6321 receives a dial tone and further conventional call processing via the telephone line 6325. For example, the user of the telephone 6321 could dial the telephone number of the telephone 6323 in a conventional manner. The computer 6303 would detect the incoming call ringing signals and directly interconnect the telephone 6323 with the telephone line 6327. Subsequent call processing would be left to that provided via the conventional phone service. Alternatively, if the user of the telephone 6321 selects the first line, the computer 6301 delivers (via its computer card) an internet dial message. The message prompts for the normal telephone number of the destination device (i.e.; the telephone 6323). In response, the computer 6301 attempts to identify (from the telephone number entered) an internet address which is used for routing information through the internet network. To perform this task, the computer 6301 uses an internet/telephone number, cross-reference database which contains various telephone numbers and associates therewith corresponding internet addresses. If the computer 6301 fails to identify the corresponding internet address, a phone message prompts for entry of that internet address via the computer 6301 into the cross-reference database. Upon successful identification of the internet address, the computer 6301 communicates via the internet network (i.e., the provider 6305, routing network 6315 and the provider 6307) and to the computer 6303 a message indicating the desire to establish a voice session (hereafter a “connection request”). If the computer 6303 is not connected to the internet provider 6307 (i.e., “offline”) at the time of the connection request, the computer 6301 will receive no response and timeout. The computer 6301 then sends a voice message to the telephone 6321 indicating that the telephone 6323 is offline. Otherwise, if the computer 6303 is online, the computer receives the connection request and checks to see if the telephone 6323 is currently available. If the telephone 6323 is currently engaged in another call, the computer 6303 responds by delivering a busy message through the internet network to the computer 6301. Upon receipt of the busy message, the computer 6301 delivers a busy tone signal to the telephone 6321. Alternatively, if the telephone 6323 is not engaged, the computer 6303 responds to the connection request by delivering a ring signal to the telephone 6323. The computer 6303 also responds by delivering a ringing message through the internet network to the computer 6301. Upon receipt of the ringing message, the computer 6301 delivers a ring signal to the telephone 6321. If the user hangs up the telephone 6321 before the call is connected, the computer 6301 detects the hang and sends a hang up message to the computer 6303. In response, the computer 6303 aborts the delivery of the ringing signals to the telephone 6323, ending the voice session setup attempt. If the user of the telephone 6323 picks up the telephone, the computer 6303 responds by sending a message to the computer 6301 via the internet network indicating that a connection has been established. Thereafter, the computer 6303 begins compressing and packetizing voice signals captured by the telephone 6323 for delivery to the telephone 6321 via the internet network. Similarly, upon receiving the message indicating that a connection has been established, the computer 6301 also begins compressing and packetizing voice signals captured by the telephone 6321. Both of the computers 6301 and 6303 begin exchanging the voice packets as they are generated via the internet network. The computers 6301 and 6303 queue up received voice packets before beginning playback to the telephones 6321 and 6323, respectively, to attempt to prevent gaps in the delivered voice signals due to the pseudo random delivery time associated with a given voice packet. During the course of the ongoing voice session, if a hang up is detected by one of the computers 6301 or 6303, the detecting computer sends a hang message to the other computer. Upon receipt of the hang message, the other computer delivers a dial tone to its corresponding telephone. Calls originating from the telephone 6323 to the telephone 6321 operate nearly the same except during initial call route selection. Upon a user's pickup of the telephone 6323 to place a call, the computer 6303 responds by delivering a dial tone to the telephone 6323. The computer 6303 then waits for the user entry of a telephone number (in this case the number of the telephone 6321). Upon receipt of the telephone number, the computer 6323 checks for an internet address in its cross reference database. If an internet address is found, the computer 6303 (via its computer card) delivers a voice message to the telephone 6323 prompting the user to select (via a keypad on the telephone 6323) either internet or telephone switching system routing. If the user selects telephone switching system routing, the computer 6303 accesses the telephone line 6331, awaits a dial tone, dials the entered number, and, thereafter, connects the telephone 6323 directly to the telephone line 6327. At that point, the telephone 6323 interacts with basic call model processing associated with the telephone switching network. Otherwise, if the user selects internet routing, the computer 6303 begins the internet connect processing described above in relation to initiation of an internet call from the telephone 6321 to the telephone 6323. Thus, voice sessions between the telephones 6301 and 6303 take place either over the conventional telephone switching network or through the internet. Operation through internet is virtually transparent with one exception. If the queuing time delay through the internet network proves to take too long (i.e., the delay is detectable by the users), the computers 6301 and 6303 can negotiate a half duplex mode of voice communication similar to that found in the speaker phone operation of conventional telephones. In addition, the computers 6301 and 6303 both attempt to identify and filter captured audio during periods of time in which voice audio is not occuring, attempting to minimize overall bandwidth usage. In addition, a computer need not be present to provide the end user with voice session transport via internet. For example, as illustrated, in one embodiment, a conventional telephone 6331 is attached to a conventional telephone switching network via a telephone line 6335. Thus, the telephone 6331 can establish and maintain voice sessions through conventional means with, for example, the telephone 6323 via the telephone line 6327. Similarly, to place a call from the telephone 6323 to the telephone 6331, conventional telephone switching network interconnection may be established via the telephone lines 6327 and 6335. The telephone 6323 may also place a call to the telephone 6331 via the internet network. Specifically, upon detecting pickup, the computer 6303 delivers a dial tone to the telephone 6323. Upon detecting the dialed number of the telephone 6331, the computer 6303 consults its cross-reference database to attempt to identify an internet address. If an exact internet address cannot be found, the computer 6303 uses the country code/area code of the entered phone number to attempt to locate a call server somewhere near the telephone 6331 (so as to minimize telephone switching network charges). In particular, the computer 6303 uses the entered country code/area code to identify the internet address of an access device 6333 maintained by an internet provider which, for example, happens to be in the same local calling area as the telephone 6331 (although remotely located from the telephone 6331). The computer 6307 then sends a connect request containing the telephone number of the telephone 6331 to the internet address of the access device 6333. In response, the access device 6333 responds by gaining access to the conventional telephone switching network, dialing the number of the telephone 6331 and sending appropriate messages to the computer 6303 regarding the status of the call. Particularly, if the telephone 6331 is engaged, the access device 6333 releases the telephone line and sends a busy message to the computer 6303. In response, the computer 6303 delivers a busy signal to the telephone 6323. Similarly, if the access device detects that the telephone 6331 is ringing, it awaits pickup and delivers a ringing message via internet to the computer 6303. The computer 6303 responds by delivering a ring signal to the telephone 6323. If the telephone 6331 is answered, the access device 6333 indicates such an event by sending a connect established message to the computer 6303 via internet. Thereafter, the access device begins packetizing voice signals from the telephone 6331. The access device sends resulting voice packets through the internet network to the computer 6303. The computer 6303 also begins packetizing voice captured by the telephone 6323 and sending the resulting voice packets through the internet network to the access device 6333. Both the access device 6333 and the computer 6303 attempt to filter periods of non-voice time periods. Similarly, both queue up incoming voice packets to take into consideration packet delivery delays within the internet network. Thus, as can be appreciated, the access device 6333 comprises rather conventional internet server functionality having at least one available outside telephone line through which call processing can be maintained. The access device 6333 further comprises call processing circuitry such as is shown in FIG. 56a for adapting voice information for transport between internet network and the telephone switching network. Such circuit functionality is also described in more detail in reference to FIG. 56a above. Moreover, the functionality mentioned in reference to the configuration of FIG. 63 is merely a further embodiment of the flow diagrams of the previous FIGS. 59-62. Thus, the present invention has been described herein with reference to particular embodiments for particular applications. However, it will be apparent to one skilled in the art having read the foregoing that various modifications, variations and applications of this communication system according to the present invention are possible and is intended to include all those which are covered by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to data communication networks having a plurality of wired and/or S wireless access servers configured to support remote processing, data storage and voice communication. More specifically, this invention relates to the intelligent routing of packetized voice communication between telephones and radio terminals through wireless and hardwired channels in a data processing network. While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility. 2. Description of Related Art To support data collection, multiple radio base station networks have been developed to overcome a variety of problems with single radio base station networks such as spanning physical radio wave penetration barriers, wasted transmission power by portable Computing devices, etc. However, multiple radio base station networks have their own inherent problems. For example, in a multiple base station network employing a single shared channel, each base station transmission is prone to collision with neighboring base station transmissions in the overlapping coverage areas between the base stations. Therefore, it often proves undesirable for each base station to use a single or common communication channel. In contradistinction, to facilitate the roaming of portable or mobile devices from one coverage area to another, use of a common communication channel for all of the base stations is convenient. A roaming device may easily move between coverage areas without loss of connectivity to the network. Such exemplary competing commonality factors have resulted in tradeoff decisions in network design. These factors become even more significant when implementing a frequency hopping spread spectrum network. Frequency hopping is a desirable transmission technique because of its ability to combat frequency selective fading, avoid narrowband interference, and provide multiple communications channels. Again, however, changing operating parameters between coverage areas creates difficulties for the roaming devices which move therebetween. In particular, when different communication parameters are used, a portable or mobile device roaming into a new base station coverage area is not able to communicate with the new base station without obtaining and synchronizing to the new parameters. This causes a communication backlog in data collection networks. Such data collection networks and their communication protocols have been specifically designed for data collection and forwarding through wireless and hardwired links. They are designed in attempts to optimize overall data flow through the network. Among other flow optimizing techniques used, the data is segmented and packetized in preparation for transmission. Packet by packet, the data is transmitted as channel bandwidth becomes available. Thus, instead of disabling a channel by dedicating bandwidth to service only a pair of participants exchanging potentially large amounts of data (data possibly having no immediate need), the channel is shared by many participants, each sending segments of data in packets whenever an opening in the channel occurs. In contrast, to support the delivery of real time voice, alternate network design constraints must be considered. For example, such networks often dedicated bandwidth to voice transmission exchanges. However, by dedicating channel bandwidth to voice, efficient communication of data through such networks is seriously impacted. Data communication would have to wait for longer periods of time until dedicated voice bandwidth has been released. Similarly, data communication would have to be immediately discontinued upon requests for voice bandwidth. Thus, there is a need for a communication network that provides efficient distribution and utilization of network resources in support of both data and voice delivery. An object of the invention is to provide a method and apparatus wherein seamless voice and data communication is provided among both roaming devices within wireless portions of a communication network and stationary devices within hardwired portions of the network. Another object of the present invention is to provide a hierarchical communications system for providing an efficient communication pathway for both data and voice. Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention solves many of the foregoing problems in a variety of embodiments. For example, in one embodiment, a communication network is disclosed which operates to support voice and data communication within a premises. The communication network comprises a plurality of mobile network devices, a stationary network device, a wireless network, a hardwired network and a telephone. Each mobile network device has a buffer that stores incoming digital voice information for a predetermined queuing period before beginning voice reproduction from the stored digital voice information. Each mobile network device uses the wireless network to selectively exchange voice and data packets with other mobile network devices. Similarly, the hardwired network is connected to both said stationary network device and the wireless network, and is used to route voice and data packets between the stationary network device and the plurality of mobile network devices which participate via the wireless network. The telephone, which is connected to the stationary network device, captures, delivers, receives and reproduces voice in an analog voice stream form. The stationary network device also has a buffer that stores digital voice information, received from the wireless network, for a predetermined queuing period before converting it into an analog voice stream. After conversion, the stationary network device delivers the analog voice stream to the telephone. In addition, the stationary network device converts analog voice streams received from the telephone into voice packets for delivery via the hardwired and wireless networks to a selected one of the mobile network devices. Further detail regarding this embodiment and variations thereof are also disclosed. For example, the predetermined queuing period can be determined through examining delays found in test signal routing. The stationary network device can be a computer. The wireless network may utilize a polling protocol and spanning tree routing. The stationary network device can provide call setup assistance for the telephone. Moreover, the communication network may further comprise a telephone switching network, connected to the stationary network device, which selectively routes analog voice streams received from the telephone onto the telephone switching network. The stationary network device may also selectively route analog voice streams received from the telephone switching network to the telephone. Further detail regarding the present invention (and embodiments thereof) may be found in reference to the claims below, in view of the following detailed description and drawings. | 20040505 | 20110913 | 20050120 | 67978.0 | 0 | HSU, ALPUS | HIERARCHICAL DATA COLLECTION NETWORK SUPPORTING PACKETIZED VOICE COMMUNICATIONS AMONG WIRELESS TERMINALS AND TELEPHONES | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,839,665 | ACCEPTED | Conversion of cinema theatre to a super cinema theatre | Methods of and equipment for converting existing standard motion picture theatres to one having highly immersive, large fields of view are addressed. Aspects of the methods including moving motion picture screens closer to the audience and employing different projection equipment to avoid or minimize appearance of unrealistic or non-natural image artefacts. Alternative sound systems too are detailed. | 1. A method of converting an existing multiplex theatre hall into a wide screen immersive motion picture theatre including the steps of: erecting a motion picture screen that stretches substantially from wall to wall and floor to ceiling in a position closer to the projector than the existing screen; and employing image projection means to increase the fidelity of projected images to compensate for the larger screen size. 2. The method of claim 1 in which employing the image projection means increases the fidelity of projected images such that the image fidelity is greater in the front row seats than the image fidelity was prior to conversion. 3. The method of claim 1 further including selecting an existing theatre hall having stadium rake seating. 4. The method of claim 1 in which the employed image projection means is a 3D projection system. 5. The method of claim 1 further including providing an emergency screen access system. 6. The method of claim 1 further including providing additional vertical height to the screen by any of the following methods: tilting the screen towards or away from the audience; curving or increasing curvature of the screen in the vertical direction; curving or increasing curvature of the screen in the horizontal direction; or modifying the ceiling to provide additional effective height to employ a higher screen. 7. The method of claim 1 further including adding a sound barrier behind screen loudspeakers to ensure optimum quality of the sound for the realistic immersive audio experience. 8. A method of converting an existing multiplex theatre hall into a significantly better quality and more realistic and immersive surround sound experience that includes the steps of: changing the sound system loudspeaker configuration to one using 5 discrete loudspeakers and one sub-bass loudspeaker assembly such that each of the 5 discrete loudspeakers is positioned at left screen, centre screen, right screen, right rear, and left rear, and all discrete loudspeakers are fed simultaneously by a separate source audio channel with appropriate amplification and equalisation, and using loudspeakers that use proportional point source technology or have characteristics similar to proportional point source loudspeakers to significantly improve balanced sound from all discrete loudspeakers over all the theatre seats. 9. The method of claim 8 that further including the step of using loudspeakers that use proportional point source technology or have characteristics similar to proportional point source loudspeakers that act as a point source of sound or a virtual point source of sound. 10. The method in claim 8 further including the step of using computer aided design to determine the optimum loudspeaker “pointing angle” for each of the 5 loudspeakers and using alignment tools, such as LASER alignment fixtures, to ensure the aim of the loudspeaker matches the predetermined “pointing angle”. 11. The method of claim 8 further including using a 5.1 sound track that is mixed differently than the standard cinema 5.1 sound track to enhance the sound image directionality and placement for a more realistic immersive audio experience. 12. The method of claim 8 further including using a digital sound reproducer that provides uncompressed digital sound with a resolution of 16 bits or greater for a minimum of 5 full range channels. | FIELD OF THE INVENTION The field of the invention is the presentation of motion picture films, and in particular in the cost effective conversion of a standard, existing multiplex theatre space into one allowing a qualitatively different motion picture presentation experience. BACKGROUND Motion picture exhibition has seen a number of changes since its inception in the late 19th century. Generally, the main variables in motion picture exhibition have been the dimensions of the theatre enclosure and correspondingly the number of seats therein, the size of the screen upon which images were projected and the dimensions or format of the film negative which contained the images for presentation. Although a number of film formats were considered, one format, 35 mm wide film having an image aspect ratio of 4:3 became the industry standard. Motion picture theatres gradually evolved in size from smaller theatres to larger so-called palace theatres featuring several hundred to thousands of seats, balconies, and elaborate facades. Despite the impressive and somewhat regal atmosphere these theatres continued to feature 35 mm film projected onto narrow width screen. Eventually in the late 1920s, motion picture producers and exhibitors started experimenting with larger film formats which could enhance the visual immersion of theatre patrons and live up to the size and scope of the large palace theatres. Some of the wide gauge/wide screen processes that appeared to challenge the 35 mm film standard included Magnascope, Polyvision, Hypergonar and Fox Grandeur. Magnascope used a novel magnifying lens to enlarge a standard 35 mm frame. Polyvision used multiple 35 mm film projectors to stitch together a composite image, while Fox Grandeur replaced 35 mm film entirely with a new 70 mm wide film format. Finally Hypergonar used a novel method of anamorphically squeezing images onto a 35 mm frame during filming and then reversing the process upon projection to fill a larger projection screen. Although technically and aesthetically successful, the proposed wide screen systems failed to replace 35 mm as a film standard in the economically depressed 1930s and were soon abandoned. Conditions had changed somewhat by the early 1950s and the motion picture industry saw a resurgence of proposals for wide gauge/wide screen systems. Foremost among the new systems were Cinerama, a multiple 35 mm projection system, Cinemascope, an anamorphic system, Vistavision a 35 mm 8 perforation format system and Todd AO, a wide gauge system using a 70 mm 5 perforation 30 frame per second format. The new formats were successful at the box office and survived for a number of years, but none was able to seriously challenge the 35 mm film standard. A third wave of wide gauge/wide screen motion picture exhibition started in 1969, led by IMAX Corporation, which featured the use of horizontally travelling 70 mm film with a film frame of 15 perforations in width resulting in an image area about ten times that of standard 35 mm. In addition to the large film format IMAX® re-conceptualized the theatre viewing space by providing significantly larger screens which extended beyond spectators fields of view, steeply raked seating area to give unobstructed viewing of said large screen, and high fidelity six channel sound to surround the audience. The net result of these advances was a theatre experience in which audience members were immersed in image and sound as never before. IMAX® theatres were successful in the institutional and exhibit marketplace. Other competing large format systems include Showscan's 70 mm 5 perforation film projected at 60 frames per second (versus the standard 24 fps) and Iwerk's 70 mm 5, 8 and 15 perforation film systems. In most cases IMAX® systems were installed in custom designed motion picture theatres having a large volume to house both the large screen and a steeply raked seating deck. Occasionally IMAX® projection systems were placed in large hall converted stage theatres. IMAX® screens could be placed in front of the stages in such theatrical structures without building structure modifications because of the large existing clear height. In some cases, such as at the Museum of Natural History in New York City, a retractable IMAX® screen was placed in front of the stage that had an existing 35 mm screen at the back of the stage. Some seats at the side of the theatre near the position of the IMAX® screen were removed because the visual quality at those locations was poor. The slope of the seating areas in these theatrical theatres is typically shallow, and financial constraints prevented conversion to a more desirable steeper slope. As a result, the viewing conditions in such converted theatres were not optimized for viewing IMAX® motion pictures. Grand theatres of the type frequented in the 1920s thru 1950s were sometimes converted to house the emerging wide gauge/widescreen systems of the 1950s. Conversion consisted of changing the width and curvature of the screen to match the new wider picture aspect ratio and removing a relatively high percentage of seats that no longer had viable viewing conditions. Screen centres were basically positioned at the original screen centre position at the rear wall of the theatre, and the rake of seats in the theatres was not a consideration in the conversion process. Another type of theatre conversion addresses the desire to present motion pictures in either of two common aspect ratio formats, which are 1:85:1 and 2.35:1. The conversion process involves adjusting the curtain masking around the screen to suit the format of presentation as well as changing the lens and aperture plate. The position of the screen itself does not change. A major trend in the motion picture industry starting in the 1970s was to group a number of small 35 mm film theatres into one large complex, or so-called multiplex theatre. These theatres, although profitable, did not provide patrons with a quality viewing experience. Over time movie attendance declined partly because of new home entertainment technologies such as cable TV, video cassette recorders, and home movie rentals. In the 1990s the motion picture exhibition industry responded to declining movie attendance by building new theatres offering stadium seating—placing each row of seats on its own tier—to improve the sight lines and thus the viewing experience of patrons. This industry advance has been very successful in improving movie attendance and is now an expected feature for theatre patrons; conventional low slope seating decks are seen as “old” and inferior. (LA Business Journal). The new stadium seat theatres, while an improvement over traditional multiplex theatres, still rely on standard 35 mm film projectors and do not provide patrons with a wide field of view or highly immersive experience. It should be noted that in the later half of the 1990s the use of digital projectors began in a few multiplex cinemas. This trend in time will increase as digital projection systems get better in quality and higher in image resolution. Another aspect of the conversion is to improve the quality of the audio portion of the immersive experience in a multiplex type theatre. Sound systems for cinema have evolved over the decades and the trend continues as an ongoing effort to attract the paying viewer. The surround sound systems used in today's Multiplex theatres can provide a degree of “ambience” in the audio experience but these systems still lack the ability to create realistic immersive audio. From the time “talkies” were introduced, motion picture cinemas had “monaural” sound systems, having only one loudspeaker located behind the center of the screen. The sound experience in such a cinema was very one dimensional and flat, with no ability to simulate sounds coming from directions other than the center of the picture. In order to improve the audio experience, cinema designers and equipment suppliers experimented with a variety of multiple loudspeaker (“multi-channel”) schemes designed to immerse the audience in a sound field which could add to the “suspension of disbelief” desired by filmmakers. One of the earliest attempts at multi-channel sound was the premier of Walt Disney's “Fantasia” in 1939. Disney experimented with a number of sound system loudspeaker configurations as outlined in an article by William E. Garity and John N. A. Hawkins published in the August 1941 issue of the journal of the SMPTE. The last two versions of the Fantasound system, known as Mark IX and X, used 5 loudspeakers and sound from 3 separate tracks. The loudspeakers were positioned such that 3 were behind the screen (i.e. left, center, and right) and one loudspeaker was in each rear corner. The two sets of rear corner loudspeakers were switched in to supplement or replace the corresponding left and right front loudspeakers at select times during the picture presentation. Unfortunately, the war and economics cut short Disney's sound system experiments. In the early 1950's, Cinerama brought multi-channel sound to the forefront again with 5 to 7 loudspeaker channels located around the audience. During the 1950's there were several theatres equipped for the playback of multi-channel sound, of which there were primarily two formats both using magnetic stripes printed on the film. The CinemaScope 35 mm film format provided four discrete channels, consisting of 3 loudspeakers behind the screen and a monaural surround channel provided by several small loudspeakers located on the side and rear walls of the cinema. These surround loudspeakers provided a degree of “ambience” to the sound experience in combination with the directional sound produced by the 3 screen loudspeakers, and thus added to the immersive effects presented to the audience. The Todd-AO 70 mm film format added two additional loudspeakers behind the screen, Left Center and Right Center, between the center loudspeaker and the left and right speakers. In the 1970's, Dolby pioneered several advances in cinema sound, including extended low-frequency sound (sub-bass), noise reduction, and Stereo Optical sound. Dolby Stereo Optical provided 4 channels of sound (left, center, right, and mono surround) using an encoding technique to store the analog soundtrack on two analog optically printed stripes on the film. This became the standard for normal cinemas, and remains in use today in non-digital cinemas. In 1979, Dolby added to the immersive effects of cinema sound by developing stereo surrounds, in which the left distributed loudspeaker channel could reproduce different sounds than the right channel. But, the surround effects were still effectively ambience sounds, and were unable to reproduce directionality with any precision due to the distributed configuration of the surround loudspeakers. In the 1980's, IMAX® Corporation standardized on a 6-channel sound system with a discrete surround sound configuration and a separate sub-bass channel for IMAX® Theatres. This type of system provides substantially better sound imaging by utilizing custom-designed loudspeakers located in each rear corner behind the audience, each powered by a separate audio channel. The immersive effects of this type system are much more impressive, and allow the filmmaker the ability to position sound more precisely—directly in front of, in front above, around, and behind the audience. In 1987, Imax installed the first Digital Sound Reproducer in an IMAX Theatre. By 1990, uncompressed Digital Sound was available to all IMAX Theatres. Also in 1990, with the release of the movie “Dick Tracy,” CDS uncompressed digital sound on 35 mm film was introduced to the general cinema industry by a joint venture of Orcon and Kodak. Because CDS was not compatible with standard optical sound on 35 mm film, the CDS format was discontinued soon thereafter. Between 1992 and 1993, three systems of digital sound for cinema were released—Dolby Digital, DTS, and Sony SDDS. All three of these formats utilized some form of digital compression to reduce the storage requirements (on CD-ROM for DTS) or to allow the digital audio signal to be printed on the 35 mm film (with Dolby Digital and SDDS) without displacing the optical track as did the CDS system. While these systems use different compression techniques—some considered “better sounding” than others—IMAX Digital Sound remains the only uncompressed digital cinema sound format in general use today. All three of the digital sound systems used in conventional 35 mm and digital cinemas make use of the same distributed side and rear surround loudspeakers to create a sense of ambience for the film soundtrack. Even though these digital systems may sound “better” than the older optical systems, sound immersion remains limited due to the inability of multiple distributed loudspeakers to provide precise directionality and image placement. Motion picture exhibitors have expressed interest in providing additional quality improvements to mainstream motion pictures by adding a special, custom designed, smaller scale Imax theatre to their multiplexes. This has proved popular with patrons and exhibitors, but has not been widely adopted because of high costs associated with constructing the adjunct theatre. It is desirable to be able to provide mainstream multiplex theatres with the same manner of widescreen presentation experience as large hall custom designed theatres, but at a lower, more affordable cost. There is a need to be able to economically convert an existing mainstream multiplex motion picture theatre into a widescreen theatre that is qualitatively superior in terms of projected image quality, field of view, and of a more realistic immersive audio experience that does not exist in multiplex type theatres. As a result of having overbuilt the number of multiplex theatres the economics of this situation dictates that converting existing multiplex theatres makes better sense than building additional new multiplexes with larger screen sizes. The following discussion of the inventive approach by the applicant addresses this need. SUMMARY OF THE INVENTION The invention is a method of cost effectively converting an existing standard motion picture theatre, such as the multiplex theatre that uses film/digital projection, to a highly immersive, large field of view motion picture theatre. Hereinafter the term “multiplex theatre” is used in a more general sense to represent all motion picture theatres that are: not the Grand Theatre hall sizes of the 1920s, not the theatrical stage theatres, and not the IMAX geometry theatre halls originally built for Imax presentations. The inventive method includes: moving the motion picture screen closer to the audience to increase the field of view; and employing projection means to improve the quality of images on the screen such that the audience does not see unrealistic or non-natural image artefacts which would occur by just simply magnifying the existing projected image. In some situations, carrying out the first step may inadvertently block access to an existing emergency exit door necessitating an additional step of moving a portion of the screen to allow access to the emergency exits. To cost effectively convert a multiplex theatre sound system so that a realistic audio immersion experience is created may involve the following: changing the loudspeaker configuration to one that uses 5 discrete loudspeakers with Proportional Point Source technology and one sub-bass loudspeaker; and driving each loudspeaker from a separate sound channel; with the sound system using a 5.1 sound track that is mixed differently than standard cinema 5.1 sound track and the sound system using uncompressed digital sound with a resolution of 16 bits or greater. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a typical multiplex theatre. FIG. 2 is an elevation view of a typical existing theatre. FIG. 3 is a plan view of a multiplex theatre after conversion. FIG. 4 is an elevation view of a multiplex theatre after conversion. FIG. 5 is a plan view of a converted multiplex theatre illustrating a novel emergency exit access system. FIG. 6 is an elevation view of a converted theatre illustrating a novel emergency exit access system. FIG. 7 is a front view of the screen in a converted theatre illustrating the novel emergency exit access system in a normal state. FIG. 8 is a front view of the screen in a converted theatre illustrating the novel emergency exit access system in an activated state. FIGS. 9a-9b are a plan view of a converted theatre and a front view of the screen illustrating the position of the PPS speakers. DETAILED DESCRIPTION OF THE DRAWINGS Referring now to FIG. 1, a plan view of a typical 35 mm film and/or digital multiplex theatre is depicted at 1. Theatre 1 includes a front projection screen 2, motion picture projector 3, a theatre enclosure rear wall 4, a seating deck 5 upon which there are seats for spectators 6. The distance d1 indicates the distance from the centre of screen 1 to the inner surface of rear wall 4. The space between the screen and the rear wall is occupied by a screen support structure (not shown) and sound system speakers (also not shown). Angle AOB represents the horizontal field of view of the motion picture theatre as seen from a location coincident with the point of projection, O. In the case of FIG. 1, this angle equals approximately 45 degrees. This represents a minimum horizontal field of view for patrons in the theatre; as one sits closer to the screen the horizontal field of view increases. A patron sitting at position X in FIG. 1, for example, would have a horizontal field of view of 55 degrees, as is indicated by angle AXB. The widest possible field of view in a theatre such as depicted in FIG. 1 is indicated by the angle AZB representing a patron sitting in a seat in the front row, and is equal to about 110 degrees. It must be noted however that in a typical multiplex cinema theatre the visual quality of images when viewed from a close position, like point Z in FIG. 1 is not as good when seated further back. In the close-up seats unnatural visual defects such as insufficient image resolution, film grain, visible pixels, blurred edges, and image unsteadiness are more easily perceived. Generally, patrons in these theatres tend to sit further from the screen when given the opportunity where image defects are less apparent. FIG. 2 illustrates an elevation view of multiplex cinema theatre 1. It can be seen that screen 2 is less than the full height of the theatre with observable gaps above the upper edge of the screen and below the lower edge of the screen. These gaps would be covered up by dark curtains or similar observant material to help conceal the limited vertical extent of screen 2. Angle COD represents the minimum vertical field of view in a theatre of this geometry and is equal to about 20 degrees. As one moves closer to the screen, the vertical field of view increases, as one would expect. At position X the vertical field of view is about 25 degrees while at position Z, it is about 50 degrees. It can be seen that seating deck 5 is sloped at an angle of about 20 degrees in the rear portion of the theatre and about 15 degrees in the section closer to the screen. This slope, or rake, of seating deck 5 allows each row of seats to be located on a separate platform thereby giving patrons a clear vertical field of view of the entire screen. The horizontal and vertical fields of view available to patrons in a typical multiplex theatre are significantly below the capabilities of the human visual system, which is estimated to have a recognizable horizontal field of view of 120 degrees and a vertical field of view of about 70 degrees. The estimated perceptual field of view is about 200 degrees horizontally and 135 degrees vertical. Referring now to FIG. 3, the same multiplex cinema theatre is shown after conversion to an improved, more visually immersive motion picture theatre. Screen 2, shown in outline, has been removed and replaced by a new, larger screen 10 which is now located at a new distance, d2, from rear wall 4. Screen 10 extends from wall to wall, and as shown in FIG. 4, extends from floor to ceiling. The hatched area in the lower part of seating deck 5 in FIG. 3 represents seats that have been removed to accommodate the new screen and viewing geometry of the improved theatre. A new projector 7 replaces the standard multiplex cinema projector and is capable of projecting images with superior quality in terms of resolution, sharpness and steadiness. The minimum horizontal field of view of the improved theatre is now about 55 degrees, while the minimum vertical field of view is about 30 degrees. At position X, the horizontal field of view is about 75 degrees and the vertical field of view is about 40 degrees. At position Z the horizontal field of view is about 130 degrees and the vertical field of view is about 80 degrees. To a viewer sitting at the seat closet to the screen centre, the new screen position and size appears 115% larger than the conventional screen size. To the viewer sitting at the position X in the theatre with the new screen position and size the screen size appears to have increased 100%. To the viewer sitting at the rear most position of the theatre with the new screen position and size the screen size appears to have increased 85%. The viewer in position X, when the screen has been moved forward, experiences an increase in image angular FOV of about 35% horizontally and 60% vertically. The increase in vertical FOV is especially significant and is an improvement that until now has been largely overlooked by the prior art traditional cinema system advances such as Cinerama which concentrated on expanding horizontal FOV. The increased FOV, both vertical and horizontal, is an important presentation improvement resulting from the inventive method of theatre conversion. It is possible to only increase the image fidelity of the projection system such that the viewers see the same fidelity of image on the forward moved screen as when the screen was positioned prior to the conversion. This would mean that viewers in the first few front row seats in the converted theatre would experience the same quality of image prior to the conversion that was already marginally low, hence, one reason viewers move further back in the theatre. The most evident image fidelity issues of front row viewing are lack of image resolution, the presence of film grain artefacts becoming apparent, or in the case of digital projection, image pixels becoming apparent. Other factors only associated with conventional film projectors that specifically contribute to image contrast MTF degradation are film transport unsteadiness and softening of film image due to heat pop of the film. In the theatre conversion front row seats have been removed, so there are fewer seats in the theatre. To give front row seats a more acceptable viewing experience the image projection fidelity can be further increased so that the front row viewers now get the same or better image quality as the viewers seated further back from the screen prior to the conversion. In the preferred embodiment one type of projector that uses film with a larger image area and does not suffer from image unsteadiness or film heat pop associated with conventional cinema film projection systems is the rolling loop projection system. The combination of improved image quality on the screen with increased horizontal and vertical fields of view significantly improves the sensation of visual immersion in the images. Applicant has confirmed through research studies in perception and cinema viewer's preferences, the improvement in the presentation of the converted theatre is significantly better than the presentation in a standard multiplex cinema theatre. In addition to significantly improving image quality and the enhancing the feeling of immersion in 2D images, the wider fields of view provided by the inventive method of theatre conversion is necessary for proper and realistic immersive experiences of 3D motion picture presentations. In some multiplex theatre designs emergency exits are at the screen end of the theatre on the side wall. These exits could be blocked by the new position of the screen in a converted theatre. This situation may not be acceptable by local safety regulations. The inventive conversion method addresses this possibility by inclusion of an emergency screen access system consisting of a system door and means for automatic activation of said door. FIGS. 5 through 8 illustrate one embodiment of such a system. Referring now to FIGS. 5 and 6, an emergency exit door 21 which was located in front of original screen 2, shown in outline, is now located behind new screen 10. Motion picture screen 10 consists of a perforated, pliable projection surface material such as vinyl which is supported and stretched by a frame (not shown) located behind the projection surface. FIG. 7 illustrates schematically how one corner of projection screen 10 is not fastened rigidly to a supporting frame, but is held in place by the magnetic attraction between metal rods 25 in the edges of screen 10 and electromagnetic means 26 attached to the wall and floor of the converted motion picture theatre. A cable 23 is attached to the rear corner of the projection surface of screen 10. The other end of cable 23 is attached to a counterweight 24 after first passing over a pulley 22 attached to the rear wall surface 4. In an emergency situation, an automatic activation means sends a signal to electromagnets 22 switching them off thereby removing the magnetic force which had been holding the metal rods firmly against the wall and floor of the theatre. The corner of the projection surface of screen 10 is then pulled backwards and upwards by the counterweight as it falls by gravity towards the ground. FIG. 8 depicts the system door to the emergency exit in an activated position with the corner of screen 10 pulled upwards and backwards and counterweight 24 resting on the ground. An illuminated sign is shown at 27 directs patrons to the newly revealed emergency exit 21. Winching means, not shown, is used to pull up the counterweight so that the system and screen can be reset after it has been activated. The activation signal may be effected by a number of activation systems, separately or in parallel, including a mechanical swing gate crash bar located at the bottom aisle stairs, pushing or applying pressure to the screen surface, by a signal from the building emergency alarm system, a manual release button at the usher station, or by a patron activated motion, IR or touch pad sensor near the vicinity of the corner of screen. In addition to the potential necessity of using the emergency screen access system there are other negative consequences associated with the inventive method of multiplex theatre conversion that must be remedied or accepted including the creation of a large sound cavity behind the new screen assembly, and the necessity to remove a number of seats near the front of the theatre which are too close to the new screen for effective viewing. The first problem is addressed by the provision of a sound absorbing acoustic wall behind the new screen, that can be built inexpensively because it need not be a load bearing structural wall. If the sound barrier is forward of the theatre exit door an additional door would have to be built into the sound barrier. The second problem, seat removal, and the loss of revenue associated with those seats, is not overly detrimental to the success of the multiplex complex because a higher admission price can be charged for the remaining seats. In addition, it is believed that the premium quality and unique immersive experience offered by the new motion picture will lead to a higher, and sustained, level of theatre occupancy over its operating lifetime. The conversion of a 35 mm film and/or digital projection multiplex theatre is not limited to the steps outlined above but can include further steps such as: tilting the screen forward or backwards with respect to the audience to increase the screen surface area in the vertical dimension or to compensate for keystoning or light reflection back to the audience; curving the screen in the vertical direction to provide a compound curved screen; or modifying the ceiling to provide additional vertical height for the new screen. The conversion is also not limited to improving the quality of the visual experience but also converting the sound system to give a significantly more realistic and immersive audio experience. A truly immersive audio environment, similar to what the audience experiences in an IMAX® Theatre, is one in which the sound system has the ability to realistically position sound images in front of, around, and behind the audience. The converted sound system must be reasonably cost effective and at the same time create a realistic immersive audio experience for the majority of seats in the theatre. A conversion that does this is described below. The theatre sound system is setup with a loudspeaker configuration as illustrated in FIGS. 9a and 9b. FIG. 9a is a plan view of the loudspeaker positions in a converted theatre and FIG. 9b is a front view of the loudspeakers behind the screen in a converted theatre. There are 5 loudspeakers 101, 102, 103, 104, and 105, each driven from a separate audio source, and each with appropriate amplification and equalization. There is a 6th Sub-Bass Loudspeaker assembly 106 consisting of several sub-woofer elements grouped together that re-produce the low-frequency sound derived from the 5 audio channels. Powered with sufficient amplification these loudspeakers provide realistic sound levels for low-frequency sounds such as rocket launches, earthquakes, and explosions. Each audio channel is fed uncompressed digital sound with a resolution of 16 bits or greater from the Digital Sound Reproducer. The Digital Sound Reproducer is normally positioned in the sound rack 120 in the projection booth. The loudspeaker positions in the theatre are referred to as: Left Rear 101, Left Screen 102, Center Screen 103, Right Screen 104, Right Rear 105 and the Sub Bass position 106. Loudspeakers 102, 103, and 104 in the front are positioned between the newly installed sound barrier 110 and the screen 10, part way between the screen base and top. Sub bass 106 is located between the sound barrier 110 and the screen 10 under Center Screen 103. The screen is perforated with tiny holes to let the sound through yet obscure speaker visibility. The complete sound system is designed to cover the entire audio spectrum and provide sufficient sound level within the theatre. Loudspeakers 101, 102, 103, 104, and 105 are designed with Proportional Point Source (PPS) Technology. The principles of the physics used in PPS Loudspeaker technology is known to those skilled in the art. In general terms PPS Loudspeaker technology refers to the ability of a loudspeaker to direct proportionately more sound energy to seats farther away than that directed to the closer seats from a single or virtually single source position. Hereinafter this will be referred to as “PPS technology.” In order to achieve optimum sound dispersion, PPS type loudspeakers must be designed for the specific theatre geometry. IMAX® Loudspeakers used in this conversion are designed with PPS Technology, using horns with asymmetrical dispersion patterns specifically designed to provide balanced sound distribution for multiplex cinemas having the appropriate geometry. During installation each loudspeaker is placed, aimed, and aligned to position the sound dispersion pattern for maximum immersive effect. The alignment process involves use of computer aided design to determine the optimum loudspeaker “pointing angle” for each of the 5 loudspeakers in the theatre. Then, with the use of LASER alignment tools, the loudspeaker can be aimed to match the predetermined “pointing angle.” A cinema sound system using PPS technology properly configured and equalized to the accepted industry standard, allows all theatre patrons to perceive sound from all channels as having essentially the same volume level and tonal quality. Thus, the sound “image” desired by the filmmaker is reproduced for the entire audience area. Surround sound systems that do not employ the use of PPS-type loudspeakers provide balanced sound, or a “sweet spot” for only a few seats—generally near the center of the theatre. Other patrons may hear only one or two loudspeakers predominantly, with little contribution from the other sound channels. There are three significantly differentiating aspects of the converted sound system with respect to multiplex cinema sound systems. Not only has this type of immersive surround sound system conversion not been done before in multiplex theatres, there are differences that make the invented sound system conversion process truly unique. The first differentiating aspect is that the sound system, as shown in FIGS. 9a-9b, uses discrete loudspeakers in the rear corners of the theatre with separate sound channels to provide the greater surround sound imaging capability. All conventional surround systems used in multiplex cinemas make use of distributed side and rear surround loudspeakers to create a sense of ambience but these lack the ability to provide precise sound directionality and sound image placement. Secondly, in a sound system with 5 discrete PPS type loudspeakers and sound channels it becomes possible to place sound images in front of, around, and behind the audience. To optimize sound placement in a 5 channel discrete source sound system the 5 sound tracks must be re-mixed in order to provide the audience with a truly more realistic immersive audio experience. Multiplex Cinemas have not configured their sound system setup in this way before. The third aspect relates to the Digital Sound Reproducer. As previously noted, other multiplex cinema sound systems utilize either optical analog audio tracks printed on the film, or one of three digital sound formats—all of which compress the digital audio by significant amounts in order to fit the storage/playback media. The Digital Sound Reproducer within the converted theatre uses uncompressed digital sound with a resolution of 16 bits or greater to provide all the audio resolution and dynamic range intended by the filmmaker and the film sound engineer. The IMAX multiplex theatre converted sound system with its unique Digital Sound Reproducer will provide very high quality digital audio surpassing all other available cinema sound formats in fidelity, resolution, dynamic range and sound image placement capability. The result is sound unrivalled in achieving the goal of a realistic immersive cinema experience, and the “suspension of disbelief” desired by filmmakers. The result of a multiplex theatre converted using some or all the steps described above creates for the audience a substantially improved realistic visual and audio immersion experience for 2D and 3D motion picture presentations. To date, this type of conversion has not been done before in multiplex theatres. The foregoing is provided for purposes of illustrating, explaining, and describing exemplary embodiments and certain benefits of the present invention. Modifications and adaptations to the illustrated and described embodiments will be apparent to those skilled in the relevant art and may be made without departing from the scope or spirit of the invention. | <SOH> BACKGROUND <EOH>Motion picture exhibition has seen a number of changes since its inception in the late 19 th century. Generally, the main variables in motion picture exhibition have been the dimensions of the theatre enclosure and correspondingly the number of seats therein, the size of the screen upon which images were projected and the dimensions or format of the film negative which contained the images for presentation. Although a number of film formats were considered, one format, 35 mm wide film having an image aspect ratio of 4:3 became the industry standard. Motion picture theatres gradually evolved in size from smaller theatres to larger so-called palace theatres featuring several hundred to thousands of seats, balconies, and elaborate facades. Despite the impressive and somewhat regal atmosphere these theatres continued to feature 35 mm film projected onto narrow width screen. Eventually in the late 1920s, motion picture producers and exhibitors started experimenting with larger film formats which could enhance the visual immersion of theatre patrons and live up to the size and scope of the large palace theatres. Some of the wide gauge/wide screen processes that appeared to challenge the 35 mm film standard included Magnascope, Polyvision, Hypergonar and Fox Grandeur. Magnascope used a novel magnifying lens to enlarge a standard 35 mm frame. Polyvision used multiple 35 mm film projectors to stitch together a composite image, while Fox Grandeur replaced 35 mm film entirely with a new 70 mm wide film format. Finally Hypergonar used a novel method of anamorphically squeezing images onto a 35 mm frame during filming and then reversing the process upon projection to fill a larger projection screen. Although technically and aesthetically successful, the proposed wide screen systems failed to replace 35 mm as a film standard in the economically depressed 1930s and were soon abandoned. Conditions had changed somewhat by the early 1950s and the motion picture industry saw a resurgence of proposals for wide gauge/wide screen systems. Foremost among the new systems were Cinerama, a multiple 35 mm projection system, Cinemascope, an anamorphic system, Vistavision a 35 mm 8 perforation format system and Todd AO, a wide gauge system using a 70 mm 5 perforation 30 frame per second format. The new formats were successful at the box office and survived for a number of years, but none was able to seriously challenge the 35 mm film standard. A third wave of wide gauge/wide screen motion picture exhibition started in 1969, led by IMAX Corporation, which featured the use of horizontally travelling 70 mm film with a film frame of 15 perforations in width resulting in an image area about ten times that of standard 35 mm. In addition to the large film format IMAX® re-conceptualized the theatre viewing space by providing significantly larger screens which extended beyond spectators fields of view, steeply raked seating area to give unobstructed viewing of said large screen, and high fidelity six channel sound to surround the audience. The net result of these advances was a theatre experience in which audience members were immersed in image and sound as never before. IMAX® theatres were successful in the institutional and exhibit marketplace. Other competing large format systems include Showscan's 70 mm 5 perforation film projected at 60 frames per second (versus the standard 24 fps) and Iwerk's 70 mm 5, 8 and 15 perforation film systems. In most cases IMAX® systems were installed in custom designed motion picture theatres having a large volume to house both the large screen and a steeply raked seating deck. Occasionally IMAX® projection systems were placed in large hall converted stage theatres. IMAX® screens could be placed in front of the stages in such theatrical structures without building structure modifications because of the large existing clear height. In some cases, such as at the Museum of Natural History in New York City, a retractable IMAX® screen was placed in front of the stage that had an existing 35 mm screen at the back of the stage. Some seats at the side of the theatre near the position of the IMAX® screen were removed because the visual quality at those locations was poor. The slope of the seating areas in these theatrical theatres is typically shallow, and financial constraints prevented conversion to a more desirable steeper slope. As a result, the viewing conditions in such converted theatres were not optimized for viewing IMAX® motion pictures. Grand theatres of the type frequented in the 1920s thru 1950s were sometimes converted to house the emerging wide gauge/widescreen systems of the 1950s. Conversion consisted of changing the width and curvature of the screen to match the new wider picture aspect ratio and removing a relatively high percentage of seats that no longer had viable viewing conditions. Screen centres were basically positioned at the original screen centre position at the rear wall of the theatre, and the rake of seats in the theatres was not a consideration in the conversion process. Another type of theatre conversion addresses the desire to present motion pictures in either of two common aspect ratio formats, which are 1:85:1 and 2.35:1. The conversion process involves adjusting the curtain masking around the screen to suit the format of presentation as well as changing the lens and aperture plate. The position of the screen itself does not change. A major trend in the motion picture industry starting in the 1970s was to group a number of small 35 mm film theatres into one large complex, or so-called multiplex theatre. These theatres, although profitable, did not provide patrons with a quality viewing experience. Over time movie attendance declined partly because of new home entertainment technologies such as cable TV, video cassette recorders, and home movie rentals. In the 1990s the motion picture exhibition industry responded to declining movie attendance by building new theatres offering stadium seating—placing each row of seats on its own tier—to improve the sight lines and thus the viewing experience of patrons. This industry advance has been very successful in improving movie attendance and is now an expected feature for theatre patrons; conventional low slope seating decks are seen as “old” and inferior. (LA Business Journal). The new stadium seat theatres, while an improvement over traditional multiplex theatres, still rely on standard 35 mm film projectors and do not provide patrons with a wide field of view or highly immersive experience. It should be noted that in the later half of the 1990s the use of digital projectors began in a few multiplex cinemas. This trend in time will increase as digital projection systems get better in quality and higher in image resolution. Another aspect of the conversion is to improve the quality of the audio portion of the immersive experience in a multiplex type theatre. Sound systems for cinema have evolved over the decades and the trend continues as an ongoing effort to attract the paying viewer. The surround sound systems used in today's Multiplex theatres can provide a degree of “ambience” in the audio experience but these systems still lack the ability to create realistic immersive audio. From the time “talkies” were introduced, motion picture cinemas had “monaural” sound systems, having only one loudspeaker located behind the center of the screen. The sound experience in such a cinema was very one dimensional and flat, with no ability to simulate sounds coming from directions other than the center of the picture. In order to improve the audio experience, cinema designers and equipment suppliers experimented with a variety of multiple loudspeaker (“multi-channel”) schemes designed to immerse the audience in a sound field which could add to the “suspension of disbelief” desired by filmmakers. One of the earliest attempts at multi-channel sound was the premier of Walt Disney's “Fantasia” in 1939. Disney experimented with a number of sound system loudspeaker configurations as outlined in an article by William E. Garity and John N. A. Hawkins published in the August 1941 issue of the journal of the SMPTE. The last two versions of the Fantasound system, known as Mark IX and X, used 5 loudspeakers and sound from 3 separate tracks. The loudspeakers were positioned such that 3 were behind the screen (i.e. left, center, and right) and one loudspeaker was in each rear corner. The two sets of rear corner loudspeakers were switched in to supplement or replace the corresponding left and right front loudspeakers at select times during the picture presentation. Unfortunately, the war and economics cut short Disney's sound system experiments. In the early 1950's, Cinerama brought multi-channel sound to the forefront again with 5 to 7 loudspeaker channels located around the audience. During the 1950's there were several theatres equipped for the playback of multi-channel sound, of which there were primarily two formats both using magnetic stripes printed on the film. The CinemaScope 35 mm film format provided four discrete channels, consisting of 3 loudspeakers behind the screen and a monaural surround channel provided by several small loudspeakers located on the side and rear walls of the cinema. These surround loudspeakers provided a degree of “ambience” to the sound experience in combination with the directional sound produced by the 3 screen loudspeakers, and thus added to the immersive effects presented to the audience. The Todd-AO 70 mm film format added two additional loudspeakers behind the screen, Left Center and Right Center, between the center loudspeaker and the left and right speakers. In the 1970's, Dolby pioneered several advances in cinema sound, including extended low-frequency sound (sub-bass), noise reduction, and Stereo Optical sound. Dolby Stereo Optical provided 4 channels of sound (left, center, right, and mono surround) using an encoding technique to store the analog soundtrack on two analog optically printed stripes on the film. This became the standard for normal cinemas, and remains in use today in non-digital cinemas. In 1979, Dolby added to the immersive effects of cinema sound by developing stereo surrounds, in which the left distributed loudspeaker channel could reproduce different sounds than the right channel. But, the surround effects were still effectively ambience sounds, and were unable to reproduce directionality with any precision due to the distributed configuration of the surround loudspeakers. In the 1980's, IMAX® Corporation standardized on a 6-channel sound system with a discrete surround sound configuration and a separate sub-bass channel for IMAX® Theatres. This type of system provides substantially better sound imaging by utilizing custom-designed loudspeakers located in each rear corner behind the audience, each powered by a separate audio channel. The immersive effects of this type system are much more impressive, and allow the filmmaker the ability to position sound more precisely—directly in front of, in front above, around, and behind the audience. In 1987, Imax installed the first Digital Sound Reproducer in an IMAX Theatre. By 1990, uncompressed Digital Sound was available to all IMAX Theatres. Also in 1990, with the release of the movie “Dick Tracy,” CDS uncompressed digital sound on 35 mm film was introduced to the general cinema industry by a joint venture of Orcon and Kodak. Because CDS was not compatible with standard optical sound on 35 mm film, the CDS format was discontinued soon thereafter. Between 1992 and 1993, three systems of digital sound for cinema were released—Dolby Digital, DTS, and Sony SDDS. All three of these formats utilized some form of digital compression to reduce the storage requirements (on CD-ROM for DTS) or to allow the digital audio signal to be printed on the 35 mm film (with Dolby Digital and SDDS) without displacing the optical track as did the CDS system. While these systems use different compression techniques—some considered “better sounding” than others—IMAX Digital Sound remains the only uncompressed digital cinema sound format in general use today. All three of the digital sound systems used in conventional 35 mm and digital cinemas make use of the same distributed side and rear surround loudspeakers to create a sense of ambience for the film soundtrack. Even though these digital systems may sound “better” than the older optical systems, sound immersion remains limited due to the inability of multiple distributed loudspeakers to provide precise directionality and image placement. Motion picture exhibitors have expressed interest in providing additional quality improvements to mainstream motion pictures by adding a special, custom designed, smaller scale Imax theatre to their multiplexes. This has proved popular with patrons and exhibitors, but has not been widely adopted because of high costs associated with constructing the adjunct theatre. It is desirable to be able to provide mainstream multiplex theatres with the same manner of widescreen presentation experience as large hall custom designed theatres, but at a lower, more affordable cost. There is a need to be able to economically convert an existing mainstream multiplex motion picture theatre into a widescreen theatre that is qualitatively superior in terms of projected image quality, field of view, and of a more realistic immersive audio experience that does not exist in multiplex type theatres. As a result of having overbuilt the number of multiplex theatres the economics of this situation dictates that converting existing multiplex theatres makes better sense than building additional new multiplexes with larger screen sizes. The following discussion of the inventive approach by the applicant addresses this need. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention is a method of cost effectively converting an existing standard motion picture theatre, such as the multiplex theatre that uses film/digital projection, to a highly immersive, large field of view motion picture theatre. Hereinafter the term “multiplex theatre” is used in a more general sense to represent all motion picture theatres that are: not the Grand Theatre hall sizes of the 1920s, not the theatrical stage theatres, and not the IMAX geometry theatre halls originally built for Imax presentations. The inventive method includes: moving the motion picture screen closer to the audience to increase the field of view; and employing projection means to improve the quality of images on the screen such that the audience does not see unrealistic or non-natural image artefacts which would occur by just simply magnifying the existing projected image. In some situations, carrying out the first step may inadvertently block access to an existing emergency exit door necessitating an additional step of moving a portion of the screen to allow access to the emergency exits. To cost effectively convert a multiplex theatre sound system so that a realistic audio immersion experience is created may involve the following: changing the loudspeaker configuration to one that uses 5 discrete loudspeakers with Proportional Point Source technology and one sub-bass loudspeaker; and driving each loudspeaker from a separate sound channel; with the sound system using a 5.1 sound track that is mixed differently than standard cinema 5.1 sound track and the sound system using uncompressed digital sound with a resolution of 16 bits or greater. | 20040505 | 20060912 | 20051110 | 96841.0 | 1 | FULLER, RODNEY EVAN | CONVERSION OF CINEMA THEATRE TO A SUPER CINEMA THEATRE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,839,668 | ACCEPTED | Invoking applications with virtual objects on an interactive display | One or more objects placed on a display surface of an interactive display system are identified by a camera that receives infrared light reflected back by the object(s) through the display surface. The interactive display system displays images on the display surface that are produced by software applications, as well as sensing objects placed proximate to the display surface. If object(s) that were placed on the display surface are identified and determined to be associated with a predefined software application, the application is automatically executed. Objects can be identified based upon shape, a pattern applied to the objects, a size of the object, or a location on the display surface where the object is placed. The object may be used in the software application after it is executed or may simply be bear a functional relationship to the software application. | 1. A method for executing a software application in response to at least one object being placed on a display surface, comprising the steps of: (a) detecting at least one characteristic of each said at least one object placed on the display surface, to identify each said at least one object as a function of said at least one characteristic thereof; and (b) determining if one object identified is uniquely associated with executing only one software application, and if so, executing said one software application if already installed for use by a current user of the display surface, and if not, determining if a plurality of objects that have been placed on the display surface and have been identified are uniquely associated with executing only one software application, and if so, executing said one software application if installed for use by the current user of the display surface. 2. The method of claim 1, wherein if the software application has not been installed for use, further comprising the steps of: (a) connecting to a predefined remote storage over a network, said predefined storage storing the software application; (b) downloading the software application from the predefined remote storage over the network; (c) installing the software application for use with the display surface; and (d) executing the software application. 3. The method of claim 2, wherein the step of installing includes the step of registering the software application. 4. The method of claim 2, further comprising the step of enabling a current user of the display surface to enter information relating to one of a debit and a credit account for use in making online purchases, said information being stored locally. 5. The method of claim 4, further comprising the step of enabling the current user of the display surface to purchase the software application prior to downloading it, by automatically transmitting the information relating to said one of the debit account and credit account to an entity associated with the remote storage. 6. The method of claim 1, wherein the step of detecting comprises the steps of: (a) illuminating said at least one object placed on the display surface with light that passes through the display surface and is incident on said at least one object placed on the display surface; (b) receiving light reflected from said at least one object placed on the display surface; (c) producing a signal corresponding to the light that is received; (d) processing the signal to determine said at least one characteristic for each object placed on the surface, to identify each said at least one object. 7. The method of claim 1, wherein said at least one characteristic comprises at least one of: (a) a shape of the object; (b) a size of the object; (c) a color of the object; (d) an electrical characteristic of the object; (e) a radio frequency signature of the object; (f) a location where the object is placed on the display surface; and (g) a pattern disposed on the object. 8. The method of claim 1, further comprising the step of employing said at least one object within the software application after the software application has been executed. 9. The method of claim 1, wherein said at least one object is related to a function of the software application. 10. The method of claim 1, wherein said at least one object comprises a component provided with the packaging in which the software application was sold, further comprising the step of detecting indicia on the component that identify the software application to be executed, and in response, executing the software application. 11. The method of 1, wherein if said at least one object is associated with a plurality of software applications, further comprising the steps of: (a) indicating the plurality of applications with which said at least one object is associated to the current user; and (b) enabling the current user to select one of the plurality of applications to be executed. 12. The method of claim 11, further comprising the step of indicating a subset of the plurality of software applications when an additional object is placed on the display surface, said subset of the plurality of software application being associated with said at least object previously placed on the display surface and with said additional object just placed on the display surface. 13. A memory medium on which machine executable instructions are stored for executing the steps of claim 1. 14. A system for executing a software application in response to at least one object being identified, comprising: (a) an interactive display system including a projector, an object detector, and a display surface on which images produced by the software application are displayed by the projector when the software application is executed; (b) a memory in which are stored machine instructions; (c) a processor that is coupled to the interactive display system and to the memory, said processor executing the machine instructions, which cause the processor to carry out a plurality of functions, including: (i) using the object detector to detect at least one characteristic of each said at least one object after said at least one object is placed on the display surface, each said at least one object being identified as a function of said at least one characteristic thereof that is detected; and (ii) determining if one object that is identified is uniquely associated with executing only one software application, and if so, executing the software application if the software application has been installed on the interactive display system, and if not, determining if a plurality of objects placed on the display surface and identified are uniquely associated with executing only one software application, and if so, executing the software application if the software application has been installed on the interactive display system. 15. The system of claim 14, wherein if the software application is not stored in the memory because it has not yet been installed on the interactive display, the machine instructions further cause the processor to: (a) connect to a predefined remote storage over a network, said predefined remote storage storing the software application; (b) download the software application from the predefined remote storage over the network; (c) install the software application for use with the display surface; and (d) execute the software application. 16. The system of claim 15, wherein the machine instructions further cause the processor to register the software application. 17. The system of claim 15, wherein the machine instructions further cause the processor to store information relating to one of debit account and a credit account in the memory, for use in making online purchases, including an online purchase of the software application. 18. The system of claim 17, wherein the machine instructions further cause the processor to enable a current user of the interactive display to purchase the software application prior to downloading it over the network, by automatically transmitting the information relating to said one of the debit account and credit account to an entity associated with the remote storage. 19. The system of claim 14, wherein the interactive display further includes a light source disposed under the display surface that illuminates said at least one object placed on the display surface with light that passes through the display surface and is incident on said at least one object, said object sensor comprising a camera that receives light reflected from said at least one object placed on the display surface and produces a signal corresponding to the light that is received, said signal being coupled to the processor, and said machine instructions further causing the processor to determine said at least one characteristic for each object placed on the surface, to identify each said at least one object. 20. The system of claim 14, wherein said at least one characteristic comprises at least one of: (a) a shape of the object; (b) a size of the object; (c) a color of the object; (d) an electrical characteristic of the object; (e) a radio frequency signature of the object; (f) a location where the object is placed on the display surface; and (g) a pattern disposed on the object. 21. The system of claim 14, wherein said at least one object is employed within the software application after the software application has been executed. 22. The system of claim 14, wherein said at least one object is related to a function of the software application. 23. The system of claim 14, wherein said at least one object comprises a component provided with the packaging in which the software application was sold, further comprising the step of detecting indicia on the component that identify the software application to be executed, and in response, executing the software application. 24. The system of claim 14, wherein the light source emits infrared (IR) light, and wherein the object detector comprises an IR bandpass filter that transmits IR light, but substantially blocks other light, so that said at least one characteristic of each said at least one object is indicated in an image formed by the object detector using IR light reflected back by the object and received by the object detector after passing through the IR bandpass filter. 25. The system of claim 23, wherein the machine instructions cause the processor to determine a shape of each object placed on the display surface using the image formed by the object detector, said shape comprising a characteristic of the object used to identify the object. 26. The system of claim 24, wherein the machine instructions cause the processor to compare the shape of each object placed on the display surface with a corresponding shape stored in memory and associated with the software program that is to be executed. 27. The system of claim 14, wherein if said at least one object is associated with a plurality of software applications, the machine instructions further cause the processor to: (a) indicate the plurality of applications with which said at least one object is associated; and (b) enable a user to select one of the plurality of applications to be executed. 28. The system of claim 27, wherein the machine instructions cause the processor to indicate a subset of the plurality of software applications when an additional object is placed on the display surface, said subset of the plurality of software application being associated with said at least object previously placed on the display surface and with said additional object just placed on the display surface. | FIELD OF THE INVENTION The present invention generally pertains to responding to a physical object that is placed on a display surface by launching a software application; and more specifically, pertains to detecting one or more physical objects placed on the display surface and in response, taking all necessary steps required to execute the software application on an interactive display system that includes the display surface. BACKGROUND OF THE INVENTION A user usually launches a software application by manipulating a mouse, joystick, wheel, game pad, track ball, or other user input device to select the application from a list of files or a group of graphic icons that represent applications installed on a personal computer (PC). Alternatively, the user may enter the path and executable file name for the application in a run dialog box to execute an application. Another form of user input for executing an application employs touch-sensitive displays that are responsive to the touch of a user's finger or a stylus on the display screen. Touch responsive displays can be pressure activated, responsive to electrical capacitance, changes in magnetic field intensity, or responsive to other variables to determine the location of a finger or stylus contacting the display screen. Another type of touch sensitive display includes a plurality of optical sensors spaced-apart around a periphery of the display screen so that the location of a finger or stylus touching the screen can be detected. Using one of these touch sensitive displays, a user can touch a graphic icon or file name of an application to select it and then tap once (or twice) on the icon or file name to execute it on the PC. However, touch sensitive systems are generally incapable of detecting more than a single point of contact and are typically unable to detect the shape of an object that is proximate to or touching a display screen. Another approach previously developed in the prior art that might be employed for launching an application uses cameras mounted to the side and above a horizontal display screen to visually capture an image of a user's finger or other object that is touching the display screen. This multiple camera mounting configuration is clearly not a compact system that most people would want to use in a residential setting. In addition, the accuracy of this imaging system in responding to an object that is on or proximate to the display surface depends upon the rather limited capability of the software used with the imaging system to visually recognize objects and their location in three-dimensional (3D) space. To address many of the problems inherent in other types of touch-sensitive displays and imaging sensing systems, particularly in regard to launching a specific application, a user interface platform was developed in the MIT Media Lab, as reported by Brygg Ullmer and Hiroshi Ishii in “The metaDESK: Models and Prototypes for Tangible User Interfaces,” Proceedings of UIST 10/1997:14-17. This article describes how the metaDESK includes a near-horizontal graphical surface that is used to display two-dimensional (2D) geographical information. Above the graphical surface is disposed an arm-mounted flat-panel display that serves as an “active lens” for use in displaying 3D geographical information. A computer vision system inside the desk unit (i.e., below the graphical surface) includes infrared (IR) lamps, an IR camera, a video camera, a video projector, and mirrors. The mirrors reflect the graphical image projected by the projector onto the underside of the graphical display surface. The IR camera can detect a distinctive pattern provided on the undersurface of passive objects called “phicons” that are placed on the graphical surface. Magnetic-field position sensors and electrical-contact sensors are also included in the metaDESK. The reference describes, for example, how the IR camera detects the IR pattern (which is transparent to visible light) applied to the bottom of a “Great Dome phicon” and responds by displaying a map of the MIT campus on the graphical surface, with the actual location of the Great Dome in the map positioned where the Great Dome phicon is located. Moving the Great Dome phicon over the graphical surface manipulates the displayed map by rotating or translating the map in correspondence to the movement of the phicon by a user. A similar approach to sensing objects on a display surface is disclosed in several papers published by Jun Rekimoto of Sony Computer Science Laboratory, Inc., in collaboration with others. These papers briefly describe a “HoloWall” and a “HoloTable,” both of which use IR light to detect objects that are proximate to or in contact with a display panel on which a rear-projected image is visible. The rear-projection panel, which is vertical in the HoloWall and horizontal in the HoloTable, is semi-opaque and diffusive, so that objects reflecting IR light back through the panel become more clearly visible to an IR camera as they approach and then contact the panel. The objects thus detected can be a user's fingers or hand, or other objects. In a paper entitled, “CyberCode: Designing Augmented Reality Environments with Visual Tags, Designing Augmented Reality Environments,” DARE (2000), Jun Rekimoto et al. disclose that the IR camera can recognize IR identification (ID) tags attached to objects that are placed on such a device. The reference teaches that “when a device with a camera recognizes these IDs, a predefined action—such as opening a specific web page—launching an application, or starting a movie, is activated automatically.” While using an ID tag on an object to launch a related application is thus known in the art, there does not seem to be any teaching about responding to a plurality of objects of about simply recognizing objects per se, such as by their shape of other characteristics. For example, it would be desirable to enable an optical sensing system to detect a specific object based on its shape, size, or other physical characteristics and respond by launching a related application. Thus, if a user places a camera on a display surface that includes an optical sensing system, it would be desirable to automatically detect the camera based upon its physical characteristic(s), and automatically launch an application to download images from the camera and to organize the images for storage, or to edit them. The prior art does not suggest how to deal with the situation that can occur when the application that should be launched in response to detecting an object is not installed on a local storage accessed by the interactive display that detects the object. It would be desirable to automatically respond by downloading the application program from a remote server or other remote storage site, if the application is not installed locally. Once downloaded, the application should be installed, registered to the current user of the interactive display (if appropriate), and then executed. Also, in some cases, a plurality of applications might be associated with one object, so that it would not be clear which software application to automatically launch when the object is detected on the display surface. Accordingly, it would be desirable to detect a plurality of objects that constitute a plurality of objects uniquely associated with a specific application, and then launch that specific application in response to detecting the plurality of objects or proximate to the display screen. SUMMARY OF THE INVENTION The present invention makes use of an interactive display system that serves both for display of text and graphics and for input in an intuitive manner. In connection with this invention, the interactive display system's ability to sense objects placed on a display surface of the interactive display system facilitates an automatic response to objects that have been associated with software applications, when the objects are placed on the display surface and are detected by the interactive display system. Accordingly, one aspect of the present invention is directed to a method for executing a software application in response to at least one object being placed on a display surface. The method includes the step of detecting at least one characteristic of one or more objects placed on the display surface in order to identify each object as a function of the characteristic(s) detected. The method then determines if one object identified is uniquely associated with executing only one software application, and if so, executes the software application if it is already installed for use by a current user of the display surface. If the one object that is identified is associated with more than one software application, the method provides for determining if a plurality of objects that have been placed on the display surface and have been identified are uniquely associated with executing only one software application. If so, the method provides for executing the one software application if it is installed for use by the current user of the display surface. An example will help to explain the significance of these steps. If dice are used for playing several different software games, a die might be a logical object to associate with each such software game. However, it will not be apparent which of the software games should be executed if a die is detected on the display surface. But, if one of the games also uses player pieces to indicate each player's position on a game board that is displayed, while each of the other games also uses some other objects during the game play, each such game software can be uniquely associated with a combination of two (or more) objects, so that when the two (or more) objects are detected on the display surface, the appropriate software game will be executed, if it is already installed on the system. If the software application has not been installed for use by the current user, the method further provides for connecting over a network to a predefined remote storage, where the software application is stored. The software application is downloaded over the network, from the predefined remote storage and is then installed and executed. The step of installing optionally also includes the step of registering the software application. In addition, if the software application can only be downloaded after a charge is paid, the method may include the step of enabling a current user of the display surface to enter information relating to either a debit or a credit account, or some other payment form arranged established by the user for making online purchases. This information will preferably be stored locally and can be transferred to the online site to complete the purchase as authorized by the user. Alternatively, the current user can purchase the software application prior to downloading it, by automatically transmitting the information relating to the user's account to an entity associated with the remote storage. The step of detecting is preferably carried out by illuminating the one or more objects placed on the display surface with light that passes through the display surface and is incident on the object(s). Light reflected from object(s) placed on the display surface is received and causes a corresponding signal to be produced. This signal is then processed to determine the one or more characteristics for each object placed on the surface, to identify the object(s). The one or more characteristic(s) can include one or more of a shape of the object, a size of the object, a location where the object is placed on the display surface, and a pattern disposed on the object. As noted above, in certain cases, the object(s) placed on the surface are used within the software application after the software application is executed, e.g., as dice, player pieces, a spinner, etc. In other cases, the object is easily perceived as being related to the software application. For example, a camera (or a plastic model of one) might be placed on the display surface to cause a photo editing software application to be executed. Alternatively, the object may be closely related to a function of the software application. Thus, a remote control may be placed on the display surface to cause a television program guide software application to be executed. If the software application was purchased in a package, placing the package on the display surface can cause that software application to be executed. Another aspect of the present invention is directed to a memory medium on which machine executable instructions are stored for carrying out functions generally consistent with the steps of the method discussed above. Yet another aspect of the invention relates to a system for executing a software application in response to at least one object being identified. The system includes an interactive display system having a projector, an object detector, and a display surface on which images produced by the software application are displayed by the projector when the software application is executed. A memory stores machine instructions, and a processor is coupled to the interactive display system and to the memory to execute the machine instructions, causing the processor to carry out a plurality of functions that are generally consistent with the steps of the method discussed above. BRIEF DESCRIPTION OF THE DRAWING FIGURES The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a functional block diagram of a generally conventional computing device or PC that is suitable for processing the input and output data used in practicing the present invention, and is alternatively also exemplary of a computing device that may be included within an interactive display system in accord with the present invention; FIG. 2A is an illustration of the interior of the interactive display table showing hardware components included, the paths followed by light within the interactive display table, and exemplary objects disposed on and above the surface of the interactive display table; FIG. 2B is a block diagram illustrating how the present invention can be implemented as an interactive display that is coupled to a stand alone personal computer or other computing device; FIG. 3 is a flowchart illustrating the logical steps employed to launch a software application in response to a specific object associated with the software application being detected on the display surface of the interactive display table of FIG. 2A; FIG. 4 is a flowchart illustrating the logical steps employed for launching a software application when a plurality of objects uniquely associated with the software application are placed on the display surface; FIG. 5 illustrates the display surface (the rest of the interactive display table is not included to simplify the drawing), showing an exemplary television programming guide that is displayed by a corresponding software application in response to a remote control being placed on the display surface of the interactive display table; FIG. 6 is an oblique view of the display surface of the interactive display table (the rest of the interactive display table is not included to simplify the drawing), showing how a puck used in an electronic hockey game is detected when placed on the display surface, causing the electronic hockey game to be executed; FIG. 7 is an oblique view of the display surface of the interactive display table (the rest of the interactive display table is not included to simplify the drawing), showing how a software package is detected when placed on the display surface, causing the software that was sold in the package to be installed and/or executed; FIG. 8 is an oblique view of the display surface of the interactive display table (the rest of the interactive display table is not included to simplify the drawing), showing how two objects used in an electronic game with which the objects are uniquely associated cause the electronic game to be loaded and executed when the two objects are detected on the display surface; FIG. 9 is a bottom view of an object illustrating an exemplary identifier code that is detected when the object is placed on the display surface of the interactive display table; and FIG. 10 is a bottom view of an object having a distinctive shape that is detected when the object is placed on the display surface of the interactive display table. DESCRIPTION OF THE PREFERRED EMBODIMENT Exemplary System for Implementing Present Invention With reference to FIG. 1, an exemplary system suitable for implementing various portions of the present invention. The system includes a general purpose computing device in the form of a conventional PC 20, provided with a processing unit 21, a system memory 22, and a system bus 23. The system bus couples various system components including the system memory to processing unit 21 and may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) 24 and random access memory (RAM) 25. A basic input/output system 26 (BIOS), containing the basic routines that help to transfer information between elements within the PC 20, such as during start up, is stored in ROM 24. The PC 20 further includes a hard disk drive 27 for reading from and writing to a hard disk (not shown), a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29, and an optical disk drive 30 for reading from or writing to a removable optical disk 31, such as a compact disk-read only memory (CD-ROM) or other optical media. Hard disk drive 27, magnetic disk drive 28, and optical disk drive 30 are connected to system bus 23 by a hard disk drive interface 32, a magnetic disk drive interface 33, and an optical disk drive interface 34, respectively. The drives and their associated computer readable media provide nonvolatile storage of computer readable machine instructions, data structures, program modules, and other data for PC 20. Although the exemplary environment described herein employs a hard disk, removable magnetic disk 29, and removable optical disk 31, it will be appreciated by those skilled in the art that other types of computer readable media, which can store data and machine instructions that are accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks (DVDs), Bernoulli cartridges, RAMs, ROMs, and the like, may also be used in the exemplary operating environment. A number of program modules may be stored on the hard disk, magnetic disk 29, optical disk 31, ROM 24, or RAM 25, including an operating system 35, one or more application programs 36, other program modules 37, and program data 38. A user may enter commands and information in to PC 20, and provide control input through input devices such as a keyboard 40 and a pointing device 42. Pointing device 42 may include a mouse, stylus, wireless remote control, or other pointer, but in connection with the present invention, such conventional pointing devices may be omitted, since the user can employ the interactive display for input and control. As used hereinafter, the term “mouse” is intended to encompass virtually any pointing device that is useful for controlling the position of a cursor on the screen. Other input devices (not shown) may include a microphone, joystick, haptic joystick, yoke, foot pedals, game pad, satellite dish, scanner, or the like. These and other input/output (I/O) devices are often connected to processing unit 21 through an I/O interface 46 that is coupled to the system bus 23. The term I/O interface is intended to encompass each interface specifically used for a serial port, a parallel port, a game port, a keyboard port, and/or a universal serial bus (USB). System bus 23 is also connected to a camera interface 59, which is coupled to an interactive display 60 to receive signals form a digital video camera that is included therein, as discussed below. The digital video camera may be instead coupled to an appropriate serial I/O port, such as to a USB version 2.0 port. Optionally, a monitor 47 can be connected to system bus 23 via an appropriate interface, such as a video adapter 48; however, the interactive display of the present invention can provide a much richer display and interaction with the user for display and input of information and control of software applications and is therefore coupled to the video adaptor. In addition to the monitor, PCs are often coupled to other peripheral output devices (not shown), such as speakers (through a sound card or other audio interface—not shown) and printers. The present invention may be practiced on a single machine, however, PC 20 can also operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 49. Remote computer 49 may be another PC, a server (which is typically generally configured much like PC 20), a router, a network PC, a peer device, or a satellite or other common network node, and typically includes many or all of the elements described above in connection with PC 20, although only an external memory storage device 50 has been illustrated in FIG. 1. The logical connections depicted in FIG. 1 include a local area network (LAN) 51 and a wide area network (WAN) 52. Such networking environments are common in offices, enterprise wide computer networks, intranets, and the Internet. When used in a LAN networking environment, PC 20 is connected to LAN 51 through a network interface or adapter 53. When used in a WAN networking environment, PC 20 typically includes a modem 54, or other means such as a cable modem, Digital Subscriber Line (DSL) interface, or an Integrated Service Digital Network (ISDN) interface for establishing communications over WAN 52, such as the Internet. Modem 54, which may be internal or external, is connected to the system bus 23 or coupled to the bus via I/O device interface 46, i.e., through a serial port. In a networked environment, program modules depicted relative to PC 20, or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used, such as wireless communication and wide band network links. Exemplary Interactive Display Table In FIG. 2A, an exemplary interactive display table 60 is shown that includes PC 20 within a frame 62 and which serves as both an optical input and video display device for the computer. In this cut-away Figure of the interactive display table, rays of light used for displaying text and graphic images are generally illustrated using dotted lines 82a and 82b, while rays of infrared (IR) light used for sensing objects on or just above a display surface 64a of the interactive table are illustrated using dash lines 80a and 80b. Display surface 64a is set within an upper surface 64 of the interactive display table. The perimeter of the table surface is useful for supporting a user's arms or other objects, including objects that may be used to interact with the graphic images or virtual environment being displayed on display surface 64a. IR light sources 66 preferably comprise a plurality of IR light emitting diodes (LEDs) and are mounted on the interior side of frame 62. The IR light that is produced by IR light sources 66 is directed upwardly toward the underside of display surface 64a, as indicated by dash lines 78a, 78b, and 78c. The IR light from IR light sources 66 is reflected from any objects that are atop or proximate to the display surface after passing through a translucent layer 64b of the table, comprising a sheet of vellum or other suitable translucent material with light diffusing properties. Although only one IR source 66 is shown, it will be appreciated that a plurality of such IR sources may be mounted at spaced-apart locations around the interior sides of frame 62 to prove an even illumination of display surface 64a. The infrared light produced by the IR sources may: exit through the table surface without illuminating any objects, as indicated by dash line 78a; illuminate objects on the table surface, as indicated by dash line 78b; or illuminate objects a short distance above the table surface but not touching the table surface, as indicated by dash line 78c. Objects above display surface 64a include a “touch” object 76a that rests atop the display surface and a “hover” object 76b that is close to but not in actual contact with the display surface. As a result of using translucent layer 64b under the display surface to diffuse the IR light passing through the display surface, as an object approaches the top of display surface 64a, the amount of IR light that is reflected by the object increases to a maximum level that is achieved when the object is actually in contact with the display surface. A digital video camera 68 is mounted to frame 62 below display surface 64a in a position appropriate to receive IR light that is reflected from any touch object or hover object disposed above display surface 64a. Digital video camera 68 is equipped with an IR pass filter 86a that transmits only IR light and blocks ambient visible light traveling through display surface 64a along dotted line 84a. A baffle 79 is disposed between IR source 66 and the digital video camera to prevent IR light that is directly emitted from the IR source from entering the digital video camera, since it is preferable that this digital video camera should produce an output signal that is only responsive to the IR light reflected from objects that are a short distance above or in contact with display surface 64a. It will be apparent that digital video camera 68 will also respond to any IR light included in the ambient light that passes through display surface 64a from above and into the interior of the interactive display (e.g., ambient IR light that also travels along the path indicated by dotted line 84a). IR light reflected from objects on or above the table surface may be: reflected back through translucent layer 64b, through IR pass filter 86a and into the lens of digital video camera 68, as indicated by dash lines 80a and 80b; or be reflected or absorbed by other interior surfaces within the interactive display without entering the lens of digital video camera 68, as indicated by dash line 80c. Translucent layer 64b diffuses both incident and reflected IR light. Thus, as explained above, “hover” objects that are closer to display surface 64a will reflect more IR light back to digital video camera 68 than objects of the same reflectivity that are farther away from the display surface. Digital video camera 68 senses the IR light reflected from “touch” and “hover” objects within its imaging field and produces a digital signal corresponding to images of the reflected IR light that is input to PC 20 for processing to determine a location of each such object, and optionally, the size, orientation, and shape of the object. It should be noted that a portion of an object (such as a user's forearm) may be above the table while another portion (such as the user's finger) is in contact with the display surface. In addition, an object may include an IR light reflective pattern or coded identifier (e.g., a bar code) on its bottom surface that is specific to that object or to a class of related objects of which that object is a member. Accordingly, the imaging signal from digital video camera 68 can also be used for detecting each such specific object, as well as determining its orientation, based on the IR light reflected from its reflective pattern. PC 20 may be integral to interactive display table 60 as shown in FIG. 2A, or alternatively, may instead be external to the interactive display table, as shown in the embodiment of FIG. 2B. In FIG. 2B, an interactive display table 182 is connected through a data cable 186 to an external PC 184 (which includes the optional monitor, as mentioned above). If the interactive display table is connected to an external PC 184 or to some other type of computing device, such as a set top box, video game, laptop computer, or media computer, then the interactive display table comprises an input/output device. Data cable 186, which connects to interactive display table 182, can be coupled to a USB 2.0 port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 (or Firewire) port, or an Ethernet port on PC 184. It is also contemplated that as the speed of wireless connections continues to improve, the interactive display table might also be connected to a computing device such as PC 184 via such a high speed wireless connection, or via some other appropriate wired or wireless data communication link. Whether included internally as an integral part of the interactive display, or externally, PC 20 executes algorithms for processing the digital images from digital video camera 68 and executes software applications that are designed to use the more intuitive user interface functionality of interactive display table 60 to good advantage, as well as executing other software applications that are not specifically designed to make use of such functionality, but can still make good use of the input and output capability of the interactive display table. As yet a further alternative, the interactive display can be coupled to an external computing device, but include an internal computing device for doing image processing and other tasks that would then not be done by the external PC. An important and powerful feature of the interactive display table (i.e., of either embodiments discussed above) is its ability to display graphic images or a virtual environment for games or other software applications and to enable an interaction between the graphic image or virtual environment visible on display surface 64a and objects that are resting atop the display surface or are hovering just above it. Again referring to FIG. 2A, interactive display table 60 includes a video projector 70 that is used to display graphic images, a virtual environment, or text information on display surface 64a. The video projector is preferably of a liquid crystal display (LCD), liquid crystal on silicon (LCosS) type, or digital light processor (DLP) type, with a resolution of at least 640×480 pixels. An IR cut filter 86b is mounted in front of the projector lens of video projector 70 to prevent IR light emitted by the video projector from entering the interior of the interactive display table where the IR light might interfere with the IR light reflected from object(s) on or above display surface 64a. A first mirror assembly 72a directs projected light traveling from the projector lens along dotted path 82a through a transparent opening 90a in frame 62, so that the projected light is incident on a second mirror assembly 72b. Second mirror assembly 72b reflects the projected light onto translucent layer 64b, which is at the focal point of the projector lens, so that the projected image is visible and in focus on display surface 64a for viewing. Alignment devices 74a and 74b are provided and include threaded rods and rotatable adjustment nuts 74c for adjusting the angles of the first and second mirror assemblies to ensure that the image projected onto the display surface is aligned with the display surface. In addition to directing the projected image in a desired direction, the use of these two mirror assemblies provides a longer path between projector 70 and translucent layer 64b to enable a longer focal length (and lower cost) projector lens to be used with the projector. Logic Employed to Execute Software Application in Response to Object(s) The logical steps implemented in detecting one or more objects and launching an associated application program are illustrated in FIGS. 3 and 4. FIG. 3 includes a flow chart 100 showing the steps that are carried out when a single object is uniquely associated with a software application. Beginning at a start block 102 the logic proceeds to a step 104 where the user places an object on display surface 64a (see FIG. 2A) of the interactive display table. Next, in a step 105 using an appropriate sensor included in the interactive display table, the object recognition system of the interactive display table recognizes an object identifier associated with the object that has been placed on the display surface. In a preferred embodiment of the present invention, the sensing technology includes the IR source that emits IR light, which passes through the display surface and is reflected back from the object that is placed on or proximate the display surface. The IR light reflected back through the display surface is received by the IR camera, producing a corresponding image of the object identifier. Since display surface 64a diffuses light, only objects that are relatively close to the display surface will reflect light that produces a discernible image that can be used by the IR camera to identify the object. If the object is too far from the display surface, its image will not be clearly discernible by the IR sensing technology (i.e., the IR camera) used in this embodiment. Although, in most cases, it is likely that the object will be detected when actually placed in contact with the display surface, the phrase referring to an object as “being placed on the display surface” as used herein and in the claims that follow, should be broadly construed to include an object being placed sufficiently close to the display surface, so that the object is discernible by the object sensing system. Various techniques can be used to identify an object identifier associated with a specific object. For example, the object identifier can be an encoded pattern disposed on the bottom of the object (as discussed below in connection with FIG. 9), or can relate to the shape of the object, its size, or the location on the display surface of which the object is placed, or a combination of these and other parameters. Next, the logical process of FIG. 3 continues with a step 106, which provides that the table (i.e., PC 20 or other computing device to which the interactive display is coupled) looks up the application that is associated with the object identifier recognized in step 105. Step 106 is implemented by accessing a registry 108 that includes entries indicating the object identifiers associated with different software applications. In a step 110, the table determines whether the application that is associated with the specific object identifier looked up in step 106 is already installed on the table. If the software application has already been installed on the table, the machine instructions for executing the application will be stored on a hard drive or other non-volatile storage of PC 20 or of another computing device to which the interactive display table is connected. An optional decision step 112 then determines if the application is resident in this storage and takes appropriate action depending on the determination of this decision step. Specifically, if the application is not resident on the table but was determined to be associated with the object that was placed on the display surface, a step 114 downloads the software application from a remote server where it is stored. In many cases, it may be necessary for the user to first purchase the software application before it is downloaded. Accordingly, if the user has previously entered credit or debit card information for making purchases over the network, and the user has authorized the transaction, the software application can be automatically downloaded to complete the purchase transaction. During this step the appropriate credit or debit card information is transferred over the network to an entity associated with the storage from which the software application is being downloaded. This debit or credit card information will thus be used to complete the purchase transaction, thereby enabling the table (i.e., PC 20) to automatically download the software application to its own storage for installation. A step 116 then invokes the application on the table. Step 116 is also implemented if the application is already resident on the table and is in a local storage that is accessible to it so that the software application does not need to be downloaded over the network from a remote storage. In step 116, unless the application has already been installed, part of the step of invoking it requires that it be installed so that the user is able to execute the application. Once installed, or if already installed, step 116 further causes the application to be executed. Typically, execution of an application will cause graphic images to be displayed on the display surface, since many such applications will be directed to enabling the user to interact with the software application using the display surface. Also, many software applications will benefit from both the user input and data display capabilities of the interactive display table. The logic is then completed. Often, an object that is employed in the software application will be placed on the display surface to cause the interactive display table to load and execute the software application. However, an object that is used in one application may also sometimes be used in one or more other software applications. In that case, a plurality of objects (perhaps including the object that is used in multiple software applications) can be uniquely associated with a specific application. For example, dice might be used in several different software applications that can be executed on the interactive display table. Accordingly, a die can only be used to launch a specific application if another object that is also placed on the display surface and recognized by the sensing technology, because the object identifiers of the die and the other object in combination are uniquely associated with the specific software application. FIG. 4 illustrates a flow chart 120 showing the logical steps employed in recognizing a plurality of objects that are uniquely associated with a software application in order to launch the application. Beginning with a start block 122, the logic proceeds to a step 123 wherein a user places an object on the display surface of the interactive display table. Again, in a step 124, the sensing technology, which in a preferred embodiment comprises the IR camera that senses IR light reflected back from an object in proximity with the display surface, is used to recognize an object identifier associated with the object. A step 126 then provides that the table (i.e., PC 20) looks up applications that are associated with the object identifier. In this case, it is presumed that the object may be associated with more than one different software application. The association between the object that was identified by the table is determined from a registry 128, which maintains the association between all object identifiers and different software applications. A decision step 130 then determines if a unique application is associated with the object identifier for the objects that has been identified as being placed in proximity to the display surface of the table. Clearly, if a single object has been placed on the display surface and its object identifier is recognized so that the object is found to be associated with more than one software application, the table will await one or more other objects to be placed on the table, which in combination with the object already identified, will be uniquely associated with a single software application. Accordingly, the logic loops back to step 122 if only a single object has been identified and is associated with more than one software application, or if the objects thus placed on the display surface are not yet found to be uniquely associated with a single software application. Once a unique association is determined in regard to a single object or a plurality of objects that have been placed on the display surface, the logic proceeds to a step 132. In step 132, the table (i.e., PC 20) determines whether the application that is uniquely associated with the object(s) identified as being placed proximate the display surface is already installed and available in the storage accessible by the table. Thus, decision step 134 determines if the application is resident on the table (i.e., in the local storage for software applications) and if not, a step 136 downloads the application from a remote server where it is stored. As previously discussed in connection with FIG. 3, the stored credit or debit card information for the user, along with that user's authorization can be employed to automatically complete the purchase of the software application so that it can be downloaded from the remote storage. In a step 138, if the application is already resident on the table, or after it has been downloaded and installed, the software application is invoked as explained above. The user can interact with the software application that is executed using the interactive display table and can provide input through the display surface while viewing images and data projected on the display surface. The logic is then complete. A further variation is also contemplated deals with the situation in which one or more objects placed on the display surface is not uniquely associated with a single application. In this case, a menu can be displayed in which the applications with which the one or more objects are associated is displayed, enabling a user to make a selection from among the options, to indicate the application that should be downloaded and/or invoked. As each additional object associated with one or more of the applications listed is added to the display surface, the list can shrink in size, to include only those application(s) that are associated with objects on the display surface. However, at anytime, the user can select an application from the choices displayed by this dynamically constructed menu to download and/or invoke. In several of the examples discussed above, an object that is placed on the display surface to launch a software application is subsequently used in the software application. Alternatively, the object used to launch a software application may have a relationship to the function of the software application, but not be used while the application is executed. For example, FIG. 5 illustrates how a television program guide 150 is displayed by a software application that is executed when a remote control 152 is placed on display surface 64a of the interactive display table. To simplify this example and several examples discussed below, only display surface 64a of the interactive display table is shown in these FIGURES. Also included on the program guide are controls 156, 158, and 160, which can be used to move through different portions of the programming guide or for another purpose, such as controlling the application. A header section 162 of the program guide indicates the date, day, and current time as well as showing the hours for which different programs are currently illustrated in the program guide. These programs and the channels on which they are playing are shown in a section 164. Remote control 152 is disposed in a region 154 on display surface 64a and is sensed by the IR light sensing system used in the interactive display table. Its object identifier can be determined based only upon the shape of the remote control, or by recognizing an object identifier provided as a pattern applied to the back surface of the remote control. Alternatively, the interactive display table may respond to any object within a predefined range of size and shape that is placed in region 154 on the display surface, when determining the object identifier of the remote control. This object identifier is associated with launching the software application that displays the television program guide shown in FIG. 5. Any combination of the size of an object, its shape, as well as the region in which the object is detected (and other parameters), can be uniquely associated with the software application that is executed. Other identifying characteristics of an object that can be detected for this purpose include a size, a color, an electrical characteristic, an radio frequency signature, or almost anything that can differentiate one object from another. FIG. 6 illustrates how an electronic game such as Ultimate Hockey game 170, which is shown in the Figure is executed when an object that is used in playing the electronic game is detected on the display surface. In this case, a hockey puck 172 is place on display surface 64a. An encoded pattern appearing on the bottom of the hockey puck (as shown in FIG. 9) is recognized as the object identifier, causing the table to load the Ultimate Hockey software application. Goals 174 are already graphically illustrated on display surface 64a, and additional graphical features of the game will be displayed as the game continues to load. A loading progress bar 176 indicates the relative portion of the software application that has been downloaded over a network from a storage at another site (if necessary). FIG. 7 illustrates yet another intuitive relationship between the software application and the object that is placed on to the display surface of the interactive display table to launch the software application associated with the object. As shown in this Figure, a Publisher software application 180 is being installed in response to the IR sensing system of the interactive display table recognizing an object identifier associated with a package 182 in which the Publisher software application was purchased. Package 182 may only have contained instruction books and other literature, but when placed upon display surface 64a of the interactive display table, the package can cause the Publisher software application to be downloaded, installed, and registered to the current user of the table. A barcode or other object identifier on the undersurface of package 182 is recognized by the sensing technology of the interactive display table using the reflected IR light from the package. Accordingly, no further purchase transaction is required, since possession of the software package indicates that the user has the right to install the Publisher software application sold in the package on the table. Once the Publisher software shown in this example has been installed on the interactive display table (or PC 20), simply placing the package for the software on the table can cause the Publisher software application to be executed, enabling the user to interact with the Publisher software application to create publications to be printed or for other purposes. FIG. 8 illustrates the case where an object such as a die 192 is associated with a plurality of different software applications so that a second object, in this case a user game piece 194 in combination with die 192 comprises a combination of two objects uniquely associated with a single software application. As shown in FIG. 8, an electronic game Adventure Quest is automatically loaded when the IR sensing technology in the interactive display table senses the object identifier of both die 192 and user game piece 194, when these object are placed on display surface 64a. The object identifier of die 192 can be determined by detecting that any of its six faces includes from one to six spots in a die pattern. The object identifier for the user game piece can be based on the shape, or an encoded pattern applied to the bottom of the user game piece. Again, status bar 176 indicates the relative progress of downloading the software application (if necessary) that will be executed by PC 20 of the interactive display table to launch the Adventure Quest software application selectively loaded by the user placing the two specific objects on the display surface. Status bar 176 need not be displayed, if the application is stored locally and needs only to be loaded into active memory. FIG. 9 illustrates an exemplary pattern 200 that is applied to the bottom of an object to serve as an object identifier that is associated with a specific software application. When pattern 200 is detected on or proximate to display surface 64a by the reflected IR light from the pattern, the table automatically will launch the software application with which the object identifier represented by the pattern is associated. If not already installed in the local storage of the table, the software application will be downloaded and installed, as explained above. In the example shown in FIG. 9, a pattern of reflective segments 202 and non-reflective segments 204 are disposed about a center of the object. A start bit 206 indicates where the annular pattern of reflective and non-reflective segments starts, to enable the pattern to be properly recognized. It must be stressed that the exemplary pattern shown in FIG. 9 is one of many different kinds of patterns that can be applied to an object to serve as an object identifier. FIG. 10 illustrates how a shape 10 of an object can also serve as an object identifier that is associated with launching a specific software application. Shape 210 is distinguished because of a notch 212 that is included on one side of an otherwise rectangular shape 214. Regardless of the orientation of shape 210, the same software application can be launched. Alternatively, by reorienting notch 212 to face in a different direction relative to a reference line (not shown) so as to present a different shape, a different object identifier may be identified and employed to launch a different software application. Although the present invention has been described in connection with the preferred form of practicing it, those of ordinary skill in the art will understand that many modifications can be made thereto within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>A user usually launches a software application by manipulating a mouse, joystick, wheel, game pad, track ball, or other user input device to select the application from a list of files or a group of graphic icons that represent applications installed on a personal computer (PC). Alternatively, the user may enter the path and executable file name for the application in a run dialog box to execute an application. Another form of user input for executing an application employs touch-sensitive displays that are responsive to the touch of a user's finger or a stylus on the display screen. Touch responsive displays can be pressure activated, responsive to electrical capacitance, changes in magnetic field intensity, or responsive to other variables to determine the location of a finger or stylus contacting the display screen. Another type of touch sensitive display includes a plurality of optical sensors spaced-apart around a periphery of the display screen so that the location of a finger or stylus touching the screen can be detected. Using one of these touch sensitive displays, a user can touch a graphic icon or file name of an application to select it and then tap once (or twice) on the icon or file name to execute it on the PC. However, touch sensitive systems are generally incapable of detecting more than a single point of contact and are typically unable to detect the shape of an object that is proximate to or touching a display screen. Another approach previously developed in the prior art that might be employed for launching an application uses cameras mounted to the side and above a horizontal display screen to visually capture an image of a user's finger or other object that is touching the display screen. This multiple camera mounting configuration is clearly not a compact system that most people would want to use in a residential setting. In addition, the accuracy of this imaging system in responding to an object that is on or proximate to the display surface depends upon the rather limited capability of the software used with the imaging system to visually recognize objects and their location in three-dimensional (3D) space. To address many of the problems inherent in other types of touch-sensitive displays and imaging sensing systems, particularly in regard to launching a specific application, a user interface platform was developed in the MIT Media Lab, as reported by Brygg Ullmer and Hiroshi Ishii in “The metaDESK: Models and Prototypes for Tangible User Interfaces,” Proceedings of UIST 10/1997:14-17. This article describes how the metaDESK includes a near-horizontal graphical surface that is used to display two-dimensional (2D) geographical information. Above the graphical surface is disposed an arm-mounted flat-panel display that serves as an “active lens” for use in displaying 3D geographical information. A computer vision system inside the desk unit (i.e., below the graphical surface) includes infrared (IR) lamps, an IR camera, a video camera, a video projector, and mirrors. The mirrors reflect the graphical image projected by the projector onto the underside of the graphical display surface. The IR camera can detect a distinctive pattern provided on the undersurface of passive objects called “phicons” that are placed on the graphical surface. Magnetic-field position sensors and electrical-contact sensors are also included in the metaDESK. The reference describes, for example, how the IR camera detects the IR pattern (which is transparent to visible light) applied to the bottom of a “Great Dome phicon” and responds by displaying a map of the MIT campus on the graphical surface, with the actual location of the Great Dome in the map positioned where the Great Dome phicon is located. Moving the Great Dome phicon over the graphical surface manipulates the displayed map by rotating or translating the map in correspondence to the movement of the phicon by a user. A similar approach to sensing objects on a display surface is disclosed in several papers published by Jun Rekimoto of Sony Computer Science Laboratory, Inc., in collaboration with others. These papers briefly describe a “HoloWall” and a “HoloTable,” both of which use IR light to detect objects that are proximate to or in contact with a display panel on which a rear-projected image is visible. The rear-projection panel, which is vertical in the HoloWall and horizontal in the HoloTable, is semi-opaque and diffusive, so that objects reflecting IR light back through the panel become more clearly visible to an IR camera as they approach and then contact the panel. The objects thus detected can be a user's fingers or hand, or other objects. In a paper entitled, “CyberCode: Designing Augmented Reality Environments with Visual Tags, Designing Augmented Reality Environments,” DARE (2000), Jun Rekimoto et al. disclose that the IR camera can recognize IR identification (ID) tags attached to objects that are placed on such a device. The reference teaches that “when a device with a camera recognizes these IDs, a predefined action—such as opening a specific web page—launching an application, or starting a movie, is activated automatically.” While using an ID tag on an object to launch a related application is thus known in the art, there does not seem to be any teaching about responding to a plurality of objects of about simply recognizing objects per se, such as by their shape of other characteristics. For example, it would be desirable to enable an optical sensing system to detect a specific object based on its shape, size, or other physical characteristics and respond by launching a related application. Thus, if a user places a camera on a display surface that includes an optical sensing system, it would be desirable to automatically detect the camera based upon its physical characteristic(s), and automatically launch an application to download images from the camera and to organize the images for storage, or to edit them. The prior art does not suggest how to deal with the situation that can occur when the application that should be launched in response to detecting an object is not installed on a local storage accessed by the interactive display that detects the object. It would be desirable to automatically respond by downloading the application program from a remote server or other remote storage site, if the application is not installed locally. Once downloaded, the application should be installed, registered to the current user of the interactive display (if appropriate), and then executed. Also, in some cases, a plurality of applications might be associated with one object, so that it would not be clear which software application to automatically launch when the object is detected on the display surface. Accordingly, it would be desirable to detect a plurality of objects that constitute a plurality of objects uniquely associated with a specific application, and then launch that specific application in response to detecting the plurality of objects or proximate to the display screen. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention makes use of an interactive display system that serves both for display of text and graphics and for input in an intuitive manner. In connection with this invention, the interactive display system's ability to sense objects placed on a display surface of the interactive display system facilitates an automatic response to objects that have been associated with software applications, when the objects are placed on the display surface and are detected by the interactive display system. Accordingly, one aspect of the present invention is directed to a method for executing a software application in response to at least one object being placed on a display surface. The method includes the step of detecting at least one characteristic of one or more objects placed on the display surface in order to identify each object as a function of the characteristic(s) detected. The method then determines if one object identified is uniquely associated with executing only one software application, and if so, executes the software application if it is already installed for use by a current user of the display surface. If the one object that is identified is associated with more than one software application, the method provides for determining if a plurality of objects that have been placed on the display surface and have been identified are uniquely associated with executing only one software application. If so, the method provides for executing the one software application if it is installed for use by the current user of the display surface. An example will help to explain the significance of these steps. If dice are used for playing several different software games, a die might be a logical object to associate with each such software game. However, it will not be apparent which of the software games should be executed if a die is detected on the display surface. But, if one of the games also uses player pieces to indicate each player's position on a game board that is displayed, while each of the other games also uses some other objects during the game play, each such game software can be uniquely associated with a combination of two (or more) objects, so that when the two (or more) objects are detected on the display surface, the appropriate software game will be executed, if it is already installed on the system. If the software application has not been installed for use by the current user, the method further provides for connecting over a network to a predefined remote storage, where the software application is stored. The software application is downloaded over the network, from the predefined remote storage and is then installed and executed. The step of installing optionally also includes the step of registering the software application. In addition, if the software application can only be downloaded after a charge is paid, the method may include the step of enabling a current user of the display surface to enter information relating to either a debit or a credit account, or some other payment form arranged established by the user for making online purchases. This information will preferably be stored locally and can be transferred to the online site to complete the purchase as authorized by the user. Alternatively, the current user can purchase the software application prior to downloading it, by automatically transmitting the information relating to the user's account to an entity associated with the remote storage. The step of detecting is preferably carried out by illuminating the one or more objects placed on the display surface with light that passes through the display surface and is incident on the object(s). Light reflected from object(s) placed on the display surface is received and causes a corresponding signal to be produced. This signal is then processed to determine the one or more characteristics for each object placed on the surface, to identify the object(s). The one or more characteristic(s) can include one or more of a shape of the object, a size of the object, a location where the object is placed on the display surface, and a pattern disposed on the object. As noted above, in certain cases, the object(s) placed on the surface are used within the software application after the software application is executed, e.g., as dice, player pieces, a spinner, etc. In other cases, the object is easily perceived as being related to the software application. For example, a camera (or a plastic model of one) might be placed on the display surface to cause a photo editing software application to be executed. Alternatively, the object may be closely related to a function of the software application. Thus, a remote control may be placed on the display surface to cause a television program guide software application to be executed. If the software application was purchased in a package, placing the package on the display surface can cause that software application to be executed. Another aspect of the present invention is directed to a memory medium on which machine executable instructions are stored for carrying out functions generally consistent with the steps of the method discussed above. Yet another aspect of the invention relates to a system for executing a software application in response to at least one object being identified. The system includes an interactive display system having a projector, an object detector, and a display surface on which images produced by the software application are displayed by the projector when the software application is executed. A memory stores machine instructions, and a processor is coupled to the interactive display system and to the memory to execute the machine instructions, causing the processor to carry out a plurality of functions that are generally consistent with the steps of the method discussed above. | 20040505 | 20081216 | 20051110 | 84710.0 | 0 | WU, JUNCHUN | INVOKING APPLICATIONS WITH VIRTUAL OBJECTS ON AN INTERACTIVE DISPLAY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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